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Gram Positive Cocci: Strep and Staph

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Gram Positive Cocci: Strep and Staph Gram Positive Cocci: Strep and Staph Organism Physiology/Structure Virulence Epidemiology Diseases Tx Staph Aureus Gram (+) cocci formed A protein evades phagocytosis Is normal flora found in mucous Gastroenteritis usually self limiting. Can Gastroenteritis is self limiting, in clusters membranes and skin. Transmission be caused by ingestion of bacteria (then and the organism is passed Coagulase forms fibrin clot around can either be endogenous or subsequent production of toxin) or by with stool Facultative Anaerobes organism, protecting it from exogenous. ingestion of heat stabile toxin produced phagocytosis before organism was killed by cooking. It is gram (+) with Catalase (+) Common contamination is found in penicillinase activity, so Beta‐ Toxic Shock Syndrome Toxin food workers that sneeze on their Scalded Skin Syndrome local infection Lactams don’t work. Coagulase (+) produces the superantigen TSST‐1 hands, then don’t wash. Found on produces a toxin distally. Causes mild that leads to toxic shock. food that has been left out, like potatoe epidermal tears, with a “sunburn like Methacillin and Nafcillin were Β‐Hemolytic salid. rash” drugs of choice because of Exfoliatin causes the skin to slough their resistance to off, disrupts desmosomes. Toxic Shock associated with tampons penicillinase. MRSA left in too long, toxin is a superantigen (methicillin resistant staph Enterotoxin causes gastroenteritis that causes fever, hypotension, and death aureus) has made treatment more difficulty. Infective Endocarditis acute onset endocarditis with fever, malaise, and a Vancomycin is now the drug heart murmur. Caused by cytolytic of choice, though resistant toxins strains are being identified. Enterrococcus Gram (+) Coccus, it is Survives Bile and Salt so can They are part of the normal flora of the UTI GI Æ GU Penicillin (Fecalis and one of the Strep colonize in the gall bladder. GI and GU tract. During a procedure, Fecium) Species they can be dislodged or displaced and Cholecystitis – infection of the presented to where they should no be. gallbladder. Lancefield Group D’ Normal Flora Can grown in Bile or in High Salt (6.5%) Most prevalent bacteria of GI tract γ­Hemolytic Endogenous Transmission PYR (+) Strep Pyogenes Gram (+) Coccus Theme is “escape or spread” Human throat, transmitted by aerosol Pharyngitis – white, purulent lesions on Culture all negatives on a rapid M protein – antiphagocytic protein. droplets or endogenous infection. the oropharynx. test. Lancelfield Group A M12 is associated with glomerular nephritis Sequellae of Disease (to fit better) Scarlet fever – if strep throat is β­Lactams work well. β­Hemolytic untreated it can then be accompanied by Streptolysin O – Oxygen Labile, Rheumatic Fever – possible sequella scarlet fever. It is described as a sand‐ In those with allergies, use Bacitracin Sensitive antigenic cytolysin that causes lysis of untreated pharyngitis ONLY. This is paper rash, also called a sun burn‐like macrolides. to separate it from of cells. a type II hypersensitivity reaction, rash, in that the skin is red. The palms Strep Agalactiae where antibodies to the strep cross and soles are spared. There is also a Streptolysin S – Oxygen Stabile, react with heart tissue. Causes strawberry tongue that presents bright non­antigenic cytolysin that causes endocartitis, a chorea, fever, and red with many bumps. lysis of cells. arthralgia. Impetigo ‐ just like staph aureus “ASE”s Streptokinase, DNAase, Poststreptococcal Glomerular Hyalurindase, all makes it easier to Nephritis – possible sequella of Necrotizing Fasciitis ‐ infection that spread in tissue. untreated strep pharyngitis or skin causes “flesh‐eating bacteria.” Rapid infection. Type III hypersensitivity spread through fascial layer can involve Exotoxin A‐C that are superantigens reaction. Immune complexes are large amounts of tissue requiring and cause symptoms of scarlet fever deposited in the kidney, causing debreidment or amputation. damage. Associated with M12 serotype Organism Physiology/Structure Virulence Epidemiology Diseases Tx Strep Pneumoniae Gram (+) Coccus Capsule – most important virulence Normal flora of the upper respiratory Acute Pneumonia rapid onset of fever Macrolides for adult bacterial factor tract. They can be colonized, but not be and chills, pain on inspiration, and an X‐ pneumonia Lancet­Shaped infected. Any immunocompromise ray with infilitrates Diplococci IgA protease – cleaves IgA that (chronic pulmonary disease, viral Third Generation allows colonization of mucosa. infection, spleen‐ectomy) can lead to Otitis Media – most common cause of Cephalosporin for meningitis No Lancelfield Group pathogenesis otitis media in children, despite