Immune Defense Against Bacterial Infections Lec Flashcards
are involved in
protecting the body against foreign materials, including
Bacteria.
Both innate and adaptive immunity
Innate immunity is also known as
Natural immunity
a nonspecific
immunity (naturally occurring) wherein it has a
standardized response to all antigens. It lacks
memory.
Innate immunity
Innate immunity Common examples are
exogenous and
endogenous materials
Defense mechanism against invading
microorganisms
Physical barriers
Physical barriers The portal of entry of the microorganisms are
the
Mucus membrane
serves as our physical barriers to that
particular invading microorganism
Skin
is the hydrochloric acid
within our stomach that serves as a prevention
of bacterial growth through the digestion
process
Endogenous material
Enzyme found in secretions such as tears and
saliva and is capable of destroying bacteria
Lysozymes
Other soluble innate components that protects
us from the pathogenic bacteria:
interleukines,
Prostaglandins, and Leukotrienes
Acute phase reactants such as
C-reactive protein,
haptoglobin, and ceruloplasmin
which either
coat bacteria or remove substances that might
promote bacterial growth
C reactive proteins, haptoglobin and ceruplasmin
are mainly involved in the
inflammation.
Acute phase reaction
is a polypeptide that acts to APRs.
They are mainly involved in the triggering
factors of the other activities of the cell.
Cytokines
process is
enhanced by the activation of the alternative
complement cascade
Phagocytosis
is the cell eating cell
Phagocytosis
It is triggered by the microbial cell walls or
other products of the microbial metabolism
Phagocytosis
are
cellular defense mechanisms that are mainly
involved in the process of Phagocytosis
Neutrophil, macrophages and monocytes
Adaptive immunity Also called
Specific immunity or acquired immunity
The secondary response is better than the primary
response because it has memory B cells.
Adaptive immunity
The mechanism of the adaptive immunity
memory of B cell
Defense mechanism against the extracellular bacteria
occurs
Adaptive immunity
Against exotoxins
and other secreted bacterial products
Antibody production
Activation of Classical pathway
Cell lysis
is the formation of membrane attack complex
and the end result is cell lysis
MAC
other branch of a specific
immune response and helpful in attacking intracellular
bacteria such as Mycobacterium tuberculosis,
Legionella pneumophila , Listeria monocytogenes and
Rickettsia species
Cell mediated immunity
Cell Mediated Immunity other branch of a specific
immune response and helpful in attacking intracellular
bacteria such as
Mycobacterium tuberculosis
Legionella pneumophila
Listeria monocytogenes
Rickettsia species
Production of _________ as by product can aid to enhance phagocytosis
opsonin’s
Three main mechanisms:
OPPOSING IMMUNE RESPONSE
- Avoiding antibody
- Blocking phagocytosis
- Inactivating the complement cascade
Bacteria that can perform this mutation.
Streptococcus agalactiae
Streptococcus pyogenes
is capable of graph rejection
Major histocompatibility complex
Different microorganisms that can cleave the IgA2:
a. Neisseria gonorrhoeae
b. Haemophilus influenza
c. Streptococcus sanguis
inhibition of several stages in phagocytosis
Blocking phagocytosis
is towards the stimulus
positive chemotaxis
is away from the stimulus
Negative chemotaxis
can inhibit the
release mechanism of chemotactic factors
Neisseria gonorrhea
M protein. A
group A streptococcus, inhibition of
adhesion
Streptococcus pyogenes
Encapsulated bacteria
Neisseria meningitides
Streptococcus pneumoniae
Yersinia pestis
Haemophilus influenzae
Klebsiella pneumoniae
inhibition of phagolysosome
formation
Mycobacterium tuberculosis
Mycobacterium leprae
Salmonella spp.
has Leukocidin that will block the
process of phagocytosis
Staphylococcus
Listeria monocytogenes has
Listeriolysin O
Streptococcus has
Streptolysin
do not bind the
complement component C3b
Encapsulated bacteria
important in
enhancing phagocytosis
C3b
takes part in the complex form of alternative
classical and elected pathway
C3b
are gram-positive spherical, ovoid, or
lancet-shaped organisms that are catalase negative and
are often seen in pairs or chains.
Streptococci
Streptococci are divided into groups or
serotypes/serogroup on the basis of certain cell wall
components.
Serotype/Serogroup
Group-Specific Carbohydrate
Serve as the virulence factor for the streptococci
through M and T protein
Serotype/serogroup
Outermost cell wall components contains two
major proteins known as the M and T protein.
Serotype/Serogroup
Interior to the protein layer is the group-specific
carbohydrate that divides streptococci into 20
defined groups, designated A through H and K
through V.
Group-Specific Carbohydrate
Group A
Streptococcus pyogenes
Group B
Streptococcus agalactiae
Group C
Equisimilis
Streptococcus equi
Streptococcus dysagalactiae
Streptococcus zooepidemicus
Group D
Streptococcus bovis
Enterococcus faecalis,
Enterococcus faecium,
Enterococcus durans
is one of the most
common and ubiquitous pathogenic bacteria and
causes a variety of infection.
