No presente estudo 64 amostras de água de superficie e 24 amostras de sedimento provenientes da Represa de Guarapiranga, SP, foram submetidas à técnica dos tubos múltiplos para a pesquisa de Aeromonas spp. As amostras eram submetidas a enriquecimento com água peptonada alcalina (APA), adicionado de 1 por cento de cloreto de sódio, pH 8,6 e isoladas em agar sangue contendo 10 mg/1 de ampicilina. As colônias que se apresentavam hemolíticas ou não, eram submetidas a triagem pelos testes de oxidase e agar ferro de Kligler (Difco) e confirmadas através de provas bioquímicas complementares. Foram isoladas A. hydrophila em 18,7 por cento das amostras, A. caviae em 31,2 por cento, A. sobria em 43,7 por cento e A. jandaei em 76,6 por cento. Não foi observada a correlação das espécies isoladas com temperatura da água, pH da amostra ou contagens de indicadores de contaminação fecal. As maiores contagens de Aeromonas spp foram encontradas em amostras de sedimento. Do total de cepas isoladas, 15 de A. hydrophila, 15 de Aromonas caviae, 15 de A. sobria e 15 de A. jandaei foram submetidas ao teste de alça ligada em coelhos e teste de hemólise em ágar sangue de coelho e humano. A pesquisa de fatores de virulência revelou que 80 por cento das cepas de A. hydrophila, 73,3 por cento de A. caviae, 46,7 por cento de A. sobria e 86,6 por cento de A. jandaei causaram acúmulo de fluido em alça ligada de coelho e que 86,6 por cento de A. hydrophila, 33,3 por cento de A. caviae, 60 por cento de A. sobria e 100 por cento de A. jandaei foram produtoras de beta-hemólise em ágar sangue, confirmando o elevado potencial patogênico desses microrganismos. Considerando os resultados obtidos pode-se concluir que cepas de Aeromonas isoladas de ambiente aquático são capazes de produzir fatores de virulência que constituem um risco à saúde da população. / In this work, 64 superfitial water samples and 24 of sedment, were colected from Guarapiranga dam in the State of São Paulo, Brazil, and were analised to the presence of Aeromonas spp. Enrichment of samples were made in Alcaline Peptone Water (APW) with sodium chloride 1 per cent pH 8,6. Blood Agar Ampicilin (10/gl) were used as isolation medium. Colonies that were hemolytic or not, were submetted to oxidase test and Kligler lron Agar (difco), and were confirmed through complementar biochemical tests. A. hydrophila were isolated in 18, 7 per cent of the samples, A. caviae in 31,2 per cent A. sobria in 43,7 per cent and A. jandaei in 76,6 per cent. No correlation was observed between Aeromonas sapecies neither with temperature or pH, nor with fecal contaminantion indicators. The highests values of Aeromonas spp, were observed in sedment samples. From the total of strains that were isolated, 15 of A. hydrophila, 15 A. caviae, 15 A. sobria and 15 of A. jandaei. were submetted to the rabbit ileal loop assay and to the hemolysis prodution on Blood agar with human and rabbit erytrocits. The virulence factors reseach revealed that 80 per cent of A. hydrophila, 73,3 per cent of A. caviae, 46,7 of A. sobria and 86,8 per cent of the A. jandaei were able to cause fluid accumulation in rabbit ileal loop, and, 86,6 per cent of A. hydrophila strains, 33,3 per cent of A. caviae, 60 per cent of A. sobria and 100 per cent of A. jandaei produced beta-hemolisis in blood agar. these results confirms the pathogenic potential of these microorganisms. Considering the given results, it was concluded that Aeromonas strains, isolated from this environment are able to produce virulence factors that are considered a risk to public health.

