Gram + Flashcards
Trueperella pyogenes virulence factors
Adhesions ,Lipoteichoic acid and peptidoglycan cell wall, Exotoxs: PyolysinO, Neuraminidase, ProteasesandDNAses.
Describe Trueperella
Acid fast staining, Pleomorphic, facultative anaerobe, non-spore forming, non-motile, non-capsulated, capnophilic, Gram-positive bacilli, catalase negative.
Where is Trueperella found
mucous membranes! Upper respiratory, gastrointestinal and genital tracts.
Are Trueperella infections endogenous or exogenous?
Most infections are probably endogenous
What is “summer mastitis” and how is it spread?
Trueperella pyogenes
n “summer mastitis” cow to cow spread is aided by flies attracted to traumatized teats
Trueperella in cows
Involved in most purulent infection of traumatic or opportunistic origins. May be local, regional, or metastatic. Common locations include:
The lung, pericardium, endocardium, pleura, peritoneum, liver, joints, uterus, renal cortex, brain, bones, and subcutaneous tissues. Also causes abortion and mastitis in cattle
Describe Actinobaculum suis
Commensal diphteroid organism. Gram + Anaerobic bacteria.
Where is Actinobaculum sues found?
prepucial mucosa of boars
Actinobaculum sues in Sows
Causes cystitis and pyelonephritis
3-4 weeks post-coitus
Anorexia, arching of the back, dysuria and hematuria
DEATH consequence of renal failure
Actinobaculum sues
Sexual transmitted pathogen to SOWS!!!
Describe Erysipelothrix rhusiopathiae
Gram-positive, non-motile, non-acid fast, non-spore forming bacillus (slender forms), catalase negative, oxidase negative, coagulase positive.
What species is Erysipelothrix rhusiopathiae most common in?
Swine. Pig less than 3 months and over 3 years of age are least susceptible
in Turkey and sheep is Erysipelothrix rhusiopathiae more frequently found in the male or female?
Male is more frequently infected – Fight wounds
Reservoir of Erysipelothrix rhusiopathiae
Recovered from sewage effluents, abattoirs, surface slime of fresh and
saltwater fish and Over 50 species of mammals and 30 of birds. Tonsils from healthy pigs
Resistance of Erysipelothrix rhusiopathiae
Resistant to drying
– Survives for up to 6 months in swine feces
Cellular Products of Medical Interest of Erysipelothrix rhusiopathiae
Capsule (Polysaccharides)
– Anti-phagocytic
– Protects intracellular organisms (allows intracellular replication)
Cell Wall
– Typical Gram-positive
– Lipoteichoic acids and peptydoglycan are pro-inflammatory
• Neuraminidase
– Its production varies directly with virulence
– Cleavage of sialic acid residues on endothelial cells leads to thrombus formation
– Adherence
• Miscellaneous Products
– Most strains produce hyaluronidase and coagulase – Its association on with virulence hasn’t been shown
Transmission of Erysipelothrix rhusiopathiae
Mainly by ingestion of contaminated material
– Wound infections and arthropod bites are other possible routes
Erysipelothrix rhusiopathiae in swine
Septic form (Acute and if untreated has high mortality rates)
– Fever, anorexia, depression, vomiting, stiff gait, reluctance to walk, palpable urticarial lesions (may become necrotic and sloughed in severe cases) are felt before visible
• Diamond skin diseases
– Acute and less severe infections (Seldom mortalities)
– Lesions are limited to the skin (but accompanied with fever) – Skin lesions are red to purple rhomboidal
– Lesions may progress to necrosis or resolve
• Chronic forms
– Significant impact in industry!!
– Progression of acute stages or without previous illness
– Vegetative endocarditis (cardiac insufficiency or sudden death) – Arthritis (limping, stiff gait, enlargement of the affected joints) – Abortion (infrequent)
Erysipelothrix rhusiopathiae in turkeys
Usually a sep:cemia
• Cyanotic skin, become droopy and die.
