Dr.T.V.Rao.MDDr.T.V.Rao.MDDr.T.V.Rao.MDDr.T.V.Rao.MD

CULTURING OF URINESKILL BASED LEARNING

Dr.T.V.Rao MD 1

OVER VIEW OF URINARY TRACT OVER VIEW OF URINARY TRACT OVER VIEW OF URINARY TRACT OVER VIEW OF URINARY TRACT

INFECTIONSINFECTIONSINFECTIONSINFECTIONS

� Most common infectious disease

� Most Numerous specimens are received in the Laboratory

� 30 to 40 % of specimens received in Microbiology laboratories are Urine specimens, to Identify the Infection.

� Diagnostic information is important for the clinician.

�Appropriate clinical information gives many clues for better diagnostic evaluations.

� Specimen collection is the primary objective in getting an ideal sample.

Dr.T.V.Rao MD 2

� an infection of one or more structures in the urinary system. Most UTIs are caused by gram-negative bacteria, most commonly Escherichia coli or species of Klebsiella, Proteus, Pseudomonas, or Enterobacter, although other strains, such as Staphlyococcus and Serratia, are emerging

WHAT IS URINARY TRACT INFECTIONWHAT IS URINARY TRACT INFECTIONWHAT IS URINARY TRACT INFECTIONWHAT IS URINARY TRACT INFECTION

Dr.T.V.Rao MD 3

� The condition is more

common in women than

in men. UTI may be

asymptomatic but is

usually characterized by

urinary frequency, burning

pain with voiding, and, if

the infection is severe,

visible blood and pus in

the urine. Fever and back

pain often accompany kidney

infections

URINARY TRACT INFECTIONS ARE MORE

COMMON IN WOMEN

Dr.T.V.Rao MD 4

COMMON UROPATHOGENSCOMMON UROPATHOGENSCOMMON UROPATHOGENSCOMMON UROPATHOGENS

� Escherichia coliEscherichia coliEscherichia coliEscherichia coli

� Other Other Other Other Enterobacteriaceae Enterobacteriaceae Enterobacteriaceae Enterobacteriaceae ((((KlebsiellaKlebsiellaKlebsiellaKlebsiella , , , , EnterobacterEnterobacterEnterobacterEnterobacter , , , , ProteusProteusProteusProteus, , , , CitrobacterCitrobacterCitrobacterCitrobacter))))

� Pseudomonas aeruginosaPseudomonas aeruginosaPseudomonas aeruginosaPseudomonas aeruginosa

� EnterococcusEnterococcusEnterococcusEnterococcus

� Staphylococcus saprophyticusStaphylococcus saprophyticusStaphylococcus saprophyticusStaphylococcus saprophyticus

� Staphylococcus aureusStaphylococcus aureusStaphylococcus aureusStaphylococcus aureus

� Streptococcus agalactiae Streptococcus agalactiae Streptococcus agalactiae Streptococcus agalactiae (group B)(group B)(group B)(group B)

� CandidaCandidaCandidaCandida

Associated with staphylococcemiaAssociated with staphylococcemiaAssociated with staphylococcemiaAssociated with staphylococcemia

Denotes vaginal colonization in pregnant womenDenotes vaginal colonization in pregnant womenDenotes vaginal colonization in pregnant womenDenotes vaginal colonization in pregnant women

Dr.T.V.Rao MD 5

�Corynebacterium Corynebacterium Corynebacterium Corynebacterium urealyticumurealyticumurealyticumurealyticum1111

�Haemophilus Haemophilus Haemophilus Haemophilus influenza influenza influenza influenza andandandand H. H. H. H. parainfluenzaeparainfluenzaeparainfluenzaeparainfluenzae2222

�Blastomyces Blastomyces Blastomyces Blastomyces dermatitidisdermatitidisdermatitidisdermatitidis3333

�Neisseria Neisseria Neisseria Neisseria gonorrhaeaegonorrhaeaegonorrhaeaegonorrhaeae4444

�Mycobacterium Mycobacterium Mycobacterium Mycobacterium tuberculosistuberculosistuberculosistuberculosis5555

