Genotypes and serotype distribution of macrolide resistant invasive and non- invasive Streptococcus pneumoniae isolates from Lebanon

Annals of Clinical Microbiology and Antimicrobials

Research

Marie-Therese Khairallah¹  Farah J Nassar¹  Ghassan M Matar¹  Nedal Taha¹  Souha S Kanj²  Zeina A Kanafani²  George F Araj³  Rima H Wakim⁴  Ghassan Dbaibo⁴  Marwa Shehab⁵  Maysa Baroud⁵  Ahmad Sabra⁵ 

[1] Department of Experimental Pathology, Immunology & Microbiology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut, Lebanon;Department of Internal Medicine, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut, Lebanon;Department of Pathology & Laboratory Medicine, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut, Lebanon;Department of Pediatrics & Adolescent Medicine, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut, Lebanon;Infectious Diseases Research Core Facility, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut, Lebanon;

关键词: Antimicrobials;    Macrolides;    Resistance;    Genes;    Serotyping;   

DOI  :  10.1186/1476-0711-11-2

 received in 2011-10-03, accepted in 2012-01-16,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThis study determined macrolide resistance genotypes in clinical isolates of Streptococcus pneumoniae from multiple medical centers in Lebanon and assessed the serotype distribution in relation to these mechanism(s) of resistance and the source of isolate recovery.MethodsForty four macrolide resistant and 21 macrolide susceptible S. pneumoniae clinical isolates were tested for antimicrobial susceptibility according to CLSI guidelines (2008) and underwent molecular characterization. Serotyping of these isolates was performed by Multiplex PCR-based serotype deduction using CDC protocols. PCR amplification of macrolide resistant erm (encoding methylase) and mef (encoding macrolide efflux pump protein) genes was carried out.ResultsAmong 44 isolates resistant to erythromycin, 35 were resistant to penicillin and 18 to ceftriaxone. Examination of 44 macrolide resistant isolates by PCR showed that 16 isolates harbored the erm(B) gene, 8 isolates harbored the mef gene, and 14 isolates harbored both the erm(B) and mef genes. There was no amplification by PCR of the erm(B) or mef genes in 6 isolates. Seven different capsular serotypes 2, 9V/9A,12F, 14,19A, 19F, and 23, were detected by multiplex PCR serotype deduction in 35 of 44 macrolide resistant isolates, with 19F being the most prevalent serotype. With the exception of serotype 2, all serotypes were invasive. Isolates belonging to the invasive serotypes 14 and 19F harbored both erm(B) and mef genes. Nine of the 44 macrolide resistant isolates were non-serotypable by our protocols.ConclusionMacrolide resistance in S. pneumoniae in Lebanon is mainly through target site modification but is also mediated through efflux pumps, with serotype 19F having dual resistance and being the most prevalent and invasive.

【 授权许可】

Unknown   
© Taha et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.