Purpose. We aimed to investigate the presence of three recently identified point mutations (A2115G, G2141A and A2144T) of the 23 S rRNA gene and compare them with the three most frequently encountered point mutations (A2142G, A2142C and A2143G) in Helicobacter pylori strains in Turkey. Methodology. A total of 63 patients (mean 47.08±12.27) were included. The E-test method (for clarithromycin) was used for the clarithromycin antimicrobial susceptibility test of isolated H. pylori strains. Real-time PCR was used to detect the point mutations. Results. A total of 24 out of 63 H. pylori strains (38.1%) were detected as clarithromycin resistant (>0.5 mg l−1 ). The new A2115G (n:6, 25%), A2144T (n:7, 29.1%) and G2141A, 8 (n:8, 33.3%) mutations and the classical A2142G (n:8, 33.3%) and A2143G (n:11, 45.8%) point mutations were detected in the 24 clarithromycin-resistant strains. The A2144T point mutation had the highest median MIC value (3 mg l−1 ) amongst the new mutations, but the classical mutations (A2142G and A2143G) had the highest median MIC values (256 mg l−1 ) overall. The presence of the A2115G (OR:31.66), A2144T (OR:36.92) or G2141A (OR:28.16) mutations increased the likelihood of clarithromycin resistance in H. pylori strains by 31.66-, 36.92- and 28.16-fold (ORs), respectively, according to the binary logistic regression analysis. Conclusion. We concluded that classical mutations of the 23 S rRNA gene resulted in higher clarithromycin MIC values than new mutations. These new point mutations caused moderate elevations in the MIC values of clarithromycin-resistant H. pylori strains.

Pseudomonas aeruginosaandStaphylococcus aureusare known as important nosocomial infectious agents also their co-infections are commonly seen in some patient groups. It is well known that host factors such as hormones have roles in modulation of growth, pathogenesis and susceptibilities to antimicrobials. In our study, the influences of norepinephrine (NE) and melatonin (MEL) on antibiotic susceptibilities were examined in mono and co-culture conditions. Methicilin resistantStaphylococcus aureus(MRSA) ATCC 43300 andPseudomonas aeruginosaATCC 27853 were investigated to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of ciprofloxacin and gentamicin in the absence/presence of NE (0.0017 and 0.04μg/mL) and MEL (6 and 60 pg/mL) by microdilution method in mono and co-culture. It was found that hormones decreased (among 2-64 fold) MIC and MBC values of both antibiotics for MRSA. However, it was shown that hormones had no effect on MIC values of both antibiotics forP. aeruginosa.MIC and MBC values of both antibiotics for co-culture were found to be reduced compared to monoculture of MRSA; were found to be increased compared to monoculture ofP. aeruginosa.Whereas, hormones decreased MIC values of both antibiotics in co-culture conditions. Our results suggest that both hormones decreased MIC values and it seems that hormones could influence antibiotic susceptibilities in a strain-dependent manner.

Tuberculosis is a public health problem that still remains significant. For prevention, diagnosis and treatment on tuberculosis more effective novel biomarkers are needed. MicroRNAs can regulate innate and adaptive immune responses, alter host-pathogen interactions and affect progression of diseases. The relationship between microRNA expression and active pulmonary tuberculosis (APT) has not been investigated in Turkish population yet. We aimed to test the potential diagnostic value of some microRNAs whose levels were previously reported to be altered in APT patients. Using two different references (U6 and miR-93), we compared the expression levels of potentially important microRNAs in serum of APT patients with healthy individuals using quantitative polymerase chain reaction (qPCR). miR-144 expression level was down-regulated in APT patients when either U6 or miR-93 was used for normalization. When data was normalized with miR-93, a statistically significant decrease in miR-125b (0.8 fold) and miR-146a (0.7 fold) expression levels were observed, while no differences were detected for U6. Receiver operating characteristic suggested that miR-144 may be a candidate biomarker for discriminating APT patients and controls (p <0.05) both for U6 and miR-93. These findings suggest that miR-144 can have potential as a biomarker for APT. Using a single reference may be misleading in evaluation of microRNA expression. U6 and miR-93 can be used in combination as reference for normalization of serum microRNA expression data.

Aim: Antibiotic resistance is a major health problem. Recently, probiotics are used in the field of alternative/supportive medicine. Thus, in this study, we aimed to evaluate the in vitro inhibitory effects of four different cell-free supernatants (CFSs) of lactobacilli species (L. fermentum, L. plantarum, L. acidophilus and L. rhamnosus) on clinically isolated Methicilin-resistant Staphylococcus aureus (MRSA) strains, Vancomycin-resistant Enterococcus (VRE) strains, and Carbapenem-resistant Klebsiella (CRK) strains. Materials and Methods: Lactobacillus strains were grown in de Man Rogosa Sharpe broth; after filtration, CFSs were diluted to obtain 25, 50, and 100% concentrations. Pathogen bacteria were grown in tryptic soy broth with and without CFSs in a micro-plate. The bacterial growths were measured using spectrophotometric method after four hours of incubation at 37°C. One-way ANOVA followed by Dunnett’s multiple comparisons and Kruskal-Wallis test were used for statistical analyses. Results: All tested CFSs at all concentrations were found to inhibit growth of MRSA, VRE, CRK strains; the results were found statistically significant (p<0.0001). At 50% concentrations, all CFSs were found to be most effective on MRSA growth. The CFSs of L.fermentum, L.acidophilus and L.plantarum were found to be most inhibitory at 50% concentration on VRE growth. 50% diluted CFSs of L.fermentum and L.plantarum were found to be effective on growth of CRK. All results were found statistically significant (p<0.0001). Conclusion: In our study, our results support that CFSs of lactobacilli strains inhibit growth of multi-drug resistant bacteria. Their inhibitory effects were dependent on microorganisms and CFS concentrations.