A cfr-positive clinical staphylococcal isolate from India with multiple mechanisms of linezolid-resistance

Rajan, V. and Kumar, V. G. S. and Shubha Gopal (2014) A cfr-positive clinical staphylococcal isolate from India with multiple mechanisms of linezolid-resistance. Indian Journal of Medical Research, 139 (MAR). pp. 463-467. ISSN 0971-5916

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Abstract

Background & objectives: Linezolid, a member of the oxazolidinone class of antibiotics, has been an effective therapeutic option to treat severe infections caused by multidrug resistant Gram positive bacteria. Emergence of linezolid resistant clinical strains is a serious issue in the healthcare settings worldwide. We report here the molecular characterization of a linezolid resistant clinical isolate of Staphylococcus haemolyticus from India. Methods: The species of the clinical isolate was identified by 16S rRNA gene sequencing. The minimum inhibitory concentrations (MICs) of linezolid, clindamycin, chloramphenicol and oxacillin were determined by E-test method. To elucidate the mechanism of linezolid-resistance, presence of cfr gene (chloramphenicol forfenicol resistance) and mutations in 23S rRNA and ribosomal proteins (L3, L4 and L22) were investigated. Staphylococcal Cassette Chromosome mec (SCCmec) typing was performed by multiplex PCR. Results: The study documented a rare clinical S. haemolyticus strain with three independent mechanisms of linezolid-resistance. The strain carried cfr gene, the only known transmissible mechanism of linezolid-resistance. The strain also possessed resistance-conferring mutations such as G 2576 T in domain V of 23S rRNA gene and Met 156 Thr in L3 ribosomal protein. The other ribosomal proteins (L4 and L22) did not exhibit mutations accountable for linezolid-resistance. Restriction digestion by NheI revealed that all the alleles of 23S rRNA gene were mutated. The isolate showed elevated MIC values (>256 μg ml -1 ) of linezolid, clindamycin, chloramphenicol and oxacillin. Methicillin resistance was conferred by type I SCCmec element. The strain also harboured lsa(B) gene which encodes an ABC transporter that can effux clindamycin. Interpretation & conclusions: The present study reports the first clinical strain from India with transmissible and multiple mechanisms of linezolid-resistance. Judicious use of linezolid in clinical practice and proper surveillance of cfr-positive strains are of utmost importance to safeguard the efficacy of linezolid.

Item Type:	Article
Uncontrolled Keywords:	human, adult, male, gentamicin, DNA, DNA sequence, genetics, Sequence Analysis, nucleotide sequence, tetracycline, article, minimum inhibitory concentration, case report, linezolid, biology, Computational Biology, antibiotic resistance, Bacterial, Drug Resistance, allele, microbial sensitivity test, Microbial Sensitivity Tests, gene mutation, gene sequence, rifampicin, RNA 16S, mutation, Mutation, bacterial protein, Bacterial Proteins, multiplex polymerase chain reaction, RNA, Ribosomal, chloramphenicol, sequence alignment, acetamide derivative, Acetamides, clindamycin, DNA Primers, gene amplification, penicillin derivative, Molecular Sequence Data, 16S, primer DNA, molecular genetics, Base Sequence, bacterial gene, 23S, antibiotic sensitivity, cefoxitin, cfr gene, cotrimoxazole, dalfopristin plus quinupristin, epsilometer test, erythromycin, gene cassette, levofloxacin, lsa gene, oxacillin, oxazolidinone derivative, Oxazolidinones, penicillin resistance, ribosome protein, RNA 23S, Staphylococcus haemolyticus, teicoplanin
Subjects:	B Life Science > Microbiology
Divisions:	Department of > Microbiology
Depositing User:	Arshiya Kousar Library Assistant
Date Deposited:	20 Aug 2019 09:44
Last Modified:	20 Aug 2019 09:44
URI:	http://eprints.uni-mysore.ac.in/id/eprint/4404

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