Chapter I General safety rules in Microbiological Laboratory

Question 1

the application of safety precautions that reduce a laboratorian’s risk of exposure to a potentially infectious microbe and limit contamination of the work environment and, ultimately, the community.

Answer 1

Biosafety

Question 2

Four biosafety levels

Answer 2

Biosafety level 1
Biosafety level 2
Biosafety level 3
Biosafety level 4

Question 3

organisms are well-characterized strains of microorganisms
not known to cause disease in healthy human adults.

Answer 3

Biosafety level 1

Question 3

organisms include in this biosafety level are non-pathogenic laboratory strains of Escherichia coli, Staphylococcus xylosus, and Bacillus megaterium.

Answer 3

Biosafety level 1

Question 4

Organisms are moderate-risk microorganisms associated with less serious human diseases whose potential for transmission is limited and a proven treatment for the disease exists.

Answer 4

Biosafety level 2

Question 4

pathogens are opportunistic, particularly in children and immunocompromised adults. Additional precautions in this biosafety level include using personal protective equipment (PPE) such as disposable gloves and laboratory coats and limiting lab access to trained individuals.

Answer 4

Biosafety level 2

Question 5

Organisms are high-risk microorganisms with a true potential for infection by aerosols and in which the resulting disease may have serious or lethal consequences.

Answer 5

Biosafety level 3

Question 5

organisms include Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella

Answer 5

Biosafety level 2

Question 6

Researchers in this biosafety level generally wear double gloves, respirators, and disposable surgical scrubs and gowns, and work in biological safety cabinets in isolated, negative-pressure containment rooms.

Answer 6

Biosafety level 3

Question 7

organisms include Mycobacterium tuberculosis, Foot-and-mouth disease virus, and Bacillus anthracis.

Answer 7

Biosafety level 3

Question 8

organisms include Avian flu viris, Ebola virus, Marburg virus, and Lassa fever virus.

Answer 8

Biosafety level 2

Question 9

organisms are easily transmitted, very-high risk microorganisms which cause life-threatening diseases for which there is no vaccine or therapy.

Answer 9

Biosafety level 4

Question 10

Laboratories work in impermeable positive pressure “space suits” with an external oxygen supply, and precautions such as chemical showers must be taken before exiting the lab.

Answer 10

Biosafety

Question 11

A very important biosafety practice. Incidents involving biological, chemical, physical, and radiological hazards can have a significant impact on the safety and health of those who work in laboratory settings.

Answer 11

Microbiological risk assessment

Question 12

Steps of risk management

Answer 12

Step 1: Identify the hazard and risk
Step 2: Evaluate the risk
Step 3: Implement a risk mitigation plan, as needed
Step 4: Evaluate the effectiveness of controls

Question 13

Ask what, where, and how the work is occurring and who is doing the work. Then, determine what could go wrong in every step of the activity or procedure and the result of the undesirable incident (e.g., injury, exposure, infection, disease).

Answer 13

Identification of the hazards and risks

Question 14

Characterize the risks
Likelihood of the risk
Consequence of risk

Answer 14

Risk evaluation

Question 15

Example; strictly implement proper disposal of waste (ie sharps)

Answer 15

Risk mitigation plan

Question 16

How to conduct risk assessment?

Answer 16

1. Identification of the hazards and risks
2. Risk evaluation
3. Risk mitigation plan:
4. Evaluation of effectiveness of control

Question 17

Example ; needle sticks or broken glass (slides, cover slips, beakers etc)

Answer 17

Characterize the risks

Question 18

Example; absence of proper disposal of sharp objects

Answer 18

Likelihood of the risk

Question 18

Example; cuts, or potential infection from exposure to biological
agents

Answer 18

Consequence of risk

Question 19

Classification of infective microorganisms

Answer 19

1. Risk Group 1 (no or low individual and community risk) 2. Risk Group 2 (moderate individual risk, low community risk)
2. Risk Group 3 (high individual risk, low community risk)
3. Risk Group 4 (high individual and community risk)

Question 19

A microorganism that is unlikely to cause human or animal disease.

Answer 19

Risk Group 1 (no or low individual and community risk)

Question 20

A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment. Laboratory exposures may cause serious infection, but effective treatment and preventive measures are available and the risk of spread of infection is limited.

Answer 20

Risk Group 2 (moderate individual risk, low community risk)

Question 20

A pathogen that usually causes serious human or animal disease but does not ordinarily spread from one infected individual to another. Effective treatment and preventive measures are available.

Answer 20

Risk Group 3 (high individual risk, low community risk)

Question 20

A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available.

Answer 20

Risk Group 4 (high individual and community risk)

Question 21

an enclosed, ventilated laboratory workspace for safely working with materials contaminated with (or potentially contaminated with) pathogens requiring a defined biosafety level. It is intended to offer protection to the user and environment from the aerosol hazards arising from the handling of infected and other hazardous biological material.