Streptococcus pyogenes
is the major virulence factor of the
group.
M protein
responsible
for the rash seen in scarlet fever and also appear
to contribute to pathogenicity.
Pyrogenic exotoxins A, B, and C
Production of enzymes also add to its virulence factor.
These includes:
Exoenzymes
The most diagnostically important antibodies are the
following:
Anti-streptolysin O (ASO), anti-DNase B,
anti-NADase, and anti-hyaluroni dase.
Presence of these antibodies is an indication of Group
A streptococcus infection and is seen in many
conditions/ disease like
Scarlet fever
Acute glomerulonephritis
Acute Rheumatic fever
Necrotizing fasciitis
streptococcal toxic shock syndrome
Employs the principle of Passive agglutination.
ASO AGGLUTINATION TEST
is the indirect type of the
agglutination
Passive agglutination
is accompanied by a carrier particle
Antigen
Significant titer: Aso
adult: 240 Todd unit or 240 IU/mL
Children: 320 Todd units or 320 IU/mL
Anti-streptolysin O agglutination test Replaced by
Nephelometry
Antigen Reagent:
Streptolysin
Reacts with patients Anti-Streptolysin
Precipitation
indicative of Streptococcal
glomerulonephritis
Anti-DNAse
ANTI-DNASE B TESTING May also be detected in
Acute rheumatic
fever
Normal Titer anti-DNAse B testing
children between the ages of 2
and 12 years range from: 240 to 640 units.
Presence of DNase is measured by its effect on a DNA
methyl-green conjugate (another reagent).
DNAse neutralization
Complex color of intact form
Green
when hydrolyzed by DNase, the methyl green is reduced and becomes
Colorless
DNAse neutralization test An overnight incubation at temperature
37C
The result is reported as the reciprocal of the
highest dilution, demonstrating a polar
intensity of between
2 and 4
Can be considered as a screening test and the
principle behind it is the passage agglutination
Slide Agglutination Test/ streptoenzyme testing
Strepto enzymes Detects antibody to
streptolysin, streptokinase,
hyaluronidase, DNase, and NADase
Sheep red blood cells coated with
streptolysin,
streptokinase, hyaluronidase, DNase, and
NADase.
Non specific test
STREPTOZYME TESTING
This gram-negative, microaerophilic spiral bacterium
is the major cause of both gastric and duodenal ulcers.
Helicobacter pylori
Helicobacter produce enzyme
Urease
If untreated, H. pylori infection will last for
the patient’s life and may lead to
Gastric carcinoma
Chronic stage in H. pylori is
Immunoglobulin G
Early and acute infection in H. pylori is
Immunoglobulin M
Helicobacter pylori Detection
Cultivation, histologically examining
gastric biopsy tissue, performing a urease biopsy test,
urea breath testing,
Helicobacter pylori Detection of antibodies
IgG
Method of choice in detecting antibody of helicobacter pylori
Enzyme linked immunosorbent assay
It is more specific and sensitive test for helicobacter pylori
Enzyme linked immunosorbent assay
remains the most commonly acquired
spirochete disease in the United States.
Syphilis
Syphilis infection Also associated with
Borellia and leptospira species
The causative agent of syphilis is
Treponema pallidium subsp. Pallidium
the agent of yaws
Treponema pallidum subsp. Pertenue
the cause of
nonvenereal endemic syphilis
T. pallidum subspecies endemicum
Mode of transmission
Congenital infection
can also occur during
pregnancy.
Congenital infection
Syphilis Easily destroyed by
Heat cold and dry
1st stage: Formation of Chancre → develops ________ day after infection AKA “primary Syphilis”
10-90
days
1st stage: Formation of Chancre → develops 10-90 days after infection AKA “_________________”
primary Syphilis
1st stage of syphilis
Formation of chancre
1st stage of syphilis could be seen
Mouth, genital area and lesion
1st stage May give positive result to
Direct detection (immunofluorescent assay)
2nd stage: Symptoms of the secondary stage include generalized give atleast 2-3
Enlargement lymph nodes
malaise
fever
pharyngitis
rash on the skin and mucous membranes
A stage of syphilis that is Systemic dissemination of microorganism and the primary lesion may still be present
2nd stage
Patients are noninfectious at this time,
with the exception of pregnant women, who can pass
the disease on to the fetus even if they exhibit no
symptoms.
