El género Arcobacter incluye especies capaces de producir patología gastrointestinal en humanos y aborto, diarrea y mastitis en ganado. Sin embargo se desconoce su prevalencia en el agua y no existen métodos que permitan la identificación de sus 9 especies. En esta tesis hemos desarrollado un protocolo (16S rDNA-RFLP) capaz de diferenciar la mayoría de las especies. Además, demostramos que la presencia de Arcobacter en aguas se correlaciona con la contaminación fecal y que tiene una elevada prevalencia y diversidad genética en el río Llobregat. Sin embargo, estos microorganismos nunca fueron detectadas en al agua potable, lo que demuestra que el tratamiento de potabilización del agua del río es efectivo para su eliminación. Comprobamos que Arcobacter presentan una elevada prevalencia tanto en diferentes tipos de carnes como en mariscos. Finalmente, se han descubierto y descrito 4 especies nuevas para el género: Arcobacter mytili, Arcobacter valdiviensis, Arcobacter defluvii y Arcobacter molluscorum. / The genus Arcobacter includes species associated with human and animal diseases. However, its prevalence in water is unknown and so far do not exist methods able to differentiate the nine accepted species. In this thesis we have developed a molecular identification method (16S rDNA-RFLP) that enables the differentiation of most of species. In addition, we have demonstrated that the presence of Arcobacter in environmental waters correlates with high level of faecal pollution. Theses microorganisms showed a high prevalence in the Llobregat River and a high genetic diversity. However, these microorganisms were never detected from drinking water, which demonstrate that the treatment of the river water is effective for its elimination. Additionally, have been demonstrated the high prevalence of Arcobacter in several types of meat and shellfish. Finally, 4 new species have been discovered and described: Arcobacter mytili, Arcobacter valdiviensis, Arcobacter defluvii y Arcobacter molluscorum.

No description available.

As espécies do gênero Arcobacter eram classificadas até a década de 1990 como pertencentes ao gênero Campylobacter. Atualmente três das cinco espécies deste gênero são consideradas potencialmente zoonóticas, podendo ser transmitidas por alimentos de origem animal. O presente estudo teve como objetivo isolar e caracterizar geneticamente amostras de Arcobacter spp., isoladas a partir de 120 amostras de carcaças, 120 amostras de fezes e 24 de amostras de músculo suíno coletadas em dois abatedouros localizados no Estado de São Paulo. Os isolados obtidos foram submetidos ao PCR-Multiplex para a determinação das espécies do gênero e analisados através da eletroforese em campo pulsado. O agente foi isolado de 71,6% das carcaças, 4,16% das amostras de fezes e 8,3% das amostras de músculo. As espécies mais prevalentes foram A. butzleri e A. cryaerophilus. A análise dos dados obtidos no PFGE (SmaI) revelou 51 perfis distintos, com um índice discriminatório de 0,98 e grande diversidade genotípica entre as amostras . O sítio de isolamento mais frequente para o agente foram as carcaças e o PFGE mostrou-se um bom instrumento para a caracterização e discriminação de cepas deste gênero / The species of Arcobacter spp. genus have been classified until 1990 as species belonging to the genus Campylobacter. Nowadays, three of five species of this genus are consider as potencially zoonotic, and can be transmitted from food of animal origin. The present study goal was to isolate and characterize genetically strains of Arcobacter spp. isolated from 120 carcasses, 120 faeces and 24 swine muscle sampled in two swine slaughterhouses located in São Paulo State. Isolates were submitted to multiplex-PCR to identify species of the genus and analyzed by pulsed field gel electrophoresis. The agent was isolated from 71,6% of carcasses, 4,16% of faeces and 8,3% of muscles samples. A. butzleri and A. cryaerophilus were the most prevalent species. The analysis of data obtained in PFGE showed 51 distinct profiles, the discriminatory index of 0,98 and it demonstrated large genotipic diversity among the strains. The main isolation site were the carcasses and the PFGE was a good tool to characterize and discriminate Arcobacter spp. strains.

