北京市西城区引起感染性腹泻主要肠道病原对头孢菌素耐药状况分析

目的结合流行病学资料了解和分析北京市西城区主要肠道病原对头孢类抗生素的耐药状况。方法收集2008-2011年本地区引起感染性腹泻主要肠道病原187株,聚合酶链反应(polymerase chain reaction,PCR)检测超广谱β-内酰胺酶类(extended spectrumβ-lactamaseas,ESBLs)耐药基因,明确基因型,阳性产物在GenBank上进行比对确定亚型;按照Kirby-Bauer法进行药物敏感性试验,测定对8种头孢类抗生素耐药情况。结果 187株肠道病原中,34株检出携带ESBLs耐药基因,其中志贺菌中检出33株,沙门菌中检出1株。18株病原携带OXA-1亚型耐药基因,11株病原携带CTX-M-14亚型,另有5株病原携带有2种ESBLs耐药基因;药敏结果显示,肠道病原对头孢噻吩耐药率最高,为40%。对1种以上头孢类抗生素耐药的肠道病原中,志贺菌耐药率为81%,副溶血性弧菌耐药率为46%,沙门菌耐药率为33%;结合流行病学资料发现,20~29岁年龄组耐药菌株检出率最高,为27%,其次为≥40岁组和10岁组,检出率分别为23%和21%。结论本地区主要肠道病原中志贺菌耐头孢类抗生素水平最高,检出携带ESBLs耐药基因菌株最多;ESBLs耐药基因以OXA-1亚型和CTX-M-14亚型为主;耐药菌株以20~29岁年龄组检出率最高。

Drug resistance to Cephalosporins of major intestinal pathogens causing infectious diarrhea in Beijing

Objective To understand the drug resistance to Cephalosporins of major intestinal pathogens causing infectious diarrhea in Xicheng district of Beijing. Methods A total of 187 strains of intestinal pathogens causing infectious diarrhea were collected in Xicheng district from 2008 to 2011. Extended spectrum β-lactamaseas（ ESBLs）was detected by using polymerase chain reaction（PCR）,then the sequencing for PCR positive products was performed,the sequencing results were aligned with those in GenBank to determine pathogens’ genetypes. The drug susceptibility of the pathogens to 8 kinds of Cephalosporins were performed by Kirby-Bauer method. Results Among the 187 strains,34 strains carrying ESBLs resistant gene were detected,33 were Shigella strains and 1 was Salmonella strain. Among 34strains carrying ESBLs resistant gene,18 were strains carrying OXA-1 subtype resistant gene,11 were strains carrying CTX-M-14 subtype and 5 were strains carrying 2 kinds of ESBLs resistant gene; The drug susceptibility test results showed that 40% of intestinal pathogens were resistant to Cephalothin,which was highest in 8 kinds of Cephalosporins.Among intestinal pathogens which resistant to more then one kind of Cephalosporins,the resistant rate of Shigella was81%,the resistant rate of Vibrio parahaemolyticus was 46% and the resistant rate of Salmonella was 33%. The analysis on epidemiological data indicated that the highest resistant rate was detected in age group 20- 29 years（27%）,followed by the age groups ＆gt; 40 years（23%） and age group ＆lt; 10 years（21%）. Conclusion Shigella had high resistant rate to Cephalosporins and had high carrying rate of ESBLs resistant gene. OXA-1 and CTX-M-14 subtype were the major ESBLs resistant gene types. The detection rate of resistant strain was highest in age group 20- 29 years.