Nowak Paweł, Paluchowska Paulina Maria, Budak Alicja
Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Jagiellonian University Medical College, Kraków, Poland.
Med Sci Monit Basic Res. 2014 Jan 27;20:9-14. doi: 10.12659/MSMBR.889811.
Acinetobacter baumannii is a significant hospital pathogen, possessing a considerable degree of antimicrobial resistance. A. baumannii resistance to carbapenems and aminoglycosides is mostly conferred by class D OXA carbapenemases and aminoglycoside-modifying enzymes, respectively. The aim of this study was to determine the prevalence of selected genes encoding OXA carbapenemases and aminoglycoside-modifying enzymes in multidrug-resistant strains of A. baumannii.
The study included 61 carbapenem-resistant and aminoglycoside-nonsusceptible A. baumannii isolates, collected between 2009 and 2011 in Cracow, Poland. Selected resistance genes, including: blaOXA-51-like, blaOXA-23-like, blaOXA-40-like, blaOXA-58-like, aac(6')-Ih, aac(3)-Ia, aac(3)-IIa, aac(6')-Ib, aph(3')-Ia and aph(3')-VI, were detected by PCR method.
The blaOXA-51-like genes were detected in all isolates, while acquired carbapenemase encoding genes were found in 96.7% of tested strains. Presence of blaOXA-40-like and blaOXA-23-like genes was observed among 65.6% and 27.9% of isolates, respectively. Assayed aminoglycoside resistance genes were found to harbor 98.4% of isolates. Among tested strains, we observed the following percentages of resistance determinants: aac(3)-Ia - 78.7%, aph(3')-VI - 78.7% and aph(3')-Ia - 27.9%. Analysis of co-occurrence of carbapenem and aminoglycoside resistance genes revealed the highest percentage of strains possessing blaOXA-40-like, aac(3)-Ia, and aph(3')-VI genes (44.3%).
The blaOXA-40-like and aac(3)-Ia/aph(3')-VI were the most prevalent genes encoding acquired OXA carbapenemases and aminoglycoside-modifying enzymes, respectively, among A. baumannii strains in Cracow, Poland. Genes conferring resistance to carbapenems and aminoglycosides coexisted in the clinical strains of A. baumannii. The phenomenon of A. baumannii resistance indicates the necessity of monitoring for the presence of the resistance genes.
鲍曼不动杆菌是一种重要的医院病原体，具有相当程度的抗菌耐药性。鲍曼不动杆菌对碳青霉烯类和氨基糖苷类的耐药性分别主要由D类OXA碳青霉烯酶和氨基糖苷类修饰酶介导。本研究的目的是确定鲍曼不动杆菌多重耐药菌株中编码OXA碳青霉烯酶和氨基糖苷类修饰酶的特定基因的流行情况。
本研究纳入了2009年至2011年在波兰克拉科夫收集的61株对碳青霉烯类耐药且对氨基糖苷类不敏感的鲍曼不动杆菌分离株。通过PCR方法检测选定的耐药基因，包括：blaOXA - 51 - 样、blaOXA - 23 - 样、blaOXA - 40 - 样、blaOXA - 58 - 样、aac(6') - Ih、aac(3) - Ia、aac(3) - IIa、aac(6') - Ib、aph(3') - Ia和aph(3') - VI。
在所有分离株中均检测到blaOXA - 51 - 样基因，而在96.7%的受试菌株中发现了获得性碳青霉烯酶编码基因。分别在65.6%和27.9%的分离株中观察到blaOXA - 40 - 样和blaOXA - 23 - 样基因的存在。检测到98.4%的分离株含有测定的氨基糖苷类耐药基因。在受试菌株中，我们观察到以下耐药决定簇的百分比：aac(3) - Ia - 78.7%、aph(3') - VI - 78.7%和aph(3') - Ia - 27.9%。碳青霉烯类和氨基糖苷类耐药基因共现分析显示，同时拥有blaOXA - 40 - 样、aac(3) - Ia和aph(3') - VI基因的菌株比例最高(44.3%)。
在波兰克拉科夫的鲍曼不动杆菌菌株中，blaOXA - 40 - 样和aac(3) - Ia/aph(3') - VI分别是编码获得性OXA碳青霉烯酶和氨基糖苷类修饰酶的最常见基因。赋予对碳青霉烯类和氨基糖苷类耐药性的基因在鲍曼不动杆菌临床菌株中共存。鲍曼不动杆菌耐药现象表明监测耐药基因存在的必要性。
