1.Antimicrobial profile of Acinetobacter baumannii from clinical samples
Oyunchimeg R ; Otgonbayar B ; Khosbayar T
Health Laboratory 2022;15(1):11-15
Acinetobacter baumannii is considered to be a worldwide threat to public health due to its high antimicrobial resistance rates and the severe infections it can cause. Little is known about this pathogen’s resistance in Mongolia. This report aims to describe the antimicrobial resistance profile of A. baumannii at a tertiary hospital in Mongolia. The cross-sectional analysis was conducted at the tertiary care laboratory hospital in the First Central Hospital of Mongolia from 2013.01 to 2013.12 and from 2020.01 to 2020.12.
A total of 141 in 2013, 227 in 2020 consecutive microbiological reports were analyzed. A. baumannii was isolated. Epidemiological and microbiological data, including the isolation setting and patient information, were recorded. Prevalence of multi-drug and extensive-drug resistance was assessed according to international standards.
The median age of individuals was 22 years (2 – 35 years); female was the predominant gender (53%). The hospital’s intensive care units had the highest number of isolates (n = 226). The most frequent specimen from which A. baumannii was isolated was secretion of respiratory tract (n = 119). Resistance to carbapenems was reported to be 35% among the isolates (n = 115) in 2013 and 74.69% (n=135) respectively. This report reveals the threat of this pathogen to public health in Mongolia and appeals for antibiotic stewardship programs throughout all tertiary hospitals and other hospitals.
2.Associations of XRCC1 S326C (rs25487) gene Polymorphism in Myelodysplastic syndrome
Undarmaa O ; Narmandakh B ; Avirmed Kh ; Khosbayar T ; Odgerel Ts ; Batchimeg N
Health Laboratory 2017;7(2):21-25
Introduction:
Base excision repair (BER) is mainly responsible for the correction of small base changes of DNA damage. BER pathway involved many enzymes including OGG1 and XRCC1. The defective DNA repair is associated with an increased risk of various cancers including hematologic malignancies-leukemia and myelodysplastic syndrome (MDS). However, it is deniably these polymorphisms alter the susceptibility and clinical outcome of MDS patients.
The aim:
This study was to evaluate the impact of polymorphisms in gene encoding one protein of BER system: XRCC1 Arg399Gln in MDS and healthy population.
Methods:
In this study, we recruited 60 health control group [median 47.9 years, 9 MDS subjects [median 56.6 years] were included in this study. Genotyping was carried out by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Allele and genotype frequencies were calculated by direct counting.
Result:
The frequencies of genotypes of XRCC1 Arg399Gln were as follows: Arg /Arg 1 (11%), Arg/Gln 6 (66%), Gln/Gln 2 (22%) in MDS and Arg /Arg 18.4%, Arg/Gln40%, Gln/Gln41.6% in health control for XRCC1 Arg399Gln. The result revealed that genotypes Arg399Gln increased the risk of MDS
In conclusion
this study is the first to analyze XRCC1 SNPs and their associated risk of MDS in Mongolian samples. To fully understand the role of DNA damage and DNA repair in the MDS, prospective studies are needed and other genes (OGG1 Ser326Cys, MUTYH Gln324His, APE Asp148Glu) of base excision repair pathway should be analyzed.
3.Results of treatment based on clarithromycin resistance for the eradication of Helicobacter pylori
Tsolmon B ; Sarantuya G ; Zoljargal G ; Khosbayar T ; Byambajav Ts
Mongolian Journal of Health Sciences 2025;86(2):65-69
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.
4.Study of exposure and vaccination coverage of the medical students
Yanjindulam B ; Naranzul B ; Ulziisuren B ; Byambasuren S ; Gantsetseg G ; Solongo G ; Narangerel P ; Nyammkhuu D ; Nyamsuren B ; Munkhzul D ; Batchimeg Ch ; Ganchimeg Ch ; Oyunbileg D ; Khosbayar T
Diagnosis 2023;106(3):109-117
Background:
To prevent and combat the spread of the COVID-19 pandemic, the Government of Mongolia has implemented measures such as movement and time restrictions, social distancing and isolation, closure of schools, kindergartens and public places, immunization, and others. It has caused adverse consequences for people, social relations, and the economy, causing health, social, economic, and humanitarian crises. Not only does this situation, medical students, as frontline healthcare workers, are more susceptible to virus infection. Vaccines against COVID-19 have been researched quickly due to the pandemic and are being used under emergency use authorization. In our country the approach of mixing vaccine doses from different manufacturers was used (fractional doses). Therefore, there is no study on the exposure of medical students to the COVID-19 infection and the adverse effects after receiving a dose of a heterologous vaccine. Objective: To study the exposure to the COVID-19 infection and vaccination status of medical students.
Methods:
The survey was conducted from November 2023 to December 2023 using a cross-sectional study design, and 170 students who study at ASUSU and live in the dormitory were included.
Results:
A total of 170 students participated in the study. 55.9% (n=95) of them were in the first year, 22.4% (n=38) were in the second year, 10% (n=17) were in the third year, 7.6% (n=13) were in the fourth year, 2.4% (n=4) were from the 5th year and 1.8% (n=3) were from the 6th year students. 88.2% (n=150) of students were female and 11.8% (n=20) were male. In this study, 37.1% of the students were infected by COVID-19 infection previously. Among them, 50% of the students were infected from family members, 16.7% from the school environment, and 15.2% did not know about the source of infection. 76.2% of the respondents were diagnosed with COVID-19 in a medical institution, and forty-one students answered that they were treated at the hospital. 83% of the cases were treated at home and were cured within 14 days. In contrast, 93.8% of the hospitalized students were treated within four months to 1 year. The current study demonstrates neurological, respiratory, sensory, cardiovascular, psychiatric, digestive, and dermatological symptoms were in 37.6%, 24.1%, 27.6%, 17.6%, 11.8%, 11.2%, and 10% of the students who participated in the study, respectively. For a year or more, symptoms of all organ systems were present, but neurological symptoms appeared to be the highest. 55.9% (n=115) of the enrolled students received 3 or 4 doses of the vaccine, 3.5% (n=6) did not receive the vaccine. In total, 35% (n=60) of the enrolled students experienced side effects and 65% (n=106) had no side effects.
Conclusion
In this study, 37.1% of the students were infected by COVID-19 infection previously. According to the current study, symptoms related to the nervous system was the most prevalent and 55.9% (n=115) of the enrolled students received 3 or 4 doses of the vaccine. In total, 35% (n=60) of the enrolled students experienced side effects.