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Biomedical Science Y1 (Sem 2) > Clinical Microbiology > Flashcards

Clinical Microbiology Flashcards

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1
Q

Size range of bacteria

A

0.5um - 5um

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2
Q

Size range of viruses

A

20nm - 400nm

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3
Q

Size range of fungi

A

2um - 50um (for yeast and hyphae)

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4
Q

Size range of parasites

A

4um - 200um (for ova and cysts, but much larger for adult parasites)

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5
Q

What is pathogenesis?

A

How an infectious organism causes disease

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6
Q

What is epidemiology?

A

The study of the distribution and determinants of disease

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7
Q

What are vaccinations?

A

They stimulate an immune response to help protect the human body from infectious disease

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8
Q

What are antimicrobial agents?

A

A chemical that has properties which inhibit the growth of, or are lethal to bacteria, fungi, viruses and parasites

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9
Q

What are some common infections?

A
  • Septicaemia
  • UTIs
  • Gastroenteritis
  • Genital infections, including STDs
  • Mucosa and soft tissue infections, wound infection
  • Upper respiratory infection, sore throat, conjunctivitis, otitis media
  • Meningitis
  • Lower respiratory tract infection
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10
Q

Gram positive organisms:

A
  • Staphylococcus aureus
  • Streptococcus pyogenes
  • Streptococcus pneumoniae
  • Clostridium difficile
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11
Q

Gram negative organisms:

A
  • Escherichia coli
  • Haemophilus influenzae
  • Pseudomonas aeruginosa
  • Neisseria gonorrhoea
  • Neisseria meningitidis
  • Chlamydia trachomatis
  • Campylobacter spp
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12
Q

Viruses organisms:

A
  • Corona virus
  • Influenza A
  • HIV
  • RSV
  • Norovirus/Rotavirus
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13
Q

Fungi/Yeast organisms:

A
  • Candida albicans
  • Dermatophyte fungi
  • Aspergillus fumigatus
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14
Q

Mycobacteria organisms:

A
  • Mycobacterium tuberculosis
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15
Q

Laboratory methods for diagnosis:

A
  • Microscopy
  • Agar culture and enrichment
  • Tissue culture
  • Immunoassays
  • Nucleic acid amplification tests
  • Nucleic acid sequencing
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16
Q

What component of a prokaryote determines the gram stain reaction?

A

Bacterial cell wall

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17
Q

What colour is gram positive organisms?

A

Purple (thick layer)

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18
Q

What colour is gram negative organisms?

A

Pink (thin layer)

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19
Q

Process in which bacteria divides

A

Binary fission (20 minutes)

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20
Q

Elements essential for bacterial growth:

A

Carbon
Hydrogen
Sulphur
Oxygen
Nitrogen
Phosphorus
Potassium

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21
Q

What are peptones?

A

It is a protein digest - they contain essential components of bacterial culture media

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22
Q

For how long and at what temperature should the agar medium be heated at?

A

Autoclave for 15 mins at 121 celcius

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23
Q

How many types of culture media are there?

A

6

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24
Q

What is non-selective agar?

A

It is a solidified medium, has nutrients to grow a wide range of bacteria but there’s nothing in it that selects a particular type of organism

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25
Q

What is enrichment broth?

A

Not selective, designed to enrich small number of organisms from samples, without trying to inhibit any of the organisms that might be present

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26
Q

What is differential agar?

A

Contains nutrients to grow our target organisms, some inhibitors are present but most importantly it has a substrate that our target organism can metabolise to produce a specific colony or colony type/appearance

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27
Q

What is chromogenic agar?

A

It identifies other enzymatic pathways in the organism, and linking a substrate to a molecule which when the substrate is cleaved the molecule attached will go from a colourless to a coloured molecule, and we can colour our colonies to make it much easier to target the organism from the non-target organism

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28
Q

What is selective enrichment broth?

A

Used to grow specific microorganisms, including food borne pathogens: salmonella, staphylococcus and listeria

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29
Q

What is selective agar?

A

Selective medium contain particular ingredients that inhibit the growth of certain microbes.

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30
Q

What colour colonies are formed when E.coli ferments lactose on CLED agar plate?

A

Yellow

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31
Q

What method can be used to examine CSF for bacterial meningitis?

A

Non-selective agar (5% whole horse blood agar and chocolate agar)

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32
Q

What method can be used to examine blood cultures for septicaemia?

