AIM: To determine the susceptibility of A. baumannii isolates to commonly-used biocides, investigate their biofilm-forming capacities and the prevalence of biocide resistance and biofilm-associated genes.

METHODOLOGY: . The minimum inhibitory concentration (MIC) values of 100 A. baumannii hospital isolates from Terengganu, Malaysia, towards the biocides benzalkonium chloride (BZK), benzethonium chloride (BZT) and chlorhexidine digluconate (CLX), were determined by broth microdilution. The isolates were also examined for their ability to form biofilms in 96-well microplates. The prevalence of biocide resistance genes qacA, qacE and qacDE1 and the biofilm-associated genes bap and abaI were determined by polymerase chain reaction (PCR).

RESULTS: Majority of the A. baumannii isolates (43%) showed higher MIC values (> 50 µg/mL) for CLX than for BZK (5% for MIC > 50 µg/mL) and BZT (9% for MIC > 50 µg/mL). The qacDE1 gene was predominant (63%) followed by qacE (28%) whereas no isolate was found harbouring qacA. All isolates were positive for the bap and abaI genes although the biofilm-forming capacity varied among the isolates.

METHODS: Prospective, surveillance study on peripheral venous catheter-associated bloodstream infections conducted from 1 September 2013 to 31 May 2019 in 262 intensive care units, members of the International Nosocomial Infection Control Consortium, from 78 hospitals in 32 cities of 8 countries in the South-East Asia Region: China, India, Malaysia, Mongolia, Nepal, Philippines, Thailand, and Vietnam. For this research, we applied definition and criteria of the CDC NHSN, methodology of the INICC, and software named INICC Surveillance Online System.

RESULTS: We followed 83,295 intensive care unit patients for 369,371 bed-days and 376,492 peripheral venous catheter-days. We identified 999 peripheral venous catheter-associated bloodstream infections, amounting to a rate of 2.65/1000 peripheral venous catheter-days. Mortality in patients with peripheral venous catheter but without peripheral venous catheter-associated bloodstream infections was 4.53% and 12.21% in patients with peripheral venous catheter-associated bloodstream infections. The mean length of stay in patients with peripheral venous catheter but without peripheral venous catheter-associated bloodstream infections was 4.40 days and 7.11 days in patients with peripheral venous catheter and peripheral venous catheter-associated bloodstream infections. The microorganism profile showed 67.1% were Gram-negative bacteria: Escherichia coli (22.9%), Klebsiella spp (10.7%), Pseudomonas aeruginosa (5.3%), Enterobacter spp. (4.5%), and others (23.7%). The predominant Gram-positive bacteria were Staphylococcus aureus (11.4%).

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 (blaTEM, blaSHV, blaCTX-M, blaOXA). Metallo-β-lactamase genes (blaVEB, blaVIM, blaNDM) 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.