RESUMEN
The bacterium Avibacterium paragallinarum is the etiologic agent of infectious coryza of chickens. Among the nine Kume serovars currently recognized in this bacterium, serovar B-1 is a common serovar in the Americas. In the current study, serovar B-1 isolates from Ecuador (seven isolates), Mexico (seven isolates) and Panama (two isolates) were genotyped. In addition one Panamanian, one Ecuadorian, and two Mexican isolates were used in a vaccination-challenge trial in which the vaccine was based on the 2671 serovar B-1 reference strain. Genotyping by enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) resulted in ten distinguishable ERIC patterns for the 16 isolates and the two reference strains of Av. paragallinarum included in the study. No ERIC patterns were shared among isolates of the three different countries. In the vaccination-challenge trial, one isolate from Panama showed a significantly lower virulence than did the three other isolates. In terms of cross-protection, chickens vaccinated with reference strain 2671 and challenged with an Ecuadorian strain showed 40% protection, a significantly lower protection than the homologous protection level. The other three field isolates gave a similar protection level to the homologous challenge.
Asunto(s)
Pollos , Infecciones por Haemophilus/veterinaria , Haemophilus paragallinarum/clasificación , Haemophilus paragallinarum/patogenicidad , Enfermedades de las Aves de Corral/inmunología , Animales , Ecuador , Genotipo , Infecciones por Haemophilus/inmunología , Infecciones por Haemophilus/microbiología , Haemophilus paragallinarum/genética , Haemophilus paragallinarum/inmunología , México , Panamá , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de las Aves de Corral/microbiología , Serotipificación/veterinaria , VirulenciaRESUMEN
Avibacterium paragallinarum is the causative agent of infectious coryza, an acute respiratory disease of chickens. In this study, a total of 28 isolates of A. paragallinarum from Ecuador were serotyped by the hemagglutinin scheme which recognizes nine serovars. Out of 28 isolates, 17 isolates belonged to serovar A-3, and five isolates to each serovars B-1 and C-1, whereas one isolate was non-typeable. This is the first report of A. paragallinarum serovar A-3 outside Brazil and serovar C-1 outside Japan.
Asunto(s)
Pollos , Infecciones por Haemophilus/veterinaria , Haemophilus paragallinarum/genética , Enfermedades de las Aves de Corral/microbiología , Animales , ADN Bacteriano/química , ADN Bacteriano/genética , Ecuador , Femenino , Infecciones por Haemophilus/microbiología , Haemophilus paragallinarum/clasificación , Pruebas de Inhibición de Hemaglutinación/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , Serotipificación/métodosRESUMEN
The isolation and identification of Avibacterium paragallinarum serovar B-1 from severe infectious coryza outbreaks in broiler breeders in Panama is reported for the first time. Infectious coryza was absent for over a decade in the breeder farms area. Disease outbreaks were characterized by an up to 45% drop in egg production and increased mortality. Use of a commercial trivalent bacterin and a strengthened biosecurity program prevented outbreaks in susceptible flocks in the farm.
Asunto(s)
Pollos , Brotes de Enfermedades/veterinaria , Infecciones por Haemophilus/veterinaria , Haemophilus paragallinarum/clasificación , Enfermedades de las Aves de Corral/microbiología , Animales , Infecciones por Haemophilus/epidemiología , Infecciones por Haemophilus/microbiología , Panamá/epidemiología , Enfermedades de las Aves de Corral/epidemiología , SerotipificaciónRESUMEN
This work evaluates the efficiency of the administration of the disinfectant N-alkyl dimethyl benzyl ammonium chloride (TIMSEN) in the prevention of the horizontal transmission of serovars A, B, and C of Avibacterium paragallinarum, the causative agent of avian infectious coryza. This disinfectant was administered in drinking water (50 ppm) and once or twice per day by coarse spray (800 ppm, 8 ml per m3 during 3 seconds). In three trials conducted with vaccinated birds, the disinfectant reduced the clinical signs of infectious coryza significantly (P < 0.05). There was no significant effect when the product was used in a fourth trial with unvaccinated birds. Furthermore, the application of only one daily environmental spraying was sufficient to significantly reduce clinical signs. According to these results, in order to diminish the clinical signs of infectious coryza in birds vaccinated against A. paragallinarum, it is recommended to administer this disinfectant in drinking water and by environmental spraying.
Asunto(s)
Pollos/microbiología , Desinfectantes/administración & dosificación , Infecciones por Haemophilus/veterinaria , Haemophilus paragallinarum , Enfermedades de las Aves de Corral/prevención & control , Aerosoles , Animales , Compuestos de Benzalconio/administración & dosificación , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/prevención & control , Infecciones por Haemophilus/transmisión , Haemophilus paragallinarum/clasificación , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/transmisión , Serotipificación , Abastecimiento de AguaRESUMEN
The protection and level of hemagglutination-inhibition (HI) antibodies conferred in infectious coryza bivalent- and trivalent-immunized chickens against Avibacterium (Haemophilus) paragallinarum field isolates of the prevalent serovars in Mexico (A-1, A-2, B-1, and C-2) were investigated. The bivalent bacterin (A-1 and C-1) conferred significant protection and increased HI antibodies against isolates of serovars A-1, A-2, and C-2, but not against a serovar B-1 isolate. The trivalent bacterin (A-1, B-1, and C-2) conferred protection and increased HI antibodies against all four of the isolates. The results confirmed that in poultry areas where serovar B-1 is prevalent, the inclusion of this serovar in bacterins is needed to confer protection against infectious coryza caused by A. (H.) paragallinarum isolates of serovar B-1.
Asunto(s)
Vacunas Bacterianas/administración & dosificación , Pollos/inmunología , Pollos/microbiología , Infecciones por Haemophilus/veterinaria , Haemophilus paragallinarum/inmunología , Enfermedades de las Aves de Corral/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/prevención & control , Haemophilus paragallinarum/clasificación , Haemophilus paragallinarum/patogenicidad , Pruebas de Inhibición de Hemaglutinación , México , Enfermedades de las Aves de Corral/microbiología , SerotipificaciónRESUMEN
The enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique was used for fingerprinting of reference strains and Mexican isolates of Haemophilus paragallinarum. A total of nine ERIC patterns were given by the nine serovar reference strains of this bacteria. Two Modesto (C-2) reference strains from different sources showed the same ERIC pattern. Seventeen ERIC patterns were obtained among 29 Mexican isolates included in the study, belonging to serovars prevalent in Mexico (A-1, A-2, B-1, and C-2). Obtained results indicate that the ERIC-PCR technique could be used as a molecular laboratory tool for subtyping of H. paragallinarum.