A total of 47 extended-spectrum-cephalosporin-resistant Escherichia coli strains isolated from stray dogs in 2006 and 2007 in the Republic of Korea were investigated using molecular methods. Extended-spectrum ␤-lactamase (ESBL) and AmpC ␤-lactamase phenotypes were identified in 12 and 23 E. coli isolates, respectively. All 12 ESBL-producing isolates carried bla CTX-M genes. The most common CTX-M types were CTX-M-14 (n ‫؍‬ 5) and CTX-M-24 (n ‫؍‬ 3). Isolates producing CTX-M-3, CTX-M-55, CTX-M-27, and CTX-M-65 were also identified. Twenty-one of 23 AmpC ␤-lactamase-producing isolates were found to carry bla CMY-2 genes. TEM-1 was associated with CTX-M and CMY-2 ␤-lactamases in 4 and 15 isolates, respectively. In addition to bla TEM-1 , two isolates carried bla DHA-1 , and one of them cocarried bla CMY-2 . Both CTX-M and CMY-2 genes were located on large (40 to 170 kb) conjugative plasmids that contained the insertion sequence ISEcp1 upstream of the bla genes. Only in the case of CTX-M genes was there an IS903 sequence downstream of the gene. The spread of ESBLs and AmpC ␤-lactamases occurred via both horizontal gene transfer, accounting for much of the CTX-M gene dissemination, and clonal spread, accounting for CMY-2 gene dissemination. The horizontal dissemination of bla CTX-M and bla CMY-2 genes was mediated by IncF and IncI1-I␥ plasmids, respectively. The clonal spread of bla CMY-2 was driven mainly by E. coli strains of virulent phylogroup D lineage ST648. To our knowledge, this is the first report of bla DHA-1 in E. coli strains isolated from companion animals. This study also represents the first report of CMY-2 ␤-lactamase-producing E. coli isolates from dogs in the Republic of Korea.

Polymorphisms in DNA repair genes may be associated with differences in the capacity to repair DNA damage and thereby influence an individual's susceptibility to smoking-related cancer. To test this hypothesis, we investigated the potential association of 7 XPC polymorphisms (-449G?C, -371G?A, -27G?C, Val499-Arg, PAT-/+, IVS11-5C?A and Lys939Gln) and their haplotypes with lung cancer risk in a Korean population. XPC genotypes were determined in 432 lung cancer patients and 432 healthy controls frequency-matched for age and sex. XPC haplotypes were predicted using a Bayesian algorithm in the Phase program. The combined -27CGþCC genotype was associated with a significantly increased risk for overall lung cancer compared to the -27GG genotype (adjusted OR = 1.97, 95% CI 1.22-3.17, p = 0.005). The other 6 polymorphisms were not significantly associated with overall risk of lung cancer. When lung cancer cases were categorized by tumor histology, the -371AA genotype was associated with a significantly increased risk of squamous cell carcinoma compared to the combined -371GG and GA genotype (adjusted OR = 2.08, 95% CI 1.09-4.00, p = 0.03). The PAT-/+, IVS11-5C?A and Lys939Gln polymorphisms were associated with a significantly decreased risk of small cell carcinoma (SM) under a dominant model for the polymorphic allele (adjusted OR = 0.49, 95% CI 0.29-0.82, p = 0.006; adjusted OR = 0.60, 95% CI 0.36-1.00, p = 0.05; and adjusted OR = 0.58, 95% CI 0.35-0.97, p = 0.04, respectively). Consistent with genotyping analyses, haplotype 4 (1112222) containing the PAT+/IVS11-5A/939Gln alleles was associated with a significantly decreased risk of SM (adjusted OR = 0.56, 95% CI 0.37-0.85, p = 0.007 and Bonferroni-corrected p = 0.049), whereas haplotype 5 (1122111) containing the -27C allele was associated with a significantly increased risk of SM (adjusted OR = 2.88, 95% CI 1.41-5.87, p = 0.004 and Bonferronicorrected p = 0.028). These results suggest that XPC polymorphisms/haplotypes may contribute to genetic susceptibility for lung cancer. ' 2005 Wiley-Liss, Inc.

