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Category Archives: antifungal
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.
Posted in Antibacterial, Antibiotic Resistance, antifungal, antimicrobial resistance, Antimicrobials, Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk
Research – Bread Biopreservation through the Addition of Lactic Acid Bacteria in Sourdough
Nowadays, the consumer seeks to replace synthetic preservatives with biopreservation methods, such as sourdough in bread. Lactic acid bacteria (LAB) are used as starter cultures in many food products. In this work, commercial yeast bread and sourdough breads were prepared as controls, as well as sourdough breads with L. plantarum 5L1 lyophilized. The impact of L. plantarum 5L1 on the properties of bread was studied. Antifungal compounds and the impact on the protein fraction by the different treatments in doughs and breads were also analyzed. In addition, the biopreservation capacity of the treatments in breads contaminated with fungi was studied and the mycotoxin content was analyzed. The results showed significant differences with respect to the controls in the properties of the bread and a higher total phenolic and lactic acid content in breads with higher amounts of L. plantarum 5L1. In addition, there was a higher content of alcohol and esters. Furthermore, adding this starter culture produced hydrolysis of the 50 kDa band proteins. Finally, the higher concentration of L. plantarum 5L1 delayed fungal growth and reduced the content of AFB1 and AFB2 compared to the control.
Posted in antifungal, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, fungi, LAB, lactic acid bacteria, Lactobacillus, Lactobacillus plantarum, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk
Research – Fighting Foodborne Pathogens with Natural Antimicrobials
The food industry has now started exploring natural alternatives for preserving food to reduce the dependency on chemical preservatives, some of which are linked to obesity and metabolic syndrome. Specifically, natural antimicrobials produced by plants and microorganisms like bacteria and fungi can kill food-borne pathogens like Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes and Clostridium botulinum and also food spoilage bacteria like Brochothrix thermosphacta, Lactobacillus spp., Bacillus spp. and Weissella spp., among others. Foodborne pathogens and spoilage microbes pose a serious health concern for consumers and destroy the appearance, texture and sensory characteristics of the food, affecting the food industry and consumers alike.
Posted in Antibacterial, antifungal, Antimicrobials, Bacillus, Brochothrix thermosphacta, Clostridium botulinum, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic, Research
Research – Unraveling the Antimicrobial Effectiveness of Coridothymus capitatus Hydrolate against Listeria monocytogenes in Environmental Conditions Encountered in Foods: An In Vitro Study
The increased resistance of bacteria to antimicrobials, as well as the growing interest in innovative and sustainable alternatives to traditional food additives, are driving research towards the use of natural food preservatives. Among these, hydrolates (HYs) have gained attention as “mild” alternatives to conventional antimicrobial compounds. In this study, the response of L. monocytogenes ATCC 7644 exposed to increasing concentrations of Coridothymus capitatus HY (CHY) for 1 h at 37 °C was evaluated by means of Phenotype Microarray, modelling the kinetic data obtained by inoculating control and treated cells into GEN III microplates, after CHY removal. The results revealed differences concerning the growth dynamics in environmental conditions commonly encountered in food processing environments (different carbon sources, pH 6.0, pH 5.0, 1–8% NaCl). More specifically, for treated cells, the lag phase was extended, the growth rate was slowed down and, in most cases, the maximum concentration was diminished, suggesting the persistence of stress even after CHY removal. Confocal Laser Scanner Microscopy evidenced a diffuse aggregation and suffering of the treated cells, as a response to the stress encountered. In conclusion, the treatment with HY caused a stressing effect that persisted after its removal. The results suggest the potential of CHY application to control L. monocytogenes in food environments.
Posted in antifungal, antimicrobial resistance, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Technology
Research – Antifungal Preservation of Food by Lactic Acid Bacteria
Fungal growth and consequent mycotoxin release in food and feed threatens human health, which might even, in acute cases, lead to death. Control and prevention of foodborne poisoning is a major task of public health that will be faced in the 21st century. Nowadays, consumers increasingly demand healthier and more natural food with minimal use of chemical preservatives, whose negative effects on human health are well known. Biopreservation is among the safest and most reliable methods for inhibiting fungi in food. Lactic acid bacteria (LAB) are of great interest as biological additives in food owing to their Generally Recognized as Safe (GRAS) classification and probiotic properties. LAB produce bioactive compounds such as reuterin, cyclic peptides, fatty acids, etc., with antifungal properties. This review highlights the great potential of LAB as biopreservatives by summarizing various reported antifungal activities/metabolites of LAB against fungal growth into foods. In the end, it provides profound insight into the possibilities and different factors to be considered in the application of LAB in different foods as well as enhancing their efficiency in biodetoxification and biopreservative activities. View Full-Text
Posted in antifungal, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, fungi, LAB, lactic acid bacteria, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Probiotic, Research
Research – The use of antifungal oat‐sourdough lactic acid bacteria to improve safety and technological functionalities of the supplemented wheat bread
In the present study, predominant lactic acid bacteria (LAB) were isolated from oat sourdough. Then, the isolates were screened based on their in vitro antifungal activity. Subsequently, biotechnological capabilities of the selected LAB were evaluated in wheat bread supplemented with controlled fermented oat containing the isolate. Pediococcus pentosaceus was molecular identified as predominant antifungal isolate. Based on our results, fermented oat not only significantly (p < .05) reduced the mold expansion on the produced breads, but also improved the quality attributes of the product. Crumb porosity and antioxidant capacity of the supplemented bread revealed the positive effects of the isolate on textural and functional characteristics of the enriched bread. Wheat bread supplemented with controlled fermented oat had also the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity compared to the other samples. Accordingly, the potential applications of P. pentosaceus isolate as profunctional starter culture in processing of mixed wheat‐oat sourdough bread were verified.
