1-1 Medical Microbiology

Question 1

Genetic changes in organisms can lead to many changes…name 3 changes

Answer 1

1. Increased pathogenicity
2. Different host range
3. Drug resistance

Question 2

Some infections have become more rare due to public health measures…what are the three broad public health measures that have led to the reduction in the spread of infectious disease

Answer 2

1. Clean water (associated with rarity of cholera)
2. Clean air (associated with reduction in tuberculosis)
3. Vaccines (smallpox, polio, measles, mumps, rubella, etc.)

In these cases, organisms have NOT changed and the infections will reappear if these public health measures are not followed

Question 3

Which of the following infections have declined in severity due to improved hygiene?

A. measles
B. diptheria
C. hepatits B
D. cholera

Answer 3

D. Cholera

The decline in cholera has been associated with public health measures to improve/test water quality

Question 4

Vaccines have helped the decline in which infectious conditions?

A. Syphilis
B. Multiple sclerosis
C. Smallpox
D. AIDS

Answer 4

C. Smallpox

No vaccine for Syphilis, MS, or AIDS

Question 5

Which of the following is most likely to be preventable by vaccines?

A. Obesity
B. Multiple sclerosis
C. Cervical cancer
D. Alzheimer’s disease

Answer 5

C. Cervical cancer

HPV vaccine

Question 6

Development of novel human infections can be caused by?

A. Mutations in the 16s rRNA gene
B. Evolutionary development of new genes
C. Changes in host range
D. Emergence of new genuses of bacteria

Answer 6

C. Changes in host range

AIDS was originally in non-human primates but changes in host range led to the ability to infect humans

SARS originally Civets/bats

Question 7

Drug resistant strains of microorganisms can arise from:

A. increased complexity of the genome
B. Development of new genes
C. Minor genetic changes such as point mutations
D. Deletions in the 16S rRNA gene

Answer 7

C. Minor genetic changes such as point mutations

Question 8

What is the 16S rRNA gene?

Answer 8

The gene for 16sRNA is unique for each species, but is flanked by common sequences…where universal regions can be used as primer binding sites for PCR or gene sequencing.

Living things can be sorted into groups by comparison of the DNA sequence of their 16sRNA gene…this allows for a broad classification into three domains-Bacteria, Archaea, and Eukarya

Question 9

Discuss how changes in infectious diseases are influenced by genetic changes in microorganisms and by public health measures.

Answer 9

Genetic Changes in Microorganisms – Leads to modification in pathogenicity, host range, and drug resistance. These changes make it necessary for us to adapt our approach to treating microbe infections.
Public Health Measures- Initiatives can be taken to improve public health conditions and lower the risk of exposure to certain pathogens. For example, John Snow’s water pump solution to the cholera outbreak in London.

Question 10

why might alzheimer’s be infectious?

Answer 10

Alzheimer’s disease has the characteristics of a slow viral disease. Some researchers believe that it is in fact due to a viral infection, but no one has discovered any related microorganism or virus yet.