Streptococcus agalactiae is a pathogen of multiple hosts. The bacterium, an aetiological agent of septicaemia and meningo-encephalitis in freshwater and saltwater fish species, is considered a major threat to the aquaculture industry, particularly for tilapia. Cattle and humans are however the main known reservoirs for S. agalactiae. In humans, the bacterium (commonly referred to as Group B Streptococcus or GBS) is a member of the commensal microflora of the intestinal and genito-urinary tracts, but it is also a major cause of neonatal invasive disease and an emerging pathogen in adults. In cattle, S. agalactiae is a well-recognized causative agent of mastitis. Numerous studies focusing on S. agalactiae from human and bovine origins have provided insight into the population structure of the bacterium, as well as the genome content and pathogenic mechanisms through identification of virulence determinants. Concerning S. agalactiae from aquatic origins, scientific information mainly focused on case reporting and/or experimental challenges, with a limited or absence of information in terms of pathogenesis, virulence determinants and genotypes of the strains involved. The objective of this study was to enhance our understanding of the molecular epidemiology, host-adaptation and pathogenicity of S. agalactiae in aquatic species, with particular emphasis on tilapia. Firstly, a collection of 33 piscine, amphibian and sea mammal isolates originating from several countries and continents was assembled, with the aim of exploring the population structure and potential host specificity of aquatic S. agalactiae. Isolates were characterised using pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and a standardised 3-set genotyping system comprising molecular serotypes, surface protein gene profiles and mobile genetic element profiles. Two major subpopulations were identified in fish. The first subpopulation consisted of non-haemolytic isolates that belonged to sequence type (ST) 260 or 261, which are STs that have been reported only from teleosts. These isolates exhibited a low level of genetic diversity by PFGE and clustered with other STs that have been reported only in fish. Another common feature was the absence of all surface protein genes or mobile genetic elements targeted as part of the 3-set genotyping and that are usually found in human or bovine isolates. The second subpopulation consisted of β-haemolytic isolates recovered from fish, frogs and sea mammals, and that exhibited medium to high genetic diversity by PFGE. STs identified among these isolates have previously been identified from strains associated with asymptomatic carriage and invasive disease in humans. The human pathogenic strain ST7 serotype Ia was detected in fish from Asia. Moreover, ST283 serotype III-4 and its novel single locus variant ST491 detected in fish from Southeast Asia shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. These observations suggested that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. STs found among the seal isolates (ST23) have also been reported from humans and numerous other host species, but never from teleosts. This work provided an excellent basis for exploration of the virulence of selected strains in experimental challenges. The virulence of two strains of S. agalactiae was experimentally investigated by intra-peritoneal infection of Nile tilapia (Oreochromis niloticus), using an isolate originally recovered from fish and belonging to ST260, and an isolate originating from a grey seal and belonging to ST23. The clinical signs, the in vivo distribution of viable bacteria and bacterial antigens, and the gross and histopathological lesions that developed during the time course of the infection were investigated. The ST260 strain was highly virulent, whereas no major clinical sign or mortalities occurred in the fish challenged with the ST23 strain. After injection, both strains however gained access to the bloodstream and viable bacteria were recovered from all organs under investigation. During the early stages of infection, bacteria were mostly found within the reticulo-endothelial system of the spleen and kidney. Thereafter, the ST260 demonstrated a particular tropism for the brain and the heart, but granulomatous inflammation and associated necrotic lesions were observed in all organs. ST23 was responsible for a mixed inflammatory response associated with the presence of bacteria in the choroid rete and in the pancreatic tissue only. After 7 days post-challenge and for both strain, the formation or containment of bacteria within granulomata or other encapsulated structures appeared to be a major component of the fish response. However, the load of viable bacteria remained high within organs of fish infected with ST260, suggesting that, unlike ST23, this strain is able to survive within macrophages and/or to evade the immune system of the fish. This work demonstrates that the lack of report of ST23 strains in fish is possibly not due to a lack of exposure but to a lack of virulence in this host. The two strains, which differ in prevalence and virulence in fish, provide an excellent basis to investigate genomic differences underlying the host-association of distinct S. agalactiae subpopulations. The genome of the ST260 strain used in challenge studies was sequenced. We therefore provided the first description for the genome sequence of a non-haemolytic S. agalactiae isolated from tilapia (strain STIR-CD-17) and that belongs by multi-locus sequence typing (MLST) to clonal complex (CC) 552, which corresponds to a presumptive fish-adapted subgroup of S. agalactiae. The genome was compared to 13 S. agalactiae genomes of human (n=7), bovine (n=2), fish (n=3) and unknown (n=1) origins. Phylogenetic analysis based on the core genome identified isolates of CC552 as the most diverged of all S. agalactiae studied. Conversely, genomes from β-haemolytic isolates of CC7 recovered from fish were found to cluster with human isolates of CC7, further supporting the possibility that some strains may represent a zoonotic or anthroponotic hazard. Comparative analysis of the accessory genome enabled the identification of a cluster of genes uniquely shared between CC7 and CC552, which encode proteins that may provide enhanced fitness in specific niches. Other genes identified were specific to STIR-CD-17 or to CC552 based on genomic comparisons; however the extension of this analysis through the PCR screening of a larger population of S. agalactiae suggested that some of these genes may occasionally be present in isolates belonging to CC7. Some of these genes, occurring in clusters, exhibited typical signatures of mobile genetic elements, suggesting their acquisition through horizontal gene transfer. It is not possible to date to determine whether these genes were acquired through intraspecies transfer or through interspecies transfer from the aquatic environment. Finally, general features of STIR-CD-17 highlighted a distinctive genome characterised by an absence of well conserved insertion sequences, an abundance of pseudogenes, a smaller genomic size than normally observed among human or bovine S. agalactiae, and an apparent loss of metabolic functions considered conserved within the bacterial species, indicating that the fish-adapted subgroup of isolates (CC552) has undergone niche restriction. Finally, genes encoding recognised virulence factors in human S. agalactiae were selected and their presence and structural conservation was evaluated within the genome of STIR-CD-17.

