Absence of the mecC gene in methicillin-resistant Staphylococcus aureus isolated from various clinical samples: The first multi-centered study in Turkey
Cikman, Aytekin and Aydin, Merve and Gulhan, Baris and Karakecili, Faruk
and Kurtoglu, Muhammet G. and Yuksekkaya, Serife and Parlak, Mehmet and
Gultepe, Bilge S. and Cicek, Aysegul C. and Bilman, Fullya B. and Ciftci,
Ihsan H. and Kara, Murat and Atmaca, Selahattin and Ozekinci, Tuncer... Show more Show less
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Abstract
Background: mecA is a predefined gene causing methicillin resistance in
Staphylococcus aureus (S. aureus) isolates; however, it has been shown
that some methicillin-resistant S. aureus (MRSA) strains do not carry
this gene. Recently, in isolates found to be MRSA-positive but
mecA-negative, a new resistance gene called mecC, which is a homolog of
mecA, has been reported. This study aimed to investigate the mecC and
mecA genes in MRSA strains isolated from different geographic regions in
Turkey.
MMethods: The sample of the study consisted of 494 MRSA strains isolated
from seven geographical regions in Turkey between 2013 and 2016. The
strains were obtained from 17 centers, comprising 13 university
hospitals, three education and research hospitals, and one state
hospital. Methicillin resistance in S. aureus strains was determined
using the agar disk diffusion method with a cefoxitin disk and the agar
dilution method with oxacillin. The mecC and mecA genes in MRSA strains
was investigated by Polymerase Chain Reaction (PCR).
Results: Of the MRSA strains investigated, 47.9\% were isolated from
intensive care units. Concerning sample type, 36.7\% were detected in
the respiratory tract (tracheal aspirate, sputum, etc.), 24.8\% in
blood, 18.7\% in skin and soft tissues, 9.3\% in nasal swabs, 5.4\% in
urine, 4.1\% in ears, and 1\% in sterile body fluid. Using PCR, mecC was
not identified in any of the S. aureus strains isolated from different
clinical microbiology laboratories. mecA gene positivity was found in
315 of the MRSA strains (63.8\%). Staphylococcal Cassette Chromosome mec
( SCCmec) type was identified in 232 strains (46.9\%), of which 136
(58.7\%) were type II, 75 (32.4\%) were type IV, 12 (5.1\%) were type
Mb, six (2.5\%) were type I, and three (1.3\%) were type III.
Conclusion: This is the first multi-centered study to investigate MRSA
strains isolated from different regions in Turkey. The mecC gene was not
detected in any of the MRSA strains. We believe that this study will
constitute an important basis for monitoring possible future changes.
(C) 2019 The Authors. Published by Elsevier Limited on behalf of King
Saud Bin Abdulaziz University for Health Sciences.... Show more Show less