Flashcards in Pathology and Microbiology Deck (140):
How can chlamydophila be detected?
- ELISA for ag
- Kosters of fluorescein-labelled ab
What does chlamydophila cause most commonly?
conjunctivitis in cats (c. felis)
- nasal discharge
- progression to interstitial bronchopnumonia
> also abortion in sheep, bird disease, zoonotic
What does chlamydophila cause in the dog?
- does not affect the dog
Is chlamydophila vax available?
Yes for cats - Fel-O-Vax 4 or 5
What type of bacteria is chlamydophila?
- Gram -ve (outer membrane present)
- INTRACELLULAR (people used to think was a virus)
- No growth on lab media (need cells)
What do chlamydophila form during their lifecycle?
- reticular bodies
What is the most common disease associated with mycoses?
- canine nasal aspergillosis
Why is dx of aspergillosis difficult?
The fungus is present everywhere! Bread, walls etc. so detecting the fungus does not indicate pathology associated
- compile radiology, endoscopy, serology, culture, microscopy
Tx of canine nasal aspergillosis?
- surgical delivery of antifungal
Pathophysiology of nasal aspergillosis? DDx?
- nasal turbinates progressively destroyed
- chronic and granulomatous (and eosinophilic) inflammation
- yellow-green mycotic exudate in the caudal nasal cavity
- may be unilateral
> Ddx nasal carcinoma
How can fungal infections be identified?
Fungal hyphae stain
- PAS stain (pink)
- silver Grocott stain (black)
> asexual sporing heads seen on microscopy typical of aspergillosis
> numerous fungal hyphae on histopath
Which dogs are predisposed to canine nasal aspergillosis?
What can be carried out to ensure tx will be effective? Common practice?
- antifungal sensitivity testing
- rarely done!
Which viruses commonly affect the resp tract of sheep and cattle?
- bovine herpesvirus
- respiratory syncytial virus
- bovine parainfluenza virus
Which bacteria commonly infect the respiratory tract of cattle and sheep?
What factors may impact resp disease? What disease complexes are generally seen in diffreent species?
- virus (usually inciting cause)
- poor ventilation
> porcine respiratoy disease complex
> bovine/ovine respiratory disease complex
> kennel cough
What is bovine respiratory disease complex (BRDC) also known as?
Which pathogens are involved in BRDC?
- PI3 (bovine parainfluenza virus)
- RSV (respiratory syncytial virus)
- IBR (bovine herpesvirus)
- Mycoplasma bovis
> followed by
- pasturella multocida
- mannhaimia haemolytica (used to be called pasturella or pasturellosis)
What does bovine herpesvirus cause?
- infectious bovine rhinotracheitis (IBR)
- red nose
> URT infection
> fibrinous laryngitis and tracheitis
> intranuclear viral inclusions
Iss BHV (IBR) vaccine available?
What family is BRSV in?
What does BRSV cause?
(Bovine Respiratory Syncitial Virus)
- URT infections
- bronchitis/bronchiolitis sometimes
> syncitia formation and membrane formation to allow replication in cytoplasm and evade immune response
What family is bovine parainfluenza virus?
What is bovine parainfluenza virus also called?
parainfluenza 3 (PI3)
What does PI3 cause?
URT infections (mild)
Are vax available for PI3?
What diseases does manheimia haemolytica cause?
- epizootic pneumonia in cattle "shipping fever" (bovine pneumonic pasteurellosis)
- pasteurellosis in sheep
What is one sybtype of mainheimia haemolytica also called?
- P. trehalosii
Is mannheimia haemolytica a commensal?
YES! NAsopharynx of ruminants
Gross path of manheimia haemoltica?
-Cranioventral lung consolidation
-fibrinosupparative effusion with neutrophils
- lots of yellowy fibrin indicates pasturella or manheimia!
What are the 2 main pathologic mechanisms of manheimia haemolytica?
What are the 2 pathogens involved in 80% bovine respiratory diseases?
- m. haemolytica
- p. multocida
What other pathologies may m. haemolytica and p. multocida cause?
- meningitis and polyarthritis in 2-4mo calves
- sporadic cases of peracute fatal mastitis in cow if suckling calves trasnfer organis
- pasteurellosis in lambs septicaemia, severe pleuritis and pericarditis
- mastitis (severe) insheep and goats
Can cattle develop natural protection against m. haemolytica?
