Microbiological and Susceptibility Profile of Clinical Gram Positive Isolates at a Tertiary Pediatric and Maternity Hospital in Ulaanbaatar, Mongolia.

Abstract

Introduction: Information on microbiological and susceptibility profiles of Monoglian bacterial isolates is scarce. Resistance profiles, patient demographics and microbiological work-up of gram positive isolates were analyzed in order to develop infection control activities and policies at the National Center for Maternity and Children's Health (NCMCH) in Ulaanbataar, Mongolia.

Methods: All gram positive isolates of specimens submitted to the microbiology laboratory at NCMCH between January 2014 and August 2017 were included. Data collected included demographic data, specimen type, in-/outpatient status, hospital ward of sample origin, and antimicrobial susceptibility testing profile. Susceptibility testing was performed by trained microbiologists at the NCMCH microbiology laboratory. T-test, Mann-Whitney, Chi-square and Fisher exact tests were used as appropriate.

Results: Of 11,889 isolates, 4012 (33.7%) were gram positive, with most identified as S. aureus (62.6%, n=2512). Rates of methicillin resistance (MRSA) remained stable at a quarter, but was significantly higher among inpatients (inpatients: 630/2002, 31.5%; outpatients 67/290, 23.1%; p≤0.05) and sterile site isolates (sterile: 83/171, 48.5%; non-sterile: 416/1678, 24.8%; p≤0.01). The vast majority of S. pneumoniae isolates (12/14; 85%) was found to be penicillin resistant by oxacillin disk diffusion. While identification of Group B streptococci was rare (n=137) due to of lack of diagnostic measures available, the number of enterococcal isolates identified increased significantly due to implementation of improved microbiological work-up (2015: n=7; 2016: n=26; 2017: n=83).

Conclusion: Compared with published studies from neighboring nations, the rates of antimicrobial resistance among gram positive isolates at NCMCH, particularly with respect to S. aureus and S. pneumoniae, were much higher. Further improvement of microbiological diagnostics and collaboration of stakeholders is required to address the pressing infection control and stewardship issues and to ensure reliable identification of relevant pathogens in Mongolia.