A Newly Identified Group of P-like (PL) Fimbria Genes from Extraintestinal Pathogenic Escherichia coli (ExPEC) Encode Distinct Adhesin Subunits and Mediate Adherence to Host Cells.

Fimbrial adhesins promote bacterial adherence and biofilm formation. Sequencing of avian pathogenic Escherichia coli (APEC) strain QT598 identified new fimbriae belonging to the π group, which we named PL (P-like) fimbriae since the genetic organization and sequence are similar to those of P and related fimbriae. Genes encoding PL fimbriae located on IncF plasmids are present in diverse E. coli isolates from poultry, human systemic infections, and other sources. As with P fimbriae, PL fimbriae exhibit divergence in adhesin-encoding genes and could be divided into 5 classes based on sequence differences in the PlfG adhesin. plf genes from two predominant PlfG adhesin classes, PlfG class I (PlfGI) and PlfGII, were cloned. PL fimbriae were visualized by electron microscopy, associated with increased biofilm, demonstrated distinct hemagglutination profiles, and promoted adherence to human bladder and kidney epithelial cells. The genes encoding hybrid fimbriae were comprised of genes from plfQT598, wherein plfG was replaced by papG; the adhesin-encoding genes were also functional and mediated adherence to epithelial cells, demonstrating compatibility between the components of these two types of fimbriae. Deletion of plf genes did not reduce colonization of the mouse urinary tract in a single-strain infection model. In contrast, loss of plf genes significantly reduced competitive colonization in the mouse kidneys. Furthermore, plf gene expression was increased over 40-fold in the bladder compared to during in vitro culture. Overall, PL fimbriae represent a new group of fimbriae demonstrating both functional differences from and similarities to P fimbriae, which mediated adherence to host cells and improved competitive colonization of the mouse kidney. IMPORTANCE Fimbriae are important colonization factors in many bacterial species. The identification of a new type of fimbriae encoded on some IncF plasmids in E. coli was investigated. Genomic sequences demonstrated these fimbrial gene clusters have genetic diversity, particularly in the adhesin-encoding plfG gene. Functional studies demonstrated differences in hemagglutination specificity, although both types of Plf adhesin under study mediated adherence to human urinary epithelial cells. A plf mutant also showed decreased colonization of the kidneys in a mouse competitive infection model. PL fimbriae may represent previously unrecognized adhesins that could contribute to host specificity and tissue tropism of some E. coli strains.

Phylogenetic Backgrounds and Virulence-Associated Traits of Escherichia coli Isolates from Surface Waters and Diverse Animals in Minnesota and Wisconsin.

Possible external reservoirs for extraintestinal pathogenic Escherichia coli (ExPEC) strains that cause infections in humans are poorly defined. Because of the tremendous human health importance of ExPEC infections, we assessed surface waters and domesticated and wild animals in Minnesota and Wisconsin as potential reservoirs of ExPEC of human health relevance. We characterized 595 E. coli isolates (obtained from 1999 to 2002; 280 from seven surface water sites, 315 from feces of 13 wild and domesticated animal species) for phylogroup and virulence genotype, including inferred ExPEC status, by using multiplex PCR-based methods. We also compared the pulsed-field gel electrophoresis (PFGE) profiles of the isolates with a large private PFGE profile library. We found a predominance of non-ExPEC strains (95% and 93% among water and animal isolates, respectively), which were mainly from phylogroups A and B1, plus a minority of ExPEC strains (5% and 7% among water isolates and animal isolates, respectively), predominantly from phylogroup B2. The ExPEC strains, although significantly associated with cats, dogs, and turkeys, occurred in several additional animal species (goat, horse, chicken, pig) and were distributed broadly across all surface water sites. Virulence gene content among the animal source ExPEC isolates segregated significantly in relation to host species, following established patterns. PFGE analysis indicated that 11 study isolates closely matched (94% to 100% profile similarity) reference human clinical and fecal isolates. These findings imply what probably is a low but non-zero risk to humans from environmental and animal source E. coli isolates, especially those from specific human-associated animal species.IMPORTANCE Our detection of potentially pathogenic strains that may pose a health threat to humans among E. coli isolates from surface waters and wild and domesticated animals suggests a need for heightened attention to these reservoirs as possible sources for human acquisition of disease-causing E. coli Although cats, dogs, and turkeys were especially high-prevalence sources, the presence of such strains in other animal species and at all sampled water sites suggests that this potential risk may be widespread.

