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Journal of Clinical Microbiology Sep 1998We describe the isolation of Actinobacillus equuli from the blood of a 53-year-old butcher with septicemia. This species of the genus Actinobacillus is primarily...
We describe the isolation of Actinobacillus equuli from the blood of a 53-year-old butcher with septicemia. This species of the genus Actinobacillus is primarily associated with animals and animal diseases, especially septicemia in foals. This is the first report of the isolation of A. equuli from a human with septicemia.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Bacteremia; Drug Therapy, Combination; Floxacillin; Gentamicins; Humans; Male; Middle Aged; Penicillin G; Shock, Septic; Zoonoses
PubMed: 9705442
DOI: 10.1128/JCM.36.9.2789-2790.1998 -
Klinicka Mikrobiologie a Infekcni... Jun 2022This is a case report of sepsis caused by the species Actinobacillus suis/equuli in a male agriculture worker that ended fatally. The article also contains information...
This is a case report of sepsis caused by the species Actinobacillus suis/equuli in a male agriculture worker that ended fatally. The article also contains information on identification and results of antibiotic susceptibility testing. This is a rare case of human infection and probably the first case of a human being infected by this species in the Czech Republic.
Topics: Humans; Adult; Male; Actinobacillus equuli; Actinobacillus; Actinobacillus Infections; Actinobacillus suis; Sepsis
PubMed: 36546469
DOI: No ID Found -
Veterinary Microbiology Mar 2003We assessed and compared host cell specificity of the haemolytic and cytotoxic activity of the RTX toxins from Actinobacillus equuli, an equine pathogen, and... (Comparative Study)
Comparative Study
We assessed and compared host cell specificity of the haemolytic and cytotoxic activity of the RTX toxins from Actinobacillus equuli, an equine pathogen, and Actinobacillus suis, which is pathogenic for pigs. The two bacterial species are closely related, phenotypically as well as phylogenetically, sharing the same 16S rRNA gene sequence. Both species contain specific protein toxins from the family of pore-forming RTX toxins, however, the two species differ in their RTX toxin profiles. Haemolytic A. equuli contains the operon for the Aqx toxin, whereas A. suis harbours genes for ApxI and ApxII. We tested the toxic activity of the corresponding proteins on erythrocytes as well as on lymphocytes isolated from horse and pig blood. The strength of the haemolytic activity for each of the toxins was independent of the origin of erythrocytes. When testing cytotoxic activity, the Aqx protein showed a higher toxic effect for horse lymphocytes than for porcine lymphocytes. On the other hand, ApxI and ApxII showed a strong cytotoxic effect on porcine lymphocytes and a reduced toxicity for horse lymphocytes; the toxicity of ApxII was generally much lower than ApxI. Our results indicate a host species specificity of the toxic activity of RTX toxins Aqx of A. equuli and ApxI and ApxII of A. suis.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Bacterial Toxins; Cytotoxins; Erythrocytes; Horse Diseases; Horses; Lymphocytes; Species Specificity; Swine; Swine Diseases; Virulence
PubMed: 12488079
DOI: 10.1016/s0378-1135(02)00353-x -
Veterinary Journal (London, England :... Nov 2011The immune responsiveness of mice (without prior natural exposure) and mares (with naturally acquired antibodies) was determined following vaccination with...
The immune responsiveness of mice (without prior natural exposure) and mares (with naturally acquired antibodies) was determined following vaccination with Actinobacillus equuli outer membrane proteins (OMPs) and/or recombinant A. equuli toxin (rAqx). Mice were vaccinated subcutaneously on days 0 and 21 with one of three doses (5, 25 or 50μg) of A. equuli OMPs, rAqx or both, together with Freund's incomplete adjuvant (FIA). Antibodies against formalin-killed whole bacterial cells (WBCs), OMPs and Aqx were determined on days 0, 21 and 42. Mares were vaccinated subcutaneously on days 0 and 21 with 100μg OMPs, 100μg rAqx or a combination of 50μg of each antigen, together with FIA. Antibodies against WBCs, OMPs and Aqx were determined at 7day intervals for the first 42days, as well as on days 56, 70, 154 and 238. Vaccination of mice stimulated an apparent dose response to OMPs and Aqx. Antibodies against OMPs and Aqx were enhanced following vaccination of mares that had naturally acquired pre-existing antibodies. There was no evidence of interference with antibody responses to the individual antigens when OMPs and rAqx were combined prior to vaccination.
Topics: Actinobacillus Infections; Actinobacillus equuli; Animals; Antibodies, Bacterial; Bacterial Outer Membrane Proteins; Bacterial Toxins; Bacterial Vaccines; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Female; Horse Diseases; Horses; Mice; Vaccination; Vaccines, Synthetic
PubMed: 21596597
DOI: 10.1016/j.tvjl.2011.04.006 -
Veterinary Journal (London, England :... Jan 2000Actinobacillus species are Gram-negative bacteria responsible for several quite distinct disease conditions of animals. The natural habitat of the organisms is primarily... (Review)
Review
Actinobacillus species are Gram-negative bacteria responsible for several quite distinct disease conditions of animals. The natural habitat of the organisms is primarily the upper respiratory tract and oral cavity. A. lignieresii is the cause of actinomycosis (wooden tongue) in cattle: a sporadic, insidiously-developing granulomatous infection. In sharp contrast is A. pleuropneumoniae which is responsible for a rapidly spreading often fatal pneumonia, common among intensively reared pigs. Detailed investigation of this organism has provided a much clearer picture of the bacterial factors involved in causing disease. A. equuli similarly causes a potent septicaemia in the neonatal foal; growing apparently unrestricted once infection occurs. Other members of the genus induce characteristic pathogenesis in their preferred host, with one, A. actinomycetemcomitans, being a cause of human periodontal disease. This article reviews recent understanding of the taxonomy and bacteriology of the organisms, and the aetiology, pathogenicity, diagnosis and control of animal disease caused by Actinobacillus species.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Antibodies, Bacterial; Cattle; Cattle Diseases; Serotyping; Sheep; Sheep Diseases; Swine; Swine Diseases
PubMed: 10640409
DOI: 10.1053/tvjl.1999.0403 -
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 -
Veterinary Pathology Jul 2008A 1-year-old pregnant Yorkshire gilt was found dead with no previous clinical signs. Gross findings included metritis, splenomegaly, and valvular endocarditis. Bacterial...
