대장균에 의한 요로감염의 연령별, 계통군별 특징

Purpose : We aimed to investigate the clinical and phylogenetic characteristics of Escherichia coli Urinary Tract Infections (E. coli UTI). Methods : We enrolled patients with culture-proven E. coli UTI, who were admitted at the study hospital from September 2008 to August 2009. We investigated clinical data of patients with E. coli UTI and characteristics of isolated E. coli strains. The phylogenetic groups were classified using triplex polymerase chain reaction (PCR), and the distribution of nine virulent genes was determined by multiplex PCR. Results : A total of 47 patients have participated in this study. Thirty (63.8%) were under 6 months; eight (17.0%) were between 6-12 months; and nine (19.1%) were over 12 months. We compared two age groups between under 6-month and over 6-month. In the age group under 6-month, higher proportion of male (P =0.002) and group B2 strains (P =0.020) were observed. In contrast, higher proportion of female and group non-B2 strains were observed in age group over 6-month. Frequencies of papC, papGII, papGIII, sfa/foc, hlyC, cnf1, fyuA, iroN and iucC were estimated as 68.1%, 57.4%, 42.6%, 46.8%, 46.8%, 31.9%, 87.2%, 48.9% and 63.8%, respectively. In the comparison of phylogenetic groups, group B2 showed higher distribution of virulent genes, while group D included more strains resistant to trimethoprim/sulfamethoxazole (TMP/SMZ) than other groups. Conclusion : We showed the age group-specific difference in the distribution of sex ratios and phylogenetic groups; more male and group B2 strains in age group under 6-month, while more female and group non-B2 in age group over 6-month. However, further evaluation including larger number of patients will be necessary to confirm above thesis in future molecular epidemiological studies. 목 적:E. coli UTI의 임상양상과 UPEC의 미생물학적 특징을 확인하여 연령별, 계통군별 연관성을 평가하고자 하였다. 방 법: 2008년 9월부터 2009년 8월까지 요로감염으로 입원하여 배양검사에서 E. coli가 검출된 환아를 대상으로 하였다. 환자의 임상양상과 검사소견을 확인하였고, 검출된 E. coli를 계통학적으로 분류하고 독성유전자의 분포와 항생제 내성률을 조사하였다. 결 과:총 47명의 E. coli UTI 환아가 연구에 참여하였다. 연령군별로 6개월 미만 30명(63.8%), 6-12개월은 8명(17.0 %), 12개월 이상 9명(19.1%)이었다. 6개월 미만 연령군에는 남아(70.0%)가 많았고 6개월 이상연령군에는 여아(76.5%)가 많았다(P =0.002). 계통학적 분석에서 UPEC의 대부분(80.8%)은 B2 혹은 D군에 속하였다. 연령군별로는 6개월 미만 연령군에는 B2군(80.0%)가 많았고 6개월이상연령군에는non-B2군(52.9%)가 많았다(P=0.020). 계통군별로는 B2군에는 몇몇 독성유전자의 높은 분포가 확인되었고(P