UNCOMMON UNCOMMON UNCOMMON UNCOMMON UROPATHOGENSUROPATHOGENSUROPATHOGENSUROPATHOGENSM.TUBERCULOSIS PRODUCES CHRONIC INFECTIONM.TUBERCULOSIS PRODUCES CHRONIC INFECTIONM.TUBERCULOSIS PRODUCES CHRONIC INFECTIONM.TUBERCULOSIS PRODUCES CHRONIC INFECTION

Dr.T.V.Rao MD 6

PATHOPHYSIOLOGY OF URINARY PATHOPHYSIOLOGY OF URINARY PATHOPHYSIOLOGY OF URINARY PATHOPHYSIOLOGY OF URINARY

TRACT INFECTIONTRACT INFECTIONTRACT INFECTIONTRACT INFECTION

� Ascending route of infection most common

� Colonization of urethra and periurethral tissue by uropathogens the initial event in urinary tract infection

� Urinary tract infection more common in women than men due to short female urethra with distention and turbulent flow that washes urethral organisms into the bladder during micturition and in close proximity to perianal areas

� Hospital infection associated with lower urinary tract instrumentation (catheterization, cystoscopy)

� Once in the bladder uropathogens multiply, then pass up the ureters (especially if vesicoureteral reflux present) to the renal pelvis and parenchyma

� Source of uropathogens: enteric bacteria

Dr.T.V.Rao MD 7

�There are several different methods for collection

of a urine sample. The most common is the

midstream cleanmidstream cleanmidstream cleanmidstream clean----catch techniquecatch techniquecatch techniquecatch technique. Hands should

be washed before beginning. For females, the

external genitalia (sex organs) are washed two or

three times with a cleansing agent and rinsed with

water. In males, the external head of the penis is

similarly cleansed and rinsed. The patient is then

instructed to begin to urinate, and the urine is

collected midstream into a sterile container.

COLLECTING THE URINE

Dr.T.V.Rao MD 8

� The urine collected in a wide mouthed container from patients

� A mid stream specimen is the most ideal for processing

� Female patients passes urine with a labia separated and mid stream sample is collected

SPECIMEN COLLECTION

Dr.T.V.Rao MD 9

10

Female patients

Urine collected with InstructionsUrine collected with InstructionsUrine collected with InstructionsUrine collected with Instructions

Spread

labia,

using plain

soap or

antiseptic

wipe front to

back,

dry with

tissues

Retract

prepuce,

using plain

soap or

antiseptic

clean glans.

Dry with

tissues.

Male patientsBegin passing urine

Stop flow in midstream

Pass several ml into pen container

without touching rim

Stop flow before it ends

Recap container

Pass remaining urine into lavatory

Send specimen to laboratory

immediately

(refrigerate if prolonged transport time)Dr.T.V.Rao MD

� Urine collected in sterile Urine collected in sterile Urine collected in sterile Urine collected in sterile specimen container must specimen container must specimen container must specimen container must be processed be processed be processed be processed within 2 within 2 within 2 within 2 hours, or refrigerated and hours, or refrigerated and hours, or refrigerated and hours, or refrigerated and processed within 24 hoursprocessed within 24 hoursprocessed within 24 hoursprocessed within 24 hours

� Urine collected in sterile Urine collected in sterile Urine collected in sterile Urine collected in sterile specimen container with specimen container with specimen container with specimen container with borate borate borate borate preservative preservative preservative preservative should be processed should be processed should be processed should be processed within 24 hours (no within 24 hours (no within 24 hours (no within 24 hours (no refrigeration required)refrigeration required)refrigeration required)refrigeration required)

COLLECTION COLLECTION COLLECTION COLLECTION AND PRESERVATION OF AND PRESERVATION OF AND PRESERVATION OF AND PRESERVATION OF URINE URINE URINE URINE

SPECIMENSSPECIMENSSPECIMENSSPECIMENS

Dr.T.V.Rao MD 11

� In infants, a urinary

collection bag (plastic

bag with an adhesive

seal on one end) is

attached over the

labia in girls or a boy's

penis to collect the

specimen.

