Resistance associated substitutions (RASs) can reduce the efficacy of direct-acting antiviral agents (DAAs) targeting hepatitis C virus (HCV) and lead to treatment failure. Clinical data of HCV NS5A RASs prevalence are limited in China and need to be investigated. A total of 878 unique patient samples with different genotypes (GT) (1b: n = 489, 2a: n = 203, 3a: n = 60, 3b: n = 78, 6a: n = 48) were collected from around mainland China by KingMed Laboratory and analyzed for NS5A RASs distribution by Sanger sequencing. Phylogeographic analyses based on NS5A domain 1 sequences indicated circulation of both locally and nationally epidemic strains. Relatively high frequency of Y93H (14.1%) was only detected in GT1b but not in other subtypes. High frequency of L31M was found in both GT2a (95.6%) and GT3b (98.7%) sequences. Due to the overlapping incidence of A30K, 96% of GT3b isolates had NS5A RASs combination A30K + L31M, which confers high levels of resistance to most NS5A inhibitors. No RASs were detected in GT6a strains. Meanwhile, baseline NS5A RASs fingerprints were also evaluated in 185 DAA treatment-naive GT1b patients with next generation sequencing method. Patients presenting with Y93H had statistically higher entropy of HCV NS5A sequences. Taken together, subtype-specific distribution patterns of NS5A RASs were observed. GT1b patients with higher HCV complexity tend to have a greater chance of Y93H presence, while GT3b patients are naturally resistant to current NS5A inhibitors and their treatment may pose a challenge to real-world DAA application.

Toxoplasma gondii rhoptry proteins (TgROPs) are the major targets as key molecules for immunodiagnosis as well as immunoprophylaxis because of their initial presentation to the host immune system. In this work, it was aimed at evaluating the protection effect of TgROP21 DNA vaccine on experimental mice subjected to T. gondii challenge. The gene sequence encoding TgROP21 was inserted into the eukaryotic expression vector pVAX I, and western blotting indicates that the lysate of BHK cells transfected with pVAX-TgROP21 was specifically recognized as a band of about 82.6 kDa by serum obtained from a T. gondii infected chicken. The efficacy of intramuscular vaccination of BALB/c mice three times at weeks 0, 2, and 4 with pVAX-ROP21 was analyzed. The levels of IgG, IgG1, and IgG2a among pVAX-ROP21 vaccinated animals were integrally increased. It was uncovered by cytokine profile analyses that IFN-γ was significantly increased, while no significant changes were detected in interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-10 (IL-10). Additionally, we found that immunization with pVAX-ROP21 significantly prolonged survival time (13.50 ± 1.65 days) after challenge infection with the virulent T. gondii RH strain, in comparison to those of control animals (died within 10 days). Moreover, the number of brain cysts (1475 ± 163) in the animals subjected to pVAX-TgROP21 vaccination decreased remarkably (P < 0.05) compared to the blank control mice (2333 ± 473), and the size of brain cysts in pVAX-TgROP21 group was significantly smaller than the groups of blank, PBS and pVAXI. It was indicated that intense cell-mediated and humoral immunity was triggered and defense against T. gondii was partially induced after vaccination by TgROP21.

Lysine acetylation is a dynamic and highly conserved post-translational modification that plays a critical role in regulating diverse cellular processes. Trichinella spiralis is a foodborne parasite with a considerable socio-economic impact. However, to date, little is known regarding the role of lysine acetylation in this parasitic nematode. In this study, we utilized a proteomic approach involving anti-acetyl lysine-based enrichment and highly sensitive mass spectrometry to identify the global acetylated proteome and investigate lysine acetylation in T. spiralis. In total, 3872 lysine modification sites were identified in 1592 proteins that are involved in a wide variety of biological processes. Consistent with the results of previous studies, a large number of the acetylated proteins appear to be involved in metabolic and biosynthetic processes. Interestingly, according to the functional enrichment analysis, 29 acetylated proteins were associated with phagocytosis, suggesting an important role of lysine acetylation in this process. Among the identified proteins, 15 putative acetylation motifs were detected. The presence of serine downstream of the lysine acetylation site was commonly observed in the regions surrounding the sites. Moreover, protein interaction network analysis revealed that various interactions are regulated by protein acetylation. These data represent the first report of the acetylome of T. spiralis and provide an important resource for further explorations of the role of lysine acetylation in this foodborne pathogen.

Bacteriocins are ribosomally synthesized peptides or proteins possessing antibacterial activity against foodborne pathogens and spoilage bacteria. A novel bacteriocin, plantaricin LPL-1 was determined as a class IIa bacteriocin according to the YGNGV motif, and producer strain Lactobacillus plantarum LPL-1 was identified based on physio-biochemical characteristics and 16S rDNA sequence. The novel bacteriocin, plantaricin LPL-1 was purified by salt precipitation, cation exchange, gel filtration, and reverse phase high-performance liquid chromatography (RP-HPLC). The molecular mass of plantaricin LPL-1 was 4347.8467 Da by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis and entire amino acid sequence of plantaricin LPL-1 was VIADKYYGNGVSCGKHTCTVDWGEAFSCSVSHLANFGHGKC. Plantaricin LPL-1 possessed the merits of easy degradation by proteases, wide pH stability (2-10), high thermal stability (121°C, 20 min), surfactants stability and bactericidal activity against foodborne spoilage and pathogens bacteria. The mode action and membrane permeabilization of plantaricin was identified. The information of plantaricin LPL-1 indicated that it is not only a novel class IIa bacteriocin, but also a promising natural and safe biologic preservative for the food preservation industry.