Ribotyping and virulence markers of Yersinia pseudotuberculosis strains isolated from animals in Brazil.

Ribotyping and virulence markers has been used to investigate 68 Yersinia pseudotuberculosis strains of serogroups O:1a and O:3. The strains were isolated from clinical material obtained from healthy and sick animals in the Southern region of Brazil. Ribotypes were identified by double digestion of extracted DNA with the restriction endonucleases SmaI and PstI, separation by electrophoresis and hybridization with a digoxigenin-labeled cDNA probe. The presence of the chromosomal virulence marker genes inv, irp1, irp2, psn, ybtE, ybtP-ybtQ, and ybtX-ybtS, of the IS100 insertion sequence, and of the plasmid gene lcrF was detected by polymerase chain reaction. The strains were grouped into four distinct ribotypes, all of them comprising several strains. Ribotypes 1 and 4 presented distinct profiles, with 57.3% genetic similarity, ribotypes 2 and 3 presented 52.5% genetic similarity, and genetic similarity was 45% between these two groups (1/4 and 2/3). All strains possessed the inv, irp1, and irp2 genes. Additionally, strains of serogroup O:1a carried psn, ybtE, ybtP-ybtQ, ybtX-ybtS, and IS100. As expected lcrF was only detected in strains harboring the virulence plasmid. These data demonstrate the presence of Y. pseudotuberculosis strains harboring genotypic virulence markers in the livestock from Southern Brazil and that the dissemination of these bacteria may occur between herds.

Ribotyping and virulence markers of Yersinia pseudotuberculosis strains isolated from animals in Brazil

Ribotyping and virulence markers has been used to investigate 68 Yersinia pseudotuberculosis strains of serogroups O:1a and O:3. The strains were isolated from clinical material obtained from healthy and sick animals in the Southern region of Brazil. Ribotypes were identified by double digestion of extracted DNA with the restriction endonucleases SmaI and PstI, separation by electrophoresis and hybridization with a digoxigenin-labeled cDNA probe. The presence of the chromosomal virulence marker genes inv, irp1, irp2, psn, ybtE, ybtP-ybtQ, and ybtX-ybtS, of the IS100 insertion sequence, and of the plasmid gene lcrF was detected by polymerase chain reaction. The strains were grouped into four distinct ribotypes, all of them comprising several strains. Ribotypes 1 and 4 presented distinct profiles, with 57.3 percent genetic similarity, ribotypes 2 and 3 presented 52.5 percent genetic similarity, and genetic similarity was 45 percent between these two groups (1/4 and 2/3). All strains possessed the inv, irp1, and irp2 genes. Additionally, strains of serogroup O:1a carried psn, ybtE, ybtP-ybtQ, ybtX-ybtS, and IS100. As expected lcrF was only detected in strains harboring the virulence plasmid. These data demonstrate the presence of Y. pseudotuberculosis strains harboring genotypic virulence markers in the livestock from Southern Brazil and that the dissemination of these bacteria may occur between herds.

Production of autoantibodies associated with polyclonal activation in Yersinia enterocolitica O: 8-infected mice.

Polyclonal lymphocyte stimulation is one of the immunomodulatory mechanisms induced by arthritogenic pathogens. In this study we examined the polyclonal activation potential of a virulent strain of Y. enterocolitica serotype O: 8 (WA 2707(+)) and its plasmidless isogenic pair (WA 2707(-)). SPF Swiss mice were infected intragastrically and spleen cells were obtained on days 7, 14, 21, 28, 35 and 42 after infection. The number of cells secreting nonspecific immunoglobulins of IgG, IgM and IgA isotypes was determined by the ELISPOT technique. The presence of serum-specific antibodies was investigated by ELISA and the presence of autoantibodies by dot-blot assay. Although the patterns of infection of the two bacterial strains were almost the same, only the animals infected with the virulent strain presented clinical anomalies. Neither arthritic nor inflammatory signs were observed in the joints of the infected animals. The greatest activation observed was that of the nonspecific IgM-secreting cells, and their peak of secretion occurred between the 28th and the 42nd day after infection, for both strains of Y. enterocolitica O: 8. Only the animals infected with the virulent strain (WA 2707(+)) produced IgG-specific antibodies in the serum, from the 28th day after infection. The serum of animals infected with either strain showed reactivity to all the autologous constituents tested, mainly on the 28th and 42nd day after infection. It was concluded that infection of mice with either the virulent strain of Y. enterocolitica O: 8 or with its plasmidless isogenic pair resulted in the polyclonal activation of the splenic B lymphocytes including some autoreactive clones.