Research -Efficient Reduction of Food Related Mould Spores on Surfaces by Hydrogen Peroxide Mist
The aim of the study was to evaluate the fungicidal effect of a H2O2 mist generating system for disinfection of spores of six food-related moulds (Alternaria alternata, Aspergillus flavus, Geotrichum candidum, Mucor plumbeus, Paecilomyces variotii, and Penicillium solitum) dried on stainless steel. Exposure to H2O2 mist for 2 or 4 h lead to >3 log reduction in mould spores in the majority of the tests. The presence of the soils 2% skim milk or 3% BSA did not significantly alter the fungicidal effect, while the presence of raw meat juice had an adverse fungicidal effect against Penicillium and Mucor in two out of three tests. Fungicidal suspension tests with liquid H2O2 confirmed the effectiveness of H2O2 on reducing the mould spores. Both the surface test and the suspension test indicated that P. variotii is more resistant to H2O2 compared to the other moulds tested. The study shows the efficiency of H2O2 mist on reducing food-related mould spores on surfaces. View Full-Text
Research – Bacteria killed by new light-activated coating
To stop the spread of disease, it could be used to coat phone screens and keyboards, as well as the inside of catheters and breathing tubes, which are a major source of healthcare-associated infections (HCAIs).
The most well known HCAIs are caused by Clostridioides difficile (C. difficile), methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). They commonly occur during in-patient medical or surgical treatment, or from visiting a healthcare setting and pose a serious health threat, making them a key priority for the NHS to address*.
The research, published today in Nature Communications, is the first to show a light activated antimicrobial coating successfully killing bacteria in low intensity, ambient light (300 Lux), such as that found in wards and waiting rooms. Previously, similar coatings needed intense light (3,000 Lux), like that found in operating theatres, to activate their killing properties.
The new bactericidal coating is made of tiny clusters of chemically modified gold embedded in a polymer with crystal violet — a dye with antibacterial and antifungal properties.
Research – Antifungal Effect of Camellia Seed Cake Extract on Aspergillus flavus
Aspergillus flavus is a well-known, widespread fungus that contaminates a great number of crops used for human and animal consumption, but previous study showed that camellia seed cake was not susceptible to A. flavus. This study was designed to evaluate the antifungal effect of the active substance in camellia seed cake on the growth and production of aflatoxins of A. flavus. Eighty percent methanol extracts of camellia seed cake showed greater activity than that of 80% ethanol, ethyl acetate, and pure water against A. flavus. The filtrate from the 80% methanol extract was extracted with ethyl acetate and saturated n-butanol; among the extracts, the n-butanol phase exhibited strong inhibitory activity against A. flavus. The inhibitory zone diameter increased from 15.25 mm at 25 mg/mL concentration up to 22.00 mm at 100 mg/mL concentration. The mycelial dry weight was reduced significantly from 0.16 g at 25 mg/mL to 0.11 g at 100 mg/mL, whereas the aqueous and ethyl acetate phases exhibited weak antifungal activity and no activity, respectively. In addition, the n-Butanol phase inhibited the production of aflatoxin B1 effectively, caused mycelia deformity, and reduced the production of conidia. n-Butanol extract of camellia seed cake exhibited apparent antagonistic effect on the growth and aflatoxin production of A. flavus. The concentration of 100 mg/mL worked best. This study provides a scientific basis for further study of its inhibiting mechanism.
Research – Fungal diversity and frequency carried by housefly (Musca domestica L.) and their relation with stored grains in rural areas of Pakistan
Housefly (Musca domestica L.) contaminates food by transferring microbes. Fungi carried by houseflies cause postharvest losses by food spoilage produce mycotoxins and spread various infectious diseases in human beings and animals. This study was planned to determine the diversity and frequency of fungal species carried by houseflies and their relation with stored grains. Houseflies in the vicinity of stored wheat and rice grains were collected from the rural areas of four districts of Pakistan. Overall, 897, 631, and 687 fungal species were isolated from houseflies, rice, and wheat grains, respectively. Aspergillus and Fusarium species followed by Alternaria and Penicillium species were found dominant in houseflies, rice, and wheat grains. Correlation analyses revealed a significant association between most of the fungal species isolated from houseflies, wheat, and rice grains. The study concludes that a strong correlation of fungi exists between stored grains and houseflies around the unhygienic storage places.
It is highly important to understand the role of houseflies in spreading various fungal species to stored grains, particularly in our persisting rural grain storage system. Our study is first of its kind in which we have studied the correlation of fungal diversity and abundance between houseflies, wheat, and rice grains stored in the same vicinity/place/house. Our findings show a strong correlation in fungal diversity and abundance, isolated from flies and stored grains. This study demonstrates the role of houseflies in the dispersal of various fungal species to contaminate the stored grains. Therefore, appropriate measures should be taken to control the houseflies or their entrance to store houses. There is a strong need to give awareness and improve the grain storage system in houses, especially in rural areas, by food regulating authorities.