Urinary Tract Infections

Detection of significant pyuria by sediment examination requires at least ____________________ of specimen. At least ____________________ of urine may be required to recover mycobacteria or fungi. If these agents are strongly suspected and previous specimens of lesser volume have tested negative, a single, ____________________ collection of at least 20 to 40 mL should be obtained for culture. In addition, ____________________ collections for urine specimens in microbiology are unacceptable.

10 mL; 20 mL; early-morning; 24-hour

The urinary tract above the urethra in normal healthy individuals is sterile, as is urine, unlike the urethra, which is colonized with perineal flora. It was understood that a finding of ____________________ or more was a positive test result, symbolizing infection. Most asymptomatic women had counts below ____________________, and the prevalence of infection was only 6%.

10⁵ CFU/mL; 10³ CFU/mL

Generally, urine should be refrigerated, received, and processed in the laboratory within ____________________ of being collected. Longer delays render examination for significant pyuria ____________________, and the extremes of pH and urea concentration and presence of antimicrobial agents may adversely affect the recovery of uropathogens.

2 hours; unreliable

____________________ to urine specimens are designed primarily to preserve the bacterial density present at collection. One example is sodium borate, which maintains the sample integrity for up to ____________________ after collection at room temperature, preventing overgrowth of nonpathogenic flora without impairing growth of existing pathogens. Regardless of the preservative used, the maximum time from collection to processing should not exceed ____________________.

Additives; 48 hours; 24 hours

____________________ is the presence of bacteria in urine in significant quantities, but without GU signs or symptoms of infection. ASB requires treatment only in some populations, such as ____________________ and patients about to undergo ____________________ of the GU tract. Disease occurs when the multiplication of organisms in the urinary tract interferes with the normal function of the involved organ.

Asymptomatic bacteriuria (ASB); pregnant women; instrumentation

Isolation of ____________________ can almost always be considered contamination because UTIs caused by this organism are exceedingly rare. In rare cases, ____________________ may be isolated from the urine of infants who acquired a perinatal infection with this organism and in 1% of patients with a systemic infection or renal transplants.

Bacillus spp.; Listeria monocytogenes

____________________ and ____________________ can cause urethritis, cystitis, and prostatitis. Identification of ____________________ in urine commonly reflects vaginal contamination, but this organism is also an emerging urinary tract pathogen.

C. trachomatis; N. gonorrhoeae; Gardnerella vaginalis

____________________, an invasive technique, reduces the risk of contamination of urine by the urethral flora; however, because the catheter is passed through the urethra, some contamination may occur. Before urine is collected with a single straight catheter, the urethral opening or vaginal vault is ____________________ with a soap solution and rinsed with sterile water. The ____________________ flow is discarded because it may contain organisms acquired as the catheter passed through the urethra.

Catheterized specimen collection; cleansed; initial urine

Of the Enterobacteriaceae, antibiotic-susceptible strains of ____________________ that exist in the patient's own fecal flora cause most uncomplicated UTIs. As the duration of hospitalization and catheterization increases, E. coli is less likely to be encountered than other organisms, such as ____________________, ____________________, ____________________, ____________________, and ____________________.

E. coli; Pseudomonas; Proteus; Klebsiella; Acinetobacter; Enterobacter spp.

____________________ patients and those residing in ____________________ facilities develop UTIs more often compared with outpatients. ____________________ are at higher risk for UTI for several reasons. Hormonal changes lead to changes in the ureter and urethra, making them more susceptible to bacterial adherence and infection. In addition, the enlarging uterus can put pressure on the bladder and impair urinary flow, leading to cystitis or pyelonephritis.

Hospitalized; long-term care; Pregnant women

____________________ should consist of the degree of pyuria, presence of nitrites, blood, and/or leukocyte esterase, and the presence or absence of bacteria or fungi. These results should be reported within ____________________ after the collection of a urine specimen.

Preliminary reports; 2 hours

____________________ is the definitive method for collecting uncontaminated specimens. Suprapubic aspirations are collected primarily from ____________________ and from patients in whom the interpretation of the results of voided specimens is ____________________ for various reasons. Following skin ____________________, urine is collected from a full bladder by using a needle and a syringe.

