The Role of Akkermansia muciniphila and Faecalibacterium prausnitzii in the Pathogenesis of Ulcerative Colitis and Crohn's Disease.

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases with uncertain etiology. We aimed to determine the amounts of Akkermansia muciniphila and Faecalibacterium prausnitzii in the intestinal microbiota of these patients and to correlate their amounts with blood IL-8, IL-10, and IL-12 cytokine levels. METHODS: Thirty UC, 30 CDs, and 46 healthy controls were included. IL-8, IL-10, and IL-12 levels of blood samples were analyzed by ELISA. The amounts of Akkermansia muciniphila and Faecalibacterium prausnitzii were determined by the LightCycler 480 qPCR system. RESULTS: F. prausnitzii, A. muciniphila, IL-10, and IL-12 decreased in patient groups, while IL-8 decreased in UC but increased in CD. A significant difference was detected between the patient and control groups in terms of F. prausnitzii, A. muciniphila, and IL-8, but not for others. The amount of F. prausnitzii was correlated with IL-8 and IL-10 in UC and with IL-10 in CD patients. CONCLUSIONS: The decrease in the amount of F. prausnitzii was associated with the increase in UC disease severity. A. muciniphila and F. prausnitzii were detected in lower amounts in both diseases. F. prausnitzii decreased more with the severity of UC, suggesting that these bacteria may have complex roles in their etiopathogenesis.

Oral microbial dysbiosis in patients with oral cavity cancers.

OBJECTIVES: The pathogenesis of oral cavity cancers is complex. We tested the hypothesis that oral microbiota dysbiosis is associated with oral cavity cancer. MATERIALS AND METHODS: Patients with primary oral cavity cancer who met the inclusion and exclusion criteria were included in the study. Matching healthy individuals were recruited as controls. Data on socio-demographic and behavioral factors, self-reported periodontal measures and habits, and current dental status were collected using a structured questionnaire and periodontal chartings. In addition to self-reported oral health measures, each participant received a standard and detailed clinical examination. DNA was extracted from saliva samples from patients and healthy controls. Next-generation sequencing was performed by targeting V3-V4 gene regions of the 16 S rRNA with subsequent bioinformatic analyses. RESULTS: Patients with oral cavity cancers had a lower quality of oral health than healthy controls. Proteobacteria, Aggregatibacter, Haemophilus, and Neisseria decreased, while Firmicutes, Bacteroidetes, Actinobacteria, Lactobacillus, Gemella, and Fusobacteria increased in oral cancer patients. At the species level, C. durum, L. umeaens, N. subflava, A. massiliensis, and V. dispar were significantly lower, while G. haemolysans was significantly increased (p < 0.05). Major periodontopathogens associated with periodontal disease (P. gingivalis and F.nucleatum) increased 6.5- and 2.8-fold, respectively. CONCLUSION: These data suggested that patients with oral cancer had worse oral health conditions and a distinct oral microbiome composition that is affected by personal daily habits and may be associated with the pathogenicity of the disease and interspecies interactions. CLINICAL RELEVANCE: This paper demonstrates the link between oral bacteria and oral cancers, identifying mechanistic interactions between species of oral microbiome.

Factors affecting medical students' satisfaction with online learning: a regression analysis of a survey.

BACKGROUND: Medical education requires the implementation of different teaching methods and strategies for future doctors to achieve broad learning objectives. This wide range of methods and strategies includes the use of Information Technologies. For a long time, there was a call for a change in medical education for blending new teaching approaches to lessen medical students' class time. The COVID-19 pandemic then sped up the transition to the new way of medical education and classroom lectures were quickly moved to a virtual environment. We expect that these changes will continue, and online learning will be one of the main teaching strategies in medical education. Therefore, educational experiences during the COVID-19 pandemic will improve our understanding of online learning and will help to develop blended medical school curricula in the future. For this reason, we aimed to determine students' overall satisfaction with their online learning experience and to define the main factors affecting students' satisfaction with their online learning program at Cerrahpasa Medical Faculty. METHODS: A cross-sectional survey study was conducted to determine medical students' overall satisfaction with online learning methods and to identify factors associated with positive and negative satisfaction levels. A questionnaire, consisting of 24 questions to collect demographic characteristics, factors associated with online education experience and overall satisfaction levels was developed and distributed to 1600 medical students. Multivariable linear regression analysis was used to determine the factors associated with positive and negative satisfaction levels. RESULTS: Regression analysis showed that being familiar with online teaching techniques (ß = 0.19, 95% CI [0.07, 0.30], faculty members' higher online teaching skill levels (ß = 0.42, 95% CI [0.32, 0.51], interactive online teaching approaches (ß = 0.54, 95% CI [0.41, 0.67], having a personal workspace (ß = 0.43, 95% CI [0.19, 0.67], and a self-reported longer attention span (ß = 0.75, 95% CI [0.57, 0.92] were associated with higher overall satisfaction with online learning. The occurrence of technical problems (ß = -0.19, 95% CI [-0.26, -0.12] was associated with lower overall satisfaction. CONCLUSIONS: Higher online teaching skills of faculty members, use of interactive approaches, students' familiarity with online teaching techniques, provision of a personal workspace, and self-reported longer attention spans positively contributed to higher levels of student satisfaction with online learning. Considering the increasing significance of online educational methods, our study identified key components that affect students' level of satisfaction. This information might contribute to the development of online educational programs in the future.

