Comparison of antimicrobial efficacy of different disinfectants on the biofilm formation in dental unit water systems using dip slide and conventional methods: A pilot study.

OBJECTIVE: Biofilm formation in dental waterlines brings opportunistic infections, especially for immunosuppressive patients. This study aimed to determine biofilm-forming microorganisms by various methods and investigate disinfectants' effects on biofilm. MATERIALS & METHODS: In the study, samples were obtained from the waterlines of 10-15 aged six dental units, before (0 min.) and after chlorine dioxide (ClO2) and hypochlorous acid (HOCl) treatment (1, 5, 10, 20, and 30 min.), and total colony counts were performed using conventional surface smear method (SSM) and dip slide method (DSM). The Congo red agar and Christensen methods were used to examine the biofilm-forming properties of the isolates. Monitoring of biofilm presence was also visualized by SEM scanning. RESULTS: When DSM and SSM are compared in all units where ClO2 and HOCl are applied, DSM can detect bacterial growth even during periods of greater exposure to disinfectant application. Although DSM can achieve a value approaching 3% even at the 10th minute in units treated with HOCl; SSM does not show reproduction at the same disinfectant exposure and duration; It was observed that in the units where ClO2 was applied, the growth was no longer observed at the 10th minute with DSM, and SSM, 50% growth in the first minute of the units treated with ClO2 could not be detected in the 5th minute. CONCLUSIONS: It is concluded that it can be advisable to routinely disinfect the dental unit water systems with non-toxic doses of ClO2 application before patient treatments in clinics and also to perform contamination controls at regular intervals with DSM, which is a sensitive and very practical method. RESEARCH HIGHLIGHTS: It has been observed that the dip slide method can count bacteria more sensitively than conventional methods in dental water systems without the need for experienced personnel and equipment. The difference between biofilm formation in water systems before and after disinfectant exposure in SEM examinations is remarkable. The effects of ClO2 and HOCl on biofilm were investigated and bacterial growth was inhibited in dental units between 5 and 10 minutes with both disinfectants.

[Investigation of Hepatitis C Virus (HCV) Genotypes by "Reverse Hybridisation Strip Assay" and DNA Sequence Analysis Methods]. / Hepatit C Virüs (HCV) Genotiplerinin "Reverse Hybridisation Strip Assay" ve DNA Dizi Analizi Yöntemleriyle Arastirilmasi.

Hepatitis C Virus (HCV) is a virus that is estimated to infect approximately 185 million people worldwide and causes 350 000 deaths each year. The target in HCV treatment is the sustained virological response (SVR), and the most important virological factors determining SVR are genotype and baseline HCV-RNA levels. In this study, it was aimed to compare the HCV genotypes and subtypes detected by the "line probe assay (LIPA)" method with sequence analysis. HCV genotypes and subtypes were investigated by line probe assay (LIPA) (NLM analytica, Italy) and sequence analysis methods in 212 patients with chronic HCV diagnosis and with HCV RNA viral load of 104 IU/ml and above. 5'UTR and core regions were studied in LIPA method and NS5B gene region was studied in the sequencing method. After amplifying 340 bp region in the NS5B gene region with the hemi-nested PCR method, sequence analysis (ABI 3500 Genetic Analyzer [Applied Biosystems, USA]) was performed. Statistical analysis of the study was determined by using TURCOSA Analytics program. In the study, HCV genotypes and subtypes that were determined in 212 patients by LIPA method were; 40 (18.8%) genotype 1a, 97 (45.75%) genotype 1b, 7 (3.3%) genotype 2, 12 (5.6%) genotype 2a/c, 2 (0.94%) genotype 2b, 19 (8.96%) genotype 3, 16 (7.55%) genotype 4, 1 (0.47%) genotype 4a, 15 (7.5%) genotype 4c/d, 1 (0.47%) genotype 4h and 2 (0.94%) genotype 5. The HCV genotypes and subtypes determined in 212 patients by sequence analysis were; 20 (9.43%) genotype 1a, 118 (55.6%) genotype 1b, 16 (7.55%) genotype 2a, 4 (1.89%) genotype 2b, 1 (0.47%) genotype 2k, 21 (9.91%) genotype 3a, 2 (0.94%) genotype 4a, 28 (13.21%) genotype 4d and 2 (0.94%) genotype 5a. The difference in results between the two methods was found to be statistically significant (p< 0.001). According to the viral load-genotype relationship, the highest viral load was detected in genotype 1a patients (p< 0.001). In conclusion, in order to determine HCV genotypes and subtypes in our study, LIPA and sequence analysis methods were compared and the genotype compatibility between the two methods were determined as 97.5% on the basis of genotype and 19% on the basis of subtype. Since the direct-acting antiviral (DEA) treatment protocol in chronic HCV patients is planned according to the genotype/subtype determination, the inconsistency of the results obtained in the LIPA method, which is routinely widely used, with the sequence analysis method is remarkable, and it was concluded that these results should be supported by studies containing more samples.

