MICROBIOLOGY

Question 1

DESCRIBE A GRAM POSITIVE CELL

Answer 1

Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane

Question 2

DESCRIBE A GRAM NEGATIVE CELL

Answer 2

Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.

Question 3

what components can make up LPS/what is involved in it?

Answer 3

Fever, endotoxin, sepsis/septic shock

Question 4

what is the microbiome

Answer 4

micro-organisms in an associated env

Question 5

what does endogenous mean

Answer 5

always present, commensal (not harmful), part of the normal microbiome. We can have MISPLACED infections which means i goes from a non-sterile to a sterile environment eg mouth to blood! an example would be S.anginosus. Also, we can have CHANGES in infection ie introduction of antibiotics!

Question 6

what does exogenous mean

Answer 6

not the normal flora, from outside the body

Question 7

describe kochs postulates

Answer 7

present in every case of disease - ABSENT IN HEALTH. it is the germ theory of disease/the basis for demonstrating cause of disease.

Question 8

what bacteria is dominated by the oral cavity?

Answer 8

STREPTOCOCCI

Question 9

what is the virulence

Answer 9

it is the capacity of microbe to cause damage to the host

Question 10

describe the stages in a fever

Answer 10

antigen interacts with the macrophage, macrophage release cytokines into blood stream, cytokines travel to hypothalamus, increased body temp, body shivers to conserve heat

Question 11

describe the stages in sepsis

Answer 11

vessels become leaky, lower blood volume, poor oxygen perfusion to organs which shut down to help the brain, blood clotting system activates, sepsis leads to septic shock

Question 12

describe features of STAPHYLOCOCCUS

Answer 12

it is gram positive, found in moist areas like the perineum and nose. staphylococcus can cause TSS-1 (toxic shock syndrome causing antigen), coagulase adhesion, PVL-toxin.

Question 13

what can the super antigen TSS-1 cause

Answer 13

stops t cells processing antigen, overstimulation of t cells occurs, this causes a massive inappropriate immune response meaning damage to the host

Question 14

describe symptoms/onesets of toxic shock syndrome

Answer 14

fever, rash, hypotension, decreased blood perfusion into tissues, ultimately leading to death.

Question 15

what causes toxic shock syndrome

Answer 15

bacteria in the perineum, bacteria colonises to tampon, toxin is absorbed through the tampon, S.AUREUS causes it

Question 16

describe the PVL toxin

Answer 16

damages skin and deeper tissues, community associated s.areus (CASA - only casa has the PVL toxin! ), it kills leukocytes (WBC’S) - resulting in recurrent infections ie severe skin infections, necrotising fascitis - THIS CAN LEAD TO NECROTIZING PNEUMONIA

Question 17

describe nectrotizing pneumonia

Answer 17

it is spread around the body and enters the LUNGS, nectrotising means tissue death, hypoxia means death, it can cause multi organ failure due to lack of oxygen

Question 18

what are the treatment options for s.areus

Answer 18

has beta-lactamase - antibiotic needs betalactamase inhibitor

NO resistance - fluxocillin OR erythromycin - IF ALLERGY

if MRSA - vancomycin, co-amoxyclav

Question 19

describe features of STREPTOCOCCUS

Answer 19

GAS, gram positive, skin infections, caries , ORAL CAVITY DOMINATION s.pyogenes!!!

Question 20

describe features of GAS

Answer 20

beta-haemolytic (means it destroys RBC’S), it affects the bodies ability to transport 02 nutrients round the cardiovascular system - inadequate 02 to tissues!

Question 21

describe what happens during IMPETIGO, CELLULITIS, NECTOTIZING FACSITIS (GAS SKIN DISEASES)

Answer 21

impetigo is a contagious skin infection in children and it occurs superficially, it then can go deeper into cellulitis - this is deeper to skin, an influx of immune cells resulting in oedema and can spread further, painful condition. DEEPER to that we can get nectrotizing fascitis - this is extrerme pain, tissue death and destroys the connective tissue

Question 22

what are the different types of oral streptococci

Answer 22

mutans, oralis, salivarius, anginosus

Question 23

what bacteria causes whooping cough

Answer 23

BORDATELLA PERTISUS - more than 2 weeks, 100 day cough. Lt in younger, milder in older.

Question 24

what bacteria causes diptheria

Answer 24

corynebacterium diptheriae - swollen neck, causing a pseudomembrane ? This disease releases a toxin therefore we must give an anti-toxin which is a med emerg.