Introdução: O tratamento da Rinossinusite Crônica (RSC) tem sofrido poucos avanços nas últimas décadas. Uma das barreiras na aquisição de novas terapias é a falta de conhecimento pleno sobre sua fisiopatogenia. A carência de avanço decorre principalmente da complexa e provável multifatorialidade da RSC, associada à inexistência de um bom modelo animal que possa mimetizar os fenômenos biológicos que ocorrem em humanos. A maioria dos modelos animais de RSC descrita na literatura mimetiza uma infecção aguda ou promove bloqueio das vias de drenagem que, na maioria das vezes, não corresponde aos mecanismos encontrados nas RSC em humanos. Por outro lado, diversas evidências indicam que as bactérias exercem importante papel na fisiopatogenia da RSC, possivelmente pela presença de biofilmes ou indução de inflamação crônica promovida por endo e exotoxinas. Objetivo: Neste estudo avaliou-se a viabilidade de um modelo experimental de RSC em coelhos, utilizando-se a exposição crônica de toxinas bacterianas em animais previamente sensibilizados à ovalbumina (OVA), analisando seus efeitos histopatológicos sobre a mucosa nasossinusal. Material e Métodos: Após indução de sensibilização com injeção subcutânea de OVA 2,5% e 0,4% de hidróxido de alumínio por duas semanas, os coelhos foram submetidos à implantação de cateter de longa duração em seio maxilar direito. Após, foram submetidos à irrigação nasossinusal com OVA 2,5% três vezes por semana, por duas semanas, e em seguida, irrigação de soluções contendo diferentes toxinas bacterianas (enterotoxina estaflocócica B (SEB) 1 ?g/mL, lipopolissacáride (LPS) 100 ng/mL e ácido lipotecóico (LTA) 100 ng/mL) por quatro semanas. Os animais foram sacrificados 24 horas após a última irrigação e a mucosa do seio maxilar direito (teste) e esquerdo (controle interno) foi coletada para avaliação histopatológica. Resultados: A exposição nasossinusal ao SEB causou espessamento epitelial, infiltração celular, eosinofilia e neutrofilia tecidual, além de redução do epitélio ciliado. A exposição ao LPS causou espessamento epitelial e subepitelial, infiltração celular, eosinofilia epitelial e subepitelial e aumento da fibrose subepitelial. O LTA causou espessamento epitelial e subepitelial, infiltração celular e eosinofílica subepitelial e aumento da fibrose subepitelial. Conclusão: A exposição crônica de toxinas bacterianas na mucosa nasossinusal promoveu alterações histológicas, como espessamento da mucosa e infiltração celular, semelhantes às encontradas em pacientes com RSC. O presente estudo demonstrou que este é um modelo animal viável de RSC. Mais estudos serão necessários para elucidar se os mecanismos patogênicos deste modelo são semelhantes aos observados em humanos. / Background: The treatment of chronic rhinosinusitis (CRS) has had little evolvement in the last decades. One of the barriers to the development of new therapies is the lack of knowledge about CRS pathophysiology. The complexity and multifactoriality of this disease, together with the inexistence of a proper animal model of CRS, are probably the causes for the few advances in CRS therapy. Most of the animal models of CRS resemble acute infection or promote sinonasal obstructions, which are not a very common etiologies in CRS patients. However, there has been a lot of evidence that bacteria play an important role in the pathophysiology of CRS, probably due to the presence of biofilms, or the chronic inflammation induced by endo e exotoxins. Objective: This study aims to evaluate the viability of an experimental model of CRS in rabbits through the use of bacterial toxins in previously sensitized animals with ovalbumin, analyzing its histopathological effects onto the sinonasal mucosa. Materials and Methods: After inducing ovalbumin (OVA) sensitization by intradermic injection of OVA 2,5% and 0,4% aluminum hydroxide for 2 weeks, rabbits underwent maxillary sinus instillation of OVA 2,5% three times a week for 2 weeks followed by sinus lavage with either one bacterial toxin (Staphylococcus aureus enterotoxin B (SEB) 1 ?g/mL, lipopolysaccharide (LPS) 100 ng/mL, lipoteichoic acid (LTA), 100 ng/mL) for 4 weeks. Rabbits were euthanised 24 hours after the last sinus lavage and the mucosa of right maxillary sinus (tested side) and left side (control) were collected for histopathological evaluation. Results: The sinonasal exposure to SEB resulted in epithelial thickening, inflammatory cells infiltration (tissue eosinophilia and neutrophilia) and reduction of ciliated cells. The exposure to LPS resulted in epithelial and subepithelial thickening, inflammatory cells infiltration, epithelial and subepithelial eosinophilia and increased subepithelial fibrosis. The exposure to LTA resulted in epithelial and subepithelial thickening, subepithelial inflammatory cells infiltration and eosinophilia and increased subepithelial fibrosis. Conclusion: This study reported the effects of bacterial toxins on the the sinonasal mucosa of ovalbumin-sensitized rabbits, demonstrating similar changes that are observed in CRS patients. Our results show that this is a viable animal model of CRS. Further studies are need to elucidate whether the pathomechanisms in this model are similar to what are observed in humans.

