Antibody-coated bacteria in the urine of preschool and school-aged girls with asymptomatic bacteriuria.

Urine samples from 3564 girls aged 2 to 13 years were screened for evidence of infection. Cultures were positive (bacteria count, more than 10(5)/ml) in 61 (1.7%) by the dipslide method and in 55 (1.5%) by standard culture techniques. In 13 (23.6%) of the 55, antibody-coated bacteria (ACB) were detected in the urine. The clinical, bacteriologic, radiologic and urinalysis findings in children with ACB were no different from those in children in whom the bacteria were not coated. Direct examination of uncentrifuged urine under high power revealed one or more bacteria per two high-power fields in 96% of infected urine samples and in only 7% of noninfected samples. Five or more leukocytes per high-power field in centrifuged urine were detected in 36.7% of infected urine samples but not in noninfected samples. The ACB test did not differentiate between asymptomatic bacteriuria with parenchymal scarring or vesicoureteral reflux or both and asymptomatic bacteriuria without these abnormalities.     

Clinical importance of significant asimptomatic bacteriuria in newborns and infants during early postnatal period

The aim of the study was to detect newborns at risk for developing renal impairment, and to point out the importance of significant asimptomatic bacteriuria in perinatal period and early infancy. Severe urinary tract anomalies are very often accompanied only by asimptomatic bacteriuria in perinatal period. Three urinalysis ware done after delivery. 212 newborns with significant asimptomatic bacteriuria underwent ultrasound examination, and were followed up to three months. Those with normal findings and with passing bacteriuria in the first 2 months were excluded. Group of 52 newborns underwent radioisotope examination. Frequency of urinary tract anomalies in newborns was 34.6%. Increased risk for renal impairment had children with urinary tract anomalies in close family, urinary tract infection or bacteriuria, EPH gestosis and prepartal symptoms of febrile infection in mother, children with IUGR, strangulated umbilical cord, prolonged jaundice and attacks of peripheral cyanosis in perinatal period.     

Medicine in Society

The degree to which quantitative urine cultures and the triphenyltetrazolium chloride (TTC) reduction test can be correlated can be directly related to the species of organism involved, the actual level of bacterial population in the urine and the presence of antibiotics. The influence of these various factors is discussed and it is concluded that, depending upon the group of patients involved, the TTC test will detect 70-90% of cases of significant bacteriuria. The TTC test would appear to be a useful screening procedure in the surveillance of large outpatient populations and in the detection of bacteriuria during pregnancy, considering the difficulty of applying the technique of complete quantitative culture to these groups.     

The Triphenyl Tetrazolium Chloride (Uroscreen) Test Alone and in Combination with the Gram Smear as a Screening Procedure for Significant Bacteriuria in Hospital Patients

Of 725 specimens of urine examined by the triphenyl tetrazolium chloride (TTC) [Uroscreen], pour plate and calibrated loop procedures, 30% yielded bacterial colony counts greater than 100,000/ml.; a 100% correlation was obtained among the three methods. Of 539 urine specimens containing more than 100,000 bacteria/ml., 517 (94.06%) gave a positive TTC test.Because of the high correlation between the TTC test and bacterial quantitative counts, the method of TTC in conjunction with smears was adopted as a routine procedure. Specimens which were TTC-negative and smear-negative were discarded. Of 1227 specimens from hospital in-patients and 349 outpatients, 369 urines showed significant bacteriuria (337 from hospital in-patients and 32 from outpatients). There was complete correlation between the TTC test and smear. Of 337 isolations, 27 (8.02%) gave a negative TTC test but a positive smear.     

Evaluation of microscopic examination for bacteriuria.

In order to find an easily available, simple, reliable and inexpensive method for demonstrating significant bacteriuria in routine urine examination, microscopic observation and bacteriological cultures have been made in parallel on total of 206 urine samples. Microscopic examinations of centrifuged deposit for both pus cells and bacteria were found to be more satisfactory in urine specimens with significant bacteriuria than the examinations for either of these elements alone. The criteria of more than five pus cells per high power field and organisms visible in methylene blue stain had sensitivity of 79% and a false positive rate of 13%.     

