Uropathogenic Escherichia Coli

Escherichia coli (abbreviated as E. coli) is a common bacterium both in daily life and scientific researches. In order to demonstrate the biophysical properties of Escherichia coli, the 3D model and simulation of E. coli are built based on Blender, helping with the visualization. First, a brief introduction to Blender explains why it's chosen as the modelling software and demonstrates the advantages of Blender by comparison; next, the whole process of how the model is built through basic shapes and modifiers is provided step by step. Lastly, several C# scripts in Unity are written to make the model move as real Escherichia coli in a low Reynolds number environment to simulate the behaviour of the cell in line with a given motion mode. The final result manifests the above methods have a great performance in the construction and simulation of E. coli, which could offer ideas for further study of the simulation of the microorganism.

Las infecciones del tracto urinario (ITU), son una de las infecciones más prevalentes y se
considera a Escherichia coli como uno de los principales agentes etiológicos
responsables. El objetivo de esta investigación, se basó en diagnostica la
antibiorresistencia en cepas de Escherichia coli aislada de pacientes con infecciones
urinarias procedentes de la ciudad de Maracaibo, estado Zulia-Venezuela. El
procedimiento para la evaluación de los urocultivos e identificación de los agentes
etiológicos se fundamentó en los protocolos sugeridos por el SEIMC (2013) y las
pruebas de sensibilidad a antibióticos se realizaron mediante los parámetros
establecidos por el CLSI (2017). Los resultados obtenidos, revelaron la prevalencia de
Escherichia coli en un 57,16% de la totalidad de las muestras analizadas, y la
antibiorresistencia con altos niveles porcentuales se registró a la ampicilina/Sulbactam
(82,14%); seguido de tobramicina (67,85%), Piperacilina, amikacina y Ceftazidime con
64,28%, ácido nalidíxico (53,57%), y el resto de los antibióticos con valores iguales o por
debajo del 50%. No obstante la susceptibilidad de igual forma se registró en todos los
antibióticos evaluados y presentó mayores niveles porcentuales que la resistencia; sin
embargo el patrón de multiresistencia reflejo que todas las cepas expresaron resistencia
a dos o más antibióticos de diferente estructura química, considerándose altamente
preocupante. Es recomendable, hacer un monitoreo permanente, en relación a las cepas
causantes de procesos de infección urinaria, ya que cada vez se ven más minimizadas
las opciones terapéuticas para el control de los microorganismos.

Urinary tract infection (UTI) is among the most common infectious diseases of humans and is the most common nosocomial infection in the developed world. They cause significant morbidity and mortality, with approximately 150 million cases globally per year. It is estimated that 40-50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic E. coli (UPEC) is the primary cause of UTI. This review presents an overview of the primary virulence factors of UPEC, the major host responses to infection of the urinary tract, the emergence of specific multidrug resistant clones of UPEC, antibiotic treatment options for UPEC-mediated UTI and the current state of vaccine strategies as well as other novel anti-adhesive and prophylactic approaches to prevent UTI. New and emerging themes in UPEC research are also discussed in the context of future outlooks.

Molecular methods that enable the detection of antimicrobial resistance determinants are critical surveillance tools that are necessary to aid in curbing the spread of antibiotic resistance. In this study, we describe the use of the Antimicrobial Resistance Determinant Microarray (ARDM) that targets 239 unique genes that confer resistance to 12 classes of antimicrobial compounds, quaternary amines and streptothricin for the determination of multidrug resistance (MDR) gene profiles. Fourteen reference MDR strains, which either were genome, sequenced or possessed well characterized drug resistance profiles were used to optimize detection algorithms and threshold criteria to ensure the microarray's effectiveness for unbiased characterization of antimicrobial resistance determinants in MDR strains. The subsequent testing of Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae hospital isolates revealed the presence of several antibiotic resistance genes [e.g. belonging to TEM, SHV, OXA and CTX-M classes (and OXA and CTX-M subfamilies) of blactamases] and their assemblages which were confirmed by PCR and DNA sequence analysis. When combined with results from the reference strains, ,25% of the ARDM content was confirmed as effective for representing allelic content from both Gram-positive and -negative species. Taken together, the ARDM identified MDR assemblages containing six to 18 unique resistance genes in each strain tested, demonstrating its utility as a powerful tool for molecular epidemiological investigations of antimicrobial resistance in clinically relevant bacterial pathogens.

