Category Archives: antimicrobial resistance

Research – Evaluation of antimicrobial activity and mechanism of Mentha longifolia L. essential oil

Wiley Online

As the interest in “natural” and “safe” products grows, the use of natural products instead of synthetic preservatives to combat food spoilage and poisoning caused by microorganisms during processing and storage has become a prioritized option. The present research evaluated the antibacterial activity of the Mentha longifolia L. essential oil (MLEO) against several pathogenic bacteria, and the mechanism of action against methicillin-resistant Staphylococcus aureus (MRSA). Gas Chromatography Quadrupole Time-of-Flight Mass Spectrometry (GC-Q-TOF MS) analysis suggested that main components of MLEO were carvone (47.39%) and limonene (12.48%). The oil showed considerable antibacterial activity with MIC values of 0.394–1.576 mg/mL, and could be a promising bactericide. Non-targeted metabolomics analysis based on GC-Q-TOF MS identified 66 different metabolites, and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of these metabolites revealed that MLEO achieves the effects by affecting amino acid metabolism in MRSA.

Research -Antimicrobial-Resistant Listeria monocytogenes in Ready-to-Eat Foods: Implications for Food Safety and Risk Assessment



Antimicrobial resistance is an existential threat to the health sector, with far-reaching consequences in managing microbial infections. In this study, one hundred and ninety-four Listeria monocytogenes isolates were profiled for susceptibility using disc diffusion techniques. Possible foodborne listeriosis risk associated with ready-to-eat (RTE) foods (RTEF) and the risk of empirical treatment (EMPT) of L. monocytogenes infections, using multiple antimicrobial resistance indices (MARI) and antimicrobial resistance indices (ARI), respectively, were investigated. Twelve European Committee on Antimicrobial Susceptibility Testing (EUCAST) prescribed/recommended antimicrobials (EPAS) for the treatment of listeriosis and ten non-prescribed antimicrobials (non-PAS)] were evaluated. Antimicrobial resistance > 50% against PAs including sulfamethoxazole (61.86%), trimethoprim (56.19%), amoxicillin (42.27%), penicillin (41.24%), and erythromycin (40.21%) was observed. Resistance > 50% against non-PAS, including oxytetracycline (60.89%), cefotetan (59.28%), ceftriaxone (53.09%), and streptomycin (40.21%) was also observed. About 55.67% and 65.46% of the isolates had MARI scores ranging from 0.25–0.92 and 0.30–0.70 for EPAs and non-PAs, respectively. There was a significant difference (p < 0.01) between the MARI scores of the isolates for EPAs and non-PAs (means of 0.27 ± 0.21 and 0.31 ± 0.14, respectively). MARI/ARI scores above the Krumperman permissible threshold (>0.2) suggested a high risk/level of antimicrobial-resistant L. monocytogenes. The MARI risks of the non-success of empirical treatment (EMPT) attributed to EPAs and non-PAs were generally high (55.67% and 65.463%, respectively) due to the antimicrobial resistance of the isolates. MARI-based estimated success and non-success of EMPT if EUCAST-prescribed antimicrobials were administered for the treatment of listeriosis were 44.329% and 55.67%, respectively. The EMPT if non-prescribed antimicrobials were administered for the treatment of listeriosis was 34.53% and 65.46%, respectively. This indicates a potentially high risk with PAs and non-PAs for the treatment of L. monocytogenes infection. Furthermore, ARI scores ≤ 0.2 for EPAs were observed in polony, potato chips, muffins, and assorted sandwiches, whereas ARI scores for non-PAs were >0.2 across all the RTE food types. The ARI-based estimate identified potential risks associated with some RTE foods, including fried fish, red Vienna sausage, Russian sausage, fruit salad, bread, meat pies, fried chicken, cupcakes, and vetkoek. This investigation identified a high risk of EMPT due to the presence of antimicrobial-resistant L. monocytogenes in RTE foods, which could result in severe health consequences.

Research – The Role of Biofilms in the Pathogenesis of Animal Bacterial Infections



Biofilms are bacterial aggregates embedded in a self-produced, protective matrix. The biofilm lifestyle offers resilience to external threats such as the immune system, antimicrobials, and other treatments. It is therefore not surprising that biofilms have been observed to be present in a number of bacterial infections. This review describes biofilm-associated bacterial infections in most body systems of husbandry animals, including fish, as well as in sport and companion animals. The biofilms have been observed in the auditory, cardiovascular, central nervous, digestive, integumentary, reproductive, respiratory, urinary, and visual system. A number of potential roles that biofilms can play in disease pathogenesis are also described. Biofilms can induce or regulate local inflammation. For some bacterial species, biofilms appear to facilitate intracellular invasion. Biofilms can also obstruct the healing process by acting as a physical barrier. The long-term protection of bacteria in biofilms can contribute to chronic subclinical infections, Furthermore, a biofilm already present may be used by other pathogens to avoid elimination by the immune system. This review shows the importance of acknowledging the role of biofilms in animal bacterial infections, as this influences both diagnostic procedures and treatment.