A Comparative Study of the Triphenyltetrazolium Chloride (Uroscreen) Test and Conventional Methods for the Detection of Bacteriuria

Acute urinary tract infection may be preceded by and active pyelonephritis may be associated with asymptomatic bacteriuria. Treatment of asymptomatic bacteriuria may prevent or arrest active, chronic pyelonephritis and its sequelae. Consequently, there is a need for a reliable and simple screening procedure to detect asymptomatic bacteriuria in large segments of the population.The reliability and practicability of tests advocated for the detection of bacteriuria, including the new chemical triphenyltetrazolium chloride (T.T.C.) (Uroscreen) test, were evaluated. Reliability was assessed by correlating results of these tests with bacterial counts of tested urines. Significant bacteriuria is defined as the presence of 100,000 or more organisms per ml. of urine.The T.T.C. (Uroscreen) test was positive in 92.5% of cases of bacteriuria; there were 7.5% false-negative and 2.8% false-positive results. Bacteria on Gram-stained smear were found in 95.5% of the cases of bacteriuria and in 14.6% of those with non-infected urine; pyuria (more than three leukocytes per high-power field), in 60% of those with bacteriuria and in 15.9% of those with presumably non-infected urine. Bacteria were conspicuous in the urinary sediment in 91.1% of cases of bacteriuria and in 3.7% of presumably non-infected urines.The T.T.C. (Uroscreen) test fulfilled the criteria for a reliable and simple screening procedure. It should be used concomitantly with other screening tests when the urine is examined routinely.     

A Real-Time PCR-Based Semi-Quantitative Breakpoint to Aid in Molecular Identification of Urinary Tract Infections

This study presents a novel approach to aid in diagnosis of urinary tract infections (UTIs). A real-time PCR assay was used to screen for culture-positive urinary specimens and to identify the causative uropathogen. Semi-quantitative breakpoints were used to screen for significant bacteriuria (presence of ≥10⁵ CFU/ml of uropathogens) or low-level bacteriuria (containing between 10³ and 10⁴ CFU/ml of uropathogens). The 16S rDNA-based assay could identify the most prevalent uropathogens using probes for Escherichia coli, Pseudomonas species, Pseudomonas aeruginosa, Staphylococcus species, Staphylococcus aureus, Enterococcus species and Streptococcus species. 330 urinary specimens were analysed and results were compared with conventional urine culture. Using a PCR Ct value of 25 as semi-quantitative breakpoint for significant bacteriuria resulted in a sensitivity and specificity of 97% and 80%, respectively. In 78% of the samples with monomicrobial infections the assay contained probes to detect the bacteria present in the urine specimens and 99% of these uropathogens was correctly identified. Concluding, this proof-of-concept approach demonstrates that the assay can distinguish bacteriuria from no bacteriuria as well as detect the involved uropathogen within 4 hours after sampling, allowing adequate therapy decisions within the same day as well as drastically reduce consequent urine culturing.     

Is screening for bacteriuria in pregnancy worth while?

A total of 4470 pregnant women were screened for bacteriuria by the dipslide method and significant growth found in 226 (5.1%). In 198 cases the urine was re-examined, in 119 by using suprapubic aspiration or catheterisation (62 (52%) samples contained bacteria) and in 79 by using midstream urine samples (26 (33%) samples contained greater than 10(8) colony forming units/1), showing the maximum prevalence of confirmed bacteriuria to be 2.6%. Overt urinary tract infection developed later in four of 80 patients with proved bacteriuria who had been given antibiotics, in one of eight untreated patients with bacteriuria, in one of 110 patients with unconfirmed bacteriuria, and in one of 226 non-bacteriuric controls. A history of urinary tract infection was given by 18% of controls and 42% of women with confirmed bacteriuria. Screening for bacteriuria and treatment with antibiotics to prevent later overt infection is expensive. Whether it is worth while and cost effective depends largely on the prevalence of bacteriuria in the local population and the proportion who develop overt infection. The screening and treatment programme reported here appeared to prevent only six cases of overt infection.     

