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Journal of Dairy Science Mar 2020Respiratory tract infections (bovine respiratory disease) are a major concern in calf rearing. The objective of this study was to identify pathogen-specific risk factors...
Respiratory tract infections (bovine respiratory disease) are a major concern in calf rearing. The objective of this study was to identify pathogen-specific risk factors associated with epidemic respiratory disease in calves. A cross-sectional study was conducted, involving 128 outbreaks (29 dairy, 58 dairy-mixed, and 41 beef) in Belgium (2016-2018). A semiquantitative PCR for 7 respiratory pathogens was done on a pooled nonendoscopic bronchoalveolar lavage sample for each herd. Potential risk factors were collected by questionnaire and derived from the national cattle registration databank. Most outbreaks occurred between October and March, and single and multiple viral infections were detected in 58.6% (75/128) and 13.3% (17/128), respectively. Bovine coronavirus (BCV) was the most frequently isolated virus (38.4%), followed by bovine respiratory syncytial virus (bRSV; 29.4%) and parainfluenzavirus type 3 (PI-3; 8.1%). Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni were detected in 33.3, 41.2, 89.1, and 36.4% of the herds, respectively. Specific risk factors for BCV detection were detection of M. haemolytica [odds ratio (OR) = 2.8 (95% confidence interval = 1.1-7.5)], increasing herd size [OR = 1.3 (1.0-1.8) for each increase with 100 animals] and detection of BCV by antigen ELISA on feces in calves in the last year [OR = 3.6 (1.2-11.1)]. A seasonal effect was shown for bRSV only {more in winter compared with autumn [OR = 10.3 (2.8-37.5)]}. Other factors associated with bRSV were PI-3 detection [OR = 13.4 (2.1-86.0)], prevalence of calves with respiratory disease [OR = 1.02 (1.00-1.04) per 1% increase], and number of days with respiratory signs before sampling [OR = 0.99 (0.98-0.99) per day increase]. Next to its association with BCV, M. haemolytica was more frequently detected in herds with 5 to 10 animals per pen [OR = 8.0 (1.4-46.9)] compared with <5 animals, and in herds with sawdust as bedding [OR = 18.3 (1.8-191.6)]. Also, for H. somni, housing on sawdust was a risk factor [OR = 5.2 (1.2-23.0)]. Purchase of cattle [OR = 2.9 (1.0-8.0)] and housing of recently purchased animals in the same airspace [OR = 5.0 (1.5-16.5)] were risk factors for M. bovis. This study identified pathogen-specific risk factors that might be useful for the development of customized control and prevention and for the design of decision support tools to justify antimicrobial use by predicting the most likely pathogen before sampling results are available.
Topics: Animals; Belgium; Bronchoalveolar Lavage; Cattle; Cattle Diseases; Coronavirus, Bovine; Cross-Sectional Studies; Disease Outbreaks; Feces; Female; Male; Mannheimia haemolytica; Mycoplasma bovis; Parainfluenza Virus 3, Bovine; Pasteurella multocida; Pasteurellaceae; Respiratory Syncytial Virus, Bovine; Respiratory Tract Infections; Risk Factors; Species Specificity; Surveys and Questionnaires
PubMed: 31954585
DOI: 10.3168/jds.2019-17486 -
Nature Communications Oct 2023The sudden mortality of African elephants (Loxodonta africana) in Botswana and Zimbabwe in 2020 provoked considerable public interest and speculation. Poaching and...
The sudden mortality of African elephants (Loxodonta africana) in Botswana and Zimbabwe in 2020 provoked considerable public interest and speculation. Poaching and malicious poisoning were excluded early on in the investigation. Other potential causes included environmental intoxication, infectious diseases, and increased habitat stress due to ongoing drought. Here we show evidence of the mortalities in Zimbabwe as fatal septicaemia associated with Bisgaard taxon 45, an unnamed close relative of Pasteurella multocida. We analyse elephant carcasses and environmental samples, and fail to find evidence of cyanobacterial or other intoxication. Post-mortem and histological findings suggest a bacterial septicaemia similar to haemorrhagic septicaemia caused by P. multocida. Biochemical tests and 16S rDNA analysis of six samples and genomic analysis of one sample confirm the presence of Bisgaard taxon 45. The genome sequence contains many of the canonical P. multocida virulence factors associated with a range of human and animal diseases, including the pmHAS gene for hyaluronidase associated with bovine haemorrhagic septicaemia. Our results demonstrate that Bisgaard taxon 45 is associated with a generalised, lethal infection and that African elephants are susceptible to opportunistically pathogenic Pasteurella species. This represents an important conservation concern for elephants in the largest remaining metapopulation of this endangered species.
