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Introduction: Real-time reverse transcription-polymerase chain reaction (RT-PCR) is the gold standard method for the diagnosis of Severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2) infection. However, real-time RT-PCR is time-consuming, expensive, and requires special laboratory conditions and experienced personnel. Thus, the diagnostic importance of faster and easier-to-perform antigen-detecting rapid diagnostic tests (Ag-RDTs) has increased. With on-site application and fast turnaround time, Ag-RDTs provide quick isolation, minimizing the risk of transmission. We aimed to compare the results of the Mö-Screen Corona Antigen Test (MöLab, Langenfeld, Germany) and real-time RT-PCR. Materials and Methods: Nasopharyngeal swabs from 863 patients from January 2022 to March 2022 were included in the study. The SARS-CoV-2 antigen was assessed for using the Mö-Screen Corona Antigen Test. The SARS-CoV-2 real-time RT-PCR results were obtained within two days in 417 patients. Results: The agreeability of the real-time RT-PCR and Ag-RDT results was 96.2%. The sensitivity and specificity of Ag-RDT were 84.8% and 100%, respectively. The test sensitivity increased to 92% in specimens with Ct value

Purpose: Urinary tract infections are among the most common infections in childhood. In this study, it was aimed to evaluate the factors of urinary tract infection in our hospital and to determine antimicrobial resistance patterns and empirical treatment options. Materials and Methods: The results of urine cultures that were sent from the Department of Pediatrics between 01.01.2015 and 31.12.2020 to the Microbiology Laboratory were evaluated retrospectively. The identification of the bacterial growth was tested in Vitek MS (Biomeriux, France) and the antimicrobial susceptibility of the isolates was tested in Vitek2 Compakt (Biomeriux, France). Results: A total of 4257 urine culture samples were evaluated. The most frequently isolated bacteria were E. coli 62.93% followed by Klebsiella spp. 19.6%, Pseudomonas spp. 5.37%, Proteus spp. 4.48%. The highest resistance rates were determined against ampicillin in E. coli (78.96%) and for cefuroxime (63.11%) in Klebsiella spp isolates. The lowest resistance rate was determined against imipenem and meropenem in E.coli (0.12%, 0.15%) isolates and, amikacin and nitrofurantoin in Klebsiella spp. isolates (6.10%, 2.46%). Conclusion: In order to provide effective treatment for urinary tract infections and to minimize morbidity and long-term complications, the frequency of the pathogens causing UTIs, local or regional antibiotic resistance should be known and empirical treatment should be arranged accordingly.

Introduction: The prevalence and spread rate of the Escherichia coli ST131 clone continue to be an important issue requiring investigation. This study investigated the presence of the ST131 clone in E. coli isolates isolated from intensive care units (ICUs) and other services using real-time polymerase chain reaction (PCR). Materials and Methods: A total of 200 E. coli isolates were included in the study. The double-disk synergy method was used to show the presence of extended-spectrum beta-lactamases (ESBL). The ST131 clones were investigated using the real-time PCR method in all isolates. Results: E. coli ST131 clones were identified in 17 of 100 strains isolated from the specimens from ICUs. Of these strains, 15 (29.4%) of the 51 ESBL positive isolates and two (4.1%) of the 49 ESBL negative isolates were identified as E. coli ST131 clones. E. coli ST131 clones were identified in 13 of 100 strains isolated from non-ICUs. Among these strains, 12 (34.3%) of 35 ESBL positive isolates and one (1.5%) of the 65 ESBL negative isolates were identified as E. coli ST131 clones. Conclusion: While the E. coli ST131 clone was common in ESBL-producing isolates, its presence did not differ in intensive or non-ICUs.