Research – Foodborne Pathogen Biofilms: Development, Detection, Control, and Antimicrobial Resistance


Bacteria can grow either as planktonic cells or as communities within biofilms. The biofilm growth mode is the dominant lifestyle of most bacterial species and 40–80% of microorganisms are associated with biofilms [1]. Biofilm is a sessile community that is irreversibly attached to a substratum or interface or to other members of the community [2]. It is surrounded by extracellular polymeric substances (EPS) that include extracellular polysaccharides, extracellular DNA, lipids, proteins, and other elements [3]. Biofilm formation is a complex but well-regulated process that can be classified into five distinct stages [4]. In the first stage, planktonic bacteria attach to a surface. Salmonella species, Listeria monocytogenesCampylobacter jejuni, or Escherichia coli have specific structures on the surface of the bacteria, such as flagella, curli, fimbriae, and pili, which help the bacteria attach [5].
The second stage is the adhesion step, which includes an initial reversible adhesion resulting in loose adhesion and a subsequent irreversible adhesion resulting in more stable adhesion. The third stage is to secrete EPS and form microcolonies. This is followed by biofilm maturation, which produces large amounts of EPS to grow in size and build three-dimensional structures. The final stage is the stage in which the biofilm is dispersed, releasing the planktonic cells and initiating the formation of a new biofilm at another location.
Microbial cells living within biofilms are protected from various environmental stresses such as desiccation, osmotic changes, oxidative stress, metal toxicity, radiation, antibiotics, disinfectants, and the host immune system [6]. Biofilms are much less sensitive to antimicrobial agents than planktonic cells, and several mechanisms contribute to their resistance to antimicrobials [7]. The exopolysaccharide matrix prevents the entry of antimicrobial agents by reducing diffusion and acting as a primary barrier [8]. Most antimicrobial agents kill rapidly dividing cells more effectively, but slow growth of biofilms leads to resistance [9]. Changes in metabolic activity within biofilms, genetic changes of antimicrobial resistant determinants in target cells, extrusion of antimicrobial agents using efflux pumps, and the presence of persistent cells also contribute to antimicrobial resistance [10].

Research – Recent insights into green antimicrobial packaging towards food safety reinforcement: A review

Wiley Online


Food packaging is widely used method of food preservation around the world. It is an element that enhances the quality and food product safety. The primary function of packaging is to protect food from contamination, undesirable chemical reactions and to provide physical protection. Food spoilage caused by food-borne pathogens and microbes is increasing tremendously posing an enormous threat. In the field of food packaging, new biodegradable and natural antimicrobial agents from plants and animals are gaining popularity. Recent foodborne outbreaks have prompted more creative and safe ways to initiate efficient packaging systems in food industries. However, as consumer demand for natural food ingredients has grown as a result of increasing safety and availability, natural substances are thought to be safer. Antimicrobial packaging that incorporates natural antimicrobials is thus a viable active packaging innovation. One possibility for increasing the safety and quality of foods while prolonging their shelf life is to employ natural antibacterial packaging. This article focuses on environmentally friendly bio-based polymers that can be utilized in food packaging to enhance mechanical strength, gas permeability, and water resistance, among other features. It also includes useful information about natural antimicrobial agents found in fruits and vegetables, as well as animal by-products, their properties, safety laws, and uses aimed at improving and increasing food quality and safety.

Research – Campylobacter jejuni and Campylobacter coli from Houseflies in Commercial Turkey Farms Are Frequently Resistant to Multiple Antimicrobials and Exhibit Pronounced Genotypic Diversity



Campylobacter is a leading foodborne pathogen, and poultry are a major vehicle for infection. Houseflies play important roles in colonization of broiler flocks with Campylobacter but comparable information for turkey farms is limited. Here, we investigated houseflies as potential vectors for Campylobacter in 28 commercial turkey flocks. We characterized species, genotypes, and the antimicrobial resistance (AMR) profiles of Campylobacter from turkey feces and houseflies in the same turkey house. Of the 28 flocks, 25 yielded Campylobacter from turkey droppings and houseflies, with an average of 6.25 and 3.11 Campylobacter log CFU/g feces and log CFU/fly, respectively. Three flocks were negative for Campylobacter both in turkey feces and in houseflies. Both C. coli and C. jejuni were detected in turkey feces and houseflies, with C. coli more likely to be recovered from houseflies than feces. Determination of Campylobacter species, genotypes, and AMR profiles revealed up to six different strains in houseflies from a single house, including multidrug-resistant strains. For the predominant strain types, presence in houseflies was predictive of presence in feces, and vice versa. These findings suggest that houseflies may serve as vehicles for dissemination of Campylobacter, including multidrug-resistant strains, within a turkey house, and potentially between different turkey houses and farms in the same region.

