Microbial Diversity (copy)

all living organisms are grouped into five categories based on their similarities called

taxa

Hierarchical scheme from most inclusive to most specific

Domain

Kingdom

Phylum/division

Class

Order

Family

Genus

Species

Hierarchial scheme is based on

evolutionary relationships and history

Binomial nomenclature

system of naming organisms; made of genus and species name

organisms names properly formated

1st letter of the genus (1st word) is always capitalized and the species name is in lower case. When hand written the scientific name is to be underlined; when typed, italicized or underlined.

Species in terms of eukaryotes means

organisms that can breed

horizontal gene transfer

donor species that passes on new genetic information to an ancestor pathogen

Phenetic classification

emphasizes morphological and physiological/biochemical similarity in estimating relatedness or similarity; how they grow

Phylogenetic classification

based on evolutionary (or presumed evolutionary) relationships rather than morphological similarity; looks at DNA sequencing

Phylogenetic classifications of domains

archaea, bacteria, and eukaryea

G + C base composition –

type of genotype method;% of Guanine and Cytosine (nucleotides, building blocks of DNA) content in the DNA is an indicator of relatedness

DNA analysis using specific probes

use of small pieces of DNA (or RNA) complementary to specific sequences of microorganism

Nucleic acid sequencing or rRNA analysis

sequence of the nitrogen bases in the ribosomal RNA

Firmicutes

gram positive bacterial prokaryotic phyla: includes endospores formers and non-endospore formers; very diverse

Actinobacteria

gram positive bacterial phyla; diverse in structure; includes Mycobacterium & Nocardia, acid fast bacteria;Streptomyces spp. Non-motile, filamentous, soil bacteria, produces spores, antibiotic producing bacteria

Proteobacteria/Pseudomonadota

gram negative; largest most diverse bacterial phyla; all gram negative rods; 6 distinct classes – α [Alpha], β [Beta], γ [Gamma], δ [Delta], ε [Epsilon], & ζ [Zeta] • Many are motile, facultatively or obligately anaerobic, with a mix of metabolic strategies; not all are pathogenic

Psudomonads

• Aerobic, flagellated, straight to slightly curved rods

• Can break down numerous organic compounds

• Ubiquitous in soil & water, aerobic, very tolerant to a variety of conditions

• Lives in a biofilm & is a nosocomial/ opportunistic pathogen

Cause HAIs

spirochetes

gram negative; internal periplasmic flagella-wrapped around the cells; moves in corkscrew motion making them better pathogens because they can burrow into tissues; digestive sybionts of termites and numinants

Cyanobacteria

gram negative; diverse; photosynthetic; utilize chlorophyll a and conduct oxygenic photosynthesis; some filamentous cyanobacteria are capable of reducing nitrogen gas to a useable form (ammonium) (nitrogen fixation)

only these can convert nitrogen to a usable form

prokaryotes

heterocyst

specialized cell in cyanobacteria for nitrogen fixation

symbionts

live in mutually beneficial relationships

chlamydia

gram negative; small obligate intracellular parasites; lack peptidoglycan; must live in a cell and harm it-they rip atp off of host cells; Bacteria have developmental cycle of infection (elementary bodies) and replication (reticulate bodies); cannot replicate without a host

elementary body of chlamydiae

attach to host and invade

reticulate body of chlamydiae

divide/reproduces

Helminths

eukaryotic-Multicellular, elaborate life cycles, chemoheterotrophic

Fungi

eukaryotic-Unicellular (yeasts) & multicellular, chemoheterotrophic, reproduce sexually & asexually

Algae

eukaryotic- Unicellular, some multicellular, photoautotrophic, reproduce sexually & asexually

Protists

eukaryotic- Unicellular, most motile, chemoheterotrophic/ photoautotrophic

unicellular yeast reproduce via

binary fission/budding

multicellular fungi-molds and mushrooms

filamentous and reproduce via sexual and asexual spores

cell walls of fungi are composed of

chitin

chemoheterotrophs

chemical nutrients synthesized by other organisms

fungi are extremely beneficial organisms-

they recycle materials

Septate hyphae

have cell wall

nonseptate hyphae

no cell wall

hyphae allows fungi to

grow into substrate (vegetative) or bearing reproductive spore (aerial spores)

