General introduction Gram-negative, obligate intracellular coccobacilli bacteria that infect mammals and arthropods Rickettsiae are transmitted in the arthropods, which serves as both vector and reservior Both dna and rna Is sensitive to antibiotic
Mycoplasmas a group of the smallest organisms that can be free living in nature, Pass bacterial filter and also grow on laboratory media. More than 80 species, belong to Mycoplasmatales of mollicute. 3 families can be divided: