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Archives of Razi Institute Mar 2019The haemolytic biovar of Gallibacterium anatis (G. anatis) is responsible for urogenital, gastrointestinal, and respiratory diseases in chickens. There are numerous...
The haemolytic biovar of Gallibacterium anatis (G. anatis) is responsible for urogenital, gastrointestinal, and respiratory diseases in chickens. There are numerous reports on the resistance of G. anatis to antibiotics and recurrence of the disease, which raise concerns about antimicrobial treatment efficiency. Vaccination has been considered as the most feasible procedure of prevention in high risk farms. Subunit vaccines containing immunogenic components can have practical protective value in preventive measures regarding the infection. The present study aimed to introduce a polytopic vaccine candidate based on epitope detection. All registered sequences of four immunogenic proteins, includig Flfa, GTxA, Gab_1309, and Gab_2348 were retrieved and directed for variational analysis. A vaccine isolate was selected for each protein and tested for B-cell epitope mapping using different tools. Furthermore, consensus selected immunogenic regions with special patterns fused together by flexible linkers were integrated into two constructs and checked for the best status of proteasomal cleavage sites, as well as hydropathy plot. Moreover, back translations, along with codon optimization were performed, and then some tags were added to the constructs. The selected consensus B-cell immunogenic epitopes were for 12656: AA114-181, 7990: AA114-181, Avicor: AA42-77, 134-197, and IPDH: 61-155 for Flfa protein, AA185-235, AA372-457, and AA807-941 for GtxA-N, AA260-305, AA340-400, and AA110-146 for Gab-1309, and AA125-AA175 for Gab-2348. Two suitable patterns of attachment were selected from the different fusion patterns of epitopes in B-cell polytopic vaccinal constructs. Finally, the examination of these constructs showed their effect and efficacy for immune system stimulation. Based on bioinformatics results, these immunogens could be utilized as potential candidates to develop polytopic protective vaccines and design diagnostic kits.
Topics: Animals; Bacterial Vaccines; Chickens; Computer Simulation; Epitopes; Pasteurellaceae; Pasteurellaceae Infections; Poultry Diseases
PubMed: 31013003
DOI: 10.22092/ari.2017.109804.1118 -
British Poultry Science Feb 20171. Infectious diseases have a large impact on poultry health and economics. Elucidating the pathogenesis of a certain disease is crucial to implement control strategies....
1. Infectious diseases have a large impact on poultry health and economics. Elucidating the pathogenesis of a certain disease is crucial to implement control strategies. 2. Multiplication of a pathogen and its characterisation in vitro are basic requirements to perform experimental studies. However, passaging of the pathogen in vitro can influence the pathogenicity, a process targeted for live vaccine development, but limits the reproduction of clinical signs. 3. Numerous factors can influence the outcome of experimental infections with some importance on the pathogen, application route and host as exemplarily outlined for Histomonas meleagridis, Gallibacterium anatis and fowl aviadenoviruses (FAdVs). 4. In future, more comprehensive and detailed settings are needed to obtain as much information as possible from animal experiments. Processing of samples with modern diagnostic tools provides the option to closely monitor the host-pathogen interaction.
Topics: Adenoviridae Infections; Animals; Aviadenovirus; Chickens; England; Fowl adenovirus A; History, 19th Century; History, 20th Century; History, 21st Century; Host-Pathogen Interactions; Pasteurellaceae; Pasteurellaceae Infections; Poultry Diseases; Protozoan Infections, Animal; Symbiosis
PubMed: 27724044
DOI: 10.1080/00071668.2016.1245849 -
Journal of Bacteriology Mar 2020The (p)ppGpp-mediated stringent response (SR) is a highly conserved regulatory mechanism in bacterial pathogens, enabling adaptation to adverse environments, and is...