vaccine. Pneumolysin O – what is Vaccines are available. The α­Hemolytic responsible for the rust colored Sinusitus – same as otitis media, pediatric vaccine covers 7 sputum associated with the disease. commonly causes sinusitis in kids common serotypes protecting Optochin Sensitive to Destroys ciliated cells by inducing against meningitis. separate it from classic complement. Adult Meningitis – since the vaccine for Viridans group H. Influenzae b (later), now is leading The adult vaccine covers 23 cause of meningitis in neonates. common serotypes to protect against pneumonia Viridans group Gram (+) Coccus Dextran Bioslime that both protect This is a variety of organisms such as Subacute Endocarditis – dental surgery Penicillin often prophylactic the organism from the immune S. Mutans. gives S. Mutans access to the blood for endocarditis. No Lancelfield Group system and increases adherence to stream where it colonizes the mitral teeth or heart valves S. Mutans is part of the normal flora of valve. In pharm, you learn you treat α­Hemolytic dental caries. These buggers cause with Clindamycin or a plaque. Plaque then allows other This is why people with prostethic valves combination of Vancomycin + Optochin Resistant to Viridans group to colonize and cause or previous valve problems get Gentamycin. separate it from S. cavities prophylactic antibiotics before dental Penuemo procedures. Gram Positive Rods: BCC LAN LM “Send an Email (BCC) over the network (LAN) to Lincoln Martin (LM)” Bacillus, Corynebacterium, Clostridium, Lactobacillus, Actinomyces, Nocardia, Listeria, Mycobacteria; you know “N” is NOT neisseria because Mycobacteria and Nocardia are similar. Organism Physiology/Structure Virulence Epidemiology Diseases Diagnosis Bacillus Anthracis Gram (+) Rod Spore Forming so they are highly Found in soil, water, and on animals Cutaneous Anthrax is 95% of all Formerly Penicillin (which resistant to drying, desiccation, (particularly sheep). anthrax cases. Spores get into wound may still work). Forms spores heating, etc. causing black painless swollen Can be inoculated into a cutaneous postules called eschars. They crust over Currently use doxycyline or Is unique for its Antiphagocytic Capsule evades wound or inhaled into the lungs. and resolve spontaneously. They can cirpofloxain polypeptide capsule phagocytosis rarely enter circulation and cause fatal (most others are Possible agent of bioterrorism (note septicemia. polysaccharide) Exotoxins the postal scare). Edema Factor – calmodulin Pulmonary Anthrax (Woolsorter’s Facultatively dependent increase in cAMP leading Disease). Inhaled spores cause Anaerobic to fluid extrusion. hemorrhagic lymphedemitis with Lethal Factor – causes tissue mediastinal widening. It resembles necrosis. many pulmonary diseases initially, and is Protective Factor ‐allows entry of rapidly fatal without treatement. toxins into target cells. Called this Normally transmitted by sheep, it is now because it is target of vaccine. a risk of bioterrorism. Bacillus Cereus Gram (+) Rod Similar virulence to Anthracis, has Found on food that was cooked and Gastroenteritis­like symptoms Self Limiting different toxins reheated. Think buffet line at a Forms spores Chinese food restaurant. Exotoxins Same as Bacillus Emetic Toxin causes N/V/D 1‐6 hrs The classic presentation is fried rice Anthracis after ingestion at a Chinese buffet. Diarrheal Toxin causes a cAMP dependent secretory diarrhea similar to Cholera or ETEC Corynebacterium Gram (+) Rod Toxin – inhibits protein synthesis. It Throat and nasopharynx, usually Diphtheria – Grey pseudomembrane Elek test will confirm toxin Diphtheriae is a classic AB toxin that inhibits EF‐ transmitted by respiratory droplets. that is on the pharynx. It is well attached producing strains. In this test, Aerobic 2 and will cause hemorrhage if removed. bacteria are streaked across a It is here that necrotic tissue, leukocytes, plate, with a elek strip placed Non‐spore formers While it colonizes the naso or and the corynebacterium are. If the across all streaks. It contains oropharynx, it is not invasive membrane gets to large, it can cause an anti‐toxin that causes Form “Chinese Letters” respiratory obstruction. precipitation on gram stain, V or L shape. Bull Neck – swelling of the neck out Antitoxin is top priority to neutralize toxin Grow Grey or Black colonies on Tellurite Antibiotics will kill bacteria, and stop the toxin production Loeffler’s Media causes granule DPT vaccine formation Organism Physiology/Structure Virulence Epidemiology Diseases Diagnosis Clostridium Same as other Tetanus Toxin (tetanospasmin)– Found in dirt, soil, or dust. Tetanus Antitoxin binds and Tetani clostridium species, no causes spastic paralysis known as Bacteria colonize a local infection, neutralizes free toxin in double zone of Tetanus. Common presentation
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