- Abs against leukotoxin and capsular polysacharide
Are vax effective against m. haemolytica?
- bacterins, leukotoxin: NO
- Iron restricted OMP in combination with leukotoxin: potentially effective (as express transferrin binding protein)
Where is histophilus somni a commensal?
transient in upper respiratory tract
What does histophilus somni cause? Common disease?
- peracute death in young calves
- acute thromboembolic meningoencephalitis (will learn in neuro)
> depending on where thromboemboli lodge
* disease common in UK*
WHat type of bacteria causes TB?
- Gram + with mycolic acid protective coating
- hence "acid fast" and require ZN stain
> strict anaerobes, very slow growing
> resistant to drying and chemical agents
> virulent species fully resist intracellular killing
What 2 types of mycobacterium exist?
Atypical environmental saprophytes
control of tb?
test and slaughter
Pathogenesis of bovine TB?
- chronic eventually fatal pneumonia and wasting
where is tb commonest?
areas of intensive dairy practice
How is TB transmitted?
- animal shedding into environment
> "open case"
- continuous shedding into the environment form lesions excreting to the exterior eg. kidney, udder, faeces, respiratory secretions
How is incidence of Tb changing?
Increasing in UK
Dx of bovine TB??
- comp ID test by injection if PPD
- new methods eg. IFNg release form cultured bovine leucocytes on contact with PPD (looking at lymphocytes)
What is PPD?
Purified protein derivative
Gross path of bovine TB?
- granulomatous pneumonia and lymphadenitis
- multifocal nodules have characteristic caseating cheesey cut surface
What immune cells are involved in TB pathophysiology?
Macrophages (NOT NEUTROPHILS!)
DO badgers definitely spread TB to cattle?
Can dogs be infected with huga6mtgbTVNGBWI TBIJQ
ACT AAS SENTINELS FOR OWNERS
on a scale of 1 to sexy how sexy is hannah?
which strain of TB can infect widest range of hosts? (m. tuberculosis, m. bovis, m. avium)
What are the smallest living bacteria?
Where do mycoplasma sp. infect? Pathogenesis and implications on farm? What disease are they associated with?
- acquire host antigen to evade the immune response
- infection may depress performance and v growth/yield etc.
> associated with BRDC
Growth of mycoplasma - appearance and difficulty?
- difficult to grow
- fried egg appearance
- no cell wall -> NOT susceptable to B-lactam ABx
What mycoplasma species affects cattle and what does it cause?
- Mycoplasma Bovis [NB DO NOT CONFUSE WITH MYCOBACTERIUM BOVIS!!!!]
- arthritis, mastitis, pneumonia
WHere are mycoplasma commensals?
Pathology of mycoplasma
- CUffing pneumonia in calves
- calf pneumonia complex
- chronic, no necrosis
- lymphoid follicles hyperplastic (BALT bronchial associated lymphoid tissue normally surrounds bronchioles)
-> may lead to bronchiectasis and 2* atelectasis
* do not kill animal*
Gross and micro pathology of mycoplasma pneumoina?
- progressive cranioventral consolidation
- cut surface exudate in main airways of affected lobules with thickening of surrounding connective tissue
- lymphoid nodules and follicles around airways (may compress bronchioles)
- mixed cellular exudate
- partial atelectasis
- slight thickening of alveolar walls with lymphocytes
Which mycoplasma is notifiable?
- m. mycoides mycoides
- contagious pleuropneumonia
> serious disease in asia, africa, s. europe
> mortality ~50% in indiginous breed cattle
> transmission by aerosol or close contact
> similar disease in goats M. Capricolum
Pathology of contagious pleuropneumonia (CBPP) M. Mycoides?
- fibrino-necrotic bronchopneumonia with fibrinous pleuritis
- dorsocaudal areas may be affected
- interstitial septa markedly widened by fibrinous exudate and oedema, and often seen UNILATERALLY (pathonomonic)
- necrotic areas encapsulated (sequestra)
*WILL KILL ANIMALS*
Which species of mycoplasma cause MINOR problems in sheep and goats?