The (p)ppGpp-mediated stringent response (SR) is a highly conserved regulatory mechanism in bacterial pathogens, enabling adaptation to adverse environments, and is linked to pathogenesis. can cause damage to the lungs of pigs, its only known natural host. Pig lungs are known to have a low concentration of free branched-chain amino acids (BCAAs) compared to the level in plasma. We had investigated the role for (p)ppGpp in viability and biofilm formation of Now, we sought to determine whether (p)ppGpp was a trigger signal for the SR in in the absence of BCAAs. Combining transcriptome and phenotypic analyses of the wild type (WT) and an double mutant [which does not produce (p)ppGpp], we found that (p)ppGpp could repress purine biosynthesis and activate antioxidant pathways. There was a positive correlation between GTP and endogenous hydrogen peroxide content. Furthermore, the growth, viability, morphology, and virulence were altered by the inability to produce (p)ppGpp. Genes involved in the biosynthesis of BCAAs were constitutively upregulated, regardless of the existence of BCAAs, without accumulation of (p)ppGpp beyond a basal level. Collectively, our study shows that the absence of BCAAs was not a sufficient signal to trigger the SR in (p)ppGpp-mediated regulation in is different from that described for the model organism Further work will establish whether the (p)ppGpp-dependent SR mechanism in is conserved among other veterinary pathogens, especially those in the family. (p)ppGpp is a key player in reprogramming transcriptomes to respond to nutritional challenges. Here, we present transcriptional and phenotypic differences of grown in different chemically defined media in the absence of (p)ppGpp. We show that the deprivation of branched-chain amino acids (BCAAs) does not elicit a change in the basal-level (p)ppGpp, but this level is sufficient to regulate the expression of BCAA biosynthesis. The mechanism found in is different from that of the model organism but similar to that found in some Gram-positive bacteria. This study not only broadens the research scope of (p)ppGpp but also further validates the complexity and multiplicity of (p)ppGpp regulation in microorganisms that occupy different biological niches.
Topics: Actinobacillus pleuropneumoniae; Amino Acids, Branched-Chain; Guanosine Pentaphosphate; Guanosine Triphosphate; Hydrogen Peroxide
PubMed: 32015147
DOI: 10.1128/JB.00640-19 -
Journal of the American Veterinary... Aug 2017
Topics: Animals; Fatal Outcome; Female; Pasteurellaceae; Pasteurellaceae Infections; Sheep; Sheep Diseases
PubMed: 28763281
DOI: 10.2460/javma.251.4.405 -
Journal of Veterinary Diagnostic... Nov 2018Histophilus somni is an opportunistic pathogen responsible for respiratory and systemic diseases of cattle and sheep. Rapid and accurate detection of H. somni is...
Histophilus somni is an opportunistic pathogen responsible for respiratory and systemic diseases of cattle and sheep. Rapid and accurate detection of H. somni is essential to distinguish H. somni from other potential pathogens for proper control and treatment of infections. Nanomaterial optical fiber biosensors (NOFS) recognize analyte interactions, such as DNA hybridization, with high specificity and sensitivity, and were applied to detect H. somni DNA in culture and clinical samples. An ionic self-assembled multilayer (ISAM) film was fabricated on a long-period grating optical fiber, and a biotinylated, nucleotide probe complementary to the H. somni 16S rDNA gene was coupled to the ISAM film. Exposure of the ISAM::probe to ⩾100 killed cells of H. somni strain 2336 without DNA amplification resulted in attenuation of light transmission of ⩾9.4%. Exposure of the complexed fiber to Escherichia coli or non- H. somni species of Pasteurellaceae reduced light transmission by ⩽3.4%. Exposure of the ISAM::probe to blood, bronchoalveolar fluid, or spleen from mice or calves infected with H. somni resulted in ⩾24.3% transmission attenuation. The assay correctly detected all 6 strains of H. somni tested from culture, or tissues from 3 separate mice and calves tested in duplicate. Six heterologous strains (representing 6 genera) reacted at below the cutoff value of 4.87% attenuation of light transmission. NOFS detected at least 100 H. somni cells without DNA amplification within 45 min with high specificity. Although different fibers could vary in signal sensitivity, this did not affect the sensitivity or specificity of the assay.
Topics: Animals; Biosensing Techniques; Cattle; DNA, Bacterial; Male; Mice; Mice, Inbred BALB C; Nanostructures; Optical Fibers; Pasteurellaceae; Pasteurellaceae Infections; Sensitivity and Specificity
PubMed: 30264658
DOI: 10.1177/1040638718803665 -
BMC Genomics Dec 2014Fimbriae are bacterial cell surface organelles involved in the pathogenesis of many bacterial species, including Gallibacterium anatis, in which a F17-like fimbriae of...
BACKGROUND
Fimbriae are bacterial cell surface organelles involved in the pathogenesis of many bacterial species, including Gallibacterium anatis, in which a F17-like fimbriae of the chaperone-usher (CU) family was recently shown to be an important virulence factor and vaccine candidate. To reveal the distribution and variability of CU fimbriae 22 genomes of the avian host-restricted bacteria Gallibacterium spp. were investigated. Fimbrial clusters were classified using phylogeny-based and conserved domain (CD) distribution-based approaches. To characterize the fimbriae in depth evolutionary analysis and in vitro expression of the most prevalent fimbrial clusters was performed.
