ACP Best Practice No 167: the laboratory diagnosis of urinary tract infection

Prevalence and Antimicrobial Sensitivity Patterns of Uropathogens in Wad Medani, Sudan: A Three Years, Cross-Sectional Study

Purpose

Urinary tract infections exert a significant negative impact on an individual's quality of life and cause significant economic and public health burdens. Therefore, this study was conducted to identify the common bacterial uropathogens associated with urinary tract infections in Wad Medani patients and their susceptibility to antibiotics.

Patients and Methods

This was a cross-sectional study. All urine samples were collected from patients at Wad Medani and investigated at the Pathology Center for Diagnosis and Research, Faculty of Medicine, University of Gezira, Sudan, from the 1st of January 2021 to the 15th of October 2023.

Results

A total of 2698 urine samples were analyzed during the three years study period, with a mean age of 45.29 ± 18.9 years. Among these patients, 1108 (41.8%) were positive for bacterial growth, and 888 (80.14%) were female. A total of 522 (47.1%) were gram positive bacteria (GPB), and 586 (52.9%) were gram negative bacteria (GNB). The most frequently isolated bacteria were S. aureus 42% (465/1108) and E. coli 38.5% (427/1108), while P. aeruginosa was less detected 3.4% (38/1108). Amikacin 91.5% was the most sensitive drug to isolated GPB, while cotrimoxazole 20.9% was the least sensitive drug. In particular, amikacin 94.1% (144/153) was the most sensitive drug to S. aureus, while cotrimoxazole 20.7% (80/386) was the least sensitive drug. Moreover, amikacin 91.5% was the most sensitive drug to the isolated GNB, while ampicillin 5.7% was the least sensitive drug. Notably, amikacin was the most sensitive drug to all the isolated GNB, and ampicillin was the least sensitive drug to all the isolated GNB.

Conclusion

This study reported a moderate uropathogen isolation rate of 41.8%. S. aureus and E. coli were the most frequently isolated bacteria, most of which were from female patients. Remarkably, amikacin was the most sensitive drug to isolated GNB and GPB.

Positive Bacterial Culture among Adults with Suspected Urinary Tract Infections Presenting to the Department of Medicine of a Tertiary Care Centre

Introduction

Urinary tract infections are the most common infections encountered in clinical practice. Treatment needs to take into account the likely organism, comorbidities and local antibiotic sensitivity pattern. This study aimed to find the prevalence of positive bacterial culture among adults with suspected urinary tract infections presenting to the department of medicine of a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted among adults with suspected urinary tract infections. Data was collected between 1 July 2022 to 31 December 2022 after obtaining ethical approval from the Institutional Review Committee. Individuals with symptomatic urinary tract infections were included in the study. The antibiotic susceptibility tests of the isolates were done. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval.

Results

Among 355 patients, positive cultures were obtained in 148 (41.69%) (36.56-46.82, 95% Confidence Interval). Escherichia coli 120 (81.08%) was the predominant organism cultured among the positive bacterial culture cases.

Conclusions

The prevalence of positive bacterial culture was found to be higher than other studies done in similar settings.

Keywords

aminoglycosides; Escherichia coli; prevalence; urinary tract infections.

Analysis of Bacterial Stent Colonization: The Role of Urine and Device Microbiological Cultures

In this study, we explored the incidence of double J (JJ) contamination of patients who underwent an endourological procedure for urinary stones and ureteral stenosis. We developed a prospective study between January 2019 and December 2021. Ninety-seven patients, 54 male and 43 female, were enrolled. Urine culture was taken during four steps: before stent insertion, a sample from selective renal pelvis catheterization, a sample two days after the JJ insertion and finally, after the stent removal procedure. At the time of the stent removal, 1 cm of proximal and distal ends were cut off and placed in the culture for bacterial evaluation. Cohen's kappa coefficient value (k) and concordance rates of microbiological culture results were evaluated. The study group comprised 56% of male patients. Proximal and distal stent cultures were positive in 81 and 78 patients. The concordance rate of microbiological cultures between proximal and distal double J stent is 88% (k 0.6). The most common pathogens isolated from urine and stent cultures were Enterococcus spp. in 52 cases and Klebsiella spp. in 27 cases.

Urinary Tract Infections in Pregnant Individuals

SUMMARY

Urinary tract infection (UTI) is one of the more common perinatal complications, affecting approximately 8% of pregnancies (1, 2). These infections represent a spectrum, from asymptomatic bacteriuria, to symptomatic acute cystitis, to the most serious, pyelonephritis. The presence of UTIs has been associated with adverse pregnancy outcomes, including increased rates of preterm delivery and low birth weight. Screening for and treating asymptomatic bacteriuria have been shown in multiple studies to reduce the incidence of pyelonephritis in pregnancy (3-5). Given the frequency at which UTIs are encountered in pregnancy, the ability to recognize, diagnose, and treat them is essential for those providing care to pregnant individuals. This Clinical Consensus document was developed using an established protocol in conjunction with the authors listed.

Effect of Mannan Oligosaccharides Extracts in Uropathogenic Escherichia coli Adhesion in Human Bladder Cells

Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.

Rezidivierende Harnwegsinfektionen – was tun?

Nicht antibiotische Therapieregime Neben allgemeiner Aufklärung und Beratung über Risikofaktoren von Harnwegsinfektionen sind vor allem die nichtantibiotischen Therapie-Optionen zur Rezidivreduktion wichtig. Das Ziel hierbei ist es, Resistenzentwicklungen und den entsprechenden unerwünschten Nebenwirkungen von Antibiotika vorzubeugen. Zu den nicht antibiotischen Strategien zählen allen voran eine persönliche Beratung mit Vermittlung von Verhaltensempfehlungen, die Immunoprophylaxe, Phytotherapeutika, sowie eine lokale Östrogensubstitution

Antibiotische Prävention Bei hohem Leidensdruck der Patientinnen ist jedoch nach entsprechender Abwägung auch eine antibiotische Prophylaxe in Betracht zu ziehen. Zusammenfassend sollte eine individuelle Beratung erfolgen und es sollte mit einem multimodalen Therapieansatz behandelt werden.

Nanomaterials in the Management of Gram-Negative Bacterial Infections

The exploration of multiplexed bacterial virulence factors is a major problem in the early stages of Escherichia coli infection therapy. Traditional methods for detecting Escherichia coli (E. coli), such as serological experiments, immunoassays, polymerase chain reaction, and isothermal microcalorimetry have some drawbacks. As a result, detecting E. coli in a timely, cost-effective, and sensitive manner is critical for various areas of human safety and health. Intelligent devices based on nanotechnology are paving the way for fast and early detection of E. coli at the point of care. Due to their specific optical, magnetic, and electrical capabilities, nanostructures can play an important role in bacterial sensors. Another one of the applications involved use of nanomaterials in fighting microbial infections, including E. coli mediated infections. Various types of nanomaterials, either used directly as an antibacterial agent such as metallic nanoparticles (NPs) (silver, gold, zinc, etc.), or as a nanocarrier to deliver and target the antibiotic to the E. coli and its infected area. Among different types, polymeric NPs, lipidic nanocarriers, metallic nanocarriers, nanomicelles, nanoemulsion/ nanosuspension, dendrimers, graphene, etc. proved to be effective vehicles to deliver the drug in a controlled fashion at the targeted site with lower off-site drug leakage and side effects.

Fosfomycin susceptibility of uropathogens at Charlotte Maxeke Johannesburg Academic Hospital

Background

Multidrug-resistant uropathogens are becoming widespread both in community and hospital setting. Safe yet effective treatments are a priority. Fosfomycin is an antibacterial that displays good activity against most bacteria causing urinary tract infections (UTIs), including multidrug-resistant bacteria. The aim of this study was to evaluate fosfomycin susceptibility for uropathogens isolated from a microbiology laboratory at a tertiary academic hospital. In addition, this was compared to the susceptibility of other oral antimicrobials.

