Urinary Tract Infection (UTI) is common both in the community and hospitalized patients. Urinary tract infection (UTI) is a broad term that encompasses both asymptomatic microbial colonization of the urine and symptomatic infection with microbial invasion and inflammation of urinary tract structures.

The widespread use of antimicrobial agents often leads to the emergence of resistant microorganisms to one or several of them. Majority of UTI are due to a single pathogen.

The Enterobacteriaceae responsible for 90% of all UTI

• Gram negative bacilli
• Facultative anaerobic
• Common intestinal flora

Escherichia coli most commonly isolated pathogen 80% of all UTI. Apart from the outer one-third of the female urethra, the urinary tract is normally sterile. From a microbiologic perspective, urinary tract infection exists when pathogenic microorganisms are detected in the urine, urethra, bladder, kidney, or prostate. In most instances, growth of more than 105 organisms per milliliter from a properly collected midstream “clean-catch” urine sample indicates infection.

However, significant bacteriuria is lacking in some cases of true UTI. Especially in symptomatic patients, a smaller number of bacteria (102 to 104/ml) may signify infection. colony counts of >105/ml of midstream urine are occasionally due to specimen contamination, which is especially likely when multiple species are found.

Every female has a 20% life time risk of coming down with a UTI. In children approximately 5% of girls and 1% of boys have a UTI by 11 years of age. Antibiotics which have been recommended to treat UTIs include Ampicillin, Trimethoprim-Sulfamethoxazole, Flouroquinolones and Nitrofurantoin. However due to incessant abuse and misuse of these antibiotics, extensive resistance of micro-organisms to these antibiotics has developed.