A

Enrichment media (brain-heart infusion broth and 5% whole horse blood agar)

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33
Q

What method can be used to examine urine?

A

Differential agar (CLED - cysteine lactose electrolyte deficient agar)

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34
Q

What method can be used to examine faeces?

A

Chromogenic agar (can also be done with selective agar)

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35
Q

What method is used to grow mycobacterium tuberculosis?

A

Lowenstein-Jensen inspissated egg yolk medium (incubated for 15 weeks, because this organism has a very slow doubling time)

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36
Q

Bacteria share genetic information in three ways:

A
  • Transformation
  • Conjugation
  • Transduction
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37
Q

What is transformation?

A

This is were a living viable cell can take up DNA from its surroundings and incorporate it into its genome or genetic composition and create advantage for itself

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38
Q

Who epitomised the classic experiments in regard to transformation?

A

Avery and Griffiths in the 1920s

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39
Q

What is conjugation?

A

Genetic material can be shared by intimate contact through the pilli, so one cell can donate a plasmid to another cell by sending it through the pilli and making an intimate connection between the cytoplasm of both cells. Therefore a donor cell can donate, copy a plasmid to the recipient cell.

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40
Q

What is a negative consequence of conjugation?

A

Antibiotic resistance - antibiotic markers or genes are transferred to another cell through conjugation. Therefore meaning that the cell contains antibiotic resistant material and when multiplied will be able to thrive and grow in selective environments which may contain the antibiotic

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41
Q

What is transduction?

A

This is where infection with a phage or bacteriophage can can take DNA into a new cell and that DNA can be incorporated into the genome of the recipient bacterium - which lead to a lytic cycle (replicating itself and bursting out of the cell causing infection and ultimately leading to death of the cell

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42
Q

Can viruses be viewed under light microscopy?

A

No, only electron microscopy

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43
Q

Types of DNA viruses:

A
  • Herpesvirus
  • Poxvirus (eg. smallpox)
  • Adenovirus
  • Papovavirus
  • Hepadnavirus (eg. Hepatitis B)
  • Parvovirus
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44
Q

Types of RNA viruses:

A
  • Paramyxovirus (eg. RSV)
  • Orthomyxovirus (eg. Influenza)
  • Coronavirus (eg. SARS)
  • Arenavirus
  • Retrovirus (eg. HIV)
  • Reovirus (eg. Rotavirus)
  • Picornavirus
  • Filovirus (eg. Ebola)
  • Rhabdovirus (eg. Rabies)
  • Togavirus
  • Bunyavirus
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45
Q

Features of Influenza A

A
  • Single stranded RNA virus
  • Enveloped
  • Helical capsid
  • Contains two antigens = haemagglutinin (for adhesion to susceptible cells) and neuraminidase (enzyme) protein antigens on the surface of the envelope
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46
Q

How many segments are there of the single stranded RNA genome?

A

8

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47
Q

On an influenza virus what are the spikes on the viron envelope?

A

Haemagglutinin and neuraminidase proteins which are immunogenic and are the basis of the influenza vaccine

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48
Q

What are Haemagglutinin and neuraminidase shortened to?

A

HN

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49
Q

When was the Russian Influenza H2N2?

A

1889

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50
Q

When was the Old Hong Kong Influenza H3N8?

A

1900

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51
Q

When was the Spanish Influenza H1N1?

A

1918

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52
Q

When was the Asian Influenza H2N2?

A

1957

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53
Q

When was the Hong Kong Influenza H3N2?

A

1968

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54
Q

When was the Pandemic Influenza H1N1?

A

2009

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55
Q

Transmission route for Influenza A?

A

Respiratory aerosols

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56
Q

Transmission route for Norovirus?

A

Food and water (infects the gut, symptoms include vomiting and diarrhoea) or by direct contact

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57
Q

Transmission route for Rotavirus?

A

Fomites (faecal-oral), mainly an infection of under 5 year olds

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58
Q

Transmission route for Herpes?

A

Direct contact with bodily fluids (saliva, semen)

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59
Q

Transmission route for HIV, HPV?

A

Sexual contact (including birth - vertical transmission, due to secretions)

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60
Q

Transmission route for Hepatitis B/C?

A

Blood and organ transplantation (sharing needles…)

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61
Q

Transmission route for Rabies?

