Urinary Tract Infection Samples Research Articles

Association between urine pH and common uropathogens in children with urinary tract infections.

Urinary tract infections (UTIs) are one of the most common pediatric infections. Our objective in this study is to investigate the association between urine pH and uropathogens in pediatric patients. The source population comprised 26 066 paired urinalysis (UA) and urine culture (UC) samples obtained from pediatric patients. We classified the paired UA-UC samples into UTI positive (N=6348) and UTI negative (N=19 718) according to the colony forming units corresponding to the sampling source. We included UTI positive patients with infection caused by a single species of pathogen (N=5201) and frequency matched them with UTI negative patients (N=4729) by age, sex, sampling source, and visit type. This study included 5201 pediatric patients with UTIs and found that urine with Proteus mirabilis or Pseudomonas aeruginosa demonstrated the least acidic pH (mean pH=6.72 and 6.62, respectively), whereas urine with Escherichia coli or Klebsiella pneumoniae exhibited the most acidic pH (pH=6.21 and 6.18). After stratifying the UTI samples by their pH range (<6, 6-6.9, 7-7.9, and ≥8). The prevalence of P. mirabilis increased significantly across increasing pH categories. This research is the first epidemiological study that linked urine pH to specific uropathogens in a pediatric population. Both urine pH and age are associated with certain causative uropathogens. Urine that grew P. mirabilis or P. aeruginosa had the least acidic pH. Additional studies should validate the role of urine pH in predicting uropathogens and UTI.

Evaluation of pap and sfa Genes Relative Frequency P and S Fimbriae Encoding of Uropathogenic Escherichia coli Isolated from Hospitals and Medical Laboratories; Yasuj City, Southwest Iran

Background: Urinary tract infections (UTI) are one of the common infections worldwide. Escherichia coli is the most common bacteria causing UTI. Objectives: The current study aimed at investigating the susceptibility pattern, biofilm formation, and the relationship between pap and sfa virulence genes and biofilm formation in E. coli strains isolated from patients with UTI from 2017 to 2018 in Yasuj City, Iran. Methods: In the current cross-sectional study, 130 E. coli strains were isolated from patients with UTI. Antimicrobial susceptibility testing was performed by disk diffusion method. The presence of pap and sfa genes was investigated by multiplex polymerase chain reaction (PCR). Biofilm formation was tested using microtiter plate assay and ELISA (enzyme-linked immunosorbent assay) reader for E. coli isolates. Results: Out of 130 E. coli strains isolated from UTI samples, 98 (75.38%) were positive for the biofilm formation, (14% strong, 31% moderate, and 53% weak). The pap and sfa genes were detected in 50% and 29% of the isolates, respectively. Majority of the isolates were resistant against ampicillin (80%) and susceptible to amikacin and meropenem (100%); the pap and sfa genes were detected in 92.85% and 85.71% of the biofilm-forming isolates, respectively. These genes in Uropathogenic E. coli (UPEC) have a significant relationship with strong biofilm formation (P < 0.0001). Conclusions: The obtained results indicated that the frequency of pap gene was higher than that of sfa in E. coli strains isolated from patients with UTI in Yasuj. The pap and sfa genes in E. coli strains had a significant relationship with strong biofilm formation. In addition, the frequency of biofilm formation in antibiotic-resistant E. coli was higher than that of antibiotic-sensitive strains. According to the results of the current study, it is recommended to administer Amikacin or Meropenem in Yasuj to treat UTI.

Antimicrobial resistance patterns of uropathogens isolated between 2012 and 2017 from a tertiary hospital in Northern Ethiopia.

Urinary tract infections (UTIs) are one of the most common infections in humans. Studies have shown that antibiotics for UTIs are usually prescribed empirically before the results of urine culture are available. The aim of the study was to assess the antimicrobial resistance patterns of bacteria isolated from urine samples over 6 years in Ayder Comprehensive Specialized Hospital (ACSH), in Mekelle, Northern Ethiopia. A retrospective study of culture results of UTI samples was conducted in ACSH from January 2012 to December 2017. Data were collected using a structured data sheet format and were analysed using SPSS v.20.0. Among 1080 urine samples tested during the 6-year period, 308 (28.5%) were positive for bacterial isolates. The majority of participants were female (57.8%). The three most commonly isolated bacteria were Escherichia coli (48.1%), Klebsiella pneumoniae (16.2%) and Pseudomonas aeruginosa (6.5%). Escherichia coli was found to be most susceptible to imipenem (100%) and most resistant to ampicillin (94.9%). Similarly, K. pneumoniae was sensitive to meropenem (100%) but resistant to penicillin (100%). Multidrug resistance to two or more antimicrobials was observed in 267 isolates (86.7%), with a non-significantly higher prevalence in females (χ2=9.65, P=0.29). The overall pooled bacterial resistance was 57.8%. This study revealed that most of the urine isolates showed high levels of antimicrobial resistance to commonly prescribed antibiotics although they remained susceptible to imipenem, nitrofurantoin and meropenem. The results call for continuous surveillance of antimicrobial resistance for better management of patients with UTIs.

