Urinary Tract Infections

Prevalence and antimicrobial resistance profile of pathogens isolated from patients with urine tract infections admitted to a university hospital in a medium-sized Brazilian city

This study aimed to determine the antibiotic profile of microorganisms isolated from urine samples of patients with community urine tract infections (UTI) admitted to the University Hospital of the Federal University of Sao Carlos to support an appropriate local empirical treatment. A retrospective cross-sectional study was conducted from October 2018 to October 2020. Data from 1,528 positive urine cultures for bacterial pathogens and antibiograms were tabulated. Bacterial species prevalence and their resistance profile were analyzed and compared by sex and age. For Gram-negative fermenting bacteria, resistance rates were compared between patients with previous hospitalization and the total of infections caused by this group. For comparisons, the Chi-square test was performed, using Fisher's exact test when necessary (BioEstat program, adopting p ≤ 0.05). A multivariate analysis was applied to assess the effect of the studied variables in predicting multidrug resistance. Infections were more prevalent in women and older adults. Gram-negative bacteria represented 90.44% of total cultures. In both sexes, E. coli prevalence was significantly higher in adults compared with older adults (p < 0.0001). For several antibiotics, resistance rates were higher in the older adults compared with other ages and in patients with Gram-negative fermenting infections and previous hospitalization compared with the total of infections by this group of bacteria. The closer to the hospitalization, the higher the number of antibiotics with superior resistance rates. Resistance rates for aminoglycosides, carbapenems, ceftazidime, nitrofurantoin, piperacillin+tazobactam, and fosfomycin were less than 20%, considered adequate for empirical treatment. Only hospitalization in the previous 90 days was statistically significant in predicting infections by multidrug-resistant bacteria.

The diagnostic performances of the Atellica® 1500 automated urinalysis system for ruling out bacterial urinary tract infection

Urinary tract infection (UTI) is one of the most common diseases occurring in both hospitalized and community subjects. Urine culture is the gold standard test for the diagnosis of UTI, but approximately 80% are negative. The aim of this study was to evaluate the performance of the automated urinalysis system Atellica® 1500 (Siemens Healthineers, Erlangen, Germany) as screening tool for ruling out UTI. A total of 5,490 urine specimens from outpatients, that had simultaneous requests for urinalysis and urine culture, were evaluated. Of the 5,490 samples, 833 (15.2 %) resulted positive for urine culture. Among UTI-related parameters, bacterial count was considered the most apt to be diagnostic of subjects affected by UTI. Using a cutoff value for bacteria count equal to 180 elements/µL, Atellica® 1500 detected bacteriuria with diagnostic sensitivity (Se) of 88.1 %, diagnostic specificity (Sp) of 82.1 %, and negative predictive value (NPV) of 95.2 %. Comparing our results with the literature's data, we observed that our Se and NPV were lower, while our Sp was higher. Our data showed that the Atellica® 1500 system detected bacteria with satisfactory analytical performance, but the results obtained do not make it a reliable tool for excluding UTI with urinalysis.

Clinical features of acute focal bacterial nephritis in adults

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidneys presenting as an inflammatory mass that can develop into renal abscess. The current reports on AFBN mostly are among children and rarely described in adults. This study was aimed to analyze the clinical features of AFBN in adults and make a review for the disease to give the clinicians some clues to suspect and recognize it in adults. From January 2014 to December 2019, AFBN was diagnosed by contrast-enhanced computed tomography (CT) in 238 adults at the Department of Nephrology, the Second Hospital of Hebei Medical University, Shijiazhuang, China. We reviewed the clinical records of these patients and asked them about their post-discharge status via telephone follow-up. Of all the patients, 195 were female and 43 were male, the median age were 46.87 years. 86.13% presented with fever, 55.89% presented with lower urinary tract symptoms and 97.9% presented with pyuria. In renal ultrasonography, abdominal findings were seen only 22.69% patients. E.coli accounted for 74.73% of the isolated pathogen. After 4 weeks of treatment, the patients had no recurrence of symptoms. We recommend that when a patient presents clinically with acute pyelonephritis, but the fever persist longer after antimicrobial treatment (≥ 4 days in our study), AFBN should be suspected. For the diagnosis, contrast-enhanced CT is the “gold standard”, magnetic resonance imaging (MRI) may be a good option, but the ultrasonography is probably not satisfied. 3–4 weeks of antibiotic therapy may be appropriate for AFBN in adults.

