Microbiology Flashcards
Other genetic cause of SLE?
Genetic complement deficiency in 50% of SLE
What uv light can cause to SLE ?
Induce apoptosis of keratinocytes
2- expression of auto nuclear antigens (e.g. Ro & La)
What microbes can cause SLE?
Retrovirus
EBV
How microbes can cause SLE?
- Molecular mimicry
- Polyclonal activation
- Cytokines production
- Release of sequesterd Ag
Relation to cytokines production?
Those with active disease have higher tighter of IFN-gamma = increase expression of class II Mhc
Molecular mimicry in SLE?
Cross reactivity of Ro and Sm with viral Ag
What happens in polyclonal activation?
IgM (anti nuclear)
How drug induced SLE occur?
By forming conjugated with self antigen resulting in altered structures causing auto reactivity
Immunological abnormalities seen in SLE?
- Decrease number and function of CD-8 T and Nk cells
- Decrease T suppressor TgF-beta
- Dysregulated cytokines
- high IL- 3,4,5,6,10 + IFN gamma
- low IL-2
- Autoantibodies to complement ( C1 q)
- Defective immune complex clearance
- Polyclonal B cell activation
Other antibodies seen in SLE ?
RF
C1 q
HSP
What genes mostly predispose to SLE?
HLA-DR2/3
Etiological agents in septic
S. Aeurs Strepto agalectica in diabetics Other strepto Aneaerobes H. Influenza in 3m to 2yrs
Characteristic of h influenza
Pleomotphic bacillli
Factors needing like hemin and bad
Most infective arthris are by hemtegonous route why?
Highly vascular synovial membrane
With no limiting basement plate like
Patho physiology of s.aures infection?
Release proteoglycans from cartilage leading to its degradation
Predilection to axial skeleton is seen in iv drug users by?
Gnb and pseudomonas
Disseminated gonococcal infection is seen in
Inherited complement deficiencies
Which cultural is more positive in gonococcal infection?
Blood better than synovial!
Even better is geniturinary
Characteristics of salmonella
Gram negative non lactose fermenting bacilli
Present with salmonella
Synovial fliudvia sterile!!
Bacteria after no pasteurized milk causing sarcoillitis with negative synovial fluid?
Bruxelles
Hiv patient with low grade inflammation of a single joint?
Mycobacterium or fungal !
RF for infective arthritis ?
Bacterima Phagocytic defect Liver disease Chronic steroid use Prexesting connective tissue disorder Hemophilia Recurrent hemarthrosis I. Drugs
One of the commonest symptoms of influenza is
Myalgia
Immunity to influenza is
Type specific
Recurrent influenza is by
Antigentically different strains
Fever, rash and joint pain think of
Ortho borne viruse
Jaundice and severe paint of muscle and joint with malaise indicates
Hep B
How parvovirus presents
Rash (slapped check) and athralgia = erythema infectiosim or fifth disease
Erythema infectiosim by
Immune complex deposition
Characteristic of osteomyelitis
Bone infection causing progressive bone destruction and formation is sequestra
Chronic osteomyelitis
Bone necrosis and vascular damage
Presence of foreign materials predisposing to nidus formation
In traumatic osteomyelitis think of
S auerus and Gnb!
C perefregis can also cause
Osteomyelitis
In diabetic foot think of
Bones of foot osteomyelitis
In severe otits external think of osteomyelitis affecting the
Skull!!
Important osteomyelitis causative agents are ?
Anaerobes
Bacteroids
Mycobacterium
What causes osteomyelitis in IV drug users
Pseudomonas in spine or pelvis
Spine involved in osteomyelitis usually seen in
Adults
Severe otitis externa then fever and tenderness in skull ?
Chronic osteomyelitis
Features is chronic osteomyelitis
Sinuses Swelling Deformity Defective healing Loosening of prosthesis
Pus from infected bone can show
AFB and s. Auerus