No presente estudo 64 amostras de água de superficie e 24 amostras de sedimento provenientes da Represa de Guarapiranga, SP, foram submetidas à técnica dos tubos múltiplos para a pesquisa de Aeromonas spp. As amostras eram submetidas a enriquecimento com água peptonada alcalina (APA), adicionado de 1 por cento de cloreto de sódio, pH 8,6 e isoladas em agar sangue contendo 10 mg/1 de ampicilina. As colônias que se apresentavam hemolíticas ou não, eram submetidas a triagem pelos testes de oxidase e agar ferro de Kligler (Difco) e confirmadas através de provas bioquímicas complementares. Foram isoladas A. hydrophila em 18,7 por cento das amostras, A. caviae em 31,2 por cento, A. sobria em 43,7 por cento e A. jandaei em 76,6 por cento. Não foi observada a correlação das espécies isoladas com temperatura da água, pH da amostra ou contagens de indicadores de contaminação fecal. As maiores contagens de Aeromonas spp foram encontradas em amostras de sedimento. Do total de cepas isoladas, 15 de A. hydrophila, 15 de Aromonas caviae, 15 de A. sobria e 15 de A. jandaei foram submetidas ao teste de alça ligada em coelhos e teste de hemólise em ágar sangue de coelho e humano. A pesquisa de fatores de virulência revelou que 80 por cento das cepas de A. hydrophila, 73,3 por cento de A. caviae, 46,7 por cento de A. sobria e 86,6 por cento de A. jandaei causaram acúmulo de fluido em alça ligada de coelho e que 86,6 por cento de A. hydrophila, 33,3 por cento de A. caviae, 60 por cento de A. sobria e 100 por cento de A. jandaei foram produtoras de beta-hemólise em ágar sangue, confirmando o elevado potencial patogênico desses microrganismos. Considerando os resultados obtidos pode-se concluir que cepas de Aeromonas isoladas de ambiente aquático são capazes de produzir fatores de virulência que constituem um risco à saúde da população. / In this work, 64 superfitial water samples and 24 of sedment, were colected from Guarapiranga dam in the State of São Paulo, Brazil, and were analised to the presence of Aeromonas spp. Enrichment of samples were made in Alcaline Peptone Water (APW) with sodium chloride 1 per cent pH 8,6. Blood Agar Ampicilin (10/gl) were used as isolation medium. Colonies that were hemolytic or not, were submetted to oxidase test and Kligler lron Agar (difco), and were confirmed through complementar biochemical tests. A. hydrophila were isolated in 18, 7 per cent of the samples, A. caviae in 31,2 per cent A. sobria in 43,7 per cent and A. jandaei in 76,6 per cent. No correlation was observed between Aeromonas sapecies neither with temperature or pH, nor with fecal contaminantion indicators. The highests values of Aeromonas spp, were observed in sedment samples. From the total of strains that were isolated, 15 of A. hydrophila, 15 A. caviae, 15 A. sobria and 15 of A. jandaei. were submetted to the rabbit ileal loop assay and to the hemolysis prodution on Blood agar with human and rabbit erytrocits. The virulence factors reseach revealed that 80 per cent of A. hydrophila, 73,3 per cent of A. caviae, 46,7 of A. sobria and 86,8 per cent of the A. jandaei were able to cause fluid accumulation in rabbit ileal loop, and, 86,6 per cent of A. hydrophila strains, 33,3 per cent of A. caviae, 60 per cent of A. sobria and 100 per cent of A. jandaei produced beta-hemolisis in blood agar. these results confirms the pathogenic potential of these microorganisms. Considering the given results, it was concluded that Aeromonas strains, isolated from this environment are able to produce virulence factors that are considered a risk to public health.

Thesis (Ph. D.)--Miami University, Dept. of Chemistry and Biochemistry, 2003. / Title from first page of PDF document. Document formatted into pages; contains xi, 150 p. : ill. Includes bibliographical references.