Topics: Humans; Animals; Cattle; Hemorrhagic Septicemia; Elephants; Pasteurella; Pasteurella multocida; Ecosystem
PubMed: 37880229
DOI: 10.1038/s41467-023-41987-z -
Microbiology Spectrum Jun 2023Avibacterium paragallinarum is the pathogen involved in infectious coryza (IC), an acute infectious upper respiratory disease in chickens. The prevalence of IC has...
Avibacterium paragallinarum is the pathogen involved in infectious coryza (IC), an acute infectious upper respiratory disease in chickens. The prevalence of IC has increased in China in recent years. There is a lack of reliable and effective procedures for gene manipulation, which has limited the research on the bacterial genetics and pathogenesis of A. paragallinarum. Natural transformation has been developed as a method of gene manipulation in by the introduction of foreign genes or DNA fragments into bacterial cells, but there has been no report on natural transformation in . In this study, we analyzed the existence of homologous genetic factors and competence proteins underlying natural transformation in and established a method for transformation in it. Through bioinformatics analysis, we identified 16 homologs of Haemophilus influenzae competence proteins in . We found that the uptake signal sequence (USS) was overrepresented in the genome of (1,537 to 1,641 copies of the core sequence ACCGCACTT). We then constructed a plasmid, pEA-KU, that carries the USS and a plasmid, pEA-K, without the USS. These plasmids can be transferred via natural transformation into naturally competent strains of . Significantly, the plasmid that carries USS showed a higher transformation efficiency. In summary, our results demonstrate that has the ability to undergo natural transformation. These findings should prove to be a valuable tool for gene manipulation in . Natural transformation is an important mechanism for bacteria to acquire exogenous DNA molecules during the process of evolution. Additionally, it can also be used as a method to introduce foreign genes into bacteria under laboratory conditions. Natural transformation does not require equipment such as an electroporation apparatus. It is easy to perform and is similar to gene transfer under natural conditions. However, there have been no reports on natural transformation in Avibacterium paragallinarum. In this study, we analyzed the presence of homologous genetic factors and competence proteins underlying natural transformation in . Our results indicate that natural competence could be induced in serovars A, B, and C. Furthermore, the method that we established to transform plasmids into naturally competent strains was stable and efficient.
Topics: Animals; Haemophilus Infections; Poultry Diseases; Chickens; Pasteurellaceae; Haemophilus paragallinarum
PubMed: 37212663
DOI: 10.1128/spectrum.05209-22 -
Veterinary Microbiology Aug 2022The serotypes of Pasteurella multocida were predicted based on whole genomic sequences (WGS) with specific genes of the capsular and liposaccharide (LPS) outer core...
The serotypes of Pasteurella multocida were predicted based on whole genomic sequences (WGS) with specific genes of the capsular and liposaccharide (LPS) outer core polysaccharide regions as targets. A total of 56 strains were whole genomic sequenced and in addition all assembled genomes from NCBI were included for comparison. BIGSdb (Bacterial Isolate Genome Sequence Database) was installed on a Linux server and targets for capsular types A, B, D, E and F were defined as gene sequences of hyaD, bcbD, dcbF, ecbJ and fcbD, respectively and targets for LPS groups 1, 2, 3, 4, 5, 6, 7 and 8 were defined as gene sequences of pcgB, nctA, gatF, latB, rmlA, nctB, ppgB and natG, respectively. The serotypes of P. multocida were predicted from WGS by designating the capsular type and LPS group as well as subtype alleles to isolates. Comparisons between WGS predictions of capsular types and classical phenotypic typing showed correspondence in 87 % of cases whereas comparisons of WGS predictions of LPS groups to phenotypic typing corresponded for 82 % of the strains. In total 93 % and 94 % of the strains available with WGS could be capsular and LPS group typed, respectively. The server is free to access from https://ivsmlst.sund.ku.dk.
