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Jeong S, Kim I, Kim BE, Jeong MI, Oh KK, Cho GS, Franz CMAP. Identification and Characterization of Antibiotic-Resistant, Gram-Negative Bacteria Isolated from Korean Fresh Produce and Agricultural Environment. Microorganisms 2023; 11:1241. [PMID: 37317216 DOI: 10.3390/microorganisms11051241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 06/16/2023] Open
Abstract
The consumption of fresh produce and fruits has increased over the last few years as a result of increasing consumer awareness of healthy lifestyles. Several studies have shown that fresh produces and fruits could be potential sources of human pathogens and antibiotic-resistant bacteria. In this study, 248 strains were isolated from lettuce and surrounding soil samples, and 202 single isolates selected by the random amplified polymorphic DNA (RAPD) fingerprinting method were further characterized. From 202 strains, 184 (91.2%) could be identified based on 16S rRNA gene sequencing, while 18 isolates (8.9%) could not be unequivocally identified. A total of 133 (69.3%) and 105 (54.7%) strains showed a resistance phenotype to ampicillin and cefoxitin, respectively, while resistance to gentamicin, tobramycin, ciprofloxacin, and tetracycline occurred only at low incidences. A closer investigation of selected strains by whole genome sequencing showed that seven of the fifteen sequenced strains did not possess any genes related to acquired antibiotic resistance. In addition, only one strain possessed potentially transferable antibiotic resistance genes together with plasmid-related sequences. Therefore, this study indicates that there is a low possibility of transferring antibiotic resistance by potential pathogenic enterobacteria via fresh produce in Korea. However, with regards to public health and consumer safety, fresh produce should nevertheless be continuously monitored to detect the occurrence of foodborne pathogens and to hinder the transfer of antibiotic resistance genes potentially present in these bacteria.
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Affiliation(s)
- Sunyoung Jeong
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
- College of Life Sciences and Biotechnology, Korea University, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Ile Kim
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
- Department of Life Science, Handong Global University, 558 Handong-ro, Buk-gu, Pohang 37554, Republic of Korea
| | - Bo-Eun Kim
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju 55365, Republic of Korea
| | - Myeong-In Jeong
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju 55365, Republic of Korea
| | - Kwang-Kyo Oh
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju 55365, Republic of Korea
| | - Gyu-Sung Cho
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
| | - Charles M A P Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
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Characterization of antibiotic-resistant, coagulase-negative staphylococci from fresh produce and description of Staphylococcus shinii sp. nov. isolated from chives. J Microbiol 2022; 60:877-889. [DOI: 10.1007/s12275-022-2100-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 10/17/2022]
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Effect of Processing Treatment and Modified Atmosphere Packing on Carrot's Microbial Community Structure by Illumina MiSeq Sequencing. Molecules 2022; 27:molecules27092830. [PMID: 35566181 PMCID: PMC9103152 DOI: 10.3390/molecules27092830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 11/28/2022] Open
Abstract
The aim of this study was to analyze the microbiome of carrot (Daucus carota subsp. sativus) subjected to minimal pre-treatment (rinsing in organic acid solution) and packaging in a high-oxygen modified atmosphere, and then stored for 17 days under refrigeration conditions (4 °C). The highest levels of bacteria in the carrot microbiome were characterized, at almost 78%, by bacteria belonging to the Enterobacteriaceae and Pseudomonadaceae families. Rinsing in a solution of ascorbic and citric acids resulted in the improvement of microbiological quality in the first day of storage. However, the use of a high-oxygen modified atmosphere extended the shelf life of the minimally processed product. Compared to carrots stored in air, those stored in high oxygen concentration were characterized by a greater ratio of bacteria belonging to the Serratia and Enterobacter genera, and a lower ratio belonging to the Pseudomonas and Pantoea genera. Moreover, the β-biodiversity analysis confirmed that the oxygen concentration was the main factor influencing the differentiation of the metabiomes of the stored carrots. The bacterial strains isolated from carrots identified by molecular methods were mostly pathogenic or potentially pathogenic microorganisms. Neither the minimal pre-treatment nor packaging in high-oxygen atmosphere was able to eliminate the threat of pathogenic bacteria emerging in the product.