The epidemiology of Aeromonas salmonicida subsp. salmonicida in the marine environment was investigated. Nutrient resuscitation and infectivity studies did not support a previous claim of dormancy in A. salmonicida and validated the use of colony-forming units (cfu) in survival studies. Survival of A. salmonicida in seawater was assessed and found to be of short duration «10 days). Survival of the bacterium in non-sterile sediment, obtained from beneath a salmon cage, appeared to be limited. The minimum infective dose of A. salmonicida to Atlantic salmon in short duration (1-3 days) bath exposure in sea water was 10' cfu ml-I. Prolonged exposure for three weeks resulted in infection with 102 cfu ml- I. Intragastric intubation of the bacterium established infection with doses >105 cfu. Shedding of A. salmonicida from infected salmon was 105-108 cfu/fish/hr. Survival and shedding results were combined in a computer model. A. salmonicida was predicted to travel >6 km suspended within the water column of a sea loch. Covert infection in freshwater farmed salmon was assessed by ELISA and the standard stress test. Results indicated that ELISA may be useful as a routine monitor of furunculosis infection. The efficacy of dot-blot immunoassay was found to be 108 cfu A. salmonicida in fish kidney tissue. Rainbow trout (Oncorhynchus mykiss) and salmon mucus were not found to inhibit the growth of A. salmonicida supporting recent evidence that fish skin is a site of carriage. In vitro studies suggested that trout serum proteins do not confer protection from fish antibody on A. salmonicida in covert infections. Preliminary work was undertaken to develop a specific DNA probe for A. salmonicida which will allow its detection in environmental samples and carrier fish. A gene library of A. salmonicida was constructed in lambda gtll and screened for "A"-protein with antibodies.

Durante la presente tesis doctoral se ha establecido la presencia de variabilidad interoperónica en el gen ARNr 16S de Aeromonas y observado que ésta afectaba a la taxonomía del género, limitando la identificación de A. caviae, A. media y A. veronii. La secuenciación del gen rpoD permitió identificar las cepas con variabilidad interoperónica a nivel de especie y reconocer 5 nuevas especies del género: A. fluvialis, A. taiwanensis, A. sanarelii, A. piscicola y A. rivuli. En colaboración con diversos hospitales españoles se han descrito los primeros aislados de A. aquariorum de origen extraintestinal, el segundo caso en adultos de síndrome urémico hemolítico (SUH) asociado a Aeromonas y se ha podido demostrar la presencia en este género del gen stx2 asociado al SUH. Se han revisado las características clínicas y microbiológicas de las infecciones de herida quirúrgicas relacionadas con Aeromonas. Finalmente, se ha descrito el primer caso de inducción in vivo de resistencia al imipenem en una cepa de A. veronii. Los resultados de esta tesis han dado lugar o contribuido a la publicación de 13 artículos científicos en revistas internacionales. / During this thesis has established the presence of inter-operon variability in 16S rRNA gene of Aeromonas and observed that it affected the taxonomy of the genus, limiting the identification of A. caviae, A. media and A. veronii. The rpoD gene sequences identified strains with variability at the species level and recognize 5 new Aeromonas species: A. fluvialis, A. taiwanensis, A. sanarelii, A. piscicola and A. rivuli. In collaboration with various Spanish hospitals have described the first isolation of A. aquariorum from extraintestinal origin, the second adult case of hemolytic uremic syndrome (HUS) associated with Aeromonas and demonstrated the presence of stx2 gene associated with HUS in Aeromonas. We reviewed the clinical and microbiological characteristics of surgical wound infections associated with Aeromonas. Finally, we described the first case of in vivo induction of resistance to imipenem in a strain of A. veronii. The results of this thesis have led or contributed to the publication of 13 scientific papers in international journals.

