Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium

Effect of carbohydrates on the adhesion of Bordetella bronchiseptica to the respiratory epithelium in rabbits

This study proposes an ecological approach for preventing respiratory tract infections caused by Bordetella bronchiseptica in mammals using a mixture of carbohydrates. In an in vivo study, 51-day-old New Zealand rabbits were treated with a solution containing 1 × 107 CFUs of B. bronchiseptica and 250 μg of one of the following carbohydrates: N acetylglucosamine (GlcNAc), N acetylgalactosamine (GalNAc), alpha methyl mannose (AmeMan), alpha methyl glucose (AmeGlc) and sialic acid (Neu5AC). Positive (B. bronchiseptica) and negative (Physiological Saline Solution (PSS)) controls were included. Animals treated with GlcNAc or AmeGlc showed no clinical signs of infection and exhibited a significant reduction (p < 0.05) in the severity of microscopic lesions evaluated in the nasal cavity and lung compared with the positive controls. Additionally, the presence of bacteria was not detected through microbiological isolation or PCR in the lungs of animals treated with these sugars. Use of a mixture of GlcNAc and AmeGlc resulted in greater inhibition of microscopic lesions, with a significant reduction (p < 0.05) in the severity of these lesions compared to the results obtained using individual sugars. Furthermore, the bacterium was not detected through microbiological isolation, Polymerase Chain Reaction (PCR) or indirect immunoperoxidase (IIP) in this group.

Profiling Chromatin Accessibility Responses in Goat Bronchial Epithelial Cells Infected with Pasteurella multocida

Pasteurella multocida can cause goat hemorrhagic sepsis and endemic pneumonia. Respiratory epithelial cells are the first line of defense in the lungs during P. multocida infection. These cells act as a mechanical barrier and activate immune response to protect against invading pathogenic microorganisms. Upon infection, P. multocida adheres to the cells and causes changes in cell morphology and transcriptome. ATAC-seq was conducted to determine the changes in the chromatin open region of P. multocida-infected goat bronchial epithelial cells based on transcriptional regulation. A total of 13,079 and 28,722 peaks were identified in the control (CK) and treatment (T) groups (P. multocida infection group), respectively. The peaks significantly increased after P. multocida infection. The specific peaks for the CK and T groups were annotated to 545 and 6632 genes, respectively. KEGG pathway enrichment analysis revealed that the specific peak-related genes in the T group were enriched in immune reaction-related pathways, such as Fc gamma R-mediated phagocytosis, MAPK signaling pathway, bacterial invasion of epithelial cells, endocytosis, and autophagy pathways. Other cellular component pathways were also enriched, including the regulation of actin cytoskeleton, adherent junction, tight junction, and focal adhesion. The differential peaks between the two groups were subsequently analyzed. Compared to those in the CK group, 863 and 11 peaks were upregulated and downregulated, respectively, after the P. multocida infection. Fifty-six known transcription factor motifs were revealed in upregulated peaks in the P. multocida-infected group. By integrating ATAC-seq and RNA-seq, some candidate genes (SETBP1, RASGEF1B, CREB5, IRF5, TNF, CD70) that might be involved in the goat bronchial epithelial cell immune reaction to P. multocida infection were identified. Overall, P. multocida infection changed the structure of the cell and caused chromatin open regions to be upregulated. In addition, P. multocida infection actively mobilized the host immune response with the inflammatory phenotype. The findings provide valuable information for understanding the regulatory mechanisms of P. multocida-infected goat bronchial epithelial cells.

Prospective bacterial and fungal sources of hyaluronic acid: A review

The unique biological and rheological properties make hyaluronic acid a sought-after material for medicine and cosmetology. Due to very high purity requirements for hyaluronic acid in medical applications, the profitability of streptococcal fermentation is reduced. Production of hyaluronic acid by recombinant systems is considered a promising alternative. Variations in combinations of expressed genes and fermentation conditions alter the yield and molecular weight of produced hyaluronic acid. This review is devoted to the current state of hyaluronic acid production by recombinant bacterial and fungal organisms.

Mass spectrometric analysis of lipid A obtained from the lipopolysaccharide ofPasteurella multocida

LC/MS-based variant profiling of lipid A component of endotoxic lipopolysaccharides ofPasteurella multocidatype B:2, a causative agent of haemorrhagic septicaemia in water buffalo and cattle.