Monitoring of the dissemination of Salmonella in the chicken Frankfurt-sausage production line of a sausage factory in the state of São Paulo, Brazil.

Poultry meat and its derivatives are among the foodstuffs considered by environmental health authorities to present the highest risks to the public. A total of 185 samples were collected in five monthly batches, from different processing stages in a sausage plant that uses mechanically-deboned chicken meat (MDCM), and tested for the presence of Salmonella. Enrichment was carried out in both Kauffman's tetrathionate broth and Rappaport-Vassiliadis broth and isolation on Salmonella-Shigella agar and brilliant-green agar. Live Salmonella bacteria were isolated from six samples of the raw meat and from the emulsion, in batches three, four, and five, but not from any sample in batches one or two. The six isolated strains were all classified as Salmonella Albany, which has not previously been reported in MDCM. Of the two enrichment broths, Rappaport-Vassiliadis gave the better results. The pattern of contamination suggests a probable common source, given that a new supplier was used in the third, fourth, and fifth months. It was also shown that the industrial cooking was effective in preventing Salmonella surviving in the final product.

Experimental kinetics of infection induced by Yersinia pseudotuberculosis isolated from stock animals.

The course of in vivo infection of five isolates of Yersinia pseudotuberculosis was followed for three weeks in Swiss mice. The strains were isolated from diarrheic and normal feces and mesenteric lymph nodes of healthy and sick stock animals. Four strains of serogroup O:3 and one of serogroup O:1a, with and without the virulence plasmid, were inoculated intragastrically and intravenously in the mice. Groups of five animals were sacrificed at 6 h and 3, 6, 10, 15, and 21 days after inoculation, and organs and tissues were checked for possible macroscopic alterations. Development of infection was monitored at these times by performing viable bacterial counts in homogenates of selected tissues. The animals were checked daily for clinical alterations. The results of the study showed that strains with the virulence plasmid infected organs and tissues at various times and at varying intensity by both routes of infection, the strain of type O:1a being the most invasive. Moreover, clinical and pathological alterations occurred only in animals inoculated with bacteria carrying the virulence plasmid, regardless of the route of infection.

Experimental kinetics of infection induced by Yersinia pseudotuberculosis isolated from stock animals

The course of in vivo infection of five isolates of Yersinia pseudotuberculosis was followed for three weeks in Swiss mice. The strains were isolated from diarrheic and normal feces and mesenteric lymph nodes of healthy and sick stock animals. Four strains of serogroup O:3 and one of serogroup O:1a, with and without the virulence plasmid, were inoculated intragastrically and intravenously in the mice. Groups of five animals were sacrificed at 6 h and 3, 6, 10, 15, and 21 days after inoculation, and organs and tissues were checked for possible macroscopic alterations. Development of infection was monitored at these times by performing viable bacterial counts in homogenates of selected tissues. The animals were cheked daily for clinical alterations. The results of the study showed that strains with the virulence plasmid infected organs and tissues at various times and at varying intensity by both routes of infection, the strain of type O:1a being the most invasive. Moreover, clinical and pathological alterations occurred only in animals inoculated with bacteria carrying the virulence plasmid, regardless of the route of infection.

Monitoring of the dissemination of Salmonella in the chicken Frankfurt-sausage productionline of a sausage factory in the state of São Paulo, Brazil

Poultry meat and its derivatives are among the foodstuffs considered by environmental health authorities to present the highest risks to the public. A total of 185 samples were collected in five monthly batches, from different processing stages in a sausage plant that uses mechanically-deboned chicken meat (MDCM), and testedfor the presence of Salmonella. Enrichment was carried out in both Kauffman's tetrathionate broth and Rappaport-Vassiliadis broth and isolation on Salmonella-Shigella agar and brilliant-green agar. Live Salmonella bacteria were isolated from six samples of the raw meat and from the emulsion, in batches three, four, and five, but not from any sample in batches one or two. The six isolated strains were all classified as Salmonella Albany, which has not previously been reported in MDCM. Of the two enrichment broths, Rappaport-Vassiliadis gave the better results. The pattern of contamination suggests a probable common source, given that a new supplier was used in the third, fourth, and fifth months. It was also shown that the industrial cooking was effective in preventing Salmonella surviving in the final product.