Mycelium

macroscopic; hyphae that grow to immense proportions

condium

found in multicellular fungi; asexual naked or free spores; not enclosed in a sac;

sporangiospores

in multicellular fungi; asexual spores in a sac

chlamydoconidia

multicellular fungi; naked asexual thick-walled survival spore; form tips or as part of hyphae

blastocondia

yeast; naked asexual spore; developed in clusters along pseudohyphae

Yeast reproduce asexually by

budding, pseudohyphae, and mitotic fission

some yeast can

mate-resulting in genetic variation

sexual reproduction requires

a fusion of DNA from 2 different sources and creates spores

Zygomycota

molds; conjugation fungi; nonseptate hyphae asexual spores are sporangiospores and sexual spores are zygospores;

zygospores

large and thick walled

Asexual vs sexual is based on

nutrients available

ascomycota

molds and yeast- sac fungi-septate hyphae or yeast cells; asexual spores are condia and sexual spores are ascospores

ascospores

results from the fusion of the nuclei of two cells produced in a sac like structure called ascus

basidiomycota

mushrooms-club fungi; septate hyphae;

asexual spores are condia and sexual spores are basidiospores; asexual reporduction can be fragmentation (break down of spores) or condia

basidiospores

formed externally on base pedestal by meiosis

Protists are the earliest

eukaryotes

protists

• The Alveolates

• Unicellular; major eukaryote organelles

Lack cell walls and are very flexible

protists can be…

Autotrophic, heterotrophic, often parasitic, some mixotrophic

motility of protists (if motile)

cilia, flagella, pseudopods

cytoplasm of protists is divided into

endo and ecto plasm

some protists have

oral grooves to direct food into food vacuoles.

amoebozoa motility

pseudopods- cytoplasm pushed against cell membrane to create extractions and retraction of microfilaments

Amoebozoa

eukaryotic-protist; asexual reproduction by fission; has a cyst cycle;• Formaniferans are shelled [CaCO3 ] amoeba [marine] • Mostly free-living; few pathogens,

Ciliates

ciliates; propels food into mouth or a groove for feeding; reproduce sexually by conjugation; develops cyst; mostly free-living; few pathogens

Apicomplexans are

nonmotile except for flagellated male gametes

Apicomplexans

pathogens; Obligate intracellular human pathogens; life cycle involves multiple hosts;Sporozoites formed via sexual reproduction is infective stage • Definitive host carries sexually reproducing stage • Intermediate host carries asexually reproducing stage

sexual reproduction of apicomplexans

definitive host

intermediate host of apicomplexans carries

asexual reproduction

Metamonads

lack mitochondria

Metamonads and trypanosomes are

flagellated protists that are very large and diverse groups; Include parasites that lack true mitochondria • Blood parasites – arthropod vectors • Most form cyst stages

Algal protists can be

phototrophic and contain chloroplasts or mixotrophic

Algael protists are

unicellular in multiple forms and can make toxins

Green algae

• Plants most likely evolved from these organisms • Includes some macrophytic forms (seaweed) • Cellulose cell walls • Oxygenic Photosynthesis • Chlorophyll a & b

Dinoflagellates

• Cellulose cell walls and cellulose embedded in cell membrane • Photosynthetic, phagotrophic, heterotrophic or parasitic • Some produce neurotoxins, especially harmful to fish, shellfish, indirectly or directly to humans

unicellular

Diatoms

• The diatoms; the most prevalent group on earth • Contain pectin and silica in their cell walls • Bivalved – cell walls fit together like two halves of a petri dish • Causes domoic acid intoxication

Helminths

• Multicellular; developed organ systems but may lack a digestive system & have a reduced nervous system • Parasitic; highly specialized to live in host • Complex & diverse life cycles – Multiple intermediate hosts for each larval stage – Adults may be dioecious or hermaphroditic (monoecious)

Aschelminthes

unsegmented body

• Roundworms, pinworms; sexual dimorphism • Thin, cylindrical, unsegmented body • Not all are parasitic

Platyhelminthes

• Flatworms – dorsoventrally flattened • Trematodes & cestodes; hermaphroditic • Obtain food through a sucker

segmented or flattened

Trematodes

Segmented Platyhelminthes

cestodes

flattened plathyelminthes

arachnids parasites

8 legs that carry parasites

insect parasites

6 legs that carry parasites

ectoparasites

bite externally