Yes / It is estimated that 5-10% of hospitalised patients in developed countries contract hospital acquired infections (HAI). Increasing levels of antimicrobial resistance manifested by many HAI-causing pathogens such as Acinetobacter spp in the intensive care unit (ICU) setting present a significant challenge to those managing these infections. Consequently, much attention has been focused on the prevention of HAIs. Particular emphasis has been placed on interventions intended to interrupt patient-to-patient transmission of pathogens, such as enhanced hand hygiene and identification of patients colonised with methicillin-resistant Staphylococcus aureus (MRSA) using rapid DNA-based screening techniques. However, comparatively little attention has been given to the hospital environment, including water supplies, as a source of nosocomial pathogens of importance for patients on the critical care unit. This article reviews the role of hospital water sources in the epidemiology of HAI and new technologies which can be employed in the prevention and control of such infections.

E. coli avec potentiel zoonotique pourrait éclore dans les réservoirs porcins et avicoles. Cette étude consiste à examiner la présence de souches E. coli porteuses de gènes virulents associés aux STEC (E. coli producteurs de Shiga-toxines), EPEC (E. coli entéropathogène), et ExPEC (E. coli pathogène extra-intestinal) chez les porcs et volailles élevés au Vietnam. Des prélèvements d’excréments et de carcasses ont été effectués dans des fermes et abattoirs porcins et avicoles sélectionnés où les animaux ont été suivis de l’élevage à l’abattage. Un total de 13,1% des souches, toutes sources confondues, ont été catégorisées comme potentiellement contaminées par ExPEC, possédant un ou plusieurs gènes de virulence iucD, tsh, papC et cnf. Peu d’isolats d’autres pathotypes ont été observés. Tous les gènes de virulence ExPEC, à l’exception de cnf, ont été identifiés plus fréquemment dans les isolats de fèces et carcasses avicoles que dans les isolats porcins. Même constatation pour le groupe du phylogénétique D. Une multirésistance aux médicaments a été régulièrement observée chez les deux isolats ExPEC. Les isolats de fèces de volailles ont souvent été associés à une résistance à l’acide nalidixique et à la ciprofloxacine (P<0.05), de même qu’au gène blaTEM, alors que les gènes qnr et aac(6’)-Ib ont peu été rencontrés des deux côtés. Cette étude démontre que les isolats ExPEC avicoles sont potentiellement plus pathogèniques que ceux porcins et que les isolats ExPEC de carcasses porcines et avicoles peuvent provenir de leurs excréments par la contamination associée au processus d'abattage. Ainsi, la volaille, particulièrement, serait un facteur de transmission de souches ExPEC zoonotiques. / Zoonotic potential pathogenic Escherichia coli could arise from poultry and pig reservoirs. The aim of this study is to investigate the occurrence of E. coli strains carrying virulence genes associated with STEC (Shiga toxin-producing E. coli), EPEC (Enteropathogenic E. coli), and ExPEC (Extraintestinal pathogenic E. coli) in pigs and poultry on-farm and at abattoirs in Vietnam. Samples of feces and carcasses were collected at selected pig and poultry farms and abattoirs, in which animals were traced from farms to the abattoir. A total of 13.1% strains from all sources were classified as potential ExPEC, possessing one or more virulence genes iucD, tsh, papC and cnf. Few isolates of other pathotypes were observed. All ExPEC virulence genes, except cnf, were more frequently found in isolates from poultry than in isolates from pigs. A higher proportion of ExPEC isolates belonging to phylogenetic group D was observed in poultry. Multi-drug resistance was frequently observed in ExPEC isolates from both pigs and poultry. Nalidixic acid and ciprofloxacin resistance were significantly associated with poultry feces isolates (P<0.05). blaTEM gene was more frequently associated with poultry isolates, whereas qnr and aac(6’)-Ib genes were present at low prevalence in pig and poultry isolates. This study demonstrates that poultry ExPEC isolates are potentially more pathogenic than pig ExPEC isolates, and ExPEC isolates in pig and poultry carcasses may originate from pig and poultry feces, due to contamination associated to slaughtering process. Thus, meats particularly from poultry, might be a vehicle for transmission of zoonotic ExPEC strains.

Plusieurs études ont examiné la sensibilité aux antimicrobiens chez les bactéries d’organismes provenant de produits issus de l’aquaculture ou de leur environnement. Aucune information n’est cependant disponible concernant la résistance aux antimicrobiens dans les bactéries de la flore de poissons ou de fruits de mer vendus au détail au Canada. C’est particulièrement vrai en ce qui a trait aux bactéries des genres Aeromonas et Vibrio, dont certaines espèces sont des agents pathogènes zoonotiques connus. Au cours de cette étude, la sensibilité aux antimicrobiens d’isolats d’Aeromonas spp. et de Vibrio spp. provenant de poissons et de crevettes domestiques et importés a été mesurée à l’aide de techniques de micro dilution en bouillon et/ou de diffusion sur disque. Les classes d’antimicrobiens examinés comprenaient les tétracyclines (TET), les inhibiteurs de la voie des folates (sulfadiméthoxine-triméthoprime, SXT), le florfenicol (FLO), et les quinolones (acide nalidixique / enrofloxacine, NA/ENO). Des valeurs seuils épidémiologiques pour Aeromonas et Vibrio ont été établies en utilisant la méthode d’interprétation normalisée des données de résistance provenant de diffusion sur disque. La recherche de gènes de résistance associés au profil de résistance des isolats a été effectuée en utilisant des PCRs et des puces ADN. Le nombre d’isolats résistants aux divers antimicrobiens parmi les 201 isolats d’Aeromonas et les 185 isolats de Vibrio étaient respectivement les suivants: TET (n=24 et 10), FLO (n=1 et 0), SXT (n=2 et 8), NA (n=7 et 5) et ENO (n= 5 et 0). Diverses associations de gènes tet(A), tet(B), tet(E), floR, sul1, sul2, et intI1 ont été détectées, les gènes tet(E), intI1, sul2 et tet(B) étant les plus communs. Les espèces d’Aeromonas et de Vibrio isolées de poissons au détail et de fruits de mer peuvent héberger une variété de gènes de résistance, bien que peu fréquemment. Le risque que représente ces gènes de résistance reste à évaluer en considérant le potentiel infectieux des bactéries, l’utilisation des ces agents antimicrobiens pour le traitement des maladies en aquaculture et en médecine humaine et leur rôle en tant que réservoir de la résistance antimicrobienne. / Multiple studies have examined antimicrobial susceptibility in bacteria from aquacultured products microorganisms and their environment. However, no information is available concerning antimicrobial resistance in bacterial flora of fish and seafood available at the retail level in Canada. This is particularly true for the common aquatic commensals, Aeromonas and Vibrio, for which some species are known zoonotic pathogens. In the course of this study, the antimicrobial susceptibility among Aeromonas spp. and Vibrio spp. from domestic and imported fish and seafood was characterized. Aeromonas and Vibrio spp. isolates cultured from finfish and shrimp samples were evaluated for antimicrobial susceptibility by broth microdilution and/or disk diffusion techniques. Antimicrobial classes examined in detail included: tetracyclines (TET), folate pathway inhibitors (sulfadimethoxine-trimethoprim, SXT), florfenicol (FLO), and the quinolones (nalidixic acid / enrofloxacin, NA/ENO). Epidemiological cut-off values (ECV’s) for Aeromonas/Vibrio were established using normalized resistance interpretation (NRI) of disk diffusion data. Isolates were further examined by PCR and microarray for genes associated with their antimicrobial resistance. Of 201 Aeromonas and 185 Vibrio isolates, those classified as resistant were as follows, respectively: TET (n=24 and 10), FLO (n=1 and 0), SXT (n=2 and 8), NA (n=7 and 5) and ENO (n=5 and 0). Various combinations of tet(A), tet(B), tet(E), floR, sul1, sul2 and intI1 genes were detected with tet(E), intI1, sul2 and tet(B) being the most common. Vibrio and Aeromonas species isolated from retail fish and seafood sources can harbor a variety of resistance determinants, although their occurrence is not high. The risk represented by these resistances remains to be evaluated in view of the potential for bacterial infection and their role as a reservoir for antimicrobial resistance.

E. coli avec potentiel zoonotique pourrait éclore dans les réservoirs porcins et avicoles. Cette étude consiste à examiner la présence de souches E. coli porteuses de gènes virulents associés aux STEC (E. coli producteurs de Shiga-toxines), EPEC (E. coli entéropathogène), et ExPEC (E. coli pathogène extra-intestinal) chez les porcs et volailles élevés au Vietnam. Des prélèvements d’excréments et de carcasses ont été effectués dans des fermes et abattoirs porcins et avicoles sélectionnés où les animaux ont été suivis de l’élevage à l’abattage. Un total de 13,1% des souches, toutes sources confondues, ont été catégorisées comme potentiellement contaminées par ExPEC, possédant un ou plusieurs gènes de virulence iucD, tsh, papC et cnf. Peu d’isolats d’autres pathotypes ont été observés. Tous les gènes de virulence ExPEC, à l’exception de cnf, ont été identifiés plus fréquemment dans les isolats de fèces et carcasses avicoles que dans les isolats porcins. Même constatation pour le groupe du phylogénétique D. Une multirésistance aux médicaments a été régulièrement observée chez les deux isolats ExPEC. Les isolats de fèces de volailles ont souvent été associés à une résistance à l’acide nalidixique et à la ciprofloxacine (P<0.05), de même qu’au gène blaTEM, alors que les gènes qnr et aac(6’)-Ib ont peu été rencontrés des deux côtés. Cette étude démontre que les isolats ExPEC avicoles sont potentiellement plus pathogèniques que ceux porcins et que les isolats ExPEC de carcasses porcines et avicoles peuvent provenir de leurs excréments par la contamination associée au processus d'abattage. Ainsi, la volaille, particulièrement, serait un facteur de transmission de souches ExPEC zoonotiques. / Zoonotic potential pathogenic Escherichia coli could arise from poultry and pig reservoirs. The aim of this study is to investigate the occurrence of E. coli strains carrying virulence genes associated with STEC (Shiga toxin-producing E. coli), EPEC (Enteropathogenic E. coli), and ExPEC (Extraintestinal pathogenic E. coli) in pigs and poultry on-farm and at abattoirs in Vietnam. Samples of feces and carcasses were collected at selected pig and poultry farms and abattoirs, in which animals were traced from farms to the abattoir. A total of 13.1% strains from all sources were classified as potential ExPEC, possessing one or more virulence genes iucD, tsh, papC and cnf. Few isolates of other pathotypes were observed. All ExPEC virulence genes, except cnf, were more frequently found in isolates from poultry than in isolates from pigs. A higher proportion of ExPEC isolates belonging to phylogenetic group D was observed in poultry. Multi-drug resistance was frequently observed in ExPEC isolates from both pigs and poultry. Nalidixic acid and ciprofloxacin resistance were significantly associated with poultry feces isolates (P<0.05). blaTEM gene was more frequently associated with poultry isolates, whereas qnr and aac(6’)-Ib genes were present at low prevalence in pig and poultry isolates. This study demonstrates that poultry ExPEC isolates are potentially more pathogenic than pig ExPEC isolates, and ExPEC isolates in pig and poultry carcasses may originate from pig and poultry feces, due to contamination associated to slaughtering process. Thus, meats particularly from poultry, might be a vehicle for transmission of zoonotic ExPEC strains.

