Patient 1 Khong Fay Fay

Bacteria are the primary organisms that cause UTIs, mostly one called Escherichia coli (E. coli).

Cystitis is the most common urinary tract infection and is sometimes referred to as acute uncomplicated UTI. It occurs in the lower urinary tract (the bladder and urethra) and nearly always in women.

Bacterial Strains in Acute Uncomplicated UTI(cystitis). The bacterial strains likely to cause acute uncomplicated UTI are the following:

• E. coli. is responsible for between 72% and 85% of cystitis cases in younger women, and more than 50% in women over 50. In most cases of UTI, E. coli, which originates as a harmless micro-organism in the intestines, spreads to the vaginal passage, where it invades and colonizes the urinary tract. One study suggests that even when infected cells lining the bladder die and slough off, carrying the E. coli bacteria with them, some bacteria can invade into deeper tissue in the bladder, where they survive to reinfect the patient later on.
• Staphylococcus saprophyticus may be another common culprit, especially in younger women. Interestingly, infections caused by this bacteria have a seasonal variation, with a higher incidence in the summer and fall than in the winter and spring.
• Klebsiella and enterococci bacteria are often found in UTIs in older women.
• Proteus mirabilis is the other common bacterium associated with these infections.
• Pseudomonas aeruginosa is a rare bacterial cause and is most often detected in hospital-acquired UTIs. Since this patient is not admitted, this organism is ruled out.
  
• Some evidence suggests that Ureaplasma urealyticum and Mycoplasma hominis, which are generally harmless organisms, may be responsible for occasional urinary tract disorders.

Organisms in Complicated Infections

• Complicated UTIs, which are related to physical or structural conditions, are apt to be caused by a wider range of organism. E. coli is still the most common organism, but others have also been detected, including the following: Other intestinal bacteria, including klebsiella, P. mirabilis, and citrobacter.
• Fungal organisms, particularly candida species. (Candida albicans, for example, causes the "yeast infections" that also occur in the mouth, digestive tract, and vagina.)
• Others include Pseudomonas aeruginosa, enterobacter, and serratia species; gram-positive organisms, including enterococcus species; and S. saprophyticus.

From the above most common organisms that are found in the Urinary Tract Infection the ones that are suspected are as follows ;

• Escherichia Coli
• Staphylococcus saprophyticus
• Proteus mirabilis
• Ureaplasma urealyticum and Mycoplasma hominis (she could be sexually-active)

Taken from ( http://www.icaa.cc/WCI/articles/000036_2.htm)

Tests done to confirm the identity of the organism

A midstream urine specimen of 2 – 15 ml should be collected in a sterile plastic wide-mouthed container.

Dipstick tests are increasingly used to obtain a diagnosis of UTIs and are now available in drug stores without a prescription. The test employ a chemical that reacts to nitrites, substances produced by many of the bacteria that cause UTIs. This chemical is available on a stick that is dipped into a urine sample. In women with symptoms, the dipstick is proving to be a quick and practical way to identify most cases of infection.

A urinalysis involves a physical and chemical examination of urine. In addition, the urine is spun in a centrifuge to allow sediments containing blood cells, bacteria, and other particles to collect. This sediment is then examined under a microscope. A urinalysis, then, offers a number of valuable clues for an accurate diagnosis:

• Simply observing the urine for color and cloudiness can be important.
• Acidity is measured.
• White blood cells (leukocytes) are counted. A high count in the urine is referred to as pyuria. (A leukocyte count of over 10 per microliter of urine indicates pyuria.) Pyuria is usually sufficient for a diagnosis of UTI in nonhospitalized patients if standard symptoms (or just fever in small children) are also present.

A urine culture is a urine specimen observed for 24 to 48 hours in a laboratory for the presence of any bacterial growth. This is done by observing for the growth of any bacteria present in the urine using various culture plates. The plates usually used in the growth are Blood, MacConkey, CLED agar. They are support the growth of microrganisms mainly from the urine. Usually, one type of bacteria is observed. When more than one type of organism is present, it is usually due to contamination. When the presence of bacteria is confirmed, additional tests are done to confirm the identity of the bacteria. Eg(Gram-stain, catalase,coagulase, indole,oxidase,using MICROBACT)