MMBIO221 Final Exam Questions and
Answers 2025/2026
Distinguish among septicemia, bacteremia, and toxemia.
septicemia: any microbial infection of the blood that produces illness
bacteremia: bacterial septicemia
toxemia: release of bacterial toxins into the blood
Describe the signs, symptoms, causes, diagnosis, treatment, and prevention of septicemia and
toxemia.
fever, chills, nausea, vomiting, diarrhea, malaise; septic shock can develop rapidly; small
hemorrhagic lesions call petechiae can develop; osteomyelitis occurs if bacteria invade the bones;
toxemia symptoms vary depending on toxin
cause by various bacteria; often opportunistic of healthcare associated infections; septicemia is
caused more often by Gram neg bacteria; bacteria that produce capsule may resist phagocytosis; use
siderophores to acquire iron needed for bacterial metabolism; endotoxin is produced by gram-neg
bacteria
septicemia is due to direct inoculation of bacteria into the blood; immunocompetent individuals
rarely have septicemia (bacterial infections self-limited in these people; Gram- neg bacteria more
often produce severe septicemia (release of endotoxin as bacteria die...activates various defensive
reactions by body)
signs and symptoms are usually diagnostic; treated with prompt diagnosis and administration of
antimicrobial drugs; prevention includes immediate treatment of infections
Describe the actions of endotoxin (lipid A).
produced by Gram-negative bacteria
can cause Leukocytes to release cytokines:
tumor necrosis factor (TNF) and interleukin 1 (IL-1): fever,
,Interleukin-1 and interleukins 6&8: leads to release of immature neutrophils, damage blood vessel
walls, plasma loss, reduction of BP and then Shock!
can cause blood-clotting reactions: disseminated intravascular coagulation (DIC)
can cause complement (C3a and C5a): inflammation and then Shock.
Describe the signs, symptoms, causes, diagnosis, treatment, and prevention of endocarditis.
inflammation of the endocardium; fever, fatigue, malaise, and difficulty breathing, tachycardia may
be detected
normal microbiota are usually responsible; viridans streptococci cause almost half the cases
patients usually have obvious source of infection; patients with abnormal heart have increased risk;
embolus can block blood vessels in other organs
diagnosis is based on symptoms; vegetations visualized by echocardiogram
treated with intravenous antibacterial drugs
prophylactic antibiotics for high-risk patients when needed (like before dental procedures)
Describe the signs, symptoms, and cause of brucellosis.
fluctuating fever that spikes every afternoon
caused by Brucella melitensis strains; endotoxin causes some of the signs and symptoms
consumption of contaminated dairy products; contact with animal blood, urine, or placentas
diagnosed by serological tests and presence of fever; usually requires no treatment; attenuated
vaccine exists for animals.
Define zoonosis, and explain the role of animal husbandry in the spread and prevention of
brucellosis.
diseases that are naturally spread from their usual animal host to humans
livestock in US are often immunized, so less of a threat; slaughter of infected animals also helps
reduce. Most cases are outside US
Describe the signs, symptoms, cause, diagnosis, treatment, and prevention of tularemia.
skin lesions and swollen lymph nodes at infection site; ascending lymphangitis
caused by Francisella tularensis (diverse host range includes mammals, birds, fish, ticks, and insects);
F. tularensis can survive within infected cells; endotoxin causes many signs and symptoms
transmitted via bite of infected tick or contact with infected animal; small size of bacteria allows
entry through seemingly unbroken skin; individuals in contact with dead animals at highest risk
, diagnosis is difficult and requires serological confirmation; treated with antimicrobials; vaccine
available for people at risk for exposure.
Describe the cause, diagnosis, treatment, and prevention of plague.
bubonic plague (characterized by enlarged lymph nodes called buboes)
pneumonic plague occurs when the bacterium spreads to the lungs; difficulty breathing can develop
rapidly)
cause by yersinia pestis; various virulence factors (encoded on virulence plasmids): adhesins, type III
secretion systems, capsules, and antiphagocytic proteins)
transmitted by contact with infected animal or flea feces; bubonic plague fatal in 50% of cases if
untreated; pneumonic plague fatal in 100% of cases if untreated
diagnosis is based on characteristic symptoms; must be diagnosed and treated immediately; treated
with various antimicrobial drugs; prevented with rodent and flea control and good hygiene
Compare and contrast the signs and symptoms of bubonic and pneumonic plague.
bubonic plague (characterized by enlarged lymph nodes called buboes)
pneumonic plague occurs when the bacterium spreads to the lungs; difficulty breathing can develop
rapidly)
Describe the features of the three stages of Lyme disease.
three phases in untreated patients: bull's eye rash at infection site; neurological symptoms; severe
arthritis
caused by the spirochete Borrelia burgdorferi; use of manganese instead of iron circumvents host
defense; avoids immune detection by altering membrane proteins
Elucidate the treatment and prevention of Lyme disease.
diagnosis is based on signs and symptoms of the disease (bacterium is rarely detected in the blood)
antimicrobial drugs are used in the early phases;
treatment of later phases is difficult (symptoms often caused by the immune system)
prevented with repellents containing DEET and with protective clothing
Describe the manifestations of ehrlichiosis and anaplasmosis.
resemble the flu; leukopenia and thrombocytopenia also occur
ehrlichia chaffeensis causes ehrlichiosis; anaplasma phagocytophilum causes anaplasmosis; both
bacteria live inside infected cells;
ticks transmit bacteria to humans
Answers 2025/2026
Distinguish among septicemia, bacteremia, and toxemia.
