What is the Difference Between Mycoplasma and Spiroplasma

The main difference between Mycoplasma and Spiroplasma is that mycoplasma infects vertebrates and humans whereas spiroplasma infects plants, causing severe plant diseases.

Mycoplasma and Spiroplasma are two types of mollicutes that are Gram-positive bacteria lacking cell walls. The extreme reduction of the genome is also a key feature of these bacteria. These bacteria live in association with their eukaryotic host.

Key Areas Covered

  1. What is Mycoplasma
    • Definition, Characteristics, Importance
  2. What is Spiroplasma
    • Definition, Characteristics, Importance
  3. Similarities Between Mycoplasma and Spiroplasma
    • Outline of Common Features
  4. Difference Between Mycoplasma and Spiroplasma
    • Comparison of Key Differences

Key Terms

Mycoplasma, SpiroplasmaMycoplasma vs Spiroplasma -  Comparison Summary

What is Mycoplasma

Mycoplasma is a genus of bacteria-like Mollicutes that lack a cell wall around the cell membranes. It does not have a peptidoglycan cell wall made up of murein. Due to the lack of a cell wall, Mycoplasma becomes characteristically resistant to antibiotics that target cell wall synthesis. Mycoplasma is either saprophytic or parasitic. Some species such as M. pneumoniae are pathogenic in humans and cause‘ walking’ pneumonia. Moreover, Mycoplasma species are among the smallest microorganisms yet discovered.

Compare Mycoplasma and Spiroplasma

Figure 1: Mycoplasma

Furthermore, Mycoplasma species can survive without oxygen. Usually, they come in different shapes. Some Mycoplasma is flask-shaped, some are elongated, and some are coccoid. More importantly, hundreds of species of Mycoplasma infect animals. It can also infect different parts of the body including the skin, lungs, or urinary tract. For example, M. pneumoniae causes infections in the lungs. In addition, some symptoms of walking pneumonia include sore throat, cough, fever, fatigue, and headache.

What is Spiroplasma

Spiroplasma is a genus of Mollicutes, a class of bacteria. Therefore, Spiroplasma also lacks a cell wall around the cell membrane as Mycoplasma. They are small bacteria. One of the morphological importance of Spiroplasma is that it has a helical-shaped cell. In addition, it shows a simple metabolism. The spiral-shaped Spiroplasma shows corkscrew motion. Spiroplasma is a disease-causing agent in the phloem of plants.

Mycoplasma vs Spiroplasma

Figure 2: Spiroplasma

Moreover, a Spiroplasma species, Spiroplasma citri causes the Citrus stubborn disease that affects the citrus species. It affects the phloem of the Citrus and causes fruit deformities. On the other hand, the Corn stunt disease is a disease of corn and other grasses that stunts plant growth. Spiroplasma kunkelii causes the Corn stunt disease. This disease is a major economic risk in the United States.  

Similarities Between Mycoplasma and Spiroplasma

  • Mycoplasma and Spiroplasma are two types of mollicutes that are Gram-positive bacteria, lacking cell walls.
  • They have an extremely reduced genome.
  • Generally, they live with their eukaryotic host.
  • They show a simple metabolism.
  • They are parasites and show fried-egg colony morphology.

Difference Between Mycoplasma and Spiroplasma


Mycoplasma refers to any of a group of small typically parasitic bacteria that lack cell walls and sometimes cause diseases while Spiroplasma refers to any of numerous bacteria of the genus Spiroplasma that have no cell walls or flagella and are parasitic in plants and arthropods.


Usually, Mycoplasma is flask-shaped, elongated, or coccoid, while Spiroplasma has a distinctive helical structure.


Mycoplasma infects vertebrates and humans while Spiroplasma infects plants.


Mycoplasma causes upper and lower respiratory tract infections and nongonococcal urethritis in men while Spiroplasma causes severe plant diseases.


In brief, Mycoplasma and Spiroplasma are two types of mollicutes that are Gram-positive bacteria. They lack cell walls and contain an extremely reduced genome. Mycoplasma is usually either flask-shaped, elongated, or coccoid-shaped while Spiroplasma is helical in shape. In addition, Mycoplasma infects humans and other vertebrates while Spiroplasma infects plants, causing severe plant diseases. Therefore, the main difference between Mycoplasma and Spiroplasma is their shape and type of infection.

  1. Mycoplasma Infections: Symptoms, Treatment, and Prevention.” WebMD, WebMD.
  2. Spiroplasma.” Spiroplasma – an Overview | ScienceDirect Topics.
Image Courtesy:
  1. M. haemofelis IP2011” By Paddlestroke – Own work (CC BY-SA 3.0) via Commons Wikimedia
  2. Spiro” By G00251 – Own Work (Public Domain) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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