武汉社区腹泻病人粪便中致病菌的构成与耐药性研究

目的了解夏秋季武汉社区引起腹泻病原菌的流行性及耐药状况。方法收集2004年7月1日至10月31日武汉社区4所大型医院4536份门诊腹泻病人粪便标本进行鉴定及药敏试验;REP-PCR对主要致病菌进行基因分型。结果4536份粪便标本中,分离出非伤寒沙门菌64株（1.4%）,志贺菌29株（0.6%）,致病性大肠杆菌33株（0.7%）。其中主要致病菌是鼠伤寒沙门菌33株（52%）,D群志贺菌16株（55%）。挑选13种抗菌药物进行体外敏感试验,并将分离的致病菌对这13种抗生素的耐药率﹑敏感率﹑中介率进行比较,其中非伤寒沙门菌对喹诺酮类的耐药率较其他两种要高,但对第三代头孢的敏感性较强。分离的3种致病菌在第三代头孢抗生素的作用中对头孢他啶的敏感性最强。32株鼠伤寒沙门菌基因分型为9种,16株D群志贺菌基因分型为7种。结论武汉社区内感染性腹泻的致病菌主要以非伤寒沙门菌﹑致病性大肠杆菌和志贺菌为主,其中非伤寒沙门菌占了51%,基因分型提示有社区流行趋势,而且这些致病菌对肠道杆菌常用抗生素的耐药性较为严重。本次调查结果对该社区临床用药起到一定的提示作用。

Epidemiological Study of Bacterial Diarrhea in Wuhan

Objective To investigate the occurrence of bacterial diarrhea and the extent of drug resistance of bacterial isolates in Wuhan. Method A total of 4536 stool samples were collected from outpatients of 4 major hospitals in Wuhan between 1st July 2004 and 31st Oct.2004. Kirby-Bauer method was used to test for antibiotic susceptibility. Bacterial genotypes were determined by REP-PCR. Result 126 pathogenic strains were isolated from 4536 stool samples. The percentage of enteropathogenic E.coli, non-typhoidal salmonella, and shigella isolated from these stool samples was 0.3%, 1.4% and 0.6%, respectively. Salmonella typhimurium （52%） and group D shigella （55%） were the major isolates. The degree of drug resistance （R%）, median （I%） and sensitivity （S%） of these isolates to 13 antibacterial drugs were calculated according to the criteria in the guidelines of NCCLS （2004）. Nontyphoidal salmonella was more resistant to quinolone than the third generation cephalosporin. All the isolated pathogenic strains were susceptible to ceftazidime. Using REP-PCR, 32 Salmonella typhimurium and 16 shigella sonnei （Group D） isolates were divided into 9 and 7 genotypes, respectively. Conclusion Non-typhoidal salmonella, enteropathogenie E.coli and shigella are the major cause of bacterial diarrhea in Wuhan community. Non-typhoidal salmonella accounted for 51% of infection. Resistance to antibiotics is common in these isolated enteric pathogens. Molecular genotyping reveals the spread of the pathogens in the community. Result from this study is useful in the future application of antibiotics for the treatment of bacterial infection.