Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

A novel vaccine strategy against Brucellosis using Brucella abortus multi-epitope OMPs vaccine based on Lactococcus lactis live bacterial vectors

Brucella infections typically occur in mucosal membranes, emphasizing the need for mucosal vaccinations. This study evaluated the effectiveness of orally administering Lactococcus lactis (L. lactis) for producing the Brucella abortus multi-epitope OMPs peptide. A multi-epitope plasmid was generated through a reverse vaccinology method, and mice were administered the genetically modified L. lactis orally as a vaccine. The plasmid underwent digestion, synthesizing a 39 kDa-sized protein known as OMPs by the target group. The sera of mice that were administered the pNZ8124-OMPs-L. lactis vaccine exhibited a notable presence of IgG1 antibodies specific to outer membrane proteins (OMPs), heightened levels of interferon (IFN-λ) and tumor necrosis factor alpha (TNF-α), and enhanced transcription rates of interleukin 4 (IL-4) and interleukin 10 (IL-10). The spleen sections from the pNZ8124-OMPs-L. lactis and IRIBA group had less morphological damage associated with inflammation, infiltration of lymphocytes, and lesions to the spleen. The findings present a novel approach to utilizing the food-grade, non-pathogenic L. lactis as a protein cell factory to synthesize innovative immunological candidate OMPs. This approach offers a distinctive way to evaluate experimental medicinal items' practicality, safety, affordability, and long-term sustainability.

Phylogenetic Analysis and Comparative Genomics of Brucella abortus and Brucella melitensis Strains in Egypt

Brucellosis is a notifiable disease induced by a facultative intracellular Brucella pathogen. In this study, eight Brucella abortus and eighteen Brucella melitensis strains from Egypt were annotated and compared with RB51 and REV1 vaccines respectively. RAST toolkit in the BV-BRC server was used for annotation, revealing genome length of 3,250,377 bp and 3,285,803 bp, 3289 and 3323 CDS, 48 and 49 tRNA genes, the same number of rRNA (3) genes, 583 and 586 hypothetical proteins, 2697 and 2726 functional proteins for B. abortus and B. melitensis respectively. B. abortus strains exhibit a similar number of candidate genes, while B. melitensis strains showed some differences, especially in the SRR19520422 Faiyum strain. Also, B. melitensis clarified differences in antimicrobial resistance genes (KatG, FabL, MtrA, MtrB, OxyR, and VanO-type) in SRR19520319 Faiyum and (Erm C and Tet K) in SRR19520422 Faiyum strain. Additionally, the whole genome phylogeny analysis proved that all B. abortus strains were related to vaccinated animals and all B. melitensis strains of Menoufia clustered together and closely related to Gharbia, Dameitta, and Kafr Elshiek. The Bowtie2 tool identified 338 (eight B. abortus) and 4271 (eighteen B. melitensis) single nucleotide polymorphisms (SNPs) along the genomes. These variants had been annotated according to type and impact. Moreover, thirty candidate genes were predicted and submitted at GenBank (24 in B. abortus) and (6 in B. melitensis). This study contributes significant insights into genetic variation, virulence factors, and vaccine-related associations of Brucella pathogens, enhancing our knowledge of brucellosis epidemiology and evolution in Egypt.

Bioinformatics approach for structure modeling, vaccine design, and molecular docking of Brucella candidate proteins BvrR, OMP25, and OMP31

