Exam 2 CH. 4, 5, and 6

Taxonomy

The science of classifying organisms using binomial nomenclature

taxonomic categories are called

taxa and are organized from broadly inclusive to only a single species

Taxonomy order (dumb kids playing cards on freeway get smashed)

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Phylogeny

evolutionary history of group of organisms. all organisms are related through evolution

group organisms are based on common properties which are ?

fossils and genomes

in phylogenetic trees genomes of organisms are ?

organisms with similar genomes are more closely related

in phylogenetic trees each group evolved from a ?

common ancestor and retained some of the characteristics of the ancestor

Classification

placing organisms in groups according to their evolutionary relationships

Identification

using dichotomous keys to determine the genus and or species based on an "unknown" organisms characteristics

Methods of Classifying and Identifying Microorganisms

differential staining ex. gram stain, acid fast stain

what do biochemical test determine?

presence of bacterial enzymes

polymerase chain reaction (PCR) to identify microbes

can be used to amplify a small amount of microbial DNA in a sample. presence or identification of an organism is indicated by amplified DNA

the key to PRC is ?

the primers are complementary to a gene sequence that is unique to a particular pathogen

prokaryotes are

unicellular, anucleate organisms

Where are prokaryotes found?

everywhere and even in extreme conditions

prokaryotes are abundant within?

the human body

Why are prokaryotes important?

for the stability of ecosystems. ex. breakdown organic matter and element recycling

prokaryotes are often ?

metabolically flexible and can switch energy sources or metabolic pathways based on availability

prokaryotes can cause

disease and food spoilage. less than 1% of prokaryotes are human pathogens

microbiome on the human body

are found on different sites of the body and have different inhabitants based on varying conditions

microbiome in the cheek and intestine

cheek has a predominance of Streptococcus , intestines are colonized with Bacteroides

changes of microbiome over time

initial Lactobacillus colonization during vaginal birth

Proteobacteria (Gram Negative) 5 classes

alphaproteobacteria, betaproteobacteria, gammaproteobacteria, deltaproteobacteria, epsilonproteobacteria

Alphaproterobacteria

oligotrophs that are capable of living in low nutrient environments

what are the two taxas of alphaproterobacteria?

chlamydias and rickettsias

Chlamydias and rickettsias are obligate intracellular pathogens. What does this mean?

part of their life cycle must occur inside other cells (host cells) and cannot synthesize their own ATP

R. rickettsia causes

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever is a form of

meningoencephalitis and is transmitted via ticks

betaproteobacteria

Are eutrophs (or copiotrophs), meaning that they require a copious amount of organic nutrients.

Examples of Betaproteobacteria

neisseria, N. gonorrhoeae, N, meningitides

Neisseria are

cocci that live on mucosal surfaces of human body, are difficult to culture, and require high levels of moisture, nutrients, and carbon dioxide

N. gonorrhoeae

causes the STI gonorrhea

N. meningitides is

a causative agent of bacterial meningitis

Gammaproteobacteria

diverse class and includes pathogens

Pseudomonas aeruginosa is responsible for

a number of infections including wound infections, UTIs and respiratory infections

Pseudomonas aeruginosa is hard to treat

because they are resistant to antibiotics and form biofilms, are strictly aerobic, non fermenting, and highly motile

Legionella pneumophila inhabit

pools of warm water ex.tanks of air conditioning units

Enterobacteriaceae Family

two categories: coliform and noncoliforms

coliform are able to

ferment lactose completely, ex. E.coli (acid and gas)

noncoliforms include

cannot ferment lactose or ferment it incompletely (acid or gas)

noncoliforms include

Salmonella spp., Shigella spp., Yersinia Pestis

Deltaproteobacteria

is a small class and includes sulfate reducing bacteria; uses sulfate as the final electron acceptor in the ETC

Epsilonproteobacteria

microaerophilic and require only small amounts of oxygen

Epsilonproteobacteria include

C. jejuni and H.pylori

Campylobacter jejuni causes

food poisoning and severe enteritis ( inflammation in small intestine)

often from contaminated poultry products

Helicobacter pylori (H. pylori)

causes chronic gastritis, stomach ulcers, and stomach cancer

it produces urease to make its environment less acidic

Nonproteobacteria Gram-Negative Bacteria

Spirochetes

The CFB Group

Planctomycetes

spirochetes are

long spiral shaped bodies, highly motile using axial filament

Treponema pallidum pallidum causes

syphilis

Borrelia burdoferi causes

Lyme disease

Lyme disease is

transmitted by the bite of an infected deer tick and produces a bulls eye rash, fever, and arthritis

Cytophaga, Fushobacterium, and Bacteroides (CFB group)

Rod shaped bacteria adapted to anaerobic environment, are avid fermenters and able to process cellulose

