Uropathogenic Specific Protein Research Articles

Detection of Uropathogenic Specific Protein Gene (usp) and Multidrug Resistant Bacteria (MDR) of Pathogenic Escherichia coli Isolated from Baghdad City

Escherichia coli is gram negative bacteria and represents a typical resident of the digestive systems of both humans and animals. The stability and equilibrium of the luminal microbial flora are significantly influenced by E. coli. The Escherichia coli uropathogenic-specific protein (Usp) represents type of genotoxins produced by uropathogenic E. coli rather than fecal E. coli isolates. In the current study E. coli was isolated from urine and stool and usp gene was detected in it. Sensitivity test was evaluated by using different types of antibiotics and the usp gene was detected by PCR in all bacterial isolates. Antibiotics sensitivity test showed variable degrees of sensitivity and resistance. High percentage of sensitivity was achieved against amikacin (86%) and that for ciprofloxacin, ceftazidime, gentamicin and tobramycin it was 80%. Whereas trimethoprim and aztreonam showed 64% and 60% sensitivity respectively. In this study, most isolates were resistant to amoxicillin 92%; while they showed different degrees of resistance against other types of antibiotics (from tetracycline 62% to amikacin 4%). The frequency of multi drug resistant (MDR) bacteria was about 64 % (32 isolates), 30 from urine and 2 from the stool. The results showed that usp gene was found in 26 bacterial isolates (52%), whereas other 24 (48%) isolates didn’t have this gene. It was concluded that source of bacterial isolates carry usp gene was urine, with the exception of one isolate from f stool, and E. coli recorded as multidrug resistant bacteria (MDR).

Abstract 713: Monoclonal antibodies for the detection of the uropathogenic specific protein (USP): A bacterial genotoxin linked to colorectal cancer

Abstract The Uropathogenic Specific Protein (USP) is an E. coli genotoxin nuclease primarily associated with urinary tract infections. Previous efforts in our laboratory found the USP gene in stool samples; more frequently found in stool samples from adenoma and CRC patients than in samples from healthy individuals. New efforts in our laboratory aim to find the USP protein in the same population of patient samples and this may require anti-USP antibodies, which at present are not commercially available. In this work, we report the first anti-USP monoclonal antibodies (mAbs) for the detection of USP in human samples. A total of 38 hybridoma supernatants containing mAbs were assayed by immunoblotting and biolayer light interferometry (BLI) for their ability to recognize purified USP(∆HNH). Results from BLI showed that the pair AB-A10 and AB-D5 presented the highest affinity with slow dissociation, moving forward for the development of a sandwich ELISA. Using AB-A10 as the capture antibody, and AB-D5 as the top antibody, results from the ELISA showed signals that were concentration-dependent above 6 ug/mL of USP. We also used the AB-D5 and AB-D10 in immunoblots for the detection of USP in proteins extracted from stool samples of patients with adenoma and CRC. The immunoblots reveal the detection of a 25 kDa protein that remains unidentified but is present only in some of the samples. This could be the first detection of USP protein directly in a biological sample. Efforts are underway to identify this protein band and confirm its identity as USP. Additional efforts are aimed at increasing the number of stool samples analyzed to establish whether USP protein is a risk factor for CRC or adenoma. Citation Format: Rachell Martínez-Ramírez, Valeria Toro-Díaz Toro-Díaz, Pearl Akamine, Kimberly Ruiz-Rosado, Ignacio Pino, Abel Baerga-Ortiz. Monoclonal antibodies for the detection of the uropathogenic specific protein (USP): A bacterial genotoxin linked to colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 713.

Characterization of Escherichia coli in Dogs with Pyometra and the Influence of Diet on the Intestinal Colonization of Extraintestinal Pathogenic E. coli (ExPEC).

