Angelena Gram negative bacteria (BLOCK4)

Characteristics of Brucella spp

- facultative intracellular

- obligate pathogens

- infect, persist, and multiply in macrophages (many cells)

- gram negative rods-coccobacillary

- aerobic

- capnophilic

- nonmotile

- survival in environment less than 30 days

- direct sunlight kills it in hours

- survive in cold conditions for months-years

What are the 4 main pathogenic Brucella species? Are they all reportable?

1. B. Abortus
2. B melitensis
3. B. suis
4. B. canis

- yes, all pathogenic spp. are reportable

What are the mechanism of transmission for Brucella spp.?

- horizontal (contact with infected reporductive tissue)
- vertical (mother to fetus)
- veneral

What is the pathogenesis of Brucella spp.?

- replicated in macrophages, dendritic cells, etc.

- organ with high replication rates

- because of its intracellular niche, the ER shelters it from detection by the immune system

What are the 3 VFS of. Brucella spp.?

1. display of reduced pathogen-associated molecular pattern (PAMP)
2. Altered PAMP fails to induce innate response which contributes to its' shealth
3. LPS is poor activator of complement and its lipid A has reduce toxicity

Brucellosis is a common disease in which animals?

- sexually mature animals due to its tropism for reproductive tracts and pregnant uterus

What allantoic factor stimulate the growth of most brucellae?

- erythritol which is present in the placenta, male gential tract of cattle, sheep, goats, and pigs

- not found in humans

Brucella abortus

- REPORTABLE

- zonootic

- incubation period 2-8 weeks

- venereal transmission

- tropism for pregnant uterus and placenta

- aborted fetus have pleuropneumonia

- aborted fetus and uterine secretion are an important source of infection with a heard

Clinical Manifestations of Brucella abortus

- abortion in 3rd trimester

- retained placenta (veterinarian exposed)

- bulls: epididymis, seminal vesculitis, orchitis, abscess on testes

How does Brucella abortus impact the cattle industry?

1. abortion
2. decrease milk production and increased SCC (somatic cell counts
3. culling or replacement loss
4. an infected cow oftern shows no CS but spread the bacteria
5. infected cow is permanent bc of intracellular and hard to eliminate

Brucella melitensis

- affect goats and sheep (goats are more susceptible)

- abortion in late gestation

- no retention of fetal membranes

- mastitis

- males: infects epididymis, testicles, seminal vesicles, different ducts

- responsible for the most human brucellosis cases

Brucella suis

- REPORTABLE

- zoonotic

- characterized biovars

- long and intermittent bacteremia

- localized in lymph nodes, joints, reproductive tissue

- causes chronic inflammation lesions in repro tissue ---> abortion, infertility and low milk production

- abortion is rare but occurs in early gestation

- eradicated in domesticated swine but not from wild pigs

Brucella ovis

- REPORTABLE

- tropism for male reproductive system

- transmitted venereal route

- rams develop epididymitis and testicular atrophy (infertility)

- recovered from semen 5-14 weeks post-infection

- typically avirulent to non-pregnant uterus but sometimes abortions in ewes

- not zoonotic

Brucella in horses

- REPORTABLE

- zoonotic

- B. abortus or B. melitensis

- can cause abortion, infection of sexual organs in stallions and infertility

- suppurative bursitis: pus in contaminated tissue over the shoulders or poll

Brucella canis

- zoonotic

- infect dogs

- tropism for repro system

- clinical signs are non-specific

- abortion mid to late gestation

- males: epididymis etc.

- transmission oronasal or general

- intervertebral disc infection

- uveitis

- zoonotic

- worldwide distribution

Brucella ceti

- infect dolphin and porpoises

- fetal abortions

- male infertility

- neurobrucellosis

- cardiopathies

- bone and skin lesions

- strand events

- death

- zoonotic impact

How to diagnosis Brucella spp.

- serology tests: Milk ring test, skin test, rapid aggulatination test (RSAT), Rose bengal test, Indirect ELISA, Complement Fixation Test (CFT)

How to control and prevent the spread of Brucella spp

- vaccinations (not for canine)

- culling of infected farm animals

- isolate new cattle for 30 days because of the incubation period

- antibiotic therapy

- removal of contaminated material

- wait 30 days before using pastures after killing

Characteristics of Bordatella spp.

- gram - rods or coccobacilli

- strict aerobes

- slow growing

- affinity for ciliated resp. epithelium

- poor survival in environment

- normal inhabitants of upper resp. tract (URT)

What 3 things do the VFs of Bordatella spp do to promote pathogenesis?

- promote adherence and colonization
- alter host tissues and promote lesion formation
- Phase variation

Describe the phase variation of Bordatella spp

- Bordatella virulence gene (locus) that controls the expression of > 500 genes is temperature-dependent

- turns on: 37° C

- turns off: 27° C

- Bvg+ is virulent

- Bvg- is avirulent

- Bvgi is intermediate

What are the 3 species of Bordatella of veterinary importance?

