Prevalence and contamination patterns of Listeria monocytogenes in Pleurotus eryngii (king oyster mushroom) production plants.

Listeria monocytogenes is a major foodborne pathogen that is well-known for its high mortality rate upon infection. In recent years, the edible mushroom has also been found to be an important source of L. monocytogenes, but the contamination sources in Pleurotus eryngii (the king oyster mushroom) were unclear. In this study, a total of 203 edible mushrooms and environmental samples from four P. eryngii production plants were obtained. As a result, 29 samples (14.3%) were positive for L. monocytogenes, including eight mushroom samples (13.3%, 8/60) and 21 associated environmental samples (14.7%, 21/143). The contamination of L. monocytogenes in plants A and B was more severe and was likely to originate from the mycelium stimulation machine. The isolates belonged to serogroups II.1 (4b-4d-4e), I.1 (1/2a-3a), and I.2 (1/2c-3c), and multilocus sequence typing (MLST) revealed that these L. monocytogenes strains belonged to five different sequence types (ST3, ST121, ST9, ST87, and ST224). The ST121 and ST3 isolates were only found in plants A and B, respectively. The isolates were carried by hly (29/29, 100%), inlB (23/29, 79.3%), inlA (29/29, 100%), inlC (29/29, 100%), inlJ (29/29, 100%), actA (19/29, 65.5%), iap (29/29, 100%), plcA (26/29, 100%), plcB (29/29, 100%), prfA (27/29, 93.1%), and mpl (29/29, 100%). Further study of inlA sequencing showed that 65.5% of strains (19/29) contained full-length InlA that was required for host cell invasion, whereas the mutation led to premature stop codons (PMSCs) at position 492 (type 6) on inlA alleles. All isolates in this survey were sensitive to gentamicin, kanamycin, sulbactam/ampicillin, trimethoprim-sulfamethoxazole, tetracycline, and doxycycline. The drug with the highest resistance is rifampicin (37.9%), followed by penicillin (24.1%) and ciprofloxacin (10.3%). Most multiply resistant strains are isolated from raw materials and equipment of the P. eryngii processing lines. Our study reflects the contamination patterns and potential risk of L. monocytogenes infection in P. eryngii production plants. The persistence of specific L. monocytogenes isolates (such as ST121 and ST3) may assist with contamination. In accordance with these results, the control of L. monocytogenes should focus on the environmental materials, especially in the mycelium stimulation stage. However, effective Listeria monitoring programs will allow for the improved development of Listeria control measures to minimize cross-contamination in the processing of P. eryngii.

IFN-α facilitates the effect of sorafenib via shifting the M2-like polarization of TAM in hepatocellular carcinoma.

Tumor-associated macrophages (TAMs) and how they are activated play critical roles in tumor progression and metastasis, and in hepatocellular carcinoma (HCC), they are associated with sorafenib resistance. Reprogramming of TAMs into M1-like macrophages has been proposed as an approach to stimulate tumor regression. Here we studied the collective effects of interferon-alpha (IFN-α) and sorafenib on HCC. We found that IFN-α delayed tumor growth and inhibited pulmonary metastasis in an orthotopic HCC implantation model. Via in vitro studies, we found that IFN-α treatment could reprogram M2-like RAW264.7 and THP-1 macrophage cells toward M1-like cells. In addition, we also found that IFN-α combined with a low dose of sorafenib has a synergistic inhibitory effect on HCC tumor growth and pulmonary metastasis without obvious toxicity in an in vivo mice model. Moreover, IFN-α increased sorafenib's therapeutic efficacy by shifting TAM polarization to an M1-like phenotype, increasing and activating intratumoral CD8+ T cells in HCCs. In conclusion, a combination of IFN-α and sorafenib have synergistic inhibitory effects on HCC growth and metastasis resulting from a shift in TAM polarization rather than their depletion. Our study supports the future clinical use of a combination of IFN-α and sorafenib for the treatment of advanced HCC.

A Comparative Transcriptome Analysis of Volvariella volvacea Identified the Candidate Genes Involved in Fast Growth at the Mycelial Growth Stage.

The edible straw mushroom, Volvariella volvacea, is one of the most important cultivated mushrooms in tropical and sub-tropical regions. Strain improvement for V. volvacea is difficult because of the unknown mechanisms involved in its growth regulation and substrate utilization. A comparative physiological and transcriptomic study was conducted between two commercially available straw mushroom strains (v9 and v26) to explore their fast-growth regulation mechanism(s). The physiological study showed that V. volvacea v9 had a shorter growth cycle and higher biological efficiency (4% higher) than that in v26. At least 14,556 unigenes were obtained from the four cDNA libraries (two replicates per strain). Among them, the expression of 1597 unigenes was up-regulated while 1352 were down-regulated. Four heat-shock proteins were highly expressed in v9, showing that v9 has the better ability to handle stresses and/or environmental changes. Moreover, up to 14 putative transporter genes were expressed at a higher level in v9 than those in v26, implying that v9 has a better ability to transport nutrients or export xenobiotics efficiently. Our report allows to identify the candidate genes involved in the fast growth requirement of V. volvacea, which represents a valuable resource for strain improvement in this commercially important edible mushroom.