Methods

We conducted a retrospective analysis of laboratory reports for uropathogens isolated at Charlotte Maxeke Johannesburg Academic Hospital from September 2015 to August 2017. Antimicrobial susceptibility testing of the isolates was performed using the Kirby–Bauer disk diffusion method or the Vitek^® 2 system according to the Clinical and Laboratory Standards Institute.

Results

Overall susceptibility of fosfomycin for the 4700 Enterobacteriaceae isolates was 95.7%; 95% confidence interval (CI) 95.1–96.2. The overall susceptibility for fosfomycin against the gram-positives was 98.6%. There were 37.9% multidrug-resistant Enterobacteriaceae (MDRE) isolated during the study period. Fosfomycin displayed activity against 94.4% of extended-spectrum β-lactamase (ESBL) producers and 90.7% for carbapenem-resistant Enterobacteriaceae (CRE). None of the methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus isolates tested was fosfomycin resistant. The overall in vitro susceptibility was significantly higher for fosfomycin (p = 0.0001) compared to amoxicillin/clavulanic acid, cephalexin, cefuroxime, ciprofloxacin, trimethoprim/sulfamethoxazole and nitrofurantoin.

Conclusion

This study confirmed the high susceptibility of fosfomycin against UTI pathogens isolated at our institution. In an era of increasing antimicrobial resistance, fosfomycin represents a potential option for the treatment of UTIs at Charlotte Maxeke Johannesburg Academic Hospital.

[What to do about recurrent urinary tract infections]

Urinary tract infections are among the most common bacterial infections. A significant proportion of urinary tract infections recur, which leads to impairments in patients' physical intimacy, social contacts and ability to work. The standardised ACSS questionnaire can provide help in establishing a diagnosis and assessing the course of the disease. In addition to general education and counselling on risk factors for urinary tract infections, non-antibiotic treatment options are particularly important for reducing recurrence. This aims to prevent the development of resistance to antibiotics and their undesirable side-effects. Non-antibiotic strategies most notably include personal counselling with communication of behavioural recommendations, immunoprophylaxis, phytotherapeutics and local oestrogen substitution. However, in cases of high patient suffering, antibiotic prophylaxis should also be considered after due deliberation. In summary, individual counselling should take place and treatment should be given in a multimodal therapeutic approach.

Prevalence of Bacterial Urinary Tract Infection and Antimicrobial Susceptibility Patterns Among Diabetes Mellitus Patients Attending Zewditu Memorial Hospital, Addis Ababa, Ethiopia

BACKGROUND

Urinary tract infection (UTI) is caused by colonization and growth of microorganisms within the urinary system. Diabetic patients are more prone to bacterial UTI due to impaired host defense and high glucose concentration in urine. Surveillance of uropathogens and their antibiogram is a key to patient management.

METHODS

A hospital-based cross-sectional study was conducted from May to July, 2018. Urine samples were collected for culture and identification based on the standard protocol. An antimicrobial susceptibility test (AST) was done for all isolates using the Kirby-Bauer disk diffusion method. Data were entered into Epi-data version 3.2.1 and exported to the Statistical Package for the Social Science (SPSS) version 20.

RESULTS

Out of 225 participants, significant bacteriuria was reported in 9.8% of the cultures. Five species of bacteria were isolated and E. coli (63.6%) was the leading uropathogen, followed by K. pneumoniae (13.6%). Duration of diabetes, previous history of UTIs and symptomatic UTI were found to be strongly associated with significant bacteriuria. Gram-negative bacterial isolates showed high sensitivity to nitrofurantoin and meropenem (100%). In contrast, a high level of resistance to ampicillin, doxycycline and cefuroxime (100%) and to amoxicillin-clavulanate (94.4%) was observed. Gram-positive bacteria showed high level of resistance to penicillin (100%). Multiple-drug resistance (MDR) was high for Gram-negative bacteria (100%).

CONCLUSION

Previous history of UTIs and duration of diabetes were found to be important factors that increase the prevalence of UTI among diabetes patients. This study also showed a high prevalence of drug resistance to doxycycline, amoxicillin-clavulanate, cefuroxime and penicillin for both Gram-negative and Gram-positive bacteria. Since therapeutic selection for empirical treatment and management should be based on knowledge of the local bacterial profile and antimicrobial response, we suggest physicians take this high resistance profile in to consideration when prescribing antimicrobials against the pathogens in question.

Bacterial uropathogens and susceptibility testing among patients diagnosed with urinary tract infections at Hiwot Fana Specialized University Hospital, Eastern Ethiopia

Background:

Urinary tract infection is a common infection posing a significant healthcare burden globally. Currently, it is becoming hard to manage due to the drug resistance of uropathogens. This study aimed to evaluate the rate of culture positivity and the susceptibility pattern of isolates among clinically diagnosed patients with urinary tract infection.

Methods:

An institution-based cross-sectional study was conducted on patients clinically diagnosed with urinary tract infections and received a drug prescription at Hiwot Fana Specialized University Hospital from August 2018 to June 2019. A clean-catch mid-stream urine specimen was collected and bacterial identification and susceptibility test were performed using standard microbiological methods. Data were entered into EpiInfo 7 and exported to STATA 15 for analysis. Data were analyzed using descriptive analysis and bi-variate and multivariate regression analyses and presented with graphs, frequency, and tables.

Results:

A total of 687 urine samples were collected from patients with clinically diagnosed urinary tract infections. The mean age was 31 years and 56.62% were female. 28.38% of the participants had a culture-positive result, of which 86.15% had monomicrobial infections. Inpatients (AOR = 3.8, 95% CI = (1.8–7.9)) and hypertensive patients (AOR = 2.1, 95% CI = (1.1–4.4)) had higher odds of culture-positive results. Staphylococcus species (35.3%), E. coli (25.34%), Pseudomonas species (6.8%), and other Enterobacterales are isolated. Most isolates showed resistance to more than one drug, and amikacin, gentamicin, and nitrofurantoin showed relatively higher activity against isolates.

Conclusion:

About one-third of the clinically diagnosed patients with urinary tract infection were culture-positive with many types of bacterial uropathogens. Inpatients and hypertensive patients had a higher risk of developing bacterial infections. Bacterial isolates showed different percentages of susceptibility to the tested antibiotics.

Bacterial Profile and Antibiotic Susceptibility Pattern of Urinary Tract Infection among Pregnant Women Attending Antenatal Care at a Tertiary Care Hospital in Southern Ethiopia

Background

Urinary tract infection is one of the most common bacterial infections encountered in pregnant women with significant morbidity. This study aimed to determine the bacterial profile and its antimicrobial susceptibility pattern of urinary tract infection among pregnant women attending antenatal care (ANC) at a Hawassa University Comprehensive Specialized Hospital (HUCSH), Southern Ethiopia.

Method

A cross-sectional study was conducted in which consecutive pregnant women enrolled in the study from March to June 2019. The structured questionnaire used to collect sociodemographic and clinical data in a face-to-face interview. Midstream urine was collected from pregnant women using sterile containers. Culture and sensitivity were performed using a standard operating procedure of the microbiology laboratory. Data entry and analysis were conducted using the statistical package for social sciences (SPSS) version 20. Descriptive and logistic regression was used to conduct the output of the data. The odds ratio at 95% confidence interval was considered as a statistically significant association with a p value <0.05.

Result

The overall magnitude of urinary tract infection in this study was 7.8% (4.7–10.8%). Escherichia coli was found to be the most frequently isolated (47.8%), followed by Klebsiella pneumoniae (17.4%), Staphylococcus aureus (8.7%), Klebsiella ozaenae, Klebsiella rhinoscleromatis, Citrobacter spp., Salmonella group A, Staphylococcus saprophyticus, and Enterobacter cloacae each (4.3%). Gram-negative bacteria were sensitive to 78.3%, 91.3%, and 100% of ciprofloxacin, gentamicin, and nitrofurantoin, respectively. Gram-positive bacteria were sensitive to clindamycin (100%), gentamicin (100%), and nitrofurantoin (100%) and fully resistant to ceftriaxone (100%) and cefuroxime (100%). There is no statistically significant association (p < 0.05) between the risk factor of urinary tract infection and UTI.

