A Multiepitope Subunit Vaccine Conveys Protection against Extraintestinal Pathogenic Escherichia coli in Mice

ABSTRACT Infections due to extraintestinal pathogenic Escherichia coli (ExPEC) are common in humans and animals and include urinary tract infections (from uropathogenic E. coli [UPEC]), septicemia, and wound infections. These infections result in significant morbidity and mortality and in high health care costs. In view of the increasing number of ExPEC infections and the ever-growing antibiotic resistance capability of ExPEC isolates, preventive measures such as an effective vaccine against ExPEC are desirable. An ExPEC vaccine may be cost-effective for select patient groups. Previous vaccine candidates consisted of single target proteins or whole ExPEC cells. Here we describe a subunit vaccine against ExPEC which is based on immunodominant epitopes of the virulence-associated ExPEC proteins FyuA, IroN, ChuA, IreA, Iha, and Usp. Using a novel approach of computer-aided design, two completely artificial genes were created, both encoding eight peptide domains derived from these ExPEC proteins. The recombinant expression of these two genes resulted in a protein vaccine directed against ExPEC but not against commensal E. coli of the gut flora. In mice, the vaccine was highly immunogenic, eliciting both strong humoral and cellular immune responses. Nasal application resulted in high secretory immunoglobulin A (sIgA) production, which was detectable on the mucosal surface of the urogenital tract. Finally, it conveyed protection, as shown by a significant reduction of bacterial load in a mouse model of ExPEC peritonitis. This study provides evidence that a novel vaccine design encompassing distinct epitopes of virulence-associated ExPEC proteins may represent a means for providing a protective and pathogen-specific vaccine.

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Intradermally administered enterotoxigenic E. coli vaccine candidate MecVax induces functional serum IgG antibodies against seven adhesins (CFA/I, CS1-CS6) and both toxins (STa, LT)

Applied and Environmental Microbiology ◽

10.1128/aem.02139-21 ◽

2021 ◽

Author(s):

Carolina Y Garcia ◽

Hyesuk Seo ◽

David A Sack ◽

Weiping Zhang

Keyword(s):

Escherichia Coli ◽

Neutralizing Antibodies ◽

Subunit Vaccine ◽

Vaccine Candidate ◽

Effective Vaccine ◽

Protein Antigens ◽

E Coli ◽

Administration Routes ◽

Heat Stable ◽

Functional Antibodies

There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading bacterial cause of children’s diarrhea and travelers’ diarrhea. MecVax, a multivalent E. coli vaccine candidate composed of two epitope- and structure-based polyvalent proteins (toxoid fusion 3xSTa N12S -mnLT R192G/L211A and CFA/I/II/IV MEFA), is to induce broad anti-adhesin and antitoxin antibodies against heterogeneous ETEC pathovars. Administered intraperitoneally (IP) or intramuscularly (IM), MecVax was shown to induce antibodies against seven ETEC adhesins (CFA/I, CS1-CS6), which are produced by ETEC pathovars causing over 60% of ETEC-associated diarrheal cases and the moderate-to-severe cases, and both toxins (heat-labile toxin - LT and heat-stable toxin - STa) expressed by all ETEC strains. To further characterize immunogenicity of this protein-based injectable subunit vaccine candidate and to explore other parenteral administration routes for the product, in this study, we intradermally (ID) immunized mice with MecVax and measured antigen-specific antibody responses and further antibody functional activities against the adhesins and toxins targeted by the vaccine. Data showed that mice ID immunized with MecVax developed robust anti-CFA/I, -CS1, -CS2, -CS3, -CS4, -CS5, -CS6, -LT and anti-STa IgG responses. Furthermore, antibodies derived from MecVax via ID route inhibited adherence of ETEC or E. coli strains expressing any of the seven target adhesins (CFA/I, CS1-CS6) and neutralized enterotoxicity of LT and STa toxins. These results confirmed broad immunogenicity of MecVax and suggested that this multivalent ETEC subunit vaccine candidate can be effectively delivered via ID route. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of diarrhea in children living in developing countries and international travelers. Developing an effective vaccine for ETEC diarrhea has been hampered because of challenges of virulence heterogeneity and difficulties of inducing neutralizing antibodies against the key STa toxin. MecVax, a subunit vaccine candidate carrying two polyvalent protein antigens for the first time induces functional antibodies against the most important ETEC adhesins which are associated with a majority of diarrheal cases and the moderate-to-severe cases but also against enterotoxicity of LT and more importantly STa toxin which plays a key role in children’s diarrhea and travelers’ diarrhea, potentially leading to development of a truly effective ETEC vaccine. Data from this study may also indicated that this ETEC subunit vaccine can be administered effectively via ID route, expanding clinical administration options for this vaccine product.