Brucellosis is a zoonotic disease with significant economic and healthcare costs. Despite the eradication efforts, the disease persists. Vaccines prevent disease in animals while antibiotics cure humans with limitations. This study aims to design vaccines and drugs for brucellosis in animals and humans, using protein modeling, epitope prediction, and molecular docking of the target proteins (BvrR, OMP25, and OMP31). Tertiary structure models of three target proteins were constructed and assessed using RMSD, TM-score, C-score, Z-score, and ERRAT. The best models selected from AlphaFold and I-TASSER due to their superior performance according to CASP 12 - CASP 15 were chosen for further analysis. The motif analysis of best models using MotifFinder revealed two, five, and five protein binding motifs, however, the Motif Scan identified seven, six, and eight Post-Translational Modification sites (PTMs) in the BvrR, OMP25, and OMP31 proteins, respectively. Dominant B cell epitopes were predicted at (44-63, 85-93, 126-137, 193-205, and 208-237), (26-46, 52-71, 98-114, 142-155, and 183-200), and (29-45, 58-82, 119-142, 177-198, and 222-251) for the three target proteins. Additionally, cytotoxic T lymphocyte epitopes were detected at (173-181, 189-197, and 202-210), (61-69, 91-99, 159-167, and 181-189), and (3-11, 24-32, 167-175, and 216-224), while T helper lymphocyte epitopes were displayed at (39-53, 57-65, 150-158, 163-171), (79-87, 95-108, 115-123, 128-142, and 189-197), and (39-47, 109-123, 216-224, and 245-253), for the respective target protein. Furthermore, structure-based virtual screening of the ZINC and DrugBank databases using the docking MOE program was followed by ADMET analysis. The best five compounds of the ZINC database revealed docking scores ranged from (- 16.8744 to - 15.1922), (- 16.0424 to - 14.1645), and (- 14.7566 to - 13.3222) for the BvrR, OMP25, and OMP31, respectively. These compounds had good ADMET parameters and no cytotoxicity, while DrugBank compounds didn't meet Lipinski's rule criteria. Therefore, the five selected compounds from the ZINC20 databases may fulfill the pharmacokinetics and could be considered lead molecules for potentially inhibiting Brucella's proteins.

Concomitant Treatment with Doxycycline and Rifampicin in Balb/c Mice Infected with Brucella abortus 2308 Fails to Reduce Inflammation and Motor Disability

Brucellosis is an infection widely distributed around the world, and in some countries it is considered a public health problem. Brucellosis causes insidious symptoms that make it difficult to diagnose. Infection can also trigger chronic pain and neuropsychiatric complications. Antibiotics are not always effective to eradicate infection, contributing to chronicity. We aimed to investigate the effects of antibiotic treatment on proinflammatory cytokines, neurotransmitters, corticosterone, and behavior in a murine model of infecrion of B. abortus strain 2308. Four study groups were created: (a) control; (b) antibiotic control; (c) infected with B. abortus 2308; and (d) infected and treated with rifampicin and doxycycline. We determined B. abortus 2308 colony-forming units (CFUs), the count of dendritic cells, and macrophages in the spleen; serum levels of cytokines and corticosterone; levels of serotonin, dopamine, epinephrine, and norepinephrine in the brain; and equilibrium, physical strength, anxiety, and hopelessness tests. The infected and treated mice group was compared with the control and infected mice to assess whether treatment is sufficient to recover neuroimmunoendocrine parameters. Our results showed that despite the treatment of brucellosis with rifampicin and doxycycline, antibiotic-treated mice showed a persistence of B. abortus 2308 CFUs, an increased count in macrophage number, and higher circulating levels of corticosterone. Furthermore, the levels of IL-12, IL-6, and TNF-α remained higher. We found a decrease in muscular strength and equilibrium concomitant to changes in neurotransmitters in the hippocampus, cerebellum, and frontal cortex. Our data suggest that the remaining bacterial load after antibiotic administration favors inflammatory, neurochemical, and behavioral alterations, partly explaining the widespread and paradoxical symptomatology experienced by patients with chronic brucellosis.

Basic concepts, recent advances, and future perspectives in the diagnosis of bovine mastitis

Mastitis is one of the most widespread infectious diseases that adversely affects the profitability of the dairy industry worldwide. Accurate diagnosis and identification of pathogens early to cull infected animals and minimize the spread of infection in herds is critical for improving treatment effects and dairy farm welfare. The major pathogens causing mastitis and pathogenesis are assessed first. The most recent and advanced strategies for detecting mastitis, including genomics and proteomics approaches, are then evaluated . Finally, the advantages and disadvantages of each technique, potential research directions, and future perspectives are reported. This review provides a theoretical basis to help veterinarians select the most sensitive, specific, and cost-effective approach for detecting bovine mastitis early.