Bacterial pathogen classification and structure

bacteria are named based on what?

Genus species

All bacteria are classified as ____________

prokaryotes

Bacteria are further broken down into what relevant divisions

• gram negative

• gram positive

• mycoplasma

From broadest to smallest what are the classes bacteria can be placed into

• orders

• families

• genera

• species

Within species bacteria can be further broken down into what categories

• strain

• subspecies

• biovar

• serovar

__________ are often derived from an initial single colony and isolated from an exogenous source

strains

a __________ is a permanent example of the species

type strain

Bacteria with notable differences within a species can be classified as a ____________

subspecies

Bacteria with special biochemical or physiologic properties within a species can be known as _________

biovars

Bacteria that have distinctive antigenic properties within a species are known as ________

serovars

What is needed to classify the phenotype of a bacteria

• morphology

• staining characteristics

• metabolic characteristics

• growth characteristics

• synthetic products

• antigenic composition

• pathogenicity

phylogenic information derived from the _________ gene sequence is currently used as the main method of phylogenetic analysis in bacteria

16s rRNA

In comparison with eukaryotes, prokaryotes only contain _____ ribosomes and sometimes have a cell wall containing _________

• 70s

• peptidoglycan

What are two common sites of antibiotic action

• 70s ribosomes

• peptidoglycan wall

capsules and slimes of bacteria are visualized by _________

negative staining

often times capsules are referred to as ____________

K antigen

What roles do capsules and slimes play in disease

• inhibit phagocytosis

• confer adherence

• cover bacterial surface antigens

If a vaccine targets a cell capsule would it be lethal?

no

What is the cell wall structure of gram negative cells

• lipopolysaccharides

• porins

• outer membrane

• thin peptidoglycan

What is the cell wall structure of gram positive cells

• thick peptidoglycan

• teichoic acid

• mycolic acid

Only some gram positive bacteria contain what two aspects of the cell wall?

• teichoic acid

• mycolic acid

What is peptidoglycan made up of?

• disaccharide polymers

• peptides

Acid fast bacteria which are considered _______________ contain __________ which makes them wax like and extremely hydrophobic

• gram positive

• mycolic

Presence of mycolic acid makes acid fast bacteria highly __________

resistant

Due to presence of mycolic acid acid fast bacteria require a different stain known as _______________

carbol-fuchsin/Siehl-neelsen

What are the 3 parts of a lipopolysaccharide

• Lipid A

• core

• O specific chain

The lipid A of a lipopolysaccharide is considered an ________ and can cause severe inflammation through interaction with ____________

• endotoxin

• immune cells

The o specific chain is called the ___________ and used for diagnosis due to it being so ________

• O antigen

• variable

What is the role of the cell wall in disease

• determine bacterial resistance in the environment

• cause inflammation

• are sites of antibiotic action

Antibiotics that inhibit peptidoglycan synthesis like penecilin are more effective against __________ bacteria than ___________

• gram positive

• gram negative

To inhibit acid-fast bacteria, a specific antibiotics that block_____________ like isoniazid is required to allow another antibiotic to penetrate the cell wall.

mycolic acid biosynthesis

Antibiotics that act on the outer membrane of bacteria like polymyxins  are effective for inhibiting _________ bacteria

gram negative

What does antibiotic susceptibility depend on?

• cell wall structure

• cellular site of infection

The flagella of bacteria is mostly composed of __________ and is also known as _________ for diagnosis

• flagellin

• H antigen

What is the role of the flagella in disease

• rapid motility to help colonization

• act as a PAMP

• used for diagnosis

What are the bacterial surface antigens used for diagnosis and their source

• Capsule - K antigen

• Flagella - H antigen

• Cell wall- O antigen

A unique version of this bacterial structure in which filaments are located in the periplasmic space between the inner and outer membrane is known as what?

Axial filaments or spirochetes

What are the two types of pili that can be present on bacteria

• common pili

• sex pili

The common pili is made of ______ and is _________ while the sex pili is made of a different protein and is _________

• pilin

• numerous

• few

common pili are mostly on ___________ bacteria

gram negative

what roles do common pili play in disease

• adherence

• antigenic

What role do sex pili play in disease

• gene transfer

• antigenic

bacterial ribosomes are ________ and their role in disease consists of protein synthesis and as _______________

• 70s

• a target of antibiotics

Bacterial nucleoid typically takes what form?

Supercoiled plasmids

What role does bacterial nucleoid play in disease

• encode genes

• target for antibiotics

What antibiotics specifically target bacterial nucleoids

Quinolones

What are the two types of spores that can be produced by bacteria

• Endospore

• exospore

What are the two main endospore producing bacteria

• clostridium

• bacillus

What are the parts of an endospore outer structure

• spore coat

• spore cortex

A spore cortex is made of poorly organized ______________ but is mostly identifiable for diagnosis due to the presence of ___________

• peptidoglycan

• dipicolinic acid

In endospores the dna is highly __________ and to protect from oxygen radicals ___________ bind

• condensed

• spore acid soluble proteins

which pathogenic bacteria are well-known to produce endospores

• bacillus

• clostridium

What roles do endospores play in disease

• highly resistant

• ensure bacterial survival not reproduction

• used for diagnosis

Exospores replicate in structures similar to _________

Fungi

Chains of exospores known as _______ are produced at the end of a bacterial _______

• conidia

• hypha

Unlike endospores exospores are not environmentally resistant and only ensure the _________ of bacteria

survival

To differentiate between fungal and bacterial hyphae you must remember that bacterial hyphae have a ______ diameter

smaller

out of the classes of bacteria list them from most resistant to least resistance

• acid fast

• gram positive

• gram negative

• mycoplasma