RESUMEN
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.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus equuli , Actinobacillus suis , Actinobacillus , Sepsis , Humanos , Adulto , Masculino , Sepsis/diagnósticoRESUMEN
Actinobacillus equuli ssp. equuli is an opportunistic pathogen in horses, mainly known to cause "sleepy foal disease". In comparison to horses, there are only few reports describing diseases in pigs associated with this gram-negative bacterium. This case report describes an outbreak of infection in a combined farrow-to-finish-farm. In September 2018, the following symptoms were noticed in one third of all newborn piglets from gilts and sows: 6-8 hours after birth piglets became weak and developed swollen joints with moderate to severe lameness. The piglets exhibited lethargy, a subset were non-ambulatory. An elevated piglet mortality within the first days within birth was noted. Seven piglets that succumbed to the disease (days 2-3 of life) were submitted for examination, 4 of which underwent pathological examination. The main findings were purulent polyarthritis and tendovaginitis. In addition, purulent inflammation was detected in the brain and kidneys of one animal. In the bacteriological examination A. equuli ssp. equuli was isolated in a total of 18 samples (brain, joints, suppurative structures of limbs), in a subset of cases as pure culture. For identification, cultural and biochemical characteristics were tested and a mass spectrometry analysis (MALDI-TOF MS) was performed. Further laboratory testing included 16 S rRNA-gene sequencing, a PCR in order to examine for special apx toxin genes as well as a PCR differentiating the two subspecies of A. equuli. It was not possible to identify the source of infection and routes of spread within the pig herd. The bacterial isolates were used for the production of an autogenous vaccine.
Asunto(s)
Actinobacilosis/microbiología , Actinobacillus equuli/aislamiento & purificación , Artritis Infecciosa/veterinaria , Enfermedades de los Porcinos/microbiología , Atrapamiento del Tendón/veterinaria , Actinobacilosis/diagnóstico , Actinobacilosis/patología , Actinobacillus equuli/genética , Actinobacillus equuli/inmunología , Animales , Anticuerpos Antibacterianos/sangre , Artritis Infecciosa/diagnóstico , Artritis Infecciosa/microbiología , Artritis Infecciosa/patología , Corteza Cerebral/patología , Riñón/patología , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/patología , Atrapamiento del Tendón/diagnóstico , Atrapamiento del Tendón/microbiología , Atrapamiento del Tendón/patologíaRESUMEN
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.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus equuli , Actinobacillus suis , Bacteriemia , Meningitis Bacterianas , Adolescente , Humanos , Masculino , Tipificación MolecularAsunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/aislamiento & purificación , Animales Recién Nacidos , Enfermedades de los Caballos/patología , Sepsis/veterinaria , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Animales , Resultado Fatal , Enfermedades de los Caballos/microbiología , Caballos , Masculino , Sepsis/patologíaRESUMEN
We report on the isolation of Actinobacillus equuli ssp. haemolyticus from wound smears of a 2-year-old girl who was admitted to the hospital due to partial amputation of the distal phalanx of her right middle finger caused by a horse bite. A. equuli typically causes diseases in horses and only very few reports describing human infections (mostly associated with wounds) are available in the literature. Interestingly, although the bacteria could be found in consecutive samples taken at different points in time, there were no signs of advancing infection or inflammation. Moreover, the fingertip regenerated after 74 days under semi-occlusive dressings with very pleasant results. For strain identification two automated systems were employed producing discrepant results: VITEK 2 described the pathogens as Pasteurella pneumotropica while MALDI-TOF MS analysis revealed A. equuli. Sequence analysis of 16S rDNA gene finally confirmed A. equuli ssp. haemolyticus as the isolated strain. The antimicrobial susceptibility testing was performed according to the CLSI criteria for Pasteurella spp. Additionally we conducted a test according to the EUCAST criteria.