Conclusion

The overall prevalence of urinary tract infection among pregnant women attending antenatal care was 7.8%. Escherichia coli were the dominant isolate followed by Klebsiella pneumoniae. Gram-negative isolates are highly sensitive to ciprofloxacin, gentamicin, nitrofurantoin, and ceftriaxone and Gram-positive isolates to gentamicin, clindamycin, and nitrofurantoin. Most of the bacteria are resistant to cotrimoxazole and cefuroxime. There is no statistically significantly associated variable. Screening for the presence of urinary tract infection during pregnancy will improve the quality of antenatal care further reducing complication. The above antibiotics can be prescribed based on the side effect to pregnant women in case empirical treatment is mandatory in the study area.

Guideline for Urine Culture and Biochemical Identification of Bacterial Urinary Pathogens in Low-Resource Settings

Medical diagnosis in low-resource settings is confronted by the lack of suitable guidelines, protocols and checklists. Online-accessible procedural documents are difficult to find, might be mistranslated or interpreted and usually do not address the needs of developing countries. Urinalysis, one of the most frequently performed diagnostic examinations worldwide, involves a series of tests aiming to detect particular disorders, such as urinary tract infections, kidney disease and diabetes. In this guideline, we present an alternative approach for clinical laboratories with limited resources to identify common bacterial uropathogens. We propose dividing the identification plan into two levels. The implicated pathogen will first be assigned into a bacterial group, basic identification, against which a suitable panel of antimicrobial agents shall be selected for the antimicrobial susceptibility testing (AST). Characterization of the pathogen to the genus or species level, advanced identification, will then be performed to ensure correct reading of the AST results and determine the epidemiology of clinically significant pathogens. Most of the proposed steps in our guideline are tailored to meet the needs of clinical laboratories in low-resource settings. Such guidelines are needed to strengthen the capacity of regional pathology laboratories and to enhance international initiatives on antimicrobial resistance and health equity.

An Intact Cell Bioluminescence-Based Assay for the Simple and Rapid Diagnosis of Urinary Tract Infection

Urinary tract infection (UTI) is one of the most common infections, accounting for a substantial portion of outpatient hospital and clinic visits. Standard diagnosis of UTI by culture and sensitivity can take at least 48 h, and improper diagnosis can lead to an increase in antibiotic resistance following therapy. To address these shortcomings, rapid bioluminescence assays were developed and evaluated for the detection of UTI using intact, viable cells of Photobacterium mandapamensis USTCMS 1132 or previously lyophilized cells of Photobacterium leiognathi ATCC 33981™. Two platform technologies-tube bioluminescence extinction technology urine (TuBETUr) and cellphone-based UTI bioluminescence extinction technology (CUBET)-were developed and standardized using artificial urine to detect four commonly isolated UTI pathogens-namely, Escherichia coli, Proteus mirabilis, Staphylococcus aureus, and Candida albicans. Besides detection, these assays could also provide information regarding pathogen concentration/level, helping guide treatment decisions. These technologies were able to detect microbes associated with UTI at less than 105 CFU/mL, which is usually the lower cut-off limit for a positive UTI diagnosis. Among the 29 positive UTI samples yielding 105-106 CFU/mL pathogen concentrations, a total of 29 urine specimens were correctly detected by TuBETUr as UTI-positive based on an 1119 s detection window. Similarly, the rapid CUBET method was able to discriminate UTIs from normal samples with high confidence (p ≤ 0.0001), using single-pot conditions and cell phone-based monitoring. These technologies could potentially address the need for point-of-care UTI detection while reducing the possibility of antibiotic resistance associated with misdiagnosed cases of urinary tract infections, especially in low-resource environments.

Direct identification and susceptibility testing of Gram-negative bacilli from turbid urine samples using VITEK2

INTRODUCTION:

Urinary tract infections (UTIs) are the most common infectious diseases occurring in either the community or healthcare setting. Turnaround time for urine culture is about 24 h, and antimicrobial susceptibility testing (AST) requires another 24 h. Consequently, initial antibiotic therapy is mostly empirical.

MATERIALS AND METHODS:

This study was conducted at Nizam's Institute of Medical Sciences, Hyderabad. Turbid urine samples which showed pus cells and Gram-negative (GN) bacilli of single morphotype were included. The turbidity of the urine was adjusted to 0.5 McFarland and uploaded directly in the VITEK 2 identification (ID) GN and N-280 panel for AST. The specimen was also inoculated on CHROMagar, and the ID and AST of the isolates from the agar plate were repeated on VITEK 2, and the results were compared.

RESULTS:

Out of 844 turbid urines screened, 62 met the inclusion criteria. Escherichia coli was the most common isolate (71.9%). Complete agreement for ID was 80.7%, misidentified were 12.2%, and unidentified were 7%. Complete agreement with AST was 94.3%, very major errors 0.5%, major errors 2.2%, and minor errors 3%.

CONCLUSION:

With a 94.3% agreement for AST and a reduced turnaround time by 24 h, the direct inoculation had a potential clinical benefit for initiating timely and appropriate antibiotic therapy for UTI.

Reincubation of culture-negative urines for an additional 20 hours does not identify additional UTI cases

Introduction

The question of whether a single day of incubation is sufficient for urine cultures has been a matter of debate.

Aim

The aim of this study was to investigate the potential benefit of prolonged incubation for initially culture-negative urines.

Methodology

Eight hundred and twelve urine specimens with no growth after incubation for 20 h were incubated for an additional 20 h to detect slower growing uropathogenic organisms.

Results

This study included a considerable number of urine cultures from immunocompromised and/or kidney-transplanted patients. For 99.9 % of the specimens, there was no difference in the interpretation of results.

Conclusion

Twenty hours of incubation did not have any negative effect on the detection of uropathogens.

Diagnosis of Bacterial Pathogens in the Urine of Urinary-Tract-Infection Patients Using Surface-Enhanced Raman Spectroscopy

(1) Background: surface-enhanced Raman spectroscopy (SERS) is a novel method for bacteria identification. However, reported applications of SERS in clinical diagnosis are limited. In this study, we used cylindrical SERS chips to detect urine pathogens in urinary tract infection (UTI) patients. (2) Methods: Urine samples were retrieved from 108 UTI patients. A 10 mL urine sample was sent to conventional bacterial culture as a reference. Another 10 mL urine sample was loaded on a SERS chip for bacteria identification and antibiotic susceptibility. We concentrated the urine specimen if the intensity of the Raman spectrum required enhancement. The resulting Raman spectrum was analyzed by a recognition software to compare with spectrum-form reference bacteria and was further confirmed by principal component analysis (PCA). (3) Results: There were 97 samples with single bacteria species identified by conventional urine culture and, among them, 93 can be successfully identified by using SERS without sample concentration. There were four samples that needed concentration for bacteria identification. Antibiotic susceptibility can also be found by SERS. There were seven mixed flora infections found by conventional culture, which can only be identified by the PCA method. (4) Conclusions: SERS can be used in the diagnosis of urinary tract infection with the aid of the recognition software and PCA.

Skin signs in juvenile- and adult-onset systemic lupus erythematosus: clues to different systemic involvement

OBJECTIVE

We aim to explore the differences of skin signs between juvenile- and adult-onset systemic lupus erythematosus and to identify their associations to the development of systemic involvement.

METHODS

A retrospective chart review of 377 systemic lupus erythematosus patients was performed.

