Authors:Tugce Unalan-Altintop, Alper Karagoz and Gulsen Hazirolan
MALDI-TOF MS provides fast, easy to perform and cost-effective diagnosis in clinical microbiology laboratories, however in some cases results of MALDI-TOF MS should be confirmed with additional tests. This confirmation is especially important for causes of life-threatening infections like Neisseria meningitidis. In our laboratory, three isolates were identified as N. meningitidis by Bruker MALDI Biotyper (BD, USA) between April 2018 and March 2019 from clinical specimens of blood, sputum, and urine. 16S rRNA sequencing was performed for further investigation. Two of the isolates were identified as Neisseria subflava and only one was confirmed as N. meningitidis by sequencing. These results show that MALDI-TOF MS is not always reliable in the diagnosis of N. meningitidis and clinical microbiologists should confirm these results with additional tests. Also, clinical correlations should be determined. Accurate identification of this microorganism is very important because of the necessity of prophylactic antimicrobial usage and biosafety precautions. Enlarged databases of Neisseria species are needed to overcome this problem.
Weeksella virosa is an atypical Gram-negative bacterium that does not grow on MacConkey agar. In this report, we present a 4-year-old female patient with Addison’s disease and end-stage renal failure secondary to focal sclerosing glomerulosclerosis. Continuous ambulatory peritoneal dialysis had been performed, and 3 months later, the patient developed fever, diarrhea, and vomiting. Peritoneal fluid culture and dialysis fluid culture were positive for W. virosa. It was identified with Phoenix (BD, USA) and confirmed via 16S rRNA sequencing. It cannot be identified by Maldi Biotyper (Bruker). The isolate was found to be resistant to cephalosporins, ciprofloxacin, and amikacin by gradient test. Intraperitoneal cefepime was initiated but since antimicrobial susceptibility testing revealed cephalosporin resistance, therapy was changed to intraperitoneal meropenem. Following the removal of peritoneal dialysis catheter, fever, abdominal distention, and vomiting were resolved. Piperacillin, aztreonam, and carbapenems can be used for empirical therapy. Antimicrobial susceptibility testing should be performed to guide the choice of treatment. Removal of peritoneal dialysis catheter is an important step of management of this infection. To our knowledge, this is the first report of W. virosa in a pediatric patient and first report from Turkey.
Authors:Nilgün Ünal, Erhan Bal, Alper Karagöz, Belgin Altun and Nadir Koçak
Vancomycin-resistant enterococcus (VRE) is a global threat to public health. Knowledge about the occurrence of vanA-carrying enterococci in broiler and environmental samples is important as antibiotic resistance can be transferred to human bacteria. The aim of this study was to investigate the presence of VRE in broiler cloacal and environmental (house) samples and to genotype the isolates. In this study, 350 swabs were collected from broiler farms. All samples were plated onto enterococcus selective agar containing 6 mg/L vancomycin and 64 mg/L ceftazidime. Minimum inhibitory concentration (MIC) values were determined for vancomycin and teicoplanin. Vancomycin-resistant Enterococcus faecium (VREfm) was isolated from 6 out of 300 (2%) broiler cloacal samples and 13 out of 50 (26%) house samples. All E. faecium isolates had vanA genes. All VREfm isolates (19 isolates) were confirmed to be 95% similar to each other. In conclusion, although 20 years have passed since the ban on avoparcin in Turkey, the present study shows that VREfm isolates are still present in broiler production and especially in broiler houses, and most importantly, a major VREfm clone was isolated from broiler cloacal and house samples.