• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.517-525
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• 2023

The emergence and spread of multidrug-resistant Pseudomonas aeruginosa (MRPA) have become a serious problem worldwide. The involvement of metallo-β-lactamases (MBLs) in inducing carbapenem resistance is particularly acute. However, unlike other members of the Enterobacteriaceae genus, new clones of P. aeruginosa are constantly emerging and rapidly replacing previously prevalent dominant clones. Therefore, this study aimed to perform antimicrobial resistance gene analysis, integron gene cassette analysis using DNA sequencing, and plasmid transfer analysis by conjugation to investigate the antimicrobial resistance dynamics of 18 P. aeruginosa strains isolated from various medical samples at a general hospital in Busan from September 2017 to September 2019. All 18 strains showed extensively drug-resistant (XDR) phenotype and were resistant to most antibiotics, except colistin (100%) but were susceptible to aztreonam (22.2%) and ceftazidime (16.6%). Approximately 66.7% of the strains had Class 1 integrons showing various antimicrobial resistances. Notably, IMP-6 ST235 (66.7%), VIM-2 ST357 (16.7%), and IMP-1 ST446(16.7%) were identified. The identification of IMP-1-producing ST446, previously unreported in Korea, is noteworthy considering the emergence and prevalence of another MRPA high-risk clone.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.155-163
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• 2019

During the time period from 2010 to 2017, out of 162,551 blood specimens, 11,233 (6.9%) specimens were positive for culture and 11,865 strains were cultured. Among the isolates, 47.8% were Gram positive cocci, 38.8% were Gram negative rods, 4.2% were Gram positive bacilli, 6.8% were fungi and 2.3% were anaerobes. When the culture results were compared according to gender, 55.0% (2,732/4,969) of the isolates were found in males and 45.0% (2,237/4,969) were isolated in females. In addition, when categorized according to age group, people in their 70s were the most separated by 28.7% (1,426/4,969) and this showed a great difference from 1.2% (62/4,969) of people in their teens. MRSA decreased significantly from 66.7% in 2016 to 46.8% in 2017. The vancomycin resistance rate of E. faecium was 35.0% (48/137). The ESBL positive rate of E. coli in intestinal bacteria was increased from 17.2% in 2010 to 28.8% in 2017, but the positive rate decreased for K. pneumoniae. 11.8% (14/119) of multidrug-resistant P. aeruginosa (MDRPA) of P. aeruginosa and 64.3% (161/252) of MDRAB of A. baumannii showed high resistance. Because the microbial susceptibility and antimicrobial susceptibility patterns of the blood specimens isolated from all the blood specimens differ according to the time period, region and patients, periodic analyses of different pathogens and understanding the changes in the degree of susceptibility to antimicrobial susceptibility have been conducted in hospitals.