Question

Cysts of this flagellated organism survive in water; when ingested, the trophozoite grows in the intestine, causing diarrhea.

Short answer

The organism described is Giardia lamblia.

Step-by-step solution

Identify the characteristics

The question describes a flagellated organism with cysts that survive in water and cause diarrhea when ingested, hinting at its life cycle and pathological effects.

Recognize the organism

Based on the description, the organism is likely Giardia lamblia (or Giardia intestinalis), which is known for being flagellated, forming cysts that survive in water, and causing gastrointestinal symptoms like diarrhea when trophozoites grow in the intestine.

Key concepts

Flagellated organisms

Flagellated organisms, like Giardia lamblia, possess tiny, whip-like structures known as flagella. These flagella provide mobility, allowing the organism to swim through its environment.
This movement is essential for their survival, as it aids in accessing nutrients and finding suitable conditions for reproduction.
In the case of Giardia lamblia, flagella help the organism move and attach to surfaces in the host's intestine.

• Flagella are crucial for motility.
• They enable the organism to navigate its ecosystem.
• Infective forms rely on flagella for attachment and survival in hosts.

Understanding these structures helps us appreciate how flagellated organisms have adapted to their unique environments.

Cysts survival in water

Giardia lamblia forms resilient cysts that can survive for long periods in water. This characteristic is critical for its transmission, as these cysts can persist even in harsh environmental conditions.
Cysts are essentially tough protective shells surrounding the organism, allowing it to endure external stresses until ingested by a host.
These cysts remain viable for weeks to months in freshwater bodies, which is why giardiasis outbreaks can occur from contaminated water sources.

• Cysts allow survival in adverse conditions.
• They are a key factor in the organism's transmission cycle.
• Waterborne transmission is a common route for infection.

By understanding cyst formation, we can implement better water treatment methods to prevent outbreaks.

Trophozoite

The trophozoite is the active stage of Giardia lamblia found in the host's small intestine. Unlike the cyst form, trophozoites are motile and biologically active.
Once ingested in cyst form, they transform into trophozoites after reaching the gastrointestinal tract. These trophozoites attach to the intestinal lining, where they multiply and cause symptoms.

• Transform from cysts after ingestion.
• Motile and active within the host.
• Responsible for causing symptoms.

Their ability to multiply rapidly in the intestines contributes to the pathogenicity, leading to symptoms in the host.

Gastrointestinal symptoms

Infection with Giardia lamblia often results in various uncomfortable gastrointestinal symptoms. The presence of trophozoites in the intestine can cause irritation and inflammation.
Common symptoms include diarrhea, abdominal pain, bloating, and sometimes nausea, as the infection disrupts normal digestive processes.
Symptoms can vary in severity, from mild discomfort to more severe cases requiring medical intervention.

• Symptoms typically include diarrhea and abdominal pain.
• Inflammation of the intestinal lining occurs.
• Discomfort can range from mild to severe.

Early detection and treatment are often effective in managing symptoms and preventing further complications.

Life cycle of Giardia

The life cycle of Giardia lamblia is a fascinating and complex process involving two major stages: the cyst and the trophozoite. The cycle begins when an individual ingests food or water contaminated with cysts.
After entering the host's digestive system, cysts transform into trophozoites in the small intestine, where they reproduce by binary fission.
These trophozoites can either attach to the intestinal wall or remain free. They eventually revert to cysts as they move toward the large intestine to be excreted in feces.

• Life cycle includes both cysts and trophozoites.
• Reproduction occurs within the host's intestine.
• Cysts are excreted in feces, resuming the cycle.

An understanding of this life cycle is crucial for controlling and preventing infections effectively.