Relative Frequency of Existence of Bro Gene and its Relation to Antibiotic Resistant Moraxella Catarrhalis Isolated From Clinical Samples

Moraxella catarrhalis shows resistance to antibiotics by using two mechanisms, beta-lactamase enzyme activity and efflux pump. Currently, Moraxella catarrhalis is considered as a bacterium that causes respiratory infections. Therefore, the aim of the present study was to determine the relative frequency of bro beta-lactamase gene and its relationship with antibiotic resistance in Moraxella catarrhalis isolated from clinical samples.

The present descriptive study was conducted at Dena hospital of Shiraz from 2020-2021 In total, 136 clinical samples were collected from pulmonary infectious patients and Moraxella catarrhalis was isolated and identified by phenotypic and Genotypic (16S rRNA) methods. At that point, antibiotic susceptibility of the isolates was determined by disk diffusion and combination disk methods. In addition the relative frequency of existence of bro gene was evaluated in them. The collected data were statistical analysis usint t-student test.

In the present study, out of 10 strains of Moraxella catarrhalis, seven strains were MDR. These bacteria were resistant to Gentamicin, Amikacin, PenicillinG, Amoxicillin, Cefazolin , Ceftazidime, Tetracyclin, Chloramphinicol and Ciproflaxacin (70%). In addition, these strains slowed less resistant character to Azithromycin, Erythromycin, Clarithromycin and Co-amoxiclav (100%). bro genes were observed in all MDR strains ( 5 strains had bro-1 and 2 strains had bro-2 genes).

The results indicated that Moraxella catarrhalis strains with MDR character carried bro genes. Therefore, based on our finding prescription of beta lactam antibiotics for treatment of Moraxella catarralis infections could not recommend; however, Azotomycin, Erythromycin clarithromycin and Co-amoxiclav could be suggested.