Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Inflammation > Bacterial Infection > Flashcards

Bacterial Infection Flashcards

(67 cards)

Start Studying
1
Q

What is gram negative bacteria

A

has LPS (O polysaccharide and lipid A). Peptidoglycan gives cell wall strength. Porin mutation allows antibiotic resistance.

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

What is gram positive bacteria

A

has teichoic acid in cell wall. Lipoteichoic acid is anchored in cell membrane (activated in immune system).

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

What are characteristics of gram +

A

survive well on drying, some produce spores (Clostridium, bacillus), produce exotoxins, have teichoic acids in their cell wall

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

What are characteristics of gram -

A

do not survive drying, no spores, have endotoxin in their cell wall

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

What is ZN stain used for

A

Mycobacterium

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

What is S. aureus

A

Skin, soft tissue and wound infection. Bloodstream infection which can lead to endocarditis. Infection of bone, causing osteomyelitis and joints, causing septic arthritis.
Pneumonia, especially following influenza
Produces numerous exotoxins - enterotoxins cause food poisoning; toxic shock toxin - staphylococcal toxic shock
Identified by golden colonies on blood agar. Positive coagulase reaction-plasma clot produced - convert fibrinogen to fibrin.

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

What is streptococci

A

Gram positive. Occurs in pairs and chains. Many different species - normal flora at various body sites - oral cavity, gut, genital tract
Several medically important species show beta haemolysis on blood agar.

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

What is Group A strep (beta)

A

Streptococcus pyogenes (sore throat, impetigo, cellulitis)

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

What is Group B strep (beta)

A

Streptococcus agalactiae (neonatal sepsis - carried in the vagina)

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

How is strep classified

A

Alpha-hemolytic species cause oxidization of iron in hemoglobin molecules within red blood cells, giving it a greenish color on blood agar. Beta-hemolytic species cause complete rupture of red blood cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is oral strep

A

Oral streptococci often alpha haemolytic and may be referred to collectively as viridans streptococci.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are clostridium species

A

Anaerboic spore forming gram positive rods

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

What are bacillus species

A

Aerobic spore former

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

What are corynebacterium diphtheria and listeria sp

A

Non spore forming gram positive rods

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

What is pseudomonas aeruginosa

A

Pseudomonas aeruginosa - aerobe; environmental organism; likes moist areas
Bloodstream and UTI; important cause of HCAI in immunocompromised patients

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

What is haemophilus influenzae

A

Commensal of throat but also causes OM, sinusitis, pneumonia

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

What are Neisseria species

A

Gram negative cocci

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

What are enterobacteriaceae species

A

facultative anaerobes - some are normal flora of the human colon
E coli, Kiebsiella, Proteus, Salmonella,
Gram negative rods

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

What is legionella

A

Gram negative - Environmental organism causing pneumonia. Lives inside fresh water amoebae.

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

What is the sepsis contiuum

A

Infection -> SIRS -> Sepsis syndrome (SIRS with a presumed or confirmed infectious process) -> Severe sepsis

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

What does sepsis cause

A

Sepsis causes endothelial injury. Increases inflammation. Increases coagulation. Decreases fibrinolysis.

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

What is SIRS

A

2 or more of
Temperature over 38 or less than 36. Heartrate over 90. Respiration over 20/min. WBC over 12,000/mm^3 or less than 4,000/mm^3

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

What is sepsis syndrome

A

Sepsis with >1 of organ failure:

  • CV (leads to shock)
  • Renal
  • Respiratory
  • Hepatic
  • Hematologic
  • CNS
  • Unexplained metabolic acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is severe sepsis

