[Evaluation of the Correlation of HCV Core Antigen Levels with HCV RNA Levels in the Diagnosis and Treatment Follow-up of Hepatitis C Virus Infections]. / Hepatit C Virüs Enfeksiyonlarinin Tani ve Tedavi Izleminde, Hepatit C Virüs Kor Antijen Düzeylerinin Hepatit C Virüs RNA Düzeyleri ile Korelasyonunun Degerlendirilmesi.

Hepatitis C virus (HCV) infections are an important public health issue across the world because of the high risk of chronicity potential, impossibility of protection by vaccination and serious complications such as hepatocellular carcinoma. The aim of this study was to evaluate the correlation of HCV core antigen test with HCV RNA in the diagnosis and treatment follow-up and to discuss the status of being an alternative test in routine use. In the first step of the study, the compatibility of the methods was investigated by applying the HCV core antigen test to 600 serum samples from patients with pre diagnosis of HCV infection for whom anti-HCV and HCV RNA tests were routinely studied in the molecular microbiology laboratory of medical microbiology department between December 2016 and December 2018. In the second step, in addition to the routine HCV RNA test, HCV core antigen test was studied in serum samples taken before the start of the treatment, at the eighth week of the treatment and at the end of the treatment of 150 patients whose treatment were decided by the gastroenterology department within this period. The correlation between the two tests was evaluated during the treatment follow-up. Forty-nine of 600 patients were diagnosed according to test results. In 28 patients, HCV core antigen was positive in addition to HCV RNA and anti-HCV which were routinely studied. The sensitivity of HCV core antigen test was 91.49%, specificity was 100%, PPD was 100%, NPD was 97.30%, accuracy was 87.76%. There was a high correlation between HCV RNA and HCV core antigen results. In the second step of the study, sensitivity (96.52%), specificity (95.28%), PPD (95.11%), NPD (95.80%) and accuracy (92.58%) of the HCV core antigen test were determined. These results show that there is a high correlation between the two tests and that HCV core antigen test can be used as an alternative test to HCV RNA test as it is an easily applicable and cost effective test during diagnosis and treatment follow-up.

Comparison of syphilis seropositivity between non-immigrant and immigrant populations in the Anatolian side of Istanbul, Turkiye: Results of five-years retrospective study.

OBJECTIVE: Our study aimed to evaluate the seropositivity for syphilis in non- immigrant and immigrant populations and compare the results regarding demographic data. METHODS: In accordance with the reverse algorithm, syphilis tests were performed between May 2014 and December 2018 in hospitals in our service zone for syphilis screening or symptomatic disease. RESULTS: A total of 135.328 non- immigrant and 6.641 immigrant were screened for syphilis. Seropositivity rates were 1.3% in the non- immigrant and 3.8% in immigrant groups (p=0.0001). There was a statistically significant difference in terms of seropositivity rates between the various age groups in the local group and immigrant groups (except 18 25 age group) (p<0.05). Syphilis seropositivity rates were found to be lower in indigenous population than immigrant groups according to the years tested (p=0.0001). The seropositivity rates were 2.4% and 3.2% among the males (p=0.025) and 0.6% and 4.0% among females (p=0.0001) in non-immigrantand immigrant groups, respectively. Whereas, 0.6% of pregnant women in the local group and 3.7% of pregnant women in immigrant groups were seropositive for syphilis (p=0.0001). Among the HIV positive group, syphilis seropositivity was only observed in the non-immigrant group with a rate of 23.0% (p=0.0001). CONCLUSION: The antibodies against syphilis were found more frequently in immigrants than non-immigrant. Among the HIV positive individuals syphilis seropositivity was only observed in the non-immigrant group.

Detection of colistin resistance among multidrug-resistant Klebsiella pneumoniae and Escherichia coli clinical isolates in Turkey.

