Cocci - DONE Flashcards
COAGULASE-NEGATIVE STAPHYLOCOCCI
- S.epidermidis
- S. saprophyticus
- S. haemolyticus
COLONIZATION of STAPHYLOCOCCUS AUREUS (epidemiology):
- Nosopharynx
- Skin
- Clothing
MODE OF TRANSMISSION of STAPHYLOCOCCUS AUREUS:
traumatic introduction
PREDISPOSING CONDITIONS of STAPHYLOCOCCUS AUREUS:
- Chronic infections
- Indwelling devices
- Skin injuries
- Immune response defects
VIRULENCE FACTORS of STAPHYLOCOCCUS AUREUS:
- CELL WALL
- PROTEIN A
- CLUMPING FACTOR
- ENZYMES
- TOXINS
- ADHESINS
STAPHYLOCOCCUS AUREUS DISEASES:
- SKIN
- SEPTICEMIA (iv related)
- ENDOCARDITIS
- PNEUMONIA
- OSTEOMYELITIS
- FOOD POISONING
- UTI
STAPHYLOCOCCUS AUREUS SKIN DISEASES:
- PYOGENIC
- WITH RASH
STAPHYLOCOCCUS AUREUS PYOGENIC SKIN DISEASES:
- FOLLICULITIS
- FURUNCLES (boil)
- CARBUNCLES
- IMPETIGO
- MASTITIS
- WOUND INFECTIONS
Habitat of coagulase-negative staphylococci:
skin and mucous membranes
Cell wall of S. epidermidis:
glycerol-teichoic acids
Virulence factor of S. epidermidis:
“slime”
Mode of transmission of S. epidermidis:
implantation of medical devices such as catheters, shunts, and prosthetic devices
Habitat of S. saprophyticus:
skin and mucosal membranes of the genitourinary tract
What is S. saprophyticus a common cause of in young, sexually active females.
urinary tract infections
What is S. saprophyticus a common cause of in young, sexually active females.
urinary tract infections
STAPHYLOCOCCUS HAEMOLYTICUS:
- IMMUNOSUPPRESSED HOSTS
- WOUND INFECTIONS
- BACTEREMIA
- ENDOCARDITIS
STAPHYLOCOCCI LABORATORY TEST CULTURE:
- CHAPMAN’S MEDIUM (mannitol salt)
- BLOOD AGAR
CATALASE TEST:
- Bubbling = POS (STAPHYLOCOCCI, O2 generated)
- No bubbling = NEG (STREPTOCOCCI and ENTEROCOCCI, no O2 generated)
VIRULENCE FACTORS STREPTOCOCCI:
SOMATIC
- capsule HYALURONIC
- M protein
- OF factor
- LTA
- peptidase
STREPTOCOCCUS PYOGENES DISEASES:
- PHARYNGITIS
- SCARLET FEVER
- RHEUMATIC FEVER
- ACUTE GLOMERULONEPHRITIS
- PYOGENIC SKIN INFECTIONS
- Impetigo, erisipelas, cellulitis
- NECROTIZING FASCIITIS
- STREPTOCOCCAL TOXIC SHOCK SYNDROME
EXTRACELLULAR STREPTOCOCCUS PYOGENES
- PYROGENIC EXOTOXINS
- HEMOLYSINS: SLO, SLS
- ENZYMES: DNA-ase, Hyaluronidase, Streptokinase, Proteinase, Amylase, Esterase
CLINICAL PICTURE OF ‘’STREP” THROAT:
- I P: 2 - 4 days
- Malaise
- Sore throat
- Fever
- Headache
- Kids also:
- Nausea
- Vomiting
- Abdominal pain
SCARLET FEVER (Streptococcus):
- rash (pyrogenic toxins )
- strawberry tongue
STREPTOCOCCAL PHARYNGITIS COMPLICATIONS SUPPURATIVE:
- Peritonsillar cellulitis or abscess
- Otitis media
- Acute sinusitis
- Meningitis
ARF =
acute rheumatic fever
STREPTOCOCCAL PHARYNGITIS COMPLICATIONS NONSUPPURATIVE:
- ARF (acute rheumatic fever)
- AGN (Acute Glomerulo-Nephritis)
AGN =
acute Glomerulo-Nephritis
ARF (acute rheumatic fever):
- Carditis
- Polyarthritis
- Chorea
- Subcutaneous nodules
- Erythema
AGN (Acute Glomerulo-Nephritis):
- Edema
- Hypertension
- Proteinuria
- After 10 days of pharyngitis
