Distribution of the Serine Protease Autotransporters of the Enterobacteriaceae among Extraintestinal Clinical Isolates of Escherichia coli

Abstract

Urinary tract infections continue to be among the most common extraintestinal diseases. Cystitis in women is by far the most common urinary tract infection; pyelonephritis in both sexes and prostatitis in men are more severe but less frequent complaints. Escherichia coli is by far the most common cause of urinary tract infection. It is believed that uropathogenic E. coli is adept at colonizing the urinary tract via the production of specific virulence factors. Recently, a novel virulence determinant, Vat, was described for the prototypical uropathogenic E. coli strain CFT073. Vat is a member of the SPATE (serine protease autotransporters of the Enterobacteriaceae) subfamily of the autotransporters. Previously, SPATEs have been described for all pathovars of E. coli, but until recently their presence had been noticeably absent in nonpathogenic E. coli. In this report we describe the prevalence and phylogenetic distribution of the SPATEs among uropathogenic E. coli and the ECOR collection, demonstrating an association between the presence of the SPATEs, including Vat, and uropathogenic E. coli phylogroups. In addition, we describe the distribution of SPATEs among nonpathogenic E. coli.Escherichia coli is the predominant cause of urinary tract infections (UTIs), accounting for 50% of all nosocomial urinary tract infections and 90% of infections among ambulatory patients (6). Among UTIs, cystitis in women is by far the most common, with the more severe complaints pyelonephritis and prostatitis being less frequent (34). The production of specific virulence factors is thought to be necessary for uropathogenic E. coli (UPEC) to colonize the urinary tract (6, 8). These factors include adhesins, capsule, aerobactin, toxins, and proteases, which may aid attachment to host mucosal tissues, allow evasion of immune defenses, and promote invasion of the normally sterile urinary tract and tissues (1,8,24,32). UPEC strains have a greater prevalence of virulence factors than commensal E. coli, with virulence determinants being more prevalent among strains causing invasive rather than noninvasive disease (13,22,32). However, half of all UPEC isolates possess none, or only one, of the virulence factors characterized thus far, and hence other as yet uncharacterized bacterial factors may be important in the pathogenesis of UTI (22).The genome sequence of the UPEC strain CFT073 has been completed, and this has propagated the identification of further potential virulence genes (35). Autotransporters are one category of secreted proteins implicated in the virulence of UPEC (17,18). Members of the serine protease autotransporters of the Enterobacteriaceae (SPATE) family are proteins from E. coli and Shigella spp. which, like the immunoglobulin A1 (IgA1) proteases and Hap autotransporters of Neisseria and Haemophilus spp

UropathogenicEscherichia coliBlock MyD88-Dependent and Activate MyD88-Independent Signaling Pathways in Rat Testicular Cells

“…Based on the relevance of UPEC in pathogen-associated fertility disturbances, our study focused on the in vitro response of testicular cells to infection with this strain (11,33,34). SC, PTC, and TM, all centrally implicated in the testicular defense system, were found to express TLR4 (5,6).…”

The Citrobacter rodentium Genome Sequence Reveals Convergent Evolution with Human Pathogenic Escherichia coli

“…Fourteen of these, including one encoded by a pseudogene, were identified as putative autotransporter adhesins and were related to AIDA-I, TibA, or pertactin, which are involved in virulence in EPEC, enterotoxigenic E. coli (ETEC), and Bordetella pertussis, respectively (5,8,27). Two other autotransporters were predicted to belong to the serine protease autotransporter of the Enterobacteriaceae (SPATE) family of proteins, members of which have been shown to contribute to virulence in other pathogens (7,23,70). The majority of the autotransporters are located in the chromosomal backbone; however, one, AdcA, which was shown to function as an adhesin but had no obvious role in colonization of mice (36), is encoded on a genomic island.…”

Molecular Characterization of the Vacuolating Autotransporter Toxin in Uropathogenic Escherichia coli

“…The vacuolating AT toxin (Vat) of E. coli is a class II SPATE (34,36,45) that exhibits cytotoxicity to chicken embryonic fibroblast cells and contributes to avian cellulitis infection (46). The vat gene was originally identified within a pathogenicity island (PAI) designated the VAT-PAI from the avian pathogenic E. coli (APEC) strain Ec222 (46).…”

“…The vat gene was originally identified within a pathogenicity island (PAI) designated the VAT-PAI from the avian pathogenic E. coli (APEC) strain Ec222 (46). The VAT-PAI is integrated into the Ec222 chromosome at the thrW tRNA site between the proA and yagU genes (45,46). The VAT-PAI from Ec222 consists of 33 open reading frames (ORFs), with the vat gene residing at ORF27.…”