Pathogenic bacteria I & II Flashcards
Defining pathogenic bacteria
PATHOGEN: ? agent, a microorganism that can cause disease upon ** IMP! ? of the host **. They harbor the required ? genes for infection (e.g. adherence, invasion and evasion of the immune system and/or toxins)
obligate pathogen: a microorganism which * ? * and cause ? in order to multiply and be transmitted from one ? to another.
facultative pathogen: microorganism which can * ? * and multiply in hosts but is also capable of multiplying in the ?.
opportunistic pathogen: microorganism which does not * ? * but under certain conditions (e.g. impaired host immunity) becomes pathogenic
Defining pathogenic bacteria
PATHOGEN: infectious agent, a microorganism that can cause disease upon colonization of the host. They harbor the required virulence genes for infection (e.g. adherence, invasion and evasion of the immune system and/or toxins)
obligate pathogen: a microorganism that * must infect a host * and cause disease in order to multiply and be transmitted from one host to another.
facultative pathogen: microorganism which can * infect * and multiply in hosts but is also capable of multiplying in the environment.
opportunistic pathogen: microorganism which does not * ordinarily cause disease * but under certain conditions (e.g. impaired host immunity) becomes pathogenic
OBLIGATE INTRACELULAR
▪ Can only reproduce inside the ? host cell (e.g. Rickettsia, Ehrlichia, Mycoplasma, Chlamydia)
- (evolved with host that it lost its ability to live in another condition)
FACULTATIVE INTRACELULAR
▪ Can survive and multiply ?- and ?cellularly (e.g. Mycobacterium, Salmonella)
OBLIGATE INTRACELULAR
▪ Can only reproduce inside the infected host cell (e.g. Rickettsia, Ehrlichia, Mycoplasma (NO CELL WALL), Chlamydia)
- (evolved with host that it lost its ability to live in another condition)
FACULTATIVE INTRACELULAR
▪ Can survive and multiply intra- and extracellularly (e.g. Mycobacterium, Salmonella)
(recall: pic of flea and skin -> inside gut of flea is not intra but rather extracellular
based on whether a cell has an outer membrane (gram-negative) or not and peptidoglycan, the pathogens are divided into subclasses:
note: spirochetes have flagella that grow inside body and not outside
Gram-positive cocci
STAPHYLOCOCCUS
▪ Reservoir: on ? and mucus membranes of ? and ?
▪ → ? !
▪ Upper respiratory tract * IMP! ? !)
▪ Lower ? tract
▪ ? tract
Species of clinical importance
▪ S. ? (humans & animals)
▪ S. ? (dogs & cats)
▪ S. ? (pigs)
▪ Pyogenic infections: suppurative infections with pus-filled lesions (~abscess)
Gram-positive cocci
STAPHYLOCOCCUS (grape like)
▪ Reservoir: on skin and mucus membranes of animals and humans
▪ → commensals!
▪ Upper respiratory tract * IMP! NOSE !)
▪ Lower urogenital tract
▪ GI tract
Species of clinical importance
▪ S. aureus (humans & animals)
▪ S. pseudintermedius (dogs & cats)
▪ S. hyicus (pigs)
▪ Pyogenic infections: suppurative (fester) infections with pus-filled lesions (~abscess)
GRAM + BACTERIA: cocci
Staphylococcus ?
Pyoderma, Otitis Externa
▪ Host: dog, cat
▪ ? (local suppurative skin infections)
▪ ? externa (ear infections): main cause often parasites, food allergies, foreign bodies with staphylococci as ? infections
sum alr there before and then staphylococcus takes adv. of it
Staphylococcus Pseudintermedius
Pyoderma, Otitis Externa
▪ Host: dog, cat
▪ pyoderma (local suppurative skin infections)
▪ otitis externa (ear infections): main cause often parasites, food allergies, foreign bodies with staphylococci as staphylococci as infections
sum alr there before and then staphylococcus takes adv. of it
Bacterial pyoderma is usually triggered by *? *of normal * ? * or ? skin microbiota
This is any skin disease that changes the normally dry, desert-like environment to a more ? environment can ? the host to ?
Bacterial pyoderma is usually triggered by *OVERGROWTH * of normal * RESIDENT * or transient skin microbiota
This is any skin disease that changes the normally dry, desert-like environment to a more humid environment can predispose the host to over-colonization.
Staphylococcus
Bovine staphylococcal mastitis
▪ S. ?
▪ Host: Cattle, small ?
▪ ? mastitis
▪ Majority not cleared by ? -> chronic, low-grade or subclinical -> ** IMP ? losses **!