RESULTS

In total, 171 patients with juvenile systemic lupus erythematosus and 206 with adult systemic lupus erythematosus were studied. All patients were of Southeast Asian descent. The mean duration of follow up was 8.18 ± 6.19 and 9.36 ± 7.68 years for juvenile systemic lupus erythematosus and adult systemic lupus erythematosus, respectively. At diagnosis, most patients presented with acute cutaneous lupus erythematosus, whereas chronic cutaneous lupus erythematosus was twice as common in adult systemic lupus erythematosus ( p < 0.001). The mean Systemic Lupus Erythematosus Disease Activity Index of juvenile systemic lupus erythematosus was significantly higher than that of adult systemic lupus erythematosus (14.29 ± 7.13 vs 11.27 ± 6.53). Multivariate analysis revealed the following associations in juvenile systemic lupus erythematosus: acute cutaneous lupus erythematosus and non-scarring alopecia with increased risk of arthralgia, mucosal ulcers with leukopenia, cutaneous vasculitis with seizure, and finding of granular casts. On the contrary, the associations for adult systemic lupus erythematosus were oral ulcers with arthralgia and cutaneous vasculitis with myositis.

CONCLUSIONS

Cutaneous signs in systemic lupus erythematosus may signal prognostic implication. Interestingly, despite similar cutaneous lesions in systemic lupus erythematosus, different ages of onset are associated with different systemic involvement.

Urothelial cells may indicate underlying bacteriuria in pregnancy at term: a comparative study

Background

Urinary tract infection is common in pregnancy. Urine is sampled from by mid-stream collection (MSU). If epithelial cells are detected, contamination by vulvo-vagial skin and skin bacteria is assumed. Outside pregnancy, catheter specimen urine (CSU) is considered less susceptible to contamination. We compared MSU and CSU methods in term pregnancy to test these assumptions.

Methods

Healthy pregnant women at term gestation (n = 32, median gestation 38 + 6 weeks, IQR 37 + 6–39 + 2) undergoing elective caesarean section provided a MSU and CSU for paired comparison that were each analysed for bacterial growth and bladder distress by fresh microscopy, sediment culture and immunofluorescent staining. Participants completed a detailed questionnaire on lower urinary tract symptoms. Epithelial cells found in urine were tested for urothelial origin by immunofluorescent staining of Uroplakin III (UP3), a urothelial cell surface glycoprotein. Urothelial cells with closely associated bacteria, or “clue cells”, were also counted. Wilcoxons signed rank test was used for paired analysis.

Results

Women reported multiple lower urinary tract symptoms (median 3, IQR 0–8). MSU had higher white blood cell counts (median 67 vs 46, z = 2.75, p = 0.005) and epithelial cell counts (median 41 vs 22, z = 2.57, p = 0.009) on fresh microscopy. The proportion of UP3+ cells was not different (0.920 vs 0.935, z = 0.08, p = 0.95), however MSU had a higher proportion of clue cells (0.978 vs 0.772, z = 3.17, p = 0.001). MSU had more bacterial growth on sediment culture compared to CSU specimens (median 8088 total cfu/ml vs 0, z = 4.86, p = 0.001). Despite this, routine laboratory cultures reported a negative screening culture for 40.6% of MSU specimens.

Conclusion

Our findings have implications for the correct interpretation of MSU findings in term pregnancy. We observed that MSU samples had greater bacterial growth and variety when compared to CSU samples. The majority of epithelial cells in both MSU and CSU samples were urothelial in origin, implying no difference in contamination. MSU samples had a higher proportion of clue cells to UP3+ cells, indicating a greater sensitivity to bacterial invasion. Urinary epithelial cells should not be disregarded as contamination, instead alerting us to underlying bacterial activity.

Electronic supplementary material

The online version of this article (10.1186/s12884-017-1606-z) contains supplementary material, which is available to authorized users.

Emerging nanotechnology based strategies for diagnosis and therapeutics of urinary tract infections: A review

At present, various diagnostic and therapeutic approaches are available for urinary tract infections. But, still the quest for development of more rapid, accurate and reliable approach is an unending process. The pathogens, especially uropathogens are adapting to new environments and antibiotics day by day rapidly. Therefore, urinary tract infections are evolving as hectic and difficult to eradicate, increasing the economic burden to the society. The technological advances should be able to compete the adaptability characteristics of microorganisms to combat their growth in new environments and thereby preventing their infections. Nanotechnology is at present an extensively developing area of immense scientific interest since it has diverse potential applications in biomedical field. Nanotechnology may be combined with cellular therapy approaches to overcome the limitations caused by conventional therapeutics. Nanoantibiotics and drug delivery using nanotechnology are currently growing areas of research in biomedical field. Recently, various categories of antibacterial nanoparticles and nanocarriers for drug delivery have shown their potential in the treatment of infectious diseases. Nanoparticles, compared to conventional antibiotics, are more beneficial in terms of decreasing toxicity, prevailing over resistance and lessening costs. Nanoparticles present long term therapeutic effects since they are retained in body for relatively longer periods. This review focuses on recent advances in the field of nanotechnology, principally emphasizing diagnostics and therapeutics of urinary tract infections.

[Urinary tract infections : What has been confirmed in therapy?]

Urinary tract infections (UTIs) affect approximately 150 million people worldwide per year, causing annual health costs of over three billion dollars just in the USA. Every second woman experiences at least one UTI in her lifetime, with every one in four experiencing recurrence. Uncomplicated infections like single or recurrent cystitis and pyelonephritis can be distinguished from complicated disease. UTIs in men can spread to the male glands, causing prostatitis and epididymitis. Antibiotic therapy is the standard procedure for UTIs. However, the extensive and sometimes irrational use of antibiotics for the treatment of infections has led to an increase in the incidence of multiresistant pathogens in recent years. Therefore, preventive nonantibiotic approaches are of great interest. This article provides an overview of the current management of urological infections as well as an outline of nonantibiotic preventive treatment modalities.

Multi-drug-resistant Enterococcus faecalis among Egyptian patients with urinary tract infection

The prevalence of Enterococcus faecalis (E. faecalis) infections among Egyptians with urinary tract infection (UTI), their antimicrobial susceptibility and mechanisms of resistance are under investigated. In this study, 300 urine samples were collected from UTI patients to identify E. faecalis. Antimicrobial susceptibility to 18 antimicrobial agents was tested. The presence of aac(6)-Ie-aph(2)Ia, erm(B) and mef(A/E) genes was examined by PCR. Fifty-seven (19%) isolates were identified as E. faecalis. All isolates were sensitive to teicoplanin and were completely resistant to nalidixic acid, cefotaxime and cefadroxil. Multi-drug-resistant (MDR) was found to be 100% with 45 different antibiotypes. The aac(6)Ia-aph(2)Ia gene was found in 100 and 90% of the isolates resistant to gentamicin at concentrations of 120 and 10 μg, respectively. erm(B) and mef(A/E) genes were present in 92.5% (37/40) and 2.5% (1/40) of erythromycin-resistant isolates, respectively. We conclude that there is a high prevalence of E. faecalis in UTI cases with a 100% MDR rate indicating a serious problem in treating infections by this organism in Egypt.

Urinary tract infection among fistula patients admitted at Hamlin fistula hospital, Addis Ababa, Ethiopia

BACKGROUND

Urinary Tract Infection (UTI) causes a serious health problem and affects millions of people worldwide. Patients with obstetric fistula usually suffer from incontinence of urine and stool, which can predispose them to frequent infections of the urinary tract. Therefore the aim of this study was to determine the etiologic agents, drug resistance pattern of the isolates and associated risk factor for urinary tract infection among fistula patients in Addis Ababa fistula hospital, Ethiopia.

METHODS

Across sectional study was conducted from February to May 2015 at Hamlin Fistula Hospital, Addis Ababa, Ethiopia. Socio-demographic characteristics and other UTI related risk factors were collected from study participants using structured questionnaires. The mid-stream urine was collected and cultured on Cysteine lactose electrolyte deficient agar and blood agar. Antimicrobial susceptibility was done by using disc diffusion method and interpreted according to Clinical and Laboratory Standards Institute (CLSI). Data was entered and analyzed by using SPSS version 20.

