chryseobacterium chryseobacterium chryseobacterium is a genus of gram-negative bacteria. chryseobacterium species are chemoorganotrophic, rod shape gram-negative bacteria. chryseobacterium form typical yellow-orange color colonies due to flexirubin-type pigment. the genus contains more than 100 described species from diverse habitats, including freshwater sources, soil, marine fish, and human hosts. chryseobacterium chryseobacterium oleae dsm25575 bacteria grown on solid lb media scientific classification domain: bacteria phylum: bacteroidota class: flavobacteriia order: flavobacteriales family: weeksellaceae genus: chryseobacteriumvandamme et al. 1994 species see text. synonyms halpernia nicholson et al. 2020 epilithonimonas o'sullivan et al. 2006 planobacterium peng et al 2009 soonwooa joung et al. 2010 kaistella kim et al. 2004 sejongia yi et al. 2005 history the genus chryseobacterium was originally created in 1994 by vandamme et al. for six bacterial taxa that, at that time, were classified as members of the genus flavobacterium: f. balustinum, f. indologenes, f. gleum, f. meningosepticum, f. indoltheticum, and f. scophthalmum. in 2005 an additional genus, elizabethkingia, was created for two species within the genus chryseobacterium; namely, c. meningosepticum and c. miricola. in 2002 standards and guidelines for description of novel taxa in the family of flavobacteriaceae were published by bernardet et al. by 2006, the genus chryseobacterium had expanded to 10 species, by 2014 more than 60 species and currently more than 100. ecology chryseobacterium spp. were recovered from soils, plant roots, flowers, decaying plant material and maple sap. some plant-associated chryseobacterium strains are able to inhibit plant pathogenic fungi. chryseobacterium spp. were also recovered from freshwater creeks, lakes, their sediments, water cooling systems, drinking water, lactic acid beverages, beer bottling plants, bioreactor sludge, polluted soil, marine sediment and permafrost. chryseobacterium spp. are associated with a multitude of animals - they have been detected in the midgut of mosquitos, within cockroach guts, millipede feces, and penguin guano, gut homogenates of freshwater copepods, bird feathers, cow's milk, raw meats and chicken. chryseobacterium spp. were recovered from the mucus of apparently healthy fish, however sometimes they are considered as a spoilage organism. three novel cold-tolerant species of chryseobacterium, c. oranimense c. haifense, and c. bovis, have been detected in raw milk in israel. pathogenesis the most pathogenic flavobacterium spp., chryseobacterium meningosepticum, which caused numerous infections, was reclassified to the genus elizabethkingia. chryseobacterium indologenes although ubiquitous in nature, mainly found in soil and water, is an uncommon human pathogen. however, in rare cases it can cause serious infections, particularly among the immunocompromised. most of the time infections are hospital acquired, often associated with immunosuppression or indwelling catheters. it has been reported as the causative agent in bacteremia, peritonitis, pneumonia, empyema, pyelonephritis, cystitis, meningitis and central venous catheter-associated infections. the numbers of reported c. indologenes infections are increasing. the majority of reported infections have been from taiwan and only about 10% have been outside of asia. a few reports have come from australia, india, europe and the usa. c. indologenes is also pathogenic to the soft tick, whereas other chryseobacterium spp. were recovered from diseased turtles, frogs and fish, in particularly c. scophthalmum, c. joostei, c. piscicola, c. chaponense, c. viscerum and c. oncorhynchi, c. aahli, c. hominis, c. shigense as well as c. indologenes which is associated with human diseases. certain chryseobacterium species were reported as having unusual matrix digesting properties, being able to degrade most difficult collagenous matrices, such as feathers or exoskeletons. these properties are likely mediated through the