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EsiB, a Novel Pathogenic Escherichia coli Secretory Immunoglobulin A-Binding Protein Impairing Neutrophil Activation

mBio ◽

10.1128/mbio.00206-13 ◽

2013 ◽

Vol 4 (4) ◽

Cited By ~ 12

Author(s):

Ilaria Pastorello ◽

Silvia Rossi Paccani ◽

Roberto Rosini ◽

Rossella Mattera ◽

Mario Ferrer Navarro ◽

...

Keyword(s):

Escherichia Coli ◽

Protective Antigen ◽

Immunoglobulin A ◽

Distribution Analysis ◽

Secretory Immunoglobulin A ◽

Content Type ◽

E Coli ◽

Novel Strategy ◽

Tract Infections ◽

Secretory Immunoglobulin

ABSTRACTIn this study, we have characterized the functional properties of a novelEscherichia coliantigen named EsiB (E. colisecretoryimmunoglobulin A-binding protein), recently reported to protect mice from sepsis. Gene distribution analysis of a panel of 267 strains representative of differentE. colipathotypes revealed thatesiBis preferentially associated with extraintestinal strains, while the gene is rarely found in either intestinal or nonpathogenic strains. These findings were supported by the presence of anti-EsiB antibodies in the sera of patients affected by urinary tract infections (UTIs). By solving its crystal structure, we observed that EsiB adopts a superhelical fold composed of Sel1-like repeats (SLRs), a feature often associated with bacterial proteins possessing immunomodulatory functions. Indeed, we found that EsiB interacts with secretory immunoglobulin A (SIgA) through a specific motif identified by an immunocapturing approach. Functional assays showed that EsiB binding to SIgA is likely to interfere with productive FcαRI signaling, by inhibiting both SIgA-induced neutrophil chemotaxis and respiratory burst. Indeed, EsiB hampers SIgA-mediated signaling events by reducing the phosphorylation status of key signal-transducer cytosolic proteins, including mitogen-activated kinases. We propose that the interference with such immune events could contribute to the capacity of the bacterium to avoid clearance by neutrophils, as well as reducing the recruitment of immune cells to the infection site.IMPORTANCEPathogenicEscherichia coliinfections have recently been exacerbated by increasing antibiotic resistance and the number of recurrent contagions. Attempts to develop preventive strategies againstE. colihave not been successful, mainly due to the large antigenic and genetic variability of virulence factors, but also due to the complexity of the mechanisms used by the pathogen to evade the immune system. In this work, we elucidated the function of a recently discovered protective antigen, named EsiB, and described its capacity to interact with secretory immunoglobulin A (SIgA) and impair effector functions. This work unravels a novel strategy used byE. colito subvert the host immune response and avoid neutrophil-dependent clearance.

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Avian Pathogenic Escherichia coli (APEC): An Overview of Virulence and Pathogenesis Factors, Zoonotic Potential, and Control Strategies

Pathogens ◽

10.3390/pathogens10040467 ◽

2021 ◽

Vol 10 (4) ◽

pp. 467

Author(s):

Dipak Kathayat ◽

Dhanashree Lokesh ◽

Sochina Ranjit ◽

Gireesh Rajashekara

Keyword(s):

