Microbiology

“scientific study of microorganisms and their effect on other living

organisms”

Naming Microorganisms

• Page 266• staphyl = “clustered together”

• coccus = “shaped like a sphere or ball”

• aureus = “a golden-yellow color”

• Staphylococcus aureus

Classification(Page 268)

• Kingdom• Division or Phylum• Class• Order• Family• *Genus• *Species• “King Phillip Came Over From Great Spain”

Staphylococcus aureus

• genus = Staphylococcus

• species = aureus

• italics : not English

• genus: abbreviated e.g. S. aureus

Categories of Cells

• Page 267• Eukaryotic (“True Nucleus”)– nuclei and cytoskeleton– DNA within the nucleus

• Prokaryotic (“Before Nucleus”)– no nuclei and no cytoskeleton– DNA float “freely”– Bacteria and cyanobacteria

Divisions

• Page 269• Bacteriology• Rickettsiology• Virology• Protozoology• Mycology

Bacteriology

• “science that studies bacteria”

Bacteria

• Page 269• “a prokaryotic one-celled microorganism of

the Kingdom Monera, existing as free living organisms or as parasites, multiplying by binary fission and having a large range of biochemical properties”

• pathogenic

Mycoplasmas

• Page 270• “bacteria of the Mycoplasma genus that are

found in humans and have no cell wall; the smallest free-living organisms presently known being intermediate in size between viruses and bacteria”

• double-stranded DNA

Chlamydia

• “a large group of nonmotile, gram negative intracellular parasites”

• replicate in cytoplasm of host cells

• use host’s ATP (Adenosine triphosphate) for energy

Rickettsiology

• “area of science that studies Rickettsia”

Rickettsia

• Page 270• “a genus of gram-negative, pathogenic,

intracellular parasitic bacteria”• rod-shaped, sphere-shaped, change shape• reproduce within host cell• “arthropod vectors”• tetracycline• sulfonamides encourage growth

Virology

• Page 272• “the study of viruses and viral diseases”• Virus: “one of a group of minute infectious

agents, with certain exceptions (e.g. pox viruses) not resolved in the light microscope, and characterized by a lack of independent metabolism and by the ability to replicate only within living host cells”

• rod-shaped, spherical, polyhedral, tad-pole

Virion

• individual particle that consists of nucleic acid (the nucleoid), DNA or RNA (not both), and a protein shell (capsid)

• viruses do not have ATP

Groups of Viruses

• bacterial, animal, and plant• classified according to:– origin: reoviruses (respiratory and enteric)– mode of transmission: arboviruses (mosquitoes)– manifestations: (symptoms)polioviruses,

poxviruses– geographic location: coxsackievirus (names after

Coxsacki, New York)

Prion

• “small proteinaceous infectious agents (particles) which almost certainly do not have a nucleic acid genome and thereby resist inactivation by procedures that modify nucleic acids”

• do not contain DNA or RNA• spongiform encephalopathies• eg: scrapie, mad cow, Creutzfeldt-Jakob

Protozoology

• Page 271• “science that deals with the study of

protozoa”

Protozoa

• “one celled organisms of the Kingdom Protista- most are unicellular although some are colonists”

• “first animals”• most abundant• “normal flora”• classified: according to shape and method of

motility

Flagellates

• smallest• whip-like projections (move like a fishtail)

Amoebae

• “ooze about” by extending parts of their cells as “pseudopods” or “false feet”

Sporozoans

• no locomotory extensions (flagella etc.)

• move by bending, creeping, and gliding

• Parasitic (part of their life-cycle is in host cell)

• “apical complex”: anterior end which helps to penetrate the host cell

Ciliates

• largest protozoa• “hair-like” projections (cilia): “tiny oars”• eat other protozoa and bacteria

Mycology

• Page 271• “the branch of science concerned with the

study of fungi”

Fungus (Fungi = plural)

• “a group of diverse and widespread unicellular and multicellular organisms, lacking chlorophyll, usually bearing spores and often filamentous”

• 3 fundamental categories: yeasts, molds, dimorphic (to be studied in depth later)

• Saprophytes: fungi that grow on decomposing matter

Human Fungal Diseases• categorized by the level of tissue penetration• 1) superficial mycoses: outermost layers of skin

and hair• 2) cutaneous mycoses: skin, hair and fingernails

and are deeper • 3) subcutaneous mycoses: usually result of

trauma; deep in the integument and underlying structures (muscle, bone)

• 4) systemic mycoses: usually originate in the lungs (histoplasmosis, blastoplasmosis)

Opportunistic Fungal Diseases

• due to suppressed immune systems

• secondary infection due to treatment for original disorder

• can be fatal and difficult to manage