5.7 Pasteurellaceae and Alcaligenaceae Flashcards
characteristics of pasteurellaceae? gram stain, environemnt, shape, nutrition?
-Small Gram-negative
-facultative anaerobic coccobacilli
-Often nutritionally fastidious (→ special media and growth conditions, may take two days to grow)
what is the oxidase test? what does it tell us?
tests for presence of Cytochrome c oxidase in Gram- negative bacteria
* Absent in anaerobes and Enterobacterales
* Present in Pasteurellaceae, and Alcaligenaceae
Main genera and species (taxonomy still in flux) of the pasteurellaceae family
Pasteurella multocida
Mannheimia haemolytica
Actinobacillus spp. (A. pleuropneumoniae)
Haemophilus-Glaesserella-Histophilus (G. parasuis) causes:
– Causes Glasser’s disease
– Polyserositis, polyarthritis, meningitis, pneumonia
Avibacterium (A. paragallinarum) causes:
– infectious coryza: acute infectious upper respiratory disease in chickens
Gallibacterium (G. anatis) causes:
– Oophoritis, salpingitis, and peritonitis, decreases egg production and mortality on chickens
Mergibacter septicum (newly described, 2021) causes:
– Septicemia in wild birds
where are members of the pasteurelacea family generally found? are they internal or external pathogens? what diseases do they cause, generally? what toxins do they have? do they survive well in the environment and in various hosts?
- Very common residents of mucosal surfaces esp. URT
- Can range from avirulent commensals to primary pathogen
- Extracellular pathogens ==> cause septicemia and/or pneumonia
- Toxins are important virulence factors (RTX toxins)
– Repeat in Toxins
– Cytotoxins - Tend to survive poorly in the environment; many are host specific
characteristics of pasteurella spp.? environment, main species, hosts, diseases, structure, virulence factors
- Multiple species (see notes),
- Commensals of upper respiratory tract and mouth, but may also be associated with disease
- Main species: Pasteurella multocida
– Broad host range (cats, birds, cattle, swine, rabbits,
etc., but not humans)
– Broad spectrum of diseases but mainly pneumonia and septicemic/systemic infections
– Several capsules types and 16 O antigen types
– Virulence factors: Capsule, adhesins, iron-acquisition systems, toxins, endotoxin.
characteristics of pasteurella spp.? environment, main species, hosts, diseases, structure, virulence factors
- Multiple species (see notes),
- Commensals of upper respiratory tract and mouth, but may also be associated with disease
- Main species: Pasteurella multocida
– Broad host range (cats, birds, cattle, swine, rabbits,
etc., but not humans)
– Broad spectrum of diseases but mainly pneumonia and septicemic/systemic infections
– Several capsules types and 16 O antigen types
– Virulence factors: Capsule, adhesins, iron-acquisition systems, toxins, endotoxin.
virulence fators of pasteurella spp.?
Virulence factors: Capsule, adhesins, iron-acquisition systems, toxins, endotoxin.
diseases caused by Pasteurella multocida and their characteristics?
Fowl cholera - Septicemia in birds (type A)
Suppurative bronchopneumonia - Swine;
BRDC in cattle (type A)
Rabbit “snuffles” complex - Otitis, rhinitis, septicemia, pneumonia, abscess (type A)
Cat, dog bite abscess - Often with anaerobes
Atrophic rhinitis of swine - URT infections swine (type D)
what is fowl cholera? what causes it? character of the disease?
Fowl cholera: septicemia in wild and domestic birds
caused by pasteurella multocida
- Acute disease: high mortality=> large number of dead birds without previous signs
- Chronic disease: lameness, swollen wattles (in chickens), pneumonia (in turkeys), and torticollis
- It is controlled through biosecurity, vaccination, and antibiotics (reduce mortality only)
characteristics of snuffles in rabits
Mucus in the nose and feet
Runny eyes
Runny nose
Pneumonia
Many rabbits are asymptomatic carriers=> careful culture interpretation
causes and characteristics/symptoms of atrophic rhinitis in pigs
P. multocida (type D) and B. bronchiseptica
- sneezing, coughing, and inflammation of the lacrimal duct
- nasal hemorrhage may occur
Toxigenic P. multocida produces a potent dermonecrotizing toxin (PMT) that causes marked turbinate atrophy as well as bony alterations in nasal and facial bones
Pasteurella multocida Treatment and Prevention
- Usually antimicrobial treatment: beta-lactams, sulphonamide- trimethoprim, tetracyclines
- Antimicrobial resistance not frequent but increasing (tetracyclines)
- Vaccines used in turkeys: live or multiple serotype bacterins
- Vaccines for atrophic rhinitis, PMT toxoids
- Good management!
what is the pathogen behind shipping fever pneumonia?