Simple Disposable Method for Quantitative Cultures of Urine

A disposable kit was tested as a means of detecting significant bacteriuria by quantitative culture of urine. The total error in 3,563 specimens tested by five investigators was less than 1%. The method was very effective in differentiating significant bacteriuria, i.e., more than 100,000 bacteria per ml of urine from uninfected urine. In specimens from patients with urinary tract abnormalities who had mixed bacterial flora, the absolute numbers obtained with the dip-inoculum method had a 10% variation when compared to results obtained by calibrated loop or dilution pour plate methods. Therefore, the main utility of the kit is for screening and following patients after therapy. A significant delay in time between inoculation of the medium in the kit with the freshly voided urine and incubation of the kit to promote growth did not affect the reliability of the kit as a method of doing quantitative urine cultures to detect bacteriuria.     

Perioperative blood transfusion in patients with malignant neoplasms

Within 1986-1988, 3,358 patients were treated at the Department of Surgery, Military Teaching Hospital in Bydgoszcz. Hundred twenty six out of these patients were operated for the malignant tumors. Indications to blood transfusion in case of patients with cancer were analysed retrospectively. In our patients about 50% whom blood was given were justified cases. It was found that the analysis of indications based on laboratory findings may decrease the amount of blood given patients who underwent surgery for cancer.     

Rapid screening for bacteriuria with a laser nephelometer

Detection of significant bacteriuria with a laser nephelometer was evaluated in this study and compared with the results obtained by the quantitative loop method. We screened 1002 urine specimens and 220 (21.95%) were found to be positive at greater than or equal to 10(5) colony-forming units (CFU)/mL of urine by the standard method. Of the 220 positive specimens, 210 (95.4%) were detected in 6 h or less and 177 (80.4%) were detected within 3 h. The false-positive rate was 2.3% at 3 h and 19.7% at 6 h. These findings suggest that a 6-h procedure is necessary to detect 95% or more of significant bacteriuria. Laser nephelometer is versatile and can be used for rapid screening of bacteriuria.     

Usefulness of the latex test for rapid detection of Salmonella O antigen in bacterial culture fluids and clinical specimens. III. Diagnostic field studies]

The aim of this study was to evaluate a latex reagent prepared in our laboratory for a routine diagnosis of Salmonellosis in humans. Liquid cultures in selenite broth (SF) (18-24 hr), previously inoculated with faeces samples of individuals suspected of being infected with Salmonella were subjected to the study. In these cultures, after 15 min. of heating at boiling temperatures, group antigens of Salmonella with an aid of polyvalent latex reagent A-E and monovalent reagents B, C1, C2, D, and E were searched. The results of latex test were compared to the results obtained by routine bacteriological examination. Studies performed in 13 laboratories of Sanitary Epidemiological Stations included 5246 faeces samples. Out of these samples 1835 (35%) reacted with monovalent latex reagent and 1897 (36.2%) samples were positive, for Salmonella by culture technique and belonged to 14 genera of group B, C1, D, and E. S. enteritidis was the most frequently isolated and encountered for 98.6% of all isolated strains. Latex test with A-E reagent was positive in 2246 (42.8%) of culture samples in SF medium, of which 1736 were positive by culture and 510 samples were negative for Salmonella in routine bacteriological examination. The samples positive in culture and with A-E latex reagent reacted in 97.2% with one monovalent reagent. Out of bacteriologically negative samples and reacting with A-E latex reagent 28.8% were positive with monovalent latex reagents. In summary, we can conclude that latex test used in a survey studies can be an usefull test in addition to routine bacteriological examination, since after 18-24 hr it allows with high credibility of 95% to confirm or exclude Salmonella in a tested sample. Such a procedure due to a shortening of routine diagnostic course brings significant savings. Moreover, latex test makes possible rapid detection of mixed infections with Salmonella of different serological groups. The use of extremely carefully, properly prepared selenite broth constitutes a basic condition for agreement between results of latex test and routine bacteriological investigation.     

Bacteriuria amongst Pregnant Women in the Buea Health District,Cameroon: Prevalence,Predictors, Antibiotic Susceptibility Patterns and Diagnosis

Background

Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community.

