TABLE 2.

ARB identified to datea

ARBHostbLife-stylePathogenicityReference
α proteobacteriad
    Afipia felis Acanthamoeba Facultative intracellularUnknown 157
    Afipia broomae Acanthamoeba Facultative intracellularUnknown 155
    Bosea spp. Acanthamoeba Facultative intracellularUnknown 154
    Bradyrhizobium japonicum Acanthamoeba Facultative intracellularUnknown 155
    Caedibacter acanthamoebae Acanthamoeba c Facultative intracellularUnknown 114
    Ehrlichia-like organism Saccamoeba c Obligate intracellularUnknown 182
    Mezorhizobium amorphae Acanthamoeba ExtracellularUnknown 155
    Odyssella thelassonicensis Acanthamoeba Facultative intracellularUnknown 27
    Paracaedibacter symbiosus Acanthamoeba c Facultative intracellularUnknown 114
    Paracaedibacter acanthamoebae Acanthamoeba c Facultative intracellularUnknown 114
    “Rasbo bacterium” Acanthamoeba ExtracellularUnknown 150
    Rickettsia-like Acanthamoeba Obligate intracellularPotential 80
β proteobacteriad
    Burkholderia cepacia Acanthamoeba ExtracellularEstablished 148, 168
    Burkholdereria pseudomallei Acanthamoeba ExtracellularEstablished 127
    Procabacter acanthamoeba Acanthamoeba c Facultative intracellularUnknown 115
    Ralstonia pickettii Acanthamoeba c ExtracellularPotential 180
γ proteobacteriad
    Coxiella burnetii Acanthamoeba Obligate intracellularEstablished 158
    Escherichia coli O157 Acanthamoeba ExtracellularEstablished 17
    Francisella tularensis Acanthamoeba Facultative intracellularEstablished 25
    Legionella pneumophilaMany speciesFacultative intracellularEstablished 209
    Legionella anisa Acanthamoeba Facultative intracellularPotential 156
    Legionella lytica (formerly Sarcobium lyticum) Acanthamoeba Facultative intracellularPotential 66, 67
    L. fallonii Acanthamoeba Facultative intracellularPotential 5
    L. rowbothamii Acanthamoeba Facultative intracellularPotential 5
    L. drozanskii Acanthamoeba Facultative intracellularPotential 5
    L. drancourtii Acanthamoeba Facultative intracellularPotential 151
    Other LLAP Acanthamoeba Facultative intracellularPotential 212
    Pseudomonas aeruginosa Acanthamoeba c ExtracellularEstablished 178
    Vibrio cholerae Acanthamoeba, NaegleriaExtracellularEstablished 237
ε proteobacteria
    Helicobacter pylori Acanthamoeba Facultative intracellularEstablished 248
Chlamydiaed
    Chlamydophila pneumoniae Acanthamoeba Obligate intracellularEstablished 71
    Neochlamydia hartmanellae Hartmanella c Obligate intracellularPotential 118
    Parachlamydia acanthamoebae Acanthamoeba c Obligate intracellularPotential 7
    Simkania negevensis Acanthamoeba Obligate intracellularEstablished 133
Flavobacteria
    Amoebophilus asiaticus Acanthamoeba c Obligate intracellularUnknown 116
    Flavobacterium spp. Acanthamoeba Facultative intracellularUnknown 116, 187
Bacilli
    Listeria monocytogenes Acanthamoeba Facultative intracellularEstablished 163
Actinobacteriad
    Molibuncus curtisii Acanthamoeba ExtracellularPotential 241
    Mycobacterium leprae Acanthamoeba Obligate intracellularEstablished 129
    Mycobacterium avium Acanthamoeba Facultative intracellularEstablished 45, 141, 224
    Mycobacterium marinum Acanthamoeba Facultative intracellularEstablished 45, 141
    Mycobacterium ulcerans Acanthamoeba Facultative intracellularEstablished 141
    Mycobacterium simiae Acanthamoeba Facultative intracellularPotential 141
    Mycobacterium phlei Acanthamoeba Facultative intracellularPotential 141
    Mycobacterium fortuitum Acanthamoeba Facultative intracellularPotential 45, 141
    Mycobacterium smegmatis Acanthamoeba Facultative intracellularPotential 141
  • a Among the ARB, some are natural hosts of free-living amoebae (identified within free-living amoebae isolated by amoebal enrichment), some were recovered by amoebal coculture (i.e., using as the cell background free-living amoebae), and some were found to be resistant to a given amoebal “host” in vitro. Some are obligate intracellular bacteria, while others are facultative intracellular bacteria or extracellular bacteria. Some are established human pathogens, while other are emerging potential pathogens, or, until now, strictly environmental species. The list does not include Enterobacteriaceae that have been shown to resist destruction by free-living amoebae only under non-physiological conditions, such as chlorination (137).

  • b Natural host, or grown by amoebal coculture.

  • c Natural host.

  • d Class, according to reference 86.