what is the most important virulence factor in N-meningicoccus? and why
the capsule, bc it is antiphagocytic
how can we classify streptococci? (hint the agar test) give ana example of bacteria for each
by hemolysis, rbc r intact on agar plate, if u put streptococci, u get 3 reactions: a-hemolytic bacteria -u get partial reduction of haemoglobin, causes greenish or brownish colour ex: viridians strepeteccoi, streptoccocus pneumonia B-hemolytic bacteria -complete lysis of RBCs -clear area surrounding the colony on agar Ex: srtepteccocus pyogenes Non-hemolytic bacteria (gamma Y) ex: enteroccous faecalis
what does pyogenic microbe mean?
Pyo>>PUS gene>>Forms pus Pus forming microbe easy!
classify staphylococcus epidermis
gram + catalase + coagulase - -normal flora of skin -infects PRODTHETIC DEVICES (heart valve, heart implant) and IV catheters by producing adherent BIOFILMS
what r some classification schemes for streptecocci? under what classification is streptococci progenies classified as?
-lancefield antigen>>method of grouping catalase-negative, coagulase-negative bacteria based on the carbohydrate composition of bacterial antigens found on their cell walls (A,B C.....) -sherman group>> whether they r.... -pyogenic -viridians -lactic STREP. Pyogenes -lancefeild A Beta haemolytic streptococcus
how does streptokinase work?
dissolves clots through conversion of plasminogen to plasmin
What creates a fuzzy appearance under the microscope when viewing a strep. pyogene?
What is most effective way of preventing MRSA infections?
Hamdwashing as a part of imfection prevention measures
What pathogen is knows as the "winter vomiting bug"
Norovirus Infection can occur at anytime of the year but 80% in winter
What characterisitc does staph. Epidermis have that allows it to adhere to prosthetic surfaces?
It produces a 'slime' (biolfim) which is an extracellurlar polysaccaride material. It is difficult to get rid of
What hcaracterisitic does C. Diff have that allows it to survive outside the host for a long time?
Formation of spores Some gram + rods undergonstructural changes to enhance their living, they produce a dormant cell called endospore within them, these endospores can be released from the original cell as FREE SPORES, these can withstand harsh environemnt and HOT places too.
what is epstein barr virus?
-can hide in immune cells to avoid detection -
which cell is first infected by epstein barr virus?
what cell does EBV subsequently infect?
infect B cells via CD 21
what type of viral infection does EBV fall into?
what is common name for EBV?
"kissing disease" Herpes-4
link btw EBV and cancer
a) burkitts lymphoma (mostly africans) -malignancy of jaw b) nasophayngeal carcinoma c) hairy leukpenia (white grey lesions in tongue) if AIDS patient is infected d) hodgkins lymphoma
how can you observe epstein barr virus in lab? what r other test can we undergo
presence of cytoxic T cells can be seen on blood smear. Paul-bunnells test-
What could be a common cause of phayngitis?
Viral 40-80% (most cases) -adenovirus -epstin barr virus -influenza virus -coomon cold virus-rhionovirus, coronavirus,RSV BACTERIAL: Group A streptecocci Fungal: Candida> vaginal thrush
Where r cervical lymph nodes common in?
Children-they often emlarge in a viral or bacterial infection
What bacteria are likely to cause Cellulitis?
what antibiotic would u give?
They are likely to be bacteria that are part of the skin commensals:
name the bacteria shown
where is this organism mostly found?
what can this bacteria cause?
Gram negative bacilli,
-LPS endotoxin>>septic shock
what is communitiy aqcuired pneumonia?
what common bacterias may lead to it?
refers to pnemuomonia in a previously healthy person, who got the infection outside the hostpital
Mary is 55 years old and presents with a two-day history of increasing cough. She has a fever of 37.8oC and a respiratory rate of 24/minute (normal 12 to 20/minute). She has normal Oxygen saturation (i.e. does not require extra oxygen). On examination she has the clinical features of pneumonia
what is the likely orgnism?
what antibiotic would u give?
Gram negative> bascilli (rod)