Category Archives: Research

Research – Genetic and Phenotypic Virulence Potential of Non-O1/Non-O139 Vibrio cholerae Isolated from German Retail Seafood

Posted on November 16, 2023 by | Leave a comment

MDPI

Abstract

Non-O1 and non-O139 Vibrio cholerae (NOVC) can cause gastrointestinal infections in humans. Contaminated food, especially seafood, is an important source of human infections. In this study, the virulence potential of 63 NOVC strains isolated from retail seafood were characterized at the genotypic and phenotypic levels. Although no strain encoded the cholera toxin (CTX) and the toxin-coregulated pilus (TCP), several virulence factors, including the HlyA hemolysin, the cholix toxin ChxA, the heat-stable enterotoxin Stn, and genes coding for the type 3 and type 6 secretion systems, were detected. All strains showed hemolytic activity against human and sheep erythrocytes: 90% (n = 57) formed a strong biofilm, 52% (n = 33) were highly motile at 37 °C, and only 8% (n = 5) and 14% (n = 9) could resist ≥60% and ≥40% human serum, respectively. Biofilm formation and toxin regulation genes were also detected. cgMLST analysis demonstrated that NOVC strains from seafood cluster with clinical NOVC strains. Antimicrobial susceptibility testing (AST) results in the identification of five strains that developed non-wildtype phenotypes (medium and resistant) against the substances of the classes of beta-lactams (including penicillin, carbapenem, and cephalosporin), polymyxins, and sulphonamides. The phenotypic resistance pattern could be partially attributed to the acquired resistance determinants identified via in silico analysis. Our results showed differences in the virulence potential of the analyzed NOVC isolated from retail seafood products, which may be considered for further pathogenicity evaluation and the risk assessment of NOVC isolates in future seafood monitoring.

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Posted in Food Microbiology Research, Research, Vibrio, Vibrio cholera, vibrio cholerae, virulence

Research – Prevalence of Multidrug-Resistant Pseudomonas aeruginosa Isolated from Dairy Cattle, Milk, Environment, and Workers’ Hands

Posted on November 15, 2023 by | Leave a comment

MDPI

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen causing severe infection in animals and humans. This study aimed to determine the ecological distribution and prevalence of multidrug-resistant (MDR) P. aeruginosa isolated from dairy cattle, the environment, and workers’ hand swabs. Samples (n = 440) were collected from farms and households (n = 3, each). Rectal swabs, udder skin swabs, milk, workers’ hand swabs, feed, water, water sources, and beddings were collected. Samples were subjected to the bacterial identification of P. aeruginosa via 16S rRNA. Antimicrobial resistance (AMR) was detected either phenotypically using an antibiotic susceptibility test or genotypically with AMR resistance genes (ARGs) such as drfA, sul1, and ermB. P. aeruginosa was detected on dairy farms and households (10.3–57.5%, respectively), with an average of 23.2%. The resistance of dairy farm strains was observed against sulfamethoxazole, imipenem, cefepime, piperacillin–tazobactam, and gentamycin (100%, 72.7%, 72.7%, 68.8%, and 63.3%, respectively). Meanwhile, the resistance of household strains was observed against sulfamethoxazole, imipenem, amoxicillin, gentamicin, cefepime, and erythromycin by 91.3%, 82.6%, 75.4%, 75.4%, 68.1%, and 63.8%, respectively. The susceptibility of farm strains was detected against norfloxacin, ciprofloxacin, and levofloxacin (90.9%, 84.8%, and 72.7%, respectively). Meanwhile, the susceptibility of household strains was detected against ciprofloxacin, amikacin, and norfloxacin (100%, 84.1%, and 72.5%, respectively). About 81.4% of P. aeruginosa strains were MDR. ARGs (drfA, sul1, and ermB) were detected in farm strains (48.5%, 72.7%, and 24.4%, respectively) and household strains (50.7%, 72.5%, and 47.8%, respectively). Almost all P. aeruginosa had MAR over 0.2, indicating repeated application of antibiotics. P. aeruginosa prevalence was fivefold higher in households than on farms. MDR strains were higher amongst household strains than farm strains.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Microbiological Risk Assessment, Pseudomonas, Pseudomonas aeruginosa, Research

What are Extensively Drug Resistant (XDR) Bacteria?