Asunto(s)
Infecciones por Actinobacillus/terapia , Actinobacillus equuli/aislamiento & purificación , Antibacterianos/uso terapéutico , Vendajes , Mordeduras y Picaduras/terapia , Caballos/microbiología , Infecciones por Actinobacillus/diagnóstico , Infecciones por Actinobacillus/microbiología , Animales , Mordeduras y Picaduras/diagnóstico , Mordeduras y Picaduras/microbiología , Preescolar , Femenino , Humanos , Resultado del TratamientoRESUMEN
RTX toxins are bacterial pore-forming toxins that are particularly abundant among pathogenic species of Pasteurellaceae, in which they play a major role in virulence. RTX toxins of several primary pathogens of the family of Pasteurellaceae are directly involved in causing necrotic lesions in the target organs. Many RTX toxins are known as haemolysins because they lyse erythrocytes in vitro, an effect that is non-specific, but which serves as a useful marker in bacteriological identification and as an easily measurable signal in vitro in experimental studies. More recent studies have shown that the specific targets of most RTX toxins are leukocytes, with RTX toxins binding to the corresponding ß-subunit (CD18) of ß2 integrins and then exerting cytotoxic activity. After uptake by the target cell, at sub-lytic concentrations, some RTX toxins are transported to mitochondria and induce apoptosis. For several RTX toxins the binding to CD18 has been shown to be host specific and this seems to be the basis for the host range specificity of these RTX toxins. Observations on two very closely related species of the Pasteurellaceae family, Actinobacillus suis, a porcine pathogen particularly affecting suckling pigs, and Actinobacillus equuli subsp. haemolytica, which causes pyosepticaemia in new-born foals (sleepy foal disease), have revealed that they express different RTX toxins, named ApxI/II and Aqx, respectively. These RTX toxins are specifically cytotoxic for porcine and equine leukocytes, respectively. Furthermore, the ApxI and Aqx toxins of these species, when expressed in an isogenetic background in Escherichia coli, are specifically cytotoxic for leukocytes of their respective hosts. These data indicate the determinative role of RTX toxins in host specificity of pathogenic species of Pasteurellaceae.
Asunto(s)
Toxinas Bacterianas/metabolismo , Especificidad del Huésped , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/patogenicidad , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli , Animales , Proteínas Hemolisinas/metabolismo , Caballos , Pasteurellaceae/metabolismo , Infecciones por Pasteurellaceae/microbiología , Porcinos , VirulenciaRESUMEN
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.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/inmunología , Proteínas de la Membrana Bacteriana Externa/inmunología , Toxinas Bacterianas/inmunología , Vacunas Bacterianas/inmunología , Enfermedades de los Caballos/inmunología , Infecciones por Actinobacillus/inmunología , Animales , Anticuerpos Antibacterianos/análisis , Proteínas de la Membrana Bacteriana Externa/administración & dosificación , Toxinas Bacterianas/administración & dosificación , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Caballos , Ratones , Vacunación/veterinaria , Vacunas Sintéticas/inmunologíaRESUMEN
The death of over 300 sows in 2 months on a 3000 sow farrow-to-isowean operation in Manitoba was attributed to infection with Actinobacillus equuli. This pathogen commonly infects foals, and is rarely reported in swine. Our report is the second recently published case of this pathogen in North American swine.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/patogenicidad , Cruzamiento , Enfermedades de los Porcinos/epidemiología , Infecciones por Actinobacillus/epidemiología , Animales , Animales Recién Nacidos , Femenino , Masculino , Manitoba/epidemiología , Prevalencia , PorcinosRESUMEN
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.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/aislamiento & purificación , Endocarditis Bacteriana/veterinaria , Enfermedades de los Porcinos/microbiología , Enfermedades Uterinas/veterinaria , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Actinobacillus equuli/genética , Animales , Secuencia de Bases , ADN Bacteriano/química , ADN Bacteriano/genética , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/patología , Resultado Fatal , Femenino , Histocitoquímica/veterinaria , Datos de Secuencia Molecular , Embarazo , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Sepsis/microbiología , Sepsis/patología , Sepsis/veterinaria , Enfermedades de los Porcinos/patología , Enfermedades Uterinas/microbiología , Enfermedades Uterinas/patologíaAsunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/patogenicidad , Celulitis (Flemón)/veterinaria , Infecciones por Escherichia coli/veterinaria , Enfermedades de los Caballos/diagnóstico , Infecciones por Actinobacillus/diagnóstico , Infecciones por Actinobacillus/patología , Infecciones por Actinobacillus/terapia , Animales , Animales Recién Nacidos , Antibacterianos/uso terapéutico , Celulitis (Flemón)/diagnóstico , Celulitis (Flemón)/patología , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/patología , Infecciones por Escherichia coli/terapia , Femenino , Enfermedades de los Caballos/patología , Enfermedades de los Caballos/terapia , Caballos , Nutrición Parenteral/veterinaria , Resultado del TratamientoRESUMEN
