Category Archives: Antimicrobials

Research – Surveillance of Antimicrobial Resistance (AMR) in E. coli and Campylobacter from retail turkey meat and E. coli from retail lamb in 2020/21-FS102109

Posted on April 2, 2022 by | Leave a comment

APHA

ecoli

This report presents results of the surveillance of antimicrobial resistance (AMR) in specific bacteria, i.e., Campylobacter and Escherichia coli (E.coli)from lamb and turkey meats on retail sale in the UK between October 2020 and February 2021.
The aim was to test by culture approximately 200 samples each of lamb and turkey meat for E.coli, and also to test the turkey samples for Campylobacter. The FSA requested testing of lamb and turkey meat as the majority of AMR surveys on UK retail meats have focused on beef, chicken and pork.
As such there is an evidence gap for AMR in lamb and turkey meat. E. coli is a normal inhabitant of the mammalian and avian gut and most isolates do not cause observable clinical disease in healthy animals and humans. Therefore, E.coli isolates can be useful “indicators” of AMR in gut bacteria. Campylobacter is frequently present in the gut of healthy poultry, and thermophilic species (Campylobacter jejuni and Campylobacter coli) typically cause food poisoning in humans.
The monitoring of lamb and turkey meat for AMR is not mandatory as part of the European Directive 2003/99/EC, but the methodology used in this survey was broadly based on the current EU methodologies for the testing of retail beef, chicken and pork. These methodologies involve culture of E. coli on selective agar media containing the antimicrobial drug cefotaxime. Growth of E. coli on such plates indicate resistance to third generation cephalosporin antimicrobial drugs, including extended-spectrum beta lactamase (ESBL) and Amp C type resistance. Such isolates should be further tested for susceptibility to a panel of antimicrobials by determining minimum inhibitory concentration (MIC) values using a broth dilution method based on EN ISO 20776-1:2006.As recommended by the EU, additional selective cultures were performed on samples to isolate any E.coli resistant to carbapenem antimicrobials. Carbapenems are termed ‘last resort’ drugs, used to treat severe infections when other treatment options are ineffective because of multiple resistances in the target Gram negative bacteria.

6At the request of the FSA (non-harmonised testing outside the remit of Decision 2013/652/EU) further screening was performed for E.coli strains resistant to colistin (another ‘last resort’ human antimicrobial drug) and those specifically producing ESBL resistance enzymes. Colistin-resistant strains may harbour mcr resistance genes, which are located on plasmids that can transfer between bacteria.

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Posted in Antibacterial, antimicrobial resistance, Antimicrobials, 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 – The Importance of Shiga Toxin-Producing Escherichia coli O145:NM[H28]/H28 Infections in Argentina, 1998–2020

Posted on March 9, 2022 by | Leave a comment

MDPI

Shiga toxin-producing Escherichia coli (STEC) is known as a pathogen associated with food-borne diseases. The STEC O145 serogroup has been related with acute watery diarrhea, bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Argentina has the highest rate of HUS worldwide with 70% of the cases associated with STEC infections. We aimed to describe the epidemiology and genetic diversity of STEC O145 strains isolated across Argentina between 1998–2020. The strains isolated from 543 cases of human disease and four cattle, were pheno-genotipically characterized. Sequencing of five strains was performed. The strains were serotyped as O145:NM[H28]/H28, O145:H25, and O145:HNT, and mainly characterized as O145:NM[H28]/stx2a/eae/ehxA (98.1%). The results obtained by sequencing were consistent with those obtained by traditional methods and additional genes involved in different mechanisms of the pathogen were observed. In this study, we confirmed that STEC O145 strains are the second serogroup after O157 and represent 20.3% of HUS cases in Argentina. The frequency of STEC O145 and other significant serogroups is of utmost importance for public health in the country. This study encourages the improvement of the surveillance system to prevent severe cases of human disease. View Full-Text

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Posted in Antimicrobials, Decontamination Microbial, E.coli O145, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Haemolytic Uremic Syndrome, HUS, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, STEC, STEC E.coli

