2013-2015年郑州67株甲型副伤寒沙门菌分子分型与耐药研究

Characteristics of molecular typing and drug resistance of 67 Salmonella paratyphi A isolated in Zhengzhou from 2013 to 2015

目的 分析2013—2015年郑州甲型副伤寒沙门菌临床分离株的耐药状况与脉冲场凝胶电泳（PFGE）分子型别特征。方法 于2013—2015年，从郑州发热伴出疹症候群监测系统2个哨点医院内，分离经病例血培养和粪便培养的67株甲型副伤寒沙门菌，其中2013年11株，2014年7株，2015年49株。根据国际PulseNet网络实验室公布的沙门菌PFGE分型操作规程与美国临床实验室标准化协会沙门菌K-B法药敏试验方案，对67株甲型副伤寒沙门菌进行药敏试验与PFGE脉冲场凝胶电泳分子分型分析。结果 67株甲型副伤寒沙门菌对13种抗生素均有不同程度的耐药，有65株为多重耐药株（97.0%），其中耐2~3种的为5株（7.5%），耐5~8种的为41株（61.2%），耐9~10种的为11株（16.4%），耐11~12种的为8株（11.9%）。经XbaⅠ酶切与脉冲场凝胶电泳后，67株甲型副伤寒沙门菌共获得10种带型（PTYA1~10），每种带型包含1~48株菌株，相似度为94.31%~100%。其中PTYA3包含48株菌，为其优势带型；PTYA1、9包含6株菌；PTYA2、4、5、6、7、8、10各包含1株菌。结论 郑州市临床分离的甲型副伤寒沙门菌耐药状况普遍比较严重，PFGE带型呈现多样性的同时又具有较显著的优势带型特点，部分带型与其对应的耐药谱具有一定的关联性与聚集性。

Objective To investigate the antimicrobial resistance and pulsed field gel electrophoresis （PFGE） patterns of S.paratyphi A strains in Zhengzhou city isolated from sentinel hospitals in 2013-2015.Methods According to Salmonella molecular typing and K-B drug susceptibility testing method published by international PulseNet bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute （CLSI2015）, we analyzed drug sensitivity and PFGE molecular characteristics of 67 S.paratyphi A strains（11 strains in 2013, 7 strains in 2014, 49 strains in 2015） isolated from blood and stool samples in two sentinel hospitals of fever with rash syndrome surveillance system established in Zhengzhou city in 2013-2015.Results The results showed 67 strains of S.paratyphi A had different levels of resistance to 13 kinds of antibiotics, 65 strains were multi-drug resistant strains （97.0%）, 5 isolates were resistant to 2-3 kinds of antibiotics （7.5%）, 41 isolates were resistant to 5-8 kinds of antibiotics （61.2%）,11 isolates were resistant to 9-10 kinds of antibiotics（16.4%）,8 isolates were resistant to 11-12 kinds of antibiotics（11.9%）. 67 strains of S.paratyphi A were divided into 10 molecular patterns（PTYA1-PTYA10） by digestion with XbaⅠ restriction endonuclease and pulsed field gel electrophoresis, each pattern contains 1-48 strains with similarity ranged from 94.31%-100%. PTYA3 contained 48 strains, which was predominant band type; PTYA1, 9 contained 6 strains; PTYA 2, 4, 5, 6, 7, 8, 10 contained 1 strains among them.Conclusion The status of drug resistance of clinical isolates of S.paratyphi A in Zhengzhou city was rather serious, PFGE patterns showed diversity and dominant characteristics. The PFGE patterns of partial strains and its corresponding anti-drug spectrum have certain relevance and cluster relationship.