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Pathogens (Basel, Switzerland) Jan 2023subsp. is the etiological agent of sleepy foal disease, an acute form of fatal septicemia in newborn foals. is commonly found in the mucous membranes of healthy...
subsp. is the etiological agent of sleepy foal disease, an acute form of fatal septicemia in newborn foals. is commonly found in the mucous membranes of healthy horses' respiratory and alimentary tracts and rarely causes disease in adult horses. In this study, we report a case of a 22-year-old American Paint gelding presenting clinical signs associated with an atypical pattern of pleuropneumonia subjected to necropsy. The gross and histopathological examinations revealed a unilateral fibrinosuppurative and hemorrhagic pleuropneumonia with an infrequent parenchymal distribution and heavy isolation of . The whole genome sequence analysis indicated that the isolate shared 95.9% homology with the only other complete genome of subsp. available in GenBank. Seven virulence-associated genes specific to the isolate were identified and categorized as iron acquisition proteins, lipopolysaccharides (LPS), and capsule polysaccharides. Moreover, four genes (, , , and ) shared higher amino acid similarity with the invasive spp. than the reference subsp. genome. Availability of the whole genome sequence will allow a better characterization of virulence determinants of subsp. , which remain largely elusive.
PubMed: 36839495
DOI: 10.3390/pathogens12020224 -
Standards in Genomic Sciences 2015Actinobacillus equuli subsp. equuli is a member of the family Pasteurellaceae that is a common resident of the oral cavity and alimentary tract of healthy horses. At the...
Actinobacillus equuli subsp. equuli is a member of the family Pasteurellaceae that is a common resident of the oral cavity and alimentary tract of healthy horses. At the same time, it can also cause a fatal septicemia in foals, commonly known as sleepy foal disease or joint ill disease. In addition, A. equuli subsp. equuli has recently been reported to act as a primary pathogen in breeding sows and piglets. To better understand how A. equuli subsp. equuli can cause disease, the genome of the type strain of A. equuli subsp. equuli, ATCC 19392(T), was sequenced using the PacBio RSII sequencing system. Its genome is comprised of 2,431,533 bp and is predicted to encode 2,264 proteins and 82 RNAs.
PubMed: 26203343
DOI: 10.1186/s40793-015-0009-x -
Australian Veterinary Journal Jun 1998The objective of this work was to examine the diversity within Australian isolates of Actinobacillus equuli and related organisms by the genotypic method of ribotyping.
OBJECTIVE
The objective of this work was to examine the diversity within Australian isolates of Actinobacillus equuli and related organisms by the genotypic method of ribotyping.
DESIGN
Ribotyping, performed using the enzyme HaeIII, was used to examine the diversity in 12 field isolates of A equuli (five being capable of fermenting L-arabinose), one field isolate of Pasteurella caballi and two unclassifiable field isolates. Isolates were obtained from Australian horses, except for three isolates of A equuli (one L-arabinose positive and two L-arabinose negative) which were obtained from horses and a pig in Africa. In addition, the type strains for A equuli and P caballi and a reference strain for Bisgaard Taxon 9 were included in the study.
RESULTS
The ribotype patterns were analysed by computerised cluster analysis, yielding five clusters (A to E). All five of the L-arabinose positive A equuli were assigned to cluster A, with all the other seven A equuli isolates (all L-arabinose negative) and the type strain being assigned to cluster B. One of the two unclassified isolates formed cluster C along with the reference strain for Bisgaard Taxon 9. The remaining unclassified isolate formed cluster D. Cluster E consisted of the field isolate and reference strain of P caballi.
CONCLUSION
The results of this study indicate that A equuli is a diverse species, with L-arabinose positive isolates of A equuli being quite distinct from typical L-arabinose negative isolates. Ribotyping appears to be a useful tool in confirming the identity of A equuli-like organisms from horses.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Australia; Cluster Analysis; DNA, Bacterial; Deoxyribonucleases, Type II Site-Specific; Genetic Variation; Horse Diseases; Horses; Restriction Mapping; Swine; Swine Diseases
PubMed: 9673769
DOI: 10.1111/j.1751-0813.1998.tb12394.x -
The Journal of Veterinary Medical... Sep 2019Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese...
Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese Thoroughbred racehorses putatively identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry as Actinobacillus were further identified by PCR of the A. equuli toxin gene, by CAMP test, and by 16S rRNA sequencing analysis. Actinobacillus equuli subsp. haemolyticus was isolated most frequently (16/27) and was related to respiratory infections. Actinobacillus equuli subsp. equuli (4/27) was isolated from chronic cases or concomitant with other bacterial infections. The remainder were A. pleuropneumoniae, unclassified Actinobacillus species and Pasteurella caballi. Actinobacillus equuli including subsp. haemolyticus and subsp. equuli were the species most frequently isolated from equine actinobacillosis in Japan.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Bacterial Proteins; DNA, Bacterial; Horse Diseases; Horses; Japan; Pasteurella; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 31292334
DOI: 10.1292/jvms.19-0192 -
Australian Veterinary Journal Jan 1997The objective of this work was to perform a comprehensive phenotypic characterisation of 16 isolates of bacteria previously identified as Actinobacillus equuli.