Aeromonas spp. isolates, which are fish and opportunistic human pathogens, form biofilms, however the factors involved in and affecting biofilm formation have not been fully elucidated. Biofilm formation is affected by motility, cell surface characteristics, and/or metabolism, thus it is important to identify factors potentially contributing to initial attachment and/or biofilm formation and their correlation with biofilm formation by Aeromonas spp. isolates. With knowledge of the stages of biofilm formation, mechanisms involved in biofilm formation and its physiology, various strategies may be applied to control aeromonad biofilms. Factors potentially involved in initial attachment and/or biofilm formation were investigated for 99 Aeromonas isolates obtained from seawater and cultured fish. Aeromonad biofilm formation was assessed using microtiter plate assays under varying physicochemical conditions. The disk diffusion method was used to determine the antimicrobial susceptibility profiles of isolates, for comparison to clinical and aquaculture isolates reported in other studies. The MICs and MBICs for antimicrobial agents (azithromycin, ceftazidime, ciprofloxacin, gentamicin and tetracycline) of planktonic cells and biofilm cells, respectively, were investigated using the broth microdilution and modified microtiter plate assays. The effect of sub-MIC (0.5 × MIC) and supra-MIC (2 × MIC) exposures on biofilm-forming cells was also determined using microtiter plate assays. The presence of efflux pump-mediated resistance in 45 Aeromonas spp. isolates was determined using the disk diffusion assay incorporating efflux pump inhibitors (EPIs) [carbonyl cyanide 3-chlorophenylhydrazone (CCCP), phenylalanine arginine β-naphthylamide (PAβN) and 1-(1-naphthylmethyl)-piperazine (NMP)]. Modified microtite plate assays were used to determine the effect of EPIs [CCCP, PAβN, and NMP], matrix-degrading DNase I and quorum-sensing inhibitors (QSIs; vanillin, 2(5H)-furanone, S-adenosylhomocysteine and cinnamaldehyde) on initial attachment and mature biofilm. Majority of isolates were motile by swimming and swarming and displayed caseinase, gelatinase, and DNase activities, as well as an A-layer phenotype. Majority of isolates displayed high levels of autoaggregation and were hydrophilic. Isolates showed varying levels of adherence, but majority were strongly adherent in nutrient-rich media at 30 ºC. Motility appeared to be a significant characteristic for biofilm formation. Majority of Aeromonas isolates spp. showed high levels of resistance to β-lactams, trimethoprim and sulphamethoxazole, and were susceptible to augmentin, piperacillin-tazobactam, aztreonam, 2nd and 3rd generation cephalosporins, carbapenems, macrolides, fluoroquinolones and aminoglycosides . High levels of resistance towards ceftazidime (MIC > 32 μg/ml) were observed for isolates, while levels of resistance towards remaining antimicrobial agents tested (tetracycline, azithromycin, ciprofloxacin, and gentamicin) were ≤ 32 μg/ml. There was a ≥16-fold increase in MBICs (4096 μg/ml) compared to the MICs for all the antimicrobial agents. The sub-MIC, MIC, and supra-MIC exposures of all antimicrobial agents had an inhibitory effect on both initial attachment and pre-formed biofilms by Aeromonas spp. isolates. Majority of isolates were more susceptible to tetracycline, norfloxacin, and azithromycin due to CCCP and NMP inhibition of the efflux pumps eliminating these antimicrobial agents. Susceptibility to erythromycin was observed for 51% and 47% of isolates, respectively, due to NMP and PAβN inhibition of the efflux pump/s eliminating erythromycin. In the microtiter plate assays, CCCP, NMP and PABN exposures resulted in significant reduction of biofilm formation by majority of Aeromonas spp. isolates in both initial attachment and mature biofilm assays, with CCCP being more effective. DNase I was more effective in reducing mature biofilm, causing reduction for 60% of isolates, compared to its effect on initial attachment. QSIs were also more effective in reducing mature biofilm compared to inhibiting initial attachment. Although increased biofilm dispersal was observed with all QSIs, vanillin and 2(5H)-furanone were more effective compared to S-adenosylhomocysteine and cinnamaldehyde. Based on data obtained in this study, antimicrobial agents, EPIs and QSIs can be used as potential biofilm-inhibiting compounds in aquaculture to control aeromonad infections and may not only prevent disease outbreaks but they could also increase the effectiveness of existing therapeutic agents. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vi, 93 p. : ill. Vita. Includes abstract. Includes bibliographical references.

University, Diss., 2004--Konstanz. / Erscheinungsjahr an der Haupttitelstelle: 2003.