RESULTS

Out of 210 fistula patients investigated 169(80.5%) of the patient were younger than 25 years. Significant bacteriuria was observed in 122/210(58.1%) and 68(55.7%) of the isolates were from symptomatic cases. E.coli 65(53.7%) were the most common bacterial pathogen isolated followed by Proteus spp. 31(25.4%). Statistical Significant difference was observed with history of previous UTI (P = 0.031) and history of catheterization (P = 0.001). Gram negative bacteria isolates showed high level of resistance (>50%) to gentamicin and ciprofloxacin, while all gram positive bacteria isolated were showed low level of resistance (20-40%) to most of antibiotic tested.

CONCLUSIONS

The overall prevalence of urinary tract infection among fistula patient is 58.1%. This study showed that the predominant pathogen of UTI were E.coli followed by Proteus spp. It also showed that amoxicillin-clavulanic acid was a drug of choice for urinary tract bacterial pathogens.

Rapid detection of E. coli cells in urine samples using a self-capacitance touchscreen device

Escherichia coli is one of the main causes of urinary tract infections (UTIs). E. coli is commonly detected from urine using standard culture method. However, the urine sampling and analysis required for these methods can be costly, time consuming (requires 24 to 48 hours) and labor-intensive. This work proposes a capacitive touch screen sensor concept as possible alternative device for rapid detection of E. coli in urine samples. E. coli solutions prepared at different concentrations and urine samples (with spiked and nor spike E. coli) obtained from healthy women participants, have been analyzed using a capacitance evaluation kit. It has been demonstrated in this study that the use of this evaluation kit provides a low-cost and simple alternative system for detecting E. coli present in urine. Several experimental tests were performed to determine the optimal testing volume, the sensitivity of the sensor, limit of detection and repeatability. The optimal testing volume was 80 microliters and the analytical sensitivity was 17 counts per picofarad (pF). The lowest detectable concentration is around 3.98 × 10(5) CFU/ml. The repeatability (r) was found to be 7.2 or 6.2 % (in r%). The capacitive touch sensor gave promising results that could be used to design and realize a portable diagnostic device for early-stage detection of UTIs.

Biofilm formation, antimicrobial susceptibility, serogroups and virulence genes of uropathogenic E. coli isolated from clinical samples in Iran

BACKGROUND

Uropathogenic Escherichia coli O- Serogroups with their virulence factors are the most prevalent causes of UTIs. The present research performed to track common uropathogenic E.coli serogroups, antibiotic resistance pattern of strains and prevalence of virulence genes in isolations having the ability to constitute biofilm.

METHODS

In this research 130 E.coli isolation from patients having UTI symptoms were collected and antimicrobial resistance pattern was performed by Kirby-Bauer method. Polymerase chain reaction was done using primer pairs to identify common serogroups of uropathogenic E.coli and studying virulence genes in isolations creating biofilm.

RESULTS

Among 130 E.coli isolates, 80 (61.53 %) were able to make biofilm that 15 isolates (18.75 %) indicated strong reaction, 20 (25 %) of medium and 45 (56.25 %) of weak biofilm reaction. Among isolations creating biofilm, the highest resistance reported to Ampicillin (87.5 %) and the lowest to Nitrofurantoin (3.75 %). The frequency of fimH, pap, sfa and afa genes in isolations having the ability to create strong biofilm reported 93.33 %, 86.66 %, 86.66 % and 66.66 %, respectively.

CONCLUSIONS

The findings indicated the importance of virulence genes in serogroups producing uropathogenic E.coli biofilm. It is recommended that strains producing biofilm before antibiotic use should be studied.

Determination of urinary coenzyme Q10 by HPLC with electrochemical detection: Reference values for a paediatric population

Kidney dysfunction is being increasingly associated with mitochondrial diseases and coenzyme Q10 (CoQ) deficiency. The assessment of CoQ status requires the biochemical determination of CoQ in biological fluids and different cell types, but no methods have been developed as yet for the analysis of CoQ in excretory systems. The aim of this study was to standardize a new procedure for urinary CoQ determination and to establish reference values for a paediatric population. Urinary CoQ was analyzed by HPLC with electrochemical detection. Reference values (n = 43) were stratified into two age groups (2-10 years: range 24-109 nmol CoQ/gram of pellet protein; 11-17 years: range 43-139 nmol CoQ/gram of pellet protein). In conclusion, urinary CoQ analysis is a noninvasive, reliable, and reproducible method to determine urinary tract CoQ status.

Rapid identification and susceptibility testing of uropathogenic microbes via immunosorbent ATP-bioluminescence assay on a microfluidic simulator for antibiotic therapy

The incorporation of pathogen identification with antimicrobial susceptibility testing (AST) was implemented on a concept microfluidic simulator, which is well suited for personalizing antibiotic treatment of urinary tract infections (UTIs). The microfluidic device employs a fiberglass membrane sandwiched between two polypropylene components, with capture antibodies immobilized on the membrane. The chambers in the microfluidic device share the same geometric distribution as the wells in a standard 384-well microplate, resulting in compatibility with common microplate readers. Thirteen types of common uropathogenic microbes were selected as the analytes in this study. The microbes can be specifically captured by various capture antibodies and then quantified via an ATP bioluminescence assay (ATP-BLA) either directly or after a variety of follow-up tests, including urine culture, antibiotic treatment, and personalized antibiotic therapy simulation. Owing to the design of the microfluidic device, as well as the antibody specificity and the ATP-BLA sensitivity, the simulator was proven to be able to identify UTI pathogen species in artificial urine samples within 20 min and to reliably and simultaneously verify the antiseptic effects of eight antibiotic drugs within 3-6 h. The measurement range of the device spreads from 1 × 10(3) to 1 × 10(5) cells/mL in urine samples. We envision that the medical simulator might be broadly employed in UTI treatment and could serve as a model for the diagnosis and treatment of other diseases.

A capacitive touch screen sensor for detection of urinary tract infections in portable biomedical devices

Incidence of urinary tract infections (UTIs) is the second highest among all infections; thus, there is a high demand for bacteriuria detection. Escherichia coli are the main cause of UTIs, with microscopy methods and urine culture being the detection standard of these bacteria. However, the urine sampling and analysis required for these methods can be both time-consuming and complex. This work proposes a capacitive touch screen sensor (CTSS) concept as feasible alternative for a portable UTI detection device. Finite element method (FEM) simulations were conducted with a CTSS model. An exponential response of the model to increasing amounts of E. coli and liquid samples was observed. A measurable capacitance change due to E. coli presence and a tangible difference in the response given to urine and water samples were also detected. Preliminary experimental studies were also conducted on a commercial CTSS using liquid solutions with increasing amounts of dissolved ions. The CTSS was capable of distinguishing different volumes of liquids, also giving an exponential response. Furthermore, the CTSS gave higher responses to solutions with a superior amount of ions. Urine samples gave the top response among tested liquids. Thus, the CTSS showed the capability to differentiate solutions by their ionic content.

Diagnostic accuracy of uriSed automated urine microscopic sediment analyzer and dipstick parameters in predicting urine culture test results

Introduction

Urinary tract infection (UTI) is one of the most common types of infection. Currently, diagnosis is primarily based on microbiologic culture, which is time- and labor-consuming. The aim of this study was to assess the diagnostic accuracy of urinalysis results from UriSed (77 Electronica, Budapest, Hungary), an automated microscopic image-based sediment analyzer, in predicting positive urine cultures.

Materials and methods:

We examined a total of 384 urine specimens from hospitalized patients and outpatients attending our hospital on the same day for urinalysis, dipstick tests and semi-quantitative urine culture. The urinalysis results were compared with those of conventional semi-quantitative urine culture.

