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IMeta Jun 2024pretreatment mitigated infection in mice. improved gut microbiota disturbed by infection and significantly increased the level of intestinal linoleic acid in mice....
pretreatment mitigated infection in mice. improved gut microbiota disturbed by infection and significantly increased the level of intestinal linoleic acid in mice. Linoleic acid strengthened the intestinal epithelial barrier and reduced pathogen translocation partly by regulating NF-κB/MLCK pathway in a GPR40-dependent manner.
PubMed: 38898984
DOI: 10.1002/imt2.196 -
Applied Microbiology and Biotechnology Jun 2024Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This...
Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This study aimed to explore the antibacterial activity of three bacteriocins (nisin, enterocin Gr17, and plantaricin RX-8) and their ability to attenuate intestinal barrier dysfunction and inflammatory responses induced by Listeria monocytogenes, respectively. Bacteriocins have shown excellent antibacterial activity against L. monocytogenes without causing any cytotoxicity. Bacteriocins inhibited the adhesion and invasion of L. monocytogenes on Caco-2 cells, lactate dehydrogenase (LDH), trans-epithelial electrical resistance (TEER), and cell migration showed that bacteriocin improved the permeability of Caco-2 cells. These results were attributed to the promotion of tight junction proteins (TJP) assembly, specifically zonula occludens-1 (ZO-1), occludin, and claudin-1. Furthermore, bacteriocins could alleviate inflammation by inhibiting the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathways and reducing the secretion of interleukin-6 (IL-6), interleukin-1 β (IL-1β) and tumor necrosis factor α (TNF-α). Among three bacteriocins, plantaricin RX-8 showed the best antibacterial activity against L. monocytogenes and the most pronounced protective effect on the intestinal barrier due to its unique structure. Based on our findings, we hypothesized that bacteriocins may inhibit the adhesion and invasion of L. monocytogenes by competing adhesion sites. Moreover, they may further enhance intestinal barrier function by inhibiting the expression of L. monocytogenes virulence factors, increasing the expression of TJP and decreasing the secretion of inflammatory factors. Therefore, bacteriocins will hopefully be an effective alternative to antibiotics, and this study provides valuable insights into food safety concerns. KEY POINTS: • Bacteriocins show excellent antibacterial activity against L. monocytogenes • Bacteriocins improve intestinal barrier damage and inflammatory response • Plantaricin RX-8 has the best protective effect on Caco-2 cells damage.
Topics: Listeria monocytogenes; Bacteriocins; Humans; Caco-2 Cells; Anti-Bacterial Agents; Inflammation; NF-kappa B; Bacterial Adhesion; Tight Junction Proteins; Cytokines; Listeriosis; Cell Movement
PubMed: 38896287
DOI: 10.1007/s00253-024-13228-w -
International Journal of Molecular... May 2024Diarrhoea remains an important public health concern, particularly in developing countries, and has become difficult to treat because of antibacterial resistance. The...
Diarrhoea remains an important public health concern, particularly in developing countries, and has become difficult to treat because of antibacterial resistance. The development of synergistic antimicrobial agents appears to be a promising alternative treatment against diarrhoeic infections. In this study, the combined effect of tetracycline together with either nitroxoline, sanguinarine, or zinc pyrithione (representing various classes of plant-based compounds) was evaluated in vitro against selected diarrhoeic bacteria (, , , , , and ). The chequerboard method in 96-well microtiter plates was used to determine the sum of the fractional inhibitory concentration indices (FICIs). Three independent experiments were performed per combination, each in triplicate. It was observed that the combination of tetracycline with either nitroxoline, sanguinarine, or zinc pyrithione produced synergistic effects against most of the pathogenic bacteria tested, with FICI values ranging from 0.086 to 0.5. Tetracycline-nitroxoline combinations produced the greatest synergistic action against at a FICI value of 0.086. The combinations of the agents tested in this study can thus be used for the development of new anti-diarrhoeic medications. However, studies focusing on their in vivo anti-diarrhoeic activity and safety are required before any consideration for utilization in human medicine.
Topics: Drug Synergism; Tetracycline; Anti-Bacterial Agents; Microbial Sensitivity Tests; Alkaloids; Bacteria; Diarrhea; Humans; Pyridines; Nitroquinolines; Organometallic Compounds
PubMed: 38892226
DOI: 10.3390/ijms25116038 -
International Journal of Molecular... May 2024Flavonoids are an abundant class of naturally occurring compounds with broad biological activities, but their limited abundance in nature restricts their use in...
