Antibiotic resistance in and significant contribution of an RND type efflux pump in erythromycin resistance.

In this study, we aimed to determine the antibiotic resistance status of spp. isolated from human infections in our region, including the role of mechanisms involved in erythromycin resistance. Standard methods were used for the isolation, identification and antibiotic susceptibility testing of spp.

One-Year Post-Vaccination Longitudinal Follow-Up of Quantitative SARS-CoV-2 Anti-Spike Total Antibodies in Health Care Professionals and Evaluation of Correlation with Surrogate Neutralization Test.

Numerous vaccines have been generated to decrease the morbidity and mortality of COVID-19. This study aims to evaluate the immunogenicity of the heterologous boosts by BioNTech against homologous boosts by CoronaVac at three-month intervals in two health care worker (HCW) cohorts, with or without prior COVID-19, for one year post-vaccination. This is a prospective cohort study in which the humoral responses of 386 HCWs were followed-up longitudinally in six main groups according to their previous COVID-19 exposure and vaccination status.

Diversity of HIV-1 Subtypes and Transmitted Drug-resistance Mutations Among Minority HIV-1 Variants in a Turkish Cohort.

Background: The World Health Organization (WHO) recommends the surveillance of transmitted drug resistance mutations (TDRMs) to ensure the effectiveness and sustainability of HIV treatment programs.

Objective: Our aim was to determine the TDRMs and evaluate the distribution of HIV-1 subtypes using and compared next-generation sequencing (NGS) and Sanger-based sequencing (SBS) in a cohort of 44 antiretroviral treatment-naïve patients.

Methods: All samples that were referred to the microbiology laboratory for HIV drug resistance analysis between December 2016 and February 2018 were included in the study.

Detection of a New Resistance-Mediating Plasmid Chimera in a -Positive Strain at a German University Hospital.

Mobile genetic elements, such as plasmids, facilitate the spread of antibiotic resistance genes in Enterobacterales. In line with this, we investigated the plasmid-resistome of seven gene-carrying isolates, which were isolated between 2013 and 2014 at the University Medical Center in Göttingen, Germany. All isolates were subjected to complete genome sequencing including the reconstruction of entire plasmid sequences.

Evaluation of two commercial methods for rapid detection of the carbapenemase-producing Klebsiella pneumoniae.

In this study, we evaluated the performance of the two commercial methods (Rapidec Carba NP and NG-Test Carba-5) for the rapid detection of carbapenemase-producing Klebsiella pneumoniae. A total of 224 Klebsiella pneumoniae strains previously characterized for carbapenemase genes by polymerase chain reaction were included in the study. The strain collection included 30 non-carbapenemase producers, 85 OXA-48-like, 59 NDM, 14 IMP, 7 KPC, 7 VIM, 19 OXA-48-like plus NDM, and 3 KPC plus NDM producers.

Evaluation of phenotypic tests for detection of carbapenemases: New modifications with new interpretation.

Introduction: The emergence and spread of carbapenemase-producing Enterobacterales (CPE) is a worldwide public health threat. Rapid and accurate detection of CPE is essential to prevent their dissemination within health care settings. The aim of this study was to evaluate the performance of CIM, mCIM and mCIM with ammonium bicarbonate (mCIM-A) methods by using different interpretation criteria for detection of carbapenemases.

Comparative in vitro activity of plazomicin and older aminoglyosides against Enterobacterales isolates; prevalence of aminoglycoside modifying enzymes and 16S rRNA methyltransferases.

Comparative in vitro activity of plazomicin and 4 older aminoglycosides was evaluated with broth microdilution in 714 blood isolates from 14 hospitals in Turkey. Isolates included Escherichia coli (n=320), Klebsiella spp. (n=294), Enterobacter spp.

Alterations in AdeS and AdeR regulatory proteins in 1-(1-naphthylmethyl)-piperazine responsive colistin resistance of .

Colistin resistant strains are of great concern worldwide. However, the role of efflux pumps in colistin resistance needs to be elucidated. We investigated the changes in colistin MICs of 29 colistin resistant isolates in response to resistance-nodulation-division (RND)-type efflux pump inhibitor (EPI) and the alterations in AdeR and AdeS two-component regulatory proteins previously associated with the overproduction of AdeAB.

