Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GSSE path > Infectious Diseases > Flashcards

Infectious Diseases Flashcards

1
Q

Gram positive bacteria

A
  1. Stain purple
  2. Thicker cell wal
  3. Capsule and then thick peptidoglycan layer beneath this
  4. Produce exotoxins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Gram negative bacteria

A
  1. Stain pink
  2. Thinner cell envelope
  3. Have an additional outer membrane containing endotoxin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Endotoxin

A

LPS that is released upon cell wall lysis of gram negative bacteria. Major contributor to SIRS and ARDS in gram negative bacteraemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cocci

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Bacilli

A

Rod-like

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sphirocaete

A

Helical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Staph aureus morphology

A

“Bunch of grapes” clusters of gram positive cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Streptococci morphology

A

Chains of gram positive cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Neisseria meningitidis, neisseria gonnorhoea morphology

A

Gram negative diplococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Staphylococcus aureus

A
  1. Most often colonizes nose and perineum
  2. Colonizes skin in patients with inflammatory derm conditions
  3. Pus forming organism
  4. Most common infective agent in many MSK infections incl. OM, septic arthritis, discitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Staph epidermidis

A
  1. Skin commensal, usually non-virulent
  2. Most common prosthetic infective agent
  3. V difficult to eradicate- often requires removal of foreign body
  4. Coagulase negative staph- antibiotic susceptibility is unpredictable
  5. Growing fluclox resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cellulitis- common causative organisms

A

Usually anaerobic organisms, clostridial and non-clostridial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bursitis- common causative organisms

A

Gram-negative organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Necrotising fasciitis- common causative organisms

A

Most common is pyogenic strep (strep pyogenes), can also be clostridium perfringens, staph aureus, vibrio vulnificus, aeromonas hydrophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Progressive bacterial synergistic gangrene- common causative organisms

A

A mixture of organisms and usually strep pyogenes and gram-negative bacillus e.g coliform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Myonecrosis- common causative organisms

A

Clostridium species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Infected vascular gangrene- common causative organisms

A

Any organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Necrotising fasciitis- skin changes

A

Pain deceptively out of proportion to skin findings that then changes to exquisitely tender, swollen area of extensive soft tissue erythema. The disease progresses at an alarming rate changing from a shiny red-purple to a pathognomonic grey-blue with ill-defined patches within 36 hours of onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Necrotising fasciitis- signs

A

Skin changes, extreme pain that can progress to no pain in effected area as cutaneous nerves are destroyed, hard wooden feeling subcut tissues, crepitance in 30% of cases, can become extremely toxic with high fever, anxiety, altered GCS, leukcytosis, shock and tachycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Fournier’s gangrene- causes

A

Spread from perianal, retroperitoneal or urinary tract infection or following genital trauma (e.g. postpartum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fournier’s gangrene- definitions

A

Perianal and anal gangrene, spreads from scrotum and rapidly progresses to perineum and anterior abdominal wall. The testes are spared due to separate blood supplyy. Urethral obstruction can occur from excessive penile oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Most common cause of diarrhoea in hospitalised patients

A

Clostridium difficile infection. Occurs due to disturbance of normal anaerobic gut flora leading to overgrowth of c. diff. Usually secondary to borad-spectrum antibiotics e.g. cephalosporins/ clindamycin. Can occur spontaneously in underlying malignancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Clostridium tetani

A

Gram-positive with terminal spores giving the appearance of drumsticks on gram staining. Lives in soil, manure and rust. Low numbers of cases due to immunisations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Clostridium tetani infection

A

Clostridium tetani exotoxin blocks inhibitory nerve impulses by preventing GABA release. This leads to tetanic muscle spasm. Patients present with either generalised spasms (lockjaw spreading to extensor muscles) or localised- characteristic risus sardonicus smile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Treatment of clostridium tetani

A

ICU management esp for airway and ventilation, wound debridement, IV metro/benpen, tetanus immunisation, anti-tetanus immunoglobulin, muscle relaxants

26
Q

Tetanus prone wounds

A

Punctures wounds if contaminated with soil or manure, extensive tissue devitalisation, containing foreign bodies, development of sepsis, compound fractures, more than 6 hours between injury and surgery

27
Q

Clostridium perfringens

A

Gram positive, obligate anaerobe, normally part of bowel flora. Produces exotoxin that can cause soft tissue necrosis and produces gas- “gas-gangrene”

28
Q

Most common causes of infection following abdominal surgery or injury

A

Coliforms (facultative anaerobes), bacteroides fragilis. These are often minor gut flora demonstrating the disease causing abilities of these organisms

29
Q

Bacteroides fragilis

A

The most important strict anaerobic non-spore former causing clinical disease. It has a prominent capsule that inhibits phagocytosis and is involved in abscess formation. Also produces low toxicity endotoxin

30
Q

Polymicrobic anaerobe infection

A

When tissue injury occurs, there is limited blood and therefore oxygen supply- this leads to opportunity for infection with anaerobic and facultative anaerobic organisms. Often a mixed infection e.g with strep milleri (often present in abscesses)

31
Q

Infected pancreatic necrosis- causative organisms

A

Often coliforms

32
Q

H. Pylori

A

Spiral shaped gram-negative bacterium that lives in the mucous layer of stomach lining. It is microaerophilic, surviives by making urease that breaks down urea into CO2 and ammonia. The ammonia increases the local pH and enables the bacteria to survive the acidic stomach environment.