• Swollen cyanotic snood (almost pathognomonic)
• Mortalities 2-25%
• Chronic manifestations include vegetative endocarditis and arthritis
Erysipelothrix rhusiopathiae in sheep
Entry through the umbilicus or wound
polyarthritis
• Associated with castrations ,docking or shearing
– Affected animals show stiff gait, and swollen joints
Erysipelothrix rhusiopathiae in dogs
Endocarditis and arthritis
Erysipelothrix rhusiopathiae in dolphins
Septicemia and urticaria
Erysipelothrix rhusiopathiae in humans
Most commonly in animals and fish-handlers
How to diagnose Erysipelothrix rhusiopathiae in lab.
Produce hydrogen sulfide, catalase and oxidase negative coagulase positive
Treatment of swine for Erysipelothrix rhusiopathiae
Acute form – Penicillin for at least 5 days – Antiserum (Equine origin) is sometimes used in conjunction • Chronic form – Is less successful
Describe Mycobacterium
Aerobic, acid-fast, non-spore forming rods
– Flagella and capsules are absent
– Cytochemically are Gram-positive
• But not stain well
– Better with Acid-fast
• Ability to bind phenol-based dyes (carbol fuchsin in 5% phenol) and resist discoloration with 3% hydrochloric acid in ethanol
Diseases in animals caused by Mycobacterium
Tuberculosis
Paratuberculosis (Johne’s Diseases)
Granulomatous diseases
• Mammals, birds, reptiles and fish
Virulence factors of Mycobacterium
Lipids, glycolipids and peptidoglycolipids, Alkyl Hydroperoxidase Reductase, Sufolipids and Phosphatidyl Inositol Mannoside, Surface Mycosides, Waxes, Glycolipid-Dimycolyl Trehalose (Cordfactor), Iron acquisition.
True or False is animal Tuberculosis a reportable disease?
True!
What is the Reservoir of Animal Tuberculosis?
Source of tubercle bacilli is tuberculous individuals • Humans(M. tuberculosis) • Cattle and wild mammals (M. bovis) – WHITE TAIL DEER in USA – BADGER IN EUROPE – BRUSH-TAILED POSSUM IN NEW ZEALAND – CAPE BUFFALO IN AFRICA • Chickens and other bird species (M. avium)
How is Animal Tuberculosis transmitted?
Via the respiratory and alimentary routes
• Contaminated airborne, feces, urine, genital discharges, milk from infected
mammary glands, contaminated feed and water
– Transplacental, transovarian and intrauterine routes are possible
Disease pattern of M. bovis
Typically is a debilitating illness – Progressive emaciation – Erratic appetite – Irregularlowgradefever – Enlargedlymphnodes – Cough – Diarrhea • Consequence of released cytokines
M. bovis in cattle
Usually Mycobacterium bovis
– Respiratory tract, adjacent lymph nodes and serous cavities
• Commonly progressive via air spaces and passages
– Hematogenous dissemination to liver and kidney
• Udder infection is rare
– Zoonotic implications
– Uterus serve as portal for fetal infection
• Surviving calves commonly develop liver and spleen lesions – M.avium
• Generally subclinical
– Abortions may occur
– M. tuberculosis
• Non-progressive lesions in cattle
M. bovis in horses
– Rarely infected (more often by M. avium)
– Usually enters alimentary tract
• Primary complexes in pharynx and intestine
• Secondary lesions in lungs, liver, spleen, serous membranes
M. bovis in swine
Usually via the alimentary route
– Mainly M. bovis causes progressive diseases with classical lesions
– M. avium predominant form in various countries
• Genetically different from birds M. avium isolates
• M. avium subspecies hominissuis
– M. tuberculosis don’t advances past regional lymph nodes
M. bovis in dogs
Mainly with M. bovis • Rarely M. avium • Dogs also with M. tuberculosis – Dogs • Hypertrophic pulmonary osteoarthropathy in dogs – Aka Marie’s diseases
M. Bovis in cats
Mainly with M. bovis • Rarely M. avium Cats • Intestinal and abdominal localization is more common in cats than in dogs – Alimentary route of exposure
