Phage - Mediated Transfer of Genetic Material

Abstract

Ten phages were isolated randomly from sewage sources and disposal points on the University of Ghana,Legon campus, purified and characterised as delivery systems for the resistance marker genes, Strr and Benr. The phages were found to have proteins of relative molecular weights ranging from 9,000 - 100,000. Eight phages were found to be morphologically related to the tailed phages. The other two were tailless phages. All the coliphages isolated were morphologically related to the T-even phages, whilst Sf RBCL 15 and Sd RBCL 5 were related to the P-phages. The tailless phages were found to be morphologically related to the p phages (06 and 0X174 phages). The coliphages were found to be closely related to each other. They did exhibit some detectable cross reactivity to Sd RBCL 5, Sd RBCL 2 3 and Sf RBCL 15. The coliphages were not related to the S. tvphi phages. Selected pathogenic bacteria from the Noguchi Memorial Institute for Medical Research and the Medical School of the university of Ghana were screened for the presence of the antibiotic resistance gene marker. All the bacteria, except three, were found to be highly resistant to the marker antibiotics used : Salmonella Group D was relatively more sensitive to all three antibiotics ; Staphylococcus aureus was sensitive to Benzylpenicillin and Salmonella typhi was sensitive to Tetracycline. The isolated phages with the exception of St RBCL 2 0 exhibited the ability to transduce the resistance marker genes from one bacterium to sensitive bacteria at a high frequency.