micro 1

which is only found in gram negative bacteria

periplasmic space

genetic recombination of 2 bacterial genomes is called

transduction

which structure contributes to antibiotic resistance

plasmid

which is a sterile anatomical site

lower respiratory tract

which of the following is a non sterile site

upper respiratory tract

tetanus

contact (cuts)

salmonella

food ingestion or fecal-oral

babesiosis

ticks/ flies/mosquitoes

black plague

ticks/ flies/ mosquitoes

tuberculosis

airborne/inhalation

syphilis

contact (intercourse)

contain only one set of chromosomes

haploid

double stranded, closed, circular, autonomously replicating extrachromosomal genetic elements

plasmid

pieces of DNA that move/exchange

genetic material between plasmids and the

chromosome. This action increases mutation

occurrences

transposons

a bacteria’s genome is

altered by the acquisition of foreign DNA from a

donor bacterial cell. The recipient bacteria will have a mixture of their

original DNA and the donors DNA

genetic recombination

when a bacteria dies, they lyse and their DNA

segments are released into the surrounding environment.

– A recipient bacterium absorbs the donors DNA segments and the

donor DNA combines with the recipients genome to form new

recombinant DNA.

transformation

A bacteriophage will integrate their DNA into a bacteria’s

chromosome.

» Viral replication occurs and viruses are formed in the

bacterium. Newly formed viruses are released through host cell

lysis which infect other bacteria.

» When the virion incorporates its own DNA into the bacteria,

the bacteria will contain or original host bacterium and/viral

recombinant DNA.

transduction

exchange of chromosomal dna and plasmids through cell to cell contact (such as a sex pilus)

conjugation

Nutrients that are able to cross the cell membrane through simple

diffusion are: Water, Oxygen & Carbon dioxide

simple diffusion

Nutrients cross the selective permeable membrane by energy

dependent pumps and carrier molecules. Upon binding the

particular nutrient, carrier molecule undergo a conformational

change (ATP required) and can transport the substance across the

cellular membrane.

active transport

Sugars, Amino acids, Organic/inorganic acids

active transport

water, oxygen, CO2

simple diffusion

nutrients are broken into (pyruvate)

precursor metabolites

The high energy phosphate bond is transferred to a high

energy phosphate containing compounds such as ADP.

– ADP + P = ATP and when hydrolysis of ATP’s phosphate

bonds occurs it produces chemical energy, driving cellular

processes.

substrate level phosphorylation

ATP can also be produced through the catabolism of

precursor nutrients coupled with oxidation reduction

reactions of high energy carrier molecules such as

nicotinamide-adenine-dinucleotide (NAD)

oxidative phosphorylation

production of ATP is used for

metabolism and for the Bio-synthesis

bacterial structures

can grow without oxygen

facultative anaerobe

cannot tolerate exygen

obligate anaerobe

Bacterium nutrient and environmental needs are

relatively basic, fast growers.

non fastidious

Type of bacterium requires very specific/complex

nutritional and environmental needs for growth,

commonly slow growers

fastidious

what structure is responsible for motility

flagella

staphylococci

clusters

streptococci

chain

2 cocci together

diplococdi

• Outer membrane

• Cell wall (also known as the murein layer)

• Periplasmic space

• Cytoplasmic membrane

cellular envelope

first layer that is exposed to the extra-cellular environment, bi-layered structure composed of lipopolysaccharides, functions as a permeability barrier, only in gram negative bacteria

outer membrane

allows the passage of molecules and provides protection against environmental/osmotic pressure changes that would cause cell lysis, contains the macromolecule peptidoglycan.

cell wall/murein layer

peptidoglycan is in the

cell wall/murein layer

has teichoic acids

gram positive

no techoic acids

gram negative

thin cell wall

gram negative

thick cell wall

gram positive

contains enzymes that are involved in the degradation of macromolecules and detoxifying environmental substances (e.g. antibiotics), only found in gram negative bacteria

periplasmic space

has perplasmic space

gram negative

• Enzymes: vital for survival. Examples

include synthesis of the cell wall, outer

membrane and generation of energy.

• Protection against environmental

osmotic pressure changes.

• Transport of solutes in/out of the cell.

• Replication: Mediation of

chromosomal segregation in binary

fission

cytoplasmic membrane

• Enzymes: involved in protein synthesis

and metabolic processes.

• Polysomes: mRNA complexes with

several ribosomes during translation.

• Inclusions: Glycogen reserve granules

and inorganic phosphates

• Chromosome: Contain genetic code

• Plasmids: Contain genetic sequences

cytosol

Plays a vital role in the mediation of infection and

Identification. Capsule, fimbriae, sex pili, flagella

cellular appendages

composed of polysaccharides. Outer most layer that protects the bacteria from the components of the immune system & facilitates biofilm formation.

capsule

gives colony wet mucus look

capsule

Long thin structures that extend from the cell membrane into the external environment. They aid in adhesion to other bacteria and human cells

fimbriae

Used in Conjugation recombination, only present in bacteria

that contain the F protein.

sex pilus

F protein (+) bacteria initiate conjugation with F-protein (-) bacteria allowing

DNA recombination

composed of the protein flagellin.