Answer 21

biosafety cabinet (BSC)—also called a biological safety cabinet or microbiological safety cabinet

Question 22

types of safety cabinet

Answer 22

Class I Class II Class III

Question 23

Safety cabinet with front opening through which the operator can carry out manipulations inside the cabinet and which is constructed so that the worker is protected and the escape of airborne particulate contamination generated within the cabinet is controlled by means of inward airflow through the working front opening and filtration of the exhaust air.

Answer 23

Class I BSC

Question 24

safety cabinet with front opening through which the operator can carry out manipulations inside the cabinet and which is constructed so that the worker is protected, the risk of product and cross-contamination is low and the escape of airborne particulate contamination generated within the cabinet is controlled by means of an appropriate filtered internal airflow and filtration of the exhaust air (laminar airflow).

Answer 24

Class II BSC

Question 24

Safety cabinet in which the working area is totally enclosed and the operator is separated from the work by a physical barrier (I.e. gloves mechanically attached to the cabinet). Filtered air is continuously supplied to the cabinet and the exhaust air is treated to prevent release of micro-organisms.

Answer 24

Class III BCS

Question 25

to examine microorganisms which can’t be seen by naked eyes

Answer 25

Microscope

Question 26

to heat or boil solution in laboratory

Answer 26

Bunsen burner

Question 26

What's the function of Autoclave

Answer 26

to sterilize the equipment medias and other solutions

Question 27

What's the function of Pressure cooker

Answer 27

to sterilize the equipment medias and other solutions

Question 28

to preserve the samples, media, reagents and other specimen

Answer 28

Refrigerator

Question 29

a laboratory device that employs a rotating magnetic field to cause a stir bar (or flea) immersed in a liquid to spin very quickly, thus stirring it.

Answer 29

Magnetic Stirring Plate

Question 30

used for bacterial or fungal cultures

Answer 30

Incubator

Question 31

To rescue the exposure of the operator and the lab contamination

Answer 31

Safety Cabinet

Question 32

(used to inoculate test samples into culture media for bacterial or fungal cultures, antibiograms, etc.)

Answer 32

Wire loop/inoculating loop

Question 33

to act as a supporting container to hold the culture medium

Answer 33

Petri dish

Question 33

a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom.

Answer 33

Test tube

Question 34

a piece of laboratory equipment designed to hold multiple test tubes upright at the same time.

Answer 34

Test tube rack

Question 34

To measure and prepare media

Answer 34

Flask

Question 35

To measure and transfer solution

Answer 35

Beaker

Question 36

to measure the weight of an specimen

Answer 36

Weighing scale

Question 37

to transfer quantified volume of specimen or solution

Answer 37

Pipettor

Question 38

Used to heat medium gently (to around 45-55℃) during media preparation

Answer 38

Water bath

Question 39

essential tools in any laboratory setting, especially for precise liquid handling.

Answer 39

Pipette tips

Question 40

thin, flat pieces of glass used to hold specimens for examination under a microscope.

Answer 40

Glass slides

Question 41

thin, square pieces of glass placed over the specimen on the slide. They help flatten the specimen, protect it from contamination, and prevent the microscope’s objective lens from coming into direct contact with the specimen.

Answer 41

Cover slip

Question 42

bottles in laboratories protect light-sensitive substances from UV and blue light, ensuring their stability and efficacy.

Answer 42

Amber bottles

Question 43

for storage of media, regeants and other materials

Answer 43

Cupboards

Question 43

securely organizes and protects PPE from contamination and damage, ensuring it is readily accessible and in good condition for use.

Answer 43

Storage cabinet for personal protective equipments (PPE’s)

Question 44

used to quickly and effectively put out small fires, preventing them from spreading and causing more damage.

Answer 44

Fire extinguisher

Question 45

Use to differentiate bacterial species into gram-negative and gram-positive groups based on the chemical and physical properties of their cell wall.

Answer 45

Gram's staining set

Question 46

treatment of work surface before and after use and spillages; disposal of used pipettes and microscope slides; in soap form for hand washing

Answer 46

Disinfectant

Question 46

sterilization of metal forceps and glass spreaders by ignition

Answer 46

Denatured 70% Alcohol

Question 47

dealing with spilled cultures

Answer 47

Spillage kit

Question 48

may be taken from animals or the environment for a variety of purposes, such as disease diagnosis, disease surveillance, health certification or monitoring the response to treatment or vaccination. T

Answer 48

Samples

Question 49

may be taken for haematology or for culture and/or direct examination for bacteria, viruses, or protozoa, in which case it is usual to use anticoagulants, such as ethylene diamine tetra-acetic acid (EDTA) or heparin

Answer 49

Blood samples

Question 50

They may also be taken for serology, which requires a clotted sample (serum/plasma).

Answer 50

Blood samples

Question 51

Ideally the skin at the site of venipuncture should first be shaved (plucked) and swabbed with ____________ and allowed to dry.

Answer 51

70% alcohol

Question 51

A blood sample is taken, as cleanly as possible, by ___________________ (not easy in delicate veins but convenient in strong veins)

Answer 51

venipuncture with a syringe and needle or by needle and vacuum tube

Question 52

Site of blood sampling of large animals

Answer 52

via jugular vein or a caudal vein, or less commonly brachial veins and mammary veins

Question 53

Site of blood sampling of Pigs

Answer 53

vena cava veins

Question 54

Site of blood sampling of birds

Answer 54

a wing vein (brachial vein) is usually selected

Question 55

For serum samples, the blood should be left to stand at ambient temperature (but protected from excessive heat or cold) for __________ until the clot begins to contract and placed in a refrigerator at ______ After several hours, or overnight, the sample can be centrifuged at about ____________________ and the serum can be decanted or removed with a pipette.

Answer 55

1–2 hours 4°C 1000 g for 10–15 minutes

Question 56

useful for surface-feeding mites, lice and fungal infections

Answer 56

Plucked hair or wool samples

Question 56

using the edge of a scalpel blade, are useful for burrowing mite

Answer 56

Deep skin scrapings

Question 57

Samples may be taken by vaginal or preputial washing, or by the use of suitable swabs.

Answer 57

Genital tracts and semen sample

Question 57

In birds, feather tips can be taken for detection of viral antigen where ________ disease is suspected.

Answer 57

Marek’s

Question 58

The cervix or urethra may be sampled by

Answer 58

Swabbing

Question 59

Best obtained using an artificial vagina or by extrusion of the penis and artificial stimulation.

Answer 59

Samples of semen

Question 60

Samples of semen are best obtained using an artificial vagina or by extrusion of the penis and artificial stimulation. The ________________ should be present in the sample and contamination by antiseptic washing solutions should be avoided.

Answer 60

sperm-rich fraction

Question 61

can be taken by holding the palpebra apart and gently swabbing the surface. The swab is then put into transport medium.

Answer 61

Samples from conjunctiva

Question 62

rapings may also be taken on to a microscope slide. The handles of metal- handled swabs are useful for this, to ensure that sufficient cells are removed for microscopic examination

Answer 62

Eye samples

Question 63

rarely useful in eye samples

Answer 63

Mucopurulent nasal and lacrimal discharges

Question 64

Samples may be taken with dacron, cotton or gauze swabs, preferably on wire handles as wood is inflexible and may snap. It may be helpful if the swab is first moistened

Answer 64

Nasal discharge (saliva)

Question 64

Long protected _____________ should be used to collect samples for some suspected viral infections.

Answer 64

nasopharyngeal swabs

Question 65

In nasal discharge sample, the swab should be allowed to remain in contact with the secretions for up to _________, then placed in transport medium and sent to the laboratory without delay at ____.

Answer 65

1 minute 4°C

Question 66

should be taken after cleansing and drying the tip of the teat, the use of antiseptics should be avoided.

Answer 66

Milk samples

Question 67

should be discarded and a tube filled with the next stream(s), a sample of bulk tank milk can

Answer 67

Initial stream of milk

Question 68

Milk for _____________ should not have been frozen, heated or subjected to violent shaking.

Answer 68

serological tests

Question 69

If there is going to be a delay in submitting them to the laboratory, ____________can be added to milk samples that are being collected for serological testing. If necessary, milk for bacterial examination can be frozen.

Answer 69

preservatives

Question 70

Samples may be taken to monitor hygiene or as part of a disease enquiry

Answer 70

Environmental and feed sampling

Question 70

should be done by trained

Answer 70

Sample collection at post-mortem

Question 71

commonly taken from litter or bedding and voided feces or urine

Answer 71

Environmental samples

Question 72

wabs may be taken from the surface of ventilation ducts, feed troughs and drains. This kind of sampling is particularly important in ____________ in which specialised equipment

Answer 72

hatcheries, artificial insemination centers and slaughterhouses

Question 73

Samples may also be taken from animal feed, in __________

Answer 73

troughs or bulk containers

Question 73

may be sampled in troughs, drinkers, header tanks or from the natural or artificial supply

Answer 73

Water

Question 74

It is essential that individual samples be clearly identified using appropriate methods. Marking instruments should be able to withstand the condition of use, i.e. being wet or frozen use ______________

Answer 74

indelible marking pen

Question 75

Possibly the most useful collection is the storage of serum samples _____________. These samples may be useful if a retrospective investigation is carried out to compare the present disease status with that of earlier times.

Answer 75

serum banks

Question 75

Information to be sent with samples

Answer 75

a) Name and address of owner, or sender and geolocation where disease occurred, with telephone and fax numbers. b) Diseases suspected and tests requested. c) The species, breed, sex, age and identity of the animals sampled. d) Date samples were collected and submitted. e) List of samples submitted with transport media used. f) A complete history would be beneficial for the laboratory and should be included if possible.

Question 76

Establishing a collection of samples for future studies can be very useful. This can include cultures for comparison with future isolates, tissue or serum samples that can be used for the validation of new tests and a collection of fixed tissues, or paraffin blocks, for future histological examination.

Answer 76

Preservation of samples for prolonged storage