Intracellular bacteria are bacteria that have the capability to enter and survive within the cells of the host organism.^[1] Many of them are capable of growth extracellularly, but some of them can grow and reproduce only intracellularly (obligate intracellular parasites). Besides bacteria, there are other kinds of intracellular microorganisms.

Examples of non-obligate intracellular bacteria include members of the genera Brucella, Legionella, Listeria, and Mycobacterium. Examples of obligate intracellular bacteria include members of the order Rickettsiales and members of the genus Mycoplasma.^[1]

References

^ ^a ^b Levinson, Warren (2018). Review of medical microbiology and immunology (15th ed.). New York. ISBN 978-1-259-64450-4. OCLC 1225889723.((cite book)): CS1 maint: location missing publisher (link)

Microbiology: Bacteria

Medical
microbiology

Biochemistry
and ecology

Oxygen preference	Aerobic Obligate Facultative Anaerobic Facultative Obligate Microaerophile Nanaerobe Aerotolerant
Other	Extremophile Human microbiome Gut Lung Mouth Skin Vaginal (in pregnancy) Placental Uterine Salivary Microbial metabolism Nitrogen fixation Microbial ecology Primary nutritional groups Substrate preference Lipophilic Saccharophilic

Shape

Structure

Cell envelope	Cell membrane Cell wall: Peptidoglycan NAM NAG DAP Gram-positive bacteria only: Teichoic acid Lipoteichoic acid Endospore Gram-negative bacteria only: Bacterial outer membrane Porin Lipopolysaccharide Periplasmic space Mycobacteria only: Arabinogalactan Mycolic acid
Outside envelope	Bacterial capsule Slime layer S-layer Glycocalyx Pilus Fimbria Non-motile bacteria
Composite	Biofilm

Taxonomy
and evolution

See also

References