A hidatidose policística é uma zoonose causada pelo cestóide Echinococcus vogeli, amplamente distribuído no norte do Brasil. Os hospedeiros definitivos são Speothos venaticus (cachorro-vinagre) e Canis familiaris (cães domésticos), enquanto Agouti paca (paca) é hospedeiro intermediário. Tanto as pacas quanto o homem (hospedeiro acidental) desenvolvem a forma larvar (metacestóide), principalmente na superfície e no interior do fígado. Esta tese tem como objetivo geral estudar as características parasitológicas e histopatológicas de metacestóides de E. vogeli, originários de pacas e humanos da região norte do Brasil, visto o conhecimento insuficiente ou mesmo o seu desconhecimento. Os fígados e mesentérios foram obtidos de oito pacientes com hidatidose policística durante ato cirúrgico na Fundação Hospital Estadual do Acre. Pacas foram capturadas no Município de Bujari, Floresta Estadual do Antimary, Acre. Durante a necropsia das pacas, foram observadas lesões macroscópicas (massas esbranquiçadas ou amareladas, semelhantes a bolhas na superfície dos fígados). Para a análise parasitológica foram aplicadas as microscopias de luz, contraste interferencial de Normaski (DIC) e varredura laser confocal. A análise morfométrica foi realizada com o auxílio do Programa Image Pro Plus Media Cybernetics. Os órgãos de pacas e humanos foram submetidos à análise histopatológica. Os pequenos e grandes ganchos rostelares apresentaram polimorfismo morfológico, enquanto a organização dos protoescólices acompanhou o padrão descrito para Echinococcus sp. Todas as pacas apresentavam cistos hepáticos, porém em apenas duas encontramos líquido hidático, comprovados pela presença dos ganchos e protoescólices. A análise histopatológica dos tecidos hepáticos das pacas confirmou a hidatidose policística e evidenciou, pela presença de agrupamentos de ovos, a coinfecção com Calodium hepaticum. As características morfológicas dos ganchos rostelares dos casos humanos não diferiram do descrito para as pacas, entretanto, os ganchos dos helmintos provenientes do fígado foram maiores que os mesentéricos. Já em relação aos protoescólices, os mesentéricos foram maiores do que os hepáticos. Cistos mesentéricos e hepáticos apresentaram protoescólices em diferentes estágios de desenvolvimento, com coroas de ganchos, formadas por grandes e pequenos ganchos, e dois pares de ventosas, além dos corpúsculos calcários. Os cistos hepáticos apresentaram as três membranas características (adventícia, anista e germinativa), enquanto os cistos mesentéricos não apresentaram a membrana adventícia, sendo a anista aquela que mais se destacou neste órgão. No mesentério, as células mononucleares foram os principais constituintes do infiltrado leucocitário, cuja intensidade foi relacionada à capacidade proliferativa da membrana germinativa. Além de cistos hepáticos típicos de fase crônica, dependendo da resposta inflamatória, foram observados cistos na fase aguda e sub-aguda. Foi encontrado um caso de coinfecção com vírus (HIV, HCB e HCV) e outro com envolvimento da vesícula biliar. Em suma, confirma-se hidatidose policística em pacas no Acre e são apresentados novos casos de infecção humana no Acre e Amazonas. Pela primeira vez, é demonstrado polimorfismo, padrão diferente de desenvolvimento dos cistos de acordo com o órgão, coinfecção e envolvimento da vesícula biliar / Polycystic hydatidosis is a zoonotic disease caused by the cestode Echinococcus vogeli, largely distributed in northern Brazil. The definitive hosts are Speothos venaticus (bush dogs) and Canis familiaris (domestic dogs), while Agouti paca (paca) is the intermediate host. Both the pacas and man (accidental host) develop the larval form (metacestodes), mainly on the surface and inside the liver. This thesis aims to study histopathological and parasitological characteristics of metacestodes of E. vogeli, from pacas and humans of the north region of Brazil, seen the insufficient knowledge or lack of it. The mesentery and livers were recovered from eight patients with polycystic hydatidosis during surgery in the Acre State Hospital Foundation. Pacas were captured in the municipality of Bujari, Antimary State Forest, Acre. During the pacas necropsy, macroscopic lesions were observed (whitish or yellowish masses, similar to blisters on the surface of the liver). Identification analyses were applied to light microscopy, interferential contrast microscopy of Normaski (DIC) and confocal laser scanning microscopy. Morphometric analysis was performed by Image Pro Plus Media Cybernetics program. The pacas and human organs were subjected to histopathological analysis. The small and large rostellar hooks presented morphological polymorphism while protoscoleces organisation accompanied the pattern described in Echinococcus sp. All pacas presented liver cysts, however in only two found proven by the presence of hydatid fluid, hooks and protoscoleces. Histopathological analysis of pacas hepatic tissues confirmed polycystic hydatidosis and evidenced by the presence of eggs clusters the Calodium hepaticum coinfection. The morphological characteristics of human cases rostellar hooks did not differ from described to the pacas; however, the hooks were greater than the mesenteric ones. Already in relation to protoscoleces, the mesenteric ones were larger than the liver. Mesenteric and liver cysts presented protoscoleces at different stages of development, with rostellar pad formed by large and small hooks, and two pairs of suckers, in addition to the calcareous corpuscles. Liver cysts showed three characteristics layers (adventitia, laminated and germinative), while mesenteric cysts did not present the adventitia, being the laminated layer the most evidenced in this organ. In the mesentery, mononuclear cells were the principal constituents of leukocyte infiltrated, whose intensity was related to the proliferative capacity of germinative layer. In addition to typical liver cysts of the chronic phase, depending on the inflammatory response, have been observed cysts in acute and subacute phase. It was found a case of co-infection with virus (HIV, HCV and HCB) and another with gallbladder involvement. In short, it is confirmed polycystic hydatidosis in pacas from Acre and is presented new cases of human infection in Acre and Amazonas. For the first time, it was demonstrated polymorphism, different development pattern of cysts depending on the organ, co-infection and gallbladder involvement

Introdução: A doença valvar aórtica grave é caracterizada por um processo de acúmulo progressivo de fibrose intersticial no tecido miocárdico. No contexto da sobrecarga mecânica crônica do VE característica dessa condição, a quantidade de fibrose intersticial pode exercer um papel importante na indesejável transição entre hipertrofia ventricular esquerda compensada e insuficiência cardíaca congestiva clinicamente manifesta. Entretanto, a avaliação quantitativa da fibrose intersticial só tem sido possível através da análise histopatológica de fragmentos miocárdicos obtidos por biopsia endomiocárdica. Objetivos: Avaliar se a ressonância magnética (RM) cardíaca com técnica do realce tardio permite a quantificação não-invasiva da fibrose miocárdica quando comparada à análise histopatológica em pacientes portadores de doença valvar aórtica grave. Adicionalmente, avaliou-se a relação entre a quantidade de fibrose miocárdica e parâmetros prognósticos importantes, tais como mortalidade e recuperação funcional do VE após cirurgia de troca valvar aórtica. Métodos: Entre Maio de 2001 e Dezembro de 2003 foram incluídos 54 pacientes com indicação de cirurgia de troca valvar aórtica. Antes da cirurgia, todos os pacientes foram submetidos a RM cardíaca com técnicas de cine-RM e realce tardio