A total of 78 Listeria monocytogenes isolates from a pork processing plant and the respective meat markets in southern China were examined. This number includes 60 isolates from pork at markets, 5 from cooked pork products at markets, 10 from pork at a processing plant, and 3 from food-contact surfaces at the processing plant. All isolates were subjected to serotyping, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and molecular basis of antibiotic resistance. Four serogroups were identified among the 78 tested isolates, with serogroup I (serotypes: 1/2a and 3a) being predominant (42.3%, 33/78). Antimicrobial resistance was most frequently observed for tetracycline (20.5%, 16/78), streptomycin (9.0%, 7/78), cefotaxime (7.7%, 6/78), and gentamicin (6.4%, 5/78). Multiple resistances occurred among 10.2% (8/78) isolates. All strains were sensitive to ampicillin, ampicillin/sulbactam, imipenem, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, and vancomycin. Two isolates were resistant to five antimicrobials. Twelve strains carried tet(M) and located on Tn916. PFGE analysis revealed genetic heterogeneity among individual serotypes. Two predominant PFGE types were found persistent from the processing plant to markets indicating that these two types of isolates were able to survive under environmental adverse conditions from the processing plant to markets, which need to be monitored. Compared to samples from the pork processing plant, the prevalence of L. monocytogenes in meat market samples tended to be higher, serovar was more variable, and the antibiotic resistance range was wider, probably due to secondary contamination. Therefore, stringent hygiene measures and bacteriological controls should be observed to reduce the risk of transmission of L. monocytogenes from food to humans.

Mycorrhizal fungi, a category of fungi that form symbiotic relationships with plant roots, can participate in the induction of plant disease resistance by secreting phosphatase enzymes. While extensive research exists on the mechanisms by which mycorrhizal fungi induce resistance, the specific contributions of phosphatases to these processes require further elucidation. This article reviews the spectrum of mycorrhizal fungi-induced resistance mechanisms and synthesizes a current understanding of how phosphatases mediate these effects, such as the induction of defense structures in plants, the negative regulation of plant immune responses, and the limitation of pathogen invasion and spread. It explores the role of phosphatases in the resistance induced by mycorrhizal fungi and provides prospective future research directions in this field.

Truffles are world-renowned premium commodities. Due to their unique aroma and rarity, the price of truffles has always been very high. In this study, Diethylaminoethyl anion exchange chromatography and gel filtration were employed for polysaccharide purification from two different species of Chinese truffles. Three polysaccharide fractions were obtained from Tuber panzhihuanense and referred to as TPZ-NP, TPZ-I, and TPZ-II. Additionally, two polysaccharide fractions were purified from T. pseudoexcavatum (TPD-NP and TPD-I). The results of structural elucidation indicated that the polysaccharide from different species showed different monosaccharide composition and linkage units, as well as molecular weight. Two of the polysaccharide fractions with the highest yield, TPZ-I and TPD-I, were chosen for biological testing. The results indicated that both fractions displayed antioxidant properties through mediation of the intestinal cellular antioxidant defense system, which could protect cultured intestinal cells from oxidative stress-induced damage and cell viability suppression. The TPD-I fraction showed stronger antioxidant effects, which may be due to the difference in structure. Further study on the structure-activity relationship is needed to be done.