Results:

Of 384 urinary specimens, 68 were positive for bacteriuria by culture, and were thus considered true positives. Comparison of these results with those obtained from the UriSed analyzer indicated that the analyzer had a specificity of 91.1%, a sensitivity of 47.0%, a positive predictive value (PPV) of 53.3% (95% confidence interval (CI) = 40.8–65.3), and a negative predictive value (NPV) of 88.8% (95% Cl = 85.0–91.8%). The accuracy was 83.3% when the urine leukocyte parameter was used, 76.8% when bacteriuria analysis of urinary sediment was used, and 85.1% when the bacteriuria and leukocyturia parameters were combined. The presence of nitrite was the best indicator of culture positivity (99.3% specificity) but had a negative likelihood ratio of 0.7, indicating that it was not a reliable clinical test.

Conclusions:

Although the specificity of the UriSed analyzer was within acceptable limits, the sensitivity value was low. Thus, UriSed urinalysis results do not accurately predict the outcome of culture.

In vitro biofilm formation by uropathogenic Escherichia coli and their antimicrobial susceptibility pattern

OBJECTIVE

To detect in vitro biofilm formation of uropathogenic Escherichia coli (E. coli) (UPEC) strains isolated from urine specimens and also to determine their antimicrobial susceptibility pattern using 13 commonly used antibiotics.

METHODS

The present study comprised of 166 urine specimens collected from tertiary care hospitals in and around Coimbatore, South India. All the specimens were subjected to gram staining, bacterial culture and the E. coli strains were screened for biofilm formation using Tube Method (TM), Congo Red Agar (CRA) and Tissue Culture Plate method (TCP) respectively. Subsequently, the antimicrobial susceptibility test was performed by Kirby Bauer-disk diffusion method for the biofilm and non-biofilm producing E. coli strains.

RESULTS

Of the 100 (60.2 %) E. coli strains, 72 strains displayed a biofilm positive phenotype under the optimized conditions in the Tube Method and the strains were classified as highly positive (17, 23.6%), moderate positive (19, 26.3 %) and weakly positive (36, 50.0 %), similarly under the optimized conditions on Congo Red agar medium, biofilm positive phenotype strains were classified as highly positive (23, 23 %), moderate positive (37, 37 %) and weakly positive (40, 40%). While in TCP method, the biofilm positive phenotype strains were also classified as highly positive (6, 6 %), moderate positive (80, 80 %) and weakly positive (14, 14 %), it didn't not correlate well with the tube method for detecting biofilm formation in E. coli. The rates of antibiotic resistance of biofilm producing E. coli were found to be 100 % for chloramphenicol and amoxyclav (amoxicillin and clavulanic acid), 86% for gentamicin and cefotaxime, 84% for ceftazidime, 83% for cotrimoxazole and piperacillin/tazobactam, 75% for tetracycline and 70% for amikacin.

CONCLUSIONS

This study reveals the prevalence and antimicrobial susceptibility pattern of biofilm and non-biofilm producing uropathogenic E. coli strains.

UF-1000i flow cytometry is an effective screening method for urine specimens

This study was undertaken to evaluate the UF-1000i™ (UF) flow cytometer to count urine constituents including bacteria. The objective was to screen urine samples and determine what white blood cell (WBC) and/or bacteria screening criteria would minimize the number of specimens cultured yet ensuring that all true positives were cultured. UF screening and culture on CHROMagar™ Orientation (CO) medium were performed on 2496 specimens. Various combinations of WBC/bacterial counts were assessed as screening criteria and correlated with significant growth on CO medium. A bacterial count of ≥20 from UF gave an overall screening sensitivity of 92.6%, allowing 35% of specimens to be screened out and not cultured. The sensitivity was 99.2% and 85.0% for Gram-negative and Gram-positive organisms, respectively, using the same bacterial count. Our study indicated that UF was a simple, rapid, and reliable method for urine screening when the bacterial count of ≥20 was used as the sole screening criterion.

Antimicrobial management and appropriateness of treatment of urinary tract infection in general practice in Ireland

Background

Urinary tract infections (UTIs) are the second most common bacterial infections in general practice and a frequent indication for prescription of antimicrobials. Increasing concern about the association between the use of antimicrobials and acquired antimicrobial resistance has highlighted the need for rational pharmacotherapy of common infections in general practice.

Methods

Management of urinary tract infections in general practice was studied prospectively over 8 weeks. Patients presenting with suspected UTI submitted a urine sample and were enrolled with an opt-out methodology. Data were collected on demographic variables, previous antimicrobial use and urine samples. Appropriateness of different treatment scenarios was assessed by comparing treatment with the laboratory report of the urine sample.

Results

A total of 22 practices participated in the study and included 866 patients. Bacteriuria was established for 21% of the patients, pyuria without bacteriuria for 9% and 70% showed no laboratory evidence of UTI. An antimicrobial agent was prescribed to 56% (481) of the patients, of whom 33% had an isolate, 11% with pyuria only and 56% without laboratory evidence of UTI. When taking all patients into account, 14% patients had an isolate identified and were prescribed an antimicrobial to which the isolate was susceptible. The agents most commonly prescribed for UTI were co-amoxyclav (33%), trimethoprim (26%) and fluoroquinolones (17%). Variation between practices in antimicrobial prescribing as well as in their preference for certain antimicrobials, was observed. Treatment as prescribed by the GP was interpreted as appropriate for 55% of the patients. Three different treatment scenarios were simulated, i.e. if all patients who received an antimicrobial were treated with nitrofurantoin, trimethoprim or ciprofloxacin only. Treatment as prescribed by the GP was no more effective than treatment with nitrofurantoin for all patients given an antimicrobial or treatment with ciprofloxacin in all patients. Prescribing cost was lower for nitrofurantoin. Empirical treatment of all patients with trimethoprim only was less effective due to the higher resistance levels.

Conclusions

There appears to be considerable scope to reduce the frequency and increase the quality of antimicrobial prescribing for patients with suspected UTI.

Midregional proadrenomedullin as a prognostic tool in community-acquired pneumonia

BACKGROUND

Midregional proadrenomedullin (MR-proADM) is a potential prognostic biomarker in patients with community-acquired pneumonia (CAP). Previous work has been hampered by sample size and illness spectrum limits. We sought to describe the pattern of MR-proADM in a broad CAP cohort, confirm its prognostic role, and compare its performance to procalcitonin, a novel biomarker of infection.

METHODS

We conducted a multicenter prospective cohort study in 28 community and teaching EDs. Patients with a clinical and radiographic diagnosis of CAP were enrolled. We stratified MR-proADM levels a priori into quartiles and quantified severity of illness using the pneumonia severity index (PSI); and confusion (abbreviated mental test score of <or= 8), urea >or= 7 mmol/L, respiratory rate >or= 30 breaths/min, BP < 90 mm Hg systolic or < 60 mm Hg diastolic, age >or= 65 years (CURB-65). The primary outcome was 30-day mortality.

RESULTS

A total of 1,653 patients formed the study cohort. MR-proADM levels consistently rose with PSI class and 30-day mortality (p < 0.001). MR-proADM had a higher area under the curve for 30-day mortality than procalcitonin (0.76 vs 0.65, respectively; p < 0.001), but adding MR-proADM to the PSI in all subjects minimally improved performance. Among low-risk subjects (PSI classes I to III), mortality was low and did not differ by MR-proADM quartile. However, among high-risk subjects (PSI class IV/V; n = 546), subjects in the highest MR-proADM quartile (n = 232; 42%) had higher 30-day mortality than those in MR-proADM quartiles 1 to 3 (23% vs 9%, respectively; p < 0.0001). Similar results were seen with CURB-65. MR-proADM and procalcitonin levels were generally concordant; only 6% of PSI class IV/V subjects in the highest MR-proADM quartile had very low procalcitonin levels (< 0.1 ng/mL).