Urinary tract infections (UTIs) are amongst the most common infections encountered in clinical practice with an estimated 150 million UTIs per annum worldwide. The introduction of antimicrobial therapy has contributed significantly to the management of UTIs. However the main problem with current antibiotic therapies is the rapid emergence of antimicrobial resistance in hospitals and the community. Aims: To determine the frequency and pattern of antibiotic resistance among uropathogens in a Tertiary Care Hospital in Silchar. Settings and Design: Outdoor and indoor wards of Silchar Medical College & Hospital, Silchar/ Retrospective study Methods and Material: An analysis was done on all the urine samples (1799) sent for culture and sensitivity to the department of Microbiology, SMCH, Silchar from 1 st January 2011 to 31 st December 2013. A total of 659 positive urinary isolates were detected from the 1799 samples. Antibiotic susceptibility was done on Mueller Hinton Agar plate by Bauer-Kirby method. Extended spectrum beta lactamase (ESBL) production was determined by the double disk approximation test and the Clinical and Laboratory Standards Institute (formerly NCCLS) confirmatory method and Methicilin Resistant Staphylococcus aureus (MRSA) production was determined by the oxacillin disc inhibition test and the Clinical and Laboratory Standards Institute (formerly NCCLS) confirmatory method. Statistical analysis used: Microsoft excel sheet was used to plot the data and prepare the graphs. Results: During the study period, 1799 consecutive urine samples were processed from OPD and indoor patients, 659 (36.63%) of these urine samples [OPD-106 (16.08%) and Indoor-553 (83.92%)] yielded significant growth of pathogens. Escherichia coli was the most frequently isolated uropathogen accounting for 38.54% of the total isolates. ESBL production was observed in 28.74% of E. coli strains and 40.74% of Klebsiella strains. MRSA producing organisms was found to be 28.40% of S. aureus strains. With the exception of nitrofurantoin and amoxycillin/clavulinic acid for gram negative bacteria and linezolid for gram positive cocci, resistance to agents commonly used as oral treatments for UTI was quite high. Conclusions: The study revealed E. coli as the predominant bacterial pathogen, followed by S. aureus for UTIs in Silchar Medical College & Hospital, Silchar, Assam. An increasing trend in the production ESBLs and MRSAs among UTI pathogens were noted.

Background:  Among  marine  organisms,  seaweeds  are  a  highly
diverse group of organisms from which many new substances have
been isolated and many of these compounds have been demonstrated
to possess a large spectrum of bioactivities.
Objective:  In  this  study,  we  aim  to  evaluate  the  antibacterial,
cytotoxic  and  antioxidant  activity  of  green  algae,  Cladophora
prolifera (Roth) Kutzing, collected from the northern Mediterranean
coast of Morocco.
Material and Method: The antibacterial activity was determined by
disk  diffusion  method.  After  fractionation  by  column
chromatography, the fractions from C. prolifera were tested against
Staphylococcus aureus ATCC 25923 using the broth microdilution
assay.  The  antitumor  effect  on  human  colon  cancer  cells  was
investigated  via  sulforhodamine-B  (SRB)  assay.  Then  the  Crude
extract has been tested in radical-scavenging assays to assess their
antioxidant activity.
Results:  In  vitro  screening  of  methanolic  extract  of  C.  prolifera
showed specific activity to inhibit the growth of five virulent strains
of  pathogenic  bacteria,  Escherichia  coli  (ATCC  25922),
Staphylococcus  aureus  (ATCC  25923),  Staphylococcus  aureus
(ATCC 29213), Enterococcus faecalis (ATCC 29212) and Klebsiella
pneumoniae (ATCC 700603). The obtained results indicated that the
extracts of C. prolifera were cytotoxic against HT29 human colon
cancer  cells.  In  addition,  based  on  the  capacity  of  the  algae  to
scavenge  the  ABTS  radical  cation,  we  revealed  that C.  prolifera
extract presented a satisfactory antioxidant activity.
Conclusion:  These  results  suggest  that  C.  prolifera  has  a  great
biological  potential,  which  could  be  considered  for  future  uses  in
food, pharmaceutical and cosmetic industries.

Objectives: Multilocus sequence typing (MLST) has been used to characterize diverse pathogens, including uropathogenic Escherichia coli (UPEC). There has been significant interest in the contribution of the O25b:H4-ST131 lineage to UPEC disease, as these isolates are often highly virulent and exhibit multidrug resistance. To reveal the wider impact of sequence type (ST) 131, we have examined its contribution to the overall population structure of UPEC isolates that were not selected on the basis of virulence or antibiotic resistance.

Molecular methods that enable the detection of antimicrobial resistance determinants are critical surveillance tools that are necessary to aid in curbing the spread of antibiotic resistance. In this study, we describe the use of the Antimicrobial Resistance Determinant Microarray (ARDM) that targets 239 unique genes that confer resistance to 12 classes of antimicrobial compounds, quaternary amines and streptothricin for the determination of multidrug resistance (MDR) gene profiles. Fourteen reference MDR strains, which either were genome, sequenced or possessed well characterized drug resistance profiles were used to optimize detection algorithms and threshold criteria to ensure the microarray's effectiveness for unbiased characterization of antimicrobial resistance determinants in MDR strains. The subsequent testing of Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae hospital isolates revealed the presence of several antibiotic resistance genes [e.g. belonging to TEM, SHV, OXA and CTX-M classes (and OXA and CTX-M subfamilies) of blactamases] and their assemblages which were confirmed by PCR and DNA sequence analysis. When combined with results from the reference strains, ,25% of the ARDM content was confirmed as effective for representing allelic content from both Gram-positive and -negative species. Taken together, the ARDM identified MDR assemblages containing six to 18 unique resistance genes in each strain tested, demonstrating its utility as a powerful tool for molecular epidemiological investigations of antimicrobial resistance in clinically relevant bacterial pathogens.

