(5) ORGANISMS OF THE MICROBIAL WORLD Flashcards
Cell shape; “berries” (e.g. S. pneumoniae, S. aureus, N. gonorrhoeae)
Cocci
Cell shape; Rod shaped (e.g. E. coli, P. vulgaris)
Bacilli
Cell shape; Have one or more twist (e.g. Vibrio cholera, Treponema pallidum)
Spiral
Cell shape; changes shape or size in response to environmental conditions
Pleomorphic
Arrangement of Cocci; One plane of division and composed of two cells
Diplo
Arrangement of Cocci; one plane of division, has many cells or “stacks”
Strepto
Arrangement of Cocci; Two plans of division
Tetrad
Arrangement of Cocci; three planes of division
Sarcinae
Arrangement of Bacilli; one plane of division
Strepto
Arrangement of Bacilli; thick, short type of bacilli which are almost the same with diplo
Coccobacillus
Arrangement of Spiral; one twist
Vibrio
Arrangement of Spiral; many twists
Spirillum
Used for synthesis of carbohydrates, lipids, and energy source
Carbon
Organisms that require carbon as energy source (e.g. glucose)
Heterotrophs
Organisms that use inorganic carbon as energy course (e.g. carbon dioxide)
Autotrophs
- Major component of proteins, nucleic acid, co-enzymes
- Terminal electron acceptor in respiration by some bacteria (nitrates)
Nitrogen
Constituent of some amino acids in proteins and some coenzymes (methionine and cystine)
Sulfur
- Constituent of water and most organic cell components
- Electron acceptor in aerobic respiration
Oxygen
- Constituent of water and organic cell components
- Ions from bonds
- Maintain pH of solutions
Hydrogen
Component of ATP, phospholipid and coenzymes
Phosphorus
Need 15-20 degree celsius for growth
Psychrophiles
Need 20-40 degree celsius for growth
Mesophiles
Need 45-80 degree celsius for growth
Thermophiles
Need 80-250 degree celsius for growth
Hyperthermophiles
Need pH < 5.4 for growth
Acidophile
Need pH of 5.4 - 8.5 for growth
Neutrophiles
Need pH of 8.5 - 11.5 for growth
Alkaliphiles
- Chemical reactions
- Way of obtaining energy
Metabolic
Organisms that absorbs light to obtain energy
Phototrophic
Organisms that make their own energy
Chemotrophic
- Distinctive antigens
Antigenic
Organisms that have absolute oxygen requirement (e.g. M. tuberculosis, Pseudomonas spp.)
Obligate Aerobes
Organisms that can multiply in the presence/absence of oxygen (e.g. Enterics)
Faculative Anaerobes
Organisms unable to multiply in the presence of oxygen (e.g. Clostridium, Bordetella, Bacteroides)
Obligate Anaerobe
Organisms that prefer presence of 5-10% carbon dioxide with small amounts of oxygen (e.g. Neisseria spp.)
Capnophilic
Organisms that require small amounts of oxygen, 2-10% for aerobic respiration (e.g. Campylobacter spp., Spirochetes)
Microaerophilic
Can grow in the presence of oxygen but does not use it
Aerotolerant
- Distinctive hereditary material
Genetic
- Ability to cause disease
Pathogenicity
- Distribution to nature, interaction between and among species
Ecological
Include algae, lichens, slime molds, and fungi
Eukaryotic Microbes
Include acellular infectious agents, domain bacteria, and domain archaea
Acellular and Prokaryotic Microbes
Include helminths, protozoa, and arthropods
Parasites
- Photosynthetic, eukaryotic organisms
- More plantlike than protozoa
- Cells consist of pellicle, a stigma, and flagella
- Pathogenicity is rare
Algae
Thickened cell membranes of algae
Pellicle
A light-sensing organelle of algae
Stigma
In the case of paralytic shellfish poisoning, some algae can secrete ________ that are poisonous
phycotoxins
- Though to be combination of two organisms - an alga (cynobacterium) and a fungus
- Recent evidence suggest that a yeast may also be present
- Not associated with human disease
Lichens
- Have both fungal and protozoal characteristics
- Starts as ameba, but progresses into multicellular organism
- Decomposer and nutrient recyclers
- Not known to cause human disease
Slime Moulds
- Divided into macroscopic and microscopic types
- Non-photosynthetic (lack chlorophyll and vascular system)
- Cell walls contain a polysaccharide called chitin
- Sterols (ergosterol) are usually present in the cell membrane
Fungi
Type of fungi that includes mushrooms, puffballs, and gill fungi
Macroscopic fungi
Type of fungi that includes molds and yeasts
Microscopic fungi
The cell walls of fungi contain a polysaccharide called _____
Chitin
Are usually present in the cell membranes of fungi
Sterols (ergosterol)
Fungi; single cells that reproduce by budding
Yeasts
Fungi; hyphae and mycelia that reproduce by mitosis
Molds
