Bacterial Endocarditis and Pericarditis

The heart of an individual who had subacute bacterial endocarditis of the mitral valve. Bacterial vegetations are visible on the valve tissues. (credit: modification of work by Centers for Disease Control and Prevention) OpenStax Microbiology The endocardium is a tissue layer that lines the muscles and valves of the heart. This tissue can become infected … Continue reading Bacterial Endocarditis and Pericarditis

Bacterial Sepsis, Septic and Toxic Shock

Thrombocytopenia with purpura on right hand in patient with septic shock.Source: By AfroBrazilian - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=53084740 OpenStax Microbiology At low concentrations, pro-inflammatory cytokines such as interleukin 1 (IL-1) and tumor necrosis factor-α (TNF-α) play important roles in the host’s immune defenses. When they circulate systemically in larger amounts, however, the resulting … Continue reading Bacterial Sepsis, Septic and Toxic Shock

Trichinosis

(a) This image shows larvae of T. spiralis within muscle. (b) In meat, the larvae have a characteristic coiled appearance, as seen in this partially digested larva in bear meat. (credit a, b: modification of work by Centers for Disease Control and Prevention) OpenStax Microbiology Trichinosis (trichenellosis) develops following consumption of food that contains Trichinella spiralis (most commonly) or other Trichinella species. These … Continue reading Trichinosis

Amoebiasis (Amebiasis)

By Koji Watanabe - https://academic.oup.com/ofid/article/5/7/ofy161/5049601, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=76095081 OpenStax Microbiology The protozoan parasite Entamoeba histolytica causes amoebiasis, which is known as amoebic dysentery in severe cases. E. histolytica is generally transmitted through water or food that has fecal contamination. The disease is most widespread in the developing world and is one of the leading causes of mortality from parasitic disease worldwide. Disease … Continue reading Amoebiasis (Amebiasis)

Tularemia

(a) A skin lesion appears at the site of infection on the hand of an individual infected with Francisella tularensis. (b) A scanning electron micrograph shows the coccobacilli cells (blue) of F. tularensis. (credit a: modification of work by Centers for Disease Control and Prevention; credit b: modification of work by NIAID) OpenStax Microbiology Infection with the gram-negative … Continue reading Tularemia

Brucellosis

Granuloma and necrosis in the liver of a guinea pig infected with Brucella suis.Source: Public Domain, https://commons.wikimedia.org/w/index.php?curid=2255655 OpenStax Microbiology Species in the genus Brucella are gram-negative facultative intracellular pathogens that appear as coccobacilli. Several species cause zoonotic infections in animals and humans, four of which have significant human pathogenicity: B. abortus from cattle and buffalo, B. canis from dogs, B. suis from swine, and B. melitensis from goats, sheep, … Continue reading Brucellosis