Question 1

The first image shows a scanning electron micrograph (SEM) of spherical, clustered bacteria. Based on the study materials, which genus is most likely depicted, and what is a key feature that allows these bacteria to survive on human skin?

Accepted Answer

Staphylococcus; tolerance to salt and desiccation

Question 2

The second image shows sliced ham. If this food is contaminated with a heat-stable exotoxin that causes rapid-onset vomiting and nausea, which organism is most likely responsible, and what is the toxin called?

Accepted Answer

Staphylococcus aureus; enterotoxin

Question 3

The third image shows a child with peeling skin and red lesions. Which disease is most likely depicted, and what is the causative agent?

Accepted Answer

Scalded skin syndrome; Staphylococcus aureus

Question 4

The fifth image is a diagram of a hair follicle infection. Which condition does this represent, and what is the most common causative organism?

Accepted Answer

Folliculitis; Staphylococcus aureus

Question 5

The sixth image shows a scalp lesion with crusting and pus. Which disease is most likely depicted, and which two organisms are common causes?

Accepted Answer

Impetigo; Staphylococcus aureus and Streptococcus pyogenes

Question 6

The seventh image shows a red, swollen arm with a spreading rash. Which disease is most likely depicted, and what is the primary virulence factor involved?

Accepted Answer

Erysipelas; hyaluronic acid capsule

Question 7

The eighth image shows a graph of toxic shock syndrome cases over time. Which organism is primarily responsible for this syndrome, and what is the main toxin involved?

Accepted Answer

Staphylococcus aureus; toxic-shock syndrome toxin

Question 8

The ninth image shows a red, inflamed throat with pus. Which disease is most likely depicted, and what is the causative agent?

Accepted Answer

Pharyngitis; Streptococcus pyogenes

Question 9

The eleventh image shows a severe, spreading wound on the leg. Which disease is most likely depicted, and what is the primary mechanism of tissue destruction?

Accepted Answer

Necrotizing fasciitis; secretion of enzymes and toxins by Streptococcus pyogenes

Question 10

The twelfth image shows a scanning electron micrograph of dental plaque. Which bacterial species is primarily responsible for the initial formation of dental plaque, and what is the key substance it produces?

Accepted Answer

Streptococcus mutans; dextran

Question 11

The thirteenth image is a diagram of tooth anatomy. Which structure is most susceptible to acid demineralization caused by bacterial fermentation, and what is the main acid produced?

Accepted Answer

Enamel; lactic acid

Question 12

The sixteenth image shows a colored SEM of bacteria on a tooth surface. If these bacteria enter the bloodstream, which two serious conditions can result?

Accepted Answer

Meningitis and endocarditis

Question 13

The seventeenth image shows severe gum recession and tooth loss. Which disease process is most likely responsible, and what is the primary microbial structure involved?

Accepted Answer

Periodontal disease; biofilm (dental plaque)

Question 14

The nineteenth image shows Gram-positive rods in a clinical sample. Which organism is most likely depicted, and what common skin condition does it cause?

Accepted Answer

Propionibacterium acnes; acne

Pathogenic Gram-Positive Bacteria: Structure, Pathogenicity, and Diseases

Study Guide - Practice Questions

Study Guide - Flashcards