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Abstract Background Knowledge on the epidemiology, genotypic and phenotypic features of antimicrobial-resistant (AMR) ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli) and their association with hospital-acquired infections (HAIs) are limited in Malaysia. Therefore, we evaluated the AMR features and resistance mechanisms of the ESKAPEE pathogens collected in a tertiary hospital located in the capital of Malaysia. Methods A total of 378 AMR-ESKAPEE strains were obtained based on convenience sampling over a nine-month study period (2019–2020). All strains were subjected to disk diffusion and broth microdilution assays to determine the antimicrobial susceptibility profiles. Polymerase chain reaction (PCR) and DNA sequence analyses were performed to determine the AMR genes profiles of the non-susceptible strains. Chi-square test and logistic regression analyses were used to correlate the AMR profiles and clinical data to determine the risk factors associated with HAIs. Results High rates of multidrug resistance (MDR) were observed in A. baumannii, K. pneumoniae, E. coli, and S. aureus (69–89%). All organisms except E. coli were frequently associated with HAIs (61–94%). Non-susceptibility to the last-resort drugs vancomycin (in Enterococcus spp. and S. aureus), carbapenems (in A. baumannii, P. aeruginosa, and Enterobacteriaceae), and colistin (in Enterobacteriaceae) were observed. Both A. baumannii and K. pneumoniae harbored a wide array of extended-spectrum β-lactamase genes (bla TEM, bla SHV, bla CTX-M, bla OXA). Metallo-β-lactamase genes (bla VEB, bla VIM, bla NDM) were detected in carbapenem-resistant strains, at a higher frequency compared to other local reports. We detected two novel mutations in the quinolone-resistant determining region of the gyrA in fluoroquinolone-resistant E. coli (Leu-102-Ala; Gly-105-Val). Microbial resistance to ampicillin, methicillin, and cephalosporins was identified as important risk factors associated with HAIs in the hospital. Conclusion Overall, our findings may provide valuable insight into the microbial resistance pattern and the risk factors of ESKAPEE-associated HAIs in a tertiary hospital located in central Peninsular Malaysia. The data obtained in this study may contribute to informing better hospital infection control in this region.

Abstract Background Carbapenem resistant Enterobacteriaceae is a growing concern worldwide including Malaysia. The emergence of this pathogen is worrying because carbapenem is one of the 'last-line' antibiotics. The main objective of this study was to determine the prevalence of genetic mechanisms and clinical risk factors of carbapenem resistant Klebsiella pneumoniae (K. pneumoniae) in Malaysia. Methods In this study, seventeen carbapenem resistant K. pneumoniae strains isolated from a tertiary teaching hospital in 2013 were studied. Minimal inhibitory concentration (MIC) of the bacterial strains was determined and genes associated with carbapenemases and extended-spectrum-beta-lactamases (ESBLs) were sequenced and compared with the closest representatives published in public domains. All strains were also sub-typed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Statistical analyses were performed to determine the correlation between risk factors for acquiring carbapenem resistant K. pneumoniae and in-hospital mortality. Results The predominant carbapenemase was bla OXA-48, detected in 12 strains (70.59%). Other carbapenemases detected in this study were bla KPC-2, bla IMP-8, bla NMC-A and bla NDM-1. Nine different pulsotypes were identified and nine strains which were affiliated with ST101, the predominant sequence type had similar PFGE patterns (similarity index of 85%). Based on univariate statistical analysis, resistance to imipenem and usage of mechanical ventilation showed a statistically significant effect separately to in-hospital mortality. Conclusion The diverse genetic mechanisms harbored by these carbapenem resistant K. pneumoniae facilitates its spread and complicates its detection. Thus, correlation between microbiological trends with host characteristics and clinical factors will provide a better insight of rational treatment strategies and pathogen control.