Lower serum levels of vitamin D in adults with urinary tract infection

PURPOSE

We aimed to explore the association between urinary tract infection (UTI) in adults and serum 25-hydroxyvitamin D (25OHD), which was used to access vitamin D status.

METHODS

Serum levels of 25OHD were retrospectively analyzed in 234 subjects (190 females and 44 males): 120 UTI patients (females = 103) and 114 age- and sex-matched healthy controls (females = 87). Serum 25OHD concentrations were categorized as follows: (1) < 20 ng/mL, 20 to < 30 ng/mL, and ≥ 30 ng/mL; (2) < 20 ng/mL and ≥ 20 ng/mL.

RESULTS

Serum 25OHD levels were lower in patients with UTI (p < 0.01). Women with UTI presented significantly lower 25OHD concentrations than those without UTI (p < 0.01). No association between serum 25OHD levels and UTI in men was found (p > 0.05). The multivariable logistic regression models showed significant associations between UTI and 25OHD, female sex, neutrophilic lymphocyte ratio and C-reactive protein (p < 0.05).

CONCLUSION

Lower 25OHD concentrations associated with UTI were most prominent among women. The associations between UTI and low serum 25OHD levels as well as female sex were independent of each other.

Examining GP online consultation in a primary care setting in east midlands, UK

Background

Increasing pressure threatens to overwhelm primary care services, affecting the quality of care and their role as gatekeepers to specialised care services. This study investigated healthcare users’ acceptability of – and the effectiveness of – an e-consultation system in primary care services.

Methods

Seven GP practices in East-Midlands, all of whom use online consultation system participated in the study, with a retrospective review being undertaken of 189 electronic patients’ records (age range of 18–76 years) over 5 months. The focus was on the electronic records of patients who accessed the service for five different conditions identified as presenting common conditions seen by the GPs practices. Statistical analysis was done using SPSS to perform an exploratory data analysis and descriptive statistics.

Results

The results showed a positive reception of the online consultation platform, with an average satisfaction score of 4.15 (most likely to recommend score = 5). Given the nature of the conditions, 47.6% of patients had experienced a previous episode of the health condition they were seeking consultation for, and a total of 72% had existing comorbidities. Follow-up activity occurred for 87.3% of patients, 66.1% of which included at least one follow-up visit for the same condition as the initial online consultation.

Conclusion

The results suggest that online consultation is convenient for patients, and it also has the potential to relieve pressure placed on primary care services. Although a number of challenges were identified, such as patient verification, this study gives insight into – and enhances our understanding of – the use of online GP consultations.

Derivatives of 1,2,4-triazole imines acting as dual iNOS and tumor cell growth inhibitors

A set of 4-(R₂-imino)-3-mercapto-5-(R₁)-4H-1,2,4-triazoles derivatives were synthesized, characterized and evaluated for their ability to inhibit nitric oxide (NO) production in PAM212 mouse keratinocytes, which led to the discovery and the subsequent evaluation of their growth inhibitory cytotoxic potency toward that same mouse cell line together with a number of human cells lines (PC3, HT-29 and HeLa). Some limited SAR could be established for both NO production inhibition potency and growth inhibition cytotoxicity. Noticeably, the compounds designed to be nitrofurantoin mimics were the most potent anti-neoplastic agents.

Microbial Resistance in Urinary Tract Infections

Objective

To determine the pattern of microbes responsible for urinary tract infections and their susceptibility to antimicrobial agents.

