Analysis of penicillin-binding proteins (PBPs) in carbapenem resistant Acinetobacter baumannii
Analysis of penicillin-binding proteins (PBPs) in carbapenem resistant Acinetobacter baumannii
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发表时间：
2011-03
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通讯作者：
J. Vashist;Vishvanath Tiwari;R. Das;A. Kapil;M. Rajeswari
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作者：
J. Vashist;Vishvanath Tiwari;R. Das;A. Kapil;M. Rajeswari
背景和目标：鲍曼不动杆菌是一种革兰氏阴性球菌需氧病原体，导致医院内感染。最近，鲍曼不动杆菌0已经对β-内酰胺，甚至碳青霉烯类产生了耐药性。青霉素结合蛋白 (PBP) 对于细胞增殖过程中的细胞壁生物合成至关重要，它们是 β-内酰胺的靶标。因此，本研究旨在鉴定鲍曼不动杆菌碳青霉烯类耐药菌株三组（低、中、高 MIC）中的 PBP。方法：获得ATCC 19606和20株β-内酰胺抗性鲍曼不动杆菌分离株。使用青霉素的非放射性荧光衍生物 Bocillin FL 对 PBP 进行选择性鉴定。结果：天然菌株 SDS-PAGE 凝胶中 Bocillin 标签的荧光发射鉴定出 8 个 PBP，表观分子量分别为 94、65、49、40、30、24、22 和 17 kDa，然而，这些 PBP 揭示了碳青霉烯类抗性分离株的变化。解释和结论：对耐药菌株中的 PBP 与 ATCC 中的 PBP 进行比较分析，发现除 65 和 17 kDa PBP 略有下调外，所有 PBP 的表达均下降，并且同时出现新的 28 kDa PBP（在低和中耐药菌株中）和鲍曼不动杆菌高美罗培南耐药组中的 36 kDa PBP。本研究表明鲍曼不动杆菌中 PBP 的改变与 β-内酰胺耐药性之间存在关联。
Background & objectives : Acinetobacter baumannii is a Gram-negative, cocco-bacillus aerobic pathogen responsible for nosocomial infections in hospitals. In the recent past A. baumannii 0had developed resistance against β-lactams, even against carbapenems. Penicillin-binding proteins (PBPs) are crucial for the cell wall biosynthesis during cell proliferation and these are the target for β-lactams. Therefore, the present study was carried out to identify the PBPs in three (low, intermediate and high MICs) groups of carbapenem resistant isolates strains of A. baumannii. Methods: ATCC 19606 and 20 β-lactam resistant isolates of A. baumannii were obtained. Selective identification of the PBPs was done using Bocillin FL, a non-radioactive fluorescent derivative of penicillin. Results: The fluorescence emission from Bocillin-tag in SDS-PAGE gel of native strain identified eight PBPs, with apparent molecular weight of 94, 65, 49, 40, 30, 24, 22 and 17 kDa, however, these PBPs revealed alteration in carbapenem-resistant isolates. Interpretation & conclusions: A comparative analysis of PBPs in the resistant isolates with those of ATCC revealed a decreased expression of all PBPs except that of 65 and 17 kDa PBPs which were marginally downregulated, and simultaneous appearance of new 28 kDa PBP (in low and intermediate resistant isolates) and 36 kDa in high meropenem resistant group of A. baumannii. The present study indicated an association between alteration in PBPs and β-lactam resistance in A. baumannii.