action of specific chitinases and collagenase-like metalloproteases. some of the species, such as chryseobacterium nematophagum were shown to be able to infect, kill and ultimately consume all nematode tissues, including the normally highly insoluble cuticular exoskeleton. chitinase, gelatinase and collagenase metalloprotease activities have been linked to chryseobacterium gliding motility exerted through type ix secretion systems. indeed, some of these enzymes possess c-terminal type ix secretion signals. chryseobacterium themselves have neither collagen nor chitin proteins or structures. chryseobacterium species belong to the bacteriodetes phylum, members of which are being increasingly describes as having unusually linked motility and secretory system. botulinum neurotoxin-like (bont-like) toxins were detected in the genome of chryseobacterium piperi str. ctm and they present a highly divergent group of bont-like toxins. one of the predicted c. piperi bont-like toxins induced necrotic cell death in human kidney cells, but was not found to cleave common snare substrates of bonts. antibiotic resistance chryseobacterium spp. are inherently resistant to a wide spectrum of antibiotics, including tetracyclines, erythromycin, linezolid, polymyxins, aminoglycosides, chloramphenicol, and many beta-lactams, while also being intermediately sensitive to vancomycin and clindamycin and vary in their sensitivity to trimethoprim-sulfamethoxazole. species species include: chryseobacterium aahli loch and faisal 2014 chryseobacterium angstadtii kirk et al. 2013 chryseobacterium antarcticum (yi et al. 2005) kämpfer et al. 2009 chryseobacterium anthropi kämpfer et al. 2009 "chryseobacterium antibioticum" dahal et al. 2021 chryseobacterium aquaticum kim et al. 2008 chryseobacterium aquifrigidense park et al. 2008 chryseobacterium arachidiradicis kämpfer et al. 2015 chryseobacterium arachidis kämpfer et al. 2014 chryseobacterium arthrosphaerae kämpfer et al. 2010 chryseobacterium artocarpi venil et al. 2014 chryseobacterium aurantiacum luo et al. 2018 chryseobacterium aureum lee et al. 2019 chryseobacterium balustinum (harrison 1929) vandamme et al. 1994 chryseobacterium bernardetii holmes et al. 2013 chryseobacterium binzhouense meng et al. 2020 chryseobacterium bovis hantsis-zacharov et al. 2008 chryseobacterium buanense (joung et al. 2010) garcía-lópez et al. 2020 chryseobacterium caeni quan et al. 2007 chryseobacterium camelliae kook et al. 2014 chryseobacterium candidae indu et al. 2020 chryseobacterium carnipullorum charimba et al. 2013 chryseobacterium carnis holmes et al. 2013 chryseobacterium chaponense kämpfer et al. 2011 "chryseobacterium chengduensis" wen et al. 2016 "chryseobacterium cheonjiense" chaudhary et al. 2021 "chryseobacterium chungangensis" huq 2018 chryseobacterium contaminans kämpfer et al. 2014 chryseobacterium cucumeris jeong et al. 2017 chryseobacterium culicis kämpfer et al. 2010 chryseobacterium daecheongense kim et al. 2005 chryseobacterium daeguense yoon et al. 2007 chryseobacterium defluvii kämpfer et al. 2003 chryseobacterium echinoideorum lin et al. 2015 chryseobacterium elymi cho et al. 2011 chryseobacterium endophyticum lin et al. 2017 chryseobacterium flavum zhou et al. 2007 chryseobacterium formosense young et al. 2005 "chryseobacterium formosus" akter et al. 2015 chryseobacterium frigidisoli bajerski et al. 2013 chryseobacterium frigidum kim et al. 2016 chryseobacterium gallinarum kämpfer et al. 2014 chryseobacterium gambrini herzog et al. 2008 chryseobacterium geocarposphaerae kämpfer et al. 2014 chryseobacterium ginsengisoli nguyen et al. 2013 "chryseobacterium ginsengiterrae" noh et al. 2017 chryseobacterium ginsengiterrae hahnke et al. 2017 chryseobacterium ginsenosidimutans im et al. 2011 chryseobacterium glaciei pal et al. 2018 chryseobacterium gleum (holmes et al. 1984) vandamme et al. 1994 chryseobacterium gregarium behrendt et al. 2008 chryseobacterium gwangjuense park et al. 2013 chryseobacterium hagamense cho et al. 2011 chryseobacterium haifense hantsis-zacharov