CONCLUSIONS

In our multicenter CAP cohort, MR-proADM levels correlate with increasing severity of illness and death. High MR-proADM levels offer additional risk stratification in high-risk CAP patients, but otherwise MR-proADM levels do not alter PSI-based risk assessment in most CAP patients.

Optimizing the diagnostic work-up of acute uncomplicated urinary tract infections

BACKGROUND

Most diagnostic tests for acute uncomplicated urinary tract infections (UTIs) have been previously studied in so-called single-test evaluations. In practice, however, clinicians use more than one test in the diagnostic work-up. Since test results carry overlapping information, results from single-test studies may be confounded. The primary objective of the Amsterdam Cystitis/Urinary Tract Infection Study (ACUTIS) is to determine the (additional) diagnostic value of relevant tests from patient history and laboratory investigations, taking into account their mutual dependencies. Consequently, after suitable validation, an easy to use, multivariable diagnostic rule (clinical index) will be derived.

METHODS

Women who contact their GP with painful and/or frequent micturition undergo a series of possibly relevant tests, consisting of patient history questions and laboratory investigations. Using urine culture as the reference standard, two multivariable models (diagnostic indices) will be generated: a model which assumes that patients attend the GP surgery and a model based on telephone contact only. Models will be made more robust using the bootstrap. Discrimination will be visualized in high resolution histograms of the posterior UTI probabilities and summarized as 5th, 10th, 25th 50th, 75th, 90th, and 95th centiles of these, Brier score and the area under the receiver operating characteristics curve (ROC) with 95% confidence intervals. Using the regression coefficients of the independent diagnostic indicators, a diagnostic rule will be derived, consisting of an efficient set of tests and their diagnostic values. The course of the presenting complaints is studied using 7-day patient diaries. To learn more about the natural history of UTIs, patients will be offered the opportunity to postpone the use of antibiotics.

DISCUSSION

We expect that our diagnostic rule will allow efficient diagnosis of UTIs, necessitating the collection of diagnostic indicators with proven added value. GPs may use the rule (preferably after suitable validation) to estimate UTI probabilities for women with different combinations of test results. Finally, in a subcohort, an attempt is made to identify which indicators (including antibiotic treatment) are useful to prognosticate recovery from painful and/or frequent micturition.

[Prevalence and bacterial susceptibility of community acquired urinary tract infection in University Hospital of Brasília, 2001 to 2005]

Urinary tract infection is among the most common infectious diseases in clinical medicine, and knowledge of its epidemiology and the sensitivity profile of the etiological agents is mandatory. The aim of this study was to identify the most frequent etiological agents and the profile of sensitivity to antimicrobial agents of the bacteria isolated from urine cultures from outpatients at the University Hospital of Brasília between 2001 and 2005. From analyses at the hospitals microbiology laboratory, there were 2,433 positive urine cultures. Escherichia coli was the most commonly isolated bacteria (62.4%), followed by Klebsiella pneumoniae (6.8%) and Proteus mirabilis (4.7%). Escherichia coli showed the highest sensitivity to amikacin (98.6%), gentamicin (96.2%), nitrofurantoin (96.3%) and the quinolones ciprofloxacin (90.9%) and norfloxacin (89.8%), with low sensitivity to sulfamethoxazole-trimethoprim (50.6%). The others bacteria presented similar sensitivity profiles. In conclusion, Escherichia coli was the most commonly isolated bacteria, and it was highly sensitive to aminoglycosides, nitrofurantoin and quinolones.

Risk prediction with procalcitonin and clinical rules in community-acquired pneumonia

STUDY OBJECTIVE

The Pneumonia Severity Index and CURB-65 predict outcomes in community-acquired pneumonia but have limitations. Procalcitonin, a biomarker of bacterial infection, may provide prognostic information in community-acquired pneumonia. Our objective is to describe the pattern of procalcitonin in community-acquired pneumonia and determine whether procalcitonin provides prognostic information beyond the Pneumonia Severity Index and CURB-65.

METHODS

We conducted a multicenter prospective cohort study in 28 community and teaching emergency departments. Patients presenting with a clinical and radiographic diagnosis of community-acquired pneumonia were enrolled. We stratified procalcitonin levels a priori into 4 tiers: I: less than 0.1; II: greater than 0.1 to less than 0.25; III: greater than 0.25 to less than 0.5; and IV: greater than 0.5 ng/mL. Primary outcome was 30-day mortality.

RESULTS

One thousand six hundred fifty-one patients formed the study cohort. Procalcitonin levels were broadly spread across tiers: 32.8% (I), 21.6% (II), 10.2% (III), and 35.4% (IV). Used alone, procalcitonin had modest test characteristics: specificity (35%), sensitivity (92%), positive likelihood ratio (1.41), and negative likelihood ratio (0.22). Adding procalcitonin to the Pneumonia Severity Index in all subjects minimally improved performance. Adding procalcitonin to low-risk Pneumonia Severity Index subjects (classes I to III) provided no additional information. However, subjects in procalcitonin tier I had low 30-day mortality, regardless of clinical risk, including those in higher risk classes (1.5% versus 1.6% for those in Pneumonia Severity Index classes I to III versus classes IV/V). Among high-risk Pneumonia Severity Index subjects (classes IV/V), one quarter (126/546) were in procalcitonin tier I, and the negative likelihood ratio of procalcitonin tier I was 0.09. Procalcitonin tier I was also associated with lower burden of other adverse outcomes. Similar results were observed with CURB-65 stratification.

CONCLUSION

Selective use of procalcitonin as an adjunct to existing rules may offer additional prognostic information in high-risk patients.

Significant bacteriuria in outpatient diabetic and non-diabetic persons

AIMS

The prevalence of significant bacteriuria (SB) in diabetes mellitus has not been clearly established. Having previously investigated SB frequency in inpatient diabetic women, we now screened for SB (both asymptomatic and symptomatic forms) in outpatients.

METHODS

We examined 511 consecutive outpatients with Type 1 (T1D) or Type 2 diabetes (T2D), and 98 non-diabetic subjects. At least one uncontaminated midstream urine sample was available from 602 subjects: 64 T1D (37 female, age 49 +/- 13 years, diabetes duration 23 +/- 15 years), 441 T2D (212 female, 66 +/- 10 years, 12 +/- 10 years), and 97 healthy control subjects (39 female, 57 +/- 12 years). On the same day, we determined: blood cell count, fasting plasma glucose (FPG), glycated haemoglobin (HbA(1c)), plasma creatinine, urinary creatinine, and urinary albumin excretion (UAE; microg/mg urinary creatinine).

RESULTS

The rate of SB was 14.1% in T1D, 9.3% in T2D and 6.2% in control subjects (P = NS). The 50 diabetic patients with SB differed from the 455 diabetic patients without SB in gender (43 male vs. 206 female, P < 0.001), FPG (10.2 +/- 3.6 vs. 9.2 +/- 2.9 mmol/l, P < 0.05), HbA(1c) (7.8 +/- 1.1 vs. 7.5 +/- 1.3%, P < 0.05), and UAE (median 15.6 vs. 7.6 microg/mg, P < 0.01). Eleven diabetic patients with SB had symptoms (vs. 48 without SB, P < 0.05); UAE levels were higher in the 39 asymptomatic diabetic patients with SB than in the 11 symptomatic patients.

CONCLUSIONS

The prevalence of SB is similar in outpatient diabetic individuals and in non-diabetic subjects. The main risk factors for SB in diabetic patients were female gender and UAE. The likelihood of asymptomatic SB increased with UAE levels, i.e. with the presence of established microangiopathy. Poor glycaemic control is associated with bacteriuria, either as a cause or consequence of bacteriuria.