Posted on November 15, 2023 by | Leave a comment

News Medical

Resistance to antimicrobial agents is a growing and worrying phenomenon. Extensively drug-resistant bacteria, or XDR bacteria, are a type of multidrug-resistant organisms that are resistant to almost all or all approved antimicrobial agents.

The origin of XDR bacteria

The term was first coined in response to Mycobacterium tuberculosis that was resistant to first-line agents (isoniazid and rifampicin), a fluoroquinolone, and to one or more second-line parenteral drugs (amikacin, kanamycin, and capreomycin). This was later expanded to include other bacteria that were resistant to most standard antimicrobial treatments.

Defining XDR bacteria

XDR bacteria are different from multidrug-resistant bacteria and pan-drug resistant bacteria. The difference is mainly interpreted as to what extent the bacteria are drug-resistant, with multidrug-resistant bacteria being unsusceptible to one or more antimicrobial agents and pan-drug resistant bacteria being unsusceptible to all antimicrobial agents.

Therefore, XDR bacteria rest somewhere in between these two categories. Occasionally, definitions are based on broader categories of antimicrobials rather than agents, which therefore narrows the bacteria fitting the description. However, this system is often seen as more informative by healthcare professionals treating afflicted patients with various antimicrobial classes.

Read more at the link above

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Posted in Antibiotic Resistance, Extensively Drug Resistant (XDR), Food Microbiology Research, Research, XDR

Research – Antimicrobial Activity of Essential Oils in Vapor Phase In Vitro and Its Application in Combination with Lactic Acid to Improve Chicken Breast Shelf Life

Posted on November 15, 2023 by | Leave a comment

MDPI

Abstract

The effect of essential oils (EOs) incorporated in their vapor phase combined with lactic acid immersion pretreatment was studied on fresh refrigerated chicken breast shelf life. Among the several EOs assayed, the in vitro results obtained from the vapor diffusion test allowed mustard, oregano, and garlic EOs to be selected due to their higher antimicrobial activity. In addition, it was possible to determine the EO minimum inhibitory concentrations against Pseudomonas aeruginosa and Escherichia coli and to identify EO binary mixtures showing synergistic or additive effects. Based on the obtained results, a ternary mixture constituted by 0.073, 0.292, and 0.146 µL/mL of headspace of mustard, oregano, and garlic, respectively, was proposed for its application to chicken breasts. The ternary mixture inhibitory action was confirmed in vitro against P. aeruginosa and E. coli. Furthermore, the presence of numerous compounds with recognized antimicrobial and antioxidant activity was found in its volatile phase through gas chromatography. When applying an EO mixture in its vapor phase in combination with 1.0% v/v of lactic acid immersion pre-treatment on refrigerated chicken breast, a decrease in mesophilic microorganisms’ growth rate as well as in lipid oxidation was observed. Moreover, in a preliminary sensory test, the treated chicken breast was found to be acceptable to consumers and showed no significant differences compared to untreated chicken. In conclusion, the combined use of lactic acid immersion and EOs in their vapor phase was an effective alternative to increase chicken breast shelf life.

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Posted in E.coli, Food Microbiology Research, Food Technology, Pseudomonas, Pseudomonas aeruginosa, Research

Hong Kong – Liver-damaging Aflatoxins found in peanut butter, with two brands exceeding EU limit

Posted on November 15, 2023 by | Leave a comment

The Standard HK

A Consumer Council’s test on 20 samples of peanut butter found that 60 percent of them contain aflatoxins, a substance that could damage liver function. The test also found the aflatoxin B1 levels of two samples exceeded the upper limit of European Union standards.

The consumer watchdog said the two samples found with aflatoxin B1 levels exceeding the EU limit are Fuyuan’s Peanut Butter and YOWE’s Peanut Butter Creamy.