Suprapubic aspiration; infants; difficult; antisepsis

____________________ samples may be used for a stained smear. The presence of ____________________ in at least five fields in a smear of uncentrifuged urine correlates with more than 10⁵ CFU/mL. ____________________ often indicates urethritis, cystitis, or pyelonephritis. Detection of 10⁵ may be performed by microscopic examination of a wet mount of a urinary sediment resulting from centrifugation of 10 mL of a specimen at 200 rpm on a tabletop centrifuge for 5 minutes. At least five fields should be examined, and each leukocyte seen per high-power field (×40) represents approximately 5 to 10 cells per microliter of urine. In this way, ____________________ in the sediment is the upper limit of normal, representing 50 to 100 cells per microliter.

Uncentrifuged urine; one or more bacterial cells per oil immersion field; Pyuria; leukocytes; 5 to 10 leukocytes per high-power field

____________________ are among the most common bacterial infections, accounting for up to 7 million episodes of cystitis and 250,000 episodes of pyelonephritis infection in the kidney in the United States annually. Upper UTIs involve the renal parenchyma (____________________) or the ureters (____________________). Lower UTIs involve the bladder (____________________), the urethra (____________________), and in males, the prostate (____________________).

Urinary tract infections (UTIs); Urinary tract infections (UTIs); pyelonephritis; ureteritis; cystitis; urethritis; prostatitis

Urine specimens obtained by straight catheterization, bilateral ureteral catheterization, bladder washout, or ileoconduits require inoculation of ____________________ and ____________________ for maximum recovery.

agar plates; liquid medium

Bacteria may gain access to the urinary tract by three routes - the ____________________, the ____________________, and ____________________. Women acquire UTIs via the ____________________. Infection of the renal parenchyma by many species of gram-positive bacteria (particularly in patients with staphylococcal bacteremia or endocarditis), mycobacteria, Candida spp., and other fungal infections clearly occurs via the ____________________. Although increased pressure on the bladder can cause ____________________ flow to be directed to the kidney, there is little evidence to indicate a role for this in pathogenesis.

ascending route; hematogenous route; lymphatic pathways; ascending route; hematogenous route; lymphatic

If the patient is ____________________, immediate antimicrobial therapy is not necessary unless the patient is pregnant or undergoing GU surgery. Identification and susceptibility testing of isolates can be achieved by any ____________________ or ____________________ method. The colony count should accompany any positive culture result to indicate the diagnosis of ____________________. Because the organisms most frequently identified include E. coli and other rapidly growing members of the Enterobacteriaceae, ____________________ of incubation at ____________________ is sufficient.

asymptomatic; conventional; automated; ASB; 24 hours; 35°C

The causative agent of acute prostatitis is usually recovered from ____________________ specimens, which should be cultured in the same manner as for specimens from symptomatic men. In cases of chronic prostatitis, ____________________ secretions are submitted, as well as urethral urine and midstream-voided urine specimens obtained before and after prostatic massage. ____________________ cultures are necessary for proper interpretation.

catheterized; prostatic; Quantitative

UTI in ____________________ is associated with great morbidity and long-term medical problems, including impaired renal function, hypertension, end-stage renal disease, and complications of pregnancy as an adult. From adulthood to age ____________________, the incidence of UTIs in men is extremely low. Among women in this age group, however, as many as ____________________ experience a UTI with associated symptoms. The increased incidence of UTIs in ____________________arises from obstructive uropathologic conditions caused by the prostate and from the loss of the bactericidal activity of prostatic secretions. In ____________________, bladder prolapse contributes to the occurrence of infection, as does soiling of the perineum from fecal incontinence.

children; 65 years; 20%; men; women

Preventing ____________________ by normal vaginal, perianal, and interior urethral flora is the most important consideration when collecting a clinically relevant urine specimen. All necessary precautions should be taken to ensure that the ____________________ represents the numbers of organisms present when the specimen was collected.

contamination; colony count

Among the gram-positive cocci, ____________________ and ____________________ are the most commonly encountered causative agents. Enterococcal UTIs occur primarily in ____________________, particularly in association with urinary tract manipulation or instrumentation or prostatic hypertrophy. ____________________ is found predominantly in symptomatic sexually active women younger than 40 years. ____________________ is found in hospitalized patients older than 50 years.

enterococci; Staphylococcus saprophyticus; older men; S. saprophyticus; S. epidermidis

Antimicrobial agents approved by the U.S. Food and Drug Administration (FDA) for routine testing and reporting by clinical microbiology laboratories for urinary tract isolates are listed as ____________________ in the 2016 Clinical and Laboratory Standards Institute (CLSI) Performance Standards for Antimicrobial Disk Susceptibility Tests, 12th edition, approved standard CLSI document M02-A12. it is imperative to remember that attainable ____________________ levels and ____________________ levels are often different; this will have an impact on the interpretation of some semiquantitative susceptibility results or the quantitative minimal inhibitory concentration of inhibitory antimicrobials.

