Objective: To study the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains.
Methods: A series of primers were designed based on potential integration site of SfII and SfX prophages in Shigella flexneri serotype 2b strains, and PCR were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. PCR products were sequenced to identify integration sites and arrangement of SfII and SfX.
Results: In all the serotype 2b strains, prophage SfII and SfX were adjacent to each other, and integrated into the thrW tRNA gene of the host, which were located between genes proA and yaiC of host. Prophage SfX was located immediately upstream of prophage SfII in all the detected 50 serotype 2b strains exception for strain 51251.
Conclusion: This was the first report on the integration site and arrangement of serotype-converting prophages SfII and SfX in Shigella flexneri 2b strains.
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Clin Vaccine Immunol
December 2017
Laboratory of Mucosal Pathogens and Cellular Immunology, U.S. FDA-Center for Biologics Evaluation and Research, Silver Spring, Maryland, USA.
We have been exploring the use of the live attenuated serovar Typhi Ty21a vaccine strain as a versatile oral vaccine vector for the expression and delivery of multiple foreign antigens, including O-antigens. In this study, we separately cloned genes necessary for the biosynthesis of the serotype 2a and 3a O-antigens, which have been shown to provide broad cross-protection to multiple disease-predominant serotypes. The cloned 2a operon, along with and , contained on the SfII bacteriophage, was sufficient in Ty21a to express the heterologous 2a O-antigen containing the 3,4 antigenic determinants.
View Article and Find Full Text PDFBackground: All Shigella flexneri serotypes except serotype 6 share a common O-antigen tetrasaccharide backbone and nearly all variations between serotypes are due to glucosyl and/or O-acetyl modifications of the common O unit mediated by glycosyltransferases encoded by serotype-converting bacteriophages. Several S. flexneri serotype-converting phages including SfV, SfX, Sf6 and SfII have been isolated and characterized.
View Article and Find Full Text PDFZhonghua Liu Xing Bing Xue Za Zhi
July 2010
State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Objective: To study the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains.
Methods: A series of primers were designed based on potential integration site of SfII and SfX prophages in Shigella flexneri serotype 2b strains, and PCR were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. PCR products were sequenced to identify integration sites and arrangement of SfII and SfX.
J Bacteriol
November 2000
Department of Microbiology and Immunology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
The sequence of the nonredundant region of the Salmonella enterica serovar Typhimurium temperate, serotype-converting bacteriophage P22 has been completed. The genome is 41,724 bp with an overall moles percent GC content of 47.1%.
View Article and Find Full Text PDFPrevious studies have shown that Shigella flexneri bacteriophage X (SfX) encodes a glucosyltransferase (GtrX, formerly Gtr), which is involved in O antigen modification (serotype Y to serotype X). However, GtrX alone can only mediate a partial conversion. More recently, a three-gene cluster has been identified next to the attachment site in the genome of two other S.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!