TNF-alpha, H2O2 and NO response of peritoneal macrophages to Yersinia enterocolitica O:3 derivatives.

In this study, the effect of Yersinia derivatives on nitric oxide (NO), hydrogen peroxide (H2O2) and tumor necrosis factor-alpha (TNF-alpha) production by murine peritoneal macrophages was investigated. Addition of lipopolysaccharide (LPS) to the macrophage culture resulted in NO production that was dose dependent. On the other hand, bacterial cellular extract (CE) and Yersinia outer proteins (Yops) had no effect on NO production. The possible inhibitory effect of Yops on macrophage cultures stimulated with LPS was investigated. Yops partially inhibited NO production (67.4%) when compared with aminoguanidine. The effects of Yersinia derivatives on H2O2 production by macrophages were similar to those on NO production. LPS was the only derivative that stimulated H2O2 release in a dose-dependent manner. All Yersinia derivatives provoked the production of TNF-alpha, but LPS had the strongest effect, as observed for NO production. CE and Yops stimulated TNF-alpha production to a lesser extent than LPS. The results indicate the possibility that in vivo Yops may aid the evasion of the bacteria from the host defense mechanism by impairing the secretion of NO by macrophages.

Yersinia enterocolitica O:3 isolated from patients with or without reactive arthritis induces polyclonal activation of B cells and autoantibody production in vivo.

The mechanisms by which arthritis-provoking pathogens such as Yersinia enterocolitica interact with the human immune system to produce inflammatory synovitis are not well known. One of the immunomodulating mechanisms used against these pathogens is the polyclonal activation of lymphocytes. In this study, we investigated the extent of the B-lymphocyte activation induced in mice by a strain of Y. enterocolitica O:3 (FCF 526) isolated from a patient with arthritis, and compared it with two other strains, a virulent one (FCF 397[+]) isolated from a patient without arthritis and its plasmidless isogenic pair (FCF397[-]). Also we investigated the production of autoantibodies in mice infected with these different strains. SPF Swiss mice were infected intravenously with a suspension of Y. enterocolitica. Spleen cells were taken on days 7, 14, 21 and 28 after infection and the number of cells secreting nonspecific and specific antibodies of IgG1, IgG2a, IgG2b, IgG3, IgM and IgA isotypes were determined by the ELISPOT technique. The presence of autoantibodies in mouse serum was investigated by the dot-blot assay. The pattern of infection of the three bacterial strains were almost the same. We observed a general increase in the number of nonspecific Ig-secreting cells with all three strains, and the greatest increases observed were in the IgG2a and IgG3 isotypes. Only a small fraction of the immunoglobulins detected were antibacterial, suggesting that the rest resulted from polyclonal B cell activation. The strain isolated from the patient with arthritis (FCF526) induced the greatest production of autoantibodies, coinciding with the period in which the greatest activation of nonspecific B lymphocytes was seen. There were no signs of arthritis or inflammation in the joints of the infected animals. Based on our results, we were unable to determine whether there is an association between the arthritogenic capability of Y. enterocolitica and polyclonal activation of B cells.

Niche-specific association of Aeromonas Ribotypes from human and environmental origin.

A total of 88 Aeromonas isolates from distinct locations and sources (39 from extraintestinal infections, 31 from diarrhoeic, ten from non-diarrhoeic faeces, all human, and eight from fresh water) were subjected to phenospecies identification, serotyping, ribotyping and detection of some virulence markers. The strains belonged to four different phenospecies marked by 19 O serogroups and 38 ribotypes. No strong correlation between these parameters was found, and no group, as defined by the typing methods, could be characterized with a particular set of virulence markers. There was a clear association of ribotypes with the source of the strains. Cluster analysis allowed the identification of a complex of ribotypes belonging to distinct but related sources, including clinical and environmental isolates. These results suggest that ribotyping may be an epidemiological tool suitable for the study of Aeromonas infections.

Effects of Yersinia enterocolitica O:3 derivatives on B lymphocyte activation in vivo.