Introduction: Aminoglycosides are the drug of choice for the treatment of Pseudomonas aeruginosa infections. Aminoglycoside resistance in P. aeruginosa often occurred via acquired aminoglycoside-modifying enzymes (AMEs). In this study, we aimed to investigate the presence of AME in P. aeruginosa in carbapenem-resistant and carbapenem-susceptible isolates. Materials and Methods: A total of 98 isolates of P. aeruginosa from various clinical samples presenting resistance to amikacin and/or gentamicin were included in this study. Fifty-four were carbapenem-resistant isolates. Polymerase chain reaction amplification of six genes for AMEs (aac(6’)-Ib,aac(6’)-IIa, aac(3’)-IIa, aph(3’)-Ia,aph(3’)-VIa, ant(2’’)-Ia) was performed. Results: The most frequent AME gene was aac(6’)-Ib (n=13, 13.2%), followed by ant(2’’)-Ia (n=7, 7.1%). aac(6’)-Ib was the most common AME in carbapenem-resistant isolates (11/54, 20.3%); however ant(2’’)-Ia was the most common AMEs in carbapenem-susceptible isolates (4/44, 9%). In 74 of the isolates, none of the AME genes was detected. aac(6’)-Ib positivity in carbapenem-resistant isolates was significantly higher than that in carbapenem-susceptible isolates. Conclusion: Aminoglycosides are one of the drug of choice in carbapenem-resistant P. aeruginosa isolates. However, given the transfer of multidrug resistance determinants, the presence of AME was significantly higher in carbapenem-resistant isolates, and monitoring resistance determinants among Gram-negative bacteria is crucial.

Introduction: Stenotrophomonas maltophilia, a non-fermentative bacterium, predominantly causes opportunistic infections in immunocompromised individuals and those receiving long-term, large-dose, broad spectrum antimicrobial agents. It is inherently resistant to most of the available antimicrobial agents. Trimethoprim-sulfamethoxazole (TMP/SMX), ceftazidime (CAZ), and levofloxacin (LVX) are the drugs of choice used for the infection treatment. The study aims to investigate the presence of plasmid-mediated quinolone resistance determinants of QnrA, QnrB, QnrC, QnrD, QnrS, and OqxAB genes in S. maltophilia isolates. Materials and Methods: A total of 122 S. maltophilia isolates from various clinical specimens were tested in the study. The susceptibility of TMP/SMX and LVX was determined by disk diffusion method. The minimum inhibitory concentration value of CAZ was determined by the gradient diffusion test. Qnr (A, B, C, S, D) determinants and OqxAB were investigated using multiplex polymerase chain reaction. OqxA was investigated in the isolates and the presence of OqxB in OqxA-positive isolates. Results: Five (4%) of the S. maltophilia isolates were resistant to TMP/SMX. Levofloxacin and CAZ resistances were determined as 6.5% and 56.5%, respectively. QnrS was detected in two of the isolates, and OqxA gene was found in three isolates. However, these isolates were not OqxB positive. One of these three positive isolates has been previously found to be QnrS-positive. Conclusion: In our study, QnrS was detected in two and OqxA gene in three of the S. maltophilia isolates.

Background In dental clinics, aerosols produced from dental instruments have become a matter of concern following breakout of coronavirus disease 19 (COVID-19) evolving into a pandemic. This study compared aerosol reduction systems and in terms of their ability to reduce Enterococcus faecalis (E. faecalis) contaminated aerosol in a simulated dental office set-up. Methods Closed clinic model with manikin and mandibular molar typodont was simulated. For 10 min, the air and water dispersed by the rotating bur mounted on an aerator was contaminated by pouring the suspension containing 1–3 × 108 CFU/mL E. faecalis directly on the bur. During and after the procedures, the air within the cabin was also sampled. CFU count was recorded and scored. The mean CFU scores obtained from agar plate count and air sampling device was compared using Kruskal–Wallis H test among groups with 5% significance threshold. Results The use of WS Aerosol Defender device led to greater CFU scores on the agars levelled to patient’s chest compared to other directions (p = 0.001). Combined use of VacStation and WS Aerosol Defender resulted in significantly decreased CFU score in the air samples compared to experimental and positive control groups (p = 0