Topics: Genome, Bacterial; Genomics; Lipopolysaccharides; Pasteurella multocida; Serogroup
PubMed: 35714528
DOI: 10.1016/j.vetmic.2022.109492 -
Toxins Jan 2022Leukotoxin A (LtxA) is the major virulence factor of an oral bacterium known as (). LtxA is associated with elevated levels of anti-citrullinated protein antibodies... (Review)
Review
Leukotoxin A (LtxA) is the major virulence factor of an oral bacterium known as (). LtxA is associated with elevated levels of anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) patients. LtxA targets leukocytes and triggers an influx of extracellular calcium into cytosol. The current proposed model of LtxA-mediated hypercitrullination involves the dysregulated activation of peptidylarginine deiminase (PAD) enzymes to citrullinate proteins, the release of hypercitrullinated proteins through cell death, and the production of autoantigens recognized by ACPA. Although model-based evidence is yet to be established, its interaction with the host's immune system sparked interest in the role of LtxA in RA. The first part of this review summarizes the current knowledge of and LtxA. The next part highlights the findings of previous studies on the association of or LtxA with RA aetiology. Finally, we discuss the unresolved aspects of the proposed link between LtxA of and RA.
Topics: Aggregatibacter actinomycetemcomitans; Anti-Citrullinated Protein Antibodies; Arthritis, Rheumatoid; Exotoxins; Humans; Pasteurellaceae Infections
PubMed: 35051027
DOI: 10.3390/toxins14010050 -
BMC Oral Health May 2021Periodontal disease represents a major health concern. The administration of beneficial microbes has been increasing in popularity over efforts to manipulate the...
BACKGROUND
Periodontal disease represents a major health concern. The administration of beneficial microbes has been increasing in popularity over efforts to manipulate the microbes using antimicrobial agents. This study determined the ability of Streptococcus salivarius to inhibit IL-6 and IL-8 production by gingival fibroblasts when activated by periodontal pathogens and their effect on the salivary microbiome.
METHODS
Primary human gingival fibroblasts were challenged with Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum and a combination of all three. IL-6 and IL-8 cytokine release were measured. Using this same model, S. salivarius K12, M18 and different supernatant and whole-cell lysate fractions of S. salivarius K12 were administered to pathogen-induced fibroblasts. A patient study of healthy participants was also conducted to determine the effect S. salivarius K12 had on the native microbiome using 16S next generation sequence analysis.
RESULTS
All pathogens tested induced a significant IL-6 and IL-8 response. S. salivarius K12 or M18, did not exhibit an increase in inflammatory cytokines. When either of the probiotic strains were co-administered with a pathogen, there were significant reductions in both IL-6 and IL-8 release. This effect was also observed when gingival fibroblasts were pre-treated with either S. salivarius K12 or M18 and then stimulated with the oral pathogens. Chewing gum containing S. salivarius K12 did not alter the salivary microbiome and did not increase inflammatory markers in the oral cavity.
CONCLUSION
S. salivarius K12 and M18 prevented immune activation induced by periodontal disease pathogens. S. salivarius K12 did not alter the salivary microbiome or induce immune activation when administered as a chewing gum. These results warrant further study to determine if it may be an effective treatment in a model of periodontal disease.
Topics: Aggregatibacter actinomycetemcomitans; Fusobacterium nucleatum; Humans; Periodontal Diseases; Porphyromonas gingivalis; Streptococcus salivarius
PubMed: 33962608
DOI: 10.1186/s12903-021-01606-z -
The European Respiratory Journal Sep 2017
Topics: Biofilms; Haemophilus Infections; Haemophilus influenzae; Humans; Kartagener Syndrome
PubMed: 28890441
DOI: 10.1183/13993003.01369-2017 -
Mikrochimica Acta Mar 2023For sensitive detection of the L-fuculokinase genome related to the Haemophilus influenzae (H. influenzae), this research work demonstrates the label-free...