The potential sequelae of intestinal infection with Yersinia enterocolitica include reactive arthritis, erythema nodosum, Reiter's syndrome and other autoimmune diseases. The role of the immune response in the pathogenesis of these diseases has not been fully defined, but autoimmune manifestations may be a consequence of the increase in autoantibodies as a result of polyclonal B-cell activation induced by Yersinia. We investigated the effects of Y. enterocolitica O:3 derivatives on B lymphocyte activation in vivo. Groups of five specific pathogen free (SPF) Swiss mice were inoculated with bacterial cell extract, Yersinia outermembrane proteins (Yops) or lipopolysaccharide (LPS) obtained from Y. enterocolitica O:3 and their immunoglobulin-secreting spleen cells were detected by isotype-specific protein A plaque assay. The presence of specific anti-Yersinia antibodies and autoantibodies was determined in mouse sera by ELISA. In all experiments a marked increase in the number of secretory cells of different isotypes was observed as early as the third day after inoculation. IgG and IgM anti-Yersinia antibodies were detected in the sera of all inoculated mice, and autoantibodies against myosin in the sera of those inoculated with bacterial cell extract. The sera from animals stimulated with LPS reacted with myelin, actin and laminin, while the sera from mice inoculated with Yops reacted with myelin, thyroglobulin and cardiolipin. These results suggest that SPF Swiss mice inoculated with any one of the Y. enterocolitica derivatives tested exhibited polyclonal activation of B lymphocytes as a result of stimulation by various bacterial components and not only LPS stimulation.

Epidemiologia da Yersinia pseudotuberculosis no Brasil / Epidemiology of the Yersinia pseudotuberculosis in Brazil

O Laboratório de Referência em Yersinia no Brasil, responsável pela identificaçäo e biossorofagotipagem de bactérias isoladas no país, caracterizou, durante os anos de 1982 a 1990, 105 cepas de Yersinia pseudotuberculosis, isoladas de animais sadios ou doentes, nos Estados do Paraná e do Rio Grande do Sul. Cepas adicionais näo foram recebidas pelo Laboratório após aquele período, bem como näo foram caracterizadas amostras de Y. pseudotuberculosis isoladas do homem. As bactérias foram isoladas de diferentes materiais clínicos de bubalinos, bovinos e de um suíno. Após a biossorotipagem, a grande maioria (97,14 por cento) dos isolados foi classificada no biotipo 2 e sorogrupo O3, ao passo que 2,8 por cento deles no biotipo 1 e sorogrupo 1b.

Comparaçäo entre a capacidade ativadora policlonal de Yersinia enterocolitica O: 3 e outros ativadores / Comparison between the polyclonal activation capability of Yersinia enterocolitica O: 3 and others activators

Ativaçäo policlonal de linfócitos induzida por endotoxinas bacterianas e superantígenos pode contribuir para o desenvolvimento de auto-imunidade. O objetivo deste trabalho foi comparar a ativaçäo policlonal de linfócitos B provocada por Yersinia enterocolitica O: 3 com aquela provocada por LPS de E. coli e por hemácias de carneiro. Camundongos Swiss foram infectados por via intraperitoneal com 10µg de LPS de E. coli ou com uma suspensäo de hemácias de carneiro a 2,5 por cento. Um grupo de animais normais foi usado como controle. No quinto dia pós-inoculaçäo, cinco animais de cada grupo foram sacrificados e as células esplênicas secretoras de imunoglobulinas detectadas pelo teste de PFC-Proteína A isotipo específico. No grupo dos animais infectados com Y. enterocolítica O: 3, a maior ativaçäo ocorreu em relaçäo às células secretoras de IgM (13 vezes aumentadas em relaçäo aos animais controles), seguida por IgG2b e IgG1 (ambos nove vezes). No grupo inoculado com LPS de E. coli, a maior ativaçäo ocorreu com relaçäo às células secretoras de IgG1 (cinco vezes), e, no grupo inoculado com hemácias de carneiro, a maior ativaçäo ocorreu com relaçäo às células secretoras de IgG1 (16 vezes) e IgM (oito vezes). O perfil comparativo do número de PFC revelou que Y. enterocolitica O: 3 apresentou maior capacidade de estimular linfócitos B in vivo do que os outros ativadores.

