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We report a nosocomial outbreak caused by a multidrug-resistant carbapenemase-producing Klebsiella pneumoniae (MDRCPKp), that was detected in six patients admitted to the medical intensive care unit between 20th of December 2023 and 15th of January 2024 in Ankara, Turkey. The investigation of this outbreak was started on 29th of December 2023. During the outbreak 11 samples were collected from the six patients with MDRCPKp. Pulsed-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness and clonality of MDRCPKp strains. MDRCPKp was isolated in the tracheal aspiration culture, blood, urine, and screening samples. Five patients with MDRCPKp colonization developed healthcare-associated infection. In one patient MDRCPKp was isolated from tracheal aspirate and the screening cultures were considered as colonization not infection. PFGE analysis revealed that all isolates belonged to the same K. pneumoniae clone. MDRCPKp strain of this outbreak exhibited multidrug resistance and co-produced OXA-48 and NDM-1. This outbreak ended after application of strict infection control measures. An outbreak of MDRCPKp can occur in hospitals, especially in the intensive care units; thus, it should be detected early by infection control teams. A strong collaboration between infection control team and microbiology laboratory is essential to cope with MDR bacterial outbreaks in hospitals.

Introduction: Ralstonia pickettii infections are rare and may be mistaken for other bacteria. This study aims to report a hospital outbreak of R. pickettii at a tertiary hospital, which was initially misidentified as Ralstonia insidiosa, along with its clinical consequences., Methodology: A bacteraemia outbreak occurred between August 14 and October 4, 2019, infecting 22 patients admitted to diverse intensive care units. All isolates were identified with the use of the automated VITEK 2 Compact system and were then subjected to a microbial identification system, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Bacterial identification and genomic DNA typing was made using pulsed-field gel electrophoresis. Investigation covered all potential sources of the outbreak., Results: An index patient and five additional patients developed fever while receiving care. Blood cultures of these patients yielded R. insidiosa by the VITEK 2 Compact system. Culture isolates were then submitted to a reference centre for confirmation by the MALDI-TOF MS system, where the bacterium turned out to be R. pickettii. No pathogen was isolated in the commercial products except for three samples of unopened sterile distilled water. Despite its discontinuation, 16 new cases were identified, in which blood cultures grew R. pickettii by the MALDI-TOF MS system. Attempts to uncover the source of the outbreak failed. Clinical manifestation was confined to fever in all the patients., Conclusions: During this outbreak, R. pickettii infections ran a relatively mild course without clinical deterioration or mortality, possibly due to low virulence., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2022 Sirin Menekse, Demet Hacıseyitoglu, Serap Suzuk Yildiz, Fatma Bayrakdar.)

Background: We report a nosocomial outbreak caused by Burkholderia cepacia that occurred among six patients admitted in the medical and surgical intensive care unit between 04 March 2019 and 02 April 2019 in Istanbul, Turkey., Methods: The outbreak investigation was launched on 11 March 2019 five days after the detection of B. cepacia in four different patients. We defined potential reservoirs and started environmental screening. We sampled the liquid solutions used in patient care activities. Pulse-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness of environmental and patient samples., Results: Burkholderia cepacia was isolated in tracheal aspiration cultures of six patients. Three out of six patients developed healthcare-associated pneumoniae due to B. cepacia. Environmental cultures in the ICUs revealed B. cepacia growth in 2% chlorhexidine-gluconate mouthwash solution that been used in the colonized patients as well as in samples obtained from the unused products. PFGE revealed the patient and a specific batch of chlorhexidine mouthwash solution samples had a 96% similarity., Conclusion: Contamination of medical solutions used in critical patient care could cause outbreaks and should be detected early by infection control teams., (© 2021. The Author(s).)