Whole-genome sequencing and characterization of Escherichia coli human isolate DP033.

The whole-genome sequence of Escherichia coli strain DP033 is reported here. DP033 was isolated from a human rectal specimen in Tilburg, the Netherlands. In silico analysis showed that DP033 possessed 36 virulence-related genes and is a presumptive extraintestinal pathogenic E. coli and uropathogenic E. coli strain.

Ruminococcus gnavus: friend or foe for human health.

Ruminococcus gnavus was first identified in 1974 as a strict anaerobe in the gut of healthy individuals, and for several decades, its study has been limited to specific enzymes or bacteriocins. With the advent of metagenomics, R. gnavus has been associated both positively and negatively with an increasing number of intestinal and extraintestinal diseases from inflammatory bowel diseases to neurological disorders. This prompted renewed interest in understanding the adaptation mechanisms of R. gnavus to the gut, and the molecular mediators affecting its association with health and disease. From ca. 250 publications citing R. gnavus since 1990, 94% were published in the last 10 years. In this review, we describe the biological characterization of R. gnavus, its occurrence in the infant and adult gut microbiota and the factors influencing its colonization of the gastrointestinal tract; we also discuss the current state of our knowledge on its role in host health and disease. We highlight gaps in knowledge and discuss the hypothesis that differential health outcomes associated with R. gnavus in the gut are strain and niche specific.

The Impact of Inflammatory Bowel Disease in Canada 2018: Extra-intestinal Diseases in IBD.

The burden of extra-intestinal disease is high in patients with IBD, some of whom respond to or are prevented by treating the bowel inflammation, whereas others require specific treatment because they are independent of the underlying bowel inflammation. Among the most common extra-intestinal manifestations are other chronic immune-mediated diseases such as erythema nodosum, ankylosing spondylitis and primary sclerosing cholangitis. Patients with IBD are at higher risk of complications in other organ systems such as osteoporosis, venous thromboembolism and cardiovascular disease. In addition, patients with IBD have a higher risk of cancer, including colon cancer. Mental health comorbidity is important and common in IBD though not always recognized and managed. Consequently, patients and care providers need to be vigilant in the surveillance of extra-intestinal manifestations and complications of IBD. HIGHLIGHTS: The burden of extra-intestinal disease is high in patients with IBD.Immune-mediated inflammatory diseases (IMIDs) commonly coexist with patients with IBD and the activity of IMIDs can be either dependent or independent of bowel inflammation.Patients with IBD can be diagnosed with coexisting diseases that affect every organ, including bones, blood, heart, liver, and others.Patients with IBD are at increased risk of cancer, including colon cancer, caused by their bowel inflammation, cholangiocarcinoma due to primary sclerosing cholangitis, and rarely lymphoma related to immunosuppressive medications.The best way to prevent or reduce the burden of many of the extra-intestinal disease is to treat the inflammation of IBD, however some extra-intestinal inflammatory diseases run courses that are independent of the intestinal disease activity. KEY SUMMARY POINTS: Patients with IBD are often burdened with extra-intestinal manifestations, some of which respond to or are prevented by treating the bowel inflammation whereas others require specific treatment because they are independent of the underlying bowel inflammation.Other immune-mediated inflammatory diseases (IMIDs) can coexist with IBD.Some IMIDs run an independent course from the bowel inflammation of IBD, such as ankylosing spondylitis, iritis, and primary sclerosing cholangitis.Immune-mediated inflammatory diseases that often have courses that match the bowel inflammation of IBD include erythema nodosum and peripheral arthritis.Immune-mediated inflammatory diseases such as multiple sclerosis and psoriasis have been associated with IBD. However, these conditions may also emerge as complications of therapy for IBD.Patients with IBD are at risk for venous thromboembolic disease, which occurs at a rate of one per 200 person-years.Venous thromboembolic disease can be reduced by treating patients admitted to hospital with an IBD diagnosis with venous thromboembolism prophylaxis.Arterial vascular disease is also increased in IBD patients, including both coronary artery disease and cerebrovascular disease.Osteoporosis is more prevalent in IBD patients and translates to a 40% increased risk of fracture. While corticosteroids increase the risk of osteoporosis, patients with IBD can also develop metabolic bone disease independent of corticosteroid use.Persons with IBD are more likely to be infected with Clostridium difficile than community controls and often without prior antibiotic exposure.Mental health comorbidity is important in IBD. Depression may antedate a diagnosis of IBD by several years and increase post-diagnosis. High stress can exacerbate symptoms in IBD but does not necessarily increase bowel inflammation.Fatigue is a common symptom in IBD and is not always explained by depression, active inflammatory disease or other apparent factors.The risk of colorectal cancer is increased twofold in Crohn's colitis and in ulcerative colitis and 10-fold in persons with primary sclerosing cholangitis with colitis.Primary sclerosing cholangitis runs a course independent of IBD and can progress to cirrhosis, liver transplantation or death. Patients with IBD and primary sclerosing cholangitis are at higher risk of cholangiocarcinoma, which is often fatal.The risk of lymphoma may be increased in older males with Crohn's disease and in patients using thiopurines or anti-TNF therapy.The risk for intensive care unit admission is nearly twofold higher for patients with IBD and higher in Crohn's disease than in ulcerative colitis. Risk factors for intensive care unit admission from the year before admission included cumulative corticosteroid use and IBD-related surgery. GAPS IN KNOWLEDGE AND FUTURE DIRECTIONS: Patients with IBD are often burdened with extra-intestinal disease. Future research should determine the collective frequency and added costs of living with extra-intestinal disease.Immune-mediated inflammatory diseases are commonly codiagnosed with IBD. Future research should focus on the pathogenesis connecting coexisting IMIDs with IBD.Care pathways that support the investigation and mitigation of extra-intestinal disease are needed. For example, when and how ambulatory patients with IBD should receive prophylaxis against venous thromboembolic disease is unknown.With an aging IBD population, the burden of extra-intestinal disease should be studied in the context of comorbidities of advancing age.Increasing mental health screening and access to mental health care should be a goal of IBD management.