A

Zoonoses - bite of an infected animal

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62
Q

The process of viral pathogenicity:

A
  • Acquisition
  • Initiation of infection (virus is absorbing itself to the cell)
  • Incubation period (once inside the virus will uncoat in which its dna/rna will be exposed and transcribed)
  • Replication in the target tissue (leading to a replication of viral nucleic acid and viral proteins to make the capsid)
  • Virus production and release to infect other cells/hosts (either by budding to the surface or lysing)
  • Immune response (cytotoxic T cells will be sent to eradicate that cell - results in rupture of cell and release if virus particles)
  • Resolution/persistence/latency (some of the particles will be collected by analysing the antigenic components and educating B/T cells to recognise…)
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63
Q

Steps of the infection cycle:

A
  • Adsorption/Attachment
  • Penetration
  • Uncoating
  • Transcription/translation (replication)
  • Assembly
  • Release
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64
Q

What are some infections that an immunodiffusion assay (LFT) can detect?

A
  • Legionella pneumophila serotype 1 in urine
  • Streptococcus pneumoniae antigen in urine
  • Influenza A and B in nasopharyngeal swabs
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65
Q

What do LFTs contain?

A

Antigens which have been extracted from different types of microorganisms - specific to the infection that it is being tested for, if the patient is infected with that organism it will be present via a nasal or saliva swab

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66
Q

How does a LFT function?

A

Once the test sample is added into the sample pad on a lateral flow device, the sample flows through a filter film. If the test sample contains target analytes, it can combine with colloidal gold-labeled antigen to form a complex, which is captured by antibody coated with a colored band. The presence of colored bands indicates a positive result of the target analyte. Most of the lateral flow assays contain a control line, which works as a procedural control to inform enough samples were added into loading well. The absence of a colored control line indicates an invalid test result.

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67
Q

What is poliomyelitis?

A
  • Can be prevented via vaccination
  • It’s a virus that infects nervous tissue, which can result in malformation of growth of lower limbs
  • Can also result in paralysis
  • Iron lung was used to decrease pressure by drawing the diaphragm down and air into the lungs
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68
Q

What is the purpose of antiviral therapies?

A

To allow the body’s immune system to keep on top of viral infections so a variety of targets are used to interrupt the cycle

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69
Q

What is the cell wall of a fungi composed of?

A
  • Chitin
  • Mannan
  • Glucan and glycoproteins
70
Q

What do fungi have instead of cholesterol in their cell membranes?

A

Ergosterol

71
Q

Are fungi prokaryotic or eukaryotic?

A

Eukaryotic

72
Q

What colour gram stain are yeast cells?

A

Gram positive - purple

73
Q

Process of Gram staining

A
  1. Apply a smear of microorganism on to a slide. Air dry and then heat fix by passing it through a flame a few times. Make sure you air dry the bacteria before heat fixing.
  2. Add about 5 drops of Crystal Violet to the culture. Let stand for one minute. Bacteria will stain purple. Wash briefly with water and shake off excess.
  3. Add about 5 drops of iodine solution to the culture. Let stand for 30 seconds, wash briefly with water and shake off excess.
  4. Tilt slide and decolorize with solvent (acetone-alcohol solution) until purple color stops running. Be careful not to over-decolorize. Wash immediately (within 5 seconds) with water and shake off excess.
  5. Add about 5 drops of Safranine O. Let stand for one minute, wash briefly with water and shake off excess
74
Q

What are the essential components of sabourad dextrose agar (fungal culture media)?

A
  • Carbon
  • Oxygen
  • Nitrogen
  • Hydrogen
  • Sulphur
  • Phosphorus
  • Potassium

Incubated at 25 degrees celcius in aerobic atmosphere

75
Q

What is oral candidiasis?

A

White plaques on the throat - generally found in warm wet areas where there may be abrasion. There is also genital and skin candidiasis

76
Q

What does candida albicans cause?

A

Infections like thrush, oral thrush in babies, vaginal thrush in females, skin irritations…

77
Q

When and where was candida auris discovered?

A
  • Discovered in 2009 in an ear infection in Japan, C. auris is difficult to distinguish from more common candida species
78
Q

What is C.auris resistant to?

A

Fluconazole (the first line treatment for candidiasis, it is also multi-resistant to antifungal agents

79
Q

Is candida a yeast like fungi?

A

Yes

80
Q

What are the most common causes of superficial mycoses?

A

Ringworm, athlete’s foot and fungal nails

81
Q

What is aspergillus fumigatus?