INTRODUCTION: Aminoglycosides are used in gram-negative bacterial infection and are frequently used against Enterobacteriaceae and nonfermentative bacteria. Recently, increased resistance to aminoglycosides has been observed. In this study, we aimed to see aminoglycoside resistance in Enterobacteriacea and nonfermentative bacteria and the effectiveness of aminoglycosides in carbapenem resistant Enterobacteriacea isolates. METHODS: Aminoglycoside resistance rates of 4076 Enterobacteriaceae and 1252 nonfermentative bacteria isolated from various clinical samples sent to microbiology laboratory between November 2015 and September 2016 were investigated. The identification of bacteria was made at the species level with the Vitek MS automated system. RESULTS: The total resistance rate in enterobacteriaceae isolates was found to be 2.72% for amikacin and 17.44% for gentamicin. In Enterobacteriaceae group, resistance to 1.13% gentamicin was found against Escherichia coli (E.coli) (56%) and 16.08% against amikacin. For Klebsiella (25.7%) isolates, amikacin was 5.91% and gentamic was 26.04%. Among nonfermentatives, amicacin was determined as 46%, gentamicin 76%, netilmicin 55% and tobramycin 40.8% in Acinetobacter species. In Pseudomonas strains, amikacin was 4.97%, gentamicin was 14.3%, netilmicin was 27.3%, and tobramycin resistance rate was 7.74%. DISCUSSION AND CONCLUSION: Amikacin was found to be more sensitive than gentamicin in Enterobacteriaceae isolates. In nonfermantative bacteria, it was found that the most sensitive aminoglycoside in the Acinetobacter isolates was tobramycin, and the most sensitive aminoglycoside in the Pseudomonas isolates was amikacin. In carbapenem resistant Enterobacteriaceae strains, amikacin was found to be more sensitive than gentamicin.

INTRODUCTION: In this study, we aimed to investigate antituberculosis drug susceptibility of the Mycobacterium tuberculosis complex isolates, between 2014 and 2017 retrospectively. METHODS: The specimens from patientswith a pre-diagnosis of tuberculosis were stained with Ehrlich-Ziehl-Neelsen method and evaluated microscopically. After then, specimens were inoculated onto Löwenstein-Jensen medium and BACTEC MGIT 960 (Becton Dickinson, USA) automated culture system. If bacterial growth was detected, Mycobacterium tuberculosis complex typing was done and antituberculosis drug susceptibilities for streptomycin, isoniazid, rifampicin and ethambutol were tested at BACTEC MGIT 960 (Becton Dickinson, USA). RESULTS: Totally 78 Mycobacterium tuberculosis complex isolates were enrolled in the study. A single strain for each patient was taken to the study. Resistance rates of isoniazid, streptomycin and ethambutol were determined as 1.2%, 8.9% and 1.2%, respectively and no resistance to rifampicin was detected. 82% of the isolates were susceptible to all drugs and the highest resistance among antimycobacterial drugs was determined for streptomycin. DISCUSSION AND CONCLUSION: The single drug resistance that determined in our study was lower than 2017 tuberculosis report however it is known that there might have been differences between the regions.

Background/purpose: Enterococcus faecalis is the bacterium most commonly isolated from infected root canals. This study evaluated the effects of four instrumentation techniques on reducing E. faecalis in curved root canals. Materials and methods: Sixty maxillary first molar teeth were used. After mesiobuccal canals had been instrumented with nickel–titanium (NiTi) K-files up to size 25, the teeth were autoclaved, immersed in a broth inoculated with E. faecalis, and incubated for 48 hours. The teeth were divided into four experimental groups (n = 15). The mesial root canals were instrumented using ProTaper, RaCe, and Mtwo rotary instruments, and hand-operated NiTi files. Irrigation was performed using sterile saline solution. For each root canal, three samplings were performed: twice before preparation and once after preparation. After serial dilutions, samples were incubated, and the colony-forming units were counted. Results: All instrumentation techniques reduced E. faecalis infection in curved root canals. However, there were statistically significant differences among the instrumentation techniques regarding the numbers of residual bacteria (P

In this study we evaluated the crystal violet decolorization assay (CVDA) for detection of minimum inhibitory concentration (MIC) of antituberculosis drugs. 53 isolates were tested in this study and 13 of them were multidrug resistant (MDR) isolates. The antibiotics concentrations were 2-0.06 mg/L for isoniazid (INH) and rifampicin (RIF) and were 16-0.25 mg/L for streptomycin (STM) and ethambutol (EMB). Crystal violet (CV-25 mg/L) was added into the microwells on the seventh day of incubation and incubation was continued until decolorization. Decolorization of CV was the predictor of bacterial growth. Overall agreements for four drugs were detected as 98.1%, and the average time was detected as 9.5 ± 0.89 day after inoculation. One isolate for INH and two isolates for STM were determined resistant in the reference method, but susceptible by the CVDA. One isolate was susceptible to EMB by the reference method, but resistant by the CVDA. All results were concordant for RIF. This study shows that CVDA is a rapid, reliable and suitable for determination of MIC values of Mycobacterium tuberculosis. And it can be used easily especially in countries with limited-sources.