Despite its high frequency and clinical relevance, the pathogenesis of canine pyometra remains poorly understood. The most accepted hypothesis is that bacteria involved ascend from the intestinal tract, causing the uterine infection. Extraintestinal pathogenic Escherichia coli (ExPEC) is the most frequent pathogen in canine pyometra, accounting for 57–100% of cases. The aim of the present study was to determine the frequency of phylogenetic groups and virulence factors in E. coli strains isolated from the uterine and rectal swabs of bitches with pyometra (n = 72) and from rectal swabs from healthy bitches fed commercial dry feed (n = 53) or a raw meat-based diet (RMBD; n = 38). A total of 512 strains of E. coli were isolated and divided into five categories according to the origin of the sample: 120 isolates from the uterine content of dogs with E. coli pyometra, 102 from the feces of bitches with E. coli pyometra, 75 from the feces of bitches without E. coli pyometra, 130 feces samples from healthy dogs fed commercial feed, and 85 feces samples from healthy dogs fed a raw meat-based diet. E. coli strains belonging to the B2 phylogroup and positive for virulence factor genes associated with adhesion (fimbriae type P [papC]) and production of toxins (α-hemolysin [hlyA] and uropathogenic specific protein [usp]) predominated in the uterine content and rectal swabs of bitches with E. coli pyometra. Interestingly, a lower growth rate of E. coli from the B2 phylogroup was observed in dogs fed a RMBD than in those fed commercial dry feed. The present study suggests that intestinal colonization by certain types of E. coli could be a risk factor for the occurrence of E. coli pyometra in bitches and that diet can influence intestinal colonization by such strains.

Kedi ve köpeklerin ürogenital sistem infeksiyonlarından izole edilen Escherichia coli'lerin virulens faktörlerinin belirlenmesi

In this study, virulence factors such as serum resistance, aerobactin iron uptake systems, adhesins (type 1 fimbria, P fimbria, S fimbria, afimbrial adhesins), haemolysine, uropathogenic spesific protein and cytotoxic necrotizing factor in 45 Escherichia coli isolates from dogs and cats with urinary tract and genital system infections, were investigated by both phenotypic methods and molecular methods. In PCR examinations of 45 E. coli, hlyA gene was detected in 73.3% of all isolates. fimH was found in 100%, papC in 71.1%, sfaDE in 82.2%, and afaBC in 0% of the isolates. iucD, traT, usp, cnf1 and cvaC genes were found in 20%, 71.1%, 84.4%, 75.5%, and 11.1% of the isolates, respectively. According to the isolation rate of hlyA and haemolytic activity on blood agar, this virulence factor is commonly seen in these strains and important in these infections especially pathogenesis. İsolates was found to be a high rate positive for usp gene. This result suggested that this strain may have higher infectivity. Cytotoxic necrotizing factor was common and important virulence factor in uropathogenic E. coli and prognosis of infection. However, colisin encoding gene (cvaC) only were detected from 5 of urine samples from dogs. This virulence factor could be important for the urinary tract infections in dogs rather than cats. Haemolysis, type 1 fimbriae, P fimbriae, S fimbriae, cnf, serum resistance, uropathogenic specific protein were detected at high rates by molecular method. In E. coli strains isolated from dogs, virulence factors were found to be higher than cat isolates.

The Uropathogenic Specific Protein Gene usp from Escherichia coli and Salmonella bongori is a Novel Member of the TyrR and H-NS Regulons.

The Escherichia coli PAIusp is a small pathogenicity island encoding usp, for the uropathogenic specific protein (Usp), a genotoxin and three associated downstream imu1-3 genes that protect the producer against its own toxin. Bioinformatic analysis revealed the presence of the PAIusp also in publically available Salmonella bongori and Salmonella enterica subps. salamae genome sequences. PAIusp is in all examined sequences integrated within the aroP-pdhR chromosomal intergenic region. The focus of this work was identification of the usp promoter and regulatory elements controlling its activity. We show that, in both E. coli and S. bongori, the divergent TyrR regulated P3 promoter of the aroP gene, encoding an aromatic amino acid membrane transporter, drives usp transcription while H-NS acts antagonistically repressing expression. Our results show that the horizontally acquired PAIusp has integrated into the TyrR regulatory network and that environmental factors such as aromatic amino acids, temperature and urea induce usp expression.