Objectives

This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD) as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women.

Methods

An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥10⁸ bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08) (BioMerieux, Marcy l''Etoile, France).

Results

Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8%) of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33%) uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively.

Conclusion

Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and leucocyte esterase tests were not sensitive enough to replace urine culture as screening tests.     

Adaptation of immunoenzymatic method for detection of antibody coated bacteria in urine

The modified immunoenzymatic method for detection of antibody coated bacteria (IP ACB) was compared with immunofluorescence technique (IF ACB) in the diagnosis of urinary tract infection. For the study 100 patients were employed with significant and insignificant bacteriuria. It was found that 81% of the results obtained by IP ACB and IF ACB were identical, however the immunoenzymatic method was more sensitive than immunofluorescence. Moreover, the IP ACB technique is simpler, less time consuming and may be performed by using the ordinary optic microscope.     

Six year follow up of infants with bacteriuria on screening.

OBJECTIVE--To determine the value of screening for bacteriuria in infants with special emphasis on the natural course of untreated asymptomatic bacteriuria, renal growth, and renal damage. DESIGN--Prospective six year follow up of infants with bacteriuria on screening in an unselected infant population. SETTING--Paediatric outpatient clinic. PATIENTS--50 Infants (14 girls, 36 boys) with bacteriuria on screening verified by suprapubic aspiration from an unselected population of 3581 infants in a defined area of Gothenburg. INTERVENTIONS--Children with asymptomatic bacteriuria and normal findings on initial urography were untreated, although other infections were treated. MAIN OUTCOME MEASURES--Culture of urine and determination of C reactive protein concentration every six weeks for the first six months after diagnosis, every three months from six months to two years, and every six months between two and three years; thereafter yearly urine culture. Evaluation of renal concentrating capacity with a desmopressin test; radiological examination, including first and follow up urography and micturition cystourethrography without antibiotic cover; and measurement of renal parenchymal thickness and renal surface area. RESULTS--Of the original 50 infants, 37 (12 girls, 25 boys) were followed up for at least six years. Two infants developed pyelonephritis within two weeks after bacteriuria was diagnosed; the others remained free of symptoms. 45 Infants were untreated; the bacteriuria cleared spontaneously in 36 and in response to antibiotics given for infections in the respiratory tract in eight. Recurrences of bacteriuria were observed in 10 of the 50 children, of whom one had pyelonephritis. No child had more than one recurrence. At follow up urography in 36 of the 50 children (9 girls, 27 boys) after a median of 32 months no child had developed renal damage. First samples tested for renal concentrating capacity showed significantly higher values than those from a reference population (mean SD score 0.50, 95% confidence interval 0.21 to 0.79; p less than 0.001), but the last samples showed no significant difference (mean SD score 0.08, -0.24 to 0.40; p greater than 0.05). CONCLUSIONS--Mass screening for bacteriuria in infancy results primarily in detection of innocent bacteriuric episodes and is not recommended.     

Isolation of L-Forms in a Clinical Microbiology Laboratory

Previous studies have demonstrated that L-forms of bacteria may play a role in persistent, chronic, or recurrent urinary-tract infections. A 2-year program was initiated to determine the feasibility of culturing for L-forms on a routine basis, and to determine the effectiveness of such a program. In relation to the total number of specimens, few L-forms were actually isolated. In comparison with the amount of equipment and technician time required, the return was negligible; only 0.5% of all urine specimens were positive for L-forms. An increase to only 1.2% was noted when culturing for L-forms was limited to patients with a diagnosis of bacteriuria or pyelonephritis. It is recommended that this technique be reserved for those patients with a long history of recurrent urinary-tract infections, after other attempts to cure the patient have met with failure.     