- M. ovipeumoniae (pneumonia)
- M. capricolum (pneumonia)
- M mycoides capri (pneumonia)
3 main respiratory viruses of sheep? Are any vaccine licensed for these?
- PI3 (parainfluenza virus) - occasionally causes pneumonia in lambs
- RSV (respiratory syncitial virus)
- adenoviruses (ovine and bovine)
> may predispose to manheimia haemolytica infection as part of enzootic pneumonia complex
> no vaccines licensed
Which fungi are associated with resp disease in cattle and sheep?
> respiraotry allergy
- type 1: rhinitis and fungal astham, type 3: allergic alveolitis
- may be chronic or acute
Which bacteria are assocaited with respiratory disease in horses?
- strep equi equi
Which viruses are associated with respiratory disease in horses?
- equine influenza virus
- equine herpes virus 1 and 4
What type of bacteria is strep equi equi?
- G+ obligate horse parasite, carried in nasopharynx without disease
- lancefield group C
- strongly b haemolytic with mucoid colonies, hyaluronic acid capsule
What disease dows strep equi equi cause and what immunity is necessary to prevent it?
- circulating Ab raised by infection or vaccination
- muscoal immunity essential
What drug is strep equi equi sensitive to?
Penicillin (but hard to peentrate abscesses with it!)
pathology of strangles technically described as..
supparative lymphadenitis and gutteral pouch empyema
- may be termed gutteral pouch chondrosis as resembles cartilage
Which vaccines are availble against strangles? Are they effective?
> Equilis strep E
- live modified bacteria
- effective but only for short lived mucosal immunity
Is strep pneumoniae infection comon?
- may occassionaly cause resp disease in training horses
What type of bacteria is rhodococcus equi? Where is it found?
G+ rod, variably acid fast
- naturally present in soil and intestines of horses
- persistent in manure for long periods of time
Alternative name for rhodococcus equi?
What disease does rhodococcus equi cause? What age horse is affected?
- chronic supparative bronchopneumonia in foals 2-6mo
*adults are immune*
Pathogenesis of rhodococcus equi? Prognosis?
- resists host digestion by complex lipid cell wall,facultative intracellular replicating inside macrophages
-> foci of caseous necoriss in lungs and sometimes bronchial LNs
- lesions often extensive before clinical signs apparent
- 40-80% mortality
- spread to abdo organs can occour eg. liver and intestin, mesenteric LNs
*Adults are immune*
What do rhodococcus lesions appear similar to?
TB (horses much less suceptable to TB)
What horses are affected by actinobacillus?
Adults esp TBs
Which mycoplasma may be involved in equine resp disease?
- M. felis relevant in pleuritis and predisposition to 2* infect
How are influenza viruses classified?
- haemaglutanin and neuraminidase eg. H7N7, H3N8 in horses
What does EIV cause? (equine influenza virus)
- URTI can spread to LRT -> bronchitis and bronchiolitis
- cough, pyrexia, depression
- 2* infection (strep, staph, klebsiella) most important to pathogenesis
EIV vax available?
- inactivated vaccine containing both H7N7 and H3N8 sybtypes but not effective against all strains
* requirement for competing horses UK
Which equine herpesviruses cause resp disesae? Clinical signs? What other signs may be seen with each?
1 + abortion and paresis
4 + mainly resp, most common
5 - equine multinodular pulmonary fibrosis NEW!
> nasal discharge, coughing, pyrexia
Vax available for EHV?
- innactivated vax for EHV1 and EHV 4
What fungus is associated with equine gutteral pouch mycoses?
Clinical signs of gutteral pounch mycosis
- severe epistaxis (internal carotid) *v serious*
- dysphagia (glossopharyngeal and vagus nn.)
Diagnostics for investigating gutteral pouch mycosis?
Tx of gutteral pouch mycosis
- Local delivery of antifungals
- ligation of carotid
- systematic azole antifungal
Bacterial respiratory disease of pigs
Viral respiratory disease of pigs
- porcine reproductive and respiratory sydrome virus (PRRSV)
- swine influenza
- porcine circovirus
What causes atrophic rhinitis in pigs?