RESULTS
Overall 48 CU fimbriae were identified in the genomes of the examined Gallibacterium isolates. All fimbriae were assigned to γ4 clade of the CU fimbriae of Gram-negative bacteria and were organized in four-gene clusters encoding a putative major fimbrial subunit, a chaperone, an usher and a fimbrial adhesin. Five fimbrial clusters (Flf-Flf4) and eight conserved domain groups were defined to accommodate the identified fimbriae. Although, the number of different fimbrial clusters in individual Gallibacterium genomes was low, there was substantial amino acid sequence variability in the major fimbrial subunit and the adhesin proteins. The distribution of CDs among fimbrial clusters, analysis of their flanking regions, and evolutionary comparison of the strains revealed that Gallibacterium fimbrial clusters likely underwent evolutionary divergence resulting in highly host adapted and antigenically variable fimbriae. In vitro, only the fimbrial subunit FlfA was expressed in most Gallibacterium strains encoding this protein. The absence or scarce expression of the two other common fimbrial subunits (Flf1A and Flf3A) indicates that their expression may require other in vitro or in vivo conditions.
CONCLUSIONS
This is the first approach establishing a systematic fimbria classification system within Gallibacterium spp., which indicates a species-wide distribution of γ4 CU fimbriae among a diverse collection of Gallibacterium isolates. The expression of only one out of up to three fimbriae present in the individual genomes in vitro suggests that fimbriae expression in Gallibacterium is highly regulated. This information is important for future attempts to understand the role of Gallibacterium fimbriae in pathogenesis, and may prove useful for improved control of Gallibacterium infections in chickens.
Topics: Animals; Conserved Sequence; Evolution, Molecular; Fimbriae Proteins; Fimbriae, Bacterial; Gene Expression; Genome, Bacterial; Molecular Chaperones; Multigene Family; Pasteurellaceae; Phylogeny; Protein Interaction Domains and Motifs; Selection, Genetic
PubMed: 25495603
DOI: 10.1186/1471-2164-15-1093 -
Journal of Clinical Microbiology Jan 2011Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia are oral pathogens associated with periodontitis. The association between these...
Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia are oral pathogens associated with periodontitis. The association between these three bacteria and periodontal disease has been reported in populations of many countries. However, corresponding data in Chinese populations are still lacking. The aim of this study was to detect these pathogens in subgingival plaque collected from 468 subjects with chronic periodontitis in a group of Chinese adults by using a PCR method and to determine the degree of association between the target bacteria and periodontal status based on logistic regression analysis. A. actinomycetemcomitans, P. gingivalis, and T. forsythia were found in 20.5%, 70.7%, and 77.1% of the subjects, respectively. About one-third (36.1%) of subjects had chronic periodontitis. Upon univariate analysis, age, male gender, current smoking status, diabetes, and the presence of A. actinomycetemcomitans or P. gingivalis were positively associated with chronic periodontitis, whereas education and income exhibited inverse associations with chronic periodontitis. Upon multivariate analysis, education, current smoking status, diabetes, and the presence of A. actinomycetemcomitans and P. gingivalis remained significant. The adjusted odds ratios for having chronic periodontitis were 2.5 and 3.4 in subjects positive for A. actinomycetemcomitans and P. gingivalis, respectively. However, no significant association was observed between the presence of T. forsythia and periodontal status. This study assesses the prevalence of periodontal pathogens and chronic periodontitis and the associations with sociodemographic characteristics among this group of Chinese adults. These findings also suggest that PCR should be considered for field oral epidemiologic studies and may be necessary in investigations presenting major logistic challenges.
Topics: Adult; Bacteroidetes; China; Chronic Periodontitis; DNA, Bacterial; Female; Humans; Male; Middle Aged; Pasteurellaceae; Polymerase Chain Reaction; Porphyromonas gingivalis; Prevalence; Risk Factors
PubMed: 21106792
DOI: 10.1128/JCM.01819-10 -
Journal of Bacteriology Oct 2006The draft genome sequence of Mannheimia haemolytica A1, the causative agent of bovine respiratory disease complex (BRDC), is presented. Strain ATCC BAA-410, isolated...
The draft genome sequence of Mannheimia haemolytica A1, the causative agent of bovine respiratory disease complex (BRDC), is presented. Strain ATCC BAA-410, isolated from the lung of a calf with BRDC, was the DNA source. The annotated genome includes 2,839 coding sequences, 1,966 of which were assigned a function and 436 of which are unique to M. haemolytica. Through genome annotation many features of interest were identified, including bacteriophages and genes related to virulence, natural competence, and transcriptional regulation. In addition to previously described virulence factors, M. haemolytica encodes adhesins, including the filamentous hemagglutinin FhaB and two trimeric autotransporter adhesins. Two dual-function immunoglobulin-protease/adhesins are also present, as is a third immunoglobulin protease. Genes related to iron acquisition and drug resistance were identified and are likely important for survival in the host and virulence. Analysis of the genome indicates that M. haemolytica is naturally competent, as genes for natural competence and DNA uptake signal sequences (USS) are present. Comparison of competence loci and USS in other species in the family Pasteurellaceae indicates that M. haemolytica, Actinobacillus pleuropneumoniae, and Haemophilus ducreyi form a lineage distinct from other Pasteurellaceae. This observation was supported by a phylogenetic analysis using sequences of predicted housekeeping genes.
