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Kalalah AA, Koenig SSK, Feng P, Bosilevac JM, Bono JL, Eppinger M. Pathogenomes of Shiga Toxin Positive and Negative Escherichia coli O157:H7 Strains TT12A and TT12B: Comprehensive Phylogenomic Analysis Using Closed Genomes. Microorganisms 2024; 12:699. [PMID: 38674643 PMCID: PMC11052207 DOI: 10.3390/microorganisms12040699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/18/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
Shiga toxin-producing Escherichia coli are zoonotic pathogens that cause food-borne human disease. Among these, the O157:H7 serotype has evolved from an enteropathogenic O55:H7 ancestor through the displacement of the somatic gene cluster and recurrent toxigenic conversion by Shiga toxin-converting bacteriophages. However, atypical strains that lack the Shiga toxin, the characteristic virulence hallmark, are circulating in this lineage. For this study, we analyzed the pathogenome and virulence inventories of the stx+ strain, TT12A, isolated from a patient with hemorrhagic colitis, and its respective co-isolated stx- strain, TT12B. Sequencing the genomes to closure proved critical to the cataloguing of subtle strain differentiating sequence and structural polymorphisms at a high-level of phylogenetic accuracy and resolution. Phylogenomic profiling revealed SNP and MLST profiles similar to the near clonal outbreak isolates. Their prophage inventories, however, were notably different. The attenuated atypical non-shigatoxigenic status of TT12B is explained by the absence of both the ΦStx1a- and ΦStx2a-prophages carried by TT12A, and we also recorded further alterations in the non-Stx prophage complement. Phenotypic characterization indicated that culture growth was directly impacted by the strains' distinct lytic phage complement. Altogether, our phylogenomic and phenotypic analyses show that these intimately related isogenic strains are on divergent Stx(+/stx-) evolutionary paths.
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Affiliation(s)
- Anwar A. Kalalah
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
| | - Sara S. K. Koenig
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
| | - Peter Feng
- U.S. Food and Drug Administration (FDA), College Park, MD 20740, USA
| | - Joseph M. Bosilevac
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
| | - James L. Bono
- U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
| | - Mark Eppinger
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases (STCEID), San Antonio, TX 78249, USA
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Rivas M, Pichel M, Colonna M, Casanello AL, Alconcher LF, Galavotti J, Principi I, Araujo SP, Ramírez FB, González G, Pianciola LA, Mazzeo M, Suarez Á, Oderiz S, Ghezzi LFR, Arrigo DJ, Paladini JH, Baroni MR, Pérez S, Tamborini A, Chinen I, Miliwebsky ES, Goldbaum F, Muñoz L, Spatz L, Sanguineti S. Surveillance of Shiga toxin-producing Escherichia coli associated bloody diarrhea in Argentina. Rev Argent Microbiol 2023; 55:345-354. [PMID: 37301652 DOI: 10.1016/j.ram.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/12/2022] [Accepted: 03/27/2023] [Indexed: 06/12/2023] Open
Abstract
In Argentina, hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC-HUS) infection is endemic, and reliable data about prevalence and risk factors have been available since 2000. However, information about STEC-associated bloody diarrhea (BD) is limited. A prospective study was performed during the period October 2018-June 2019 in seven tertiary-hospitals and 18 referral units from different regions, aiming to determine (i) the frequency of STEC-positive BD cases in 714 children aged 1-9 years of age and (ii) the rate of progression of bloody diarrhea to HUS. The number and regional distribution of STEC-HUS cases in the same hospitals and during the same period were also assessed. Twenty-nine (4.1%) of the BD patients were STEC-positive, as determined by the Shiga Toxin Quik Chek (STQC) test and/or the multiplex polymerase chain reaction (mPCR) assay. The highest frequencies were found in the Southern region (Neuquén, 8.7%; Bahía Blanca, 7.9%), in children between 12 and 23 month of age (8.8%), during summertime. Four (13.8%) cases progressed to HUS, three to nine days after diarrhea onset. Twenty-seven STEC-HUS in children under 5 years of age (77.8%) were enrolled, 51.9% were female; 44% were Stx-positive by STQC and all by mPCR. The most common serotypes were O157:H7 and O145:H28 and the prevalent genotypes, both among BD and HUS cases, were stx2a-only or -associated. Considering the endemic behavior of HUS and its high incidence, these data show that the rate of STEC-positive cases is low among BD patients. However, the early recognition of STEC-positive cases is important for patient monitoring and initiation of supportive treatment.
