investigation of ctpa in listeria monocytogenes and transfer it to e.coil

introduction: listeria monocytogenes is a gram positive bacteria, frequently found in the environment and is responsible for food-borne disease such as perinatal infections, septicameia and meningeonceohalitis in human and animals. material and methods: for this reason, distribution of the ctpa determinate among l. monocytogenes isolated from clinical environment, diry and poultry samples were investigated. then, ctpa gene was tranfered into e.coil dh5-alfa. this investigation was carried out in 2 steps (ctpa was found listeria monocytogenes isolated from different sources, which was kept in culture collection of adelaiede university, australia. then ctpa gene was transferred into e.coil dh5-alfa). ctpa dna from listeria monocytogenes was ampilified by pcr, identified on agarose gel, purified by phenol, and ligated into pgem-t vector. then transferred on x-gal plate contaning ampicilin. the sequencing of ctpa dna in with colonies was determined by using by terminator kit and sequencing machine. results: using pcr to identify the homologous dna in 69 isoltes, 38% of isolates tested contained the ctpa determinate. our results showed that 90% of clinical and dairy isolates, 85% of environmental isolates and 7% of poultry isolates of l. monocytogenes into e.coil dh5-alfa was successful. conclusion: since, the existence of ctpa in clinical, dairy and environmental samples was 90% and in poultry was 7%, so, the virulence of all of strains of this bacteria are not the same, by introducing of such (ctpa gene) into suitable carrier strains, could be expected to producted to produce a good oral immunogen against l. monocytogenes.