miocárdico. A quantificação da fibrose miocárdica pela RM baseou-se na análise das imagens de realce tardio utilizando um novo algoritmo semi-automático. As regiões de fibrose miocárdica foram definidas como o somatório de todos os pixels do tecido miocárdico com intensidade de sinal acima de um limiar definido como: intensidade de sinal média do miocárdio + 2 desvios padrão da intensidade de sinal média da área remota + 2 desvios padrão da intensidade de sinal média do ar. Amostras de tecido miocárdico obtidas por miectomia durante o ato cirúrgico foram submetidas a coloração pelo picrosírius para quantificação da fibrose intersticial. Os pacientes foram submetidos a um segundo exame de RM cardíaca 6 meses após a cirurgia para se avaliar as alterações evolutivas dos parâmetros funcionais do VE e todos foram acompanhados por pelo menos 24 meses quanto à sobrevida após a cirurgia de troca valvar aórtica. Resultados: O percentual de fibrose miocárdica pela RM apresentou boa correlação com os valores obtidos pela histopatologia (r=0,69; y=3,10x+13,0; p<0,0001). A quantidade de fibrose miocárdica, tanto pela histopatologia como pela RM, apresentou correlação inversa significativa com a FE ventricular esquerda basal (r=-0,63 e -0,67 respectivamente; p<0,0001). Adicionalmente, o percentual de fibrose miocárdica apresentou correlação inversa significativa com o grau de recuperação funcional do VE após a cirurgia de troca valvar (r=- 0,42, p=0,04 para a histopatologia; r=-0,47, p=0,02 para a RM). Mais importante, a análise de Kaplan-Meier revelou que o acúmulo de fibrose miocárdica associou-se a menor sobrevida 52±17 meses após a cirurgia de troca valvar (teste log-rank: 2=6,32; p=0,01 para histopatologia; 2=5,85; p=0,02 para RM). Conclusões: A RM cardíaca permite quantificar as regiões de fibrose miocárdica com boa acurácia quando comparada à análise histopatológica nos pacientes portadores de doença valvar aórtica grave. A magnitude de acúmulo de fibrose miocárdica está associada a pior recuperação funcional do VE e a menor sobrevida após a cirurgia de troca valvar aórtica. / Introduction: Severe aortic valve disease is characterized by a process of progressive accumulation of interstitial fibrosis in the myocardial tissue. It has been shown that the amount of interstitial myocardial fibrosis can play an important role in the transition from well-compensated hypertrophy to overt heart failure in the setting of chronic left ventricular mechanical overload typical of this condition. However, assessment of interstitial myocardial fibrosis has only been possible through histological analyses of myocardial fragments obtained from endomyocardial biopsies, which is a complex and invasive procedure and, therefore, with limited clinical applicability. Objectives: Determine whether delayedenhancement cardiac magnetic resonance imaging (MRI) allows for the non-invasive quantification of myocardial fibrosis when compared against histopathological analyses in patients with severe aortic valve disease. Additionally, we evaluated the relationship between the amount of myocardial fibrosis and important prognostic parameters, such as all-cause mortality and LV functional recovery after aortic valve replacement. Methods: Fifty-four patients scheduled to undergo aortic valve replacement surgery were enrolled between May 2001 and December 2003. Before surgery, all patients underwent cine and delayedenhancement MRI in a 1.5 Tesla scanner. Quantification of myocardial fibrosis by cardiac MRI was based on the assessment of the delayed-enhancement dataset using a novel semiautomatic algorithm. The regions of myocardial fibrosis were defined as the sum of pixels with signal intensity above a threshold value defined as: mean signal intensity of the myocardium + 2 standard deviations of mean signal intensity of a remote area + 2 standard deviations of mean signal intensity of air. During open-heart surgery, myectomy samples were acquired from the LV septum and later stained with picrosirius for interstitial myocardial fibrosis quantification. A second cardiac MRI study was performed 6 months after surgery to assess long-term changes in LV functional parameters, and all patients were followed for at least 24 months to evaluate survival after aortic valve replacement. Results: There was a good correlation between the values of myocardial fibrosis measured by MRI and those obtained by histopathological analyses (r=0.69; y=3.10x+13.0; p<0.0001). The amount of myocardial fibrosis, either by MRI or by histopathology, exhibited a significant inverse correlation with LV ejection fraction before surgery (r=-0.63 e -0.67 respectively; p<0.0001). Additionally, the amount of myocardial fibrosis displayed a significant inverse correlation with the degree of LV functional recovery after aortic valve replacement (r=-0.42, p=0.04 for histopathology; r=-0.47, p=0.02 for MRI). Most importantly, Kaplan-Meier and Cox regression analyses revealed that higher degrees of myocardial fibrosis accumulation were associated with worse survival 52±17 months after aortic valve replacement surgery (log-rank test: 2=6.32; p=0.01 for histopathology; 2=5.85; p=0.02 for MRI). Conclusions: Cardiac MRI allows for the non-invasive quantification of myocardial fibrosis with good accuracy when compared with histopathological analyses in patients with severe aortic valve disease. The degree of myocardial fibrosis accumulation is associated with impaired LV functional recovery and worse survival after aortic valve replacement surgery.

Color theory was first formalized in the seventeenth century by Isaac Newton just a couple of decades after the first microscope was built. But it was not until the twentieth century that technological advances led to the integration of color theory, optical spectroscopy and light microscopy through spectral image processing. However, while the focus of image processing often concerns modeling of how images are perceived by humans, the goal of image processing in natural sciences and medicine is the objective analysis. This thesis is focused on color theory that promotes quantitative analysis rather than modeling how images are perceived by humans. Color and fluorescent dyes are routinely added to biological specimens visualizing features of interest. By applying spectral image processing to histopathology, subjectivity in diagnosis can be minimized, leading to a more objective basis for a course of treatment planning. Also, mathematical models for spectral image processing can be used in biotechnology research increasing accuracy and throughput, and decreasing bias. This thesis presents a model for spectral image formation that applies to both fluorescence and transmission light microscopy. The inverse model provides estimates of the relative concentration of each individual component in the observed mixture of dyes. Parameter estimation for the model is based on decoupling light intensity and spectral information. This novel spectral decomposition method consists of three steps: (1) photon and semiconductor noise modeling providing smoothing parameters, (2) image data transformation to a chromaticity plane removing  intensity variation while maintaining chromaticity differences, and (3) a piecewise linear decomposition combining advantages of spectral angle mapping and linear decomposition yielding relative dye concentrations. The methods described herein were used for evaluation of molecular biology techniques as well as for quantification and interpretation of image-based measurements. Examples of successful applications comprise quantification of colocalization, autofluorescence removal, classification of multicolor rolling circle products, and color decomposition of histological images.