Pathotypic and Phylogenetic Study of Diarrheagenic Escherichia coli and Uropathogenic E. coli Using Multiplex Polymerase Chain Reaction.

Background:Acute diarrheal disease and urinary tract infection are leading causes of childhood morbidity and mortality in the developing world. Diarrheagenic Escherichia coli (DEC) has been identified as a major etiologic agent of diarrhea worldwide, and urinary tract infection (UTI) caused by uropathogenic Escherichia coli (UPEC) is one of the most common bacterial infections among human beings. Quick and precise detection of these bacteria help provide more effective intervention and management of infection.Objectives:In this study we present a precise and sensitive typing and phylogenetic study of UPEC and DEC using multiplex PCR in order to simplify and improve the intervention and management of diarrheal and UT infections.Materials and Methods:In total, 100 urinary tract infection samples (UTI) and 200 specimens from children with diarrhea, which had been diagnosed with E. coli as the underlying agent by differential diagnosis using MacConkey’s agar and biochemical study, were submitted for molecular detection. Pathotyping of E. coli pathotypes causing urinary tract infection and diarrhea were examined using a two set multiplex PCR, targeting six specific genes. Phylogenetic typing was done by targeting three genes, including ChuA, YjaA and TspE4C2.Results:Overall, 88% of DEC and 54% of UTI isolates were positive for one or more of the six genes encoding virulence factors. Prevalence of the genes encoding virulence factors for DEC were 62%, 25%, 24%, 13%, 7% and 5% for ST (ETEC), LT (ETEC), aggR (EAggEC), daaD (DAEC), invE (EIEC) and eae (EPEC), respectively; whereas, the prevalence rates for the UTI samples were 23%, 14%, 6%, 6% and 4% for aggR (EAggEC), LT (ETEC), daaD (DAEC), invE (EIEC) and ST (ETEC), respectively. No coding virulence factors were detected for eae (EPEC). Group B2 was the most prevalent phylogroup and ST was the most frequently detected pathotype in all phylogroups.Conclusions:ETEC and EAggEC were the most detected E. coli among stool and UTI samples, emphasizing the need to dedicate more health care attention to this group. In addition, our phylogenetic study may be helpful in figuring out the infection origin and for epidemiological studies. Nonetheless, more research studies with larger sample sizes are suggested for confirming our results.

The relationship between biofilm formation and presence of fimH and mrkD genes among E. coli and K. pneumoniae isolated from patients in Mosul

Background and objectives: Biofilms have a major medical significance as they decrease susceptibility to antimicrobial agents. The decreased susceptibility to microbial agents within a biofilm arises from multiple factors, including physical impairment of diffusion of antimicrobial agents, reduced bacterial growth rates, and local alterations of the microor-ganisms (M.O) that may impair activity of the antimicrobial agent. The aim of the study was to investigate the biofilm formation among coliforms and study the relationship between biofilm formation and the presence of fimH and mrkD genes among E. coli and K. pneumonia isolates respectively . Materials and method: One hundred and seventy three clinical samples were collected from both gender who visited or admitted to AL- Salam General Teaching Hospital and AL- Wafa’a center for diabetic patients in Mosul city from April 2013 to February 2014, (110) urine samples from patients suffering from urinary tract infections (UTIs) and (63 ) from patients with diabetic foot infections (DFIs). All samples were cultured on selective media as MacConkey and blood agar aerobically. Coliform isolates are identified to species level depending on biochemical and physiological tests and using Rapid ™ ONE panel kit to be conformed to the diagnosis. The ability of coliforms spp. for biofilm formation was assessed using qualitative and quantitative assay. The Congo red agar (CRA) method was used in the qualitative biofilm assay. Results: Out of (85) bacterial spp. , 44(51.8%) species were biofilm producers. The tissue culture plate (TCP) method was used in the quantitative biofilm formation assay. The results showed that 46(54.1%) spp. produced biofilm strongly. All biofilm producing E. coli and K. pneumoniae spp. which gives strong biofilm formation by CRA method and non-biofilm producer spp. were subjected to PCR for determining the relation between biofilm formation and the presence of fimH gene in E. coli isolates and mrkD gene in K. pneumoniae isolates. The results revealed that all biofilm producing E. coli 15(100%) isolated from UTI samples were positive for fimH gene. While all biofilm producing K. pneumoniae 9(100%) and 5(100%) isolated from UTIs and DFIs respectively were positive for mrkD gene.

