Background: Helicobacter pylori (H. pylori) is a gram-negative, microaerophilic bacterium that colonizes the human gastric mucosa, with an estimated global prevalence exceeding 50%. The increasing resistance of H. pylori to clarithromycin, a key antibiotic in eradication regimens, has led to a decline in the efficacy of standard treatment to below 80%. Consequently, international guidelines advocate for susceptibility-guided therapy to optimize treatment outcomes. Detection of clarithromycin resistance-associated mutations, including A2143G, A2142G, A2142C, and A2144G, is essential for improving therapeutic efficacy and mitigating the propagation of antimicrobial resistance. Aim: To evaluate the efficacy of tailored H. pylori eradication therapy based on clarithromycin resistance profiling. Materials and Methods: A total of 125 treatment-naïve patients diagnosed with H. pylori infection were enrolled in this study. The infection was confirmed through upper gastrointestinal endoscopy with histopathological analysis, the urea breath test, and stool antigen detection. Clarithromycin resistance-associated mutations were identified using polymerase chain reaction (PCR) analysis on gastric biopsy and stool samples. Based on the presence or absence of resistance mutations, patients were stratified into two treatment cohorts and received targeted eradication therapy. Treatment success was assessed 28 days post-therapy using a stool antigen test to confirm H. pylori eradication. Results: Among the 120 patients who met the inclusion criteria and completed treatment, 41.6% (n=50) were male, and 58.4% (n=70) were female, with a mean age of 39±9.1 years. Clarithromycin resistance-associated mutations were detected in 36 patients (30%), with A2143G identified in 35 cases (97.2%) and A2142G in 1 case (2.7%). In the clarithromycin-sensitive cohort, 84 patients underwent eradication therapy, and among the 60 who completed post-treatment assessment, the eradication rate was 91.6%. In the clarithromycin-resistant cohort, 36 patients received treatment, and among the 20 who completed post-treatment assessment, the eradication rate was 80% (p=0.038). Conclusion A substantial prevalence of clarithromycin resistance-associated mutations was observed among the study population. Susceptibility-guided eradication therapy demonstrated superior efficacy, with eradication rates exceeding 90%. These findings underscore the necessity of implementing resistance-based treatment strategies to optimize clinical outcomes and limit the further dissemination of antimicrobial resistance. Future investigations should focus on refining therapeutic approaches for H. pylori strains exhibiting clarithromycin resistance.

Background: Helicobacter pylori (H.pylori) infection is highly prevalent worldwide, with an overall infection rate of 50% of the total population. Effective and accurate eradication treatment for H.pylori is considered one of the most important preventative measures against gastric cancer. However, the increasing prevalence of clarithromycin-resistant H. pylori strains has significantly compromised the success rates of standard eradication regimens. In recent years, many countries have adopted molecular diagnostic methods to detect H.pylori infection and assess clarithromycin resistance. These approaches, which are often non-invasive, enhance both diagnostic accuracy and the ability to tailor treatment strategies. Although numerous studies have investigated methods for detecting H. pylori and clarithromycin resistance using gastric tissue specimens, relatively few have focused on the clinical application of stool-based diagnostics, despite their potential advantages in non-invasive testing. Aim: To detect H.pylori infection and clarithromycin resistance using molecular biological methods from both gastric tissue and stool samples, and to comparatively evaluate the diagnostic outcomes. Materials and Methods: The hospital-based cross-sectional study was conducted at the Gastroenterology department of the Mongolia-Japan Hospital. A total of 125 dyspeptic patients aged 18-80 years were enrolled. Eligibility criteria required the H.pylori infection to be confirmed by at least two diagnostic methods. Each participant underwent both invasive (histological examination, gastric biopsy-based real-time PCR) and non-invasive (urea breath test, stool antigen test, stool-based real-time PCR) methods. Gastric biopsies and stool samples were analyzed by real-time PCR to detect H.pylori and identify clarithromycin resistance-associated 23S rRNA point mutations (A2143G, A2142G, A2142C) Results: Among the study participants, 60.0% (n=75) were female and 40.0% (n=50) were male, with a mean age of 39±1 years. Comparative evaluation of the diagnostic methods for H.pylori infection demonstrated that the stool antigen test, performed in 104 individuals, yielded positive results in 91 cases (87.5%), whereas the urea breath test, performed in 51 individuals, was positive in 45 cases (88.2%). Using real-time polymerase chain reaction (PCR), H.pylori was detected in 76 of 101 stool samples (75.2%) collected in ENAT transport medium, and in 43 of 87 raw stool samples (49.4%). The estimated diagnostic sensitivities were 94% for the urea breath test, 91% for the stool antigen test, 78% for real-time PCR using ENAT-preserved stool, and 49% for real-time PCR using raw stool specimens. Clarithromycin resistance was found in 36 participants (28.8%), while 89 participants (71.2%) carried H.pylori strains susceptible to clarithromycin. Clarithromycin resistance was detected in 27.6% of stool samples and 30.5% of gastric biopsy specimens. Among the clarithromycin-resistant isolates identified from gastric tissue, 35 cases (97.2%) carried the A2143G point mutation, while the A2142G mutation was detected in only 1 case (2.8%). All resistant cases detected from stool samples carried the A2143G mutation, whereas the A2142G mutation was not observed. Conclusion Real-time PCR demonstrated high efficacy for the detection of H.pylori infection and clarithromycin resistance in gastric biopsy specimens. While the sensitivity of stool-based real-time PCR was comparatively lower, detection rates improved with the use of ENAT transport medium. These findings highlight the potential of stool-based real-time PCR as a non-invasive diagnostic tool; however, further investigations are warranted to optimize assay performance through rigorous standardization and refinement of sample processing protocols for the accurate detection of clarithromycin-resistant H.pylori.

Background: Studying the human embryonic and fetal organ systems development patterns and determining their quantitative indicators is of scientific and practical importance in medicine and health in every nation.
Distortions and pathologies during the development of the embryo are the causes of congenital disabilities. Among the congenital malformations, facial malformations are the 3rd place, including cleft lip and palate in 70% and Srouzon's syndrome in 30%. In addition, abnormalities due to changes in the size, shape, and position of the jaw are also mentioned in the 2021.04.21 issue of Morphology magazine in the study "Morphometric parameters of the bones of the skull and face during the development of newborns and fetuses". In our country, Ariuntuul G (2005) determined that cleft lip and cleft palate occur at 0.76/1000 or 1 in 1314 live births, while Ayanga G (2012) found that it occurs at 1 in 1072 live births or 0.93/1000. Moreover, the eye cup dimensions of Mongolian fetuses aged 16 36 weeks have a positive linear relationship with the gestational age determined using ultrasound by Nandintsetseg B (2015) et al. Compared with the other countries, the eyecup is slightly wider, and the outer edge distance is similar, whereas the inner edge distance is shorter. Purpose: To summarize research work and determine the embryonic development of bones involved in the formation of the face and facial parts, the period of bone formation, the point of ossification, and the period of formation. Methods: During fetal development, human organ systems grow and develop at different rates but in a particular relationship. This feature of growth and development is also clearly observed in the structure of the head and facial bones, and the results of researchers who have studied this aspect are selected in the articles. Results: Embryonic and fetal development of bone are clinically significant not only from the point of view of its morphogenesis but also from the point of view of congenital disabilities. Conclusion In the analysis of the sources, most of the works on the prenatal period of the development of the same body have studied the development of specific structures of the face and facial area, such as the palatine bones and nasal bones, or have generally covered the development of particular systems in the embryo and fetus, and face, there are relatively few works that show the entire dynamics of growth and development of facial bones.