In this study investigation of plasmid-mediated mcr 1-5 resistance genes was performed among multidrug-resistant (MDR) colistin sensitive and resistant Klebsiella pneumoniae and Escherichia coli strains isolated in our laboratory. We aimed to evaluate automated system (Vitek-2), broth microdilution (BMD) reference method and chromogenic media performance. Totally 94 MDR K. pneumoniae and six E. coli isolates were included in the study. CHROMID® Colistin R agar (COLR) (bioMerieux, France) was used to determine the colistin resistance by chromogenic method. Standard PCR amplification was performed using specific primers to screen the plasmid-mediated mcr 1-5 genes. Sixty-one isolates were resistant to colistin and 39 were susceptible with reference BMD. The essential and categorical agreement of Vitek-2 was determined as 100 and 99%. The sensitivity of COLR medium was 100%, the specificity was 97.5%. In our study mcr-1 was detected in eight isolates, while other mcr genes were not detected. Due to the high sensitivity and specificity of the COLR medium, it can be used in routine diagnostics for the detection of colistin resistance. In our study we detected 8% prevalence of mcr-1 among MDR strains however, two mcr-1 positive isolates were found sensitive to colistin by BMD.

[Evaluation of the Two Commercial Methods Based on Broth Microdilution Against Reference Microdilution Method for Klebsiella pneumoniae Isolates]. / Klebsiella pneumoniae Izolatlarinda Sivi Mikrodilüsyon Temelli Iki Ticari Sistemin Referans Mikrodilüsyon Yöntemine Göre Degerlendirilmesi.

A rapid and reliable method for antimicrobial susceptibility test of colistin is needed because of increasing numbers of multi-resistant gram negative bacterial infections and simultaneus increasing of colistin resistance. Although broth microdilution (BMD) is recommended by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) as a reference method, the use in routine laboratory practice is limited because of the difficulties in application and time-consuming characteristics. Recently, many BMD based commercial products were developed. The study was aimed to compare the results of the two commercial systems available for the detection of colistin sensitivity with the reference method. Totally 38 Klebsiella pneumoniae strains isolated from various clinical specimens between 2017-2018 were included in our study. Identification and antibiotic susceptibility tests were performed with "matrix-assisted laser desorption/ionization timeof-flight, mass spectrometry (MALDI-TOF MS)" and Vitek-2 (bioMérieux, Marcyl'Etoile, France) systems. BMD tests were performed with Sensititre (Sensititre custom plate, Thermo Fisher Scientific, UK) and Micronaut MIC-Strip (Merlin Diagnostika GmbH, Germany) kits. Commercial BMD assays containing dehydrated colistin in the concentration range of 0.0625-128 mg/L were tested with 0.5 McFarland bacterial suspensions prepared according to the manufacturer recommendations. The reference BMD test was performed by following the recommendations of the International Organization for Standardization (ISO-20776-1). ATCC 25922 colistin-susceptible Escherichia coli and NCTC 13846 (mcr-1 positive) colistin-resistant E.coli strains were used as the quality control strains. According to the recommendations of EUCAST version 9.0, strains with minimum inhibitory concentration value of ≤ 2 mg/L were considered susceptible and strains > 2 mg/L as resistant. Thirty-five isolates were resistant to colistin by the reference method and three of them were susceptible. The Sensititre kit detected a very major error (2.8%) in one isolate; no major or very major errors were detected for the Micronaut kit. The essential and categorical agreement of the Sensititre and Micronaut kits with the reference method was defined as 74-76% and 97-100%, respectively. Colistin is the last agent for the treatment of the multi drug resistant severe bacterial infections so major and very major error for colistin should be considered equally serious. Although a very major error was detected by the Sensititre kit in one isolate, the categorical agreement of both commercial kits was greater than 90% when compared with the reference method. It was concluded that, commercially available, BMD based systems that do not require additional equipment and experience can be routinely used.

Genetic Diversity and Antifungal Susceptibility of Candida parapsilosis Sensu Stricto Isolated from Bloodstream Infections in Turkish Patients.

