Prevalence of β-lactamase classes A, C, and D among clinical isolates of Pseudomonas aeruginosa from a tertiary-level hospital in Bangkok, Thailand

Abstract

Pseudomonas aeruginosa is one of the most important causes of nosocomial infection and it has increasing resistance to many antimicrobial agents. β-lactamase production is the most frequent mechanism for β-lactam resistance in P. aeruginosa. We evaluated the prevalence of β-lactamase genes in P. aeruginosa for classes A, C, and D by polymerase chain reaction, and investigated clonal diversity by pulsed-field gel electrophoresis (PFGE). We used the disk diffusion method to test 118 non-duplicate clinical isolates of P. aeruginosa for antimicrobial susceptibility. We identified 51 isolates (43.22%) as multidrug-resistant P. aeruginosa, approximately 44.91% of which were resistant to ceftazidime. β-lactamase genes were found in 80 isolates of P. aeruginosa (67.80%). The genes that encode VEB-1, AmpC, and OXA-10 were detected in 9 (7.62%), 75 (63.56%), and 18 (15.25%) of these isolates, respectively. The genes that encode PER-1, CTX-M, TEM-1 and derivatives, and SHV-1 were not found in any of the P. aeruginosa isolates. We identified 29 different pulsotypes by PFGE. Two predominant pulsotypes were found. In pulsotype 1, OXA- 10, which was co-produced with the AmpC gene, was predominant. Moreover, VEB-1-producing strains were found to be scattered in many pulsotypes, and AmpC-producing strains showed high pulsotype diversity. The prevalence of β-lactamase genes in P. aeruginosa was represented by the genetic heterogeneity of OXA-10, AmpC, and VEB-1. The predominant clone of P. aeruginosa clinical isolates was OXA-10. This raises concern about oxacillinases among P. aeruginosa clinical isolates.

Distribution of Ambler Class A Β-lactamase Genes and Evaluation of Resistance Patterns in Multi-Drug and Extensively-Drug Resistant P. aeruginosa Clinical Isolates

“…In the present study, 95% of the P. aeruginosa isolates were MDR, which is similar to the results of studies performed by Safaei et al (24) and Mirsalehian et al (25). However, this rate is lower than the rates reported by Katvoravutthichai (21,26,27). The prevalence of XDR strains (5%) in our study was lower than that reported by Palavutitotai et al (2018) in Thailand (22%) (28).…”

“…In a study in South Africa, 94% of P. aeruginosa isolates were resistant to aztreonam and piperacillin, and the frequency of resistance to imipenem, ticarcillin, meropenem and ceftazidime was 88%, 88%, 82% and 76%, respectively (20). In a study in Thailand, the rate of resistance to ceftazidime, cefepime, amikacin, gentamicin, ciprofloxacin, levofloxacin, imipenem, meropenem and ciprofloxacin was 44.91%, 28.81%, 18.64%, 25.42%, 43%, 49.15%, 31.36%, 33% and 48.3%, respectively (21). In Iran, most studies have reported high resistance rates to amikacin and aztreonam and low resistance rate to levofloxacin and polymexin B (22,23), which might indicate the imprudent use of amikacin and aztreonam in Iran.…”

“…However, these plasmids are reportedly prevalent in other Asian countries, Southeastern Europe and Africa (Kosovo, Algeria, and Tunisia) (18, [30][31][32]. In a study in Thailand, from 118 nonduplicate clinical isolates of P. aeruginosa, 6.7% carried the bla VEB-1, bla PER-1 and bla TEM-1 (and derivatives) genes, and bla SHV-1 was not observed (21). The notably high prevalence of bla PER-1 , bla VEB-1 , bla TEM and bla SHV observed in this study indicates the wide-spread dissemination of ESBL-encoding β-lactamase genes in Iran, which is in accordance with previous reports (22,25,33 (25).…”

Phenotypic and molecular characterization of extended spectrum -lactamase producing Pseudomonas aeruginosa in Nigeria

“…This finding is in agreement with the work conducted by Porjafari et al, (2013) who reported similar occurrence of OXA-50 gene among the P. aeruginosa strains collected in their hospitals. In Bangkok, Thailand Oxa-10 was the predominant clone of P. aeruginosa clinical isolates (Katvoravutthichai et al, 2016). This raises concern about oxacillinases among P. aeruginosa clinical isolates.…”

“…The genomic DNA extraction was performed using the modified boiling method (Katvoravutthichai et al, 2016). First, P. aeruginosa isolates were inoculated into a sterile brain heart infusion broth (Oxoid, U.K.) and incubated at 37°C for 72 h. One millilitre of the incubated broth was centrifuged at 12,000×g for 5 min and harvested cells were washed and re-suspended in 50 µl of Nuclease-free water (Norgen, Biotek Corop, Canada).…”