Infections On Surfaces Flashcards
(32 cards)
Name some surfaces found on a patient
Skin: epithelium, hair, nails
Muscosal surfaces: conjunctival, GI, respiratory, genitourinary
Name some viruses found on the skin (2)
Papilloma
Herpes simplex
Name some bacteria found on the skin (4), specify whether they’re gram negative or positive
Gram positive: staph aureus,
Coagulate negative staphylococci
Corynebacterium
Gram negative: enterobacteriaceae
Name some fungi that are found on the skin (2)
Yeasts
Dermatophytes
Name a parasite that can be found on the skin (1)
Mites
Why is it important to always clean the skin site before taking blood?
Because the natural fora on the skin can get into the blood culture
Give some examples of the natural flora found in the eye?
Coagulate negative staphylococci, diphtheriods, saprophytic neisseria species, viridans group streptococci
Name a bacteria that can be found in the nares (nose)
Staph aureus
What can be given prior to a cardiovascular operation to prevent infections of the wound?
Nasal antibiotics
What natural flora can be found in the nasopharynx?
Neisseria meningitidis, streptococcus pneumoniae, haemophilus influenzae
Name some infections that you can get on the external surfaces of the body (6)
Cellulitis Pharyngitis Conjunctivitis Gastroenteritis UTI Pneumonia
Name some infection that you can get on internal surfaces of the body (4)
Endovascular (endocarditis, vasculitis)
Septic arthritis
Osteomyelitis (bone infection)
Empyema (infection of alveoli in pleural space)
Name some prosthetic surfaces that may offer a site for potential infections to occur?
- intravascular lines
- peritoneal dialysis catheters
- prosthetic joints *
- cardiac valves
- pacing wires
- endovascular grafts
- ventriculo-peritoneal shunts
**bacteria can be introduced at the time of the surgery and lay dormant for months whilst there is internal conflict between the host immune system.
What bacteria is most likely to be the cause of pacemaker endocarditis?
Coagulative negative staphylococci
What organism is likely to be the cause of native and prosthetic valve endocarditis >1 year post-operation? (5)
Viridans streptococci Enterococcus faecalis Staph aureus HACEK group Candida
What is the organism likely to cause prosthetic valve endocarditis <1 year post-operation?
Coagulate negative staphylococci
What are the two most likely organisms that will cause prosthetic limb infections? (2)
Coagulase negative staphylococci
Staphylococcus aureus
What are the likely organisms that cause Cardiac pacing wire endocarditis? (2)
Coagulate negative staphylococci
Staphylococcus aureus
What are the 4 stages of pathogenesis of infection at surfaces?
1) adherence to host cells or prosthetic surface
2) biofilm formation
3) invasion and multiplication
4) host response (pyogenic/granulomatous)
What do bacteria have to help them adhere to surfaces?
Pili
What is a biofilm?
A thick slim layer which can help protect bacteria against attack and host defence.
*aggregated cells can become detached, or roll or ripple along the surface and remain in their protected biofilm state
**although antimicrobial damages out cells, the biofilm community is resistant
What is quorum sensing?
Quorum sensing is a system of stimuli and response correlated to population density. Quorum sensing (QS) allows bacteria to restrict the expression of specific genes to the high cell densities at which the resulting phenotypes will be most beneficial. Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population.
What does a biofilm contain?
Proteins, nucleic acids, polysaccharides
What does quorum sensing control?
- sporulation
- biofilm formation
- virulence factor secretion
