Korean J Infect Dis.  1999 Oct;31(5):390-401.

Mechanism of beta-lactam Resistance in Gram-negative Rods Isolated from Surgical Site Infection

• Shin HS
• Kim YS
• Cho DT

Abstract

BACKGROUND: There have been few studies about the kinds of species causing surgical site infections and their resistance pattern in Korea. An increase of extended-spectrum beta-lactamase (ESBL) producing strains is a worldwide problem. However, there is not enough data on the prevalence of ESBL-producing strains in Korea and the true extent of this problem seems to be under-recognized.
METHODS
Minimal inhibitory concentrations of gram-negative bacilli isolated from surgical site infections were tested using the standard agar dilution method according to the National Committee for Clinical Laboratory Standards. To identify and characterize beta-lactamases, we performed conjugation test, isoelectric focusing, Southern hybridization, and polymerase chain reaction.
RESULTS
A total of 54 strains of gram-negative enteric bacilli were identified:two strains of Acinetobacter spp., one of Citrobacter freundii, nine of Enterobacter cloacae, one of Enterobacter sakazakii, one of Escherichia coli, two of Klebsiella pneumoniae, one of Morganella morganii, one of Proteus vulgaris, 23 of Pseudomonas aeruginosa, four of Xanthomonas maltophila, and nine of Serratia marcescens. Three strains produced ESBL.
CONCLUSION
Various species of gram-negative organisms isolated from surgical site infections showed complex antibiograms to various beta-lactams, even to the new generation of antibiotics. A large proportion of these strains showed conjugally transferable, plasmid-mediated, beta-lactam resistance. Some strains were ESBL-producing. This evidence suggests that there has been a molecular evolution of beta-lactamase genes to a great extent in Korea, possibly due to indiscriminate use of antibiotics.

Keyword

Drug resistance; Beta-lactamase; Extended-spectrum Beta-lactamase; Isoelectric focusing; Gram-negative bac- teria

MeSH Terms

Acinetobacter
Agar
Anti-Bacterial Agents
beta-Lactam Resistance*
beta-Lactamases
beta-Lactams
Citrobacter freundii
Cronobacter sakazakii
Drug Resistance
Enterobacter cloacae
Escherichia coli
Evolution, Molecular
Isoelectric Focusing
Klebsiella pneumoniae
Korea
Microbial Sensitivity Tests
Morganella morganii
Polymerase Chain Reaction
Prevalence
Proteus vulgaris
Pseudomonas aeruginosa
Serratia marcescens
Xanthomonas
Agar
Anti-Bacterial Agents
beta-Lactamases
beta-Lactams