Lower Urinary tract infection:Cystitis, Urethritis, and Prostatitis in men.

Cystitis: is the inflammation of urinary bladder (the sac that temporarily holds urine until urination) caused by microbial colonization and infection.

Hemorrhagic cystitis : is characterized by large quantities of visible blood in the urine. It can be caused by an infection (bacterial or adenovirus).

Urethritis : It is the inflammation of urethra ( the tube that carries urine from the bladder during urination) caused by microbial infection.

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Symptoms include a burning sensation during urination and fever. Most of the cases of urethritis without cystitis are sexually transmitted.

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Chronic bacterial prostatitis: The prostate is a small gland and part of the male reproductive system. It produces fluid that becomes part of a man's semen, the liquid that helps transport sperm. If the prostate becomes inflamed, the condition is called prostatitis.

Etiology of Cystitis and Urethritis (Non-Sexual origin) :Causes: Pathogens may ascending the urethra of fecal origin.

1 -Escherichia coli .2 -Staphylococcus saprophyticus.

3 -Other genera of Enterobacteriaceae : Klebsiella, Enterobacter, Proteus, and Serratia .

4 -Pseudomonas aeruginosa (Hospital-acquired infection due to contaminated catheter.)

5 -Enterococcus faecalis. (Hospital-acquired infection due to contaminated catheter.)

Laboratory diagnosis of UTI:Collection of Clinical Specimens :

Urine specimens: A- Midstream catch urine: One to Ten ml: must be collected in sterile urine container , the first portion must be discarded to avoid contamination with urethra and vaginal bacteria. B- Catheterized Urine: One to Ten ml Must be collected in sterile urine container.

C- Suprapubic Urine: One to Ten mL Aspirated from urinary bladder by fine needle collected in sterile anaerobic tube. ( young babies, children, obstruction cases).

Cultivation of urine specimens:

Urine specimens should be cultivated on Enriched media (blood agar) and differential media (MacConkey’s agar or CLED) by the following methods:

1- Four quadrant streaking method: depends on Calibrated Loop. :( Semi-quantitative). 2- Network Streaking method: depends on Calibrated Loop. : ( quantitative). 3- Microbroth dilution method. ( quantitative) Calibrated loop carry only one microliter.

Isolation of microbe from urine and calculation of CFU :

Bacterial loop carry one microlitre. When 50 colonies are isolated = 50 cells per/1 µl = 50 CFU/ µl In one mL : 50 * 1000= 50000 CFU/mL.

CFU cutoff value and significant bacteriuria:

The CFU cutoff value is associated with type of urine specimens.

It is calculated to be equal to: For Midstream catch urine: 50000- 100000 CFU/m L. For Catheterized Urine: 100 CFU/m L. For Suprapubic Urine: Any growth.

Significant bacteriuria: Is the isolation of microbes of infectious dose cutoff value from urineSpecimen in presence of signs and symptoms of UTI.

It is mainly associated with pyuria and dysuria .

Isolation of Enterobacteriaceae from urine specimens:The most important genera that could be isolated from urine are:

Escherichia coli , Klebsiella, Enterobacter, Proteus mirabilis, and Serratia species.

Enterobacteriaceae genera are classified according to lactose fermentation into two groups: 1- Lactose none fermenters. 2- Lactose fermenters.

Identification of E. coli:-Some strains of uropathogenic E. coli are verotoxin producers.-All strains are oxidase negative and catalase positive.-Metallic green sheen on EMB agar. -Uropathogenic E. coli species are indole positive.

Differentiation of Lactose fermenter genera by IMVC test: A

Citrate Vogus-Pros Methyl-red Indole

- - + + E.coli

+ - - - Citrobacter

+ + - - Klebsiella

+ + - - Enterobacter

The Rapid biochemical identification system: The API20E: n

Identification of Proteus species: All species are Gram’s negative bacilli that illustrate swarming growth on blood agar. All are H2S and urease positive.

Isolation of Pseudomonas species from urine specimens:Cultural characteristics: -All species of Pseudomonas produce Water soluble Exopigment on nutrient agar. (greenish yellowish pyoverdin) . -All species are oxidase positive.

Isolation of Serratia marcescens from urine: Microorganisms that produce pigment during growth are said to be chromogenic.Serratia marcescens produces a deep red pigment ( water-insoluble) at 25°C, but does not produce pigment at 37°C.

Serratia marcescens Pseudomonas

Isolation of Gram’s positive Cocci : -The most important Gram’s positive Cocci that associated with UTI are: 1-Staphylococcus saprophyticus. 2-Enterococcus faecalis. -Staphylococcus aureus is also considered as a causative agent of UTI.

Differentiation of Staphylococcus aureus and other Staphylococcus species: -All Staphylococcus species are Gram’s positive Cocci arranged in clusters.-All species are Catalase positive.-Staphylococcus aureus are coagulase positive. -Staphylococcus epidermidis and Staphylococcus saprophyticus are coagulase negative.

Staph. aureus coagulase positive

Other Staph. Coagulase negative.

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-Staphylococcus saprophyticus species are Mannitol fermenters and Novobiocin resistant.

Novobiocin sensitive Staph. Mannitol fermentation pattern.

Isolation of Enterococcus faecalis from urine specimens:

Urine specimens should be cultivated on bile esculine salt agar when Nosocomial UTI is suspected. Black discoloration of media is a distinctive characteristics of group D streptococcus growth ( Enterococcus faecalis).

Parasitic infection of urinary system:Schistosomiasis: Classification (phylum): Trematoda. Classification according to morphology: Flattened non-segmented unisexual flukes.

Schistosoma hematobium: •Found in Middle East, Africa, Portugal and Cyprus

•Definitive host: man •Intermediate host: snail

•It causes urinary bilharziasis (female deposits eggs in the vesical and pelvic plexus of venous circulation .(

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Male: 10-20 x I mm with short anterior cylindrical pan and posterior

flattened part which incurved ventrally to form the gynaeccphoric canal .

It has well developed oral and ventral suckers.Female:

15-25 x 0.25 mm:, cylindrical, ovary may "be central, anterior or posterior, uterus

may be short or long containing eggs .

Schistosoma hematobium ova:-140x50 µ, oval with terminal spine .

-Passes in urine.

Life cycle:n

CLINICAL PICTURE:

The clinical picture is divided into three stage:1-Incubation period; (acute Schistosomiasis 6-12 Weeks):

This stage is characterized by skin irritation after coming from water, and coughing .

Late in the incubation period, patients complains of enlarged liver, fever, headache, anorexia, loss of weigh.

CBC shows Eosinophilia.

2 -Stage of egg deposition: (1- 5 years after infection). Urinary bilharziasis :

caused by S.hematobium, characterized by terminal haematuria , burning sensation during urination.

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3-Stage of complication: -Due to a fibrosis around the eggs in bladder, liver and lung. - Obstruction of bladder. Urinary bilharziasis: cystitis, hydronephrosis and Pyonephrosis , sterility in males, renal failure ,urinary bladder carcinoma, pulmonary hypertension and heart failure.