OBJECTIVE
The objective of this work was to perform a comprehensive phenotypic characterisation of 16 isolates of bacteria previously identified as Actinobacillus equuli.
DESIGN
The 16 isolates that had been obtained from Australian animals--15 from horses and one from a rabbit--were compared with reference strains of A equuli, A capsulatus, Pasteurella caballi and Bisgaard Taxa 9 and 11.
RESULTS
The characterisation study demonstrated that only nine of the isolates were A equuli. The other isolates were identified as A capsulatus (the isolate from rabbit), P caballi (one isolate), Bisgaard Taxon 11 (two isolates) and Bisgaard Taxon 9 (one isolate). The final two isolates could not be assigned to any recognised species or taxa.
CONCLUSION
This study has highlighted the importance of a complete characterisation of Actinobacillus-like organisms isolated from horses and rabbits. The study represents the first time that A capsulatus, P caballi and Bisgaard Taxa 9 and 11 have been recognised as being present in Australia.
Topics: Actinobacillosis; Actinobacillus; Animals; Australia; Brain; Heart; Horses; Kidney; Liver; Lung; Myocardium; Pasteurella; Pasteurella Infections; Phenotype; Rabbits; Spleen
PubMed: 9034500
DOI: 10.1111/j.1751-0813.1997.tb13831.x -
Veterinary Research 2003Equine Actinobacillus species were analysed phylogenetically by 16S rRNA gene (rrs) sequencing focusing on the species Actinobacillus equuli, which has recently been...
Equine Actinobacillus species were analysed phylogenetically by 16S rRNA gene (rrs) sequencing focusing on the species Actinobacillus equuli, which has recently been subdivided into the non-haemolytic A. equuli subsp. equuli and the haemolytic A. equuli subsp. haemolyticus. In parallel we determined the profile for RTX toxin genes of the sample of strains by PCR testing for the presence of the A. equuli haemolysin gene aqx, and the toxin genes apxI, apxII, apxIII and apxIV, which are known in porcine pathogens such as Actinobacillus pleuropneumoniae and Actinobacillus suis. The rrs-based phylogenetic analysis revealed two distinct subclusters containing both A. equuli subsp. equuli and A. equuli subsp. haemolyticus distributed through both subclusters with no correlation to taxonomic classification. Within one of the rrs-based subclusters containing the A. equuli subsp. equuli type strain, clustered as well the porcine Actinobacillus suis strains. This latter is known to be also phenotypically closely related to A. equuli. The toxin gene analysis revealed that all A. equuli subsp. haemolyticus strains from both rrs subclusters specifically contained the aqx gene while the A. suis strains harboured the genes apxI and apxII. The aqx gene was found to be specific for A. equuli subsp. haemolyticus, since A. equuli subsp. equuli contained no aqx nor any of the other RTX genes tested. The specificity of aqx for the haemolytic equine A. equuli and ApxI and ApxII for the porcine A. suis indicates a role of these RTX toxins in host species predilection of the two closely related species of bacterial pathogens and allows PCR based diagnostic differentiation of the two.
Topics: Actinobacillus; Animals; Bacterial Toxins; Genes, Bacterial; Horses; Phylogeny; RNA, Ribosomal, 16S; Species Specificity; Swine
PubMed: 12791244
DOI: 10.1051/vetres:2003010 -
Journal of Clinical Microbiology Sep 1980Actinobacillus lignieresii and Actinobacillus equuli were cultured from a total of 36 guinea pigs, rats, and mice. The organisms were isolated from the oropharynx, the...
Actinobacillus lignieresii and Actinobacillus equuli were cultured from a total of 36 guinea pigs, rats, and mice. The organisms were isolated from the oropharynx, the conjunctiva, and middle ear. Isolates were initially screened by eight biochemical tests to determine whether they were of the genus Actinobacillus. Actinobacillus spp. were then differentiated by fermentation reactions of nine carbohydrates. In the past, actinobacilli may have been mistakenly identified as Pasteurella spp., especially Pasteurella pneumotropica. The importance of realizing that Actinobacillus spp. are frequently isolated from laboratory rodents was stressed.
Topics: Actinobacillus; Animals; Animals, Laboratory; Carbohydrate Metabolism; Conjunctiva; Ear, Middle; Fermentation; Guinea Pigs; Humans; Mice; Oropharynx; Pasteurella; Rats; Rodentia
PubMed: 7217333
DOI: 10.1128/jcm.12.3.351-354.1980 -
Veterinary Research Apr 2023Actinobacillus equuli is mostly associated with disease in horses and is most widely known as the causative agent of sleepy foal disease. Even though existing phenotypic...
