The validity evaluation of different 16srRNA gene primers for helicobacter detection urgently requesting to design new specific primers.

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori. Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using in silico and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276, 16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the Non-Helicobacter pylori Helicobacters should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. In addition, in silico evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory.

Evaluation of the diagnostic performance and the utility of Helicobacter pylori stool antigen lateral immunochromatography assay.

Background: Helicobacter pylori causes the most common human gastric infection. H. pylori Stool Antigen Lateral Flow Immunochromatography assay (HpSA-LFIA) is considered one of the most cost-effective and rapid non-invasive assays (active tests). Evaluating HpSA-LFIA is of crucial for ensuring accuracy and utility assurance. This study aimed to evaluate the polyclonal antibody-based HpSA-LFIA in comparison to a monoclonal antibody-based ELISA kit. Methodology: Stool samples were collected from 200 gastric patients for HpSA-LFIA and semiquantitative HpSA-ELISA tests. A statistical analysis of the diagnostic performance was performed using MedCalc software. Chi-square tests were performed to determine the effects of gender and age. Results and conclusion: The results showed that HpSA-LFIA achieved remarkable sensitivity (93.75%) and NPV (98.00%). However, it had poor specificity, PPV, and accuracy of 59.76%, 31.25%, and 65.31%, respectively. LR+ and LR-were 2.33% & 0.1%, respectively. Gender didn't affect the diagnostic performance of HpSA-LFIA. Age groups had irrelevant sensitivity; however, specificity was significantly higher in patients aged >45 years. We can conclude that HpSA-LFIA was not accurate enough to be the sole test for diagnosis and suggest developing other confirmatory tests in case of positive conditions.

Occurrence of Salmonella infection and antimicrobial susceptibility for local Salmonella isolates from different sources in a cross-sectional study.

Salmonellosis is a considerable public health problem worldwide, with high economic importance in developed countries. The main purpose of this study was to determine the prevalence of Salmonella infection and antibiogram analysis of isolated strains in a cross-sectional study in Egypt 2016-2017. The study investigated twenty-eight Salmonella isolates from different areas in Egypt and different types of samples, such as human stool (9.3%), Egyptian cattle egrets and storks (28.5%) and grilled chicken from electric grills (36.6%). No isolates were detected from grilled chicken from charcoal grills or drinking water. The main Salmonella serotype detected in the isolates was S. typhimurium (86.5%). Molecular characterization of the invA gene by PCR was carried out and then confirmed by sequencing, and the results were submitted to GenBank. Antibiogram analysis of Egyptian isolates carried out on 9 antimicrobial discs reported that the routine regimes of treatment were not yet effective for recent new Salmonella generations in 2016-2017. The new isolates could be treated with levofloxacin, cefaperazone/sulbactam, chloramphenicol, imipenem or meropenem.