septicemia: any microbial infection of the blood that produces illness
bacteremia: bacterial septicemia
toxemia: release of bacterial toxins into the blood
Describe the signs, symptoms, causes, diagnosis, treatment, and prevention of septicemia and
toxemia.
fever, chills, nausea, vomiting, diarrhea, malaise; septic shock can develop rapidly; small
hemorrhagic lesions call petechiae can develop; osteomyelitis occurs if bacteria invade the bones;
toxemia symptoms vary depending on toxin
cause by various bacteria; often opportunistic of healthcare associated infections; septicemia is
caused more often by Gram neg bacteria; bacteria that produce capsule may resist phagocytosis; use
siderophores to acquire iron needed for bacterial metabolism; endotoxin is produced by gram-neg
bacteria
septicemia is due to direct inoculation of bacteria into the blood; immunocompetent individuals
rarely have septicemia (bacterial infections self-limited in these people; Gram- neg bacteria more
often produce severe septicemia (release of endotoxin as bacteria die...activates various defensive
reactions by body)
signs and symptoms are usually diagnostic; treated with prompt diagnosis and administration of
antimicrobial drugs; prevention includes immediate treatment of infections
Describe the actions of endotoxin (lipid A).
produced by Gram-negative bacteria
can cause Leukocytes to release cytokines:
tumor necrosis factor (TNF) and interleukin 1 (IL-1): fever,
,Interleukin-1 and interleukins 6&8: leads to release of immature neutrophils, damage blood vessel
walls, plasma loss, reduction of BP and then Shock!
can cause blood-clotting reactions: disseminated intravascular coagulation (DIC)
can cause complement (C3a and C5a): inflammation and then Shock.
Describe the signs, symptoms, causes, diagnosis, treatment, and prevention of endocarditis.
inflammation of the endocardium; fever, fatigue, malaise, and difficulty breathing, tachycardia may
be detected
normal microbiota are usually responsible; viridans streptococci cause almost half the cases
patients usually have obvious source of infection; patients with abnormal heart have increased risk;
embolus can block blood vessels in other organs
diagnosis is based on symptoms; vegetations visualized by echocardiogram
treated with intravenous antibacterial drugs
prophylactic antibiotics for high-risk patients when needed (like before dental procedures)
Describe the signs, symptoms, and cause of brucellosis.
fluctuating fever that spikes every afternoon
caused by Brucella melitensis strains; endotoxin causes some of the signs and symptoms
consumption of contaminated dairy products; contact with animal blood, urine, or placentas
diagnosed by serological tests and presence of fever; usually requires no treatment; attenuated
vaccine exists for animals.
Define zoonosis, and explain the role of animal husbandry in the spread and prevention of
brucellosis.
diseases that are naturally spread from their usual animal host to humans
livestock in US are often immunized, so less of a threat; slaughter of infected animals also helps
reduce. Most cases are outside US
Describe the signs, symptoms, cause, diagnosis, treatment, and prevention of tularemia.
skin lesions and swollen lymph nodes at infection site; ascending lymphangitis
caused by Francisella tularensis (diverse host range includes mammals, birds, fish, ticks, and insects);
F. tularensis can survive within infected cells; endotoxin causes many signs and symptoms
transmitted via bite of infected tick or contact with infected animal; small size of bacteria allows
entry through seemingly unbroken skin; individuals in contact with dead animals at highest risk
, diagnosis is difficult and requires serological confirmation; treated with antimicrobials; vaccine
available for people at risk for exposure.
Describe the cause, diagnosis, treatment, and prevention of plague.
bubonic plague (characterized by enlarged lymph nodes called buboes)
pneumonic plague occurs when the bacterium spreads to the lungs; difficulty breathing can develop
rapidly)
cause by yersinia pestis; various virulence factors (encoded on virulence plasmids): adhesins, type III
secretion systems, capsules, and antiphagocytic proteins)
transmitted by contact with infected animal or flea feces; bubonic plague fatal in 50% of cases if
untreated; pneumonic plague fatal in 100% of cases if untreated
diagnosis is based on characteristic symptoms; must be diagnosed and treated immediately; treated
with various antimicrobial drugs; prevented with rodent and flea control and good hygiene
Compare and contrast the signs and symptoms of bubonic and pneumonic plague.
bubonic plague (characterized by enlarged lymph nodes called buboes)
pneumonic plague occurs when the bacterium spreads to the lungs; difficulty breathing can develop
rapidly)
Describe the features of the three stages of Lyme disease.
three phases in untreated patients: bull's eye rash at infection site; neurological symptoms; severe
arthritis
caused by the spirochete Borrelia burgdorferi; use of manganese instead of iron circumvents host
defense; avoids immune detection by altering membrane proteins
Elucidate the treatment and prevention of Lyme disease.
diagnosis is based on signs and symptoms of the disease (bacterium is rarely detected in the blood)
antimicrobial drugs are used in the early phases;
treatment of later phases is difficult (symptoms often caused by the immune system)
prevented with repellents containing DEET and with protective clothing
Describe the manifestations of ehrlichiosis and anaplasmosis.
resemble the flu; leukopenia and thrombocytopenia also occur
ehrlichia chaffeensis causes ehrlichiosis; anaplasma phagocytophilum causes anaplasmosis; both
bacteria live inside infected cells;
ticks transmit bacteria to humans