A

Sepsis with acute organ dysfunction (including hypoperfusion and hypotension) caused by sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is septic shock
Sepsis with persistent or refractory hypotension (circulatory collapse in surgical patients thought to have normal blood volume but cannot maintain adequate circulation)
26
What microbacteria cause shock
Endotoxin (LPS) - Gram negative Lipoteichoic Acid - Gram positive Direct - vascular endothelium Indirect: TLR, complement cascade, coagulation cascade, depletion of protein C
27
What are super antigens
Super antigens can bring T cells with MHC II without APCs. Much higher inflammatory response. Much quicker. E.g. Group A strep, Staph aureus TSST-1
28
What's the management of sepsis
Fluids, dopamine, transfusion Resolution of precipitating problems Monitoring of: blood gases, Glasgow coma score, renal function, LFTs, CNS, myocardial function Antimicrobial
29
What is the management of community acquired infection
Origin unknown or gut, renal or binary: Co-amoxiclav (Augmentin - covers gram positive) + gentamicin. Add vancomycin if MRSA. Cefuroxime + metronidazole (covers anaerobes) + gentamicin Ciprofloxacin (covers gram negative) + metronidazole + gentamicin (gram negative) Covers a large group of bacteria
30
What is the management of skin/soft tissue infection
Flucloxacillin + penicillin. Add gentamicin (Add clindamycin if Group A strep or Staph aureus toxic shock)
31
What is the management of pneumonia
Co-amoxiclav + doxycycline OR Cefuroxime + erythromycin
32
What is the treatment of malaria
Quinine
33
What is the alternative if px has penicillin or cephalosporin allergy
ciprofloxacin, vancomycin, erythromycin
34
What is used to treat hospital acquired infection shock
use gentamicin + piperacillin-tazobactam MRSA (Vancomycin) ESBL positive GNR i.e. highly resistant GNR (Meropenem, Colistin), VRE - vancomycin resistant enterococci (Linezolid and others)
35
What are the examination findings of infection
High index of suspicion if recent tropical travel or immunodeficiency Examination findings: fever (or hypothermia - especially in elderly), local evidence of inflammation e.g. red/swollen leg (cellulitis), red throat, enlarged lymph nodes (arms, inguinal, back of knees, neck), signs of sepsis (fast pulse, rapid breathing, low blood pressure, confusion)
36
Disease and travel
Africa - malaria common Asia - typhoid common SE Asia - dengue virus common
37
What is the incubation for falciparum malaria
Minimum 7 days from mosquito bite -> symptoms. Usually less than 1 month from return to onset of illness
38
What is the incubation period for dengue fever
less than 10 days
39
What is Pneumocystis jirovecii
The causative organism of Pneumocystis pneumonia, esp in immunocompromised px
40
What is meningitis
Inflammation of the meninges
41
What is acute bacterial meningitis
Purulent inflammation of the meninges surrounding the brain and spinal cord caused by bacterial infection
42
What is the pathogenesis of acute bacterial meningitis
Organisms usually enter via the bloodstream | Direct spread of contiguous parameniogeal focus e.g. sinusitis, otitis media (inflammatory diseases of the medial ear)
43
What are the likely causative meningitis agents in neonates
Early onset: S. agalactiae (group B Streptococcous) - acquired from maternal reproductive system. E Coli or other gram negative bacilli, L monocytogenes
44
What are the likely causative meningitis agents in infants and children
N. meningitidis (meningococcus), S. pneumoniae (pneumococcus)
45
What is the likely causative meningitis agent as the px gets get older
patients are more susceptible to pneumococcus | Viral meningitis common in 20-40 year olds
46
What are the symptoms of meningitis
fevers, altered mental state, neck stiffness, headache, nausea, vomiting, lethargy/irritability/reduced feeding, photophobia Classic triad of fever, altered mental state and neck stiffness Clinical features cannot distinguish between viral and bacterial meningitis. Old people less likely to present with neck stiffness
47
What is the gold standard of meningitis diagnosis
: Examine CSF through lumbar puncture
48
What are CSF findings for meningitis
