tailieunhanh - báo cáo hóa học:" Barriers to coliphage infection of commensal intestinal flora of laboratory mice"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Barriers to coliphage infection of commensal intestinal flora of laboratory mice | Virology Journal BioMed Central Research Open Access Barriers to coliphage infection of commensal intestinal flora of laboratory mice Laura M Kasman Address Department of Microbiology and Immunology Medical University of South Carolina BSB-201 . Box 250504 173 Ashley Avenue Charleston SC 29403 USA Email Laura M Kasman - kasmanl@ Corresponding author Published 15 April 2005 Received 08 April 2005 Accepted 15 April 2005 Virology Journal 2005 2 34 doi 186 1743-422X-2-34 This article is available from http content 2 1 34 2005 Kasman licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Growth characteristics of coliphage viruses indicate that they are adapted to live with their Eschericia coli hosts in the intestinal tract. However coliphage experimentally introduced by ingestion persist only transiently if at all in the gut of humans and other animals. This study attempted to identify the barriers to long term establishment of exogenous coliphage in the gastrointestinal GI tracts of laboratory mice. Intestinal contents were screened for the presence of coliphage and host bacteria and strains of E. coli bacteria from different segments of the GI tract were tested for susceptibility to six common laboratory coliphages. Results Contrary to expectations coliphage were not evident in the GI tracts of laboratory mice although they were occasionally detected in feces. Commensal flora showed extreme variability within groups of mice despite identical handling and diet. Less than 20 of 48 mice tested carried E. coli in their gut and of 22 commensal E. coli strains isolated and tested 59 were completely resistant to infection by lambda M13 P1 T4 T7 and PhiX174 coliphage. Lysogeny could not