Open AccessPrevalence, resistance, and extended-spectrum beta-lactamases among Salmonella from patients in northeast China
Author(s) -
Zhijie Zhang,
Xingning Wang,
Ruihua Li,
Wei Xue,
Rubo Zhai,
Liwen Liu,
Yong Liu,
Hong Jin
Publication year - 2017
Publication title -
journal of infection in developing countries
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.322
H-Index - 49
eISSN - 2036-6590
pISSN - 1972-2680
DOI - 10.3855/jidc.9218
Subject(s) - cephalosporin , microbiology and biotechnology , pulsed field gel electrophoresis , salmonella , ciprofloxacin , cefepime , biology , serotype , ampicillin , salmonella enteritidis , ceftazidime , antibiotic resistance , ceftriaxone , virology , antibiotics , imipenem , genotype , bacteria , gene , pseudomonas aeruginosa , genetics
Salmonella is an important infection in Liaoning Province. Serotype and resistance levels are poorly studied. Knowledge of cephalosporin-resistant genes is needed to provide information to support the clinical diagnosis and to guide therapy.
Methodology: A total of 172 isolates were collected from January 2009 to March 2014. Resistance to cephalosporin, fluoroquinolones, and other conventional first-line antibiotics was detected using the disk diffusion and agar dilution methods. The relatedness of isolates with the same serotype was analyzed by pulsed-field gel electrophoresis (PFGE). Genes encoding extended-spectrum β-lactamase enzymes (blaCTX-M, blaTEM, blaSHV, and blaOXA) were identified by polymerase chain reaction (PCR) and sequencing in cephalosporin-resistant strains.
Results: S. Enteritidis, 1,4,[5],12:i:-, and S .Typhimurium were the most common serotypes. The resistance rate of Salmonella to conventional first-line antibiotics sulfamethoxazole-trimethoprim, tetracycline, chloramphenicol, and ampicillin was 21%,33%,37%, and 55%,respectively. To fluoroquinolones (gatixacin, levofloxacin, and ciprofloxacin), the resistance rates were 7%,18%, and 23%, respectively, whereas for extended-spectrum cephalosporins(ceftazidime, cefepime, and ceftriaxone), there sistance rates were 4%,8%, and 9%. In total, 14blaCTX-M, 14 blaTEM-1, and 1blaOXA-1 were found in 15 Salmonella isolates resistant to cephalosporin. No blaSHVwas detected. The blaCTX-M-55 gene was the most frequently encountered gene. The blaCTX-M-65 gene from S. Enteritidis is described for first time in Salmonella from humans. Results of PFGE indicated strong similarity among Salmonella isolates in Liaoning Province.
Conclusions: Extended-spectrum cephalosporins are the first choice for the treatment of infection with Salmonella, but blaCTX-M-encoded resistance, including blaCTX-M-65, is present.