A Rapid (4-6-hour) Urine-culture System for Direct Identification and Direct Antimicrobial Susceptibility Testing

Heinze, Paul A.; Thrupp, Lauri; Anselmo, Carl R.

doi:10.1093/ajcp/71.2.177

Cited by 28 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most studies do not report an average cell concentration, but instead report the percentage of individuals having a positive and negative result. And microscopy results have been scored as positive if there has been greater than 0 (24,25,35), 1 or more (3,36,47), 2 or more (5,8,46), and 5 or more (20) bacterial cells per oil immersion field. These differing criteria can significantly impact the reported percentage of positive samples.…”

Section: Discussionmentioning

confidence: 99%

Viable but Nonculturable Bacteria Are Present in Mouse and Human Urine Specimens

et al. 2004

View full text Add to dashboard Cite

The presence of viable but nonculturable bacteria in human clean-catch and mouse bladder-isolated urine specimens was investigated. Viable but nonculturable bacteria are alive but do not give rise to visible growth under nonselective growth conditions. Urine specimens obtained from human female volunteers with or without an active urinary tract infection were found to contain, on average, significantly more viable than culturable forms of bacteria. Additional support for the presence of viable but nonculturable cells in urine specimens considered sterile was obtained from examination of urine specimens obtained directly from the bladder of healthy mice. Because the viability assay used to study the viable but nonculturable condition is by necessity growth independent, and hence indirect, the accuracy of this assay that scores cells with intact cell membranes as being viable was studied. Greater than 95% of Escherichia coli cells exposed to lethal doses of UV irradiation were found to lose their membrane integrity within a day, a time frame similar to that used to examine urine specimens. These data suggest that viable but nonculturable cells can occur within regions of the urinary tract previously considered sterile.Urinary tract infections (UTIs) affect as many as 50% of women at least once during their lifetime (29, 32), and 25% of those who acquire a UTI will have another infection within the following 6 months (17). A UTI occurs when the urinary tract is infected with microorganisms, and uropathogenic Escherichia coli accounts for greater than 80% of all UTI cases (4, 30). One method of diagnosing a UTI is by culturing urine specimens; a threshold of 100,000 CFU/ml in clean-catch urine specimens is considered to indicate a UTI (4, 28). This threshold is not an absolute indicator, as both asymptomatic bacteriuria and patients with UTI symptoms having no culturable urine bacteria occur (29,32).Urine within the urinary tract is generally considered sterile (14). This conclusion is based upon a lack of culturable cells present in urine specimens obtained via clean-catch and catheterization methods. The presence of viable bacteria in the urine specimens of healthy patients would impact on hypotheses to explain recurrent UTIs as well as diagnostic procedures. Most recurrent UTIs result from reinfection; however, a higher percentage than would be expected by chance are caused by the index strain (6,18,26,27,41). The physical location and physiological status of index strain cells that remain after successful antibiotic therapy are unknown. Observations with a mouse model indicate that uropathogenic E. coli cells can remain in the urinary tract following antibiotic ther-

show abstract

Section: Discussionmentioning

confidence: 99%

Viable but Nonculturable Bacteria Are Present in Mouse and Human Urine Specimens

et al. 2004

View full text Add to dashboard Cite

show abstract

“…screening of urines have included disappearance of glucose [ 14], tetrazolium reduction [15 ], nitrite detection [12], presence of catalase [12], bacterial adenosine 5'-triphosphate concentration [ 11 ], pyuria [19], Gram-stain [9,19], and automated photometric and nephelometric techniques [10,18]. Thrupp et al [18] and Jenkins et al [10] have reported satisfactory results with urine screening by light-scatter nephelometry and photometry, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…This was a modification of previously described methods [7,9,19]. Ten microliters of unsedimented urine was placed with a calibrated platinum loop on a clean microscope slide and spread in a 25-30 mm circle.…”

