Introduction: Mycoplasma hyopneumoniae (Mhp) infection significantly challenges Guangxi’s pig farms, yet its prevalence and molecular characteristics remain poorly understood. This study aimed to define circulating Mhp genotypes and their distribution in the region.Methods: From 2022–2023, 1,362 pig lung samples were randomly collected from 14 Guangxi regions. Mhp was detected using TaqMan Real-time PCR. Strong positive samples underwent multilocus sequence typing (MLST) of adk, rpoB, and tpiA genes to assess genetic relationships.Results: Of 1,362 samples, 655 (48.1%) were Mhp-positive. MLST amplification succeeded for 61 samples, revealing 27 sequence types (24 novel) across all 14 regions. Phylogenetic analysis indicated predominant circulation of Mhp types I and V. High Mhp incidence and substantial genetic diversity were observed.Discussion: This study provides comprehensive analysis of Mhp in Guangxi, revealing high prevalence and genetic diversity dominated by types I and V. These findings expand understanding of Mhp epidemiology in China and offer a theoretical foundation for developing prevention and control strategies in Guangxi.

Porcine Teschovirus (PTV) is a highly prevalent pathogen within swine populations, primarily associated with encephalitis, diarrhea, pneumonia, and reproductive disorders in pigs, thereby posing a significant threat to the sustainable development of the pig farming industry. In this study, a novel strain of PTV was isolated from the feces of a pig exhibiting symptoms of diarrhea, utilizing PK-15 cell lines. The structural integrity of the viral particles was confirmed via transmission electron microscopy, and the viral growth kinetics and characteristics were evaluated in PK-15 cells. High-throughput sequencing facilitated the acquisition of the complete viral genome, and subsequent phylogenetic analysis and full-genome alignment identified the strain as belonging to the PTV 2 genotype. Further investigation revealed that infection with the PTV-GXLZ2024 strain induces phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α) in PK-15 cells, indicating activation of the unfolded protein response (UPR) through the PERK pathway, with minimal involvement of the IRE1 or ATF6 pathways. Notably, ATF4 protein expression was progressively downregulated throughout the infection, while downstream CHOP protein levels remained unchanged, indicating an incomplete UPR induced by PTV-GXLZ2024. Furthermore, PERK knockdown was found to enhance the replication of PTV-GXLZ2024. This study provides critical insights into the molecular mechanisms underlying PTV pathogenesis and establishes a foundation for future research into its evolutionary dynamics and interactions with host organisms.

Background Mycoplasma hyopmneumoniae (Mhp) is a swine pathogen bacterium, causing significant economic losses worldwide. In this study, total of 1362 samples of swine lung from 14 cities in Guangxi were collected randomly. And TaqMan Real-time PCR Detection Method was applied in the detection of Mhp. The strongly positive samples were used in the multilocus sequence typing (MLST). The purpose of this study is to investigate the prevalence of Mhp in Guangxi and to reveal the genotypes and distribution of Mhp in swine herds in Guangxi based on MLST. Results Out of 1362 samples, 655 samples were detected mhp positive. Among them 61 samples were successfully amplified three housekeeping genes (adk, rpoB and tpiA) simultaneously using MLST method. What is more, this study recorded 27 sequence types from 14 cities in Guangxi Province, including 24 new STs. From genetic evolution tree analysis, it can be revealed that the prevalent strains of Mhp in Guangxi, China are types II and V. All in all, the Mhp popular in Guangxi China have a high genetic diversity. Conclusions This is one of the most comprehensive study available for reporting the prevalence and molecular typing of Mhp in Guangxi China which will enrich the local database of Mhp prevalence in China and provide a theoretical basis for the prevention and control of Mhp in the Guangxi region of China.

Enterovirus G (EV-G) is an important enteric pathogen widely circulating in swine populations and is characterized by considerable genetic diversity and recombination potential. In recent years, recombinant EV-G strains carrying exogenous papain-like cysteine protease (PLCP) gene insertions have been increasingly reported; however, their genotype distribution and molecular characteristics in major pig-producing regions remain poorly understood. In this study, 356 clinical samples collected from Guangxi, southern China, between 2020 and 2025 were screened for EV-G, and 13 representative strains were subjected to whole-genome sequencing and sequence analysis. The overall EV-G positivity rate in Guangxi was 20.51% (73/356). Phylogenetic analysis showed that the 13 Guangxi EV-G strains were mainly classified into three genotypes, G1, G2, and G8, with G1 being the predominant genotype. Notably, PLCP gene insertions of 573–642 nt were identified at the 2C/3A junction in seven strains belonging to three distinct genotypes, G1, G2, and G8, demonstrating the cross-genotype distribution of PLCP insertions within a single geographic region. Phylogenetic analysis of the PLCP sequences demonstrated that all Guangxi-derived PLCP sequences clustered within the EV-G-PLCP clade and were clearly separated from the torovirus PLCP clade. Recombination analysis retained three potential recombination events with clearer combined support from RDP4 and SimPlot analyses, involving Guangxi strains GX3008, GX3022, and GX4292. Selection pressure analysis showed that the VP1 gene was overall under negative selection. Collectively, these findings demonstrate the co-circulation of multiple EV-G genotypes, the cross-genotype distribution of PLCP insertions, and the presence of potential recombination events in Guangxi. This study provides new evidence for understanding the genetic diversity, genomic plasticity, and regional molecular characteristics of EV-G, and also provides an important basis for future PLCP-related functional studies and continued EV-G surveillance.