Question
Microbiology Study Guide
29. Whicdh of the following is true for whty penicillin cammot be used to treat atypical yneumonia cnuised by Mfycoplasma pmeumoniae? W. Mycoplasma is a virus Y?Mbeoplasma lacks DNA and RNA. Mcoplasma lacks cellular structure Mycoplasma lacks cell wall Mycoplasma lacks cytoplasmic membranes Physicians do not prefer to treat parients with a broad-spectrum antimicrobial chemical because it can lead to serious, subsequent superinfections by one or A. True B. False 30. more members of the normal microbiota. 31. Most regions and surfaces of the human body lack bacteria and must be kept sterile. A. True B. False 32. In order to treat diseases, physicians depend on pathology labs to study specific pathogens and run sensitivity test to assess the effectiveness of the antimicrobial agents on them. Which of the following test is performed to classify the pathogens into susceptible, intermediate or resistant to cach drug tested? A. Diffusion susceptibility or Kirby-Bauer test B. Minimum inhibitory concentration (MIC) test C. Minimum bactericidal concentration (MBC) test 33. Use of probiotics is becoming more popular! Which of the following is true for probiotics? A. Probioties are antimicrobial agents used to treat infections. B. Probiotics are extracts of bacteria that are part of the normal microbiota. C. Probiotics is an alternate term for antibiotics D Probiotics are beneficial microbes introduced in the body to help prevent diseases. E. Probiotics is just a myth when it comes to treating infections and promoting human health. 34. Most common way for bacteria to become resistant to an antimicrobial agent is by acquiring plasmids with R gene. A. True B. False 35. All of the following are ways to treat a patient with resistant bacteria types except A. Withdraw the use of antimicrobial drugs. B. Use sufficiently high concentration of the drug C. Use a combination of drugs. D. Use new chemical variation or synthetic drug complementary to the shape of microbial proteins. E. Use the drug for longer period of time. 36. All of the following are prokaryotic except A. Viruses B. Bacteria C. Archaea
Explanation / Answer
29) mycoplasma lacks cell wall.
Pencilin belongs to the beta-lactam family of antibiotics. These antibiotics inhibits the bacterial cell wall synthesis. Mycoplasma pneumoniae belongs to the genus Mycoplasma and all the species of this genus lack a cell wall. Hence any of the beta-lactum antibiotic is not affective against this genus of bacteria.
30) True
If physicians administer broad spectrum antibiotics, the microbiota in human gut can develop drug resistance. This can result in a super infection by a common microbe in the microbiota which is multi drug resistant. hence treating this infection can be difficult and can sometimes be fatal.
31)False
Almost all surfaces of human body is covered by microbes.
32) MIC or Minimum inhibitory concentration
The MIC test is used to classify a pathogen as susceptible , resistant and intermediate.
'The "susceptible" category pathogens are the ones inhibited by the usually achievable concentrations of antimicrobial agent (normal dosage of drug).
'The "resistant" pathogens are not inhibited by the normal dosage schedules.
'The "intermediate" patogens are those that at MICs that have a lower response rate than that of susceptible pathogens.