• These structures are responsible for motility.

flagella

bacteria germinate under adverse conditions or when nutrients are scarce

endospores

endospores

bacteria that live on us and in us.

normal flora

bacteria in us throughout our lives

resident microbiota

present for days, weeks, months

transient microbiota

Parasitic spore-producing organisms; cause

many skin diseases like ringworm and athlete's foot;

other types can infect your lungs or nervous system.

fungi

Organisms living in, with, or on another

organism; can be transmitted to humans from bites

(i.e., malaria from a mosquito bite) or from animal or

human feces (i.e., giardia).

parasites

An organisms ability to cause a

disease/infection depends upon an

organisms:

pathenogenicity and virulence

ability to cause disease

pathogenicity

degree of disease severity caused by microbe

virulence

factors that protect the

organism from the host and mediate damage to the

host

virulence mechanisms

Specific genetic sequences in their pathogenicity

islands sequencing regions that encode virulence

factors

genome

biochemically active, allow the microbe to establish infection and

disseminate in the host

toxins

produced by Gram positive

bacteria

• Bacteria can secrete the toxin

when alive

– Damages connective tissue and

cells

– Damaged tissue allows the

microbes to further spread into

deep tissue and systemic

circulation

exotoxins

destroys the integrity of polysaccharides that holds human cells together, allowing the pathogen to spread through tissue

hyaluronidases

destroy structural connective tissue

collegenases

destroy nucleic acids

nucleases

Produced by Gram negative bacteria

• composed of the

lipopolysaccharide structure of the cell

envelop

• Cause cell damage upon direct contact or by

bacterial cell lysis

endotoxin

first step in the infection process

attachment

– Prevents foreign antigen recognition by phagocytes

– Inhibits complement activation

– Prevents intracellular lysosome lysis by phagocytes.

capsule

Allows the bacteria to be motile and

colonize different areas of the body or

penetrate into deeper tissue.

flagella

– allows bacteria to attach

to host cells on the skin, connective

tissues, other bacteria or medical

devices.

– This allows bacteria to colonize, exert

destructive enzymes and avoid host

defensive mechanisms

fimbriae

an accumulation of bacteria in a polysaccharide matrix.

biofilm

S. aureus, pseudomonas, and yeast are capable of forming a

biofilm

may cause disease/infection when host

immune status is compromised (i.e. flu, chemo, HIV, elderly,

pregnancy, diabetes, hormones, medications).

opportunistic pathogens

bacteria that are not normal flora in the

human-microbe interaction. Regarding colonization, no matter

how healthy an individual is, with optimal immune function, the

organisms can cause disease/infection

strict pathogens

normal flora of throat and oropharynx

alpha strep, staph sp., neisseria sp., gram pos rods, anaerobes

expected pathogens in throat/oropharynx

strep group A, corynebacterium diptheriae, bordetella pertussis, and haemophilus influenzae

normal flora of eye

alpha strep, staph sp., neisseria sp., gram pos rods, anaerobes (in lesser numbers)

expected pathogens of the eye

chlamydia, neisseria gonorrhoea

expected pathogens of the ear

alpha strep, staph sp., neisseria sp., gram pos rods, anaerobes (in lesser numbers)

expected pathogens in lower respiratory tract sputum

H. influenzae, S. aureus, streptococcus pneumoniae, klebsiella pneumoniae, mycoplasma pneumoniae, mycobacterium tuberculosis, legionella, fungi

expected pathogens of lung tissue and transtrachial aspirate

anaerobes

normal flora of bronchial washing

resident oral flora

expected pathogens of gastric specimens

helicobacter pylori

normal flora of colon

profuse flora

expected pathogens of colon

shigella, salmonella, campylobacter jejuni, yersinia entercolitica, vibrio cholerae, toxigenic E. coli, clostridium difficile

normal flora of urinary tract

sterile or contaminated with fecal flora

expected pathogens of urinary tract

E. coli, gram neg rods, E. faecalis, staphylococcus sp.

normal flora of genital tract

none

expected pathogens of genital tract

neisseria gonorrhoea, chlamydia trachomatis, strep group b, herpes simplex, trichomonas vaginalis, treponema pallidum, gardnerella vaginalis

normal flora of csf

normally sterile

expected pathogens of CSF

H. influenzae, neisseria meningitidis, E. coli, strep group B, cryptococcus, listeria

expected pathogens of deep wounds or abcesses

anaerobes and aerobes depending on site

normal pathogens of superficial wounds

S. aureus, strep group A, pseudomonas aeruginosa

expected flora of blood

normally sterile

normal flora of lower respiratory tract sputum

none