Escherichia coli est un agent de mammites environnementales. Par contre, E. coli peut persister dans la glande mammaire. Les objectifs de cette étude étaient de confirmer la présence d’infection persistante chez des vaches laitières canadiennes et d’identifier la possibilité de contagion entre les quartiers d’une vache dans une cohorte de 91 fermes suivies durant deux ans. De plus, les souches persistantes ont été comparées à des souches transitoires. Les profils génétiques ont été obtenus à l’aide de l’électrophorèse sur gel en champs pulsés. La détection de la résistance pour sept antibiotiques s’est faite par microdilution. Vingt-sept gènes de virulence ont été déterminés par hybridation sur colonies. De la persistance a été détectée chez 18 vaches et de la contagion entre quartiers, chez deux vaches. La proportion de résistance chez les E. coli persistants était de 0,0 % (enrofloxacin) à 27,8 % (ampicilline et tétracycline) et de 0,0 % (enrofloxacin) à 16,8 % (tétracycline) pour les E. coli transitoires. Pour chacune des résistances additionnelles, les probabilités d’être une souche persistante augmentaient par un facteur 1,6 (95% IC : 1.1, 2.4). Une souche résistante à l’ampicilline et à la céphalothine avait une plus forte probabilité d’être persistante. Une souche possédant le gène iroN avait 5.4 fois plus de probabilité (95% IC: 1.2, 24.0) d’être persistante. Aussi, une souche positive pour le gène sitA avait 8.6 fois plus de probabilité (95% IC: 2.8, 27.1) d’être persistante. En conclusion, cette étude confirme qu’E. coli peut persister dans la glande mammaire des vaches laitières canadiennes et que ces E. coli sont différents de ceux impliqués lors d’infection transitoire. / Escherichia coli is part of the environmental mastitis pathogens. However, in some cases, persistence in the mammary gland occurs. The objectives of this study were to confirm persistent infection in Canadian dairy cows and to identify possible spread between quarters of a same cow in a cohort of 91 herds monitored over two years. Also, persistent strains were compared to transient strains. Antimicrobial susceptibility was determined by the broth microdilution method. Genetic profiles were obtained for same cow isolates by DNA fingerprinting with pulsed field gel electrophoresis. Twenty-seven virulence genes were determined by colony hybridization. Persistence was detected in 18 cows and contagion between quarters, in 2 cows. Proportions of resistance in persistent E.coli ranged from 0.0% (enrofloxacin) to 27.8% (ampicillin and tetracycline). Proportion of resistance in transient E.coli ranged from 0.0% (enrofloxacin) to 16.8% (tetracycline). For each additionnal antimicrobial resistance, odds of being classified as a persistent isolate increased by a factor of 1.6 (95% CI: 1.1, 2.4). Resistance to ampicillin and to cephalothin were both associated with higher odds of being a persistent E. coli. Isolates harboring gene iroN had 5.4 times higher odds (95% CI: 1.2, 24.0) of being classified as persistent isolates. Similarly, isolates positive to virulence gene sitA had 8.6 times higher odds (95% CI: 2.8, 27.1) of being classified as persistent isolates. In conclusion, this study confirmed that E. coli can persist in the udder of Canadian dairy cows and that these E. coli are different when compared to transient E. coli.