Bacteroides make up

about 30% of the entire gut microbiome

bactericides help us

break down cellulose are mutualistic benefit from nutrients and prevent pathogenic colonization

planctomycetes

found in aquatic environments and reproduce by budding (bud detaches from mother cell and lives as independent cell)

Gram-positive bacteria

Actinobacteria, clostridia, lactobacillus, bacilli, mycoplasmas

Actinobacteria

is a very diverse group, mostly aerobic, and includes acid fast Mycobacterium and Nocardia

M. tuberculosis causes

tuberculosis

M. leprae causes

leprosy which impacts peripheral nerves and integrity of the skin and respiratory tract

difficult to treat antibiotics have to be taken for certain time period

Actinobacteria

Corynebacterium diphtheria causes diphtheria a disease that can be fatal, especially in children

C. diphtheria produces

a toxin that forms a pseudomembrane in the patients throat causing swelling, and difficulty breathing

C. diphtheria contains

metachromatic granules, intracellular storage of inorganic phosphates that are useful for identification of corynebacterium

Bifidobacterium

constitute a substantial part of gut microbiota and are frequently used as probiotics and in yogurt production

Clostridia are

are generally obligate anaerobes that produce endospores , can be found in anaerobic habitats like soil and aquatic sediments rich in organic nutrients

C. perfringens

the third most common cause of food poisoning (when ingested) and causative agent of gas gangrene.

Gas gangrene occurs when

endospores enter a wound and germinate , become viable bacterial cells producing necrosis of tissue

C. tetanu causes

tetanus which produces a neurotoxin that blocks the inhibition of nerve impulses involved in muscle contractions and cause life threatening spastic paralysis

C. botulinum produces

the most lethal biological toxin , this toxin blocks the release of acetylcholine in neuromuscular junction s causing flaccid paralysis

Lactobacilliales include genera

lactobacillus, leuconostoc, enterococcus, and streptococcus

genus streptococcus is responsible for

many types of infectious diseases and forms chains of spherical cells

S.pyogenes is associated with

pus production (pyogenic) and is most common cause of strep throat

S. pneumonia can cause

pneumonia, meningitis, septicemia, osteomyelitis and endocarditis

Bacilli includes both

bacillus shaped and coccus shaped genera

bacillus bacteria are

rod shaped endospore producers

B. anthraces causes

anthrax presents in ulcers (open wounds), enterocolitis (ingesting) or pneumonia (breathing in) depending on transmission

Staphylococcus bacteria are

coccus

S. aureus causes

variety of skin conditions, many strains developed antibiotic resistance

ex. MRSA and VRSA

Mycoplasmas

do not have cell wall

is pleomorphic (has all types of shapes)

M. pneumoniae causes

walking pneumonia is less severe than other forms

Archaea

unicellular prokaryotes, cell wall contains pseudopeptidoglycan or pseudomurein

Archaea are

large and complex genomes

Archaea may live in extreme environments

extreme temp, high salt or high energy sources

not known to cause disease

Characterisitics of fungi

acidic, low moisture, high osmotic pressure environments, cell walls made of chitin

fungal cell membrane contain

ergosterol

fungi are

decomposer, absorb and metabolize complex carbohydrates, only a few are pathogenic to plants and animals

molds are

multicellular fungi, require oxygen, and made up of filaments called hyphae

Hyphae can form

a tangled network called mycelium that makes the body of mold

Hyphae can be either

septate or aseptate

septate meaning it divides molds into uninucleate units

fungi sexual reproduction

1. germination: mycelia form. if two mating types (+ and -) are in close proximity extensions called gametangia form

2. plasmogsmy: fusion between + and - mating types result in zygoporangium

3. Karyogamy: the nuclei fuse to form a zygote

4. Meiosis and germination: sporangium grows on a short stalk. haploid spores are formed inside

yeast are

unicellular fungi, can divide through budding or fission, and are facultative anaerobes

budding yeast the

parent cell buds off a smaller daughter cell asexually

fission yeast divide

evenly to produce two new cells

fungi may be

dimorphic (yeast at 37 and modlike at 25) meaning they have more than one appearance during life cycle

reproduction of fungi

sexual or asexual, produce spores called zygospores, ascospores, or basidiospore

Fungi asexual reproduction by mitosis

mitosis with budding, fragmentation of hyphae, formation of asexual spores by mitosis

reproduction of fungi sexually

1. germination: mycelia form if the two mating types + and - are in close proximity gametangia form between them

2. plamogamy:

fusion between + and - mating types result in zygosporangium with multiple haploid nuclei it forms thick protective coat

3. Karyogamy:

nuclei fuse to form zygote w multiple diploid nuclei

4. Meiosis and germination

sporangium grows on short stalk. haploid spores are formed inside

Fungal Diseases (Mycoses)

systemic mycosis: infection deep within body affects many tissues and organs