Category Archives: Microbiology

Research – Microbiological Food Safety of Seaweeds

Posted on November 14, 2021 by | Leave a comment

MDPI

The use of seaweeds in the human diet has a long history in Asia and has now been increasing also in the western world. Concurrent with this trend, there is a corresponding increase in cultivation and harvesting for commercial production. Edible seaweed is a heterogenous product category including species within the green, red, and brown macroalgae. Moreover, the species are utilized on their own or in combinatorial food products, eaten fresh or processed by a variety of technologies. The present review summarizes available literature with respect to microbiological food safety and quality of seaweed food products, including processing and other factors controlling these parameters, and emerging trends to improve on the safety, utilization, quality, and storability of seaweeds. The over- or misuse of antimicrobials and the concurrent development of antimicrobial resistance (AMR) in bacteria is a current worldwide health concern. The role of seaweeds in the development of AMR and the spread of antimicrobial resistance genes is an underexplored field of research and is discussed in that context. Legislation and guidelines relevant to edible seaweed are also discussed. View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – First report on the molecular characterization and the occurrence of extended-spectrum β-lactamase producing Enterobacteriaceae in unpasteurized bovine’s buttermilk

Posted on November 13, 2021 by | Leave a comment

Wiley Online

The dairy products have been reported as a source of extended-spectrum β-lactamase (ESBL)-producing bacteria. The aim of this study is to determine the potential transfer of ESBL Enterobacteriaceae to humans due to the consumption of buttermilk made from raw, unpasteurized milk collected in Batna province (Northeast of Algeria) as well as to identify isolates and genes encoding resistance in these isolates. Two hundred and forty-three samples of buttermilk made from raw, unpasteurized milk were collected and screened for the presence of ceftazidime-resistant Enterobacteriaceae. The suspected isolates were identified by molecular methods. Enterobacteriaceae isolates were subjected to antimicrobial susceptibility testing and were examined phenotypically for ESBL production and confirmed by using PCR assay and DNA sequencing. Thirteen ceftazidime-resistant Enterobacteriaceae were observed at a rate of 5.76% including Escherichia coli (n = 4), Klebsiella pneumoniae (n = 4), Klebsiella oxytoca (n = 1), Hafnia paralvei (n = 3), and Citrobacter freundii (n = 1). Eight Enterobacteriaceae (61.53%, 8) revealed multidrug resistance, while (61.53%, 8) were confirmed as ESBL-producing Enterobacteriaceae. Polymerase chain reaction assay revealed that blaTEM (87.5%, 7) was the most common gene, followed by the blaCTX-M gene (75%, 6) and finally the blaSHV gene (50%, 4). The sequencing of genes identified blaTEM-1D, blaSHV-1, and blaSHV-11. Our findings signified that buttermilk made from raw, unpasteurized milk could be the reservoir for the prevalence of ESBL-producing Enterobacteriaceae and the potential source of transmission for the consumer. Pasteurization of buttermilk is critical to reduce the risk associated with ESBL-producing isolates.

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Posted in Decontamination Microbial, Enterobacteriaceae, ESBL, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Attachment of Shiga Toxin-Producing Escherichia coli (STEC) to Pre-Chill and Post-Chill Beef Brisket Tissue

Posted on November 13, 2021 by | Leave a comment

MDPI

Shiga toxin-producing Escherichia coli (STEC) has caused numerous foodborne illness outbreaks where beef was implicated as the contaminated food source. Understanding how STEC attach to beef surfaces may inform effective intervention applications at the abattoir. This simulated meat processing conditions to measure STEC attachment to adipose and lean beef tissue. Beef brisket samples were warmed to a surface temperature of 30 °C (warm carcass), while the remaining samples were maintained at 4 °C (cold carcass), prior to surface inoculation with an STEC cocktail (O26, O45, O103, O111, O121, O145, and O157:H7). Cocktails were grown in either tryptic soy broth (TSB) or M9 minimal nutrient medium. Loosely and firmly attached cells were measured at 0, 3, 5, and 20 min and 1, 3, 8, 12, 24 and 48 h. TSB-grown STEC cells became more firmly attached throughout storage and a difference in loosely versus firmly attached populations on lean and adipose tissues was observed. M9-grown STEC demonstrated a 0.2 log10 CFU/cm2 difference in attachment to lean versus adipose tissue and variability in populations was recorded throughout sampling. Future research should investigate whether a decrease in intervention efficacy correlates to an increase in firmly attached STEC cells on chilled carcasses and/or subprimals, which has been reported. View Full-Text

