AUTHOR=Goudarzi Mehdi , Kobayashi Nobumichi , Dadashi Masoud , Pantůček Roman , Nasiri Mohammad Javad , Fazeli Maryam , Pouriran Ramin , Goudarzi Hossein , Miri Mirmohammad , Amirpour Anahita , Seyedjavadi Sima Sadat 

TITLE=Prevalence, Genetic Diversity, and Temporary Shifts of Inducible Clindamycin Resistance Staphylococcus aureus Clones in Tehran, Iran: A Molecular–Epidemiological Analysis From 2013 to 2018

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00663

DOI=10.3389/fmicb.2020.00663

ISSN=1664-302X

ABSTRACT=<p>The prevalence of <italic>Staphylococcus aureus</italic> as an aggressive pathogen resistant to multiple antibiotics causing nosocomial and community-acquired infections is increasing with limited therapeutic options. Macrolide-lincosamide streptogramin B (MLSB) family of antibiotics represents an important alternative therapy for staphylococcal infections. This study was conducted over a period of five years from August 2013 to July 2018 to investigate the prevalence and molecular epidemiology in Iran of inducible resistance in <italic>S. aureus</italic>. In the current study, 126 inducible methicillin-resistant <italic>S. aureus</italic> (MRSA) (<italic>n</italic> = 106) and methicillin-sensitive <italic>S. aureus</italic> (MSSA) (<italic>n</italic> = 20) isolates were characterized by <italic>in vitro</italic> susceptibility analysis, resistance and virulence encoding gene distribution, phenotypic and genotypic analysis of biofilm formation, prophage typing, <italic>S. aureus</italic> protein A locus (<italic>spa</italic>) typing, staphylocoagulase (SC) typing, staphylococcal cassette chromosome <italic>mec</italic> (SCC<italic>mec</italic>) typing, and multilocus sequence typing. Of the 126 isolates, 76 (60.3%) were classified as hospital onset, and 50 (39.7%) were classified as community onset (CO). Biofilm formation was observed in 97 strains (77%). A total of 14 sequence types (STs), 26 <italic>spa</italic> types, 7 coagulase types, 9 prophage types, 3 <italic>agr</italic> types (no <italic>agr</italic> IV), and 9 clonal complexes (CCs) were identified in this study. The prevalence of the inducible MLSB (iMLSB) <italic>S. aureus</italic> increased from 7.5% (25/335) to 21.7% (38/175) during the study period. The iMLSB MRSA isolates were distributed in nine CCs, whereas the MSSA isolates were less diverse, which mainly belonged to CC22 (7.95%) and CC30 (7.95%). High-level mupirocin-resistant strains belonged to ST85-SCC<italic>mec</italic> IV/t008 (<italic>n</italic> = 4), ST5-SCC<italic>mec</italic> IV/t002 (<italic>n</italic> = 4), ST239-SCC<italic>mec</italic> III/t631 (<italic>n</italic> = 2), and ST8-SCC<italic>mec</italic> IV/t064 (<italic>n</italic> = 2) clones, whereas low-level mupirocin-resistant strains belonged to ST15-SCC<italic>mec</italic> IV/t084 (<italic>n</italic> = 5), ST239-SCC<italic>mec</italic> III/t860 (<italic>n</italic> = 3), and ST22-SCC<italic>me</italic>c IV/t790 (<italic>n</italic> = 3) clones. All the fusidic acid–resistant iMLSB isolates were MRSA and belonged to ST15-SCC<italic>mec</italic> IV/t084 (<italic>n</italic> = 2), ST239-SCC<italic>mec</italic> III/t030 (<italic>n</italic> = 2), ST1-SCC<italic>mec</italic> V/t6811 (<italic>n</italic> = 1), ST80-SCC<italic>mec</italic> IV/t044 (<italic>n</italic> = 1), and ST59-SCC<italic>mec</italic> IV/t437 (<italic>n</italic> = 1). The CC22 that was predominant in 2013–2014 (36% of the isolates) had almost disappeared in 2017–2018, being replaced by the CC8, which represented 39.5% of the 2017–2018 isolates. This is the first description of temporal shifts of iMLSB <italic>S. aureus</italic> isolates in Iran that identifies predominant clones and treatment options for iMLSB <italic>S. aureus</italic>–related infections.</p>