Agent Of Urinary Tract Infections Research Articles

English

This study was designed to bring to the fore the prevalent causative agents of urinary tract infections (UTIs) and their antibiotic susceptibility patterns in Nigeria, using patients attending University of Abuja Teaching Hospital (UATH) as a case study. Using microbiological/biochemical methods, prevalence of uropathogens amongst sexes, was compared between 2010 and 2015. Bacterial counts (105/ml) in the urine was used as quantitative standard and the total number of patients in the study was 214 (166 females and 48 males). The prevalence of UTIs in samples collected from 214 patients between 2010 and 2015 shows that Escherichia coli (57.5%) was the most prevalent organism causing UTIs, followed by Klebsiella species (18.5%), Staphylococcus aureus (11.2%) and Proteus species (12.4%). Antibiotics used include nitrofurantoin, ofloxacin, nalidixic acid, amoxicillin, gentamicin, tetracycline, levofloxacin, and augumentin, with bacterial causing UTI displaying greatest resistance to tetracycline and nitrofurantoin the highest sensitivity. This study indicates most of the uropathogens are still susceptible to antibiotics commonly used in the hospital. However, E. coli exhibited resistance to amoxicillin. The development of antimicrobials for prevention and treatment of infections should be tackled from a worldwide understanding of infection patterns so as to overcome the increasing level of superbugs in general and UTIs in particular.   Key words: Urinary tract infections, microbial resistance, adaptive immune response.

Identification through MALDI-TOF mass spectrometry and antimicrobial susceptibility profiling of bacterial pathogens isolated from sow urinary tract infection

ABSTRACTBackground: Urinary tract infection (UTI) is a common disease in sows due to intensification of pig production. Despite direct economic losses, UTI prevalence and respective microbial identification are still poorly studied.Objective: The aims of this study were to identify the causative agents of UTI in sows through MALDI-TOF MS and to characterize their antimicrobial resistance profiles.Materials and Methods: Urine samples from 300 sows of three herds from São Paulo State (Brazil) were screened for UTI; suggestive samples were submitted to bacterial isolation. Species identification was performed by MALDI-TOF MS and susceptibility profiles were determined using disc diffusion method.Results: 128 samples suggestive of UTI were analyzed; 48% of the animals presented UTI caused by a single pathogen, while the remaining 52% presented mixed infection. Escherichia coli stood out with the highest frequency among both single and mixed infections. The Gram-positive were exclusively associated with 27% of single infections. The mixed infections were further classified into 49 profiles. The high frequency of multiresistant profiles stood out for most of the studied isolates.Conclusions: MALDI-TOF MS enabled the identification of rare pathogens related to UTI which may represent higher risk for porcine health, especially considering high frequency of multiresistant profiles.

Thiol Starvation Induces Redox-Mediated Dysregulation of Escherichia coli Biofilm Components.

A hallmark of bacterial biofilms is the production of an extracellular matrix (ECM) that encases and protects the community from environmental stressors. Biofilm formation is an integral portion of the uropathogenic Escherichia coli (UPEC) life cycle. Approximately 2% of UPEC isolates are cysteine auxotrophs. Here, we investigated how cysteine homeostasis impacted UPEC UTI89 strain biofilm formation and, specifically, the production of the ECM components curli and cellulose. Cysteine auxotrophs produced less cellulose and slightly more curli compared to wild-type (WT) strains, and cysteine auxotrophs formed smooth, nonrugose colonies. Cellulose production was restored in cysteine auxotrophs when YfiR was inactivated. YfiR is a redox-sensitive regulator of the diguanylate cyclase, YfiN. The production of curli, a temperature-regulated appendage, was independent of temperature in UTI89 cysteine auxotrophs. In a screen of UPEC isolates, we found that ∼60% of UPEC cysteine auxotrophs produced curli at 37°C, but only ∼2% of cysteine prototrophic UPEC isolates produced curli at 37°C. Interestingly, sublethal concentrations of amdinocillin and trimethoprim-sulfamethoxazole inhibited curli production, whereas strains auxotrophic for cysteine continued to produce curli even in the presence of amdinocillin and trimethoprim-sulfamethoxazole. The dysregulation of ECM components and resistance to amdinocillin in cysteine auxotrophs may be linked to hyperoxidation, since the addition of exogenous cysteine or glutathione restored WT biofilm phenotypes to mutants unable to produce cysteine and glutathione.IMPORTANCE Uropathogenic Escherichia coli (UPEC) bacteria are the predominant causative agent of urinary tract infections (UTIs). UTIs account for billions of dollars of financial burden annually to the health care industry in the United States. Biofilms are an important aspect of the UPEC pathogenesis cascade and for the establishment of chronic infections. Approximately 2% of UPEC isolates from UTIs are cysteine auxotrophs, yet there is relatively little known about the biofilm formation of UPEC cysteine auxotrophs. Here we show that cysteine auxotrophs have dysregulated biofilm components due to a change in the redox state of the periplasm. Additionally, we show the relationship between cysteine auxotrophs, biofilms, and antibiotics frequently used to treat UTIs.

