Influence of Genetic Variations of Mgrb and PhoQ System on Colistin-resistant in Klebsiella pneumoniae Clinical Isolates

Khalid, Meena Yahya; Ghareeb, Abdulameer M.

doi:10.21608/ejhm.2022.274808

Influence of Genetic Variations of Mgrb and PhoQ System on Colistin-resistant in Klebsiella pneumoniae Clinical Isolates

Document Type : Original Article

Authors

10.21608/ejhm.2022.274808

Abstract

Background: Colistin is the only effective treatment for carbapenem-resistant K. pneumoniae, and the rise of antibiotic-resistant strains is a major health concern. Objective: The current study aimed to look at the prevalence of colistin resistance among carbapenem-resistant K. pneumoniae in a population of Iraqi patients by conducting a PCR-based molecular screening of the targeted genes (Mgrb and PhoQ system genes) in colistin-resistant Klebsiella pneumoniae isolates.
Patients and methods: A total of 182 clinical samples were collected from Medical City in Baghdad. The VITEK2 technology was used to identified and confirmed K. pneumonia isolates, and determine antibiotic sensitivity. The minimum inhibitory concentration (MIC) of colistin-resistant was determined by using E-test. The gene expression of PhoQ and Mgrb genes was done by using RT-qPCR. Results: All 23 Klebsiella spp. were molecularly diagnosed by PCR using a Rpsl gene primer, and the E-test showed that 25% were colistin-resistant. The molecular screening for additional genes indicated that 22 isolates (95.7%) contained the Mgrb gene and 20 (87.0%) had the Blashv and PhoQ genes. The PhoQ gene increased following colistin exposure, indicating that this mechanism is being employed to compensate for colistin. Conclusion: Mgrb and PhoQ genes were upregulated in response to colistin in particular; when colistin concentration increased the expression of these genes was upregulated.

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