Table 2. Key issues for isolating main emerging bacteria.

	Medium			Conditions for incubation
Group	Axenic specific medium	Living system (embryonated egg, cell line)		Low temperature (<37°C)	O2 and CO2 conditions	Extended incubation
Alpha1 Proteo- bacteriae		Ehrlichia sp. Rickettsia sp. Chlamydia sp.		ELB agent (“Rickettsia felis”) (28°C)		Ehrlichia sp. Rickettsia sp.
Alpha2 Proteo- bacteriae	Afipia sp.	Afipia sp. Bartonella sp.		Bartonella bacilliformis (28°C)		Bartonella sp.
Spirochetae	Borrelia sp.			Treponema pallidum
Delta-Xi Proteo- bacteriae					Campylobacter sp. (microaerophilic) Helicobacter sp. (microaerophilic)	Helicobacter pylori
Gamma Proteo- bacteriae	Legionella sp.	Legionella sp.		Yersinia pestis
Mycobacteria	Mycobacterium sp.			Mycobacterium leprae	Mycobacterium malmoense (microaerophilic)	Mycobacterium sp.
Mycoplasmas	Mycoplasma sp.					Mycoplasma fermentans
Gram-positive bacteria		Tropheryma whipplei			Clostridium difficile (anaerobic)	Tropheryma whipplei