Sorovares e perfil de suscetibilidade a antimicrobianos em Salmonella spp. isoladas de produtos de origem suína / Serovars and antimicrobial susceptibility of Salmonella spp. product isolated from swine

Foi analisado um total de 1824 cepas de Salmonella, isoladas de alimentos de origem suína, no período de janeiro/2005 a junho/2010. As cepas, provenientes de diferentes regiões do país, foram recebidas pelo Labent/IOC/FIocruz para caracterização antigênica conclusiva. Foram identificados 41 sorovares, destacando-se: Typhimurium, Derby, Enteritidis, Panama, Infantis e Anatum. Aspectos bacteriológicos e epidemiológicos relacionados a esses sorovares foram discutidos. O teste de suscetibilidade aos antimicrobianos foi realizado em 357 amostras, 257 (72%) foram resistentes a uma ou mais drogas, e destas, 31,9% mostraram-se multirresistentes. A variedade de sorovares observada neste estudo confirma o papel dos suínos na cadeia alimentar como importantes reservatórios de Salmonella, agravado ainda pelo elevado percentual de cepas resistentes a um ou mais antimicrobianos, alertando para uma condição de risco à saúde pública.

We analyzed a total of 1824 strains of Salmonella isolated from swine-origin foods from January/2005 to June/2010. The strains from different regions of the country were received by Labent/IOC/FIOCRUZ for conclusive antigenic characterization. We identified 41 serovars, of which these stood out: Typhimurium, Derby, Enteritidis, Panama, Infantis and Anatum. Bacteriological and epidemiological aspects related to these serovars were discussed. The antimicrobial susceptibility test was performed on 357 samples, 257 (72%) were resistant to one or more of these drugs and 31,9% were multiresistant. A variety of serovars were identified reinforcing the swine as an important reservoir of Salmonella in the food chain. The high rates of antimicrobial resistance obtained in this evaluation may represent a risk condition to human health.

Chicken feet bacteriological quality at 4 steps of technological processing.

The production of chicken feet is primarily intended for foreign markets, and there is still no specific legislation in Brazil that determines the quality standard of these products. The bacteriological quality of chicken feet was evaluated as a product for human consumption at different steps of the technological processes. Eighty broiler feet from 20 lots at 4 steps of processing were collected for quantitative analysis, total count of aerobic mesophilic bacteria, and determining the most probable number of coliforms and fecal coliforms. Thirty-eight pools of 15 broiler feet each from 19 lots were used for qualitative analysis and the isolation of Salmonella enterica spp. and Escherichia coli O157:H7. Escherichia coli O157:H7 was not found in any of the samples. Salmonella spp. were isolated in 68% (13/19) of the lots. The Salmonella Schwarzengrund serotype was found in 12 of the 13 lots of positive samples and the Salmonella Anatum and Salmonella Corvallis serotypes were identified in the remaining lot. Processing is effective in reducing contamination by mesophilic bacteria, coliforms, and Salmonella spp. in these products. This work constitutes the first study in Brazil on microbiological quality of chicken feet.

Incidence and antimicrobial resistance of enteropathogens isolated from an integrated aquaculture system.

AIMS: To evaluate an integrated aquaculture system, microbiological analyses of water used in this system were carried out and the incidence and antimicrobial resistance of enteropathogens were determined in the related ecosystem. METHODS AND RESULTS: Microbiological analysis was undertaken for Salmonella sp., Shigella sp., Vibrio sp. and Aeromonas sp. The disc-diffusion method was performed according to the Clinical and Laboratory Standards Institute. Water samples tested had 32.9% of faecal coliform rates (≤1600 per 100 ml) in accordance with WHO for pisciculture in wastewater. Salmonella spp. were detected in 14.5% of the samples. From a total of 33 strains, 15.1% were resistant to one or two antimicrobial drugs tested and multidrug resistance was not observed. Aeromonas spp. were identified in 91.6% of the samples. From a total of 416 strains, resistance to one antimicrobial class was observed in 66.3% and multidrug resistance in 37.7%. CONCLUSIONS: This system reflects the community profile, drawing attention to the circulation of pathogens, because the genes coding for resistance to classical antibiotics and broad spectrum are a public health problem. SIGNIFICANCE AND IMPACT OF THE STUDY: The reuse of water resources requires continuous monitoring as the system is subject to treatment failure, which can result in the spread of bacterial pathogens.

Antimicrobial resistance and subtyping of Salmonella enterica subspecies enterica serovar Enteritidis isolated from human outbreaks and poultry in southern Brazil.