A case of fatal pulmonary hemorrhage in a 6-year-old American Paint mare with a 2-week history of intermittent coughing, fever, and epistaxis is described. Significant macroscopic abnormalities at postmortem examination were restricted to the respiratory system, and microscopically, severe pulmonary hemorrhage with suppurative bronchopneumonia was found. Actinobacillus equuli subsp. haemolyticus was cultured from a transtracheal wash performed antemortem as well as from the lungs at necropsy. The presence of airway-associated hemorrhage in conjunction with bacterial bronchopneumonia suggested endothelial damage caused by a locally elaborated bacterial toxin, possibly produced by the A. equuli strain isolated from the lungs. The objective of this report was to indirectly document the presence of hemolysin repeat in structural toxin (RTX) in the lungs of the reported mare. A real-time polymerase chain reaction (PCR) assay targeting the recently described aqx gene of A. equuli subsp. haemolyticus was established and validated. Transcriptional activity of the aqx gene was used as a surrogate method to document toxin production. Real-time PCR analysis of the transtracheal fluid and lung tissue of the affected mare confirmed the presence and the transcriptional activity of the aqx gene at the genomic (gDNA) and complementary DNA (cDNA) levels, respectively. The presence of pneumonia associated with hemorrhagic pulmonary fluid and the culture of large numbers of hemolytic A. equuli should prompt the clinician to consider endothelial damage caused by bacterial toxins.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/metabolismo , Proteínas Bacterianas/biosíntesis , Enfermedades de los Caballos/microbiología , Enfermedades Pulmonares/veterinaria , Infecciones por Actinobacillus/microbiología , Actinobacillus equuli/genética , Animales , ADN Bacteriano/química , ADN Bacteriano/genética , Resultado Fatal , Femenino , Histocitoquímica/veterinaria , Caballos , Enfermedades Pulmonares/microbiología , Reacción en Cadena de la Polimerasa/veterinaria , EmbarazoRESUMEN
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.
Asunto(s)
Actinobacillus equuli/inmunología , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Proteínas de la Membrana Bacteriana Externa/inmunología , Toxinas Bacterianas/inmunología , Caballos/sangre , Caballos/inmunología , Animales , Animales Recién Nacidos/inmunología , Antígenos Bacterianos , Femenino , Inmunidad Materno-Adquirida , Factores de TiempoRESUMEN
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.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/clasificación , Actinobacillus equuli/aislamiento & purificación , Infecciones por Clostridium/veterinaria , Conejos/microbiología , Infecciones por Actinobacillus/complicaciones , Infecciones por Actinobacillus/microbiología , Actinobacillus equuli/genética , Animales , Infecciones por Clostridium/complicaciones , Infecciones por Clostridium/epidemiología , ADN Bacteriano/química , ADN Bacteriano/genética , Resultado Fatal , Hígado/microbiología , Pulmón/microbiología , Masculino , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 16S/genéticaRESUMEN
Microbiological and pathological data from a case of equine valvular endocarditis are reported. Limited information is available on the pathogenic potential of equine Actinobacillus species as several strains originate from apparently healthy horses. After the establishment of two subspecies within this species, this seems to be the first report of an etiological association between A. equuli subsp. equuli and equine endocarditis. Furthermore, new information on some phenotypical characteristics of this subspecies is reported, compared to previous findings.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus equuli/aislamiento & purificación , Endocarditis Bacteriana/veterinaria , Enfermedades de las Válvulas Cardíacas/veterinaria , Enfermedades de los Caballos/microbiología , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Actinobacillus equuli/genética , Animales , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/patología , Enfermedades de las Válvulas Cardíacas/microbiología , Enfermedades de las Válvulas Cardíacas/patología , CaballosRESUMEN
Actinobacillus equuli is found in the normal oral flora of horses, but has been associated with several diseases, and particularly with the usually fatal septicaemia in neonatal foals which is thought to be associated with a failure of the passive transfer of immunoglobulins via the colostrum. The Aqx protein of A equuli, belonging to the RTX family of pore-forming toxins, is also cytotoxic to horse lymphocytes. The presence of antibodies to Aqx was investigated in sera from individual horses from different regions; the sera from adult horses and foals 24 hours after birth reacted with Aqx, and sera from foals sampled shortly after an intake of colostrum also reacted with Aqx, but sera from foals taken before an intake of colostrum did not react with Aqx.