> early colonisation of nasal planum with
- Bordatella Bronchiseptica (dermonecrotic toxin damages osteoblasts -> turbinate atrophy)
- and Pasturella Multocida (osteolytic toxin stimulates osteoclasts -> atrophic rhinitis)
- produce osteolytic toxin
-> malformed twisted snout in growing pigs and ^ risk 2* disease
Is atrophic rhinitis common?
Not any more (effective vax)
What pathogen causes contagious pleurpneumonia?
- actinobacillus pleuropneumoniae
- G- rod
Pathogenesis of actinobacillus pleuropneumonia? Which species get this commonly?
- acute/chronic fibrinohaemorrhagic/necrotic bronchopneumonia with pleuritis (pleurisy) and pleural adhesions due to fibrin deposition
- all lung lobes (cranioventral distribution may not be evident similar to M. haemolytica in cattle)
- intensive PIG production
- worldwide distribution
- high morbidity and mortality if newly introduced to the herd, progresses to chronic status with sporadic cases
- subclinical carriers and recovered carriers with degrees of immunity
Is fibrin deposition seen with mycoplasma?
only m. mycoides, otherwise no
how is actinobacillus pleurppneumoniae grown in the lab? how many serotypes exist?
- chocolate agar (NAD dependant)
- waxy, sticky colonies, delicate G- organism
- 15 serotypes
pathogenicity factors of actinobacillus pleuropneumoniae?
- apx toxins
- capsule polysacharide
- takes iron from porcine transferrin
> pulmonary inflam stimulated -> haemorrhage and oedema
Vax available for actinobacillus pleuropnuemoniae?
- suvaxyn HPP no longer available
- porcillis APP no available in UK but effective
Which pathogens can cause disease in high health status animals?
- actinobacillus suis
- haemophilus parasuis
Which pathogen causes glassers disease? Clinical signs?
- haemophilus parasuis
- multisystemic disease of pigs
- polyserositis (pleuritis, pericarditis, peritonitis) meningitis, polyarthritis and supparative bronchopneumonia with fibrinous exudate in high health status animals
- mortality high in young animals
Predisposing factors for Glassers disease?
- stress eg. mixing, weaning, adverse environmental conditions
What does mycoplasma hyopneumoniae cause?
- enzootic pneumonia (EP)
- wipdespread and v common in young pigs
- predisposes other resp disease
- transmission by aerosol -> coughing -> resolves
Pathology of mycoplasma hypopneumoniae infections in pigs
- enzootic pneumonia
- chronic, non-fatal disease unless 2* disease sets in
- commonly seen at slaughter
- v growth rate and coughing
> cranioventral consolidation (apical and cardiac lobes,) red/grey discolouration, bronchopnuemonia
> microscopic features similar to cuffing pneumonia in calves
Is m. hyopneumoniae easy to culture? Alternative dx?
No difficult and slow
- serological dx by competition ELISA
Vax for m. hyopneumoniae?
Yes, very efffective
- eg. Stellamune
Strategic medication is common
Which other mycoplasmas may affect the pig and what do they cause?
- m. hyosynoviae: arthritis
- m. hyorhinis: commonly found in resp tract, cause of polyserositis and arthritis
What type of virus is PRRS?
PRRS clinical signs and pathogenesis?
- URT, systemic spread in macrophages
- resp signs, interstital pneumonia
- frequently subclinical
- predisposes/enhances effects of infection with other pathogens (eg. influenza, m. hyopneumoniae)
*highly pathogenic varient recently emerged in E. Asia
What is PRRS part of?
Porcine respiratory disease complex
Clinical signs of swine influenza?
- sudden outbreaks of respiratory disease
- barking cough
- resp disease
- naive herds
- bronchiolitis and pneumonia
> if endemic in herds, weaned piglets develop clinical signs as soon as MDA wanes
Is swine influenza a 1* pathogen?
- 1* pathogen
- if endemic may also contribute to porcine respiratory disease complex
Vaccines for swine influezna?
Why is swine influenza dangerous?
PAthogenesis of porcine circovirus?
- immune suppressive
- predisposes other infections
> possible involvement in:
- porcine respiratory disease complex
- post weaning multisystemic wasting syndrome (PSWS)
- porcine dermatitis and nephropathy sydrome (PDNS)
Vax for porcine circovirus?
2 in UK
Where is bacteria normally present within the resp tract?
Upper only - lower should be sterile (bronchi onwards)
BActeria normally present in URT...
