RESUMEN

Staphylococcus aureus is an opportunistic and ubiquitous pathogen found in the skin, nares, and mucosal membranes of mammals. Increasing resistance to antimicrobials including methicillin has become an important public concern. One hundred and eight (108) S. aureus strains isolated from a total of 572 clinical and animal products samples, were investigated for their biofilm capability, methicillin resistance, enterotoxin genes, and genetic diversity. Although only one strain isolated from raw retail was found as a strong biofilm producer, the percentage of antimicrobial resistance pattern was relatively higher. 17.59% of S. aureus strains tested in this study were resistant to cefoxitin and identified as methicillin-resistant S. aureus (MRSA) isolates. mecA and mecC harboring S. aureus strains were detected at a rate of 2.79% and 0.93%, respectively. In addition, staphylococcal enterotoxin genes including Sea, Seb, Sec, and Sed genes were found to be 18.5%, 32.4%, 6.5% and 3.7%, respectively. The phylogenetic relationship among the isolates showed relationship between joint calf and cow milk isolates. Multi locus sequence typing (MLST) revealed three different sequence types (STs) including ST84, ST829, and ST6238. These findings highlight the development and spread of MRSA strains with zoonotic potential in animals and the food chain throughout the world.

Staphylococcus aureus é um patógeno dúctil e ubíquo encontrado na pele, narinas e membranas mucosas de mamíferos. O aumento da resistência aos antimicrobianos, incluindo a meticilina, tornou-se uma importante preocupação pública. Cento e oito (108) cepas de S. aureus isoladas de um total de 572 amostras clínicas e de produtos animais foram investigadas por sua capacidade de biofilme, resistência à meticilina, genes de enterotoxinas e diversidade genética. Embora apenas uma cepa isolada do cru tenha sido encontrada como forte produtora de biofilme, a porcentagem do padrão de resistência antimicrobiana foi relativamente maior. Parte das cepas (17,59%) de S. aureus testadas neste estudo eram resistentes à cefoxitina e identificadas como isolados de MRSA. mecA e mecC abrigando cepas de S. aureus foram detectados a uma taxa de 2,79% e 0,93%, respectivamente. Além disso, verificou-se que os genes da enterotoxina estafilocócica, incluindo os genes Sea, Seb, Sec e Sed, eram 18,5%, 32,4%, 6,5% e 3,7%, respectivamente. A relação filogenética entre os isolados mostrou relação entre os isolados de bezerro e leite de vaca. A tipagem de sequência multiloco (MLST) revelou três tipos de sequência diferentes (STs), incluindo ST84, ST829 e ST6238. Essas descobertas destacam o desenvolvimento e a disseminação de cepas de MRSA com potencial zoonótico em animais e na cadeia alimentar em todo o mundo.

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RESUMEN

ABSTRACT: Staphylococcus aureus is an opportunistic and ubiquitous pathogen found in the skin, nares, and mucosal membranes of mammals. Increasing resistance to antimicrobials including methicillin has become an important public concern. One hundred and eight (108) S. aureus strains isolated from a total of 572 clinical and animal products samples, were investigated for their biofilm capability, methicillin resistance, enterotoxin genes, and genetic diversity. Although only one strain isolated from raw retail was found as a strong biofilm producer, the percentage of antimicrobial resistance pattern was relatively higher. 17.59% of S. aureus strains tested in this study were resistant to cefoxitin and identified as methicillin-resistant S. aureus (MRSA) isolates. mecA and mecC harboring S. aureus strains were detected at a rate of 2.79% and 0.93%, respectively. In addition, staphylococcal enterotoxin genes including Sea, Seb, Sec, and Sed genes were found to be 18.5%, 32.4%, 6.5% and 3.7%, respectively. The phylogenetic relationship among the isolates showed relationship between joint calf and cow milk isolates. Multi locus sequence typing (MLST) revealed three different sequence types (STs) including ST84, ST829, and ST6238. These findings highlight the development and spread of MRSA strains with zoonotic potential in animals and the food chain throughout the world.

RESUMO: Staphylococcus aureus é um patógeno dúctil e ubíquo encontrado na pele, narinas e membranas mucosas de mamíferos. O aumento da resistência aos antimicrobianos, incluindo a meticilina, tornou-se uma importante preocupação pública. Cento e oito (108) cepas de S. aureus isoladas de um total de 572 amostras clínicas e de produtos animais foram investigadas por sua capacidade de biofilme, resistência à meticilina, genes de enterotoxinas e diversidade genética. Embora apenas uma cepa isolada do cru tenha sido encontrada como forte produtora de biofilme, a porcentagem do padrão de resistência antimicrobiana foi relativamente maior. Parte das cepas (17,59%) de S. aureus testadas neste estudo eram resistentes à cefoxitina e identificadas como isolados de MRSA. mecA e mecC abrigando cepas de S. aureus foram detectados a uma taxa de 2,79% e 0,93%, respectivamente. Além disso, verificou-se que os genes da enterotoxina estafilocócica, incluindo os genes Sea, Seb, Sec e Sed, eram 18,5%, 32,4%, 6,5% e 3,7%, respectivamente. A relação filogenética entre os isolados mostrou relação entre os isolados de bezerro e leite de vaca. A tipagem de sequência multiloco (MLST) revelou três tipos de sequência diferentes (STs), incluindo ST84, ST829 e ST6238. Essas descobertas destacam o desenvolvimento e a disseminação de cepas de MRSA com potencial zoonótico em animais e na cadeia alimentar em todo o mundo.