Orientador: Percilia Cardoso Giaquinto / Resumo: Pesquisas recentes têm considerado aspectos individuais de personalidade em seus resultados. As personalidades podem explicar o sucesso adaptativo e aptidões individuais, além de outros fatores, como a variação imunológica. Estudos realizados em mamíferos comprovam a existência de variação em fatores imunológicos, dependendo do tipo de personalidade. Em peixes, os estudos em relação à personalidade são incipientes e são poucos os estudos que correlacionem perfil de personalidade e predisposição a doenças nesses animais. Assim, testamos a suscetibilidade dos perfis de personalidade tímido e ousado em tilápia do Nilo infectando o ambiente aquático com a bactéria Aeromonas hydrophila. Como resultados obtivemos que as lâminas histológicas com esfregaços sanguíneos apresentaram hifas fungicas e alterações nas membranas dos eritrócitos dos indivíduos com perfil tímido. A infecção bacteriana interferiu no comportamento alimentar de ambos os perfis, com diminuição da ingestão. Por outro lado, a infecção não afetou os demais parâmetros comportamentais e nem o número de células sanguíneas. / Abstract: Recent studies have considered individual aspects of personality in their results. Personalities can explain the adaptive success and individual fitness, and other factors, such as immune variation. Studies in mammals prove the existence of variation in immune factors, depending on type of character. In fishes, the studies on personality are incipient and there isn't study that correlates personality profile and susceptibility to disease in these animals. Thus, we tested the susceptibility of “shy-bold” personality profiles in Nile tilapia infecting the aquatic environment with the bacterium Aeromonas hydrophila. As a result we found that the histological slides with blood scrub showed fungal hyphae and alterations in the erythrocyte membranes of individuals with a shy profile. The bacterial infection interfered in the feeding behavior of both profiles, with decreased ingestion. Still, the infection did not affect the other behavioral parameters nor the number of blood cells. / Mestre

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2010 / Made available in DSpace on 2012-10-25T10:36:24Z (GMT). No. of bitstreams: 1 285130.pdf: 230840 bytes, checksum: 3fd8eaff1a8926c2458f7dc1a645529d (MD5) / Este estudo avaliou o efeito de vacina polivalente sobre as respostas hematológica e imunológica da tilápia do Nilo desafiada com Aeromonas hydrophila. Duas doses de vacina (1x104 e 1x108 Unidades Formadoras de Colônia (UFC) x mL-1), contendo proporções iguais de Aeromonas hydrophila, Pseudomonas aeruginosa e Enterococcus durans inativadas em formalina, foram testadas por injeção intraperitoneal (i.p.). Os peixes foram desafiados seis dias após a vacinação i.p. com a dose de desafio de 1x107 UFC de A. hydrophila x mL-1 diluída em 1 mL de solução salina estéril. Seis dias após a imunização e 48h após o desafio, foi realizada a análise hematológica, atividades antimicrobiana e aglutinante do soro. Antes do desafio, o número de eritrócitos foi superior nos peixes vacinados com 1x108 UFC x mL-1. Após o desafio, o número total de trombócitos também foi maior nos peixes vacinados com a maior dose. Antes e após o desafio, o número total de leucócitos e o número de linfócitos apresentaram os maiores valores nos peixes vacinados. O número de monócitos nos peixes vacinados e nos injetados com salina foi maior antes do desafio. Após a imunização e o desafio, o soro de peixes vacinados com a maior dose apresentaram maior título de aglutinação contra A. hydrophila, P. aeruginosa e E. durans. Antes do desafio a atividade antimicrobiana do soro foi maior nos peixes não vacinados e nos vacinados com a maior dose, sendo que após o desafio os peixes não vacinados e os injetados com salina apresentaram maior atividade antimicrobiana. Este estudo mostrou que após seis dias, a vacina polivalente na concentração de 1 x108 UFC x mL-1 estimulou a produção de eritrócitos, leucócitos, trombócitos e linfócitos circulantes e reduziu os níveis de glicose.