Objective: Although there are limited numerous reports of candidemia in adults, data on paediatrics are stil limeted. The aim of the present study was to compare the aetiology and risk factors of nosocomial candidemia among the paediatric and adults in our hospital. Materials and Methods: This study includes the patients hospitalised and diagnosed as fungemia at Ondokuz Mayis University Hospital between June 30, 2007 and June 30, 2009 whose blood cultures sent to our microbiology laboratory. After fungal growth was observed in blood cultures, the yeast cells were inoculated onto Saboraud glucose agar. The colonies were identified by conventional yeast identification methods and ID 32C yeast identification system according to the manifacturer’s instructions. Results: During this period 51 paediatric and 69 adults were studied. The most common yeast form was Candida albicans (43.3%) followed by C. parapsilosis (25.0%) and C. tropicalis (17.5%). Although the non-albicans Candida species represent more than half (56.7%) of all candidemic cases C. albicans was the most common frequent etiologic agent. There was no statistically significant difference between patient age (paediatric and adult) and distribution of Candida species (p>0.05) Neoplasia (in adults) and prematurity (in paediatrics) were the main underlying diseases. Predisposing factors and mortality rates were not different among paediatrics and adults.Conclusion: We reinforce the necessity of continous epidomiologic surveillance to follow the dynamics of candidemia.

The susceptibility of 49 Mycobacterium tuberculosis clinical isolates to isoniazid (INH) and rifampisin (RIF) (28 multi-drug resistant-tuberculosis samples) was determined by a nitrate reductase assay (NRA) on blood agar. Agreement between the NRA and other testing methods was found to be 93.8% for both INH and RIF. The sensitivity, specificity, positive predictive value and negative predictive value for INH were 92.8%, 94.2%, 86.6% and 97%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for RIF were 90.4%, 96.4%, 95% and 93.1%. In conclusion, we show here that blood agar can be used effectively for the NRA test.

BACKGROUND Mycobacterium tuberculosis (MTB) is one of the most significant causes of mortality and morbidity. Early diagnose is important especially in multiple drug resistant tuberculosis to avoid transmission. Traditional techniques requires at least one to three weeks for diagnosis of tuberculosis. Diagnostic delays with multiple drug resistant tuberculosis are associated with worse clinical outcomes and increased transmission The Xpert MTB/RIF assay is one of the new diagnostic device for the diagnosis of tuberculosis and rapid detection of rifampicin resistance. OBJECTIVE We assessed the performance of Xpert MTB/RIF assay for detecting rifampicin resistance using phenotypic drug susceptibility tests as automated BD MGIT 960. METHODS Total of 2136 specimens were included in the study. Xpert MTB/RIF testing was performed on samples, using version 4 cartridges, according to the manufacturer's recommendations. The MTBC culture and first-line phenotypic DST were performed in automated BD MGIT 960 (Becton & Dickinson, USA) according to the recommendations of the manufacturer. Agar proportion was used in the case of inconsistency for rifampicin resistance. FINDINGS Thirty-four samples (19 respiratory and 15 nonrespiratory samples) were determined as positive for M. tuberculosis complex by Xpert MTB/RIF (Cepheid GeneXpert® System, USA). Xpert MTB/RIF assay detected 4/34 (11.7%) specimens as rifampicin resistant. One of the rifampicin resistant isolates was determined susceptible in MGIT 960 automated system. This isolate was also tested with agar proportion method and found susceptible to rifampicin. MAIN CONCLUSION The Xpert MTB/RIF assay can be used as first-line assay for the detection of M. tuberculosis. However, microbiologists must be aware of the limitations of the assay.