Name S aureus Gram Stain Shape Cocci Natural Habitat Anterior nares humans Color of colonies Golden yellow or white Staphylococci Pathogenicity virulence produces exotoxins that damage membranes 1 toxin pierce mammalian cell membranes 2 toxin damages rbc membranes 3 leukocidin destroys neutrophils lyse red cells produces superantigen toxins that causes overproduction of cytokines 1 exfoliative toxins damage cell layer of skin redness blistering resembles a burn 2 Toxic shock syndrome toxin fever skin rash multi organ failure Cause by Mg deficiency 3 enterotoxins food poisoning nausea vomiting no fever brief in duration Infections Disease abscess accumulation of pus furuncles boils carbuncles larger deeper lesions impetigo crusted infection of the skin children wound and bloodstream infections Treatment penicillinase resisant penicillin community acquired vancomycin aminoglycoside systemic or invasive i e hospital acquired penicillin Identification characteristics forms best on BHI agar cell envelope contains peptidoglycan and techoic acid stimulate monocytes cause septic shock envelope has surface proteins for adherence major pathogen coagulase positive activates blood clotting factors facultative anaerobes Protein A binds to immnoglobulins resistant to novobiocin through a disc test coagulase negative methicillin resistant resistant to multiple antibiotics most important skin flora opportunist coagulase negative S saprophyticus Cocci GI tract causes urinary tract infection esp in young women UTI S epidermis Cocci Skin fewer virulence factors wound infections catheter infections bacteremia S Aureus strains can vary in terms of antibiotic resistance o Methicillin resistant S aureus MRSA resistant to ALL lactam antibiotics o o Anti staphylococcal penicillins are effective as long as they bind anywhere but the lactamase Vancomycin resistant S aureus VRSA occurs in patients who have been treated repeatedly with vancomycin Larger white yellow opaque colonies Catalase producing Name S pyogenes Gram Stain Shape Cocci Natural Habitat Color of colonies Yellow tan Pathogenicity virulence Infections Diseases Streptococci M protein anchored in plasma membrane Prevents activation of complement by alternate pathway erythrogenic toxin causes rash of scarlet fever exoenzymes DNAase hyaluronidase streptokinase can be used therapeutically in the case of a blood clot hemolysins oxygen sensitive oxygen stable pharyngitis strep throat scarlet fever fever and skin becomes red pyoderma infection of the skin erysipelas deeper infection of the skin cellulitis infection of subcutaneous soft tissue IV drug use necrotizing fasciitis pyomyositis destroys muscle tissue swelling fever pain streptococcal toxic strep syndrome caused by strains puerperal sepsis occurs after delivery spread locally or via the bloodstream acute rheumatic fever ARF follows pharyngitis damage heart valves Acute glomerulonephritis AGN injury to kidney after skin pharyngeal infections not prevented by penicillin septicemia meningitis of newborns uterine infection of mother S agalactiae Cocci Lower GI tracts female repro tract E faecalis and E faecium Cocci GI tract mucus membranes may cause infection by spread from the GI tract polymicrobial infection UTI abdominal abscesses S pneumoniae S bovis Cocci pairs Cocci blood stream oropharynx spread to ear sinuses lungs Large intestine human green Antiphagocytic polysaccharide capsule ID factor otitis media meningitis lobar pneumonia infection confined to one segment or lobe of the lung septicemia endocarditis infection highly correlated with presence of colon cancer Facultative anaerobes cannot make heme no respiration Catalase negative Oral strep hemolytic Small translucent grayish colonies Any strep cause destruction of red cells around colonies Treatment penicillin G Identification Characteristics Group A Pus formation hemolytic sensitive to bacitracin penicillin G treatment of mother prior to delivery penicillin UTI or wound infections vancomycin invasive infections penicillin if outside CNS otherwise it is resistant Group B identified by the CAMP test hemolytic Group D Enterococci genetically distinct from streptococcus hemolytic cells elongate often in pairs optochin lysis hemolytic Bile resistant Fail to grow in 6 5 NaCl hemolytic Group D Name Bacillus Gram Stain Shape Rods Natural Habitat Pathogenicity virulence Infections Disease Identification characteristics Treatment Clostridium Rods production of protein toxins anthrax toxin with edema and lethal factors capsule antiphagocytic protective antigen antibodies to it are protective edema factor adenyl cyclase cAMP inhibits phagocytes Infection by spores secrete hydrolases which destroy cells and tissue the spores it creates like to reside on meats make it rot and then is eaten unbeknownst by the host penicillin G ciprofloxacin metronidazole penicillin equine antitoxin Resistant to boiling spores Spore forming capsule is made up of amino acid residues aerobic obligates anaerobes facultative macrophages are principal cells infected facultative Obligate anaerobes can infect only tissue whose oxygen supply has been compromised spores require tissue ischemia to flourish histotoxic killed by oxygen infection occurs when wounds are contaminated with soil Other B cereus food poisoning enterotoxins diarrheal fried rice syndrome motile B anthracis anthrax cutaneous and pulmonary gastrointestinal oropharyngeal non motile 1 neurotoxic C tetani C botulinum toxins cleave proteins tetanus toxin inhibits neurotransmitter release at synapses blocking communication between nerve cells neonatal tetanus mom lacked immunity botulism flaccid paralysis limp baby ingestion of the toxin in contaminated food canned foods or bacterial colonization of the intestine for children honey 2 histotoxic C perfringens and gas gangrene wound contamination by spores rapid tissue destruction lecithinase destroys RBC membranes increase of hydrogen gas in tissue boxcar shaped big double zone of hemolysis 3 enterotoxic C difficile Antibiotics reduce normal floura makes them more pathogenic meningitis in newborns Listeria monocytogenes pathogen of livestock contaminated food esp unpasteurized dairy products endotoxin producing all other gram positive are exotoxin producing Flagellum Numbers None Single Multiple Name of Bacteria Shigella Vibrio Cholera E coli Flagellum Spores Clostridium Bacillus Capsules S pneumoniae B anthracis N meningitidis E coli Haemophilus influenzae