A

Common mold that is found in the environment, it produces ‘fruiting’ heads - hyphal growth, contains lots of spores which can be released into the air and can be easily inhaled. Chronic inhalation of aspergillus can cause allergic hypersensitivity or highly aggressive disseminated disease often in the immunocompromised

82
Q

What is cryptococcus neoformans?

A
  • A yeast that can cause meningitis
  • It is widely dispersed in soil and found in bird droppings
  • Disease usually occurs in immunocompromised patients
  • It affects around 10% of AIDS patients
83
Q

What is pneumocystis jiroveci?

A
  • A yeast like organism which can cause pneumonia in immunocompromised patients
  • Originally discovered as one of the key AIDS defining illnesses and thought to be a parasite but recently reclassified as a fungi
84
Q

In summary, what are the common fungal infections of the body?

A
  • Genital infections
  • Mucosa and soft tissue infections
  • Meningitis
  • Lower respiratory tract infection
85
Q

What laboratory methods can be used to identify and diagnose fungi?

A
  • Microscopy
  • Agar culture
86
Q

Four main groups of ectoparasites:

A
  • Fleas
  • Lice
  • Mites
  • Ticks
87
Q

Fleas -

A

Pulex irritans
- Bites cause localized inflammation and itching but mostly known as a vector for the plague (yersinia pestis) in endemic areas

88
Q

Ticks -

A

The black legged tick (ixodes scapularis) is responsible for the spread of Lyme disease caused by the bacterium borrelia burgdorferi

89
Q

Lice -

A

Phthrus pubis (crab louse), pediculus humanus capitis (head louse), pediculus humanus corporis (body louse). Bites cause itching and inflammation but are not vectors of disease. Treatment includes wet combing to remove lice and insecticide as permethrin

90
Q

Mites -

A

Sarcoptes scabiei causes scabies. Bites cause itching and inflammation but are not vectors for disease. Treatment with permethrin or malathion creams or lotions.
Avoid: close personal contact with others, do not share bedding or towels

91
Q

Arthropods as vectors

A

Malaria is trasmitted through the bite of a mosquito - spreads the parasite plasmodium falciparum

92
Q

How does a mosquito infect another individual with malaria?

A

When a mosquito bites a person already infected with malaria, it ingests gametocytes, the gametocytes mature inside the gut of the mosquito and they then go through part of their life cycle to turn into sporozoites and when that pregnant mosquito is hungry for a blood meal to be able to feed the developing eggs - the mosquito bites and ejects some of the sporozoites into another individual (therefore infecting them with malaria)

93
Q

How does malaria spread inside an individual?

A

The malaria parasites enter that person’s bloodstream and travel to the liver. When the parasites mature, they leave the liver and infect red blood cells. Once inside the body, the malaria parasites grow and multiply inside the red blood cells. When the red blood cells burst releasing merozoites (usually every 48-72 hours), it results in an attack of flu-like symptoms such as fever, sweating, shivering and shaking, muscle aches, nausea and headache.

94
Q

What are the main antimalarial drugs recommended in the UK malaria treatment guidelines:

A
  • Artesunate = used to treat severe or complicated malaria
  • Quinine = may be used inItially to treat severe or complicated malaria if artesunate is unavailable

OVERDOSE OF ANTIMALARIAL DRUGS, PARTICULARLY CHLORIQUE CAN CAUSE SEVERE TOXICITY AND BE FATAL

95
Q

What does malaria treatment depend on?

A
  • Plasmodium species
  • Severity of infection
  • Drug tolerance of patient
  • Drug resistance in parasites
96
Q

Name the intestinal parasites:

A
  • Protozoa
  • Helminths (worms)
  • Nematodes
  • Trematodes
  • Cestodes
97
Q

Enteric parasites:

A
  • Ascaris sp (round worm)
  • Giardia (protozoa)
  • Cryptosporidium

Most associated with poor water quality and sanitation

98
Q

Techniques for detection of parasites

A
  • Microscopy (unstained wet preparations - to identify size and structure or staining), fluorescence to improve sensitivity for smallest parasites
  • Immunoassay = to detect parasite antigens when in high numbers
  • PCR = to detect parasite DNA and improves sensitivity over microscopy and immunoassay
99
Q

Who discovered the first microscope?

A

Anton von Leeuwenhoek, 1681 - animalcules

100
Q

For what parasites are unstained formal saline wet preparations used?