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De Bock T, Zhao X, Jacxsens L, Devlieghere F, Rajkovic A, Spanoghe P, Höfte M, Uyttendaele M. Evaluation of B. thuringiensis-based biopesticides in the primary production of fresh produce as a food safety hazard and risk. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bozkurt H, Bell T, van Ogtrop F, Phan-Thien KY, McConchie R. Assessment of microbial risk during Australian industrial practices for Escherichia coli O157:H7 in fresh cut-cos lettuce: A stochastic quantitative approach. Food Microbiol 2021; 95:103691. [PMID: 33397620 DOI: 10.1016/j.fm.2020.103691] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 11/21/2022]
Abstract
Escherichia coli O157:H7 risk associated with the consumption of fresh cut-cos lettuce during Australian industrial practices was assessed. A probabilistic risk assessment model was developed and implemented in the @Risk software by using the Monte Carlo simulation technique with 1,000,000 iterations. Australian preharvest practices yielded predicted annual mean E. coli O157:H7 levels from 0.2 to -3.4 log CFU/g and prevalence values ranged from 2 to 6.4%. While exclusion of solar radiation from the baseline model yielded a significant increase in concentration of E. coli O157:H7 (-5.2 -log fold), drip irrigation usage, exclusion of manure amended soil and rainfall reduced E. coli O157:H7 levels by 7.4, 6.5, and 4.3-log fold, respectively. The microbial quality of irrigation water and irrigation type both had a significant effect on E. coli O157:H7 concentrations at harvest (p < 0.05). The probability of illness due to consumption of E. coli O157:H7 contaminated fresh cut-cos lettuce when water washing interventions were introduced into the processing module, was reduced by 1.4-2.7-log fold (p < 0.05). This study provides a robust basis for assessment of risk associated with E. coli O157:H7 contamination on fresh cut-cos lettuce for industrial practices and will assist the leafy green industry and food safety authorities in Australia to identify potential risk management strategies.
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Affiliation(s)
- Hayriye Bozkurt
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia.
| | - Tina Bell
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Floris van Ogtrop
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Kim-Yen Phan-Thien
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
| | - Robyn McConchie
- ARC Industrial Transformation Training Centre for Food Safety in the Fresh Produce Industry, Sydney Institute of Agriculture, Faculty of Science, The University of Sydney, NSW, 2006, Australia
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Cho GS, Stein M, Fiedler G, Igbinosa EO, Koll LP, Brinks E, Rathje J, Neve H, Franz CMAP. Polyphasic study of antibiotic-resistant enterobacteria isolated from fresh produce in Germany and description of Enterobacter vonholyi sp. nov. isolated from marjoram and Enterobacter dykesii sp. nov. isolated from mung bean sprout. Syst Appl Microbiol 2020; 44:126174. [PMID: 33370657 DOI: 10.1016/j.syapm.2020.126174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 11/29/2022]
Abstract
Forty-two antibiotic-resistant enterobacteria strains were isolated from fresh produce obtained from the northern German retail market. A polyphasic characterization based on both phenotypic and genotypic methods was used to identify predominant strains as Citrobacter (C.) gillenii, C. portucalensis, Enterobacter (En.) ludwigii, Escherichia (E.) coli and Klebsiella (K.) pneumoniae. 38.1% of the enterobacteria strains were resistant to tetracycline, while 23.8% and 9.5% of strains were resistant to streptomycin and chloramphenicol, respectively. A high percentage of Klebsiella (100%), Enterobacter (57.1%) and Citrobacter (42.9%) strains were also resistant to ampicillin, with some strains showing multiple resistances. For unequivocal species identification, the genomes of thirty strains were sequenced. Multilocus sequence analysis, average nucleotide identity and digital DNA-DNA hybridization showed that Enterobacter strains E1 and E13 were clearly clustered apart from Enterobacter species type strains below the species delineation cutoff values. Thus, strains E1T (=DSM 111347T, LMG 31875T) represents a novel species proposed as Enterobacter dykesii sp. nov., while strain E13T (=DSM 110788T, LMG 31764T) represent a novel species proposed as Enterobacter vonholyi sp. nov. Strains often possessed different serine β-lactamase genes, tet(A) and tet(D) tetracycline resistance genes and other acquired antibiotic resistance genes. Typical plasmid replicon types were determined. This study thus accurately identified the enterobacteria from fresh produce as species belonging to the genera Citrobacter, Enterobacter, Escherichia and Klebsiella, but also showed that these can carry potentially transferable antibiotic resistance genes and may thus contribute to the spread of these via the food route.