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Posted in E.coli, E.coli O103, E.coli O111, E.coli O145, E.coli O157, E.coli O157:H7, E.coli O26, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, O45, Research, STEC, STEC E.coli

Research – Case Study on the Microbiological Quality, Chemical and Sensorial Profiles of Different Dairy Creams and Ricotta Cheese during Shelf-Life

Posted on November 13, 2021 by | Leave a comment

MDPI

This work investigated the microbiological quality and chemical profiles of two different dairy creams obtained by centrifugation vs. natural creaming separation systems. To this aim, an untargeted metabolomics approach based on UHPLC-QTOF mass spectrometry was used in combination with multivariate statistical tools to find potential marker compounds of the two different types of two dairy creams. Thereafter, we evaluated the chemical, microbiological and sensorial changes of a ricotta cheese made with a 30% milk cream (i.e., made by combining dairy creams from centrifugation and natural creaming separation) during its shelf-life period (12 days). Overall, microbiological analysis revealed no significant differences between the two types of dairy creams. On the contrary, the trend observed in the growth of degradative bacteria in ricotta during shelf-life was significant. Metabolomics revealed that triacylglycerols and phospholipids showed significant strong down-accumulation trends when comparing samples from the centrifugation and natural creaming separation methods. Additionally, 2,3-Pentanedione was among the best discriminant compounds characterising the shelf-life period of ricotta cheese (VIP score = 1.02), mainly related to sensorial descriptors, such as buttery and cheesy. Multivariate statistics showed a clear impact of the shelf-life period on the ricotta cheese, revealing 139 potential marker compounds (mainly included in amino acids and lipids). Therefore, the approach used showed the potential of a combined metabolomic, microbiological and sensory approach to discriminate ricotta cheese during the shelf-life period. View Full-Text

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Research

Australia – Monitoring the incidence and causes of disease potentially transmitted by food in Australia: Annual report of the OzFoodNet network, 2016The OzFoodNet Working Group

Posted on November 13, 2021 by | Leave a comment

AU 

In 2016, a total of 44,455 notifications of enteric diseases potentially related to food were received by state and territory health departments in Australia. Consistent with previous years, campylobacteri-osis (n = 24,171) and salmonellosis (n = 18,060) were the most frequently-notified infections. Notable increases in incidence were observed for shiga toxin-producing Escherichia coli (n = 343; 166% increase), shigellosis (n = 1,408; 93% increase), campylobacteriosis (33% increase) and salmonellosis (30% increase) when compared with the historical five-year mean. The extent to which the intro-duction of culture-independent testing as a method of diagnosis has contributed to these increases remains unclear. In total, 188 gastrointestinal outbreaks, including 177 foodborne outbreaks, were reported in 2016. The 11 non-foodborne outbreaks were due to environmental or probable environ-mental transmission (nine outbreaks) and animal-to-person or probable animal-to-person transmis-sion (two outbreaks). No outbreaks of waterborne or probable waterborne transmission were reported in 2016. Foodborne outbreaks affected 3,639 people, resulting in at least 348 hospital admissions and four deaths. Eggs continue to be a source of Salmonella Typhimurium infection across the country: 35 egg-related outbreaks, affecting approximately 510 people, were reported across six jurisdictions in 2016. Three large multi-jurisdictional Salmonella outbreaks associated with mung bean sprouts (n = 419 cases); bagged salad products (n = 311 cases); and rockmelons (n = 144 cases) were investigated in 2016. These outbreaks highlight the risks associated with fresh raw produce and the ongoing need for producers, retailers and consumers to implement strategies to reduce potential Salmonellacontamination.

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Posted in food bourne outbreak, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, outbreak, Research

USA – FDA Core Investigations Table Update

Posted on November 12, 2021 by | Leave a comment

FDA

The FDA has closed an investigation of an outbreak of infections from Listeria monocytogenes without being able to identify a source.

