Antimicrobial resistance and epidemiological patterns of Streptococcus pyogenes in Türkiye.

Background: Drug-resistant Group A beta-hemolytic streptococci remain significant infectious agents globally. This study investigated the major S. pyogenes strains responsible for infections in Türkiye and their susceptibility to beta-lactam and macrolide antibiotics.

[The Importance of Gram-stained Smears in the Diagnosis of Nocardia Infections].

Nocardia species are low virulence bacteria found in nature. They can be an infectious agent, especially in patients with risk factors such as underlying immunosuppression, chronic lung disease, and malignancy. They can be easily overlooked because they are not seen frequently and has no pathognomonic symptoms.

Serotype distribution of and pneumococcal vaccine coverage in adults in Turkey between 2015 and 2018.

Objective: To evaluate the serotype distribution and antibiotic resistance in pneumococcal infections in adults and to provide a perspective regarding serotype coverage of both current and future pneumococcal vaccines.

Patients And Methods: This passive surveillance study was conducted with the strains isolated from the specimens of patients with pneumonia (materials isolated from bronchoalveolar lavage), bacteraemia, meningitis, pleuritis and peritonitis between 2015 and 2018. Serogrouping and serotyping were performed by latex particle agglutination and by conventional Quellung reaction using commercial type-specific antisera, respectively.

Whole-Genome Sequence Analysis of Carbapenem-Heteroresistant Klebsiella pneumoniae and Escherichia coli Isolates.

Carbapenem-heteroresistant isolates can be misclassified as susceptible by in vitro susceptibility tests, leading to treatment failure. The underlying mechanisms of heteroresistance, where the bacterial isolate harbors both resistant and susceptible subpopulations, are poorly understood. The aim of the current study was to clarify molecular mechanisms responsible for carbapenem heteroresistance.

A twenty years' results of the antimicrobial resistance profile and multidrug resistance trend of invasive Streptococcus pneumoniae isolates recovered from adult patients in Turkey: A literature review.

Purpose: The aim of this study is to analyze antimicrobial resistance and multidrug (MDR)/extensively (XDR) resistance trend among Streptococcus pneumoniae isolates causing invasive disease in adult patients.

Methods: We analyzed antimicrobial resistance and multidrug resistance trend among invasive S.pneumoniae isolates recovered from adult patients (≥18-years) in a tertiary University Hospital, Turkey between 1996 and 2018.

Factors Associated with Gram-Negative Bacteremia and Mortality in Neutropenic Patients with Hematologic Malignancies in a High-Resistance Setting.

Objective: Patients with hematological malignancies (HMs) have a substantial incidence of febrile neutropenic episodes. Gram-negative bacteremia (GNB) is still the major cause of these episodes. We evaluated the factors associated with GNB and mortality of bacteremic patients with HMs in a high-resistance setting.

Comparison of a novel antigen detection test with reverse transcription polymerase chain reaction assay for laboratory diagnosis of SARS-CoV-2 infection.

Molecular diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription polymerase chain reaction (RT-PCR) in respiratory specimens is considered the gold standard method. This method is highly sensitive and specific but it has some limitations such as being expensive and requiring special laboratory equipment and skilled personnel. RapidFor™ Antigen Rapid Test Kit is a commercially available Ag-RDT which is produced in Turkey and designed to detect the nucleocapsid antigen of SARS-CoV-2 in nasopharyngeal swab samples.

[The Use of Resapolymyxin NP Test in Determining the Sensitivity of Colistin in Escherichia coli, and Klebsiella pneumoniae Isolates].

Colistin is used as the last choice of drug in multidrug resistant gram-negative bacilli infections; therefore, accurate detection of colistin susceptibility has gained critical importance. Unfortunately, many of the widely used and practical methods in the clinical laboratory have various limitations for the determination of colistin susceptibility. This situation has led researchers to search for new methods to determine colistin susceptibility.

Sensitivity Affected by Disease Severity and Serum Sampling Time: a Performance Evaluation of Six SARS-CoV-2 Antibody Immunoassays.

Comparative validation and clinical performance data are essential for the reliable interpretation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibody test results. This study aimed to assess the performance of six SARS-CoV-2 IgG immunoassays in the context of different disease severities. Four automated chemiluminescence immunoassays (Access [Beckman Coulter], Architect [Abbott], Atellica-IM [Siemens], and Elecsys [Roche]) as well as two ELISA assays (SARS-CoV-2 IgG-S1-based and NCP IgG [Euroimmun]) were evaluated using samples from 143 patients as well as 50 pre-pandemic control serum samples.

A retrospective observational cohort study of the clinical epidemiology of bloodstream infections due to carbapenem-resistant Klebsiella pneumoniae in an OXA-48 endemic setting.

This study aimed to characterize the epidemiology and clinical outcomes of patients with bloodstream infections (BSIs) due to carbapenem-resistant Klebsiella pneumoniae (CRKP) in an OXA-48-predominant environment. This was a retrospective single-centre cohort study including all consecutive patients with CRKP BSIs treated between 1 January 2014 and 31 December 2018. Multivariate analysis, subgroup analysis and propensity-score-matched analysis were employed to analyse 30-day mortality as the primary outcome.

Evaluation of a Commercial Broth Microdilution Panel for Colistin Susceptibility Testing of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae.

Background: Colistin is among the last resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. Antimicrobial susceptibility testing of colistin is challenging due to its physicochemical properties. Broth microdilution (BMD) is the recommended method for colistin susceptibility testing.