Tracking the footsteps of Burkholderia mallei: determination of the molecular differences and potential resistance genes.

Background/aim: Chemical biological radiological nuclear threats are at an important point in the agenda of world health today, as they can cause mass deaths. B. mallei attracts attention as a potential biological warfare agent due to its features such as multidrug resistance, a rapid transmission mechanism via aerosol, the absence of a complete treatment protocol for the infection it causes, and the absence of an approved vaccine for protection against the bacteria. B. mallei suspect samples must be studied by experienced personnel in biosafety level III laboratories. B mallei is a difficult and troublesome pathogen to diagnose and many unknowns about B. mallei today. Therefore, the aim of the study was to determine the molecular differences and potential resistance genes of B mallei strains. Materials and methods: Determination of the molecular differences and potential resistance genes of B mallei strains with new bioinformatics approaches by comparatively examining the data of 29 B mallei strains, 10 of which were isolated from Türkiye, on the genome list of the National Biotechnology Information Center (NCBI). Results: According to the genome annotations of the origins, the origin containing the highest number of CDS which is 5172 was found as the 11th strain obtained in Türkiye in 1949. The origin with the highest number of pseudogenes was determined as 23,344 (China 7) origin. Two hundred and eighty-five pseudogenes found in this strain were obtained from a knee effusion in Myanmar. According to chromosome 2 data, B. mallei strain was determined as the most similar strain to ATCC 23344, line 11 with NCTC 10229 strain, and SAVP1 strain was determined as the least similar strain. When the antimicrobial resistance gene markers of the isolates included in the study were examined, amrA and amrB, qacG ade, Burkholderia pseudomallei Omp38 were found to be carrying. Conclusion: In terms of public health, it was thought that the data obtained as a result of our study about B mallei, which is defined as a biological weapon, is very valuable for creating treatment protocols to be applied to possible epidemics in the future. In addition, the available genetic epidemiological data of these strains belonging to a category that is dangerous to work with in a laboratory environment were reviewed.

Cerebrolysin provides effective protection on high glucose-induced neuropathy in cultured rat dorsal root ganglion neurons.

Cerebrolysin, an endogenous peptide with neuroprotective and neurotrophic properties, indicated to be beneficial on diabetic neuropathy by preliminary clinical and experimental studies but without evidence on central or peripheral action. Dorsal root ganglion (DRG) neurons, based on involvement of pain sensation in both health and disease as first relay centers for transmission and processing of peripheral nociceptive sensory signals, was used to investigate possible effects of Cerebrolysin on high glucose-induced neuropathy, as model. DRG's were obtained from adult rats and the isolated neurons were seeded on E-Plate®'s equipped with gold microelectrodes, and incubated in culture media in a CO2 incubator at 37 C. DRGs were exposed to high glucose (50 mM) in the absence and presence of different concentrations of Cerebrolysin ® (2-40 mg/ml). Cell index (derived from cell viability and neurite outgrowth) was recorded with Real-Time Cell Analyzer and was used as primary outcome measure. High glucose-induced cellular neuropathy and neuroprotective effects of Cerebrolysin was evaluated from area under the curve (AUC) of cell index-time graphs. Exposure of DRG neurons to high glucose caused a rapid and persistent decrease in the mean AUC values compared to normoglycemic controls. Co-treatment with Cerebrolysin (40 mg/ml) attenuated this high glucose-induced effect in a concentration-dependent manner. In normoglycemic conditions, treatment with Cerebrolysin caused a dose-dependent increase in the mean AUC values. Cerebrolysin treatment resulted in maintenance of the functional integrity, survival, and promotion of neurite outgrowth of the cultured DRG neurons exposed to high glucose, indicating involvement of peripheral sensory neurons.