The Effect of Aqueous and Alcoholic Extracts of Thyme, Eucalyptus, Chamomile and Fennel on Virulence Factors of Escherichia Coli, Causative Agent of Urinary Tract Infection

The Effect of Aqueous and Alcoholic Extracts of Thyme, Eucalyptus, Chamomile and Fennel on Virulence Factors of Escherichia Coli, Causative Agent of Urinary Tract Infection

Genomic characterization, phylogenetic analysis, and identification of virulence factors in Aerococcus sanguinicola and Aerococcus urinae strains isolated from infection episodes

Aerococcus sanguinicola and Aerococcus urinae are emerging pathogens in clinical settings mostly being causative agents of urinary tract infections (UTIs), urogenic sepsis and more seldomly complicated infective endocarditis (IE). Limited knowledge exists concerning the pathogenicity of these two species. Eight clinical A. sanguinicola (isolated from 2009 to 2015) and 40 clinical A. urinae (isolated from 1984 to 2015) strains from episodes of UTIs, bacteremia, and IE were whole-genome sequenced (WGS) to analyze genomic diversity and characterization of virulence genes involved in the bacterial pathogenicity.A. sanguinicola genome sizes were 2.06–2.12 Mb with 47.4–47.6% GC-contents, and 1783–1905 genes were predicted whereof 1170 were core-genes. In case of A. urinae strains, the genome sizes were 1.93–2.44 Mb with 41.6–42.6% GC-contents, and 1708–2256 genes of which 907 were core-genes.Marked differences were observed within A. urinae strains with respect to the average genome sizes, number and sequence identity of core-genes, proteome conservations, phylogenetic analysis, and putative capsular polysaccharide (CPS) loci sequences. Strains of A. sanguinicola showed high degree of homology. Phylogenetic analyses showed the 40 A. urinae strains formed two clusters according to two time periods: 1984–2004 strains and 2010–2015 strains.Genes that were homologs to virulence genes associated with bacterial adhesion and antiphagocytosis were identified by aligning A. sanguinicola and A. urinae pan- and core-genes against Virulence Factors of Bacterial Pathogens (VFDB). Bacterial adherence associated gene homologs were present in genomes of A. sanguinicola (htpB, fbpA, lmb, and ilpA) and A. urinae (htpB, lap, lmb, fbp54, and ilpA). Fifteen and 11–16 CPS gene homologs were identified in genomes of A. sanguinicola and A. urinae strains, respectively. Analysis of these genes identified one type of putative CPS locus within all A. sanguinicola strains. In A. urinae genomes, five different CPS loci types were identified with variations in CPS locus sizes, genetic content, and structural organization.In conclusion, this is the first study dealing with WGS and comparative genomics of clinical A. sanguinicola and A. urinae strains from episodes of UTIs, bacteremia, and IE. Gene homologs associated with antiphagocytosis and bacterial adherence were identified and genetic variability was observed within A. urinae genomes. These findings contribute with important knowledge and basis for future molecular and experimental pathogenicity study of UTIs, bacteremia, and IE causing A. sanguinicola and A. urinae strains.