Assessment of Transmitted HIV-1 Drug Resistance Mutations Using Ultra- Deep Pyrosequencing in a Turkish Cohort.

Background: Antiretroviral treatment (ART) reduces morbidity and mortality caused by human immunodeficiency virus (HIV) infection; however, the emergence of drug-resistant strains poses an important obstacle to treatment success. Using conventional sequencing methods to determine antiretroviral resistance, mutations present in ≥20% of quasispecies can be identified, but drug-resistant minority variants can lead to virologic failure.

Objective: We aimed to assess transmitted drug resistance mutations (TDRMs) within minority variants using ultra-deep pyrosequencing (UDPS).

Performance of "RESIST-3 O.K.N. K-SeT" immunochromatographic assay for the detection of OXA-48 like, KPC, and NDM carbapenemases in Klebsiella pneumoniae in Turkey.

In this study, the performance of the "RESIST-3 O.K.N.

The impact of a pneumococcal conjugate vaccination program on the nasopharyngeal carriage, serotype distribution and antimicrobial resistance of Streptococcus pneumoniae among healthy children in Turkey.

Background: The 7-valent conjugate pneumococcal vaccine (PCV7) was introduced by the Turkey National Immunization Program in 2008 and replaced by the PCV13 in 2011. We assessed the impact of PCV vaccination on the nasopharyngeal (NP) carriage, serotype distribution and antimicrobial resistance of Streptococcus pneumoniae (SP) among healthy Turkish children.

Methods: A prospective surveillance study was performed between September 2011 and September 2013 in Istanbul, Turkey.

[Investigation of carbapenemases in carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains isolated in 2014 in Turkey].

Carbapenems are the choice of treatment in infections caused by multidrug resistant Enterobacteriaceae. In recent years carbapenem-resistant Enterobacteriaceae isolates due to carbapenemases have been increasingly reported worldwide. Multicenter studies on carbapenemases are scarce in Turkey.

[Serotype distribution and antibiotic susceptibilities of Streptococcus pneumoniae causing acute exacerbations and pneumonia in children with chronic respiratory diseases].

This study aimed to investigate serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates obtained from children with chronic respiratory diseases admitted to hospital with a diagnosis of acute exacerbations between 2008-2010 at Marmara University Hospital, Istanbul, Turkey. Sixty one S.pneumoniae strains isolated from the respiratory samples of patients were studied for erythromycin, clindamycin, tetracyline, trimethoprim-sulphametoxazole (TMP-SMX), vancomycin, levofloxacin susceptibilities by disk diffusion method; MIC values of penicillin and ceftriaxone were determined by E-test (AB Biodisk, Sweden).

[The role of cell wall organization and active efflux pump systems in multidrug resistance of bacteria].

Multiple antibiotic resistance of clinically important bacteria are of major concern worldwide. Alterations of drug targets or enzymatic inactivation of antimicrobial agents are the well known mechanisms of antimicrobial drug resistance. Besides these well known mechanisms, recent studies have shown that a further resistance mechanism, active drug efflux, has become increasingly important in the current threat of multidrug resistance.

Simple and reliable detection of slime production of Candida spp. directly from blood culture bottles: comparison of visual tube method and transmission electron microscopy.

Early detection of slime production may be useful for clinical decision because of its suggestive property for potential pathogenic capacity of a Candida strain especially in patients with a prosthetic device. In this study we aimed to compare the visual tube method (VTM) with transmission electron microscopy (TEM) in order to confirm the reliability of the former method. In order to demonstrate the reproducibility of the tube method and to determine the correct timing for the test, Candida isolates directly obtained from blood culture (DBC) bottles and their two subsequent subcultures were used.

Detection and prevalence of active drug efflux mechanism in various multidrug-resistant Klebsiella pneumoniae strains from Turkey.

The prevalence of active drug efflux pump and porin alterations was investigated in Turkish nosocomial strains of Klebsiella pneumoniae exhibiting a multidrug-resistant phenotype. MICs of various antibiotics, including quinolones, chloramphenicol, tetracycline, and beta-lactams, for those strains were determined either with or without the efflux pump inhibitor phenylalanine arginine beta-naphthylamide (PAbetaN). Thirty-nine percent of the strains exhibited a PAbetaN-modulated resistance for quinolones, chloramphenicol, and tetracycline.