Background: Antimicrobial-resistant infections result in hospital stays costing between $18,000 and $29,000. As of 2009, Centers for Medicare and Medicaid Services no longer upgrade payments for hospital-acquired infections. Hospital epidemiologists monitor and document rates of individual resistant microbes in antibiogram reports. Overall summary measures capturing resistance within a hospital may be useful. Objectives: We applied four techniques (L1- and L2-principal component analysis (PCA), desirability functions, and simple summary) to create summary measures of resistance and described the four summary measures with respect to reliability, proportion of variance explained, and clinical utility. Methods: We requested antibiograms from hospitals participating in the University HealthSystem Consortium for the years 2002–2008 (n=40). A clinical team selected organism-drug resistant pairs (as resistant isolates per 1,000 patient days) based on 1) virulence, 2) complicated or toxic therapies, 3) transmissibility, and 4) high incidence with increasing levels of resistance. Four methods were used to create summary scores: 1) L1- and L2-PCA: derived multipliers so that the variance explained is maximized; 2) desirability function: transformed resistance data to be between 0 and 1; 3) simple sum: each resistance rate was added and divided by the square root of the total number of microbes summed. Simple correlation analyses between time and each summary score evaluated reliability. For each year, we calculated the proportion of explained variance by dividing each summary score’s variance by the variance in the original data. Clinical utility was checked by comparing the trends for all of the individual microbe’s resistance rates to the trends seen in the summary scores for each hospital. Results: Proportion of variance explained by L1- and L2-PCA and the simple sum was 0.61, 0.62, and 0.29 respectively. Simple sum and L1- and L2-PCA summary scores best followed the trends seen in the individual antimicrobial resistance rates; trends in desirability function scores deviated from those seen in individual trends of antimicrobial resistance. L1- and L2-PCA summary scores were more influenced by MRSA rates, and the simple sum score was less influenced. Pearson correlation coefficients revealed good reliability through time. Conclusion: Deriving summary measures of antimicrobial resistance can be reliable over time and explain a high proportion of variance. Infection control practitioners and hospital epidemiologists may find the inclusion of a summary score of antimicrobial resistance beneficial in describing the trends of overall resistance in their yearly antibiogram reports.

Les marchés traditionnels et maintenant les supermarchés approvisionnent les demandes sans cesse en augmentation pour la viande de volaille au Vietnam. Peu d’études ont examiné la présence des E. coli pathogènes extra-intestinaux (ExPEC), une cause commune d’infection urinaire chez les humains, de même que la résistance aux antimicrobiens, la multi-résistance des Escherichia coli dans la viande de volaille au Vietnam. Le but de cette étude était d’évaluer la salubrité de la viande de volaille au Vietnam et de comparer les patrons de résistance aux antimicrobiens entre le Canada et le Vietnam. Des carcasses fraîches et congelées des marchés traditionnels et des supermarchés ont été échantillonnées au Vietnam. Les E. coli obtenus par rinçage des carcasses ont été caractérisé pour les gènes de virulence ExPEC (iucD, cnf, papC, tsh, Kps, afa, sfa) et pour la résistance aux antimicrobiens, phénotypiquement (Sensititre Aris®) et génotypiquement par PCR. Une multi-résistance et une fréquence élevée de résistance aux antimicrobiens d’importance pour les humains ont été détectées dans les isolats ExPEC. Les E. coli producteurs de β-lactamases à spectre élargi et de type AmpC et les gènes de résistance CTX-M et CMY correspondant ont été détectés. Des isolats multi-résistants BLSE putatif ont été identifiés appartenant au phylogroupe F. Les stratégies sur les antimicrobiens employés sur la ferme au Canada et au Vietnam pourraient influencer les profils de résistance des E. coli provenant des carcasses de poulets. En conclusion, la présence des ExPEC, la fréquence élevée de la résistance aux antimicrobiens et la détection des beta-lactamases soulignent la présence de danger pour la santé humaine de la viande de volaille crue ou insuffisamment cuite au Vietnam. / Traditional markets and recently supermarkets are meeting the continually rising demands for chicken meat of consumers in Vietnam. Little is known of the presence of Extraintestinal pathogenic E. coli (ExPEC), a recognized cause of urinary tract infections in humans, as well as of multidrug resistance and E. coli producing ESBLs or AmpC beta-lactamases in this meat. The objective of this study was to evaluate antimicrobial resistance and virulence of E. coli in chicken meat from various retail systems in Vietnam and to compare resistance profiles of E. coli between Canada and Vietnam. Fresh and frozen chicken carcasses from traditional markets and supermarkets were sampled in Vietnam. E. coli isolates from carcass rinses were characterized for ExPEC virulence factors (iucD, cnf, papC, tsh, Kps, afa, sfa) and for antimicrobial resistance phenotypically by Sensititre Aris® as well as genotypically by PCR. Multi-drug resistance and a high frequency of resistance to antimicrobials of high importance for human medicine were detected in ExPEC isolates. Extended spectrum (ESBL) and AmpC beta-lactamase producing-E. coli with CTX-M and CMY resistance genes respectively were found. Multi-drug resistant putative ESBL-producing ExPEC isolates from the phylo-group F were identified. Antimicrobial strategies on poultry farms in Canada and in Vietnam could influence resistance profiles of E. coli from chicken carcasses. In conclusion, ExPEC presence with high frequency of antimicrobial resistance and multi-drug resistance in addition to detection of ESBL producing-E. coli of phylo-group F underline the current potential health threat for humans associated with handling undercook or raw chicken meat in Vietnam.