group U supplemental for urine only; antibiotic blood; urine

Specimens may be rejected because of an ____________________ or ____________________ method of collection or transport. Samples to be rejected include ____________________ and ____________________; these should not be processed.

inadequate; inappropriate; 24-hour urine specimens; Foley catheter tips

UTI is the most common infection in ____________________ recipients, occurring in up to 86% of recipients. Several factors contribute to this increased risk of UTI, including significant immunosuppression, foreign bodies, such as stents and urinary catheters, stricture, obstruction, scarring, or other abnormalities of the ureter and urethra, graft trauma, and diabetes mellitus. Up to ____________________ are related to bladder catheterization and/or manipulation. In a catheterized patient, the risk of acquiring a UTI depends on the ____________________, ____________________, and ____________________.

kidney transplant; 95%; duration of catheterization appropriate catheter care; host susceptibility

Suprapubic aspirates may contain bacteria likely to be present in ____________________ numbers and may include ____________________ species. Such specimens should be routinely inoculated on a ____________________ plate, ____________________ plate, and ____________________ for up to 48 hours. For recovery of G. vaginalis, ____________________ is acceptable. Anaerobic bacteria are recovered in approximately ____________________ of cases and therefore need only be sought after consultation.

low anaerobic; blood agar; MAC agar; trypticase soy broth; chocolate agar; 1%

Specimens from patients with symptoms of ____________________ should be processed in the same manner as for suspected cases of pyelonephritis. If there is significant ____________________ in a patient who is symptomatic and no recognized urinary pathogen is detected, then C. trachomatis, Mycoplasma spp., U. urealyticum, N. gonorrhoeae, or M. tuberculosis should be suspected. For gonococcus and chlamydia, ____________________ (not midstream urine) is recommended. Urine ____________________ is available to test for N. gonorrhoeae and C. trachomatis.

lower UTI; pyuria; first morning voided urine; polymerase chain reaction (PCR)

Historically, one of the primary functions of the clinical microbiology laboratory has been to ____________________. This was generally accomplished by using an annual ____________________ that established cumulative percentage susceptibilities for selected UTI bacteria-antibiotic combinations. Today, this is even more important and requires focused antibiograms that tailor these historical resistance fingerprints to selected patient ____________________, ____________________ versus ____________________ status, disease type, and patient ____________________.

measure antibiotic resistance trends; antibiogram; locations; inpatient; outpatient; disease type; age

Urine specimens submitted from patients suspected of having ____________________ generally contain high numbers of bacteria. Microscopic examination of urine for ____________________ and ____________________ quickly provides therapeutically useful information. Plates should be incubated for ____________________ at ____________________, and the method may include a drop of specimen inoculated into ____________________ for optimal recovery.

pyelonephritis; leukocytes; bacteria; 48 hours; 35°C; trypticase soy broth

The normal urinary tract is ____________________ to colonization and subsequent infection by bacteria. The urinary tract efficiently and rapidly eliminates virulent and avirulent microorganisms. Although urine is frequently considered a good culture medium for bacterial growth, the extremely high urine osmolarity (____________________) and low pH levels inhibit the growth of many uropathogens and almost all normal urethral flora. In addition, ____________________ urine fails to support the growth of most bacterial species. In terms of antibacterial activity, urine from ____________________ is more inhibitory than urine from women because of the bactericidal effect of prostatic fluids in their, as well as the difference in pH and osmolarity.

resistant; concentration; low pH; very dilute; men

There are two clinical schemas for classifying UTIs: (1) single versus recurrent episode, and (2) complicated versus uncomplicated episode. A ____________________ occurs once and does not recur. Patients with chronic or recurrent UTIs have repeated episodes of ____________________, with or without clinical manifestations. These episodes are arbitrarily divided into relapse and reinfection. ____________________ involves the same organism and implies a focus of infection in the renal or prostatic parenchyma; ____________________ implies a different organism and is usually limited to the bladder. ____________________ occur primarily in sexually active young women with normal GU tracts and no prior instrumentation; these are usually caused by antibiotic-susceptible bacteria. ____________________ occur in individuals who have one or more structural or functional GU abnormalities or have indwelling catheters and whose conditions cannot be controlled with therapy.

single-episode UTI; bacteriuria; Relapse; reinfection; Uncomplicated UTIs; Complicated UTIs

