Pathovar

Pathovar is a term used in microbiology to describe a bacterial strain or set of strains with the same or similar characteristics that distinguish them from other strains of the same species. Pathovars are often associated with specific host plants or animals, causing a particular disease in that host. This concept is particularly important in the study of plant pathogens but can also apply to bacteria that infect animals, including humans.

Definition

A pathovar (pv.) is defined based on the pathogenicity and host range of a bacterial strain. It is a subspecific classification, below the level of species and subspecies, used when different strains of the same species or subspecies show distinct pathogenic characteristics in their host organisms. The term is derived from "pathogenic variety," indicating its focus on the pathogenic interaction between the bacterium and its host.

Classification and Nomenclature

The classification into pathovars is based on phenotypic characteristics, particularly the ability to cause disease in specific hosts. Molecular techniques, such as DNA sequencing and PCR, are increasingly used to support and refine pathovar classification. The International Code of Nomenclature of Bacteria provides guidelines for naming pathovars, which typically include the species name followed by "pv." and the pathovar name, e.g., Pseudomonas syringae pv. tomato.

Importance in Agriculture and Medicine

Pathovars are of significant interest in agriculture due to their impact on crop health and yield. Understanding the specific pathovar responsible for a disease can inform targeted interventions to manage or prevent outbreaks. In medicine, identifying pathovars can help in diagnosing bacterial infections and tailoring treatments to the specific pathogen causing the disease.

Examples

• Pseudomonas syringae pv. tomato causes bacterial speck disease in tomatoes.
• Xanthomonas campestris pv. vesicatoria is responsible for bacterial spot disease in pepper and tomato plants.
• Shigella spp. are divided into pathovars based on their serotype and the specific human diseases they cause, such as dysentery.

Research and Control

Research on pathovars involves studying their pathogenic mechanisms, host interactions, and resistance to control measures. This knowledge can lead to the development of resistant plant varieties, effective antimicrobials, and accurate diagnostic tools. Control strategies may include crop rotation, the use of resistant plant varieties, and the application of bactericides or biological control agents.

See Also

• Microbiology
• Plant pathology
• Bacterial taxonomy
• Infectious disease

References

• Bacterial black spot of mango caused by Xanthomonas citri pv. mangiferae indicae
  Bacterial black spot of mango caused by Xanthomonas citri pv. mangiferae indicae
• Bacterial leaf blight of Panax
  Bacterial leaf blight of Panax