Objectives: To assess the prevalence of carbapenemase genes among multidrug-resistant Pseudomonas aeruginosa (P. aeruginosa) isolates from tertiary care centers in Southern Thailand. Methods:The prevalence of carbapenemase genes in P. aeruginosa isolates collected from patients hospitalized between 2015-2017 in 2 tertiary care hospitals in Songkhla Province, Southern Thailand, was investigated. Standard laboratory procedures were followed and disk diffusion test was used for bacterial identification and susceptibility evaluations. Carbapenemase genes were detected using multiplex polymerase chain reaction (PCR) and genotyping by pulsed field gel electrophoresis. Original ArticleResults: Among the 289 P. aeruginosa isolates, 55% was from sputum, 19.4% was from urine, and 8% was from secretions. The prevalence was 55.7% in carbapenemresistant multidrug-resistant P. aeruginosa (CR-MDR-PA) and 39.4% in multidrug-resistant P. aeruginosa (MDR-PA). Resistance to imipenem, meropenem, gentamicin, and ceftazidime ranged from 50-60%, and amikacin was the most effective antibiotic (38.4%). The carbapenemase genes bla VIM (27.7%), bla IMP (23.9%), and bla OXA48 (4.8%) were detected; however, bla SPM and bla BIC were not detected in any of the isolates. Pulsed field gel electrophoresis analysis revealed clonal diversity among 17 CR-MDR-PA strains. Conclusion:A high percentage of CR-MDR-PA carries carbapenemase genes in our area; therefore, more emphasis on and application of molecular techniques for infection prevention and control may provide useful insights on disease epidemiology.

Introduction Vancomycin-resistant enterococci (VRE) are important causative agents of healthcare-associated infections. This study investigated the prevalence of VRE isolates of clinical specimens from a tertiary hospital in Southern Thailand and their biofilm formation and associated virulence factors. Methods This retrospective study was conducted from February 2011 to March 2021 at a 1,000-bed tertiary care hospital in Songkhla Province in Southern Thailand. Results In total, 95 VRE isolates were collected. Urine had the highest VRE prevalence (38%), followed by pus or secretions (23%) and the digestive tract (19%). VRE infections were most common in medical (45%) and surgical wards (19%). VRE strains were equally resistant (85–100%) to the six classes of antibiotics commonly used in a tertiary care hospital. Biofilms were produced by 73% of the multidrug-resistant strains; however, 93% of VRE isolates lacking hyl were highly capable of producing biofilms. Conclusions No relationship was observed between virulence genes and biofilm formation. Thus, efforts to establish appropriate treatment and control measures are necessary, as distinctive VRE characteristics are relevant to the treatment of enterococcal infections in hospitals.