Colorectal cancer (CRC), a common malignant neoplasm of the digestive system globally, demonstrates pathological progression that is intricately linked not only to dysbiosis of the gut microbiota but also to the oral microbial ecosystem. The emerging concept of the “oral-gut axis” offers novel insights into the regulation of microbial interactions across different organs. Recent research indicates that Peptostreptococcus, a predominant genus within the oral microbiome, exhibits spatiotemporal correlations with the initiation and progression of CRC. This genus may influence intestinal microecological changes and CRC pathogenesis through the “oral-gut axis”. We explore the microbial interactions between oral and intestinal ecosystems, examining the multidimensional associations between specific Peptostreptococcus species (such as P. stomatis and P. anaerobius) and CRC development. Key considerations include the population heterogeneity of these species among CRC patients with varying clinical profiles, their dynamic evolution during the adenoma-carcinoma sequence, and their spatial distribution across different pathological stages. We synthesize mechanistic evidence illustrating the role of Peptostreptococcus in promoting tumorigenesis by enhancing cancer cell proliferation, inducing epithelial-mesenchymal transition, and remodeling the tumor microenvironment. Additionally, this article assesses the clinical potential of Peptostreptococcus as predictive biomarkers and therapeutic targets for CRC. Finally, we propose future directions for the development of targeted microbial intervention strategies against oral-derived pathogens, with the aim of stimulating scientific interest and encouraging further investigation in this emerging research area.

Heterotrophic nitrifying-aerobic denitrifying (HN-AD) bacteria can simultaneously complete nitrification and denitrification processes under aerobic conditions, significantly simplifying wastewater treatment procedures. These strains exhibit rapid growth, tolerance to extreme environments, and are widely applied in various wastewater treatments. This review summarizes the nitrogen removal pathways of HN-AD bacteria and highlights the potential of novel immobilization carriers (composite materials, magnetic nanocarriers, and biochar) for nitrogen removal across diverse wastewater sectors. It focuses on elucidating the fundamental principles, application cases, current research status, and future prospects of emerging immobilization technologies, including biomimetic mineralization immobilization, electrospun fiber immobilization, and 3D printing carrier immobilization. The enhanced effects of novel immobilization strategies on improving nitrogen removal efficiency and system stability are discussed. Finally, challenges and future prospects for HN-AD bacterial immobilization technology during fabrication and application are outlined.

The β-barrel assembly machinery (BAM) complex is an essential apparatus that is responsible for the assembly of β-barrel outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria. Its functional defects can lead to bacterial death, and thus it is established as a new target for antibacterial drug development. The subunit composition of the BAM complex varies across different bacterial species and in Escherichia coli, it is composed of a core subunit BamA and auxiliary lipoproteins BamB-E. BamA, as a member of the Omp85 family, mediates the folding and release of substrate OMPs through the dynamic conformational changes of its β-barrel structure that are regulated by lipoproteins. In the present review, we summarized recent progress in distinguishing the minimal functional unit, complete functional unit, and other functional units of the BAM complex in E. coli. Moreover, by reviewing the drug screening studies targeting the BAM complex, we provided an overview of new strategies to combat the drug resistance of Gram-negative bacteria.

In recent years, the widespread application of new technologies such as viral metagenomics has expanded our understanding of viral diseases in giant pandas. In addition to the previously reported infections with canine distemper virus, rotavirus, and parvovirus, the viruses carried by giant pandas exhibit increasing diversity and unique genetic variation characteristics. The growing population size and density of giant pandas post serious challenges to the population biosecurity, especially the prevention and control of viral diseases. To better understand the epidemiological characteristics of viral diseases in giant pandas, as well as the current status of the prevention and control for the development of effective strategies, we review the studies about viral diseases in giant pandas. This paper systematically elucidates the infection characteristics and hazards of major viral pathogens, as well as diagnostic methods, treatment measures, and preventive strategies. Additionally, the paper explores the bottlenecks and challenges encountered in developing and applying vaccines for giant pandas and the difficulties faced in viral disease research and proposes future research directions and recommendations, aiming to provide a scientific basis for preventing and controlling viral diseases in giant pandas.

Amino acids serve as indispensable components and nutrients for living organisms, while recent studies have revealed that amino acid metabolism in pathogenic bacteria plays a pivotal role in their pathogenic processes. This review summarizes current research on the roles of different amino acids in facilitating the pathogenicity of pathogenic bacteria. Specifically, we highlight how Salmonella enterica utilizes l-aspartate to achieve colonization and dissemination within the inflamed intestine, and how branched-chain amino acids indirectly regulate the virulence of Staphylococcus aureusvia the global transcriptional regulator CodY. Additionally, we briefly outline the vital roles of amino acid metabolism throughout the infection processes of pathogenic bacteria. In-depth research into how amino acid metabolism promotes pathogenic processes will deepen our understanding of the underlying mechanisms and provide a theoretical basis for developing novel antibacterial strategies.

In recent years, as the antibiotic resistance of bacteria is aggravating, bacterial infections have brought severe challenges to disease prevention and control. Rapid and accurate identification of bacteria and their basic characteristics is extremely important for disease prevention and control, medical diagnosis, and scientific research. Compared with conventional detection methods such as plate culture counting, polymerase chain reaction (PCR), and adenosine triphosphate bioluminescence (ATP) bioluminescence, single-cell Raman spectroscopy has shown advantages and broad application prospects in bacterial classification and identification, bacterial pathogenicity and antibiotic resistance detection, and bacterial viability evaluation. This paper reviews the application of single-cell Raman technology in the field of bacteria, aiming to provide technical and application reference for practitioners engaged in the research on bacteria and Raman technology.