The incidence of some virulence factors among thebacterial isolates from the patients with prostatitis and their relation with antibiotic susceptibility

Background:Inflammation is observed in theprostate tissue from patients with prostatitis and the bacteria may involving due to their ability to produce virulence factors. Recent studies have suggested that the decrease in the pathogenicity of Escherichia coli is due to acquisitionof resistance to some antibiotics. This study was performed to investigate three virulence factors includingcytotoxic necrotizing factor-1(cnf-1),uropathogenic specific protein (usp) and group II capsule(kpsMTII) in bacterial isolates from the patients with prostatitis and determine their antibiotics susceptibility patterns
 Methods:The drug sensitivity of (11) bacterial isolates including (10)E. coli isolates and (1) Enterobacteraerogenes isolate from patients with prostatitiswere evaluated by using a disc diffusion method. The prevalence ofvirulence genes (cnf-1, uspandkpsMTII ) was determined by PCR.Results:The isolates were highly sensitive to amikacin (81.81%).But the isolates showed a high resistant to other antibiotics , ampicillin (100%), Cotrimoxazole (100%) , Azithromycin (81.81%) , Cefotaxime (81.81%) , Ciprofloxacin (72.72%) and Gentamicin (63.63%) . PCR showed that kpsMTII (72.72%) was more prevalent than usp(18.18%) and the cnf-1 was not detected in all isolates .Conclusion: We propose that the isolates from patients with prostatitis were low virulent in combination with high resistance to many antibiotics.

Polymerase chain reaction-restriction fragment length polymorphism method for differentiation of uropathogenic specific protein gene types.

The putative pathogenicity island (PAI) containing the uropathogenic specific protein (usp) gene and three small open reading frames (orfU1, orfU2, and orfU3) encoding 98, 97, and 96 amino acid proteins is widely distributed among uropathogenic Escherichia coli (UPEC) strains. This PAI was designated as PAIusp. Sequencing analysis of PAIusp has revealed that the usp gene can be divided into two types - uspI and uspII - based on sequence variation at the 3' terminal region and the number and position of orfUs differ from strain to strain. Based on usp gene types and orfU sequential patterns, PAIusp can be divided into four subtypes. Subtyping of PAIusp is a useful method to characterize UPEC strains. In this study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to differentiate usp gene types. This method could correctly identify the usp gene type in usp-positive UPEC strains in our laboratory.

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The Escherichia coli uropathogenic-specific-protein-associated immunity protein 3 (Imu3) has nucleic acid -binding activity

BackgroundThe Escherichia coli uropathogenic-specific protein (Usp) is a bacteriocin-like genotoxin, active against mammalian cells and associated with E. coli strains that provoke pyelonephritis, prostatitis and bacteraemia. Usp is encoded by a small pathogenicity island with three downstream small open reading frames (Imu1-3) that are believed to provide immunity to the producer. To prevent host suicide, colicins, bacteriocins of E. coli, form tight complexes with their cognate immunity proteins. Colicin – immunity protein complexes are among the strongest protein complexes known. Here, the Usp associated immunity protein 3 (Imu3) was partially characterized to gain insight into its role and mechanism of activity.ResultsIsolation and partial characterisation of the Usp-associated immunity protein-3 (Imu3) revealed that, while Usp and Imu3 do not form a high affinity complex, Imu3 exhibits DNA and RNA binding activity. Imu3 was also shown to protect DNA against degradation by colicin E7.ConclusionsOur data infer that nonspecific DNA binding of the Imu3 immunity protein, prevents suicide of E. coli producing the genotoxin Usp.