Molecular characteristics of Staphylococcus aureus strains isolated from nasal samples of sixth year medical students during their pediatric services practices.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are prevalent in healthcare services. Medical students are at risk for MRSA carriage, subsequent infection and potential transmission of nosocomial infection.Few studies have examined MRSA carriage among medical students.

Comparison of Conventional Methods, Automated Systems, and DNA Sequence Analysis Methods in the Identification of and Bacteria Isolated from Blood and Catheter Culture Samples.

The aim of this study is to compare different methods due to the difficulties in identifying coryneform bacteria to species level and to determine antibiotic resistance profiles. Isolates identified as (:45) by VITEK 2 Compact and (:1) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), isolated from blood and catheter cultures between 2015 and 2017 were included in the study. For identification of the isolates, conventional tests and 16S rDNA sequence analysis were performed.

Low prevalence of hypervirulent Klebsiella pneumoniae in Anatolia, screened via phenotypic and genotypic testing.

Hypervirulent Klebsiella pneumoniae (hvKP) strains are associated with vigorous clinical presentation and relapses. Initially reported from Asia, these variants have spread globally and become an emerging agent of significant health threat. This study was carried out to identify hvKP strains in a previously uninvestigated region and to evaluate the impact of commonly-employed phenotypic and genotypic markers as diagnostic assays.

Prevalence of O25b-ST131 clone and fosfomycin resistance in urinary Escherichia coli isolates and their relation to CTX-M determinant.

Escherichia coli ST131 clone and H30-R/H30-Rx subclones are the most common multidrug-resistant high-risk clones in UTIs. Antimicrobial susceptibility of fosfomycin was compared to five other agents in consecutively collected 299 urinary isolates using the agar dilution method. Prevalence of the ST131 clone and the occurrence of blaCTX-M were also investigated.

Stenotrophomonas maltophilia bacteremia in children - A 10-year analysis.

Stenotrophomonas maltophilia is a multidrug-resistant, Gramnegative, and biofilm-forming pathogen. Information is limited concerning S. maltophilia bacteremia in children.

Epidemiologic and Molecular Characteristics of Staphylococcus aureus Strains Isolated From Hospitalized Pediatric Patients.

Background: We aimed to determine molecular characteristics of Staphylococcus aureus isolates cultured from hospitalized pediatric patients.

Methods: All accessible S. aureus isolates cultured from hospitalized pediatric patients were analyzed for staphylococcal cassette chromosome mec (SCCmec) types, Panton-Valentine Leukocidin (PVL) encoding genes and antibiotic resistance patterns.

Resistance and heteroresistance to colistin among clinical isolates of Acinetobacter baumannii.

Colistin is one of the most effective alternatives for treating Acinetobacter baumannii infections. The aim of this study was to determine colistin resistance and heteroresistance rates in A. baumannii from clinical samples in Hacettepe University clinical microbiology laboratory between June 2016 and January 2017.

Uropathogens and Gestational Outcomes of Urinary Tract Infections in Pregnancies that Necessitate Hospitalization.

Background And Objectives: Our aim is to identify uropathogens that cause urinary tract infections (UTIs) that necessitate hospitalization, and analyze outcomes of gestational UTIs.

Methods: This study consisted of 30 pregnant women who necessitate hospitalization because of UTI (7.8% of gestational UTIs during the same period of time).

A case of Raoultella ornithinolytica urinary tract infection in a pediatric patient.

Raoultella ornithinolytica is a Gram-negative, non-motile, encapsulated, biofilm producing, facultative aerobic bacillus and is found in natural environment. Human infections with R.ornithinolytica is rare in children with only five cases having been reported previously.

Streptococcus mitis/oralis Causing Blood Stream Infections in Pediatric Patients.

Viridans streptococci are still under investigation concerning epidemiology, pathogenesis and clinical presentations. We aimed to investigate the clinical presentations and outcomes of pediatric patients infected with Streptococcus mitis/oralis. Based on the accumulation of bloodstream infections (BSI) caused by S.

Clinical Strains of Chryseobacterium and Elizabethkingia spp. Isolated from Pediatric Patients in a University Hospital: Performance of MALDI-TOF MS-Based Identification, Antimicrobial Susceptibilities, and Baseline Patient Characteristics.

Our objective was to evaluate the performance of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identification of the Chryseobacterium and Elizabethkingia spp. isolated from pediatric patients at Hacettepe University Hospital using 16S rRNA gene sequencing as the gold standard and to determine the antimicrobial susceptibility patterns of the isolates and baseline characteristics of patients. All stored Chryseobacterium and Elizabethkingia spp.

A comparison of blood stream infections with extended spectrum beta-lactamase-producing and non-producing Klebsiella pneumoniae in pediatric patients.

Background: Rapid development and global spread of multidrug resistant Klebsiella pneumonia (K. pneumoniae) as a major cause of nosocomial infections is really remarkable. The aim of this study was to explore risk factors for health care associated blood stream infections (BSI) caused by ESBL-producing K.

Current epidemiology of resistance among Gram-negative bacilli in paediatric patients in Turkey.

Objectives: The increasing incidence of infections caused by drug-resistant Gram-negative organisms has led to a re-emergence worldwide. This study attempted to investigate the changes in resistance of Gram-negative bacteria to different classes of antibiotics and the treatment options for invasive infections.

Methods: A retrospective study was performed between January 2012 and January 2017 in a Turkish tertiary care university hospital.