Topics: Actinobacillus pleuropneumoniae; Adhesins, Bacterial; DNA, Bacterial; Gene Expression Regulation, Bacterial; Genome, Bacterial; Haemophilus ducreyi; Mannheimia haemolytica; Phylogeny; Prophages; Sequence Analysis, DNA; Transcription, Genetic; Transformation, Bacterial; Virulence
PubMed: 17015664
DOI: 10.1128/JB.00675-06 -
Anais Da Academia Brasileira de Ciencias 2021Pasteurella multocida subsp. multocida is responsible for different diseases that generate great economic losses in farm animal. The effectiveness of immunization...
Pasteurella multocida subsp. multocida is responsible for different diseases that generate great economic losses in farm animal. The effectiveness of immunization against those bacteria are variable and the use of antibiotics is questioned; for that reason, we investigated the potential inhibitory effect of different carbohydrates on the adherence in vivo of P. multocida to the rabbit respiratory epithelium as an alternative for the prevention of respiratory infections. Rabbits were intranasally and intratracheally inoculated with a solution containing 200 µl of 1x107 CFU of P. multocida that was previously mixed with 250 µg /200 µl of N-acetylglucosamine, alphamethylglucoside, alphamethylmannoside, N-acetylgalactosamine or sialic acid. The animals that received N-acetylglucosamine, alphamethylglucoside or alphamethylmannoside individually or a mixture of these three carbohydrates plus the bacterium, showed a significant decrease (P <0.05) of the clinical symptoms, microscopic and macroscopic lesions in the nasal septa and in the lungs; also, the number of adhered bacteria to the nasal epithelium were also significantly reduced. This research demonstrates for the first time that such an approach could convert into a method for prevention of P. multocida infection in rabbits that is ecologically and economically safe and effective.
Topics: Animals; Carbohydrates; Nasal Mucosa; Pasteurella; Pasteurella Infections; Pasteurella multocida; Rabbits
PubMed: 34259794
DOI: 10.1590/0001-3765202120190989 -
Journal of Microbiology, Immunology,... Dec 2021This study aimed to investigate the clinical characteristics and outcomes of bacteremia caused by Haemophilus and Aggregatibacter species in patients who were treated at...
BACKGROUND/PURPOSE
This study aimed to investigate the clinical characteristics and outcomes of bacteremia caused by Haemophilus and Aggregatibacter species in patients who were treated at a medical center between 2006 and 2018.
METHODS
Haemophilus and Aggregatibacter isolates were identified up to the species level using Bruker Biotyper MALDI-TOF analysis and ancillary 16S rRNA gene sequencing analysis (in case of ambiguity). Clinical characteristics and outcomes of patients with bacteremia caused by these organisms were evaluated.
RESULTS
Sixty-five Haemophilus and Aggregatibacter species isolates causing bacteremia were identified from nonduplicated patients, including 51 (78.5%) Haemophilus influenzae, 6 (9.2%) Haemophilus parainfluenzae, 1 (1.5%) Haemophilus haemolyticus, 3 (4.6%) A. aphrophilus, and 4 (6.2%) A. segnis. Hospital mortality was observed in 18 (28.1%) of 64 patients with bacteremia caused by Haemophilus (n = 57) and Aggregatibacter species (n = 7). The majority of patients with bacteremia had community-acquired disease with low severity. The average Sequential Organ Failure Assessment (SOFA) score was low (4.4 ± 4.7). But, a higher SOFA score (adjusted odds ratio 2.5, 95% confidence interval 1.22-5.12; P = 0.01) was an independent factor predicting poor 7-day clinical outcomes in patients with community-acquired H. influenzae bacteremia (n = 39).
CONCLUSIONS
The overall hospital mortality of 28.1% was observed among patients with bacteremia due to Haemophilus and Aggregatibacter species. A higher SOFA score was and independent predictor of poor 7-day clinical outcomes in patients with community-acquired H. influenzae bacteremia.
Topics: Adult; Aged; Aggregatibacter; Anti-Bacterial Agents; Bacteremia; Female; Haemophilus; Hospital Mortality; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Organ Dysfunction Scores; RNA, Ribosomal, 16S
PubMed: 33390332
DOI: 10.1016/j.jmii.2020.12.002