The two samples contained aflatoxin B1 at levels of 4.27μg and 2.01μg respectively, which exceeded the EU limit of 2.0μg. The total aflatoxins level of Fuyuan’s Peanut Butter of 4.94μg also exceeded the EU limit of 4.0μg.

The watchdog warned that aflatoxins could cause acute and chronic poisoning in animals and humans, and could lead to acute liver damage, cirrhosis, cancer and even death.

It said it has referred the information of the relevant samples to the Centre for Food Safety for follow-up.

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Posted in Aflatoxin, Aflatoxin B1, Aspergillus Toxin, Food Microbiology Research, Food Toxin, Mold Toxin, Mould Toxin, Mycotoxin, Research

Research – Synergistic Strategies of Heat and Peroxyacetic Acid Disinfection Treatments for Salmonella Control

Posted on November 12, 2023 by | Leave a comment

MDPI

Abstract

The food industry has recognized a pressing need for highly effective disinfection protocols to decrease the risk of pathogen emergence and proliferation in food products. The integration of antimicrobial treatments in food production has occurred as a potential strategy to attain food items of superior quality with respect to microbiological safety and sensory attributes. This study aims to investigate the individual and synergistic effects of heat and peroxyacetic acid on the inactivation of bacterial cells, considering various contact times and environmental conditions. Four Salmonella serotypes, isolated from industrial meat production surfaces, were employed as model organisms. By systematically assessing the impacts of individual factors and synergistic outcomes, the effectiveness of bacterial cell inactivation and the efficiency of heat and peroxyacetic acid could be predicted. To better approximate real-world food processing conditions, this study also incorporated a bovine albumin-rich condition as a simulation of the presence of organic loads in processing steps. The findings revealed the essential need for a synergistic interplay of investigated parameters with the following optimized values: 1.5% concentration of peroxyacetic acid, temperature range of 60–65 °C, and contact time of 3 min for the complete effect regardless of the degree of contamination.

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Posted in Food Microbiology Research, Food Technology, Research, Salmonella, Technology

Research – Risks for animal health related to the presence of Ochratoxin A (OTA) in feed

Posted on November 12, 2023 by | Leave a comment

EFSA

Abstract

In 2004, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks to animal health and transfer from feed to food of animal origin related to the presence of ochratoxin A (OTA) in feed. The European Commission requested EFSA to assess newly available scientific information and to update the 2004 Scientific Opinion. OTA is produced by several fungi of the genera Aspergillus and Penicillium. In most animal species it is rapidly and extensively absorbed in the gastro‐intestinal tract, binds strongly to plasma albumins and is mainly detoxified to ochratoxin alpha (OTalpha) by ruminal microbiota. In pigs, OTA has been found mainly in liver and kidney. Transfer of OTA from feed to milk in ruminants and donkeys as well as to eggs from poultry is confirmed but low. Overall, OTA impairs function and structure of kidneys and liver, causes immunosuppression and affects the zootechnical performance (e.g. body weight gain, feed/gain ratio, etc.), with monogastric species being more susceptible than ruminants because of limited detoxification to OTalpha. The CONTAM Panel considered as reference point (RP) for adverse animal health effects: for pigs and rabbits 0.01 mg OTA/kg feed, for chickens for fattening and hens 0.03 mg OTA/kg feed. A total of 9,184 analytical results on OTA in feed, expressed in dry matter, were available. Dietary exposure was assessed using different scenarios based on either model diets or compound feed (complete feed or complementary feed plus forage). Risk characterisation was made for the animals for which an RP could be identified. The CONTAM Panel considers that the risk related to OTA in feed for adverse health effects for pigs, chickens for fattening, hens and rabbits is low.

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Posted in Animal Feed, Animal Feed Mould Toxin, Animal Feed Mould/Mold, Animal Feed Testing, Food Microbiology Research, Mycotoxin, Ochratoxin, Ochratoxin A, Research

Research – New Insights into Inhibiting the Spread of Cholera-causing Bacteria

Posted on November 11, 2023 by | Leave a comment

Express Health Care Management

A recent research article published in The Proceedings of the National Academy of Sciences (PNAS) has provided new insights into inhibiting the spread and infection of Vibrio cholerae, the bacteria responsible for causing cholera. The study, titled “A peptide-binding domain shared with an Antarctic bacterium facilitates Vibrio cholerae human cell binding and intestinal colonization,” was coauthored by Karl Klose, director of The South Texas Center for Emerging Infectious Diseases (STCEID), and Cameron Lloyd, a UTSA doctoral student.