A hidatidose policística é uma zoonose causada pelo cestóide Echinococcus vogeli, amplamente distribuído no norte do Brasil. Os hospedeiros definitivos são Speothos venaticus (cachorro-vinagre) e Canis familiaris (cães domésticos), enquanto Agouti paca (paca) é hospedeiro intermediário. Tanto as pacas quanto o homem (hospedeiro acidental) desenvolvem a forma larvar (metacestóide), principalmente na superfície e no interior do fígado. Esta tese tem como objetivo geral estudar as características parasitológicas e histopatológicas de metacestóides de E. vogeli, originários de pacas e humanos da região norte do Brasil, visto o conhecimento insuficiente ou mesmo o seu desconhecimento. Os fígados e mesentérios foram obtidos de oito pacientes com hidatidose policística durante ato cirúrgico na Fundação Hospital Estadual do Acre. Pacas foram capturadas no Município de Bujari, Floresta Estadual do Antimary, Acre. Durante a necropsia das pacas, foram observadas lesões macroscópicas (massas esbranquiçadas ou amareladas, semelhantes a bolhas na superfície dos fígados). Para a análise parasitológica foram aplicadas as microscopias de luz, contraste interferencial de Normaski (DIC) e varredura laser confocal. A análise morfométrica foi realizada com o auxílio do Programa Image Pro Plus Media Cybernetics. Os órgãos de pacas e humanos foram submetidos à análise histopatológica. Os pequenos e grandes ganchos rostelares apresentaram polimorfismo morfológico, enquanto a organização dos protoescólices acompanhou o padrão descrito para Echinococcus sp. Todas as pacas apresentavam cistos hepáticos, porém em apenas duas encontramos líquido hidático, comprovados pela presença dos ganchos e protoescólices. A análise histopatológica dos tecidos hepáticos das pacas confirmou a hidatidose policística e evidenciou, pela presença de agrupamentos de ovos, a coinfecção com Calodium hepaticum. As características morfológicas dos ganchos rostelares dos casos humanos não diferiram do descrito para as pacas, entretanto, os ganchos dos helmintos provenientes do fígado foram maiores que os mesentéricos. Já em relação aos protoescólices, os mesentéricos foram maiores do que os hepáticos. Cistos mesentéricos e hepáticos apresentaram protoescólices em diferentes estágios de desenvolvimento, com coroas de ganchos, formadas por grandes e pequenos ganchos, e dois pares de ventosas, além dos corpúsculos calcários. Os cistos hepáticos apresentaram as três membranas características (adventícia, anista e germinativa), enquanto os cistos mesentéricos não apresentaram a membrana adventícia, sendo a anista aquela que mais se destacou neste órgão. No mesentério, as células mononucleares foram os principais constituintes do infiltrado leucocitário, cuja intensidade foi relacionada à capacidade proliferativa da membrana germinativa. Além de cistos hepáticos típicos de fase crônica, dependendo da resposta inflamatória, foram observados cistos na fase aguda e sub-aguda. Foi encontrado um caso de coinfecção com vírus (HIV, HCB e HCV) e outro com envolvimento da vesícula biliar. Em suma, confirma-se hidatidose policística em pacas no Acre e são apresentados novos casos de infecção humana no Acre e Amazonas. Pela primeira vez, é demonstrado polimorfismo, padrão diferente de desenvolvimento dos cistos de acordo com o órgão, coinfecção e envolvimento da vesícula biliar / Polycystic hydatidosis is a zoonotic disease caused by the cestode Echinococcus vogeli, largely distributed in northern Brazil. The definitive hosts are Speothos venaticus (bush dogs) and Canis familiaris (domestic dogs), while Agouti paca (paca) is the intermediate host. Both the pacas and man (accidental host) develop the larval form (metacestodes), mainly on the surface and inside the liver. This thesis aims to study histopathological and parasitological characteristics of metacestodes of E. vogeli, from pacas and humans of the north region of Brazil, seen the insufficient knowledge or lack of it. The mesentery and livers were recovered from eight patients with polycystic hydatidosis during surgery in the Acre State Hospital Foundation. Pacas were captured in the municipality of Bujari, Antimary State Forest, Acre. During the pacas necropsy, macroscopic lesions were observed (whitish or yellowish masses, similar to blisters on the surface of the liver). Identification analyses were applied to light microscopy, interferential contrast microscopy of Normaski (DIC) and confocal laser scanning microscopy. Morphometric analysis was performed by Image Pro Plus Media Cybernetics program. The pacas and human organs were subjected to histopathological analysis. The small and large rostellar hooks presented morphological polymorphism while protoscoleces organisation accompanied the pattern described in Echinococcus sp. All pacas presented liver cysts, however in only two found proven by the presence of hydatid fluid, hooks and protoscoleces. Histopathological analysis of pacas hepatic tissues confirmed polycystic hydatidosis and evidenced by the presence of eggs clusters the Calodium hepaticum coinfection. The morphological characteristics of human cases rostellar hooks did not differ from described to the pacas; however, the hooks were greater than the mesenteric ones. Already in relation to protoscoleces, the mesenteric ones were larger than the liver. Mesenteric and liver cysts presented protoscoleces at different stages of development, with rostellar pad formed by large and small hooks, and two pairs of suckers, in addition to the calcareous corpuscles. Liver cysts showed three characteristics layers (adventitia, laminated and germinative), while mesenteric cysts did not present the adventitia, being the laminated layer the most evidenced in this organ. In the mesentery, mononuclear cells were the principal constituents of leukocyte infiltrated, whose intensity was related to the proliferative capacity of germinative layer. In addition to typical liver cysts of the chronic phase, depending on the inflammatory response, have been observed cysts in acute and subacute phase. It was found a case of co-infection with virus (HIV, HCV and HCB) and another with gallbladder involvement. In short, it is confirmed polycystic hydatidosis in pacas from Acre and is presented new cases of human infection in Acre and Amazonas. For the first time, it was demonstrated polymorphism, different development pattern of cysts depending on the organ, co-infection and gallbladder involvement

