Question

microbiology case study (worth 25 points)

1) A first-year microbiology student clad in shorts overturns his motorcycle on a patch of gravel. He sustains considerable abrasions and deep lacerations of the right leg. Emergency room personnel have great difficulty trying to remove embedded gravel and dirt. Later many areas of infection develop, and dead tissue can be seen at other sites of the abrasions.

A) Describe any pathogenic processes that could be occurring at the sites of injury [invasion, attachment, colonization etc.]. To be AT least A Paragraph

B) What type of antibiotic [broad or narrow spectrum] would most likely first be administered? HOW does your antibiotic effect the MICROBE? [what structure is affected and HOW]

C) Are his infections most likely due to pathogens or opportunists? Explain your answer.

2) A young mother tried to save money by buying cracked eggs at a local farm. The eggs were labeled “not for human consumption - for pets only”. She cooked some of the eggs and fed them to her toddler son, who became intensely ill with severe cramps, shortness of breath and loss of kidney function within a few hours. He was hospitalized with a diagnosis of salmonellosis. He nearly died.

A) Did the boy suffer from an infection or intoxication? What clinical data could support your conclusion? [NOT that he nearly died]

B) Why didn’t cooking the eggs protect him?

C) What is the etiology of his disease? Was the chicken ill? [this requires more than yes or no, say WHY]

D) Is the boy now immunized against future occurrences? Why or why not?

3) There are over 150 known strains of bacteria that are considered normal human flora.

A. What are some factors enable these “normal biota” to become pathogenic and invade the host? [I am looking for microbe Virulence factors]

B. Explain why some bacteria infect specific tissues or regions of the host. (This was in the movie, Bacteria and Humans)

C. What are some properties of the bacteria that allow these organisms to evade host defense mechanisms?

4) Recall the last time that you [or your patient] fell ill from a microbe.

a. Was the condition due to a bacterial or viral infection? Which microbe(s) could be causing the illness?

b. What media and tests can be performed IN THE LAB to identify the suspect organism? EXPLAIN FOUR LAB protocols and the expected results. (This should be consistent with what you write for a.)

c. What was happening in the body over the course of this illness? Describe the microbes’ growth, AND virulence factors produced.

d. What was your body’s immediate defenses against the microbe?

Answer 1

Question

1.

A. The bacterial cell attach to the host injury cell specific receptors and this process is known as invasion. The bacterial cells basically receptors that are mainly specific carbohydrate or peptide residue. Once the bacterial invade the bacterial cells, they start colonizing inside the bacterial cells . The opportunistic bacteria invade the host body taking advantage of injuries or breaches. The bacteria are able to cross host barriers and where they proliferate and cause severe infection at the wound.

B. The broad -spectrum antibiotics are best against this bacterial infection. This is because we are unsure whether the bacteria that inavde at the injury sites are gram-positive or gram-negative. Therefore, broad-spectrum antibiotics that could kill both gram-positive and gram-negative bacteria is the best option to treat bacterial infection. The antibiotics are able to the bacterial structure that are important for the growth and survival of the bacteria. For example, antibiotics hit the ribosome, cell wall and other metabolic pathway of bacteria.

C. The infection are most likely to opportunist bacteria. This is because these bacteria invade the body of the host by taking advantage of the injury. At the time of injury, the body immune system get weak and the bacteria take advantage of this situation and enter in the host body. Therefore , infection are most likely to take place by opporunistic bacteria.