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[Clinical cases of infectious coryza and the properties of isolated Haemophilus strains]
Insights
Haemophilus paragallinarum causes coryza in poultry, often alongside other infections like CRD. Effective treatments include specific antibiotics and aerosol disinfection for disease control.
Area of Science:
- Avian Pathology
- Bacteriology
Context:
- Coryza is a common respiratory disease in poultry.
- Mixed infections complicate diagnosis and treatment of avian respiratory diseases.
Purpose:
- To identify the causative agent of coryza in sixteen poultry cases.
- To determine the pathogenicity of isolated Haemophilus strains.
- To evaluate therapeutic strategies for Haemophilus paragallinarum infections.
Summary:
- Sixteen cases of coryza were studied; Haemophilus paragallinarum was identified as the primary pathogen in most.
- Isolated strains were pathogenic to young birds and chick embryos.
- Disk-diffusion tests showed sensitivity to multiple antibiotics, with sulfotin, cosumix, linkospectin, and trimedin proving effective therapeutically.
Impact:
- Highlights the importance of differentiating Haemophilus paragallinarum-induced coryza from other avian diseases.
- Provides evidence for effective antibiotic and disinfection protocols in poultry respiratory disease management.
Abstract:
Studied were a total of sixteen cases with the clinical picture of coryza. Leading role in eleven of them had Haemophilus, in one the signs of chronical cholera and pox were seen, and in three there was a Pseudomonas aeruginosa infection. All cases were serologically positive for CRD. By their needs of nutrient growth factors the isolated Haemophilus strains belonged to H. paragallinarum, and they proved pathogenic for 8-week-old birds and poults that were about to lay their first eggs, killing 4-7-day-old chick embryos up to the 48 h hour. Tests for resistance to therapeutic means with the use of the disk-diffusion method revealed sensitivity to streptomycin, tetracycline, chloramphenicol, gentamycin, erythromycin, spectinomycin, furazolidon, imekil, cosumix, trimetoprim, and sulfadoxin. Good and very good therapeutic and prophylactic effects were produced with the use of sulfotin, cosumix, linkospectin, and trimedin coupled with aerosol disinfection with rivanol, the birds being present on the premise. It is stated that with regard to differential diagnosis coryza caused by Haemophilus paragallinarum should not be confused with fowl cholera, pox, CRD, and Pseudomonas aeruginosa infection which may run their course in a mixed infection.