[The Relationship of Enterotoxigenic Bacteroides fragilis and Fusobacterium nucleatum Intestinal Colonization with Colorectal Cancer: A Case-Control Study Performed with Colon Biopsies]. / Enterotoksijenik Bacteroides fragilis ve Fusobacterium nucleatum Bagirsak Kolonizasyonunun Kolorektal Kanser ile Iliskisi: Kolon Biyopsileri ile Yapilan Bir Olgu Kontrol Çalismasi.

In recent years, it has been shown that some bacteria may be associated with colorectal cancer (CRC). In this study, it was aimed to investigate the role of Fusobacterium nucleatum and enterotoxigenic Bacteroides fragilis (ETBF) in the etiology of CRC by comparing the amounts of these bacteria in colon biopsy tissues of patients with CRC and healthy individuals. The amounts of F.nucleatum and ETBF were determined by quantitative polymerase chain reaction (qPCR) in colon biopsy samples taken from 35 CRC and 35 healthy individuals, and the results were compared in the patient and control groups. The detection rate and amounts of F.nucleatum were found to be statistically significantly higher in tissues of female patients with CRC compared to male patients (p= 0.003, p= 0.013, respectively). There was no statistically significant difference between the tissues of female and male patients with CRC in terms of detection rate and amount of ETBF (p= 0.521, p= 0.515, respectively). It was found that in the 50-74 age group, the amount of ETBF was statistically significantly higher in women and men with CRC compared to the controls (p= 0.005, p= 0.047, respectively), while the amount of F.nucleatum was statistically significantly higher in female patients compared to controls. However, no difference was found between male patients and controls (p= 0.009, p= 0.083). It was determined that the detection rate and amount of F.nucleatum in the tissues of patients with CRC, regardless of age and gender, were not statistically different from the controls (p= 0.473, p= 0.995, respectively), however, the detection rate of ETBF and the amount of ETBF were found to be statistically significantly higher (p= 0.002, p= 0.004, respectively). It has been determined that ETBF can play a role in the etiology of CRC in both men and women, and F.nucleatum only in women, in the age range of 50-74 years, when routine screenings for CRC are performed.

Efficacy of antimicrobial peptide LL-37 against biofilm forming Staphylococcus aureus strains obtained from chronic wound infections.

The antimicrobial peptide LL-37 showed inhibitory effects against Staphylococcus aureus strains, which often responsible for wound infections. Understanding the molecular mechanisms of biofilm-containing wound infections is important. Thus, this study aimed to investigate both the antimicrobial and biofilm efficacy of LL-37 against biofilm-positive methicillin-susceptible S. aureus (MSSA) strains and biofilm-positive methicillin-resistant S. aureus (MRSA) strains obtained from chronic wound infections and its effect on different quorum sensing and virulence genes at suboptimal concentrations. Fifteen biofilm-forming MRSA and 15 biofilm-forming MSSA strains were included in this study. The minimum inhibitory concentration (MIC) values and biofilm formation were tested by microdilution methods. Real-time PCR was performed to determine gene expression levels. MIC values for LL-37 were 89.6 mg/L and 132.3 mg/L for MSSA and MRSA strains, respectively. No statistically significant difference was found between MRSA and MSSA strains in terms of the effect of LL-37 on biofilm formation. A statistically significant difference was found between MRSA and MSSA strains for atlA, RNAIII, and agrA gene expression levels following exposure to a suboptimal concentration of LL-37. Ultimately, the required LL-37 antimicrobial concentration was quite high; however, LL-37 antibiofilm concentration may be acceptable for use in humans against biofilm-forming MRSA and MSSA strains. This is the first study to investigate to effect of a suboptimal LL-37 concentration on gene expression levels of biofilm-forming MSSA and MRSA strains. LL-37 affected quorum sensing and biofilm producing mechanisms, even at suboptimal MIC concentrations.