CSF opening: raised intracranial pressure Turbid Raised CSF WCC CSF protein is raised CSF/plasma glucose ratio is very low Neutrophils differential count WBC may be normal especially in early infection. CSF may be lymphocytic in early stages of bacterial meningitis, if antibiotics given prior to LP, in Listeria monocytogenes or Leptospiral infection.
49
Where does meningococcus often colonise
Meningococcus often colonises the throat. Can invade the bloodstream and enter CNS in some people
50
What is likely causative organism of meningitis when a rash is present
N. meningitides is causative in 92
51
What is meningococcal sepssi
Endotoxins ->Inflammatory response Widespread vasodilation, myocardial damage, and intravascular coagulation causes CV shock Vessel damage leads to haemorrhage into tissues (e.g. petechial rash)
52
What is pneumococcal vaccination
Prevenar
53
What are the red flag symptoms of meningitis
limb pain ,cold hands and feet or pale and motted skin. Sepsis Limb pain - highly specific for meningococcal. Younger: drowsy, fast/laboured breathing, diarrhoea Older children: thirst
54
What is miliary TB
wide dissemination into the human body and has tiny lesions. Typically occurs in immunocompromised patients. Don't have CD4 cells to cause cavitating TB. Arrest at multiple granuloma stage.
55
What is spinal TB
typically evolve in adjacent thoracic bodies. Leads to collapse of spin (Pott's diseases of the spine)
56
What do M avium/intracellulare, M kansaii, M xenopi, M malmoense cause
Resp disease
57
What do M fortuitum/absecessus/chelonae cause
skin and soft tissue infection related to indwelling devices/respiratory
58
What does M marinum cause
SSTI (fish tank granuloma)
59
What are nosocomial infections
New symptoms and signs of infection appearing >48 hours after admission which had not been present on admission.
60
What are the commonest HCAI
Lower respiratory tract infection (usually pneumonia) - causes 34% of all HCAI and 57% of HCAI in patients in intensive care UTI Surgical site GI infection: inc. C. dif and hospital acquired norovirus Bloodstream infection
61
What is C.dif
Ubiquitous in nature Gram positive spore forming bacilli; produce exotoxins with diverse effects Spores are resistant to heat, drying, freezing, UVl light and many disinfectants
62
What does s. aureus cause
Cellulitis, infection of traumatic and surgical wounds, impetigo Upper respiratory tract infections - sinusitis, ottis media Lower respiratory tract infection - pneumonia secondary to influenza infection Severe deep seated and systemic infection: osteomyelitis and septic arthritis; bloodstream infection and endocarditis Toxin mediated diseases: staphylococcal toxic shock; food poisoning
63
What is the treatment of MRSA
MSSA can be treated with anti-staphylococcal penicillin such as flucoaxcillin MRSA has mecA gene encoding altered penicillin binding protein ,pbp 2 Altered pbp has low affinity for all beta lactams - penicillin, cephalosporin, carbapenems, including beta lactamase inhibitor combinations such as co-amoxicalv Frequently resistant to other abx classes - macrolides, tetracycline Glycopeptides such as vancomycins
64
What is VRE
VRE: vancomycin resistant enterococci | Gram positive cocci, part of normal gut microflora
65
What does VRE cause
UTI (usually in structurally or functionally abnormal urinary tract), as part of polymicrobial infection in intraabdominal sepsis, bloodstream infection and increasingly important cause of endocarditis
66
How is VRE transmitted
Unwell patients acquire skin colonisation as well as gut and other sites and contaminate their local environment. HCW hands. VRE survives well in the environment - mode of transmission. Resistant to vancomycin and usually teicoplanin. May require oxazolidinone abx linezolid and strains resistant to linezolid are also reported
67
What is norovirus
ssRNA virus of the family Caliciviridae Sudden onset of vomiting and diarrhoea Recovery within 48-72 hours Very common in the community, especially in winter Small infective dose - may be as low as 100 virus particles and vomit contains many millions

Inflammation (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions