MICROB 3200 (Baldwin) Virus Classification, Microbiology
Final Exam, 2026 Complete Exam Questions with Verified
Answers
Introduction
This document contains comprehensive MICROB 3200 final
exam questions and verified answers focused on virus
classification, viral replication, viral pathogenesis, the
Baltimore classification system, and microbiology laboratory
diagnosis. It also covers major bacterial pathogens, virulence
factors, diseases, treatments, and diagnostic characteristics
relevant to microbiology exam preparation.
The material is presented in a question-and-answer format for
efficient studying and review. It includes detailed
explanations of virology concepts, bacterial identification, and
clinically important infectious diseases commonly tested on
final examinations.
Exam Questions and Answers
general purpose medium --- correct precise answer ---low
cost medium to enrich many types of bacteria (trypticase soy
agar (TSA))
Blood agar
Staphylococcus aureus --- correct precise answer ---coagulase
+
-large colonies
,-creamy white to golden color
-beta-hemolytic (straw colored zone of clearance around
colony)
coagulase -
-large colonies
-creamy white color
-non-hemolytic (lysis of RBCs)
mannitol salt agar (selective and differential medium) ---
correct precise answer ----high salt inhibits most organisms
(streptococci, gram -)
-mannitol sugar: termination results in acid production,
phenol red in media turns yellow
baird parker agar (selective and differential medium) ---
correct precise answer ---staphylococci produce dark gray to
black colonies due to tellurite reduction
-S. aureus - produces lecithinase (lipase) which breaks down
egg yolk and causes clear zones around respective colonies
(halos)
-S. epidermidis & S. saprophyticus - no halo
coagulase test --- correct precise answer ---positive: S. aureus
negative: S. epidermidis/saprophyticus
oxidase test --- correct precise answer ---used to determine if
bacterium contains cytochrome c oxidase and can therefore
,use oxygen for energy production by converting O2 to H2O2 or
H2O with an ETC
--negative (all staphylococci)
catalase test --- correct precise answer ---catalase catalyzes
the conversion of hydrogen peroxide to oxygen and water
streptococcus and enterococcus spp. --- correct precise
answer ----low G+C
-facultative anaerobic metabolism
-capnophiles - increased CO2 required for growth
-gram + cocci in chains
-catalase negative
-hemolysis: A, B, Y
-part of human resident microbiota
--S. progenies is a primary pathogen
streptococcus pneumoniae --- correct precise answer ---alpha
hemolysis (green color)
streptococcus pyogenes --- correct precise answer ---beta
hemolysis (straw color)
enterococcus faecalis --- correct precise answer ---gamma
hemolysis (no hemolysis)
Streptococcus agalactiae --- correct precise answer ---
NARROW zone of beta hemolysis
, streptococcus pyogenes (Group A) virulence factors --- correct
precise answer ---cell associated factors
-capsule -> blocks phagocytosis by neurophils
-M protein -> binds to factor H -> prevents opsonization by
complement (highly antigenic)
-LTA (lipoteichoic acid) -> cell attachment
toxins
-streptococcal pyrogenic exotoxins (superantigens)
-streptolysins S and O (B-hemolysins)
-hyluronidase (connective tissue)
-streptokinase (fibrin)
-deoxyribonucleases (DNA)
SSTIs (streptococcus pyogenes) --- correct precise answer ---
pharyngitis (strep throat)
cellulitis
impetigo
necrotizing fasciitis (s. pyogenes) --- correct precise answer -
--severe infection of the subcutaneous tissues and fascia ->
very rapid dissemination of bacteria
treatment: surgical debridement of dead, damaged, and
infected tissues is essential; large dose of penicillin and/or
clindamycin
Final Exam, 2026 Complete Exam Questions with Verified
Answers
Introduction
This document contains comprehensive MICROB 3200 final
exam questions and verified answers focused on virus
classification, viral replication, viral pathogenesis, the
Baltimore classification system, and microbiology laboratory
diagnosis. It also covers major bacterial pathogens, virulence
factors, diseases, treatments, and diagnostic characteristics
relevant to microbiology exam preparation.
The material is presented in a question-and-answer format for
efficient studying and review. It includes detailed
explanations of virology concepts, bacterial identification, and
clinically important infectious diseases commonly tested on
final examinations.
Exam Questions and Answers
general purpose medium --- correct precise answer ---low
cost medium to enrich many types of bacteria (trypticase soy
agar (TSA))
Blood agar
Staphylococcus aureus --- correct precise answer ---coagulase
+
-large colonies
,-creamy white to golden color
-beta-hemolytic (straw colored zone of clearance around
colony)
coagulase -
-large colonies
-creamy white color
-non-hemolytic (lysis of RBCs)
mannitol salt agar (selective and differential medium) ---
correct precise answer ----high salt inhibits most organisms
(streptococci, gram -)
-mannitol sugar: termination results in acid production,
phenol red in media turns yellow
baird parker agar (selective and differential medium) ---
correct precise answer ---staphylococci produce dark gray to
black colonies due to tellurite reduction
-S. aureus - produces lecithinase (lipase) which breaks down
egg yolk and causes clear zones around respective colonies
(halos)
-S. epidermidis & S. saprophyticus - no halo
coagulase test --- correct precise answer ---positive: S. aureus
negative: S. epidermidis/saprophyticus
oxidase test --- correct precise answer ---used to determine if
bacterium contains cytochrome c oxidase and can therefore
,use oxygen for energy production by converting O2 to H2O2 or
H2O with an ETC
--negative (all staphylococci)
catalase test --- correct precise answer ---catalase catalyzes
the conversion of hydrogen peroxide to oxygen and water
streptococcus and enterococcus spp. --- correct precise
answer ----low G+C
-facultative anaerobic metabolism
-capnophiles - increased CO2 required for growth
-gram + cocci in chains
-catalase negative
-hemolysis: A, B, Y
-part of human resident microbiota
--S. progenies is a primary pathogen
streptococcus pneumoniae --- correct precise answer ---alpha
hemolysis (green color)
streptococcus pyogenes --- correct precise answer ---beta
hemolysis (straw color)
enterococcus faecalis --- correct precise answer ---gamma
hemolysis (no hemolysis)
Streptococcus agalactiae --- correct precise answer ---
NARROW zone of beta hemolysis
, streptococcus pyogenes (Group A) virulence factors --- correct
precise answer ---cell associated factors
-capsule -> blocks phagocytosis by neurophils
-M protein -> binds to factor H -> prevents opsonization by
complement (highly antigenic)
-LTA (lipoteichoic acid) -> cell attachment
toxins
-streptococcal pyrogenic exotoxins (superantigens)
-streptolysins S and O (B-hemolysins)
-hyluronidase (connective tissue)
-streptokinase (fibrin)
-deoxyribonucleases (DNA)
SSTIs (streptococcus pyogenes) --- correct precise answer ---
pharyngitis (strep throat)
cellulitis
impetigo
necrotizing fasciitis (s. pyogenes) --- correct precise answer -
--severe infection of the subcutaneous tissues and fascia ->
very rapid dissemination of bacteria
treatment: surgical debridement of dead, damaged, and
infected tissues is essential; large dose of penicillin and/or
clindamycin
