Brainscape's Knowledge GenomeTM

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


See full index

BDS3 BAMS Microbiology and Oral Pathology > Role of Microbiology Lab > Flashcards

Role of Microbiology Lab Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

role of microbiology lab

A

diagnosis of infections performed by the laboratory has two important functions:

  • clinical
  • epidemiological

Clinical and epidemiological role of the microbiology laboratory are very much connected: knowledge of an infective microbe in a patient helps find its source and route of transmission and prevent the spread to other patients.

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

clinical role of microbiology lab

A
  • Diagnosis of infection in an individual patient for everyday management of infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

epidemiological role of microbiology lab

A
  • Support for infection prevention and control in searching for source and route of transmission of HAI
    • Bigger picture – drives infection control and prevention measures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

6 minimal requirements for microbiology services

A
  1. set up insider the facility
  2. available every day, including sundays and holidays
  3. able to examine different clinical specimens
  4. identify common bacteria and fungi to species level
  5. perform susceptibility testing using disc-diffusion methodology/broth microdilution
  6. perform basic phenotyping
  • serotyping
  • biotyping

Every microbiology laboratory has to have quality assurance procedures and a microbiologist with good communication skills.

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

if not possible to have microbiology service set up within facility

A

negotiate a contract for diagnostic microbiology with the nearest laboratory

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

operating times of microbiology lab

A

24 hours, every day

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

every microbiology lab MUST

A

have quality assurance procedures and a microbiologist with good communication skills.

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

e.g. clinical samples variety which lab needs to be able to examine

A

blood, cerebrospinal fluid, urine, stool, wound exudate or swab, respiratory secretions, and perform basic serological tests (HIV, HBV, HCV)

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

e.g. organisms ID by serotyping phenotyping

A
  • Salmonellae, Shigellae, P. aeruginosa, N. meningitidis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

e.g. organism ID by biotyping phenotyping

A

S.typhi

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

3 things microbiology lab should be able to determine

A
  • what the species is
  • what it is senstive to
  • any differences between the species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how to send sample and grow it

A
  • appropriate device (sheath) to microbiology lab*
  • Most organisms from clinical samples grow well on blood agar (non-selective)*
  • place in incubator (generally 37o), looking for single colonies – take colony and spread over agar dish with antibiotic disc to see if a zone of inhibition forms*
  • Obligate anaerobes – grow without oxygen – need to get to lab quickly or they will die*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

issue with obligate anaerobes

A

grow without oxygen

need to get to lab quickly or they will die

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

what clinical sample would be taken for an abscess

A

pus

  • Insert needle into abscess and withdrawing the pus*
  • Tends to be anaerobic organisms in pus – need to get specimen to lab quickly as organism may die*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

diagnosis should be

A

rapid and accurate to the species level wherever possible

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

4 methods of diagnosis

A

classical bacteriological methods

sensitivity testing

antibody detection

molecular methods

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

3 classical bacteriological methods of diagnosis

A
  • Direct smear – pseudomembranous candidiasis
  • Culture
  • Antigen detection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

sensitivity testing for diganosis helps determine

A

if pt non compliance or organism resistant

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

antibody detection useful

A

in later stages of infection

not very useful in early stages of infection as none developed

e.g. viruses – COVID, hepatitis – indicator of active infection

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

molecular methods use

A

Rarely used in routine work for the diagnosis of bacterial HAI – expense

  • Limitation is that culture is important – to enable sensitivity tests for HAIs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why do we need to know the aetiology of infection ASAP in HAIs

A

we can give to the patient targeted antimicrobial therapy – in that case patient’s causative agent will be eradicated earlier

so he/she will stop to be a source for other patients earlier than if the therapy would be unsuccessful

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

when is antibody detection useful

A

only in some viral diseases when we can detect IgM

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

who can give advice to ward staff about collection and transport of specimens

A

labratory staff

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

6 stages in simplified scheme for bacterial identification

A
  • specimen
  • direct examination
  • culture
  • pure culture and identification of species
  • species name established
  • typing or fingerprinting for taxonomic or epidemiological purposes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

specimen collection involves

A

stating site of origin

collection correctly

transport correctly to labratory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

direct examination involves

A

microscopy

  • wet film and gram stain
  • smell
  • gross appearance
  • types of bacteria and other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

culture involves

A

plate culture

  • non selective or selective mediu
  • gaseous enviroment - aerobic, anaerobic, microaerophillic, CO2
  • quantitive or non-quantitive
  • enrichment broth culture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

pure culture and identification to species involves

A

colonal morphology

  • microscopy
    • wet film for observation of motility and spores and gram stain for gram reaction and cell morphology
  • biochemical (metabolic) tests
    • traditional or commercial ‘kit’

a.k.a APIs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

typing or fingerprinting for taxonomic or epidemiologycal purposes involves

A

serological, phenotypic and genotypic methods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