Dentre as espécies do gênero Yersinia, Yersinia enterocolitica é a espécie mais prevalente como causa de doença em humanos e animais. Y. enterocolitica é dividida em seis biotipos. Os biotipos 1B, 2, 3, 4 e 5 compreendem linhagens associadas à doença em humanos e animais, enquanto o biotipo 1A consiste de linhagens consideradas não patogênicas. Apesar de Y. enterocolitica biotipo 2 ser de importância clínica, há uma escassez de estudos no país, o que dificulta avaliar o envolvimento dessa bactéria como causa de doença em humanos e em animais, bem como, determinar o impacto de sua presença no meio-ambiente. O objetivo deste trabalho foi investigar o potencial patogênico, determinar o perfil de suscetibilidade a antimicrobianos e verificar a diversidade genotípica de linhagens de Y. enterocolitica biotipo 2 isoladas no Brasil. Foram estudadas 40 linhagens de Y. enterocolitica biotipo 2, isoladas de humanos (5), ambiente (34) e animal (1), entre os anos de 1979 e 1998. Ademais, nas análises filogenéticas, foram acrescidas 26 linhagens de Y. enterocolitica pertencentes aos outros biotipos, com o intuito de comparar as linhagens de Y. enterocolitica biotipo 2 aos biotipos 1A, 1B, 3, 4 e 5. As linhagens de humanos e animal foram sensíveis a todos os 14 antimicrobianos testados. Dentre as 34 linhagens de ambiente, sete (20,6%) foram resistentes a um ou dois antimicrobianos, sendo esses, amicacina, cefoxitina, gentamicina, e sulfametoxazol - trimetoprima. Todas as linhagens apresentaram os genes inv, ail, ystA, hreP, tccC e myfA. Os genes fepD e fes foram detectados em 39 (97,5%) linhagens, o gene virF foi encontrado em três (7,5%) linhagens, os genes ystB e fepA não foram detectados em nenhuma linhagem. Todas as linhagens apresentaram comportamento relacionado à virulência frente aos testes fenotípicos de atividade da pirazinamidase, hidrólise da esculina e fermentação da salicina. O dendrograma de similaridade genética de Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) agrupou as linhagens de Y. enterocolitica biotipo 2 em cinco grupos denominados A, B, C, D e E. Todas as linhagens, com exceção de duas, apresentaram similaridade genética superior a 88,3%. O dendrograma de similaridade genética de Pulsed field gel electrophoresis (PFGE) agrupou as linhagens de Y. enterocolitica biotipo 2 em três grupos denominados I, J e K. A maioria das linhagens (72,5%) apresentou similaridade ii genética superior a 78,3%. O dendrograma de similaridade genética de Multilocus variable number tandem repeat analysis (MLVA) agrupou as linhagens de Y. enterocolitica biotipo 2 em dois grupos denominados O e P com similaridade genética superior a 37,7%. Pode-se concluir que o potencial patogênico das linhagens de Y. enterocolitica biotipo 2 foi evidenciado pela prevalência da maioria dos marcadores de virulência, bem como, pelo comportamento relacionado à virulência frente aos testes fenotípicos pesquisados. Algumas linhagens apresentaram-se resistentes a antimicrobianos de primeira escolha no tratamento de yersiniose, o que pode acarretar em falha terapêutica. Os resultados de ERIC-PCR e PFGE mostraram a alta similaridade entre as linhagens de Y. enterocolitica biotipo 2, sugerindo que as mesmas pouco se diferenciaram ao longo dos 19 anos e que possivelmente o meio ambiente tem sido uma fonte de contaminação para humanos e animais no Brasil. A técnica de MLVA agrupou as linhagens de Y. enterocolitica biotipo 2 quanto à sua origem e a técnica de ERIC-PCR agrupou as linhagens de Y. enterocolitica biotipos 1A, 1B, 2, 3, 4, e 5 quanto às diferentes patogenicidades características de cada biotipo. / Among the species of the genus Yersinia, Yersinia enterocolitica is the most prevalent species that cause illness in humans and animals. Y. enterocolitica is divided into six biotypes. Biotypes 1B, 2, 3, 4 e 5 comprise strains associated to illness in humans and animals, while biotype 1A comprise strains considered nonpathogenic. Despite of the fact that Y. enterocolitica biotype 2 is of clinical importance, there is a paucity of studies in this country, which makes difficult to assess the involvement of this bacteria as a cause of illness in humans and animals, as well as to determine the impact of its presence in the environment. The aim of this work was to investigate the pathogenic potential, to determine the antimicrobial resistance profile and to verify the genetic diversity of Y. enterocolitica biotype 2 strains isolated in Brazil. Forty strains of Y. enterocolitica biotype 2 isolated from humans (5), environment (34) and animal (1), between 1979 and 1998 were studied. Besides, in the phylogenetic analyzes it was added 26 Y. enterocolitica strains belonging to the other biotypes, in order to compare the Y. enterocolitica biotype 2 strains to biotypes 1A, 1B, 3, 4 e 5. Humans and animals strains showed susceptibility to all 14 antibiotics tested. Among the 34 environment strains, seven (20.6%) were resistant to one or two antibiotics used such as amikacin, cefoxitin, gentamicin and sulfamethoxazole-trimethoprim. All the