Objective To confirm the function of the farnesyl diphosphate (FPP) cyclase encoded by orf2064 in Streptomyces exfoliatus UC5319. Methods orf2064 was expressed in Escherichia coli, and the recombinant protein was purified and assayed with FPP as the substrate. The reaction products were detected by GC-MS. An FPP-overproducing E. coli strain was engineered for heterologous expression of orf2064. The fermentation products were analyzed by GC-MS, and the target compound was isolated and structurally characterized by nuclear magnetic resonance spectroscopy (NMR). In addition, orf2064 was heterologously expressed in Streptomyces, and the fermentation products were analyzed by GC-MS. Results GC-MS revealed that both the in vitro reaction of the recombinant protein ORF2064 and the heterologous expression products in E. coli and Streptomyces consistently produced a compound with identical retention time and [M⁺] of m/z 204. Subsequent isolation, purification, and NMR analysis confirmed this compound as calarene. Conclusion The FPP cyclase encoded by orf2064 in S. exfoliatus is identified as an calarene synthase.

Objective Screening fungi with the ability to degrade polyacrylamide (PAM) and analyzing the characteristics of their degradation products can provide a basis for clarifying the degradation mechanism. Methods Fungi capable of degrading PAM were screened from bauxite sludge and used to construct a composite fungal community, with the degradation products and morphological characteristics being determined under optimized conditions. Results The results showed that the three strains of fungi screened out were Trichoderma asperellum, Aspergillus flavus, and Aspergillus niger, which showed the degradation rates of 27.35%, 25.20%, and 23.04%, respectively, for PAM. The degradation conditions were optimized by the response surface method as initial pH 5.5, inoculum amount of 5.1%, and incubation temperature of 32 ℃, under which the fungal complex constructed with T. asperellum and A. flavus showed the PAM degradation rate of 45.44%, a viscosity reduction rate of 84.57%, and laccase and urease activities of 13.90 U/mL and 17.70 U/mL, respectively. A large number of hollows and cavities were formed on the surface of PAM after degradation. In addition, mycelial biofilm was observed on the surface. The degradation products showed -COOH and -OH functional groups. Conclusion The above results suggest that the fungal complex may degrade PAM into small molecules through the synergistic effects of mycelial physical erosion and extracellular enzymes.

Objective To systematically understand the antibiotic resistance and the distribution of resistance genes of intestinal antibiotic-resistant bacteria in Corvidae species on plateaus. Methods The conventional culture method and sequencing were employed to analyze 71 intestinal samples from five typical Corvidae species in plateau cities. Results A total of 70 bacterial strains were isolated, belonging to 25 species, 14 genera of 3 phyla. The highest number of strains was isolated from the medium containing sulfamethoxazole and the intestinal samples of Corvus macrorhynchos, with Enterococcus and Enterococcus mundtii being the dominant genus and species, respectively. The Kirby-Bauer disk diffusion test revealed that the isolated strains had the highest resistance rate to polymyxin antibiotics, and all the strains exhibited multidrug resistance, with nearly 40% being superbugs resistant to 10 or more antibiotics. Among the seven major categories of resistance genes, carbapenem resistance genes showed the highest detection rate, with tetD being the most frequently detected resistance gene. The detection rates of integrons and gene cassettes were both low. Conclusion Avian species of Corvidae exhibit high diversity and widespread prevalence of multidrug-resistant bacterial strains in their intestinal microbiota. Antibiotic resistance genes are widely present within these strains and exhibit significant transmission potential. As a result, they serve as veritable reservoirs and vectors for antibiotic-resistant bacteria and resistance genes, posing challenges and threats to human public health, medical care, and environmental safety. This study fills the gap in research on intestinal antibiotic-resistant bacteria and their antibiotic resistance in Corvidae birds, providing a scientific basis for subsequent assessments of the transmission risk of antibiotic resistance mediated by wild birds and the formulation of prevention and control strategies.

Objective To explore the application of hutC sequence analysis in the identification of Burkholderia cepacia complex (Bcc) at the species level. Methods We compared the sequences of hutC and the amino acid sequences of the encoded proteins and conducted phylogenetic analysis to theoretically assess the feasibility of using hutC for species-level identification of Bcc. Primers targeting the hutC of Bcc were designed, and the amplification conditions were optimized. With those of standard strains as templates, the hutC sequences of representative Bcc species were amplified. The sequencing results were compared with NCBI sequences for phylogenetic analysis to validate the theoretical hypothesis. Additionally, single nucleotide polymorphism analysis of hutC sequences was performed to identify species-level characteristic barcodes of Bcc. Results The hutC gene was relatively conserved between Bcc and non-Bcc. With the designed primers and amplification conditions, a 692 bp fragment of hutC was successfully amplified from 12 Bcc standard strains. Except for one strain with taxonomic errors, the remaining 11 strains had the comparison results consistent with those from the culture collection centers. The phylogenetic analysis based on hutC showed that different Bcc species could be clustered with high bootstrap values. A 12 nucleotide characteristic barcode of hutC was identified, which can rapidly distinguish different species of Bcc. Conclusion The gene hutC can serve as a new housekeeping gene target for accurate identification of Bcc at the complex and species levels.