24株布鲁菌的种型鉴定和流行病学分析

Biotype identification and epidemiological analysis of twenty-four Brucella strains

目的对广东省基层地区24株布鲁菌进行种型鉴定和流行病学分析。方法对24株来自于2009年10月至2015年10月广东省基层医院血培养阳性的布鲁菌进行传统生化鉴定、VITEK2仪器鉴定、16SrRNA基因测序、血清学试验和噬菌体试验，比较不同鉴定和诊断技术对于布鲁菌感染的诊断能力。对于确诊病例，进一步结合临床症状和流行病学资料，系统分析其临床感染特征。结果24株菌均为革兰阴性球杆菌，经16SrRNA基因测序和生物学分型鉴定，确认2株菌为猪种布鲁菌3型，4株菌为羊种布鲁菌1型．18株菌为羊种布鲁菌3型。采用VITEK2仪器法发现，3株菌出现错误鉴定，其中l株菌被错误鉴定为支气管炎鲍特菌，2株菌错误鉴定为人苍白杆菌。16SrRNA基因可排除支气管炎鲍特菌，但与中间苍白杆菌和人苍白杆菌具有较高的序列相似度。流行病学资料显示，24例患者均为成人，平均年龄为49．0岁，男性和女性分别为12人，无明显性别差异，大部分患者无明显的职业暴露和接触史，患者入院时临床症状及体征各有不同，但均未怀疑布鲁菌病。结论广东省基层医院布鲁菌感染以羊种布鲁菌3型为主，临床表现为隐匿性感染，流行病学特征为散发性流行。

Objective To identify the biotype and analyze the epidemiological characteristics of twentyfour BruceUa strains from the primary hospitals in Guangdong Province. Methods The twenty-four BruceUa strains, collected from Oct. 2009 to Oct. 2015, were identified by routine biochemical methods, VITEK 2 COMPACT automatic microbial identification analyzer, 16S rRNA gene sequencing and biology phenotype based on serological and bacteriophages lysis test. The etiology was analyzed based on clinical data, biotypes of the isolates and other clinical information. Results All of the twenty-four strains were Gram-negative coccobacilli, including two strains of Brucella suis biotype Ⅱ, four strains of Brucella melitensis biotype Ⅰ and eighteen strains of Brucella melitensis biotype Ⅲ. By GN card of VITEK 2 COMPACT automatic microbial identification analyzer, one strain was mistaken as Bordetella bronchiseptica and two strains were mistaken as Ochrobaetrum anthropi. The 16S rRNA gene sequencing showed they were high homology to Ochrobactrum intermedium and Ochrobaetrum anthropi, which completely excluded the possibility of Bordetella bronchiseptica. The clinical data showed that all of the twenty-four patients were adults with an average age of 49.0 years old, men and women were twelve people respectively, with no significant gender differences and no occupational exposure, which presenting a wide and diverse range of nonspecific clinical signs and symptoms, but brucellosis was not aware of by the physician. Conclusion Brucella melitensis biotype m is the main pathogen of brucellosis, with the characteristics of sporadic outbreak and occult infection in the primary hospitals in Guangdong Province.