What is the clinical impact of occult HBV infections and anti-HBc positivity in patients with chronic hepatitis C?

Occult hepatitis B infection (OBI) is defined by the persistence of the hepatitis B virus (HBV) genome in the liver of individuals testing negative for hepatitis B surface antigen (HBsAg). Hepatitis B core antibody (anti-HBc) is the serological marker that indicates HBV exposure. The impact of anti-HBc and OBI on patients with chronic hepatitis C remains unclear. The aim of the present study was to determine the prevalence of anti-HBc and OBI and to evaluate their impact on the clinical and pathological outcomes of patients with chronic hepatitis C. The study included 59 HBsAg-negative chronic hepatitis C patients who underwent a liver parenchymal biopsy. The presence of HBV DNA was investigated using an in-house nested PCR method. OBI was detected in 16 (27.1%) of the 59 cases and also in 10 (62.5%) of 22 (37.3%) anti-HBc-positive patients. None of the patients had positive serum HBV DNA. OBI was associated with the presence of anti-HBV antibodies (P < 0.05). There was also an association between anti-HBc positivity and the activity grades and fibrosis stages of the liver and also a prevalence of liver steatosis (P < 0.05). Positive anti-HBc results may predict OBI and may also be associated with the progression of liver injury in HBsAg-negative patients with chronic hepatitis C. Therefore, it is suggested that patients with chronic hepatitis C should be screened for anti-HBc positivity, and anti-HBc-positive patients should be carefully evaluated for disease progression.

Firmicutes/Bacteroidetes Ratio in the Gut Microbiota and IL-1ß, IL-6, IL-8, TLR2, TLR4, TLR5 Gene Expressions in Type 2 Diabetes.

BACKGROUND: The aim of this study was to determine the Firmicutes/Bacteroidetes ratio in the gut microbiota and IL-1ß, IL-6, IL-8, TLR2, TLR4 and TLR5 gene expression levels in the blood of adult type 2 diabetes (T2D) patients and compare it with that of adult nondiabetic healthy controls (HC). METHODS: Between May 2016 and April 2017, 99 T2D patients and 99 HCs were enrolled in the study. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and IL-1ß, IL-6, IL-8, TLR2, TLR4, and TLR5 gene expression levels assesed from blood sample RNA via qPCR from both T2D patients and healthy controls. RESULTS: The Firmicutes/Bacteroidetes ratio detected in the stool of type 2 diabetes patients was found to be higher with a statistically significant difference (p < 0.0001). Gene expression levels of IL-1ß, IL-6, IL-8, TLR2, TLR4, and TLR5 were found to be upregulated. CONCLUSIONS: The highest upregulation was detected in IL-6 with 11 fold in T2D patients comparing with HCs. F/B ratio and gene expression levels were elevated in T2D patients. Firmicutes were positively correlated with studied gene expressions. A better understanding of the complex interaction between gut microbiota, environment, and diabetes will allow for more effective prevention and treatment strategies for T2D.

Evaluation of Bacterial Colonization and Clinical Properties of Different Suture Materials in Dentoalveoler Surgery.

PURPOSE: This study aimed to compare the effects of 10 different suture materials commonly used in dentoalveolar surgery on wound healing, their postoperative microbial colonization, and related clinical parameters. METHODS: A total of 172 suture samples from patients who had undergone extraction of impacted third molars were included in the study. The suture materials studied were poly-glycolide-colactide, fast absorbable poly-glycolide-colactide, poly-glycolic acid-cocaprolactone, polydioxanone, silk, polypropylene, polyvinylidene difluoride, polyamide, polyester, and polytetrafluoroethylene (PTFE). The microbial colonization in all sutures and clinical parameters were evaluated after 1 week. RESULTS: Multifilament sutures had higher bacterial colonization compared with monofilament sutures (P < .001). No dental plaque accumulation was observed in any samples of polypropylene sutures. Polydioxanone, PTFE, and poly-glycolic acid-cocaprolactone sutures exhibited less postoperative slack compared with all other sutures after 1 week. Patients with silk, polyvinylidene difluoride, and PTFE sutures had less suture-related discomfort. According to the Landry index score, monofilament sutures demonstrated superior wound healing to multifilament sutures (P = .019). In addition, nonabsorbable sutures showed significantly better wound epithelization than absorbable sutures (P ˂ .001). CONCLUSIONS: Bacterial colonization and tissue reactions due to the surface properties of the suture affected the wound healing after dentoalveolar surgery. Multifilament sutures should not be applied for prolonged periods because of their tendency for microbial colonization. The tissue reaction to the absorbable suture materials may adversely affect wound healing.

