1
|
Williams A, Gaoh SD, Savenka A, Paredes A, Alusta P, Ahn Y, Buzatu DA. A flow cytometric assay to detect viability and persistence of Salmonella enterica subsp. enterica serotypes in nuclease-free water at 4 and 25°C. Front Microbiol 2024; 15:1342478. [PMID: 38435692 PMCID: PMC10906097 DOI: 10.3389/fmicb.2024.1342478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Salmonella spp. is one of the most isolated microorganisms reported to be responsible for human foodborne diseases and death. Water constitutes a major reservoir where the Salmonella spp. can persist and go undetected when present in low numbers. In this study, we assessed the viability of 12 serotypes of Salmonella enterica subsp. enterica for 160 days in nuclease-free water at 4 and 25°C using flow cytometry and Tryptic Soy Agar (TSA) plate counts. The results show that all 12 serotypes remain viable after 160 days in distilled water using flow cytometry, whereas traditional plate counts failed to detect ten serotypes incubated at 25°C. Moreover, the findings demonstrate that 4°C constitutes a more favorable environment where Salmonella can remain viable for prolonged periods without nutrients. Under such conditions, however, Salmonella exhibits a higher susceptibility to all tested antibiotics and benzalkonium chloride (BZK). The pre-enrichment with Universal Pre-enrichment Broth (UP) and 1/10 × Tryptic Soy broth (1/10 × TSB) resuscitated all tested serotypes on TSA plates, nevertheless cell size decreased after 160 days. Furthermore, phenotype microarray (PM) analysis of S. Inverness and S. Enteritidis combined with principal component analysis (PCA) revealed an inter-individual variability in serotypes with their phenotype characteristics, and the impact of long-term storage at 4 and 25°C for 160 days in nuclease-free water. This study provides an insight to Salmonella spp. long-term survivability at different temperatures and highlights the need for powerful tools to detect this microorganism to reduce the risk of disease transmission of foodborne pathogens via nuclease-free water.
Collapse
Affiliation(s)
- Anna Williams
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Soumana Daddy Gaoh
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Alena Savenka
- Office of Scientific Research, Nanotechnology Branch, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Angel Paredes
- Office of Scientific Research, Nanotechnology Branch, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Pierre Alusta
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Youngbeom Ahn
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| | - Dan A. Buzatu
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States
| |
Collapse
|
2
|
Zhuang L, Gong J, Zhao Y, Yang J, Liu G, Zhao B, Song C, Zhang Y, Shen Q. Progress in methods for the detection of viable Escherichia coli. Analyst 2024; 149:1022-1049. [PMID: 38273740 DOI: 10.1039/d3an01750h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Escherichia coli (E. coli) is a prevalent enteric bacterium and a necessary organism to monitor for food safety and environmental purposes. Developing efficient and specific methods is critical for detecting and monitoring viable E. coli due to its high prevalence. Conventional culture methods are often laborious and time-consuming, and they offer limited capability in detecting potentially harmful viable but non-culturable E. coli in the tested sample, which highlights the need for improved approaches. Hence, there is a growing demand for accurate and sensitive methods to determine the presence of viable E. coli. This paper scrutinizes various methods for detecting viable E. coli, including culture-based methods, molecular methods that target DNAs and RNAs, bacteriophage-based methods, biosensors, and other emerging technologies. The review serves as a guide for researchers seeking additional methodological options and aiding in the development of rapid and precise assays. Moving forward, it is anticipated that methods for detecting E. coli will become more stable and robust, ultimately contributing significantly to the improvement of food safety and public health.
Collapse
Affiliation(s)
- Linlin Zhuang
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering & Basic Medicine Research and Innovation Center of Ministry of Education, Zhongda Hospital, Southeast University, Nanjing 211102, P. R. China.
| | - Jiansen Gong
- Poultry Institute, Chinese Academy of Agricultural Sciences, Yangzhou 225125, P. R. China
| | - Ying Zhao
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering & Basic Medicine Research and Innovation Center of Ministry of Education, Zhongda Hospital, Southeast University, Nanjing 211102, P. R. China.
| | - Jianbo Yang
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
| | - Guofang Liu
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
| | - Bin Zhao
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
| | - Chunlei Song
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
| | - Yu Zhang
- State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering & Basic Medicine Research and Innovation Center of Ministry of Education, Zhongda Hospital, Southeast University, Nanjing 211102, P. R. China.