Methods

This was a prospective, observational study conducted at Benazir Bhutto Hospital, Rawalpindi, Pakistan. The urine samples of 440 patients were collected and sent for culture and sensitivity analysis. The results were recorded on a proforma. The data were analyzed using IBM Statistical Package for Social Sciences (SPSS) version 22 (IBM Corp., Armonk, NY). Descriptive statistics were used to describe the data. Chi-square test was applied to determine the significance of the difference between gender and microorganisms as well as microorganism and antimicrobial sensitivity. P-value of less than 0.05 was considered significant.

Results

Out of 440 urine samples, 144 culture-positive samples had been obtained from male participants and 296 culture-positive samples had been obtained from female participants. The most common organism on analysis was Escherichia coli. There were more rates of resistance in males. The organisms were most susceptible to fosfomycin and imipenem (p = 0.01). The organisms were resistant to ceftazidime (p = 0.01).

Conclusion

In Pakistan, most patients with resistance present with mild symptoms instead of severe clinical manifestations. Therefore, there is a need to reduce the over-prescription of antibiotics for urinary tract infections, especially in cases when other non-antimicrobial agents can be used.

To reveal pharmacological targets and molecular mechanisms of curcumol against interstitial cystitis

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A PPI network showing protein interaction was produced.

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3 top biotargets of curcumol against IC were identified.

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Human IC sections showed increased PTK2, p-PTK2^Tyr397 expressions.

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Curcumol-treated IC mice benefited reduced PTK2, p-PTK2^Tyr397 expressions.

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PTK2 may be a potential biomarker for screening and treating IC.

This study was designed to reveal the predictive targets and biological mechanisms of curcumol against interstitial cystitis (IC). By use of available databases and bioinformatic assays, pathogenetic targets of IC and functional targets of curcumol were identified respectively. A network of functional protein-protein interaction (PPI) was produced before screening the main predictive targets, biological processes and signaling pathways of curcumol against IC. In bioinformatic findings, the data of ingenuity pathway analysis (IPA) delineated that curcumol exerted anti-IC benefits through regulating multipronged signaling pathways, including tyrosine protein kinase-2 (PTK2) pathway. Further, optimal 18 biotargets of curcumol against IC were harvested through differential expression analysis. And the predictive targets of receptor tyrosine-protein kinase erbB-2 (ERBB2), epidermal growth factor receptor (EGFR) and PTK2 were the most important molecules. In further validated experiments, PTK2 and phosphorylation PTK2 (p-PTK2) were representatively selected for testing by human and animal IC samples. As results, increased immunoreactive proteins of tumor necrosis factor alpha (TNF-α), PTK2 and p-PTK2^Tyr397 in human IC sections were observed, accompanied with altered urinary parameters. Interestingly, curcumol-treated IC mice showed that intracellular expressions of PTK2, p-PTK2^Tyr397 in bladder samples were reduced, accompanied with lowered blood inflammatory cytokines of interleukin 6 (IL-6), TNF-α. In conclusion, the current bioinformatic data and preliminary findings unravel that the predominant targets of curcumol against IC may be the potential biological markers for screening and treating IC, such as PTK2 molecule.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

Escherichia coli bacteriophage Gostya9, representing a new species within the genus T5virus

Escherichia coli bacteriophage Gostya9 (genus T5virus) was isolated from horse feces collected in Moscow, Russia, in 2013. This phage was associated in a single plaque with the previously reported phage 9g and was subsequently purified. Analysis of the complete genomic sequence of Gostya9 revealed that it is closely related to the T5-like bacteriophage DT57C, which had been isolated at the same location in 2007. These two viruses share 79.5% nucleotide sequence identity, which is below the 95% threshold applied currently to demarcate bacteriophage species. The most significant features distinguishing Gostya9 from DT57C include 1) the presence of one long tail fiber protein gene, 122c (ltf), instead of the two genes, ltfA and ltfB, that are present in DT57C; 2) the absence of the gene for the receptor-blocking lytic conversion lipoprotein precursor llp; and 3) the divergence of the receptor-recognition protein, pb5, which is only distantly related at the amino acid sequence level. The observed features of the Gostya9 adsorption apparatus are suggestive of a possible novel specificity for the final receptor and make this phage interesting for possible direct application in phage therapy of E. coli infections or as a source of receptor-recognition protein for engineering new phage specificities.