M. bovis in primates
M. tuberculosis, M. bovis (MAINLY)
M. avium and non-tuberculous Mycobacteria (IMMUNOSUPPRESSED)
– Mainly by airborne route (M. tuberculosis) • Mainly a respiratory tract infection
• Homeless shelters, prisons, etc
– Via ingestion (M. bovis in unpasteurized milk)
• Primary regional lymphadenitis
• Hematogenous dissemination to vertebrae could result in hunchback
Epi of Avian Tuberculosis
Eradication of cattle tuberculosis in industrial countries
– Game farm, animal parks and zoos are foci of M. bovis
• Sporadic cases of canine tuberculosis and non-human
primates tuberculosis
– REVERSE ZOONOSES
• M. avium has been eradicated from commercial poultry
establishments
– Rapid population turnover (<1 year)
– Remains a problem in barnyard flocks
• Agent can survive in soil for years
Reservoir of M. avium subsp. paratuberculosis
Reservoir
– Symptomatic and asymptomatic wild and domestic ruminants, swine and rabbits
• Intestinal tract
– Feces, colostrum, milk, semen
Transmission of M. avium subsp. paratuberculosis
Ingestion or contact with fecally contaminated
materials
– In utero infection and ingestion of contaminated colostrum or milk are also possible routes
Describe Listeria
Typical Gram positive (non‐acid fast) – Catalase Positive, Oxidase Negative • Non‐spore forming (acapsular) • Small coccoid rod‐shaped bacteria – Usually occur in chains • Motile (peritrichous flagella) • Facultative anaerobe
Two important pathogens of Listeria
L. invanovii
• CAMP+withR.equiandfermentsD‐xylose
L. monocytogenes
CAMP+withS.aureusandfermentsL‐rhamnose
Cellular products of medical interest of Listeria
ActA
– Important protein in intracellular movement by actin polymerization
– Plays a role in cell tropism (adhesion) and invasion
– Move at a rate of 1.5μm/second
• Cell Wall
– Typical Gram‐positive
– Lipoteichoic acids and peptidoglycan are pro‐inflammatory
Internalins
– Surface proteins responsible for adhesion and entry into target cells
– Induce phagocytosis
– Cell to cell spread does not involve internalins
• Adhesins
– Internalins, ActA, and protein 60 (p60)
Listeriolysin O (LLO)
– MAINVIRULENCEFACTOR
– Pore‐formingcytolisin
– Releasesthebacteriafromthephagosomeintothecytosolfollowing phagosome acidification, under which conditions LLO is most active
– Lysisofferritinvacuoles
– Induceapoptosisinhepatocytes
– Ivanolysin(Counter‐partinL.ivanovii)
– Hemolysin
Phospholipase C
– Important in mediating membrane lysis • Miscellaneous Products
– Bile salt hydrolase
• Promotes survival and persistence in intestinal lumen
Reservoir of listeria
Worldwide distribution
• Soil, silage, sewage effluent, stream water, and over 50 species of animals
• The natural habitat is probably decomposing plant matter, where they live as saprophytes
• Up to 70% humans are asymptomatic fecal carriers in some cases
transmission of listeria
Soil contamination – Fecal‐oral enrichment • Ingestion of contaminated feed – Poor quality silage (“Silage diseases”) • Also nasal mucosa and conjunctivae
listeria in ruminants
Encephalitis (Circling diseases)
– Most common form in cattle • Subacute‐chronic
– Depression, anorexia
• Tendency to circle on one direction ,head pressing or turning of the
head to one side
• Unilateral facial paralysis and bilateral keratoconjunctivitis
• Death follows in 2‐3days
• If treated, less than 40% of animals will recover – Most with permanent brain damage
– In sheep and goats also but more acute and higher mortalities
listeria in weird animals
Chinchillas
– Particularly susceptible to listerial septicemia
classic source of infection for listeria
Contaminated silages
listeria camp neg or pos?