A 1-year-old pregnant Yorkshire gilt was found dead with no previous clinical signs. Gross findings included metritis, splenomegaly, and valvular endocarditis. Bacterial endocarditis (in the mitral and tricuspid valves) and metritis with dissemination to multiple organs was diagnosed by using histologic examination. Gram-negative coccobacillary organisms present in the valvular lesions were characterized as Actinobacillus equuli by using polymerase chain reaction examination on formalin-fixed, paraffin-embedded tissues (FFPE). A. equuli is rarely reported as a cause of septicemia in pigs in Europe. A. equuli in pigs in the United States has been reported only twice and not, to our knowledge, in the last 30 years. This is the first time that molecular techniques have been used to characterize this organism in FFPE porcine tissues.
Topics: Actinobacillus Infections; Actinobacillus equuli; Animals; Base Sequence; DNA, Bacterial; Endocarditis, Bacterial; Fatal Outcome; Female; Histocytochemistry; Molecular Sequence Data; Pregnancy; RNA, Ribosomal, 16S; Reverse Transcriptase Polymerase Chain Reaction; Sepsis; Swine Diseases; Uterine Diseases
PubMed: 18587096
DOI: 10.1354/vp.45-4-495 -
Veterinary Microbiology Jun 2002Actinobacillus equuli, a member of the family Pasteurellaceae is the etiologic agent of a frequently lethal septicemia in neonatal foals as well as other more chronic...
Actinobacillus equuli, a member of the family Pasteurellaceae is the etiologic agent of a frequently lethal septicemia in neonatal foals as well as other more chronic diseases like arthritis, pleuritis, pneumonia or peritonitis. It may also be isolated from the oral cavity of healthy horses. Hemolytic isolates of A. equuli are known but so far no virulence determinants have been described for this bacterial species. By screening hemolytic A. equuli strains with specific gene probes, a hemolysin, designated Aqx (A. equuli RTX (repeats in the structural toxin)) was identified. This hemolysin was shown to be an RTX type of toxin by characterization of the aqxCABD operon. All hemolytic A. equuli isolates contained a functional aqxCABD operon and expressed the Aqx hemolysin as shown by genetic and phenotypic assays. The structural toxin AqxA is the hemolysin of A. equuli as shown by expression of recombinant aqx constructs in E. coli. Its hemolytic activity can be inhibited by specific antibodies raised against AqxA. Sequence analysis of the 16S rRNA gene (rrs) of the taxonomically diffuse group of A. equuli and related strains defined two phylogenetically distinct groups. The presence of the Aqx operon is not correlated with this phylogenetic grouping. The operon is found in both groups of A. equuli strains where it specifies the hemolytic activity and is supposedly to be a determinative virulence factor. The aqx operon was not found in closely related members of the Pasteurellaceae family. The description of the Aqx hemolysin will open new ways for studying the pathogenesis of A. equuli.
Topics: Actinobacillus; Actinobacillus Infections; Animals; Bacterial Toxins; Base Sequence; Blotting, Western; Cloning, Molecular; DNA Probes; DNA, Bacterial; Horse Diseases; Horses; Molecular Sequence Data; Neutralization Tests; Operon; Phylogeny; Polymerase Chain Reaction; Recombinant Proteins; Sequence Alignment; Sequence Analysis, DNA
PubMed: 12034544
DOI: 10.1016/s0378-1135(02)00048-2 -
Australian Veterinary Journal Feb 1976
Topics: Abortion, Veterinary; Actinobacillus; Animals; Female; Fetus; Horse Diseases; Horses; Pregnancy
PubMed: 988818
DOI: 10.1111/j.1751-0813.1976.tb13871.x -
Veterinary Microbiology Sep 2007Actinobacillus equuli was isolated in pure culture from the liver and lungs of an adult rabbit with Tyzzer's disease (Clostridium piliforme). Based on the haemolytic...
Actinobacillus equuli was isolated in pure culture from the liver and lungs of an adult rabbit with Tyzzer's disease (Clostridium piliforme). Based on the haemolytic features on blood agar plates, a positive reaction in the CAMP-test, hydrolysis of esculin, the inability to ferment l-arabinose, tDNA-PCR and sequencing of the 16S rRNA gene, the isolate was classified as A. equuli subsp. haemolyticus biovar 1. However, the aqxA gene, characteristic for haemolytic A. equuli strains, was not detected by PCR.
Topics: Actinobacillus Infections; Actinobacillus equuli; Animals; Clostridium Infections; DNA, Bacterial; Fatal Outcome; Liver; Lung; Male; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Rabbits
PubMed: 17482388
DOI: 10.1016/j.vetmic.2007.04.013