| | - Qiuping Shen
- School of Animal Husbandry and Veterinary Medicine, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, P. R. China.
| |
Collapse
|
3
|
Daddy Gaoh S, Williams A, Le D, Kweon O, Alusta P, Buzatu DA, Ahn Y. Specific Detection and Enumeration of Burkholderia cepacia Complex by Flow Cytometry Using a Fluorescence-Labeled Oligonucleotide Probe. Microorganisms 2022; 10:1170. [PMID: 35744688 PMCID: PMC9227203 DOI: 10.3390/microorganisms10061170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022] Open
Abstract
Burkholderia cepacia complex (BCC) contamination has resulted in recalls of non-sterile pharmaceutical products. The fast, sensitive, and specific detection of BCC is critical for ensuring the quality and safety of pharmaceutical products. In this study, a rapid flow cytometry-based detection method was developed using a fluorescence-labeled oligonucleotide Kef probe that specifically binds a KefB/KefC membrane protein sequence within BCC. Optimal conditions of a 1 nM Kef probe concentration at a 60 °C hybridization temperature for 30 min were determined and applied for the flow cytometry assay. The true-positive rate (sensitivity) and true-negative rate (specificity) of the Kef probe assay were 90% (18 positive out of 20 BCC species) and 88.9% (16 negative out of 18 non-BCC), respectively. The detection limit for B. cenocepacia AU1054 with the Kef probe flow cytometry assay in nuclease-free water was 1 CFU/mL. The average cell counts using the Kef probe assay from a concentration of 10 μg/mL chlorhexidine gluconate and 50 μg/mL benzalkonium chloride were similar to those of the RAPID-B total plate count (TPC). We demonstrate the potential of Kef probe flow cytometry as a more sensitive alternative to culture-based methods for detecting BCC in non-sterilized pharmaceutical raw materials and products with regards to water-based environments.
Collapse
Affiliation(s)
- Soumana Daddy Gaoh
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.D.G.); (D.L.); (O.K.)
| | - Anna Williams
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (A.W.); (P.A.); (D.A.B.)
| | - David Le
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.D.G.); (D.L.); (O.K.)
| | - Ohgew Kweon
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.D.G.); (D.L.); (O.K.)
| | - Pierre Alusta
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (A.W.); (P.A.); (D.A.B.)
| | - Dan A. Buzatu
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (A.W.); (P.A.); (D.A.B.)
| | - Youngbeom Ahn
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA; (S.D.G.); (D.L.); (O.K.)
| |
Collapse
|
4
|
A comparison of culture-based, real-time PCR, droplet digital PCR and flow cytometric methods for the detection of Burkholderia cepacia complex in nuclease-free water and antiseptics. J Ind Microbiol Biotechnol 2020; 47:475-484. [PMID: 32671501 DOI: 10.1007/s10295-020-02287-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/17/2020] [Indexed: 12/14/2022]
Abstract
The presence of Burkholderia cepacia complex (BCC) strains has resulted in recalls of pharmaceutical products, since these opportunistic pathogens can cause serious infections. Rapid and sensitive diagnostic methods to detect BCC are crucial to determine contamination levels. We evaluated bacterial cultures, real-time PCR (qPCR), droplet digital PCR (ddPCR), and flow cytometry to detect BCC in nuclease-free water, in chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions. Twenty BCC strains were each suspended (1, 10, 100, and 1000 CFU/ml) in autoclaved nuclease-free water, 10 μg/ml CHX, and 50 μg/ml BZK. Five replicates of each strain were tested at each concentration (20 strains × 4 concentrations × 5 replicates = 400 tests) to detect BCC using the aforementioned four methods. We demonstrated the potential of ddPCR and flow cytometry as more sensitive alternatives to culture-based methods to detect BCC in autoclaved nuclease-free water and antiseptics samples.
