An Investigation of the Carriage Rate of Methicillin-Resistant Staphylococcus aureus in Pigs in the Western Province of Vietnam

Methicillin-resistant Staphylococcus aureus (MRSA) transmission between pigs and humans can be a dangerous infection source for the community. To control and prevent such disease, MRSA research in healthy pigs has been conducted in the US and Holland. This paper reports the first such study in Vietnam. This study aims to optimize the method for investigating MRSA carriage in tonsil and nasal swabs of healthy pigs. Potential samples were selected rapidly by Multiplex PCR (M-PCR) assay with 3 primers (Staph 756, mecA, Sa442) and then combined with conventional methods to detect and pick up MRSA strains. These strains were grouped based on genome pattern by pulsed field gel electrophoresis (PFGE). This study showed that we successfully isolated MRSA and the rate of MRSA carriage samples was 3.63%, much lower than that reported in the USA (49%) and Holland (39%), however the USA and Holland studies investigated pigs from industrial scale piggeries, whereas our study investigated pigs from small farms, which is the usual approach to pig farming in Vietnam. The MRSA patterns identified and associated MRSA strains were different from identified MRSA strains in other countries. This research provides important information about the carriage rate of MRSA in pigs in the Western province of Vietnam and demonstrates the importance of ongoing investigations in this area.