Clinical analysis of urine bacteria culture in children with urolithiasis

Objective To study the correlation between age, gender, stone size, bilateral or unilateral urinary calculi, anatomical location of calculi and the positive rate of urine culture, and to investigate the pathogenic bacteria and drug resistance in children with urolithiasis. Methods Files of patients from department of urology in People′s Hospital of Xinjiang Uygur Autonomous Region from January 2013 to March 2017 were reviewed. The observed indexes included age, gender, stone size, bilateral or unilateral renal involvement, anatomical location of calculi, and the results of urine culture and drug susceptibility test.Only those patients with calculi and less than 12 years were studied.All files of patients with documented urological procedures prior to urinary tract infection occurrence were excluded from the study. CT technique was used to determine stone size and location.Collected urine samples were screened for urinary tract infection. Results A total of 107 patients were studied. The mean age was (4.37±2.97) years.Seventy-four cases (69.2%) were males; 33 cases(30.8%) were females. Urinary tract infection was found in 27 cases(25.2%). The most common pathogenic bacteria found on our culture plate of urinary tract infection positive patients was Escherichia coli (48.1%; 13/27). Gram negative bacteria were most sensitive to imipenem(100.0%; 24/24), cefoxitin (88.2%; 15/17), and Piperacillin/Tazobactam(87.5%; 21/24). Gram negative bacteria had a high resistance rate to ampicillin (84.2%; 16/19), cefazolin(81.0%; 17/21), cefuroxime(80.0%; 16/20), TMP-SMX(77.3%; 17/22)and ceftriaxone(73.9%; 17/23) in our center. Conclusions There was no association between these parameters(age, sex, stone size, bilateral or unilateral renal involvement, and anatomical location of calculi) and positive rate of urine culture in children with urolithiasis. Escherichia coli was the most common causative agent of urinary tract infection in children with urolithiasis.Gram negative bacteria had a high resistance rate to ampicillin, cefazolin, and cefuroxime in our center. Key words: Child; Urinary tract infections; Urinary calculi; pathogenic bacteria; antimicrobial resistance

KPC: an important mechanism of resistance in K. pneumoniae isolates from intensive care units in the Midwest region of Brazil.

Infections caused by multidrug-resistant Klebsiella pneumoniae are difficult to treat and pose a serious threat to public health worldwide. Here, we describe the presence of carbapenemase-producing K. pneumoniae in intensive care units (ICU) of three major Mato Grosso do Sul hospitals located in the Midwest region of Brazil. A total of 165 K. pneumoniae isolates with reduced susceptibility to carbapenems as identified by the VITEK-2 compact system were studied. Antimicrobial susceptibility testing was performed using the disk diffusion method, as recommended by the Clinical and Laboratory Standards Institute, and the E-test method. The detection of carbapenemase was performed using the modified Hodge test and polymerase chain reaction. The blaKPC gene was identified in 88.1% (n=89) of the selected K. pneumoniae isolates from Beneficent Association of Campo Grande, 94.9% (n=34) of the isolates from the Regional Hospital of Mato Grosso do Sul and 95.2% (n=26) of the isolates from Maria Aparecida Pedrossian University Hospital. Resistance greater than 80% was observed against cephalosporins, aztreonam, ciprofloxacin and piperacillin/tazobactam. Carbapenemase-producing K. pneumoniae (Kp-KPC)isolates were considered important causative agents of urinary tract infections, pneumonia and bloodstream infections in ICU patients. While rarely reported in the literature, we documented three cases of meningoencephalitis caused by Kp-KPC. Our study documents the presence of Kp-KPC in three major Mato Grosso do Sul state hospitals, providing key national epidemiology data. This is an important mechanism of resistance in K. pneumoniae isolates from ICU patients and is associated with resistance to multiple classes of antimicrobial drugs.

The Histidine Residue of QseC Is Required for Canonical Signaling between QseB and PmrB in Uropathogenic Escherichia coli.

Two-component systems are prototypically comprised of a histidine kinase (sensor) and a response regulator (responder). The sensor kinases autophosphorylate at a conserved histidine residue, acting as a phosphodonor for subsequent phosphotransfer to and activation of a cognate response regulator. In rare cases, the histidine residue is also essential for response regulator dephosphorylation via a reverse-phosphotransfer reaction. In this work, we present an example of a kinase that relies on reverse phosphotransfer to catalyze the dephosphorylation of its cognate partner. The QseC sensor kinase is conserved across several Gram-negative pathogens; its interaction with its cognate partner QseB is critical for maintaining pathogenic potential. Here, we demonstrate that QseC-mediated dephosphorylation of QseB occurs via reverse phosphotransfer. In previous studies, we demonstrated that, in uropathogenic Escherichia coli, exposure to high concentrations of ferric iron (Fe3+) stimulates the PmrB sensor kinase. This stimulation, in turn, activates the cognate partner, PmrA, and noncognate QseB to enhance tolerance to polymyxin B. We demonstrate that in the absence of signal, kinase-inactive QseC variants, in which the H246 residue was changed to alanine (A) aspartate (D) or leucine (L), rescued a ΔqseC deletion mutant, suggesting that QseC can control QseB activation via a mechanism that is independent of reverse phosphotransfer. However, in the presence of Fe3+, the same QseC variants were unable to mediate a wild-type stimulus response, indicating that QseC-mediated dephosphorylation is required for maintaining proper QseB-PmrB-PmrA interactions.IMPORTANCE Two-component signaling networks constitute one of the predominant methods by which bacteria sense and respond to their changing environments. Two-component systems allow bacteria to thrive and survive in a number of different environments, including within a human host. Uropathogenic Escherichia coli, the causative agent of urinary tract infections, rely on two interacting two-component systems, QseBC and PmrAB, to induce intrinsic resistance to the colistin antibiotic polymyxin B, which is a last line of defense drug. The presence of one sensor kinase, QseC, is required to regulate the interaction between the other sensor kinase, PmrB and the response regulators from both systems, QseB and PmrA, effectively creating a "four-component" system required for virulence. Understanding the important role of the sensor kinase QseC will provide insight into additional ways to therapeutically target uropathogens that harbor these signaling systems.