Latent stage
Latent stage also known as
Latent syphilis
Stage of syphilis that is Vertical transmission follows the disappearance of
the secondary syphilis, lack of clinical symptoms
Latent stage
This stage appears anywhere from
months to years after secondary infection
Third stage
3rd stage This stage appears anywhere from
________to _______ (timeline) after secondary infection
months
years
3rd stage Typically, this occurs most often between ______ to. _________ years
10 to 30 years
Tertiary syphilis has three major manifestations:
Gummas/ Gummatous syphilis
Cardiovascular disease
Neurosyphilis
more
severe than chancre, localized area of
granulomatous inflammation often found in
bones, skin or subcutaneous tissue
Gummas
it appears anywhere from
months to years after the secondary infection
Tertiary syphilis
Traditional laboratory tests for syphilis can be
classified into three main types:
Direct detection of Spirochetes
Nontreponemal serological test
Treponemal Serological Test
Fluorescent labeled antibody
Direct and indirect immunofluorescence assay
Fluorescent labeled antibody
Direct and indirect immunofluorescence assay
which
detect antibody to cardiolipin, have
traditionally been used to screen for syphilis
because of their high sensitivity and ease of
performance
Nontreponemal serological test:
Specific type
of precipitation that occurs over a
narrow range of antigen
concentrations.
Flocculation
Examples of Non-Treponemal Test:
VDRL, RPR, TRUST, USR, RST
Non-Treponemal Test most widely used
VDRL (Venereal disease research laboratory) AND RPR (rapid plasma reagent)
Detecting the treponemal antibodies
Treponemal Serological Test
Other test for treponemal testing
Fluorescence Treponemal Antibody Absorption
Test (FTA-ABS)
Is both a qualitative and quantitative slide flocculation
test for serum and spinal fluid.
Venereal disease research laboratory
VDRL sample of choice
Serum
Serum is the sample of choice
50 ul /0.05 mL
How to Inactivated Serum in VDRL
heating serum for 56o C for 30
min.
The reagent (antigen) is consist of :
0.03% cardiolipin
0.9% cholesterol
0.21% lecithin
The reagent (antigen) is consist of :
0.03% cardiolipin
0.9% cholesterol
0.21% lecithin
VDRL antigen via a dropper
Hamilton Syringe
diameter ring for VDRL
14 mm
For serum VDRL: rpm and mins
180rpm
for 4 minutes
For CSF VDRL: rpm and mins
180 rpm
for 8 minutes
Tests must be performed at room temperature within
the range of
23C to 29C
VRDL two-fold dilutions of serum ranging that initially used
1:2 and 1:32
Qualitative Serum VDRL syringe used
HAMILTON SYRINGE
Qualitative Serum VDRL: uses a gauge
18 gauge
Hamilton syringe Could deliver a drop for atleast
1:60 or 60
Hamilton syringe: If the delivery is off by more than (drops)
2 out of 60
VDRL Quantitative Serum VDRL: uses a gauge of
19 gauge
Quantitative Serum VDRL: It can accommodate a drops for about (19 gauge)
75 drops
Quantitative Serum VDRL: other gauge may use
23 gauge
Quantitative Serum VDRL: It can accommodate a drops for about (23 gauge)
100 drops per mL
CSF VDRL: use gauge
21 or 22 gauge
CSF VDRL: Appropriate volume of drops (21 or 22 gauge)
100 drop/mL
CSF VDRL: Appropriate volume of drops (21 or 22 gauge)
100 drop/mL
Remarks OF FLOCCULATION: reactive
MEDIUM TO LARGE
CLUMPS
Remarks of flocculation: WEAKLY REACTIVE
Small clumps of
Remarks of flocculation: non reactive
NO CLUMPS OR SLIGHT
ROUGHNESS
Modification of VDRL which involves macroscopic
agglutination.
Rapid plasma reagent
Rapid plasma reagent containing antigen suspension
Cardiolipin
Rapid plasma reagent formation of
Black floccules
RPR Specimen is about
50ul or 0.05 ml
Reagent that can inactivate the
complement of RPR
Chloride
Gauge use for RPR
20
Rpr gauge Can accommodate
60 drops/ml
diameter ring for RPR
18 mm
diameter ring for RPR
18 mm
Time and speed RPR:
100rpm 8mins
an indirect fluorescent antibody test.
Fluorescence Treponemal Antibody Absorption
Test (FTA-ABS)
Used to inactivated patient serum
is incubated with a sorbent consisting of an
extract of nonpathogenic treponemes
Heat
removes the cross strain activity with
treponemes other than Treponema pallidum
Reiter strain
Slides used for this test have the ____________ of T. pallidum fixed to them.
Nichols strain
FTA-abs meduim is applied, and coverslips
are placed on the slides.
Mounting medium
Type of Agglutination test used for RPR
Passive hemagglutination test
short rods, or coccobacilli,
that are obligate, intracellular, gram-negative
bacteria.
Rickettsiae and coxiella
is translated via inhalation and
contact through fomites or ingestion of
contaminated milk
Coxiella burnetti
Rickettsiae has two distinct group
Spotted Fever group (SFG)
Typhus group (TG)
transmitted through a
fleas/lice/mites/tick bite.
Vector Borne Disease
SEROLOGICAL DIAGNOSI rickettsia
Weil-felix agglutination test
Rickettsia Significant titer is
160
More sensitive and specific test of rickettsia
Immunofluorescence assay, immunoperoxidase assay, enzyme linked immunosorbent assay