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Holland Davenport posted an update 5 hours, 31 minutes ago
Heterofermentative Lentilactobacillus hilgardii isolated from sugarcane silage, has recently been proposed as a silage inoculant to increase aerobic stability. Various conditions can influence the activity of LAB and their ability to alter silage quality (e.g., DM content and length of conservation). The aim of this study has been to evaluate the effect of L. hilgardii on the fermentation quality and aerobic stability of whole crop corn silage with different DM contents (from 26 to 45%), conserved for various conservation lengths (13-272 days). The silages were analyzed for their DM content, pH, fermentative profile, microbial count, and aerobic stability. L. hilgardii showed a positive effect on improving the aerobic stability of silages, due its ability to produce acetic acid, and reduced the yeast count. VBIT-12 nmr The acetic acid content increased as the conservation period increased and decreased as the DM content increased. The yeast count was reduced during conservation in a DM dependent manner and the inoculation with LH determined a reduction in the count of 0.48 log cfu/g. The aerobic stability increased as the conservation period increased, and the treatment with LH on average increased the aerobic stability by 19 h. The results of this experiment suggest that higher aerobic stability could be achieved in corn silages by ensiling at medium or low DM contents, or by increasing the length of conservation if a higher DM content at ensiling is needed. The inoculation with LH helps to improve the aerobic stability of corn silages by reducing the yeast count.The long-term colonization of Helicobacter pylori can cause various gastrointestinal diseases, and its high genetic variability is prone to antibiotic resistance and leads to failure of clinical treatment. Intracellular survival also contributes to the drug tolerance of H. pylori. Patchouli alcohol (PA) shows a highly efficient activity against H. pylori in vitro and in vivo. And this study aims to explore whether PA can reduce the resistance of H. pylori and determine the underlying mechanism. Checkerboard and time-kill bactericidal curve assay reveal that the combination of PA and clarithromycin (CLR) promoted the inhibition and bactericidal effect against H. pylori. Stimulation of CLR leads to the internalization of H. pylori, but PA can effectively inhibit the invasion induced by CLR. Compared with antibiotics, PA remarkably eradicated the intracellular H. pylori, and this intracellular sterilized ability was further improved in combination with antibiotics (CLR and metronidazole). The expression of H. pylori efflux pump genes (hp0605, hp1327, and hp1489) was dose-dependently downregulated by PA. Digital droplet PCR indicated that the H. pylori mutant of A2143G can be inhibited by PA. Cellular uptake and transport assays showed that PA is rapidly absorbed, which promotes its activity against intracellular bacteria. Therefore, PA can act synergistically with CLR as a candidate treatment against drug-resistant H. pylori.Listeria monocytogenes (L. monocytogenes) is often associated with processed food as it can form biofilms that represent a source of contamination at all stages of the manufacturing chain. The control and prevention of biofilms in food-processing plants are of utmost importance. This study explores the efficacy of prospect molecules for counteracting bacterial mechanisms leading to biofilm formation. The compounds included the phytomolecule tomatidine, zinc chloride (ZnCl2), ethylenediaminetetraacetic acid (EDTA), and a more complexed mixture of bacterial compounds from coagulase-negative staphylococci (CNS exoproducts). Significant inhibition of L. monocytogenes biofilm formation was evidenced using a microfluidic system and confocal microscopic analyses (p less then 0.001). Active molecules were effective at an early stage of biofilm development (≥50% of inhibition) but failed to disperse mature biofilms of L. monocytogenes. According to our findings, prevention of surface attachment was associated with a disruption of bacterial motility. Indeed, agar cell motility assays demonstrated the effectiveness of these molecules. Overall, results highlighted the critical role of motility in biofilm formation and allow to consider flagellum-mediated motility as a promising molecular target in control strategies against L. monocytogenes in food processing environments.For microbial source tracking (MST), the 16S ribosomal RNA genes (rDNA) of host-specific bacteria and mitochondrial DNA (mtDNA) of animal species, known to cause fecal contamination of water, have been commonly used as molecular targets. However, low levels of contamination might remain undetected by using these DNA-based qPCR assays. The high copy numbers of ribosomal RNA (rRNA) could offer a solution for such applications of MST. This study compared the performance of eight MST assays GenBac3 (general Bacteroidales), HF183 (human), BacCan (dog), Rum-2-Bac (ruminant), Pig-2-Bac (swine), Gull4 (gull), GFD, and Av4143 (birds) between rRNA-based and rDNA-based approaches. Three mtDNA-based approaches were tested DogND5, SheepCytB, and HorseCytB. A total of 151 animal fecal samples and eight municipal sewage samples from four regions of Finland were collected for the marker evaluation. The usability of these markers was tested by using a total of 95 surface water samples with an unknown pollution load. Overall, e rRNA-based approach for MST assays targeting bird fecal contamination. In the case of mammal-specific MST assays, the use of the rRNA template increases the sensitivity but may reduce the specificity and accuracy of the assay. The finding of increased sensitivity calls for a further need to develop better rRNA-based approaches to reach the required assay performance.Bacterial conjugation is a widespread and particularly efficient strategy to horizontally disseminate genes in microbial populations. With a rich and dense population of microorganisms, the intestinal microbiota is often considered a fertile environment for conjugative transfer and a major reservoir of antibiotic resistance genes. In this mini-review, we summarize recent findings suggesting that few conjugative plasmid families present in Enterobacteriaceae transfer at high rates in the gut microbiota. We discuss the importance of mating pair stabilization as well as additional factors influencing DNA transfer efficiency and conjugative host range in this environment. Finally, we examine the potential repurposing of bacterial conjugation for microbiome editing.