Research – Distribution and Characteristics of Listeria spp. in Pigs and Pork Production Chains in Germany

Posted on March 6, 2022 by | Leave a comment

MDPI

Listeria (L.) monocytogenes is a foodborne pathogen that can cause disease, mainly in elderly, pregnant or immunocompromised persons through consumption of contaminated food, including pork products. It is widespread in the environment and can also be found in asymptomatic carrier animals, for example, in different tissues of pigs. To learn more about their nature, 16 Listeria spp. isolates found in tonsils and intestinal content of pigs and 13 isolates from the slaughterhouse environment were characterized using next-generation sequencing (NGS). A wide distribution of clonal complexes was observed in pigs, as well as in the pork production chain, suggesting multiple sources of entry. Hypervirulent clones were found in pig tonsils, showing the potential risk of pigs as source of isolates causing human disease. The presence of closely related isolates along the production chain suggests a cross-contamination in the slaughterhouse or recontamination from the same source, strengthening the importance of efficient cleaning and disinfection procedures. The phenotypical antimicrobial resistance status of L. monocytogenes isolates was examined via broth microdilution and revealed a low resistance level. Nevertheless, genotypical resistance data suggested multiple resistances in some non-pathogenic L. innocua isolates from pig samples, which might pose a risk of spreading resistances to pathogenic species. View Full-Text

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Posted in antimicrobial resistance, Antimicrobials, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research

Research – Multidrug resistance of Escherichia coli in fish supply chain: A preliminary investigation

Posted on February 26, 2022 by | Leave a comment

Wiley Online

Abstract

Ninety-five Escherichia coli isolates recovered from different supply points of freshwater fish namely fish pond (W1, n = 16), wholesale fish market (W2, n = 14), retail fish market (R1, n = 29), street fish vending unit (R2, n = 30), and modern fish vending unit (R3, n = 6) were investigated for antimicrobial-resistant profile and prevalence of antibiotic-resistant genes. Overall, multidrug-resistant (MDR) E. coli in the fish supply chain was 21% with higher MDR incidence in the downstream fish supply points. MDR was relatively higher in the tertiary fish supply points viz., retail fish market (45%), street fish vending unit (30%), and modern fish vending unit (15%) compared to the secondary fish supply point, that is, wholesale fish market (5%) and primary fish supply point, that is, fish pond (5%). All the ampicillin-resistant isolates carried ampC gene, whereas only 21% of the β-lactam resistant isolates carried blaCTX-M-gp1. The tetracycline resistance determinant, tetA (89%) was predominant in the tetracycline-resistant isolates compared to tetB and tetD (11%). The trimethoprim resistance gene, dfrA and sulfonamide-resistance gene, Sul1 were detected in 9% of the trimethoprim-resistant isolates and 9% of the sulfonamide-resistant isolates, respectively. Enterobacterial repetitive intergeneric consensus-PCR has delineated the MDR isolates from the different fish supply points into three major clusters but all the MDR isolates from the street fish vending point are grouped into a single cluster. The results indicate an increase in the proportion of MDR E. coli and the occurrence of diverse MDR profiles in the downstream points of the fish supply chain that needs to be addressed to avoid fish-food-borne antimicrobial resistance.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, E.coli, escherichia coli, food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Strategies for Biocontrol of Listeria monocytogenes Using Lactic Acid Bacteria and Their Metabolites in Ready-To-Eat Meat- and Dairy-Ripened Products

Posted on February 22, 2022 by | Leave a comment

MDPI

Listeria monocytogenes is one of the most important foodborne pathogens. This microorganism is a serious concern in the ready-to-eat (RTE) meat and dairy-ripened products industries. The use of lactic acid bacteria (LAB)-producing anti-L. monocytogenes peptides (bacteriocins) and/or lactic acid and/or other antimicrobial system could be a promising tool to control this pathogen in RTE meat and dairy products. This review provides an up to date about the strategies of use of LAB and their metabolites in RTE meat products and dairy foods by selecting the most appropriate strains, by analysing the mechanism by which they inhibit L. monocytogenes and methods of effective application of LAB, and their metabolites in these kinds of products to control this pathogen throughout the processing and storage. The selection of LAB with anti-L. monocytogenes activity allows to dispose of effective strains in meat and dairy-ripened products, achieving reductions form 2–5 logarithmic cycles of this pathogen throughout the ripening process. The combination of selected LAB strains with antimicrobial compounds, such as acid/sodium lactate and other strategies, as the active packaging could be the next future innovation for eliminating risk of L. monocytogenes in meat and dairy-ripened products.