What we have learned to date from the omics approach to non-Alzheimer's dementias.

Worldwide, more than 50 million people live with dementia, and due to the rapidly aging population, dementia cases are expected to increase at least five times in 2050. 30%-40% of dementia cases are diagnosed as non-Alzheimer's dementia. Common subtypes of non-Alzheimer's dementia are known as vascular, Lewy body, and frontotemporal dementia. Despite advances in modern medicine, the mechanism of dementia is still not fully understood. The term "omics" is a general term and is used to comprehensively characterize molecules by functional and biological similarities, focusing on the basic biological processes of a living organism and these techniques have enabled us to examine the unknown areas of biology, such as the genome, transcriptome, proteome, microbiome, and metabolome. This review highlights the progress that has been made in omics research while noting the gaps in our knowledge.

Synergistic effect of thymoquinone and nystatin in the treatment of oral candidiasis; an in vitro study.

The effectiveness of antifungal agents may be insufficient against resistant strains in some cases of oral candidiasis. The aim of this study was to evaluate the antifungal effect of thymoquinone against Candida albicans, Candida tropicalis, Candida glabrata and Candida krusei strains and the synergistic antifungal activity of these strains in combination with nystatin. To evaluate in vitro antifungal activity and interactions between thymoquinone and nystatin, substances were tested against Candida albicans ATCC 10,231, C. tropicalis ATCC 750, C.krusei ATCC 6258 and C. glabrata ATCC 2001 standard strains both individually and combinationally via microdilution method. MIC and ΣFIC index value were analysed. The Kruskal Wallis test and Bonferroni test were used for statistical evaluations. Statistical significance was set at p < 0.05. A statistically significant difference was observed between the mean ranks of all Candida species and doses of thymoquinone, nystatin, and the combination thymoquinone-nystatin (p < 0.05). MIC values for thymoquinone were determined as 15 µg/mL for C. albicans, C. tropicalis and C. krusei while it was 30 µg/mL for C. glabrata. Moreover, MIC for nystatin was found as 1.875 µg/mL for C. albicans, C. tropicalis and C. krusei, whereas it was 7.5 µg/mL in C. glabrata. Interaction assays and ΣFIC index value revealed that, TQ and nystatin have a synergistic effect against to all strains. Thymoquinone was found to have antifungal activity on Candida species and synergistic effect when combined with nystatin.

[Malaria and Gut Microbiota: Microbial Interactions in the Host]. / Sitma ve Bagirsak Mikrobiyotasi: Konakta Mikrobiyal Etkilesimler.

Malaria is still considered an important public health problem among parasitic diseases all over the world and poses a significant risk for half of the world's population. In recent years, both the human and animal experimental models pointed out that Plasmodium species that cause malaria changes the composition of the human gut microbiota and particularly certain gut bacterial communities are associated with the risk and severity of malaria infection. These data take the host-microbiota relationship to the next level and enable the scientific world to focus on the interaction in the host-microbiota-pathogen triangle. Plasmodium-gut microbiota interaction has attracted attention in the severe malaria infection, whose immunopathogenesis mechanism is still unknown and can show severe clinical symptoms from person to person. Studies on Plasmodium-gut microbiota are limited in the literature. Although it is difficult to compare the data due to the differences in method and purpose in the studies, in the case of Plasmodium infection, a decrease abundances of Bacteroidetes and Verrucomicrobia phyla and an increase abundances of Firmicutes and Proteobacteria phyla were observed in the gut microbiota. It has been noticed that Plasmodium can cause changes in the gut microbiota of the host and can differentiate the host immune response, especially by changing the short-chain fatty acids producing gut bacteria. The human immune response targets different stages in the complex life cycle of Plasmodium. The major immune response elements in the preerythrocytic and erythrocytic stages of Plasmodium are CD8+ T cells and antibodies, respectively. Germinal center B cells in the spleen have critical roles for the longevity of specific antibodies required in Plasmodium infections. Gut bacteria can influence germinal center B cell response in mice via CD40 ligand. Genes causing differentiation of Th17 cells are also upregulated in the late immune response to Plasmodium, and differentiation of Th17 cells has been found to be associated with changes in Sutterella and Parabacteroides distasonis in the gut microbiota. Data are currently limited to reveal causesconsequences relationships but the correlation of host cytokine responses due to malaria pathogenesis with the gut microbiota profile draws attention to the relationship. Although the changes in the human gut microbiota is examined in this review, it should be kept in mind that the microbiota in the midgut microbiota of Anopheles can have a negative effect on the physiology of Plasmodium. It was thought that the contribution of these differentiations in the host gut microbiota to the immune response and the host-microbiota-pathogen interaction, especially in severe malaria infections whose immunopathogenesis mechanism is not clear, should be investigated with standardized and comprehensive clinical studies. In this review article, human or animal studies on the interaction of Plasmodium-gut microbiota have been discussed.