Modulation of antimicrobial resistance in clinical isolates of Enterobacter aerogenes: A strategy combining antibiotics and chemosensitisers

OBJECTIVE

The main focus of this study was to evaluate the antimicrobial susceptibility profiles of a number of human clinical isolates of Enterobacter aerogenes isolates and to explore the effects of selected chemosensitisers on reversal of the resistant phenotype of these isolates.

METHODS

This study design was accomplished by: (i) characterising several multidrug-resistant (MDR) E. aerogenes clinical isolates; (ii) evaluating the contribution of target gene mutations to the resistance phenotype, focusing on fluoroquinolones and chloramphenicol only; (iii) evaluating the contribution of membrane permeability and efflux to the MDR phenotype; (iv) assessing the combined action of selected antimicrobials and chemosensitisers in order to identify combinations with synergistic effects able to reduce the minimum inhibitory concentration (MIC); and (v) understanding how these combinations can modulate the permeability or efflux of these isolates.

RESULTS

Resistance to ciprofloxacin could not be totally reversed owing to pre-existing mutations in target genes. Chloramphenicol susceptibility was efficiently restored by the addition of the selected chemosensitisers. From the modulation kinetics it was clear that phenothiazines were able to increase the accumulation of Hoechst dye.

CONCLUSIONS

Modulation of permeability and efflux in the presence of chemosensitisers can help us to propose more appropriate chemotherapeutic combinations that can set the model to be used in the treatment of these and other MDR infections.

Cell death-based approaches in treatment of the urinary tract-associated diseases: a fight for survival in the killing fields

Urinary tract-associated diseases comprise a complex set of disorders with a variety of etiologic agents and therapeutic approaches and a huge global burden of disease, estimated at around 1 million deaths per year. These diseases include cancer (mainly prostate, renal, and bladder), urinary tract infections, and urolithiasis. Cell death plays a key role in the pathogenesis and therapy of these conditions. During urinary tract infections, invading bacteria may either promote or prevent host cell death by interfering with cell death pathways. This has been studied in detail for uropathogenic E. coli (UPEC). Inhibition of host cell death may allow intracellular persistence of live bacteria, while promoting host cell death causes tissue damage and releases the microbes. Both crystals and urinary tract obstruction lead to tubular cell death and kidney injury. Among the pathomechanisms, apoptosis, necroptosis, and autophagy represent key processes. With respect to malignant disorders, traditional therapeutic efforts have focused on directly promoting cancer cell death. This may exploit tumor-specific characteristics, such as targeting Vascular Endothelial Growth Factor (VEGF) signaling and mammalian Target of Rapamycin (mTOR) activity in renal cancer and inducing survival factor deprivation by targeting androgen signaling in prostate cancer. An area of intense research is the use of immune checkpoint inhibitors, aiming at unleashing the full potential of immune cells to kill cancer cells. In the future, this may be combined with additional approaches exploiting intrinsic sensitivities to specific modes of cell death such as necroptosis and ferroptosis. Here, we review the contribution of diverse cell death mechanisms to the pathogenesis of urinary tract-associated diseases as well as the potential for novel therapeutic approaches based on an improved molecular understanding of these mechanisms.

Direct Detection and Identification of Bacterial Pathogens from Urine with Optimized Specimen Processing and Enhanced Testing Algorithm

