Prevalence of Plasmid-mediated AmpCβ-Lactamases inEscherichia coliandKlebsiella pneumoniaein Korea

Abstract

Cefoxitin-resistant Escherichia coli and Klebsiella pneumoniae are relatively prevalent in Korea, suggesting dissemination of plasmid-mediated AmpC beta-lactamases. In this study, 238 isolates of cefoxitin-resistant E. coli and K. pneumoniae (not including subspecies ozaenae and rhinoscleromatis) were collected in 2003 from 16 Korean hospitals. The prevalence of plasmid-mediated AmpC beta-lactamases was determined by PCR. The AmpC gene alleles detected in E. coli and K. pneumoniae were bla(DHA-1), 10 (8.6%) and 93 (76.2%); bla(CMY-1)-like, 14 (12.1%) and 2 (1.6%); and bla(CMY-2)-like, 38 (32.7%) and 1 (0.8%) isolates, respectively. The genes identified were bla(DHA-1), bla(CMY10)-like, and bla(CMY-2)-like, and a new variant, bla(CMY-18). Plasmidmediated AmpC gene allele-positive isolates were present both in large city and in small province hospitals, as well as in isolates from outpatients. The proportions of plasmid-mediated AmpC gene-positive isolates were similar in both expanded spectrum beta-lactamase (ESBL)-producing and -nonproducing isolates. In conclusion, DHA-1, CMY-2-like, and CMY-10-like plasmid-mediated AmpC beta-lactamase-producing K. pneumoniae and E. coli isolates are widely disseminated in both large city and small province hospitals. Absence of bla(CMY-1) and detection of a novel variant of bla(CMY-2), bla(CMY-18), indicate continued evolution of the prototype genes. Similar proportions of plasmid-mediated AmpC gene-positive isolates in both ESBL-producing and -nonproducing isolates suggest unhindered future spread of these resistances.

Laboratory Surveillance for Prospective Plasmid-Mediated AmpC β-Lactamases in the Kinki Region of Japan

“…The prevalence of PABL producers in this study was found to be 0.13% overall (range, 0.02 to 0.5%). This rate of prevalence was much lower than that reported for other countries, such as Korea (3.1%) (26), China (2.8%) (14), and the United States (1.2%) (8). However, we isolated PABL producers from 13 of 17 laboratories in the Kinki region, suggesting that PABL producers may be on the increase.…”

“…In addition to these enzyme types, DHA-type enzymes have been identified in Taiwan (31) and China (15). In Korea (14,26), DHA-, CMY/MOX-, and ACT-1/MIR-1-type enzymes have also been identified, while in the United States (1,17), in addition to the types mentioned above, DHA-, ACT-1/MIR-1-, and FOX-type enzymes have been identified. To date, in Japan, MOX-1 (11), CMY-9 (9,28), , CFE-1 (19), CMY-2 (18), and DHA-1 (18) have been found in clinical isolates.…”

What traits are carried on mobile genetic elements, and why?

“…Many traits that have been shown to be involved in bacterial cooperation and virulence are coded by mobile elements, such as traits that are capable of breaking down toxins in the local environment (Knothe et al, 1983;Philppon et al, 2002;Lee et al, 2006;Ellis et al, 2007) and secreted toxins (O'Brien et al, 1984;Waldor and Mekalanos, 1996;Ahmer et al, 1999). One theoretical study (Smith, 2001) suggested that if cooperation is coded on plasmids, these plasmids will be able to reinstate cooperation by forcing non-producing strains (through infection) to start secreting the extracellular public good (Smith, 2001).…”

Antibiotic Resistance Patterns and Detection ofblaDHA-1inSalmonellaSpecies Isolates from Chicken Farms in South Korea

“…However, the use of antibiotics in treatment of clinical enteric infection has been heavily compromised by emerging multidrug-resistant microbes (4,17,18,23). In particular, resistance due to extended-spectrum ␤-lactamases (ESBLs) and AmpC ␤-lactamases is of special concern as these enzymes confer resistance to some of the front-line antibiotics used to treat enteric infection in humans and animals (4,13,14,19).…”