[Evaluation of the Diagnostic Performance of SARS-CoV-2 Rapid Antigen Tests in COVID-19 Patients]. / SARS-CoV-2 Hizli Antijen Testlerinin COVID-19 Hastalarindaki Tanisal Performanslarinin Degerlendirilmesi.

The gold standard in the definitive diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is nucleic acid amplification tests (NAAT) due to their high sensitivity and specificity in detecting viral ribonucleic acid. However, while leaving two years behind in the pandemic, resources have come to the point of exhaustion in terms of both the economy and the manpower working in the field of health services. Therefore, the need for rapid, simple and accurate tests to diagnose SARS-CoV-2 infection continues. In this study, it was aimed to compare the performance characteristics of SARS-CoV-2 rapid antigen tests (RAgT) in the diagnosis of coronavirus disease 2019 (COVID-19) cases with the real-time reverse transcription-polymerase chain reaction (rRT-PCR) method. In Istanbul University-Cerrahpasa Faculty of Medicine COVID-19 Molecular Diagnosis Laboratory, SARS-CoV-2 RNA positive respiratory tract samples with viral loads of <25 Ct (cycle of treshold), 25-29 Ct, 30-35 Ct and 35

Point Mutations at gyrA and gyrB Genes of Levofloxacin Resistant Helicobacter pylori Strains and Dual Resistance with Clarithromycin.

BACKGROUND: Spontaneous point mutations in genes encoding gyrA/B subunits of DNA gyrase are responsible for fluoroquinolone resistance. We aimed to determine the clarithromycin and levofloxacin resistance phenotypically in H. pylori strains and to investigate the mutations responsible for levofloxacin resistance and the effects of these mutations on dual antibiotic resistance. METHODS: A total of 65 H. pylori isolates were included. The E-test method was used for the clarithromycin and le-vofloxacin antimicrobial susceptibility test. Real-time PCR was used to detect the point mutations. RESULTS: Twenty-four (36.9%) of 65 H. pylori strains were phenotypically resistant to clarithromycin and 14 (21.5%) to levofloxacin. The phenotypic levofloxacin resistance rate of strains with Asn87Lys and Asp91Asn mutations were significantly higher (gyrA gene) (p < 0.05). The phenotypic levofloxacin resistance rate of strains with Arg484Lys and Asp481Glu mutations were significantly higher (gyrB gene) (p < 0.05). The Asn87Lys mutation increased the risk of phenotypes being resistant to levofloxacin 70.156 times and Asp91Asn mutation increased 125,427 times higher. Seven (10.8%) of 65 H. pylori strains showed dual resistance to both levofloxacin and clarithromycin. The rate of being dual resistant with A2143G mutation (clarithromycin resistance) was found to be significantly higher (p < 0.05). CONCLUSIONS: The Asn87Lys and Asp91Asn mutations in the gyrA gene had a phenotypically enhancing effect on levofloxacin resistance, while the presence of Asp481Glu and Arg484Lys mutations in the gyrB gene did not. The existence of dual resistance was developed with the increase in clarithromycin and levofloxacin resistance rates.

Epstein-Barr Virus and Helicobacter pylori co-infection in patients with gastric cancer and duodenale ulcer.

