Multi-system Pathogens Flashcards
- What are the three characteristics of a multi-system infection?
- An infection caused by an agent that can:
* *disseminate** to multiple tissues
* *replicate** and/or persist in those tissues
* *cause disease** in multiple tissues
What 4 mechanisms allow “professional” multi-system pathogens to evade the immune system?
Antigenic variation, serum resistance, cloaking, cell invasion
- What survival mechanisms are utilized by Borrelia?
- What survival mechanisms are utilized by Treponema pallidum?
- What two multi-system bugs utilize phagocytosis prevention?
- What multi-system bugs utilize cell invasiveness? (intracellular replication, spread)
- Antigenic variation, Complement inactivation, tissue invasiveness
- Antigenic variation, few surface proteins, tissue invasiveness (extracellular replication/spread)
- Bacillus anthracis, Yersinia pestis
- Anaplasma, Ehrlichia, Rickettsia, Bartonella, Chlamydia, Coxiella
- What are three examples of antigenic variation (recombination) and what bugs do each of these?
- How do *Borrelia *and Leptospira inactivate complement?
- How do many bacteria manage to “cloak” themselves?
- Recombination of Vls & Vmp loci
Recombination of TprK locus
(Treponema pallidum)
- Borrelia and Leptospira inactivate complement by binding to factor H.
- They bind to fibronectin and other plasma proteins.
(*Borrelia - *Lyme disease/Relapsing fever)
There are three main mechanisms for cell invasion:
- What organism binds to, enters, replicates in late endosomes, and autophagosomes of NEUTROPHILS ?
- What organism binds to, enters, replicates in early endosomes of **MONOCYTIC CELLS **?
- What organism binds to, enters, replicates in cytoplasm of ENDOTHELIAL CELLS ?
- Anaplasma phagocytophilum
- Ehrlichia chaffeensis
- Rickettsia species
There are 3 main types of tissue invasion. Which organism:
- Sequesters and activates host plasminogen and matrix metalloproteinases ?
- Utilizes endogenous proteases ?
- Penetrates between cells ?
- Borrelia, Leptospira
- Teponema pallidum
- Borrelia, Leptospira
What is the difference between and “opportunist” and a “professional” pathogen from a multi-system infectious stand point?
Opportunists are otherwise typically benign bugs put in places they don’t belong and affect immunocompromised patients
Professional pathogens all can cause disease in immunocompetent hosts and some are transmitted by an arthropod vector.
What are some routes of entry/disruptions that allow opportunists to set up shop?
- Disruptions to physical barriers: CVADs, Injections, Surgery, Dialysis
- SYSTEMIC disruptions: Chemo, Radiation, Immunosuppression, Immunodeficiency
- What does Biological transmission by a vector mean?
- What does Vector competence mean?
- What does transstadial transmission mean?
- What is transovarial transmission?
- Specific life stage in a vector
- Ability of a vector to transmit a pathogen
Three processes: Acquire-Maintain-Transmit - Pathogen is transmitted/maintained in different life stages. (Lyme, Anaplasmosis, Ehrlichiosis)
- Transmitted from one generation to another.
(Rocky Mountain Spotted Fever, Rickettsiosis)
What are the tick-borne, Gram-negative, intracellular bacilli that replicate in vacuoles?
- Anaplasmosis*
- Ehrlichiosis*
What is the tick-borne, gram-negative intracellular bacilli that replicates in cytoplasm?
Rocky Mountain Spotted Fever
What tick-borne, Gram-negative extracellular spirochete replicates outside of host cells?
Lyme disease
- What diseases can result from Ixodes scapularis**?
- What diseases can result from Ixodes pacificus?
- Anaplasmosis
Lyme disease
Ehrlichiosis - Anaplasmosis
Lyme disease
- What is the key difference between tick larvae and nymphs/adults?
- When is the peak season for transmission of Ixodes scapularis?
- When is the secondary peak from adult ticks?
- Larvae have 6 legs and are often not infected
Nymphs/Adults have 8 legs, are potentially infected
- Spring to early summer.
- Fall
- What organism causes Human Granulocytic Anaplasmosis?
- What is its physical characteristics?
- How does it function?
- What does it do to its neutrophil host?
- Anaplasma phagocytophilum
- TINY Gram negative coccobacillus
- OBLIGATE intracellular that replicates in vauoles b/c it has no LPS or peptidoglycan. It has type IV secretion.
- Disrupts whole array of function yet activates chemokine expression and degranulation