Atypical bacteria

Definition

Atypical bacteria are a diverse group of bacteria that do not stain well with Gram staining and often lack the characteristics of typical bacterial cell walls. They include organisms like Mycoplasma, Chlamydia, and Legionella.

5 Must Know Facts For Your Next Test

1. Atypical bacteria often require specialized growth media and conditions for cultivation.
2. They can cause respiratory infections, including atypical pneumonia, which is not caused by the common pathogens associated with typical pneumonia.
3. Mycoplasma species lack a cell wall entirely, making them resistant to antibiotics like penicillin that target cell wall synthesis.
4. Chlamydia species have a unique developmental cycle involving elementary bodies and reticulate bodies.
5. Legionella pneumophila is commonly found in water systems and can lead to Legionnaires' disease.

Review Questions

• What structural characteristic makes Mycoplasma resistant to certain antibiotics?
• Which atypical bacterium is known for causing Legionnaires' disease?
• Describe the developmental cycle of Chlamydia species.

Related terms

Mycoplasma: A genus of bacteria lacking a cell wall, making them unique among prokaryotes.

Chlamydia: Intracellular bacteria with a biphasic lifecycle, responsible for various infections including sexually transmitted diseases.

Legionella: A genus of bacteria primarily found in aquatic environments, known for causing Legionnaires' disease.