types of bacteria

Question 1

what is the most important virulence factor in N-meningicoccus? and why

Answer 1

the capsule, bc it is antiphagocytic

Question 2

how can we classify streptococci? (hint the agar test) give ana example of bacteria for each

Answer 2

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

Question 3

what does pyogenic microbe mean?

Answer 3

Pyo>>PUS gene>>Forms pus Pus forming microbe easy!

Question 4

classify staphylococcus epidermis

Answer 4

gram + catalase + coagulase - -normal flora of skin -infects PRODTHETIC DEVICES (heart valve, heart implant) and IV catheters by producing adherent BIOFILMS

Question 5

what r some classification schemes for streptecocci? under what classification is streptococci progenies classified as?

Answer 5

-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

Question 6

how does streptokinase work?

Answer 6

dissolves clots through conversion of plasminogen to plasmin

Question 7

What creates a fuzzy appearance under the microscope when viewing a strep. pyogene?

Answer 7

M proteins

Question 8

What is most effective way of preventing MRSA infections?

Answer 8

Hamdwashing as a part of imfection prevention measures

Question 9

What pathogen is knows as the “winter vomiting bug”

Answer 9

Norovirus Infection can occur at anytime of the year but 80% in winter

Question 10

What characterisitc does staph. Epidermis have that allows it to adhere to prosthetic surfaces?

Answer 10

It produces a ‘slime’ (biolfim) which is an extracellurlar polysaccaride material. It is difficult to get rid of

Question 11

What hcaracterisitic does C. Diff have that allows it to survive outside the host for a long time?

Answer 11

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.

Question 12

what is epstein barr virus?

Answer 12

-can hide in immune cells to avoid detection -

Question 13

which cell is first infected by epstein barr virus?

Answer 13

.

Question 14

what cell does EBV subsequently infect?

Answer 14

infect B cells via CD 21

Question 15

what type of viral infection does EBV fall into?

Answer 15

;

Question 16

what is common name for EBV?

Answer 16

“kissing disease” Herpes-4

Question 17

link btw EBV and cancer

Answer 17

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

Question 18

how can you observe epstein barr virus in lab? what r other test can we undergo

Answer 18

presence of cytoxic T cells can be seen on blood smear. Paul-bunnells test-

Question 19

What could be a common cause of phayngitis?

Answer 19

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

Question 20

Where r cervical lymph nodes common in?

Answer 20

Children-they often emlarge in a viral or bacterial infection

Question 21

What bacteria are likely to cause Cellulitis?

what antibiotic would u give?

Answer 21

They are likely to be bacteria that are part of the skin commensals:

Staph aureus!

Flucloxacillin!

Question 22

name the bacteria shown

where is this organism mostly found?

what can this bacteria cause?

Answer 22

E coli

Gram negative bacilli,

• large bowel
• UTI
• neonatal meningitis
• pneumonia
• LPS endotoxin>>septic shock

Question 23

what is communitiy aqcuired pneumonia?

what common bacterias may lead to it?

Answer 23

refers to pnemuomonia in a previously healthy person, who got the infection outside the hostpital

• Strep Pneumonia
• Hemophilus Influnezna

Question 24

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?

Answer 24

Haemophilus

Gram negative> bascilli (rod)

Amoxicillin