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Affiliation(s)
- Marta Rivas
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina.
| | - Mariana Pichel
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
| | - Mariana Colonna
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
| | | | - Laura F Alconcher
- Hospital Interzonal "Dr. José Penna", Av. Laínez 2401, B8000 Bahía Blanca, Buenos Aires, Argentina
| | - Jimena Galavotti
- Hospital Interzonal "Dr. José Penna", Av. Laínez 2401, B8000 Bahía Blanca, Buenos Aires, Argentina
| | - Iliana Principi
- Hospital de Niños "Dr. Humberto Notti", Av. Bandera de los Andes 2603, M5521 Guaymallén, Mendoza, Argentina
| | - Sofía Pérez Araujo
- Hospital de Niños "Dr. Humberto Notti", Av. Bandera de los Andes 2603, M5521 Guaymallén, Mendoza, Argentina
| | - Flavia B Ramírez
- Hospital Provincial Neuquén Dr. Castro Rendón, Buenos Aires 450, Q8300 Neuquén, Argentina
| | - Gladys González
- Hospital Provincial Neuquén Dr. Castro Rendón, Buenos Aires 450, Q8300 Neuquén, Argentina
| | - Luis A Pianciola
- Laboratorio Central, Gregorio Martínez 65, Q8300 Neuquén, Argentina
| | - Melina Mazzeo
- Laboratorio Central, Gregorio Martínez 65, Q8300 Neuquén, Argentina
| | - Ángela Suarez
- Hospital De Niños "Sor María Ludovica", Calle 14 1631 entre 65 y 66, B1904CSI La Plata, Buenos Aires, Argentina
| | - Sebastián Oderiz
- Hospital De Niños "Sor María Ludovica", Calle 14 1631 entre 65 y 66, B1904CSI La Plata, Buenos Aires, Argentina
| | - Lidia F R Ghezzi
- Hospital Italiano de Buenos Aires, Tte. Gral. Juan Domingo Perón 4190, C1199AB, Buenos Aires, Argentina
| | - Diego J Arrigo
- Hospital Italiano de Buenos Aires, Tte. Gral. Juan Domingo Perón 4190, C1199AB, Buenos Aires, Argentina
| | - José H Paladini
- Hospital Dr. Orlando Alassia, Mendoza 4151, 3000 Santa Fe, Argentina
| | - María R Baroni
- Hospital Dr. Orlando Alassia, Mendoza 4151, 3000 Santa Fe, Argentina
| | - Susana Pérez
- Hospital "Dr. Lucio Molas", Raúl B. Díaz Pilcomayo, 6300 Santa Rosa, La Pampa, Argentina
| | - Ana Tamborini
- Hospital "Dr. Lucio Molas", Raúl B. Díaz Pilcomayo, 6300 Santa Rosa, La Pampa, Argentina
| | - Isabel Chinen
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas, ANLIS "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, 1281 Buenos Aires, Argentina
| | - Elizabeth S Miliwebsky
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas, ANLIS "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, 1281 Buenos Aires, Argentina
| | - Fernando Goldbaum
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
| | - Luciana Muñoz
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
| | - Linus Spatz
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
| | - Santiago Sanguineti
- Inmunova S.A., Av. 25 de Mayo 1021, San Martín, 1650 Buenos Aires, Argentina
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Bova RA, Lamont AC, Picou TJ, Ho VB, Gilchrist KH, Melton-Celsa AR. Shiga Toxin (Stx) Type 1a and Stx2a Translocate through a Three-Layer Intestinal Model. Toxins (Basel) 2023; 15:toxins15030207. [PMID: 36977098 PMCID: PMC10054274 DOI: 10.3390/toxins15030207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
Shiga toxins (Stxs) produced by ingested E. coli can induce hemolytic uremic syndrome after crossing the intact intestinal barrier, entering the bloodstream, and targeting endothelial cells in the kidney. The method(s) by which the toxins reach the bloodstream are not fully defined. Here, we used two polarized cell models to evaluate Stx translocation: (i) a single-layer primary colonic epithelial cell model and (ii) a three-cell-layer model with colonic epithelial cells, myofibroblasts, and colonic endothelial cells. We traced the movement of Stx types 1a and 2a across the barrier models by measuring the toxicity of apical and basolateral media on Vero cells. We found that Stx1a and Stx2a crossed both models in either direction. However, approximately 10-fold more Stx translocated in the three-layer model as compared to the single-layer model. Overall, the percentage of toxin that translocated was about 0.01% in the epithelial-cell-only model but up to 0.09% in the three-cell-layer model. In both models, approximately 3- to 4-fold more Stx2a translocated than Stx1a. Infection of the three-cell-layer model with Stx-producing Escherichia coli (STEC) strains showed that serotype O157:H7 STEC reduced barrier function in the model and that the damage was not dependent on the presence of the eae gene. Infection of the three-layer model with O26:H11 STEC strain TW08571 (Stx1a+ and Stx2a+), however, allowed translocation of modest amounts of Stx without reducing barrier function. Deletion of stx2a from TW08571 or the use of anti-Stx1 antibody prevented translocation of toxin. Our results suggest that single-cell models may underestimate the amount of Stx translocation and that the more biomimetic three-layer model is suited for Stx translocation inhibitor studies.