Rapid and accurate detection and identification of microbial pathogens causing urinary tract infections allow prompt and specific treatment. We optimized specimen processing to maximize the limit of detection (LOD) by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and evaluated the capacity of combination of MALDI-TOF MS and urine analysis (UA) for direct detection and identification of bacterial pathogens from urine samples. The optimal volumes of processed urine, formic acid/acetonitrile, and supernatant spotted onto the target plate were 15 ml, 3 μl, and 3 μl, respectively, yielding a LOD of 1.0 × 10⁵ CFU/ml. Among a total of 1,167 urine specimens collected from three hospital centers, 612 (52.4%) and 351 (30.1%) were, respectively, positive by UA and urine culture. Compared with a reference method comprised of urine culture and 16S rRNA gene sequencing, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MALDI-TOF MS alone and MALDI-TOF MS coupled with UA were 86.6% versus 93.4% (χ² = 8.93; P < 0.01), 91.5% versus 96.3% (χ² = 7.06; P < 0.01), 81.5% versus 96.4% (χ² = 37.32; P < 0.01), and 94.1% versus 93.1% (χ² = 0.40; P > 0.05), respectively. No significant performance differences were revealed among the three sites, while specificity and NPV of MALDI-TOF MS for males were significantly higher than those for females (specificity, 94.3% versus 77.3%, χ² = 44.90, P < 0.01; NPV, 95.5% versus 86.1%, χ² = 18.85, P < 0.01). Our results indicated that the optimization of specimen processing significantly enhanced analytical sensitivity and that the combination of UA and MALDI-TOF MS provided an accurate and rapid detection and identification of bacterial pathogens directly from urine.

Fosfomycin: A First-Line Oral Therapy for Acute Uncomplicated Cystitis

Fosfomycin is a new agent to Canada approved for the treatment of acute uncomplicated cystitis (AUC) in adult women infected with susceptible isolates of E. coli and Enterococcus faecalis. We reviewed the literature regarding the use of oral fosfomycin for the treatment of AUC. All English-language references from 1975 to October 2015 were reviewed. In Canada, fosfomycin tromethamine is manufactured as Monurol® and is available as a 3-gram single dose sachet. Fosfomycin has a unique chemical structure, inhibiting peptidoglycan synthesis at an earlier site compared to β-lactams with no cross-resistance with other agents. Fosfomycin displays broad-spectrum activity against ESBL-producing, AmpC-producing, carbapenem-non-susceptible, and multidrug-resistant (MDR) E. coli. Resistance to fosfomycin in E. coli is rare (<1%). Fosfomycin is excreted unchanged in the urine by glomerular filtration with peak urinary concentration ~4000 µg/mL and remains at concentrations >100 µg/mL for 48 hours after a single 3-gram oral dose. No dosage adjustments are required in elderly patients, in pregnant patients, or in either renal or hepatic impairment. Fosfomycin demonstrates a favorable safety profile, and clinical trials have demonstrated efficacy in AUC that is comparable to ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole. Fosfomycin's in vitro activity against common uropathogens, including MDR isolates, its favorable safety profile including pregnancy patients, drug interactions, and clinical trials data demonstrating efficacy in AUC, has resulted in Canadian, US, and European guidelines/authorities recommending fosfomycin as a first line agent for the treatment of AUC.

Effects of Selected Egyptian Honeys on the Cellular Ultrastructure and the Gene Expression Profile of Escherichia coli

The purpose of this study was to: (i) evaluate the antibacterial activities of three Egyptian honeys collected from different floral sources (namely, citrus, clover, and marjoram) against Escherichia coli; (ii) investigate the effects of these honeys on bacterial ultrastructure; and (iii) assess the anti-virulence potential of these honeys, by examining their impacts on the expression of eight selected genes (involved in biofilm formation, quorum sensing, and stress survival) in the test organism. The minimum inhibitory concentration (MIC) of the honey samples against E. coli ATCC 8739 were assessed by the broth microdilution assay in the presence and absence of catalase enzyme. Impacts of the honeys on the cellular ultrastructure and the expression profiles of the selected genes of E. coli were examined using transmission electron microscopy (TEM) and quantitative real-time polymerase chain reaction (qPCR) analysis, respectively. The susceptibility tests showed promising antibacterial activities of all the tested honeys against E. coli. This was supported by the TEM observations, which revealed “ghost” cells lacking DNA, in addition to cells with increased vacuoles, and/or with irregular shrunken cytoplasm. Among the tested honeys, marjoram exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. The qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Our results indicate that some varieties of the Egyptian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets.

