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Objective: This study aimed to identify subspecies of Mycobacterium abscessus complex (MABC) isolates from clinical samples by a molecular technique and to determine mutations responsible for macrolide and aminoglycoside resistance. We also aimed to investigate the correlation of phenotypic and molecular test results by examining the resistance to antimicrobial agents according to CLSI standard using the liquid microdilution test. Methods: 27 MABC isolates from clinical samples were examined. Molecular subspecies identification and mutations responsible for aminoglycoside (rrs mutation) and macrolide resistance (rrl mutation) were determined using the GenoType NTM-DR test. The resistance phenotypes of the strains to various antimicrobial agents were investigated by the Sensititre™ RAPMYCOI AST microdilution test. Results: Of the 27 isolates tested, 21 were M. abscessus subsp. abscessus, three were M. abscessus subsp. bolletii, and three were M. abscessus subsp. massiliense; rrs and rrl mutations were not observed in any strains. Except for one isolate, all M. abscessus subsp. abscessus strains showed the erm(41) T28 genotype, which indicates inducible macrolide resistance. The correlation between the GenoType NTM-DR and phenotypic susceptibility test results was 81% (k=0.5, p=0.02) for inducible macrolide resistance and 89% for acquired macrolide resistance. The most effective antimicrobial agents were amikacin, cefoxitin, imipenem, linezolid, and tigecycline. Conclusion: Although the GenoType NTM-DR test is reliable in identifying and detecting molecular macrolide and aminoglycoside resistance, there were discrepancies in the results. We recommend confirming the results with the phenotypic susceptibility method after growth on culture. Although the M. abscessus complex is resistant to many antimicrobial agents, it has shown high sensitivity to amikacin, cefoxitin, imipenem, linezolid, and tigecycline. High levels of inducible macrolide resistance in isolates indicate the importance of subtyping and sensitivity testing of isolates in patients where culture conversion has not been achieved. [ABSTRACT FROM AUTHOR]

Objective: Our objective was to investigate the antimicrobial susceptibilities of Escherichia coli isolated from urinary cultures in Central Laboratory of Hacettepe University Faculty of Medicine Hospital and to examine the differences between antimicrobial susceptibilities of E. coli isolated from different patient groups. Methods: E. coli isolated from urinary cultures between January 1, 2017 and April 30, 2018 were included in our study. Automated systems, i.e. VITEK® 2 Compact (bioMérieux, Marcy l'Etoile, France) and BD Phoenix (Becton Dickinson, Sparks, MD, USA) and disk diffusion test were used for the determination of antimicrobial susceptibilities. The patients from whom the bacteria were isolated were divided into groups according to age (<18 years, 18-64 years, and >64 years), gender and patient care (outpatients/inpatients). Results: The highest susceptibility rates were observed for carbapenems (>99%), fosfomycin (98.5%), nitrofurantoin (98.3%) and amikacin (94.2%), whereas the highest resistance rates were observed for ampicillin (61.3%) and amoxicillin--clavulanate (37.5-45.7%). Antimicrobial resistance rates of isolates from patients aged 65 years and over were higher than those of patients in other age groups, with the exception of piperacillintazobactam, amikacin and ertapenem. The resistance rates of isolates belonging to male patients were higher than those belonging to female patients for all antimicrobials. Also, the resistance rates of isolates belonging to inpatients were higher than those belonging to outpatients for all antimicrobials. When the rates of extended-spectrum-lactamase (ESBL)-producing E. coli from different age groups were compared, the highest rate (34.2%) was observed among the isolates from patients aged 65 years and over. The rates of ESBL-producing E. coli from males (33.9%) and inpatients (36.3%) were higher than those from females (23.8%) and outpatients (23.3%), respectively. Conclusions: Antimicrobial susceptibilities of E. coli isolates may vary among different patient groups. Demographic features of patients may guide for selecting the antimicrobials for empiric treatment of urinary tract infections. [ABSTRACT FROM AUTHOR]

Objective: Production of extended-spectrum β-lactamases (ESBLs) is the most important antimicrobial resistance mechanism among Gram-negative pathogens. In this study, ESBL frequency and antimicrobial resistance of Escherichia coli and Klebsiella spp. isolated from community-acquired urinary tract infections (UTIs) are investigated. Methods: In this retrospective cross-sectional study, ESBL rates and the results of antimicrobial susceptibility tests were determined for E. coli and Klebsiella spp. grown in the urine cultures of 520 patients with community-acquired UTI, and the changes in the antimicrobial resistance rates of the isolates were compared in terms of ESBL production. Results: E. coli had grown in 220 samples and Klebsiella spp. in 38 samples. ESBL production frequencies of the isolates were found as 40% and 47.4%, respectively, and the rate of carbapenem resistance was found as 3.1%. Among the isolates, the highest resistance was found for amoxicillin-clavulanate (46%), ciprofloxacin (44.9%), and ceftriaxone (42.2%), while the lowest resistance was found for colistin (0.3%), fosfomycin (1.5%), amikacin (3.1%), and nitrofurantoin (4.2%). In ESBL-producers, significantly higher resistance was found for all antibiotics studied, except colistin, nitrofurantoin and fosfomycin. Conclusions: In this study, it was shown that almost half of the community-acquired isolates were ESBL-producers, and these isolates had acquired resistance against many antimicrobials including the last resorts such as carbapenems and colistin. To reduce the progress of resistance rates in E. coli and Klebsiella spp. which are the most common pathogens in community-acquired UTIs, their therapies should be planned according to the results of susceptibility tests as much as possible. [ABSTRACT FROM AUTHOR]