RESUMEN

Specific microbiological parameters and the presence of Salmonella spp. were investigated in 72 chicken meat samples (36 wings and 36 drumsticks) collected from markets and butcher shops. The specific microbiological parameters were determined using a conventional cultural method and the presence of Salmonella spp. in chicken samples was determined using conventional and immunomagnetic separation (IMS)-polymerase chain reaction (PCR) methods. In addition, antimicrobial susceptibility of the isolates was revealed using the Kirby-Bauer disc diffusion method. The results indicated that 30 of the 72 samples were positive for Salmonella spp. by the conventional method, and 42 of the 72 were positive by the IMS-PCR method. However, 30 of the 72 samples were positive for Salmonella spp. by both methods. The Salmonella spp. isolates were confirmed by the VITEK2 Compact System and PCR. The susceptibilities of the isolates against 10 antibiotics were determined. The results indicated that isolates (27/30) showed the highest susceptibility to gentamycin (90.00%), while the highest resistance was to nalidixic acid and tetracycline at the 100 and 93.34% levels, respectively. These results indicate a high prevalence of Salmonella spp. in poultry meat from Erzurum city, Turkey, and the antimicrobial resistance profile of these isolates should be considered for public health. The results also show that the IMS-PCR technique was superior to the conventional method for detecting Salmonella in poultry meat.KEYWORDS:Chicken meat. Salmonella. IMS. PCR. Antimicrobial. INTRODUCTION Chicken is one of the most popular food products worldwide, because of nutritional, sensorial and economic factors. Chicken is widely consumed in homes and fast-food establishments, but can become contaminated during processing. The contamination of poultry products with Salmonella and other microorganismsis due to unhygienic conditions during the production, processing, distribution, marketing and preparationstages (DOOKERAN et al., 2012). The genus Salmonella includes short rod-shaped, facultative anaerobe, Gram-negative bacteria. Warm-blooded animals and humans are natural hosts for Salmonella spp. Detecting Salmonella spp. during production and before consumption is important to prevent food-borne salmonellosis. A Salmonella infection in humans is usually caused by consuming undercooked meat or other cross-contaminated foods, such as vegetables,milk and eggs (HASSANEIN et al., 2011). According to a report published by the Centres for Disease Control and Prevention (CDC), it is estimated that about 1.2 million people in the US have been exposed to Salmonella infections, and that an average of 23.000 hospitalisations and 450 deaths occur from these infections. The prevalence rates of Salmonella spp. in chicken meat sold in Turkey are 34-68.75%. Not only in Turkey, but in most developing countries, the absence of an epidemiological surveillance system for salmonellosis cases makes it difficult to effectively assess prevalence (KÄFERSTEIN, 2003). However, Received: 09/05/18 Accepted: 05/12/18

Parâmetros microbiológicos específicos e a presença de Salmonella spp. foram investigados em 72 amostras de carne de frango (36 asas e 36 baquetas) coletadas em mercados e açougues. Os parâmetros microbiológicos específicos foram determinados utilizando um método cultural convencional e a presença de Salmonella spp. em amostras de frango foi determinada utilizando métodos de reação em cadeia da polimerase (PCR) por separação convencional e imunomagnética (IMS). Além disso, a suscetibilidade antimicrobiana dos isolados foi revelada pelo método de difusão do disco de Kirby-Bauer. Os resultadosindicaram que 30 das 72 amostras foram positivas para Salmonella spp. pelo método convencional, e 42 das 72 foram positivas pelo método IMS-PCR. No entanto, 30 das 72 amostras foram positivas para Salmonella spp. por ambos os métodos. Os isolados de Salmonella spp. foram confirmados pelo sistema VITEK2 Compact e PCR. As susceptibilidades dos isolados a 10 antibióticos foram determinadas. Os resultados indicaram que os isolados (27/30) apresentaram maior suscetibilidade à gentamicina (90,00%), enquanto a maior resistência foi ao ácido nalidíxico e à tetraciclina nos níveis de 100 e 93,34%, respectivamente. Estes resultados indicam uma alta prevalência de Salmonella spp. em carne de frango da cidade de Erzurum, Turquia, e o perfil de resistência antimicrobiana desses isolados deve ser considerado para a saúde pública. Os resultados também demonstram que a técnica de IMS-PCR foi superior ao método convencional para detecção de Salmonella em carne de frango.

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