Infection Review Sessions 5- Flashcards
What is the last antibody to appear when the body is clearing a hep b virus
HbsAb
The post exposure prophylaxis for hep C is
Nothing - wait until test positive and cure it
Gentamicin mainly targets
Gram negative (sepsis)
Which immune cell expresses the bacterial peptides on MHC class II molecules
Dendritic cells (has APC properties)
Why does CRP increase
CRP is an acute phase protein produced by the liver in response to infection
How would you describe bacteria quorum sensing
Modulation of gene expression in response to changes in cell population density
3 Characteristics of biofilms
Low metabolic activity
Low penetration of antibiotics
Secretion of virulence factors
What is the Planktonic phase of biofilm formation
Enter a spore-like state and move freely without being in a colony
Formation of extracellular matrix occurs after
Attachment of the spore-like bacteria to body cell
What substance has the phagocytic cell produced to trigger inflammation
Cytokines, Il1 and 6, TNFR
What are most staph resistant to?
Penicillin
UTI treatment
Nitrofurantoin or trimethoprim
Cell or cellular product responsible for controlling HIV infection initially
HIV specific CD8+ T cell
Patients who have cleared an infection will have
Surface antibody response HBcAg
Core antibody response IgG
Chesty symptoms in HIV positive patient likely to be caused by
Pneumocystis jiroveci (PJP/PCP infection)
Why does staphylocccus epidermis cause an infection in central lines
Produces a slime that adheres to plastic surfaces
Likely causative organism for infection following mitral valve replacement
Staph epidermis
Mechanism of action for antibiotic used to treat endocarditis caused by staph epidermis
Cell wall synthesis inhibitor (vancomycin plus rifampin)
How does HIV bind to lymphocyte
Gp120 docking glycoprotein binds to CD4 receptor
In malaria, low haemoglobin is due to
Action of merozoites
Legionnaires disease commonly presents with similar signs and symptoms to what other condition
Pneumonia
- clarithromycin
Name a common feature of malaria
Dark coloured urine due to haemolysis of RBCs leaking Hb into urine
Which antibiotic do you prescribe for C. difficile e
Metronidazole
Most important factor in reduction of MRSA infections
Hand washing
high ratio of IgM to IgG means
Patient has not encountered the virus previously
Patient has encountered virus before
High ratio of IgG to IgM
Any infection would trigger both
IgG and IgM
Any infection is associated with an
Antibody response
Description of CVID
Have B cells but they cannot produce antibodies
Di george syndrome description
Deletion on chromosome 22 causes hypoplastic thymus so no B cells can be matured
Description of Hyper-IgM syndrome
No isotope switching occurs so no IgG produced
Examples of supportive treatments for immunodeficiency
Prophylactic antibiotics and UV-irradiated/CMV negative blood products only
Example of specific treatment for immunodeficiency
Immunoglobulin therapy
Which malaria species is most commonly associated with severe malaria
Falciparum
Which pattern of infection is seen in HSV cold sores
Latent
Pattern of high igG and absent IgM usually means
Past infection
In which cell is EBV maintained for life
B cell
Which wbc is responsible for raised wbc count in EBV
CD8 T cell
What kind of murmur is suggestive of aortic stenosis
An ejection systolic murmur in 2nd intercostal space on the right
What is likely to be heard in tricuspid valve endocarditis
Systolic murmur in left lower sternal border
Features of IgA
Found on mucosal surfaces. Protects respiratory tract.
Features of IgA deficiency
Recurrent ear infection, sinusitis, bronchitis and pneumonia
Some also have GI infections and chronic diarrhea
Important virulence factor that is part of cell wall and inhibits phagocytosis in streptococci
M protein (interfered with complement)
Toxin A is produced by
C. difficile
What microbial feature is important in strep pyogenes
M protein - prevents phagocytosis
Impetigo- lesions, beta haemolysis, cocci.
Suggestive of
Streptococcus pyogenes
Does E. coli contain rna genetic material
No
Also Is prokaryote
What 2 pathogens are associated with toxic shock syndrome
Strep pyogenes
MRSA
Which treatments are needed in a case of necrotising fascilitis
IV antibiotics (normally penicillin) Antibody transfusion and debridement/amputation
What does alpha haemolytic mean
Partially oxidise iron in Hb to cause greenish colour
2 classes of antibiotic to treat cellulitis
Penicillins
Carbapenems
