Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología, Laboratorio de Resistencia Bacteriana, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología, Laboratorio de Resistencia Bacteriana, Ciudad Autónoma de Buenos Aires, Argentina.
Rev Argent Microbiol. 2020 Jan-Mar;52(1):13-18. doi: 10.1016/j.ram.2019.03.004. Epub 2019 Jun 26.
Different phenotype-based techniques and molecular tools were used to describe the distribution of different Achromobacter species in patients with cystic fibrosis (CF) in Argentina, and to evaluate their antibiotic resistance profile. Phenotypic identification was performed by conventional biochemical tests, commercial galleries and MALDI-TOF MS. Genetic approaches included the detection of A. xylosoxidans specific marker bla, the amplification and sequencing of the 16S rRNA gene, nrdA and bla complete sequence, and MLST analysis. Phenotypic approaches, even MALDI-TOF, rendered inconclusive or misleading results. On the contrary, concordant results were achieved with the nrdA sequencing or sequence type (ST) analysis, and the complete bla sequencing, allowing a reliable discrimination of different Achromobacter species. A. xylosoxidans accounted for 63% of Achromobacter infections and A. ruhlandii accounted for 17%. The remaining species corresponded to A. insuavis, A. dolens, A. marplatensis and A. pulmonis. Antimicrobial susceptibilities were determined by the agar dilution method according to CLSI guidelines. Piperacillin, piperacillin/tazobactam and carbapenems were the most active antibiotics. However, the emergence of carbapenem-resistant isolates was detected. In conclusion, prompt and accurate identification tools were necessary to determine that different Achromobacter species may colonize/infect the airways of patients with CF. Moreover, antimicrobial therapy should be administered based on the susceptibility profile of individual Achromobacter sp. isolates.
不同表型的技术和分子工具被用于描述阿根廷囊性纤维化（CF）患者中不同阿克曼菌物种的分布，并评估它们的抗生素耐药谱。表型鉴定通过常规生化试验、商业图库和 MALDI-TOF MS 进行。遗传方法包括检测 A. xylosoxidans 特异性标记物 bla、16S rRNA 基因、nrdA 和 bla 完整序列的扩增和测序，以及 MLST 分析。表型方法，甚至 MALDI-TOF，都得出了不确定或误导性的结果。相反，nrdA 测序或序列型（ST）分析和 bla 完整序列的一致性结果，允许对不同的阿克曼菌物种进行可靠的区分。A. xylosoxidans 占阿克曼菌感染的 63%，A. ruhlandii 占 17%。其余的物种分别为 A. insuavis、A. dolens、A. marplatensis 和 A. pulmonis。根据 CLSI 指南，通过琼脂稀释法测定抗菌药物敏感性。哌拉西林、哌拉西林/他唑巴坦和碳青霉烯类是最有效的抗生素。然而，已经检测到耐碳青霉烯类的分离株的出现。总之，需要快速准确的鉴定工具来确定不同的阿克曼菌物种可能会定植/感染 CF 患者的气道。此外，应根据个体阿克曼菌分离株的药敏谱来进行抗菌治疗。