Collapse
|
5
|
Michelutti L, Bulfoni M, Nencioni E. A novel pharmaceutical approach for the analytical validation of probiotic bacterial count by flow cytometry. J Microbiol Methods 2020; 170:105834. [PMID: 31917164 DOI: 10.1016/j.mimet.2020.105834] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Flow cytometry is a powerful and sensitive technique able to characterize single cells within a heterogeneous population. Different fluorescent dyes can be combined and used together to analyze a great variety of parameters simultaneously. In particular, flow-cytometry allows to measure viability and vitality of probiotics measuring their metabolic activity, fermentation capacity, acidification potential or oxygen uptake ability (Hayouni et al., 2008). To now, plate counting is considered the gold standard in microbiological technique for probiotic enumeration. However, this approach is limited to the detection of only those viable cells which are able to proliferate and form colonies on a solid medium but is not able to recognize not cultivable bacteria and nonviable cells. AIM The aim of the present study was to apply The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) parameters for the validation of new analytical methods in microbiology. ICH requirements, which are commonly employed for the analysis of drugs and chemical analytes, have been here applied to live cells for the comparison between a flow-cytometric assay and the traditional plate count method for the quantification of viable probiotics bacteria. METHODS AND RESULTS Combining specific viability dyes such as thiazole orange (TO) and propidium iodide (PI), probiotic counts of Lactobacillus and Bifidobacterium species were carried out using a FACS Verse (BD Biosciences) cytometer. Analyses were conducted in parallel with the traditional plate count, on specific media. Raw data were analyzed using the FACSuite software (BD Biosciences) and then elaborated with the statistical software Neolicy (VWR International). Results indicated that flow cytometry provides very similar results in cell counting if compared to classical microbiology approaches, showing better performances (ICH parameters) than the traditional plate count method. CONCLUSIONS This work demonstrated the analytical ICH validation of probiotic counts in food supplement products using a robust flow cytometric approach able to enumerate and to assess bacteria viability with stronger results in comparison to the traditional plate count.
Collapse
Affiliation(s)
- Luca Michelutti
- Biofarma SpA, Via Castelliere 2, 33036 Mereto di Tomba UD, Italy
| | - Michela Bulfoni
- Institute of Pathology Department of Medicine, University of Udine, 33100 Udine, Italy
| | | |
Collapse
|
6
|
Walper SA, Lasarte Aragonés G, Sapsford KE, Brown CW, Rowland CE, Breger JC, Medintz IL. Detecting Biothreat Agents: From Current Diagnostics to Developing Sensor Technologies. ACS Sens 2018; 3:1894-2024. [PMID: 30080029 DOI: 10.1021/acssensors.8b00420] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although a fundamental understanding of the pathogenicity of most biothreat agents has been elucidated and available treatments have increased substantially over the past decades, they still represent a significant public health threat in this age of (bio)terrorism, indiscriminate warfare, pollution, climate change, unchecked population growth, and globalization. The key step to almost all prevention, protection, prophylaxis, post-exposure treatment, and mitigation of any bioagent is early detection. Here, we review available methods for detecting bioagents including pathogenic bacteria and viruses along with their toxins. An introduction placing this subject in the historical context of previous naturally occurring outbreaks and efforts to weaponize selected agents is first provided along with definitions and relevant considerations. An overview of the detection technologies that find use in this endeavor along with how they provide data or transduce signal within a sensing configuration follows. Current "gold" standards for biothreat detection/diagnostics along with a listing of relevant FDA approved in vitro diagnostic devices is then discussed to provide an overview of the current state of the art. Given the 2014 outbreak of Ebola virus in Western Africa and the recent 2016 spread of Zika virus in the Americas, discussion of what constitutes a public health emergency and how new in vitro diagnostic devices are authorized for emergency use in the U.S. are also included. The majority of the Review is then subdivided around the sensing of bacterial, viral, and toxin biothreats with each including an overview of the major agents in that class, a detailed cross-section of different sensing methods in development based on assay format or analytical technique, and some discussion of related microfluidic lab-on-a-chip/point-of-care devices. Finally, an outlook is given on how this field will develop from the perspective of the biosensing technology itself and the new emerging threats they may face.
