101
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Entrapment of HETS recombinant protein onto PLGA and alginate NPs improves the immunogenicity of the protein against E. coli O157:H7. Mol Immunol 2019; 114:612-619. [PMID: 31542606 DOI: 10.1016/j.molimm.2019.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/05/2019] [Accepted: 09/13/2019] [Indexed: 12/22/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are known as the gastrointestinal pathogens and major causes of enterohemorrhagic colitis since decades ago. There is no efficient approved vaccine against EHEC O157 and non-O157. In the present study, a recombinant candidate vaccine against enterohemorrhagic E. coli (EHEC) O157:H7 entrapped in the sodium alginate and PLGA nanoparticles and the efficiency of the immunization of these formulations were investigated. nanoparticles due to their properties like controlled cargoes release, adjuvanticity, cargo protection, increased bioavailability, etc have been noticed for drug delivery. A chimeric protein composed of HcpA, EspA, Tir and Stx2B antigens was designed, recombinantly expressed, purified and entrapped in nanoparticles. BALB/c mice were administrated with nano-formulated and free proteins. IgG titer, EHEC fecal shedding and the ability of the immune sera to neutralize Stx toxin and inhibit the bacterial attachment to Caco-2 cells were analyzed. Fecal shedding analysis demonstrated that the colonization of the bacteria in the intestine of the mice was reduced significantly (P > 0.01). Immune mice were able to tolerate up to 200 LD50 of the active Stx toxin. About 80% of the bacterial binding capacity to Caco-2 cells was declined, especially in groups immunized with nano-formulations. Considering the importance of EHEC, especially O157 serotype, on public health and the other hand, the lack of an efficient vaccine in this regard, delivery of HETS candidate vaccine with NPs can be applied to prevent the infection by the pathogen.
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102
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Bacteriological analysis of wheat flour associated with an outbreak of Shiga toxin-producing Escherichia coli O121. Food Microbiol 2019; 82:474-481. [DOI: 10.1016/j.fm.2019.03.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 02/19/2019] [Accepted: 03/19/2019] [Indexed: 01/18/2023]
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103
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Abstract
Plasmids have a major role in the development of disease caused by enteric bacterial pathogens. Virulence plasmids are usually large (>40 kb) low copy elements and encode genes that promote host-pathogen interactions. Although virulence plasmids provide advantages to bacteria in specific conditions, they often impose fitness costs on their host. In this Review, we discuss virulence plasmids in Enterobacteriaceae that are important causes of diarrhoea in humans, Shigella spp., Salmonella spp., Yersinia spp and pathovars of Escherichia coli. We contrast these plasmids with those that are routinely used in the laboratory and outline the mechanisms by which virulence plasmids are maintained in bacterial populations. We highlight examples of virulence plasmids that encode multiple mechanisms for their maintenance (for example, toxin-antitoxin and partitioning systems) and speculate on how these might contribute to their propagation and success.
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104
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Silva MA, Santos ARR, Rocha LB, Caetano BA, Mitsunari T, Santos LI, Polatto JM, Horton DSPQ, Guth BEC, Dos Santos LF, Piazza RMF. Development and Validation of Shiga Toxin-Producing Escherichia coli Immunodiagnostic Assay. Microorganisms 2019; 7:E276. [PMID: 31438570 PMCID: PMC6780578 DOI: 10.3390/microorganisms7090276] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 01/29/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) and its subgroup enterohemorrhagic E. coli are important pathogens involved in diarrhea, which may be complicated by hemorrhagic colitis and hemolytic uremic syndrome, the leading cause of acute renal failure in children. Early diagnosis is essential for clinical management, as an antibiotic treatment in STEC infections is not recommended. Previously obtained antibodies against Stx1 and Stx2 toxins were employed to evaluate the sensitivity and specificity of the latex Agglutination test (LAT), lateral flow assay (LFA), and capture ELISA (cEIA) for STEC detection. The LAT (mAb Stx1 plus mAb stx2) showed 99% sensitivity and 97% specificity. Individually, Stx1 antibodies showed 95.5% and 94% sensitivity and a specificity of 97% and 99% in the cEIA and LFA assay, respectively. Stx2 antibodies showed a sensitivity of 92% in both assays and a specificity of 100% and 98% in the cEIA and LFA assay, respectively. These results allow us to conclude that we have robust tools for the diagnosis of STEC infections.
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Affiliation(s)
- Miriam A Silva
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | | | - Leticia B Rocha
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Bruna A Caetano
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Thais Mitsunari
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Luanda I Santos
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Juliana M Polatto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Denise S P Q Horton
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Beatriz E C Guth
- Departamento de Microbiologia, Imunologia, Parasitologia, Escola Paulista de Medicina Universidade Federal de São Paulo, São Paulo 04023-062, Brasil
| | | | - Roxane M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil.
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105
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Greig DR, Jenkins C, Gharbia S, Dallman TJ. Comparison of single-nucleotide variants identified by Illumina and Oxford Nanopore technologies in the context of a potential outbreak of Shiga toxin-producing Escherichia coli. Gigascience 2019; 8:giz104. [PMID: 31433830 PMCID: PMC6703438 DOI: 10.1093/gigascience/giz104] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/12/2019] [Accepted: 08/07/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND We aimed to compare Illumina and Oxford Nanopore Technology sequencing data from the 2 isolates of Shiga toxin-producing Escherichia coli (STEC) O157:H7 to determine whether concordant single-nucleotide variants were identified and whether inference of relatedness was consistent with the 2 technologies. RESULTS For the Illumina workflow, the time from DNA extraction to availability of results was ∼40 hours, whereas with the ONT workflow serotyping and Shiga toxin subtyping variant identification were available within 7 hours. After optimization of the ONT variant filtering, on average 95% of the discrepant positions between the technologies were accounted for by methylated positions found in the described 5-methylcytosine motif sequences, CC(A/T)GG. Of the few discrepant variants (6 and 7 difference for the 2 isolates) identified by the 2 technologies, it is likely that both methodologies contain false calls. CONCLUSIONS Despite these discrepancies, Illumina and Oxford Nanopore Technology sequences from the same case were placed on the same phylogenetic location against a dense reference database of STEC O157:H7 genomes sequenced using the Illumina workflow. Robust single-nucleotide polymorphism typing using MinION-based variant calling is possible, and we provide evidence that the 2 technologies can be used interchangeably to type STEC O157:H7 in a public health setting.
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Affiliation(s)
- David R Greig
- National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Claire Jenkins
- National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Saheer Gharbia
- National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Timothy J Dallman
- National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
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106
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Trotter KD, Owojaiye O, Meredith SP, Keating PE, Spicer MD, Reglinski J, Spickett CM. The interaction of silver(II) complexes with biological macromolecules and antioxidants. Biometals 2019; 32:627-640. [PMID: 31098734 PMCID: PMC6647504 DOI: 10.1007/s10534-019-00198-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/30/2019] [Indexed: 12/16/2022]
Abstract
Silver is widely used for its antimicrobial properties, but microbial resistance to heavy metals is increasing. Silver(II) compounds are more oxidizing and therefore have the potential to overcome resistance via extensive attack on cellular components, but have traditionally been hard to stabilize for biological applications. Here, the high oxidation state cation was stabilised using pyridinecarboxylate ligands, of which the 2,6-dicarboxypyridine Ag(II) complex (Ag2,6P) was found to have the best tractability. This complex was found to be more stable in phosphate buffer than DMSO, allowing studies of its interaction with water soluble antioxidants and biological macromolecules, with the aim of demonstrating its potential to oxidize them, as well as determining the reaction products. Spectrophotometric analysis showed that Ag2,6P was rapidly reduced by the antioxidants glutathione, ascorbic acid and vitamin E; the unsaturated lipids arachidonic and linoleic acids, model carbohydrate β-cyclodextrin, and protein cytochrome c also reacted readily. Analysis of the reaction with glutathione by NMR and electrospray mass spectrometry confirmed that the glutathione was oxidized to the disulfide form. Mass spectrometry also clearly showed the addition of multiple oxygen atoms to the unsaturated fatty acids, suggesting a radical mechanism, and cross-linking of linoleic acid was observed. The seven hydroxyl groups of β-cyclodextrin were found to be completely oxidized to the corresponding carboxylates. Treatment of cytochrome c with Ag2,6P led to protein aggregation and fragmentation, and dose-dependent oxidative damage was demonstrated by oxyblotting. Thus Ag2,6P was found to be highly oxidizing to a wide variety of polar and nonpolar biological molecules.
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Affiliation(s)
- Katherine D Trotter
- Department of Pure & Applied Chemistry, Strathclyde University, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Olawale Owojaiye
- Department of Pure & Applied Chemistry, Strathclyde University, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Stuart P Meredith
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Pat E Keating
- Department of Pure & Applied Chemistry, Strathclyde University, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Mark D Spicer
- Department of Pure & Applied Chemistry, Strathclyde University, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - John Reglinski
- Department of Pure & Applied Chemistry, Strathclyde University, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Corinne M Spickett
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Strathclyde University, 161 Cathedral Street, Glasgow, G4 0NR, UK.
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107
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Obaidat MM, Stringer AP. Prevalence, molecular characterization, and antimicrobial resistance profiles of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 on dairy cattle farms in Jordan. J Dairy Sci 2019; 102:8710-8720. [PMID: 31351714 DOI: 10.3168/jds.2019-16461] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/28/2019] [Indexed: 12/15/2022]
Abstract
This study determined the prevalence, pulsed-field gel electrophoresis profiles, and antimicrobial resistance profile of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 isolates from dairy cattle farms in Jordan. Samples from bulk tank milk (n = 305), cattle feces (n = 610), and rectoanal mucosal swabs (n = 610) were collected from 61 dairy cattle farms. We confirmed 32 L. monocytogenes, 28 S. enterica, and 24 E. coli O157:H7 isolates from the samples. The farm-level prevalence (at least 1 positive sample per farm) of L. monocytogenes, S. enterica, and E. coli O157:H7 was 27.9, 19.7, and 23.0%, respectively. The prevalence of L. monocytogenes, S. enterica, and E. coli O157:H7 in bulk tank milk was 7.5, 1.6, and 3.3%, respectively. The prevalence of L. monocytogenes and S. enterica in fecal samples was 1.5 and 3.8%, respectively, and the prevalence of E. coli O157:H7 in rectoanal mucosal swabs was 2.3%. Based on disk diffusion testing, all L. monocytogenes, S. enterica, and E. coli O157:H7 isolates exhibited resistance to at least 1 antimicrobial class. Multidrug resistance (resistance to 3 or more classes of antimicrobials) was exhibited by 96.9% of L. monocytogenes, 91.7% of E. coli O157:H7, and 82.1% of S. enterica isolates. Moreover, 93.8, 79.2, and 57.1% of the L. monocytogenes, E. coli O157:H7, and S. enterica isolates, respectively, were resistant to 5 or more antimicrobial classes. More than 50% of L. monocytogenes isolates were resistant to ampicillin, clindamycin, penicillin, erythromycin, quinupristin-dalfopristin, streptomycin, teicoplanin, linezolid, vancomycin, kanamycin, and tetracycline. More than 50% of S. enterica and E. coli O157:H7 isolates were resistant to ampicillin, cephalothin, nalidixic acid, kanamycin, streptomycin, amoxicillin-clavulanic acid, and tetracycline. The prevalence of the studied pathogens this study was comparable to reports from other countries. The isolated pathogens exhibited a high degree of antimicrobial resistance, suggesting that the bacterial flora of dairy cattle in Jordan are under intense antimicrobial selection pressure. Additional research is required to determine the causes and drivers of resistance, and to develop approaches to mitigating antimicrobial resistance.