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Posted in food bourne outbreak, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, outbreak

Research – Ochratoxin A and zearalenone in poultry feed samples from South China

Posted on November 12, 2021 by | Leave a comment

Wiley Online

Data regarding ochratoxin A (OTA) and zearalenone (ZEA) contamination in feed in South China are limited. Here, we evaluated OTA and ZEA contamination in 514 poultry feed samples collected from South China. We validated a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and the mycotoxins were quantified by high-pressure liquid chromatography–tandem mass spectrometry. OTA and ZEA were detected in 2.92% and 100% of the feed samples, respectively. Furthermore, 0%, 0.68%, and 7.0% of Hainan, Guangdong, and Guangxi feed samples were contaminated with OTA, at mean concentrations of 0.00, 1.14, and 0.88 μg/kg, respectively. All samples were contaminated with ZEA, and the mean concentrations were 2094.1, 14.3, and 8.73 μg/kg in the samples from Hainan, Guangdong, and Guangxi, respectively. The findings of this study indicate the strong need for intense monitoring of mycotoxin, especially ZEA, contamination in feed.

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Posted in Animal Feed Mould Toxin, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, mold, Mold Toxin, Mould Toxin, Moulds, Mycotoxin, Ochratoxin, Research, Zearalenone

RASFF Alert – Animal Feed – Aflatoxin – Groundnuts

Posted on November 12, 2021 by | Leave a comment

RASFF

Aflatoxin in USA groundnuts (FEED) in the Netherlands

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Posted in Aflatoxin, Animal Feed, Animal Feed Testing, Food Micro Blog, Food Microbiology Blog, Food Microbiology Testing, Food Toxin, microbial contamination, Microbiology, Microbiology Investigations, Mold Toxin, Mould Toxin, Mycotoxin

RASFF Alerts – Animal Feed – Mold/Moulds – Dried Beet – Feed Material

Posted on November 12, 2021 by | Leave a comment

RASFF

Mold – sheepskin growth on the surface and in the depth of the material, discoloration, change in structure to spongy, disgusting smell of mold and rotting of the feed material from Ukraine in Poland .

RASFF

Mold – sheepskin growth on the surface and in the depth of the material, discoloration, change in structure to spongy, disgusting smell of mold and rotting of the feed material in Poland

RASFF

Dried beet pulp from Ukraine infested with moulds in Poland

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Posted in Animal Feed, Animal Feed Mould Toxin, Animal Feed Testing, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, mold, Mold Toxin, Mould Toxin, Moulds, RASFF

Research – Gaseous chlorine dioxide inactivation of microbial contamination on whole black peppercorns

Posted on November 12, 2021 by | Leave a comment

Wiley Online

Black peppercorn is a common ingredient imported and used in uncooked or ready-to-eat foods in the United States. They might be exposed to fecal coliforms and other microbial contamination due to a lack of good agricultural and manufacturing practices in some developing countries under which they were grown and harvested, thus causing economic losses to the peppercorn industry in the United States. We investigated the effect of gaseous chlorine dioxide (ClO2) on reducing the microbial population levels of coliforms, aerobic bacteria, yeasts, and molds on unprocessed black peppercorns. Treatments on peppercorns were conducted in a 30-L airtight chamber, and equal amounts of dry media precursors were used to generate gaseous ClO2. Whole peppercorns (200 g) were exposed to 20, 30, and 40 g of precursor dose for up to 60 min at 21 ± 0.4°C and in combination with mild heat at 40 ± 2°C. Aerobic bacteria, coliforms, yeasts, and molds on peppercorns were enumerated before (7.4, 7.2, and 7.1 log CFU/g, respectively) and after treatments. Results after treatment demonstrated 0.8–1 log10 (90%) reduction for all the microbes post-treatment at 21 ± 0.4°C. The treatments conducted with a 30 g precursor dose for 60 min at 21 ± 0.4°C reduced statistically higher (p < .05) microorganisms than those at 40 ± 2°C. Our work demonstrated that gaseous ClO2 could be used as a part of an overall hurdle technology to reduce the coliforms, aerobes, yeasts, and molds on black peppercorns without affecting the visual quality.

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Posted in Coliforms, Decontamination Microbial, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Mould Toxin, Moulds, Research, Technology, Yeasts