Clinical Microbiology

What three aspects are involved in the triad relationship?

Drug

Pathogen

Host

What are the different levels of microbiology classification?

Bacteria, viruses, fungi, parasites

What are three broad categories of bacteria?

Typical, atypical, higher order

What are categories are considered typical bacteria?

Gram positive, Gram negative, Aerobic, Anaerobic

What are examples of typical bacteria?

Pseudomonas aeruginosa

Staphylococcus aureus

What are three examples of atypical bacteria?

Legionella pneumophilia

Chlamydia pneumophilia

Mycoplasma pneumoniae

What are examples of higher order bacteria?

Mycobacteria, Actinomyces, Nocardia

Describe Gram positive bacteria

Have a thick layer of peptidoglycan that stains purple when performing a Gram stain

Describe Gram negative bacteria

Have a thin layer of peptidoglycan, followed by the periplasmic space and another thin peptidoglycan layer, all enclosed by the outer membrane

Define anaerobic metabolism

Can metabolize without the presence of oxygen

Define aerobic metabolism

Can metabolize with the presence of oxygen

Define bacilli

Rod shaped

What are examples of aerobic bacteria?

Streptococcus spp.

Staphylococcus spp.

Enterobacterales

What are examples of anaerobic bacteria?

Clostridium spp,

Bacteroides spp.

Prevotella spp.

Define facultative metabolism

Possess both aerobic and anaerobic pathways

Describes most bacteria

Define cocci

Circle shaped

What classes of aerobic Gram positive cocci bacteria are found in chains or pairs?

Streptococcus

Enterococcus

What are examples of beta-hemolytic streptococcus?

S. pyogenes

S. agalactiae

What are examples of alpha-hemolytic streptococcus?

Viridians Streptococci

Streptococcus pneumoniae

What class of aerobic Gram positive cocci bacteria are found in clusters?

Staphylococcus

What Staphylococcus is coagulase positive?

Staphylococcus aureus

What are classes are considered Gram-positive rods?

Listeria

Corynebacteria

Bacillus

Erysipelothrix

What Gram positive organisms do we NEED to know?

Staphylococcus aureus

Coagulase-negative Staphylococcus

Streptococcus pneumoniae

Viridians Group Streptococcus

Streptococcus agalactiae

Enterococcus

Listeria monocytogenes

Corynebacterium spp. or Diptheroid

Staphylococcus aureus

Coagulase positive Gram positive cocci found in clusters

What is an example of a coagulase negative Staphylococcus?

Staphylococcus epidermidis

Streptococcus pneumoniae

alpha-hemolytic Gram positive cocci found in chains or pairs

Viridians Group Streptococcus

alpha-hemolytic Gram positive cocci found in chains or pairs

What are examples of Viridians Group Streptococcus?

Streptococcus mitis

Streptococcus bovis

Streptococcus pyogenes

Group A beta-hemolytic Streptococcus

Streptococcus agalactiae

Group B beta-hemolytic Streptococcus

Enterococcus

Gram positive cocci found in chains or pairs

Listeria monocytogenes

Gram positive rod

Corynebacterium spp. or Diphtheroid

Gram positive rod

Often a contaminant

Define enterobacterales

NOT a bacteria

A family or grouping of ENTERIC Gram-negative rods

What are examples of enterobacterales?

Escherichia coli

Klebsiella pneumoniae

Klebsiella oxytoca

Enterobacter spp.

Citrobacter spp.

Salmonella spp.

Proteus mirabilis

Proteus vulgaris

Serratia marcescens

What Gram negative cocci do we need to know?

Neisseria meningitidis

Neisseria gonorrhoeae

What bacteria are fermenting Gram-negative rods?

Enterobacterales

What enterobacterales do we need to know?

Escherichia coli

Klebsiella pneumoniae

Klebsiella oxytoca

Enterobacter cloacae

Serratia marcescens

Proteus mirabilis

Proteus vulgaris

Citrobacter freundii

What non-fermenting Gram-negative rods do we need to know?

Pseudomonas aeruginosa

Acinetobacter baumannii

What anaerobes are found above the diaphragm?

Peptostreptococcus spp.

What anaerobes are found below the diaphragm?

Clostridiodes difficile

Bacteroides fragilis

What are notable anaerobes we should know?

Bacteroides fragilis

Clostridiodes difficile

Cutibacterium acnes

Peptostreptococcus

What is important to note about the structure of community-acquired respiratory atypical pathogens?

Lack cell wall

What are examples of community-acquired respiratory atypical pathogens?

Legionella pneumophilia

Chlamydia pneumoniae

Mycoplasma pneumoniae

What are examples of spirochetes?

Treponema pallidum

Borrelia burgdoferi

What does Treponema pallidum cause?

Syphilis

What does Borrelia burgdoferi cause?

Lyme Disease

What are examples of acid fast bacilli?

Mycobacterium tuberculosis complex

Non-tuberculosis Mycobacterium

Gram positive cocci in clusters

Staphylococcus spp.

Coagulase positive Gram positive cocci in clusters

Staphylococcus aureus

Coagulase negative Gram positive cocci in clusters

Many, ex: Staphylococcus epidermidis

Gram positive cocci in pairs/chains

Streptococcus spp. OR Enterococcus spp.

Gram negative coccobacilli

Haemophilus spp. OR Neisseria spp.

Fermenting Gram negative rods

Enterobacterales

Non-fermenting Gram negative rods

Pseudomonas aeruginosa (Oxidase positive)

Acid fast bacilli

Mycobacterium spp.

Anaerobes

Bacteroides fragilis

Peptostreptococcus spp.

Which bacteria can be MRSA or MSSA?

Staphylococcus aureus

Which Staphylococcus is virulent?

Staphylococcus aureus (MSSA, CA-MRSA, HA-MRSA)

Staphylococcus lugdumesis

Where is S. epidermidis found?

Frequent contaminant found on the skin and mucous membranes

NOT VIRULENT

Which bacteria is responsible for strep throat?

Streptococcus pyogenes

Which bacteria is the number one cause of neonatal morbidity and mortality?

Streptococcus agalactiae

Where does Streptococcus pneumoniae live?

In the nasopharyngeal space

Which bacteria are part of normal oral and GI flora?

Viridians group Streptococci

Which Enterococcus is not as virulent?

Enterococcus faecalis

Which bacteria are part of the normal GI and female GI tract flora?

Enterococcus faecalis

Enterococcus faecium

Which diphtheroid is a common food borne pathogen?

Listeria monocytogenes

Which enterobacteriaceae is part of the normal GI tract flora?

Escherichia coli