2 shapes of bacteria

A

cocci

rods (bacilli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

cocci

A

round, grape like

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

rods (bacilli)

A

length of bacteria

33
Q

gram positive bacteria features

A

thick peptidoglycan wall

34
Q

gram negative bacteria feature

A

thin peptidoglycan wall

35
Q

gram +ve Vs gram -ve

A

gram +ve has a thick peptidoglycan wall

gram -ve has a thin peptidoglycan wall with outer membrane

36
Q

gram stain test

A
  • prepare a heat fixed film of bacteria on a glass slide
  • stain with crystal violet for 1 mins and rinse with water
    • stains everything
  • treat with Gram Iodine for 1 mine and rinse with water
    • helps fix the crystal violet
  • briefuly decolourise with acetone/ethanole (a few secs depening on thickness of film)
    • gram -ve will loose crystal violet as thin peptidoglycan
  • counter stain with basic fushin or safranin (pink dye) for 1 min and rinse with water
    • Gram +ve no effect as purple stained
    • gram -ve will go clear to pink
  • blot dry and view under oil immersion
37
Q

purpose of gram stain test

A

allows differentiation

  • shape
  • structure of cell wall
38
Q

describe this bacteria

A

Long strands gram positive streptococci

39
Q

describe this bacteria

A
  • Short, dumpy rods*
  • Pink gram -ve*
40
Q

describe this culture

A

mixed

41
Q

when would dentist send away a chairside sample

A
  • Unlikely to get quick answer from chairside sample*
  • Consider*
  • Do you need this information
    • Not responding to antimicrobials
    • Immunosuppressed

Help know to Tx effective

42
Q

why is gram stain test one of the first tests performed

A

Need to know cell wall composition so can do subsequent down stream testing

43
Q

4 roles of microbiology lab in prevention and control of HAIs

A
  1. Outbreak investigation
  2. Surveillance of HAIs
  3. Alert microorganisms reports
  4. Designing antibiotic policy

Every health board have different specific microbe concerns for their area

44
Q

outbreak investigation aims

A
  • To determine the cause of a single-source outbreak the causative agent must be defined
  • Then microbiology laboratory determines if two or more isolated strains are same or different

microbial species may contain subspecies and variants, moreover individual bacteria of the same species can differ as much as 30% in their genomes and differ in phenotypes

genotypes determination more favourable than phenotypes

45
Q

possible additional tests carried out by IP&C team during outbreak (7)

A
  • Blood products
  • Environmental surfaces
  • Disinfectants and antiseptics
  • Air
  • Water
  • Hands of personnel
  • Anterior nares of personnel
46
Q

benefit of knowing pathogen involved in outbreak

A

microbiology labs can use special media for culture for rapid and inexpensive identification of the pathogen in environmental specimens.

47
Q

reports made by microbiology labs for HAI surveillance

A

The microbiology laboratory should produce routine reports of bacterial isolates

  • Allows the IP&C team to create statistics (figures/tables) for specific pathogens, wards, and groups of patients
    • E.g. amoxicillin for gingivitis – all pts sensitive to – great work, over prescribing see change in trends where Mos associated with gingivitis
      • Need to capture data continuously to see change
  • A ‘baseline incidence’ can be established
    • Any new isolate can then be compared with this incidence
  • If the laboratory is computerised, these data can be made readily available
48
Q

key benefit of regular microbiology lab reports

A
  • enable IP&C team to discover an outbreak earlier than it could be discovered from clinical data only
  • point to the trends in the specific pathogen occurrence and are very useful in planning preventive measures
  • may also report clustering of infections (two related isolates in different patients in the same time frame
49
Q

most reliable data from microbiology lab

A

isolates from blood culture, urine and infected wounds,

data from respiratory tract infections should be very carefully interpreted in the light of clinical picture.

50
Q

alert organisms reports

A

wide varierty of agreed alert organisms

The isolation and immediate report of an unusual microorganism (unusually pathogenic or unusually resistant) enables IP&C Team to take appropriate measures and stop it from spreading.

51
Q

e.g. alert organisms

A
  • Methicillin-resistant Staphylococcus aureus (MRSA)
  • Vancomycin-intermediate S.aureus (VISA)
  • Vancomycin-resistant enterococci (VRE)
  • MDR Pseudomonas aeruginosa
  • MDR Acinetobacter baumannii
  • MDR Mycobacterium tuberculosis
  • ESBL enterobacteria
  • Clostridium difficile
  • Candida auris
  • COVID-19
52
Q

antibiotic policy

A

Regular reporting of changing resistance patterns

  • Newsletters
  • Specialty specific data

Restricted antibiotic reporting

  • Routinely only first line antibiotics
  • Reserve antibiotics only if pathogen is resistant to first line antibiotics
    • Problems arise if reserve used before first line – increase chance of resistant form
53
Q

why is regular reporting in antibiotic resistance patterns important

A
  • Allow to think why – antibiotic over use, coincidence*
  • Don’t determine resistance – need to link to reason*
  • Organisms don’t suddenly become resistant – they are driven there
54
Q

importance of restricted antibiotic reporting in individual pts

A

important for saving of reserve antibiotics.

