30株苍白杆菌的分离鉴定和药物敏感性分析

Identification and drug sensitivity analysis of 30 strains of Ochrobactrum isolated from clinical specimens

目的分析临床苍白杆菌分离株的种型特征和药物敏感性。方法收集临床分离苍白杆菌共30株。用手工生化试验、Vitek 2 Compact GN鉴定卡、API 20NE鉴定试条进行生化鉴定,扩增16S rRNA基因并进行测序鉴定和序列分析。用Vitek 2Compact AST-GN13药敏鉴定卡进行微量稀释法的药敏实验。结果经生化鉴定和基因测序,17株为人苍白杆菌、10株为中间苍白杆菌、1株为嗜血苍白杆菌、1株疑为苍白杆菌属内未分类的新种、1株为解糖精假苍白杆菌。药敏试验显示对喹诺酮类和亚胺培南的敏感率分别为100%和93.3%;对三代头孢类抗菌药物和哌拉西林/他唑巴坦的耐药率为93.3%和96.7%;对氨基糖苷类抗菌药物敏感性因菌种而异,人苍白杆菌对阿米卡星、庆大霉素和妥布霉素的敏感率分别为94.1%、88.2%和94.1%,而中间苍白杆菌为0%、10%和0%,差异具有统计学意义(χ2=14.50,P<0.05)。结论临床苍白杆菌感染主要由人苍白杆菌和中间苍白杆菌引起,二者对氨基糖苷类抗菌药物敏感率的差异可用于其种型的区分。

Objective To analyze the isotype characteristics and drug susceptibility of Ochrobactrum isolates from clinical specimens.Methods Thirty strains of Ochrobactrum were isolated from clinical specimens,and identified by Vitek GN card,API 20 NE strip and16 S rRNA gene sequencing. The drug sensitivity test was performed by the microdilution method with Vitek 2 compact AST-GN13 card. Results Based on the phenotypic and genotypic analysis,30 strains of Ochrobactrum consisted of 17 O. anthropi,10 O. intermedium,1 O. haematophilum,1 Pseudochrobactrum asaccharolyticum,and 1 novel unclassified Ochrobactrum. The drug sensitivity test showed that all strains of Ochrobactrum were sensitive to quinolones,93. 3% of isolates to imipenem. The drug resistance rate of the strains to cephalosporin Ⅲ antibiotics and sulfamethoxazole / trimethoprim was 93. 3% and 96. 7%. For aminoglycoside antibiotics,these isolates had different sensitivity. For example,the sensitivities of O. anthropi to amikacin,gentamicin and tobramycin were94. 1%,88. 2% and 94. 1%,respectively,while those of O. intermedium were 0%,10% and 0%,respectively,with significant difference between them（ χ^2= 14. 50,P〈0. 05）. Conclusion In the clinical infection of Ochrobactrum,O. anthropi and O. intermedium are the most common pathogenic bacteria,which can be distinguished by the sensitivity to aminoglycoside antibiotics.