Marcadores de virulência em Aeromonas spp isoladas de materiais clínicos humanos e de água doce / Virulence markers in Aeromonas spp isolated from human clinical materials and fresh water

Foram estudadas 88 cepas de Aeromonas isoladas de materiais clínicos de humanos e de água doce. Dessas, 31 foram isoladas de fezes diarréicas, 10 de fezes näo diarréicas, 39 de material humano extra-intestinal e oito de água. Essas cepas foram estudadas quanto ao perfil de virulência. Foram submetidas aos seguintes testes: adesäo e invasäo em células Hela, produçäo de citotoxina, enterotoxina, hemolisinas alfa e beta, auto-aglutinaçäo a 37ºC, resistência ao soro humano normal, absorçäo do Vermelho Congo, isolamento e extraçäo de plasmídeo. Os marcadores de virulência foram caracterizados em proporçöes variadas: 68,2 por cento aderiram e 45,5 por cento invadiram células HeLa, 36,4 por cento produziram citotoxina, 31,8 por cento enterotoxina, 100 por cento produziram hemolisina ß e 34,1 por cento produziram hemolisina alfa quando semeadas em profundidade nas placas de ágar sangue, 73,9 por cento produziram hemolisina ß e 47,7 por cento hemolisina alfa em microplacas, 17 por cento auto-aglutinaram a 37ºC, 31,8 por cento foram resistentes ao soro humano e 100 por cento absorveram o Vermelho Congo. Das cepas estudadas, 8 por cento apresentaram um ou mais plasmídeos de tamanho variado. Conclui-se pela pouca correlaçäo entre fatores de virulência e tipo de material clínico com exceçäo da citotoxina que foi encontrada com maior freqüência em cepas isoladas de infecçöes extra-intestinais e a enterotoxina mais comum em fezes diarréicas.

Características gerais de enteropatógenos bacterianos / Bacterial enteropathogens: general characteristics

Este trabalho realiza uma revisäo sobre os principais enteropatógenos bacterianos, enfocando principalmente aspectos de sistemática, fatores de virulência e algumas características fisiológicas

Evaluation of different techniques for the differentiation of pathogenic and non pathogenic strains of Yersinia enterocolitica

Diferentes métodos e testes para avaliar o potencial patogênico de Y. enterocolitica de sorotipos diversos têm sido utilizados. Testamos 60 cepas do microrganismo, sendo 25 de origem humana (sorotipo 03 biotipo 4 e sorotipo 05 biotipo 1): 6 de origem animal (sorotipo 03 biotipo 4 ); 19 isoladas do meio ambiente (sorotipo 05.27 biotipos 1 e 2 ) isoladas de alimentos (sorotipo 05 biotipo 1 e sorotipo 05.27 biotipo 1 ). Foram utilizados testes relacionadosà expressäo de genes plasmidiais (autoaglutinaçäo, dependência ao cálcio a 37ºC e absorçäo do corante Vermelho Congo), de genes cromossomais (presença de enzima pirazinamidase, fermentaçäo da salicina e hidrólise da esculina) além do teste de invasäo em células HEp-2. Todas as Y enterocolitica 03 exceto uma, foram potencialmente patogênico frente aos testes pirazinamidase-salicina-escalina, o mesmo näo ocorrendo com os testes relacionados a genes plasmidiais, quando os resultados näo foram täo uniformes, provavelmente pela perda do plasmídeo; o teste de invasibilidade em células HEp-2 apresentou os resultados monos uniformes. As cepas de Y. enterocolitica 05 também tiveram comportamento uniforme, sendo näo potogênicas frente aos dois grupos de testes (plasmidiais e cromossomais); em relaçäo ao teste de invasäo em células HEp-2 näo houve uniformidade. As cepas do sorotipo 05.27 biotipo 1, mostraram-se uniformes em relaçäo aos testes cromossomais, sendo näo patogênicas; näo apresentaram no entanto, resultados conclusivos nos testes relacionados à genes plasmidiais e invasäo em células HEp-2. Conclui-se que os testes relacionados a genes cromossomais (esculinasalicina-pirazinamidase) säo simples e muito eficazes na detecçäo de Y. enterocolitica potencialmente patogênicas, originárias de caos clínicos

Characterization of plasmid-related antigen of Yersinia enterocolitica by immunological techniques