COLLECTING URINE IN INFANTS AND YOUNG COLLECTING URINE IN INFANTS AND YOUNG COLLECTING URINE IN INFANTS AND YOUNG COLLECTING URINE IN INFANTS AND YOUNG

CHILDREN DIFFERS FROM ADULTSCHILDREN DIFFERS FROM ADULTSCHILDREN DIFFERS FROM ADULTSCHILDREN DIFFERS FROM ADULTS

Dr.T.V.Rao MD 12

� Non invasive methods are safe and ideal

� Follow the Broomhall et al method

By tapping just above the pubis with two fingers place on suprapubic region after 1 hour of feed, tapping on at the rate of 1 tap/second for a period of 1 minute, if not successful tapping is repeated once aging.

The child spontaneously pass the Urine and to be collected in a steri le container

SPECIMEN COLLECTION IN INFANTS SPECIMEN COLLECTION IN INFANTS SPECIMEN COLLECTION IN INFANTS SPECIMEN COLLECTION IN INFANTS

AND YOUNG CHILDRENAND YOUNG CHILDRENAND YOUNG CHILDRENAND YOUNG CHILDREN

Dr.T.V.Rao MD 13

� Another method is the catheterized urine specimen in which a lubricated catheter (thin rubber tube) is inserted through the urethra (tube-like structure in which urine is expelled from the bladder) into the bladder. This avoids contamination from the urethra or external genitalia.

CATHETERIZED URINECATHETERIZED URINECATHETERIZED URINECATHETERIZED URINE

Dr.T.V.Rao MD 14

� If the patient already has a urinary catheter in place, a urine specimen may be collected by clamping the tubing below the collection port and using a sterile needle and syringe to obtain the urine sample; urine cannot be taken from the drainage bag, as it is not fresh and has had an opportunity to grow bacteria at room temperatur

SPECIMEN CAN BE COLLECTED AFTER CLAMPING

THE CATHETER

Dr.T.V.Rao MD 15

�On rare occasions, the health care provider may collect a urine sample by inserting a needle directly into the bladder (suprapubic tap) and draining the urine; this method is used only when a sample is needed quickly and technically competent staff are available

SUPRAPUBIC PUNCTURE A SUPRAPUBIC PUNCTURE A SUPRAPUBIC PUNCTURE A SUPRAPUBIC PUNCTURE A

TECHNICALLY DEMANDING METHODTECHNICALLY DEMANDING METHODTECHNICALLY DEMANDING METHODTECHNICALLY DEMANDING METHOD

Dr.T.V.Rao MD 16

� If delivery of the urine specimen to the laboratory within one hour of collection is not possible, it should be refrigerated. The health care provider should be informed of any antibiotics currently or recently taken.

SENDING THE SPECIMEN TO LABORATORYSENDING THE SPECIMEN TO LABORATORYSENDING THE SPECIMEN TO LABORATORYSENDING THE SPECIMEN TO LABORATORY

Dr.T.V.Rao MD 17

DIAGNOSIS OF URINARY TRACT DIAGNOSIS OF URINARY TRACT DIAGNOSIS OF URINARY TRACT DIAGNOSIS OF URINARY TRACT

INFECTIONINFECTIONINFECTIONINFECTION

�Step 1Microscopy of Urine for detection of Pyuria,Leucocytes should be found in numbers of at least as great as 104 / ml before the pyuria is established

Dr.T.V.Rao MD 18

WET FILM EXAMINATION OF URINEWET FILM EXAMINATION OF URINEWET FILM EXAMINATION OF URINEWET FILM EXAMINATION OF URINE

� All wet films to be examined with high power ( x 40 ) objective.

� Prepare the drop of urine after mixing the urine without centrifugation

� Transfer 0.05 ml on the middle of the microscope slide and cover slip is applied.

� The prepared specimen show a small excess of fluid along the edges of the cover slip.

� A approximate finding of 1 leukocyte / 7 high power fields corresponds to presence of pyuria.

