摘要
目的了解杭州市及浙江省部分地区O139群霍乱弧菌分离株的核糖体基因分型特征及其与抗生素抗性关系.方法对1994～2004年杭州市分离的105株及2000年浙江省部分地区分离的5株O139群菌株,PCR法检测ctxA和tcpA基因,纸片扩散法测定抗生素抗性,应用核糖体基因分型技术进行分子分型;并与1997～2001年分离的20株O1群霍乱弧菌流行株代表菌株的分子分型结果进行比较.结果杭州市105株O139群菌株中,95株ctxA阳性菌株分为8个型(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅶ和Ⅷ型),其中Ⅱ型菌株为2000年后的优势克隆群(占73.7%,70/95),并于2004年引起一起较大规模的爆发;10株ctxA阴性菌株被分为3个型(α、β和γ型).2000年浙江绍兴市4株ctx4阳性O139群分离株属Ⅱ型,浙江湖州市1株ctxA阴性分离株属γ型.20株O1群流行代表菌株被分为5个型(A、B、C、D和E型),其中A型和B型分别与O139群中的Ⅵ型和Ⅶ型的带谱相同.ctxA阳性和ctxA阴性O139群菌株间的耐药谱显著不同.67株Ⅱ型O139群菌株中共有28种耐药谱,最少的仅对2种抗生素同时耐药,最多对¨种抗生素同时耐药;分别有对11种和10种抗生素耐药的菌株在2002～2004年间成为优势菌(81.5%,22/27).结论1994～2004年间多种核糖体基因型O139群霍乱弧菌在杭州同时或替换流行,多重耐药的核糖体基因型Ⅱ型O139群菌株于2002～2004年间成了杭州优势流行菌株.
Objective To understand the ribotyping characteristics of vibrio cholerae O139 serogroup isolates in Hangzhou and other cities in Zhejiang, China, and their relationships to antibiotic resistances. Methods Among 105 isolates of O139 in Hangzhou from 1994 to 2004 and 5 isolates in another two cities in Zhejiang during 2000, two virulence genes, ctxA and tcpA, the antibiotic resistance patterns, and molecular characteristics were determined by PCR, Kirby-Bauer methods, and ribotyping rcspectively. Moreover, tbe ribotypes of 20 representative epidemic isolates of O1 serogroup in Hangzhou from 1997 to 2001 were characterized. Results Among 105 isolates of O139 in Hangzhou, 95 toxigenic O139 isolates were classified into 8 ribotypes （from Ⅰ to Ⅷ）, in which isolates of ribotype Ⅱ had become dominant since 2000 with proportion of 73.7% （70/95） and were responsible for an outbreak during 2004, and 10 non-toxigenic isolates were classified into other 3 distinct ribotypes （α, β, and У）. 4 toxigenic isolates and one non-toxigenic isolate from two other cities in Zhejiang during 2000 were cataloged to ribotype Ⅱ and У, respectively. 20 representative epidemic isolates of O1 serogroup belonged to 5 ribotypes （from A to E）, in which the ribotype A and B shared the identical fingerprints with fibotype Ⅵ and Ⅶ found in O139 serogroup, respectively. The antibiotic resistance patterns between toxigenic and nontoxigenic O139 isolates differed obviously. Total 28 antibiotic resistance patterns were found in 67 isolates of ribotype Ⅱ, and the antibiotics which these O139 isolates resisted multiplely to varied from 2 to 11. The ribotype Ⅱ isolates with patterns of multiple resistances to 10 or 11 antibiotics had become dominant during 2002 to 2004 with proportion of 81.5% （22/27）. Conclusions Genetic diversity was found among O139 isolatcs in Hangzhou during 1994 to 2004. The ribotype Ⅱ O139 isolates with multlple antibiotic resistance had become dominant in Hangzhou during 2002 to 2004.