Pathogenic identification and antibiotic susceptibility of the microorganisms isolated from urine samples of UTI patients

Urinary tract infection (UTI) is the infection that occurs in the urinary tract by the invasion of pathogenic bacteria, fungi, virus etc. under some circumstances only. Some common pathogenic bacteria associated with UTI include Escherichia coli, Proteus spp., Streptococcus spp., Staphylococcus spp., Pseudomonas spp. In the ongoing research work, about 30 UTI patients were selected randomly to detect the pathogen responsible for causing urinary tract infection and also to demonstrate their drug resistant traits. Among the 30 samples, about 14 samples were found to harbor Proteus spp. (1×104 cfu/ml to 1×105 cfu/ml). Escherichia coli was found to be the second predominant agent for UTI and recovered from 13 samples. Among the rest 3 samples, Pseudomonas spp. was found in 2 samples and Klebsiella spp. was found in one sample. Identified isolates showed resistance against different ranges of antibiotics. The study findings revealed the fact that emerging drug resistance of different pathogenic bacteria could become the major difficulties in the treatment of infectious diseases like UTI.Stamford Journal of Microbiology, Vol.6(1) 2016: 34-38

Effect of some antibiotics on aerobic pathogenic bacteria causing otitis media and urinary tract infection in Al- Manathera city in Iraq: A comparative in vitro study

Background: Otitis Media (OM) is an inflammation of the middle ear drum and the inner ear, including a duct known as the eustachian tube. Otitis media is very common in children. Over 60 percent of the cases of otitis media are caused by bacteria. Urinary tract infection(UTI) refer to the presence of microbial pathogens within the urinary tract. A urinary tract infection is a condition where one or more structures in the urinary tract becomes infected after bacteria overcome its strong natural defenses. In spite of these defenses, urinary tract infections are the most common of all infections and can occur at any time in the life of an individual. Almost 95% of cases of UTIs are caused by bacteria that typically multiply at the opening of the urethra and travel up to the bladder. Escherichia coli, K. pneumoniae and Proteus mirabilis are the bacteria most commonly cause UTI, followed by other gram-negative and gram-positive bacteria. A number of studies have reported on the prevalence of otitis media and urinary tract infection. However, majority of these studies have focused on clinical diagnosis with little or no report on the bacteriological etiology of otitis media and urinary tract infection so this study aimed to isolate, characterize and identify the bacteriological etiologic agents of otitis media and urinary tract and to select the best antibiotic for the treatment of such infections. Objective: The study aimed to identify the aerobic pathogenic bacteria cause otitis media and urinary tract infection and to compare between pencillins, gentamicin, ciprofloxacin, refampicin, cefotaxim, trimethoprime, and nitrofurantoin effects on this bacteria. Materials and methods: The study was carried out on 130 out patients (65 patients 36 male and 24 female infected with otitis media and 65 patients 24 male and 41 female infected with urinary tract infection). The specimens were collected with sterile swab sticks (for patient infected with O.M) and collected with sterile container (for patient infected with UTI) which were properly labeled for each patient. Specimens were inoculated onto Blood, Chocolate , MacConkey and Manitol salt agar plates. All plates were incubated immediately for 24 hours aerobically with the exception of Chocolate agar that was incubated in a candle jar. Emergent colonies were identified according to standard bacteriological methods Results:From the 130 specimens from out patients (65 ear swab from patients infected with otitis media and 65 urine specimens from patients infected with urinary tract infection) , there were 60 bacterial isolates from patients infected with otitis media (36 male 60% and 24 female 40%) with 5 specimens no growth. Pseudomonas aeruginosa was the most prevalent bacteriological etiologic agent of otitis media (25 isolates 41.666%).While from the 65 urine specimens from patients infected with urinary tract infection , there were 65 bacterial isolates(24 male 36.923% and 41 female 63.077%) K. pneumoniae was the most prevalent etiologic agent of urinary tract infection (27 isolates 41.53%). Conclusions:Nitrofurantoin antibiotic was active against all of the bacterialisolates from patients infected with otitis media and from patients infected with urinary tract infection. While Ampicillin and Pencillin were not active against most of bacterial isolates. Recommendations: Otitis media and UTI characterized by the presence of many drug resistant cases due to different pathogenic bacteria involved in their etiology so further clinical studies are required to select the most appropriate and effective antibiotic in the treatment of such cases.