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Affiliation(s)
- Mohammad M Obaidat
- Department of Veterinary Pathology and Public Health, Faculty of Veterinary Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan.
| | - Andrew P Stringer
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh 27607
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108
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Jiang Y, Li S, Qiu Z, Le T, Zou S, Cao X. Rolling circle amplification and its application in microfluidic systems for
Escherichia coli
O157:H7 detections. J Food Saf 2019. [DOI: 10.1111/jfs.12671] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Yuqian Jiang
- Department of Chemical and Biological EngineeringUniversity of Ottawa Ottawa Ontario Canada
- Measurement Science and StandardsNational Research Council Canada Ottawa Ontario Canada
| | - Shuying Li
- Department of Chemical and Biological EngineeringUniversity of Ottawa Ottawa Ontario Canada
- Measurement Science and StandardsNational Research Council Canada Ottawa Ontario Canada
| | - Zhenyu Qiu
- Division of Advanced FabricationsNanchang Institute of Technology Nanchang Jiangxi Province China
| | - Tao Le
- College of Life ScienceChongqing Normal University Shapingba Chongqing China
| | - Shan Zou
- Measurement Science and StandardsNational Research Council Canada Ottawa Ontario Canada
| | - Xudong Cao
- Department of Chemical and Biological EngineeringUniversity of Ottawa Ottawa Ontario Canada
- Ottawa‐Carleton Institute of Biomedical EngineeringUniversity of Ottawa Ottawa Ontario Canada
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109
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Response to Questions Posed by the Food and Drug Administration Regarding Virulence Factors and Attributes that Define Foodborne Shiga Toxin-Producing Escherichia coli (STEC) as Severe Human Pathogens †. J Food Prot 2019; 82:724-767. [PMID: 30969806 DOI: 10.4315/0362-028x.jfp-18-479] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
-
- NACMCF Executive Secretariat, * U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, PP3, 9-178, 1400 Independence Avenue S.W., Washington, D.C. 20250-3700, USA
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110
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Tominaga T. Rapid detection of coliform bacteria using a lateral flow test strip assay. J Microbiol Methods 2019; 160:29-35. [DOI: 10.1016/j.mimet.2019.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/16/2019] [Accepted: 03/16/2019] [Indexed: 12/17/2022]
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111
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Chhetri VS, Janes ME, King JM, Doerrler W, Adhikari A. Effect of residual chlorine and organic acids on survival and attachment of Escherichia coli O157: H7 and Listeria monocytogenes on spinach leaves during storage. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.02.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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112
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Lee MS, Tesh VL. Roles of Shiga Toxins in Immunopathology. Toxins (Basel) 2019; 11:E212. [PMID: 30970547 PMCID: PMC6521259 DOI: 10.3390/toxins11040212] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 12/20/2022] Open
Abstract
Shigella species and Shiga toxin-producing Escherichia coli (STEC) are agents of bloody diarrhea that may progress to potentially lethal complications such as diarrhea-associated hemolytic uremic syndrome (D+HUS) and neurological disorders. The bacteria share the ability to produce virulence factors called Shiga toxins (Stxs). Research over the past two decades has identified Stxs as multifunctional toxins capable of inducing cell stress responses in addition to their canonical ribotoxic function inhibiting protein synthesis. Notably, Stxs are not only potent inducers of cell death, but also activate innate immune responses that may lead to inflammation, and these effects may increase the severity of organ injury in patients infected with Stx-producing bacteria. In the intestines, kidneys, and central nervous system, excessive or uncontrolled host innate and cellular immune responses triggered by Stxs may result in sensitization of cells to toxin mediated damage, leading to immunopathology and increased morbidity and mortality in animal models (including primates) and human patients. Here, we review studies describing Stx-induced innate immune responses that may be associated with tissue damage, inflammation, and complement activation. We speculate on how these processes may contribute to immunopathological responses to the toxins.
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Affiliation(s)
- Moo-Seung Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Daejeon 34141, Korea.
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), 127 Gajeong-ro, Yuseong-gu, Daejeon 34113, Korea.
| | - Vernon L Tesh
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77807, USA.
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113
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Abstract
Foodborne disease is a major concern in Canada and represents a significant climate change-related threat to public health. Climate variables, including temperature and precipitation patterns, extreme weather events and ocean warming and acidification, are known to exert significant, complicated and interrelated effects along the entire length of the food chain. Foodborne diseases are caused by a range of bacteria, fungi, parasites and viruses, and the prevalence of these diseases is modified by climate change through alterations in the abundance, growth, range and survival of many pathogens, as well as through alterations in human behaviours and in transmission factors such as wildlife vectors. As climate change continues and/or intensifies, it will increase the risk of an adverse effect on food safety in Canada ranging from increased public health burden to the emergence of risks not currently seen in our food chain. Clinical and public health practitioners need to be aware of the existing and emerging risks to respond accordingly.
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114
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Antibiotic Resistance Profile and Clonality of E. coli Isolated from Water and Paediatric Stool Samples in the North-West, Province South Africa. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2019. [DOI: 10.22207/jpam.13.1.58] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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115
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Bosilevac JM, Dwivedi HP, Chablain P, Ullery M, Bailey JS, Dutta V. Comparative Performance Evaluation of Real-Time PCR and Dual-Labeled Fluorescence Resonance Energy Transfer Probe-Based Melt Peak Analysis for the Detection of Escherichia coli O157:H7 in Beef Products. J Food Prot 2019; 82:507-512. [PMID: 30810380 DOI: 10.4315/0362-028x.jfp-18-366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Contaminated beef and beef products remain a frequent vehicle for the transmission of Escherichia coli O157:H7. The current U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) regulatory testing for E. coli O157:H7 uses the method described in the USDA-FSIS Microbiology Laboratory Guidebook (MLG), chapter 5. At times, described presumptive test results are nonconfirmable, suggesting that recent PCR technological advancements and presumed enhanced sensitivity and specificity may offer beneficial changes. Here, we have evaluated the precision and sensitivity of a fluorescence resonance energy transfer-based real-time PCR assay called ECO for the detection of E. coli O157:H7. ECO detects the gene target specific to both E. coli O157:H7 and E. coli O157:non-H7 but distinguishes the two by using a melt curve analysis. A total of 3,113 O157:H7 and O157:non-H7 isolates were used to define this melting temperature-based criteria. The simulated comparative performance evaluation in the spiked beef samples indicated detection of 3 of 3 samples by ECO at <3.3 log CFU/mL, whereas MLG only detected 1 of 3 (<3.3 log CFU/mL). Using modified tryptic soy broth-enriched natural beef and veal product samples ( n = 452), the comparative sensitivity, specificity, false-positive rate, and false-negative rate against culture between MLG and ECO were 75 versus 92%, 91 versus 99%, 8.9 versus 0.77%, and 25 versus 8.3%, respectively. Positive predictive value, negative predictive value, and the overall accuracy were found to be 56 versus 94%, 96 versus 98%, and 88 versus 98%, for MLG and ECO, respectively. These data demonstrate that the ECO assay is comparable to MLG detection of E. coli O157:H7 and offers improved sensitivity.
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Affiliation(s)
- Joseph M Bosilevac
- 1 U.S. Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Spur 18D, Clay Center, Nebraska 68933, USA
| | - Hari P Dwivedi
- 2 bioMérieux, Inc., 595 Anglum Road, Hazelwood, Missouri 63042, USA
| | | | - Michael Ullery
- 2 bioMérieux, Inc., 595 Anglum Road, Hazelwood, Missouri 63042, USA
| | - Joseph S Bailey
- 2 bioMérieux, Inc., 595 Anglum Road, Hazelwood, Missouri 63042, USA
| | - Vikrant Dutta
- 2 bioMérieux, Inc., 595 Anglum Road, Hazelwood, Missouri 63042, USA
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116
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Silva CJ, Lee BG, Yambao JC, Erickson-Beltran ML, Quiñones B. Using Nanospray Liquid Chromatography and Mass Spectrometry to Quantitate Shiga Toxin Production in Environmental Escherichia coli Recovered from a Major Produce Production Region in California. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:1554-1562. [PMID: 30485086 DOI: 10.1021/acs.jafc.8b05324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A set of 45 environmental strains of Shiga toxin producing Escherichia coli (STEC) from three California counties were analyzed for Shiga toxin production by nanospray liquid chromatography-mass spectrometry and Vero cell bioassay. The STEC in this set comprised six serotypes ((O113:H21, O121:H19, O157:H7, O6:H34, O177:H25, and O185:H7) each containing either the stx2a or stx2c operon. Six of the seven O113:H21 were found to contain two distinct stx2a operons. Eight strains of O157:H7 possessed a stx2c operon whose A subunit gene was interrupted by an insertion sequence (IS1203v). Shiga toxin production was induced by nutrient depletion and quantitated by mass spectrometry. The 37 strains produced Shiga toxins in a near 50-fold range (1.4-49 ng/mL). The IS-interrupted strains expressed low but measurable amounts of the B subunits (0.5-1.9 ng/mL). Another strain possessed an identical stx operon without an IS interruption and produced intact Stx2c (5.7 ng/mL).
