RESUMO
We investigated the third-generation cephalosporins-resistant Shigella and its genotype in Ningbo,China,providing a basis for disease prevention and control.Pathogenic bacteria were analyzed by direct isolation combined with enrichment culture isolation.Antimicrobial susceptibility was determined by K-B disk diffusion method and PCR was used for detecting multidrug resistance genes like CTX-M,OXA,TEM and SHV.BLAST analysis was used to determine the genotype.Results showed that 69 strains of third-generation cephalosporins-resistant Shigella were detected by drug sensitivity screening,accounting for 74.19％ of ESBLs Shigella.Drug resistance gene CTX-M(CTM-M-1 and CTM-M-9),OXA and TEM were detected.The detection rate were 79.71％,79.01％ and 26.09％ respectively.With no CTX-M-2 and SHV,DNA sequence alignment showed CTX-M-1 group were mainly of CTX-M-15 type besides seven other types;CTX-M-9 group were mainly of CTX-M-14 type besides six other types;49 strains of OXA and 18 strains of TEM were sequenced to be type 1 (OXA-1 and TEM-1 type).The 21 Shigella strains carrying more than two drug resistance genes accounts for 30.43 ％.Shigella in Ningbo has high third-generation cephalosporins-resistance rate and many kinds of ESBLs enzymes were detected.The mainstream enzyme type was CTX-M,meanwhile they also carried a variety of drug resistance genes,which could bring difficulties to disease prevention and control.The high carrying rate of OXA-1 type suggests that we should pay more attention.The detection rate of group B was higher than that of group D,including not only the phenotype resistance but also the drug-resistance genes;these findings will be useful in the study of the drug resistance prevalence of Shigella.
RESUMO
To investigated the toxin genes distribution and molecular characteristics of Vibrio parahaemolyticus from pa‐tients in Ningbo ,V .parahaemolyticus strains were collected from patients with food poisoning and diarrhea .Thermostable di‐rect hemolysin gene (tdh) and TDH‐related hemolysin gene (trh) were detected by polymerase chain reaction (PCR) .Molecu‐lar characteristics were acquired by multi‐locus sequence typing (MLST ) .Of 248 clinical strains were isolated from 2006 to 2012 .Forty‐eight strains were selected to detect virulence genes and MLST genotyping .Forty‐two isolates were detected as tdh+ and 11 isolates were detected as trh+ .There were 9 STs and one undifferentiated type in Ningbo clinical strains .Thirty‐two strains were classified into ST3 ,5 strains into ST265 and 3 strains into ST120 .ST265 was found in Ningbo strains com‐pared with strains from other regions of China .Strains with tdh+ accounted for the majority in Ningbo clinical strains .Twen‐ty‐five strains of ST3 clone were tdh+ /trh‐.There were 9 STs coexsited in Ningbo clinical strains .ST3 clone was dominant , followed by ST265 and ST120 .Strains with tdh+ /trh‐were dominant in the ST3 clone .The unique ST262 was found in Ning‐bo clinical strains .