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Affiliation(s)
- Gyu-Sung Cho
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Maria Stein
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Gregor Fiedler
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Etinosa O Igbinosa
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany; Department of Microbiology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria
| | - Linnéa Philine Koll
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Erik Brinks
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Jana Rathje
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany
| | - Charles M A P Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut Kiel, Hermann-Weigmann-Str. 1, 24103 Kiel, Germany.
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Complete Genome Sequence of a Shiga Toxin-Producing Escherichia coli O26:H11 Strain (Sequence Type 21) and Two Draft Genome Sequences of Listeria monocytogenes Strains (Clonal Complex 1 [CC1] and CC59) Isolated from Fresh Produce in Germany. Microbiol Resour Announc 2020; 9:9/49/e00973-20. [PMID: 33272986 PMCID: PMC7714840 DOI: 10.1128/mra.00973-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The complete genome sequence of a Shiga toxin-producing Escherichia coli (STEC) O26:H11 strain, MBT-5 (sequence type 21 [ST21], stx1a, stx2a, eae, ehxA), and two draft genome sequences of Listeria monocytogenes strains MBT-6 and MBT-7 belonging to the virulent sequence types 1 (ST1, clonal complex 1 [CC1]) and 59 (ST59, CC59), respectively, were determined. The strains were isolated in 2015 from ready-to-eat mixed greens in Germany. The complete genome sequence of a Shiga toxin-producing Escherichia coli (STEC) O26:H11 strain, MBT-5 (sequence type 21 [ST21], stx1a, stx2a, eae, ehxA), and two draft genome sequences of Listeria monocytogenes strains MBT-6 and MBT-7 belonging to the virulent sequence types 1 (ST1, clonal complex 1 [CC1]) and 59 (ST59, CC59), respectively, were determined. The strains were isolated in 2015 from ready-to-eat mixed greens in Germany.
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Arienzo A, Murgia L, Fraudentali I, Gallo V, Angelini R, Antonini G. Microbiological Quality of Ready-to-Eat Leafy Green Salads during Shelf-Life and Home-Refrigeration. Foods 2020; 9:foods9101421. [PMID: 33049952 PMCID: PMC7601731 DOI: 10.3390/foods9101421] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 11/23/2022] Open
Abstract
The market of ready-to-eat leafy green salads is experiencing a noticeable growth in Europe. Since they are intended to be consumed without additional treatments, these ready-to-eat products are associated with a high microbiological risk. The aim of this work was to evaluate the microbiological quality and safety of ready-to-eat leafy green salads sold in widespread supermarket chains in Lazio, Italy, on the packaging date during shelf-life and during home-refrigeration. The study also aimed to determine the differences between low-, medium-, and high-cost products. Salmonella spp. and L. monocytogenes were chosen as safety indicators as specified by European regulations while total aerobic mesophilic bacteria and Escherichia coli were chosen as quality indicators as suggested by national guidelines. Analyses were performed following the ISO standards and in parallel for the evaluation of total aerobic mesophilic bacteria, with an alternative colorimetric system, the Micro Biological Survey method, in order to propose a simple, affordable and accurate alternative for testing the microbiological quality of products, especially suitable for small and medium enterprises and on-site analyses. The study revealed high, unsatisfactory, total bacterial loads in all analyzed samples on the packaging date and expiry date and a very high prevalence of Salmonella spp. (67%) regardless of the selected varieties and cost categories; L. monocytogenes was not recovered aligning with the results obtained in other studies.
