Microbiology Exam 3 - Gram Positive Bacteria

Staphylococcus aureus

leading cause of skin and soft tissue infections, catalase positive

Staphylococcus epidermidis

common skin bacterium, coagulase negative, ferments mannose

Staphylococcus saprophyticus

a leading cause of uncomplicated UTI infections, coagulase negative, does not ferment

Methicillin-Resistant Staphylococcus aureus (MRSA)

acquired chromosomal DNA segment (mecA gene that encodes Penicillin-Binding Protein 2a)

Streptococcus pyogenes

strep throat and impetigo; many long-term complications including rheumatic fever

Necrotizing fasciitis

flesh-eating Streptococcus (caused by S. pyogenes)

Streptococcus agalactiae

leading cause of postpartum infection & neonatal meningitis, pneumonia, & sepsis

Enterococcal species

second most common intestinal disease after salmonellosis in industrialized countries

Streptococcus mutans

produce slime layers that adhere to teeth, basis for plaque

Streptococcus pneumoniae

causes 60–70% of all bacterial pneumonia in adults

Bacillus anthracis

anthrax

Bacillus cereus

grows in foods; spores survive cooking and reheating; no treatment

Clostridium perfringens

gas gangrene

Clostridium tetani

muscles contract uncontrollably; death due to paralysis of respiratory muscles

Clostridium difficile

prey on weak hospitalized patients; second or third most common cause of hospital-acquired infections; resistant to vancomycin

Clostridium botulinum

botulinum toxin: potent, blocks acetylcholine release at neuromuscular junctions

Listeria monocytogenes

virulence attributed to ability to replicate in cytoplasm after inducing phagocytosis, avoiding humoral immunity

Corynebacterium diphtheriae

pleomorphic bacterium causing diphtheria

Mycobacterium leprae

Hansen’s Disease (leprosy)

Mycobacterium tuberculosis

virulence factors: cord factor (Trehalose 6,6′-dimycolate; TDM)