Collapse
Affiliation(s)
- Scott A. Walper
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Guillermo Lasarte Aragonés
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University Fairfax, Virginia 22030, United States
| | - Kim E. Sapsford
- OMPT/CDRH/OIR/DMD Bacterial Respiratory and Medical Countermeasures Branch, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Carl W. Brown
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University Fairfax, Virginia 22030, United States
| | - Clare E. Rowland
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- National Research Council, Washington, D.C. 20036, United States
| | - Joyce C. Breger
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| |
Collapse
|
7
|
Wilkinson MG. Flow cytometry as a potential method of measuring bacterial viability in probiotic products: A review. Trends Food Sci Technol 2018. [DOI: 10.1016/j.tifs.2018.05.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
8
|
Williams AJ, Cooper WM, Ramsaroop S, Alusta P, Buzatu DA, Wilkes JG. Rapid Flow Cytometry Detection of a Single Viable Escherichia coli O157:H7 Cell in Raw Spinach Using a Simplified Sample Preparation Technique. Front Microbiol 2017; 8:1493. [PMID: 28855894 PMCID: PMC5558463 DOI: 10.3389/fmicb.2017.01493] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/25/2017] [Indexed: 11/13/2022] Open
Abstract
Very low cell count detection of Escherichia coli O157:H7 in foods is critical, since an infective dose for this pathogen may be only 10 cells, and fewer still for vulnerable populations. A flow cytometer is able to detect and count individual cells of a target bacterium, in this case E. coli O157:H7. The challenge is to find the single cell in a complex matrix like raw spinach. To find that cell requires growing it as quickly as possible to a number sufficiently in excess of matrix background that identification is certain. The experimental design for this work was that of a U.S. Food and Drug Administration (FDA) In-House Level 3 validation executed in the technology’s originating laboratory. Using non-selective enrichment broth, 6.5 h incubation at 42°C, centrifugation for target cell concentration, and a highly selective E. coli O157 fluorescent antibody tag, the cytometry method proved more sensitive than a reference regulatory method (p = 0.01) for detecting a single target cell, one E. coli O157:H7 cell, in 25 g of spinach. It counted that cell’s daughters with at least 38× signal-to-noise ratio, analyzing 25 samples in total-time-to-results of 9 h.
Collapse
Affiliation(s)
- Anna J Williams
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, JeffersonAR, United States
| | - Willie M Cooper
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, JeffersonAR, United States
| | | | - Pierre Alusta
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, JeffersonAR, United States
| | - Dan A Buzatu
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, JeffersonAR, United States
| | - Jon G Wilkes
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, JeffersonAR, United States
| |
Collapse
|
9
|
Baker CA, Park SH, Kim SA, Rubinelli PM, Roto SM, Lee SI, Ramsaroop S, Miller M, Ricke SC. Formalin-fixed cells as an internal standard approach for the detection and quantitative assessment of Shiga toxin-producing Escherichia coli (STEC). Food Control 2016. [DOI: 10.1016/j.foodcont.2015.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
10
|
Rapid screening of waterborne pathogens using phage-mediated separation coupled with real-time PCR detection. Anal Bioanal Chem 2016; 408:4169-78. [PMID: 27071764 DOI: 10.1007/s00216-016-9511-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/14/2016] [Accepted: 03/22/2016] [Indexed: 12/26/2022]
Abstract
Escherichia coli O157:H7 is a ubiquitous pathogen which can be linked to foodborne outbreaks worldwide. In addition to the significant illnesses, hospitalizations, and deaths resulting from the outbreaks, there can be severe economic consequences to farmers, food manufacturers, and municipalities. A rapid detection assay which can validate sanitation and water quality would prove beneficial to these situations. Here, we report a novel bacteriophage-mediated detection of E. coli O157:H7 which utilizes the specific recognition between phages and their host cell as well as the natural lysis component of the infection cycle for DNA release. Carboxylic acid-functionalized magnetic beads were conjugated with bacteriophage and used to separate and concentrate E. coli O157:H7. The effects of bead incubation time, salinity, pH, and temperature on the bio-magnetic separation were investigated and compared to an antibody-based counterpart. The conditions of 0.01 M PBS, pH 7.0, and 20 min of reaction at 37 °C were found to be optimal. The capture efficiency of the coupled assay was approximately 20 % higher than that of antibody-based separation under extreme conditions. The resulting bead-phage-bacteria complexes were quantitatively detected by real-time PCR (qPCR). Our results demonstrated that the use of phage-based magnetic separation coupled with qPCR improved the sensitivity of detection by 2 orders of magnitude compared that without phage-based pre-concentration. Specificity and selectivity of the assay system was evaluated, and no cross-reactivity occurred when Salmonella typhimurium, Staphylococcus aureus, and Pseudomonas aeruginosa were tested. The total assay time was less than 2 h.