33
Q

H. Pylori treatment

A

Triple therapy: PPI, amoxicillin and clarithromycin

34
Q

Mycobacterium tuberculosis

A

Acid-fast bacillus, obilgate aerobe (hence why normally occurs in the lungs). Grows very slowly on agar, faster in liquid (2 weeks)

35
Q

Mycobacterium tuberculosis extra-pulmonary manifestations

A

Pott’s disease- spinal TB, may require surgery if spinal instability or nerve root compression. Psoas abscess “cold abscess”. Scrofula- cervical lymph node TB, can occasionally produce abscess that can sinus to skin

36
Q

Mycobacterium treatment

A

“RIPE” Rifampicin, isoniazid, pyrazinamide, ethambutol. Usually 6 month course

37
Q

Infectious causes of psoas abscess

A

Staph aureus, coliforms in secondary psoas abscess, rarely mycobacterium tuberculosis

38
Q

Neisseria Gonorrhoea- aetiology

A

Gram-negative diplococcus, sexually transmitted, most common cause of septic monoarthritis in the USA. Can also present with asymetric septic polyarthritis- knee, ankle, elbow and wrist joints. If joint aspirate and blood cultures negative- reactive arthritis

39
Q

Gonococcal septic arthritis epidemiology

A

Most common cause of monoarthritis in the USA. Young people, 3 to 4 times higher in women common during menstruation/ pregnancy.

40
Q

Reiters syndrome

A

Can occur due to gonococcal infection or GI infection e.g salmonella/ shigella. Pathophysiology is poorly understood. Triad of conjunctivitis, reactive arthritis and urethritis

41
Q

Treatment of neisseria gonorrhoea septic arthritis

A

Joint washout and cephalosporins

42
Q

Chlamydia Trachomatis

A

Most common, treatable sexually transmitted disease. Incubation period of 13 weeks, is asymptomatic in ~80% of women and ~50% of men. Can cause PID

43
Q

Fitz-Hugh-Curtis syndrome

A

Perihepatitis secondary to inflammation of liver capsule in PID causing adhesions. Often mimics ectopic pregnancy, pyelo/renal colic, cholecystitis, viral hepatitis, PE, appendicitis

44
Q

Actinomyces

A

branching, filamentous, gram-positive bacilli that are anaerobic to micro-aerophilic. May colonise the oral cavity, lower GI tract and female genital tract

45
Q

Actinomycosis

A

Subacute to chronic bacterial infection that is often polymicrobial. It is characterized by contiguous spread, suppurative and granulomatous inflammation, and formation of multiple abscesses, sinus tracts and fistulae that may discharge ‘sulphur granules’ within the pus. Commonly affects cervicofacial, thoracic and abdomino-pelvic areas

46
Q

Treatment of actinomycosis

A

Ben pen, or penicillin V. Surgical excision may be required for abscesses/ sinus tracts/ fistulae

47
Q

What type of bacteria is pseudomonas aeruginosa?

A

Pseudomonas aeruginosa is an encapsulated, gram-negative rod and a highly pathogenic, opportunistic microorganism.

48
Q

What are some virulence factors of pseudomonas aeruginosa?

A

Pseudomonas aeruginosa has several virulence factors, including phospholipase C, endotoxin, exotoxin A, pyoverdine, and pyocyanin.

49
Q

What type of endocarditis are IV drug users most at risk of?

A

Tricuspid valve/ right sided endocarditis

50
Q

Are primary or secondary lung abscesses more common?

A

Primary- 80%

51
Q

What are the characteristics of primary lung abscesses?

A

Usually as a result of aspiration and polymicrobial

52
Q

What are characteristics of secondary lung abscesses?

A

P. aeurginosa and gram negative rods are common causes

53
Q

Which organisms can cause necrotising pneumonia and lung abscesses?

A

Necrotising lung infections and abscesses are common with aggressive infections by organisms such as Staphylococcus aureus, Klebsiella pneumonia, Streptococcus pyogenes, anaerobic bacteria, and, uncommonly, type 3 pneumococci.

54
Q

What is silver nitrate stain used for?

A

Fungi e.g. pneumocystis jiroveci

55
Q

What is sudan black stain used for?

A

Identifying fat deposits in tissues

56
Q

What is Prussian blue stain used for?

A

Identifying iron deposits in tissues

57
Q

What is gram stain/ giemsa stain used for?

A

Identifying bacteria and parasites

58
Q

What are live attenuated vaccines?

A

MMR, rotavirus, nasal flu, shingle, chickenpox, BCG vaccine, Yellow fever, oral typhoid

59
Q

What are inactivated vaccines?

A

Inactivated polio vaccine, some flu vaccines, hepatitis A vaccine, rabies vaccine, japanese encephalitis vaccine

60
Q

What are toxoid vaccines

A

diphtheria, tetanus, pertussis,

61
Q

What are recombinant vaccines?

A

Heb B, Pfizer, Moderna, Astrazeneca

62
Q

What are conjugate vaccines?

A

Hib, MenC, PCV, MenACWY

GSSE path (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions