El-Domany Ramadan Ahmed, Emara Mohamed, El-Magd Mohammed A, Moustafa Walaa H, Abdeltwab Nesma M
1 Department of Microbiology and Immunology, Faculty of Pharmacy, Kafrelsheikh University , Kafrelsheikh, Egypt .
2 Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University , Cairo, Egypt .
Microb Drug Resist. 2017 Sep;23(6):682-686. doi: 10.1089/mdr.2016.0234. Epub 2017 Jan 13.
Pseudomonas aeruginosa is an important human pathogen and the leading cause of nosocomial infections. P. aeruginosa is characterized by massive intrinsic resistance to a multiple classes of antibiotics with carbapenems being the most potent inhibitor of P. aeruginosa and considered the first choice for its treatment. Therefore, it is crucial to investigate novel mechanisms of resistance of P. aeruginosa to carbapenems for achieving successful therapy. A total of 114 P. aeruginosa isolates from two university hospitals in Egypt were recruited in this study. Antimicrobial susceptibility testing revealed that 50 isolates (43.8%) exhibited multidrug-resistant (MDR) phenotype, of them 14 isolates (12.2%) were imipenem (IPM)-resistant. Of these 14 isolates, 13 isolates (11.4%) exhibited the metallo-β-lactamase (MBL) phenotype. MBLs encoding genes, VIM and IMP, were identified by PCR. PCR results revealed that four isolates harbored the VIM gene alone, one isolate harbored IMP gene alone, and four isolates harbored both genes. The correct size of PCR products of VIM and IMP genes (390 and 188 bp, respectively) were sequenced to confirm results of PCR and to look for any possible polymorphism among MBL genes of tested isolates. Data analysis of these sequences showed 100% identity of nucleotide sequences of MBL genes among tested Egyptian patients. To our knowledge, this is the first report of IMP carbapenemase-encoding gene in Africa and the first detection of the emergence of P. aeruginosa coproducing VIM and IMP genes in Egypt.
铜绿假单胞菌是一种重要的人类病原体，也是医院感染的主要原因。铜绿假单胞菌的特点是对多种抗生素具有大量内在抗性，碳青霉烯类是铜绿假单胞菌最有效的抑制剂，被认为是其治疗的首选药物。因此，研究铜绿假单胞菌对碳青霉烯类的新耐药机制对于实现成功治疗至关重要。本研究共收集了埃及两家大学医院的114株铜绿假单胞菌分离株。药敏试验显示，50株（43.8%）表现出多重耐药（MDR）表型，其中14株（12.2%）对亚胺培南（IPM）耐药。在这14株分离株中，13株（11.4%）表现出金属β-内酰胺酶（MBL）表型。通过PCR鉴定了编码MBL的基因VIM和IMP。PCR结果显示，4株分离株仅携带VIM基因，1株分离株仅携带IMP基因，4株分离株同时携带这两个基因。对VIM和IMP基因PCR产物的正确大小（分别为390和188bp）进行测序，以确认PCR结果，并寻找受试分离株MBL基因之间的任何可能多态性。这些序列的数据分析显示，受试埃及患者中MBL基因的核苷酸序列100%相同。据我们所知，这是非洲首次报道IMP碳青霉烯酶编码基因，也是埃及首次检测到同时产生VIM和IMP基因的铜绿假单胞菌的出现。
