Identification of Bacterial Strains Isolated from Patients with Urinary Tract Infection and the Role of Plasmids in their Antibiotic Resistance

One hundred fifty bacterial strains were isolated from patients with urinary tract infections (UTIs). They were belong to ten different species of gram-negative bacteria and to two genera of gram– positive bacteria. E. coli was the major causative agent and comprise 40% of all cases. Klebsiella pneumoniae and Proteus mirabilis were second and third with 18.67% 18.0% respectively. Other gram-negative bacteria were belong to the genera Enterobacter, Acinitobacter, Pseudomonas, Citrobacter and Serratia. Ten cases (6.67%) were caused by genus Staphylococcus and seven (4.66%) were caused by Streptococcus. Out of the 150 positive cases, 96(64%) were from female patients, while 54(36%) were from males. High percentage of all isolates were resistant to all used antibiotics except for the nitrofuranation to which all isolates were sensitive . the second most effective antibiotic for all isolates was Nalidixic acid (25% of all isolates were resistant), while the Gentamycin was the third most effective antibiotic (39% were resistant). 75% of E. coli isolates and 86% of all isolates were resistant to Ampicillin. High percentages of resistance to antibiotics is a reflection for the misuse of antibiotics. Conjugation experiments showed that E. coli strains harbor a self transmissible plasmid carrying resistant genes for tetracycline (TEr), Chloramphenicol (Cr), streptomycin (Sr) and Trimethoprime (SXTr). It seems that this plasmid is widely spread in the Iraqi isolates since it was detected in all the three examined E. coli strains. No conjugation was detected between E. coli and other members of Enterobacteriaceae like proteus, Serratia and Acinitobacter.