Aminoglycoside resistance mechanisms in Pseudomonas aeruginosa isolates from non-cystic fibrosis patients in Thailand

Abstract

This study aimed to examine aminoglycosides (AMGs) resistance mechanisms, including the AMG-modifying enzyme genes, mexXY, rplY, nuoG, and galU, in the Pseudomonas aeruginosa non-cystic fibrosis (CF) isolates in Thailand. One hundred P. aeruginosa isolates from non-CF patients were examined for susceptibility to AMGs and for the presence of 10 AMG-modifying enzyme genes. Thirty randomly selected isolates were tested for transcription of mexXY and nuoG and mutations in rplY and galU. All the P. aeruginosa isolates exhibited simultaneous resistance to at least 4 AMGs. High resistance rates to amikacin (92%), gentamicin (95%), streptomycin (99%), and tobramycin (96%) were observed, and all isolates were resistant to kanamycin, neomycin, and spectinomycin. Nine AMG-modifying enzyme genes were detected, including aadA1 (84%), aadB (84%), aadA2 (67%), ant(2″)-Ia (72%), strA-strB (70%), aph(3')-IIb (57%), aac(3')-Ia (40%), and aac(6')-IIa (27%). None of the isolates harbored aac(6')-IIb. Of 30 isolates tested, all but 1 isolate expressed MexXY. Two isolates did not express nuoG. Six isolates carried an amino acid change in RplY, but none of the isolates harbored mutation in galU. The results indicated that the AMG-modifying enzyme genes were widespread among the P. aeruginosa non-CF isolates. The MexXY efflux pump and inactivation for rplY played a role in AMG resistance but disruption of nuoG or galU did not.

Prevalence of Class 1 Integron and Antibiotic Resistance Pattern in Pseudomonas aeruginosa Isolated from Iranian Clinical Specimens; a Systematic Review and Meta-Analysis

“…According to the studies conducted in Latin America and Europe, 25-30% of P. aeruginosa isolates were also resistant to Ciprofloxacin[ 31,32]. In addition, we encountered a broad resistance rate against beta-lactams and aminoglycosides in P. aeruginosa strainswhich is in line with the results of previous studies[ 26,33]. On the contrary, others have described low resistance rates of P. aeruginosa against aminoglycosides is noteworthy that hospital acquired infections caused by MDR bacterial isolates are relatively frequent in developing countries such as Iran in comparison with developed nations such as the USA and most European countries.…”

Multidrug resistance and integron carriage in clinical isolates ofPseudomonas aeruginosa in Tehran, Iran

“…Brazilian studies have also shown high rates of class 1 integron carriage (41.5% and 63.5%) in P. aeruginosa clinical isolates (15,22). Similarly, studies in Malaysia, Thailand, and Nigeria have shown that 60%, 69.3%, and 57% of P. aeruginosa clinical isolates harbored class 1 integrons, respectively (23)(24)(25). Two reports from Iran have shown the presence of class 1 integrons in 56.3% and 82.6% of P. aeruginosa clinical isolates, respectively (18,26).…”

Prevalence of Antibiotic Resistance and Class 1 Integrons in Clinical and Environmental Isolates ofPseudomonas aeruginosa

“…Many mobile genetic elements such as plasmids, transposons, integrons, and phages are responsible for the horizontal gene transfer of antibiotic resistance. Recent studies suggest that integrons play a significant role in disseminating antibiotic resistance genes in clinical environments (6,7). Moreover, their role as a mobile genetic element in horizontal transfer of antibiotic resistance is proved (8).…”