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2 pages, 161 KiB

Open AccessEditorial

The Special Issue: Transmission and Detection of Food and Environmental Pathogens

by Nigel Cook

Microorganisms 2021, 9(12), 2611; https://doi.org/10.3390/microorganisms9122611 - 17 Dec 2021

Viewed by 1450

Abstract

To progress towards a full comprehension of the risk caused by pathogenic microorganisms transmitted via food and environmental routes, extensive information on the prevalence, the mechanisms of contamination, and the survival of pathogens is required, particularly to assist with the development of effective [...] Read more.

To progress towards a full comprehension of the risk caused by pathogenic microorganisms transmitted via food and environmental routes, extensive information on the prevalence, the mechanisms of contamination, and the survival of pathogens is required, particularly to assist with the development of effective systems to reduce contamination, and to formulate procedural control measures, such as the implementation of food safety criteria [...] Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

Research

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10 pages, 955 KiB

Open AccessArticle

Detection of Infectious Cryptosporidium parvum Oocysts from Lamb’s Lettuce: CC–qPCR’s Intake

by Sophie Kubina, Damien Costa, Loïc Favennec, Gilles Gargala, Angélique Rousseau, Isabelle Villena, Stéphanie La Carbona and Romy Razakandrainibe

Microorganisms 2021, 9(2), 215; https://doi.org/10.3390/microorganisms9020215 - 21 Jan 2021

Cited by 5 | Viewed by 2047

Abstract

Cryptosporidium spp. is responsible for several food and waterborne disease outbreaks worldwide. Healthier lifestyles attract consumers to eat, notably, fresh food like fruits and vegetables. The consumption of raw or under-cooked food increases the risk of foodborne transmission of Cryptosporidiosis. The assessment of [...] Read more.

Cryptosporidium spp. is responsible for several food and waterborne disease outbreaks worldwide. Healthier lifestyles attract consumers to eat, notably, fresh food like fruits and vegetables. The consumption of raw or under-cooked food increases the risk of foodborne transmission of Cryptosporidiosis. The assessment of the consumer’s exposure to Cryptosporidium danger is crucial for public health. Still, the standardized method to detect this parasite in fresh leafy greens and berry fruits has only been available since 2016 and suffers from weaknesses. Consequently, in this study, we propose a method with minimum processing steps that combines cell culture and the quantitative PCR (CC–qPCR) for detecting infectious C. parvum oocysts recovered from lamb’s lettuce. This CC–qPCR is a rapid and easy method that can detect up to one oocyst, whereas it is undetectable by classic qPCR. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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14 pages, 1170 KiB

Open AccessArticle

Impacts of Wet Market Modernization Levels and Hygiene Practices on the Microbiome and Microbial Safety of Wooden Cutting Boards in Hong Kong

by Wing Yui Ngan, Subramanya Rao, Long Chung Chan, Patrick T. Sekoai, Yang Pu, Yuan Yao, Aster Hei Yiu Fung and Olivier Habimana

Microorganisms 2020, 8(12), 1941; https://doi.org/10.3390/microorganisms8121941 - 07 Dec 2020

Cited by 11 | Viewed by 6272

Abstract

Accessing food through wet markets is a common global daily occurrence, where fresh meat can be purchased to support an urbanizing world population. Similar to the wet markets in many other metropolitan cities in Asia, Hong Kong wet markets vary and are characterized [...] Read more.

Accessing food through wet markets is a common global daily occurrence, where fresh meat can be purchased to support an urbanizing world population. Similar to the wet markets in many other metropolitan cities in Asia, Hong Kong wet markets vary and are characterized by differing hygiene routines and access to essential modern technologies. The lack of risk assessments of food contact surfaces in these markets has led to substantial gaps in food safety knowledge and information that could help improve and maintain public health. Microbial profiling analyses were conducted on cutting boards that had been used to process pork, poultry, and seafood at 11 different wet markets. The markets differed in hygiene protocols and access to modern facilities. Irrespective of whether wet markets have access of modern infrastructure, the hygiene practices were largely found to be inefficient based on the prevalence of bacterial species typically associated with foodborne pathogens such as Campylobacter fetus, Clostridium perfringens, Staphylococcus aureus, and Vibrio parahaemolyticus; indicator organisms such as Escherichia coli; as well as nonfoodborne pathogenic bacterial species potentially associated with nosocomial infections, such as Klebsiella pneumoniae and Enterobacter cloacae. Other Vibrio species, V. parahaemolyticus and V. vulnificus, typically associated with contaminated raw or undercooked seafood with the potential to cause illness in humans, were also found on wooden cutting boards. This study indicated that the hygienic practices used in Hong Kong wet markets are not sufficient for preventing the establishment of spoilage or pathogenic organisms. This study serves as a basis to review current hygiene practices in wet markets and provides a framework to reassess existing safety protocols. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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14 pages, 653 KiB

Open AccessArticle

Prevalence and Antimicrobial Susceptibility of Indicator Organisms Escherichia coli and Enterococcus spp. Isolated from U.S. Animal Food, 2005–2011

by Beilei Ge, Kelly J. Domesle, Stuart A. Gaines, Claudia Lam, Sonya M. Bodeis Jones, Qianru Yang, Sherry L. Ayers and Patrick F. McDermott

Microorganisms 2020, 8(7), 1048; https://doi.org/10.3390/microorganisms8071048 - 15 Jul 2020

Cited by 10 | Viewed by 2554

Abstract

The role animal food plays in the introduction of antimicrobial-resistant bacteria into the human food chain is not well understood. We conducted an analysis of 1025 samples (647 pet food and 378 animal feed) collected across the United States during 2005–2011 for two [...] Read more.

