DNA Gyrase and Topoisomerase IV Mutations and their effect on Quinolones Resistant Proteus mirabilis among UTIs Patients.

Randa Hassan Abdelkreem,Miskelyemen Abdelatti Elmekki,Mogahid Mohammed Elhassan,Amjad Mohammed Yousuf

doi:10.12669/pjms.36.6.2207

Randa Hassan Abdelkreem, Miskelyemen Abdelatti Elmekki + Show 2 more

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https://doi.org/10.12669/pjms.36.6.2207

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Abstract

Objective:This study aimed to highlight the importance of mutations within Proteus mirabilis genome that are related to fluoroquinolone resistance.Methods:This is a cross sectional study performed in different teaching hospitals in Khartoum State from June 2016 to May 2017. A total of (120) P mirabilis isolates from patients with symptoms of UTIs attending different hospitals in Khartoum State were examined. First, modified Kurby Bauer method was performed for phenotypical detection of resistant isolates. Then polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) followed by sequencing were applied for detection of mutations in GyrA, GyrB, ParC and ParE genes of isolates.Results:P. mirabilis showed 30% resistance to ciprofloxacin. All samples revealed mutation at (serine 83) of GyrA and (serine 84) of ParC by Hinf1 restriction endonuclease digestion. Sequencing was performed for 12 samples. For each gene, two resistant and one susceptible strains were randomly selected. The mutations associated with ciprofloxacin resistant P. mirabilis were as follows; (1/3) GyrA (Ser 83 to Ile) and (2/3) ParC (Ser 81 to Ile). Also it revealed silent mutations at codons of GyrB 474 leucine (3/3), 585 valine (2/3), 612 histidine (1/3) and 639 asparagine (1/3) and ParE 469 isoleucine (2/3), 531 aspartic (2/3) and 533 glycine (1/3).Conclusions:Ciprofloxacin resistance in P. mirabilis could be monitored through detection of mutations within DNA gyrase (encoded by gyrA and gyrB) and topoisomerase IV (encoded by parC and parE).

Highlights

Proteus mirabilis is a small gram-negative bacilli and a facultative anaerobe, it ferments maltose, but not lactose
Though wild-type strains of P. mirabilis are usually susceptible to fluoroquinolones[2,3] but a progressive increase in fluoroquinolone resistance has been seen in the clinical isolates of the bacterium recently.[3,4]
Polymerase Chain Reaction (PCR): PCR for the amplification of GyrA, GyrB, ParC and ParE Genes: Degenerate oligonucleotide primers from conserved regions of the GyrA, GyrB, ParC and ParE genes were designed from alignments of known DNA sequences in the Gen Bank database lane 3: negative control

Summary

Introduction

Proteus mirabilis is a small gram-negative bacilli and a facultative anaerobe, it ferments maltose, but not lactose. Ciprofloxacin is a recommended drug for the treatment of UTIs.[2] Though wild-type strains of P. mirabilis are usually susceptible to fluoroquinolones[2,3] but a progressive increase in fluoroquinolone resistance has been seen in the clinical isolates of the bacterium recently.[3,4]. The degree of resistance of different regions (QRDRs) encoded by gyrA and parC gene mutations have been described in several studies.[5] In Sudan, a recent study that analyzed the antimicrobial susceptibility patterns of several species of Gram-negative bacteria, including P mirabilis, to four different groups of antibiotics showed that (22.3%) of the isolates were resistant to three or more classes of antibiotics, including cephalosporins, β-lactam–β-lactamase inhibitor, quinolones, aminoglycosides and carbapenems.[6]

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