For sensitive detection of the L-fuculokinase genome related to the Haemophilus influenzae (H. influenzae), this research work demonstrates the label-free electrochemical-based oligonucleotide genosensing assay relying on the performing hybridization process. To enhance the electrochemical responses, multiple electrochemical modifier-tagged agents were effectively utilized. For attaining this goal, NiCr-layered double hydroxide (NiCr LDH) has been synthesized and combined with biochar (BC) to create an efficient electrochemical signal amplifier that has been immobilized on the surface of the bare Au electrode. Low detection and quantification limits (LOD and LOQ) associated with the designed genosensing bio-platform to detect L-fuculokinase have been achieved to 6.14 fM and 11 fM, respectively. Moreover, the wide linear range of 0.1 to 1000 pM demonstrates the capability of the designed platform. Investigated were the 1-, 2-, and 3-base mismatched sequences, and the negative control samples clarified the high selectivity and better performance of the engineered assay. The values of 96.6-104% and 2.3-3.4% have been obtained for the recoveries and RSDs, respectively. Furthermore, the repeatability and reproducibility of the associated bio-assay have been studied. Consequently, the novel method is appropriate for rapidly and quantitatively detecting H. influenzae, and is considered a better candidate for advanced tests on biological samples such as urine samples.
Topics: Haemophilus influenzae; Point-of-Care Systems; Reproducibility of Results; Amplifiers, Electronic; Biological Assay
PubMed: 36869922
DOI: 10.1007/s00604-023-05687-1 -
Proceedings of the National Academy of... Oct 2019is associated with aggressive periodontitis resulting in premature tooth loss in adolescents. Tooth adherence and biofilm persistence are prerequisites for survival in...
is associated with aggressive periodontitis resulting in premature tooth loss in adolescents. Tooth adherence and biofilm persistence are prerequisites for survival in the oral domain. Here, using a rhesus monkey model, 16S rRNA sequencing, and weighted network analysis, we assessed colonization of variants and ascertained microbial interactions in biofilm communities. Variants in leukotoxin () were created, labeled, inoculated, and compared with their progenitor strain for in vivo colonization. Samples of tooth-related plaque were assessed for colonization at baseline and after debridement and inoculation of labeled strains. Null, minimal, and hyper-Ltx-producing strains were created and assessed for hydroxyapatite binding and biofilm formation in vitro. Ltx-hyperproducing strains colonized with greater prevalence and at higher levels than wild type or mutants ( = 0.05). Indigenous and inoculated strains that attached were associated with lactate-producing species (i.e., Leptotrichia, Abiotrophia, and Streptoccocci). was found at 0.13% of the total flora at baseline and at 0.05% 4 wk after inoculation. In vivo data were supported by in vitro results. We conclude that hyper-Ltx production affords these strains with an attachment advantage providing a foothold for competition with members of the indigenous microbiota. Increased attachment can be linked to gene expression and up-regulation of adherence-associated genes. Growth of attached in vivo was enhanced by lactate availability due to consorting species. These associations provide with the constituents required for its colonization and survival in the complex and competitive oral environment.
Topics: Aggregatibacter actinomycetemcomitans; Animals; Bacterial Adhesion; Biofilms; Durapatite; Exotoxins; Lactic Acid; Macaca mulatta; Male; Microbiota; Mouth; Periodontitis
PubMed: 31611409
DOI: 10.1073/pnas.1905238116 -
ELife Jan 2018The functions of most proteins are yet to be determined. The function of an enzyme is often defined by its interacting partners, including its substrate and product, and...
The functions of most proteins are yet to be determined. The function of an enzyme is often defined by its interacting partners, including its substrate and product, and its role in larger metabolic networks. Here, we describe a computational method that predicts the functions of orphan enzymes by organizing them into a linear metabolic pathway. Given candidate enzyme and metabolite pathway members, this aim is achieved by finding those pathways that satisfy structural and network restraints implied by varied input information, including that from virtual screening, chemoinformatics, genomic context analysis, and ligand -binding experiments. We demonstrate this integrative pathway mapping method by predicting the L-gulonate catabolic pathway in Rd KW20. The prediction was subsequently validated experimentally by enzymology, crystallography, and metabolomics. Integrative pathway mapping by satisfaction of structural and network restraints is extensible to molecular networks in general and thus formally bridges the gap between structural biology and systems biology.
Topics: Computational Biology; Enzymes; Haemophilus influenzae; Metabolic Networks and Pathways; Systems Biology
PubMed: 29377793
DOI: 10.7554/eLife.31097