Bacteriology (part2) Flashcards
Known to hemolyze RBC (Red Blood cell)
Streptococci
complete disruption of erythrocytes with clearing of the blood around the bacterial growth
Alpha hemolysis
incomplete lysis of the erythrocytes with reduction of hemoglobin and formation of green pigment
Beta hemolysis
non-hemolytic
Gamma hemolysis
Disease caused by Streptococcus pyogenes
-Cellulitis
-Streptococcal pyoderma
-Necrotizing fasciitis (Streptococcal gangrene)
-Tonsilitis
-Pharyngitis
-Streptococcal toxic shock syndrome
-Scarlet fever
-Rheumatic fever
An acute rapidly spreading infection of the skin and SC tissues. Due to mild trauma, burns, wounds or surgical incisions
Cellulitis
Enters through abrasions and wounds infecting the tissue
Streptococcal pyoderma
Streptococcus pyogenes Usually susceptible to
Bacitracin
β hemolytic streptococci
Streptococcus pyogenes
Streptococcus pyogenes is known as
β-hemolytic Group A streptococci
Transforms plasminogen of human
plasma into plasmin, an active proteolytic enzyme that digests fibrin and other proteins allowing the bacteria to escape from blood clots
Streptokinase (Fibrinolysin)
promotes hemolysis
Hemolysins
small, flattened red patches that develop into oozing pus-filled vesicles on a red base
Impetigo
Tx under streptococcal pyoderma
Tx: Topical mupirocin, oral erythromycin, and dicloxacillin
Extensive and very rapidly spreading necrosis of the skin, tissues and fascia “Flesh-eating bacteria” other name of Group A streptococci that causes necrotizing fasciitis
Necrotizing fasciitis (Streptococcal gangrene)
Tx under Necrotizing fasciitis (Streptococcal gangrene)
Tx: Immediate IV broad-spectrum antimicrobial drugs; removal o
necrotic tissue; clindamycin + PCN
Swollen tonsils, sore throat, difficulty swallowing, tender lymph nodes
Tonsilitis
intense redness and edema of the mucus membranes, with purulent exudates, enlarged and tender lymph nodes and high fever
Pharyngitis
Shock, bacteremia, respiratory failure and multiorgan failure. Tend to occur after minor trauma with several presentations of soft tissue infections
Streptococcal toxic shock syndrome
Scarlet fever is caused by
pyrogenic exotoxins A-C
Diagnosing of scarlet fever
(+) Quellung test and Optochin test
Tx under scarlet fever
Tx: Penicillin (DOC); erythromycin, cephalosporin
Surgery removing tonsil
Tonsillectomy
Autoimmune disease. Can damage the heart valves and muscles especially if pharyngitis or tonsillitis is not treated well or if there is recurrent streptococcal infections
Rheumatic fever
Tx under Rheumatic fever
Treatment: Uniformly susceptible to Pen G; Macrolides such as
erythromycin and clindamycin – used for patients who are allergic to
penicillin and for necrotizing fasciitis
Part of the normal vaginal flora and lower GIT in women
Streptococcus agalactiae
Disease caused by Streptococcus agalactiae
Disease: neonatal sepsis and meningitis; UTI
Tx under Streptococcus agalactiae
Tx: IV Ampicillin
Lancet-shaped diplococci and α hemolytic
Streptococcus pneumoniae
Diseases caused by Streptococcus pneumoniae
Community Acquired Pneumonia (CAP) or Hospital Acquired
Pneumonia (HAP)
Tx under Streptococcus pneumoniae
PCN, Erythromycin
Helical shape, flexible and Contain two or more axial filaments
Spirochete
Two or more axial filaments
Endoflagella
Disease caused by Treponema pallidum
Syphilis
Enzyme in Treponema pallidum
hyaluronidase
Formation of a chancre at the site of infection. In 1/3 of populations, the disappearance of the chancre
is the end of the disease
Primary syphilis
Untreated syphilis has four phases:
Primary
Secondary
Latent
Tertiary
Treponema has invaded the bloodstream and spreads throughout the body Rash lesions are filled with spirochetes and are extremely contagious
Secondary syphilis
After several weeks r months, the rash gradually disappears
Latent syphilis
Gummas.
Destruction of cardiovascular and CNS tissue, personality changes, insanity, and blindness
Tertiary syphilis
Results when Treponema crosses the placenta from an infected mother to her fetus.
Congenital syphilis
Tx under treponema pallidum
Penicillin G (IV); Ceftriaxone if allergic to PCN
Prevention for syphilis
Prevention: sexual abstinence, mutual monogamy, use condoms
Disease caused by Borrelia
Lyme Disease and Relapsing fever
Lyme disease caused by
Borrelia burgdorferi
Treatment for Lyme disease
Doxycycline, PCN, or Amoxicillin; antibiotic treatment for three to four weeks if the disease is caught early
Prevention for Lyme disease
Prevention: Wear light-colored, tight-fitting clothes outdoors to limit tick exposure, use tick repellent, promptly remove ticks, examine skin for ticks and bites and avoid tick infested areas.
Relapsing fever is caused by
Borrelia recurrentis
Tx for Relapsing fever
Treatment: TCN and Erythromycin
Aerobic spirochete
Leptospira interrogans
Disease caused by Leptospira interrogans
Leptospirosis
Tx for Leptospirosis
Treatment: Oral doxycycline, chloramphenicol, erythromycin, or IV
ampicillin for more severe cases
Prevention for Leptospirosis
Prevention: use of rodent controls, and avoid water contaminated
with animal urine. A vaccine is available for pets and livestock
Most common bacterial food-borne intestinal disease
Campylobacter diarrhea
Tx for Campylobacter diarrhea
Tx: Most cases resolve without treatment; for severe cases Azithromycin is given
Prevention for Campylobacter diarrhea
Prevention: culinary hygiene
Disease caused by Helicobacter pylori
Peptic ulcer
Tx for Peptic ulcer
Tx: Quadruple therapy (PPI with bismuth, Metronidazole and Tetracycline)
Prevention gor peptic ulcer
Prevention: Good personal hygiene, adequate sanitation and proper food handling to decrease fecal-oral transmission, and lifestyle changes
