临床分离沙门菌的耐药性及超广谱β-内酰胺酶类耐药基因

目的研究北京地区2012—2015年沙门菌临床分离株的血清型分布、耐药状况及超广谱β-内酰胺酶(ESBLs)耐药基因特征。方法采用最小抑菌浓度法测定北京市肠道门诊分离的677株沙门菌株对16种抗菌药物的耐药情况,采用聚合酶链反应(PCR)方法对244株β-内酰胺酶类耐药菌株进行耐药基因检测。结果677株沙门菌分为68种血清型,其中肠炎沙门菌、鼠伤寒沙门菌和山夫登堡沙门菌位居前3位。沙门菌对氨苄西林和阿莫西林/克拉维酸的耐药率分别为42.54%、40.77%,至少耐3种以上抗菌药物的菌株占57.16%。244株对氨苄西林和阿莫西林/克拉维酸耐药的沙门菌,携带至少一种ESBLs基因的菌株174株(71.31%),146株bla_(TEM-1)型,30株bla_(OXA-1)型,18株bla_(CTX-M)型(其中7株bla_(CTX-M-15),6株bla_(CTX-M-55)和5株bla_(CTX-M-14));20株同时携带2种耐药基因。结论该地区沙门菌携带ESBLs耐药基因水平较高,以bla_(TEM-1)为主,同时伴有bla_(OXA-1)和3种bla_(CTX-M)基因亚型,呈现基因多样性。

Antimicrobial resistance and extended spectrum β lactamases resistance genes of clinically isolated Salmonella

ObjectiveTo study the serotype distribution, antimicrobial resistance, and characteristics of extended spectrum β lactamases (ESBLs) resistance genes of clinically isolated Salmonella in Beijing from 2012 to 2015.MethodsAntimicrobial resistance of 677 Salmonella strains isolated from gastrointestinal clinic in Beijing to 16 kinds of antimicrobial agents was detected by minimal inhibitory concentration method, resistance genes in 244 β lactamase resistance strains were detected by polymerase chain reaction (PCR). Results677 Salmonella strains were divided into 68 serotypes, the top three were Salmonella enteritis, Salmonella typhimurium, and Salmonella senftenberg, antimicrobial resistance of Salmonella to ampicillin and amoxicillin clavulanic acid were 42.54% and 40.77% respectively, 57.16% of strains were resistant to at least 3 kinds of antimicrobial agents. Of 244 strains of ampicillin and amoxicillin/clavulanic acid resistant Salmonella, 174 (71.31%) carried at least one kind of ESBLs gene, 146 were for type blaTEM 1, 30 for blaOXA 1, and 18 for blaCTX M (7 were for blaCTX M 15, 6 blaCTX M 55, 5 blaCTX M 14); 20 strains harbored two kinds of drug resistance genes at the same time. ConclusionSalmonella in this area has a high carrying rate of ESBLs resistance genes, mainly blaTEM 1, accompanied by blaOXA 1 and 3 kinds of blaCTX M subtypes, showing a genetic diversity.