Antibiotic resistance is one of the most important public health problem and one of the most critical steps in preventing resistance is the monitorization of the resistance. Local, regional and global monitoring enables the spread of antibiotic resistance to be understood more clearly. In this study, it was aimed to evaluate the results of the pilot study for the establishment of molecular-based carbapenem surveillance system in Escherichia coli and Klebsiella pneumoniae isolates and to investigate the carbapenemase epidemiology in Turkey. Hospitals (n= 28) from 26 different statistical level II regions from Turkey were included in the study. The hospitals participated in the study submitted ten carbapenem susceptible and ten carbapenem resistant E.coli and K.pneumoniae isolates to our laboratory that were isolated in two different periiods of six-month either between 1 March-31 August or 1 April-30 September 2019. A total of 509 isolates were collected from 26 of the 28 participating hospitals in the study. Isolates were identified by matrix assisted laser desorptionization-time of flight mass spectrophotometry (MALDI TOF MS) (Bruker Daltonics, Germany) method and antibiotic susceptibility tests for imipenem, meropenem and colistin were studied by broth microdilution. Moreover, susceptibilities to amikacin, amoxicillin-clavulanic acid, ampicillin, aztreonam, cefepime, cefotaxime, ceftazidime, ciprofloxacin, ertapenem, gentamicin, piperacillin-tazobactam, tobramycin and trimethoprim-sulfamethoxazole were determined by disc diffusion method. The resistance genes were investigated in isolates which were found to be phenotypically resistant to carbapenem and colistin, in house method was used to investigate carbapenemase genes and a commercial colistin resistant real-time PCR kit (Biospeedy, Turkey) was used for colistin resistance genes. In total, 493 of the 509 isolates collected from hospitals were identified as E.coli (25.7%, n= 127) and K.pneumoniae (74.3%, n= 366) and included in the study. It was determined that 31% of the isolates evaluated were from community-acquired infections and 69% were either from healthcare-associated infections or from colonization sites. Among the tested isolates, 248 (50.3%) were susceptible to carbapenems and 245 (49.7%) were resistant. The types of carbapenemases in carbapenemase-producing were OXA-48 (52.2%), KPC (16.1%), NDM-1 (15%), OXA-48 + NDM-1 (12.6%), KPC + NDM-1 (2.8%) and VIM (0.5%) and OXA-48+VIM (0.5%). Resistance to colistin was detected in 23.3% of the isolates but mcr1-8 genes were not detected. It was found that all colistin resistant isolates are resistant to at least one of the carbapenems. The importance of a molecular-based antimicrobial resistance surveillance system in our country was demonstrated with this pilot study. It is thought that continuous monitoring of these epidemiological features will contribute to the management of infections due to carbapenemase-producing organisms.

It has been reported that direct identification from blood culture bottles with positive signals and reporting the results to the clinics earlier has positive effects on mortality and morbidity. Extraction methods especially using detergents are used for the direct identification from the bottles which give positive signal. For this purpose, in-house methods developed based on the usage of saponin are widely available in the literature. In this study, it was aimed to develop a simple, easy-to-apply and reliable protocol for identifying the agent directly from the blood culture bottle that gives positive signal with the use of detergent Tween® 80, and to study the obtained protocol in clinical samples in a routine microbiology laboratory and to evaluate the results. The study was carried out in two stages, the experimental stage where the method was developed and the clinical stage where the method was applied. In the experimental stage, blood culture bottles were created with standard strains and isolates previously diagnosed with the 16S rRNA method. 10% solution of Tween® 80 was prepared with distilled water. 1 ml sample was transferred from the bottle that gave positive signal to the microcentrifuge tube, 100 µl of 10% solution of Tween® 80 was added, vortexed for 10 seconds and then incubated for 5 minutes at room temperature. The tubes were centrifuged for 5 min at 14.000 rpm, the supernatant was discarded and the pellet was washed with 1 ml of distilled water and centrifuged at 14.000 rpm for 5 minutes in three times. Samples taken from the pellets were rubbed on the slide and dried on air. Firstly, 1 µl of 70% formic acid, then 1 µl, of matrix solution was added and it was used after drying. In the second stage of the study, the method was applied to the 502 vials giving positive signal in the Microbiology Laboratory of Ankara University Faculty of Medicine Ibni Sina Hospital between 17 April 2018-31 August 2018 and the results were compared with the subculture results. The results obtained at the end of extraction in the experimental stage were compared with the subculture results and no statistical difference was found. In 383 (82.9%) bottles among 462 (92.1%) bottles with monomicrobial positive cultures, compatible results with the subculture results were obtained. Of the microorganisms correctly identified, 350 (91.3%) were bacteria and 33 (8.7%) were fungi. On the other hand, 216 (56.4%) of the bacteria were gram positive and 134 (34.9%) of them were gram negative bacteria. At least one microorganism was correctly identified in 19 (47.5%) of 40 (7.9%) bottles with polymicrobial blood cultures. Their distribution was gram negative (n= 10) and gram positive (n= 8) and yeast (n= 1). No microorganisms were identified in six bottles with polymicrobial cultures. According to the results, we believe that this in-house method developed using Tween® 80 will be a routinely applicable method for blood culture bottles that give positive signal in microbiology laboratories and it will contribute to the early diagnosis.