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Affiliation(s)
- Rebecca A. Bova
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA
- Center for Biotechnology (4DBio3), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA
- The Geneva Foundation, Tacoma, WA 98402, USA
| | - Andrew C. Lamont
- Center for Biotechnology (4DBio3), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA
- The Geneva Foundation, Tacoma, WA 98402, USA
| | - Theodore J. Picou
- Center for Biotechnology (4DBio3), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA
- The Geneva Foundation, Tacoma, WA 98402, USA
| | - Vincent B. Ho
- Center for Biotechnology (4DBio3), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA
| | - Kristin H. Gilchrist
- Center for Biotechnology (4DBio3), Department of Radiology and Radiological Sciences, Uniformed Services University, Bethesda, MD 20814, USA
- The Geneva Foundation, Tacoma, WA 98402, USA
| | - Angela R. Melton-Celsa
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA
- Correspondence:
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Alharbi MG, Al-Hindi RR, Esmael A, Alotibi IA, Azhari SA, Alseghayer MS, Teklemariam AD. The "Big Six": Hidden Emerging Foodborne Bacterial Pathogens. Trop Med Infect Dis 2022; 7:356. [PMID: 36355898 PMCID: PMC9693546 DOI: 10.3390/tropicalmed7110356] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 04/20/2024] Open
Abstract
Non-O157 Shiga toxin-producing Escherichia coli (STEC) are emerging serogroups that often result in diseases ranging from diarrhea to severe hemorrhagic colitis in humans. The most common non-O157 STEC are O26, O45, O103, O111, O121, and O145. These serogroups are known by the name "big six" because they cause severe illness and death in humans and the United States Department of Agriculture declared these serogroups as food contaminants. The lack of fast and efficient diagnostic methods exacerbates the public impact of the disease caused by these serogroups. Numerous outbreaks have been reported globally and most of these outbreaks were caused by ingestion of contaminated food or water as well as direct contact with reservoirs. Livestock harbor a variety of non-O157 STEC serovars that can contaminate meat and dairy products, or water sources when used for irrigation. Hence, effective control and prevention approaches are required to safeguard the public from infections. This review addresses the disease characteristics, reservoirs, the source of infections, the transmission of the disease, and major outbreaks associated with the six serogroups ("big six") of non-O157 STEC encountered all over the globe.
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Affiliation(s)
- Mona G. Alharbi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Rashad R. Al-Hindi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ahmed Esmael
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
- Botany and Microbiology Department, Faculty of Science, Benha University, Benha 13518, Egypt
| | - Ibrahim A. Alotibi
- Health Information Technology Department, Applied College, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Sheren A. Azhari
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Mazen S. Alseghayer
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Monitoring and Risk Assessment Department, Saudi Food and Drug Authority, Riyadh 13513, Saudi Arabia
| | - Addisu D. Teklemariam
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Nakanishi K, Takase T, Ohira Y, Ida R, Mogi N, Kikuchi Y, Matsuda M, Kurohane K, Akimoto Y, Hayakawa J, Kawakami H, Niwa Y, Kobayashi H, Umemoto E, Imai Y. Prevention of Shiga toxin 1-caused colon injury by plant-derived recombinant IgA. Sci Rep 2022; 12:17999. [PMID: 36289440 PMCID: PMC9606113 DOI: 10.1038/s41598-022-22851-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/20/2022] [Indexed: 01/24/2023] Open
Abstract
Immunoglobulin A (IgA) is a candidate antibody for oral passive immunization against mucosal pathogens like Shiga toxin-producing Escherichia coli (STEC). We previously established a mouse IgG monoclonal antibody (mAb) neutralizing Shiga toxin 1 (Stx1), a bacterial toxin secreted by STEC. We designed cDNA encoding an anti-Stx1 antibody, in which variable regions were from the IgG mAb and all domains of the heavy chain constant region from a mouse IgA mAb. Considering oral administration, we expressed the cDNA in a plant expression system aiming at the production of enough IgA at low cost. The recombinant-IgA expressed in Arabidopsis thaliana formed the dimeric IgA, bound to the B subunit of Stx1, and neutralized Stx1 toxicity to Vero cells. Colon injury was examined by exposing BALB/c mice to Stx1 via the intrarectal route. Epithelial cell death, loss of crypt and goblet cells from the distal colon were observed by electron microscopy. A loss of secretory granules containing MUC2 mucin and activation of caspase-3 were observed by immunohistochemical methods. Pretreatment of Stx1 with the plant-based recombinant IgA completely suppressed caspase-3 activation and loss of secretory granules. The results indicate that a plant-based recombinant IgA prevented colon damage caused by Stx1 in vivo.