A Population-Based Surveillance Study of Shared Genotypes of Escherichia coli Isolates from Retail Meat and Suspected Cases of Urinary Tract Infections.

There is increasing evidence that retail food may serve as a source of Escherichia coli that causes community-acquired urinary tract infections, but the impact of this source in a community is not known. We conducted a prospective, population-based study in one community to examine the frequency of recovery of uropathogenic E. coli genotypes from retail meat samples. We analyzed E. coli isolates from consecutively collected urine samples of patients suspected to have urinary tract infections (UTIs) at a university-affiliated health service and retail meat samples from the same geographic region. We genotyped all E. coli isolates by multilocus sequence typing (MLST) and tested them for antimicrobial susceptibility. From 2016 to 2017, we cultured 233 E. coli isolates from 230 (21%) of 1,087 urine samples and 177 E. coli isolates from 120 (28%) of 427 retail meat samples. Urine samples contained 61 sequence types (STs), and meat samples had 95 STs; 12 STs (ST10, ST38, ST69, ST80, ST88, ST101, ST117, ST131, ST569, ST906, ST1844, and ST2562) were common to both. Thirty-five (81%) of 43 meat isolates among the 12 STs were from poultry. Among 94 isolates in the 12 STs, 26 (60%) of 43 retail meat isolates and 15 (29%) of 51 human isolates were pan-susceptible (P < 0.005). We found that 21% of E. coli isolates from suspected cases of UTIs belonged to STs found in poultry. Poultry may serve as a possible reservoir of uropathogenic E. coli (UPEC). Additional studies are needed to demonstrate transmission pathways of these UPEC genotypes and their food sources.IMPORTANCE Community-acquired urinary tract infection caused by Escherichia coli is one of the most common infectious diseases in the United States, affecting approximately seven million women and costing approximately 11.6 billion dollars annually. In addition, antibiotic resistance among E. coli bacteria causing urinary tract infection continues to increase, which greatly complicates treatment. Identifying sources of uropathogenic E. coli and implementing prevention measures are essential. However, the reservoirs of uropathogenic E. coli have not been well defined. This study demonstrated that poultry sold in retail stores may serve as one possible source of uropathogenic E. coli This finding adds to a growing body of evidence that suggests that urinary tract infection may be a food-borne disease. More research in this area can lead to the development of preventive strategies to control this common and costly infectious disease.