Objective: Recommended combination for the treatment of serious Stenotrophomonas maltophilia infections is ticarcillinclavulanate and co-trimoxazole (SXT). However, first agent is not available in our country, and the second component may be a matter of antimicrobial resistance or intolerance. Therefore, we aimed to evaluate antimicrobial susceptibility testing results of S. maltophilia and in vitro activity of ceftazidime and moxifloxacin as a potential therapeutic alternative. Methods: S. maltophilia strains isolated from clinical samples in Infectious Diseases and Clinical Microbiology Laboratory between 1 October 2007-23 November 2017 were included in the study. Disk diffusion antimicrobial susceptibility test results of the strains were evaluated retrospectively. The in vitro activity of combination of ceftazidime and moxifloxacin against 24 of these strains was investigated by Etest®. Results: During the study period, 649 S. maltophilia strains were isolated from 649 different patients, and 94%, 93%, 92%, 81%, 60%, 55%, 45%, 41%, 38% of the strains were susceptible to tigecycline, moxifloxacin, SXT, ciprofloxacin, cefoperazonesulbactam, ceftazidime, netilmicin, gentamicin and amikacin, respectively. For the 24 strains included in the combination study, the moxifloxacin minimal inhibitory concentration (MIC)50/MIC90 values were defined as 0.064/0.125 µg/mL (MIC range 0.023-4 µg/mL) and ceftazidime MIC50/MIC90 values were defined as 32/256 µg/mL (MIC range 1.5-256 µg/mL). According to the results of fractional inhibitor concentration (FIC) index; ceftazidime and moxifloxacin combination displayed synergism, additivity and indifference for 1 (4%), 18 (75%) and 5 (21%) strains, respectively and there was no antagonism. The FIC50/ FIC90 value is calculated as 0.75/1.01 (FIC range 0.5-1.01). Conclusions: SXT resistance in S. maltophilia strains is below 10%, but it should be closely monitored because of the limited treatment options. Tigecycline and moxifloxacin can be among the treatment alternatives because of their high sensitivity rates similar to SXT. The combination of moxifloxacin plus ceftazidime demonstrated in vitro synergism or additivity against majority of the strains. So, this combination may be used as an alternative for the treatment of patients with S. maltophilia infections if there is resistance or side effects to the antibiotics used as the first option. [ABSTRACT FROM AUTHOR]

Objective: We aimed to present clinical and laboratory findings of patients and the molecular analysis of strains isolated in a Salmonella typhimurium outbreak associated with food served at a wedding reception. Methods: A total of 108 patients admitted to the hospital after eating food served at a wedding reception were included in the study. The patients whose symptoms continued even after supportive care were hospitalized for further treatment. Two sets of blood and stool cultures were obtained from all the hospitalized patients, and samples were taken from the implicated food source as well. The VITEKR 2 Compact (bioMerieux, Marcy l'Etoile, France) automated microbiology system was used together with conventional methods to identify the isolates and determine their antibiotic susceptibility. Serotyping was performed according to the Kauffmann-White scheme using the slide agglutination method. The molecular epidemiology of the isolates was determined by pulsed-field gel electrophoresis using the XbaI enzyme. Results: All the patients presented with common complaints such as fatigue, abdominal pain, fever, diarrhea, nausea, and vomiting that had started 8 to 16 hours after the consumption of the food served. 45 patients were treated in the hospital whereas 63 patients were followed in an ambulatory setting after 4-6 hours of supportive care. Their hospitalization period varied between 1 and 5 days, and all patients were discharged with full recovery. S. typhimurium was isolated from stool cultures of 14 patients, and two of them were also blood culture-positive. All the isolates revealed a single clonal cluster in molecular analysis. All of them were susceptible to ampicillin, ceftriaxone, and ciprofloxacin, but resistant to amikacin. Conclusions: Despite the developments in the food industry in Turkey and across the world, food-borne disease outbreaks still occur. Hygiene rules should be strictly followed and appropriate inspections should be undertaken in the food sector to prevent food-borne outbreaks. [ABSTRACT FROM AUTHOR]

Chronic suppurative otitis media was diagnosed in a 30-year old female with left ear pain and ear discharge lasting since 5 years intermittently. Lactose-negative, oxidase-negative, Gram-negative small bacilli grown as flat and gray colonies with smooth margins were identified as Kerstersia gyiorum by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA analysis. Minimum inhibitory concentration values were determined by broth microdilution method (ciprofloxacin >2 µg/mL, ertapenem <0.25 µg/mL, imipenem 0.5 µg/mL, ceftazidime 2 µg/mL, amikacin ≤4 µg/mL, ceftriaxone ≤0.5 µg/mL, gentamicin 2 µg/mL and tigecycline 1 µg/mL). It was learned that her clinical findings resolved by oral amoxycillin-clavulanic acid and topical ciprofloxacin given empirically. [ABSTRACT FROM AUTHOR]