strains presented the genes inv, ail, ystA, hreP, tccC and myfA. Genes fepD and fes were detected in 39 (97.5%) strains, virF was found in three (7.5%) strains, and ystB and fepA were not detected in any strains. All the strains exhibited behavior related to virulence against the phenotypic tests of pyrazinamidase activity, esculin hydrolysis and salicin fermentation. The dendrogram of genetic similarity of Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) grouped the Y. enterocolitica biotype 2 strains in five groups, designated A, B, C, D and E. All the strains, except two, showed a genetic similarity of more than 88.3%. The dendrogram of genetic similarity of Pulsed field gel electrophoresis (PFGE) grouped the Y. enterocolitica biotype 2 strains in three groups, designated I, J and K. The majority of the strains (72.5%) showed a genetic similarity of more than 78.3%. The dendrogram of genetic similarity of Multilocus variable number tandem repeat analysis (MLVA) grouped the Y. enterocolitica iv biotype 2 strains in two groups, designated O and P with a genetic similarity of more than 37.7%. It is possible to conclude that the pathogenic potential of the Y. enterocolitica biotype 2 strains was highlighted by the prevalence of the majority of the virulence markers searched, as well as by the behavior related to virulence against the phenotypic tests. Some strains were resistant to antimicrobials that are the first choice for yersiniosis treatment, which can result in therapeutic failure. The results of ERIC-PCR and PFGE showed a high genetic similarity between the Y. enterocolitica biotype 2 strains, suggesting that the strains differed little over 19 years, and that the environment has been possibly a source of humans and animals infections in Brazil. The MLVA technique grouped the Y. enterocolitica biotype 2 strains according their origins, and the ERIC-PCR technique grouped the Y. enterocolitica biotypes 1A, 1B, 2, 3, 4 and 5 strains according to the different pathogenicity characteristics of each biotype.

Introdução. A resistência bacteriana é facilitada pela pressão seletiva do uso de antimicrobianos na clínica e em outras atividades, como a agricultura e pecuária, além de poder ser disseminada para a natureza por meio do lançamento inadequado do esgoto ou pela aplicação do lodo de esgoto na agricultura. As -lactamases de espectro estendido (ESBL) são uma das formas mais prevalentes de resistência em Gram negativos no mundo, e seus genes codificadores são disseminados por meio de diversos elementos genéticos, principalmente transposons e integrons mobilizados para plasmídios. Objetivo. Identificar e caracterizar genes codificadores de ESBL, bem como suas prováveis formas de mobilização, em enterobactérias isoladas de fontes ambientais e clínicas. Material e Métodos. Quarenta e cinco cepas isoladas de um hospital público em 2004 e 2005, responsáveis por infecções hospitalares (14), infecções comunitárias (7) e colonizações (24), e 7 isoladas de estações de tratamento de esgoto (ETE) em 2009, em São Paulo, geneticamente distintas e produtoras de ESBL da família Enterobacteriaceae, foram estudadas. A técnica de PCR seguida de sequenciamento foi utilizada para a identificação dos genes blaESBL, triagem de elementos móveis e mapeamento do ambiente genético de blaESBL. A identificação dos grupos de incompatibilidade plasmidial (Inc) foi realizada pela técnica de PBRT, e a determinação dos tamanhos dos plasmídios pela técnica de S1-PFGE. Resultados. Os genes blaESBL identificados foram: amostras clínicas - blaTEM-15, blaTEM-197, blaSHV-5, blaSHV-12, blaSHV-27, blaSHV-28, blaSHV-45, blaSHV-55, blaSHV-110, blaCTX-M-2, blaCTX-M-59 e blaCTX-M-131; amostras ambientais blaSHV-28, blaCTX-M-15 e blaCTX-M-8. Os genes blaTEM- 15 e blaTEM-197 estavam associados aos elementos Tn2* e Tn3, respectivamente. Os genes blaSHV-5 e blaSHV-12 estavam associados à IS26, e não foi possível determinar o ambiente genético dos demais genes blaSHV. Os genes blaCTX-M-2, blaCTX-M-59 e blaCTXM- 131 estavam inseridos em integrons de classe 1 complexos, blaCTX-M-15 estava associado à ISEcp1 interrompida pela IS26, e blaCTX-M-8 estava associado à IS10, também interrompida pela IS26. Os principais grupos Inc detectados foram IncA/C (37 por cento ) e IncF (30,4 por cento ). Exceto por 7 cepas clínicas, todas apresentavam plasmídios de alto peso molecular, entre 48,5kb e 388kb. Conclusões. Este estudo detectou 15 genes blaESBL diferentes, dos quais dois são genes novos (blaTEM-197 e blaCTX-M-131) e três são inéditos no Brasil (blaTEM-15, blaSHV-55 e blaSHV-110). A maioria das cepas deste estudo possuía genes blaESBL associados a elementos mobilizáveis, bem como continham plasmídios de grupos Inc envolvidos na disseminação da resistência antimicrobiana. Além disso, carreavam plasmídios provavelmente conjugativos. Os resultados deste estudo mostram genes de resistência associados a elementos mobilizáveis em cepas contendo elementos transferíveis. As cepas foram isoladas tanto em uma instituição de saúde como nas ETEs da Grande São