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Affiliation(s)
- Christopher J Silva
- Produce Safety & Microbiology Research Unit , U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center , Albany , California 94710 , United States
| | - Bertram G Lee
- Produce Safety & Microbiology Research Unit , U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center , Albany , California 94710 , United States
| | - Jaszemyn C Yambao
- Produce Safety & Microbiology Research Unit , U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center , Albany , California 94710 , United States
| | - Melissa L Erickson-Beltran
- Produce Safety & Microbiology Research Unit , U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center , Albany , California 94710 , United States
| | - Beatriz Quiñones
- Produce Safety & Microbiology Research Unit , U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center , Albany , California 94710 , United States
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117
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Affiliation(s)
- James L. Smith
- Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania
| | - Pina M. Fratamico
- Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania
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118
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Hu J, Huang R, Wang Y, Wei X, Wang Z, Geng Y, Jing J, Gao H, Sun X, Dong C, Jiang C. Development of duplex PCR-ELISA for simultaneous detection of Salmonella spp. and Escherichia coli O157: H7 in food. J Microbiol Methods 2018; 154:127-133. [PMID: 30393180 DOI: 10.1016/j.mimet.2018.10.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 10/26/2018] [Indexed: 11/28/2022]
Abstract
In the current study, a duplex PCR-ELISA method was developed targeting the specific genes, invA of Salmonella spp. and rfbE of Escherichia coli O157: H7, to detect one or both bacteria in food. In brief, PCR product amplified by PCR primer labeled with digoxin at the 5'-end and a probe labeled with biotin at the 3'-end can form dimer by nucleic acid hybridization which can be captured by binding of biotin to streptomycin coated in ELISA plate before using enzyme-labeled anti-digoxin antibody and substrate to develop color. Also, evaluation of the duplex PCR-ELISA method was conducted in different food samples including milk, juice, cabbage, shrimp, chicken, pork and beef. Results indicated that the duplex PCR-ELISA developed here was specific when using 25 non-target bacteria strains as controls and was sensitive with a limit of detection (LOD) of 1 CFU/mL, 1, 000 times higher than that of the duplex PCR method and was repeatable regardless of inter- and intra-batch variations. The duplex PCR-ELISA method established in the present study has proven to be highly specific, sensitive and repeatable. It has the potential to be applied in such fields as clinical diagnosis of food-borne diseases, food hygiene monitoring and pathogen detection in food.
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Affiliation(s)
- Jinqiang Hu
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China; International Joint Laboratory of Food Safety, Zhengzhou 450000, Henan Province, China; Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450000, Henan Province, China; Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou 450000, Henan Province, China.
| | - Runna Huang
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
| | - Yi Wang
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
| | - Xiangke Wei
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
| | - Zhangcun Wang
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
| | - Yao Geng
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China; International Joint Laboratory of Food Safety, Zhengzhou 450000, Henan Province, China
| | - Jianzhou Jing
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China; International Joint Laboratory of Food Safety, Zhengzhou 450000, Henan Province, China
| | - Hui Gao
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China; International Joint Laboratory of Food Safety, Zhengzhou 450000, Henan Province, China
| | - Xincheng Sun
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China; International Joint Laboratory of Food Safety, Zhengzhou 450000, Henan Province, China
| | - Caiwen Dong
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
| | - Chunpeng Jiang
- School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450000, Henan Province, China
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119
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Omer MK, Álvarez-Ordoñez A, Prieto M, Skjerve E, Asehun T, Alvseike OA. A Systematic Review of Bacterial Foodborne Outbreaks Related to Red Meat and Meat Products. Foodborne Pathog Dis 2018; 15:598-611. [DOI: 10.1089/fpd.2017.2393] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Mohamed K. Omer
- Animalia–Norwegian Meat and Poultry Research Center, Oslo, Norway
| | - Avelino Álvarez-Ordoñez
- Department of Food Hygiene and Food Technology, Faculty of Veterinary Medicine, University of León, León, Spain
- Institute of Food Science and Technology, University of León, León, Spain
| | - Miguel Prieto
- Department of Food Hygiene and Food Technology, Faculty of Veterinary Medicine, University of León, León, Spain
- Institute of Food Science and Technology, University of León, León, Spain
| | - Eystein Skjerve
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Tekie Asehun
- Department of Applied Mathematics, University of Twente, Enschede, the Netherlands
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120
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Physicochemical, antimicrobial and antioxidant properties of chitosan/TEMPO biocomposite packaging films. Food Packag Shelf Life 2018. [DOI: 10.1016/j.fpsl.2018.06.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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121
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Karmali MA. Factors in the emergence of serious human infections associated with highly pathogenic strains of shiga toxin-producing Escherichia coli. Int J Med Microbiol 2018; 308:1067-1072. [PMID: 30146439 DOI: 10.1016/j.ijmm.2018.08.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/29/2018] [Accepted: 08/17/2018] [Indexed: 10/28/2022] Open
Abstract
The appearance of highly pathogenic strains of Shiga toxin (Stx)-producingEscherichia. coli (STEC) has owed largely to the acquisition of Stx-encoding prophages by strains of E. coli that have pre-existing potential as enteric pathogens, such as atypical enteropathogenic E. coli (aEPEC) and enteroaggregative E. coli (EAEC). However, while high pathogenic potential is necessary, it is not sufficient for such strains to have a serious public health impact (i.e., large outbreaks, many cases of HUS, or both). To do so requires susceptible hosts and additional elements related to transmission, such as, socio-economic, societal, and lifestyle, factors. Two examples are discussed to illustrate this. The factors involved in the emergence of serious disease associated with E. coli O157:H7 in the 1980s probably included a massive increase in population exposure to this pathogen, likely as a result of the introduction of factory farming of cattle in the 1960s, and the development and wide patronage of fast food hamburger restaurants, and, potentially, waning immunity to intimin as a result of the reduction of incidence of enteropathogenic E. coli (EPEC) infection. In the devastating outbreak of Stx2-positiveEAEC O104:H4 in 2011, the wide distribution of the proposed vehicle of transmission, imported fenugreek seeds, was decisive in the exposure of a large population in Central Europe to this pathogen. Contributing factors likely included a preference for eating raw sprouts as a healthy food choice by the affected cases, many of whom were women. Low population levels of immunity to Stx2 probably contributed to the severe clinical outcome. A better understanding of the factors responsible for the emergence of potentially dangerous STEC pathogens as well as of extensive and serious disease associated with them can enhance public health strategies to respond to them.
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Affiliation(s)
- Mohamed A Karmali
- Public Health Consultant, 388 Princess Avenue, Toronto, M2N 3S9, Canada.
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122
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Lee JB, Han D, Lee HT, Wi SM, Park JH, Jo JW, Cho YJ, Hahn TW, Lee S, Kang B, Kwak HS, Kim J, Yoon JW. Pathogenic and phylogenetic characteristics of non-O157 Shiga toxin-producing Escherichia coli isolates from retail meats in South Korea. J Vet Sci 2018; 19:251-259. [PMID: 29284205 PMCID: PMC5879073 DOI: 10.4142/jvs.2018.19.2.251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/25/2017] [Indexed: 11/21/2022] Open
Abstract
Herein, we report the pathogenic and phylogenetic characteristics of seven Shiga toxin (Stx)-producing Escherichia coli (STEC) isolates from 434 retail meats collected in Korea during 2006 to 2012. The experimental analyses revealed that all isolates (i) were identified as non-O157 STEC, including O91:H14 (3 isolates), O121:H10 (2 isolates), O91:H21 (1 isolate), and O18:H20 (1 isolate), (ii) carried diverse Stx subtype genes (stx1, stx2c, stx2e, or stx1 + stx2b) whose expression levels varied strain by strain, and (iii) lacked the locus of enterocyte effacement (LEE) pathogenicity island, a major virulence factor of STEC, but they possessed one or more alternative virulence genes encoding cytotoxins (Cdt and SubAB) and/or adhesins (Saa, Iha, and EcpA). Notably, a significant heterogeneity in glutamate-induced acid resistance was observed among the STEC isolates (p < 0.05). In addition, phylogenetic analyses demonstrated that all three STEC O91:H14 isolates were categorized into sequence type (ST) 33, of which two beef isolates were identical in their pulsotypes. Similar results were observed with two O121:H10 pork isolates (ST641; 88.2% similarity). Interestingly, 96.0% of the 100 human STEC isolates collected in Korea during 2003 to 2014 were serotyped as O91:H14, and the ST33 lineage was confirmed in approximately 72.2% (13/18 isolates) of human STEC O91:H14 isolates from diarrheal patients.
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Affiliation(s)
- June Bong Lee
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Dalmuri Han
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Hyung Tae Lee
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Seon Mi Wi
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Jeong Hoon Park
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Jung-Woo Jo
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Young-Jae Cho
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Tae-Wook Hahn
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Sunjin Lee
- Division of Enteric Diseases, Centers for Infectious Diseases, National Research Institute of Health, Cheongju 28159, Korea
| | - Byunghak Kang
- Division of Enteric Diseases, Centers for Infectious Diseases, National Research Institute of Health, Cheongju 28159, Korea
| | - Hyo Sun Kwak
- Division of Enteric Diseases, Centers for Infectious Diseases, National Research Institute of Health, Cheongju 28159, Korea
| | - Jonghyun Kim
- Division of Enteric Diseases, Centers for Infectious Diseases, National Research Institute of Health, Cheongju 28159, Korea
| | - Jang Won Yoon
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
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123
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Silva CJ. Food Forensics: Using Mass Spectrometry To Detect Foodborne Protein Contaminants, as Exemplified by Shiga Toxin Variants and Prion Strains. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:8435-8450. [PMID: 29860833 DOI: 10.1021/acs.jafc.8b01517] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Food forensicists need a variety of tools to detect the many possible food contaminants. As a result of its analytical flexibility, mass spectrometry is one of those tools. Use of the multiple reaction monitoring (MRM) method expands its use to quantitation as well as detection of infectious proteins (prions) and protein toxins, such as Shiga toxins. The sample processing steps inactivate prions and Shiga toxins; the proteins are digested with proteases to yield peptides suitable for MRM-based analysis. Prions are detected by their distinct physicochemical properties and differential covalent modification. Shiga toxin analysis is based on detecting peptides derived from the five identical binding B subunits comprising the toxin. 15N-labeled internal standards are prepared from cloned proteins. These examples illustrate the power of MRM, in that the same instrument can be used to safely detect and quantitate protein toxins, prions, and small molecules that might contaminate our food.