The role animal food plays in the introduction of antimicrobial-resistant bacteria into the human food chain is not well understood. We conducted an analysis of 1025 samples (647 pet food and 378 animal feed) collected across the United States during 2005–2011 for two indicator organisms (Escherichia coli and Enterococcus spp.). The overall prevalence ranged from 12.5% for E. coli to 45.2% for Enterococcus spp., and 11.2% of samples harbored both organisms. Regardless of bacterial genus, animal feed had significantly higher prevalence than pet food (p < 0.001). A general downward trend in prevalence was observed from 2005 to 2009 followed by an upward trend thereafter. Among E. coli isolates (n = 241), resistance was highest to tetracycline (11.2%) and below 5% for fourteen other antimicrobials. Among Enterococcus spp. isolates (n = 1074), Enterococcus faecium (95.1%) was the predominant species. Resistance was most common to tetracycline (30.1%) and ciprofloxacin (10.7%), but below 10% for thirteen other antimicrobials. Multidrug-resistant organisms were observed among both E. coli and Enterococcus spp. isolates at 3.3%. Compared to National Antimicrobial Resistance Monitoring System (NARMS) 2011 retail meat and animal data, the overall resistance for both organisms was much lower in animal food. These findings help establish a historic baseline for the prevalence and antimicrobial resistance among U.S. animal food products and future efforts may be needed to monitor changes over time. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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13 pages, 3221 KiB

Open AccessArticle

Metagenomic Analysis of Regularly Microwave-Treated and Untreated Domestic Kitchen Sponges

by Susanne Jacksch, Jyothi Thota, Sudarshan Shetty, Hauke Smidt, Sylvia Schnell and Markus Egert

Microorganisms 2020, 8(5), 736; https://doi.org/10.3390/microorganisms8050736 - 14 May 2020

Cited by 10 | Viewed by 8316

Abstract

Kitchen sponges massively absorb and spread microorganisms, leading to contamination of kitchen appliances, surfaces, and food. Microwaving as an effective and widespread technique can rapidly reduce the microbial load of kitchen sponges. However, long-term effects of such treatments are largely unknown. Notably, it [...] Read more.

Kitchen sponges massively absorb and spread microorganisms, leading to contamination of kitchen appliances, surfaces, and food. Microwaving as an effective and widespread technique can rapidly reduce the microbial load of kitchen sponges. However, long-term effects of such treatments are largely unknown. Notably, it has been speculated that regularly applied domestic cleaning and disinfection may select for microbial communities with a higher pathogenic potential and/or malodorous properties. In this study, we distributed newly purchased polyurethane kitchen sponges to 20 participants, with the instruction to use them under normal household conditions for four weeks. Ten of the participants sanitized their sponges regularly by a standardized microwaving protocol, while the remaining ten sponges remained untreated. Metagenomic sequence data evaluation indicated that, in addition to bacteria, viruses, eukaryotes, and archaea were also part of the kitchen sponge microbiome. Comparisons of sanitized and untreated kitchen sponges indicated a trend towards a reduced structural microbial diversity while functional diversity increased. Microwave sanitization appeared to alter composition and metabolic properties of the microbial communities. Follow-up studies will have to show whether these changes are more positive or negative in terms of domestic hygiene, human health, and well-being. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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10 pages, 1507 KiB

Open AccessArticle

The Response to Oxidative Stress in Listeria monocytogenes Is Temperature Dependent

by Beatriz Manso, Beatriz Melero, Beatrix Stessl, Isabel Jaime, Martin Wagner, Jordi Rovira and David Rodríguez-Lázaro

Microorganisms 2020, 8(4), 521; https://doi.org/10.3390/microorganisms8040521 - 05 Apr 2020

Cited by 18 | Viewed by 3005

Abstract

The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood [...] Read more.

The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood company) and sample types (floor, wall, drain, boxes, food products and water machine). Isolates were exposed to two oxidizing agents: 13.8 mM cumene hydroperoxide (CHP) and 100 mM hydrogen peroxide (H₂O₂) at 10 °C and 37 °C. Temperature affected the oxidative stress response as cells treated at 10 °C survived better than those treated at 37 °C. H₂O₂ at 37 °C was the condition tested resulting in poorest L. monocytogenes survival. Strains belonging to STs of Lineage I (ST5, ST6, ST87, ST1) were more resistant to oxidative stress than those of Lineage II (ST7, ST9, ST199 and ST321), with the exception of ST7 that showed tolerance to H₂O₂ at 10 °C. Isolates of each ST5 and ST9 from different food industry origins showed differences in oxidative stress response. The gene expression of two relevant virulence (hly) and stress (clpC) genes was studied in representative isolates in the stressful conditions. hly and clpC were upregulated during oxidative stress at low temperature. Our results indicate that conditions prevalent in food industries may allow L. monocytogenes to develop survival strategies: these include activating molecular mechanisms based on cross protection that can promote virulence, possibly increasing the risk of virulent strains persisting in food processing plants. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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10 pages, 1031 KiB