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Affiliation(s)
- Katsuhiro Nakanishi
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Taichi Takase
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Yuya Ohira
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Ryota Ida
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Noriko Mogi
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Yuki Kikuchi
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Minami Matsuda
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Kohta Kurohane
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Yoshihiro Akimoto
- grid.411205.30000 0000 9340 2869Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611 Japan
| | - Junri Hayakawa
- grid.411205.30000 0000 9340 2869Laboratory for Electron Microscopy, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611 Japan
| | - Hayato Kawakami
- grid.411205.30000 0000 9340 2869Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611 Japan
| | - Yasuo Niwa
- grid.469280.10000 0000 9209 9298Laboratory of Plant Molecular Improvement, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Hirokazu Kobayashi
- grid.469280.10000 0000 9209 9298Laboratory of Plant Molecular Improvement, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Eiji Umemoto
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
| | - Yasuyuki Imai
- grid.469280.10000 0000 9209 9298Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka 422-8526 Japan
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Alconcher LF, Balestracci A, Coccia PA, Suarez ADC, Ramírez FB, Monteverde ML, Perez Y Gutiérrez MG, Carlopio PM, Principi I, Estrella P, Micelli S, Leroy DC, Quijada NE, Seminara C, Giordano MI, Hidalgo Solís SB, Saurit M, Caminitti A, Arias A, Liern M, Rivas M. Hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli infection in Argentina: update of serotypes and genotypes and their relationship with severity of the disease. Pediatr Nephrol 2021; 36:2811-2817. [PMID: 33604727 DOI: 10.1007/s00467-021-04988-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/23/2021] [Accepted: 02/04/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Shiga toxin-producing Escherichia coli (STEC) infection is the most common cause of hemolytic uremic syndrome (HUS). Only few studies correlated serotypes and stx genotypes with disease severity. This study aimed to update STEC serotypes, stx genotypes, and virulence factors (eae and ehxA) in a cohort of patients with STEC-HUS and investigate whether they influence the severity of disease. METHODS In this multicentric study, children hospitalized between 2005 and 2016 with STEC-HUS confirmed by the National Reference Laboratory were included. Serotypes (O157, O145, O121, and others), stx genotypes (stx1a, stx2a, stx2c, stx2d, and others), and virulence factors were analyzed, and their association with dialysis requirement (>10 days); severe neurological, cardiovascular, and/or bowel involvement; and death was assessed. RESULTS The records of 280 patients were reviewed; 160 females, median age 21 months (IQR18m). STEC O157 was isolated in 206 (73.6%) patients, O145 in 47 (16.8%), O121 in 15 (5.4%), and other serotypes in 12 (4.2%). The stx2a/2c genotype was carried by 179 (63.9%) strains, stx2a by 94 (33.6%), stx1a/stx2a by five (1.8%), and stx1a only by two (0.7%). All strains except six harbored eae and ehxA genes. Fifty-nine (21.1%) patients had severe neurological involvement, 29 (10.4%) severe bowel injury, 14 (5%) cardiovascular involvement, 53 (18.9%) required > 10 days of dialysis, and 12 (4.3%) died. Neither serotypes nor stx genotypes detected were significantly linked to severity. CONCLUSIONS Serotype O157 and virulence stx2a/2c, eae, ehxA genotype are prevalent in Argentina, and no relationship was found between severity and serotypes and genotypes of STEC detected.
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Affiliation(s)
- Laura F Alconcher
- Pediatric Nephrology Unit, Pediatric Department, Hospital Interzonal Dr. José Penna Bahía Blanca, Las Lomas 217, (8000) Bahía Blanca, Buenos Aires, Argentina.
| | - Alejandro Balestracci
- Nephrology Unit, Hospital General de Niños Pedro de Elizalde CABA, Buenos Aires, Argentina
| | - Paula A Coccia
- Pediatric Nephrology Division, Department of Pediatrics, Hospital Italiano Ciudad Autónoma de Buenos Aires (CABA), Buenos Aires, Argentina
| | - Angela Del C Suarez
- Department of Nephrology, Hospital de Niños Sor María Ludovica La Plata, Buenos Aires, Argentina
| | - Flavia B Ramírez
- Pediatric Nephrology Division, Department of Pediatrics, Hospital Dr. Castro Rendon Neuquén, Neuquén, Argentina
| | - Marta L Monteverde
- Hospital Nacional de Pediatría JP Garrahan CABA, Buenos Aires, Argentina
| | | | - Paula M Carlopio
- Pediatric Nephrology Division, Department of Pediatrics, Hospital Posadas, Buenos Aires, Argentina
| | - Illiana Principi
- Department of Nephrology, Hospital Pediátrico Humberto J Notti Mendoza, Mendoza, Argentina
| | - Patricia Estrella
- Dirección de Epidemiología de La Pampa - Hospital Lucio Molas, Santa Rosa, La Pampa, Argentina
| | - Susana Micelli
- Department of Nephrology, Hospital del Niño Jesús, San Miguel de Tucumán, Tucumán, Argentina
| | - Daniela C Leroy
- Department of Pediatrics, Hospital Interzonal de Agudos Abrahan Piñeyro Junín, Buenos Aires, Argentina
| | | | | | | | | | - Mariana Saurit
- Hospital Público Materno Infantil de Salta, Salta, Argentina
| | - Alejandra Caminitti
- Department of Nephrology, Hospital Provincial de Santa Fé, Santa Fé, Argentina
| | - Andrea Arias
- Department of Nephrology, Hospital Materno Infantil Dr. Héctor Quintana Jujuy, San Salvador de Jujuy, Argentina
| | - Miguel Liern
- Department of Nephrology, Hospital Gutiérrez CABA, Buenos Aires, Argentina
| | - Marta Rivas
- Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires, Argentina
