Bacteria — Flashcards

Flashcard 741: Clostridium perfringens binds _____, resulting in watery diarrhea due to destruction of tight junctions

Answer: claudins

Flashcard 742: Which form of E. coli presents with dysentery (bloody, mucousy diarrhea)?

Answer: Enteroinvasive E. coli (EIEC)

Extra: EIEC invades the intestinal mucosa (clinically similar to Shigella), leading to inflammation and necrosis. This presents as dysentery (fever, abdominal cramps, and blood/mucus in the stool). In contrast, Enterohemorrhagic E. coli (EHEC) causes hemorrhagic colitis (bloody diarrhea) via Shiga-like toxin but does not invade the mucosa, so it typically lacks fever and mucus/leukocytes in the stool.

Flashcard 743: During the _____ phase of bacterial growth, there is no increase in number of cells since you added them to the culture

Answer: lag

Flashcard 744: IgA protease is a virulence factor used by Neisseria that allows bacteria to colonize and adhere to _____.

Answer: mucous membranes

Flashcard 745: _____ of High Frequency bacterial strains allows us to perform genetic mapping

Answer: Conjugation

Flashcard 746: _____ is normal flora of the skin and thus can contaminate blood cultures.

Answer: Staph epidermidis

Flashcard 747: Which bacterial genetics phenomenon involves the uptake of naked DNA from the environment?

Answer: Transformation

Extra: Transformation is a mechanism of horizontal gene transfer where bacteria take up "naked" DNA from their environment. It was famously demonstrated by Griffith's experiment with Streptococcus pneumoniae. This is distinct from conjugation (cell-to-cell contact) and transduction (viral-mediated).

Flashcard 748: Shigella spp. uses host cell _____ to spread from cell to cell

Answer: actin filaments

Flashcard 749: What bacteria releases a toxin that cleaves SNARE proteins in Renshaw cells? _____

Answer: Clostridium tetani

Flashcard 750: Streptococcus agalactiae (GBS) is bacitracin _____

Answer: resistant