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Affiliation(s)
- Alyexandra Arienzo
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, 00146 Rome, Italy; (A.A.); (I.F.); (R.A.)
| | - Lorenza Murgia
- Interuniversity Consortium INBB National Institute of Biostructures and Biosystems, Viale delle Medaglie d’Oro, 305, 00136 Rome, Italy; (L.M.); (V.G.)
| | - Ilaria Fraudentali
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, 00146 Rome, Italy; (A.A.); (I.F.); (R.A.)
| | - Valentina Gallo
- Interuniversity Consortium INBB National Institute of Biostructures and Biosystems, Viale delle Medaglie d’Oro, 305, 00136 Rome, Italy; (L.M.); (V.G.)
| | - Riccardo Angelini
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, 00146 Rome, Italy; (A.A.); (I.F.); (R.A.)
| | - Giovanni Antonini
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, 00146 Rome, Italy; (A.A.); (I.F.); (R.A.)
- Interuniversity Consortium INBB National Institute of Biostructures and Biosystems, Viale delle Medaglie d’Oro, 305, 00136 Rome, Italy; (L.M.); (V.G.)
- Correspondence:
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Microbiological safety of ready-to-eat fresh-cut fruits and vegetables sold on the Canadian retail market. Int J Food Microbiol 2020; 335:108855. [PMID: 32949906 DOI: 10.1016/j.ijfoodmicro.2020.108855] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 12/21/2022]
Abstract
Following implementation of Health Canada's Policy on Listeria monocytogenes in Ready-to-Eat Foods by Canadian food safety authorities in 2011, a four-year study (2012-2016) was carried out to gain baseline information on the occurrence of bacterial pathogens, notably the prevalence and levels of Listeria monocytogenes (L. monocytogenes) in various product types of ready-to-eat (RTE) fresh-cut fruits and fresh-cut vegetables sold at retail in Canada. A total of 10,070 pre-packaged samples, including 4691 fresh-cut fruit and 5379 fresh-cut vegetable samples were collected from retail stores across Canada and analyzed for bacterial pathogens and generic Escherichia coli (E. coli). Salmonella species (spp.), E. coli O157:H7, Shigella and Campylobacter were not detected in any of the tested samples. L. monocytogenes was identified in 0.51% (95% CI [0.34, 0.76]) of the fresh-cut fruit and in 0.24% (95% CI [0.14, 0.41]) of the fresh-cut vegetable samples. Of the 37 L. monocytogenes positive samples identified, levels of L. monocytogenes <5 CFU/g, 5-<100 CFU/g, and ≥100 CFU/g were found in 67.6% (25/37), 24.3% (9/37) and 8.1% (3/37) of the samples, respectively. The results of this study indicate that the vast majority of fresh-cut fruits and vegetables sold on the Canadian retail market are safe for consumption. However, contamination by L. monocytogenes can infrequently occur in fresh-cut fruits and vegetables, with certain types of fresh-cut fruits (i.e., melons, apples) and vegetables (i.e., mushrooms, cauliflower) being more likely to be contaminated than others. Safe handling practices are recommended for producers, retailers and consumers including storage at refrigerated temperatures.
