HlyA knock out yields a safer Escherichia coli A0 34/86 variant with unaffected colonization capacity in piglets |
| |
Authors: | Sheshko Valeria Hejnova Jana Rehakova Zuzana Sinkora Jiri Faldyna Martin Alexa Pavel Felsberg Jurgen Nemcova Radomira Bomba Alojz Sebo Peter |
| |
Institution: | Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic. |
| |
Abstract: | Escherichia coli A0 34/86 (O83:K24:H31) has been successfully used for prophylactic and therapeutic intestinal colonization of premature and newborn infants, with the aim of preventing nosocomial infections. Although E. coli A0 34/86 was described as a nonpathogenic commensal, partial sequencing revealed that its genome harbours gene clusters highly homologous to virulence determinants of different types of E. coli, including closely linked genes of the alpha-haemolysin operon (hlyCABD) and for the cytotoxic necrotizing factor (cnf1). A haemolysin-deficient mutant (Delta hlyA) of E. coli A0 34/86 was generated and its colonization capacity was determined. The results show that a single dose of the A0 34/86 wild-type or Delta hlyA strains resulted in efficient intestinal colonization of newborn conventional piglets, and that this was still considerable after several weeks. No difference was observed between the wild-type and the mutant strains, showing that haemolysin expression does not contribute to intestinal colonization capacity of E. coli A0 34/86. Safety experiments revealed that survival of colostrum-deprived gnotobiotic newborn piglets was substantially higher upon colonization by the nonhaemolytic strain than following inoculation by its wild-type ancestor. We suggest that the E. coli A0 34/86 Delta hlyA mutant may represent a safer prophylactic and/or immunomodulatory tool with unaffected colonization capacity. |
| |
Keywords: | Escherichia coli haemolysin colonization safety germ-free piglets |
本文献已被 PubMed 等数据库收录! |
|