As espécies do gênero Arcobacter eram classificadas até a década de 1990 como pertencentes ao gênero Campylobacter. Atualmente três das cinco espécies deste gênero são consideradas potencialmente zoonóticas, podendo ser transmitidas por alimentos de origem animal. O presente estudo teve como objetivo isolar e caracterizar geneticamente amostras de Arcobacter spp., isoladas a partir de 120 amostras de carcaças, 120 amostras de fezes e 24 de amostras de músculo suíno coletadas em dois abatedouros localizados no Estado de São Paulo. Os isolados obtidos foram submetidos ao PCR-Multiplex para a determinação das espécies do gênero e analisados através da eletroforese em campo pulsado. O agente foi isolado de 71,6% das carcaças, 4,16% das amostras de fezes e 8,3% das amostras de músculo. As espécies mais prevalentes foram A. butzleri e A. cryaerophilus. A análise dos dados obtidos no PFGE (SmaI) revelou 51 perfis distintos, com um índice discriminatório de 0,98 e grande diversidade genotípica entre as amostras . O sítio de isolamento mais frequente para o agente foram as carcaças e o PFGE mostrou-se um bom instrumento para a caracterização e discriminação de cepas deste gênero / The species of Arcobacter spp. genus have been classified until 1990 as species belonging to the genus Campylobacter. Nowadays, three of five species of this genus are consider as potencially zoonotic, and can be transmitted from food of animal origin. The present study goal was to isolate and characterize genetically strains of Arcobacter spp. isolated from 120 carcasses, 120 faeces and 24 swine muscle sampled in two swine slaughterhouses located in São Paulo State. Isolates were submitted to multiplex-PCR to identify species of the genus and analyzed by pulsed field gel electrophoresis. The agent was isolated from 71,6% of carcasses, 4,16% of faeces and 8,3% of muscles samples. A. butzleri and A. cryaerophilus were the most prevalent species. The analysis of data obtained in PFGE showed 51 distinct profiles, the discriminatory index of 0,98 and it demonstrated large genotipic diversity among the strains. The main isolation site were the carcasses and the PFGE was a good tool to characterize and discriminate Arcobacter spp. strains.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 37-38). Also available via the Internet.

The present study investigates Acanthamoeba-bacteria interaction and how this relation can influence human health aiming at the influence of bacteria on Acanthamoeba in terms of their isolation and diversity, and the effect of Acanthamoeba on bacteria focusing on two emerging human bacterial pathogens Arcobacter butzleri and Rhodococcus equi. To first objective was investigated by the test question “can the presence of a particular type of bacteria play role in the diversity of Acanthamoeba by masking and/or favouring certain genotypes of Acanthamoeba?” To answer this, two different bacteria the Gram+ve Enterococcus the Gram-ve Arcobacter were used as food source for isolation of Acanthamoeba from 102 soil samples while E. coli was used as control. It was found that the presence of different bacteria could affect the isolation of genotypes specially the subgroups and subtypes of Acanthamoeba as manifested by greater diversity of 18S rRNA sequences of Acanthamoeba isolated from environmental samples on Arcobacter (Arc) and Enterococcus (Ent) than those isolated on E. coli (Eco). The Eco isolates consisted of only T4 > T11=T13 compared to Ent isolates with T4 > T16 > T13/16 and the Arc isolates which comprised of T4 > T2 > T2/6 = T13 > T13/16. The T13/16 were the intermediate sequence types with no match to any T types. There were also considerable differences among the T4 subgroups; the Eco isolates consisted of T4-A > T4-B > T4-N > T4- E > T4-D > T4-C while Ent isolates comprised of T4-A > T4-C=T4-D=T4-E=T4-N > T4-B and the Arc isolates had only T4-E > T4-A > T4-B > T4-N. In both Eco and Ent isolates 11 subtypes were recovered with T4-36 being the most abundant, however, in Arc isolates eight subtypes were recovered with T4-12 as the most abundant. The non-Eco isolates were also different in their bacterial endosymiotic profile from Eco isolates with Arc isolates having the greatest proportion of bacterial endosymbionts (15.7%) as compared to 7.8% of Eco and 12.9% of Ent isolates. Together these results indicate a prominent role of prey bacteria on favouring certain genotypes and thus compelling consideration for use of different types of bacteria for isolation of Acanthamoeba to help surface the masked populations as well for more realistic prevalence that will help in better designing of prevention and control strategies. The influence of Acanthamoeba on bacteria was investigated for A. butzleri and R. equi