• Clinical and Experimental Pediatrics
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• v.62 no.12
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• pp.433-437
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• 2019

Acute pyelonephritis (APN) should be detected and treated as soon as possible to reduce the risk of the development of acquired renal scarring. However, in the medical field, urine culture results are not available or considered when the prompt discrimination of APN is necessary and empirical treatment is started. Furthermore, urine culture cannot discriminate APN among children with febrile urinary tract infection (UTI) (pyelitis, lower UTI with other fever focus). Therefore, the usefulness of urine culture for diagnostic purposes is small and the sampling procedure is invasive. Congenital hypoplastic kidney is the most common cause of chronic kidney injury in children. Thus, it is desirable that a main target be detected as early as possible when imaging studies are performed in children with APN. However, if APN does not recur, no medical or surgical treatment or imaging studies would be needed because the acquired renal scar would not progress further. Therefore, the long-term prognosis of APN in young children, particularly infants, depends on the number of recurrent APN, not other febrile UTI. New methods that enable prompt, practical, and comfortable APN diagnosis in children are needed as alternatives to urinary catheterization for urine culture sampling.

• Clinical and Experimental Pediatrics
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• v.58 no.5
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• pp.183-189
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• 2015

Purpose: Catheter urine (CATH-U) and suprapubic aspiration (SPA) are reliable urine collection methods for confirming urinary tract infections (UTI) in infants. However, noninvasive and easily accessible collecting bag urine (CBU) is widely used, despite its high contamination rate. This study investigated the validity of CBU cultures for diagnosing UTIs, using CATH-U culture results as the gold standard. Methods: We retrospectively analyzed 210 infants, 2- to 24-month-old, who presented to a tertiary care hospital's pediatrics department between September 2008 and August 2013. We reviewed the results of CBU and CATH-U cultures from the same infants. Results: CBU results, relative to CATH-U culture results (${\geq}10^4$ colony-forming units [CFU]/mL) were widely variable, ranging from no growth to ${\geq}10^5CFU/mL$. A CBU cutoff value of ${\geq}10^5CFU/mL$ resulted in false-positive and false-negative rates of 18% and 24%, respectively. The probability of a UTI increased when the CBU bacterial count was ${\geq}10^5/mL$ for all infants, both uncircumcised male infants and female infants (likelihood ratios [LRs], 4.16, 4.11, and 4.11, respectively). UTIs could not be excluded for female infants with a CBU bacterial density of $10^4-10^5$ (LR, 1.40). The LRs for predicting UTIs based on a positive dipstick test and a positive urinalysis were 4.19 and 3.11, respectively. Conclusion: The validity of obtaining urine sample from a sterile bag remains questionable. Inconclusive culture results from CBU should be confirmed with a more reliable method.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.3
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• pp.359-368
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• 1999

Background : The purpose of this study was to determine whether cleansing the perineum and urethral meatus and using midstream urine affect the rate of bacterial contamination of urine specimens, and to determine the optimum urine collection method. We studied 41 asymptomatic healthy nursing school students. Women who were menstruating were not excluded from this study. Method : The first and midstream urine samples were collected during consecutive urinationsby each woman. The first sample was not a clean-catch specimen, and the second one was a clean-catch specimen. Both specimens were studied by urinalysis and bacterial culture with standard methods. Results : 41 women met the study criteria and 39 successfully completed the study. None of the urine cultures were positive. 68.3% of the non clean-catch first urine cultures, 53.7% of the non clean-catch midstream cultures, 33.3% of the first clean-catch urine culteres and 30.8% of the midstream clean-catch urine were found to be contaminated. There was a significant difference in the bacterial contamination rates between the first and midstream urine, and the clean-catch and non clean-catch urine(p=0.035, p =0.001 respectively). On urinalysis, 7.3% of the non clean-catch first urine, 7.3% of the non clean-catch midstream urine, 2.6% of the clean-catch first urine and 2.6% of clean-catch midstream urine were found to be above grade 2. Conclusions : According to our results, the bacterial contamination rate was the lowest in midstream and clean catch urine specimens. Threrfore it is recommended that the midstream clean-catch technique is the standard practice for collecting urine specimens for bacterial culture in women.

