الفهرس | Only 14 pages are availabe for public view |
Abstract Klebsiella pneumoniae (K. pneumoniae) is an important multidrugresistant (MDR) Gram negative pathogen that affects human and causes serious opportunistic infections. The significant spread of carbapenem resistance among K. pneumoniae isolates represents a serious threat to both hospitals and community. In this study, out of 1005 different clinical samples, obtained from four hospitals in Kafrelsheikh city; Egypt, 230 K. pneumoniae isolates (22.8%) were recovered during the period from July 2015 to April 2016. All recovered K. pneumoniae isolates were identified using conventional standard biochemical tests and confirmed by automated Vitek2® compact system. Antimicrobial susceptibility test was performed by Kirby-Bauer disk diffusion method and confirmed also by automated Vitek2® compact system. The results showed high incidence (21.7%) of carbapenem resistance where among the tested K. pneumoniae, 50 isolates were found to be imipenem and meropenem non-susceptible. For other tested antimicrobials, K. pneumoniae isolates recorded also high incidence of resistance that ranged from 98.3% for ampicillin to 60% for tobramycin. The detected carbapenem resistant K. pneumoniae isolates were selected for further study. It was observed that those isolates were resistant to all tested β-lactams and tobramycin. On the other hand, tigecycline and colistin represented the most active agents. As a result, the tested carbapenem resistant K. pneumoniae isolates showed different resistance profiles where 44 isolates were MDR, 6 isolates were XDR but none of the tested isolates was PDR. Carbapenemases production among all carbapenem resistant K. pneumoniae isolates was examined phenotypically using Modified Hodge Abstract III test (MHT) and combined disk synergy test (CDST). The results showed that 90% of isolates were carbapenemases producers while 66% were found to be metallo beta lactamases (MBLs) producers. Carbapenem resistant K. pneumoniae isolates were further subjected to molecular analysis using polymerase chain reaction (PCR) technique for screening and detection of carbapenem resistance-associated genes (including blaKPC, blaGES, blaNDM-1, blaVIM, blaIMP and blaOXA-48 genes). The results revealed that blaNDM-1 and blaOXA-48 were the only detected genes (with incidence of 70% and 52% respectively) among tested carbapenem resistant K. pneumoniae isolates. Up to 37 isolates harbored at least one of these genes; among them 24 isolates co-harbored both detected genes while other 11 isolates harbored only blaNDM-1 and the remaining 2 isolates harbored only blaOXA-48. For further molecular analysis, DNA sequencing of the detected blaNDM-1 and blaOXA-48 genes was carried out for nine isolates representing different resistance patterns. The sequences of amplified blaNDM-1 and blaOXA48 genes were submitted to the Gene Bank databases and assigned the following accession numbers MG594615 and MG594616, respectively. In conclusion, our study reported high incidence of MDR and XDR profiles with emergence of blaNDM-1 and blaOXA-48 co-existence among carbapenem resistant K. pneumoniae isolates from Kafrelsheikh city, Egypt. Hence, our findings highly recommended the necessity for applying strict infection control strategies against the dissemination of such serious carbapenem resistant K. pneumoniae pathogens otherwise it would be seriously difficult to control and limit the infections caused by such pathogens. |