The Medical Bulletin of Sisli Etfal Hospital

Objectives: The diagnosis of hepatitis C virus (HCV) infection starts with the detection of antibodies against recombinant or synthetic HCV proteins by Enzyme Immunoassay (EIA). Although EIA tests are highly sensitive, false positivity rates are not low. Positive anti-HCV results are generally confirmed with complementary tests such as Nucleic Acid Amplification Tests (NAAT), or Western Blot modifications. Methods: The anti-HCV results of 199,516 individuals referred from various clinics between 2015 and 2019 were evaluated retrospectively at University of Health Sciences, Şişli Hamidiye Etfal Training and Research Hospital, Medical Microbiology Laboratory. From the 2039 samples, of which EIA tests resulted borderline and reactive, 1419 samples having Line Immunoassay (LIA) confirmatory test results were included in the study. Results: LIA tests yielded positive, negative and indeterminate for 820 (57.8%), 519 (36.6%) and 80 (5.6%) of 1419 samples, respectively. The optimal threshold point for EIA anti-HCV signal to cut-off (S/Co) according to LIA was found to be 15.85 corresponded to diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 94.9%, 94.8%, 96.6%, 92.1%, 94.9%, respectively. The most common proteins detected in LIA positive samples were C1 96.3%, C2 90.4%, and NS3 93.2%. Conclusions: To prevent false positivities, confirmatory tests must be used for samples with low S/Co ratios. The use of S/Co value will make significant contribution to reducing both false-positive results and the LIA confirmatory test consumption. There was no correlation between the number of bands and EIA index values in LIA positive samples, while the relationship between the number of 3+ bands and index values was remarkable.

Objective Antimicrobial resistance poses a serious threat to children's health. In recent years, high-risk Escherichia coli ST131 has become an important target for global surveillance studies. The E.coli ST131 clone is associated with extended spectrum β-lactamase (ESBL) production, as well as multidrug resistance and treatment failure. Studies on this clone in the pediatric age group are limited. We aim to investigate the rate of high-risk E. coli ST131 clone in ESBL-positive E. coli isolates obtained from pediatric patients.Methods A total of 292 ESBL-positive E. coli isolates from clinical samples of pediatric patients was included in the study. MALDI-TOF MS system was used for bacterial identification. Susceptibility tests were performed using BD Phoenix automated system. ST131 detection was done by MALDI-TOF-MS. Fisher's exact test was used to compare the groups (significance <0.05).Results A total of 292 isolates was analyzed. The high-risk ST131 clone was detected in 117 (40%) of the 292 ESBL-positive isolates. ST131 rates were found to be significantly higher in children under the age of 5 years compared with children over the age of 5 years (49.3 vs. 31.1%, p = 0.0019). Ciprofloxacin resistance was higher in ST131 isolates (45.6 vs. 31.7%; p < 0.05).Conclusion The rate of the ST131 clone was found to be high in the pediatric population. The significantly high rate of resistance to ciprofloxacin, which is not commonly used in the pediatric population, in ST131 isolates reveals the importance of the spread of high-risk clones for the development of resistance.

Actinotignum schaalii (formerly known as Actinobaculum schaalii) is an anaerobic or facultative anaerobic gram -positive bacillus that can be found commensally in the urogenital region. It can be overlooked because it grows slowly and is difficult to identify with classical microbiology laboratory techniques. Colonies become visible after 48-72 hours of incubation on blood agar in anaerobic or CO2-rich media. While it typically causes urinary tract infection in older individuals, cases of bacteremia, vertebral osteomyelitis, endocarditis and cellulitis have been reported. Fournier's gangrene caused by A.schaalii has been reported very rarely so far. Fournier's gangrene has been defined as necrotizing fasciitis of the external genitalia, perineal and perianal region. Diabetes, immunosuppression, peripheral vascular disease, urethral anomalies, chronic alcoholism and smoking are important predisposing factors. In addition, approximately 25% of the cases have no known or identifiable etiology. The bacteria causing the infection may originate from skin, urogenital or intestinal microbiota. In this case report, a new case of Fournier's gangrene caused by A.schaalii was presented. A 65 -year -old male patient admitted to the emergency department with the complaints of pain, swelling, redness in the left testis and also nausea, vomiting and chills that started three days ago. Physical examination revealed increased diameter of the scrotum, intense hyperemia of the skin and foci of necrosis. It was learned that the patient had no known chronic disease other than benign prostatic hyperplasia. The patient reported smoking of 25 packs of cigarettes per year. Routine laboratory tests revealed leukocyte= 32.41 x 109/L, neutrophil= 89.9%, procalcitonin= 1.62 ug/L, CRP= 265.07 mg/L and the patient was operated with the diagnosis of Fournier's gangrene. Gram staining of the abscess specimen obtained during the operation showed gram -positive bacilli both inside and outside the leukocytes. After 24 hours, grampositive bacilli were detected in the Gram staining of thin, transparent/gray colonies grown on 5% sheep blood and chocolate agar. The isolate was identified as A.schaalii by matrix -assisted laser desorption ionization -time of flight mass spectrometry (MALDI-TOF MS) VITEK (R) MS (bioMerieux, France) microbial identification system. VITEK (R) 2 ID ANC (bioMerieux, France) bacterial identification card was also used for comparison but the bacteria could be identified. As a result of the sequence analysis performed for confirmation, it was shown to be 100% homologous with Actinobaculum schaalii (GenBank accession no: FJ711193.1). For susceptibility tests, 5% sheep blood Schaedler agar was used and incubated in anaerobic environment. According to the minimal inhibitory concentration (MIC) results evaluated after 48 hours, penicillin was found to be 0.032 mg/L, clindamycin 0.125 mg/L, ciprofloxacin 0.19 mg/L, ceftazidime 4 mg/L, and amoxicillin 0.19 mg/L. The primary cause that initiated the infection in the case could not be identified, but it was thought that the presence of prostatic hyperplasia and smoking history may have contributed to the occurence or the progress of the disease. It is noteworthy that the ciprofloxacin MIC result was quite low compared to other studies. In addition, this study revealed the value of MALDI-TOF MS based methods in identification. In conclusion, it is thought that a significant proportion of A.schaalii infections may be overlooked due to the difficulty in growth and identification. Increasing the diagnostic power of clinical microbiology laboratories for poorly identified bacteria and renewing the databases of commercial identification systems are important for the early and accurate diagnosis and treatment of serious infections that may occur with such agents.

Group B Streptococcus (GBS), Streptococcus agalactiae, is generally found as a colonizer of the genital and gastrointestinal tracts, and vertical transmission from colonized mothers to newborns during childbirth can result in serious infections. This bacterium is a leading cause of sepsis and meningitis in neonates and is also associated with several invasive and non-invasive