An early diagnosis of melanoma is essential to reduce mortality of patients. The diagnosis is also fundamental to predict the outcome of patients and to select the most adapted treatment. Current diagnostic assessments are obtained after visual inspection of the histological section of the primary tumor. The pathologist has first to determine the malignant nature of the lesion and then to assess the potential of the lesion to form metastases. Depending on several characteristics of the primary tumor (mainly tumor thickness, ulceration and mitotic rate), the sentinel node is surgically removed and the detection of tumor cells is based on its histopathological examination. These assessments are time consuming, to some degree subjective and are particularly challenging. Among melanoma patients that are not subject to sentinel node surgery, 6.5 % will develop metastases while 20 % of patients that undergo sentinel node surgery will effectively present metastases. The search for biomarkers that can identify malignant cells, evaluate potential of invasion or help selecting a treatment is still on.<p>In this thesis we used a new and promising technique of imaging based on infrared spectroscopy to study melanoma primary tumors and metastatic lymph nodes. Infrared spectroscopy brings information on the biochemical composition of the main components of the cells. When combined with a microscope and with multivariate statistical analyses, images that are generated allow the identification of melanoma cells and stromal cells in the biopsy. We also focused on the immune infiltration as it was shown to carry an important prognosis value for melanoma patients.<p>The first part of the thesis was a prerequisite for the rest of the study. It addresses the effects of the process of fixation that tissues obtained by surgical resection undergo for their long term preservation. In chapter III, we showed that Formalin-Fixation and Paraffin-Embedding (FFPE) procedure induces small but significant modifications in the infrared spectra of cells but these are very similar for different cell lines. In turn, it preserves the potential to identify closely-related cell lines by infrared spectroscopy.<p>We thus pursued our study on primary melanomas. In chapter IV, we first developed an automatic tool capable of identifying melanoma cells and the main cells of the tumor microenvironment in tissue sections. Importantly, we built a second model that brings information on the presence of metastases on the basis of the spectral signature of the primary tumor.<p>The next chapter is dedicated to the prediction of the response of melanoma to dacarbazine, the first-line chemotherapy to treat stage IV patients. Infrared spectra of the primary tumor were shown to contain information capable of predicting whether dacarbazine will be a useful treatment.<p>In the last two chapters, we focused on lymphocytes. In chapter VI, we first demonstrated that helper and cytotoxic T cells purified from peripheral blood can be identified on the basis of their infrared signature. Then, in chapter VII we investigated metastatic lymph nodes. We created different statistical models using infrared spectra that first identified the melanoma cells invading the lymph nodes and secondly, the different subpopulations of lymphocytes (B and T cells).<p>In conclusion, we developed an automatic and reliable tool of imaging to help pathologists in the anatomopathological assessment of primary lesions and lymph nodes./Le mélanome est la forme de cancer cutané la plus mortelle, provoquant environ 80% des décès dus à un cancer de la peau. Lorsque le mélanome est localisé, la chirurgie est le principal traitement et est suffisante pour 80% des patients. A l’opposé, lorsque le mélanome primaire a formé des métastases, le cancer devient beaucoup plus difficile à traiter et la survie de ces patients diminue drastiquement. Seuls 10% des patients vont vivre 5 ans lorsqu’ils développent des métastases à distance. C’est pourquoi un diagnostic précoce est essentiel pour diminuer la mortalité causée par le mélanome. L’étape du diagnostic est également très importante pour donner un pronostic et pour planifier les traitements. Le diagnostic actuel du mélanome est basé sur l’analyse en microscopie optique de sections de la tumeur primaire. Sur base de la morphologie cellulaire et de l’architecture du tissu, cette étape permet premièrement d’identifier le caractère cancéreux de la lésion et deuxièmement d’évaluer son potentiel métastatique. Une analyse du ganglion sentinelle permet également de détecter la présence de métastases. Dans le cadre de cette thèse, nous proposons d’utiliser une nouvelle technique d’imagerie basée sur la spectroscopie infrarouge qui apporte une information complète et unique sur la biochimie de la cellule et des tissus. Les résultats présentés ici indiquent que lorsque les spectres infrarouges sont combinés à des analyses statistiques multivariées, des images sont reconstituées et révèlent les structures et les composants cellulaires majeurs présents dans les coupes de mélanomes. Une étude préliminaire a d’abord pu démontrer que la fixation au formol subies par les biopsies pour les conserver n’entrave pas l’étude de celles-ci par spectroscopie infrarouge. Nous nous sommes alors intéressés aux tumeurs primaires de mélanome et avons développé un modèle statistique, à partir des spectres infrarouges, identifiant automatiquement les cellules de mélanome dans le tissu ainsi que les autres cellules du microenvironnement de la tumeur. Dans ce chapitre, nous avons également créé un autre modèle statistique capable de prédire le potentiel métastatique de la tumeur primaire en se basant sur sa signature spectrale. Nous avons ensuite mis en évidence une signature spectrale corrélée à la réponse à la dacarbazine chez des patients traités pour leurs métastases. Nous avons également montré que des sous-populations de lymphocytes purifiées d’échantillons sanguins pouvaient être identifiées sur base de leur spectre. Cette capacité de la spectroscopie infrarouge à distinguer les différents types de lymphocytes a ensuite été démontrée pour les lymphocytes infiltrant les métastases. Finalement, nous avons mis en évidence l’utilité de cette technique d’imagerie pour la détection de métastases ganglionnaires.<p> / Doctorat en sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-26T20:24:00Z No. of bitstreams: 1 katiabatistadoamaral.pdf: 5840188 bytes, checksum: bc96f4a6457a961cca6e272ba1aaaa5d (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:29:35Z (GMT) No. of bitstreams: 1 katiabatistadoamaral.pdf: 5840188 bytes, checksum: bc96f4a6457a961cca6e272ba1aaaa5d (MD5) / Made available in DSpace on 2016-09-26T20:29:35Z (GMT). No. of bitstreams: 1 katiabatistadoamaral.pdf: 5840188 bytes, checksum: bc96f4a6457a961cca6e272ba1aaaa5d (MD5) Previous issue date: 2015-12-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O roedor Nectomys squamipes, também conhecido como rato d’água, é considerado o mais importante reservatório silvestre do parasito Schistosoma mansoni no Brasil, contribuindo para a epidemiologia da esquistossomose mansônica humana. Além disso, quando infectado, não apresenta sinais clínicos da doença, apresentando lesões teciduais extremamente brandas decorrentes da infecção. Parâmetros relacionados à infecção esquistossomótica em modelos murinos de infecção experimental já foram bem documentados; porém, em modelos de infecção natural, ainda são pouco conhecidos. A relação parasito-hospedeiro neste modelo de infecção natural é de grande relevância e motivou o desenvolvimento deste trabalho. Foi realizado estudo comparativo da esquistossomose mansônica em N. squamipes naturalmente infectado pelo parasito S. mansoni e no camundongo Swiss experimentalmente infectado, nas fases aguda e crônica da infecção, através de análises histopatológicas, bioquímicas e ultraestruturais, objetivando obter uma melhor compreensão de como o rato d’água lida com o parasitismo pelo S. mansoni. Foram realizadas análises de