Introduction to Microbiology

Question 1

Louis pasteur

Answer 1

Louis Pasteur demonstrated that microorganisms to not arise spontaneously in media but when introduced from the environment he also established that microorganisms can be inactivated by heat and pressure and therefore that food could be preserved by process that we know as pasteurization. He also develop vaccines against chicken cholera, anthrax and rabies

Question 2

Joseph lister

Answer 2

After reading the work of Louis Pasteur Joseph Lister a surgeon started to employ a number of aseptic techniques in his surgery is sterilized the surgical instruments with heat and use fennel in surgical dressings these techniques resulted in fewer postoperative infections providing strong indirect evidence that microorganisms play a role in disease

Question 3

Robert Koch

Answer 3

Robert Koch was the first person to demonstrate directly that bacteria cause disease cause she initially worked on anthrax and demonstrated at Derek relationship between exposure to bacillus anthracis and the disease anthrax he developed what we known as Koch postulates which a list of criteria to verify a particular age and is responsible for a specific disease he then worked on mycobacterium tuberculosis and prove that it is the causative agent of tuberculosis

Question 4

Kosh postulates

Answer 4

The criteria developed by Robert cost to demonstrate relationship between a microorganism and a specific disease.
1 the microorganism must be present in every case of the disease but absent from healthy animals
2 suspected microorganisms must be isolated and grown in pure culture
3 the same disease must result when isolated microorganisms is inoculated into healthy
4 same microorganism must be isolated again from diseased host

Question 5

Pathogen

Answer 5

Biological asian that can cause disease in a host the host maybe a plan and animal fantasizing microorganisms

Question 6

Pathogens may be

Answer 6

Cellular as in the case of bacteria fungi and protozoa or they may be non-cellular as in the case of viruses and prions

Question 7

Pathogens can be divided into

Answer 7

Obligate pathogens that can only survive and reproduce within a host they cause disease before the degree of illness may vary
Accidental or incidental pathogens that can survive without causing disease in a host Many fall into this group living either as part of normal flora and sometimes causing disease or living in other host or reservoirs and causing disease when suitable conditions and susceptible host present themselves

Question 8

Bacterial pathogens can be divided onto

Answer 8

Opportunistic pathogens seldom cause disease in individuals with intact natural defences and immune system
and primary pathogens can cause infection and disease in otherwise healthy people have intact immune systems

Question 9

Conditions for opportunistic bacteria

Answer 9

Compromised immune system example from diseases surgery or malnutrition
when competing bacteria have been removed when bacteria enter sites where they are not normally found

Question 10

Epidemiology

Answer 10

Study of the frequency distribution causes and effects of health and disease in populations

Question 11

Pathology

Answer 11

Study and diagnosis of disease through the examination of organs tissues and bodily fluids

Question 12

Virulence

Answer 12

The degree of pathogenicity of an organism and its related to the ability of the organism to invade and damaged tissues of the host

Question 13

The infectious process

Answer 13

Involves interaction between a pathogen host and the environment

Question 14

Virulence of an organism depends on

Answer 14

It’s invasiveness
it’s toxicity
the dosage
Thee portal of entry

Question 15

Spread of infection

Answer 15

Carriers affected and transmit disease yet remain healthy some diseases are contagious during incubation and still other diseases are acquired from animal or environmental sources

Question 16

Mode of transmission

Answer 16

Direct contact indirect contact a food and waterborne transmission animal vectors transplacental transmission

Question 17

Portals of entry

Answer 17

Respiratory tract upper and lower airways the mouth the genital area the urinary tract damage skin cuts and Burns
Symptoms of the illness can also promote the transmission of disease for example runny nose diarrhoea cough genital discharge

Question 18

Bacterial pathogenicity

Answer 18

Bacteria a haploid and reproduce by binary fission the binary fission process does not allow for the exchange of genetic material however but you have develop mechanisms for exchanging genetic information through the transfer of extrachromosomal genetic elements for example plasmids the genes associated with virulence factors often included on extrachromosomal genetic elements and if they are transferred between bacteria the back to receiving the genetic material gain the genes for those virulence factors

Question 19

Virulence factors

Answer 19

Elements that enhance enhance effective is ability to cause infection and disease adherence factors invasive factors toxins enzymes and antiphagocytic eptic factors bacteria secretion systems

Question 20

Diagnostic specimen

Answer 20

Tissue samples
Blood
Urine
Cerebrospinal fluid
Respiratory secretions
Gastrointestinal tract specimen
Genital discharge

Question 21

Diagnostic tools and techniques

Answer 21

Microscopy
Cultures
Serology 
Antigen and antibody detection
Biochemical analysis
Molecular techniques

Question 22

Treatment

Answer 22

But two infections are usually treated with antibiotics viral infections are treated with anti-viral compounds and fungal infections are treatable antifungal parasites are treated with a variety of antiparasitic drugs immunization with vaccines is an effective way of preventing illness caused by pathogens vaccines work by exposing the body to elements of the pathogen and other in the immune system to become a lot to that pathogen this strengthens the body’s defence against pathogens or if the individual ever becomes infected the immune system is able to attack and destroy the pathogen before it causes disease

Question 23

Hospital infections nosocomial

Answer 23

Infections which were not present at the time the patient was admitted but instead are acquired while the patient is in hospital these infections become apparent only after the patient has been discharged

Question 24

Nosocomial infections may be acquired from

Answer 24

Exogenous sources from other patients or environment
Endogenous from diff site within same patient
Most common nosocomial infections are of the urinary tract surgical site or pneumonia
Infection controlled by sanitation of surfaces hand washing or changing gloves between patients changing gown regularly sterilisation or equipment and isolation of infective patients