<i>Escherichia coli</i>
            Isolates Associated with Uncomplicated and Complicated Cystitis and Asymptomatic Bacteriuria Possess Similar Phylogenies, Virulence Genes, and O-Serogroup Profiles

Takahashi, Akira; Kanamaru, Sojun; Kurazono, Hisao; Kunishima, Yasuharu; Tsukamoto, Taiji; Ogawa, Osamu; Yamamoto, Shingo

doi:10.1128/jcm.02070-06

Cited by 76 publications

(65 citation statements)

References 28 publications

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“…Comparing to researchers' results from China, geographically located closest to our country, Luo et al [29] and Cao et al [30] reported the most common phylogenetic group in the UPEC isolates was B2 and D. Our results support these findings. Phylogenetic group A, associated with commensal strains, represented 19.6% of isolates, which was higher than in some studies [31,32], suggesting that the gastrointestinal tract is the main reservoir of strains that may be able to colonize the urinary tract, in accordance with previous observations. UPEC strains encode a number of virulence genes that enable the bacteria to colonize the urinary tract and persist in the face of highly effective host defense [33].…”

Section: Discussionsupporting

confidence: 77%

Detection of virulence genes, phylogenetic group and antibiotic resistance of uropathogenic Escherichia coli in Mongolia

Yandag

Gunregjav

Altantsetseg

et al. 2017

J Infect Dev Ctries

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Introduction: The severity of urinary tract infection (UTI) produced by uropathogenic Escherichia coli (UPEC) is due to the expression of a wide spectrum of virulence genes. E. coli strains were divided into four phylogenetic groups (A, B1, B2 and D) based on their virulence genes. The present study aimed to assess the relationship between virulence genes, phylogenetic groups, and antibiotic resistance of UPEC. Methodology: A total of 148 E. coli were tested for antimicrobial resistance against 10 drugs using the disk diffusion method. The isolates were screened by polymerase chain reaction (PCR) for detection of virulence genes and categorized into the four major phylogenetic groups. Results: Phylogenetic group B2 was predominant (33.8%), followed by D (28.4%), A (19.6), and B1 (18.2%). A higher prevalence of fimH (89.9%), fyuA (70.3%), traT (66.2%), iutA (62.2%), kpsMTII (58.8%), and aer (56.1%) genes were found in UPEC, indicating a putative role of adhesins, iron acquisition systems, and protectins that are main cause of UTIs. The most common antibiotic resistance was to cephalotin (85.1%), ampicillin (78.4%) and the least to nitrofurantoin (5.4%) and imipenem (2%). In total, 93.9% of isolates were multidrug resistant (MDR). Conclusions: This study showed that group B2 and D were the predominant phylogenetic groups and virulence-associated genes were mostly distributed in these groups. The virulence genes encoding components of adhesins, iron acquisition systems, and protectins were highly prevalent among antibiotic-resistant UPEC. Although the majority of strains are MDR, nitrofurantoin is the drug of choice for treatment of UTI patients in Ulaanbaatar.

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Section: Discussionsupporting

confidence: 77%

Detection of virulence genes, phylogenetic group and antibiotic resistance of uropathogenic Escherichia coli in Mongolia

Yandag

Gunregjav

Altantsetseg

et al. 2017

J Infect Dev Ctries

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“…Our analysis revealed that the majority of the ABU and CA-ABU strains belonged to phylogenetic groups B2 and D. These phylogenetic groups are most commonly associated with extraintestinal pathogenic E. coli (2,23,30,39). In support of this typing, we also observed a widespread occurrence of virulence factors for ABU and CA-ABU strains.…”

Section: Discussionsupporting

confidence: 66%

Escherichia coli Isolates Causing Asymptomatic Bacteriuria in Catheterized and Noncatheterized Individuals Possess Similar Virulence Properties