Escherichia coli Uropathogenic-Specific Protein, Usp, Is a Bacteriocin-Like Genotoxin

Bacterial genotoxins provoke DNA damage and carcinogenesis. The Escherichia coli uropathogenic-specific protein gene, usp, and its linked genes, imu1-3, are associated with strains from pyelonephritis, prostatitis, and bacteremia of urinary tract origin. While the Usp C-terminal domain exhibits similarity with DNase-like colicins and pyocins, its role and mechanisms of action, as well as those of the 3 associated proteins, is unknown. We isolated Usp and Imu1-3 and examined their activity on plasmid DNA, human umbilical vein endothelial cells, and human embryonic kidney cells (cell line HEK293). The affect of Usp and Imu1-3 was assessed by MTT and Comet assays, infection assays, caspase 3/7 activity, fluorescently labeled actin staining, and Western blotting. Usp possesses DNase activity and, particularly when coapplied with Imu2, exhibits genotoxic activity in mammalian cells. Infection assays demonstrated that E. coli usp(+) imu1-3(+) affects the viability of mammalian cells, induces increased caspase 3/7 activity, and perturbs cell cytoskeleton structure. Usp is a novel E. coli genotoxin active against mammalian cells. Optimal in vivo activity of Usp requires Imu2. Infection with E. coli usp(+) imu1-3(+) induces a response characteristic of apoptosis.

Uropathogenic specific protein gene, highly distributed in extraintestinal uropathogenic Escherichia coli, encodes a new member of H-N-H nuclease superfamily

BackgroundThe uropathogenic specific protein (Usp) and three OrfU proteins (OrfU1, OrfU2 and OrfU3) are encoded in the putative small pathogenicity island which is closely associated with Uropathogenic Escherichia coli. Although homology search revealed that Usp and OrfUs have a homology with nuclease-type bacteriocins, which possess H-N-H nuclease motif, and immunity proteins respectively, the molecular activity of these proteins was never investigated. In this study, we try to over-express Usp in E. coli, purify Usp and characterize its molecular activity.MethodRecombinant Usp protein was expressed in E. coli BL21(DE3) cells together with 6× Histidine tagged OrfU1 (OrfU1-His) protein, and purified with affinity chromatography using Ni2+ chelating agarose. The nuclease activity of the purified Usp was examined in vitro by using plasmid DNA as a substrate. The importance of H-N-H motif in nuclease activity of Usp was examined by site-directed mutagenesis study.ResultsWe revealed that pET expression vector encoding Usp alone could not be maintained in E. coli BL21(DE3), and insertion of the orfUs as well as usp in the constructed plasmid diminished the toxic effect, suggesting that co-expressed OrfUs masked the activity of Usp. To purify Usp protein, we employed the expression vector encoding untagged Usp together with OrfU1-His. A tight complex formation could be observed between Usp and OrfU1-His, which allowed the purification of Usp in a single chromatographic step: binding of Usp/OrfU1-His complex to Ni2+ chelating agarose followed by elution of Usp from the complex with denaturing reagent. The purified free Usp was found to have the nuclease activity, and the activity was constitutively higher than Usp/OrfU1-His complex. H-N-H motif, which is found in various types of nucleases including a subfamily of nuclease-type bacteriocin, had been identified in the C-terminal region of Usp. Site-directed mutagenesis study showed that the H-N-H motif in Usp is indispensable for its nuclease activity.ConclusionThis is the first evidence of the molecular activity of the new member of H-N-H superfamily and lays the foundation for the biological characterization of Usp and its inhibitor protein, OrfUs.