We aimed to detect EBV/Hp (Epstein-Barr Virus/Helicobacter pylori) co-infection by determining the number of copies of EBV/EBER-1 in the gastric biopsy samples of the Hp (+) GC, peptic ulcer (PU), and non-ulcer dyspepsia (NUD) cases. The patient group (PG), with 34 patients (34 GC and 30 PU patients) and a control group with 40 NUD cases were included. All patients and controls were Hp positive. EBV/EBNA-1 IgG were measured by the Anti-EBNA-1 ELISA IgG kit. Determination and quantification of EBV/EBER-1 gene region was performed by qPCR. EBV/EBER-1 positivity was 35.29% (12/34), 6.6% (2/30) and 2.5% (1/40) in GC, PU and 40 NUD cases, respectively. A significant difference was found between the GC and NUD cases (p=0.001). A significant difference was found between the groups for mean EBV/EBER-1 copy numbers (p=0.019). No significant difference was found between GC and the NUD cases (p=0.1455) for EBV/EBNA-1 IgG antibody positivity. EBV/EBER-1 positivity (OR=3.319), and age ≥55 years old (OR=2.331) were found to be a significant in multivariate logistic regression. In conclusion, our data suggest that the GC risk by EBVand Hp co-infection increased 3.3 times.

The Prevalence of Periodontal Pathogenic Bacteria in Atherosclerotic Cardiovascular Disease.

BACKGROUND: A possible link between periodontal pathogenic bacteria and atherosclerosis may exist based on the inflammatory mechanisms initiated by bacteria found in periodontal lesions. Our aim was to investigate the presence of DNA originating from T. denticola, C. rectus, T. forsythia, and P. gingivalis in the vascular tissue specimens obtained from patients who underwent surgery for arteriosclerotic vascular disease in this study. METHODS: A total of 96 patients diagnosed with valvular heart disease due to atherosclerosis and 85 patients with advanced aortic valve stenosis due to rheumatic fever and had undergone aortic valve replacement were included as the study (PG) and the control groups (CG), respectively. Atheroma plaques and vascular tissue specimens were collected from PG and CG during cardiovascular surgical procedures. Revitalization of the lyophilized T. denticola, ATCC 35405; C. rectus, ATCC 33238; P. gingivalis, ATCC 33277 and T. forsythia, ATCC 43037 strains was performed according to the manufacturer's instructions. C. rectus, T. forsythia, and T. denticola DNA samples were analyzed using the one-step in-house PCR method. RESULTS: In one (1.04%) and three (3.13%) out of 96 atherosclerotic PG tissue specimens, P. gingivalis and T. for-sythia DNA were detected, respectively. No T. denticola or C. rectus DNA was found in the study specimens. Periodontal pathogenic bacteria were not observed in 85 CG tissue specimens. There was no statistically significant difference between PG and CG for the presence of P. gingivalis and T. forsythia DNA using Fischer's Exact test (p > 0.05). CONCLUSIONS: In conclusion, with the case-control studies on a small scale such as in our study, it is not possible to determine a causality relationship between periodontal pathogenic bacteria and formation of atherosclerosis. Periodontal pathogenic bacteria may not be the only factor that causes inflammatory diseases associated with atherosclerosis. Host response and inflammatory mechanisms may be affected by other factors such as ethnicity, dietary habits, nutritional availability, and lifestyle. Taken together, it is difficult to conclude a causal link between periodontal pathogenic bacteria and formation of atherosclerosis.

Molecular Mechanisms of Colistin Resistance Among Klebsiella Pneumoniae Strains.

BACKGROUND: The increasing rate of infections caused by multiple drug resistant gram-negative bacteria has led to resuscitation of colistin. As a result, colistin resistance, mainly among Klebsiella pneumoniae strains has also been increased. The aim of this study was to investigate molecular mechanisms behind colistin resistance. METHODS: Twenty colistin-resistant K. pneumoniae strains isolated from clinical samples of different patients were involved in this study. VITEK2 automated ID/AST system (Biomeriux, France) was used for the identification and also the susceptibility testing for antibiotics other than colistin. Colistin susceptibility was determined by broth microdilution method. To identify the mechanisms of resistance, mutations on mgrB genes, expression levels of pmrA, pmrB, pmrC, pmrD, pmrE, pmrK, phoQ, and phoP genes, and the presence of plasmid mediated colistin resistance genes, mcr-1 and mcr-2 were investigated. RESULTS: As a result of the study, increased expression levels of the pmrA, pmrB, pmrD, pmrK, phoP, and phoQ genes were observed. All colistin resistant strains were found wild type for the mgrB gene which is thought to be esponsible for colistin resistance. Also, no mcr-1 or mcr-2 genes which are the causes of plasmid mediated colistin resistance have been detected in any of the strains. CONCLUSIONS: Among the colistin resistant K. pneumoniae strains included in our study, increased expression Levels of the genes responsible for cell membrane modifications related with colistin resistance were the most common mechanisms.