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Diversity of Non-O157 Shiga Toxin-Producing Escherichia coli Isolated from Cattle from Central and Southern Chile. Animals (Basel) 2021; 11:ani11082388. [PMID: 34438845 PMCID: PMC8388633 DOI: 10.3390/ani11082388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/10/2021] [Accepted: 06/22/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Cattle are the main reservoir of Shiga toxin-producing E. coli (STEC), foodborne pathogens that cause severe disease and outbreaks. However, not all STEC cause human illnesses or have the same virulence potential. Characterizing strains isolated worldwide allows insights into how strains spread and which isolates have a more significant risk potential. This study described STEC isolation rates from cattle in Chile and characterized 30 isolates. We obtained 93 STEC isolates from 56/446 (12.6%) fecal cattle samples. Then, 30 non-O157 STEC isolates were selected for complete characterization; we found isolates of 16 different sequence types and 17 serotypes. One isolate was resistant to tetracycline and carried resistance genes against the drug. Surveyed virulence genes (n = 31) were present from 13% to 100% of isolates, and one isolate carried 26/31 virulence genes. Most isolates (90%; 27/30) carried the stx2 gene, which is frequently linked to strains causing severe disease. A phylogenetic reconstruction demonstrated that isolates clustered based on serotypes, independent of their geographical origin (Central or Southern Chile). These results indicate that cattle in Chile carry a wide diversity of STEC potentially pathogenic for humans based on the presence of virulence genes. Abstract Cattle are the main reservoir of Shiga toxin-producing Escherichia coli (STEC), one of the world’s most important foodborne pathogens. The pathogen causes severe human diseases and outbreaks. This study aimed to identify and characterize non-O157 STEC isolated from cattle feces from central and southern Chile. We analyzed 446 cattle fecal samples and isolated non-O157 STEC from 12.6% (56/446); a total of 93 different isolates were recovered. Most isolates displayed β-glucuronidase activity (96.8%; 90/93) and fermented sorbitol (86.0%; 80/93), whereas only 39.8% (37/93) were resistant to tellurite. A subgroup of 30 representative non-O157 STEC isolates was selected for whole-genome sequencing and bioinformatics analysis. In silico analysis showed that they grouped into 16 different sequence types and 17 serotypes; the serotypes most frequently identified were O116:H21 and O168:H8 (13% each). A single isolate of serotype O26:H11 was recovered. One isolate was resistant to tetracycline and carried resistance genes tet(A) and tet(R); no other isolate displayed antimicrobial resistance or carried antimicrobial resistance genes. The intimin gene (eae) was identified in 13.3% (4/30) of the genomes and 90% (27/30) carried the stx2 gene. A phylogenetic reconstruction demonstrated that the isolates clustered based on serotypes, independent of geographical origin. These results indicate that cattle in Chile carry a wide diversity of STEC potentially pathogenic for humans based on the presence of critical virulence genes.
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Tack DM, Kisselburgh HM, Richardson LC, Geissler A, Griffin PM, Payne DC, Gleason BL. Shiga Toxin-Producing Escherichia coli Outbreaks in the United States, 2010-2017. Microorganisms 2021; 9:microorganisms9071529. [PMID: 34361964 PMCID: PMC8307841 DOI: 10.3390/microorganisms9071529] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) cause illnesses ranging from mild diarrhea to ischemic colitis and hemolytic uremic syndrome (HUS); serogroup O157 is the most common cause. We describe the epidemiology and transmission routes for U.S. STEC outbreaks during 2010–2017. Health departments reported 466 STEC outbreaks affecting 4769 persons; 459 outbreaks had a serogroup identified (330 O157, 124 non-O157, 5 both). Among these, 361 (77%) had a known transmission route: 200 foodborne (44% of O157 outbreaks, 41% of non-O157 outbreaks), 87 person-to-person (16%, 24%), 49 animal contact (11%, 9%), 20 water (4%, 5%), and 5 environmental contamination (2%, 0%). The most common food category implicated was vegetable row crops. The distribution of O157 and non-O157 outbreaks varied by age, sex, and severity. A significantly higher percentage of STEC O157 than non-O157 outbreaks were transmitted by beef (p = 0.02). STEC O157 outbreaks also had significantly higher rates of hospitalization and HUS (p < 0.001).
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9
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Travert B, Rafat C, Mariani P, Cointe A, Dossier A, Coppo P, Joseph A. Shiga Toxin-Associated Hemolytic Uremic Syndrome: Specificities of Adult Patients and Implications for Critical Care Management. Toxins (Basel) 2021; 13:306. [PMID: 33925836 PMCID: PMC8145702 DOI: 10.3390/toxins13050306] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 01/28/2023] Open
Abstract
Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is a form of thrombotic microangiopathy secondary to an infection by an enterohemorrhagic E. coli. Historically considered a pediatric disease, its presentation has been described as typical, with bloody diarrhea at the forefront. However, in adults, the clinical presentation is more diverse and makes the early diagnosis hazardous. In this review, we review the epidemiology, most important outbreaks, physiopathology, clinical presentation and prognosis of STEC-HUS, focusing on the differential features between pediatric and adult disease. We show that the clinical presentation of STEC-HUS in adults is far from typical and marked by the prevalence of neurological symptoms and a poorer prognosis. Of note, we highlight knowledge gaps and the need for studies dedicated to adult patients. The differences between pediatric and adult patients have implications for the treatment of this disease, which remains a public health threat and lack a specific treatment.
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Affiliation(s)
- Benoit Travert
- Service de Médecine Interne, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, 75018 Paris, France; (B.T.); (A.D.)
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
| | - Cédric Rafat
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Urgences Néphrologiques et Transplantation Rénale, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, 75020 Paris, France
| | - Patricia Mariani
- Service de Microbiologie, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 75019 Paris, France; (P.M.); (A.C.)
| | - Aurélie Cointe
- Service de Microbiologie, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 75019 Paris, France; (P.M.); (A.C.)
| | - Antoine Dossier
- Service de Médecine Interne, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, 75018 Paris, France; (B.T.); (A.D.)