Applied Technology in Diaper-Based UTI Testing for Elder People by Using Nitrite Ion Selective Electrode

Urinary tract infections (UTI) are common infection diseases in the hospitals, especially for the elder people. Detecting UTI for the elder people is difficult and time-consuming procedure. Since measuring nitrite directly in urine is often employed in the diagnosis of UTI, a nitrite ion selective electrode (ISE) was investigated in this study in order to detect UTI samples directly on used diapers of patients. With a commercial ISE sensor for nitrite, the detecting system was built to quickly and precisely quantify different concentrations of nitrite ions in both water solutions and real human urine samples. Good results were shown in the experiment that the nitrite can be precisely detected in the fresh urine by the ISE with the relations as Ε=224.7-21.259×Lg (C+13.476), where E is the electrode potential and C is the concentration of nitrite ions. Besides, the method of extracting urine samples from used diapers was also studied for further research. The investigation suggested that a sampling module for used diapers could be simply realized if necessary.

Multidrug resistant Escherichia coli isolated from urinary tract infections in a tertiary care hospital, Bangalore, South India

Background: Escherichia coli is the most common etiological agent in both community acquired and hospital acquired urinary tract infections (UTI). Emergence of multidrug resistance (MDR) among E.coli isolates is quite alarming. The goal of the study was to define the current prevalence and phenotypes of MDR E. coli among UTI samples in our hospital. Methods: Urine samples from 1225 patients received in the microbiology department of our hospital were processed. Wet mount to detect presence of pus cells and bacteria was done. All the samples were inoculated on to Hi Media Hi chrome agar and plates incubated at 370 C for 18-24 hours. Growth showing significant bacteriuria (≥ 105 cfu/ml) was identified by the colour imparted by the colonies. Further identification was done by the standard biochemical procedures. Antibiotic sensitivity was performed by disc diffusion method as per CLSI guidelines. Various classes of antibiotics were included in the sensitivity panel. Results: Out of 1225 samples processed, significant bacterial isolates were obtained in 357 (29.1%) The total number of E.coli isolated were 179(50.1%). More number of females (56.9%) had significant UTI due to E.coli compared to males (43%). The total number of samples received in pediatric age group was 60. E.coli comprised 58.3% of the pediatric isolates. Total numbers of multidrug resistant E.coli isolates were 148 (82.6%). High degree of resistance was observed to amoxycillin (93.2%) and amoxycillin -clavulanic acid (90.5%). More than 80% sensitivity was seen only to imipenem (98.4%), amikacin (83.3%) and nitrofurantoin (86.6%). Conclusion: Multidrug resistant strains of E.coli are widely prevalent and isolation of the same in the community acquired urinary tract infections is a matter of grave concern. Antibiotics like imipenem and amikacin require hospitalization, parentral administration, drug monitoring for toxicity, all of which incurs high cost to the patient and cannot be used as the first line of treatment. Judicious use of antibiotics is the need of the hour to prevent spread of the multidrug resistant strains in the community

Increased human pathogenic potential of Escherichia coli from polymicrobial urinary tract infections in comparison to isolates from monomicrobial culture samples

The current diagnostic standard procedure outlined by the Health Protection Agency for urinary tract infections (UTIs) in clinical laboratories does not report bacteria isolated from samples containing three or more different bacterial species. As a result many UTIs go unreported and untreated, particularly in elderly patients, where polymicrobial UTI samples are especially prevalent. This study reports the presence of the major uropathogenic species in mixed culture urine samples from elderly patients, and of resistance to front-line antibiotics, with potentially increased levels of resistance to ciprofloxacin and trimethoprim. Most importantly, the study highlights that Escherichia coli present in polymicrobial UTI samples are statistically more invasive (P<0.001) in in vitro epithelial cell infection assays than those isolated from monomicrobial culture samples. In summary, the results of this study suggest that the current diagnostic standard procedure for polymicrobial UTI samples needs to be reassessed, and that E. coli present in polymicrobial UTI samples may pose an increased risk to human health.