Yersínia enterocolitica tem sua virulência relacionada a plasmídeo de 40-48-MDa que codifica proteínas que podem ser expressas nas membranas ou excretadas no meio de cultura. Procurou-se determinar o perfil dessas proteínas em cepas de Y. enterocolitica com e sem o plasmídeo de 40-48-MDa, através de gel de poliacrilamida com SDS (SDS-PAGE). Procurou-se também estudar as condiçöes ótimas de cultura de bactérias para expressäo dessas proteínas e finalmente analisá-las empregando a técnica de Immunoblot e utilizando anti-soro preparado com a amostra com e sem plasmídeo. Esses estudos resultaram na demonstraçäo da ocorrência, entre outros, de uma proteína de 38-kDa, presente apenas na cepa com plasmídeo e que era excretada quando o cultivo era realizado a 37ºC em meio de MOX

Rotavirus and adenovirus in diarrheic and non-diarrheic feces of children, in Araraquara, SP, Brazil

Procurando verificar a participaçäo de rotavirus e adenovirus na etiologia da gastrenterite infantil, 280 amostras de fezes de crianças da faixa etária de 0 a 5 anos foram coletadas em Araraquara-SP, sendo 140 de crianças com diarréia e 140 do grupo de controle. A pesquisa desses vírus foi realizada através de um ensaio imunoenzimático (EIARA) e adicionalmente, rotavirus foi pesquisado através da eletroforese em gel de poliacrilamida (PAGE). No grupo diarréico, rotavirus foi detectado em 8,6% das amostras usando EIARA e em 7,9% usando PAGE. Nenhuma das amostras do grupo controle se mostrou positiva para esse vírus. Adenovirus foi detectado em 2,9% das amostras do grupo diarréico e em 1,4 % das fezes do grupo controle. Os resultados mostram que o rotavirus participam ativamente da etiologia da diarreia infantil em nossa cidade

Prevalência e distribuiçäo de micobactérias nas águas de algumas regiöes do Estado de Säo Paulo - Brasil / Prevalence and distribution of mycobacteria in water of some regions of Säo Paulo State - Brazil

A ocorrência de micobactérias em águas de diferentes regiöes do Estado de Säo Paulo foi pesquisada em 302 amostras de origem diversa, como águas naturais (lago, rio, mina, poço artesiano e raso), águas tratadas (potável de torneira e piscina) e águas destinadas à criaçäo de peixes (aquários e tanque de psicicultura). As amostras de águas provenientes de aquários apresentaram a maior frequência de positividade (88,6%), seguidas pelas amostras de águas de poços rasos (33,3%), de lagos e rios (29,4%), de piscinas (28,2%) de tanque de psicicultura (16,6%), de minas (12,5% e de águas de torneira (4,2%). Näo foram encontradas micobactérias em águas de poços artesianos. Das cepas isoladas, 63,3% foram caracterizadas como micobactérias de crescimento rápido e as demais como de crescimento lento. M. fortuitum esteve presente nos diversos tipos de águas, constituindo 36,7% das cepas isoladas. Outras micobactérias potencialmente patogências foram encontradas em menor frequência. Verificou-se que a maioria das águas examinadas estavam contaminadas por micobactérias potencialmente patogênicas ou saprofíticas, sendo os principais reservatórios as águas que entram em contato com peixes e humanos como as de aquário e piscina

Presence of Mycobacterium marinum and other opportunist Mycobacteria in swimming pool waters in Araraquara, SP

O isolamento de Mycobacterium marinum é relatado pela primeira vez no Brasil. Analisaram-se amostras de águas de piscinas quanto à presença de micobactérias, para avaliar a participaçäo dessas águas como possível fonte de micobactérias patogênicas. Isolaram-se 24 cepas de micobactérias a partir de 72 amostras analisadas. A freqüência de isolamento foi de 37,5% para M. gordonae, de 20,8% para M. chelonae, de 4,2% para M. marinum, de 4,2% para M. scrofulaceum, de 4,2% para M. avium-intracellulare e de 29,2% para cepas näo pertencentes a qualquer espécie de micobactérias conhecida. As cepas näo identificadas constituem um novo grupo de micobactérias com características morfológicas e bioquímicas semelhantes às de M. gordonae mas com um perfil de ácidos micólicos distinto. Salienta-se, em conseqüência, a importância do estudo dos ácidos micólicos no rastreio de identificaçäo de micobactérias do ambiente. Concluiu-se que as águas das piscinas de Araraquara contêm micobactérias oportunistas potencialmente patogênicas para o homem