When the problem with carbapenem-resistant Enterobacteriaceae (CRE) increases, the older antimicrobial agents such as colistin and fosfomycin are used for the treatment of these infections. In this study, the broth microdilution method for colistin and the agar dilution method for fosfomycin were used for a total of 147 multidrug-resistant (MDR) or extensively drug-resistant (XDR) strains of CRE. The study included Klebsiella pneumoniae (91.16%), Escherichia coli (7.48%), Enterobacter cloacae (0.68%), and Serratia marcescens (0.68%). All these strains produce various types of carbapenemase, including OXA-48, NDM, and KPC. Some of these strains also have three different carbapenemase mechanisms, including OXA-48 (78.23%), NDM (2.04%), and KPC (0.68%) or OXA-48 and NDM (10.88%), or OXA-48 and KPC (0.68%). About 76.19% of the strains and 67.35% of the strains were resistant for colistin and fosfomycin, respectively. A total of 21 out of 35 colistin-susceptible strains were found to be susceptible to fosfomycin. This study showed that the resistance rates of colistin and fosfomycin are high. The MDR and XDR strains of CRE are spreading in our region and thus a monitoring system for CRE should be followed. Moreover, the applicability of antimicrobial stewardship programs should be increased in all inpatient and outpatient settings.

Purpose: Anthrax, caused by the bacterium Bacillus anthracis, is one of the oldest documented infectious diseases in both livestock and humans. We aimed to evaluate clinical findings and risk factors of patients with cutaneous anthrax infection and report anti-lethal factor (LF) IgG and anti-protective antigen (PA) IgG titers in the serologic diagnosis of disease., Methods: In this study, serum samples of 18 cutaneous anthrax patients were collected and anti-LF IgG and anti-PA IgG titers were measured by enzyme-linked immunosorbent assay (ELISA)., Results: Twelve (67%) males and 6 (33%) females, with a mean age of 36.06 ± 16.58 years were included in the study. Risk factors identified in the patient population studied were slaughtering (28%), flaying (56%), chopping meat (67%), burying diseased animal corpses (17%) and milking (6%) livestock. Black eschar formation (94%), pruritus (78%) and painful lymphadenopathy (61%) were first three common clinical signs and symptoms, respectively. Fourteen (78%) patients produced a positive IgG response against PA, 11 (61%) patients produced against LF. Three (17%) patients had no response to either antigen., Conclusions: A detailed history of contact with sick animals or animal products along with clinical findings should be taken at the first step for the diagnosis of cutaneous anthrax infection. Serologic detection of anti-LF IgG and anti-PA IgG with ELISA may be useful auxillary method for establishing the diagnosis.

Establishment of sustainable and evidence-based surveillance systems are recommended for prevention of microbial resistance by the World Health Organization (WHO). As a necessity of these surveillance systems, participants are recommended to implement an external quality assessment (EQA) program. In this scope, National Antimicrobial Resistance Surveillance System (NARSS) has been established within the Public Health Institute of Turkey (PHIT) in our country since 2011. In the scope of this surveillance, NARSS EQA program has been implemented in a cycle per year and four isolates were sent to participants per cycle every year since 2011. In this study, it was aimed to evaluate the six years results of the EQA programs being implemented on NARSS participants between 2011 and 2016. The surveillance system consisted of 118 laboratories. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecium/faecalis and Acinetobacter baumannii bacteria included in scope of the surveillance were sent to participants. Identification of bacteria to the species level, verification of the antibiotic susceptibility test results and existence of specified resistance of the isolates performed with valid test methods required from the participants. Identified isolates were cultured with routine microbiological methods and sent to participants in ambient temperature in triple carrying pouches inside suitable carrying media via PTT Cargo. The results were entered by means of passwords prepared by PHIT and sent to the web based system. The analysis of results were made with SPSS program. A total of twenty-three isolates were sent to participants between 2011 and 2016. It was determined that participants commonly preferred automated systems for bacterial identification and antibiotic sensitivity test results. The use of MALDI TOF MS system was determined to be raised up to 15.65% in 2016. It has been determined that usually little mistakes were done in bacterial identification but the error rate was high especially in antimicrobial susceptibility test results with close clinical threshold values. Although not required for antibiotic susceptibility test results, it was determined that phenotypic tests have been used more widely in determining the specific resistance mechanisms that are important for epidemiological data. It was determined that 80% of participants have used EUCAST standards in 2016. As a result of this research, we have observed that EQA studies of NARSS EQA are a good performance tool for sustainable and evidence based surveillance studies, that the national antimicrobial resistance data quality is sufficiently good and that the data can be shared on international platforms. In addition, the regular maintenance of national surveillance studies shown that laboratories have positive reflections on self improvement in achieving up to date and accurate results.

