What is sepsis?
blood poisoning causes by bacteria, overreaction of the immune system due to septicaemia
What are the symptoms of sepsis?
slurred speech or confusion
fever/loss of appetite
extreme shivering
passing no urine all day
severe breathlessness
skin mottles or discolouration
blue skin/ lethargy
Where does sepsis come from?
bacterial infection -> bacteraemia (gets into bloodstream and disseminates) -> sepsis
When should the first blood culture be taken?
post fever spike before antibiotics are administered
should be repaid every 24hrs until clear
What are the blood culture bottles for adults?
- 1 FN Anaerobic blood bottle
- 1FA Aerobic blood bottle
Which blood bottle is used for children?
1 x PF Plus blood culture bottle
Why shouldn’t blood culture bottles be refrigerated?
it can kill any bacteria that we needed to identify
Which machine is used to measure bacterial growth and what happens when it detects positive?
BacTec
immediately alerts the ward to a sportive culture -> BMS must process the positive within 2 hours
what tests are done after the BacTec tests positive?
- add a drop to a blood agar plate and quadrant streak
- add a drop to a fastidious anaerobe agar and quadrant agar and quadrant streak
- incubate the plate
- heat fix and gram stain
What happens after the gram stain is positive?
- second blood agar plate with optochin disc is set up (using staph aureus select agar) -> zone of inhibition means positive result = may be strep pneumoniae
- Tube coagulase test is done if there is a positive staph aureus result
What happens if the gram stain is negative?
- chocolate agar = differentiates between meningitis and influenza
- macConkey agar = differentiates between E. coli (lactose fermenter) and Salmonella (non lactose fermenter)
-Neomycin plate= identifies anaerobic bacteria
Describe how Staph Aureus causes bacteraemia
- enters bloodstream from infected site in the body
- causes infected lesions in skin
- causes abcesses in tissues or organs
- infected joints
- Pneumonia with S Aureus leads to septicaemia
- S Aureus bacteraemia indicates source of infection elsewhere in the body
Which test can differentiate between different strep variations?
the lance field test: bacterial sample is mixed with specific antibodies that bind to group specific carbohydrate antigens, if antibodies bind to the bacteria this indicates a positive result for that group
Which lance field group is streptococcus pyogenes from?
group A
Which lance field group is streptococcus agalactiae from?
Group B
What conditions can E.Coli cause?
-UTI’s: mainly affects immunocompromised individuals such as the elderly
What does the presence of Neisseria Meningitidis indicate?
- septicaemia with the possibility of meningitis
- has a serious and rapid clinical progression
-requires aggressive antibiotic therapy
What are the characteristics of Candida albicans?
- fungal bacteraemia
- common in immunocompromised individuals, elderly
- BS antibiotics may predispose candida infections
-cytotoxic therapy for cancer may damage gut mucosa and allow candida to move from bowel to bloodstream - some candida species are resistant to antifungals
What is polymicrobial bacteraemia?
- where 2 or more significant organisms are isolated
- usually associated with serious underlying illnesses
What can salmonella spp cause?
biliary sepsis in cases of severe food poisoning = enteric fever, needs rapid diagnosis and treatment
what do all non lactose fermenting, oxidase negative, gram negative bacilli isolated bacterium need to be checked for?
salmonella spp
Why is enterococcal septicaemia problematic to treat?
due to limited therapeutics