Mannheimia haemolytica
where is Mannheimia haemolytica commonly found? what types are there? what disease is it often implicated in and what is the consequence?
- Normal in upper respiratory tract (nasopharynx and tonsils) of cattle and sheep
- Several serotypes with variable virulence (A1 most virulent)
- Main pathogen in the “bovine respiratory disease complex”
(BRDC) in cattle - BRDC is the most common and costly disease in North American beef cattle $$$
- Sheep=> cause of septicemia and pneumonia
what does mannheimia haemolytica cause in sheep?
- Sheep=> cause of septicemia and pneumonia
what factors come together to cause bovine respiratory disease complex” (BRDC) in cattle?
In the presence of adverse environmental factors in addition to infection with primary viral agents, bacterial commensals of the upper respiratory tract (mainly M. haemolytica) reach the lower respiratory tract. Lung consolidation is caused by the accumulation of neutrophils and ROS release due to leukotoxin driven lysis.
what factors come together to cause bovine respiratory disease complex” (BRDC) in cattle?
In the presence of adverse environmental factors in addition to infection with primary viral agents, bacterial commensals of the upper respiratory tract (mainly M. haemolytica) reach the lower respiratory tract. Lung consolidation is caused by the accumulation of neutrophils and ROS release due to leukotoxin driven lysis.
Treatment and prevention of shipping fever and BRDC
- Vaccinations for viral and bacterial pathogens
- Prophylactic antibiotics (resistance becoming a real problem!)
- Early recognition and treatment
Vaccines: bacterins, toxoid (LKT), live attenuated mutants
important actinobacillus spp. for us, and the diseases they cause
A. equuli - Septicemia foals
A. pleuropneumoniae -
Fibrinohaemorrhagic pleuropneumonia swine
A. suis -
Septicemia and sequelae swine
Actinobacillus pleuropneumoniae type od bacteria, where it is found, diseases/symptoms it causes, types and toxins
- AAP
- Common commensal of tonsils
- Complex nutritional requirements (fastidious)
- Causes hemorrhagic fibrinous pleuropneumonia (peracute to chronic)
- 16-18 serotypes, 4 types of RTX toxins (called Apx toxins)
> > important for pigs
Actinobacillus pleuropneumoniae control and treatment
- Antibiotics (increasing resistance)
- Vaccination:
– Apx toxoids, bacterins (serotypes specific=>limited protection)
– New vaccine: cross protective for all serotypes (subunit vaccine) - Management based on serological status (LPS-O antigen, RTX toxins, capsule)→Do not mix pigs of different serological status
important Alcaligenaceae
Bordetella bronchiseptica
Taylorella equigenitalis
Bordetella bronchiseptica characteristics: shape, stain, hosts, diseases, where found
- Small Gram-negative coccobacilli, nutritionally fastidious
- B. bronchiseptica is a broad host-range pathogen
- B. bronchiseptica→tracheobronchitis in several species
- Found URT-nose of carrier animals
diseases caused by bordetella bronchiseptica in dogs and cats, pigs, rabbits, hamsters, guinea pigs, horses
Dog and Cat - Kennel cough, infectious tracheobronchitis
Pig-
Atrophic rhinitis predisposition, pneumonia (often mixed infections)
Rabbits, hamsters, guinea pigs, horses-
URT infections, tracheobronchitis
what is ciliostasis caused by Bordetella bronchiseptica? what toxins does this bacteria have? how long does it act for?
- Attaches to ciliated epithelium tracheo-bronchial tree
- Toxins destroy ciliated epithelium
- Hemolysin (toxin): enters cells=> apoptosis of neutrophils
- Persistent (weeks) chronic tracheal inflammation → Persistent coughing
Taylorella equigenitalis characteristics: gram, shape, environment, growth, diseases caused, where found…
- Small Gram-negative coccobacilli, nutritionally fastidious, slow growing
- Agent of Contagious Equine Metritis (CEM) which causes temporary infertility in mares
- Genital tract healthy carrier state (mares and stallions) can be identified by culture and PCR
where geographically do we find taylorella equigenitalis? what is special about in terms of lab testing and import requirements?
- Never detected in Canada, but present throughout the world
- Needs specific transport medium for samples
- Rigid import requirements into Canada from infected countries
***Reportable disease