▪ Ranging from ? gangrenous mastitis to ? mastitis
Staphylococcus
Bovine staphylococcal mastitis
▪ S. aureus
▪ Host: Cattle, small ruminants
▪ Contagious mastitis
▪ Majority not cleared by immune system -> chronic, low-grade or subclinical (not severe enough) -> ** IMP production losses **!
▪ Ranging from peracute gangrenous mastitis to chronic mastitis
Streptococcus
▪ Reservoir: on * IMP ? * membranes of animals and humans→commensals!* (note: here not on ? unlike staphylococci)
▪ Upper respiratory tract
▪ Lower urogenital tract
▪ Bacteria have ** IMP ? ** to evade phagocytosis ▪ Species of clinical importance:
▪ S. ? (humans)
▪ S. ? (cattle) -> ? mastitis (milk ?)
▪ S. ? (cattle) -> ? mastitis (skin, buccal cavity)
▪ S. ? subsp. equi (horses) -> strangles
▪ Host-? suppurative infections, local and systemic including septicemia, ? and adjacent ? infections
Streptococcus
▪ Reservoir: on mucus membranes of animals and humans→commensals!* (note: here not on skin unlike staphylococci)
▪ Upper respiratory tract
▪ Lower urogenital tract
▪ Bacteria have ** IMP CAPSULES!! ** to evade phagocytosis ▪ Species of clinical importance:
▪ S. pyogenes (humans)
▪ S. agalactiae (cattle) -> contagious mastitis (milk dult)
▪ S. dysgalactiae (cattle) -> environmental mastitis (skin, buccal cavity)
▪ S. equi subsp. equi (horses) -> strangles
▪ Host-specific suppurative infections, local and systemic including septicemia, throat and adjacent lymph node infections
STREPTOCOCCUS
Strangles = equine ?
▪ S. equi subsp. equi, not a ** IMP! ? *
▪ Host: ?
▪ Highly ? (having or showing symptoms of fever) disease involving the upper respiratory tract with abscessation of regional ? in equines→ swollen lymph nodes can cause airway obstruction leading to death (~ strangles)
▪ Transmission: direct or ? contact with purulent exudates
▪ ? disease in many states of the US.
Streptococcal mastitis
▪ Host: cattle, small ?
▪ S. ? colonizes milk ducts -> persistent infection with intermittent bouts of acute mastitis
( ~ ? mastitis)
▪ S. dysgalactiae colonizes ? cavity, ? and ? of mammary gland -> ? mastitis
STREPTOCOCCUS
Strangles = equine distemper
▪ S. equi subsp. equi, not a ** IMP! commensal *
▪ Host: equines
▪ Highly contagious febrile (having or showing symptoms of fever) disease involving the upper respiratory tract with abscessation of regional lymph nodes in equines→ Swollen lymph nodes can cause airway obstruction leading to death (~ strangles)
▪ Transmission: direct or indirect contact with purulent exudates
▪ notifiable disease in many states of the US.
Streptococcal mastitis
▪ Host: cattle, small ?
▪ S. agalactiae colonizes milk ducts -> persistent infection with intermittent bouts of acute mastitis
( ~ chronic mastitis)
▪ S. dysgalactiae colonizes the buccal cavity, genitalia, and skin of the mammary gland -> acute mastitis
Gram-positive rods: Bacilli
Listeria monocytogenes:
▪ Reservoir: Ubiquitous in the environment (herbage, ?, fresh water, ? from healthy animals)
▪ ** IMP!! ? **(which temp. do they live in) -> growth in fridge!
▪ ** IMP!! ? ** that can persist in ?: Uses actin filaments to travel through cells
? with three clinical symptoms, rarely overlap
▪ ?
▪ ?
▪ ?
? disease, ? disease, listeriosis
▪ Host: ?, small ?
▪ * ? * is the most readily recognized form of listeriosis in ruminants
▪ Affecting all ?, both ?
▪ Winter-spring disease of feedlot or housed ruminants: less ? pH of
? (grass or green foder) enhances multiplication of L. monocytogenes
(Listeria monocytogenes, altho can be destroyed by fire but it can live in ? temperatures such as ?
- foods that it can live in?
- listeria can live in soil microbiota, contaminated water source, weather, fresh produce, humans and thus cycle continues.
Gram-positive rods: Bacilli
Listeria monocytogenes:
▪ Reservoir: Ubiquitous in the environment (herbage, sewage effluent, fresh water, feces from healthy animals)
▪ ** IMP!! PSYCHOPHRILES **(which temp. do they live in) -> growth in fridge!