Escherichia Coli ◽

Current Status ◽

Neonatal Meningitis ◽

Clear Understanding ◽

Zoonotic Potential ◽

Secretion Systems ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli ◽

Tract Infections

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avian species, and recent reports have suggested APEC as a potential foodborne zoonotic pathogen. Herein, we discuss the virulence and pathogenesis factors of APEC, review the zoonotic potential, provide the current status of antibiotic resistance and progress in vaccine development, and summarize the alternative control measures being investigated. In addition to the known virulence factors, several other factors including quorum sensing system, secretion systems, two-component systems, transcriptional regulators, and genes associated with metabolism also contribute to APEC pathogenesis. The clear understanding of these factors will help in developing new effective treatments. The APEC isolates (particularly belonging to ST95 and ST131 or O1, O2, and O18) have genetic similarities and commonalities in virulence genes with human uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC) and abilities to cause urinary tract infections and meningitis in humans. Therefore, the zoonotic potential of APEC cannot be undervalued. APEC resistance to almost all classes of antibiotics, including carbapenems, has been already reported. There is a need for an effective APEC vaccine that can provide protection against diverse APEC serotypes. Alternative therapies, especially the virulence inhibitors, can provide a novel solution with less likelihood of developing resistance.

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Antimicrobial activity of Syzygium aromaticum L. essential oil on extended-spectrum beta-lactamases-producing Escherichia coli

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00458-x ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

E. L. Mejía-Argueta ◽

J. G. Santillán-Benítez ◽

M. M. Canales-Martinez ◽

A. Mendoza-Medellín

Keyword(s):

Escherichia Coli ◽

Essential Oil ◽

Genetic Material ◽

Gastrointestinal Diseases ◽

Syzygium Aromaticum ◽

Antibiotic Resistant ◽

Plant Essential Oils ◽

E Coli ◽

Extended Spectrum ◽

Tract Infections

Abstract Background To test the antimicrobial potential of clove essential oil that has been less investigated on antimicrobial-resistant organisms (extended-spectrum β-lactamase-ESBL-producing Escherichia coli), we collected 135 ESBL-producing Escherichia coli strains given that E. coli is the major organism increasingly isolated as a cause of complicated urinary and gastrointestinal tract infections, which remains an important cause of therapy failure with antibiotics for the medical sector. Then, in this study, we evaluated the relationship between the antibacterial potential activity of Syzygium aromaticum essential oil (EOSA) and the expression of antibiotic-resistant genes (SHV-2, TEM-20) in plasmidic DNA on ESBL-producing E. coli using RT-PCR technique. Results EOSA was obtained by hydrodistillation. Using Kirby-Baüer method, we found that EOSA presented a smaller media (mean = 15.59 mm) in comparison with chloramphenicol (mean = 17.73 mm). Thus, there were significant differences (p < 0.0001). Furthermore, EOSA had an antibacterial activity, particularly on ECB132 (MIC: 10.0 mg/mL and MBC: 80.0 mg/mL), and a bacteriostatic effect by bactericidal kinetic. We found that the expression of antibiotic-resistant gene blaTEM-20 was 23.52% (4/17 strains) and no expression of blaSHV-2. EOSA presented such as majority compounds (eugenol, caryophyllene) using the GC–MS technique. Conclusions Plant essential oils and their active ingredients have potentially high bioactivity against a different target (membranes, cytoplasm, genetic material). In this research, EOSA might become an important adjuvant against urinary and gastrointestinal diseases caused by ESBL-producing E. coli.

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1671. Diagnosis and management of Escherichia coli bacteriuria at a Veterans Affairs hospital

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1849 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S821-S821

Author(s):

Niyati H Shah ◽

Brooke K Decker ◽

Gaetan Sgro ◽

Monique Y Boudreaux-Kelly ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Treatment ◽

