Campylobacter
coli - concisus - curvus - fetus - helveticus - hyointestinalis - jejuni - lari - mucosalis - rectus - showae - sp. - sputorum - upsaliensis

Capnocytophaga
canimorsus - cynodegmi - gingivalis - granulosa - haemolytica - ochracea - sputigena

Carbophilus
carboxidus

Cardiobacterium
hominis

Carnimonas
nigrificans

Carnobacterium
alterfunditum - divergens - funditum - gallinarum - inhibens - maltaromaticum - mobile

Catellatospora
citrea - koreensis - tsunoense

Caulobacter
henricii - leidyi - segnis - vibrioides

Cedecea
davisae - genomospecies - lapagei - neteri

Cellulomonas
biazotea - bibula - cellasea - fermentans - fimi - flavigena - gelida - hominis - humilata - sp. - uda

Cellulophaga
baltica - lytica

Cellulosimicrobium
cellulans

Cellvibrio
mixtus

Centipeda
periodontii

Chromobacterium
violaceum

Chromohalobacter
canadensis - israelensis

Chryseobacterium
balustinum - gleum - indologenes - indoltheticum - joostei - scophthalmum - sp.

Citrobacter
amalonaticus - braakii - farmeri - freundii - genomospecies - gillenii - koseri - murliniae - ostermanii - rodentium - sedlakii - werkmanii - youngae

Clavibacter
michiganense

Clostridium
absonum - aminovalericum - aurantibutyricum - barati - beijerinckii - bifermentans - bifermentens - butyricum - cadaveris - carnis - celatum - chauvoei - cochlearium - difficile - estertheticum - fallax - glycolicum - haemolyticum - histolyticum - novyi - pascui - perfringens - putrificum - septicum - sordellii - sp. - sphenoides - spiroforme - sporogenes - tertium - tyrobutyricum

Cobetia
marina

Coenonia
anatina

Colwellia
hornerae - maris

Comamonas
sp. - terrigena - testosteroni

Corynebacterium
accolens - acetoacidophilum - afermentans - ammoniagenes - amycolatum - argentoratense - auris - auriscanis - bovis - callunae - camporealensis - capitovis - confusum - coyleae - cystitidis - diphtheriae - durum - falsenii - fastidiosum - felinum - flavescens - freneyi - genitalium - glucuronolyticum - glutamicum - hoagii - imitans - jeikeium - kroppenstedtii - kutscheri - lipophiloflavum - macginleyi - mastitidis - matruchotii - minutissimum - mucifaciens - mycetoides - phocae - pilosum - propinquum - pseudodiphtheriticum - pseudotuberculosis - renale - riegelii - segmentosum - seminale - simulans - singulare - sp. - striatum - sundsvallense - terpenotabidum - thomssenii - tuberculostearicum - ulcerans - urealyticum - variabile - vitaeruminis - xerosis

Craurococcus
roseus

Cryobacterium
psychrophilum

Cupriavidus
basilensis - gilardii - necator - pauculus

Curtobacterium
albidum - citreum - flaccumfaciens - luteum - pusillum - sp.

Curvibacter
lanceolatus

Cytophaga
arvensicola - fermentans - hutchinsonii