CAMP POSITIVE
Describe bacillis
Large, gram positive, spore forming, facultative anaerobic rods
• Catalase positive, oxidase negative and non-motile
• Catalase production important to distinguish from Clostridia
• Typically inhabit soil and water
• Only consistent pathogen of vertebrates is B. anthracis
• However, B. cereus and B. thuringiensis are closely related
• Group is informally referred to as B. cereus group
Cellular Products of Medical Interest of bacillus
Plasmids,Regulatory proteins of virulence factors, Capsule
Important mineral associated with Bacillus anthracis
Ca
reservoir of Bacillus anthracis
Soil (herbivores)
– Most susceptible species
– Infected animals and animal products (humans and other species)
– Carnivores comparatively resistant
– Birds are almost totally resistant – High body temperatures
Transmission of Bacillus anthracis
Endospore is the infectious unit
– Infection takes place by
• Ingestion of contaminated feed or water
• Via wound infection and arthropod bites
– Humans via:
• Skin wounds (malignant carbuncle)
• Inhalation(wool-sorter’sdiseases)
• Ingestion (likely exposure for predators)
post mortem findings in Bacillus anthracis cases
Widespread hemorrhages
• Black, engorged, friable spleen
• Tarry, non-clotting blood
• Absence of rigor mortis
Bacillus anthracis in ruminants
Cattle and sheep are the most susceptible species
– SEPTICEMIA!!!
– Incubation (1-5 days)
– Diseases (hours-few days)
• Mortality without clinical signs can occur
• Epistaxis is common and rigor mortis is often absent
• High fever, agalactia, abortion, congestion of mucous membranes,
hematuria, hemorrhagic diarrhea, regional edema
• Usually fatal
differentials for Bacillus anthracis
Blackleg – Clostridium chavuoei • Botulism – Clostridium botulinum • Poisoning – Plants – Heavy metal – Snake bite • Lightening strike • Peracute babesiosis
disease patterns of Bacillus anthraces in horses
Usually acute to sub-acute (~96 h)
– Colic and diarrhea
– Edema mainly in point of infection: • Intestine
• Throat (cause asphyxiation) – Septicemia as in ruminant
disease patterns of Bacillus anthraces in swine
Typically in the pharyngeal tissue
• Ulcerative lesion serves as portal of entry • Followedbyregionallymphadenitis
• Associated with meat and bone meal
– Obstructive edema may cause death
– Ulcerative hemorrhagic enteritis and mesenteric
lymphadenitis
disease pattern of Bacillus anthraces in predators
Similar to swine patterns
– Exposure through tainted meat may trigger septicemia
vacine for Bacillus anthraces
Sterne strain vaccine (lacks pX02 plasmid)
do you take field samples for Bacillus anthraces
NO FIELD NECROPSY!!!!!!!!!!!!!!!
what stain do you use for direct examination of contaminated Bacillus anthraces
McFadyean’smethyleneblue
– Blue staining organisms with a pink capsule
what is the String of pearls test
Characteristic blebbing that occurs when B. anthracis contacts penicillin
is Bacillus anthraces reportable?
YES
describe Clostridium
Gram positive, spore-forming, anaerobic rods
– Endospores impart resistance to drying, heat, irradiation and disinfectants
– The size, shape and location of the endospore can be used for species differentiation
• Fermentative, catalase negative, oxidase negative
• Clostridial cultures typically emit putrid odors
– Peptide catabolism
• MOST COMMON MODE OF ENERGY PRODUCTION
• Most are motile by peritrichous flagella – C. perfringens is nonmotile
• Invasive diseases
– Histotoxic and enterotoxaemias
• C. perfringens, C. difficile, C. novyi, C. haemolyticum, C. septicum, C. chauvoei, C. sordelii • Non-invasive diseases
– Neurotoxic
• C. botulinum and C. tetani
differentials for clostridium
Malignant edema
• Black leg
• Big head of rams