Collapse
|
11
|
Xue Y, Wilkes JG, Moskal TJ, Williams AJ, Cooper WM, Nayak R, Rafii F, Buzatu DA. Development of a Flow Cytometry-Based Method for Rapid Detection of Escherichia coli and Shigella Spp. Using an Oligonucleotide Probe. PLoS One 2016; 11:e0150038. [PMID: 26913737 PMCID: PMC4767227 DOI: 10.1371/journal.pone.0150038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 02/08/2016] [Indexed: 11/18/2022] Open
Abstract
Standard methods to detect Escherichia coli contamination in food use the polymerase chain reaction (PCR) and agar culture plates. These methods require multiple incubation steps and take a long time to results. An improved rapid flow-cytometry based detection method was developed, using a fluorescence-labeled oligonucleotide probe specifically binding a16S rRNA sequence. The method positively detected 51 E. coli isolates as well as 4 Shigella species. All 27 non-E. coli strains tested gave negative results. Comparison of the new genetic assay with a total plate count (TPC) assay and agar plate counting indicated similar sensitivity, agreement between cytometry cell and colony counts. This method can detect a small number of E.coli cells in the presence of large numbers of other bacteria. This method can be used for rapid, economical, and stable detection of E. coli and Shigella contamination in the food industry and other contexts.
Collapse
Affiliation(s)
- Yong Xue
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
- * E-mail:
| | - Jon G. Wilkes
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| | - Ted J. Moskal
- Life Sciences Consultant, 515 W. Matthews Ave., Jonesboro, AR, United States of America
| | - Anna J. Williams
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| | - Willie M. Cooper
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| | - Rajesh Nayak
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| | - Fatemeh Rafii
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| | - Dan A. Buzatu
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, United States of America
| |
Collapse
|
12
|
|
13
|
Level 2 validation of a flow cytometric method for detection of Escherichia coli O157:H7 in raw spinach. Int J Food Microbiol 2015; 215:1-6. [DOI: 10.1016/j.ijfoodmicro.2015.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 08/10/2015] [Accepted: 08/14/2015] [Indexed: 11/17/2022]
|
14
|
Alusta P, Buzatu D, Williams A, Cooper WM, Tarasenko O, Dorey RC, Hall R, Parker WR, Wilkes JG. Instrumental improvements and sample preparations that enable reproducible, reliable acquisition of mass spectra from whole bacterial cells. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1961-1968. [PMID: 26443394 PMCID: PMC4600233 DOI: 10.1002/rcm.7299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/30/2015] [Accepted: 08/03/2015] [Indexed: 05/31/2023]
Abstract
RATIONALE Rapid sub-species characterization of pathogens is required for timely responses in outbreak situations. Pyrolysis mass spectrometry (PyMS) has the potential to be used for this purpose. METHODS However, in order to make PyMS practical for traceback applications, certain improvements related to spectrum reproducibility and data acquisition speed were required. The main objectives of this study were to facilitate fast detection (<30 min to analyze 6 samples, including preparation) and sub-species-level bacterial characterization based on pattern recognition of mass spectral fingerprints acquired from whole cells volatilized and ionized at atmospheric pressure. An AccuTOF DART mass spectrometer was re-engineered to permit ionization of low-volatility bacteria by means of Plasma Jet Ionization (PJI), in which an electric discharge, and, by extension, a plasma beam, impinges on sample cells. RESULTS Instrumental improvements and spectral acquisition methodology are described. Performance of the re-engineered system was assessed using a small challenge set comprised of assorted bacterial isolates differing in identity by varying amounts. In general, the spectral patterns obtained allowed differentiation of all samples tested, including those of the same genus and species but different serotypes. CONCLUSIONS Fluctuations of ±15% in bacterial cell concentrations did not substantially compromise replicate spectra reproducibility.