Section: Screening Proceduresmentioning

confidence: 99%

“…Urines comprise the most numerous specimen type submitted to 9 the clinical microbiology laboratory [4]. Methods recently described for rapid urine processing include Gram-stain screening [9,19] and rapid identification with Pathotec strips [9], screening with light-scatter nephelometry and identification with Pathotec strips [18], and screening by light-scatter photometry with identification by Micro-ID [10].…”

Section: Introductionmentioning

confidence: 99%

“…[9] and Tilton and Tilton [19], with direct identification of Enterobacteriaceae in positive specimens by the Micro-ID method [1,2,5,6,8]. Results of Gram-screening are compared with conventional plating methods, and those of direct saline or broth culture inoculation of Micro-ID with standardized isolated colony inoculation of both Micro-ID and API 20E [16].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evaluation of Gram-stain screen and Micro-ID methods for direct identification ofEnterobacteriaceae from urines

Appelbaum

Olmstead

1982

Med Microbiol Immunol

View full text Add to dashboard Cite

A rapid method of urine screening and enterobacterial identification was evaluated. Results indicated that an average of 13.5 bacteria/oil immersion field (threshold value greater than or equal to 1) was observed in unsedimented urine of patients with significant bacteriuria, with an average of less than 1 bacterium/field in urines of patients without significant bacteriuria. In centrifuged urines, numbers of bacteria divided by amount of urine sedimented yielded similar results. Of 1758 urines studied, 136 yielded greater than or equal to 10(5) bacteria/ml, and 58 greater than 10(4) but less than 10(5) bacteria/ml, by conventional techniques. Gram-screening of unsedimented specimens gave sensitivity rates of 94.1%, specificity of 97.7%, and predictive positive and negative values of 78.5%, 99.5%, respectively; similar values were obtained with sedimented urines. Sensitivity rates of both screening methods for the 58 urines with greater than 10(4) but less than 10(5) bacteria/ml were 9.0%, 10.0%, respectively. Total correct enteric identification in 113 urines with positive screens and significant bacteriuria (greater than or equal to 10(5)/ml) was 82.3% and 90.3% with direct saline and broth Micro-ID methods, respectively. In 99 urines yielding pure or predominantly pure growth of 1 species of Enterobacteriaceae identification by direct saline and broth Micro-ID corresponded with isolated colony identification in 85.9%, 94.9% of cases, respectively. Gram-stain screening (together with back-up conventional plating in certain patient categories) and enterobacterial identification by direct broth Micro-ID, of urines with pure stains suggestive of greater than or equal to 10(5) Gram-negative rods/ml has been shown to be useful in laboratories without automated equipment for urine screening.

show abstract

Review of Urine Microscopy for Bacteriuria

Jenkins¹

1986

JAMA

View full text Add to dashboard Cite

Urine microscopy for bacteriuria remains a useful and valid technique for the evaluation of urinary tract infection; however, established interpretive criteria are not agreed on. Our own data and a review of the literature demonstrate that reliable data can be obtained by enumerating the organisms observed in stained or unstained centrifuged and stained uncentrifuged urine specimens. Criteria are given for the interpretation of urine microscopy for maximum sensitivity and specificity for each method reviewed. For clinicians desiring to perform urine microscopy, we recommend the use of oil-immersion microscopy of Gram-stained centrifuged urine sediment and suggest that observing at least one organism per oil-immersion field corresponds with 95% sensitivity and that observing more than five organisms corresponds with 95% specificity for bacteriuria at a level of 10(5) or more colony-forming units per milliliter. Further testing will be required on any negative specimen from a symptomatic patient.

show abstract

A Rapid (4-6-hour) Urine-culture System for Direct Identification and Direct Antimicrobial Susceptibility Testing

Cited by 28 publications

References 0 publications

Viable but Nonculturable Bacteria Are Present in Mouse and Human Urine Specimens

Viable but Nonculturable Bacteria Are Present in Mouse and Human Urine Specimens

Evaluation of Gram-stain screen and Micro-ID methods for direct identification ofEnterobacteriaceae from urines

Review of Urine Microscopy for Bacteriuria

Contact Info

Product

Resources

About