Abstract The aim of this study was to investigate the presence of virulence and antimicrobial resistance genes and clonal profile of Enterobacteriaceae isolated from calves, cows, feeding buckets and the milk bucket. A a total of 31 Enterobacteriaceae isolates from calves (6), milk bucket (6), feeding buckets (6) and from cows’ rectum (13) were used. The presence of LT, STa, STb, STx1, STx2, eae, rmpA, wabG, mrkD, kfu, mcgA, fimH and uge as well as the antimicrobial resistance genes: AmpC MOX, FOX, MIR, ACT, DHA, ACC, CTX-M-1, CTX-M2, TEM KPC and MCR-1 and SH were evaluated by PCR. The LT toxin gene were detected in five isolates (16.1%) and the mrkD gene was detected in three isolates (9.0%). The CTX-M-1 gene was detected in 13 isolates (41.9%), CTX-M-2 in five isolates (16.1%) and ACC-M in four isolates (12.9%). Most of the isolates obtained demonstrated, resistance to cephalothin (87.5%), ampicillin, (87.5%) and streptomycin (84.3%) with multidrug resistance observed in all isolates. Isolates from bucket and cow’s rectum, calves and milk bucket, calf and cow’s rectum shared the same pulsotypes. These findings may suggest that enterobacteria carring virulence and resistance genes may persist in the environment and became a reservoir of these genes.

Abstract The consumption of raw milk cheese has been growing worldwide with S. aureus and E. coli been the leading agents in food poisoning. The present work aims to evaluate the microbiological quality of raw milk cheeses commercialized in Brazil, regarding microbiology safety and enterotoxin gene presence. Forty-three raw milk cheeses samples from five different suppliers were analyzed. Counting and identification of S. aureus, E. coli and Salmonella spp were performed according to BAM from the FDA. Further S. aureus identification was performed by the cydB and Salmonella spp by the invA gene. S. aureus toxin genes (sea, seb, sec, see, ses, seh and sei) and E. coli gene LT, STa, Stb, stx1, stx2, eae, rmpA, wabG, mrkD, kfu, mcgA, fimH and uge were analysed. From the 43 samples analyzed, 18 presented S. aureus with two isolates positive for the tst gene, two for the sec gene, two for the seh gene and four for the sei gene. Thirty-five E. coli and seven. Salmonella spp isolates were obtained. E. coli isolates harbored sta and stx2 genes. The results revealed that raw milk cheeses sold can cause harm consumer's health and highlights the importance of adoption good hygienic-sanitary practices and consumers awareness.

ABSTRACT Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

RESUMO: Cepas de Escherichia coli patogênica para aves (APEC) estão isoladas das lesões de frangos com colibacilose, uma doença que causa sinais clínicos sistêmicos ou localizados. As APEC compartilham algumas características com as cepas de Escherichia coli que produzem doenças extraintestinais nos seres humanos. Ainda não há um consenso sobre a definição de patotipos das cepas de APEC, no que diz respeito à presença das características de virulência. Entretanto, nos últimos anos, foram definidos cinco indicadores mínimos para a identificação de patotipos das cepas de APEC. Os isolados de E. coli utilizados neste trabalho foram testados por meio de reação em cadeia de polimerase (PCR) para os cinco indicadores mínimos e para cva C. Os isolados que possuíam os cinco indicadores mínimos foram definidos como potenciais cepas de APEC. As categorias APEC e não APEC apresentaram alta resistência (> 50%) à cefalotina, eritromicina, estreptomicina, sulfametoxazol mais trimetoprim, ampicilina e amoxicilina. Possíveis cepas de APEC foram significativamente mais resistentes à cefalotina (p < 0,05) e neomicina (p < 0,01) do que as cepas não-APEC. Estas foram significativamente mais resistentes à tetraciclina (p < 0,01) do que as possíveis cepas de APEC. Esses resultados demonstram que as fezes dos frangos de corte albergam cepas de E.coli com características de resistência, apresentando ou não potencialidade de causar colibacilose. Em função das características de similaridade entre APEC e doenças extraintestinais nos seres humanos, estas cepas resistentes são de interesse à saúde pública.

ABSTRACT: Avian pathogenic Escherichia coli (APEC) strains are isolated from lesions of poultry presenting colibacillosis, which is a disease that causes either systemic or localized clinical signs. Such strains share many characteristics with E. coli strains that cause extra-intestinal illness in humans. There is not a consensus on how to define the APEC pathotype with regard to the presence of virulence traits. On the other hand, in the past few years, five minimal predictors for APEC detection were proposed. The E. coli isolates in this work were tested through polymerase chain reaction (PCR) to the five proposed minimal predictors and cva C. The strains presenting them were categorized as potential APEC. The APEC and non-APEC categories showed high resistance (> 50%) to cephalotin, erythromycin, streptomycin, sulphametoxazol/trimethoprim, ampicillin, and amoxicillin. Potential APEC strains were significantly more resistant to cephalotin (p < 0.05) and neomcycin (p < 0.01) than non-APEC. These latter were significantly more resistant to tetracycline (p < 0.01) than the potential APEC strains. These results demonstrate that feces of poultry present E. coli strains with resistant features, showing or not the potential of causing colibacillosis in poultry. Because APEC and extra-intestinal illness in humans may be similar, these resistant strains are of interest to public health.