both of which appeared to exploit the former as an environmental reservoir and for modulation of their pathogenic potential. A. butzleri which are closely related to Campylobacter, appeared to have a smooth interaction with Acanthamoeba. They were shown to be easily located through chemotaxis, readily attached and internalized using monosaccharide receptors and a complex phagocytic process, and could survive/proliferate in Acanthamoeba by defying the intra-vacuolar killing processes. Intracellular survival in Acanthamoeba did play a role in promoting the pathogenicity of these bacteria enabling them to survive more than three times longer. Co-culturing of the two organisms also seemed to benefit the bacteria but not Acanthamoeba. A. butzleri were found to be able to sense the environmental changes and thus modulate their virulence, a feature that together with selection pressure for intracellular survival in Acanthamoeba can cause rapid adaptation to intra-amoebal environment and enhance the pathogenic potential of these bacteria for humans and animals. Exploitation of Acanthamoeba for survival was also found to be exhibited by the Mycobacterium-resembling Gram+ve R. equi by utilizing similar strategies for survival/proliferation as used for macrophages, which involved the definite presence of virulence plasmid and its activation at higher temperatures. Moreover, similar genes (vapA, vapC and vapF) were found to play role in intracellular survival in both the macrophages and amoeba cells. The intra-amoebal survival/proliferation capabilities of A. butzleri and R. equi appear to support the notion that free living protists like Acanthamoeba act as environmental reservoirs/virulence trait selectors and are strong candidates for the “missing link” between the ecology and pathology of these emerging pathogenic pathogens. Overall, the observations made in this study explore the vital role of Acanthamoeba-bacteria interaction not only mutually on each other but as a consequence the impact on human health either as a result of masked genotypes in clinical diagnosis of Acanthamoeba or due to environmental reservoir role of Acanthamoeba in selecting virulence traits of bacteria, can pose serious challenges leaving ample opportunities for more emerging bacterial pathogens. These observations call for revising the protocols for Acanthamoeba prevalence, eradication and control strategies.

Arcobacter spp., anteriormente conhecido como Campylobacter aerotolerante, é considerado um gênero bacteriano que inclui espécies consideradas patógenos emergentes que podem ser veiculados por alimentos. O gênero Arcobacter tem sido associado a gastroenterites, diarreia persistente e bacteremia em humanos. É uma bactéria Gram negativa, termosensível, embora possa sobreviver à 4°C. No Brasil, há poucos estudos de ocorrência de Arcobacter em alimentos, inclusive os de origem animal, especialmente os mais consumidos, como as carnes de frango e suína. Existem estudos pontuais de sua ocorrência em produtos resfriados, como cortes e em carcaças de frango resfriadas do varejo. O objetivo deste estudo foi avaliar a ocorrência de Arcobacter spp. em cortes e carcaças de frango refrigeradas e congeladas do varejo e em coxas de frango livres de antibiótico e orgânico refrigeradas provenientes de abatedouro, por técnica de isolamento convencional com posterior confirmação do gênero por reação de polimerase em cadeia (PCR). Foram analisadas 153 amostras de carne de frango, das quais 39,21% (59/153) resultaram positivas para o gênero Arcobacter. Foi obtido o total de sessenta e quatro isolados positivos para Arcobacter spp., que corresponderam a 89,06% (57/64) de A. lacus, 4,7% (3/64) de A. thereius, 3,12% (2/64) de A. butzleri, e 3,12% (2/64) de Arcobacter spp. espécie não identficada até o momento. Foram realizadas análises fenotípicas de resistência a 12 antibióticos com 34 isolados, previamente selecionados, de quatro diferentes fontes de carnes de frango obtidos nesse trabalho, e de três linhagens utilizadas como controle positivo de Arcobacter. A resistência fenotípica frente aos antimicrobianos foi de 100% para ácido nalidíxico e clindamicina, 29,73% para eritromicina, 24,32% para canamicina, 21,62% para tetraciclina, 18,42% para cloranfenicol, 13,51% para gentamicina, 8,11% para estreptomicina, 5,41% para azitromicina e ciprofloxacina, 2,10% para vancomicina e 0,00% para ampicilina. / Arcobacter spp., previously known as aerotolerant Campylobacter, is considered a bacterial genus that includes species considered emerging pathogens that can be transmitted by food. Arcobacter has been associated with gastroenteritis, persistent diarrhea and bacteremia in humans. It is a gram negative, thermosensitive bacterium, although it can