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de Oliveira Elias S, Noronha TB, Tondo EC. Salmonella spp. and Escherichia coli O157:H7 prevalence and levels on lettuce: A systematic review and meta-analysis. Food Microbiol 2019; 84:103217. [PMID: 31421760 DOI: 10.1016/j.fm.2019.05.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 04/17/2019] [Accepted: 05/01/2019] [Indexed: 11/15/2022]
Abstract
Lettuce (Lactuca sativa), one of the most consumed leafy vegetables in the world, is frequently implicated with foodborne disease (FBD) outbreaks, with Salmonella spp. and Escherichia coli O157:H7 being the most common bacteria to cause this illness. Estimates of prevalence and levels of these pathogens on lettuce are scarce in developed or in developing countries, which hinders risk assessment attempts. In here, we present a systematic review and meta-analysis of reported prevalence and levels of Salmonella spp. and E. coli O157:H7 on lettuce using the worldwide available data. Literature was reviewed and examined the results for inclusion of articles in the meta-analysis. Data (prevalence and/or concentration of Salmonella spp. and E. coli O157:H7 on lettuce, sample characteristic, country of origin, and Salmonella identified serovars) were extracted, and meta-analysis was performed using Open Meta-Analyst, Task Order # 2 software. Although only one work reported the presence of E coli O157:H7 on lettuce, several reports indicated the presence of other, distinct enterohemorrhagic E. coli (EHEC) strains, with a mean prevalence of 0.041 (95% CI: 0.005-0.078) and concentration varying from <3.0 MPN/g to >1100 MPN/g. Furthermore, the mean prevalence of Salmonella spp. on lettuce was 0.041 (95% CI: 0.030-0.052), with reported concentrations varying between 0.054 ± 0.058 CFU/g to 218.78 MPN/g. In addition, subgroup analysis of the presence of Salmonella spp. in lettuce revealed a mean prevalence of the bacteria of 0.028 (95% CI: 0.014-0.042) in developed nations and 0.064 (0.041-0.087) in developing nations, with reports varying from 0.001 in Japan to 0.5 in Burkina Faso. Despite a relatively low prevalence, consumption of lettuce is inherently risky because it usually is eaten raw, without thermal treatment to inactivate pathogens. This potential risk further supports performance of quantitative risk assessments to quantify the probability of FBD caused by Salmonella spp. and E. coli O157:H7 transmitted to lettuce.
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Affiliation(s)
- Susana de Oliveira Elias
- Departamento de Ciências dos Alimentos - Universidade Federal do Rio Grande do Sul, Instituto de Ciência e Tecnologia de Alimentos, Av. Bento Gonçalves, 9500 Prédio 43212 Agronomia, CEP: 91505-970, Porto Alegre, RS, Brazil.
| | - Tiago Baptista Noronha
- Departamento de Ensino, Pesquisa e Extensão - Instituto Federal de Educação, Ciência e Tecnologia Sul-rio-grandense, Rua General Balbão, 81, CEP 96745-000, Charqueadas, RS, Brazil.
| | - Eduardo Cesar Tondo
- Departamento de Ciências dos Alimentos - Universidade Federal do Rio Grande do Sul, Instituto de Ciência e Tecnologia de Alimentos, Av. Bento Gonçalves, 9500 Prédio 43212 Agronomia, CEP: 91505-970, Porto Alegre, RS, Brazil.
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Saksena R, Malik M, Gaind R. Bacterial contamination and prevalence of antimicrobial resistance phenotypes in raw fruits and vegetables sold in Delhi, India. J Food Saf 2019. [DOI: 10.1111/jfs.12739] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rushika Saksena
- Department of MicrobiologyVardhman Mahavir Medical College and Safdarjung Hospital New Delhi India
| | - Manika Malik
- Department of MicrobiologyVardhman Mahavir Medical College and Safdarjung Hospital New Delhi India
| | - Rajni Gaind
- Department of MicrobiologyVardhman Mahavir Medical College and Safdarjung Hospital New Delhi India
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Fiedler G, Schneider C, Igbinosa EO, Kabisch J, Brinks E, Becker B, Stoll DA, Cho GS, Huch M, Franz CMAP. Antibiotics resistance and toxin profiles of Bacillus cereus-group isolates from fresh vegetables from German retail markets. BMC Microbiol 2019; 19:250. [PMID: 31706266 PMCID: PMC6842220 DOI: 10.1186/s12866-019-1632-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 10/29/2019] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND This study aimed to evaluate the safety of raw vegetable products present on the German market regarding toxin-producing Bacillus cereus sensu lato (s.l.) group bacteria. RESULTS A total of 147 B. cereus s.l. group strains isolated from cucumbers, carrots, herbs, salad leaves and ready-to-eat mixed salad leaves were analyzed. Their toxinogenic potential was assessed by multiplex PCR targeting the hemolysin BL (hbl) component D (hblD), non-hemolytic enterotoxin (nhe) component A (nheA), cytotoxin K-2 (cytK-2) and the cereulide (ces) toxin genes. In addition, a serological test was used to detect Hbl and Nhe toxins. On the basis of PCR and serological results, none of the strains were positive for the cereulide protein/genes, while 91.2, 83.0 and 37.4% were positive for the Hbl, Nhe and CytK toxins or their genes, respectively. Numerous strains produced multiple toxins. Generally, strains showed resistance against the β-lactam antibiotics such as penicillin G and cefotaxim (100%), as well as amoxicillin/clavulanic acid combination and ampicillin (99.3%). Most strains were susceptible to ciprofloxacin (99.3%), chloramphenicol (98.6%), amikacin (98.0%), imipenem (93.9%), erythromycin (91.8%), gentamicin (88.4%), tetracycline (76.2%) and trimethoprim/sulfamethoxazole combination (52.4%). The genomes of eight selected strains were sequenced. The toxin gene profiles detected by PCR and serological test mostly agreed with those from whole-genome sequence data. CONCLUSIONS Our study showed that B. cereus s.l. strains encoding toxin genes occur in products sold on the German market and that these may pose a health risk to the consumer if present at elevated levels. Furthermore, a small percentage of these strains harbor antibiotic resistance genes. The presence of these bacteria in fresh produce should, therefore, be monitored to guarantee their safety.