Question 25

describe haemophilus influenza

Answer 25

it is not viral, can cause many diseases eg pneumonia, it is spread through droplets, can spread systemically

Question 26

what type of bacteria cause caries

Answer 26

s.mutans

Question 27

describe veilonella

Answer 27

gram negative , increases with caries but it is not pathogenic as it uses lactic acid as an energy source , changing lactic acid to weaker (beneficial to us as removes it sort of)

Question 28

name other types of carcinogenic bacteria

Answer 28

lactobacilli - adheres to dentine, gram positive, it only produces LACTIC ACID, it is used to determine caries risk. actinomyces - gram positive, found supra and sub, found in root caries, difficult to remove due to its sticky network

Question 29

name the different types of supra bacteria

Answer 29

strep, actinomyces, lactobacilli and vionella (all found in plaque)

Question 30

name the different types of sub bacteria

Answer 30

strep, actinomyces, vionella, (found in supra too) prevotella, fusobacteria, porfamoris gingivalis, treponema (these are not found supra, just sub gram negative)

Question 31

describe the sokrasnky study

Answer 31

took plaque samples from patients with different levels of perio disease. analysis - this experiment identified how often the species were found together. he found 5 clusters...

Question 32

name the 5 clusters found in sokranskys study

Answer 32

red, orange, yellow, purple, green complexes (we are more focused on the red and orange studies due to it being related to deep perio pockets!)

Question 33

describe the red complex

Answer 33

this complex is associated with ACTIVE pockets and includes the bacteria - p.gingivalis, t.forsythia, t.denticola

Question 34

describe the orange complex

Answer 34

has 2 bacteria - prevotella and fusobacterium (anaerobes)

Question 35

name the black pigmented bacteria

Answer 35

porphyromonas gingivalis (part of the red complex), prevotella (part of the orange complex)

Question 36

what types of epidemiology are there

Answer 36

sporadic (infrequent), endemic (constant presence within area), epidemic (sudden, high levels), pandemic (sudden, over 2 continents, high levels)

Question 37

name the throat infections and the stages

Answer 37

strep throat - this can be either viral or bacterial. viral symptoms include no fever, a cough and a runny nose. bacterial symptoms include sudden, pain and a fever. There is a toxin produced which then results in scarlet fever. symptoms include, severe strep throat, destroys vascular tissues as RBCs leak out, there is an associated red rash. If scarlet fever is left untreated, we can get rheumatic fever. This is an auto-immune disease which attacks tissues such as heart and joints

Question 38

name some of the treatments for GAS conditions

Answer 38

Penicillin/erythromycin in children amoxycillin in children coamoxycillin if repeat infecitons

Question 39

explain the process of oral streptococci and IE

Answer 39

Pathogen gains temporary access to the bloodstream - Route is important Pathogens rapidly adhere (stick) via platelet fibrin deposition Some species obtain intracellular access Proliferation of microbes formation of vegetation Heart function impaired due to the vegetation Embolization or haematogenous spread leading to range of complications as heart is not working as it should be! - e.g. stroke, meningeal reaction, brain abscess etc.

Question 40

there are 4 components on the outer membrane of bacteria - what are they ..

Answer 40

Assymetric membrane Lipopolysaccharides (LPS) Peptidoglycan Lipoproteins

Question 41

treatment/vaccinations for whooping cough

Answer 41

vaccination policy 6in1 - UK CHILDREN the vaccination targets pertactin which kills leukocytes. -removes mucus build up antibiotics - erhythromycin can be used too

Question 42

treatment/vaccination for diptheria

Answer 42

vaccination policy 6in1 antitoxin as it is a med emergency antibiotics- penicillin/erhythromycin

Question 43

treatment/vaccination for haemophilus influenza

Answer 43

uk vaccination policy 6in1 same ab resistance - DIFF ABS FOR DIFF DISEASES

Question 44

PNEUMONIA bacteria and symptoms

Answer 44

strep. pneumoniae it is inflammation of the lungs, alpha haemolytic (partial breakdown of rbcs)

Question 45

treatment of pneumonia

Answer 45

vaccination amoxycillin, erythromycin reistance in elderly and immunocompramised

Question 46

TUBERCULOSIS symptoms and bacteria

Answer 46

mycobacterium tuberculosis productive cough, malaise, weight loss, night fever/sweats

Question 47

what are the risk factors of tuberculosis?

Answer 47

areas with vaccine policy, institutions, drug/alcohol use, homelessness, HIV/AIDS. it is very infective - only 3 min bacteria needed!!!! bacteria causing it has a waxy cell wall meaning it is protecting against antibiotics and immune system!

Question 48

what is the treatment of tuberculosis

Answer 48

a chest x ray, sputum test, skin test antibiotic cocktail for 6-9 months also a vaccination BCG - enhances macrophages to kill bacteria and IS NOW THE TARGETED POLICY!!!!!!!