The purpose of this study was to determine the prevalence and characteristics of CTX-M β-lactamases in Escherichia coli among healthy swine and cattle in Korea. A total of 1212 fecal samples obtained from healthy pigs (n=558) and cattle (n=654) were screened for CTX-M-type extended spectrum β-lactamase (ESBL)-producing E. coli isolates. One hundred and twenty-one E. coli that produced ESBL were subjected to phenotypic and genotypic characterization. A high number (120/558, 21.5%) of swine fecal samples showed the presence of CTX-M β-lactamase-producing E. coli compared to cattle samples (1/654, 0.2%). The most predominant CTX-M-type identified was CTX-M-14 (n=82), followed by CTX-M-15 (n=16). Isolates producing CTX-M-3, CTX-M-27, CTX-M-55, and CTX-M-65 were also identified. Overall, the bla(TEM-1) gene was associated with CTX-M β-lactamase in 55 E. coli isolates. Transfer of bla(CTX-M) gene was demonstrated from 76 out of 121 bla(CTX-M)-positive E. coli isolates to the recipient E. coli J53 by conjugation. Plasmid DNA isolation from the transconjugants revealed a large (90-120 Kb) conjugative plasmid. ISEcp1 and IS903 were detected upstream and downstream of bla(CTX-M) genes in 117 and 91 E. coli isolates, respectively. Our results demonstrated that a combination of clonal expansion and horizontal transmission is spreading bla(CTX-M) genes among swine E. coli. The horizontal dissemination of bla(CTX-M) genes among E. coli was mostly mediated by IncF or IncI1-Iγ plasmids. To the best of our knowledge, this study represents the first report of CTX-M-3, CTX-M-27, CTX-M-55, and CTX-M-65 β-lactamases in bacterial isolates from food animals in Korea. This study revealed that the CTX-M β-lactamase-producing E. coli are widely disseminated among healthy pigs but very rare in cattle in Korea. Increasing prevalence of bla(CTX-M) genes in intestinal E. coli of food animals is a matter of concern and should be carefully monitored.

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These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung.

Polymorphisms in the DNA repair genes may be associated with differences in the capacity to repair DNA damage, and so this can influence an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of hMSH2 À118T>C, IVS1+9G>C, IVS10+12A>G, and IVS12À6T>C genotypes and their haplotypes with the risk of lung cancer in a Korean population. The hMSH2 genotypes were determined in 432 lung cancer patients and in 432 healthy controls who were frequency matched for age and gender. The hMSH2 haplotypes were estimated based on a Bayesian algorithm using the Phase program. The presence of at least one IVS10+12G allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the IVS10+12AA genotype [adjusted odds ratio (OR), 0.59; 95% confidence interval (95% CI), 0.40-0.88; P = 0.01], and the presence of at least one IVS12-6C allele was associated with a significantly increased risk of adenocarcinoma, as compared with the IVS12-6TT genotype (adjusted OR, 1.52; 95% CI, 1.02-2.27; P = 0.04). Consistent with the results of the genotyping analysis, the TGGT haplotype with no risk allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the TCAC haplotype with two risk allele [i.e., IVS10+12A and IVS12-6C allele; adjusted OR, 0.49; 95% CI, 0.30-0.78; P = 0.003 and P c (Bonferroni corrected P value) = 0.012]. The effect of the hMSH2 haplotypes on the risk of adenocarcinoma was statistically significant in the never smokers and younger individuals (adjusted OR, 0.45; 95% CI, 0.27-0.75; P = 0.002 and P c = 0.004; and adjusted OR, 0.44; 95% CI, 0.23-0.85; P = 0.014 and P c = 0.028, respectively) but not in the ever-smokers and older individuals. These results suggest that the hMSH2 polymorphisms and their haplotypes may be an important genetic determinant of adenocarcinoma of the lung, particularly in never smokers. (Cancer Epidemiol Biomarkers Prev 2006;15(4):762-8)