Candida parapsilosis sensu stricto is an emerging cause of hospital-acquired Candida infections, predominantly in southern Europe, South America, and Asia. We investigated the genetic diversity and antifungal susceptibility profile of 170 independent C. parapsilosis sensu stricto strains obtained from patients with candidemia who were treated at the Ege University Hospital in Izmir, Turkey, between 2006 and 2014. The identity of each strain was confirmed via PCR amplification and digestion of the secondary alcohol dehydrogenase-encoding gene. The 24-h geometric mean minimum inhibitory concentrations of the antifungal agents, in increasing order, were as follows: posaconazole, 0.10 µg/mL; voriconazole, 0.21 µg/mL; caspofungin, 0.38 µg/mL; amphotericin B, 0.61 µg/mL; anidulafungin, 0.68 µg/mL; and fluconazole, 2.95 µg/mL. Microsatellite genotyping of the isolates (using fluorescently labeled primers and a panel of four different short-nucleotide repeat fragments) identified 25, 17, 17, and 8 different allelic genotypes at the CP6, B5, CP4, and CP1 locus, respectively. Posaconazole, caspofungin, and amphotericin B showed the greatest in vitro activity of the tested systemic azole, echinocandin, and polyene agents, respectively, and the observed antifungal susceptibility of the isolates was shown to be independent of their isolation source. We obtained a combined discriminatory power of 0.99 with a total of 130 genotypes for 170 isolates tested. Finally, microsatellite profiling analysis confirmed the presence of identical genotype between separate isolates, supporting that effective surveillance and infection-prevention programs are essential to limit the impact of C. parapsilosis sensu stricto on hospitalized patients' health.

The effect of clinical characteristics on the performance of galactomannan and PCR for the diagnosis of invasive aspergillosis in febrile neutropenic patients.

Rapid diagnosis and early treatment of invasive aspergillosis is crucial for the management of the patients with haematological malignancy. We evaluated 358 sera from 78 febrile neutropenic episodes in patient with invasive aspergillosis (IA) (one proven, 17 probable, and 60 possible) and 83 episodes in patients with no IA according to the EORTC/MSG criteria. Patient's specimens were tested by Mycassay Aspergillus PCR (first commercial real-time PCR test) and in house real-time PCR to investigate the presence of Aspergillus DNA, and by ELISA for detect the galactomannan (GM) antigen. We systematically investigated the medical background that can be effective on the test results. The hospitalisation period was longer in proven/probable episodes when compared with no IA (P = 0.001) and possible episodes. With regard to duration of neutropenia, the differences between both proven/probable with no IA (P = 0.023) and possible with no IA (P = 0.002) were highly significant. Similarly, the rates of T cell suppressant therapy in group proven/probable and possible episodes were significantly higher than in no IA (P = 0.005). There are significant differences in the performance of GM and PCR-based tests among studies, and standardisation is required. Therefore, it can be useful to determine the effective factors on these tests. The use of larger volume of sera improved the performance of real-time PCR for detection of Aspergillus DNA in high-risk adult patients in the present study. Some host factors such as duration of neutropenia and administration of T cell suppressants related to the development of IA.

Potential of polymerase chain reaction and galactomannan for the diagnosis of invasive aspergillosis in patients with febrile neutropenia.

The incidence of invasive aspergillosis (IA) has increased over the last years, especially in immuncompromised patients with high mortality rates. Because of difficulties about the diagnosis; serological methods [galactomannan (GM) antigen test] and polymerase chain reaction (PCR) developed in recent years. MycAssay Aspergillus PCR performance in the diagnosis of IA was evaluated and compared with the GM and in-house PCR. This study was conducted with 358 serum samples obtained from 99 patient with febrile neutropenic episodes who were followed in haematology and bone marrow transplantation units. Patients were classified by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 18 of them is proven and probable IA. GM antigen test and two different real-time PCR; one of them is fist commercial PCR for IA; Mycassay Aspergillus and the other one is in-house real-time PCR performed. Sensitivity values were Mycassay Aspergillus PCR, in-house PCR, and GM 65.38%, 11.53% and 23.07%, respectively. The high sensitivity obtained from Mycassay Aspergillus PCR and sensitivity is increased by using a combination of diagnostic methods. GM antigen test and real-time PCR could be beneficial for early diagnosis and treatment of IA. For routine usage of PCR as diagnostic assay more studies needed in future.