Flashcards in I&I Deck (56):
State cytokines released by Th1 and Th2
Th1 - TNF alpha, IFN-gamma
Th2 - IL 4, 5, 10
characteristics of HIV? pathology and acute symptoms?
pathogen - SS+ RNA
Binds to GP120 on cell --> reverse transcriptase + integrase then incubation for 1-3 weeks
acute - fever, rash, myalgia
detection and treatment of HIV?
Detect - PCR, p24 antigen via ELISA. All after 6 months
Treatment - HAART therapy - 2NRT inhibitors, integrase inhibitor, fusion inhibitor, protease inhibitor, NNRTI
Acute and chronic symptoms of Hep B?
acute - after 1-6 mths fever, malaise, jaundice
Chronic - jaundice, liver failrue, cirrhosis,, liver cancer
commensal bacteria both pathogenic and symbiotic that live on a body surface
Give examples of microbiota
HPV, herpes simplex
Gram + - s aureus, strep viridans, cornyebacterium
gram - - enterobacteriacae
what are the gram positive bacteria?
Strange, staphys act list entered my new carrier bag
streptococcus, staphylococcus, actinomyces, listeria, enterococcus, mycobacteria, pneumonia, cornyebacteria, bacillus
mechanism of infection of a surface/
adherence via fimbriae > invasion + multiplication > biofilm > quorum sensing > host response of fever and granuloma
what bacteria infect heart valves?
native + >1yr prosthetic - HACEK group, strep viridans, candida, staph aureus
how do you diagnose and treat infected surfaces?
blood culture + sonication
treat with antibiotics or surgery
Explain the sensitisation and effector phase of type 1 hypersensitivity reactions
sensitisation - antigen contact --> IgE produced
effector - antigen binds to IgE on mast cell --> release of chemoattractants, cytokines, histamines --> effects depend on location
treat and manage anaphylaxis?
treat - adrenaline, monitor pulse oximetry, BP
manage - steroids, antihistamines, anti-ige
give examples of hospital acquired infections
pneumonia, UTI, legionella, MRSA, c diff
how do you diagnose and treat c diff
stool and elisa diagnose
treat - metronidazole or vancomycin
define basic reproductive number
no of cases 1 case generates on average over the course of the infectiuous period
1 - infection will spread
what are the principles of antimicrobial stewardship
prevent inappropriate use of antibiotcs and resistance, minimise adverse effects, reduce cost of infection
what are some possible causes of chronic infections?
vascular, infection, trauma, autoimmune, metabollic, idiopathic, neoplasia, degenerative, environmental, inflammation
what is the pattern of inheritance of cf? what organisms infect a cf patient? what disease can cf progress to?
h influenzae --> staph aureus --> atypical mycobacteria --> pseudomonas aeroginosa
can become COPD
why does DM lead to increased risk of infection?
hyperglycaemia and acidosis results in reduced humoral immunity (antibodies) and decreased neutrophil and lymphocyte function
what diseases are DM patients at higher risk of?
otitis externa - pain and discharge of external ear and meatus
rhinocerebral mucormycosis - mould infection of sinuses due to DKA resulting in soft tissue and bony necrosis
what symptoms does a immunocompromised patient have?
SPUR - severe, persistent, unusual, recurrent
Give example b cell deficiencies
CVID - b cells dont mature
IgA or IgG deficiency
Brutons - X linked
Hyper IgM syndrome - cant switch to IgG
what cell secretes antiobides? what are the types of antibodies and what is their funciton?
B cell secretes. MAGED
IgA - mucosal areas + saliva, sweat, tears, breast milk
IgD - immature b cells
IgE - allergies and parasitic worms
IgG - majority of antibody immunity against pathogens. Only ab that can cross placenta
IgM - eliminates pathogens in early stages of humoral immunity
give examples of phagocyte deficiencies -
cyclic neutropenia, leukocyte adhesion deficiencym chronic granulomatous disease
give example t cell deficiencies. How do you treat
digeorge syndrome, SCID
Dg treat - antibiotics, correct calcium and heart, no live vaccines, X irradiated and CMV -ve blood, BM transplant
give examples of secondary immunodeficiency
HIV, malnutrition, liver disease, drug induced, splenectomy
give examples of encapsulated bacteria
strep pneumoniae, n mengitidis
how do you manage asplenic patients
penicillin prophylaxis, immunisation, medic bracelet
function of spleen?
removes opsonised and encapsulated bacteria, synthesis Antibodies
how do b cell deficiencies present? manage?
resp infections, gi complications,
manage - prophylaxis, immunoglobin replacement, avoid radiation
how do phagocyte deficiencis present? manage?
ulcer, osteomyeleitis, abscesses
manage - prophylaxis, stem cell transplant
how does SCID present?
failure to thrive, deep abscesses, decreased lymphocyte, viral + fungal infection
how do organisms cause disease?
exposure --> adherence --> invasion --> multiplication --> dissemination
antibiotics in the beta lactam group?
monobactams, carbapenems, cephalosporins, penicillin
what are the resistance mechanisms in bacteria/
vertical (reproduction), horizontal (transformation (from environment), transduction (bateriophage), conjugation)
sepsis commonest pathogen?
RR > 20, HR >90, temp >38, WBC 12x10(9)
what is sepsis and severe sepsis?
sepsis - sirs + infection
severe sepsis - sepsis + organ hypoperfusion or failure
how do you manage sepsis ASAP/
sepsis 6 within 1 hr
IV fluids and antibiotics, blood culture, serum lactate, urine output measured, oxygen
what is the characteristics of innate and adaptive immunity?
innate - fast, non specific, no memory
adaptive - slow, specific, memory
what structures and cells involved in innate and adaptiv eimmunity?
innate - WBCs, anatomical barriers, inflammation, complement proteins
adaptive - b and t lymphocytes
how do macrophages recognise pathogens?
have Pathogen recognition receptors (PRRs) to recognise PAMPs + phagocytose
how do macrophages kill?
oxygen dependent - superoxide
oxygen independent - lactoferrins, proteases, lysozyme
what complement proteins do you know nad their functions
c3a and 5a - chemoattractants for phagocytes
c3b and 4b - opsonise
c5-9 - membrane attack complex
How do you treat malaria
falcifiparum - quinine / artemesinin
other species - chloroquine
pathology of enteric fever and symptoms?
caused by salmonella enterica, adheres to ileal lymphoid tissue called peyers patches.
symptoms - fever, malaise, abdo pain, consitpation, hepatosplenomegaly, dry cough, intestinal hemorrhage
how do you investigate and treat enteric fever?
investigate - blood culture, raised LFTs, lymphopenia
treat - typhoid vaccine, ceftriaxone
symptoms of brucellosis and treatment/
symptoms - fever, myalgia (most important), arthralgia
characteristics of flu A
fever, diarrhoea, chils, myalgia, tiredness
what is antigenic drift and shift?
drift - mutation
shift - combo of different strains
how are extracellular PAMPs targetted?
phagocytosed by antigen presenting cells (APCs) --> MHS class 2 binds to PAMP --> activates CD4 cell --> activates B cells, eosinophils, mast cells
how are intracellular PAMPs targetted
antigen enters ER --> Binds to MHC1 --> activates CD8 --> activates killer t cells --> release perforins and granzymes