MMSC 428 Exam 1 Questions and Answers Fully Solved Latest Version 2025-2026
what is mutualism? give an example - Answersboth organisms benefit (ex: lactobacilli in female
genital tract keeps pH low so other bacteria can't live there)
what is commensalism? give an example - Answersone organism benefits, the other isn't
harmed or benefitted (ex: human's intestinal flora)
what is parasitism? give an example - Answersan organism benefits at the expense of its host
(ex: viruses and parasites)
define endemic and give an example - Answersdisease that occurs regularly in a population as a
matter of course (malaria in africa, lyme in delaware)
define epidemic and give an example - Answersrise in incidence of a disease in a region that is
short-lived (ebola or influenza)
define pandemic and give an example - Answerswidespread disease in a country or worldwide
(covid or hiv/aids)
what are some of the most deadly infectious diseases worldwide? - Answerslower respiratory
infections (pneumonia), neonatal conditions, diarrheal disease
why are infectious diseases more commonly deadly in low income countries? - Answersless
access to medicine and doctors, as well as less education about disease and prevention
what are the four types of emerging infectious diseases? - Answers- newly identified pathogen
with new disease (like ebola or covid)
- old pathogen with new presentation (like group a strep
- increase in incidence/ geographical distribution of infection (like west nile in the US)
- human pathogen recently associated with old disease (helicobacter pylori - peptic ulcers,
porphyromonas gingivalis - alzheimer's (?)
explain the ecologic factors in the emergence of infectious diseases - Answersoften associated
with agricultural development, frequently zoonotic (originally in animals, then "jump" to humans)
due to deforestation/reforestation
explain the climate factors in the emergence of infectious diseases - Answersglobal warming
explain the human demographic factors in the emergence of infectious diseases -
Answersurbanization
explain the international travel factors in the emergence of infectious diseases -
Answerstravelers facilitate (historically) transmission of infectious agents
,explain the shipping/transport factors in the emergence of infectious diseases - Answers-
mosquitoes in shipping containers carrying dengue and yellow fever
- microorganisms (like cholera) living in ppl and brought to other countries
- anthrax found in animal wool/food when not cleaned/sterilized properly
explain the public health factors in the emergence of infectious diseases - Answers- public
health and sanitation, monitoring inspection of food for e. coli (meat and produce), salmonella
(chicken and eggs), listeria (dairy)
- drinking water/waterborne pathogens
explain the adaptability of microorganisms factor in the emergence of infectious diseases -
Answers- microogranisms reproduce and evolve faster than ppl
- resistance to antimicrobial agents AMR/AR)
explain how biofilms work - Answers- biofilms build up in pipes that run drinking water
- start small, build bubbles, then burst and release bacteria into the water
- planktonic: the bacteria released
- sessile: bacterial secretions formed in the biofilm
define antibiotic resistance - Answerswhen bacteria and fungi develop the ability to defeat the
antibiotics designed to kill them
how do people develop HAIs (nosocomial infections)? - Answerswhile receiving care in a
hospital/healthcare setting (abt 1/25 are affected), and a lower rate of incidence is a reflection
on how the hospital is run
who is at high risk for developing an HAI? - Answers- immunocompromised
- patients in ICU
- patients getting dialysis
- patients on ventilators
- patients with severe burns
- invasive/surgical procedures
- intravascular catheters/indwelling urinary catheters
what is MRSA? (common causative agent of HAIs) - Answersmethicillin-resistant s. aureus
, found on skin, but can grow resistant to beta lactams (penicillin)
what is VRE? (common causative agent of HAIs) - Answersvancomycin-resistant Enterococcus
in GI tract, becomes resistant to drugs for gram (+); can't get rid of this once you have it
what is CNS? (common causative agent of HAIs) - Answerscoagulase-negative staphylococci
found on skin normally, when in catheter it can get into blood
what are pseudomonas and acinetobacter? (common causative agents of HAIs) - Answersmulti
drug resistant
normally in aquatic envts in nature, can be in healthcare envts
what is e. coli? (common causative agent of HAIs) - Answerstypically comes from the person's
own bacteria becoming resistant
what is klebsiella pneumoniae? (common causative agent of HAIs) - Answersmulti drug
resistant
resistant to almost all antibiotics
what is clostridium difficile? (common causative agent of HAIs) - Answersc diff comes in
spores
causes antibiotic associated diarrhea
explain the difference between biological warfare and bioterrorism - Answersbiological warfare
are biological agents targeted at the military, but bioterrorism targets civilians to incite panic
and chaos
what is category A (tier 1) of bioterrorism agents? list examples - Answers- immediate dangers
to people
- transmitted thru water/air, can infect anyone
- found normally, but can be weaponized
- clostridium botulinum (botulinum toxin, botox), bacillus anthracis (anthrax)
what is category B (tier 2) of bioterrorism agents? list examples - Answers- moderate risk to
people
- TB an cholera
what are the three levels of laboratory response networks (LRNs) and what is each responsible
for? - Answers- sentinel (commercial/hospital) labs: recognize, rule out, refer
what is mutualism? give an example - Answersboth organisms benefit (ex: lactobacilli in female
genital tract keeps pH low so other bacteria can't live there)
what is commensalism? give an example - Answersone organism benefits, the other isn't
harmed or benefitted (ex: human's intestinal flora)
what is parasitism? give an example - Answersan organism benefits at the expense of its host
(ex: viruses and parasites)
define endemic and give an example - Answersdisease that occurs regularly in a population as a
matter of course (malaria in africa, lyme in delaware)
define epidemic and give an example - Answersrise in incidence of a disease in a region that is
short-lived (ebola or influenza)
define pandemic and give an example - Answerswidespread disease in a country or worldwide
(covid or hiv/aids)
what are some of the most deadly infectious diseases worldwide? - Answerslower respiratory
infections (pneumonia), neonatal conditions, diarrheal disease
why are infectious diseases more commonly deadly in low income countries? - Answersless
access to medicine and doctors, as well as less education about disease and prevention
what are the four types of emerging infectious diseases? - Answers- newly identified pathogen
with new disease (like ebola or covid)
- old pathogen with new presentation (like group a strep
- increase in incidence/ geographical distribution of infection (like west nile in the US)
- human pathogen recently associated with old disease (helicobacter pylori - peptic ulcers,
porphyromonas gingivalis - alzheimer's (?)
