Serotype, Virulence and Drug Resistance of Vibrio parahaemolyticus from Ningbo Small Aquatic Products

Objective To understand the serotype distribution, toxin-producing characteristics and resistance to antibiotics of the Vibrio parahaemolyticus isolated from small aquatic products.Method Using the standard technique GB/T 4789.7—2003, 27 stains of Vibrio parahaemolyticus were isolated from small aquatic products collected from Ningbo market. Their serotypes were determined by PCR and virulence genes tdh and trh were also determined. Agar diffusion method was used to test the antibiotic susceptibility. Results 27 strains of Vibrio parahaemolyticus consisted of nine serum groups: O∶4 33.3% (9/27), O∶3 14.8% (4/27),O∶2 14.8% (4/27), O∶11 11.1% (3/27), O∶5 7.4% (2/27), O∶1 7.4% (2/27), O∶7 3.7% (1/27), O∶9 3.7% (1/27), O∶10 3.7% (1/27). Neither nor tdh nor trh virulence gene was identified in any of the 27 strains. Susceptibility tests showed that some of the 27 strains were resistant to penicillins, β-lactams, aminoglycosides, sulfonamides, quinolones and cephalosporins.Conclusion The Vibrio parahaemolyticus isolated from the small aquatic products in Ningbo City have diversified characteristics of serological type and antibiotic susceptibility.