Traditionally, V. cholerae is found naturally on various surfaces within marine environments. When contaminated water or food is consumed by humans, the bacteria colonize the gastrointestinal tract and cause cholera, leading to symptoms such as diarrhea, vomiting, and circulatory collapse. If left untreated, severe cases of cholera can be fatal.

The research team, in collaboration with other international laboratories, identified a peptide, a short chain of amino acids, that can inhibit the virulence of V. cholerae. They discovered that the peptide inhibitors, which bind to an Antarctic bacterium called Marinomonas primoryensis, can disrupt V. cholerae from adhering to human cells, forming biofilms, and colonizing the gastrointestinal tract.

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Posted in Biofilm, Contaminated water, Food Microbiology Research, Research, Vibrio cholera, vibrio cholerae, water microbiology

Research -Systematic Review and Meta-Analysis of Campylobacter Species Contamination in Poultry, Meat, and Processing Environments in South Korea

Posted on November 11, 2023 by | Leave a comment

MDPI

Abstract

Campylobacter spp. constitute a significant global threat as a leading cause of foodborne illnesses, with poultry meat as a prominent reservoir for these pathogens. South Korea is known for its diverse poultry consumption habits, and continuous outbreaks make it a matter of concern to perform a meta-analysis to identify the primary source of contamination. This systematic review and meta-analysis aimed to assess and compare the prevalence of Campylobacter in various poultry and meat types while also considering the importance of environmental factors in South Korea. The meta-analysis revealed that duck meat exhibited the highest prevalence of Campylobacter, with a pooled estimate of 70.46% (95% CI: 42.80% to 88.38%), followed by chicken meat at a pooled prevalence of 36.17% (95% CI: 26.44% to 47.91%). Additionally, our analysis highlighted the predominance of C. jejuni and C. coli in South Korea. These findings underscore the importance of implementing rigorous food safety measures and establishing robust surveillance programs in the poultry industry to mitigate the risk of Campylobacter-related foodborne illnesses associated with meat consumption in South Korea.

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Posted in Campylobacter, campylobacter coli, Campylobacter jejuni, Food Illness, Food Microbiology Research, Foodborne Illness, Illness, Research

Research – Monophasic Variant of Salmonella Typhimurium 4,[5],12:i:- (ACSSuGmTmpSxt Type) Outbreak in Central Italy Linked to the Consumption of a Roasted Pork Product (Porchetta)

Posted on November 11, 2023 by | Leave a comment

MDPI

Abstract

The monophasic variant of S. Typhimurium 4,[5],12:i:- (MVST) is the third most commonly reported Salmonella serovar involved in human infections (8.8%) in the EU and ranks after S. Enteritidis (54.6%) and S. Typhimurium (11.4%). In Italy, in contrast, the MVST has achieved peculiar epidemiological and ecological success which has allowed it to be, since 2011, the serovar most frequently isolated from humans. In the summer of 2022, a foodborne outbreak of the MVST involving 63 people occurred in the Marche Region (Central Italy). A common food exposure source among some human cases was a roasted, ready-to-eat (RTE) pork product, porchetta, which is a typical product of Central Italy. This paper describes the results of investigations conducted to clarify this outbreak. The porchetta was produced by a local manufacturing plant and distributed to at least two local retail stores, one of which was the retail outlet for the manufacturing plant. The MVST was isolated from surface samples collected at the porchetta manufacturing plant and at both local retail stores via bacterial analysis, and the porchetta sampled at one store contained the MVST. These data confirm this type of RTE pork product can be a source of Salmonella infection in humans.

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Posted in food bourne outbreak, Food Illness, Food Microbiology Research, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, outbreak, Research, Salmonella