A

Very good for fresh or preserved stool for protozoa, helminth ova, trophozoites and worms

101
Q

What can be used to detect enteric parasites?

A
  • ELISA
  • Lateral flow device
102
Q

Geo distribution of Giardia Lamblia

A

Worldwide, common in the UK

103
Q

Main symptoms of Giardia Lamblia

A
  • Diarrhoea
  • Foul smelling fatty stool
  • Abdominal pain
104
Q

Diagnosis for Giardia Lamblia

A

Faecal sample:
- Microscopy
- Immunoassay
- NAAT

105
Q

Treatment for Giardia Lamblia

A

Metronidazole tinidazole

106
Q

Causes for Giardia Lamblia

A
  • Poor sanitation
  • Spreads human to human but in some cases animal to human (through faecal-oral contact)
  • We ingest the cyst form of giardia lamblia
107
Q

Size of Giardia Lamblia trophozoite

A

15um in length

108
Q

Size of Giardia Lamblia cyst

A

12um in length

109
Q

Geo distribution of Cryptosporidium parvum

A

Worldwide, common in the UK

110
Q

Main symptoms of Cryptosporidium parvum

A
  • Watery diarrhoea
  • Abdominal pain
  • Fever
  • Weight loss
111
Q

Diagnosis for Cryptosporidium parvum

A

Faecal sample:
- Microscopy (fluorescent staining)
- Immunoassay
- NAAT = PCR

112
Q

Treatment for Cryptosporidium parvum

A
  • Will resolve without treatment
  • Life threatening for HIV positive = immunocompromised
113
Q

Geo distribution of Helminths

A

Warmer resource limited countries

114
Q

Main symptoms of Helminths

A

(faecal oral spread)
- Diarrhoea
- Obstruction
- Anemia

115
Q

Diagnosis for Helminths

A

Ova in stool samples

116
Q

Treatment for Helminths

A

Anti-helminthic = mebendazole

117
Q

Geo distibution for Enterobius vermicularis

A

Resource rich countries, common in the UK

118
Q

Main symptoms of Enterobius vermicularis

A
  • Mild itching
119
Q

Diagnosis of Enterobius vermicularis

A

By ova or worms seen on morning sellotape impressions from peri-anal area

120
Q

Treatment for Enterobius vermicularis

A

Mebendazole

121
Q

What are laminar flow cabinets?

A

High efficiency HEPA filter remove all (99.97%) of particles larger that 0.3um

  • Provides a constant flow of filtered air
122
Q

What is dry heat?

A

Dry heat is often used to sterilize items that can be reused, often used for metal objects, powders and heat resistant materials.

  • Hot air oven at 160C for 2 hours
  • Bunsen burner 1500C for 1 second
123
Q

What is moist heat?

A
  • Autoclaving at 121C for 15 mins
124
Q

What is membrane filtration?

A

Used for heat sensitive materials
- Membrane filters can remove all particles larger that 0.22um
- Does not remove viruses

125
Q

What are antiseptics?

A

They are disinfectants designed to reduce the number of microbes on the skin

126
Q

What is an endogenous source?

A

Autoinfection from the patients’ own microbiome - skin flora, intestinal tract

127
Q

What is an exogenous infection?

A

Cross infection from a source outside of the patients’ own microbiome

128
Q

Common hospital acquired infections

A
  • Surgical wound infections (staphylococcus aureus, e coli…)
  • Bacteraemia
  • Respiratory infections
  • Gastrointestinal infections (clostridium difficile)
  • Urinary Tract infections
129
Q

Hospital acquired viral infection

A
  • Respiratory route = influenza
  • Direct contact = varicella zoster virus
  • Fomites = norovirus/rotavirus
  • Blood borne = hepatitis B virus, hepatitis C virus and HIV (Human immunodeficiency virus)
130
Q

Susceptibility to infection

A
  • Age (<5 and >65)
  • Lacking specific immunity (unvaccinated)
  • Underlying disease (diabetes, cancer…)
  • Medication (steroids, antibiotics, cytotoxic drugs)
  • Other infections
  • Trauma
131
Q

Methods of enhancing resistance to infection:

A
  • Boosting specific immunity for healthcare workers and patients
  • Prophylactic use of antibiotics during procedures
  • Care of invasive devices - cannula and catheters
132
Q

Factors of pathogenicity of bacterial infection

A
  • Adhesion and colonisation
  • Invasion
  • Exotoxins
  • Superantigens
  • Endotoxin
133
Q

Name the membrane cellular active toxins of bacteria

A
  • Lecithinase
  • Haemolysin
134
Q

Cholera toxin

A

Cholera toxin goes into a cells and alters its function, secreted by the organism in the gut lumen - taken in by endocytosis

135
Q

Name the extracellular matrix toxins of bacteria

A
  • Hyaluronidase
  • Collagenase
  • Elastase
    (breakdown tissue)
136
Q

What is cellulitis?