Dr.T.V.Rao MD 19

� Plate: provide large surface for isolation and observation of colonies

� Using a sterile loop or a sterile swab streak your sample on the petri plate

� Important let your sterilized loop cool before you pick up your sample

INOCULATING THE CULTURE PLATE WITH

URINE

SELECTION OF LOOP FOR SELECTION OF LOOP FOR SELECTION OF LOOP FOR SELECTION OF LOOP FOR

SEMIQUANTITATIVE METHODSEMIQUANTITATIVE METHODSEMIQUANTITATIVE METHODSEMIQUANTITATIVE METHOD

Dr.T.V.Rao MD 21

SPECIMEN INOCULATIONS

� All cultures processed by Semiquantitative method a loop of standard dimension of approximately known volume is inoculated into selected culture plate

� In general a loop of SWG – 28 with a diameter of 3.26 mm internal diameter which can hold a drop of water or urine 0.004 ml.

� After inoculation the culture plates are incubated at 370c extending to > 18 hours are read

� The colony counts are made, as each colony corropsdes to number of viable bacteria per ml of urine

Dr.T.V.Rao MD 22

CULTURING OF URINE FOR ISOLATION OF

BACTERIAL PATHOGENS

�Semiquantitative Semiquantitative Semiquantitative Semiquantitative culturecultureculturecultureSelect the Media

For common isolates

Mac Conkey’s agar

helps in differentiation of Lactose fermenting organisms from non lactose fermenting pathogens

Dr.T.V.Rao MD 23

�MacConkey agar utilized as selective differential agar for gram-negative bacteria,

�Colistin nalidixic acid agar as selective agar for gram-positive bacteria, and chocolate agar for fastidious gram-negative bacteria (Haemophilus)

CHOOSING MEDIA TO SUIT CHOOSING MEDIA TO SUIT CHOOSING MEDIA TO SUIT CHOOSING MEDIA TO SUIT

MICROORGANISMS IS IMPORTANT MICROORGANISMS IS IMPORTANT MICROORGANISMS IS IMPORTANT MICROORGANISMS IS IMPORTANT

Dr.T.V.Rao MD 24

� Inoculation of urine for quantitative culture (colony forming units→cfu’s) performed with a calibrated 0.001 mL and 0.01 mL plastic or wire loop

�Sheep blood agar (SBA) utilized for quantitative urine culture

INOCULATION OF URINEINOCULATION OF URINEINOCULATION OF URINEINOCULATION OF URINE

Dr.T.V.Rao MD 25

CULTURE MEDIA FOR ISOLATIONS CULTURE MEDIA FOR ISOLATIONS CULTURE MEDIA FOR ISOLATIONS CULTURE MEDIA FOR ISOLATIONS

CLEDCLEDCLEDCLED MEDIUMMEDIUMMEDIUMMEDIUMIt is also an excellent universal It is also an excellent universal It is also an excellent universal It is also an excellent universal

culture medium owing to its culture medium owing to its culture medium owing to its culture medium owing to its wide spectrum of nutrients, wide spectrum of nutrients, wide spectrum of nutrients, wide spectrum of nutrients, lack of inhibitors and the fact lack of inhibitors and the fact lack of inhibitors and the fact lack of inhibitors and the fact that it allows a certain degree that it allows a certain degree that it allows a certain degree that it allows a certain degree or dif ferentiation between the or dif ferentiation between the or dif ferentiation between the or dif ferentiation between the colonies. It contains lactose as colonies. It contains lactose as colonies. It contains lactose as colonies. It contains lactose as a reactive compound which, a reactive compound which, a reactive compound which, a reactive compound which, when degraded to acid, causes when degraded to acid, causes when degraded to acid, causes when degraded to acid, causes bromothymol blue to change its bromothymol blue to change its bromothymol blue to change its bromothymol blue to change its colour to yellow. Alkalinization colour to yellow. Alkalinization colour to yellow. Alkalinization colour to yellow. Alkalinization produces a deep blue produces a deep blue produces a deep blue produces a deep blue colouration. The lack of colouration. The lack of colouration. The lack of colouration. The lack of electrolytes suppresses the electrolytes suppresses the electrolytes suppresses the electrolytes suppresses the swarming of Proteus swarming of Proteus swarming of Proteus swarming of Proteus Laboratories which have Laboratories which have Laboratories which have Laboratories which have dif ficulty in availability of dif ficulty in availability of dif ficulty in availability of dif ficulty in availability of blood agar, CLED medium is blood agar, CLED medium is blood agar, CLED medium is blood agar, CLED medium is optedoptedoptedopted