Uropathogenic Escherichia coli dominantly suppress the innate immune response of bladder epithelial cells by a lipopolysaccharide- and Toll-like receptor 4-independent pathway

Urinary tract infections are a major source of morbidity among women, with the majority caused by uropathogenic Escherichia coli. Our objective was to test if uropathogenic E. coli suppress the innate immune response of bladder epithelial cells. We found that bladder epithelial cells secrete interleukin-6 and interleukin-8 in response to non-pathogenic E. coli, whereas they failed to do so in response to uropathogenic E. coli. Uropathogenic E. coli prevented interleukin-6 secretion in response to non-pathogenic E. coli and a panel of Toll-like receptor agonists, as well as to interleukin-1beta, but not to tumor necrosis factor alpha. These results indicate that receptors with a Toll/interleukin-1 receptor domain are specifically targeted, and that suppression is not a consequence of toxicity. One candidate for mediating immune suppression is bacterial lipopolysaccharide. However, lipopolysaccharide isolated from either uropathogenic or non-pathogenic E. coli stimulated interleukin-6 secretion to similar levels. In addition, uropathogenic E. coli did not stimulate interleukin-6 secretion from cells expressing a dominant negative Toll-like receptor 4, and prevented cells lacking Toll-like receptor 4 from secreting interleukin-6 in response to synthetic lipoprotein. We conclude that uropathogenic E. coli suppress the innate immune response through a pathway partially independent of lipopolysaccharide and Toll-like receptor 4.

[Influence of non-complicated urinary tract infection on renal relapses in proliferative lupus nephritis]

OBJECTIVE

In patients with proliferative lupus nephritis treated with IV cyclophosphamide, analyze urinary tract infection (UTI) as a cause of treatment delay and renal relapses, compared with lupus nephritis patients without infection.

PATIENTS AND METHODS

We studied SLE patients (ACR criteria) with renal biopsy showing nephritis class IV. All patients received monthly intravenous cyclophosphamide (CYC) treatment during 6 months. Thereafter patients were assigned to 2 groups: patients who developed UTI, and those who did not; renal function tests, UTI and renal relapses were bimonthly evaluated during one year (follow-up period). To analyze data, t student test, χ(2), Fisher exact (when appropiate), and bivariate analysis, were performed.

RESULTS

We studied 50 patients, 25 with UTI (Group I) and 25 without UTI (G-II).The mean age was 30.07 ± 8.15 years, 82% were female. E. coli was the pathogen most frequently isolated (73%). UTI (G-I) was the cause for treatment delay in 19 cases (76%), compared with 3 patients (12%) in G-II whose treatment was delayed because of some other causes (severe leucopenya, hypersensibility and gastrointestinal side effects) (OR 23.22, 95% CI, 5.26-105.1; P=001). During the follow up, 90.9% of patients in G-I reached partial or complete renal remission within 3 months, but only 35% mantained remission after the year of follow up. Meanwhile, patients in G-II had complet and partial renal remission of 85% and 63%, respectively. In the first group we observed persistent albuminuria (P<05), low complement levels and high ab-dsDNA titers. Renal flares were present in 18 patients in G-I and 9 in G-II.

CONCLUSIONS

UTI in lupus nephritis patients has a negative impact. It leads to delayed CYC therapy and to a higher renal flare rate.

The use of urinary dipstick tests to exclude urinary tract infection: a systematic review of the literature

Several systematic reviews have examined the use of dipstick tests to diagnose or rule in urinary tract infection (UTI). We examined the evidence relating to the use of urine leukocyte esterase and nitrite tests in adults to exclude or rule out UTI. A search of the literature from 1966 to 2003 revealed 30 studies as containing relevant and suitable information and 23 of these, which used a cut-off of 108 colony-forming units per liter, were combined in a meta-analysis. The leukocyte esterase or nitrite test combination, with one or the other test positive, was used in 14 studies, showed the highest sensitivity and the lowest negative likelihood ratio. While there was significant heterogeneity between the studies, 7 of 14 demonstrated significant decreases in pretest to posttest probability with a pooled posttest probability of 5% for the negative result. In certain circumstances, there is evidence for the use of urinalysis as a rule-out test for UTI.

Demonstration of regulatory cross-talk between P fimbriae and type 1 fimbriae in uropathogenic Escherichia coli

The majority of Escherichia coli strains isolated from urinary tract infections have the potential to express multiple fimbriae. Two of the most common fimbrial adhesins are type 1 fimbriae and pyelonephritis-associated pili (Pap). Previous research has shown that induced, plasmid-based expression of a Pap regulator, papB, and its close homologues can prevent inversion of the fim switch controlling the expression of type 1 fimbriae. The aim of the present study was to determine if this cross-regulation occurs when PapB is expressed from its native promoter in the chromosome of E. coli K-12 and clinical isolates. The regulation was examined in three ways: (1) mutated alleles of the pap regulatory region, including papB and papI, that maintain the pap promoter in either the off or the on phase were exchanged into the chromosome of both E. coli K-12 and the clinical isolate E. coli CFT073, and the effect on type 1 fimbrial expression was measured; (2) type 1 fimbrial expression was determined using a novel fimS : : gfp(+) reporter system in mutants of the clinical isolate E. coli 536 in which combinations of complete fimbrial clusters had been deleted; (3) type 1 fimbrial expression was determined in a range of clinical isolates and compared with both the number of P clusters and their expression. All three approaches demonstrated that P expression represses type 1 fimbrial expression. Using a number of novel genetic approaches, this work extends the initial finding that PapB inhibits FimB recombination to the impact of this regulation in clinical isolates.

Testing by Sysmex UF-100 flow cytometer and with bacterial culture in a diagnostic laboratory: a comparison

A large proportion of the samples tested in routine diagnostic microbiology laboratory are urine samples. The gold standard is bacterial culture, but a high proportion of samples cultured are negative. Unnecessary testing can be reduced and an improved service provided by an effective screening test. The Sysmex UF-100 flow cytometer has been developed to count cells and casts accurately in urine samples. Its performance in a screening test was compared with bacterial culture by using 1005 consecutive urine samples, and cut-off criteria were established. Cut-off values of 3000 bacteria/microl and 111 WBC/microl provided the best discrimination. Of 1005 samples, 606 (60%) would be cultured. Sixteen samples that were not selected according to these criteria were culture positive. This was considered acceptable for our routine use. The use of a testing algorithm incorporating the Sysmex UF-100 flow cytometer has improved the quality and efficiency of urine testing within the routine microbiology laboratory.

Are true-negative nitrite results affected by a two-hour delay in dipstick/pad analysis of urine in incontinence pads?

OBJECTIVES

To determine if true-negative nitrite results of a urine dipstick pressed into an incontinence pad (dipstick/pad method) are affected by a 2-hour delay in analysis.

DESIGN

A quantitative study.

SETTING AND SUBJECTS

Clean-catch urine specimens from a convenience sample of clinic patients, staff, and long-term care facility residents.

INSTRUMENT

Changes from negative to positive for each group of urine specimens were evaluated using percentages within the groups.

METHODS

Urine specimens were collected and a portion was cultured. Urine specimens negative for a urinary tract infection were included in the study. A portion of the specimen was poured into an incontinence pad. Initial nitrite results were determined using a dipstick pressed into an incontinence pad. Pads with true-negative dipstick/pad nitrite results were tested 2 hours later in the same manner. Urine culture results determined groups: mixed colonies; 50,000 to 75,000 colony-forming units per milliliter of a single type of uropathogen; greater than or equal to 50,000 cfu/mL diphtheroids; no significant growth; and no growth.

RESULTS

Of the 443 urine cultures negative for a urinary tract infection, 441 initial dipstick/pad nitrite results were negative. Two initial true-negative nitrite dipstick/pad results, or 0.5%, changed from negative to positive over the 2-hour period: 1 in the "mixed colonies" group (0.4%) and 1 in the "no growth" group (0.7%).

CONCLUSIONS

Results of this study indicate that true-negative nitrite results of a dipstick pressed into urine in an incontinence pad do not appear to be affected by a 2-hour delay in analysis.