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
| | - Paul Coppo
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Service d’Hématologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 75012 Paris, France
| | - Adrien Joseph
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Médecine Intensive Réanimation, Hôpital Saint Louis, Assistance Publique-Hôpitaux de Paris, 75010 Paris, France
- Centre de Recherche des Cordeliers, Équipe Labellisée par la Ligue Contre le Cancer, Inserm U1138, Université de Paris, Sorbonne Université, 75006 Paris, France
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10
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Pan Z, Chen Y, McAllister TA, Gänzle M, Plastow G, Guan LL. Abundance and Expression of Shiga Toxin Genes in Escherichia coli at the Recto-Anal Junction Relates to Host Immune Genes. Front Cell Infect Microbiol 2021; 11:633573. [PMID: 33816337 PMCID: PMC8010187 DOI: 10.3389/fcimb.2021.633573] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/15/2021] [Indexed: 12/01/2022] Open
Abstract
Shiga toxin (Stx) is the main virulence factor of Shiga toxin-producing Escherichia coli (STEC), and ruminants are the main reservoir of STEC. This study assessed the abundance and expression of Stx genes and the expression of host immune genes, aiming to determine factors affecting these measures and potential gene markers to differentiate Stx gene expression in the recto-anal junction of feedlot beef cattle. Rectal tissue and content samples were collected from 143 feedlot steers of three breeds (Angus, Charolais, and Kinsella Composite) over 2 consecutive years 2014 (n=71) and 2015 (n=72). The abundance and expression of stx1 and stx2 were quantified using qPCR and reverse-transcription-qPCR (RT-qPCR), respectively. Four immune genes (MS4A1, CCL21, CD19, and LTB), previously reported to be down-regulated in super-shedder cattle (i.e., > 104 CFU g-1) were selected, and their expression was evaluated using RT-qPCR. The stx1 gene abundance was only detected in tissue samples collected in year 2 and did not differ among breeds. The stx2 gene was detected in STEC from all samples collected in both years and did not vary among breeds. The abundance of stx1 and stx2 differed (P < 0.001) in content samples collected across breeds (stx1:AN>CH>KC, stx2: AN=CH>KC) in year 1, but not in year 2. Expression of stx2 was detected in 13 RAJ tissue samples (2014: n=6, 2015: n=7), while expression of stx1 was not detected. Correlation analysis showed that the expression of stx2 was negatively correlated with the expression of MS4A1 (R=-0.56, P=0.05) and positively correlated with the expression of LTB (R=0.60, P=0.05). The random forest model and Boruta method revealed that expression of selected immune genes could be predictive indicators of stx2 expression with prediction accuracy of MS4A1 >LTB >CCL21 >CD19. Our results indicate that the abundance of Stx could be affected by cattle breed and sampling year, suggesting that host genetics and environment may influence STEC colonization of the recto-anal junction of feedlot cattle. Additionally, the identified relationship between expressions of host immune genes and stx2 suggests that the host animal may regulate stx2 expression in colonizing STEC through immune functions.
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Affiliation(s)
- Zhe Pan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Yanhong Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Tim A McAllister
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Graham Plastow
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Le Luo Guan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
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11
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Switching Shiga Toxin (Stx) Type from Stx2d to Stx2a but Not Stx2c Alters Virulence of Stx-Producing Escherichia coli (STEC) Strain B2F1 in Streptomycin (Str)-Treated Mice. Toxins (Basel) 2021; 13:toxins13010064. [PMID: 33467588 PMCID: PMC7829771 DOI: 10.3390/toxins13010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 11/23/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) strain B2F1 produces Stx type 2d, a toxin that becomes more toxic towards Vero cells in the presence of intestinal mucus. STEC that make Stx2d are more pathogenic to streptomycin (Str)-treated mice than most STEC that produce Stx2a or Stx2c. However, purified Stx2d is only 2- or 7-fold more toxic by the intraperitoneal route than Stx2a or Stx2c, respectively. We hypothesized, therefore, that the toxicity differences among Stx2a, Stx2c, and Stx2d occur at the level of delivery from the intestine. To evaluate that hypothesis, we altered the toxin type produced by stx2d+ mouse virulent O91:H21 clinical isolate B2F1 to Stx2a or Stx2c. Because B2F1 encodes two copies of stx2d, we did these studies in a derivative of B2F1 in which stx2d1 was deleted. Although the strains were equivalently virulent to the Str-treated mice at the 1010 dose, the B2F1 strain that produced Stx2a was attenuated relative to the ones that produced Stx2d or Stx2c when administered at 103 CFU/mouse. We next compared the oral toxicities of purified Stx2a, Stx2c, and Stx2d. We found that purified Stx2d is more toxic than Stx2a or Stx2c upon oral administration at 4 µg/mouse. Taken together, these studies suggest that Stx2 toxins are most potent when delivered directly from the bacterium. Furthermore, because Stx2d and Stx2c have the identical amino acid composition in the toxin B subunit, our results indicate that the virulence difference between Stx2a and Stx2d and Stx2c resides in the B or binding subunit of the toxins.
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12
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A Toxic Environment: a Growing Understanding of How Microbial Communities Affect Escherichia coli O157:H7 Shiga Toxin Expression. Appl Environ Microbiol 2020; 86:AEM.00509-20. [PMID: 32358004 DOI: 10.1128/aem.00509-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.