Dr.T.V.Rao MD 26

ENRICHED CULTURE MEDIA FOR ENRICHED CULTURE MEDIA FOR ENRICHED CULTURE MEDIA FOR ENRICHED CULTURE MEDIA FOR

ISOLATION ISOLATION ISOLATION ISOLATION

�Blood agarBlood agarBlood agarBlood agar

helps in isolation of fastidious, extracting strains May extended incubation for isolation of pathogens for more than 48 hours with added atmosphere of 5 – 10 % co2

Dr.T.V.Rao MD 27

READING THE CULTURE PLATESREADING THE CULTURE PLATESREADING THE CULTURE PLATESREADING THE CULTURE PLATES

� A true infection in the absence of prior antibiotic therapy the number of bacteria is likely to be at least 101010105555 or more.

� Contaminated specimens present with colony counts <104,

however even less than 103

� On several occasions the colonies are diverse species

� Several studies prove counts >104 to be considered as presence of Urinary tract infection with the supporting clinical history

� On some occasions more than one pathogen is isolated but should be processed for all practical purposes

eg E.coli along with Streptococcus fecalis

On few occasions even counts 103 are proved significant

Dr.T.V.Rao MD 28

IDENTIFICATION OF GRAM + IDENTIFICATION OF GRAM + IDENTIFICATION OF GRAM + IDENTIFICATION OF GRAM +

ORGANISMSORGANISMSORGANISMSORGANISMS

� All colonies identified morphologically as

Staphylococcus to be characterized as

Staphylococcus aureus

Staphylococcus saprophyticus

Staphylococcus epidermidis

Enterococci - fecal group of organisms

Dr.T.V.Rao MD 29

�With 0.001 ml loop, 1 colony on SBA equivalent to 1,000 cfu’s per mL of urine

�With 0.01 ml loop, 1 colony on SBA equivalent to 100 cfu’s per mL of urine

COUNTING THE COLONIES

Dr.T.V.Rao MD 30

� A single species of Enterobacteriaceae

recovered at >105 cfu’s/mL urine: with patients symptomatic for urinary tract infection, 95% probability of true bacteriuria

� A single species of Enterobacteriaceae

recovered at 104-105 cfu’s/mL urine: with patients symptomatic for urinary tract infection, 33% probability of true bacteriuria

INTERPRETATION OF INTERPRETATION OF INTERPRETATION OF INTERPRETATION OF

ENTEROBACTERIACEAEENTEROBACTERIACEAEENTEROBACTERIACEAEENTEROBACTERIACEAE

Dr.T.V.Rao MD 31

�A single species of Enterobacteriaceaerecovered at >105

cfu’s/mL urine: with patients symptomatic for urinary tract infection, 95% probability of true bacteriuria

�A single species of Enterobacteriaceae recovered at 104-105

cfu’s/mL urine: with patients symptomatic for urinary tract infection, 33% probability of true bacteriuria

INTERPRETATION OF ENTEROBACTERIACEAEINTERPRETATION OF ENTEROBACTERIACEAEINTERPRETATION OF ENTEROBACTERIACEAEINTERPRETATION OF ENTEROBACTERIACEAE

Dr.T.V.Rao MD 32

� Significant bacteriuria in an asymptomatic patient is 100,000 or more colonies per milliliter of urine from a midstream, clean-catch specimen; yet, a colony count of 200 Escherichia coli per ml may be significant in a midstream male void or catheterized female. About 95% of all positive UTI cultures will produce essentially pure cultures if urine is collected carefully and the media inoculated promptly.

