Introduction: In the United States, Staphylococcus aureus (S.aureus) is considered one of the top five pathogens causing domestically acquired foodborne diseases and is responsible for an estimate of 241,000 illnesses per year. Foods that have been frequently implicated in Staphylococcal food-borne disease are meat, meat products, egg products, milk, dairy products, salads and bakery products. β-lactam antibiotics are routinely prescribed for treating S. aureus caused infections, but antibiotic resistance is increasing at an alarming rate. Aim: Detection of virulence factors and antibiotic resistance in S.aureus isolated from retail beef Materials and Methods : A total of 100 meat samples were collected from markets including Kharkhorin 28, Bars 4, Bayanzurkh 15, Huchit shonkhor 33, Denjiin myanga 4 and Bumbugur 16. S.aureus strains were determined on the basis of MNS 6308:2012 standard using Baird-Parker selective agar and confirmed by polymerase chain reaction (PCR) in retail beefs. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method. Results: Overall, 81% meat samples were contaminated with staphylococcal of which 54.3% were low, 28% were moderate, 11.1% were high and 6.1% were very high. PCR amplification of the thermostable nuclease-encoding nuc gene using the gene-specific primers and the chromosomal DNA preparation yielded a 270 bp amplicon, as expected and 35 (43.2%) confirmed as S. aureus. According to the findings of the current study, S.aureus strains isolated from the beef were high resistant (88.6% -97.1%) to antibiotics of penicillins group and low resistant (8.6%) to chloramphenicol. In total, 48.6% of isolates were multidrug resistant. Conclusion The contamination of staphylococcal was high in retail beef in Ulaanbaatar. Most S.aureus isolates exhibited resistance to a antibiotics of penicillin group. The half of the isolates were multidrug resistant and high virulence.

Introduction: Health care workers of First Central Hospital of Mongolia have vaccinated with three different vaccines against SARS-CoV-2. We detected SARS-CoV-2 N and S-RBD antibodies after 30-90 days of second dose of vaccination. Method: Quantitation of antibodies to the spike protein of SARS-CoV-2 was performed for the detection of adaptive immune response in 291 HCWs vaccinated with Covishield, Sinopharm and Pfizer Biontech. Detection and quantitation of SARS-CoV-2 N and S antibodies were performed by the electrochemiluminesce assay Cobas e411, Roche. Result: SARS-CoV-2-S-RBD IgG titer were negative 0%, weak positive 0.4%, positive 17.5%, strong positive 82.1% of 246 HCWs vaccinated with Covishield and were negative 2.8%, weak positive 8.5%, positive 57.1%, strong positive 31.4% of 35 HCWs vaccinated with Sinopharm.
In all HCWs vaccinated with Pfizer Biontech SARS-CoV-2-S-RBD IgG titers were strong positive. Conclusion Humoral immunity was produced in HCWs after two doses of Covishield vaccine 100%, Sinopharm 97.0%, Pfizer Biontech 100% respectively. Antibody titer was higher among younger age workers.