A
  • Deep seated infection
  • Following wound or abrasion
  • Requires systematic antibacterial treatment
  • Common causes: staphylococcus aureus or streptococcus pyogenes
137
Q

What is impetigo?

A

Caused by either staphylococcus aureus or streptococcus pyogenes
- Crusted form or
- Bullous form (pus filled)
- Communicable disease
- Common in young children

138
Q

What are superantigens?

A

Microbial surface antigens that elicit massive activation of immune cells and inflammatory mediators. Resulting hypotension, shock, organ failure, death

139
Q

What are lipopolysaccharide?

A

Major component of the gram negative cells wall
- Can bind to immune cells and activates them to release interleukins - which can result in fevr, vasodilation, antibody production… and with very high levels can result in septic shock

140
Q

Pathogenesis of malaria

A

-Severe anaemia and thrombocytopenia.
-Fever, chills, headache, vomiting, muscle ache, rigor.
-Anorexia and diarrhoea
-Cough and respiratory distress
-Hypoglycaemia, metabolic acidosis.
-Coma associated with increased intracranial pressure (cerebral malaria).
-Complications of pregnancy, preterm birth and low birth weight infants.

141
Q

Pathogenesis of Giardia lamblia

A

-Trophoziotes attach themselves to the surface of the intestinal mucosa via the ventral disc
-Inflammation of the intestinal mucosa results in tissue damage to the intestinal epithelium.
-This interferes with the normal absorptive function of the microvilli.
-Symptoms include: abdominal pain, diarrhoea, foul smelling fatty stools.

142
Q

Pathogensis of dermatophyte infection

A

-Dermatophytes invade keratinised tissue (skin, hair, and nails).
-In immunocompetent hosts they cannot penetrate viable tissue.
-Dermatophytes use proteinases, elastase, keratinases to thrive in the keratinised layers.
-Invasion elicits a host response ranging from mild to severe itching with dry, scaly skin.
-More severe infection with broken skin may allow secondary bacterial infection.

143
Q

What is epidemiology?

A

The study of how often diseases occur in different groups of people and why

144
Q

Define cases

A

Individuals who become infected, these may or may not be confirmed by a lab diagnostic test

145
Q

Define endemic

A

Disease specific to an area

146
Q

Define epidemic

A

A widespread occurrence of an infectious disease in a community at a particular time

147
Q

Define pandemic

A

An epidemic of infectious disease that has spread across a large region; for instance multiple continents, or even worldwide at a particular time

148
Q

Define outbreak

A

An incident in which two / more people experiencing a similar illness are linked in time or place to a common source

149
Q

How do vaccines work?

A
  • Vaccines induce active immunity and provide immunological memory
  • Antibody mediated immunity = stimulation and production of antigen specific B cells and antibody secreting plasma cells
  • Cell mediated immunity = T helper cells (help B cells to produce specific antibody), cytotoxic T cells to kill infected ‘self’ cells and T regulatory cells which suppress the immune system after infection
150
Q

What are adjuvants?

A

An adjuvant is an ingredient used in some vaccines that helps create a stronger immune response in people receiving the vaccine

151
Q

What is passive immunity?

A

Passive immunity can occur naturally, such as when an infant receives a mother’s antibodies through the placenta or breast milk, or artificially, such as when a person receives antibodies in the form of an injection (gamma globulin injection).
- eg. VZIG = varicella zoster immunoglobulin

152
Q

How is the diphtheria vaccine made?

A

The vaccine is made from a cell-free purified toxin extracted from a strain of C. diphtheriae
This is treated with formaldehyde, which converts it into diphtheria toxoid.
This is adsorbed on to an adjuvant to improve its immunogenicity.

153
Q

How is the tetanus vaccine made?

A

The vaccine is made from a cell-free purified toxin extracted from a strain of C. tetani
This is treated with formaldehyde, which converts it into tetanus toxoid.
This is adsorbed on to an adjuvant to improve its immunogenicity.