Evaluation of pathogenicity islands in uropathogenic Escherichia coli isolated from patients with urinary catheters.

Uropathogenic Escherichia coli (UPEC), an important causative agent of urinary tract infections (UTIs), carries virulence factors which are clustered on pathogenicity islands (PAIs). The goal of this study was to characterize the PAIs among the UPEC isolated from patients with urinary catheters. A descriptive cross-sectional study was designed and from December 2014 to April 2015, 78 non-duplicate E. coli were collected from hospitalized patients with UTIs, including patients with and without indwelling urinary catheters. Two multiplex polymerase chain reaction (PCR) assays were performed to evaluate the presence of the eight most studied PAIs (I 536, II 536, III 536, IV536, I CFT073, II CFT073, PAI IJ96, and PAI IIJ96). Of 78 patients with a UTI 31 (39.7%) used indwelling catheters. Of these 31 patients, 27 (87.1%) carried PAIs markers, including 25 (80.6%) PAI IV536, 12 (38.7%) PAI ICFT073, 6 (19.4%) PAI IICFT073, 6 (19.4%) PAI III536 and 3 (9.7%) PAI II536. PAI I536, PAI IJ96, and PAI IIJ96 were not detected in the UPEC strains. The findings of this study revealed that the frequency of PAI markers in UPEC isolates from patients with indwelling urinary catheters was high. The rate of multiple PAIs carriage was notable among those patients, suggesting that UPEC strains that colonize the indwelling urinary catheters have the potential to cause complicated urinary infections. PAI ICFT073, which was found in association with pyelonephritis, prostatitis, and sepsis, could be considered as a target for medical interventions.

Evaluation of prevalence, immunogenicity and efficacy of FyuA iron receptor in uropathogenic Escherichia coli isolates as a vaccine target against urinary tract infection

Uropathogenic Escherichia coli (UPEC) are among the most prevalent agents of urinary tract infections (UTIs). Antibiotic resistance reaches the need for alternative treatment approaches such as vaccination against UTIs. There is no ideal vaccine against UTIs, thus there is a need to evaluate different targets of uropathogens against UTIs. Ferric scavenger receptor FyuA in UPEC has the properties of an ideal vaccine candidate against UTIs. In the present study, the prevalence of FyuA among UPEC isolates, its immunogenicity with and without alum adjuvant, and its efficacy against experimental UTI were assessed. Totally, fyuA gene was present in 77% of the UPEC isolates tested. Alignments of FyuA exhibited a high degree of conservation among different submitted UPEC isolates in GenBank. The bioinformatics studies showed the high confidence value and stability of the FyuA structure. SDS-PAGE and Western blot confirmed the purification of FyuA with high yield by nickel resins. Mice vaccinated subcutaneously with the FyuA induced a significantly higher humoral response (total IgG, IgG1 and IgG2a) than control mice that alum enhanced these responses. The FuyA alone showed the ability to reduce the colonization of UPEC in bladder and kidney of mice as compared to the control group. But the addition of alum to FyuA increased the protection level against UPEC in these organs. Since, FyuA induced significant IgG1 (Th2) and IgG2a (Th1) responses and protected the mice against experimental UTI, it could be a promising target against UPEC infections.