Flavonoids are an abundant class of naturally occurring compounds with broad biological activities, but their limited abundance in nature restricts their use in medicines and food additives. Here we present the synthesis and determination of the antibacterial and antioxidant activities of twenty-two structurally related flavonoids (five of which are new) by scientifically validated methods. Flavanones (-) had low inhibitory activity against the bacterial growth of MRSA 97-7. However, (C5,7,3',4' = OH) and (C5,7 = OH; C4' = SCH) had excellent bacterial growth inhibitory activity against Gram-negative (MIC = 25 µg/mL for both), while Chloramphenicol (MIC = 25 µg/mL) and (C5,7,3' = OCH; 4' = OH) showed inhibitory activity against Gram-positive (MIC = 25 µg/mL). From the flavone series (-), (C5,7,3',4' = OH), (C5,7,4' = OH; 3' = OCH) and (C5,7,4' = OH) showed good inhibitory activity against Gram-positive MRSA 97-7 (MIC = 50, 12, and 50 µg/mL, respectively), with being more active than the positive control Vancomycin (MIC = 25 µg/mL). (C5,7= OH; 4' = OCH) showed high inhibitory activity against and (MIC = 25 and 15 µg/mL, respectively). These data add significantly to our knowledge of the structural requirements to combat these human pathogens. The positions and number of hydroxyl groups were key to the antibacterial and antioxidant activities.
Topics: Anti-Bacterial Agents; Antioxidants; Flavonoids; Microbial Sensitivity Tests; Escherichia coli; Listeria monocytogenes; Flavanones; Methicillin-Resistant Staphylococcus aureus
PubMed: 38892186
DOI: 10.3390/ijms25115999 -
Animals : An Open Access Journal From... May 2024The inflammasome is a vital part of the host's innate immunity activated by cellular infection or stress. Our previous research identified the bovine SP110c isoform...
The inflammasome is a vital part of the host's innate immunity activated by cellular infection or stress. Our previous research identified the bovine SP110c isoform (bSP110c) as a novel activator of the inflammasome that promoted the secretion of proinflammatory cytokines IL-1β and IL-18 in macrophages infected with or stimulated with lipopolysaccharide (LPS). However, the exact molecular mechanism for inhibiting bSP110c-induced inflammasome activation requires further clarification. Here, the researchers identified bovine DDX3X (bDDX3X) as an NLRP3-associated protein and an inhibitor of the bSP110c-induced inflammasome in the human THP1 macrophage cell line. Immunoprecipitation showed that bDDX3X interacted with the bSP110c CARD domain via its helicase domain. The co-expression of bSP110c and bDDX3X in THP1 macrophages significantly prevented the bSP110c-induced activation of inflammasomes. In addition, both bDDX3X and bSP110c interacted with bovine NLRP3 (bNLRP3), and bDDX3X enhanced the interaction between bSP110c and bNLRP3. The expression of bDDX3X in nigericin-stimulated THP1 macrophages significantly suppressed NLRP3 inflammasome activation, ASC speck formation, and pyroptosis. These findings demonstrate that bDDX3X negatively regulates the bSP110c-mediated inflammatory response by restricting the activation of the NLRP3 inflammasome. This discovery unveils a novel regulatory mechanism involving bDDX3X and bSP110c in coordinating inflammasome activation and subsequent cell-fate decisions in LPS-treated macrophages and, in turn, constitutes a step forward toward the implementation of marker-assisted selection in breeding programs aimed at utilizing cattle's immune defenses.
PubMed: 38891697
DOI: 10.3390/ani14111650 -
Foods (Basel, Switzerland) May 2024() is an opportunistic foodborne pathogen that causes listeriosis in humans and animals, reaching up to 30% case mortality. There are only a few reports in Mexico...
() is an opportunistic foodborne pathogen that causes listeriosis in humans and animals, reaching up to 30% case mortality. There are only a few reports in Mexico about the strains found in various foods. The aim of this study was to determine the prevalence of , serogroups, virulence genes, and antimicrobial resistance in different foods from Reynosa, Tamaulipas, Mexico. strains were characterized by microbiological and molecular methods. Susceptibility to 12 antibiotics was determined according to CLSI and EUCAST. A total of 300 samples of seafood, pasteurized and raw milk, cheese, beef, and chicken were collected from supermarkets and retail markets. The presence of was detected in 5.6% of the samples. Most strains belonged to serogroups 4b, 4d, and 4e (68.4%). All strains presented a minimum of four virulence genes; the most common were , , and (92.1%). A high percentage of antimicrobial susceptibility was observed, with resistance only to STX-TMP (78.9%), STR (26.3%), MEM (21.0%), and E (2.6%). These results show that the foods in Reynosa, Tamaulipas, are a reservoir of and represent a potential health risk.
PubMed: 38890883
DOI: 10.3390/foods13111656 -
Foods (Basel, Switzerland) May 2024Brazilian artisanal cheeses have recently gained significant commercial prominence and consumer favor, primarily due to their distinctive sensory attributes and cultural... (Review)
Review
Brazilian artisanal cheeses have recently gained significant commercial prominence and consumer favor, primarily due to their distinctive sensory attributes and cultural and historical appeal. Many of these cheeses are made with raw milk and undergo a relatively short ripening period, sometimes ranging from 4 to 8 days, though it is usually shorter than the period stated by law. Moreover, there is insufficient evidence regarding the efficacy of a short ripening period in reducing certain zoonotic foodborne pathogens, such as spp., , and (as part of the complex). Additionally, a literature analysis revealed that the usual ripening conditions of Brazilian artisanal cheeses made with raw milk may be inefficient in reducing the levels of some hazardous bacterial, including spp., , coagulase-positive , , and , to the acceptable limits established by law, thus failing to ensure product safety for all cheese types. Moreover, the assessment of the microbiological safety for this type of cheese should be broader and should also consider zoonotic pathogens commonly found in bovine herds. Finally, a standardized protocol for evaluating the effectiveness of cheese ripening must be established by considering its peculiarities.