survive at 4 ° C. In Brazil, there are few studies of the occurrence of Arcobacter in animal products including those of animal origin, especially those most consumed, such as poultry and pork. There are occasional studies of their occurrence in cooled products, such as cuts and in refrigerated chicken carcasses. The objective of this study was to evaluate the occurrence of Arcobacter spp. in refrigerated chicken cuts and carcasses of the retail and in chicken thighs free of antibiotic and organic refrigerated from slaughterhouse by conventional isolation and genotyping by polymerase chain reaction (PCR). A total of 153 chicken meat samples were analyzed, of which 39.21% (59/153) were positive for the Arcobacter genus. A total of sixty-four isolates positive for Arcobacter spp., corresponding 89.06% (57/64) of A. lacus, 4.7% (3/64) of A. thereius, 3.12% (2/64) of A. butzleri, and 3.12% (2/64) of Arcobacter spp. species not yet identified. Phenotypic resistance analyzes were performed on 12 antibiotics with 34 isolates, previously selected from four different sources of chicken meat obtained in this study, and three strains used as positive control of Arcobacter spp. Phenotypic resistance to antimicrobials were 100% for nalidixic acid and clindamycin , 29.73% for erythromycin, 24.32% for kanamycin, 21.62% for tetracycline, 18.42% for chloramphenicol, 13.51% for gentamycin, 8.11% for streptomycin, 5.41% for azithromycin and ciprofloxacin, 2.10% for vancomycin and 0.00% for ampicillin.

Dentre as espécies conhecidas do gênero Arcobacter, as espécies A. butzleri, A. cryaerophilus e A. skirrowii são consideradas potecialmente zoonóticas, podendo ser transmitidas por alimentos de origem animal. O presente estudo teve como objetivos isolar e caracterizar fenotipica e genotipicamente cepas de Arcobacter spp. provenientes de carcaças de suínos e amostras de ambiente de abatedouro localizado no Estado de São Paulo. As cepas isoladas foram submetidas a reação em cadeia pela polimerase para a identificação e detecção de um grupo de genes de virulência. A concentração inibitória mínima frente a nove antimicrobianos usados para o controle da infecção pelo agente foi determinada e as cepas foram analisadas através do PFGE e pelo AFLP. Dentre as 30 carcaças avaliadas, 25 foram positivas para o agente e 70 cepas foram selecionadas e identificadas como Arcobacter spp. As espécies isoladas foram A. butzleri (n=61), A. cryaerophilus (n=7) e A. skirrowii (n=2). A frequência dos possíveis genes de virulência encontrada variou de 71,4% a 100% para os genes tlyA, pldA, cj1349, ciaB, cadF e mviN. Não foram detectados os genes hecA, hecB e irgA. O perfil de virulência ciaB/ cj1349/ mviN/ cadF/ pldA/ tlyA foi o mais frequente e detectado em 66% das cepas. Todas as cepas foram sensíveis à gentamicina e tetraciclina e 77,1% foram multirresistentes, dentre estas o perfil mais frequente foi de resistência a azitromicina/ florfenicol/ ácido nalidíxico/ telitromicina/ clindamicina Houve grande diversidade genotípica entre as cepas através do PFGE e do AFLP, e ambas a técnicas apresentaram o mesmo poder discriminatório na análise das cepas isoladas. / Among the known species of the genus Arcobacter, the species A. butzleri, A. cryaerophilus and A. skirrowii are considered potentially zoonotic and can be transmitted by food of animal origin. This study aimed to isolate and characterize phenotypically and genotypically strains of Arcobacter spp from swine carcasses and slaughterhouse environment samples located in the State of São Paulo. The isolated strains were subjected to polymerase chain reaction for identification and detection of a group of putative virulence genes. The minimum inhibitory concentration was determined against nine antimicrobials indicated for the control of infection by the agent and the strains were analyzed by PFGE and by AFLP. Among the 30 carcasses evaluated, 25 were positive for the agent and 70 strains were selected and identified as Arcobacter spp. The isolated species were A. butzleri (n = 61), A. cryaerophilus (n = 7) and A. skirrowii (n = 2). The frequency of virulence genes found ranged from 71.4 % to 100 % for genes tlyA , pldA , cj1349 , ciaB , cadF and mviN . The genes hecA, hecB and irgA were not detected. The virulence profile ciaB/ cj1349/ mviN/ cadF/ pldA/ tlyA was the most frequent and detected in 66 % of the strains. All strains were susceptible to gentamicin and tetracycline and 77.1% were multirresistant, among these the most common profile of resistance was azithromycin/ florfenicol/ nalidixic acid/ telithromycin/ clindamycin There were large genotypic diversity among strains by PFGE and AFLP and both techniques showed the same discriminatory power in the analysis of the isolated strains.

