Bacterial co-infected pneumonia is an acute inflammatory reaction of the lungs mainly caused by Gram-negative bacteria. Antibiotics are urgently important but have the disadvantage of antibacterial resistance, and alternative treatments with medicinal plants are attractive. On the Qinghai–Tibet Plateau, Thalictrum delavayi Franch. (T. delavayi) is an important member of the buttercup family (Ranunculaceae), is rich in alkaloids and has been used in folk medicine for thousands of years. In this study, the extraction process of total alkaloids from the whole T. delavayi plant was optimized and the extract’s therapeutic potential against pulmonary infection caused by Klebsiella pneumoniae and Escherichia coli was investigated. The results showed that the optimum experimental conditions for the total alkaloids (2.46%) from T. delavayi were as follows: hydrochloric acid volume fraction of 0.8%, solid–liquid ratio of 1:12 and sonication time of 54 min. The treatment reduced bacterial counts, white blood cell counts and inflammatory cell classification in bronchoalveolar lavage fluid (BALF) and the levels of inflammatory cytokines interleukin-4 (IL-4), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), procalcitonin (PCT) and C-reactive protein (CRP), procalcitonin (PCT) and C-reactive protein (CRP) in the serum in experimental groups. The results in our experimental preliminary work suggested that the total alkaloids from T. delavayi had therapeutic effects on mice with Klebsiella pneumoniae and Escherichia coli mixed infectious pneumonia, providing experimental support for the plant’s therapeutic potential in treating pulmonary infections caused by Klebsiella pneumoniae and Escherichia coli.

Tibetan pig is a unique pig breed native to the Qinghai–Tibet Plateau. To investigate viral communities associated with porcine respiratory disease complex (PRDC), 167 respiratory samples were collected from Tibetan pigs in the Ganzi Tibetan autonomous prefecture of Sichuan province. Following library construction and Illunima Novaseq sequencing, 18 distinct viruses belonging to 15 viral taxonomic families were identified in Tibetan pigs with PRDC. Among the 18 detected viruses, 3 viruses were associated with PRDC, including porcine circovirus type 2 (PCV-2), Torque teno sus virus (TTSuV), and porcine cytomegalovirus (PCMV). The genomic sequences of two PCV-2 strains, three TTSuV strains, and one novel Porprismacovirus strain were assembled by SOAPdenovo software (v2). Sequence alignment and phylogenetic analysis showed that both PCV-2 strains belonged to PCV-2d, three TTSuVs were classified to TTSuV2a and TTSuV2b genotypes, and the Porprismacovirus strain PPMV-SCgz-2022 showed a close genetic relationship with a virus of human origin. Recombination analysis indicated that PPMV-SCgz-2022 may have originated from recombination events between Human 16,806 × 66-213 strain and Porcine 17,668 × 82-593 strain. Furthermore, the high proportion of single infection or co-infection of PCV2/TTSuV2 provides insight into PRDC infection in Tibetan pigs. This is the first report of the viral communities in PRDC-affected Tibetan pigs in this region, and the results provides reference for the prevention and control of respiratory diseases in these animals.

Cryptosporidium spp. and Giardia intestinalis are important zoonotic protozoa that are closely related to diarrhea and cause considerable economic losses in the livestock breeding industry. Ganzi is one of the main production areas for yaks in China, but there have been few reports on the occurrence of Cryptosporidium spp. and G. intestinalis in yaks. This study used PCR-based sequencing techniques to survey the prevalence and species/genotypes of Cryptosporidium spp. and G. intestinalis in faecal samples from 223 yaks in Ganzi, Sichuan Province. The positive rate of Cryptosporidium spp. was 7.2% (16/223), with the highest positive rate of yaks found in Yajiang (37%, 10/27), which was significantly higher than that in Litang (3.1%, 4/130) and Seda (3%, 2/66). The positive rate of Cryptosporidium spp. in young animals aged 24 months (3.3%, 3/90). Three Cryptosporidium species were found by sequence analysis of 18S rRNA locus, namely C. andersoni, C. ryanae, and C. bovis. The total positive rate of G. intestinalis was 15.7% (35/223), with significant differences identified between Yajiang (40.7%, 11/27), Litang (17.7%, 23/130), and Seda (1.5%, 1/66). One genotype (assemblage E) was found by analyzing the sequence of gdh, bg, and tpi loci. Meanwhile, co-infection of Cryptosporidium spp. and Giardia intestinalis was identified in five samples. The present study explores the infection of Cryptosporidium spp. and G. intestinalis from yaks in Ganzi, aiming to enrich our understanding of the occurrence of these protozoa in livestock.

Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), is a major infectious disease that poses a severe threat to the global swine industry. To investigate the role of miRNAs in the infection and susceptibility of PRRSV, four miRNA libraries were constructed and sequenced from PRRSV-infected and mock-infected of Tibetan pigs and Large White pigs at 7 days post-infection. A novel miRNA, miR-novel-80, was differentially expressed between PRRSV-infected and mock-infected porcine alveolar macrophages from 2 pig breeds. Importantly, the over-expression of miR-novel-80 inhibited the replication of a PRRSV-1 strain and multiple lineages (L1, L5, and L8) of PRRSV-2 strains in a dose-dependent manner. Bioinformatic predictions and experimental validation demonstrated that miR-novel-80 restricts viral replication through a dual antiviral mechanism. Directly, it targets the PRRSV nsp1-coding region within the ORF1a to suppress viral proliferation. Indirectly, miR-novel-80 specifically down-regulates the expression of host factor CXXC finger protein 4 (CXXC4). This reduction relieves the suppression of the Wnt/β-catenin signaling pathway, which in turn activates NF-κB-dependent innate immune responses to further inhibit PRRSV infection. Collectively, this study investigates the biological characteristics of miR-novel-80 and unveils its underlying molecular mechanisms in restricting PRRSV infection in vitro. However, its biological function and anti-PRRSV therapeutic effect in vivo need further investigation.

Porcine reproductive and respiratory syndrome (PRRS), caused by PRRS virus (PRRSV), poses a serious threat to the global swine industry. Although modified live virus (MLV) vaccines have been widely used in the field for PRRS prevention for decades, the safety and efficacy of these vaccines have long been controversial. Here, we report a rare recombination pattern in China: the emergence of a novel NADC30-like PRRSV strain recombined from two MLV-like strains. Genome comparative analysis reveals that the SCMS2025 isolate has a non-continuous 136-amino acid deletion in the NSP2 protein and shares the highest nucleotide identity of 87.6% with lineage 5 (L5) strains. Phylogenetic analysis showed that SCMS2025 was classified into L1 (NADC30-like) strains based on ORF5 genotyping, whereas it belonged to a single branch between L1 and L5 strains based on the complete genomic sequences. Strikingly, genomic recombination analysis revealed that the newly emerged PRRSV isolate likely resulted from complex recombination events between NADC30-like and two MLV-like strains (RespPRRS MLV and TJbd14-1 MLV-like strains). Furthermore, SCMS2025 infection caused transient overt clinical signs followed by rapid recovery, indicating that the novel PRRSV isolate is a low pathogenic strain. Notably, all SCMS2025-inoculated piglets remained seronegative for PRRSV-specific antibodies throughout the entire 14-day observation period, suggesting a delayed onset of the host humoral immune response. Our study provides evidence for the ongoing evolution of PRRSV through inter lineage recombination and highlights the urgent need for safe and effective vaccines.