The presence of genes encoding for different virulence factors in clonally related Escherichia coli that produce CTX-Ms

Successful international clones have recently emerged among Escherichia coli that produce CTX-M β-lactamases as important causes of community-onset urinary tract and bloodstream infections. One hundred and seven isolates that belong to sequence types (STs) ST38, ST131, ST405, ST648, and 38 nonrelated CTX-M–producing E. coli from Canada and the Netherlands were assigned to phylogenetic groups and tested for the presence of genes encoding for virulence factors (VFs) using established multiplex polymerase chain reaction. The STs E. coli were significantly more resistant to antibiotics—ST38, ST405, and ST648 belonged to phylogenetic group D while ST131 belonged to B2. Secreted autotransporter toxin (sat), aerobactin receptor, and pathogenicity island marker were significantly more common among the STs; the heat-resistant agglutinin (hra) was present in ST38, sat, and uropathogenic-specific protein, and putative adhesin-siderophore receptor was more common in ST131, while outer membrane protease T was present in ST648. ST131 had a significantly higher VF score. In conclusion, the precise role of these VFs remains to be elucidated; however, we have identified certain putative VFs that possibly contribute to the fitness and success of certain sequence types.

High frequency of false‐positive signals in a real‐time PCR‐based “Plus/Minus” assay

Molecular biological methods using real-time polymerase chain reaction (RT-PCR) for detection of bacterial and viral genes in different environments have been developed into assays from different commercial sources. Applied Biosystems include and support two applications with their TaqMan instrument: the "Plus/Minus" and the "Allelic Discrimination" assays. These approaches are RT-PCR based, use short primers and fluorescent-labeled TaqMan probes and include three processes: a pre-read run, a PCR-amplification run, and a post-read run. In the "Plus/Minus" assay, samples and controls (distilled water) are loaded into the instrument, which calculates a positive or a negative outcome based on differences in signals between samples and the controls. When testing the "Plus/Minus" assay for detection of usp genes encoding a uropathogenic specific protein in Escherichia coli, an inordinately high proportion of false-positive signals was observed. This was shown to be due to a serious methodological deficiency. Our observations indicate that an adequate no-template control closely matching the target samples in all aspects, including amount of DNA, is required to establish a correct threshold in the pre-read run that forms the basis for further calculations in the post-read run of the "Plus/Minus" assay.

Virulence factors and biofilm production among Escherichia coli strains causing bacteraemia of urinary tract origin

The aim of the present study was to gain an insight into the role of virulence determinants and biofilm production in bacteraemia of urinary tract origin. For this purpose 105 Escherichia coli isolates from patients with bacteraemia of urinary tract origin, isolated at the Institute of Microbiology and Immunology, University of Ljubljana, Slovenia, were investigated. A total of 88 strains (84 %) were isolated from immunocompromised patients and 17 (16 %) from non-immunocompromised patients. The prevalence of virulence factor (VF)-encoding genes and associations with phylogenetic background, antibiotic resistance, biofilm production and patient status were analysed by PCR and bioassay. Biofilm was produced by 55 (53 %) of the strains. No combination of VFs was highly associated with biofilm production. Of the tested VF-encoding genes, usp, papC and the adhesin-encoding sfa/foc were significantly more prevalent among strains from non-immunocompromised patients. Our results indicate that the uropathogenic specific protein (USP) may be, as judged by predominance and associations of the usp gene, an important VF contributing significantly to bacteraemia of urinary tract origin.

PREVALENCE OF TOXIN ENCODING GENES IN ESCHERICHIACOLI ISOLATES FROM URINARY TRACT INFECTIONS INSLOVENIA

Methods 110 uropathogenic Escherichia coli strains (UPEC) obtained from the Institute of Microbiology and Immunology of the Medical Faculty in Ljubljana were screened by PCR withprimers specific for the following toxin encoding genes: hlyA (haemolysin), cnf1 (cytotoxicnecrotising factor 1), usp (uropathogenic specific protein USP) and ibeA (invasin). Dotblot hybridisation experiments were performed to validate the PCR assays.Results In 44% of the strains usp gene sequences were detected. The prevalence of hlyA and cnf1was 25% and 23%, respectively. Only 9% of the strains harbored ibeA. The majority of thetested toxin encoding genes was found in strains belonging to the B2 phylogenetic group.Conclusions The toxin encoding genes hlyA, cnf1 and usp were strongly co-associated. Further, we founda statistically significant co-association of ibeA and usp. The prevalence of the testedtoxin encoding genes in E. coli strains from urinary tract infections isolated in Slovenia iscomparable to those from studies in other geographic regions.