Arcobacter spp. é um micro-organismo Gram negativo que provoca diarreia aquosa e sepse em seres humanos. A. butzleri, A. cryaerophilus e A. skirrowii são espécies patogênicas para humanos. O objetivo deste estudo foi detectar a presença de Arcobacter spp. na carne de aves comercializadas em açougues na cidade de São Paulo, verificando os genes de virulência e o perfil genotípico. Um total de 300 cortes de carne de frango foram submetidos ao cultivo e isolamento sob condições aeróbicas, a 30°C por 72 horas. Colônias suspeitas de Arcobacter spp. foram selecionadas para a detecção molecular pela reacção em cadeia da polimerase (PCR), a fim de determinar as espécies e os genes de virulência. Os resultados revelaram a presença de Arcobacter spp. em 18.3% (55/300) de amostras de carne de aves, sendo identificado como A. butzleri 63,6% (35/55) e A. cryaerophilus 36,3% (20/55). Os genes de virulência pesquisados demonstraram positividade de 100% (55/55) para o ciaB e mviN, seguidos de cj1349 98,1% (54/55), pldA 94,4% (52/55), cadF 72,7% (40/55), tlyA 92,7% (51/55), hecA 49% (27/55), irgA 47,2% (26/55) e hecB 34,5% (19/55). Estas cepas foram submetidas ao AFLP gerando dois dendogramas. Foram identificados 19 perfis genotípicos para A. butzleri e 17 para A. cryaerophilus. Os resultados desta pesquisa apontam a presença de A. butzleri e A. cryaerophilus na fase final da distribuição de carne de frangos nos açougues. A falta de inocuidade dos alimentos de origem animal, bem como a presença de estirpes virulentas representam riscos de Saúde Pública, com especial atenção para a possibilidade de contaminação cruzada gerados por alimentos crus e utensílios de cozinha / Arcobacter spp. is a Gram negative microorganism that causes watery diarrhea and septicemia in humans. A. butzleri, A. cryaerophilus and A. skirrowii are pathogenic for humans. The aim of this study was to detect the presence of Arcobacter spp. in poultry meat from butcher shops in the city of São Paulo, checking the virulence genes and profile genotypic. A total of 300 chicken cuts were used for cultivation and isolation in broth and JM agar, under aerobic conditions, at 30 °C for 72 hours. Arcobacter colonies were selected and submitted to molecular detection by polymerase chain reaction (PCR), in order to determine species and virulence genes. Results show the presence of Arcobacter spp. in 18.3% (55/300) of poultry meat samples, identified as A. butzleri 63.6% (35/55) and A. cryaerophilus 36.3% (20/55) in chicken isolates. The virulence genes on Arcobacter spp. researched demonstrated positive these 100% (55/55) for ciaB and mviN, followed by cj134998,1% (54/55), pldA 94,4% (52/55), cadF 72.7% (40/55), tlyA 92,7% (51/55), hecA 49% (27/55), irgA 47,2% (26/55) and hecB 34,5% (19/55). These strains were submitted to AFLP generating two dendogramas. Nineteen profiles genotypins were obtained for A. butzleri and seventeen for A. cryaerophilus. The results of this research point to the presence of Arcobacter butzleri and A. cryaerophilus in the final stage of distribution of poultry meat to butcher shops. The lack of safety of food of animal origin, as well as the presence of virulent strains pose risks to Public Health, with special focus on cross contamination risks generated by uncooked food and utensils