Collapse
Affiliation(s)
- Pierre Alusta
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - Dan Buzatu
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - Anna Williams
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - Willie-Mae Cooper
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - Olga Tarasenko
- University of Arkansas at Little Rock, Department of BiologyLittle Rock, AR, USA
| | - R Cameron Dorey
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - Reggie Hall
- Bionetics Corp., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| | - W Ryan Parker
- Department of Chemistry, University of TexasAustin, TX, USA
| | - Jon G Wilkes
- Innovative Safety Technologies Branch, Systems Biology Div., National Center for Toxicological Research, Food Drug AdministrationJefferson, AR, USA
| |
Collapse
|
15
|
Baker CA, Rubinelli PM, Park SH, Ricke SC. Immuno-based detection of Shiga toxin-producing pathogenic Escherichia coli in food – A review on current approaches and potential strategies for optimization. Crit Rev Microbiol 2015; 42:656-75. [DOI: 10.3109/1040841x.2015.1009824] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Christopher A. Baker
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - Peter M. Rubinelli
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - Si Hong Park
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - Steven C. Ricke
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
16
|
The use of flow cytometry to accurately ascertain total and viable counts of Lactobacillus rhamnosus in chocolate. Food Microbiol 2015; 46:176-183. [DOI: 10.1016/j.fm.2014.07.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/05/2014] [Accepted: 07/02/2014] [Indexed: 11/18/2022]
|
17
|
Comparison of the RAPID-B® flow cytometer and the BAX® system for the detection of non-O157 shiga toxin-producing Escherichia coli (STEC) in beef products. Food Control 2015. [DOI: 10.1016/j.foodcont.2014.08.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
18
|
Shen Z, Hou N, Jin M, Qiu Z, Wang J, Zhang B, Wang X, Wang J, Zhou D, Li J. A novel enzyme-linked immunosorbent assay for detection of Escherichia coli O157:H7 using immunomagnetic and beacon gold nanoparticles. Gut Pathog 2014; 6:14. [PMID: 24864164 PMCID: PMC4033681 DOI: 10.1186/1757-4749-6-14] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/14/2014] [Indexed: 12/31/2022] Open
Abstract
This paper presents a functional nanoparticle-enhanced enzyme-linked immunosorbent assay (FNP-ELISA) for detection of enterohemorrhagic Escherichia coli (EHEC) O157:H7. Immunomagnetic nanoparticles (IMMPs) conjugated with monoclonal anti-O157:H7 antibody were used to capture E. coli O157:H7. Beacon gold nanoparticles (B-GNPs) coated with polyclonal anti-O157:H7 and biotin single-stranded DNA (B-DNA) were then subjective to immunoreaction with E. coli O157:H7, which was followed by streptavidin-horseradish peroxidase (Strep-HRP) conjugated with B-GNPs based on a biotin-avidin system. The solutions containing E. coli O157:H7, IMMPs, B-GNPs, and Strep-HRP were collected for detecting color change. The signal was significantly amplified with detection limits of 68 CFU mL-1 in PBS and 6.8 × 102 to 6.8 × 103 CFU mL-1 in the food samples. The FNP-ELISA method developed in this study was two orders of magnitude more sensitive than immunomagnetic separation ELISA (IMS-ELISA) and four orders of magnitude more sensitive than C-ELISA. The entire detection process of E. coli O157:H7 lasted only 3 h, and thus FNP-ELISA is considered as a time-saving method.
Collapse
Affiliation(s)
- Zhiqiang Shen
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Nannan Hou
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Min Jin
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Zhigang Qiu
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Jingfeng Wang
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Bin Zhang
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Xinwei Wang
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| | - Jie Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Junwen Li
- Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China
| |
Collapse
|
19
|
Buzatu DA, Moskal TJ, Williams AJ, Cooper WM, Mattes WB, Wilkes JG. An integrated flow cytometry-based system for real-time, high sensitivity bacterial detection and identification. PLoS One 2014; 9:e94254. [PMID: 24718659 PMCID: PMC3981798 DOI: 10.1371/journal.pone.0094254] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 03/13/2014] [Indexed: 11/18/2022] Open
Abstract
Foodborne illnesses occur in both industrialized and developing countries, and may be increasing due to rapidly evolving food production practices. Yet some primary tools used to assess food safety are decades, if not centuries, old. To improve the time to result for food safety assessment a sensitive flow cytometer based system to detect microbial contamination was developed. By eliminating background fluorescence and improving signal to noise the assays accurately measure bacterial load or specifically identify pathogens. These assays provide results in minutes or, if sensitivity to one cell in a complex matrix is required, after several hours enrichment. Conventional assessments of food safety require 48 to 56 hours. The assays described within are linear over 5 orders of magnitude with results identical to culture plates, and report live and dead microorganisms. This system offers a powerful approach to real-time assessment of food safety, useful for industry self-monitoring and regulatory inspection.
