305 microbiology and pathology Flashcards
Microorganisms that have the capability of producing a disease are referred to as what?
Pathogenic microorganisms/Pathogens
Microorganisms that do not have the capability of producing illnesses or diseases are referred to as what?
Non pathogens
what are the 3 main groups of pathogenic microorganisms?
Bacteria: Microscopic single cell organisms that can survive as inactive spores when conditions do not let them grow or reproduce.
Viruses: Ultra microscopic organisms that live within cells of other organisms
Fungi: Types of microscopic plant organisms that grow across tissue cells as an extensive branching network of fungal tissue
What is the fourth type of microorganism, but has no relevance to dentistry as the microorganism does not cause diseases within the oral cavity?
Protozoa
What are prions?
Not living microorganisms but an infectious protein that is capable of causing disease
What are the diseases caused by prions?
Kuru in humans, Mad cow disease and its human variant called Creutzfeldt-Kakob disease (CJD) and its new variant VCJD
Why is the transmission of CJD and VCJD becoming a concern in dentistry?
Prions are not killed by decontamination or sterilisation which means an infected patient could pass on CJD to another patient when instruments are sterile
Prions are specifically known to effect what?
Nerve tissue
Why are endodontic instruments considered single use items?
They come in contact with the nerve tissue found within the pulp of the teeth, using single use items avoids the possibility of passing prions from one patient to another
What are the 3 bacteria’s?
Cocci: Circular microorganisms. Those living in clusters are called Staphlococci. Those living in chains are called Streptococci
Bacilli: Rod shaped with pointed ends. Rounded ends are called Lactobacilli
Spirochaetes: Spiral shaped like a helix
What can bacteria survive as and why?
Spores. When bacteria can not grow it can survive as spores. This is because spores have a hard outer coating that protects the bacteria within from chemicals, drought and change in temperature. This means they can survive cleaning chemicals used for disinfection so items have to be sterilised or used once
What is anaerobic bacteria,why is it harmful and what is it also known as?
This type of bacteria is an organism that doesn’t require oxygen to grow. It is harmful because these are difficult to remove physically and require drug treatment methods. Also known as an anaerobe
what is aerobic bacteria?
Organisms that require an oxygenated environment
To fight against bacteria the most important drug groups are?
Antibiotics: Taken to kill bacteria causing illness but can kill useful bacteria in the body e.g digestive system-associated with stomach pains and diarrhoea. Different antibiotics are required when infections are anaerobic or aerobic.
Bactericidal agents: Chemicals used to clean externally that act to kill bacteria e.g on work surfaces.
Bacteriostatic agents: Chemicals used to clean externally, don’t kill externally but prevent them from reproducing
What is the associated disease with the bacteria called Streptococcus mutans?
Dental caries
Initial ineffective bacteria found in a caries, when a cavity first forms. Also responsible for most of the production of the weak organic acids that cause enamel demineralisation
What is the associated disease with the bacteria called Lactobacillus?
Established dental caries
Later colonisation of an established caries lesion, as the deeper tooth tissues become infected
what is the associated disease with the bacteria Actinomyes, Prophyromonas gingivalis, Prevotella, Intermedia, Treponema, Denticola, fusobacterium, nucleatum, Campylobacter, Rectus? And what is it?
Periodontal disease
Periodontal disease is the bacterial infection of the supporting structures of the teeth e.g gingivae, periodontal ligament, cementum, alveolar bone
What is the associated disease with the bacteria staphylococci?
Skin boils, gingival boils and impetigo
What is the associated disease with the bacteria bacillus fusiformis and borrelid vincentii?
Gingivitis
Acute necrotising ulcerative gingivitis, a specific periodontal infection seen in young adults when their oral hygiene is particularly poor
What is the structure of a virus?
Reproductive chemicals
protein capsule
base to attach to host
What is a anti-viral agent?
Drugs to treat viral infections
What drug is used to treat cold sore lesions on the lip caused by herpes simplex type 1 virus?
The drug Aciclovir used as a topical cream
What is acquired immunity?
Immunity that develops after exposure to a dead virus or its protein capsule which is injected in to the individual or given orally. The presence of this causes the bodys immune system to fight against it making anti-bodies, so if the person is exposed to the viral disease the body can fight it
How are viruses killed?