To investigate antimicrobial resistance, 96 Salmonella enterica subspecies enterica serovar Enteritidis strains isolated from salmonellosis outbreaks and poultry-related products obtained in southern Brazil were analyzed. Macrorestriction patterns, obtained by pulsed-field gel electrophoresis and phage types, were assessed. Although 43.75% of samples were sensitive to all drugs tested, resistance to sulfonamide (34.37%), trimethoprim-sulfamethoxazole (25.00%), nalidixic acid (14.58%), streptomycin (2.08%), gentamicin, and tetracycline (1.04%) was identified. Furthermore, 89.60% of strains belonged to phage type 4, and a predominant pulsed-field gel electrophoresis genotype represented by 82.29% of the strains was identified, suggesting that a clonal group was distributed in poultry, food, and human isolates. Although it was not possible to associate strains from different sources, the occurrence of antimicrobial-resistant Salmonella Enteritidis strains supports the need to establish monitoring programs to identify the emergence of potential resistance patterns and to direct policies for use of these drugs in food-producing animals.

Clonality and antimicrobial resistance gene profiles of multidrug- resistant Salmonella enterica serovar infantis isolates from four public hospitals in Rio de Janeiro, Brazil.

In Brazil, Salmonella enterica serovar Infantis resistant to various antimicrobials, including cephalosporins, has been identified as an etiological agent of severe gastroenteritis in hospitalized children since 1994. In this study, 35 serovar Infantis strains, isolated from children admitted to four different Rio de Janeiro, Brazil, hospitals between 1996 and 2001, were characterized by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing in order to determine their genetic relatedness and antimicrobial resistance profiles. Thirty-four serovar Infantis strains were resistant to at least two antibiotic classes, and all 35 strains were susceptible to fluoroquinolones, cephamycin, and carbapenem. Extended-spectrum beta-lactamase (ESBL) screening by double-disk diffusion indicated that 32 serovar Infantis strains (91.4%) produced beta-lactamases that were inhibited by clavulanic acid. Antimicrobial resistance gene profiles were determined by PCR for a subset of 11 multidrug-resistant serovar Infantis strains, and putative ESBLs were detected by isoelectric focusing. Ten serovar Infantis strains carried bla(TEM), catI, ant(3")Ia and/or ant(3")Ib, sulI and/or sulII, and tet(D) genes as well as an integron-associated aac(6')-Iq cassette. Eight strains possessed at least four different beta-lactamases with pI profiles that confirmed the presence of both ESBLs and non-ESBLs. Our PFGE profiles indicated that 33 serovar Infantis strains isolated from Rio de Janeiro hospitals came from the same genetic lineage.

Characterization of a Salmonella enterica serovar Agona strain harbouring a class 1 integron containing novel OXA-type beta-lactamase (blaOXA-53) and 6'-N-aminoglycoside acetyltransferase genes [aac(6')-I30].

OBJECTIVE: To characterize by molecular methods a multidrug-resistant Salmonella enterica serovar Agona (S. enterica Agona) isolated from a hospitalized patient in Rio de Janeiro, Brazil. METHODS: The S. enterica Agona strain was screened by PCR and DNA sequencing for TEM, SHV and CTX-M-type beta-lactamase genes, tet(A), (B), (C) and (D) tetracycline resistance genes, chloramphenicol resistance genes and class 1 integrons. Plasmid characterization was carried out by PCR and Southern hybridization analysis. PCR and PFGE were used to characterize nine other S. enterica Agona strains collected from hospitals in Rio de Janeiro. RESULTS: The study strain was found to harbour a 105 kb plasmid, which contained catA1, bla(TEM-1), a class 1 integron with two novel genes labelled bla(OXA-53) and aac(6')-I30, respectively, and an additional unidentified aminoglycoside resistance gene. A second 53 kb plasmid from the same strain contained tet(D) and bla(SHV-5). OXA-53 was shown to provide reduced susceptibility to ceftazidime, and its activity was inhibited in the presence of clavulanic acid. PFGE analysis of the nine other S. enterica Agona strains revealed two clusters of related strains (78% similarity), and PCR analysis showed that all strains contained the novel integron. CONCLUSION: An S. enterica Agona strain was found to harbour three plasmid-encoded beta-lactamases, one (OXA-53) on a novel class 1 integron that also contains a new aminoglycoside resistance gene, aac(6')-I30. The multidrug resistance plasmids appear to have disseminated to other city hospitals via other S. enterica Agona strains.