Open AccessArticle

Occurrence, Diversity of Listeria spp. Isolates from Food and Food-Contact Surfaces and the Presence of Virulence Genes

by Franca Rossi, Carmela Amadoro, Daniele Conficoni, Valerio Giaccone and Giampaolo Colavita

Microorganisms 2020, 8(2), 294; https://doi.org/10.3390/microorganisms8020294 - 20 Feb 2020

Cited by 7 | Viewed by 2554

Abstract

This study evaluates the hazards posed by foodborne bacteria of the Listeria genus by analyzing the occurrence, diversity and virulence of Listeria spp.in food and food-manufacturing plants. Seventy-five isolates obtained from the routine analysis of 653 samples taken by three diagnostic laboratories in [...] Read more.

This study evaluates the hazards posed by foodborne bacteria of the Listeria genus by analyzing the occurrence, diversity and virulence of Listeria spp.in food and food-manufacturing plants. Seventy-five isolates obtained from the routine analysis of 653 samples taken by three diagnostic laboratories in Northern Italy were genotypically differentiated by Repetitive Extragenic Palindrome (rep) PCR, with the GTG5 primer identified by sequencing the 16S rRNA gene and examined by specific PCR tests for the presence of L. monocytogenes virulence determinants occasionally found to occur in other species of the genus. Within this sample, 76% (n = 57) isolates were identified as L. innocua, 16% (n = 12) as L. monocytogenes, 6.6% (n = 5) as L. welshimeri and 1.3% (n = 1) as L. seeligeri. All L. monocytogenes isolates belonged to the serotype 1/2a and were predicted to be virulent for the presence of the inlJ internalin gene. Potentially virulent strains of L. innocua, L. seeligeri and L. welshimeri, carrying the L. monocytogenesinlA gene and/or hly gene, were identified, and most isolates were found to possess the toxin–antitoxin system mazEF for efficient adaptation to heat shock. Results indicated the need to reinforce food-contamination-prevention measures against all Listeria species by defining efficiently their environmental distribution. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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17 pages, 1222 KiB

Open AccessArticle

Predominance of Distinct Listeria Innocua and Listeria Monocytogenes in Recurrent Contamination Events at Dairy Processing Facilities

by Irene Kaszoni-Rückerl, Azra Mustedanagic, Sonja Muri-Klinger, Katharina Brugger, Karl-Heinz Wagner, Martin Wagner and Beatrix Stessl

Microorganisms 2020, 8(2), 234; https://doi.org/10.3390/microorganisms8020234 - 10 Feb 2020

Cited by 26 | Viewed by 4384

Abstract

The genus Listeria now comprises up to now 21 recognized species and six subspecies, with L. monocytogenes and L. innocua as the most prevalent sensu stricto associated species. Reports focusing on the challenges in Listeria detection and confirmation are available, especially from food-associated [...] Read more.

The genus Listeria now comprises up to now 21 recognized species and six subspecies, with L. monocytogenes and L. innocua as the most prevalent sensu stricto associated species. Reports focusing on the challenges in Listeria detection and confirmation are available, especially from food-associated environmental samples. L. innocua is more prevalent in the food processing environment (FPE) than L. monocytogenes and has been shown to have a growth advantage in selective enrichment and agar media. Until now, the adaptive nature of L. innocua in FPEs has not been fully elucidated and potential persistence in the FPE has not been observed. Therefore, the aim of this study is to characterize L. innocua (n = 139) and L. monocytogenes (n = 81) isolated from FPEs and cheese products collected at five dairy processing facilities (A–E) at geno- and phenotypic levels. Biochemical profiling was conducted for all L. monocytogenes and the majority of L. innocua (n = 124) isolates and included a rhamnose positive reaction. L. monocytogenes isolates were most frequently confirmed as PCR-serogroups 1/2a, 3a (95%). Pulsed-field gel electrophoresis (PFGE)-typing, applying the restriction enzymes AscI, revealed 33 distinct Listeria PFGE profiles with a Simpson’s Index of Diversity of 0.75. Multi-locus sequence typing (MLST) resulted in 27 STs with seven new L. innocua local STs (ST1595 to ST1601). L. innocua ST1597 and ST603 and L. monocytogenes ST121 and ST14 were the most abundant genotypes in dairy processing facilities A–E over time. Either SSI-1 (ST14) or SSI-2 (ST121, all L. innocua) were present in successfully FPE-adapted strains. We identified housekeeping genes common in Listeria isolates and L. monocytogenes genetic lineage III. Wherever there are long-term contamination events of L. monocytogenes and other Listeria species, subtyping methods are helpful tools to identify niches of high risk. Full article

(This article belongs to the Special Issue Transmission and Detection of Food and Environmental Pathogens)

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