Uropathogenic Escherichia coli (UPEC) is the leading causative agent of urinary tract infections (UTI) in the developed world. Among the major virulence factors of UPEC, surface expressed adhesins mediate attachment and tissue tropism. UPEC strains typically possess a range of adhesins, with type 1 fimbriae and P fimbriae of the chaperone-usher class the best characterised. We previously identified and characterised F9 as a new chaperone-usher fimbrial type that mediates biofilm formation. However, the regulation and specific role of F9 fimbriae remained to be determined in the context of wild-type clinical UPEC strains. In this study we have assessed the distribution and genetic context of the f9 operon among diverse E. coli lineages and pathotypes and demonstrated that f9 genes are significantly more conserved in a UPEC strain collection in comparison to the well-defined E. coli reference (ECOR) collection. In the prototypic UPEC strain CFT073, the global regulator protein H-NS was identified as a transcriptional repressor of f9 gene expression at 37uC through its ability to bind directly to the f9 promoter region. F9 fimbriae expression was demonstrated at 20uC, representing the first evidence of functional F9 fimbriae expression by wild-type E. coli. Finally, glycan array analysis demonstrated that F9 fimbriae recognise and bind to terminal Galb1-3GlcNAc structures.

Aim: To study the prevalence and molecular basis of antimicrobial resistance in UPEC. Methods and Results: PCR was used to detect the presence of the Class I integron variable region (VR). The VR amplicons were then characterized by partial sequencing and restriction digestion with AluI. VR negative isolates showed more antibiotic susceptibility than VR positive isolates. 30% of the isolates were positive for the VR and carried the genes dfrA7, dfrA17-aadA5, dfrA1-aadA1, dfrA12-orf5-aadA2 and bla OXA-30 -aadA1. Five restriction patterns were detected and isolates with the same VR amplicon size had the same restriction pattern. Conclusions: Our data demonstrated that Class I integrons are widely disseminated in Lebanon and showed their importance for the occurrence and transmission of multidrug resistance. Significance and Impact of the Study: These findings will facilitate greater understanding of the factors that contribute to the presence and transfer of integron-associated antibiotic resistance genes in UPEC.

Urinary tract infection (UTI) is among the most common infectious diseases of humans and is the most common nosocomial infection in the developed world. They cause significant morbidity and mortality, with approximately 150 million cases globally per year. It is estimated that 40-50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic E. coli (UPEC) is the primary cause of UTI. This review presents an overview of the primary virulence factors of UPEC, the major host responses to infection of the urinary tract, the emergence of specific multidrug resistant clones of UPEC, antibiotic treatment options for UPEC-mediated UTI and the current state of vaccine strategies as well as other novel anti-adhesive and prophylactic approaches to prevent UTI. New and emerging themes in UPEC research are also discussed in the context of future outlooks.

Transcriptional profiles of uropathogenic Escherichia coli CFT073 exposed to cranberry-derived proanthocyanidins (PACs) were determined. Our results indicate that bacteria grown on media supplemented with PACs were iron deprived. To our knowledge, this is the first time that PACs have been shown to induce a state of iron limitation in this bacterium.

Vaxign is the first web-based vaccine design system that predicts vaccine targets based on genome sequences using the strategy of reverse vaccinology. Predicted features in the Vaxign pipeline include protein subcellular location, transmembrane helices, adhesin probability, conservation to human and/or mouse proteins, sequence exclusion from genome(s) of nonpathogenic strain(s), and epitope binding to MHC class I and class II. The precomputed Vaxign database contains prediction of vaccine targets for >70 genomes. Vaxign also performs dynamic vaccine target prediction based on input sequences. To demonstrate the utility of this program, the vaccine candidates against uropathogenic Escherichia coli (UPEC) were predicted using Vaxign and compared with various experimental studies. Our results indicate that Vaxign is an accurate and efficient vaccine design program.

Uropathogenic Escherichia coli (UPEC) causes serious infections in people at risk and has a significant environmental prevalence due to contamination by human and animal excreta. In developing countries, UPEC assumes importance in certain dwellings because of poor community/personal hygiene and exposure to contaminated water or soil. We report the complete genome sequence of E. coli strain NA114 from India, a UPEC strain with a multidrug resistance phenotype and the capacity to produce extended-spectrum betalactamase. The genome sequence and comparative genomics emanating from it will be significant in understanding the genetic makeup of diverse UPEC strains and in boosting the development of new diagnostics/vaccines.

