Occurrence of Methicillin Resistant Staphylococcus aureus from Bovine Raw Milk in Chennai

Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) presence in milk is of significant importance as they are often involved in food borne intoxications. Effective surveillance and detection are the most important tools in outbreak investigation and control. Our study was designed to ascertain the occurrence Staphylococcus aureus and Methicillin-Resistant S. aureus (MRSA) from raw milk collected from apparently healthy cattle in Chennai city, Tamil Nadu, India. A total of 89 (89/258; 34.49%) positive isolates of Staphylococcus aureus obtained from 258 raw milk samples screened. Of which 24 (24/258; 9.3%) isolates positive for MRSA. Studying the antimicrobial resistance and its patterns in foods of animal origin will be of immense help to various regulatory agencies and authorities to devise and implement control measures and to note the compliance of our foods with the prescribed standards.

Diagnóstico laboratorial da resistência à oxacilina em Staphylococcus aureus / Laboratory diagnosis of oxacillin resistance in Staphylococcus aureus

Apesar das diversas recomendações disponíveis na literatura sobre o diagnóstico laboratorial da resistência à oxacilina em Staphylococcus aureus, a verdade é que ainda não existe consenso absoluto sobre qual ou quais métodos utilizar e quando utilizar cada um deles. Segundo a literatura, a maioria dos métodos disponíveis apresenta um índice não desprezível de erros diagnósticos. Em casos de isolados de processos infecciosos invasivos, ou de infecções persistentes e/ou refratárias aos antimicrobianos, o uso de um método adicional ou confirmatório pode ser importante. Além disso, a contínua reavaliação desses testes é necessária.

Despite guidelines published in the literature, the optimal routine phenotypic method for detecting methicillin resistance in Staphylococcus aureus remains controversial. Most available methods have a considerable rate of errors, according to the literature. When testing invasive isolates or isolates from persistent/refractory infections, using an additional or confirmatory method could be important. In addition, the continual evaluation of these tests is necessary.