Molds that have transverse walls
Septate hyphae
Molds that are multinucleated
Nonsepate hyphae
Fungi that inhabit organic matter
Saprophytic (Saprobes)
Fungi that inhabit living animals or plants
Parasitic
Fungi that get nutrients from organic compound
Heterotrophic (all fungi)
Reproduction through spores (e.g. basidiospores and ascospores)
Sexual
Reproduction through budding and binary fission
Asexual
Are for reproduction and not thermoresistant unlike bacterial spores
Spore Forms
Reproduction process of hyphae
Elongation and fragmentation
• Decomposers
• For chemotherapy
• Biotechnology, bread and wine industry
• Protein supplements
• Production of cellulose, herbicides
Desirable Effects of Fungi
• Spoilage of food and grains
• Plant pathogens
• Cause human diseases
• Hypersensitivity reactions
• Toxicosis (mycotoxicosis)
• Mycoses
Undesirable Effects of Fungi
Two types of host response to fungi
Granulomatous or Pyogenic Response
Fungi pathogenesis can be detected by using _________ for delayed hypersensitivity reaction
skin tests
Reduced ____________ predisposes to disseminated disease from fungi
cell mediated immunity
Causes liver necrosis due to amanitin and phylloidin
Amanita Mushrooms
Ingestion of contaminated peanuts and grains causes liver cancer due to aflatoxin
Aspergillus flavus
Inhalation of the spores causes allergic bronchopulmonary aspergillosis (IgE-mediated)
Asperigillus fumigatus
Laboratory diagnosis of fungi that involves dissolving of human cells, allowing visualization
Microscopy of KOH Preparation
Laboratory diagnosis of fungi where low pH inhibits growth of bacteria
Sabouraud Agar
Laboratory diagnosis of fungi for early infection
DNA Probes
- Obligate intracellular parasites of plants
- Acellular
- Naked RNA
- No human disease knwon
Viroids
- Non-cellular infectious proteins
- Naked proteins that have the same amino acid sequence as certain normal human cell surface proteins folded differently
- Resistant to nucleases, proteases, many chemicals, and normal autoclaving
- Associated with spongiform enceplaophaties (e.g. Creutzfeldt-Jakob Disease, Kuru, and Fatal Familial Insomia)
Prions
Caused by prions that have the appearance of vacuolated neurons with loss of function and lack of an immune response or inflammation
Spongiform Encephalopathies
Transmission of Spongiform Encephalopathies
(1) _________ - cuts in skin, transplantation of contaminated tissues (e.g. cornea)
(2) Use of contaminated _________ such as brain electrodes
(3) __________ - ingestion of infected tissue
(1) Infected Tissue
(2) Medical Devices
(3) Cannibalism
Susceptible Population for spongiform encephalopathies:
- Women and children of the (1) ________ in New Guinea
- (2) __________ and brain surgery patients
- (3) __________ surgeons and patients
(1) Fore Tribe
(2) Neurosurgeons
(3) Transplant
- Smallest infectious agents
- Contain only either DNA or RNA as the genome
- Inert in the extracellular environment
- Replicate only in living cells
Virus
Virus that can infect bacteria
Bacteriophage
Surround the center of the virion
Capsid/Protein Coat
Combination of the nucleic acid and capsid of viruses
Nucleocapsid
Helps the virus attach to the host cell
Protein Spikes
The complete viral particle
Virion
- Surrounds the nucleocapsid
- Lipid membrane derived from the host cell
Membrane Envelope
The membrane envelope, which is a lipid membrane derived from the host cell is acquired as the virus exits from the cell in a process called _______
budding
All enveloped viruses acquire their envelope from plasma membrane except ________ (from nuclear membrane)
Herpes virus
Enveloped viruses are (1) _____ and more easily (2) ______
(1) less stable
(2) inactivated
- Include helical and icosahedral shapes of viruses
Morphology
A geometric shape with 20 triangular sides (most stable)
Icosahedral
Morphologic units seen in electron microscope on the surface of icosahedral viral particles
Capsomeres
Morphology of viruses such as influenza, measles, and rabies
Helical
Types of viruses that has two types; positive stranded or negative stranded
RNA Viruses
- Viruses that have RNA just like an mRNA
- When it enters host cell, its RNA can immediately be translated by the host ribosomes into protein
Positive Stranded RNA Viruses
- Viruses that cannot begin translation immediately
- Must transcribe negative stranded to positive strand
- Virion has its own RNA dependen polymerase that will carry out transcription of the negative strand into positive
Negative Strand RNA Viruses