• Annals of Clinical Microbiology
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• v.21 no.4
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• pp.75-79
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• 2018

Background: Urine culture is one of the most frequently requested tests in microbiology. Automated urine analyzers yield much infection-related information. The Sysmex UF-5000 analyzer (Sysmex, Japan) is a new flow cytometry urine analyzer capable of quantifying urinary particles, including bacteria, WBCs, and yeast-like cells (YLCs) and can provide a Gram stainability flag. In this work, we evaluated how many unnecessary urine cultures could be screened out using the UF-5000. Methods: We compared the culture results of 126 urine samples among 453 requested urine cultures (from sources other than the Urology and Nephrology departments) with urinalysis results. Urine cultures were considered positive if bacterial or YLC growth was ${\geq}10^4CFUs/mL$. Results: We used urinalysis cut-off values of $50/{\mu}L$ and $100/{\mu}L$ for bacteria and YLC, respectively. Forty eight of the 126 (38.1%, or 10.6% of 453 requested) cultures were below these cut-off values and did not contain any culture-positive samples. Conclusion: Bacteria and YLC counts generated using the UF-5000 analyzer could be used to screen out negative cultures and reduce urine culture volume by ~10% without sacrificing detection of positive cultures.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.346-350
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• 2009

Purpose : Since children under two years with suspected urinary tract infections (UTIs) cannot control urination, urine cultures in such children are usually performed via urine bags. This method is noninvasive but has a high contamination rate. We studied the contamination rate of bag urine culture in diagnosing UTI in infants under two years and the factors responsible for contamination. Methods : We examined patients under 2 years in whom urine culture through the urine bag method yielded over 105 colonies of a single pathogen. We defined UTI by referring to the guidelines of The Korean Society of Pediatric Nephrology, 2005. We examined the factors responsible for contamination according to sex, duration of urine collection, and whether diarrhea took place with contamination rate. Results : We examined 717 patients (412 males and 305 females). The contamination rate of one bag urine culture was 37.9%. Gender was not related to the contamination rate (P>0.05). Duration of urine collection showed an association with the contamination rate. The longer the duration of collecting urine, the higher was the contamination rate. Duration of urine collection was divided into three groups: first group, <2 hours; second group, 24 hours; and third group, ${\geq}4$ hours. Contamination rates were 30.0%, 42.2%, and 43.7% for the first, second, and third groups, respectively, with statistical significance (P=0.001). Diarrhea at admission had no impact on the contamination rate (P>0.05). Conclusion : The contamination rate of urine culture in the examined patients was 37.9%. Gender and diarrhea symptoms were not responsible for contamination. In infants with a suspected UTI, urine should be collected within 2 hours through the urine bag method. If urine collection takes >2 hours, the urine bag should be resterilized and reattached to the patient.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.619-628
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• 2022

In general, as a method to confirm a urinary tract infection (UTI) in a medical institutions, urine culture including a urinalysis and an antimicrobial susceptibility test is performed. It is important to disinfect the area around the urethra and perineum before collecting urine samples, and it is important to collect it intermediate urine, not the first-void urine. We invented a patent urine cup (Patent No. 10-1732843) that can automatically and easily separate first-void urine and midstream urine and using this, the patent cup and the general cup were compared and evaluated using this. Nitrite (P<0.001), WBC (P=0.005), Bacterial colony count (P=0.001), colony positivity rate (P=0.004) in first-void urine (N=24), midstream urine (N=24) separated by patent cup to obtain a significantly higher value. This can be seen from the fact that the first-void urine and midstream urine separated using the patent cup were well separated. Also, the number of Bacterial colonies was statistically significantly higher in the midstream urine isolated using a patent cup (N=24) than in the midstream urine collected using a general cup (N=24) (average 7.9 vs. 4.0 on average, P= 0.002). Which means that the midstream urine separated using the patent cup is more sensitive to the UTI test than the midstream urine collected using a general cup.

