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    Results of a Multicenter Study Investigating Plasmid Mediated Colistin Resistance Genes (mcr-1 and mcr-2) in Clinical Enterobacteriaceae Isolates from Turkey
    (Ankara Microbiology Soc, 2017) Sari, Ayse Nur; Suzuk, Serap; Karatuna, Onur; Ogunc, Dilara; Karakoc, Ayse Esra; Cizmeci, Zeynep; Aliskan, Hikmet Eda
    Colistin is a polymyxin antibiotic which is considered as one of the last line agents against infections due to multidrug resistant or carbapenem resistant gram-negative pathogens. Colistin resistance is associated with chromosomal alterations which can usually cause mutations in genes coding specific two component regulator systems. The first plasmid-mediated colistin resistance gene, mcr-1 was described in Escherichia coli and Klebsiella pneumoniae isolates in December 2015 and followed by another plasmid-mediated colistin resistance gene mcr-2 in 2016. The rapid and interspecies dissemination of plasmid-mediated resistance mechanisms through horizontal gene transfer, have made these genes considerably threatening. After the first reports, although mcr-1/mcr-2 producing Enterobacteriaceae isolates have been reported from many countries, there have been no reports from Turkey. Thus, the aim of this study was to investigate the presence of mcr-1/mcr-2 in clinical Enterobacteriaceae isolates from different parts of our country. A total of 329 Enterobacteriaceae isolates from 22 laboratories were collected which were isolated between March, 2015 and February, 2016. mcr-1/mcr-2 were investigated by polymerase chain reaction during February-March, 2016. Two hundred and seventeen of Klebsiella pneumoniae (66%), 75 of Salmonella spp. (22.8%), 31 of Esherichia coli (9.4%), 3 of Enterobacter cloacae (0.9%), 2 of Klebsiella oxytoca (0.6%) and 1 of Enterobacter aerogenes (0.3%) isolates were included to the study. Agarose gel electrophoresis results of PCR studies have shown expected band sizes for positive control isolates as 309 bp for mcr-1 and 567 bp for mcr-2. However, the presence of mcr-1/mcr-2 genes was not detected among the tested study isolates of Enterobacteriaceae. Although mcr-1/mcr-2 were not detected in our study isolates, it is highly important to understand the mechanism of resistance dissemination and determine the resistant isolates by considering that colistin is a last-line antibiotic against infections of multidrug or carbapenem resistant gram-negative bacteria. Thus, it is suggested that these mechanisms should be followed-up in both clinical and non-clinical (e.g. isolates from food animals, raw meats and environment) isolates of special populations.
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    Six-year distribution pattern of hepatitis C virus in Turkey: a multicentre study
    (Taylor & Francis Ltd, 2016) Altindis, Mustafa; Dal, Tuba; Akyar, Isin; Karatuna, Onur; Gokahmetoglu, Selma; Ulger, Seda Tezcan; Kulah, Canan
    Hepatitis C infection is a public health problem. The aim of this retrospective study was to determine the distribution of hepatitis C virus (HCV) genotypes in seven regions of Turkey, by evaluating 7002 patients with chronic HCV in a six-year period. During the 2009-2014 period, serum/plasma samples from 7002 new consecutive HCV RNA positive patients were collected. The female patients were 3867 (55.2%). The genotype distribution of HCV patiens was evaluated by ages and years. Statistical analysis was performed by using the Mann-Whitney test and the chi(2) analysis. During the six-year period, genotype 1b was the most common genotype (67.7%) followed by untypeable genotype 1 (7.7%), genotype 4 (7.3%) and genotype 3 (6.7%). In 2014, genotype 3 was the second most common one (11.3%) and genotype 4 was the third most common one (9.8%). In the group with <25 years old patients, genotype 1b was most common (78.48%, 62/79) between the years of 2009 and 2011, whereas genotype 3 (34.8%, 86/247), between the years of 2012 and 2014. Genotype 1b was the most common in the groups between 26 and 35 years, 36 and 45 years, 46 and 55 years, 56 and 65 years. The rate of genotype 3 was increased from 4.78% to 10.06% and the rate of genotype 4 was increased from 1.3% to 3.84%, from 2009-2011 to 2012-2014. In recent years, genotypes 3 and 4 have gained importance. New therapeutic strategies and survey studies may be required for the modified HCV genotype pattern.