- Cannot be translated directly into proteins and must be transcribed into mRNA with subsequent translation of mRNA into structural proteins
- Most have both negative and positive strand
DNA Viruses
Strand in DNA viruses that is read and used for transcription
Negative Strand
Strand in DNA viruses that is ignored
Positive Strand
Outcome of viral infections where visual or functional change is seen in infected cells
Cytopathic Effects
Outcome in viral infections where oncogenic viruses induce transformation and unrestrained growth
Malignant Transformation
Outcome of viral infections where infected cell appear normal but are producing large number of progeny viruses
Commensal Symbiosis
- “True” Bacteria
- Prokaryotic organisms with peptidoglycan cell walls
Eubacteria
Reproduction process for bacteria
Binary Fission
- Ancient bacteria
- Previously referred to as archaebacterial and archeobacteria
- Non pathogenic
Archaea
Archaeans that fuel production from sewage
Methanogens
- Organisms that live on or in other living organisms (host)
- Not all organisms studied under this study are microorganisms
Parasites (Parasitology)
- Parasite that is established in or on the exterior surface of a host (e.g. mites, ticks, and lice)
Ectoparasite
- Parasite that is established inside of a host (e.g. parasitic protozoa and helminths)
Endoparasite
- Parasite that is capable of existing independently of a host
Faculative Parasite
- Parasite that cannot survive outside of a host
Obligate Parasite
Host other than the normal that is harboring a parasite
Accidental/Incidental Host
Host that harbors the adult or sexual stage of the parasite or the sexual phase of the life cycle
Definitive Host
Host harboring parasites that are parasitic for humans from which humans may become infected
Reservoir Host
Host responsible for transferring a parasite from one place to another
Transport Host
Parasite harboring host that is not exhibiting any symptoms but can infect others
Carrier
A host from which the parasite cannot continue its life cycle
Dead-end Host
- “First animal”
- Exhibits some characteristics typical of animal life
Protozoa
Morphology of Protozoa:
• (1) ________
• (2) Change ________ as they move along surfaces
• No cell wall, has (3) _______ for protection
• Has (4) _______ – “False feet”
• (5) ________ – have metabolic processes closer to those of the human host than the prokaryotic bacterial pathogens
(1) Unicellular
(2) shape
(3) pellicle
(4) pseudopods
(5) Eukaryotes
Reproduction of Protozoa
Asexual; Binary Fission
- Parasitic worms
- Some are relatively large
- Endoparasites
Helminths
Helminths; Roundworms
Nematodes
Helminths; Flatworms
Platyhelminthes
Flatworms; Tapeworms
Class Cestoda (Cestodes)
Flatworms; Flukes
Class Trematoda (Trematodes)
- Type of Helminths
- Thin and often segmented
- Includes cestodes (tapeworms), and trematodes (flukes)
Flatworms (Platyhelminthes)
- Type of helminths
- Elongate
- Cylindrical
- Unsegmented
Roundworms (Nematodes)
In most, adults derive nutrients and reproduce sexually in a _______
host’s body
Reproduction for Helminths
• (1) ________ - separate sexes
• (2) ________ - separate sexes or hermaphroditic
(1) Nematodes
(2) Trematodes
[TRUE OR FALSE]
Helminths must complete the life cycle by transmitting an infective form to the body of another host
TRUE
Reproduction for helminths in an intermediate host (larval stage)
Asexual
Reproduction for helminths in a definitive host (adult worm, for mating)
Sexual
- Invertebrae animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages
- Includes the insects, arachnids, and crustaceans
Arthropods
Athropods means “jointed feet”
(1) _______ - “joint”
(2) _______ - “foot”
(1) arthron
(2) podos
Includes lice, fleas, flies, mosquitoes, and kissing bugs (reduviid)
Insects
Includes mites and ticks
Arachnids
Pathogenicity of Arthropods
- Actual cause of disease:
(1) ______ - microscopic mites live in subcutaneous tunnels and cause pruritus
Scabies
Pathogenicity of Arthropods
- Intermediate host in the life cycle of a parasite:
(1) ______ in the life cycle of the fish tape worm
(2) ______ in the life cycle of African trypanosomiasis
(3) ______ in the life cycle of filariasis
(1) Cyclops sp.
(2) Tsetse fly
(3) Mosquito
Pathogenicity of Arthropods
- Definitive host in the life cycle of a parasite:
(1) ______ in malaria
Anopheles mosquito
Pathogenicity of Arthropods
- Vector in the transmission of disease:
(1) _____ in transmission of Rocky Mountain Spotted Fever and Lyme Disease
Tick