The aim of this work was to analyze the current of IRT β-lactamases in uropathogenic Escherichia coli. Isolates were prospectively collected in our hospital (2013 and 2014) from urine of hospitalized patients (100%). From a total of 60 E. coli isolates recovered during the study period, 22 showed reduced susceptibility to Beta lactam Beta lactamase inhibitor (BLBLI) combination antibiotics, with 17 of them producing IRT enzymes. These were mostly recovered from urine (100%). A high degree of IRT was detected (TEM-2, CTX-M, bla-SHV, SHV-2, TEM-1,OXA-1, and AMPC). The results of this study are recorded for the first time in Iraq.

Bladder infections affect millions of people yearly, and recurrent symptomatic infections (cystitis) are very common. The rapid increase in infections caused by multidrug-resistant uropathogens threatens to make recurrent cystitis an increasingly troubling public health concern. Uropathogenic Escherichia coli (UPEC) cause the vast majority of bladder infections. Upon entry into the lower urinary tract, UPEC face obstacles to colonization that constitute population bottlenecks, reducing diversity, and selecting for fit clones. A critical mucosal barrier to bladder infection is the epithelium (urothelium). UPEC bypass this barrier when they invade urothelial cells and form intracellular bacterial communities (IBCs), a process which requires type 1 pili. IBCs are transient in nature, occurring primarily during acute infection. Chronic bladder infection is common and can be either latent, in the form of the quiescent intracellular reservoir (QIR), or active, in the form of asymptomatic bacteriuria (ASB/ABU) or chronic cystitis. In mice, the fate of bladder infection, QIR, ASB, or chronic cystitis, is determined within the first 24 h of infection and constitutes a putative host-pathogen mucosal checkpoint that contributes to susceptibility to recurrent cystitis. Knowledge of these checkpoints and bottlenecks is critical for our understanding of bladder infection and efforts to devise novel therapeutic strategies.

Escherichia coli clonal group A (CgA) causes disease in humans. This is the first study investigating the prevalence of CgA among E. coli from non-urine, extraintestinal infections in a northern European country. E. coli blood (n = 196) and paired urine (n = 195) isolates from the same patients with bacteraemia of urinary tract origin were analysed. The isolates were collected from January 2003 through May 2005 at four hospitals in Copenhagen, Denmark. Pulsed-field gel electrophoresis (PFGE) patterns, antimicrobial resistance and patient characteristics were determined for all CgA isolates; presence of virulence-associated genes (VAGs) and serotypes were determined for the blood CgA isolates. Thirty blood isolates (15%) belonged to CgA. CgA blood isolates were associated with female patients and sulfamethoxazole-trimethoprim resistance and they harboured a distinctive VAG profile. The blood and urine isolates from each pair were found to be related in 26 of 27 CgA blood/urine pairs, confirming a urinary tract origin of infection. Furthermore, a relationship between the PFGE patterns of CgA blood/urine isolates and CgA isolates from UTI patients in general practice and a CgA isolate from a community-dwelling human reported previously, was found, suggesting a community origin of CgA. The finding of CgA strains in 15% of the E. coli bloodstream infections with a urinary tract origin in Denmark suggests that CgA constitutes an important clonal lineage among extraintestinal pathogenic E. coli. A reservoir of this pathogenic E. coli group in the community causing not only UTI but also more severe infections such as bacteraemia has implications for public health.

Urinary tract infections (UTIs) afflict over 9 million women in America every year, often necessitating long-term prophylactic antibiotics. One risk factor for UTI is frequent sexual intercourse, which dramatically increases the risk of UTI. The mechanism behind this increased risk is unknown; however, bacteriuria increases immediately after sexual intercourse episodes, suggesting that physical manipulation introduces periurethral flora into the urinary tract. In this paper, we investigated whether superinfection (repeat introduction of bacteria) resulted in increased risk of severe UTI, manifesting as persistent bacteriuria, high titer bladder bacterial burdens and chronic inflammation, an outcome referred to as chronic cystitis. Chronic cystitis represents unchecked luminal bacterial replication and is defined histologically by urothelial hyperplasia and submucosal lymphoid aggregates, a histological pattern similar to that seen in humans suffering chronic UTI. C57BL/6J mice are resistant to chronic cystitis after a single infection; however, they developed persistent bacteriuria and chronic cystitis when superinfected 24 hours apart. Elevated levels of interleukin-6 (IL-6), keratinocyte cytokine (KC/CXCL1), and granulocyte colony-stimulating factor (G-CSF) in the serum of C57BL/6J mice prior to the second infection predicted the development of chronic cystitis. These same cytokines have been found to precede chronic cystitis in singly infected C3H/ HeN mice. Furthermore, inoculating C3H/HeN mice twice within a six-hour period doubled the proportion of mice that developed chronic cystitis. Intracellular bacterial replication, regulated hemolysin (HlyA) expression, and caspase 1/11 activation were essential for this increase. Microarrays conducted at four weeks post inoculation in both mouse strains revealed upregulation of IL-1 and antimicrobial peptides during chronic cystitis. These data suggest a mechanism by which caspase-1/11 activation and IL-1 secretion could predispose certain women to recurrent UTI after frequent intercourse, a predisposition predictable by several serum biomarkers in two murine models.