Paulo, mostrando o potencial de disseminação da resistência da clínica para o ambiente em nossa região. / Introduction. Bacterial resistance is facilitated by selective pressure of antimicrobial use in clinical and other activities, as agriculture and livestock, and can be spread to nature through the inadequate discharge of sewage or by the use of sludge in agriculture. Extended-spectrum -lactamases (ESBL) are the most prevalente forms of resistance in Gram-negative bacteria in the world, and their encoding genes are disseminated through several genetic elements, especially transposons and integrons mobilized to plasmids. Objective. To identify and characterize ESBL-encoding genes, as well as their probable mobilization pathways, in enterobacteria isolated from clinical and environmental sources. Material and Methods. Forty-five strains isolated from a public hospital in 2004 and 2005, responsible for hospital infections (14), community-acquired infections (7) and colonizations (24), and 7 isolated from sewage treatment plants (ETE) in 2009, in São Paulo, genetically distinct and ESBL producers from Enterobacteriaceae family, were studied. PCR technique followed by sequencing was used for blaESBL genes identification, mobile elements screening and blaESBL genetic environment mapping. Plasmid incompatibility groups (Inc) were identified by PBRT technique, and plasmid sizes were determined by S1-PFGE technique. Results. The blaESBL genes identified were: clinical samples - blaTEM-15, blaTEM-197, blaSHV-5, blaSHV-12, blaSHV-27, blaSHV-28, blaSHV-45, blaSHV-55, blaSHV-110, blaCTX-M-2, blaCTX-M-59 and blaCTX-M-131; environmental samples blaSHV-28, blaCTX-M-15 and blaCTX-M-8. Genes blaTEM-15 and blaTEM-197 were associated to the elements Tn2* and Tn3, respectivelly. Genes blaSHV-5 and blaSHV-12 were associated to IS26, and it was not possible to detect the genetic environment of the other blaSHV genes. Genes blaCTX-M-2, blaCTX-M-59 and blaCTX-M-131 were inserted in complex class 1 integrons, blaCTX-M-15 was associated to ISEcp1 interrupted by IS26, and blaCTX-M-8 was associated to IS10, also interrupted by IS26. The most common Inc grups detected were IncA/C (37 per cent ) and IncF (30,4 per cent ). Except for 7 clinical strains, all isolates showed high molecular weight plasmids, rangng from 48,5kb to 388kb. Conclusions. This study detected 15 different blaESBL genes, from which 2 are new genes (blaTEM-197 e blaCTX-M-131) and 3 are still unpublished in Brazil (blaTEM-15, blaSHV-55 and blaSHV-110). Most of the strains from this study had blaESBL genes associated to mobile elements, as well as they had plasmids from Inc groups involved in the spread of antimicrobial resistance. Moreover, the strains probably carried conjugative plasmids. Results from the present work show resistance genes associated to mobile elements in strains carrying transferable elements. The strains were isolated either from a healthcare institution or from ETEs in São Paulo, which shows the spread potential of resistance from the clinic to the environment in our region.

A resistência bacteriana a antibióticos é um grave e crescente problema de saúde pública de âmbito mundial. O principal, e mais eficiente, mecanismo de resistência aos &#946-lactâmicos em bacilos Gram-negativos é a produção de &#946-lactamases, que possuem a capacidade de hidrolisar o anel &#946-lactâmicos e consequentemente inativar essa classe de antibióticos. Vale ressaltar, que atualmente os antibióticos &#946-lactâmicos são os mais utilizados clinicamente, particularmente em infecções graves. Dentre as &#946-lactamases existentes destacam-se as carbapenemases, enzimas capazes de inativar a maioria dos antibióticos &#946-lactâmicos. Uma grande preocupação é o fato dessas enzimas, em sua maioria, serem codificadas por plasmídeos, o que propicia a disseminação desses genes de resistência; portanto, é de extrema importância a realização de um rápido e efetivo monitoramento da presença de patógenos portadores desses genes de resistência, para que assim se possa prevenir a disseminação desses determinantes. Foram incluídos neste estudo 230 amostras únicas de Acinetobacter e Pseudomonas aeruginosa resistentes a imipenem detectados em pacientes internados em hospitais privados da cidade de São Paulo durante o período de fevereiro a outubro de 2013. As amostras foram avaliadas quanto à hidrólise de imipenem por espectrofotometria, quanto à presença de genes de carbapenemases por PCR e sequenciamento, e quanto à clonalidade por eletroforese em campos pulsados (PFGE) ou ERIC-PCR. Foram realizados ensaios de conjugação, transformação e sequenciamento completo de plasmídeos. Dentre as amostras de Acinetobacter spp. 80% (88) foram capazes de hidrolisar o imipenem. Dentre esses 76,1% (67) foram positivos para blaOXA-51-like, 19,3% (17) foram positivos para blaOXA-72. blaOXA-23, blaOXA-482 e blaIMP-1 foram detectados isoladamente em isolados distintos. O gene blaIMP-1 foi detectado em A. ursingii inserido em integron de classe 1 e representa a primeira descrição no Brasil. Uma