Community and hospital acquired bacterial infections Flashcards
what are the factors that contribute to bacterial virulence?
§ Diverse secretion systems.
§ Flagella – for movement, attachment.
§ Pili – adherence.
§ Capsule – protect against phagocytosis.
–>Streptococcus pneumoniae.
§ Endospores – metabolically dormant forms of bacteria.
–> Bacillus sp. And Clostridium sp.
§ Biofilms – aggregates of bacteria embedded in polysaccharide matrix – antibiotic resistant.
–> Pseudomonas aeruginosa and Staphylococcus epidermidis.
what are examples of exotoxins secreted by infectious bacteria?
neurotoxins- act on nerves
–>tetanus or botulinum toxins
enterotoxins- act on GI tract
- ->infections diarrhoea (cholera, e.coli)
- ->food poisoning (staphylococcus aureus)
pyrogenic exotoxins- stimulate release of cytokines
–>staphylococcus aureus
tissue invasive exotoxin- allow bacteria to destroy nd tunnel through tissue)
miscellaneous exotoxin- specific to a certain bacterium
what are endotoxins
only found in gram negative bacteria.
contained within the cell wall
Not a protein but the lipid A moiety of LPS
treating infection with antibiotics can worsen the infection as when the bacteria lyse they release large quantites of endotoxin –> septic shock
what is an outbreak of a disease??
a sudden increase in the incidence of a disease in a particular place at a particular time.
greater than normal/expected number of individuals infected
how are outbreaks identified?
§ Possible epidemic case:
–> Any person that has developed the symptoms AND has met a laboratory criteria (e.g. isolation of agent).
§ Probable epidemic case:
–> Any person that has met the above criteria AND has been in epidemic country, consumed possibly contaminated food, been in close contact with a confirmed epidemic case.
§ Confirmed epidemic case:
–>Any person meeting criteria for a possible case AND has had strain isolated.
what technique is used to detect/confirm an outbreak strain?
polymerase chain reaction
what is the difference between exo and endo toxins?
exo- protein
endo- lipid A
what are some respiratory tract infections?
Influenza
Animal influenzas, including avian influenza
SARS - Severe acute respiratory syndrome
Legionnaires’ disease (legionellosis)
Tuberculosis
what are some communicable diseases in europe?
1) Respiratory tract infections
2) Sexually transmitted infections, including HIV and blood-borne viruses
3) Food- and waterborne diseases and zoonoses
4) Emerging and vector-borne diseases
5) Vaccine-preventable diseases
6) Antimicrobial resistance and healthcare-associated infections
what is Legionella pneumophila and what is its infection route?
gram negative bacteria
in amoeba
inhalation of contaminated aerosols
what is mycobacterium tuberculosis?
gram positive bacteria (looks different as has different cell wall structure)
cell wall makes it very hard to be affected by antimicrobials as has extra lipid layer
give examples of bacteria that cause sexually transmitted infections.
Chlamydia trachomatis infection
Gonorrhoea
Syphilis
give examples of bacteria that cause food and waterbourne diseases
cholera salmonella shigellosis listeria botulin
what are 2 vector borne disease causing bacteria?
Plague
Q fever
what is an antimicrobial
interferes with growth and reproduction of a microbe