Urinary tract infection (UTI) is among the most common infectious diseases of humans and is the most common nosocomial infection in the developed world. They cause significant morbidity and mortality, with approximately 150 million cases globally per year. It is estimated that 40-50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic E. coli (UPEC) is the primary cause of UTI. This review presents an overview of the primary virulence factors of UPEC, the major host responses to infection of the urinary tract, the emergence of specific multidrug resistant clones of UPEC, antibiotic treatment options for UPEC-mediated UTI and the current state of vaccine strategies as well as other novel anti-adhesive and prophylactic approaches to prevent UTI. New and emerging themes in UPEC research are also discussed in the context of future outlooks.

Urinary tract infections are among the most common infectious diseases encountered in humans and Escherichia coli is their leading etiologic agent. Uropathogenic E. coli encompasses a group of bacteria possessing a variable virulence gene assortment. It is generally agreed that many urovirulence factors remain to be discovered and that this information is required to gain knowledge on the pathogenic processes underlying the different clinical presentations of urinary tract infections. The production of higher-molecular-mass microcins, a group of ribosomally-synthesized peptide antibiotics comprising microcins H47, I47, E492, M and ColV, has been proposed as a virulence trait of some uropathogenic E. coli. To study this possibility, clones producing any of these microcins were selected from a collection of 160 Gram-negative clinical isolates from urine cultures and their virulence profile was analyzed. The study consisted in surveying genetic loci known to be relevant to urinary tract infection caused by E. coli. Depending on the type of microcin produced, different virulence patterns were observed which seemed to be determined by the degree of compatibility between virulence and microcin loci. In conclusion, results pointed to a relationship between higher-molecular-mass microcins and urovirulence.

The dried stigmata from Zea mays L. are used traditionally for the treatment of uncomplicated urinary tract infections. A recent screening has indicated that hydroalcoholic extract of the herbal material inhibits the adhesion of uropathogenic Escherichia coli (UPEC) to T24 bladder cells. For verification of these data EtOH-water (1:1) extracts from 4 different batches of Maydis stigmata were investigated. Within an in vitro adhesion assay (UPEC strain 2980 and human T24 bladder cells) a dose-dependent antiadhesive activity against UPEC was verified (IC 50 1040 μg/mL). Bioassay guided fractionation of M. stigmata, batch S1, by EtOH-water extraction, followed by chromatography on Sephadex LH20 revealed two active fractions (I and XI). Further purification of fraction I and structure elucidation of the isolated compound revealed the presence of significant amounts of the biocide benzethonium chloride as contaminant. Benzethonium chloride was also identified in subsequent investigations in 2 different batches of M. stigmata. The presence of such nondeclared and illegal contaminants in the herbal raw material market has to be discussed intensively. From benzethonium-free raw material (batch S2) as well as from batch S1 fraction XI was further fractionated by MPLC and preparative HPLC, leading to a still complex subfraction XI G , which was analyzed by UHPLC/+ESI-QTOF-MS analysis. Advanced data processing and species-metabolite relationship database revealed the tentatively existence of the unusual C-glycosidic flavones derhamnosylmaysin (6), 3′-deoxyrhamnosylmaysin (4), 3′-O-methylderhamnosylmaysin (3), apiferol (2) and alternanthin (8) which might be related to the antiadhesive activity of this subfraction against UPEC.

Molecular methods that enable the detection of antimicrobial resistance determinants are critical surveillance tools that are necessary to aid in curbing the spread of antibiotic resistance. In this study, we describe the use of the Antimicrobial Resistance Determinant Microarray (ARDM) that targets 239 unique genes that confer resistance to 12 classes of antimicrobial compounds, quaternary amines and streptothricin for the determination of multidrug resistance (MDR) gene profiles. Fourteen reference MDR strains, which either were genome, sequenced or possessed well characterized drug resistance profiles were used to optimize detection algorithms and threshold criteria to ensure the microarray's effectiveness for unbiased characterization of antimicrobial resistance determinants in MDR strains. The subsequent testing of Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae hospital isolates revealed the presence of several antibiotic resistance genes [e.g. belonging to TEM, SHV, OXA and CTX-M classes (and OXA and CTX-M subfamilies) of blactamases] and their assemblages which were confirmed by PCR and DNA sequence analysis. When combined with results from the reference strains, ,25% of the ARDM content was confirmed as effective for representing allelic content from both Gram-positive and -negative species. Taken together, the ARDM identified MDR assemblages containing six to 18 unique resistance genes in each strain tested, demonstrating its utility as a powerful tool for molecular epidemiological investigations of antimicrobial resistance in clinically relevant bacterial pathogens.