1. B. bronchiseptica
2. B. avium
3. B. parapertussis

B. bronchiseptica in pigs

- infection occurs in first weeks of life

- atrophic rhinitis: release dermonecrotic toxin that damges osteoblasts and prevent bone formation

- turbinate atrophy

- can cause bronchopneumonia in young and older pigs

- vaccine available

What are the two forms of atrophic rhinitis of B. bronchiseptica?

1. 'Progressive': B. bronchiseptica and Pasteurella multocida; turbinate bone atrophy is permanent and progressive

2.'Non-progressive': B. bronchiseptica alone; atrophy will resolve, bronchopneumonia

B. bronchiseptica in dogs

- kennel cough: complex of resp. infection in dogs

- most cases involve a primary viral infection or secondary bacterial involvement

- common disease when dogs are housed in groups

- dogs have "honking" cough

- vaccine available

B. bronchiseptica in rabbits

- snuffles-like

- 5-10% otitis media

- blindness

- bronchopneumonia or septicemia

B. bronchoseptica in horses

- can be isolated from the trachea of healthy horses

- opportunistic pathogen

- clinicals signs: mucopurulent nasal discharge, cough, lethargy, weight loss

- reports of pnemonia, conjunctivitis, and infertility

B. bronchiseptica in guinea pigs

- one of the most susceptible animals

- severe pneumonia ---> high mortality

- morbidity and mortality in young animals

- CS: ruffled fur, labored breathing, anorexia, mucopurulent or catarrhal nasal exudate

B. bronchiseptica in cats

- less common

- transmission between dogs and cats

- more severe in kittens

Bordatella avium

- Bordelletosis - Turkey Coryza - Infectious Coryza

- highly infectious URT infection in poultry

- turkeys are natural host

- 2-8 week old turkeys

- high morbidity, low mortality

- B. avium can survive 1-6 months in litter

- Turkey Coryza: rhinotacheitis and sinusitis

- swollen head syndrome

- Common URT signs

- Prevention: husbandry

Bordatella parapertussis in lambs

- nonprogressive form of pneumonia of lambs

- a mild form of whooping cough in humans

- two lineages between ovine and human strains but not zoonotic

- CS: pyrexia, bronchosepticema, tracheobronchitis

- rapid clearance

- potential initiate more severe resp. disease

Characterstics fo Moraxella spp.

- gram - rods or cocci

- diplococci/short chains

- haemolytic

- commensals of mucous membranes

- non-motile

- resistant to the environment

- infects the eyes

Characteristics of Moraxella bovis (infectious bovine keratoconjunctivitis-IBK)

- commensals on the mucous membranes

- transmission by direct contact or flying insects

- shed in nasal secretions

- incident rate highest in the summer

What are the early signs IBK?

- lacrimation
- blepharospasm
- photophobia
- conjunctivitis

Describe the pathogenesis of M. bovis

- severe corneal edema, keratoconus

- healing stage: granulation tissue forms and ulcer and red cone on cornea

- leaves a white corneal scar when healed

What is the control and treatment of Morexalla?

- good management practices

- fly control

- vaccines (controversial)

Characteristics of Ornithobacterium rhinotracheale

- gram -

- highly pleomorphic rod-shaped

- clinical cases of resp. disease in birds

- first identified in Germany in 1990s

- facultative anaerobe

- capnophilic

Pathogenesis of Ornithobacterium rhinotracheale

- ornithobacteriosis

- sinusitis, airsacculitis, pneumonia, arthritis

- mainly affect turkeys and chickens

- coinfections with other viral or bacterial resp pathogens

- older birds show more severe signs

- transmission vertical or horizontal

- CS non-specific

- biofilm formation

How to treat Ornithobacterium rhinotracheale

- most strains sensitive to amoxycillin and oxytetracycline
- resist to enrofloxacin

Characteristics of Pasteurella spp

- worldwide distribution

- wide host range

- predilection for oral and resp. tracts

- commensal of upper resp. and GI tracts

- opportunistic

- gram - rods or coccobacilli

- facultative anaerobic

- fastidious

- encapsulated

- non-hemolytic

What are the 3 subspecies of P. multocida? What are the capsule serogrroups?

