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Australian Veterinary Journal Aug 2001To review the clinical findings, diagnosis and treatment of 51 horses with peritonitis attributed to Actinobacillus equuli.
OBJECTIVE
To review the clinical findings, diagnosis and treatment of 51 horses with peritonitis attributed to Actinobacillus equuli.
DESIGN
Retrospective study of clinical cases.
METHODS
Breed, age and gender of horse, history, physical examination findings, treatment and outcome were determined from the hospital records of 51 horses in which a diagnosis of peritonitis attributed to A. equuli was made between January 1993 and June 1999. Results of abdominal fluid cytology and bacteriology, antimicrobial sensitivity patterns, haematology and faecal egg counts, when performed, were also retrieved.
RESULTS
There was a variety of breeds of horses affected. There were 35 male and 17 female horses, aged from 9 months to 22 years, presented. Lethargy, signs of depression with mild to moderate signs of abdominal pain and inappetence were the most common reasons for presentation. Most horses had elevated heart and respiratory rates, an elevated rectal temperature and reduced intestinal borborygmi heard on auscultation of the abdomen. Abnormal colour with an elevated protein were features of an abdominal fluid sample in 98% of horses and a marked elevation in nucleated cell count was present in all samples. Pleomorphic gram-negative rods were seen on cytology in 53% of samples and a positive culture of A. equuli was returned in 72% of samples. Other laboratory findings in some horses included mild haemoconcentration, hypoproteinaemia, an elevated circulating nucleated cell count with a left shift, an elevation in fibrinogen concentration and an elevated faecal egg count. All horses demonstrated a rapid response to treatment with procaine penicillin alone, or a combination of procaine penicillin and gentamicin sulphate. Where antimicrobial sensitivity tests were performed, all but two isolates were sensitive to procaine penicillin. All horses responded to antimicrobial and supportive therapy and were discharged from hospital.
CONCLUSION
Horses with A. equuli peritonitis present with similar clinical signs as horses with other causes of abdominal pain. However, these signs, when evaluated in conjunction with the results of abdominal fluid analysis and response to treatment, are characteristic of A. equuli peritonitis. Pleomorphic gram-negative bacteria may be seen on a cytological preparation of the abdominal fluid sample, and a positive bacterial culture may be obtained in some, but not all, cases. Most isolates are sensitive to procaine penicillin, so treatment with procaine penicillin and gentamicin sulphate is recommended until antimicrobial sensitivity is known.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Breeding; Female; Horse Diseases; Horses; Male; New South Wales; Peritonitis; Records; Retrospective Studies
PubMed: 11599812
DOI: 10.1111/j.1751-0813.2001.tb10741.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 -
Journal of Clinical Microbiology Jun 2015We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses,...
We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses, respectively. Identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and real-time PCR assay. A previous visit to a farm was suspected as the source of infection.
Topics: Actinobacillus Infections; Actinobacillus equuli; Actinobacillus suis; Adolescent; Bacteremia; Humans; Male; Meningitis, Bacterial; Molecular Typing
PubMed: 25878346
DOI: 10.1128/JCM.00339-15 -
Veterinary Microbiology Mar 2004The taxonomy of the members of the genus Actinobacillus associated with animals has been reviewed with focus on classification and identification including molecular... (Review)
Review
The taxonomy of the members of the genus Actinobacillus associated with animals has been reviewed with focus on classification and identification including molecular based characterization, typing and identification. Out of the 22 species or species like taxa reported as Actinobacillus, 19 are associated with animals. When classified on the basis of 16S rRNA sequence based phylogenetic analysis, DNA-DNA hybridizations and phenotypic analysis, Actinobacillus sensu stricto is restricted to include A. lignieresii, A. pleuropneumoniae, A. equuli subsp. equuli, A. equuli subsp. haemolyticus (taxon 11 of Bisgaard), A. hominis, A. suis, A. ureae, A. arthritidis (taxon 9 of Bisgaard), Actinobacillus genomospecies 1 and 2 and the taxa 8 and 26 of Bisgaard. The remaining 11 species of Actinobacillus are unrelated to A. sensu stricto and should consequently be grouped with other genera or be renamed as new genera depending on new data. Identification of members of Actinobacillus at species level is possible through phenotypic characterization combined with information on host of isolation. PCR tests are available for specific detection of A. pleuropneumoniae. Only A. pleuropneumoniae is presently considered as a primary pathogen. Based on different types of RTX genes it is possible to PCR type A. pleuropneumoniae to serotype level. PCR might also be used for the specific detection of A. equuli subsp. haemolyticus. Epidemiological investigations and surveillance have so far included serotyping, multilocus enzyme electrophoresis (MLEE), ribotyping and restriction fragment length profiling.