▪ ** IMP!! FACULTATIVE INTRACELLULAR BACTERIA ** that can persist in macrophages: Uses actin filaments to travel through cells
LISTERIOSIS with three clinical symptoms, rarely overlap (SAE)
▪ septicemia
▪ abortion
▪ encephalitis*
circling disease, silage disease, listeriosis
▪ Host: cattle, small ruminants
▪ * Encephalitis * is the most readily recognized form of listeriosis in ruminants
▪ Affecting all ages, both sexes
▪ Winter-spring disease of feedlot or housed ruminants: less acidic pH of
spoiled silage (grass or green foder) enhances the multiplication of L. monocytogenes
Listeria monocytogenes, altho can be destroyed by fire but it can live in low temperatures such as fridge (psychrophiles: love low temp.)
- foods that it can live in: cheese, curd etc. so can lead to HUGE LOSSES OF FOOD in factories
Erysipelothrix rhusiopathiae
▪ Reservoir: widespread in ** ? ** and intestines of many species
▪ Up to ?% of healthy pigs harbor E. rhusiopathiae in tonsillar tissues
▪ Susceptible animals: pigs ? months to ? year old (stress factors)
Four syndromes
▪ Septicemia
▪ ?
▪ ?
▪ ?
▪ ? skin disease in swine or swine ?
Erysipelothrix rhusiopathiae
▪ Reservoir: widespread in ** tonsils ** and intestines of many species
▪ Up to 50% of healthy pigs harbor E. rhusiopathiae in tonsillar tissues
▪ Susceptible animals: pigs 3 months to 1 year old (stress factors)
Four syndromes
▪ Septicemia
▪ arthritis
▪ endocarditis
▪ dermatopathy
▪ Diamond skin disease in swine or swine erysipelas
Corynebacterium pseudotuberculosis
▪ Reservoir: ?, ? membranes→commensals
▪ Host: small ?
▪ Facultative ? pathogens that survive in macrophages
▪ ? ?: abscessation and enlargement of ? or ? lymph nodes in sheep and goats
Corynebacterium pseudotuberculosis
▪ Reservoir: soil, mucous membranes→commensals
▪ Host: small ruminants
▪ Facultative intracellular pathogens that survive in macrophages
▪ caseous lymphadenitis: abscessation and enlargement of superficial or internal lymph nodes in sheep and goats
Bacillus anthracis
▪ Aerobes or facultative anaerobes, * ? ? pathogen, *** IMP ? “
▪ Reservoir: ubiquitous in ?
▪ Anthrax: mostly restricted to ?, source of infection is soil contaminated with ?
Virulence factors:
Bacillus anthracis capsule
Tripartite anthrax toxin
▪ Protective Antigen: ? factor
▪ Edema factor: disturbance of water homeostasis -> is known as ?
▪ Lethal factor: ? death and ?-induced tissue injury -> necrosis and hemorrhage
Per acute septicemia in ruminants:
▪ Rapidly ? disease with respiratory distress and shock
▪ Bleeding from ?
▪ Postmortem: dark ? blood incomplete ?, splenomegaly
Bacillus anthracis
▪ Aerobes or facultative anaerobes, * obligate mammalian pathogen, *** IMP ENDOSPORE-FORMING “
▪ Reservoir: ubiquitous in soil
▪ Anthrax: mostly restricted to cattle, source of infection is soil contaminated with spores
Virulence factors:
Bacillus anthracis capsule
Tripartite anthrax toxin
▪ Protective Antigen: cell-binding factor
▪ Edema factor: disturbance of water homeostasis -> EDEMA
▪ Lethal factor: cell death and hypoxia-induced tissue injury -> necrosis and hemorrhage
Per acute septicemia in ruminants:
▪ Rapidly fatal disease with respiratory distress and shock
▪ Bleeding from orifices
▪ Postmortem: dark unclotted blood incomplete rigor motris, splenomegaly
Gram-positive ANAEROBIC rods/bacilli
Clostridium
▪ Obligate anaerobes and powerful IMP ? * producers
▪ “ ** IMP ?-forming “
▪ Widespread in soil, gastro-intestinal tract of animals and humans and in feces
Neurotoxic clostridia: Affect neuromuscular function without inducing ? tissue damage
its disease: ?