- 3 weeks of pyoderma
- LAB: HRA circulating Antibodies
STREPTOCOCCUS AGALACTIAE EPIDEMIOLOGY:
- Asymptomatic colonization
- Transmission to neonates
- Vertical
- Infant to infant
STREPTOCOCCUS AGALACTIAE PATHOGENESIS:
VIRULENCE FACTORS:
- THICK PEPTIDOGLYCAN
- CAPSULE
- HYDROLYTIC ENZYMES
STEREPTOCOCCUS PNEUMONIAE CAN CAUSE:
- MAJOR RESPIRATORY TRACT PATHOGEN
- Pneumonias
- Meningitis
- Otitis media (Children)
STREPTOCOCCUS PNEUMONIAE EPIDEMIOLOGY:
- Closed communities
- Men > women
- Above 40 y. 3-4 times often
- Winter/ early spring
- Nasopharyngeal carriage
- 5% adults
- 15% children
STREPTOCOCCUS PNEUMONIAE PATHOGENESIS:
- CAPSULE (polysaccharide)
- PNEUMOLYSIN O
- NEURAMINIDASE
- Ig A PROTEASE
STREPTOCOCCUS GROUP D AND ENTEROCOCCUS:
- GRAM-POSITIVE COCCI
- CATALASE (-)
- Members of the gut flora
- Emerge of VRE = Vancomycin resistant Enterococci
- Diseases:
- Bacteremia
- Urinary tract infections
- Wound infections
- Endocarditis
ENTEROCOCCI:
- E.faecalis
- E. faecium
- E. durans
GROUP D STREPTOCOCCI:
- S. bovis
- S. equinus
ENTEROCOCCI PATHOGENESIS:
- Hemolysins
- Proteases
- Aggregation substances
- Lipoteichoic acid
- Hyaluronidase
GRAM-NEGATIVE COCCI - MICROAEROPHILIC:
- Neisseria gonorrhoeae
- Neisseria meningitidis
GRAM-NEGATIVE COCCI - AEROBIC:
Moraxella catarrhalis
NEISSERIA GONORRHOEAE EPIDEMIOLOGY:
- STD – GONORRHEA
- HUMANS ONLY
- ASYMPTOMATIC CARRIAGE
NEISSERIA GONORRHOEAE VIRULENCE FACTORS
- Fimbrae (common pili)- enhance the ability of bacterial cells to adhere to host cells and to each other
- Lipooligosaccharide (LOS)
- IgA protease
- β-lactamase
OUTER MEMBRANE PROTEINS:
- Por proteins (Protein I): demonstrated in patients with disseminated disease; also found in rectal cultures of male homosexuals; resistant to serum bactericidal effects
- Opa proteins (Protein II): sensitive to bactericidal effects; associated with adherence to mucosal cells
- Rmp proteins (Protein III): major binding site for immunoglobin-G – blocking antibody
NEISSERIA GONORRHOEAE :DISEASES
- URETHRITIS
- CERVICITIS
- SALPINGITIS
- P I D
- PROCTITIS
- BACTERIEMIA
- ARTHRITIS
- CONJUCTIVITIS
- PHARYNGITIS
NEISSERIA MENINGITIDIS EPIDEMIOLOGY:
- HUMANS ONLY
- Colonization of nosopharynx (asymptomatic carriage)
- Respiratory droplets
- Worldwide (Epidemics in developing countries)
- Dry & cold season
RISK GROUPS of NEISSERIA MENINGITIDIS:
- children < 5 years, soldiers,
- patients with complement deficiencies
ANTIGENIC STRUCTURES of NEISSERIA MENINGITIDIS:
- Capsular polysaccharide: nine serotypes
- A, B, C, D, X, Y, Z, W135, 29E.
- Contribute to invasive properties by inhibiting phagocytosis
NEISSERIA MENINGITIDIS DISEASES:
- MENINGITIS, MENINGOENCEPHALITIS
- Serogroups B, C
- PNEUMONIA
- Serogroups Y, W135
- BACTERIEMIA
- ARTHRITIS
- URETHRITIS
- In developing countries infections by serogroup A
NEISSERIA MENINGITIDIS CLINICAL MANIFESTATION:
- Bacteremia (meningococcemia)
* Appearance of skin petechiae
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