ABSTRACT
Objective To analyze serotype distribution, drug resistance, quinolone resistance gene carrying status and genetic relationship of foodborne Salmonella and human Salmonella isolates in Changzhou from 2012 to 2018, to provide scientific basis for the prevention and control of Salmonella. Methods The serum type was identified by serum agglutination and liquid chip. The antibiotic sensitivity was determined by micro broth dilution method. The quinolone antibiotic resistance gene was determined by gene sequencing method. The multilocus sequence typing ( MLST ) typing was performed on quinolone-resistant Salmonella, and the genetic relationship was analyzed by BioNumerics 8.0. Results A total of 10 and 36 serotypes were detected in 46 foodborne Salmonella strains and 152 human Salmonella strains, respectively. The dominant serotypes were Indiana Salmonella and Salmonella typhimurium. Erythromycin resistance rate was the highest in both Salmonella strains, and the proportion of multidrug-resistant bacteria was 93.47 % ( 43 / 46 ) and 80.92 % ( 123 / 152 ), respectively. 38 strains of quinolone-resistant foodborne Salmonella GyrA subunit mainly occurred double mutations Asp87Asn, Ser83Phe, ParC subunit mainly occurred single mutation Ser80Arg, 119 strains of quinolone-resistant human Salmonella qnrS gene detection rate was higher, reached 68.1 % ( 81 / 119 ) ; The dominant ST types of quinolone-resistant Salmonella from two sources were ST17 and ST19, respectively. Conclusions The antibiotic sensitivity of the two Salmonella resistant strains from Changzhou was the same ; Synergistic drug resistance, but both quinolone resistance genemutations and carry inconsistent ; The ST type distribution of quinolone resistant strains isalso inconsistent, and the genetic relationship is far. It is suggested that the probability of Salmonella resistant bacteria infection caused by food transmission in our region is small, and the treatment of the two should be differentiated.
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Objective To study the prevalence of plasmid-mediated quinolone resistance (PMQR) genes in carbapenem-resistant Enterobacteriaceae (CRE) and its resistance mechanism.Methods Clinically isolated CRE strains in a hospital from March 2015 to March 2018 were collected, then identified and performed antimicrobial susceptibility test by VITEK2 Compact analyzer, carriage of PMQR genes qnrA, qnrB, qnrS, qepA and acc (6') Ib-cr were determined by polymerase chain reaction (PCR) and sequencing, the horizontal transfer of PMQR genes were verified by plasmid conjugation test.Results Resistance rates of carbapenem-resistant Escherichia coli and carbapenem-resistant Klebsiella pneumoniae to quinolones were 100％ and 15.56％-33.33％ respectively.Detection rate of acc (6') Ib-cr gene was the highest (87.72％), followed by qnrB (77.19％) and qnrS (17.54％), 2 strains (3.51％) carried qnrA gene, qepA gene was not isolated, 84.21％ of strains harbored 2 or 3 PMQR genes.PMQR gene was transfected into all the 8 conjugated strains, but minimum inhibitory concentration value of quinolones didn't change significantly.Conclusion The detection rate of PMQR genes in CRE in this hospital is high, but there is a certain sensitivity to quinolones.
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OBJECTIVE To investigate the appearance of quinolone resistance gene(qnr)in Enterobacter cloacae for clinical treatment.METHODS E.cloacae was identified by VITEK-AMS;detection of qnr and extended-spectrum ?-lactamases(ESBLs)resistant genes were performed by PCR.Plasmid conjugation test was used to determine the transmission of qnr.The antibotic susceptibility of E.cloacae was detected according to the CLSI guideline.RESULTS The incident rate of E.cloacae with qnr was 23.6% in 55 strains.The sensitive rate to ciprofloxacin was 46.2% in isolates with qnr,but it was 83.3% in isolates without qnr.qnr Genes of 38.2% ESBLs isolates were positive.Two strains harboring qnr genes were conjugated successfully.CONCLUSIONS ESBLs strains usually harbor qnr genes.qnr Genes can be horizontally transferred to recipient by plasmid conjugated test.