Zinc oxide combats foodborne pathogensActive Packaging of Immobilized Zinc Oxide Nanoparticles Controls Campylobacter jejuni in Raw Chicken Meat.
We set out to explore how zinc oxide nanoparticles (ZnO NPs) could help control the bacteria responsible for food poisoning in raw chicken meat. Our approach involved integrating these nanoparticles into packaging materials to see if they could effectively inactivate Campylobacter jejuni, a common and concerning pathogen in poultry.
Through our experiments, we discovered that immobilizing ZnO NPs in functional pads placed under raw chicken could dramatically reduce bacterial counts. In fact, we saw a reduction from about 4 log CFU to an undetectable level within just three days when storing chicken at 4°C. Notably, we monitored zinc levels in the chicken meat, confirming a safe release of zinc without any migration of nanoparticles onto the food. This means that we can help keep raw chicken safe and fresh without compromising its integrity or quality.
Not only did we find that these functional pads inactivated the harmful bacteria, but we also noted a related increase in lactic acid production, which plays a role in further protecting the meat. Our findings open up new avenues for using zinc in food packaging, offering a way to enhance food safety without directly adding chemicals to the food itself. Overall, this study highlights the potential for nanotechnology to play a significant role in managing foodborne pathogens like Campylobacter in poultry products.
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Calcium enhances antimicrobial efficacyImpact of the calcium concentration on the efficacy of phage phiIPLA-RODI, LysRODIΔAmi and nisin for the elimination of Staphylococcus aureus during lab-scale cheese production.
We examined how calcium concentration impacts the effectiveness of different antimicrobials in reducing Staphylococcus aureus, a harmful pathogen that can cause food poisoning. Our study focused on a combination of three agents: a bacteriophage called phiIPLA-RODI, an engineered lytic protein named LysRODIΔAmi, and the bacteriocin nisin.
The experiments took place during lab-scale cheese production using two calcium chloride (CaCl) concentrations (0.2% and 0.02%) and involved storing the cheese at two different temperatures (4°C and 12°C). Through our observations, we noticed that mixing these antimicrobials typically resulted in a better reduction of S. aureus than using them individually.
However, this enhanced effectiveness was generally additive rather than synergistic. We did find one noteworthy exception: at 12°C, where the pathogen could still grow, the combination of all three agents showed a synergistic effect after 14 days of storage. Importantly, we also discovered that higher levels of calcium significantly boosted the activity of LysRODIΔAmi, allowing us to use substantially less protein while still being effective against the contamination.
Our findings suggest that using these antimicrobials together, especially in the presence of higher calcium concentrations, could be a promising strategy for controlling Staphylococcus aureus in dairy products without increasing the risk of resistance, ultimately keeping costs down.
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Calcium's importance in spore germinationDivalent Cation Signaling in Spore Germination.
We explored how calcium affects spore germination, which is crucial in the context of food poisoning. The research aimed to understand if calcium, particularly in a complex with dipicolinic acid (Ca-DPA), could initiate spore germination, as previous studies suggested it played a vital role.
Through our experiments, we observed that while Ca-DPA effectively stimulated spore germination, dipicolinic acid alone did not produce the same effect. This indicates that calcium is essential for promoting germination. Moreover, we found that not only calcium salts but also other divalent cations like manganese and magnesium contributed to this process, while zinc did not.
Interestingly, the study revealed that endogenous calcium and magnesium stored within spores were not critical for germination induction. Instead, it was the external calcium and manganese that proved necessary. Overall, our findings suggest that exogenous sources of divalent cations are more significant in triggering spore germination than the spores' internal reserves.
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Calcium enhances endolysin effectivenessCharacteristics for phage-encoded cell wall hydrolase of LysSAP27 to reduce staphylococcal food poisoning.
We investigated the effects of a phage-encoded cell wall hydrolase, known as LysSAP27, in combating staphylococcal food poisoning (SFP). This research focused on the potential role of calcium ions in enhancing the lytic activity of LysSAP27, which had been produced using recombinant technology.
Our findings revealed that LysSAP27 displays the greatest effectiveness at neutral pH and at a temperature of 30°C. We observed that the presence of calcium ions increased the enzyme’s lytic activity, suggesting that calcium might play a crucial role in enhancing the bactericidal action of this endolysin.
Importantly, when we applied 2 µM of LysSAP27 to milk contaminated with Staphylococcus, we noted a significant reduction in bacterial counts. Specifically, the treatment resulted in a decrease of 2.8 log CFU/mL within the first hour and 3.4 log CFU/mL after two hours. However, while we highlighted the stimulating effect of calcium on LysSAP27, we didn’t isolate the impact of calcium alone, which limits our ability to fully understand its direct contribution to preventing food poisoning.
As such, while LysSAP27 proves to be an effective antimicrobial agent against SFP, there’s still more to uncover regarding how calcium specifically influences this dynamic.
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Magnesium oxide shows promise against EHECA Macroporous Magnesium Oxide-Templated Carbon Adsorbs Shiga Toxins and Type III Secretory Proteins in Enterohemorrhagic , Which Attenuates Virulence.
We investigated how a macroporous magnesium oxide-templated carbon (MgOC) could help combat Enterohemorrhagic E. coli (EHEC), a common foodborne threat. MgOC effectively adsorbed harmful Shiga toxins and secretory proteins that contribute to EHEC's virulence while not affecting the bacteria's growth itself. Notably, infected mice treated with MgOC showed an extended survival period. This innovative material didn't harm healthy cells or gut bacteria. However, it also absorbed several antimicrobial agents, suggesting it could be combined with specific antibiotics to improve treatment options against EHEC infections.
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