High Yield ◽

Comorbid Conditions ◽

Provider Education ◽

Transmitted Infection ◽

Physician Practices ◽

E Coli ◽

Diagnosis And Management ◽

Tract Infections

Abstract Background The IDSA recommends against screening for and treating ASB in all patients except for those pregnant or undergoing urologic procedures. Nevertheless, antibiotic treatment of ASB is widespread. We conducted a retrospective analysis of physician practices in diagnosis and management of Escherichia coli (E. coli) ASB in a male Veteran population, and compared outcomes in ASB patients treated or not treated with antibiotics. Methods Patients with an E. coli positive urine culture during an ED visit or inpatient admission from 01/2017 to 12/2017 were screened. Patients admitted to the intensive care unit or diagnosed with a sexually transmitted infection, pyelonephritis, prostatitis, or epididymitis/orchitis were excluded. A total of 163 patients were included. Demographics, clinical comorbidities and severity of illness, and outcomes were compared in ASB patients managed with or without antibiotics. ANOVA and Chi-square or Fisher’s exact tests were utilized for comparing measurements. Results ASB was present in 92/163 patients. The majority (74%) of these patients were given antibiotics. Regardless of qSOFA score or alternate infection, there were no significant differences in outcomes between ASB patients treated or not treated with antibiotics: 3-month mortality (15% vs 21%; p = 0.53), emergence of newly resistant bacterial pathogens (7% vs 13%; p = 0.43), recurrent urinary tract infections (61% vs 50%; p = 0.72), clearance of urinary pathogens (75% vs 58%; p = 0.45), length of hospital stay (7 vs 6 days, p = 0.67). Factors that were predictive of physician treatment of ASB included patient comorbid conditions such as benign prostatic hyperplasia, pyuria, and the absence of hematuria. The incidence of adverse events with antibiotic treatment of ASB was low. Conclusion The rate of antibiotic treatment of E. coli ASB in male veterans is high. Outcomes do not differ among ASB patients managed with or without antibiotics. Future studies examining outcomes in patients prescribed antibiotics for multiple episodes of ASB may yield differences, particularly in emergence of resistant pathogens. Focusing on patients with comorbid conditions who are not critically ill would be a high yield target for provider education to reduce ASB treatment. Disclosures All Authors: No reported disclosures

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Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

Microorganisms ◽

10.3390/microorganisms9020310 ◽

2021 ◽

Vol 9 (2) ◽

pp. 310

Author(s):

Masayuki Hashimoto ◽

Yi-Fen Ma ◽

Sin-Tian Wang ◽

Chang-Shi Chen ◽

Ching-Hao Teng

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Caenorhabditis Elegans ◽

Large Scale ◽

Iron Acquisition ◽

Infection Model ◽

High Throughput Analysis ◽

E Coli ◽

C Elegans ◽

Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

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The prevalence of the iutA and ibeA genes in Escherichia coli isolates from severe and non-severe patients with bacteremic acute biliary tract infection is significantly different

Gut Pathogens ◽

10.1186/s13099-021-00429-1 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Mahoko Ikeda ◽

Tatsuya Kobayashi ◽

Fumie Fujimoto ◽

Yuta Okada ◽

Yoshimi Higurashi ◽

...

Keyword(s):

Escherichia Coli ◽

Tract Infection ◽

Biliary Tract ◽

Iron Acquisition ◽

Tertiary Care ◽

Care Hospital ◽

Biliary Tract Infection ◽

E Coli ◽

Severe Group ◽

Tract Infections

Abstract Background Although Escherichia coli is the most frequently isolated microorganism in acute biliary tract infections with bacteremia, data regarding its virulence are limited. Results Information on cases of bacteremia in acute biliary tract infection in a retrospective study was collected from 2013 to 2015 at a tertiary care hospital in Japan. Factors related to the severity of infection were investigated, including patient background, phylogenetic typing, and virulence factors of E. coli, such as adhesion, invasion, toxins, and iron acquisition. In total, 72 E. coli strains were identified in 71 cases, most of which primarily belonged to the B2 phylogroup (68.1%). The presence of the iutA gene (77.3% in the non-severe group, 46.4% in the severe group, P = 0.011) and the ibeA gene (9.1% in the non-severe group, and 35.7% in the severe group, P = 0.012) was significantly associated with the severity of infection. Among the patient characteristics, diabetes mellitus with organ involvement and alkaline phosphatase were different in the severe and non-severe groups. Conclusions We showed that bacteremic E. coli strains from acute biliary tract infections belonged to the virulent (B2) phylogroup. The prevalence of the iutA and ibeA genes between the two groups of bacteremia severity was significantly different.

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Three-Year Trend in Escherichia coli Antimicrobial Resistance among Children’s Urine Cultures in an Italian Metropolitan Area

Children ◽

10.3390/children8070597 ◽

2021 ◽

Vol 8 (7) ◽

pp. 597

Author(s):

Luca Pierantoni ◽

Laura Andreozzi ◽

Simone Ambretti ◽

Arianna Dondi ◽

Carlotta Biagi ◽

...

