5_Microbial Culture of Clinical Samples: Urine Microbial Culture

Kidneys, Bladder, Urethra

Microbial cultures of properly collected urine, can provide a picture of active microbial infection or urinary tract infections (UTI) in 3 areas:

cystitis

in the bladder, as bacteria colonize the ureter and ascends to the urinary bladder called ___(bladder only) or ascending pyelonephritis (both ureter and bladder),

ascending pyelonephritis

in the bladder, as bacteria colonize the ureter and ascends to the urinary bladder called cystitis (bladder only) or ___(both ureter and bladder),

Escherichia coli

Among the most common UTI agents of infection,___ , is primary etiologic agent especially in cystitis and pyelonephritis.

nosocomial (hospital-related) and indwelling catheters

Other agents known are Enterobacter, Proteus, Klebsiella, Pseudomonas, Serratia, and enterococci are associated as ____

10 ul

How many ul for BAP and MAC?

2 ul

How many ul for NA?

the voided urine and the catheterized.

Clinically, there are two samples of urine collected:

Glucose, Protein, pH, Specific Gravity

A 4p urine dipstick reads what?

Leuokocytes, Nitrite, Urobilinogen, Protein, pH, Blood, Specific gravity, Ketone, Bilirubin, Glucose

A 10p disptick reads what?

Methylene Blue

In microscopic observation, after smear, what is added?

bacteria, yeast cells, RBCs, WBCs, Mucus threads

In microscopic observation, what should you find?

Staphylococci (S. saprophyticus) •Enterococci (E. faecalis, E. faecium) •Streptococcus pyogenes

Most bacteria responsible for UTI: Gram positive cocci (plus gram neg) captured in Blood agar

Escherichia coli •Proteus sp. •Pseudomonas sp. •Enterobacter-Klebsiella group

Most bacteria responsible for UTI: Gram negative bacilli – captured in Mac Conkey or eosin-methylene blue (EMB) agar

Cystitis

urinary infection limited to urethra and bladder

Glomerulonephritis

an inflammation and destruction of the renal corpuscles

100,000 or more bacteria per milliliter (mL)

of urine may be caused by an infection.

100 to 100,000

could be either caused by infection or by contamination of the sample (you may need a repeat urine culture).

100 or less

___, infection is unlikely; however, a count of 100 or less may also be seen if you are already taking antibiotics.

antibiotics

100 or less, infection is unlikely; however, a count of 100 or less may also be seen if you are already taking ___

(number of colonies X DF) / volume plated

CFU/mL formula

not significant

Less than 10^4organisms/ml:

doubtful significance (suggest repeat collection)

10^4– 10^5organisms/ml:

significant bacteriuria

More than 10^5organisms/ml:

“mixed bacterial flora.”

When 3 or more types of bacteria grow and no single one predominates (i.e., none is present at >100,000 CFU/mL), the results may be reported as ___