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Posted in Antibacterial, antimicrobial resistance, Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, LAB, lactic acid bacteria, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Antibacterial Properties of TMA against Escherichia coli and Effect of Temperature and Storage Duration on TMA Content, Lysozyme Activity and Content in Eggs

Posted on February 20, 2022 by | Leave a comment

MDPI

Studies on trimethylamine (TMA) in egg yolk have focused on how it impacts the flavor of eggs, but there has been little focus on its other functions. We designed an in vitro antibacterial test of TMA according to TMA concentrations that covered the TMA contents typically found in egg yolk. The change in TMA content in yolk was analyzed at different storage temperatures and for different storage durations. The known antibacterial components of eggs, including the cuticle quality of the eggshell and the lysozyme activity and content in egg white, were also assessed. The total bacterial count (TBC) of different parts of eggs were detected. The results showed that the inhibitory effect of TMA on Escherichia coli (E. coli) growth increased with increasing TMA concentration, and the yolk TMA content significantly increased with storage duration (p < 0.05). The cuticle quality and lysozyme content and activity significantly decreased with storage time and increasing temperature, accompanied by a significant increase in the TBC on the eggshell surface and in the egg white (p < 0.05). This work reveals a new role for trace TMA in yolks because it reduces the risk of bacterial colonization, especially when the antibacterial function of eggs is gradually weakened during storage.

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Posted in Antibacterial, Antimicrobials, Decontamination Microbial, E.coli, escherichia 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, Technology

Research – Comparative efficiency of carbohydrates on the biofilm-forming ability of enteroaggregative Escherichia coli

Posted on February 12, 2022 by | Leave a comment

Wiley Online

The biofilm-forming ability of microbes is often correlated with drug resistance; however, this association among enteroaggregative Escherichia coli (EAEC) strains remains naïve. Moreover, the investigations exploring uptake and assimilation of sugars either qualitatively or quantitatively by the biofilm-forming EAEC strains have not yet been documented. Hence, this study investigated the role of various categories of sugars (monosaccharides, disaccharides, and polysaccharide) on the biofilm-forming ability of three each of multi-drug-resistant (MDR) as well as non-MDR typical EAEC strains. The EAEC strains exhibited black colonies on congo red agar (CRA) with monosaccharides and disaccharides, whereas all the strains exhibited red colonies on CRA with the polysaccharide. Although significant (p < 0.001) biofilm-forming ability was observed by all the EAEC strains in sugar-dependent microtiter plate assay, color change from pink to orange and yellow was noticed in presence of monosaccharides and disaccharide, while absent in polysaccharides. Besides, significantly higher bacterial counts were observed in presence of monosaccharides and disaccharides (p < 0.01); however, such significant bacterial counts were not noticed with the polysaccharide. Further, the real-time PCR data exhibited comparatively higher relative expression of biofilm-associated fis gene among EAEC strains grown in presence of monosaccharides, followed by disaccharide and polysaccharide, respectively that concurred with the flow cytometry data. No significant (p > 0.05) difference was observed in the biofilm-forming ability between MDR- and non-MDR EAEC strains. This study illustrated the role of carbohydrates on the biofilm-forming ability of EAEC and warranted utmost attention concerning the usage of carbohydrates in food processing industries, for its incorporation as functional food additives.

