Molecular Characterization of Moraxella Catarrhalis and it's Antibiotics Susceptibility Patterns from Different Respiratory Tract Infection Patient's Clinical Samples

Abstract

IntroductionMoraxella catarrhalis is a gram negative, oxidase positive, cocci mainly causing upper and lowerrespiratory tract infections. The RND family efflux pumps lead to multidrug resistance in most ofthe gram negative bacteria. One of the well- known pumps in M. catarrhalis is arcAB and oprMsystem. The objective of this study was to investigate the antibiotic resistance in M. catarrhalis andto determine its resistance dependence on the efflux pump. MethodsIn this study, 283 different respiratory tract infection samples processed out of that 73 were confirmedby biotyping and molecular characterization as a M. catarrhalis. The antibiotic susceptibility testswere performed by disc diffusion method according to CLSI. Molecular characterization formultidrug resistance isolates was also done along with genes responsible for efflux pumps. PCRwas done M. catarrhalis and acrAB and oprM genes. The factor for association of efflux pump withantibiotic resistance was investigated using phenylalanine argine β-naphthylamide. ResultsThe antibiotics susceptibility result showed 12 out of 73 isolates were MDR, selectively takenfor PCR using 16SrRNA specific primer. The MDR isolates were further confirmed by PCR. Theamplification results of acra, acrb and oprm genes for the M. catarrhalis having multidrug resistancegenes by PCR band size products seen on 2% agrose gel. The highest resistance towards the drugsviz penicillin, ampicillin, amoxicillin, amoxiclave, cotrimoxazole, cefazolin, cefuroxime, ceftrixoneand cefepime were seen in M. catarrhalis. ConclusionsThe result showed that Moraxella catarrhalis is one of the major causes for respiratory tract infection.The drug resistance in this species is increasing day by day. The 90% of isolates have acrAB andoprM genes for efflux pump responsible for multiple drug resistance. The efflux pump inhibitorhas important clinical significance for the proper treatment.