Dezesseis eqüinos adultos foram distribuídos aleatoriamente em 4 grupos (GI, GII, GIII e GIV) constituídos por quatro animais, recebendo cada grupo o seguinte inóculo por via intraperitoneal: GI (100 X 10(7) unidades formadoras de colônia (UFC) de Escherichia coli diluídos em 500 ml de solução salina 0,9% estéril); GII (100 X 10(7) UFC de Bacteroides fragilis diluídos em 500 ml de solução salina 0,9% estéril); GIII (100 X 10(7) UFC de Escherichia coli associados a 100 X 10(7) UFC de Bacteroides fragilis diluídos em 500 ml de solução salina 0,9% estéril); GIV (testemunho - 500 ml de solução salina 0,9% estéril). Leucopenia ocorreu em todos os animais inoculados com bactérias, nas primeiras seis horas após as inoculações. Posteriormente a este período, verificou-se em alguns eqüinos inoculados leucocitose. Os eqüinos inoculados com culturas puras de E. coli ou B. fragilis apresentaram peritonites brandas e autolimitantes, enquanto os inoculados com a associação destas bactérias, apresentaram alterações laboratoriais de maior intensidade e duração.

Sixteen adult horses were randomly divided into 4 equal groups (GI, GII, GIII and GIV) of 4 animals and each group was injected intraperitoneally with one of the following suspension: Group I, 100 x 10(7) colony-forming units (CFU) of E. coli diluted in 500 ml of 0.9% saline; Group II, 100 x 10(7) CFU of Bacteroides fragilis in 500 ml of 0.9% saline; Group III, 100 x 10(7) CFU of E. coli in combination with 100 x 10(7) CFU of B. fragilis in 500 ml of 0.9% saline; Group IV, 500 ml of 0.9% saline. Leukopenia appeared in all animals inoculated with bacteria within the first six hours of the experiment. After this period, leukocytosis was observed in some inoculated horses. Horses inoculated with pure cultures of either E. coli or B. fragilis demonstrated mild and self-limiting peritonitis, whereas those inoculated with a combination of both bacteria demonstrated laboratory findings of higher intensity and duration.

Dezesseis eqüinos adultos foram distribuídos aleatoriamente em 4 grupos (GI, GII, GIII e GIV), constituídos por quatro animais, recebendo cada grupo o seguinte inóculo por via intraperitoneal: GI (100 X 10(7) unidades formadoras de colônia (UFC) de Escherichia coli diluídos em 500ml de salina 0,9%); GII (100 X 10(7) UFC de Bacteroides fragilis diluídos em 500ml de salina 0,9%); GIII (100 X 10(7) UFC de E. coli associados a 100 X 10(7) UFC de B. fragilis diluídos em 500ml de salina 0,9%); GIV (testemunho - 500ml de salina 0,9%). Aumento da sensibilidade e tensão da parede abdominal, diarréia, diminuição dos sons intestinais e aumento da freqüência cardíaca foram os sinais mais freqüentemente observados nos eqüinos inoculados com cepas bacterianas. Eqüinos inoculados com culturas puras de E. coli ou B. fragilis apresentaram peritonites brandas e autolimitantes, enquanto que os inoculados com a associação dessas bactérias apresentaram sinais de maior intensidade e duração.

Sixteen adult horses were randomly divided into 4 equal groups (GI, GII, GIII and GIV) of 4 animals and each group was injected intraperitoneally with one of the following suspension: GI (100 x 10(7) colony-forming units (CFU) of Escherichia coli diluted in 500ml of 0.9% saline); GII (100 x 10(7) CFU of Bacteroides fragilis in 500ml of 0.9% saline); GIII (100 x 10(7) CFU of E. coli in combination with 100 x 10(7) CFU of B. fragilis in 500ml of 0.9% saline); GIV (500ml of 0.9% saline). Abdominal wall sensitivity to external pressure and tension, diarrhea, decreased intestinal sounds and increased of heart rate were the clinical signs more frequently observed in inoculated horses. Horses inoculated with pure cultures of either E. coli or B. fragilis demonstrated mild and self-limiting peritonitis, while those inoculated with the combination of both bacteria demonstrated clinical signs of higher intensity and duration.