A simple method for evaluating Cryptosporidium-specific antibodies used in monitoring environmental water samples

A simple method is described for the evaluation and quality control of Cryptosporidium- specific antibodies used in monitoring environmental water samples. Purified oocysts were fluorescently labelled with a test antibody at the appropriate concentration. Labelled oocysts were analysed using flow cytometry and a region was defined on a bivariate dotplot of fluorescence versus light scatter that enclosed all oocysts. Concentrates of environmental water samples that did not contain oocysts were then incubated with the test antibody and analysed using flow cytometry. The number of particles that appeared in the region defined for oocysts was recorded and was a measure of non-specific binding. The technique provides a simple, rapid and quantitative tool for both evaluating the binding specificity of test antibodies and optimizing sample staining conditions.     

Bacteriuria testing by the ATP method as an integral part in the diagnosis and therapy of urinary tract infection (UTI)

Rapid tests for bacteriuria have the highest value, if the test result is available while the patient is with the doctor. At the bacteriological laboratory rapid testing of samples obtained by mail may be cost-effective but is of little clinical value. In a previous study performed at a health care centre using conventional urine culture as a reference the ATP test came out as the most reliable one among several rapid bacteriuria tests. The present study was performed to see how the ATP test could be fitted into the routine of the health care centre. Female patients with UTI symptoms were asked to deliver a urine sample to the health care centre laboratory and to wait for the result before seeing the doctor. After having the symptoms confirmed the doctor based the diagnosis on the ATP value. A low ATP value ruled out UTI and a high ATP value confirmed UTI. In patients with an intermediary ATP value (10–50 nmol/I) a positive nitrite test was used to confirm UTI. Only those patients with intermediary ATP values and negative nitrite test had to wait for conventional urine culture. Thus in most patients the decision on antibiotic therapy or not was based on clinical symptoms and ATP results only. Antibiotics (trimethoprim) were given as single dose or as a conventional 7-day regime in a double-blind comparison. The correlation between the ATP method and conventional culture was good. Although results of the present study are promising the ATP test as performed is too complicated to become widely accepted at health care centres. However, the dipstick version of the ATP test at present being developed will make the method ideally suited for rapid bacteriuria testing at health care centres and similar doctor's surgery situations.     

Detection of pulmonary tuberculosis; comparative value of routine radiologic examinations and routine laboratory procedures

The abnormalities disclosed by the usual laboratory diagnostic procedures (blood cell count and hemoglobin determination, sedimentation rate determination, urinalysis, and serologic test for syphilis) are compared with the number revealed by stereophotoroentgen chest examination in a series of 951 patients. The number of significant abnormalities uncovered by the routine stereophotoroentgen examination of the chest was comparable to the number disclosed by the usual laboratory procedures used in patient evaluation. Some form of radiologic examination of the chest should be included in the routine laboratory procedures required for patient evaluation.     

Suprapubic aspiration under ultrasound guidance in children with fever of undiagnosed cause.

OBJECTIVES--To assess the ease of use of suprapubic aspiration of urine under ultrasound guidance in babies with fever of uncertain cause and to assess the importance of bacterial counts and pyuria in relation to abnormalities of the urinary tract and the importance of pyuria in the absence of bacteriuria. DESIGN--Analysis of urine samples obtained by suprapubic aspiration in babies and children from July 1991 to June 1992. The clinical records of the children with bacteriuria and sterile pyuria were examined retrospectively. SETTING--Neonatal and paediatric wards of a district general hospital. SUBJECTS--508 babies and children who had fever of uncertain cause or were seriously ill. RESULTS--No difficulties arose in the collection of 545 specimens. Bacteria were isolated from the specimens of 44 children, 24 of whom had abnormalities of the urinary tract. The bacterial count was < 10(8)/l in 18 of the children with bacteriuria, 10 of whom had abnormalities. No white cells were seen in 22 of the 46 bacteriuric specimens; nine of the children with no pyuria had vesicoureteric reflux. 439 of the 499 non-bacteriuric specimens showed no white cells. 60 children had pyuria without bacteriuria. CONCLUSIONS--The use of ultrasound guidance simplifies suprapubic aspiration of urine in babies. Low bacterial counts may be associated with abnormalities of the urinary tract. Laboratory techniques capable of detecting such counts reliably should be used. Pyuria is absent in half of babies and very young children with bacteriuria. It rarely occurs without bacteriuria, and if it does an explanation should be sought.