[Investigation of Ganciclovir Resistance in Cytomegalovirus Strains Obtained from Immunocompromised Patients]. / Immün Yetmezlikli Hastalardan Elde Edilen Sitomegalovirüs Izolatlarindaki Gansiklovir Direncinin Arastirilmasi.

CMV is a virus that is asymptomatic in healthy individuals but can cause serious mortality and morbidity in transplant patients and patients with acquired immunodeficiency syndrome (AIDS). Ganciclovir (GCV) is a nucleoside analog that significantly reduces morbidity and mortality in CMV-related infections and is used as the first choice in treatment. It is the first drug shown to be effective in the treatment of CMV disease in humans, and is also homologous to acyclovir. Long-term antiviral therapy is required to prevent or treat CMV disease, but this can cause antiviral resistance which was reported to be 8-14% in CMV. In CMV strains, GCV resistance is most common in the UL97 kinase gene region. The aim of this study was to investigate GCV resistance in CMV strains obtained from the patients with immune deficiency. A total of 49 patients, including 20 children, 29 adults, who were followed in the department of hematology were included in the study. Fifty-three samples from 49 patients with CMV DNA viral load ≥ 103 copies/ml were examined for GCV resistance. In the study, DNA sequences were determined by Sanger sequence analysis method 3500 Abi Prism Genetic Analyser (Applied Biosystems, Thermo Fisher Scientific, USA) in the 674 bp part of the UL97 gene region. The next generation sequencing (NGS) method was applied to the samples that could not be evaluated with this method. GCV resistance was not detected in 35 (66%) of 53 samples with the Sanger method. C592G, C607S and M460I GCV resistance mutation was detected in three patients. Since the sequences were mixed, resistance analysis could not be evaluated with Sanger in 15 patient samples and the resistance was not detected in these samples studied with NGS. Antiviral resistance mutation was detected in three of 49 patients (6.1%). In 20 patients included in the study, three variant sequences (A442G, C592F, A427V) reported in the literature and determined to be sensitive to drugs by phenotypic tests and 78 variant sequences that were not reported in the literature were detected. As a result, the detection of antiviral resistance is important in the follow-up of the patients and guides the clinician in planning of the treatment. It was concluded that the samples that could not be evaluated with the Sanger method should be studied with NGS and further studies are needed to determine the role of the variant sequences detected for the first time in drug resistance.

Publication rates of abstracts presented at the annual congress of the Turkish Society of Colorectal Surgery (years 2003-2011).

OBJECTIVE: The aim of our study is to examine the Publication Rate of Congress of Turkish Society of Colorectal Surgery meeting abstracts and determine the factors affecting publication rate. MATERIAL AND METHODS: All presentations at Congress of Turkish Society of Colorectal Surgery congresses held in 2003, 2007, 2009, 2011 were retrospectively assessed. Manuscripts indexed in Google-Scholar database were included. The meeting year, study type, presentation type, title and time to publication of studies were assessed. Actual impact factor values were assessed to introduce the scientific power of the journals. RESULTS: Among a total of 614 abstracts presented at these congresses, 139 (22.6%) presentations were published in various medical journals. The publication rate was higher in oral presentations as group compared to poster presentations (29.7% vs. 19.5%) (p<0.001). Mean time to publication period was 20.4 (±21.1) months. 78 (56.1%) of published articles were published in SCI-E journals while 61 (43.9%) were published in non-SCI-E journals. Experimental studies had a higher Publication Rate in analysis of publication rate according to study type (p<0.001). Prospective clinical studies had a higher publication rate than retrospective studies. The journals in which oral presentations had been published had greater impact factor than journals in which poster presentations had been published (p=0.02). If published; prospective clinical studies were published in journals with greater impact factor than retrospective studies (p=0.04). CONCLUSION: The quality of a meeting is correlated with the publication of abstracts accepted as presentations. Congress of Turkish Society of Colorectal Surgery congress is an efficient meeting for researchers, and have a lower PR as compared to international congresses while having a similar publication rate to equivalent scientific meetings. Being more selective during abstract acceptance should increase the Publication Rate and quality of Congress of Turkish Society of Colorectal Surgery congresses.