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Posted in antimicrobial resistance, Antimicrobials, Biofilm, Decontamination Microbial, EAEC, escherichia coli, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Illuminating Human Norovirus: A Perspective on Disinfection of Water and Surfaces Using UVC, Norovirus Model Organisms, and Radiation Safety Considerations

Posted on February 9, 2022 by | Leave a comment

MDPI

Food Borne Illness - Norovirus -CDC Photo

Abstract

Human noroviruses (HuNoVs) are a major cause of gastroenteritis and are associated with high morbidity because of their ability to survive in the environment and small inoculum size required for infection. Norovirus is transmitted through water, food, high touch-surfaces, and human-to-human contact. Ultraviolet Subtype C (UVC) light-emitting diodes (LEDs) can disrupt the norovirus transmission chain for water, food, and surfaces. Here, we illuminate considerations to be adhered to when picking norovirus surrogates for disinfection studies and shine light on effective use of UVC for norovirus infection control in water and air and validation for such systems and explore the blind spot of radiation safety considerations when using UVC disinfection strategies. This perspective also discusses the promise of UVC for norovirus mitigation to save and ease life.

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Posted in Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Norovirus, Research, Technology, UV Microbiology

Research – Antibacterial Effect of Oregano Essential Oil against Vibrio vulnificus and Its Mechanism

Posted on February 6, 2022 by | Leave a comment

MDPI

Oregano essential oil (OEO) is an effective natural antibacterial agent, but its antibacterial activity against Vibrio vulnificus has not been widely studied. The aim of this study was to investigate the inhibitory effect and germicidal activity of OEO on V. vulnificus and its possible inhibition mechanism. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of OEO against four V. vulnificus strains (ATCC 27562 and three isolates from seafoods) were from 0.06 to 0.15 μL/mL. Compared with untreated bacteria, OEO reduced the concentration of intracellular adenosine triphosphate (ATP), hyperpolarized the cell membrane, increased the level of reactive oxygen species (ROS), and increased the concentration of intracellular malondialdehyde (MDA), but there was no obvious DNA damage at the OEO test concentration. It was indicated that OEO inactivated V. vulnificus by generating ROS which caused lipid peroxidation of cell membranes, thereby reducing the permeability and integrity of cell membranes and causing morphological changes to cells, but there was no obvious damage to DNA. In addition, OEO could effectively kill V. vulnificus in oysters at 25 °C, and the number of bacteria decreased by 48.2% after 0.09% OEO treatment for 10 h. The good inhibitory effect and bactericidal activity of OEO showed in this study, and the economy and security of OEO make it possible to apply OEO to control V. vulnificus contamination in oysters and other seafoods. View Full-Text

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Posted in Antibacterial, Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Technology, Vibrio, Vibrio vulnificans, Vibrio vulnificus

Research – Novel Biocomposite Films Based on High Methoxyl Pectin Reinforced with Zeolite Y for Food Packaging Applications

Posted on January 30, 2022 by | Leave a comment

MDPI

Pectin is a natural biopolymer with broad applications in the food industry and it is suitable to prepare edible films to prolong food shelf-life. However, the main limitation of pectin-based films is their poor mechanical and barrier properties. Zeolite Y is a hydrophobic clay that can be used as film reinforcement material to improve its physicochemical and mechanical properties. In this work, the influence of high methoxyl citrus and apple pectin on physicochemical properties of biopolymer films modified with zeolite Y (0.05–0.2 wt%) was investigated. The films were characterized by FTIR, TGA, WAXD, mechanical analysis, and water vapor permeability analysis, and a potential film application is presented. The WAXD and FTIR analysis demonstrated that the strongest interaction between pectin chains and zeolite Y occurred when citrus high methylated pectin was used. Adding 0.2 wt% of zeolite Y into citrus high methylated pectin matrix enhanced the tensile strength by 66%, thermal stability by 13%, and water vapor barrier by 54%. In addition, fruit shelf-life test was performed, where strawberries were sealed in film. It was shown that sealed strawberries maintained a better color and healthy appearance than the control treatment after 7 days at 10 °C. This study enabled the development of biocomposite films with improved properties for potential application in food packaging. View Full-Text

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Posted in Antimicrobials, 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, Shelf Life