Collapse
Affiliation(s)
- Dan A. Buzatu
- National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, Arkansas, United States of America
- * E-mail:
| | - Ted J. Moskal
- Vivione Biosciences, Pine Bluff, Arkansas, United States of America
| | - Anna J. Williams
- National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, Arkansas, United States of America
| | - Willie Mae Cooper
- National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, Arkansas, United States of America
| | - William B. Mattes
- PharmPoint Consulting, Poolesville, Maryland, United States of America
| | - Jon G. Wilkes
- National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, Arkansas, United States of America
| |
Collapse
|
20
|
Rapid Sample Preparation for Molecular Biological Food Analysis Based on Magnesium Chloride. FOOD ANAL METHOD 2014. [DOI: 10.1007/s12161-013-9774-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
21
|
Flow cytometry immunodetection and membrane integrity assessment of Escherichia coli O157:H7 in ready-to-eat pasta salad during refrigerated storage. Int J Food Microbiol 2014; 168-169:47-56. [DOI: 10.1016/j.ijfoodmicro.2013.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/25/2013] [Accepted: 10/21/2013] [Indexed: 11/24/2022]
|
22
|
Photobleaching with phloxine B sensitizer to reduce food matrix interference for detection of Escherichia coli serotype O157:H7 in fresh spinach by flow cytometry. Food Microbiol 2013; 36:416-25. [PMID: 24010624 DOI: 10.1016/j.fm.2013.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/09/2013] [Accepted: 07/17/2013] [Indexed: 02/05/2023]
Abstract
A flow cytometric method (RAPID-B™) with detection sensitivity of one viable cell of Escherichia coli serotype O157:H7 in fresh spinach (Spinacia oleracea) was developed and evaluated. The major impediment to achieving this performance was mistaking autofluorescing spinach particles for tagged target cells. Following a 5 h non-selective enrichment, artificially inoculated samples were photobleached, using phloxine B as a photosensitizer. Samples were centrifuged at high speed to concentrate target cells, then gradient centrifuged to separate them from matrix debris. In external laboratory experiments, RAPID-B and the reference method both correctly detected E. coli O157:H7 at inoculations of ca. 15 cells. In a follow-up study, after 4 cell inoculations of positives and 6 h enrichment, RAPID-B correctly identified 92% of 25 samples. The RAPID-B method limit of detection (LOD) was one cell in 25 g. It proved superior to the reference method (which incorporated real time-PCR, selective enrichment, and culture plating elements) in accuracy and speed.
Collapse
|
23
|
Sandrin TR, Goldstein JE, Schumaker S. MALDI TOF MS profiling of bacteria at the strain level: a review. MASS SPECTROMETRY REVIEWS 2013; 32:188-217. [PMID: 22996584 DOI: 10.1002/mas.21359] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 06/18/2012] [Accepted: 06/18/2012] [Indexed: 05/16/2023]
Abstract
Since the advent of the use of matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF MS) as a tool for microbial characterization, efforts to increase the taxonomic resolution of the approach have been made. The rapidity and efficacy of the approach have suggested applications in counter-bioterrorism, prevention of food contamination, and monitoring the spread of antibiotic-resistant bacteria. Strain-level resolution has been reported with diverse bacteria, using library-based and bioinformatics-enabled approaches. Three types of characterization at the strain level have been reported: strain categorization, strain differentiation, and strain identification. Efforts to enhance the library-based approach have involved sample pre-treatment and data reduction strategies. Bioinformatics approaches have leveraged the ever-increasing amount of publicly available genomic and proteomic data to attain strain-level characterization. Bioinformatics-enabled strategies have facilitated strain characterization via intact biomarker identification, bottom-up, and top-down approaches. Rigorous quantitative and advanced statistical analyses have fostered success at the strain level with both approaches. Library-based approaches can be limited by effects of sample preparation and culture conditions on reproducibility, whereas bioinformatics-enabled approaches are typically limited to bacteria, for which genetic and/or proteomic data are available. Biological molecules other than proteins produced in strain-specific manners, including lipids and lipopeptides, might represent other avenues by which strain-level resolution might be attained. Immunological and lectin-based chemistries have shown promise to enhance sensitivity and specificity. Whereas the limits of the taxonomic resolution of MALDI TOF MS profiling of bacteria appears bacterium-specific, recent data suggest that these limits might not yet have been reached.
Collapse
Affiliation(s)
- Todd R Sandrin
- School of Mathematical and Natural Sciences, Arizona State University, Phoenix, Arizona 85069, USA.
| | | | | |
Collapse
|