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13
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Ardissino G, Possenti I, Vignati C, Daprai L, Capone V, Brigotti M, Luini MV, Consonni D, Montini G. Is Shigatoxin 1 protective for the development of Shigatoxin 2-related hemolytic uremic syndrome in children? Data from the ItalKid-HUS Network. Pediatr Nephrol 2020; 35:1997-2001. [PMID: 32734345 DOI: 10.1007/s00467-020-04697-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/16/2020] [Accepted: 06/25/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Shigatoxin (Stx)-producing Escherichia coli (STEC) are the most common causes of hemolytic uremic syndrome (STEC-HUS). The aim of our study is to compare the risk of developing STEC-HUS in relation to the type of Stx genes (Stx1, Stx2, or both). METHODS This is a prospective, observational, multicenter study involving 63 pediatric units in Northern Italy (ItalKid-HUS Network). STEC-infected children were identified within a screening program for bloody diarrhea during a 10-year period (2010-2019). Stx genes were detected by reverse dot blot or real-time PCR. After the identification of STEC infection, children were followed until diarrhea complete recovery for the possible development of STEC-HUS. RESULTS Of the 214 Stx-positive patients, 34 (15.9%) developed STEC-HUS. The risk of HUS in STEC-infected children with Stx1 (n: 62; 29.0%) and Stx2 (n: 97; 45.3%) was respectively 0% and 23.7%, while in patients carrying both Stx1 and Stx2 (n: 55; 25.7%), the risk was 12.7% (p: 0.001). CONCLUSIONS Our data confirm that Stx1 is a very rare cause of STEC-HUS and demonstrate that the risk of STEC-HUS halves in the case of Stx1+2-producing Escherichia coli infection compared with infections where Stx2 is present alone. This observation is helpful in assessing the risk of individual STEC-infected patients for the development of HUS and suggests that Stx1, in the presence of Stx2, might exert a protective role possibly by receptor competition.
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Affiliation(s)
- Gianluigi Ardissino
- Center for HUS Prevention, Control and Management, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Commenda 9, 20122, Milan, Italy.
| | - Ilaria Possenti
- Pediatric Unit, Ospedale Infantile C.Arrigo, Spalto Marengo 46, 15121, Alessandria, Italy
| | - Chiara Vignati
- Unit of Microbiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Commenda 9, 20122, Milan, Italy
| | - Laura Daprai
- Unit of Microbiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Commenda 9, 20122, Milan, Italy
| | - Valentina Capone
- Center for HUS Prevention, Control and Management, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Commenda 9, 20122, Milan, Italy
| | - Maurizio Brigotti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40126, Bologna, Italy
| | - Mario Vittorio Luini
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, 26900, Lodi, Italy
| | - Dario Consonni
- Epidemiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via San Barnaba 8, 20122, Milan, Italy
| | - Giovanni Montini
- Center for HUS Prevention, Control and Management, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Commenda 9, 20122, Milan, Italy.,Giuliana and Bernardo Caprotti Chair of Pediatrics, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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14
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Pintara A, Jennison A, Rathnayake IU, Mellor G, Huygens F. Core and Accessory Genome Comparison of Australian and International Strains of O157 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2020; 11:566415. [PMID: 33013798 PMCID: PMC7498637 DOI: 10.3389/fmicb.2020.566415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/17/2020] [Indexed: 12/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen, and serotype O157:H7 is typically associated with severe disease. Australian STEC epidemiology differs from many other countries, as severe outbreaks and HUS cases appear to be more often associated with non-O157 serogroups. It is not known why Australian strains of O157 STEC might differ in virulence to international strains. Here we investigate the reduced virulence of Australian strains. Multiple genetic analyses were performed, including SNP-typing, to compare the core genomes of the Australian to the international isolates, and accessory genome analysis to determine any significant differences in gene presence/absence that could be associated with their phenotypic differences in virulence. The most distinct difference between the isolates was the absence of the stx2a gene in all Australian isolates, with few other notable differences observed in the core and accessory genomes of the O157 STEC isolates analyzed in this study. The presence of stx1a in most Australian isolates was another notable observation. Acquisition of stx2a seems to coincide with the emergence of highly pathogenic STEC. Due to the lack of other notable genotypic differences observed between Australian and international isolates characterized as highly pathogenic, this may be further evidence that the absence of stx2a in Australian O157 STEC could be a significant characteristic defining its mild virulence. Further work investigating the driving force(s) behind Stx prophage loss and acquisition is needed to determine if this potential exists in Australian O157 isolates.
