Investigation of gyrA and parC mutations and the prevalence of plasmid-mediated quinolone resistance genes in Klebsiella pneumoniae clinical isolates.
BMC Microbiol
; 24(1): 265, 2024 Jul 18.
Article
in En
| MEDLINE
| ID: mdl-39026143
ABSTRACT
BACKGROUND:
The emergence of fluoroquinolone resistance in clinical isolates of Klebsiella pneumoniae is a growing concern. To investigate the mechanisms behind this resistance, we studied a total of 215 K. pneumoniae isolates from hospitals in Bushehr province, Iran, collected between 2017 and 2019. Antimicrobial susceptibility test for fluoroquinolones was determined. The presence of plasmid mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining region (QRDR) of gyrA and parC genes in ciprofloxacin-resistant K. pneumoniae isolates were identified by PCR and sequencing.RESULTS:
Out of 215 K. pneumoniae isolates, 40 were resistant to ciprofloxacin as determined by E-test method. PCR analysis revealed that among these ciprofloxacin-resistant isolates, 13 (32.5%), 7 (17.5%), 40 (100%), and 25 (62.5%) isolates harbored qnrB, qnrS, oqxA and aac(6')-Ib-cr genes, respectively. Mutation analysis of gyrA and parC genes showed that 35 (87.5%) and 34 (85%) of the ciprofloxacin-resistant isolates had mutations in these genes, respectively. The most frequent mutations were observed in codon 83 of gyrA and codon 80 of parC gene. Single gyrA substitution, Ser83â Ile and Asp87âGly, and double substitutions, Ser83âPhe plus Asp87âAla, Ser83âTyr plus Asp87âAla, Ser83âIle plus Asp87âTyr, Ser83âPhe plus Asp87âAsn and Ser83âIle plus Asp87âGly were detected. In addition, Ser80âIle and Glu84âLys single substitution were found in parC gene.CONCLUSIONS:
Our results indicated that 90% of isolates have at least one mutation in QRDR of gyrA orparC genes, thus the frequency of mutations was very significant and alarming in our region.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plasmids
/
Klebsiella Infections
/
Microbial Sensitivity Tests
/
Quinolones
/
DNA Gyrase
/
DNA Topoisomerase IV
/
Drug Resistance, Bacterial
/
Klebsiella pneumoniae
/
Anti-Bacterial Agents
/
Mutation
Limits:
Humans
Country/Region as subject:
Asia
Language:
En
Journal:
BMC Microbiol
Journal subject:
MICROBIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Iran