Genotyping and toxin gene detection of Staphylococcus aureus isolated from market fresh meat

ObjectiveTo investigate the contamination situation, molecular diversity and virulence gene distribution of Staphylococcus aureus isolated from market fresh meat, providing basis for its prevention and control.

MethodsS.aureus strains were isolated and identified according to GB 4789.10—2016.MLST(multilocus sequence typing) method was used for genotyping these isolates, and the distribution of 11 toxin genes were tested by PCR.

ResultsA total of 56 S.aureus-positive samples (30.1%) were found out of 148 samples from market fresh meat, and finally 56 strains were isolated.MLST results showed that these strains could be typed into 11 different sequence types (STs).Among them ST7 (28.6%) was dominant, and followed by ST188 (23.2%), ST1 (8.93%) and ST88 (8.93%).Six toxin genes were detected in 27 strains (48.2%), in which the most frequent toxin gene was pvl gene (26.8%), followed by enterotoxin genes sec (12.5%), seh (10.7%), sea (7.1%) and sed (5.4%).

ConclusionS.aureus has a high pollution rate in raw meat commodities.The high genetic diversity of the strains implies multiple sources of contamination.The toxin genes associated with food poisoning and clinical infection show a high distribution proportion.The monitoring of S.aureus in market fresh meat should be strengthened.