The potential of autofluorescence spectroscopy to detect human urinary tract infection

Urinary tract infections (UTIs) are known to alter the normal urine composition which, in principle, can lead to changes in urine autofluorescence. This paper describes the study of human urine (normal and UTI) by using UV fluorescence excitation/emission matrices and synchronous spectra and proposes a method of diagnosing UTI without any sample preparation. The method is based on excitation in the shorter UV region (250–350 nm) which shows good discrimination between the normal urine and UTI samples. The synchronous scans with an offset of Δ λ = 90 nm were also able to differentiate between normal urines and UTI samples. These differences were observed even though the two known major urine fluorophores, tryptophan and indoxyl sulfate were present in the normal urine and UTI samples in similar concentration as established by HPLC analysis. Although the identity of substances responsible for the altered autofluorescence in UTI is not established, our study shows that autofluorescence has the potential to differentiate between normal human urine samples and those with UTI.

Evaluation of the Sysmex UF-1000i for the Diagnosis of Urinary Tract Infection

Diagnosis of urinary tract infection (UTI) is primarily done by microbiologic culture, which is time-consuming and can produce false-positives and false-negatives. Flow cytometry allows for rapid screening of many samples and eliminates culturing. We analyzed the Sysmex UF-1000i (TOA Medical Electronics, Kobe, Japan) for accuracy in identifying RBCs and WBCs, casts, bacteria, and epithelia. We also evaluated its precision, linear estimation of results, carryover contamination rate, and anti-interference. UF-1000i agreement with manual counting was approximately 95% for RBCs and WBCs, epithelia, and casts. Its coefficient of variation for bacteria ranged from 4.7% to 15.2%. UF-1000i screening for UTIs exhibited great sensitivity (97%), specificity (79%), positive predictive value (70%), negative predictive value (99%), and accuracy (85%). The negative predictive value remained high even with complex UTI samples. The Sysmex UF-1000i shows great promise in excluding more than 50% of true-negative samples, improving detection efficiency, and reducing laboratory costs.

Capillary electrophoresis‐time of flight‐mass spectrometry using noncovalently bilayer‐coated capillaries for the analysis of amino acids in human urine

A capillary electrophoresis-time of flight-mass spectrometry (CE-TOF-MS) method for the analysis of amino acids in human urine was developed. Capillaries noncovalently coated with a bilayer of Polybrene (PB) and poly(vinyl sulfonate) (PVS) provided a considerable EOF at low pH, thus facilitating the fast separation of amino acids using a BGE of 1 M formic acid (pH 1.8). The PB-PVS coating proved to be very consistent yielding stable CE-MS patterns of amino acids in urine with favorable migration time repeatability (RSDs <2%). The relatively low sample loading capacity of CE was circumvented by an in-capillary preconcentration step based on pH-mediated stacking allowing 100-nL sample injection (i.e. ca. 4% of capillary volume). As a result, LODs for amino acids were down to 20 nM while achieving satisfactory separation efficiencies. Preliminary validation of the method with urine samples showed good linear responses for the amino acids (R(2) >0.99), and RSDs for peak areas were <10%. Special attention was paid to the influence of matrix effects on the quantification of amino acids. The magnitude of ion suppression by the matrix was similar for different urine samples. The CE-TOF-MS method was used for the analysis of urine samples of patients with urinary tract infection (UTI). Concentrations of a subset of amino acids were determined and compared with concentrations in urine of healthy controls. Furthermore, partial least squares-discriminant analysis (PLS-DA) of the CE-TOF-MS dataset in the 50-450 m/z region showed a distinctive grouping of the UTI samples and the control samples. Examination of score and loadings plot revealed a number of compounds, including phenylalanine, to be responsible for grouping of the samples. Thus, the CE-TOF-MS method shows good potential for the screening of body fluids based on the analysis of endogenous low-molecular weight metabolites such as amino acids and related compounds.

Production by Escherichia coli isolates of siderophore and other virulence factors and their pathogenic role in a cutaneous infection model

Escherichia coli isolates from urinary tract infections (UTIs) (n = 124), extra-urinary sites (n = 37) and normal faecal samples (n = 51) were examined for the presence of virulence factors, including siderophores (aerobactin and enterobactin). The proportion of aerobactin producers was significantly higher in UTI (69.4%; p 0.001) and extra-urinary samples (70.3%; p 0.007) than in controls (41.2%), while the proportion of enterobactin producers was significantly lower in the UTI samples than in the controls (p 0.027). In a cutaneous infection model, aerobactin-positive E. coli showed more growth than non-aerobactin and non-enterobactin isolates, even when other virulence factors were identical.