A study on heavy metal compounds and Antibiotic resistant pseudomonas isolated from different environmental samples.

number: 
239
إنجليزية
Degree: 
Imprint: 
Biotechnology
Author: 
Sada Jasim Abd Al-Ameer
Supervisor: 
Dr. Subhi J. Hamza
Dr. A. S. Abbas
year: 
1999
Abstract:

Ninety locals Pseudomonas isolates able to grow in the presence of different concentration Hg2+, Cd2* or AsO43- was selected from different environmental samples. These isolates were screened for their resistance to ten antibiotics. Multiple metal resistance distribution represent 63.4% of the total isolates. However, sensitive isolates to heavy metals were also isolated. Three local Pseudomonas isolates designated as P.73, P.84, P.63 were chosen for futhaer microbiological and genetic studies.. Different patterns of heavy metals and antibiotics resistance were developed. The isolates were found resistant to Hg2+, Cd2+ or AsO43- when used at 20, 400, and 3200 \ug.ml1 respectively. Curing experiment-using ethidium bromide indicate the localization of encoded genes on plasmids. This results further verified by genetic analysis experiment which indicate the presence of 2-3 plasmid related to heavy metals and antibiotics resistance. Spread of resistance genotype occurs by conjugal transfer of genes from resistant strains to sensitive one. Moreover, conjugal gene transfer was also successful between resistant donor Pseudomonas and sensitive E.coli strain, which suggested wide spread ability of these genes among bacterial community in natural ecosystem. Isolating plasmid DNA for comparison did final verification of the results. Conjugation results indicates a high frequency of transfer for heavy metal and antibiotics resistance in Pseudomonas population.