Ch. 25 - Microbial Diseases of the Digestive System

Tortora - Microbiology: An Introduction 14th Edition

Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook

Tortora 14th Edition

Ch. 25 - Microbial Diseases of the Digestive System

Problem 6

Chapter 25, Problem 6

Explain how the following diseases differ and how they are similar: giardiasis, amebic dysentery, cyclosporiasis, and cryptosporidiosis.

Verified step by step guidance

Step 1: Identify the causative agents of each disease. Giardiasis is caused by the protozoan Giardia lamblia, amebic dysentery by Entamoeba histolytica, cyclosporiasis by Cyclospora cayetanensis, and cryptosporidiosis by Cryptosporidium species.

Step 2: Compare the mode of transmission for all four diseases. Typically, these diseases are transmitted via the fecal-oral route, often through contaminated water or food, which is a key similarity.

Step 3: Examine the clinical symptoms and disease manifestations. Giardiasis often causes diarrhea and malabsorption, amebic dysentery leads to bloody diarrhea and intestinal ulcers, cyclosporiasis causes watery diarrhea and cramping, and cryptosporidiosis results in watery diarrhea, especially severe in immunocompromised individuals.

Step 4: Discuss the life cycle differences. For example, Entamoeba histolytica can invade tissues causing dysentery, while Giardia lamblia primarily colonizes the small intestine without tissue invasion. Cyclospora and Cryptosporidium have oocysts that require environmental maturation before becoming infectious.

Step 5: Summarize the similarities such as being protozoan infections transmitted fecal-orally causing gastrointestinal symptoms, and differences including the specific pathogens involved, severity and type of symptoms, and life cycle characteristics.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Causative Agents and Classification

Understanding the specific protozoan parasites responsible for each disease is essential. Giardiasis is caused by Giardia lamblia, amebic dysentery by Entamoeba histolytica, cyclosporiasis by Cyclospora cayetanensis, and cryptosporidiosis by Cryptosporidium species. These organisms differ in taxonomy and life cycle, influencing disease characteristics.

Transmission and Infection Mechanisms

All four diseases are transmitted primarily through ingestion of contaminated water or food containing infectious cysts or oocysts. Knowing how each parasite infects the host, including their environmental resilience and modes of transmission, helps explain similarities in epidemiology and prevention strategies.

Clinical Manifestations and Pathology

While all cause gastrointestinal symptoms like diarrhea, the severity and pathology vary. Amebic dysentery often involves invasive colonic ulcers and bloody diarrhea, whereas giardiasis typically causes malabsorption and watery diarrhea. Cyclosporiasis and cryptosporidiosis also cause watery diarrhea but differ in immune response and disease duration.

Related Practice

Textbook Question

A cholera epidemic in Peru had all of the following characteristics. Which one led to the others?

a. Eating raw fish

b. Sewage contamination of water

c. Catching fish in contaminated water

d. Vibrio in fish intestine

e. Including fish intestines with edibles

views

Textbook Question

Microscopic examination of a patient’s fecal culture shows comma-shaped bacteria. These bacteria require 2-4% NaCl to grow. The bacteria probably belong to the genus

a. Campylobacter.

b. Escherichia.

c. Salmonella.

d. Shigella.

e. Vibrio.

views

Textbook Question

Differentiate among the following factors of bacterial intoxication and bacterial infection: prerequisite conditions, causative agents, onset, duration of symptoms, and treatment.

views

Textbook Question

E. coli bacteria are part of the normal microbiota of the intestines and can cause gastroenteritis. Explain why this one species is both beneficial and harmful.

views

Textbook Question

Use the following choices to answer the following question:

a. Campylobacter

b. Cryptosporidium

c. Escherichia

d. Salmonella

e. Trichinella

Identification is based on the observation of oocysts in feces.

views

Textbook Question

Define mycotoxin. Give an example of a mycotoxin.

views