[Agglutination of hen egg-yolk immunoglobulins (IgY) against Salmonella enterica, serovar enteritidis]. / Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad enteritidis.

Two groups of 6 laying hens were used to produce IgY. In the vaccinated group (V), hens were injected by intramuscular route with two doses of a Salmonella enterica serovar Enteritidis bacterin at 20-day interval. In the control group (T) hens remained unvaccinated. Four IgY extractions were performed on the egg production of both groups. The first two extractions were carried out using the yolks obtained from the eggs produced during the 4th and 5th post-vaccination week (extracts 1V and 1T) and the other two using the ones from the 6th, 7th and 8th week (2V and 2T). Starting from the extracts 1V and 1T other products were obtained by freezing-thawing (1V-A and 1T-A) and simple (1V-B and 1T-B) or double (1V-C and 1T-C) flow capillary dialysis concentration. All these products were compared using an ELISA test specific for the detection of chicken antibodies against flagellar antigens of S. Enteritidis. In this test, V extracts were positive whereas T extracts were negative. The extract 1V was more positive than the extract 2V. The extract 1V-C was the most positive and was therefore selected to be used as an antiserum in the agglutination tests. This extract contained 1.9 g/dl of total proteins, 0.028 g/dl of triglycerides and 0.012 g/dl of cholesterol and showed an electrophoretic pattern characteristic of IgY. The 1T-C extract was used as a negative control in the agglutination tests. Slide somatic and tube flagellar agglutination tests were simultaneously carried out using both IgY extracts and a standard rabbit anti-Salmonella (IgG) sera. Overall 367 strains from the Enterobacteriaceae family were tested together with two other strains belonging to the Vibrionaceae family. The 1V-C extract specifically agglutinated S. Enteritidis strains in the same way as the rabbit sera. This extract also agglutinated other Salmonella strains antigenically related to S. Enteritidis. Salmonella which did not share somatic or flagellar antigens with S. Enteritidis, other different species of the Enterobacteriaceae family and the two strains of the Vibrionaceae family were all negative. None of the strains tested was agglutinated by the 1T-C extract. This paper show that it is possible to use specific IgY to identify S. enterica serovars. The more extended use of IgY for diagnostic purposes may be a convenient way to complement the current use of mammal polyclonal antibodies.

Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad Enteritidis / Agglutination of chicken egg yolk immunoglobulins (IgY) against Salmonella enterica serovar Enteriditis

Para producir extractos de IgY se emplearon dos lotes de 6 gallinas ponedoras cada uno. En el lote vacunado (V) las aves se inocularon por vía intramuscular con dos dosis de una bacterina contra Salmonella enterica serovariedad Enteritidis. En el lote testigo (T) las aves no se vacunaron. Con las yemas de ambos lotes se efectuaron 4 extracciones de IgY. Las dos primeras se realizaron con las yemas de los huevos producidos durante la 4º y 5º semana post-vacunación (extractos 1V y 1T) y las otras dos con las de la 6º, 7º y 8º semana (2V y 2T). Los extractos 1V y 1T se congelaton y descongelaron (1V-A y 1T-A) y se concentraron por diálisis simple (1V-B y 1T-B) o doble (1V-C y 1T-C). Media

Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad Enteritidis / Agglutination of chicken egg yolk immunoglobulins (IgY) against Salmonella enterica serovar Enteriditis

Para producir extractos de IgY se emplearon dos lotes de 6 gallinas ponedoras cada uno. En el lote vacunado (V) las aves se inocularon por vía intramuscular con dos dosis de una bacterina contra Salmonella enterica serovariedad Enteritidis. En el lote testigo (T) las aves no se vacunaron. Con las yemas de ambos lotes se efectuaron 4 extracciones de IgY. Las dos primeras se realizaron con las yemas de los huevos producidos durante la 4§ y 5§ semana post-vacunación (extractos 1V y 1T) y las otras dos con las de la 6§, 7§ y 8§ semana (2V y 2T). Los extractos 1V y 1T se congelaton y descongelaron (1V-A y 1T-A) y se concentraron por diálisis simple (1V-B y 1T-B) o doble (1V-C y 1T-C). Mediante una prueba de ELISA para detectar antígenos flagelares de S. Enteritidis, los extractos V fueron positivos y los T negativos. El extracto 1V-C fue el más positivo y se seleccionó para realizar las aglutinaciones. Este extracto contenía 1,9 g/dl de proteínas totales y presentó bandas electroforéticas características de IgY. El extracto 1T-C fue usado como control negativo de aglutinación. Emplenado ambos extractos IgY y antisueros policlonales de conejo (IgG) se efectuaron aglutinaciones somáticas en placa y flagelares en tubo. Se estudiaron 357 cepas de S. enterica, 10 cepas de diferentes especies de la familia Enterobacteriaceae y dos cepas de la familia Vibrionaceae. El extracto 1V-C aglutinó a distintas cepas de Salmonella con estructura antigénica somática o flagelar relacionada con la cepa vacunal, mientras que las salmonelas con antígenos diferentes y otras especies de la familia Enterobacteriaceae y Vibrionaceae fueron negativas. Este trabajo demuestra que es posible emplear las IgY para identificar serovariedades de S. enterica

Evaluation of inactivated infectious coryza vaccines in chickens challenged by serovar B strains of Haemophilus paragallinarum.