Topics: Actinobacillus; Actinobacillus Infections; Animals; DNA, Bacterial; Molecular Epidemiology; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Serotyping
PubMed: 15019108
DOI: 10.1016/j.vetmic.2003.12.002 -
Veterinary Immunology and... Aug 2007Actinobacillus equuli is carried in the alimentary tract of mares and can cause severe septicemia of neonatal foals. A hemolytic subspecies, A. equuli subsp....
Actinobacillus equuli is carried in the alimentary tract of mares and can cause severe septicemia of neonatal foals. A hemolytic subspecies, A. equuli subsp. haemolyticus, and a non-hemolytic subspecies, A. equuli subsp. equuli, have been identified. Hemolytic strains produce the RTX toxin Aqx. The purpose of this study was to demonstrate sequentially in two sets of mare-foal pairs antibodies to A. equuli whole bacterial cells, outer membrane proteins, and recombinant Aqx and to compare the transfer of antibodies to these antigens between mares and their foals. Two mare/foal sets of sera were evaluated. Cohort A consisted of 18 mare-foal pairs obtained in the spring of 2005. Cohort B consisted of 10 mare-foal pairs obtained in the spring of 2006. For both sets, mare and foal sera were obtained immediately after foaling and prior to nursing (time 0) as well as at 12 and 24h and daily thereafter for 7 days. For Cohort B, sera were also obtained 30 days after birth. At parturition all mares had detectable antibodies to A. equuli whole cells and outer membranes; however, of those mares, two in Cohort A had undetectable antibodies to Aqx and their foals likewise had undetectable anti-Aqx antibodies. Antibodies against whole cells, outer membrane proteins, and Aqx were readily transferred from mares to foals. In most cases, there were significant correlations (p<0.05) between antibodies against whole cells, outer membrane proteins, and Aqx in mares' sera at the time of parturition and foal sera 24 after birth. Antibodies against the three antigen preparations had declined insignificantly (p>0.05) by day 30.
Topics: Actinobacillus equuli; Animals; Animals, Newborn; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Outer Membrane Proteins; Bacterial Toxins; Female; Horses; Immunity, Maternally-Acquired; Time Factors
PubMed: 17604847
DOI: 10.1016/j.vetimm.2007.05.013 -
The Veterinary Record Feb 1973
Topics: Actinobacillus; Actinobacillus Infections; Animals; England; Kidney; Kidney Cortex; Kidney Medulla; Necrosis; Swine; Swine Diseases; Tetracycline
PubMed: 4692514
DOI: 10.1136/vr.92.7.178 -
International Journal of Systematic and... Oct 2019Ten strains of an -like organism were isolated from alpaca () in the UK over a period of 5 years, with no known epidemiological linkages. The isolates are distinct,...
Ten strains of an -like organism were isolated from alpaca () in the UK over a period of 5 years, with no known epidemiological linkages. The isolates are distinct, based on both phenotype and genotype, from any previously described species. Molecular analysis, based on 16S rRNA, and gene sequences, placed the isolates as a novel, early branching, lineage within the currently recognised . In agreement with the results of the single-gene analysis, average nucleotide identity values, based on whole genome sequences, showed very similar identities to a number of members of the notably , and . At least two phenotypic characteristics differentiate the alpaca isolates from other species, and from taxa likely falling within this group but awaiting formal species description, with and subsp. being the most closely related phenotypically. The alpaca isolates can be differentiated from by production of β-galactosidase (ONPG) and acid from raffinose, and from subsp. by production of acid from d-sorbitol and failure to produce acid from d-xylose. Isolates were obtained from multiple sites in alpaca including respiratory tract, alimentary tract and internal organs although further evidence is required to understand any pathogenic significance. Based on the results of characterization described here, it is proposed that the isolates constitute a novel species, sp. nov. The type strain is W1618 (LMG30745 NCTC14090) isolated in the UK in 2012 from oesophageal ulceration in an alpaca ().
Topics: Actinobacillus; Animals; Bacterial Typing Techniques; Base Composition; Camelids, New World; DNA, Bacterial; Female; Genes, Bacterial; Male; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; United Kingdom
PubMed: 31395108
DOI: 10.1099/ijsem.0.003607 -
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 -
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