Development of a new protocol for rapid bacterial identification and susceptibility testing directly from urine samples

The current gold standard method for the diagnosis of urinary tract infections (UTI) is urine culture that requires 18-48 h for the identification of the causative microorganisms and an additional 24 h until the results of antimicrobial susceptibility testing (AST) are available. The aim of this study was to shorten the time of urine sample processing by a combination of flow cytometry for screening and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for bacterial identification followed by AST directly from urine. The study was divided into two parts. During the first part, 675 urine samples were processed by a flow cytometry device and a cut-off value of bacterial count was determined to select samples for direct identification by MALDI-TOF-MS at ≥5 × 10(6) bacteria/mL. During the second part, 163 of 1029 processed samples reached the cut-off value. The sample preparation protocol for direct identification included two centrifugation and two washing steps. Direct AST was performed by the disc diffusion method if a reliable direct identification was obtained. Direct MALDI-TOF-MS identification was performed in 140 urine samples; 125 of the samples were positive by urine culture, 12 were contaminated and 3 were negative. Reliable direct identification was obtained in 108 (86.4%) of the 125 positive samples. AST was performed in 102 identified samples, and the results were fully concordant with the routine method among 83 monomicrobial infections. In conclusion, the turnaround time of the protocol described to diagnose UTI was about 1 h for microbial identification and 18-24 h for AST.

Presence of Virulence-Associated Genes and Ability to Form Biofilm among Clinical Isolates of Escherichia coli Causing Urinary Infection in Domestic Animals

Background:

Urinary tract infection caused by Escherichia coli is a frequently observed condition both in humans and animals. Uropathogenic E. coli (UPEC) has been shown to have a pathogenicity island that enables them to infect the urinary tract. Because there is little information about the presence of UPEC-associated virulent genes in animal isolates this work was carried out with the intent to enhance the understanding about the strains of E.coli that cause infections in animals.

Results:

We screened 21 E. coli strains isolated causing urinary tract infection in domestic animals. Primers were designed to amplify urinary infection-associated genes. Nine genes, papA, tcpC, fyuA, tpbA, Lma, hylA, picU, tonB, and flicC were then amplified and sequenced. Different from the human isolate CFT073, all the animals E. coli lack some of the pathogenesis-associated genes. Genes encoding for proteins used to scavenge iron appear not to be so necessary during animal infections as they are in human infection. In further investigation of phenotypic properties, it was observed that animal UPECs have significantly more impaired ability to form biofilms than human UPEC strain.

Conclusions:

This study identified significant differences between human and animal UPECs. This may have its roots in the fact that it is difficult to determine if an animal has symptoms. Future studies will focus on some of the observations.

The Bacterial Spectrum and Antimicrobial Susceptibility in Female Recurrent Urinary Tract Infection: How Different They Are From Sporadic Single Episodes?

OBJECTIVE

To analyze and compare the etiological uropathogens and the susceptibility profile findings on urine culture between sporadic cases of community-acquired, uncomplicated urinary tract infection (UTI) and recurrent UTI cases in women.

MATERIALS AND METHODS

We retrospectively analyzed the clinical data of 1629 women with uncomplicated UTI evaluated at our hospital between January 2007 and December 2012. Patients were divided into 2 groups: (1) no recurrent UTI and (2) recurrent UTI. We analyzed the microbiological findings and compared susceptibility profiles between groups.

RESULTS

A total of 420 women were included. Group 1 had 233 (55.5%) patients and group 2 had 187 (44.5%). Escherichia coli was the most common agent in both groups (76.4% and 74.3%, respectively; P = .625), whereas Staphylococcus saprophyticus (8.2%) was the second most common in group 1, and Enterococcus faecalis was the second most common in group 2 (8.0%). Nitrofurantoin was the only oral agent that maintained the susceptibility profile in both groups (87.1% and 88.7%, respectively; P = .883). For E coli infections, only nitrofurantoin and amoxicillin/clavulanate maintained susceptibility rates more than 90% in both groups.

CONCLUSION

UTI episodes in patients with recurrent UTI had similar bacterial spectra, but different susceptibility profiles compared with those from patients with nonrecurrent infections. The susceptibility rate for nitrofurantoin in patients with recurrent UTI remained high and comparable to the observed in patients with sporadic UTI, reinforcing its indication for empirical treatment while waiting for urine culture results.

