BIOL 250 - Chapter 19: Gram-Positive Bacteria

firmicutes and acintobacteria

catalase positive, salt tolerant (up to 10% NaCl)

Staphylococcus aureus, Staphylococcus epidermidis

defense: Protein A enzymes: coagulase, hyaluronidase, staphylokinase, lipase, penicillinase (beta-lactamase) toxins: cytolytic toxins, exfoliative toxins, TSS toxins, enterotoxin

a protein that coats S. aureus that interferes with the antibody immune responses by binding to the stems of IgG; inhibits opsonization

triggers blood clotting

hydrolyzes hyaluronic acid, a major component of the matrix between cells

dissolves fibrin threads in blood clots, allowing S. aureus to free itself from clots

digests lipids, allowing staphylococci to grow on the surface of the skin and in cutaneous oil glands

breaks down penicillin to help, allowing bacteria to survive antimicrobial treatment

work by degrading cytoplasmic membrane integrity, causing cell lysis and death

cause skin cells to separate and slough off

protein that causes TSS

cause intestinal disturbance

noninvasive, cutaneous, systemic

food poisoning

scalded skin syndrome, impetigo, folliculitis

pyogenic lesions whereby epidermal layers peel off--does not contain staph cells, just the toxin

staph infection (contains cells)

inflammation of the hair follicle

TSS, bacteremia, endocarditis, pneumonia, empyema, osteomyelitis

potentially fatal condition characterized by fever, vomiting, red rash, low blood pressure, and loss of sheets of skin

presence of bacteria in the blood

inflammation stemming from bacterial invasion of the outer layers of the heart and heart valves

inflammation of the alveoli and bronchioles and the accumulation of fluid

accumulation of pus in the space between the lung and chest wall

inflammation of the bone marrow and bone tissue

catalase negative, cocci arranged in chains or pairs

hemolysis reactions and serological reactions (Lancefield antigens). group A streptococci (ex. Streptococcus pyogenes) have large zones of beta-hemolysis, group B streptococci (ex. Streptococcus agalactiae) have small zones of beta-hemolysis. viridans group have alpha-hemolysis

defense: M protein, hyaluronic acid capsule toxins: pyrogenic toxins, streptolysins

interferes with complement; prevents opsonization; allows strep to adhere to cells

protects/hides from phagocytosis

stimulate fever

lyse RBC, WBC, and platelets--interfering with the oxygen-carrying capacity of the blood, immunity, and blood clotting

pharyngitis, scarlet fever, pyoderma and erysipelas, toxic-shock-like syndrome, rheumatic fever, glomerulonephritis, necrotizing fasciitis

inflammation of the pharynx; "strep throat"

rash and systemic toxemia following pharyngitis

pus-filled lesions on skin (pyoderma); localized swelling and inflammation (erysipelas)

bacteremia and multi-system inflammation and failure

damage to heart valves following pharyngitis

inflammation of the glomeruli and nephrons

"flesh-eating" bacteria disease

capsules (not very effective); mainly infect newborns and now the elderly

neonatal bacteremia, meningitis, pneumonia

inflammation of the meninges

dental caries

cavities

capsules, adhesins, pneumolysins

bind cholesterol and make holes in host cells

sinusitis, otitis media, bacteremia, endocarditis, pneumococcal meningitis

acute infection of the paranasal sinuses

acute infection of the ear

catalase negative, Lancefield group D (but unencapsulated) and are not hemolytic

E. faecalis and E. faecium (both found in the human colon)

bacteriocins

cytolysins that inhibit growth of Gram-positives

10% of nosocomial infections, bacteremia, endocarditis and wound infections

soil dwelling organisms that produce endospores, arranged single, in pairs, or in chains; most notable pathogenic species is Bacillus anthracis

anthrax toxins

create holes in host cells; stimulate apoptosis

anthrax (GI anthrax, cutaneous anthrax, inhalation anthrax)

can be fatal without aggressive treatment; caused by ingestion, inoculation, or inhalation of spores of Bacillus anthracis

ubiquitous in the soil, water and GI tract of animals, produces endospores

Clostridium perfringens (gas gangrene) Clostridium difficile (pseudomembranous colitis) Clostridium botulinum (botulism) Clostridium tetani (tetanus)

produces 7 distinct botulism toxins, which are very deadly and prevent neurotransmitter release resulting in flaccid paralysis

produces tetanospasmin (tetanus toxin) that causes both muscles in an antagonistic pair to contract

low G + C, Gram-positive, non-endospore-forming, rod-shaped bacterium with end-over-end, tumbling motility outside the body. It is found in soil, water, and animals, including insects. It enters the body through consumption of contaminated drink or food, typically deli meats, hot dogs, soft cheeses, and yogurt

enters body through contaminated food/drink and causes listeriosis; rarely pathogenic in health adults, but can infect pregnant women, fetuses, newborns, the elderly, and immunocompromised people resulting in meningitis. Listeria is tolerant of cold temperatures, so it can

nonspecific flulike symptoms in healthy, nonpregnant adults. In contrast, infection in pregnant women, fetuses, newborns, the elderly, and immunocompromised patients can be severe, causing bacterial meningitis and possibly death

ampicillin and other antimicrobials

high G + C, pleomorphic, non-endospore forming, snapping division; all species are pathogenic--Corynebacterium diptheriae

lysogenic bacteriophage in cell that produces the diptheria toxin; cells lacking bacteriophage are non-pathogenic

blocks polypeptide synthesize; formation of pseudomembrane

high G + C, non-endospore-forming pathogen; cell walls with waxlike mycolic acid; two notable disease in humans are M. tuberculosis and M. leprae (tuberculosis and leprosy)

a respiratory disease caused by infection with M. tuberculosis; its disseminated form can result in wasting away of the body and death

disease caused by infection with M. leprae that produces either a non-progressive tuberculoid form or a progressive lepromatous form that destroys tissue, including facial features, digits, and other structures

non-endospore forming, found on skin, produce propionic acid as a byproduct of fermentation; causative agent of acne in 85% of adolescents and young adults

common inhabitor of soils rich in organic matter; mycolic acid in cell wall; acid fast stain

hypha-like cells; causes actinomycosis

characterized by formation of multiple, interconnected abscesses in skin or mucous membrane