Relationship between virulence factors, resistance to antibiotics and phylogenetic groups of uropathogenic Escherichia coli in two locations in Mexico

IntroductionEscherichia coli is the major causative agent of urinary tract infections (UTI), and virulence factors are responsible for the severity of these emerging infections. The aim of this study was to evaluate the relationship between virulence determinants and antibiotic susceptibility with phylogenetic groups of E. coli isolates of UTI in two locations in Mexico. MethodsAn analysis was performed on 50 isolates of E. coli from the centre of the country and 57 from a town in the southwest. The isolates were characterised by phenotype (serotyping assays, in vitro adhesion, biofilm formation, production of haemolysin, and antibiotic susceptibility) and genotype (phylogenetic groups and virulence genes). ResultsIn the centre of the country location the phylogenetic group B2 (60%) and F (12%) were significantly more prevalent and had a higher frequency of genes, fimH (96%), iutA (66%), sat (36%), compared to the southwest location, where the group A (35%) and B1 (21%) were significantly predominant and had fewer virulence genes. About one-fifth (21.5%) of all isolates belonged to the O25-ST131 group. Haemolysin and biofilm producing strains were significantly higher in the southwest location. Resistance to ampicillin (92.5%), tetracycline (76.6%), and trimethoprim/sulfamethoxazole (70.1%) were the most common in both groups. ConclusionThe phylogenetic group, virulence factors, and antibiotic susceptibility of the E. coli that causes UTI in the community, varies significantly among the Mexican populations studied. Phylogenetic groups A and B1 may be multidrug resistant and have the ability to produce UTI.

Comparative Study between Community Acquired and Hospital Acquired UTI Caused by E. Coli

Background : Uropathogenic Escherichia coli (UPEC) are the primary causative agent of urinary tract infection (UTIs). The pathogenic potential of E.coli strains depends on the presence of virulence markers, which in turn are associated with the severity of the infection. Objectives: To compare the presence of five virulence genes (fimH, PAI, papG, hlyA, traT), antibiotic susceptibility between community acquired (CA) and hospital acquired (HA) UPEC strains. Methodology : A total of 62 UPEC strains divided into 2 groups, 28 CA and 34 HA were tested for antimicrobial resistance against 15 drugs using the disc diffusion method. Screening and confirmatory tests for extended spectrum β lactamases were done as described by clinical laboratory standard institute (CLSI). Strains were tested for the five virulence genes by multiplex polymerase chain reaction. Results: FimH gene was the most detected one in the 62 UPEC strains followed by PAI, papG, hlyA, traT (33.87%, 27.42%, 20.97%, 11.29%, 6.45% respectively). No statistical difference was found between CA and HA as regard gene detection. A positive correlation was found between detection of one gene (PAI) and CA (p-value<0.001), detection of multiple genes with urinary catheter in HA (p-values was <0.001). Antibiotic resistance to ceftazidime, cefepime, amikacin, ciprofloxacin, levofloxacin, cotrimoxazole and nitrofurantoin were significantly higher in HA than CA (p-values were 0.009, 0.011, 0.035, 0.001, 0.017, 0.025 and 0.002 respectively). ESBL producing strains, MDR and Quinolone resistance were significantly higher in HA than CA (p-values were 0.028, <0.001 and 0.050 respectively). Conclusion : There was no statistical difference between CA and HA as regard the presence of virulence genes. Antibiotic resistance did not correlate with the studied virulence genes.

Frequency of Uropathogens and Antimicrobial Susceptibility in Childhood Urinary Tract Infection at Kamenge University Hospital, Bujumbura, Burundi

Background: Increasing resistance to antimicrobials is a worldwide problem. The aim of our study was to determine the pathogens and antimicrobial susceptibility of bacteria causing urinary tract infection (UTI) in children. Methods: This is a prospective cohort study conducted over a 10-month period with 101 children hospitalised at Kamenge University Hospital for acute UTI. The infections were confirmed by Kass urinalysis criteria, and culture and susceptibility antibiotic tests were performed for isolated microbial agents. Results: Frequency of UTI in the overall population of children hospitalised at Kamange University Hospital was 8.4%. Of the 101 children with UTIs, 87 (86.1%) were under the age of 24 months. Diagnosis of pyelonephritis (82%) was the most common, followed by cystitis (18%). Escherichia coli (82%) was the most frequent pathogen causing UTI. We found E coli and Klebsiella pneumonia to be resistant to aminopenicillins (100%), cotrimoxazole (98.2%, 100%), Augmentin (amoxicillin/clavulanic acid) (70.5%, 80%), cefotaxime (45.8%, 28.6%), cefuroxime (36.8 to 45.5%, 50%), fluoroquinolones (33.3 to 53.6%, 28.6 to 50%), gentamicin (27.5%, 20%), and nitrofurantoin (9.3%, 50%). Conclusion: E coli is the main causal agent of UTI in childhood with a high resistance to antibiotics. Appropriate antibiotics for empiric therapy should be based on local circulating bacterial strains and resistance profiles.