PubMed: 38890872
DOI: 10.3390/foods13111644 -
Foods (Basel, Switzerland) May 2024Loop-mediated isothermal amplification, LAMP, is nowadays the most popular isothermal nucleic acid amplification technique, and as such, several commercial, ready-to-use...
Loop-mediated isothermal amplification, LAMP, is nowadays the most popular isothermal nucleic acid amplification technique, and as such, several commercial, ready-to-use master mixes have flourished. Unfortunately, independent studies to determine their performance are limited. The current study performed an independent evaluation of the existing ready-to-use commercial LAMP master mixes WarmStart LAMP Kit, LavaLAMP™ DNA Master Mix, Saphir Bst Turbo GreenMaster, OptiGene Fast Master Mix ISO-004, and SynLAMP Mix. To reduce bias, three different genes, namely ( spp.), ( O157), and (), were targeted. The comparison was based on amplification speed, performance with decreasing DNA concentrations, and the effect of five typical LAMP reaction additives (betaine, DMSO, pullulan, TMAC, and GuHCl). Significant differences were observed among the different master mixes. OptiGene provided the fastest amplification and showed less detrimental effects associated with the supplements evaluated. Out of the chemicals tested, pullulan provided the best results in terms of amplification speed. It is noteworthy that the different additives impacted the master mixes differently. Overall, the current study provides insights into the performance of commercial LAMP master mixes, which can be of value for the scientific community to better select appropriate reagents when developing new methods.
PubMed: 38890864
DOI: 10.3390/foods13111635 -
Foods (Basel, Switzerland) May 2024Nisin is used as a natural food preservative because of its broad-spectrum antimicrobial activity against Gram-positive bacteria. However, free nisin is susceptible to...
Nisin is used as a natural food preservative because of its broad-spectrum antimicrobial activity against Gram-positive bacteria. However, free nisin is susceptible to various factors that reduce its antimicrobial activity. Milk protein, a protein derived from milk, has self-assembly properties and is a good carrier of bioactive substances. In this study, lactoferrin-nisin nanoparticles (L-N), bovine serum albumin-nisin nanoparticles (B-N), and casein-nisin nanoparticles (C-N) were successfully prepared by a self-assembly technique, and then their properties were investigated. The studies revealed that lactoferrin (LF) and nisin formed L-N mainly through hydrophobic interactions and hydrogen bonding, and L-N had the best performance. The small particle size (29.83 ± 2.42 nm), dense reticular structure, and good thermal stability, storage stability, and emulsification of L-N laid a certain foundation for its application in food. Further bacteriostatic studies showed that L-N enhanced the bacteriostatic activity of nisin, with prominent inhibitory properties against , , and , which mainly disrupted the cell membrane of the bacteria. The above results broaden our understanding of milk protein-nisin nanoparticles, while the excellent antibacterial activity of L-N makes it promising for application as a novel food preservative, which will help to improve the bioavailability of nisin in food systems.
PubMed: 38890836
DOI: 10.3390/foods13111606 -
Scientific Data Jun 2024Listeria monocytogenes (Lm) is a highly pathogenic bacterium that can cause listeriosis, a relatively rare food-borne infectious disease that affects farm, domestic,...
Listeria monocytogenes (Lm) is a highly pathogenic bacterium that can cause listeriosis, a relatively rare food-borne infectious disease that affects farm, domestic, wild animals and humans as well. The infected livestock is the frequent sources of Lm. Vaccination is one of the methods of controlling listeriosis in target farm animals to prevent Lm-associated food contamination. Here we report the complete sequence of the Lm strain AUF attenuated from a fully-virulent Lm strain by ultraviolet irradiation, successfully used since the 1960s as a live whole-cell veterinary vaccine. The de novo assembled genome consists of a circular chromosome of 2,942,932 bp length, including more than 2,800 CDSs, 17 pseudogenes, 5 antibiotic resistance genes, and 56/92 virulence genes. Two wild Lm strains, the EGD and the 10403S that is also used in cancer Immunotherapy, were the closest homologs for the Lm strain AUF. Although all three strains belonged to different sequence types (ST), namely ST12, ST85, and ST1538, they were placed in the same genetic lineage II, CC7.
Topics: Animals; Bacterial Vaccines; Genome, Bacterial; Listeria monocytogenes; Listeriosis; Vaccines, Attenuated
PubMed: 38886393
DOI: 10.1038/s41597-024-03440-8