Detection Of Urinary Tract Pathogens Research Articles

Evaluation of New bioMérieux Chromogenic CPS Media for Detection of Urinary Tract Pathogens

Four chromogenic media were compared for their ability to detect urinary tract pathogens in 299 urine specimens, of which 175 were found positive, allowing the growth of 279 microorganisms. After 18 to 24 h of incubation, the CPS ID4, CPSE, CPSO (bioMérieux), and UriSelect4 (Bio-Rad) media showed sensitivities of 97.1%, 99.3%, 99.6%, and 99.6%, respectively.

Rapid detection of urinary tract pathogens using microcalorimetry: principle, technique and first results

What's known on the subject? and What does the study add? Microcalorimetry has been applied in several microbiological studies, but never in a clinical urological context. In addition, basic knowledge on the growth of urinary pathogens in urine is still scarce and data regarding the growth rate of many urinary pathogens in urine are still not available. The study demonstrates that this innovative application of microcalorimetry is useful in (i) investigating the growth of urinary pathogens in sterilized urine and (ii) as a rapid tool for diagnosis of urinary infection as well as for further identification of the causative infectious agent. To investigate the value of isothermal microcalorimetry (IMC) in the detection and differentiation of common urinary tract pathogens in urine. IMC is a non-specific analytical tool for the measurement of heat in the microwatt range. A microcalorimeter equipped with 48 channels was used. Detection was accomplished, and growth was monitored for four bacterial strains in sterilized urine at 37 °C by measuring metabolic heat flow (µW = µJ/s) as a function of time. The strains were Escherichia coli, Proteus mirabilis, Enterococcus faecalis and Staphylococcus aureus. Bacterial growth was detected after 3.1 to 17.1 h with decreasing inocula. The detection limit was 1 colony-forming unit (CFU)/mL for E. coli, 10 CFU/mL for P. mirabilis and E. faecalis and 10(3) CFU/mL for S. aureus. The total heat was highest in P. mirabilis ranging from 10 to 12 J, followed by E. coli (3-4 J), S. aureus (2-3 J) and E. faecalis (1.3-1.5 J). The shape of the heat flow curves was characteristic for each species independent of its initial concentration. IMC allows rapid detection of bacteriuria, much faster than conventional culture. Urinary tract pathogen detection after only 3.1 h is realistic. Clearly different heat flow patterns enable accurate pathogen differentiation. Due to expeditious identification of urine samples that contain only low colony counts (i.e. less than 10(3) CFU/mL), IMC may become a valuable screening tool for detecting the presence of significant bacteriuria.

Use of chromogenic Agar in detection of urinary tract pathogens and antimicrobial Susceptibility

Use of chromogenic Agar in detection of urinary tract pathogens and antimicrobial Susceptibility

Evaluation of a new chromogenic medium, Uriselect 4, for the isolation and identification of urinary tract pathogens

Aims: To compare the performance of a new chromogenic medium, Uriselect 4, with cystine lactose electrolyte deficient (CLED) agar and an established chromogenic agar, CPS ID 2 medium, for detection...

Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens.

CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar's surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from reference media. Owing to the ease in differentiating mixed flora on CHROMagar Orientation, antimicrobic susceptibility tests were performed directly from primary isolates in all cases without the need for subcultures.