Frequency of Uropathogens and Antimicrobial Susceptibility in Childhood Urinary Tract Infection at Kamenge University Hospital, Bujumbura, Burundi.

Background:Increasing resistance to antimicrobials is a worldwide problem. The aim of our study was to determine the pathogens and antimicrobial susceptibility of bacteria causing urinary tract infection (UTI) in children.Methods:This is a prospective cohort study conducted over a 10-month period with 101 children hospitalised at Kamenge University Hospital for acute UTI. The infections were confirmed by Kass urinalysis criteria, and culture and susceptibility antibiotic tests were performed for isolated microbial agents.Results:Frequency of UTI in the overall population of children hospitalised at Kamange University Hospital was 8.4%. Of the 101 children with UTIs, 87 (86.1%) were under the age of 24 months. Diagnosis of pyelonephritis (82%) was the most common, followed by cystitis (18%). Escherichia coli (82%) was the most frequent pathogen causing UTI. We found E coli and Klebsiella pneumonia to be resistant to aminopenicillins (100%), cotrimoxazole (98.2%, 100%), Augmentin (amoxicillin/clavulanic acid) (70.5%, 80%), cefotaxime (45.8%, 28.6%), cefuroxime (36.8 to 45.5%, 50%), fluoroquinolones (33.3 to 53.6%, 28.6 to 50%), gentamicin (27.5%, 20%), and nitrofurantoin (9.3%, 50%).Conclusion:E coli is the main causal agent of UTI in childhood with a high resistance to antibiotics. Appropriate antibiotics for empiric therapy should be based on local circulating bacterial strains and resistance profiles.

Transcriptional Control of Dual Transporters Involved in α-Ketoglutarate Utilization Reveals Their Distinct Roles in Uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) are the primary causative agents of urinary tract infections. Some UPEC isolates are able to infect renal proximal tubule cells, and can potentially cause pyelonephritis. We have previously shown that to fulfill their physiological roles renal proximal tubule cells accumulate high concentrations of α-ketoglutarate (KG) and that gene cluster c5032–c5039 contribute to anaerobic utilization of KG by UPEC str. CFT073, thereby promoting its in vivo fitness. Given the importance of utilizing KG for UPEC, this study is designed to investigate the roles of two transporters KgtP and C5038 in KG utilization, their transcriptional regulation, and their contributions to UPEC fitness in vivo. Our phylogenetic analyses support that kgtP is a widely conserved locus in commensal and pathogenic E. coli, while UPEC-associated c5038 was acquired through horizontal gene transfer. Global anaerobic transcriptional regulators Fumarate and nitrate reduction (FNR) and ArcA induced c5038 expression in anaerobiosis, and C5038 played a major role in anaerobic growth on KG. KgtP was required for aerobic growth on KG, and its expression was repressed by FNR and ArcA under anaerobic conditions. Analyses of FNR and ArcA binding sites and results of EMS assays suggest that FNR and ArcA likely inhibit kgtP expression through binding to the –35 region of kgtP promoter and occluding the occupancy of RNA polymerases. Gene c5038 can be specifically induced by KG, whereas the expression of kgtP does not respond to KG, yet can be stimulated during growth on glycerol. In addition, c5038 and kgtP expression were further shown to be controlled by different alternative sigma factors RpoN and RpoS, respectively. Furthermore, dual-strain competition assays in a murine model showed that c5038 mutant but not kgtP mutant was outcompeted by the wild-type strain during the colonization of murine bladders and kidneys, highlighting the importance of C5038 under in vivo conditions. Therefore, different transcriptional regulation led to distinct roles played by C5038 and KgtP in KG utilization and fitness in vivo. This study thus potentially expanded our understanding of UPEC pathobiology.

Prevalence of uropathogen and their antibiotic resistance pattern among diabetic patients.