WHAT IS WHAT IS WHAT IS WHAT IS SIGNIFICANT BACTERIURIA SIGNIFICANT BACTERIURIA SIGNIFICANT BACTERIURIA SIGNIFICANT BACTERIURIA

Dr.T.V.Rao MD 33

34

CONCEPT OF SIGNIFICANT BACTERIURIACONCEPT OF SIGNIFICANT BACTERIURIACONCEPT OF SIGNIFICANT BACTERIURIACONCEPT OF SIGNIFICANT BACTERIURIA

� Up to 104/ml considered normal

i .e. Insignificant

� 105/ml and above considered to

be Significant

� Concept valid only for voided

specimen of urine

� Exceptions - slow growing

organisms, patient on antibiotic

therapy, diuretic therapy

Dr.T.V.Rao MD

�A single species of

Enterobacteriaceae

recovered at 104-105

cfu’s/mL urine: with

patients symptomatic

for urinary tract

infection, 33%

probability of true

bacteriuria

WHAT CAN BE A SIGNIFICANT COUNTWHAT CAN BE A SIGNIFICANT COUNTWHAT CAN BE A SIGNIFICANT COUNTWHAT CAN BE A SIGNIFICANT COUNT

Dr.T.V.Rao MD 35

�Gram-positive, fungal, and fastidious uropathogens often present in lower numbers (104-105

cfu’s/mL urine)

�Urethral commensals recovered at <104

cfu’s/mL urine

GRAM POSITIVES AND FUNGI THE COUNTS

MAY BE <105

Dr.T.V.Rao MD 36

IDENTIFICATION OF ISOLATESIDENTIFICATION OF ISOLATESIDENTIFICATION OF ISOLATESIDENTIFICATION OF ISOLATES

GRAM + ISOLATESGRAM + ISOLATESGRAM + ISOLATESGRAM + ISOLATES

�The minimal tests to differentiate Gram + cocci include

1 Catalase1 Catalase1 Catalase1 Catalase

2 Coagulase test

3 Bile esculin testing

4 Bacitracin in Streptococcus isolates

Dr.T.V.Rao MD 37

BIOCHEMICAL TESTS IN

GRAM - VE BACILLI

� Catalase test

� Oxidase test

� Nitrite reduction test

� Indole test

� Methyl red test

� V P test

� Citrate test

� Decarboxylation tests

Lysine, ornithine, Arginine tests

Dr.T.V.Rao MD 38

39Dr.T.V.Rao MD

PEER REVIEWED URINE

CULTURE

INTERPRETATIONS

�Routine: uncomplicated urinary tract infection in ambulatory outpatients (0.001 mL loop, SBA, MAC; 24 hr. incubation)

�Surveillance: neurogenic bladder, indwelling catheter, geriatric patents (0.001 mL loop, SBA, MAC, CNA; 24 hr. incubation)

�Special: suprapubic aspirates or straight catheter specimens where previous cultures negative, unresponsive to therapy, or possibility of unusual urinary tract pathogen (0.001 and 0.01 mL loop, BA, MAC, CHOC; minimum 48 hr. incubation

� 1111Clarridge, Johnson, Pezzlo, and Weissfeld, ASM Cumitech 2B, Clarridge, Johnson, Pezzlo, and Weissfeld, ASM Cumitech 2B, Clarridge, Johnson, Pezzlo, and Weissfeld, ASM Cumitech 2B, Clarridge, Johnson, Pezzlo, and Weissfeld, ASM Cumitech 2B, November 1998.November 1998.November 1998.November 1998.

CUMITECH GUIDELINESCUMITECH GUIDELINESCUMITECH GUIDELINESCUMITECH GUIDELINES FOR INOCULATION OF FOR INOCULATION OF FOR INOCULATION OF FOR INOCULATION OF

URINE CULTURESURINE CULTURESURINE CULTURESURINE CULTURES1111

Dr.T.V.Rao MD 40

�One isolate at >104:

Full ID and

Susceptibility

�One or two gram-

negative isolates at >105

and other isolates at

least 10X less: Full ID

and Susceptibility of

gram-negative isolates

CUMITECH GUIDELINESCUMITECH GUIDELINESCUMITECH GUIDELINESCUMITECH GUIDELINES FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF

ROUTINE URINE CULTURESROUTINE URINE CULTURESROUTINE URINE CULTURESROUTINE URINE CULTURES1111

Dr.T.V.Rao MD 41

�Other patterns of isolates at >104: Presumptive ID only�Ignore mixed

urethral flora at <104

� 1111Clarridge, Johnson, Pezzlo, and Clarridge, Johnson, Pezzlo, and Clarridge, Johnson, Pezzlo, and Clarridge, Johnson, Pezzlo, and Weissfeld, ASM Cumitech 2B, Weissfeld, ASM Cumitech 2B, Weissfeld, ASM Cumitech 2B, Weissfeld, ASM Cumitech 2B, November 1998.November 1998.November 1998.November 1998.