Experimental Mouse Lethality ofEscherichia coliIsolates, in Relation to Accessory Traits, Phylogenetic Group, and Ecological Source

Whether accessory traits, phylogenetic background, or ecological source best predicts extraintestinal virulence within Escherichia coli is undefined. A total of 90 E. coli strains (18 fecal isolates and 72 extraintestinal-infection isolates) were characterized for 55 accessory traits and phylogenetic group (A, B1, B2, or D). Bacterial traits and ecological source were compared with experimental mouse lethality. Of the 90 strains, 41% were "killers" (i.e., killed > or =90% of mice). By univariate analysis, multiple group B2-associated traits (including malX [pathogenicity-island marker], pap [P fimbriae] elements, usp [uropathogenic-specific protein], and fyuA [yersiniabactin system]) were most closely associated with killer status, followed by group B2 (or non-group A) status and then by nonfecal origin. Stepwise multivariate analysis identified pap, malX, usp, fyuA, and B2 (all of which were positive predictors) and ireA (which was a negative predictor) as significant predictors of killer status. Killer strains segregated significantly from nonkiller strains, according to accessory-trait profiles. Factorial analysis of correspondence placed group B2 among the traits most closely associated with killer status, but not as the closest. Specific group B2-associated accessory traits are more potent predictors of experimental virulence among E. coli isolates than is either phylogenetic background or ecological source. Molecular typing can estimate an E. coli isolate's extraintestinal virulence potential, regardless of source.

Subtyping of uropathogenic Escherichia coli according to the pathogenicity island encoding uropathogenic‐specific protein: Comparison with phylogenetic groups

Phylogenetic analysis has been used widely to characterize extraintestinal pathogenic Escherichia coli in molecular epidemiological studies. We have recently reported a putative pathogenicity island (PAI), carrying uropathogenic-specific protein (usp) and a unique mosaic structure of small open reading frames following usp, providing four subtypes of PAIusp classified from their sequential patterns. A total of 427 E. coli isolates from uncomplicated urinary tract infections (194 cystitis, 76 pyelonephritis, and 107 prostatitis) and 50 fecal isolates were examined for phylogenetic grouping and PAIusp subtyping as well as the prevalence of virulence factors (VF) and O serogroups. Both phylogenetic group B2 and usp-positive strains were equally predominant in cystitis, pyelonephritis and prostatitis (B2, 80.9%, 86.8%, and 86.9%; usp, 79.4%, 93.4%, and 88.8%, respectively). Furthermore, each PAIusp subtype was shown to be closely associated with several VF genes as well as several common O serogroups of uropathogenic E. coli. In molecular epidemiological studies, PAIusp subtyping will provide additional informative findings of E. coli strains belonging to phylogenetic group B2.

E. coli virulence factors in children with neurogenic bladder associated with bacteriuria

The value of E. coli virulence factors in patients with neurogenic bladder has not been established. The aim of this study is to correlate E. coli virulence factors with asymptomatic and symptomatic UTI in children with neurogenic bladder. Fifty E. coli strains, which were collected in sequence, underwent analysis in relation to: the association to pyuria, serotype (O:H), the presence of genes and expression of fimbriae P, type 1, S and hemagglutinin Dr, the presence of the gene and production of hemolysins and cytotoxins (CNF1). We also analyzed the cell adherence capability and pattern and presence of usp (uropathogenic-specific protein). Pyuria was present in most of the positive urine cultures, with 86% AB and 97% UTI. Low rates of uropathogenic strains were observed in the two groups, with 18% AB and 21% UTI. Type 1 fimbria predominated in 44% of the E. coli strains. Of the bacteria studied, 30% (15 strains) exhibited papG genotypes (11 class II and 4 class III). Of these, 12/15 patients presented AB. Production of hemolysins was detected in 38% of the strains (16 AB and 3 UTI) and usp in only 18% of the strains, with 8 AB and 1 UTI. Adherence tests demonstrated the adhesive capacity in all samples analyzed. Neither group (AB or symptomatic UTI) presented a statistically significant difference in relation to the virulence factors studied. E. coli clones that caused symptomatic UTI in children with neurogenic bladder expressed few virulence factors, with no statistically significant difference in comparison to the AB group.