Histotoxic clostridia: Localized lesions in ? and ?, subsequently causing toxemia
Diseases: ?, ? edema, ? disease
? and ?-producing clostridia: infers with ? synthesis in cells
Diseases: Enterotoxaemia, ? colitis
Gram-positive ANAEROBIC rods/bacilli
Clostridium
▪ Obligate anaerobes and powerful IMP toxin * producers
▪ “ ** IMP ENDOSPORE-FORMING “
▪ Widespread in soil, gastro-intestinal tract of animals and humans and in feces
Neurotoxic clostridia: Affect neuromuscular function without inducing observable tissue damage
its disease: tetanus botulism
Histotoxic clostridia: Localized lesions in muscle and liver, subsequently causing toxemia
Diseases: blackleg, malignant edema, black disease
enteropathogenic and exterotoxaemia-producing clostridia: infers with protein synthesis in cells
Diseases: Enterotoxaemia, pseudomembranous colitis
Clostridium
Tetanus
▪ C. ?
▪ Reservoir: soil, mammalian intestines
▪ Host: ?, ?
▪ ACUTE OR CHRONIC?, potentially fatal intoxication with neurotoxic clostridia causing spastic ? (after growth of bacteria in contaminated wounds e.g.)
▪ Produces ** IMP ?, a potent neurotoxin and ** IMP ?, a haemolysin destructing tissues
Clostridium
Tetanus
▪ C. tenani
▪ Reservoir: soil, mammalian intestines
▪ Host: humans, equines
▪ ACUTE, potentially fatal intoxication with neurotoxic clostridia causing spastic paralysis (after growth of bacteria in contaminated wounds e.g.)
▪ Produces TETANOSPASMIN, a potent neurotoxin and TETANOLYSIN, a haemolysin destructing tissues
spasm: a sudden involuntary muscular contraction or convulsive movement:
SPIROCHETES
Leptospira
▪ Gram-negative bacteria
▪ Spirochete = ? motile bacteria with ?
▪ ? (easily broken down) in the environment and ? to desiccation
▪ ?: free living in ponds, rivers, surface waters, moist soil
▪ Multiple reservoir animals
▪ Pathogenic leptospiral spp. persist in ? tubules or ? tract
** IMP
▪ ? and ? zoonotic disease (St Kitts!)
▪ Epidemics following ? **
Leptospirosis in LIST 4
▪ ? failure, ?, ?
▪ Acute ? disease
Leptospirosis in humans (zoonosis)
▪ ?-like illness, occasionally ? or ? disease
SPIROCHETES
Leptospira
▪ Gram-negative bacteria
▪ Spirochete = spiral motile bacteria with endo flagellum
▪ labile (easily broken down) in the environment and sensitive to desiccation
▪ SAPROPHYTES: free living in ponds, rivers, surface waters, moist soil
▪ Multiple reservoir animals
▪ Pathogenic leptospiral spp. persist in renal tubules or genital tract
** IMP
▪ WIDESPREAD and UNDERDIAGNOSED zoonotic disease (St Kitts!)
▪ Epidemics following NATURAL DISASTERS **
Leptospirosis in dogs, horses, cattle and pigs
▪ reproductive failure, aboritoins, stillbirth
▪ Acute septicemic disease
Leptospirosis in humans (zoonosis)
▪ infleunza-like illness, occasionally liver or kidney disease
Borrelia burgdoferi
▪ Spirochete causing * IMP ? * in animals and humans
▪ vector: ? (Ixodes)
▪ Most infections are ? (not severe enough)
▪ Clinical disease is reported frequently in dogs: ?, ?, ?
cardiac, renal or ? disturbance
MYCOPLASMA
Mycoplasma
▪ ? free-living prokaryotic microorganisms that * IMP!!!! ? *
▪ Not susceptible to ?
▪ ?, contagious ? ? and arthritis in cattle
▪ Stance with ? and ? extended and elbows ?
▪ Expiratory ? and mucopurulent ? discharge
▪ ? (relating to or denoting a disease that regularly affects animals in a particular district or at a particular season) ? in pigs
Borrelia burgdoferi
▪ Spirochete causing * IMP LYME DISEASE * in animals and humans
▪ Vector: ticks (Ixodes)
▪ Most infections are subclinical (not severe enough)
▪ Clinical disease is reported frequently in dogs: fever, lethargy, arthritis
cardiac, renal or neurological disturbance
MYCOPLASMA
Mycoplasma
▪ SMALLEST free-living prokaryotic microorganisms that * IMP!!!! lack cell wall *
▪ Not susceptible to PENICILLIN
▪ Mastitis, contagious bovine pleuropneumonia and arthritis in cattle
▪ Stance with head and neck extended and elbows abducted
▪ Expiratory grunting and mucopurulent nasal discharge
▪ Enzootic (relating to or denoting a disease that regularly affects animals in a particular district or at a particular season) pneumonia in pigs