55
Q

antibiotic stewardship

A
  • Role of Clinical Microbiologist/ID specialist
    • Provide leadership to antimicrobial team
    • Antibiotic ward rounds
    • Interpretation of patient specific data to optimise treatment
      • culture and sensitivity
  • Active surveillance/ awareness
    • Screening for carriage of resistant bacteria – programmes, swabs
    • Molecular detection and typing
56
Q

role of clinical mircrobiologist/ ID specialist in antibiotic sterwardship

A
  • Provide leadership to antimicrobial team
  • Antibiotic ward rounds
  • Interpretation of patient specific data to optimise treatment
    • culture and sensitivity
57
Q

active surveillance/awareness in antibiotic stewardship

A
  • Screening for carriage of resistant bacteria – programmes, swabs
  • Molecular detection and typing

know what is in the communtiy

58
Q

who interpret microbiologucal data

A

Microbiologists interpret microbiological data for IP&C staff

  • Results of isolation, identification, susceptibility tests, typing

Ideally should be medical doctor specialistt

  • If this is not possible, then a properly educated scientist is required
59
Q

what to consider when interpreting microbiological data

A
  • nature of isolated organisms (primary or opportunistic pathogen),
  • specimen from which the organism was isolated,
  • clinical picture of the patient and actual immunological status of the patient.

To interpret microbiology data for epidemiological purposes one should take into account the properties and main habitat of isolated organism, as well as the opportunity to be transmitted to a specific patient.

60
Q

microbiology lab educates (3)

A
  • Infection prevention staff
  • Other healthcare workers
  • Students (medical and nursing)
61
Q

IP&C staff are educated by microbiology lab on

A

how to interpret microbiological reports/charts

62
Q

other healthcare workers are educated by microbiology staff on

A

specimen collection and transport, interpretation of reports and sensitivity tests

63
Q

students are educated by microbiology lab on

A

basic microbiology

64
Q

3 key transmission routes for dental

A
  • aerosol
  • hands
  • blood
65
Q

chain of infection

A
66
Q

how to break chain of infection

A
  • contact tracing
  • infectious agent
    • isolation
    • early treatment
  • source
    • education/ policy (social distancing)
    • environmental sanitation
    • disinfection
  • exit
    • handwashing
    • control of aerosols/splatter
  • means of transmission
    • isolation
    • disinfection
    • handwashing
  • portal of entry
    • first aid
    • personal hygiene
    • handwashing
  • susceptible host
    • vaccination
    • treatment of underlying diseases

antibiotic prophylaxis (e.g. meningitis)

67
Q

airborne transmission examples

A

e.g. S.aureus, S.pyogenes, M.tuberculosis, S. pneumoniae, Respiratory viruses, Legionella

68
Q

direct contact e.g

A

e.g. S.aureus, Enterobacteria, psudomonas, vancomycin resisted enterococci (VRE)

69
Q

solutions to try and break transmission

A
  • hospital/ward design
  • isolation facilities
  • maintenance of ventilation
  • adequate space
  • infection control policies
  • staff education
  • good clinical practice
  • sterile supplies, equipment sterilisation or single use items
  • disinfection policy
70
Q

5 points of hand hygiene

A
  • before pt contact
  • before an aseptic task
  • after body fluid exposure risk
  • after pt contact
  • after contact with pt surroundings
71
Q

microbes prevalence

A
  • infectious agents not visible to the naked eye
    • Widespread and ubiquitous in nature and some cause human disease
72
Q

key epidemiological role of microbiology lab

A

perform basic typing of microorganisms

73
Q

reports from microbiology labs can be used to construct

A

incidence graphs for specific pathogens, wards, and groups of patients

74
Q

why handhygiene before pt contact

A

to protect pt against harmful germs carried on your hands

75
Q

why HH before aspectic task

A

to protect the pt against harmful germs, inc the pts own germs, entering his or her body

76
Q

why HH after body fluid exposure risk

A

to protect yourself and the health care enviorment from harmful pt germs

77
Q

why HH after pt contact

A

to protect yourself and the health care enviroment from harmful pt germs

78
Q

why HH after contact with pt surroundings

A

to protect youself and the health care environment from harmud pt germs

BDS3 BAMS Microbiology and Oral Pathology (6 decks)

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