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Affiliation(s)
- Christopher J Silva
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, Agricultural Research Service , United States Department of Agriculture , Albany , California 94710 , United States
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124
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Huang CY, Sheen S, Sommers C, Sheen LY. Modeling the Survival of Escherichia coli O157:H7 Under Hydrostatic Pressure, Process Temperature, Time and Allyl Isothiocyanate Stresses in Ground Chicken Meat. Front Microbiol 2018; 9:1871. [PMID: 30154776 PMCID: PMC6102346 DOI: 10.3389/fmicb.2018.01871] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 07/25/2018] [Indexed: 12/30/2022] Open
Abstract
Shiga toxin-producing Escherichia coli O157:H7 (STEC) is a common contaminant in meat and poultry. We investigated the use of non-thermal high pressure processing (HPP), with or without allyl isothiocyanate (AITC) essential oil, to kill STEC in ground chicken meat. Temperature was found an important factor affecting the inactivation of STEC in addition to pressure and process time. A full factorial experiment design (4 factors × 2 levels) was used to facilitate and evaluate the effect of pressure (250–350 MPa), operation temperature (−15–4°C), AITC concentration (0.05–0.15%, w/w), and pressure-holding time (10–20 min) on the inactivation of STEC. A linear model (a polynomial equation) was developed to predict/describe those four parameters’ impact on E. coli O157:H7 survival (R2 = 0.90), as well as a dimensionless non-linear model. Both types of models were validated with data obtained from separate experimental points. The dimensionless model also demonstrated that it may predict the lethality (defined as the log CFU/g reduction of STEC before and after treatment) reasonably well with some factors set slightly outside the design ranges (e.g., a wider application than the linear model). The results provide important information regarding STEC survival as affected by HPP (e.g., pressure, time and temperature) and AITC. With the addition of AITC, the hydrostatic pressure may be lowered to the 250–350 MPa level. Regulatory agencies and food industry may use those models for STEC risk assessment in ground chicken meat. A storage test (at 4 and 10°C, 10 days) after HPP+AITC treatment indicated that AITC may continue depressing or killing the pressure-damaged cells.
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Affiliation(s)
- Chi-Yun Huang
- Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan.,Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, United States
| | - Shiowshuh Sheen
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, United States
| | - Christopher Sommers
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, United States
| | - Lee-Yan Sheen
- Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan
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125
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Loo YY, Rukayadi Y, Nor-Khaizura MAR, Kuan CH, Chieng BW, Nishibuchi M, Radu S. In Vitro Antimicrobial Activity of Green Synthesized Silver Nanoparticles Against Selected Gram-negative Foodborne Pathogens. Front Microbiol 2018; 9:1555. [PMID: 30061871 PMCID: PMC6054941 DOI: 10.3389/fmicb.2018.01555] [Citation(s) in RCA: 246] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/22/2018] [Indexed: 11/17/2022] Open
Abstract
Silver nanoparticles (AgNPs) used in this study were synthesized using pu-erh tea leaves extract with particle size of 4.06 nm. The antibacterial activity of green synthesized AgNPs against a diverse range of Gram-negative foodborne pathogens was determined using disk diffusion method, resazurin microtitre-plate assay (minimum inhibitory concentration, MIC), and minimum bactericidal concentration test (MBC). The MIC and MBC of AgNPs against Escherichia coli, Klebsiella pneumoniae, Salmonella Typhimurium, and Salmonella Enteritidis were 7.8, 3.9, 3.9, 3.9 and 7.8, 3.9, 7.8, 3.9 μg/mL, respectively. Time-kill curves were used to evaluate the concentration between MIC and bactericidal activity of AgNPs at concentrations ranging from 0×MIC to 8×MIC. The killing activity of AgNPs was fast acting against all the Gram-negative bacteria tested; the reduction in the number of CFU mL-1 was >3 Log10 units (99.9%) in 1–2 h. This study indicates that AgNPs exhibit a strong antimicrobial activity and thus might be developed as a new type of antimicrobial agents for the treatment of bacterial infection including multidrug resistant bacterial infection.
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Affiliation(s)
- Yuet Ying Loo
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia
| | - Yaya Rukayadi
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia
| | | | - Chee Hao Kuan
- Department of Agricultural and Food Science, Faculty of Science, Universiti Tunku Abdul Rahman, Kampar, Malaysia
| | - Buong Woei Chieng
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Selangor, Malaysia.,Materials Processing and Technology Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, Selangor, Malaysia
| | | | - Son Radu
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia.,Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security (ITAFoS), Universiti Putra Malaysia, Selangor, Malaysia
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126
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Kiel M, Sagory-Zalkind P, Miganeh C, Stork C, Leimbach A, Sekse C, Mellmann A, Rechenmann F, Dobrindt U. Identification of Novel Biomarkers for Priority Serotypes of Shiga Toxin-Producing Escherichia coli and the Development of Multiplex PCR for Their Detection. Front Microbiol 2018; 9:1321. [PMID: 29997582 PMCID: PMC6028524 DOI: 10.3389/fmicb.2018.01321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/30/2018] [Indexed: 12/22/2022] Open
Abstract
It would be desirable to have an unambiguous scheme for the typing of Shiga toxin-producing Escherichia coli (STEC) isolates to subpopulations. Such a scheme should take the high genomic plasticity of E. coli into account and utilize the stratification of STEC into subgroups, based on serotype or phylogeny. Therefore, our goal was to identify specific marker combinations for improved classification of STEC subtypes. We developed and evaluated two bioinformatic pipelines for genomic marker identification from larger sets of bacterial genome sequences. Pipeline A performed all-against-all BLASTp analyses of gene products predicted in STEC genome test sets against a set of control genomes. Pipeline B identified STEC marker genes by comparing the STEC core proteome and the "pan proteome" of a non-STEC control group. Both pipelines defined an overlapping, but not identical set of discriminative markers for different STEC subgroups. Differential marker prediction resulted from differences in genome assembly, ORF finding and inclusion cut-offs in both workflows. Based on the output of the pipelines, we defined new specific markers for STEC serogroups and phylogenetic groups frequently associated with outbreaks and cases of foodborne illnesses. These included STEC serogroups O157, O26, O45, O103, O111, O121, and O145, Shiga toxin-positive enteroaggregative E. coli O104:H4, and HUS-associated sequence type (ST)306. We evaluated these STEC marker genes for their presence in whole genome sequence data sets. Based on the identified discriminative markers, we developed a multiplex PCR (mPCR) approach for detection and typing of the targeted STEC. The specificity of the mPCR primer pairs was verified using well-defined clinical STEC isolates as well as isolates from the ECOR, DEC, and HUSEC collections. The application of the STEC mPCR for food analysis was tested with inoculated milk. In summary, we evaluated two different strategies to screen large genome sequence data sets for discriminative markers and implemented novel marker genes found in this genome-wide approach into a DNA-based typing tool for STEC that can be used for the characterization of STEC from clinical and food samples.
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Affiliation(s)
- Matthias Kiel
- Institute of Hygiene, University of Münster, Münster, Germany
| | | | - Céline Miganeh
- Genostar Bioinformatics, Montbonnot-Saint-Martin, France
| | - Christoph Stork
- Institute of Hygiene, University of Münster, Münster, Germany
| | | | | | | | | | - Ulrich Dobrindt
- Institute of Hygiene, University of Münster, Münster, Germany
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127
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Vasant BR, Stafford RJ, Jennison AV, Bennett SM, Bell RJ, Doyle CJ, Young JR, Vlack SA, Titmus P, El Saadi D, Jarvinen KAJ, Coward P, Barrett J, Staples M, Graham RMA, Smith HV, Lambert SB. Mild Illness during Outbreak of Shiga Toxin-Producing Escherichia coli O157 Infections Associated with Agricultural Show, Australia. Emerg Infect Dis 2018; 23:1686-1689. [PMID: 28930030 PMCID: PMC5621556 DOI: 10.3201/eid2310.161836] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
During a large outbreak of Shiga toxin−producing Escherichia coli illness associated with an agricultural show in Australia, we used whole-genome sequencing to detect an IS1203v insertion in the Shiga toxin 2c subunit A gene of Shiga toxin−producing E. coli. Our study showed that clinical illness was mild, and hemolytic uremic syndrome was not detected.
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128
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Hunt D, Figley C, Manage DP, Lauzon J, Figley R, Pilarski LM, McMullen LM, Pilarski PM. Monitoring food pathogens: Novel instrumentation for cassette PCR testing. PLoS One 2018; 13:e0197100. [PMID: 29746561 PMCID: PMC5945031 DOI: 10.1371/journal.pone.0197100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 04/26/2018] [Indexed: 01/13/2023] Open
Abstract
In this manuscript, we report the design and development of a fast, reliable instrument to run gel-based cassette polymerase chain reactions (PCR). Here termed the GelCycler Mark II, our instrument is a miniaturized molecular testing system that is fast, low cost and sensitive. Cassette PCR utilizes capillary reaction units that carry all reagents needed for PCR, including primers and Taq polymerase, except the sample, which is loaded at the time of testing. Cassette PCR carries out real time quantitative PCR followed by melt curve analysis (MCA) to verify amplicon identity at the expected melt temperature (Tm). The cassette PCR technology is well developed, particularly for detecting pathogens, and has been rigorously validated for detecting pathogenic Escherichia coli in meat samples. However, the work has been hindered by the lack of a robust and stable instrument to carry out the PCR, which requires fast and accurate temperature regulation, improved light delivery and fluorescent recording, and faster PCR reactions that maintain a high sensitivity of detection. Here, we report design and testing of a new instrument to address these shortcomings and to enable standardized testing by cassette PCR and commercial manufacture of a robust and accurate instrument that can be mass produced to deliver consistent performance. As a corollary to our new instrument development, we also report the use of an improved design approach using a machined aluminum cassette to meet the new instrument standards, prevent any light bleed across different trenches in each cassette, and allow testing of a larger number of samples for more targets in a single run. The GelCycler Mark II can detect and report E. coli contamination in 41 minutes. Sample positives are defined in as having a melt curve comparable to the internal positive control, with peak height exceeding that of the internal negative control. In a fractional analysis, as little as 1 bacterium per capillary reaction unit is directly detectable, with no enrichment step, in 35 cycles of PCR/MCA, in a total time of 53 minutes, making this instrument and technology among the very best for speed and sensitivity in screening food for pathogenic contamination.