Actinobacillus equuli is mostly associated with disease in horses and is most widely known as the causative agent of sleepy foal disease. Even though existing phenotypic tools such as biochemical tests, 16S rRNA gene sequencing, and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) can be used to identify members of the Actinobacillus genus, these methods struggle to differentiate between certain species and do not allow strain, virulence, and antimicrobial susceptibility typing. Hence, we performed in-depth analysis of 24 equine Actinobacillus isolates using phenotypic identification and susceptibility testing on the one hand, and long-read nanopore whole genome sequencing on the other hand. This allowed to address strain divergence down to the whole genome single nucleotide polymorphism (SNP) level. While lowest resolution was observed for 16S rRNA gene classification, a new multi-locus sequence typing (MLST) scheme allowed proper classification up to the species level. Nevertheless, a SNP-level analysis was required to distinguish A. equuli subspecies equuli and haemolyticus. Our data provided first WGS data on Actinobacillus genomospecies 1, Actinobacillus genomospecies 2, and A. arthritidis, which allowed the identification of a new Actinobacillus genomospecies 1 field isolate. Also, in-depth characterization of RTX virulence genes provided information on the distribution, completeness, and potential complementary nature of the RTX gene operons within the Actinobacillus genus. Even though overall low prevalence of acquired resistance was observed, two plasmids were identified conferring resistance to penicillin-ampicillin-amoxicillin and chloramphenicol in one A. equuli strain. In conclusion our data delivered new insights in the use of long-read WGS in high resolution identification, virulence gene typing, and antimicrobial resistance (AMR) of equine Actinobacillus species.
Topics: Animals; Horses; Actinobacillus; Anti-Bacterial Agents; Multilocus Sequence Typing; RNA, Ribosomal, 16S; Virulence; Drug Resistance, Bacterial; Whole Genome Sequencing
PubMed: 37020296
DOI: 10.1186/s13567-023-01160-2 -
Genomics Jan 2019Actinobacillus spp. are Gram-negative bacteria associated with mucosal membranes. While some are commensals, others can cause important human and animal diseases. A....
Actinobacillus spp. are Gram-negative bacteria associated with mucosal membranes. While some are commensals, others can cause important human and animal diseases. A. pleuropneumoniae causes severe fibrinous hemorrhagic pneumonia in swine but not systemic disease whereas other species invade resulting in septicemia and death. To understand the invasive phenotype of Actinobacillus spp., complete genomes of eight isolates were obtained and pseudogenomes of five isolates were assembled and annotated. Phylogenetically, A. suis isolates clustered by surface antigen type and were more closely related to the invasive A. ureae, A. equuli equuli, and A. capsulatus than to the other swine pathogen, A. pleuropneumoniae. Using the LS-BSR pipeline, 251 putative virulence genes associated with serum resistance and invasion were detected. To our knowledge, this is the first genome-wide study of the genus Actinobacillus and should contribute to a better understanding of host tropism and mechanisms of invasion of pathogenic Actinobacillus and related genera.
Topics: Actinobacillus; Animals; Gene Rearrangement; Genetic Variation; Genome-Wide Association Study; Genomics; Host Specificity; N-Acetylneuraminic Acid; Neuraminidase; Phenotype; Phylogeny; Pseudogenes; Sequence Inversion; Serine Endopeptidases; Swine; Type V Secretion Systems; Virulence; Whole Genome Sequencing
PubMed: 29317305
DOI: 10.1016/j.ygeno.2018.01.001 -
American Journal of Veterinary Research Aug 2006To identify Actinobacillus spp isolates recovered from fetuses and pericardial fluid from horses affected with mare reproductive loss syndrome (MRLS) and determine...
OBJECTIVE
To identify Actinobacillus spp isolates recovered from fetuses and pericardial fluid from horses affected with mare reproductive loss syndrome (MRLS) and determine whether these bacterial species are the same as those isolated from clinically normal horses.
SAMPLE POPULATION
Isolates of actinobacilli recovered from 18 horses with pericarditis and 109 fetuses aborted by mares affected by MRLS. Procedures-Actinobacillus spp isolates were identified to the level of species or subspecies by use of conventional phenotypic tests and biochemical and enzyme test kits. The 16S rRNA gene from selected isolates was amplified, purified, and sequenced. Sequence data were compared with sequence data for actinobacilli in GenBank.
RESULTS
Of the 109 isolates obtained from fetuses, 14 were Actinobacillus equuli subsp equuli, 65 were A equuli subsp haemolyticus, 28 were Bisgaard taxon 10-like bacterium, and 2 were Actinobacillus genomospecies 1. Of the 18 isolates from horses with pericarditis, 4 were A equuli subsp equuli, 13 were A equuli subsp haemolyticus, and 1 was Bisgaard taxon 10-like bacterium. Comparisons with published data and GenBank data revealed that the isolates recovered from horses with MRLS were the same as those isolated from the oral cavity or alimentary tract of healthy horses.
CONCLUSIONS AND CLINICAL RELEVANCE
Actinobacillus spp isolates recovered from fetuses and pericardial fluid samples of horses affected by MRLS in 2001 to 2003 were identical to Actinobacillus spp found in the oral cavity and alimentary tracts of healthy horses.
Topics: Aborted Fetus; Abortion, Veterinary; Actinobacillus; Animals; Female; Horse Diseases; Horses; Pericardial Effusion; RNA, Ribosomal, 16S
PubMed: 16881857
DOI: 10.2460/ajvr.67.8.1426