This study describes the genotypic characteristics of a collection of 100 multidrug-resistant (MDR) Escherichia coli strains recovered from cattle and the farm environment in Ireland in 2007. The most prevalent antimicrobial resistance identified was to streptomycin (100%), followed by tetracycline (99%), sulfonamides (98%), ampicillin (82%), and neomycin (62%). Resistance was mediated predominantly by strA-strB (92%), tetA (67%), sul2 (90%), bla(TEM) (79%), and aphA1 (63%) gene markers, respectively. Twenty-seven isolates harbored a class 1 integrase (intI1), while qacEΔ1 and sul1 markers were identified in 25 and 26 isolates, respectively. The variable regions of these integrons contained aminoglycoside, trimethoprim, and β-lactam resistance determinants (aadA12, aadB-aadA1, bla(OXA-30)-aadA1, dfrA1-aadA1, dfrA7). Class 2 integrons were identified less frequently (4%) and contained the gene cassette array dfrA1-sat1-aadA1. Resistance to ampicillin, neomycin, streptomycin, sulfonam...

The virulence determinants of uropathogenic Escherichia coli have been studied extensively over the years, but relatively little is known about what differentiates isolates causing various types of urinary tract infections. In this study, we compared the genomic profiles of 45 strains from a range of different clinical backgrounds, i.e., urosepsis, pyelonephritis, cystitis, and asymptomatic bacteriuria (ABU), using comparative genomic hybridization analysis. A microarray based on 31 complete E. coli sequences was used. It emerged that there is little correlation between the genotypes of the strains and their disease categories but strong correlation between the genotype and the phylogenetic group association. Also, very few genetic differences may exist between isolates causing symptomatic and asymptomatic infections. Only relatively few genes that could potentially differentiate between the individual disease categories were identified. Among these were two genomic islands, namely, pathogenicity island (PAI)-CFT073-serU and PAI-CFT073-pheU, which were significantly more associated with the pyelonephritis and urosepsis isolates than with the ABU and cystitis isolates. These two islands harbor genes encoding virulence factors, such as P fimbriae (pyelonephritis-associated fimbriae) and an important immunomodulatory protein, TcpC. It seems that both urovirulence and growth fitness can be attributed to an assortment of genes rather than to a specific gene set. Taken together, urovirulence and fitness are the results of the interplay of a mixture of factors taken from a rich menu of genes.

Urinary tract infections (UTIs) are among the most common infections in most countries and they are usually caused by the so-called uropathogenic (UP) microorganisms, including Escherichia coli (80%-90%), Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae. Over the years, the growth of resistance to antibiotics has complicated the treatment of UTIs and has direct consequences on the cost of treatment, the severity of infections, and the length of hospitalization. Medicinal plants, used for thousands of years to treat various diseases, constitute a serious alternative to antibiotics in the public health issue of antimicrobial resistance. In this review, the in vitro and in vivo use of medicinal plants and their nanoparticles (silver, gold, zinc, copper oxide, magnesium oxide, iron, etc.) in the management of uropathogens and their virulence factors (VFs) as well as in the management of UTIs themselves have been discussed. Given the advantages offered by the biologically active compounds of medicinal plants as well as their green-synthetized nanoparticles whether used as such or in combination with conventional antibiotics, it can be concluded that herbal medicine can significantly help in the management of UTIs.

Urinary tract infections (UTIs) are among the most common infections in most countries and they are usually caused by the so-called uropathogenic (UP) microorganisms, including Escherichia coli (80%-90%), Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae. Over the years, the growth of resistance to antibiotics has complicated the treatment of UTIs and has direct consequences on the cost of treatment, the severity of infections, and the length of hospitalization. Medicinal plants, used for thousands of years to treat various diseases, constitute a serious alternative to antibiotics in the public health issue of antimicrobial resistance. In this review, the in vitro and in vivo use of medicinal plants and their nanoparticles (silver, gold, zinc, copper oxide, magnesium oxide, iron, etc.) in the management of uropathogens and their virulence factors (VFs) as well as in the management of UTIs themselves have been discussed. Given the advantages offered by the biologically active compounds of medicinal plants as well as their green-synthetized nanoparticles whether used as such or in combination with conventional antibiotics, it can be concluded that herbal medicine can significantly help in the management of UTIs.

