Pasteurella

• You can’t always get what you want, but when you try, sometimes you get what you need
• 100 of 500 range turkeys (6 - 8 months) ill and several died with symptoms of yellow, watery diarrhea, listlessness, thirst, poor eating, gelatinous exudate in mouths and nostrils, and swollen joints.
• Necropsy showed necrotic foci in a pale liver, purulent joint fluid, caseous nodules in lungs, pus and caseous material in the air sacs, air passages, sinuses, and body cavities.
• Treated with sulfa drug in water, no new cases.
• A 65-year-old woman was bitten by her cat on the dorsal aspect of the right middle finger at 8 AM, noting pain and swelling in the finger and dorsum of the right hand by 4 PM, with pain in the axilla, red streaking up the forearm, and chills.
• Lab results showed elevated white cells (12,000/mm3) with a left shift.
• The abscess was aspirated for culture, followed by incision and draining of the abscess, resulting in a gram-negative coccobacillus growth on chocolate, but not MacConkey agar.
• Pasteurella and Mannheimia are gram-negative coccobacilli that stain bipolar with Wright or Giemsa stain, ferment most sugars without gas, and TSI turns orange.
• All species of Pasteurella colonize the respiratory tract, except P. aerogenes, which colonizes the GI tract.
• Pasteurella multocida prefers blood for initial isolation, does not grow on MacConkey agar, is indole +, has a mousy odor, and its colony types may be mucoid, smooth, or rough, with only mucoid and smooth types being encapsulated and virulent.
• Pasteurella multocida is not as host-specific as Haemophilus, as infections can occur in many animals and humans.
• This agent is primarily carried in the oral cavity and respiratory tract, and transmission is by contact, direct inoculation, aerosol, water, or is endogenous.
• Pasteurella multocida is a normal flora of the upper respiratory tract of many mammals, and most infections occur following stress.
• Haemolytica is a primary cause of bacterial bovine shipping fever.
• Clinical signs and stress factors for respiratory disease in ovines are the same as for cattle except for shipment.
• Ovine mastitis (bluebag) is caused by Mannheimia haemolytica, which is transmitted to teats by suckling lambs, and leukotoxin causes necrosis and lack of blood flow to udder.
• Apical and cardiac lobes in shipping fever are dark red, slightly swollen, firm, and contain microabscesses.
• Hemorrhagic septicemia in nursing lambs is caused by T biotypes of Mannheimia haemolytica, which are more common in lambs but not exclusive to lambs.
• Virulence properties of Mannheimia spp. include a capsule that is antiphagocytic, LPS that provides protection but has endotoxic properties, and leukotoxin that is specific for bovine white blood cells and lyses phagocytic cells, causing inflammation as well as direct damage to host tissue.
• Lesions of shipping fever are primarily caused by RTX leukotoxin which lyses bovine white blood cells.
• Bronchioles in shipping fever contain fibrinopurulent exudate.
• Stress can compromise the disease caused by Mannheimia spp.
• Ovine enzootic pneumonia is caused by A biotypes of Mannheimia haemolytica.
• Clinical signs of shipping fever include dyspnea, fever, cough, nasal discharge, and fibrinous pneumonia at necropsy.
• Pneumonic areas in shipping fever have scattered, pale yellow abscesses or hemorrhage and consolidation.
• Mannheimia varigena causes meningitis, middle ear infection, milk, and spleen.
• The disease requires stress such as shipment or viral/mycoplasma infection.
• Bilateral, mucopurulent nasal discharge is a clinical sign of shipping fever.
• Lesions of ovine respiratory disease are hemorrhagic with pleurisy and pericarditis.
• Mannheimia granulomatis, which causes mastitis, abscesses, pneumonia, and meningitis, is not a common pathogen.
• Cross-sections of shipping fever show fibrinous lobar pneumonia with red-brown consolidated areas and thickened interlobular septa.
• Shipping fever (BRD) is characterized by a head and neck that are extended, open-mouth breathing, and froth on lips due to difficulty in breathing.
• Pasteurella multocida produces LPS (or LOS), which is an endotoxin with 16 antigenic serotypes, and strains are characterized by capsule and LOS type.
• The dorsal surface of the lung is affected in pneumonia.
• Such lesions are scored to determine the severity of disease.
• Lacrimal ducts can become blocked in atrophic rhinitis.
• AT is a polymicrobial and biofilm disease.
• Secondary respiratory pathogen following influenza and hog cholera is pneumonia.
• Snuffles is a respiratory infection of rabbits, which can cause mild mucopurulent discharge that occludes nares and conjunctiva, or pneumonia with fever, nasal discharge, and respiratory distress.
• Virulence properties of Pasteurella multocida include a capsule that is antiphagocytic, nonimmunogenic, and nontoxic, and a specific antibody can overcome its protective function.