Host and Bacterial Virulence Factors Predisposing to Emphysematous Pyelonephritis

Emphysematous pyelonephritis (EPN) is a rare, severe, gas-forming infection of the kidney, and its precise pathogenesis remains obscure. To investigate the roles of host and bacterial virulence factors in the pathogenesis of EPN, we compared: (1) host factors in patients with EPN (n = 47) with those in patients with acute renal infections without gas formation (non-EPN; n = 79), (2) the prevalence of virulence gene in causative Escherichia coli strains from 16 of the 47 EPN cases with all 79 non-EPN cases by means of polymerase chain reaction analysis, and (3) gas volumes produced by EPN and non-EPN strains cultured in broths at 3 glucose concentrations (100, 180, and 250 mg/dL [5.6, 10.0, and 13.9 mmol/L]). Diabetes mellitus (DM) with poor glycemic control (ie, hemoglobin A1c level > 11%) and urinary tract obstruction were more prevalent in the EPN group. However, DM with poor glycemic control was the only host factor independently associated with EPN (odds ratio, 4.9; P = 0.018). EPN strains had a greater prevalence of the uropathogenic-specific protein (usp) genes. Multivariate analyses also showed the association between usp and EPN with borderline significance (odds ratio, 8.4; P = 0.057). There was no significant difference in gas production by E coli isolated from patients with or without EPN. DM with poor glycemic control and urinary tract obstruction are host factors predisposing to EPN. There was no difference in gas production between EPN and non-EPN E coli strains. The distribution of E coli virulence genes was remarkably similar between the 2 groups. However, the PapG II adhesin (papG II) gene is significantly decreased and the usp gene is increased with borderline significance in EPN E coli strains.

Distribution and Genetic Association of Putative Uropathogenic Virulence Factors Iron, iha, kpsMT, ompT and usp in Escherichia Coli Isolated From Urinary Tract Infections in Japan

Many virulence factors (VFs) have been reported in uropathogenic Escherichia coli. Recently we found a putative uropathogenic island including a gene encoding uropathogenic specific protein (USP). We have described the association between usp and other VFs reported previously. In the current study we examined epidemiological associations among 5 putative uropathogenic VFs. In 427 E. coli strains, including 194, 76 and 107 isolates from patients with cystitis, pyelonephritis and prostatitis, respectively, and 50 isolates from the stool of healthy adults, we detected catecholate siderophore receptor (iroN), iron regulated gene A homologue adhesin (iha), group II capsule (kpsMT) and outer membrane protease T (ompT) by polymerase chain reaction assays. We analyzed their distribution and genetic association. Relative prevalence ratios of iroN, iha, kpsMT, ompT and usp were 2.0 to 4.3 times more frequently in urinary tract infection isolates than in fecal isolates. Isolates from prostatitis were frequently associated with iroN, ompT and usp, whereas isolates from pyelonephritis frequently harbored usp. Together with iroN and iha we noted S-/F-fimbriae and iucD aerobactin (OR 95.9 and 187.2), while usp showed a close association with kpsMT and ompT (OR 38.3 and 38.4, respectively). Of the putative uropathogenic VFs examined iroN, iha, kpsMT, ompT and usp were frequently associated with urinary tract infection. Especially iroN and usp were most frequently associated with prostatitis. Some VFs were closely associated with a specific anatomical site of infection. Strong associations among several VFs might indicate not only well-known genetic linkages, but also unknown functional linkages among these VFs.