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Affiliation(s)
- Gregor Fiedler
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
| | - Carmen Schneider
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany
| | - Etinosa O. Igbinosa
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
- Present Address: Department of Microbiology, Faculty of Life Sciences, University of Benin, Private Mail Bag 1154, Benin City, 30001 Nigeria
| | - Jan Kabisch
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
| | - Erik Brinks
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
| | - Biserka Becker
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany
| | - Dominic A. Stoll
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany
| | - Gyu-Sung Cho
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
| | - Melanie Huch
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany
| | - Charles M. A. P. Franz
- Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103 Kiel, Germany
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Assessment of the non-lactic acid bacteria microbiota in fresh cucumbers and commercially fermented cucumber pickles brined with 6% NaCl. Food Microbiol 2019; 77:10-20. [DOI: 10.1016/j.fm.2018.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 11/18/2022]
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Becker B, Stoll D, Schulz P, Kulling S, Huch M. Microbial Contamination of Organically and Conventionally Produced Fresh Vegetable Salads and Herbs from Retail Markets in Southwest Germany. Foodborne Pathog Dis 2018; 16:269-275. [PMID: 30484714 DOI: 10.1089/fpd.2018.2541] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A total of 189 samples of fresh products (leafy salads, ready-to-eat mixed salads, and fresh herbs) bought in retail in Southwest Germany were investigated for their microbiological quality and the presence of pathogenic bacteria, including Salmonella spp., Listeria monocytogenes, and presumptive Bacillus cereus. Total aerobic mesophilic plate counts (TAC) ranged from 5.5 to 9.6 log colony-forming units (CFUs) per gram. Enterobacteria and pseudomonads were the predominant microorganisms and were detected in all samples with counts between 5.0 and 9.2 log CFU/g. Strains of Escherichia coli were detected in 9 salad (7.9%) and 25 herb samples (33.3%). Significant differences in bacterial counts were found between conventionally and organically-grown products: in herbs the counts of moulds were significantly higher in organically-grown products, while E. coli was only detected in conventionally-grown products. In conventionally-grown salad samples, yeast counts were significantly higher. Salmonella Enteritidis was only detected in two conventionally- and in one organically-produced salad samples (2.6%). No coagulase-positive staphylococci were detected in fresh salads as well as in herbs. High levels of B. cereus sensu lato (≥3 log CFU/g) were detected in 19 vegetable salads (16.7%) and even in 55 samples of fresh herbs (73.3%). Listeria monocytogenes could not be detected in fresh herbs; however, three L. monocytogenes strains were isolated from two conventionally-produced salad samples and belonged to PCR serogroup IIa. Although our results indicate a high microbial load in fresh salads and herbs in Southwest Germany in 2015, the incidences of human pathogenic bacteria, that is, L. monocytogenes, Salmonella spp., and coagulase-positive staphylococci strains, were low.
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Affiliation(s)
- Biserka Becker
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Karlsruhe, Germany
| | - Dominic Stoll
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Karlsruhe, Germany
| | - Patrick Schulz
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Karlsruhe, Germany
| | - Sabine Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Karlsruhe, Germany
| | - Melanie Huch
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food , Karlsruhe, Germany
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