CUMITECH GUIDELINES CUMITECH GUIDELINES CUMITECH GUIDELINES CUMITECH GUIDELINES FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF

ROUTINE URINE CULTURESROUTINE URINE CULTURESROUTINE URINE CULTURESROUTINE URINE CULTURES1111

Dr.T.V.Rao MD 42

�One or two isolates at >102

to 105: Full ID and Susceptibility is essential before confirmed as uncommon isolates

CUMITECH GUIDELINES CUMITECH GUIDELINES CUMITECH GUIDELINES CUMITECH GUIDELINES FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF

SPECIAL OR UNCOMMON SPECIAL OR UNCOMMON SPECIAL OR UNCOMMON SPECIAL OR UNCOMMON URINE CULTURESURINE CULTURESURINE CULTURESURINE CULTURES1111

Dr.T.V.Rao MD 43

� Midstream, female with cystitis, >102 with positive urine leukocyte esterase

� Midstream, female with pyelonephritis, >105 with positive urine leukocyte esterase

� Midstream, asymptomatic, >105 with negative urine leukocyte esterase (usually)

� Midstream, male with UTI: >103 with leukocyte with urine leukocyte esterase positive

� Straight catheter: >102 with urine leukocyte esterase positive

� Indwelling catheter: >103 with urine leukocyte esterase positive or negative

1111Manual of Clinical Microbiology, 8Manual of Clinical Microbiology, 8Manual of Clinical Microbiology, 8Manual of Clinical Microbiology, 8 thththth Edition, ASM, 2003Edition, ASM, 2003Edition, ASM, 2003Edition, ASM, 2003

ASM MANUAL GUIDELINES FOR URINE CULTURE ASM MANUAL GUIDELINES FOR URINE CULTURE ASM MANUAL GUIDELINES FOR URINE CULTURE ASM MANUAL GUIDELINES FOR URINE CULTURE

RESULTS LIKELY TO BE SIGNIFICANTRESULTS LIKELY TO BE SIGNIFICANTRESULTS LIKELY TO BE SIGNIFICANTRESULTS LIKELY TO BE SIGNIFICANT1111

Dr.T.V.Rao MD 44

�Urine leukocyte esterase positiveUrine leukocyte esterase positiveUrine leukocyte esterase positiveUrine leukocyte esterase positive

One One One One or two organisms at >10or two organisms at >10or two organisms at >10or two organisms at >103333: Full : Full : Full : Full ID ID ID ID and and and and SusceptibilitySusceptibilitySusceptibilitySusceptibility

One One One One organism at >10organism at >10organism at >10organism at >104444 with others (2 or with others (2 or with others (2 or with others (2 or moremoremoremore) at least 10X less: Full ID and ) at least 10X less: Full ID and ) at least 10X less: Full ID and ) at least 10X less: Full ID and susceptibility susceptibility susceptibility susceptibility of predominant of predominant of predominant of predominant organism organism organism organism

Report Report Report Report all group B all group B all group B all group B ββββ----hemolytic hemolytic hemolytic hemolytic streptococci streptococci streptococci streptococci for women < 50 yearsfor women < 50 yearsfor women < 50 yearsfor women < 50 years

1111Modified from ASM Cumitech, ASM Manual, and CDC Modified from ASM Cumitech, ASM Manual, and CDC Modified from ASM Cumitech, ASM Manual, and CDC Modified from ASM Cumitech, ASM Manual, and CDC MMWR 2002;51 (RRMMWR 2002;51 (RRMMWR 2002;51 (RRMMWR 2002;51 (RR----11):111):111):111):1----22222222

NMH GUIDELINES FOR INTERPRETATION OF NMH GUIDELINES FOR INTERPRETATION OF NMH GUIDELINES FOR INTERPRETATION OF NMH GUIDELINES FOR INTERPRETATION OF

