CSCC MLT 1112 Microbiology

Prokaryotes

Microorganisms that lack an enclosed nucleus.

Direct Transmission + Examples

Contact with organisms or discharges, hand-to-hand, congenital (across placenta or birth canal), sexual transmission

Indirect Transmission + Examples

Organisms carried on vehicles, fomites, arthropod vectors, animals, contaminated air (droplet nucleus).

Nosocomial Infections

Infections originating in a health care facility.

Gram Negative

Pink. Cell wall has more lipids. Decolorized and then stained pink.

Gram Positive

Purple. More complex cell wall structure with amino acids and polysaccharides. Violet dye can't pass through.

Fomite

Inanimate objects like utensils used while eating that have been contaminated with microorganisms.

Flagella

Facilitates mobility; can't be seen by microscope light without special stains.

Obligate Aerobe

Microorganisms that only grow in the presence of oxygen.

Facultative Anaerobe

Microorganisms that grow in the absence or presence of oxygen.

Communicable

Transmissible; contagious.

Culture Smear

Slide containing bacteria grown from a culture of a specimen.

Direct Smear

Slide containing a specimen that came directly from the patient.

Eukaryotes

Microorganisms with membrane-bound nucleus and specialized organelles.

Conjunctivitis

Infection and swelling of membranes of the eye.

Lysosome

Organelle that contains enzymes that break down proteins.

Mesophile

Microorganism that prefers temperatures 20°C to 40°C.

Necrotizing fasciitis

Infection of the membrane covering the muscles.

Pharyngitis

Sore throat.

Psychrophile

Microorganism that prefers temperatures 0°C to 30°C.

Vector

Agents able to carry microorganisms from an infected person to another.

Urine Culture

Uses sheep blood and MacConkey agar; Loop placed into specimen then agar, vertical line + horizontal lines, incubate 18-25 hours. Microorganisms counted and multiplied by 1000 in CFU (colony forming units).

Clostridium

Causes tetanus, food poisoning, gas gangrene; Large, gram-positive bacilli; Spores from human feces are ingested after touching contaminated surfaces or direct contact.

Staphylococcus aureus

Causes infections, pneumonia, food poisoning, TSS, bacteremia; Gram-positive cocci in clusters; Direct contact or skin penetration by contaminated objects.

Streptococcus pyogenes

Causes sore throat, scarlet/rheumatic fever glomerulonephritis, necrotizing fasciitis; Diagnosed with beta strip throat culture with sheep blood; Respiratory droplets or direct contact with nose, throat, skin lesions or touching contaminated surfaces.

Mycobacterium tuberculosis

Causes coughing (of blood), chest pain, fatigue, weight loss, chills and fever; Diagnosed with acid-fast stain and specialized media; Droplet inhalation.

Mononucleosis

Caused by Epstein-Barr; Symptoms include fatigue, fever, sore throat, swollen lymph nodes; Serology for antibodies; Bodily fluids, especially saliva, blood transfusion and organ transplantation.

Enterobius vermicularis

Causes itchy anal region; Diagnosed by stool specimen with iodine staining or cellulose tape method with microscope; (In)directly ingesting pinworm eggs.

Lyme Disease

Causes arthritis, facial paralysis, heart palpitations, carditis; Diagnosed with a two-step blood test; Tick bites

Treponema pallidum

Causes syphilis, brain/nerve damage, heart issues, stillbirth or neonatal death; Diagnosed with serology blood tests; Sexually transmitted

Campylobacter species

Causes diarrhea, abdominal pain, fever, nausea, vomiting; Diagnosed by stool sample culture; Fecal-oral or direct contact with infected animals.

Dermatophytes

Cause superficial infections of skin, hair, and nails, fungal infections; Diagnosed with skin scrapings or culture of plucked hairs; Direct contact with infected animal, human, soil, or fomites.