Accurate identification of viridans group streptococci (VGS) frequently encountered as a causative agent of infective endocarditis is always a challenge for the clinical microbiology laboratory. Clinical microbiology laboratories generally use semi automatic/full automatic systems, molecular methods and also conventional methods for the identification of these bacteria. There are recent published studies that have used MALDI-TOF (Matrix Assisted Laser Ionization Mass Spectrometry-Time of Flight) systems in the identification of VGS. The aim of the study was to compare the performance of the conventional methods, semi automatic and MALDI-TOF MS system used in identification of VGS in oral microbiota of persons under the risk of infective endocarditis, with the gold standard method 16S rRNA sequence analysis and to create a diagnosis algorithm for the identification of VGS in clinical microbiology laboratories according to the obtained data.The study was conducted with 51 VGS strains isolated from oral microbiota of the patients with rheumatologic cardiac, valve and/or prosthetic valve diseases, under the risk of development of infective endocarditis, who have admitted to Ankara Numune Training and Research Hospital, Department of Cardiology, between February-June 2015. Standard microbiology procedures, optochin susceptibility and bile solubility tests were done for the isolation of bacteria. Bacteria were also identified with APISTREP (bioMérieux, France) and MALDI-TOF MS Bruker Microflex (Bruker Biotyper; Bruker Daltonics, Bremen, Germany) methods. BSF-8 (5´-AGAGTTTGATCCTGGCTCAG-3´) and BSR-534(5´-ATTACCGCGGCTGCTGGC-3´) primers were used in the 16S rRNA sequence analysis of bacteria. ABI PRISM 3100 Avan t Genetic Analyzer (Applied Biossytems, Foster City, CA, USA) were used for the sequence analysis. Electropherograms were analyzed in SeqScape Software (Applied Biosystems, Foster City, CA, USA) and compared with the reference sequences in GenBank with BLASTN (NCBI). According to the result of optochin and bile solubility tests, with API STREP system, 16 (31,37%) of the isolates were identified as Mitis group, 15 (29.41%) as Anginosus group, 9 (17.5%) as Salivarius group, 7 (13,73%) as Sanguinis group and 4 (7.84%) as Bovis group among optochin and bile resistant alpha hemolytic streptococci. Moreover, of the same isolates 20 (39.22%) were identified as Mitis group, 14 (27.45%) as Anginosus group, 13 (25.49%) as Salivarius group and 4 (7.84%) as Sanguinis group with MALDI-TOF system. In the identification with 16S rRNA, 25 (49.02%) of the isolates were identified as Mitis group, 13 (25.49%) as Anginosus group, 12 (23.53%) as Salivarius group and 1 (1.96%) as Sanguinis group. According to the results, it was determined that 33 (64.70%) of the isolates identified in MALDI-TOF MS system and 31 (60.78%) of the isolates identified in API STREP system were compatible with 16S rRNA sequence analysis method. For Mitis group, API STREP test sensitivity was 48.00% and specificity was 84.62% and MALDI-TOF system sensitivity was 80.00% and specificity was 100%. As VGS identification is a complicated process, we believe a single method will be insufficient for the identification of these isolates in clinical microbiology laboratories. We suggest that MALDI-TOF system can be used for VGS diagnosis, however, optochin test and/or molecular methods should also be included in the diagnosis algorithm when necessary.