URINE CULTURESURINE CULTURESURINE CULTURESURINE CULTURES1111

Dr.T.V.Rao MD 45

NMH GUIDELINES NMH GUIDELINES NMH GUIDELINES NMH GUIDELINES FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF FOR INTERPRETATION OF

URINE CULTURESURINE CULTURESURINE CULTURESURINE CULTURES1111

�Urine leukocyte esterase negativeOne or two organisms at >105: Full and Susceptibility One gram-negative organism (pure culture) at >104: Full ID and SusceptibilityYeast in pure culture: ID as Candida albicans or not C. albicans

Report all group B β-hemolytic streptococci for women <50 years

1111Modified from ASM Cumitech, ASM Manual, and CDC MMWR 2002;51 (RRModified from ASM Cumitech, ASM Manual, and CDC MMWR 2002;51 (RRModified from ASM Cumitech, ASM Manual, and CDC MMWR 2002;51 (RRModified from ASM Cumitech, ASM Manual, and CDC MMWR 2002;51 (RR----11) :111):111):111):1 ----22222222

Dr.T.V.Rao MD 46

ANTIBIOTIC SENSITIVITY TESTING

�All the isolated

bacteria identified

as pathogenic to be

tested for Antibiotic Sensitivity/Resistance

pattern by disk

diffusion methods

Dr.T.V.Rao MD 47

ANTIBIOTIC SENSITIVITYANTIBIOTIC SENSITIVITYANTIBIOTIC SENSITIVITYANTIBIOTIC SENSITIVITY

�Always use a pure

growth of the isolate.

�Perform testing for

antibiotic sensitivity

with inoculum which

is comparable to

defined McFarland McFarland McFarland McFarland

standards

Dr.T.V.Rao MD 48

�High potency disks used

�Antibiotics normally active in urine selected

�Antibiotics found in higher concentration in urine preferred

�Primary sensitivity test frequently used

49

ANTIBIOTIC SENSITIVITY TESTINGANTIBIOTIC SENSITIVITY TESTINGANTIBIOTIC SENSITIVITY TESTINGANTIBIOTIC SENSITIVITY TESTING

Dr.T.V.Rao MD

� Microscopy helps to detect pus cells and epithelial cells, an insignificant growth with few pus cells can ignored as contaminants

� In females even the presence of leucocytes with Squamous epithelial cells without a defined significant growth should be ignored.

REPORTING OF CONTAMINATED REPORTING OF CONTAMINATED REPORTING OF CONTAMINATED REPORTING OF CONTAMINATED

SPECIMENSSPECIMENSSPECIMENSSPECIMENS

Dr.T.V.Rao MD 50

�Negative culture results showing no bacterial growth are available after 24 hours. Positive results require 24-72 hours to complete identification of the number and type of bacteria found

REPORTING OF NEGATIVE URINE REPORTING OF NEGATIVE URINE REPORTING OF NEGATIVE URINE REPORTING OF NEGATIVE URINE

CULTURESCULTURESCULTURESCULTURES

Dr.T.V.Rao MD 51

CLINICAL PROBLEMS MANIFESTING AS

URINARY TRACT INFECTIONS

�An infection of the Genitourinary tract where the Microbes Donot grow on selected media as in Mycobacterium tuberculosis

Gonococcus

Nutritionally exacting or anaerobic bacteria

should be considered.

Dr.T.V.Rao MD 52

�Most over diagnosed condition, both by the clinicians and microbiologists.

�Makes the physicians to miss the existing condition.

�Unnecessary antibiotic prescription lead to drug resistance, loss of resources

URINARY TRACT INFECTION ARE OVER URINARY TRACT INFECTION ARE OVER URINARY TRACT INFECTION ARE OVER URINARY TRACT INFECTION ARE OVER

DIAGNOSED DIAGNOSED DIAGNOSED DIAGNOSED

Dr.T.V.Rao MD 53

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Microbiologists in the Developing Microbiologists in the Developing Microbiologists in the Developing Microbiologists in the Developing World

�Email

�doctortvrao@gmail.com

Dr.T.V.Rao MD 54