Schistosoma haematobium infection and asymptomatic bacteriuria in young South African females

Schistosoma haematobium eggs can induce lesions in the urinary and genital tract epithelia, as eggs pass through or get trapped in the tissue. Local inflammatory reactions induced by S. haematobium eggs might affect the ability of bacteria to establish mucosal super-infection foci. S. haematobium infection and asymptomatic bacteriuria can both portray haematuria, proteinuria and leukocyturia. This shared set of proxy diagnostic markers could fuel routine misdiagnosis in S. haematobium endemic areas. Furthermore, S. haematobium infected individuals might be at a higher risk of contracting bacterial urinary tract infections, which could manifest either as symptomatic or asymptomatic bacteriuria. The aim of the current study was to explore whether schistosomal lesions are susceptible to super-infection by bacteria measured as asymptomatic bacteriuria. S. haematobium infection was determined by microscopy of urine samples. Furthermore, urine samples were tested with dipslides for asymptomatic bacteriuria and with dipsticks for haematuria, proteinuria and leukocytes. We found no association between asymptomatic bacteriuria and S. haematobium infection in a sample of 1040 female primary and high school students from a schistosomiasis endemic area in KwaZulu-Natal, South Africa. Furthermore, it was demonstrated that asymptomatic bacteriuria is not a bias for use of micro-haematuria as a proxy diagnostic measure for S. haematobium infection in this population.

Virulence factors of uropathogenic E. coli and their interaction with the host

Urinary tract infections (UTIs) belong to the most common infectious diseases worldwide. The most frequently isolated pathogen from uncomplicated UTIs is Escherichia coli. To establish infection in the urinary tract, E. coli has to overcome several defence strategies of the host, including the urine flow, exfoliation of urothelial cells, endogenous antimicrobial factors and invading neutrophils. Thus, uropathogenic E. coli (UPEC) harbour a number of virulence and fitness factors enabling the bacterium to resist and overcome these different defence mechanisms. There is no particular factor which allows the identification of UPEC among the commensal faecal flora apart from the ability to enter the urinary tract and cause an infection. Many of potential virulence or fitness factors occur moreover with high redundancy. Fimbriae are inevitable for adherence to and invasion into the host cells; the type 1 pilus is an established virulence factor in UPEC and indispensable for successful infection of the urinary tract. Flagella and toxins promote bacterial dissemination, while different iron-acquisition systems allow bacterial survival in the iron-limited environment of the urinary tract. The immune response to UPEC is primarily mediated by toll-like receptors recognising lipopolysaccharide, flagella and other structures on the bacterial surface. UPEC have the capacity to subvert this immune response of the host by means of actively impacting on pro-inflammatory signalling pathways, or by physical masking of immunogenic structures. The large repertoire of bacterial virulence and fitness factors in combination with host-related differences results in a complex interaction between host and pathogen in the urinary tract.

Reusable, robust, and accurate laser-generated photonic nanosensor

Developing noninvasive and accurate diagnostics that are easily manufactured, robust, and reusable will provide monitoring of high-risk individuals in any clinical or point-of-care environment. We have developed a clinically relevant optical glucose nanosensor that can be reused at least 400 times without a compromise in accuracy. The use of a single 6 ns laser (λ = 532 nm, 200 mJ) pulse rapidly produced off-axis Bragg diffraction gratings consisting of ordered silver nanoparticles embedded within a phenylboronic acid-functionalized hydrogel. This sensor exhibited reversible large wavelength shifts and diffracted the spectrum of narrow-band light over the wavelength range λpeak ≈ 510-1100 nm. The experimental sensitivity of the sensor permits diagnosis of glucosuria in the urine samples of diabetic patients with an improved performance compared to commercial high-throughput urinalysis devices. The sensor response was achieved within 5 min, reset to baseline in ∼10 s. It is anticipated that this sensing platform will have implications for the development of reusable, equipment-free colorimetric point-of-care diagnostic devices for diabetes screening.