Diabetes mellitus (DM) and antibiotic resistance is an emerging public health problem in Ethiopia. Urinary tract infections (UTIs) are common and occasionally life-threatening condition among diabetic patients. Despite, all these problems, antibiotics are prescribed empirically which may adversely affect antibiotic resistance so far. Therefore the aim of this study was to identify the etiologic agents of UTI and their antibiotic resistance pattern among diabetic patients attending diabetic clinic of Hawassa University Referral Hospital. A cross-sectional study was conducted in a total of 240 diabetic patients from June to October, 2014. After obtaining an informed written consent, socio-demographic and clinical data were collected using pre-structured questionnaire. Clean catch mid-stream urine samples were collected and processed for identification of uropathogen through culture using standard microbiologic procedure. Antibiotic susceptibility test was carried out using Kirby-Bauer disc diffusion method. The overall prevalence of diabetic UTI was 13.8%. Out of the total number of patients, 11.2% and 23.1% had asymptomatic and symptomatic bacteriuria respectively. DM patients with no previous history of UTI [AOR=3.55; 95% CI=1.186-10.611] and illiterate [AOR=2.5; 95% CI=1.052-5.989] had higher odds of UTI compared with their counterparts. E. coli was the commonest isolated uropathogen followed by coagulase-negative Staphylococci. All the isolated bacteria were resistant to ampicillin but sensitive to nitrofurantoin. Gram-negative isolates demonstrated high level of resistance to trimethoprim-sulphamethoxazole in 9 (81.8%), gentamicin in 8 (72.7%) and ceftriaxone in 7 (63.6%) patients. Gram-positive bacteria showed resistance to penicillin in 14 (87.5%), norfloxacin in 10 (62.5%) and ciprofloxacin in 8 (50.0%) patients. Multidrug resistance was observed in 93.9% of the isolated uropathogens. Illiterate DM patients with no previous history of UTI were significantly associated with UTI. Nitrofurantoin can be used as a drug of choice for empiric treatment of UTI in the study area. Multidrug resistance to commonly used antibiotics is an alarming phenomenon. Therefore, performing of urine cultures and periodic surveillance of UTI among DM patients is necessary.

Bacterial agents of Urinary tract infection in renal allograft recipients and their antimicrobial resistance pattern.

Urinary tract infection (UTI) is the most common infectious complications after renal transplantation. Recently many researchers reported that the bacterial agents of UTI in renal allograft recipients changed and demonstrated increased antimicrobial resistance to commonly used cephalosporins. This study was undertaken to isolate the bacteria which are responsible for UTI and their susceptibility pattern for appropriate antibiotic therapy in renal allograft recipients. This was an observational study conducted in the Department of Microbiology Bangabandhu Sheikh Mujib Medical University (BSMMU) from December 2010 to 2011. Twenty one renal allograft recipients from Department of Nephrology were evaluated for UTI after surgery up to six weeks. Microscopic examination, culture and sensitivity of urine specimen were performed. Out of 21 renal allograft recipients, 13 (61.90%) patients developed UTI during initial post transplant period. Of 69 urine specimens collected from them 22(31.88%) yielded positive results for culture. Enterococcus spp. (50%) was the major bacterial pathogen isolated and showed 100% resistance to Cefuroxime, Ceftriaxone and Ceftazidime. Enterococcus spp. is an emerging pathogen responsible for development of UTI in renal allograft recipients which showed 100% resistance to 2nd and 3rd genaration cephalosporin group.Bangladesh J Med Microbiol 2015; 9 (1): 13-16

Repeated Treatments with Chitosan in Combination with Antibiotics Completely Eradicate Uropathogenic Escherichia coli From Infected Mouse Urinary Bladders.

Uropathogenic Escherichia coli (UPEC), the primary causative agents of urinary tract infections, colonize and invade the epithelial cells of the bladder urothelium. Infection of immature urothelial cells can result in the formation of persistent intracellular reservoirs that are refractory to antibiotic treatments. Previously, we defined a novel therapeutic strategy that used the bladder cell exfoliant chitosan to deplete UPEC reservoirs. However, although a single treatment of chitosan followed by ciprofloxacin administration had a marked effect on reducing UPEC titers within the bladder, this treatment failed to prevent relapsing bacteriuria. We show here that repeated use of chitosan in conjunction with the antibiotic ciprofloxacin completely eradicates UPEC from the urinary tract and prevents the development of relapsing bouts of bacteriuria. In addition, microscopy revealed rapid restoration of bladder integrity following chitosan treatment, indicating that chitosan can be used to effectively combat recalcitrant bladder infections without causing lasting harm to the urothelium.