Research – Zoonoses, foodborne outbreaks and antimicrobial resistance guidance for reporting 2022 data



This technical report of the European Food Safety Authority (EFSA) presents the guidance to reporting European Union (EU) Member States and non‐Member States in data transmission using extensible markup language (XML) data transfer covering the reporting of isolate‐based quantitative antimicrobial resistance data, as well as reporting of prevalence data on zoonoses and microbiological agents and contaminants in food, foodborne outbreak data, animal population data and disease status data. For data collection purposes, EFSA has created the Data Collection Framework (DCF) application. The present report provides data dictionaries to guide the reporting of information deriving from 2022 under the framework of Directive 2003/99/EC, Regulation (EU) 2017/625, Commission Implementing Regulation (EU) 2019/627 and Commission Implementing Decision (EU) 2020/1729. The objective is to explain in detail the individual data elements that are included in the EFSA data models to be used for XML data transmission through the DCF. In particular, the data elements to be reported are explained, including information about the data type, a reference to the list of allowed terms and any additional business rule or requirement that may apply.

Research – Manual for reporting on zoonoses and zoonotic agents, within the framework of Directive 2003/99/EC, and on some other pathogenic microbiological agents for information derived from the year 2022



This reporting manual provides guidance to European Union (EU) Member States (MSs) for reporting on zoonoses and zoonotic agents in animals, food and feed under the framework of Directive 2003/99/EC, Regulation (EU) 2017/625, Commission Implementing Regulation (EU) 2019/627 and of Commission Delegated Regulation (EU) 2018/772 and also on the reporting of other pathogenic microbiological agents or contaminants in food. The objective of this manual is to harmonise and streamline reporting by MSs to ensure that the data collected are relevant and comparable for analysis at the EU level. This manual covers all the zoonoses and zoonotic agents included under the current data collection system run by the European Food Safety Authority (EFSA). Detailed instructions are provided on the reporting of data in tables and information in text forms. The instructions given relate to the description of the sampling and monitoring schemes applied by the MSs, as well as the monitoring results. Special reference is made to data elements which allow trend watching over time and the analysis of sources of zoonotic agents at the EU level. This manual is specifically aimed at guiding the reporting of information deriving from the year 2022.

Research – Study on bacterial infection in older individuals

News Medical

The older population is prone to microbial infections, which can lead to death. Hence, it is important to understand why this group is vulnerable to microbial infection, especially bacterial infection. A recent Scientific Reports study linked data from two sources to understand the determining factors for microbial infection in the older population in the UK.

The prevalence of bacterial infection significantly increases with age. According to English surveillance data, the incidence of Escherichia coli (E. coli) bacteria is around ten times more in men who are between 45 and 64 years of age and around 100 times more in men above 75 years of age, compared to the younger age group, i.e., those between 15 and 44 years of age. Similar trends were observed with Staphylococcus aureusStreptococcus pneumoniae, and Streptococcus pyogenes bacteria.

Currently, there is no clear explanation for why older individuals are more vulnerable to microbial infections. Nevertheless, environmental risk factors, such as nutrition, lifestyle, and housing, have been deemed possible contributing factors. In addition, the levels of C reactive proteins (CRP) could contribute to individual infection risk.

Serological studies have indicated that aging is associated with a gradual decrease in adaptive immunity, i.e., T-cell responses and antibody levels, which leads to an increase in pneumococcal pneumonia and herpes zoster infections.

In addition to radiological imaging, microbiological sampling (e.g., blood, urine, sputum, peritoneal fluid, and cerebrospinal fluid) can also be used to diagnose an infection by identifying the causal organism of the infection. In England, microbiological specimens are typically processed in hospital laboratories under the National Health Service.

About the Study

The current study used a large-scale population cohort, namely the UK Biobank (UKB), to understand the determining factors of bacterial infection and how it influences subsequent health-related problems.

UKB is a prospective cohort that contains information on around 500,000 men and women aged between 40 and 69 between 2006 and 2010. Initially, this cohort was designed to evaluate the environmental and genetic determinants that lead to common life-threatening diseases.

Public Health England (PHE) has established a second-generation surveillance system (SGSS) to monitor and improve public health. The SGSS dataset contains regularly updated information on human pathogens, such as Campylobacter, Salmonella, and other foodborne pathogens. Additionally, it contains antimicrobial test reports against important pathogens.

The current study demonstrated the possibility of linking UKB prospective cohort data with a national dataset containing information on microbial culture in England (SGSS).

Research – Antimicrobial Phage Spray Effective Against Foodborne Bacteria, Including Multidrug Resistant E. Coli

Food Safety.Com

Researchers at McMaster University have developed a new, highly effective tool to mitigate bacterial contamination of foods, including pathogens displaying antimicrobial resistance (AMR). The technology involves the application of bacteriophages (phages)—benign viruses that eat bacteria—to goods in the form of microgels.

Phages are natural predators to bacteria, and because phages attack bacteria in a highly targeted manner, they can be used in food and agriculture without disturbing the balance of microbial communities. Phage products have been approved by the US Food and Drug Administration (FDA) for controlling dangerous bacterial contaminants such as Escherichia coli in food products. Though they do not affect the taste, texture, and nutritional quality of foods, phages are not widely used by industry due to challenges with delivery and stability of phage products.