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Affiliation(s)
- Darin Hunt
- CBF Systems Inc., College Plaza, Edmonton, AB, Canada
| | - Curtis Figley
- CBF Systems Inc., College Plaza, Edmonton, AB, Canada
| | - Dammika P. Manage
- Department of Oncology, University of Alberta and Cross Cancer Institute, Edmonton, AB, Canada
| | - Jana Lauzon
- Department of Oncology, University of Alberta and Cross Cancer Institute, Edmonton, AB, Canada
| | - Rachel Figley
- CBF Systems Inc., College Plaza, Edmonton, AB, Canada
| | - Linda M. Pilarski
- Department of Oncology, University of Alberta and Cross Cancer Institute, Edmonton, AB, Canada
| | - Lynn M. McMullen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Patrick M. Pilarski
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of Alberta, 5–005 Katz Group Centre for Pharmacy and Health Research, Edmonton, AB, Canada
- * E-mail:
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129
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Motro Y, Carriço JA, Friedrich AW, Rossen JW, Moran-Gilad J. ESCMID postgraduate education course: regional capacity building for integration of next-generation sequencing in the clinical microlab. Microbes Infect 2018; 20:275-280. [DOI: 10.1016/j.micinf.2018.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 02/15/2018] [Accepted: 02/17/2018] [Indexed: 01/16/2023]
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130
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Usein CR, Ciontea AS, Militaru CM, Condei M, Dinu S, Oprea M, Cristea D, Michelacci V, Scavia G, Zota LC, Zaharia A, Morabito S. Molecular characterisation of human Shiga toxin-producing Escherichia coli O26 strains: results of an outbreak investigation, Romania, February to August 2016. ACTA ACUST UNITED AC 2018; 22. [PMID: 29183554 PMCID: PMC5710660 DOI: 10.2807/1560-7917.es.2017.22.47.17-00148] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
At the beginning of 2016, an increase in paediatric haemolytic uremic syndrome (HUS) cases was observed in Romania. The microbiological investigations allowed isolation of Shiga toxin-producing Escherichia coli (STEC) O26 as the causative agent from most cases. Methods: An enhanced national surveillance of HUS and severe diarrhoea was established across the country following the identification of the first cases and was carried out until August 2016. A total of 15 strains were isolated from 10 HUS and five diarrhoea cases. Strains were characterised by virulence markers (i.e. stx type/subtype, eae, ehxA genes), phylogroup, genetic relatedness and clonality using PCR-based assays, PFGE and multilocus sequence typing (MLST). The first six strains were further characterised by whole genome sequencing (WGS). Results: Five PCR-defined genotypes were distinguished. All strains from HUS cases harboured stx2a and eae, with or without stx1a, while strains from diarrhoea cases carried exclusively stx1a and eae genes. PFGE resolved strains into multiple pulsotypes, compatible with a certain geographic segregation of the cases, and strains were assigned to phylogroup B1 and sequence type (ST) 21. WGS confirmed the results of conventional molecular methods, brought evidence of O26:H11 serotype, and complemented the virulence profiles. Discussion/conclusion: This first description of STEC O26 strains from cases in Romania showed that the isolates belonged to a diverse population. The virulence content of most strains highlighted a high risk for severe outcome in infected patients. Improving the national surveillance strategy for STEC infections in Romania needs to be further considered.
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Affiliation(s)
- Codruţa-Romaniţa Usein
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.,Cantacuzino National Institute of Research, Bucharest, Romania
| | | | | | - Maria Condei
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Sorin Dinu
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Mihaela Oprea
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Daniela Cristea
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Valeria Michelacci
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
| | - Gaia Scavia
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
| | - Lavinia Cipriana Zota
- National Center for Surveillance and Control of Communicable Diseases, National Institute of Public Health, Bucharest, Romania
| | - Alina Zaharia
- National Center for Surveillance and Control of Communicable Diseases, National Institute of Public Health, Bucharest, Romania
| | - Stefano Morabito
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
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131
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Paquette SJ, Stanford K, Thomas J, Reuter T. Quantitative surveillance of shiga toxins 1 and 2, Escherichia coli O178 and O157 in feces of western-Canadian slaughter cattle enumerated by droplet digital PCR with a focus on seasonality and slaughterhouse location. PLoS One 2018; 13:e0195880. [PMID: 29649278 PMCID: PMC5897018 DOI: 10.1371/journal.pone.0195880] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/31/2018] [Indexed: 01/06/2023] Open
Abstract
Often Escherichia coli are harmless and/or beneficial bacteria inhabiting the gastrointestinal tract of livestock and humans. However, Shiga toxin-producing E. coli (STEC) have been linked to human disease. Cattle are the primary reservoir for STEC and STEC “super-shedders” are considered to be a major contributor in animal to animal transmission. Among STEC, O157:H7 is the most recognized serotype, but in recent years, non-O157 STEC have been increasingly linked to human disease. In Argentina and Germany, O178 is considered an emerging pathogen. Our objective was to compare populations of E. coli O178, O157, shiga toxin 1 and 2 in western Canadian cattle feces from a sampling pool of ~80,000 beef cattle collected at two slaughterhouses. Conventional PCR was utilized to screen 1,773 samples for presence/absence of E. coli O178. A subset of samples (n = 168) was enumerated using droplet digital PCR (ddPCR) and proportions of O178, O157 and shiga toxins 1 & 2 specific-fragments were calculated as a proportion of generic E. coli (GEC) specific-fragments. Distribution of stx1 and stx2 was determined by comparing stx1, stx2 and O157 enumerations. Conventional PCR detected the presence of O178 in 873 of 1,773 samples and ddPCR found the average proportion of O178, O157, stx1 and stx2 in the samples 2.8%, 0.6%, 1.4% and 0.5%, respectively. Quantification of stx1 and stx2 revealed more virulence genes than could be exclusively attributed to O157. Our results confirmed the presence of E. coli O178 in western Canadian cattle and ddPCR revealed O178 as a greater proportion of GEC than was O157. Our results suggests: I) O178 may be an emerging subgroup in Canada and II) monitoring virulence genes may be a more relevant target for food-safety STEC surveillance compared to current serogroup screening.
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Affiliation(s)
- Sarah-Jo Paquette
- Alberta Agriculture and Forestry, Lethbridge, Alberta, Canada
- University of Lethbridge, Lethbridge, Alberta, Canada
| | - Kim Stanford
- Alberta Agriculture and Forestry, Lethbridge, Alberta, Canada
| | - James Thomas
- University of Lethbridge, Lethbridge, Alberta, Canada
| | - Tim Reuter
- Alberta Agriculture and Forestry, Lethbridge, Alberta, Canada
- * E-mail:
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Abstract
In May 2016, an outbreak of Shiga toxin-producing Escherichia coli O157 infections occurred among children who had played in a stream flowing through a park. Analysis of E. coli isolates from the patients, stream water, and deer and coyote scat showed that feces from deer were the most likely source of contamination.
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133
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Curran KG, Heiman Marshall KE, Singh T, Doobovsky Z, Hensley J, Melius B, Whitlock L, Stevenson L, Leinbach J, Oltean H, Glover WA, Kunesh T, Lindquist S, Williams I, Nichols M. An outbreak of Escherichia coli O157:H7 infections following a dairy education school field trip in Washington state, 2015. Epidemiol Infect 2018; 146:442-449. [PMID: 29271327 PMCID: PMC9134535 DOI: 10.1017/s0950268817002862] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/30/2017] [Accepted: 11/21/2017] [Indexed: 11/07/2022] Open
Abstract
On 27 April 2015, Washington health authorities identified Escherichia coli O157:H7 infections associated with dairy education school field trips held in a barn 20-24 April. Investigation objectives were to determine the magnitude of the outbreak, identify the source of infection, prevent secondary illness transmission and develop recommendations to prevent future outbreaks. Case-finding, hypothesis generating interviews, environmental site visits and a case-control study were conducted. Parents and children were interviewed regarding event activities. Odds ratios (OR) and 95% confidence intervals (CI) were computed. Environmental testing was conducted in the barn; isolates were compared to patient isolates using pulsed-field gel electrophoresis (PFGE). Sixty people were ill, 11 (18%) were hospitalised and six (10%) developed haemolytic uremic syndrome. Ill people ranged in age from <1 year to 47 years (median: 7), and 20 (33%) were female. Twenty-seven case-patients and 88 controls were enrolled in the case-control study. Among first-grade students, handwashing (i.e. soap and water, or hand sanitiser) before lunch was protective (adjusted OR 0.13; 95% CI 0.02-0.88, P = 0.04). Barn samples yielded E. coli O157:H7 with PFGE patterns indistinguishable from patient isolates. This investigation provided epidemiological, laboratory and environmental evidence for a large outbreak of E. coli O157:H7 infections from exposure to a contaminated barn. The investigation highlights the often overlooked risk of infection through exposure to animal environments as well as the importance of handwashing for disease prevention. Increased education and encouragement of infection prevention measures, such as handwashing, can prevent illness.
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Affiliation(s)
- K. G. Curran
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - T. Singh
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Z. Doobovsky
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - J. Hensley
- Whatcom County Health Department, Bellingham, WA, USA
| | - B. Melius
- Washington State Department of Health, Shoreline, WA, USA
| | - L. Whitlock
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - L. Stevenson
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - J. Leinbach
- Whatcom County Health Department, Bellingham, WA, USA
| | - H. Oltean
- Washington State Department of Health, Shoreline, WA, USA
| | - W. A. Glover
- Washington State Public Health Laboratories, Shoreline, WA, USA
| | - T. Kunesh
- Whatcom County Health Department, Bellingham, WA, USA
| | - S. Lindquist
- Washington State Department of Health, Shoreline, WA, USA
| | - I. Williams
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M. Nichols
- Centers for Disease Control and Prevention, Atlanta, GA, USA
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134
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Shah M, Eklund B, Conde Lima LG, Bergholz T, Hall C. Microbial and Chemical Shelf-Life of Vacuum Steam-Pasteurized Whole Flaxseed and Milled Flaxseed. J Food Sci 2018; 83:300-308. [PMID: 29350755 DOI: 10.1111/1750-3841.14050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/11/2017] [Accepted: 12/20/2017] [Indexed: 11/30/2022]
Abstract
Flaxseed is an oilseed with many health benefits. Flaxseed may be consumed raw or in processed form. In the raw form, there is a potential for microbial contamination. Several pasteurization methods have been used to reduce microbial contamination. However, such treatments may affect chemical properties of foods. In this study, vacuum steam-pasteurization was conducted on whole flaxseed and milled flaxseed using 4 different conditions (3 min at 75 °C, 3 min at 90 °C, 9 min at 90 °C, and 3 min at 105 °C). Microbial and chemical shelf-life was monitored for 28 wk (36 wk for aerobic plate counts). Significant reduction (P < 0.05) in microbial counts (total aerobic plate counts, and yeast and mold counts) occurred after pasteurization and during storage of both whole flaxseed and milled flaxseed. Although both the moisture content and aw increased after pasteurization, they were similar to the unpasteurized samples during storage. Peroxide value, free fatty acid, headspace volatiles, fatty acid profiles, oil content, and secoisolariciresinol diglucoside (SDG) content were chemical indices measured. Only small changes were observed in the chemical indices after vacuum steam-pasteurization for both pasteurized whole flaxseed and milled flaxseed as compared to the unpasteurized flaxseed at most instances. Vacuum steam-pasteurization can be used as a safe alternative for the microbial reduction of low-moisture products, such as flaxseed, without significantly affecting chemical stability. PRACTICAL APPLICATION Vacuum steam-pasteurization can be effectively used for the treatment of whole flaxseed and milled flaxseed to reduce spoilage microorganisms, such as total aerobes and yeasts and molds. In addition, this pasteurization method had minimal effects on several chemical shelf-life parameters with positive impact on SDG of the processed flaxseed.
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Affiliation(s)
- Manoj Shah
- the Dept. of Microbiological Sciences, North Dakota State Univ., Fargo, N.D. 58108, U.S.A
| | - Bridget Eklund
- the Dept. of Microbiological Sciences, North Dakota State Univ., Fargo, N.D. 58108, U.S.A
| | | | - Teresa Bergholz
- the Dept. of Microbiological Sciences, North Dakota State Univ., Fargo, N.D. 58108, U.S.A
| | - Clifford Hall
- the Dept. of Plant Sciences, North Dakota State Univ., Fargo, ND 58108, U.S.A
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135
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Bi X, Wang Y, Hu X, Liao X. iTRAQ-Based Proteomic Analysis of Sublethally Injured Escherichia coli O157:H7 Cells Induced by High Pressure Carbon Dioxide. Front Microbiol 2017; 8:2544. [PMID: 29375496 PMCID: PMC5770692 DOI: 10.3389/fmicb.2017.02544] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 12/07/2017] [Indexed: 11/23/2022] Open
Abstract
High pressure carbon dioxide (HPCD) could cause sublethally injured cells (SICs), which may cause food poisoning and spoilage during food storage and limit its application. Therefore, the formation of SICs of Escherichia coli O157:H7 was investigated by isobaric tag for relative and absolute quantification (iTRAQ) proteomic methods in this study for better controlling the SICs induced by HPCD. A total of 2,446 proteins was identified by iTRAQ, of which 93 and 29 were significantly differentially expressed in the SICs compared with live control cells (CKL) and dead control cells (CKD), respectively. Among the 93 differentially expressed proteins (DEP) in the SICs compared with CKL, 65 proteins showed down-regulation and 28 showed up-regulation. According to the comprehensive proteome coverage analysis, the SICs survived under HPCD by reducing carbohydrate decomposing, lipid transport and metabolism, amino acid transport and metabolism, transcription and translation, DNA replication and repair. Besides, the SICs showed stress response, DNA damage response and an increased carbohydrate transport, peptidoglycan synthesis and disulfide bond formation to HPCD. Among the 29 DEP in the SICs compared with CKD, 12 proteins showed down-regulation and 17 showed up-regulation. According to the comprehensive proteome coverage analysis, the SICs survived under HPCD by accumulation of cell protective agents like carbohydrates and amino acids, and decreasing transcription and translation activities. Results showed that the formation of the SICs with low metabolic activity and high survival ability was a survival strategy for E. coli O157:H7 against HPCD.
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Affiliation(s)
- Xiufang Bi
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China.,Sichuan Key Laboratory of Food Bio-technology, College of Food and Bioengineering, Xihua University, Chengdu, China
| | - Yongtao Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China
| | - Xiaosong Hu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China
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136
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Çam D, Öktem HA. Optimizations needed for lateral flow assay for rapid detection of pathogenic E. coli. Turk J Biol 2017; 41:954-968. [PMID: 30814860 DOI: 10.3906/biy-1705-50] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Lateral flow assay (LFA), or the immunochromatographic strip test, is popular to use for rapid and sensitive immunoassays. Gold nanoparticles (GNPs), due to tunable optical characteristics and easy manipulation of size or shape, represent an attractive approach for LFA technology. Since most enterohemorrhagic infections result from water and food contaminations of Escherichia coli O157:H7, selective and rapid detection of this organism in environmental and biological complexes is necessary. In this study, optimized parameters of antibody (Ab)-based LFA for rapid detection of pathogenic E. coli O157:H7 are described. GNPs were used as visualizing agents. The measuring parameters include the Ab concentration on the capture lines, the concentration of gold conjugate, and flow rate. M180 and 36 nm were the ideal membrane and GNP size, respectively, for bacterial detection of LFA. The target, E. coli O157:H7, could be detected with a visual limit of detection of 105 cfu/mL in 3-5 min. Selectivity of the system was very high and the target was recognized by developed strips, regardless of its presence singly or in mixed bacterial samples.
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Affiliation(s)
- Dilek Çam
- Department of Biological Sciences, Middle East Technical University , Ankara , Turkey.,Department of Biology, Çankırı Karatekin University , Çankırı , Turkey
| | - Hüseyin Avni Öktem
- Department of Biological Sciences, Middle East Technical University , Ankara , Turkey.,Nanobiz R & D Ltd. , METU Science Park, Ankara , Turkey
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137
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Kalule JB, Keddy KH, Smith A, Nicol MP, Robberts L. Development of a real-time PCR assay and comparison to CHROMagar TM STEC to screen for Shiga toxin-producing Escherichia coli in stool, Cape Town, South Africa. Afr J Lab Med 2017; 6:609. [PMID: 29435423 PMCID: PMC5803521 DOI: 10.4102/ajlm.v6i1.609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 09/19/2017] [Indexed: 12/20/2022] Open
Abstract
Introduction Shiga toxin-producing Escherichia coli (STEC) is an emerging infectious pathogen which could lead to haemolytic uremic syndrome. Even though previous studies have compared the performance of CHROMagarTMSTEC to real-time polymerase chain reaction (PCR) in Europe, no study has been done to assess its performance on African isolates. Objectives This project aimed to validate and test an in-house-developed duplex real-time PCR and use it as a reference standard to determine the performance of CHROMagarTMSTEC on African isolates from diarrhoeic stool samples. Methods This study evaluated STEC diagnostic technology on African isolates. An in-house-developed duplex real-time PCR assay for detection of stx1 and stx2 was validated and tested on diarrhoeic stool samples and then used as a reference standard to assess the performance of CHROMagarTMSTEC. Real-time PCR was used to screen for stx in tryptic soy broth and the suspected STEC isolates, while conventional PCR was used to detect the other virulence genes possessed by the isolates. Results The real-time PCR limit of detection was 5.3 target copies/μL of broth. The mean melting temperature on melt-curve analysis for detection of stx1 was 58.2 °C and for stx2 was 65.3 °C. Of 226 specimens screened, real-time PCR detected stx in 14 specimens (6.2%, 95% confidence interval = 3.43% - 10.18%). The sensitivity, specificity, negative predictive value and positive predictive value of the CHROMagarTMSTEC were 33.3%, 77.4%, 95.3% and 11.3%. Conclusions The in-house developed real-time PCR assay is a sensitive and specific option for laboratory detection of STEC as compared to CHROMagarTMSTEC in this setting.
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Affiliation(s)
- John B Kalule
- Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Karen H Keddy
- Center for Enteric Disease Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Anthony Smith
- Center for Enteric Disease Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Mark P Nicol
- Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Lourens Robberts
- Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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138
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Enhanced sensitivity of lateral-flow test strip immunoassays using colloidal palladium nanoparticles and horseradish peroxidase. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2017.08.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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139
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Bailey G, Huynh L, Govenlock L, Jordan D, Jenson I. Low Prevalence of Salmonella and Shiga Toxin-Producing Escherichia coli in Lymph Nodes of Australian Beef Cattle. J Food Prot 2017; 80:2105-2111. [PMID: 29166174 DOI: 10.4315/0362-028x.jfp-17-180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella contamination of ground beef has been viewed as originating from the surface of carcasses. Recent studies have identified lymph nodes as a potential source of Salmonella contamination because these tissues play an active role in containment of pathogens in the live animal and because some lymph nodes are unavoidably present in manufacturing beef trimmings or primal cuts that may be incorporated into ground beef. A survey was conducted of the microbiological status of lymph nodes from Australian cattle at the time of slaughter to determine the prevalence of microbiological contamination. Sets of lymph nodes (n = 197), consisting of the superficial cervical (prescapular), prepectoral, axillary, presternal, popliteal, ischiatic, subiliac (precrural), coxalis, and iliofemoralis (deep inguinal), were collected from five geographically separated Australian abattoirs over a period of 14 months. Samples were tested for the presence of Salmonella spp. and Shiga toxin-producing Escherichia coli by BAX PCR assay. Aerobic plate count, E. coli, and coliforms were enumerated with a lower limit of detection of 80 CFU per node. The observed prevalence of Salmonella within peripheral lymph nodes was 0.48% (7 of 1,464). Two of the seven lymph nodes in which Salmonella organisms were detected came from the same animal. Grass-fed, grain-fed, and cull dairy cattle were all found to have detectable Salmonella in lymph nodes. All Salmonella detections occurred during cooler months of the year. No Shiga toxin-producing E. coli were detected. Aerobic microorganisms were detected above the limit of quantification in 3.2% of nodes (median count 2.24 log per node), and E. coli was detected in 0.8% of nodes (median count 3.05 log per node). The low prevalence of Salmonella and low concentration of aerobic microorganisms in Salmonella-positive lymph nodes of Australian cattle at the time of slaughter suggest that the likelihood of lymph nodes contributing significantly to the presence of Salmonella in ground beef is low.
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Affiliation(s)
- Gavin Bailey
- 1 DTS Food Assurance, 148 Tennyson Memorial Avenue, Brisbane, Queensland 4105, Australia
| | - Long Huynh
- 2 Meat & Livestock Australia, P.O. Box 1961, North Sydney, New South Wales 2059, Australia (ORCID: http://orcid.org/0000-0002-3111-4217 [I.J.]); and
| | - Lachlan Govenlock
- 1 DTS Food Assurance, 148 Tennyson Memorial Avenue, Brisbane, Queensland 4105, Australia
| | - David Jordan
- 3 New South Wales Department of Primary Industries, 1243 Bruxner Highway, Wollongbar, New South Wales 2477, Australia (ORCID: http://orcid.org/0000-0002-1763-9551 )
| | - Ian Jenson
- 2 Meat & Livestock Australia, P.O. Box 1961, North Sydney, New South Wales 2059, Australia (ORCID: http://orcid.org/0000-0002-3111-4217 [I.J.]); and
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140
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Weller DL, Kovac J, Kent DJ, Roof S, Tokman JI, Mudrak E, Kowalcyk B, Oryang D, Aceituno A, Wiedmann M. Escherichia coli transfer from simulated wildlife feces to lettuce during foliar irrigation: A field study in the Northeastern United States. Food Microbiol 2017; 68:24-33. [PMID: 28800822 DOI: 10.1016/j.fm.2017.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 06/12/2017] [Accepted: 06/12/2017] [Indexed: 11/20/2022]
Abstract
Wildlife intrusion has been associated with pathogen contamination of produce. However, few studies have examined pathogen transfer from wildlife feces to pre-harvest produce. This study was performed to calculate transfer coefficients for Escherichia coli from simulated wildlife feces to field-grown lettuce during irrigation. Rabbit feces inoculated with a 3-strain cocktail of non-pathogenic E. coli were placed in a lettuce field 2.5-72 h before irrigation. Following irrigation, the E. coli concentration on the lettuce was determined. After exclusion of an outlier with high E. coli levels (Most Probable Number = 5.94*108), the average percent of E. coli in the feces that transferred to intact lettuce heads was 0.0267% (Standard Error [SE] = 0.0172). Log-linear regression showed that significantly more E. coli transferred to outer leaves compared to inner leaves (Effect = 1.3; 95% Confidence Interval = 0.4, 2.1). Additionally, the percent of E. coli that transferred from the feces to the lettuce decreased significantly with time after fecal placement, and as the distance between the lettuce and the feces, and the lettuce and the sprinklers increased. These findings provide key data that may be used in future quantitative risk assessments to identify potential intervention strategies for reducing food safety risks associated with fresh produce.
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Affiliation(s)
- Daniel L Weller
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA
| | - Jasna Kovac
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA
| | - David J Kent
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA
| | - Sherry Roof
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA
| | - Jeffrey I Tokman
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA
| | - Erika Mudrak
- Cornell Statistical Consulting Unit, Savage Hall, Cornell University, Ithaca, NY 14853, USA
| | | | - David Oryang
- U.S. Food and Drug Administration, 5001 Campus Drive, College Park, MD 20740, USA
| | - Anna Aceituno
- RTI International, 3040 E Cornwallis Rd, Durham, NC 27709, USA
| | - Martin Wiedmann
- Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA.
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141
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Li B, Liu H, Wang W. Multiplex real-time PCR assay for detection of Escherichia coli O157:H7 and screening for non-O157 Shiga toxin-producing E. coli. BMC Microbiol 2017; 17:215. [PMID: 29121863 PMCID: PMC5679507 DOI: 10.1186/s12866-017-1123-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/27/2017] [Indexed: 12/22/2022] Open
Abstract
Background Shiga toxin-producing Escherichia coli (STEC), including E. coli O157:H7, are responsible for numerous foodborne outbreaks annually worldwide. E. coli O157:H7, as well as pathogenic non-O157:H7 STECs, can cause life-threating complications, such as bloody diarrhea (hemolytic colitis) and hemolytic-uremic syndrome (HUS). Previously, we developed a real-time PCR assay to detect E. coli O157:H7 in foods by targeting a unique putative fimbriae protein Z3276. To extend the detection spectrum of the assay, we report a multiplex real-time PCR assay to specifically detect E. coli O157:H7 and screen for non-O157 STEC by targeting Z3276 and Shiga toxin genes (stx1 and stx2). Also, an internal amplification control (IAC) was incorporated into the assay to monitor the amplification efficiency. Methods The multiplex real-time PCR assay was developed using the Life Technology ABI 7500 System platform and the standard chemistry. The optimal amplification mixture of the assay contains 12.5 μl of 2 × Universal Master Mix (Life Technology), 200 nM forward and reverse primers, appropriate concentrations of four probes [(Z3276 (80 nM), stx1 (80 nM), stx2 (20 nM), and IAC (40 nM)], 2 μl of template DNA, and water (to make up to 25 μl in total volume). The amplification conditions of the assay were set as follows: activation of TaqMan at 95 °C for 10 min, then 40 cycles of denaturation at 95 °C for 10 s and annealing/extension at 60 °C for 60 s. Results The multiplex assay was optimized for amplification conditions. The limit of detection (LOD) for the multiplex assay was determined to be 200 fg of bacterial DNA, which is equivalent to 40 CFU per reaction which is similar to the LOD generated in single targeted PCRs. Inclusivity and exclusivity determinants were performed with 196 bacterial strains. All E. coli O157:H7 (n = 135) were detected as positive and all STEC strains (n = 33) were positive for stx1, or stx2, or stx1 and stx2 (Table 1). No cross reactivity was detected with Salmonella enterica, Shigella strains, or any other pathogenic strains tested. Conclusions A multiplex real-time PCR assay that can rapidly and simultaneously detect E. coli O157:H7 and screen for non-O157 STEC strains has been developed and assessed for efficacy. The inclusivity and exclusivity tests demonstrated high sensitivity and specificity of the multiplex real-time PCR assay. In addition, this multiplex assay was shown to be effective for the detection of E. coli O157:H7 from two common food matrices, beef and spinach, and may be applied for detection of E. coli O157:H7 and screening for non-O157 STEC strains from other food matrices as well.
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Affiliation(s)
- Baoguang Li
- Division of Molecular Biology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD, 20708, USA.
| | - Huanli Liu
- Branch of Microbiology, Office of Regulatory Affairs, Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Weimin Wang
- Division of Molecular Biology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD, 20708, USA
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142
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Bauwens A, Kunsmann L, Marejková M, Zhang W, Karch H, Bielaszewska M, Mellmann A. Intrahost milieu modulates production of outer membrane vesicles, vesicle-associated Shiga toxin 2a and cytotoxicity in Escherichia coli O157:H7 and O104:H4. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:626-634. [PMID: 28675605 DOI: 10.1111/1758-2229.12562] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Outer membrane vesicles (OMVs) are important virulence tools of enterohaemorrhagic Escherichia coli (EHEC), but other biological functions of these nanostructures are unknown. We tested the hypothesis that modulation of OMV production enables EHEC to resist the intrahost environment during infection by investigating if simulated human gastrointestinal conditions affect OMV production in EHEC O157:H7 and O104:H4. All the conditions tested including a low pH, simulated ileal and colonic media, presence of mucin, intestinal epithelial cell lysate or antimicrobial peptides, as well as iron limitation, significantly increased OMV production by these pathogens. Accordingly, a maximum vesiculation in EHEC O104:H4 was observed immediately after its isolation from a patient's intestine, and rapidly decreased during passages in vitro. Most of the simulated intrahost conditions also upregulated the OMV-associated Shiga toxin 2a (Stx2a), the major EHEC virulence factor, and, as a result, OMV cytotoxicity. The data indicates that upregulation of OMV production by the human gastrointestinal milieu contributes to EHEC survival and adaptation within the host during infection. Moreover, the intrahost increase of vesiculation and OMV-associated Stx2a may augment EHEC virulence.
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Affiliation(s)
- Andreas Bauwens
- Institute for Hygiene, University of Münster, 48149 Münster, Germany
| | - Lisa Kunsmann
- Institute for Hygiene, University of Münster, 48149 Münster, Germany
| | - Monika Marejková
- National Reference Laboratory for E. coli and Shigella, National Institute of Public Health, 100 42 Prague, Czech Republic
| | - Wenlan Zhang
- Institute for Hygiene, University of Münster, 48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, 48149 Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, 48149 Münster, Germany
| | | | - Alexander Mellmann
- Institute for Hygiene, University of Münster, 48149 Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, 48149 Münster, Germany
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Wang X, Du Y, Hua Y, Fu M, Niu C, Zhang B, Zhao W, Zhang Q, Wan C. The EspF N-Terminal of Enterohemorrhagic Escherichia coli O157:H7 EDL933w Imparts Stronger Toxicity Effects on HT-29 Cells than the C-Terminal. Front Cell Infect Microbiol 2017; 7:410. [PMID: 28983470 PMCID: PMC5613159 DOI: 10.3389/fcimb.2017.00410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/05/2017] [Indexed: 11/22/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 EspF is an important multifunctional protein that destroys the tight junctions of intestinal epithelial cells and promotes host cell apoptosis. However, its molecular mechanism remains elusive. We knocked out the espF sequence (747 bp, ΔespF), N-terminal sequence (219 bp, ΔespFN), and C-terminal sequence (528 bp, ΔespFC) separately using the pKD46-mediated λ Red homologous recombination system. Then, we built the corresponding complementation strains, namely, ΔespF/pespF, ΔespFN/pespFN, and ΔespFC/pespFC by overlap PCR, which were used in infecting HT-29 cells and BALB/C mice. The level of reactive oxygen species, cell apoptosis, mitochondrial trans-membrane potential, inflammatory factors, transepithelial electrical resistance (TER), and animal mortality were evaluated by DCFH-DA, double staining of Annexin V-FITC/PI, JC-1 staining, ELISA kit, and a mouse assay. The wild-type (WT), ΔespF, ΔespF/pespF, ΔespFC, ΔespFC/pespFC, ΔespFN, and ΔespFN/pespFN groups exhibited apoptotic rates of 68.3, 27.9, 64.9, 65.7, 73.4, 41.3, and 35.3% respectively, and mean TNF-α expression levels of 428 pg/mL, 342, 466, 446, 381, 383, and 374 pg/mL, respectively. In addition, the apoptotic rates and TNF-α levels of the WT, ΔespF/pespF, and ΔespFC were significantly higher than that of ΔespF, ΔespFN, ΔespFC/pespFC, and ΔespFN/pespFN group (p < 0.05). The N-terminal of EspF resulted in an increase in the number of apoptotic cells, TNF-α secretion, ROS generation, mitochondria apoptosis, and pathogenicity in BalB/c mice. In conclusion, the N-terminal domain of the Enterohemorrhagic E. coli O157:H7 EspF more strongly promotes apoptosis and inflammation than the C-terminal domain.
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Affiliation(s)
- Xiangyu Wang
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
| | - Yanli Du
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
| | - Ying Hua
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
| | - Muqing Fu
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
| | - Cong Niu
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
| | - Bao Zhang
- Key Laboratory of Tropical Disease Research of Guangdong Province, Southern Medical UniversityGuangzhou, China
| | - Wei Zhao
- Key Laboratory of Tropical Disease Research of Guangdong Province, Southern Medical UniversityGuangzhou, China
| | - Qiwei Zhang
- Key Laboratory of Tropical Disease Research of Guangdong Province, Southern Medical UniversityGuangzhou, China
| | - Chengsong Wan
- Department of Microbiology, School of Public Health, Southern Medical UniversityGuangzhou, China
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144
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Real-time genomic investigation underlying the public health response to a Shiga toxin-producing Escherichia coli O26:H11 outbreak in a nursery. Epidemiol Infect 2017; 145:2998-3006. [PMID: 28925349 DOI: 10.1017/s0950268817001923] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carrying stx2a and intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak.
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145
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Brusa V, Restovich V, Galli L, Teitelbaum D, Signorini M, Brasesco H, Londero A, García D, Padola NL, Superno V, Sanz M, Petroli S, Costa M, Bruzzone M, Sucari A, Ferreghini M, Linares L, Suberbie G, Rodríguez R, Leotta GA. Isolation and characterization of non-O157 Shiga toxin-producing Escherichia coli from beef carcasses, cuts and trimmings of abattoirs in Argentina. PLoS One 2017; 12:e0183248. [PMID: 28829794 PMCID: PMC5568767 DOI: 10.1371/journal.pone.0183248] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/01/2017] [Indexed: 11/18/2022] Open
Abstract
Several foods contaminated with Shiga toxin-producing Escherichia coli (STEC) are associated with human diseases. Some countries have established microbiological criteria for non-O157 STEC, thus, the absence of serogroups O26, O45, O103, O104, O111, O121, and O145 in sprouts from the European Union or ground beef and beef trimmings from the United States is mandatory. While in Argentina screening for O26, O103, O111, O145 and O121 in ground beef, ready-to-eat food, sausages and vegetables is mandatory, other countries have zero-tolerance for all STEC in chilled beef. The aim of this study was to provide data on the prevalence of non-O157 STEC isolated from beef processed in eight Argentinean cattle slaughterhouses producing beef for export and local markets, and to know the non-O157 STEC profiles through strain characterization and genotypic analysis. Samples (n = 15,965) from 3,205 beef carcasses, 9,570 cuts and 3,190 trimmings collected between March and September 2014 were processed in pools of five samples each. Pools of samples (n = 3,193) from 641 carcasses, 1,914 cuts and 638 trimming were analyzed for non-O157 STEC isolation according to ISO/CEN 13136:2012. Of these, 37 pools of carcasses (5.8%), 111 pools of cuts (5.8%) and 45 pools of trimmings (7.0%) were positive for non-O157 STEC. STEC strains (n = 200) were isolated from 193 pools of samples. The most prevalent serotypes were O174:H21, O185:H7, O8:H19, O178:H19 and O130:H11, and the most prevalent genotypes were stx2c(vh-b) and stx2a/saa/ehxA. O103:H21 strain was eae-positive and one O178:H19 strain was aggR/aaiC-positive. The prevalence of non-O157 STEC in beef carcasses reported here was low. None of the non-O157 STEC strains isolated corresponded to the non-O157 STEC serotypes and virulence profiles isolated from human cases in Argentina in the same study period. The application of microbiological criteria for each foodstuff should be determined by risk analysis in order to have a stringent monitoring system. Likewise, zero-tolerance intervention measures should be applied in beef, together with GMP and HACCP. Further, collaborative efforts for risk assessment, management and communication are extremely important to improve the safety of foodstuffs.
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Affiliation(s)
- Victoria Brusa
- IGEVET—Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
- Laboratorio de Microbiología de Alimentos, Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
| | - Viviana Restovich
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucía Galli
- IGEVET—Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
| | - David Teitelbaum
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Signorini
- CONICET—EEA Rafaela, Instituto Nacional de Tecnología Agropecuaria (INTA), Santa Fe, Argentina
| | - Hebe Brasesco
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandra Londero
- IGEVET—Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
| | - Diego García
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Nora Lía Padola
- CIVETAN–Centro de Investigación Veterinaria Tandil (CONICET, CICPBA), Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina
| | - Valeria Superno
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Sanz
- CIVETAN–Centro de Investigación Veterinaria Tandil (CONICET, CICPBA), Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina
| | - Sandra Petroli
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Magdalena Costa
- IGEVET—Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
| | - Mariana Bruzzone
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Adriana Sucari
- Centro Estudios Infectológicos “Dr. Daniel Stamboulian”, División Alimentos, Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcela Ferreghini
- IPCVA–Instituto de Promoción de la Carne Vacuna Argentina, Ciudad Autónoma de Buenos Aires, Argentina
| | - Luciano Linares
- Laboratorio de Microbiología de Alimentos, Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
| | - Germán Suberbie
- SENASA–Servicio Nacional de Sanidad y Calidad Agroalimentaria, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ricardo Rodríguez
- Instituto de Economía (CICPES, INTA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Gerardo A. Leotta
- IGEVET—Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, La Plata, Argentina
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146
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Adams DA, Thomas KR, Jajosky RA, Foster L, Baroi G, Sharp P, Onweh DH, Schley AW, Anderson WJ. Summary of Notifiable Infectious Diseases and Conditions - United States, 2015. MMWR-MORBIDITY AND MORTALITY WEEKLY REPORT 2017; 64:1-143. [PMID: 28796757 DOI: 10.15585/mmwr.mm6453a1] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The Summary of Notifiable Infectious Diseases and Conditions - United States, 2015 (hereafter referred to as the summary) contains the official statistics, in tabular and graphical form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2015. Unless otherwise noted, data are final totals for 2015 reported as of June 30, 2016. These statistics are collected and compiled from reports sent by U.S. state and territories, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at https://www.cdc.gov/MMWR/MMWR_nd/index.html. This site also includes summary publications from previous years.
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Affiliation(s)
- Deborah A Adams
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Kimberly R Thomas
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Ruth Ann Jajosky
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Loretta Foster
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Gitangali Baroi
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Pearl Sharp
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Diana H Onweh
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Alan W Schley
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
| | - Willie J Anderson
- Division of Health Informatics and Surveillance, Office of Public Health Scientific Services, CDC
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147
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Weller DL, Kovac J, Roof S, Kent DJ, Tokman JI, Kowalcyk B, Oryang D, Ivanek R, Aceituno A, Sroka C, Wiedmann M. Survival of Escherichia coli on Lettuce under Field Conditions Encountered in the Northeastern United States. J Food Prot 2017; 80:1214-1221. [PMID: 28632416 DOI: 10.4315/0362-028x.jfp-16-419] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.
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Affiliation(s)
- Daniel L Weller
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Jasna Kovac
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Sherry Roof
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - David J Kent
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Jeffrey I Tokman
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
| | - Barbara Kowalcyk
- 2 RTI International, Research Triangle Park, North Carolina 27709
| | - David Oryang
- 3 U.S. Food and Drug Administration, College Park, Maryland 20740
| | - Renata Ivanek
- 4 Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York 14853
| | - Anna Aceituno
- 2 RTI International, Research Triangle Park, North Carolina 27709
| | - Christopher Sroka
- 5 Department of Economics, Applied Statistics, and International Business, New Mexico State University, Las Cruces, New Mexico 88003, USA
| | - Martin Wiedmann
- 1 Department of Food Science, Cornell University, Ithaca, New York 14853
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148
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Antimicrobial activity and inactivation mechanism of lactonic and free acid sophorolipids against Escherichia coli O157:H7. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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149
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Stein RA, Katz DE. Escherichia coli, cattle and the propagation of disease. FEMS Microbiol Lett 2017; 364:3059138. [PMID: 28333229 PMCID: PMC7108533 DOI: 10.1093/femsle/fnx050] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/28/2017] [Indexed: 12/21/2022] Open
Abstract
Several early models describing host–pathogen interaction have assumed that each individual host has approximately the same likelihood of becoming infected or of infecting others. More recently, a concept that has been increasingly emphasized in many studies is that for many infectious diseases, transmission is not homogeneous but highly skewed at the level of populations. In what became known as the ‘20/80 rule’, about 20% of the hosts in a population were found to contribute to about 80% of the transmission potential. These heterogeneities have been described for the interaction between many microorganisms and their human or animal hosts. Several epidemiological studies have reported transmission heterogeneities for Escherichia coli by cattle, a phenomenon with far-reaching agricultural, medical and public health implications. Focusing on E. coli as a case study, this paper will describe super-spreading and super-shedding by cattle, review the main factors that shape these transmission heterogeneities and examine the interface with human health. Escherichia coli super-shedding and super-spreading by cattle are shaped by microorganism-specific, cattle-specific and environmental factors. Understanding the factors that shape heterogeneities in E. coli dispersion by cattle and the implications for human health represent key components that are critical for targeted infection control initiatives.
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Affiliation(s)
- Richard A Stein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.,Department of Natural Sciences, LaGuardia Community College, City University of New York, Long Island City, NY 11101, USA
| | - David E Katz
- Department of Internal Medicine, Shaare Zedek Medical Center, Hebrew University School of Medicine, Jerusalem 91031, Israel
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150
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The Contribution of Bacteriophages to the Biology and Virulence of Pathogenic Clostridia. ADVANCES IN APPLIED MICROBIOLOGY 2017; 101:169-200. [PMID: 29050666 DOI: 10.1016/bs.aambs.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacteriophages are key players in the evolution of most bacteria. Temperate phages have been associated with virulence of some of the deadliest pathogenic bacteria. Among the most notorious cases, the genes encoding the botulinum neurotoxin produced by Clostridium botulinum types C and D and the α-toxin (TcnA) produced by Clostridium novyi are both encoded within prophage genomes. Clostridium difficile is another important human pathogen and the recent identification of a complete binary toxin locus (CdtLoc) carried on a C. difficile prophage raises the potential for horizontal transfer of toxin genes by mobile genetic elements. Although the TcdA and TcdB toxins produced by C. difficile have never been found outside the pathogenicity locus (PaLoc), some prophages can still influence their production. Prophages can alter the expression of several metabolic and regulatory genes in C. difficile, as well as cell surface proteins such as CwpV, which confers phage resistance. Homologs of an Agr-like quorum sensing system have been identified in a C. difficile prophage, suggesting that it could possibly participate in cell-cell communication. Yet, other C. difficile prophages contain riboswitches predicted to recognize the secondary messenger molecule c-di-GMP involved in bacterial multicellular behaviors. Altogether, recent findings on clostridial phages underline the diversity of mechanisms and intricate relationship linking phages with their host. Here, milestone discoveries linking phages and virulence of some of the most pathogenic clostridial species will be retraced, with a focus on C. botulinum, C. novyi, C. difficile, and Clostridium perfringens phages, for which evidences are mostly available.
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