광주지역에서 분리된 Salmonella enterica의 특성에 관한 연구

Abstract

From January 2001 to December 2007, the serotype of Salmonella enterica isolated from diarrhea patients in the Gwangju area consisted of 30 types, There were 99 strains of Enteritidis (42.9%) and showed the highest isolation frequency followed by 61 strains (26.4%) of Typhimurium. The pattern of antibiotics resistance is a trend Which is increasing, the frequency of bacteria resistant to TE was 47.4% which was highest, followed by the order of 45.7% of AM as well as TIC, SAM was 27.6%, NA was 22.8%, and CM was 21.6%. The serotype Typhimurium to TE was 82.2% and most bacteria showed the resistance, to AM and TIC were approximately 50%, and the frequency of resistance to CM, SAM, and GM was high. The serotype Enteritidis was 59.6% the penicillins antibiotic AM and TIC was 59.6%, SAM was 40.4% and the frequency of antibiotics resistance was higher than other serotypes, and resistance to CIT and SXT was not detected. Concerning other serotypes, to TE was 41.7% and the frequency of antibiotic resistance was highest followed by the order of 27.6% SAM, 23.6% AM, and the frequency of antibiotic resistance to all antibiotics was relatively low. In addition, in the multidrug resistance pattern, higher than 68% of Typhimurium, and approximately 65% of Enteritidis showed resistance to more than two types of antibiotics. Particularly, the frequency of multidrug resistance of Typhimurium to 3-8 antibiotics was approximately 52% and it was higher than other serotypes. In addition, regarding other serotypes, Blockley, Brandenburg, Haardt, Panama, Paratyphi B, Rissen, and Saintpaul showed multidrug resistance. Overall, antibiotics that showed resistance simultaneously were AM, SAM, TIE and TE of which resistance was relatively high in each serotype. The plasmid DNA of 37 strains of the serotype Typhimurium with high antibiotics resistance and multidrug resistance were analyzed and the results showed that all strains contained more than one plasmid 2 kb-22.9 kb in size and generally 4-6 plasmids, nonetheless, the correlation of the pattern of antibiotic resistance to the Plasmid DNA pattern could not be detected. In multidrug resistant strains analyzed by polymerase chain reaction, 72 strains containing the Class 1 Integron were isolated, and among them, 60 strains contained an integron showing one 1,200 bp amplification product, There were 3 bacterial strains containing 1,000 bp and 1,200 bp, There were 3 bacterial strains, containing 1,200 bp and 1,600 bp, 4 strains of bacteria etc. showing 1,200 bp and 2,000 bp contained an ingegron with more than 2 amplification products. Among bacteria resistant to more than 4 types of antibiotics, bacteria with more than two types of integron were observed only in the serotype Paratyphi B. Particularly, 1,200 and 1,600 bp integron showed resistance to AM, GM, KM, TIC, and TE, and the characteristic was that bacteria with 1,200 as well as 2,000 bp integron showed resistance to NA and SXT. Among the resistant gene cassette within integron, β-lactamase gene and blaP1 (pse1) gene were not detected at all except in 2 strains of the serotype Paratyphi B, and 2 strains of the blaP1 positive serotype Paratyphi B were resistant to SAM. Among bacteria resistant to AM or TIC, etc., on bacteria negative for PCR using the Primer in-F and blaP1-B, PCR using blaP!-F and blaP1-B primer was performed and 420 bp amplification products were observed. PCR was performed using the primer qacE 1-F and sul1-B, and 1,130 bp amplification products were shown, and in some bacteria, 800 bp amplification products were observed. It is necessary that in future, more studies on the examination of different several resistant genes within the integron and their structure are required. As cytotoxicity to HeLa cells, treated cells with bacteria, more than 20 % of cells died, and particularly, When treated with the serotype Panama, approximately more than 80 % died. When treated with cell culture supernatant, cytotoxicity was not be observed in most cases, nonetheless, When treated with the culture supernatant of the serotype Brandenburg, Indiana, Panama and Schwarzengrund, more than 30% cells died. The cytotoxicity to HeLa cells was thought to be due to Cly A production. Such result suggests for the first time that NTS inducing diseases within the intestinal tract could produce toxin with cytotoxicity. It is thought that in future, studies investigating the characteristics of bacteria with cytotoxicity should be investigated more comprehensively.