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Affiliation(s)
- Alexander Pintara
- Centre for Immunology and Infection Control, Queensland University of Technology, Herston, QLD, Australia
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Amy Jennison
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, QLD, Australia
| | - Irani U. Rathnayake
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, QLD, Australia
| | - Glen Mellor
- CSIRO Animal, Food and Health Sciences, Archerfield, QLD, Australia
| | - Flavia Huygens
- Centre for Immunology and Infection Control, Queensland University of Technology, Herston, QLD, Australia
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
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15
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Hauser JR, Atitkar RR, Petro CD, Lindsey RL, Strockbine N, O'Brien AD, Melton-Celsa AR. The Virulence of Escherichia coli O157:H7 Isolates in Mice Depends on Shiga Toxin Type 2a (Stx2a)-Induction and High Levels of Stx2a in Stool. Front Cell Infect Microbiol 2020; 10:62. [PMID: 32175286 PMCID: PMC7054288 DOI: 10.3389/fcimb.2020.00062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/07/2020] [Indexed: 12/28/2022] Open
Abstract
In this study we compared nine Shiga toxin (Stx)-producing Escherichia coli O157:H7 patient isolates for Stx levels, stx-phage insertion site(s), and pathogenicity in a streptomycin (Str)-treated mouse model. The strains encoded stx2a, stx1a and stx2a, or stx2a and stx2c. All of the strains elaborated 105-106 cytotoxic doses 50% (CD50) into the supernatant after growth in vitro as measured on Vero cells, and showed variable levels of increased toxin production after growth with sub-inhibitory levels of ciprofloxacin (Cip). The stx2a+stx2c+ isolates were 90–100% lethal for Str-treated BALB/c mice, though one isolate, JH2013, had a delayed time-to-death. The stx2a+ isolate was avirulent. Both an stx2a and a recA deletion mutant of one of the stx2a+stx2c+ strains, JH2010, exhibited at least a three-log decrease in cytotoxicity in vitro and both were avirulent in the mice. Stool from Str-treated mice infected with the highly virulent isolates were 10- to 100-fold more cytotoxic than feces from mice infected with the clinical isolate, JH2012, that made only Stx2a. Taken together these findings demonstrate that the stx2a-phage from JH2010 induces to higher levels in vivo than does the phage from JH2012. The stx1a+stx2a+ clinical isolates were avirulent and neutralization of Stx1 in stool from mice infected with those strains indicated that the toxin produced in vivo was primarily Stx1a. Treatment of mice infected with Stx1a+Stx2a+ isolates with Cip resulted in an increase in Stx2a production in vivo and lethality in the mice. Our data suggest that high levels of Stx2a in stool are predictive of virulence in mice.
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Affiliation(s)
- Jocelyn R Hauser
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Rama R Atitkar
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Courtney D Petro
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Rebecca L Lindsey
- Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Nancy Strockbine
- Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Alison D O'Brien
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Angela R Melton-Celsa
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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16
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Bimodal Response to Shiga Toxin 2 Subtypes Results from Relatively Weak Binding to the Target Cell. Infect Immun 2019; 87:IAI.00428-19. [PMID: 31527121 DOI: 10.1128/iai.00428-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/07/2019] [Indexed: 01/15/2023] Open
Abstract
There are two major antigenic forms of Shiga toxin (Stx), Stx1 and Stx2, which bind the same receptor and act on the same target but nonetheless differ in potency. Stx1a is more toxic to cultured cells, but Stx2 subtypes are more potent in animal models. To understand this phenomenon in cultured cells, we used a system that combines flow cytometry with a fluorescent reporter to monitor the Stx-induced inhibition of protein synthesis in single cells. We observed that Vero cells intoxicated with Stx1a behave differently than those intoxicated with Stx2 subtypes: cells challenged with Stx1a exhibited a population-wide loss of protein synthesis, while cells exposed to Stx2a or Stx2c exhibited a dose-dependent bimodal response in which one subpopulation of cells was unaffected (i.e., no loss of protein synthesis). Cells challenged with a hybrid toxin containing the catalytic subunit of Stx1a and the cell-binding subunit of Stx2a also exhibited a bimodal response to intoxication, while cells challenged with a hybrid toxin containing the catalytic subunit of Stx2a and the cell-binding subunit of Stx1a exhibited a population-wide loss of protein synthesis. Other experiments further supported a primary role for the subtype of the B subunit in the outcome of host-Stx interactions. Our collective observations indicate that the bimodal response to Stx2 subtypes is due to relatively weak binding between Stx2 and the host cell that reduces the total functional pool of Stx2 in comparison to that of Stx1a. This explains, in part, the molecular basis for the differential cellular toxicity between Stx1a and Stx2 subtypes.
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17
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Tarr GAM, Stokowski T, Shringi S, Tarr PI, Freedman SB, Oltean HN, Rabinowitz PM, Chui L. Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence. Toxins (Basel) 2019; 11:toxins11100607. [PMID: 31635282 PMCID: PMC6832461 DOI: 10.3390/toxins11100607] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/14/2019] [Accepted: 10/16/2019] [Indexed: 01/17/2023] Open
Abstract
Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) −0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI −87.8%, −2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.
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Affiliation(s)
- Gillian A M Tarr
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada.
| | - Taryn Stokowski
- Department of Laboratory Medicine and Pathology, University of Alberta and Alberta Public Labs, Edmonton, AB T6G 2J2, Canada.
| | - Smriti Shringi
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99163, USA.
| | - Phillip I Tarr
- Division of Gastroenterology, Hepatology, and Nutrition, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Stephen B Freedman
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada.
| | - Hanna N Oltean
- Washington State Department of Health, Shoreline, WA 98155, USA.
| | - Peter M Rabinowitz
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
| | - Linda Chui
- Department of Laboratory Medicine and Pathology, University of Alberta and Alberta Public Labs, Edmonton, AB T6G 2J2, Canada.
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