frequências e tipos de granulomas, suas áreas médias e do comprometimento tecidual dos órgãos alvos da infecção (fígado e intestinos), nos dois modelos experimentais. A participação dos eosinófilos durante a resposta inflamatória granulomatosa também foi avaliada, visto que estas células estão presentes em grandes números nos granulomas. Dosagens bioquímicas das transaminases hepáticas auxiliaram na avaliação do dano hepatocelular. Além disso, a influência da esteatose hepática neste modelo de infecção natural foi estudada, visto que seus efeitos não são conhecidos em animais silvestres. Assim, dosagens séricas de glicose, colesterol total e triglicerídeos foram importantes para avaliar o perfil glicêmico e lipídico dos animais estudados. Os tecidos hepáticos dos animais foram submetidos à espectroscopia Raman, para avaliar o grau de insaturação presente. Finalmente, análises ultraestruturais ajudaram a aprofundar o conhecimento sobre os papéis dos eosinófilos e dos corpúsculos lipídicos presentes nos hepatócitos nestes dois modelos de esquistossomose mansônica. Os resultados revelaram que N. squamipes apresentou excelente modulação das lesões teciduais no fígado, com baixo comprometimento tecidual neste órgão e uma reação granulomatosa mais exacerbada no intestino delgado, favorável à eliminação dos ovos do parasito nas fezes. Além disso, os níveis séricos das transaminases não se alteraram em decorrência da infecção neste roedor silvestre, ao contrário do que ocorreu no camundongo Swiss. N. squamipes infectados e não infectados apresentaram os maiores graus de insaturação presentes nos tecidos hepáticos. Características ultraestruturais intrigantes dos eosinófilos de N. squamipes foram observadas por MET. Através dos dados obtidos, concluímos que o rato d’água apresenta uma relação ecológica bem estabelecida com o parasito S. mansoni, sendo que esta adaptação ao parasitismo pode estar relacionada ao metabolismo lipídico deste reservatório silvestre. / The rodent Nectomys squamipes, also known as water rat, is considered the most important wild reservoir of the parasite Schistosoma mansoni in Brazil, contributing to the epidemiology of human schistosomiasis. Furthermore, when infected, it shows no clinical signs of the disease with extremely soft tissue injuries resulting from infection. Parameters related to the infection in murine models of experimental infection have been well documented; however, in natural infection models, they are still largely unknown. The host-parasite relationship in this model of natural infection is highly relevant and motivated the development of this work. So, It was conducted a comparative study of schistosomiasis in N. squamipes naturally infected by the parasite Schistosoma mansoni and in Swiss experimentally infected mice, at the acute and chronic phases of the infection through histological, biochemical and ultrastructural analysis, aiming to gain a better understanding of how the water rat handles with parasitism by S. mansoni. Analysis of frequencies and types of granulomas were held, their average areas and tissue impairment of the target organs of infection (liver and intestines) in both experimental models. The involvement of eosinophils during granulomatous inflammatory response was also evaluated, as these cells are present in large numbers in the granulomas. Biochemical testing of liver transaminases contributed to the evaluation of hepatocellular damage. Furthermore, the influence of hepatic steatosis in the natural infection model was studied, since their effects are not known in wild animals. Thus, serum levels of glucose, total cholesterol and triglycerides were important to assess the glycemic and lipid profile of the animals studied. The liver tissues of animals were subjected to Raman spectroscopy, to assess the degree of unsaturation. Finally, ultrastructural analysis helped to deepen understanding of the roles of eosinophils and lipid bodies present in hepatocytes in these two models of schistosomiasis. The results revealed that N. squamipes showed excellent modulation of tissue lesions in the liver, with low tissue impairment and a more exacerbated granulomatous reaction in the small intestine, favoring the elimination of the parasite eggs in feces. Furthermore, serum transaminases levels did not change as a result of the infection in wild rodents, unlike what occurred in Swiss mice. N. squamipes infected and uninfected showed the highest degree of unsaturation present in liver tissue. Intriguing ultrastructural characteristics of N. squamipes eosinophils were observed by TEM. Through the data obtained, we concluded that the water rat has a wellestablished ecological relationship with the parasite Schistosoma mansoni, and this adaptation to parasitism may be related to lipid metabolism of this wild reservoir.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-08-03T15:13:23Z No. of bitstreams: 1 mariacristinacardosodemendonca.pdf: 5593456 bytes, checksum: 3765ccabf0d5e517d8bc0b46070c90b6 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-08-28T13:46:27Z (GMT) No. of bitstreams: 1 mariacristinacardosodemendonca.pdf: 5593456 bytes, checksum: 3765ccabf0d5e517d8bc0b46070c90b6 (MD5) / Made available in DSpace on 2018-08-28T13:46:27Z (GMT). No. of bitstreams: 1 mariacristinacardosodemendonca.pdf: 5593456 bytes, checksum: 3765ccabf0d5e517d8bc0b46070c90b6 (MD5) Previous issue date: 2018-07-12 / Introdução: A aparência física da população, que vive cada dia mais, vem assumindo um papel significativo quando nos referimos à saúde e bem-estar geral. Portanto as questões dermatológicas assumem, a cada dia, uma grande importância médica. Os peelings químicos são um importante arsenal terapêutico, sendo o peeling de fenol classicamente recomendado para tratamento de clareamento de pele, atenuação das rugas estáticas e flacidez cutânea da face, exigindo sedação em ambiente hospitalar. Na técnica pontuada, sua execução pode ser feita em ambiente ambulatorial, com segurança. Objetivo: investigar os mecanismos pelos quais a técnica se mostra eficaz quando aplicado de forma pontuada, avaliando as alterações da matriz extracelular colagenosa, das fibras elásticas e as fibras colágenas Tipo I e Tipo III, por morfometria automática, e o aumento de células de origem mesenquimal da derme através da imuno-histoquímica. Métodos: Foram utilizados blocos de biópsias de pele da face de pacientes do sexo feminino (n = 17) realizadas antes e depois do tratamento que foram atendidas no Serviço de Dermatologia do Hospital Universitário da Universidade Federal de Juiz de Fora, submetidas ao protocolo de cinco sessões de peeling de fenol pontuado. Os cortes histológicos foram submetidos à análise histopatológica de rotina (HE), análise histoquímica para fibras elásticas (Verhöeff) e para fibras colágenas Tipo I e Tipo III (picrosirius red) e à análise imuno-histoquímica para células com expressão vimentina positiva na derme. Três pacientes foram excluídas, por material insuficiente nos blocos para todas essas colorações. Os dados foram expressos em média aritmética simples ± desvio padrão, mediana e expostos em boxplot. Resultados: Ao compararmos as concentrações de matriz extracelular colagenosa pelo HE e de fibras elásticas (Verhöeff) houve uma relação inversa na histomorfometria, onde das oito pacientes que apresentavam as menores concentrações de fibras colágenas do grupo, seis possuíam as maiores concentrações de fibras elásticas. Das seis pacientes que apresentavam as maiores concentrações de fibras colágenas do grupo, todas apresentavam concentração abaixo da média do grupo para fibras elásticas. Quanto a análise da relação entre fibras colágenas Tipo III e Tipo I, houve uma inversão de valores por maior ganho de fibras colágenas Tipo I em relação as fibras colágenas Tipo III. Na imuno-histoquímica, 64,28% das pacientes (n = 9) apresentou aumento da celularidade mesenquimal. Conclusão: os resultados sugerem que a melhora clínica no tratamento do fotoenvelhecimento facial com a técnica proposta pode estar correlacionada com o maior equilíbrio entre material colágeno e elástico, com maior produção de fibras colágenas Tipo I em relação as fibras colágenas Tipo III e com o aumento do número de células mesenquimais nas amostras pós-tratamento. Diante dos resultados sugerimos que novos estudos sejam realizados, tanto clínicos quanto experimentais, para melhor elucidar os mecanismos de ação da técnica. / Introduction: The physical appearance of the population has been increasingly taking on a significant role when we speak of general health and well-being. Thus, dermatological questions take on an ever greater medical significance. Chemical peels are an important therapeutic arsenal, with phenol peeling being classically recommended for treatment of skin lightening, attenuation of static wrinkles and facial skin flaccidity, requiring sedation in a hospital environment. In the punctuated technique, treatment can safely be done in an outpatient setting. Objective: investigating the mechanisms by which the technique proves effective when applied in a punctuated form and evaluating the changes in the collagenous extracellular matrix, elastic fibers and Type I and Type III collagen fibers, by automatic morphometry, and the increase of dermal mesenchymal cells, through immunohistochemistry. Methods: Facial skin biopsy blocks from female patients (n = 17), taken before and after treatment at the Dermatology Service of the Universidade Federal de Juiz de Fora University Hospital, were used. Patients were submitted to the protocol of five punctuated phenol peeling sessions. The histological sections were submitted to routine histopathological analysis (HE), histochemical analysis for elastic fibers (Verhöeff) and for Type I and Type III collagen fibers (picrosirius red), and immunohistochemical analysis for cells with positive vimentin expression in the dermis. Three patients were excluded because of insufficient material in the blocks for all of these stains. The data were expressed as simple arithmetic mean ± standard deviation, median, and shown in boxplot. Results: Upon comparing the collagenous extracellular matrix concentrations by HE and for elastic fibers (Verhöeff), there was an inverse relation in the histomorphometry, where of the eight patients with the lowest concentrations of collagen fibers in the group, six had the highest concentrations of elastic fibers. Of the six patients who had the highest concentrations of collagen fibers in the group, all of them had a concentration for elastic fibers below the group mean. Regarding the analysis of the relationship between Type III and Type I collagen fibers, there was an inversion of values due to the higher gain of Type I collagen fibers in relation to Type III collagen fibers. In the immunohistochemistry, 64. 28% of the patients (n = 9) presented increased mesenchymal cellularity. Conclusion: the results suggest that the clinical improvement in the treatment of facial photoaging with the proposed technique may be correlated with the greater balance between collagen and elastic material, with a higher production of Type I collagen fibers in relation to Type III collagen fibers, and with the increase of the number of mesenchymal cells in the post-treatment samples. In view of the results, we suggest that new studies be conducted, both clinical and experimental, to better elucidate the action mechanisms of the technique.

M.Sc. (Aquatic Health) / South Africa’s freshwater ecosystems are under threat due to anthropogenic activities. Recent reports have shown that the Hartbeespoort- (HBPD), Klipvoor- (KD) and Bospoort Dam (BD) impoundments situated in the North-West Province are polluted as a result of mining, industrial and agricultural activities. These impoundments are classified as being in a hypertrophic state. The health status of fish in these impoundments is of concern, and needs to be investigated. For this purpose, Clarias gariepinus and Cyprinus carpio were collected for a histology-based fish health assessment. These two species are present in the selected dams and are some of the preferred fish species for human consumption by the local people. The aim of the study was to determine the health status of these fish species in HPBD, KD and BD using a semi-quantitative histopathological assessment on selected target organs and compare the results to fish from a reference site, the Marico-Bosveld Dam (MBD). Gill nets were used for the collection of specimens. Fish were macroscopically examined, weighed and measured for the calculation of the condition factor. Blood samples were collected for haematocrit, leukocrit and total protein determination. Once sacrificed, a necropsy-based health assessment (HAI) was performed to determine any abnormalities within the visceral cavity. The selected target organs were excised and weighed for the calculation of selected biometric indices. Collected tissue samples were processed using standard histological techniques and the prepared slides were stained using Haematoxylin and Eosin. Macroscopically, a number of fish from polluted sites exhibited liver with fatty change and focal discoloration as well as severe parasites within the visceral cavity. As a result, higher HAI values were recorded in polluted sites compared to the reference site. The haematocrit values varied from normal to below and above the normal range. Leukocrit values were within the normal range except for C. gariepinus from HBPD, which was above the normal range. Total protein values were within the normal range for both species for all sites. The condition factor and hepatosomatic index (HSI) values were within the accepted range except for the HSI of C. gariepinus from MBD. The mean organ index for all study sites fell within class 1 with the exception of the liver index from HBPD, KD and BD which was in class 2. Class 1 (index value <10) is indicative of slight histological alterations while class 2 (index value 10-25) translates to moderate histological alterations. Overall, a higher prevalence of histopathological alterations was noted among fish from polluted sites compared to fish from the reference site. Hence, on the basis of the macroscopic and histopathological results, the fish from the polluted sites were more affected in terms of these parameters compared to fish from the reference site. The results therefore provide valuable information for future bio-monitoring studies in the HBPD, KD and BD impoundments.