Trends in Isolation and Antimicrobial Susceptibility of Enteropathogenic Bacteria in 2001-2010 at a Korean Tertiary Care Hospital

Abstract

Background: Trends in the isolation of enteropatho- genic bacteria may differ depending on environmental sanitation. The aims of this study were to determine trends in the isolation and antimicrobial resistance patterns of enteropathogenic bacteria over the last 10 years. Methods: We analyzed stool cultures of Salmonella spp., Shigella spp., Plesiomonas shigelloides, Yersinia spp., Vibrio spp., and Campylobacter spp. collected at Severance Hospital between 2001 and 2010. Anti- microbial susceptibility testing was performed using the disk diffusion method for nontyphoidal Salmonella (NTS) and Campylobacter. Results: The number of specimens for stool culture significantly increased from 13,412 during 1969-1978 to 60,714 over the past 10 years, whereas the ratio of positive specimens significantly decreased from 12.9% (1,732) to 1.1% (648). The proportion of Sal- monella Typhi decreased from 97.2% in 1969-1978 to 0.8% in 2001-2010, whereas the proportion of NTS increased from 2.8% to 99.2%. The proportion of Shigella among all enteric pathogens was over 50% from 1969 to 1983, while only seven strains were isolated from 2001 to 2010, with the exception of one outbreak. Campylobacter is the second most prevalent organism. The rates of susceptibility to am- picillin and cotrimoxazole were 61% and 92%, respe- ctively, for NTS isolated from 2006 to 2010. The ci- profloxacin susceptibility rate was 79.5% for Campy- lobacter between 2006 and 2010. Conclusion: The number of isolates of Salmonella Typhi and Shigella significantly decreased, while the proportion of NTS and Campylobacter increased. Con- tinuous monitoring of ciprofloxacin-resistant Campylo- bacter isolates is necessary. (Ann Clin Microbiol 2013; 16:45-51)