Sterilisation/use of viricidal chemicals
What does a viricidal chemicals do?
Viricidal/viracide is a chemical agent that destroys viruses
What is the associated disease with the virus name Hepatitis A,B,C?
Various inflammatory liver disease some are fatal.
Hepatitis B vaccinations are an occupational health requirement
What is the associated disease with the virus Human Papillomavirus (HPV)?
Oral cancers
Certain types of this virus have been inked to oral cancer, especially those occurring in the oropharyngeal regien- the part of the throat at the back of the mouth
What is the associated disease with the virus Herpes varicella?
Chicken pox
Chicken pox which effects the area supplied by the trigeminal nerve (cranial nerve v) as well as the torso.
Trigeminal nerve is responsible for sensations in the face and motor functions such as biting and chewing
What is the associated disease with the virus Human Immunodeficiency virus (HIV)?
Aids
A blood borne infection which was initially found in certain patient groups; drug users/homosexuals but can now be found in the wider population
What is the associated disease with the virus herpes zoster?
Shingles
A painful blistering skin rash which can involve the area supplied by the trigeminal nerve (cranial nerve v) as well as the torso
What is the associated disease with the virus Herpes simplex type 1?
Cold sores
Blister lesions occurring on the lips, highly infectious in their initial stages if touched
What is the associated disease with the virus Epstein-Barr virus
Glandular fever
A debilitating viral infection which results in painfully swollen lymph glands including those found in the neck. Lymph glands are also known as lymph nodes
What is the associated disease with the virus Paramyxovirus?
Mumps
A viral infection of the parotid salivary glands (either one or both) but doesn’t effect any other salivary glads.
What is the associated disease with the virus Coxsackievirus?
Hand, foot and mouth disease
A common infection seen in young children which presents as painful blistering in the oral cavity, on the palms of their hands and soles of their feet
What are the characteristics of fungi/how do they grow?
Plant like organism. Grow as an extensive network of branches lying across the body tissues called hyphae and reproduce by budding out from the ends of the hyphae or by the producing of spores from fruiting bodies like microscopic mushrooms
Which fungal infection is important in dentistry?
Candida albicans
What is the fugal infection caused by Candida albicans responsible for?
lesions and diseases in the mouth called:
Acute oral candidosis (oral thrush)
Chronic oral candidosis
Angular cheilitis
Give an explanation of Acute oral candidosis (oral thrush)?
Removable white film with red sore patches on the soft tissues of the oral cavity-hard palate and cheeks. Associated with ill health in the elderly or those suffering from disease e.g aids.
In a healthy individual this would develop because of the disruption in the populations of the normal oral bacteria usually following a cause of antibiotics, known as denture sore mouth.
Give an explanation of Chronic oral candidosis/what is it also known as?
Also known as denture stomatitis. Occurs in healthy patients beneath both dentures and removable orthodontic appliances as a reddened but painless area lying exactly across the platal section of the appliance. It is associated with poor appliance hygiene and raised moisture levels beneath the appliance allowing the fungus to colonise the underlying oral tissues
Give an explanation of Angular chelitis?
Involves the angles of the mouth, appears inflamed/ cracked which is often crusted over. wide mouth opening will split the lesion and cause bleeding and more splitting. Associated with constant saliva leakage into the angles, allowing the fungal infection to occur-patients usually have deep tissue folds here or a ‘crumpled face’ appearance due to loss of their occlusal face height. This may be due to edentulousness, worn dentures or tooth surface loss with age
How are fungal infections treated?
Treated with ani-fungal agents:
Tablets
oral gels
oral solutions/pastille
What are some examples of antifungal agents?
Topical nystatin pastilles or solution
Amphotericin lozenges tablets
Miconazole gel
Sustemic fluconazole tablets
What are the effects of disease on the body?
Infection/Inflammation
Ulceration
Oral white/Red Patches
Formation of a cyst
Formation of a tumore- Bengin or malignant
Congenital or development defect
What is an infection?
An infection is an invasion of the body cells by the pathogens, resulting in a inflammatory response of cells that produces the five signs of inflammation
What are the five signs of inflammation?
Heat
Swelling
Pain
Redness
Loss of function