日化产品中洋葱伯克霍尔德氏菌复合群(Bcc)的分类和神秘伯克霍尔德氏菌的耐药性研究

【目的】对从2020–2022年不同日化产品中分离的29株洋葱伯克霍尔德氏菌复合群(Burkholderia cepacia complex,Bcc)进行分类和分型，另将2020年前来源于日化产品中6株被鉴定为Burkholderia lata的菌株进行分类更正。探究神秘伯克霍尔德氏菌(Burkholderia aenigmatica)的耐药性。【方法】本文主要应用多位点分型研究方法(multilocus sequence typing,MLST),PCR扩增atpD、gltB、gyrB、recA、lepA、phaC和trp B 7个管家基因片段，将测序结果与MLST数据库中的数据比对分析，获得菌株各管家基因的编号和ST型(sequence type)，对本检测中心分离自日化产品的Bcc进行分型；利用多位点序列分析(multilocus sequence analysis,MLSA)，结合MLST中等位基因的核苷酸序列构建进化树，从而对Bcc进行系统发育分析和鉴定。利用最小抑菌浓度法(minimum inhibitory concentration,MIC)测定Bcc对常见防腐剂(1,...

Typing and identification of Burkholderia cepacia complex and drug resistance of Burkholderia aenigmatica from daily chemical products

Objective] To type and identify 29 strains of Burkholderia cepacia complex (Bcc) isolated from daily chemical products in 2020–2022, re-identify 6 isolates identified as Burkholderia lata from daily chemicals products before 2020, and reveal the antibiotic resistance of Burkholderia aenigmatica sp. nov. Methods] Bcc isolates from daily chemical products were subjected to multilocus sequence typing (MLST). Seven housekeeping genes, atpD, gltB, gyrB, recA, lepA, phaC, and trpB, were amplified by PCR. The sequencing results were compared with the data in MLST database to obtain the accession number of each housekeeping gene and the sequence type of each strain. Multilocus sequence analysis (MLSA) was employed to construct a phylogenetic tree based on the nucleotide sequences of alleles in MLST. The resistance of Bcc to common preservatives (1,3-dimethylmethylol-5,5-dimethylhydantoin, kathon, sodium benzoate, and potassium sorbate) and antibiotics (ceftazidime, kanamycin, and tetracycline) were determined by the minimum inhibitory concentration (MIC) method. Results] The 29 Bcc isolates were identified as 5 species (B. cenocepacia, B. contaminans, B. aenigmatica, B. vietnamiensis, and B. stabilis) and typed as 15 sequence types. Seven new alleles and seven new sequence types (ST2118, ST2120, ST2122, ST2127, ST2128, ST2129, and ST2130) were identified in this study. The six B. lata strains from the samples before 2020 were re-identified as B. aenigmatica sp. nov. Only one of the 11 B. aenigmatica isolates was resistant to ceftazidime, and nine and eight B. aenigmatica isolates were resistant to kanamycin and tetracycline, respectively. Kathon and 1,3-dimethylmethylol-5,5-dimethylhydantoin (DMDMH) within the maximum permissible concentrations can effectively inhibit the growth of B. aenigmatica. Nine B. aenigmatica strains showed resistance to sodium benzoate and potassium sorbate. Conclusion] The identification of Bcc is complex and there are unknown alleles and sequence types. B. aenigmatica has become the main Bcc species contaminating daily chemical products. Most strains of B. aenigmatica are resistant to aminoglycosides and tetracyclines. Most B. aenigmatica isolates from the daily chemical products have resistance to sodium benzoate and potassium sorbate.