• Journal of Microbiology
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• v.40 no.4
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• pp.267-273
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• 2002

Urinary tract infection (UTI) is one of the most common domiciliary and nosocomial bacterial infections prevalent in both males and females. UTI is diagnosed on the basis of clinical symptoms, microscopy and culture of urine. In order to evaluate the efficacy of microscopic detection for presumptive diagnosis of UTI we analyzed urine samples of Nepalese patients. We have conducted Gram staining and counting of pus cells, red blood cells (RBC) and epithelial cells. We observed that RBC and epithelial cell counts were not sensitive enough to be used for presumptive diagnosis of UTI. However, pus cell counts as well as Gram stain are sensitive and significant enough to presume UTI. When the Gram stain result was compared with the culture result, it was statistically significant. From this, we suggest that Gram stain of centrifuged urine is a very sensitive screening method to detect bacteriuria. In addition, we found that E. coli was the most predominant microorganism causing UTI and nitrofurantoin was the most effective antibiotic against the isolated urinary pathogens.

• Clinical and Experimental Pediatrics
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• v.58 no.9
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• pp.341-346
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• 2015

Purpose: To evaluate the practical applications of the diagnosis algorithms recommended by the American Academy of Pediatrics urinary tract infection (UTI) guideline. Methods: We retrospectively reviewed the medical records of febrile UTI patients aged between 2 and 24 months. The patients were divided into 3 groups: group I (patients with positive urine culture and urinalysis findings), group II (those with positive urine culture but negative urinalysis findings), and group III (those with negative urine culture but positive urinalysis findings). Clinical, laboratory, and imaging results were analyzed and compared between the groups. Results: A total of 300 children were enrolled. The serum C-reactive protein level was lower in children in group II than in those in groups I and III (P<0.05). Children in group I showed a higher frequency of hydronephrosis than those in groups II and III (P<0.05). However, the frequencies of acute pyelonephritis (APN), vesicoureteral reflux (VUR), renal scar, and UTI recurrence were not different between the groups. In group I, recurrence of UTI and presence of APN were associated with the incidence of VUR (recurrence vs. no recurrence: 40% vs.11.4%; APN vs. no APN: 23.3% vs. 9.2%; P<0.05). The incidence of VUR and APN was not related to the presence of hydronephrosis. Conclusion: UTI in febrile children cannot be ruled out solely on the basis of positive urinalysis or urine culture findings. Recurrence of UTI and presence of APN may be reasonable indicators of the presence of VUR.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.2
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• pp.131-137
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• 1995

Improving validity and reliability is the important components of clinical laboratory tests. And the quality control of the test should be started with the accurate collection of specimen. Urinalysis is one of the useful and common tests in diseases diagnosis and determining the process of medical treatment. Since urinalysis is requested routinely in hospital setting, the importance of the quality control for urine specimen is often ignored. To improve the validity of urinalysis, a clinical trial was done on the method of collecting urine specimen. The result was as follows : 1. The rate of presumtive UTI(urinary tract infection) was decreased in 21.6% with experiment method for collecting urine specimen. 2. The rate of presumtive UTI in female patients was decreased in 43.2% with the experiment method. 3. The rate of negative urine culture was decreased in 6.6% with the experiment method.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.359-368
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• 1998

Cytomegalovirus is the most common cause of life-threatening viral infection in HIV-infected patients. This study was done prospectively to investigate the incidence of CMV infection according to the decrease of CD4+ T cell count (CD4+) in Korean AIDS patients. Thirty-nine HIV-infected patients diagnosed before 1994 were followed for regular immunological monitoring. We have used urine shell vial method for the CMV detection from 1994 and have also checked clinical findings. Positive urine culture rate definitely depended on the CD4+ as follows; 45%, 22%, 17%, 11% and 0%, CD4+ <50, 50-100, 100-200, 200-500 and >500, respectively. Except culture positive 2 patients with CD4+ of $200{\sim}300/{\mu}l$, all eight culture positive patients with CD4+ less than $200/{\mu}l$ showed CMV related diseases on or before urine culture. But, we could not get a positive culture for a late AIDS patient with vision loss. With ganciclovir therapy, all culture results were at least negative just after or on late of first 14 days-ganciclovir infusion-course. These data suggest that the incidence of CMV disease in Korean AIDS patients is very high, and early diagnosis and treatment for CMV diseases is required for the prevention of life threatening results.