bacterial pathogens Flashcards
what bacteria is MRSA?
staphylococcus aureus
what is responsible for rheumatic fever and what is a symptom?
streptococcus pyogenes and can give a fever
what does streptococcus agalactiae result in?
neonatal meningitis and pneumonia and sepsis - group B strep
what causes gonorrhoea and what is another name for gonorrhoea?
urethritis and is from steptococcus gonorrhoeae
what causes UTIs?
proteus
what is clostridium difficile?
it is antibiotic related diarrhoea, PMC
what does barrielia and leptospira result in?
barrielia - relapsing fever
leptospira - meninigitis
what do S and R in a blood culture report mean?
S means sensitive and R means resistant
what will happen to gram stain with a thick cell wall?
the cell wall will retain the gram stain - gram positive
what are the characteristics of a cell wall in a gram negative bacteria?
thin cell wall - they will contain lipopolysaccharides - fatty outer cell membrane layer
which one is more common on skin?
positive - they are more resistant to drying, negative will only survive in places with more moisture
what shape are bacilli and cocci?
bacilli are rods and cocci are circular
what are examples of virulence factors?
resistance factors or enzymes to break tissue down - they are designed to help the bacteria invade the host tissue
what does invasion depends on?
host factors, bacterial factors and opportunity (distance, exposure)
why are females more prone to UTIs?
they have a shorter urethra
why is E coli the commonest cause of UTIs?
E coli is normal flora in the bowel. It can ascend in the perineum by colonising the urethral meatus and then adheres to the urinary cells or urethral catheter equipment causing an inflammatory response and can develop resistance to antibiotics
what is the commonest form of skin and soft tissue infections and how does this occur?
S. Aureus - it adheres to damaged skin and secretes exoenzymes and toxins which can damage cells or promote the host inflammatory response such as pus. it can colonise the nasal carriages of up to 50% of people
what are some examples of diseases Staphylococcus aureus can cause?
UTIs, meningitis, pneumonia, endocarditis, osteomyelitis, septic arthritis, bacteriaemia or septicaemia
what does S aureus look like with a gram stain?
a bunch of grapes - clusters formed
what is staphylococcus epidermidis?
it is an opportunistic bacteria, commensal on skin - most people have it. It is described as a coagulase negative staphylococci