The ____________________, in which the patient collects the urine specimen, is the most commonly used method in clinical practice. The urine is contaminated with bacteria from the urethra unless the ____________________ of the voided specimen is discarded. Voided urine collection kits should contain ____________________ for the patient on proper specimen procurement.

voided midstream collection; first portion; Voided urine collection kits; instructions

UTIs occur more frequently in ____________________ than in men, with up to 50% of all women experiencing a UTI during their lifetime. Others at risk for UTI include ____________________, ____________________, patients who have had renal transplantation, patients with ____________________, patients with ____________________, and patients with ____________________ abnormalities.

women; older adults; pregnant women; spinal cord injuries; catheters; genitourinary (GU) tract

UTIs in children ____________________ than 2 years usually manifest themselves with nonspecific symptoms, such as failure to thrive, vomiting, lethargy, and fever. Children ____________________ than 2 years are more likely to complain of more localized symptoms, such as dysuria, frequency, and abdominal pain. ____________________ with uncomplicated lower UTIs limited to the urethra or bladder present primarily with dysuria, often in combination with frequency, urgency, suprapubic pain, and hematuria. Most ____________________ patients have atypical presentations, such as delirium, failure to thrive, and/or weakness. Dysuria may be present in infections with ____________________, ____________________, or ____________________.

younger; older; Adults; older; herpes simplex virus; Chlamydia trachomatis; Neisseria gonorrhoeae

When clinical studies using the latter method of determining pyuria were reviewed, the following conclusions emerged: - A urine leukocyte count of ____________________ or higher occurs in less than 1% of asymptomatic patients without bacteriuria but in more than 96% of symptomatic men and women with significant bacteriuria. - Most symptomatic women with pyuria but without significant bacteriuria have UTIs with bacterial uropathogens present in colony counts from ____________________ or have infections with C. trachomatis or U. urealyticum. - Asymptomatic women with ____________________ probably should be categorized as having true infection associated with pyuria or having transient self-limited bladder colonization and no pyuria. - Most patients with catheter-associated bacteriuria also have ____________________ - hence infection. - Simultaneously, an impregnated paper strip that measured urine ____________________ was introduced and found to correlate well with hemocytometer chamber counts. The ____________________ is inexpensive and quick (1 minute) and requires no technical skills or equipment, just the classic dipstick.

- 10 μL/mm³ - 10² to 10⁵ CFU/mL - ASB - pyuria - leukocyte esterase; leukocyte esterase test (LET)

Several key points should be considered when using screening methods: - Screening methods capable of detecting bacterial densities of ____________________ or higher are appropriate for the detection of ASB in pregnant women. - False-positive results occur more often with methods that test for more than one parameter (e.g., bacteria and WBC count). - Methods of detecting significant pyuria and bacteriuria with sensitivities of ____________________ per microliter and ____________________ may be appropriate for screening voided urine specimens or those from indwelling urinary catheters in symptomatic patients. - ____________________ methods are not appropriate for urine collected by using straight catheterization, cystoscopy, suprapubic aspiration, or bladder washout or for testing cure specimens and specimens collected from ileal conduits.

- 10⁵ CFU/mL - False-positive - 50 to 100 leukocytes per microliter; 10² CFU/mL - Screening

Microbial Virulence Factors

- Adherence (bacterial adhesions) - Biofilms - Calculi formation (kidney stones) - Capsular polysaccharide - Hemolysins - Lipopolysaccharides - Toxin production

Three features that should be considered in all UTIs are:

- Colony count of a pure or predominant organism - Measurement of pyuria - Presence or absence of symptoms (dysuria and frequency)

These guidelines recommend the following, keeping in mind that cost-effective strategies may define different algorithms for inpatient and outpatient cases: - Multiple uropathogens (i.e., ____________________) in a specimen indicates probable contamination. - One or two significant uropathogens present (____________________) should be routinely identified. - ____________________ should be performed for inpatients. Outpatient cases may use a different algorithm that does not routinely call for susceptibility tests; rather, it emphasizes empiric selection based on ____________________. - One or two uropathogens present in small numbers (____________________) should be routinely identified (____________________) if the clinical situation warrants, such as in acute urethral syndrome or cases of previous antibiotic therapy.

- three or more - ≥ 10⁵ CFU/mL - Susceptibility testing; antibiograms - ≥ 10² CFU/mL; ≥ 10² to < 10⁵ CFU/mL

Calibrated loops of ____________________ should be used. Incubation beyond ____________________ yields noise or background urethral flora that may impair the clinical usefulness of the urine culture.

0.001 mL (1 μL) to 0.01 mL; 24 hours