Four monovalent experimental vaccines (VI, V2, V3 and V7) containing an Argentinean serovar B strain (H8) of Haemophilus paragallinarum and three different commercial vaccines, either bivalent (V4 and V5) containing serovars A and C, or trivalent (V6) containing serovars A, B and C were administered by subcutaneous or intramuscular routes as a single or double dose (at 3-week intervals) to chickens of between 6 and 10 weeks. Three to 7 weeks after the last vaccination, vaccinated and non-vaccinated chickens were challenged by intrasinus inoculation with Argentinean serovar B strains of H. paragallinarum. When the vaccinated chickens were exposed to a severe challenge with the vaccinal strain (H8) some experimental vaccines protected, whereas all commercial vaccines failed to protect. The experimental vaccines manufactured in broth (V2, V3 and V7) protected more effectively than the vaccine produced in chicken embryos (VI). Failure of the commercial trivalent vaccine V6 to protect may be related to the method of manufacture. Vaccine V7 protected against challenge from either the vaccinal strain (H8) or three Argentinean serovar B strains (H6, Hll and HI2). These results confirm the necessity of including serovar B regional strains in the formulation of local vaccines.

Complicated infectious coryza outbreaks in Argentina.

Seventeen complicated outbreaks of infectious coryza in layer, broiler-breeder, and broiler flocks were studied. In the layer flock outbreaks, drops in egg production of up to 35% were seen. In the broiler flocks and several of the layer flocks, losses due to persistent mortality and/or culling varied between 2 and 5%. Signs of infectious coryza in both layers and broiler-breeders were typical; in broilers, however, swollen head-like syndrome was seen. Except in one flock, no viral diseases were clinically or serologically detected. Excluding broiler-breeders, birds from most other flocks were serologically positive for Mycoplasma gallisepticum, and some were also positive for M. synoviae. Haemophilus paragallinarum was isolated from all of the outbreaks, but only as a pure culture in three outbreaks. Isolation of H. paragallinarum from sites such as liver, kidney, and particularly tarsal arthritis and ocular globes appears to be reported for the first time. Serovar A was isolated in eight outbreaks, serovar B in six, serovar C in one, and untypable serovars in two. The severity of these infectious coryza outbreaks may have been increased by concurrent salmonellosis, pasteurellosis, and mycoplasmosis, although under certain conditions H. paragallinarum is able to cause septicemia. Ten of the outbreaks occurred in birds vaccinated against infectious coryza; this may be due to the use of vaccines that do not provide protection against the types of H. paragallinarum that affect poultry in the region.

Characterization of two monoclonal antibodies directed against serovar A Haemophilus paragallinarum.

Two monoclonal antibodies (MAbs) raised against a serovar A Haemophilus paragallinarum were evaluated for their ability to react with 11 reference strains that represented all the recognized serovars and with 27 field isolates of Page serovar A collected from around the world. The MAbs were used in a hemagglutination-inhibition assay. Both MAbs recognized type strains of Page serovar A and Kume serovars A-1 and A-2 but not the type strains of Kume serovars A-3 and A-4. Neither MAb recognized the type strains of Page serovars B and C or Kume serovars B-1, C-1, C-2, C-3, or C-4. When evaluated with the 27 Page serovar A field isolates, both MAbs recognized only 10 isolates. All of the recognized isolates belonged to Kume serovars A-1 (nine isolates) or A-2 (one isolate). All of the field isolates that were not recognized by one or the other of the MAbs either were Kume serovar A-4 (seven isolates) or could not be placed in an existing Kume A serovar (10 isolates). The results indicate that the epitope recognized by these MAbs is present only in strains of H. paragallinarum that belong to Kume serovars A-1 and A-2.

Characterization of isolates of Haemophilus paragallinarum from Argentina.

The biochemical and serological properties of Haemophilus paragallinarum isolates recovered from 11 recent outbreaks of infectious coryza in layer hens and one case of swollen-head syndrome in broilers in Argentina are described. Twenty-four isolates had the typical biochemical properties of H. paragallinarum. All isolates were serotyped according to the Page scheme. Ten of the isolates were serovar A, 11 were serovar B, one was serovar C, and two isolates could not be serotyped. The isolates were also examined using a panel of monoclonal antibodies (MAbs) for Page serovars A (one MAb available) and C (three MAbs available). The serovar B isolates all failed to react with any MAb. The serovar C isolate reacted with all three serovar C MAbs but not with the serovar A MAb. Only six of the 10 serovar A isolates reacted with the serovar A MAb. These results indicate that H. paragallinarum isolates from Argentina are antigenically distinct from those examined in other countries, and it is suggested that coryza vaccines intended for use in Argentina may be more effective if based on local strains.