explain the ecologic factors in the emergence of infectious diseases - Answersoften associated
with agricultural development, frequently zoonotic (originally in animals, then "jump" to humans)
due to deforestation/reforestation
explain the climate factors in the emergence of infectious diseases - Answersglobal warming
explain the human demographic factors in the emergence of infectious diseases -
Answersurbanization
explain the international travel factors in the emergence of infectious diseases -
Answerstravelers facilitate (historically) transmission of infectious agents
,explain the shipping/transport factors in the emergence of infectious diseases - Answers-
mosquitoes in shipping containers carrying dengue and yellow fever
- microorganisms (like cholera) living in ppl and brought to other countries
- anthrax found in animal wool/food when not cleaned/sterilized properly
explain the public health factors in the emergence of infectious diseases - Answers- public
health and sanitation, monitoring inspection of food for e. coli (meat and produce), salmonella
(chicken and eggs), listeria (dairy)
- drinking water/waterborne pathogens
explain the adaptability of microorganisms factor in the emergence of infectious diseases -
Answers- microogranisms reproduce and evolve faster than ppl
- resistance to antimicrobial agents AMR/AR)
explain how biofilms work - Answers- biofilms build up in pipes that run drinking water
- start small, build bubbles, then burst and release bacteria into the water
- planktonic: the bacteria released
- sessile: bacterial secretions formed in the biofilm
define antibiotic resistance - Answerswhen bacteria and fungi develop the ability to defeat the
antibiotics designed to kill them
how do people develop HAIs (nosocomial infections)? - Answerswhile receiving care in a
hospital/healthcare setting (abt 1/25 are affected), and a lower rate of incidence is a reflection
on how the hospital is run
who is at high risk for developing an HAI? - Answers- immunocompromised
- patients in ICU
- patients getting dialysis
- patients on ventilators
- patients with severe burns
- invasive/surgical procedures
- intravascular catheters/indwelling urinary catheters
what is MRSA? (common causative agent of HAIs) - Answersmethicillin-resistant s. aureus
, found on skin, but can grow resistant to beta lactams (penicillin)
what is VRE? (common causative agent of HAIs) - Answersvancomycin-resistant Enterococcus
in GI tract, becomes resistant to drugs for gram (+); can't get rid of this once you have it
what is CNS? (common causative agent of HAIs) - Answerscoagulase-negative staphylococci
found on skin normally, when in catheter it can get into blood
what are pseudomonas and acinetobacter? (common causative agents of HAIs) - Answersmulti
drug resistant
normally in aquatic envts in nature, can be in healthcare envts
what is e. coli? (common causative agent of HAIs) - Answerstypically comes from the person's
own bacteria becoming resistant
what is klebsiella pneumoniae? (common causative agent of HAIs) - Answersmulti drug
resistant
resistant to almost all antibiotics
what is clostridium difficile? (common causative agent of HAIs) - Answersc diff comes in
spores
causes antibiotic associated diarrhea
explain the difference between biological warfare and bioterrorism - Answersbiological warfare
are biological agents targeted at the military, but bioterrorism targets civilians to incite panic
and chaos
what is category A (tier 1) of bioterrorism agents? list examples - Answers- immediate dangers
to people
- transmitted thru water/air, can infect anyone
- found normally, but can be weaponized
- clostridium botulinum (botulinum toxin, botox), bacillus anthracis (anthrax)
what is category B (tier 2) of bioterrorism agents? list examples - Answers- moderate risk to
people
- TB an cholera
what are the three levels of laboratory response networks (LRNs) and what is each responsible
for? - Answers- sentinel (commercial/hospital) labs: recognize, rule out, refer
