Pasteurellaceae

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Pasteurellaceae is a family of Gram-negative bacteria within the order Pasteurellales. Members of this family are typically small, non-motile, and facultatively anaerobic. They are known to inhabit the mucosal surfaces of animals, including humans, and can be pathogenic, causing a variety of diseases.

Characteristics

Pasteurellaceae are characterized by their Gram-negative cell wall structure, which includes an outer membrane containing lipopolysaccharides. They are generally rod-shaped or coccobacillary and do not form spores. These bacteria are oxidase-positive and catalase-positive, which are important diagnostic features.

Genera

The family Pasteurellaceae includes several important genera, such as:

• Pasteurella - Known for causing pasteurellosis in animals and humans.
• Haemophilus - Includes species like Haemophilus influenzae, which can cause respiratory infections and meningitis.
• Actinobacillus - Includes species that are pathogenic to animals, such as Actinobacillus pleuropneumoniae, which causes pleuropneumonia in pigs.
• Mannheimia - Known for Mannheimia haemolytica, a significant pathogen in bovine respiratory disease.

Pathogenicity

Many members of the Pasteurellaceae family are pathogenic and can cause diseases in both animals and humans. For example:

• Pasteurella multocida - Causes pasteurellosis in animals and can lead to soft tissue infections in humans following animal bites or scratches.
• Haemophilus influenzae - Can cause a range of infections, from mild respiratory infections to severe diseases like meningitis and septicemia.
• Actinobacillus actinomycetemcomitans - Associated with periodontal disease in humans.

Ecology

Pasteurellaceae are commonly found in the upper respiratory tract of animals, including humans. They can also be found in the gastrointestinal and genital tracts. These bacteria are part of the normal flora but can become opportunistic pathogens under certain conditions.

Diagnosis and Treatment

Diagnosis of infections caused by Pasteurellaceae typically involves microbiological culture and identification using biochemical tests. Molecular methods such as PCR can also be used for more precise identification. Treatment usually involves the use of antibiotics, although resistance can be an issue with some species.

Importance in Veterinary Medicine

In veterinary medicine, Pasteurellaceae are significant due to their impact on livestock and companion animals. Diseases caused by these bacteria can lead to economic losses in agriculture due to decreased productivity and increased veterinary costs.

See Also

• Gram-negative bacteria
• Bacterial infections
• Veterinary microbiology
• Zoonosis