> strep (non-/a-/b- haemolytic)
- pasteurella [b]
> staph (coag+/-)
- E. COli
> not exhaustive so many more too!!
How does viral resp infection differ to bacterial?
- viruses commonly spread URT -> LRT (bronchitis-bronchiolitis)
- bacteria may preferentially infect LRT only
> NB. all viruses predispose to 2* bacterial infections which may be more likely to cause morbitity
How may infections be classified?
- 1*/2* (2* more important)
Main pathogens causing resp disease in smallies?
- Actinomyces and nocardia (branching)
-B Haemolytic strep (?)
4 species of Bordatella?
- b. bronchiseptica
- b. pertussis (whooping cough humans, NOT animals)
- b. parapertussis (humans and sheep)
- b. avium (coryza in turkeys, not UK)
What type of bacteria is bordatella bronchiseptica? How is it spread?
- strict aerobe
- G- rod
- slow growing
- commensal of URT
> endogenous/exogenous infection, survival outside host is poor
What diseases is b. bronchiseptica associated with?
- tracheaobronchitis (KC)
- bronchopneumonia following distemper infection (rarer now due to vax)
Vax for b. bronchiseptica? Is this cross protective across strains?
- Intrac (? efficacy)
- Nobivac KC
> all strains have same LPS so will cross protect after vax or infection
> BUT NO VAX VERY EFFECTIVE
Does b. bronchiseptica affect the cat? Vax?
- yes, early exposure to kittens
- link between b.b. and disease unclear
> vax: Nobivac BB
PAthogenesis of b. bronchiseptica?
- initial trauma or viral infection
- adherance to cilia
- proliferation and toxin release -> irritation and coughing, destruction of inflam cells (leucocyte toxin)
- epithelial necrosis
- peribronchial inflammation and interstitial pneumonia with chronic infection (not true interstitial pneumonia)
- severe pneumonia due to 2* pathogens eg. b-haemolytic strep s. zooepidemicus
Distribution of pneumonia seen with b. bronchiseptica?
What type of bacteria is pasteurella multocida?
- G- rod
- firms mucoid colonies
- strong catarrhal smell
- normal oral bacteria
-> 2* infection in URTI and bite wounds
Is vax against pasteurella multocida available?
No, not appropriate
- as noramly present in URT
Pathogenesis of pasteurella multocida in dogs and cats
- severe supparative pneumonia and pleuritis (pyothorax/empyema)
- seen following cat bite wounds
- important in MIXED infections eg. anaerobes like clostridia
Does pasteurella multocida affect other species?
- Rabbit snuffles (enzootic pasteurellosis)
- endemic in rabbit population (often no clinical signs)
- some rabbits not infected but difficult to eradicate disease as highly contagious
> chronic nasal discharge and sneezing, epiphora, chronic supparative rhinitis and sinusitis, abscessates in lungs, sometimes fatal
> colonises U/LRT, middle ear, sinuses, genitaloia, occasionally lungs (CILIOTROPIC)
How may rabbit snuffles be controlled?
- vax available but ineffective
- long term Abx (enrofloxacin) needed for control/eradication in an individual
How does the physiology of a rabbit abscess differ from other animals?
- have heterophils instead of neutrophils
- tend to form cottage cheese, dry abscesses (not watery pus)
What type of bacteria is actinomyces viscosus?
- G+, filamentous and branching
- commensal in oral cavity of dog
What does actinomyces viscosus cause?
- granulomatous thoracic infection in dogs
- EXUDATE CONTAINING SULPHUR GRANULES!!
- localised granulomatous abscesses of skin (chronic and progressive)
What type of bacteria are nocardia spp? Pathogenesis?
- G+ rods, short but filamentous
- partially acid fast
- growth within and destruction of macrophages
> supparative chronic, progressive thoracic granulomas
Which antimicrobials are nocardia spp. resistnat to?
- penicillin and others
- need TMP, tetracycline, ampicillin prolonged use
Where are actinomyces and nocardia found naturally?
pathogenesis of nocardiosis?
- red-brown exudate in pleural cavity (strawberry milkshake)
- may form adhesions
- EXUDATE CONTAINS SULPHUR GRANULES!!
> yellow lumps, not actually sulphur