154
Q

How is the pertussis vaccine made?

A

The vaccines are not whole cells (acellular) but made from highly purified selected components of the Bordetella pertussis organism.
These components are treated with formaldehyde or glutaraldehyde and then adsorbed onto adjuvants, to improve immunogenicity.

155
Q

How is the poliovirus vaccine made?

A

Inactivated polio vaccine (IPV) is made from three polio virus strains
Mahoney (Salk serotype 1) MEF-1 (Salk serotype 2) Saukett (Salk serotype 3)
These are grown in Vero cell culture and then treated with formaldehyde and then adsorbed onto adjuvants to improve immunogenicity.

156
Q

How is the haemophilus influenzae type B vaccine made?

A

Hib-containing vaccines are made from capsular polysaccharide that has been extracted from cultures of Hib bacteria.
The polysaccharide is linked to a protein which increases the immunogenicity, especially in young children, in whom the plain polysaccharide vaccines are not immunogenic.

157
Q

How is the pneumococcal conjugate vaccines made?

A

There are three licensed pneumococcal vaccines in the UK.
Pneumococcal conjugate vaccine (PCV13) contains polysaccharide from thirteen common capsular types conjugated to a protein to increase its immunogenicity in infants.
E.g. Prevenar 13®
Other risk groups include >65 with respiratory disease and splenectomy patients.

158
Q

How is the Hepatitis B virus vaccine made?

A

Hepatitis B vaccines contain Hepatitis B surface antigen (HBsAg) prepared from yeast cells using recombinant DNA technology adsorbed onto an adjuvant.
Engerix B®, Fendrix®, HBvaxPRO®
Passive immunity can be given with Hepatitis B immunoglobulin in urgent circumstance

159
Q

How is the Neisseria meningitidis serogroup C and ACWY vaccine made?

A

The polysaccharides are conjugated to a carrier protein, either CRM197 (a non-toxic variant of diphtheria toxin) or tetanus toxoid

160
Q

How is the rotavirus vaccine made?

A

Rotarix®is the vaccine offered as part of the UK national childhood immunisation programme. It is a live attenuated vaccine derived from a virus initially isolated from a 15-month-old child and then attenuated by serial cell culture passage.
The live vaccine does not require an adjuvant.
The vaccine is over 85% effective at protecting against severe rotavirus gastroenteritis in the first two years of life

161
Q

How is the MMR vaccine made?

A

MMR vaccines are freeze-dried preparations containing live, attenuated strains of measles, mumps and rubella viruses.

162
Q

How is the Human papilloma virus vaccine made?

A

HPV vaccines are sub-unit vaccines made from the major protein of the viral-coat or capsid of HPV. These are recombinant proteins expressed in yeast or baculovirus.
Both vaccines are given with an adjuvant

163
Q

How is the varicella zoster virus vaccine made?

A

Varicella vaccines are lyophilised preparations containing live, attenuated virus.
Varilrix®and Varivax® are used in the UK.
VZIG is prepared from pooled plasma of non-UK donors with suitably high titres of VZ antibody use is restricted to those at high risk.

164
Q

What are antibiotics?

A
  • Treating bacterial infections
  • Disrupt bacterial cell wall and bacterial protein or DNA synthesis
  • Resistance can be intrinsic and acquired and spread
165
Q

What is b-lactam?

A

It’s an antibiotic that inhibits peptidoglycan synthesis, cell and leading to cell death

166
Q

What are antifungals?

A
  • Drugs used to treat fungal infections
  • Disrupts cell wall and cell membrane
  • Many treatments are toxic
167
Q

What are fungicidals used for?

A

Killing fungal cells

168
Q

What are fungistatics used for?

A

Preventing the fungal cell from growing and reproducing

169
Q

What are the 2 groups of antifungals?

A
  • Antifungal antibiotics
  • Synthetic antifungal drugs
170
Q

What are antivirals?

A
  • Drugs used to treat viral infections
  • Non–retrovirals = inhibits viral DNA polymerase and inhibits viral escape from infected cells
171
Q

What is oseltamivir?

A

Binds to active site of neuraminidase - blocks enzymatic activity, preventing release of new viral particles

172
Q

What are echinocandins?

A

They interfere with Inhibits synthesis of 1,3-β-glucan weakening the cell wall leading osmotic stress and cell rupture and death.

Biomedical Science Y1 (Sem 2) (6 decks)

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