Keyword(s):

Escherichia Coli ◽

Metropolitan Area ◽

Bacterial Infections ◽

Asymptomatic Bacteriuria ◽

Multidrug Resistant ◽

Resistance Rate ◽

First Line ◽

E Coli ◽

First Line Therapy ◽

Tract Infections

Urinary tract infections (UTIs) are among the most common bacterial infections in children, and Escherichia coli is the main pathogen responsible. Several guidelines, including the recently updated Italian guidelines, recommend amoxicillin-clavulanic acid (AMC) as a first-line antibiotic therapy in children with febrile UTIs. Given the current increasing rates of antibiotic resistance worldwide, this study aimed to investigate the three-year trend in the resistance rate of E. coli isolated from pediatric urine cultures (UCs) in a metropolitan area of northern Italy. We conducted a retrospective review of E. coli-positive, non-repetitive UCs collected in children aged from 1 month to 14 years, regardless of a diagnosis of UTI, catheter colonization, urine contamination, or asymptomatic bacteriuria. During the study period, the rate of resistance to AMC significantly increased from 17.6% to 40.2% (p < 0.001). Ciprofloxacin doubled its resistance rate from 9.1% to 16.3% (p = 0.007). The prevalence of multidrug-resistant E. coli rose from 3.9% to 9.2% (p = 0.015). The rate of resistance to other considered antibiotics remained stable, as did the prevalence of extended spectrum beta-lactamases and extensively resistant E. coli among isolates. These findings call into question the use of AMC as a first-line therapy for pediatric UTIs in our population, despite the indications of recent Italian guidelines.

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Characterization of Anti-Bacterial Effect of the Two New Phages against Uropathogenic Escherichia coli

Viruses ◽

10.3390/v13071348 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1348

Author(s):

Lívia Slobodníková ◽

Barbora Markusková ◽

Michal Kajsík ◽

Michal Andrezál ◽

Marek Straka ◽

...

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Urinary Tract Infections ◽

Therapeutic Potential ◽

Medical Intervention ◽

Uropathogenic Escherichia Coli ◽

E Coli ◽

Phage Cocktail ◽

Causative Agents ◽

Tract Infections

Urinary tract infections (UTIs) are among the events that most frequently need medical intervention. Uropathogenic Escherichia coli are frequently their causative agents and the infections are sometimes complicated by the presence of polyresistant nosocomial strains. Phage therapy is a tool that has good prospects for the treatment of these infections. In the present study, we isolated and characterized two bacteriophages with broad host specificity against a panel of local uropathogenic E. coli strains and combined them into a phage cocktail. According to genome sequencing, these phages were closely related and belonged to the Tequatrovirus genus. The newly isolated phages showed very good activity on a panel of local clinical E. coli strains from urinary tract infections. In the form of a two-phage cocktail, they were active on E. coli strains belonging to phylogroups B2 and D, with relatively lower activity in B1 and no response in phylogroup A. Our study is a preliminary step toward the establishment of a national phage bank containing local, well-characterized phages with therapeutic potential for patients in Slovakia.

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Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum

Applied and Environmental Microbiology ◽

10.1128/aem.03079-14 ◽

2014 ◽

Vol 81 (2) ◽

pp. 713-725 ◽

Cited By ~ 44

Author(s):

John W. Schmidt ◽

Getahun E. Agga ◽

Joseph M. Bosilevac ◽

Dayna M. Brichta-Harhay ◽

Steven D. Shackelford ◽

...

Keyword(s):

Escherichia Coli ◽

Salmonella Enterica ◽

Generation Cephalosporin ◽

Resistant Bacteria ◽

Processing Plant ◽

Cattle Production ◽

Content Type ◽

E Coli ◽

Beef Processing ◽

Tract Infections

ABSTRACTSpecific concerns have been raised that third-generation cephalosporin-resistant (3GCr)Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr)E. coli, 3GCrSalmonella enterica, and nalidixic acid-resistant (NALr)S. entericamay be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n= 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GCrSalmonellawas detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NALrS. entericawas detected on only one hide. 3GCrE. coliand COTrE. coliwere detected on 100.0% of hides during processing. Concentrations of 3GCrE. coliand COTrE. colion hides were correlated with pre-evisceration carcass contamination. 3GCrE. coliand COTrE. coliwere each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenicE. coli(ExPEC) virulence-associated markers. Only two COTrE. coliisolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria.

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