Urinary tract infections (UTIs) are mainly caused by uropathogenic Escherichia coli (UPEC). Acute and recurrent UTIs are commonly treated with antibiotics, the efficacy of which is limited by the emergence of antibiotic resistant strains. The natural sugar d-mannose is considered as an alternative to antibiotics due to its ability to mask the bacterial adhesin FimH, thereby preventing its binding to urothelial cells. Despite its extensive use, the possibility that d-mannose exerts "antibiotic-like" activity by altering bacterial growth and metabolism or selecting FimH variants has not been investigated yet. To this aim, main bacterial features of the prototype UPEC strain CFT073 treated with d-mannose were analyzed by standard microbiological methods. FimH functionality was analyzed by yeast agglutination and human bladder cell adhesion assays. Our results indicate that high d-mannose concentrations have no effect on bacterial growth and do not interfere with the activity of different antibiotics. d-mannose ranked as the least preferred carbon source to support bacterial metabolism and growth, in comparison with d-glucose, d-fructose, and l-arabinose. Since small glucose amounts are physiologically detectable in urine, we can conclude that the presence of d-mannose is irrelevant for bacterial metabolism. Moreover, d-mannose removal after long-term exposure did not alter FimH's capacity to bind to mannosylated proteins. Overall, our data indicate that d-mannose is a good alternative in the prevention and treatment of UPEC-related UTIs.

Uropathogenic Escherichia coli (UPEC) is a major cause of urinary tract and bloodstream infections and possesses an array of virulence factors for colonization, survival, and persistence. One such factor is the polysaccharide K capsule. Among the different K capsule types, the K1 serotype is strongly associated with UPEC infection. In this study, we completely sequenced the K1 UPEC urosepsis strain PA45B and employed a novel combination of a lytic K1 capsule-specific phage, saturated Tn5 transposon mutagenesis, and high-throughput transposon-directed insertion site sequencing (TraDIS) to identify the complement of genes required for capsule production. Our analysis identified known genes involved in capsule biosynthesis, as well as two additional regulatory genes (mprA and lrhA) that we characterized at the molecular level. Mutation of mprA resulted in protection against K1 phage-mediated killing, a phenotype restored by complementation. We also identified a significantly increased ...

Shiga toxin-producing Escherichia coli (STEC) isolates (N = 38) that were incriminated in human disease from 2006 to 2013 in South Africa were characterized by serotype, virulence-associated genes, antimicrobial resistance and pulsed-field gel electrophoresis (PFGE). The isolates belonged to 11 O:H serotypes. STEC O26:H11 (24%) was the most frequent serotype associated with human disease, followed by O111:H8 (16%), O157:H7 (13%) and O117:H7 (13%). The majority of isolates were positive for key virulence-associated genes including stx1 (84%), eaeA (61%), ehxA (68.4%) and espP (55%), but lacked stx2 (29%), katP (42%), etpD (16%), saa (16%) and subA (3%). stx2 positive isolates carried stx2c (26%) and/or stx2d (26%) subtypes. All pathogenicity island encoded virulence marker genes were detected in all (100%) isolates except nleA (47%), nleC (84%) and nleD (76%). Multidrug resistance was observed in 89% of isolates. PFGE revealed 34 profiles with eight distinct clusters that shared ≥80% intra-serotype similarity, regardless of the year of isolation. In conclusion, STEC isolates that were implicated in human disease between 2006 and 2013 in South Africa were mainly non-O157 strains which possessed virulence genes and markers commonly associated with STEC strains that have been incriminated in mild to severe human disease worldwide. Improved STEC monitoring and surveillance programs are needed in South Africa to control and prevent STEC disease in humans.

ABSTRACTThepstSCAB-phoUoperon encodes the phosphate-specific transport system (Pst). Loss of Pst constitutively activates the Pho regulon and decreases bacterial virulence. However, specific mechanisms underlying decreased bacterial virulence through inactivation of Pst are poorly understood. In uropathogenicEscherichia coli(UPEC) strain CFT073, inactivation ofpstdecreased urinary tract colonization in CBA/J mice. Thepstmutant was deficient in production of type 1 fimbriae and showed decreased expression of thefimAstructural gene which correlated with differential expression of thefimB,fimE,ipuA, andipbAgenes, encoding recombinases, mediating inversion of thefimpromoter. The role offimdownregulation in attenuation of thepstmutant was confirmed using afimphase-locked-on derivative, which demonstrated a significant gain in virulence. In addition, thepstmutant was less able to invade human bladder epithelial cells. Since type 1 fimbriae contribute to UPEC virulence by promoting coloniz...

Consumption of cranberries is known to exert positive health effects, especially against urinary tract infections. For this reason, presumably, they are widely used in folk medicine. Different aspects of cranberry phenolics activity were studied in individual papers but complex study in this matter is missing. The aim of the present study is to provide complex data concerning various aspects of cranberry extract activity. We studied the effects of subinhibitory concentrations of commercially available extract (Żuravit S•O•S ®) against two Escherichia coli strains isolated from urine of patients with pyelonephritis. Additionally the main extract anthocyanins were characterized. The activity of extract against lipid peroxidation and its radical scavenging ability were also assessed.Żuravit S•O•S ® decreased the hydrophobicity of one of the studied E. coli strains, reduced swimming motility and adhesion to epithelial cells of both studied strains, it also limited the ability of bacteria to form biofilm. Expression of curli was not affected by cranberry extract, the assessment of P fimbriae expression was not reliable due to extract-induced agglutination of erythrocytes. Cranberry extract caused filamentation in both studied E. coli strains. It also showed pronounced antioxidant and radical scavenging properties. The properties of the studied cranberry extract show that it could be effectively used in prevention and/or elimination of urinary tract infections, specially the recurrent ones.