nova carbapenemase OXA-482-like foi detectada em A. baumanii. Utilizando-se ERIC-PCR, observou-se uma grande diversidade de grupos clonais, com o máximo de quatro isolados por grupo. Dentre as amostras de P. aeruginosa, apenas 35,3% foram capazes de hidrolisar o imipenem. Dessas amostras, 14 possuíam o gene blaSPM-1, e isolados únicos possuíam, individualmente, os genes blaIMP, blaVIM, blaKPC-2 ou blaGES-23. O gene blaKPC-2 foi detectado inserido em contexto genético diferente dos descritos anteriormente, em plasmídeo IncU de 32 Kb, mobilizável, mas não conjugativo. Esta é a primeira descrição da sequencia completa de plasmídeo albergando o gene blaKPC-2 em P. aeruginosa no Brasil. Nas demais amostras (20) com atividade hidrolítica, não foram detectados genes de carbapenemase conhecidos, o que sugere a presença de genes de carbapenemase ainda não descritos. Em três amostras foi possível obter transformantes com plasmídeos, resistentes a carbapenêmicos. As amostras com blaSPM-1 apresentaram perfis de PFGE estreitamente relacionados. Em contraste, os perfis de PFGE das amostras com potenciais novas carbapenemases apresentaram índice de similaridade de Dice inferior ix a 80%, evidenciando grande diversidade clonal. Nossos achados evidenciam que a carbapenemase não intrínseca predominante em Acinetobacterem hospitais privados da cidade de São Paulo é OXA-72, e em hospitais privados há uma grande diversidade clonal. Em P. aeruginosa, a carbapenemase predominante é SPM-1, cuja disseminação é mediada por um único clone. Há potencialmente um número significativo de novas carbapenemases em Acinetobacter e P. aeruginosa, algumas delas mediadas por plasmídeos. / Bacterial resistance to antibiotics is a serious and growing public health problem worldwide. The main and most efficient mechanism of resistance to &#946-lactams in Gram-negative bacilli is the production of &#946-lactamases, which have the ability to hydrolyze the &#946-lactam ring and consequently inactivate this class of antibiotics. It is worth mentioning that currently &#946-lactam antibiotics are the most used clinically, particularly in severe infections. Among the existing &#946-lactamases, carbapenemases are capable of inactivating most &#946-lactam antibiotics. A major concern is that these enzymes are mostly encoded by plasmids, which facilitates the spread of these resistance genes; therefore, it is of extreme importance to carry out a rapid and effective monitoring of the presence of pathogens bearing these resistance genes, in order to prevent the dissemination of these determinants. This study included 230 unique samples of imipenem-resistant Acinetobacterand Pseudomonas aeruginosa detected in patients hospitalized in private hospitals in the city of São Paulo during the period from February to October 2013. The samples were evaluated for the imipenem hydrolysis by spectrophotometry, the presence of carbapenemase genes by PCR and sequencing, and concerning clonality by pulsed field electrophoresis (PFGE) or ERIC-PCR. Conjugation, transformation and complete sequencing of plasmids were performed. Among Acinetobacter spp. samples, 80% (88) were able to hydrolyze imipenem. Among these, 76.1% (67) were positive for blaOXA-51-like genes and 19.3% (17) were positive for blaOXA-72. The blaOXA-23, blaOXA-482 and blaIMP-1 genes were detected alone in distinct isolates. The blaIMP-1 gene was detected in A. ursingii inserted in class 1 integron and represents the first description in Brazil. A novel OXA-482-like carbapenemase was detected in A. baumanii. Using ERIC-PCR, a great diversity of clonal groups was observed, with a maximum of four isolates per group. Among P. aeruginosa samples, only 35.3% were able to hydrolyze imipenem. Of these samples, 14 had the blaSPM-1 gene, and single isolates individually possessed the blaIMP, blaVIM, blaKPC-2 or blaGES-23 genes. The blaKPC-2 gene was found inserted in a genetic context different from those described previously, in a mobilizable, but not conjugative, 32 Kb IncU plasmid. This is the first description of the complete nucleotide sequence of a plasmid harboring the blaKPC-2 gene in P. aeruginosa in Brazil. In the remaining samples (20) with hydrolytic activity, no known carbapenemase genes were detected, suggesting the presence of carbapenemase genes not yet described. In three samples it was possible to obtain transformants with plasmids, resistant to carbapenems. Samples with blaSPM-1 showed closely related PFGE profiles. In contrast, the PFGE profiles of the samples with potential new carbapenemases showed Dice similarity index lower than 80%, evidencing a great clonal diversity. Our findings show that the predominant non-intrinsic carbapenemase in Acinetobacter in the city of São Paulo is OXA-72, and in private hospitals there is great clonal diversity. In P. aeruginosa, the predominant carbapenemase is SPM-1, the spread of this enzyme is mediated by a single clone. There are potentially a significant number of new carbapenemases in Acinetobacter and P. aeruginosa, some of them plasmid mediated.