triple sugar iron (TSI) agar, which is often used to help differentiate salmonellae and shigellae from other enteric Gram-negative rods in stool cultures

sympathetic preganglionic fibers originate in the thoracic (T1–T12), lumbar (L1–L5), and if confirmed, the S2–S4 segments of the cord.

nerve nuclei III, VII, IX, and X

subacute endocarditis is most frequently caused by members of the normal microbiota of the respiratory or intestinal tract that have accidentally reached the blood

Tetracyclines are used for long-term treatment.

S. aureus produces an extracellular coagulase, an enzyme-like protein that clots oxalated or citrated plasma. Coagulase binds to prothrombin; together they become enzymatically active and initiate fibrin polymerization. Coagulase may deposit fibrin on the surface of staphylococci, perhaps altering their ingestion by phagocytic cells or their destruction within such cells. Coagulase production is considered synonymous with invasive pathogenic potentia

Listeria grows well on media such as 5% sheep blood agar on which it exhibits the characteristic small zone of hemolysis around and under colonies. The organism is a facultative anaerobe and is catalase positive, esculin hydrolysis positive, and motile. Listeria produces acid but not gas from utilization of a variety of carbohydrates.

Diphtheria toxin is absorbed into the mucous membranes and causes destruction of epithelium and a superficial inflammatory response. The necrotic epithelium becomes embedded in exuding fibrin and red and white cells so that a grayish “pseudomembrane” is formed—commonly over the tonsils, pharynx, or larynx. Any attempt to remove the pseudomembrane exposes and tears the capillaries and thus results in bleeding. The regional lymph nodes in the neck enlarge, and there may be marked edema of the entire neck, with distortion of the airway, often referred to as “bull neck” clinically. The diphtheria bacilli within the membrane continue to produce toxin actively. This is absorbed and results in distant toxic damage, particularly parenchymatous degeneration, fatty infiltration, and necrosis in heart muscle (myocarditis), liver, kidneys (tubular necrosis), and adrenal glands, sometimes accompanied by gross hemorrhage. The toxin also produces nerve damage (demyelination), often resulting in paralysis of the soft palate, eye muscles, or extremities.

. Most isolates of Mycobacterium, Nocardia, and Rhodococcus species are acid fast and are therefore readily distinguished from the coryneform bacteria.

On Löffler’s serum medium, corynebacteria grow much more readily than other respiratory organisms, and the morphology of organisms is typical in smears made from these colonies.

When toxigenic diphtheria bacilli are serially subcultured in specific antiserum against the temperate phage that they carry, they tend to become nontoxigenic.

On agar containing potassium tellurite, the colonies are brown to black with a brown-black halo because the tellurite is reduced intracellularly

anaerobic, non–spore-forming Gram-positive bacilli such as Propionibacterium species and Actinomyces

. LPS enhances glycolysis in many cell types and can lead to hypoglycemia

e following can be observed clinically or experimentally: fever, leukopenia, and hypoglycemia; hypotension and shock resulting in impaired perfusion of essential organs (eg, brain, heart, and kidney); intravascular coagulation; and death from massive organ dysfunction