Trends in Isolation and Antimicrobial Susceptibility of Enteropathogenic Bacteria in 2011-2019 at a Korean Tertiary Care Hospital

Abstract

Background: Trends in the isolation of enteropathogenic bacteria may differ depending on environmental sanitation. This study aimed to determine trends in the isolation and antimicrobial resistance patterns of enteropathogenic bacteria between 2011 and 2019. Methods: A retrospective analysis was performed using data from stool cultures of Salmonella spp., Shigella spp., Plesiomonas shigelloides, Yersinia spp., Vibrio spp., and Campylobacter spp. The sample was collected at Severance Hospital between 2011 and 2019. Antimicrobial susceptibility testing was performed using the disk diffusion method for nontyphoidal Salmonella (NTS) and Campylobacter spp. following CLSI guideline. Results: The number of specimens for stool culture significantly increased from 13,412 during 1969-1978 to 48,476 over the past nine years, whereas the ratio of positive specimens significantly decreased from 1,732 (12.9%) to 449 (0.9%). The proportion of Salmonella Typhi decreased from 472 (93.6%) in 1969-1978 to 4 (1.5%) in 2011-2019, whereas the proportion of NTS increased from 14 (2.8%) to 261 (96.7%). The proportion of Shigella among all enteropathogenic bacteria was 1,039 (60.0%) from 1969-1978, while only 7 (1.6%) were isolated from 2011-2019. Campylobacter is the second most prevalent organisms, which were isolated 132 (29.4%). The susceptibility rate to ampicillin and cotrimoxazole were 51.1% and 85.2%, respectively, for NTS isolated from 2016 -2019. The ciprofloxacin susceptibility rate was 15.8% for Campylobacter from 2016-2019. Conclusion: The number of isolates of Salmonella Typhi and Shigella significantly decreased, while the proportion of NTS and Campylobacter increased. Continuous monitoring of ciprofloxacin-resistant Campylobacter isolates is necessary.