Uropathogenic Escherichia coli (UPEC) is a leading etiological agent of bacteremia in humans. Virulence mechanisms of UPEC in the context of urinary tract infections have been subjected to extensive research. However, understanding of the fitness mechanisms used by UPEC during bacteremia and systemic infection is limited. A forward genetic screen was utilized to detect transposon insertion mutants with fitness defects during colonization of mouse spleens. An inoculum comprised of 360,000 transposon mutants in the UPEC strain CFT073, cultured from the blood of a patient with pyelonephritis, was used to inoculate mice intravenously. Transposon insertion sites in the inoculum (input) and bacteria colonizing the spleen (output) were identified using high-throughput sequencing of transposon-chromosome junctions. Using frequencies of representation of each insertion mutant in the input and output samples, 242 candidate fitness genes were identified. Coinfection experiments with each of 11 defined mutants and the wild-type strain demonstrated that 82% (9 of 11) of the tested candidate fitness genes were required for optimal fitness in a mouse model of systemic infection. Genes involved in biosynthesis of poly-N-acetyl glucosamine (pgaABCD), major and minor pilin of a type IV pilus (c2394 and c2395), oligopeptide uptake periplasmic-binding protein (oppA), sensitive to antimicrobial peptides (sapABCDF), putative outer membrane receptor (yddB), zinc metallopeptidase (pqqL), a shikimate pathway gene (c1220) and autotransporter serine proteases (pic and vat) were further characterized. Here, we report the first genome-wide identification of genes that contribute to fitness in UPEC during systemic infection in a mammalian host. These fitness factors may represent targets for developing novel therapeutics against UPEC.

Introduction: Antibiotic resistance, especially in Gram-negative uropathogens such as Escherichia coli, is the main barrier to treat urinary tract infection (UTI). In recent years, the dramatically increased resistance of E. coli to quinolones, a group of widely used antibiotics, has become a significant concern. Methods: In this descriptive cross-sectional study, we collected 261 E. coli isolates from the urine and stool samples of patients, referred to or hospitalized at Loghman hospital in Tehran, Iran, with either acute or recurrent UTI. The susceptibility testing for quinolones was performed by the disk diffusion method according to the recent protocols. Results: The frequency of resistant E. coli isolates was higher against nalidixic acid than ciprofloxacin and norfloxacin (67.8% vs. 48.7% and 44.1% respectively). When comparing acute and recurrent phases of UTI, in the urine samples, no significant difference was seen in the frequency of resistant isolates against nalidixic acid and norfloxacin, while this frequency against ciprofloxacin was significantly higher in recurrent UTI (68% vs. 48.2%). However, in the stool samples, the frequency of resistant isolates against nalidixic acid was higher in recurrent UTI (77.1% vs. 55.7%), while no significant difference was seen against ciprofloxacin and norfloxacin in these phases. Conclusion: Regarding the antibiotic type and frequency of the administration, the resistance pattern of E. coli to quinolones seems to differ in acute and recurrent phases of UTI.

FimH, the type 1 pilus adhesin of uropathogenic Escherichia coli (UPEC), contains a receptor-binding domain with an acidic binding pocket specific for mannose. The fim operon, and thus type 1 pilus production, is under transcriptional control via phase variation of an invertible promoter element. FimH is critical during urinary tract infection for mediating colonization and invasion of the bladder epithelium and establishment of intracellular bacterial communities (IBCs). In silico analysis of FimH gene sequences from 279 E. coli strains identified specific amino acids evolving under positive selection outside of its mannose-binding pocket. Mutating two of these residues (A27V/V163A) had no effect on phase variation, pilus assembly, or mannose binding in vitro. However, compared to wild-type, this double mutant strain exhibited a 10,000-fold reduction in mouse bladder colonization 24 h after inoculation and was unable to form IBCs even though it bound normally to mannosylated receptors in the urothelium. In contrast, the single A62S mutation altered phase variation, reducing the proportion of piliated cells, reduced mannose binding 8-fold, and decreased bladder colonization 30-fold in vivo compared to wild-type. A phase-locked ON A62S mutant restored virulence to wild-type levels even though in vitro mannose binding remained impaired. Thus, positive selection analysis of FimH has separated mannose binding from in vivo fitness, suggesting that IBC formation is critical for successful infection of the mammalian bladder, providing support for more general use of in silico positive selection analysis to define the molecular underpinnings of bacterial pathogenesis.