1. P. multocida
2. P. gallicida
3. P. septica

- A, B, D, E, and F

Name the 2 presentationa of P. multocida in pigs

1. Atrophic Rhinitis
2. Pneumoina

P. Multocida and Atrophic rhinitis in pigs

- progressive atrophic rhinitis

- affects nasal cavities of young pigs

- colonization with pre-existing infection with Bordatella bronchiseptica

- rhinitis scores from 0 to 5

P. multocida and pneumonia in pigs

- secondary respiratory pathogen

- growing and finishing pigs are the most susceptible

- Mycoplasma hyopneumoniae, influenza or porcine repro and resp. syndrome damage mucocilliary apparatus ----> P. multocida migrates down and colonize alveoli

- creates fibrin and adhesions btwn lungs and pleura

- becomes systemic to cause pericarditis and lymph nodes enlarged

P. multocida in rabbits

- resides in nasopharnyx

- causes "snuffles" ----> mucopurulent rhinosinusitis

- develops during stressful conditions: pregancy, lactation or mismanagement

- co-infection with B. bronchiseptica

P. multocida in birds

- aka Fowl (avian) cholera

- capsule serogroups A, F or D

- comes in 4 forms: peracute, acute, subacute, and chronic

- bacterium can persist in URT, LRT, liver and lymphatics (reservoir for future outbreaks)

What the 4 forms on P. multocida in bird?

- Peracute: fatal before CS are seen

- Acute: listlessness, anorexia, diarrhea, and nasal/ocular discharge, low mortality

- Subacute: respiratory and mucopurulent nasal discharge

- Chronic: caseous lesions

4 forms of P. multocida in bovines

1. Pneumonia "shipping fever"
2. Hemorrhagic septicemia
3. Genital tract disease
4. Severe mastitis

Penumonia "shipping fever": in bovines

- Bronchopneumonia, fibrinous pleuropneumonia

- serogroup type A most common

- low pathogenic serovars

- induced by stress conditions

- fever, inappetence, listlessness, resp. signs

Hemorrhagic septicemia (HS) in bovines

- acute systemic infections

- affects buffalo, cattle, and wild populations of ungulates

- high mortality

- high pathogenic serovars

- all excretions/secretions highly infectious

- asymptomatic form can occur

- depression, fever, swelling of the throat and neck

P. multocida in rodents

- related to mass die offs in china

P. multocida in humans

- zoonotic from cat or dog bites

- birds bitten from cat develop septicemia

- edema, cellulitis, purulent exudate

- may lead to necrotizing fascilitis

How to diagnosis Pasteurella multocida

- serology

- microscopy: distinctive bipolar staining

- culture: non-hemolytic colonies on blood agar

Treatment and control of P. multocida

- vaccines for swine and cattle
- antibiotics
- treatment for HS occurs too late because of rapid infection

Characteristics of Mannheimia spp.

- gram - rods and coccobacillia

- bipolar staining

- hemolytic

- mucosal commensals

Name the 3 species of Mannheima and who it infects

1. M. haemolytica: all animals

2. M. granulomatis: cattle, deer, hares

3. M. varigena: pigs and cattle

Characteristics of M. haemolytica

- main spp of veterinary significance

- opportunistic pathogen causes pneumonia (primary and secondary)

- 12 serotypes

- affect sheep, goats, bovine and rarely pigs

- occurs during stress full conditions

What the acute pneumonia clinical signs of M. haemolytica?

- depression
- low feed intake
- reluctance to move
- ear droop
- cough
- increase resp. rate
- nasal discharge
- fever
- increased lung sounds

How to diagnosis and treat M. haemolytica

- clinical signs

- elevated serum haptoglobin or plasma fibrinogen levels

- hemolytic colonies on blood agar

- growth on MacConkey bc of tolerance on bile salts

- antibiotics: beware of high level of resistance

- vaccination

Characteristics of Bibersteinia trehalosi

- single species

- biotype T (trehalose fermentation)

- four capsular serotypes (3, 4, 10, 15)

- causes septicemia in weaned lambs (5-12 months)

- acute mortality

- member of resp. disease complex of cattle and sheep

- hemolytic

- postmortem lesions indistinguishable from M. haemolytica

Characteristics of Haemophilus-like spp.

- gram - rods

- not haemophilus anymore: Histophilus, Glaesserlla, Avibacterium

- fastidious

- non motile

- facultative anaerobes

- produce acid from glucose, reduce nitrates, oxidase

- host specificity

Characteristics of Histophilus and Glaesserella

- commensals of the mucous membranes: URT and lower genital tracts

Characteristics of Glaesserella parasuis

- Glasser's disease

- host specific for pigs

- most prevalent bacterial infection in swine

- polyserositis and meningitis in young pigs

- arthritis and pneumonia in older pigs

VFs of G. parasuis

- capsule ---> many strains

- Lipooligosaccharide (LOS endo toxin, w/o the O antigen but maintain toxicity with Lipid A)

- 15 serovars

Prevention of G. parasuis

- good herd management: decrease stress

- vaccination

- strategic use of meds

Characteristics of Histophilus somni in cattle

- sleeper's disease

- infectious thromboembolic meningoencephalitis (TME)

- resp disease: pneumonia and pleurisy

- genital infections

- mastitis

Characteristics of Histophilus somin in sheep

- commensal of genitals

- can cause epididymitis and orchitis in rams

- may cause pneumonia, mastitis, polyarthritis, meningitis, and septicemia