Helicobacter pylori-miRNA interaction in gastric cancer tissues: First prospective study from Turkey.

Helicobacter pylori (H. pylori) is involved in the etiology of gastric cancer (GC). miRNAs are short RNAs that regulate gene expression by marking mRNAs for degradation. miRNAs are involved in tumorigenesis, metastasis, and cell proliferation. We aimed to investigate the miRNA expression profiles of tissues from H. pylori (+) and (-) GC patients. Forty GC patients, 20 H. pylori (+) and 20 H. pylori (-), and a healthy control group were included. The miRNA expression levels were investigated by microarrays and quantitative RT-PCR. We detected 9 upregulated and 4 downregulated miRNAs by microarray. We selected 5 upregulated and 5 downregulated miRNAs for the quantitative RT-PCR assay. The relative fold changes of miRNAs in the cancerous tissue and non-tumor mucosa specimens of H. pylori (+) GC patients for hsa-miR-194 were 4.24- and 3.83-fold higher, respectively, whereas the hsa-miR-145 expression levels were downregulated 0.33-fold and 0.43-fold, respectively, in the same group. The presence of H. pylori significantly upregulated hsa-miR-194 and downregulated hsa-miR-145 expression levels in H. pylori (+) GC cases, compared to H. pylori (-) GC cases. Regional differences in the virulence of H. pylori strains may also be involved in the up- or downregulation of miRNA expression levels.

Antibacterial effects of lidocaine and adrenaline.

The most commonly used local anaesthetics (LAs) for postoperative analgesia and surgical anaesthesia are lidocaine and bupivacaine. Adrenaline is a vasopressor agent, which is widely used in anaesthesia for many purposes. This study aims to determine the antibacterial efficacy of lidocaine, mupirocin, adrenaline, and lidocaine + adrenaline combination. In our study, the in vitro antimicrobial effect of 1 mL of sterile saline, 20 mg/mL mupirocin, 20 mg/mL lidocaine, 1 mg/mL adrenaline, and 20 mg/mL lidocaine and adrenaline were tested against Staphylococcus aureus American-type culture collection (ATCC) 29213, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922, classified as Group C (control), Group M (mupirocin), Group L (lidocaine), Group A (adrenaline), and Group LA (lidocaine+adrenaline), respectively. S. aureus ATCC 29213, P. aeruginosa ATCC 27853, and E. coli ATCC 25922 were cultured on Mueller-Hinton agar (Oxoid, UK) plates for 18 to 24 hours at 37°C. Colonies from these plates were suspended in sterile saline, and a 0.5 McFarland turbidity standard suspension (corresponding to 1.5 × 108 CFU/mL) of each isolate was prepared. In terms of inhibition zone diameters, S. aureus ATCC 29213 values obtained after 12 and 24 hours of incubation were significantly different between groups (P < .001). According to inhibition zone diameters, Group M > Group LA > Group L > Group C = Group A. P. Aeruginosa ATCC 27853 values obtained after 12 and 24 hours of incubation were significantly different between groups (P < .001). According to inhibition zone diameters, Group M > Group LA > Group L = Group C = Group A. E. coli ATCC 25922 values obtained after 12 and 24 hours of incubation were significantly different between groups (P < .001). According to inhibition zone diameters, Group M > Group LA > Group L > Group C = Group A. It is known that LAs have antimicrobial effect potential in addition to their anaesthetic, analgesic, antiarrhythmic, and anti-inflammatory effects. There are also studies showing the antimicrobial effects of vasopressor agents, which are frequently used, particularly in intensive care unit (ICUs). However, it has been observed in the present study that adrenaline alone did not have any antimicrobial effect. Adrenaline, when used in combination with lidocaine, provides a stronger and broad-spectrum antimicrobial activity, suggesting that its combined use in proper indications will be clinically significant. Because the prevention and treatment of wound infections make a positive contribution to wound healing, the potential of antimicrobial effect of LAs can provide successful results in the prevention and treatment of ICU and wound infections. Thus, an important contribution can be made in terms of reducing the costs of antibacterial treatment and reducing morbidity.