Week 3 - Inflammation and Infectious Disease Flashcards
Endogenous infection
Normal to your body but when somewhere else in your body = pathogenic
Exogenous infection
Something from outside
Type of microbial infectious agent most likely associated with endogenous infection
Candida albicans
Extracellular bacteria
Don’t invade tissues/particular cells in order to reproduce
Portals of entry for infection
Penetrate skin, penetrate mucous membrane, cross placenta
What microscopic appearance/feature might indicate the presence of Actinomyces or Nocardia in tissue section
Branching and/or thin and filamentous gram positive bacteria
Actinomyces
Catalase negative
Nocardia
Catalase positive, partially acid fast
Stain used to visualise AFB
Ziehl Neelson/Kinyoun
Type of immune cell generally associated with extracellular bacterial infection
Neutrophils
Type of immune cell usually involved with immune response to intracellular organism
Macrophage
Infectious agents normally associated with lymphocytes
Virus
Infectious agents normally associated with neutrophils
Bacteria
Infectious agents normally associated with eosinophils
Parasites
Type of infection H. pylori associated with
Peptic ulcer, chronic gastritis, evident in gastric non-hodgkin lymphoma
Infectious agents normally associated with monocytes (blood) / macrophages (tissue)
Universal/everything
Methods available for H. pylori diagnosis
Gastric and duodenal biopsy or breath test (carbon), urine test (nitrogen)
Breath test for detection of H.pylori
Urea tablet with radio labelled carbon/nitrogen, if urease is present, tablet is broken down, radio labelled carbon/nitrogen goes in blood stream (will breathe it out in CO2) or seen in urine
Organisms that are members of Mycobacerium tuberculosis complex
M. tuberculosis, M. bovis, M. microti, M. caprae
Why are members of the mycobacterium tuberculosis complex said to be “tough”
Resistant to gram stain, decolourisation with acid, desiccation, disinfectants, antibiotics, strong acids and alkali
Why are mycobacterium tuberculosis complex organisms so slow to culture/grow
Hydrophobic -> clump together so tightly -> prevents easy access of nutrients into cell
Mycobacterium tuberculosis complex organisms transmission
Droplet nuclei (aerosols) with exception of M. bovis (ingestions)
Events leading to development of tubercle
Inhalation of mycobacterium tuberculosis organism, organisms enter alveoli, macrophages engulf organism, some macrophages start dying, accumulation of more cells = layering, centre = oldest material/dead material = caseous necrosis
Structure of tubercle
Caseous necrosis (middle) surrounded by activated macrophages and occasional giant Langhan cell, lymphocytes surrounding macrophages
Scientific names for three categories of helminths and their corresponding shapes
Platyhelminths - flat worms (trematodes - flukes , cestodes - tape worms), nematodes - round
Pathways that parasites can use to gain entry to host
Oral, percutaneous, inhalation, transplacental, sexual intercourse
Main virulence factor of Cryptococcus neoformans + how does it benefit the organism
It has a large capsule
Where is Crytococcus neoformans found in the environment
Piegon droppings/soil
Role of fungal spores in lifecycle of fungus
Reproduction
Role of fungal spores in pathogenesis of fungal infection
Survival
Individuals most at risk of acquiring serious fungal/yeast infection
Immunocompromised individuals
How does drug therapy predispose an individual to candidasis
Broad spectrum antibiotics alters the composition of commensal microflora, decrease normal microbes, decrease in competition for space and nutrients
Cryptococcus neoformans
Less common yeast that can cause significant systemic infection mostly present in CNS and lungs
Where is cryptococcus neoformans found
Dry piegon dung (powdery) -> inhaled
Where is cryptococcus gattii found
Eucalyptus trees
Name of yeast structure that invades tissue when candida sp. invades through tissue
Hyphal (mycelial) phase
Basic lifecycle for enterobius vermicularis
In humans, adult worms in intestine -(adult worm lays eggs in rectum)-> eggs in faeces -(distributed by hands as a result of itching)-> infective eggs develop in soil -(4-6 hours under optimal condition)-> eggs ingested -> eggs hatch in intestine -(1 month to develop into mature adult)-> young worms remain and mature in intestine
Main clinical outcomes of viral infection
Cell death, cell proliferation, latent infection
Two infections that can be caused by CMV
Mononucleosis, hepatitis
DNA vs RNA virus
RNA virus only needs to enter the cytoplasm (ribosomes) whereas DNA virus need to enter nucleus
Viral cytopathic effect
The effect the virus has on the cell monolayer
Development of CPE
Syncytial formation (fusion of neighbouring cells) or rounding up and cell lysis
Rounding up and cell lysis in Polio
Infected cells = cellular adhesion proteins disappear => round up and lyse
Herpes simplex viruses can form latency in what type of cell
T helper cells or macrophages
TWO HPV types that are the major cause of cervical cancer
16 and 18
HPV type that causes genital warts
6 and 11
Tests used to diagnose cervical cancer
Pap smear, PCR, cervical biopsy
HPV vaccine production
L1 capsid gene into a yeast cell to make shell of virus without DNA inside
Negri bodies
Eosinophilic rounded cytoplasmic inclusions
Diagnosis of negri bodies
Rabies
Suppurative
Process of pus formation
Febrile
Relating to fever
Abscess
Collection of pus within cavity
Process of occurrence of miliary tuberculosis
Early phase of tuberculous infection, acute haematogenous dissemination. Caseous necrosis rupture into blood stream, Mtb spread and enter into different organs and tissues via tuberculous lymph node. Allergic changes of blood capillaries wall => becomes rough and penetrative
How can a person be free of disease yet have viable Tb organisms in their lung
Treatment of H. Pylori
Antibiotics
Potential pathological tissue reactions associated with H. Pylori
chronic inflammatory infiltrate, seagull drawing rods in mucosal epithelium seen with toluidine blue positive, IHC, loss of regular structure, formation of scar tissue
Why is PAS positive for cryptoccous neoformans
Has a large capsule with thick phospholipid coat
