Circulation and etiological characterization of Salmonella enterica serotype in human in Guangdong province, 2007-2016 / 中华流行病学杂志

ABSTRACT

Objective To understand the circulation,drug resistance and molecular characteristics of Salmonella 1,4,[5],12i-in human in Guangdong province.Methods Salmonella 1,4,[5],12i-isolated from diarrhea patients in Guangdong during 2007-2016 were detected for drug resistance,genes and PFGE characteristics.Results A total of 2 960 strains Salmonella 1,4,[5],12i-were isolated from human diarrhea cases during this period.The positive rates of the isolation increased year by year.The male to female ratio of the infection cases was 1.58 ∶ 1,and the infection mainly occurred in infants and young children.Except imipenem,Salmonella 1,4,[5],12i-was resistant to other 17 antibiotics to some extent.The drug resistant rates to ceftazidime,cefotaxime and ciprofloxacin increased from 2011 to 2016.Multi-drug resistance was serious,for example,the multi-drug resistant strains with ASSuT accounted for 70.62％ (435/616) and the multi-drug resistant strains with ACSuGSTTm accounted for 27.11％ (167/616).The lack offljA,fljB and hin genes,as well as the retaining of iroB,STM2740,STM2757 genes,resulted in the unable expression of FljBenx gene with 8 different defection profiles.There were 934 different PFGE patterns observed in 2 347 strains,which displayed a relatively large fingerprint polymorphism.The major PFGE pattern was JPXX01.GD0226,which was found in 97 strains,accounting for 4.13％ (97/2 347).The PFGE patterns in 168 Salmonella 1,4,[5],12i-strains were consistent with that of Salmonella typhimurium.Conclusions Salmonella 1,4,[5],12i-strains has become the major serotype of Salmonella that cause diarrhea in human in Guangdong.The multi-drug resistance of Salmonella 1,4,[5],12i-was serious,and since the defection offljA,fljB and hin genes,the expression of FljBenx protein failed.The PFGE results were diverse,which displayed polymorphism in inheritance.