et al. 2010

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Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli being responsible for >80% of all cases. Asymptomatic bacteriuria (ABU) occurs when bacteria colonize the urinary tract without causing clinical symptoms and can affect both catheterized patients (catheterassociated ABU [CA-ABU]) and noncatheterized patients. Here, we compared the virulence properties of a collection of ABU and CA-ABU nosocomial E. coli isolates in terms of antibiotic resistance, phylogenetic grouping, specific UTI-associated virulence genes, hemagglutination characteristics, and biofilm formation. CA-ABU isolates were similar to ABU isolates with regard to the majority of these characteristics; exceptions were that CA-ABU isolates had a higher prevalence of the polysaccharide capsule marker genes kpsMT II and kpsMT K1, while more ABU strains were capable of mannose-resistant hemagglutination. To examine biofilm growth in detail, we performed a global gene expression analysis with two CA-ABU strains that formed a strong biofilm and that possessed a limited adhesin repertoire. The gene expression profile of the CA-ABU strains during biofilm growth showed considerable overlap with that previously described for the prototype ABU E. coli strain, 83972. This is the first global gene expression analysis of E. coli CA-ABU strains. Overall, our data suggest that nosocomial ABU and CA-ABU E. coli isolates possess similar virulence profiles.Urinary tract infections (UTIs) are among the most common infectious diseases acquired in nosocomial settings. UTIs may be symptomatic (e.g., cystitis and pyelonephritis) or asymptomatic. Asymptomatic bacteriuria (ABU) is an asymptomatic carrier state that resembles commensalism. ABU patients often carry Ͼ105 CFU/ml of urine of a single bacterial strain without symptoms; in nosocomial settings, ABU frequently occurs in both catheterized and noncatheterized patients. In catheterized patients, the risk of bacteriuria is estimated to be 5 to 10% per day (46), and most patients with an indwelling urinary catheter for 30 days or longer develop bacteriuria (35). ABU in catheterized and noncatheterized patients may also lead to symptomatic UTIs, with patients experiencing fever, suprapubic tenderness, and, in some cases, bacteremia, acute pyelonephritis, and death (16,45).ABU is caused by a range of Gram-negative and Grampositive organisms, including Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Providencia stuartii, Staphylococcus epidermidis, and Enterococcus faecalis (16,46). In many cases, the bacteria that cause these infections are resistant to multiple antibiotics, and thus, they pose a serious threat to the safety and proper functioning of health care facilities. E. coli is one of the most common causes of nosocomial UTIs (including ABU) (17, 36). Many ABU E. coli strains are phylogenetically related to virulent uropathogenic E. coli (UPEC) strains, with the differences in virulence properties being multifactorial and associated with various co...

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“…In another study, the genotypic characterization of UPEC and CA-ABU E. coli strains demonstrated that UPEC and CA-ABU E. coli strains predominantly belonged to phylogenetic group B2 and shared virulence determinants. As expected, virulence-associated genes, such as the P-fimbrial determinant (pap), the UPEC pathogenicity island marker malX, as well as iha and ompT, were, however, more common in UPEC isolates than in CA-ABU isolates (55).…”

Section: Discussionmentioning

confidence: 95%

Comparison of Asymptomatic Bacteriuria Escherichia coli Isolates from Healthy Individuals versus Those from Hospital Patients Shows that Long-Term Bladder Colonization Selects for Attenuated Virulence Phenotypes

et al. 2012

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Asymptomatic bacteriuria (ABU) is a condition where bacteria stably colonize the urinary tract, in a manner closely resembling commensalism at other mucosal sites. The patients carry >10 5 CFU/ml for extended periods of time and rarely develop symptoms. Contrasting the properties of ABU strains to those of uropathogenic isolates causing symptomatic infection is therefore highly relevant to understand mechanisms of bacterial adaptation. The prototype ABU strain Escherichia coli 83972 has a smaller genome than uropathogenic E. coli (UPEC) strains with deletions or point mutations in several virulence genes, suggesting that ABU strains undergo a programmed reductive evolution within human hosts. This study addressed if these observations can be generalized. Strains causing ABU in outpatients or hospitalized patients after catheterization or other invasive procedures were compared to commensal E. coli isolates from the intestinal flora of healthy individuals. Notably, clonal complex 73 (CC73) was a prominent phylogenetic lineage dominated by ABU isolates. ABU isolates from outpatients and hospitalized patients had a similar overall virulence gene repertoire, which distinguished them from many commensals, but typical UPEC virulence genes were less frequently attenuated in hospital strains than in outpatient strains or commensals. The decreased virulence potential of outpatient ABU isolates relative to that of ABU strains from hospitalized patients supports the hypothesis that loss of expression or decay of virulence genes facilitates long-term carriage and adaptation to host environments.

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Escherichia coli Isolates Associated with Uncomplicated and Complicated Cystitis and Asymptomatic Bacteriuria Possess Similar Phylogenies, Virulence Genes, and O-Serogroup Profiles

Cited by 76 publications

References 28 publications

Detection of virulence genes, phylogenetic group and antibiotic resistance of uropathogenic Escherichia coli in Mongolia

Detection of virulence genes, phylogenetic group and antibiotic resistance of uropathogenic Escherichia coli in Mongolia

Escherichia coli Isolates Causing Asymptomatic Bacteriuria in Catheterized and Noncatheterized Individuals Possess Similar Virulence Properties

Comparison of Asymptomatic Bacteriuria Escherichia coli Isolates from Healthy Individuals versus Those from Hospital Patients Shows that Long-Term Bladder Colonization Selects for Attenuated Virulence Phenotypes

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