and halpern 2007 chryseobacterium halperniae hahnke et al. 2017 chryseobacterium hispalense montero-calasanz et al. 2013 chryseobacterium hispanicum gallego et al. 2006 chryseobacterium hominis vaneechoutte et al. 2007 chryseobacterium humi pires et al. 2010 chryseobacterium hungaricum szoboszlay et al. 2008 chryseobacterium indologenes (yabuuchi et al. 1983) vandamme et al. 1994 chryseobacterium indoltheticum (campbell and williams 1951) vandamme et al. 1994 chryseobacterium jejuense weon et al. 2008 chryseobacterium jeonii (yi et al. 2005) kämpfer et al. 2009 chryseobacterium joostei hugo et al. 2003 chryseobacterium koreense (kim et al. 2004) kämpfer et al. 2009 chryseobacterium kwangjuense sang et al. 2013 chryseobacterium lactis holmes et al. 2013 chryseobacterium lacus zhang et al. 2020 chryseobacterium lathyri cho et al. 2011 chryseobacterium limigenitum kämpfer et al. 2015 chryseobacterium lineare zhao et al. 2017 chryseobacterium luteum behrendt et al. 2007 "chryseobacterium manosquense" boxberger et al. 2020 chryseobacterium marinum (lee et al. 2007) kämpfer et al. 2009 "candidatus chryseobacterium massiliense" corrig. greub et al. 2004 chryseobacterium molle herzog et al. 2008 chryseobacterium montanum guo et al. 2016 "chryseobacterium mucoviscidosis" tetz and tetz 2018 chryseobacterium mulctrae yoon et al. 2019 chryseobacterium nakagawai holmes et al. 2013 "chryseobacterium nematophagum" page et al. 2019 chryseobacterium nepalense chaudhary and kim 2017 chryseobacterium oleae montero-calasanz et al. 2014 chryseobacterium oncorhynchi zamora et al. 2012 chryseobacterium oranimense hantsis-zacharov et al. 2008 chryseobacterium pallidum herzog et al. 2008 chryseobacterium palustre pires et al. 2010 "chryseobacterium panacis" singh et al. 2016 chryseobacterium pennipullorum oosthuizen et al. 2019 "chryseobacterium phocaeense" abou abdallah et al. 2019 chryseobacterium phosphatilyticum jeong et al. 2019 chryseobacterium piperi strahan et al. 2011 chryseobacterium piscicola ilardi et al. 2009 chryseobacterium piscium de beer et al. 2006 chryseobacterium polytrichastri chen et al. 2015 chryseobacterium populi bortniak et al. 2019 chryseobacterium profundimaris xu et al. 2015 "chryseobacterium proteolyticum" yamaguchi and yokoe 2000 chryseobacterium psychrotolerans (ge et al. 2015) hahnke et al. 2017 chryseobacterium reticulitermitis zhao et al. 2017 chryseobacterium rhizoplanae kämpfer et al. 2015 chryseobacterium rhizosphaerae cho et al. 2011 chryseobacterium rigui park et al. 2013 chryseobacterium salipaludis divyasree et al. 2018 chryseobacterium salivictor kim and yu 2020 chryseobacterium scophthalmum (mudarris et al. 1994) vandamme et al. 1994 chryseobacterium sediminis kämpfer et al. 2015 "chryseobacterium senegalense" lo et al. 2016 chryseobacterium shandongense yang et al. 2015 chryseobacterium shigense shimomura et al. 2005 "chryseobacterium siluri" oh et al. 2020 chryseobacterium solani du et al. 2015 chryseobacterium soldanellicola park et al. 2006 chryseobacterium soli weon et al. 2008 chryseobacterium solincola benmalek et al. 2010 chryseobacterium taeanense park et al. 2006 chryseobacterium taichungense shen et al. 2005 chryseobacterium taihuense wu et al. 2013 chryseobacterium taiwanense tai et al. 2006 chryseobacterium takakiae zhao et al. 2015 chryseobacterium taklimakanense (peng et al. 2009) holmes et al. 2013 chryseobacterium tenax (o'sullivan et al. 2006) hahnke et al. 2017 "candidatus chryseobacterium timonense" corrig. drancourt et al. 2004 "chryseobacterium timonianum" abou abdallah et al. 2017 chryseobacterium treverense yassin et al. 2010 chryseobacterium tructae zamora et al. 2013 chryseobacterium ureilyticum herzog et al. 2008 chryseobacterium vaccae lee et al. 2020 chryseobacterium vietnamense li and zhu 2012 chryseobacterium viscerum zamora et al. 2012 chryseobacterium vrystaatense de beer et al. 2005 chryseobacterium wanjuense weon et al. 2006 chryseobacterium xinjiangense zhao et al. 2011 chryseobacterium xixisoli (feng et al. 2014) hahnke et al. 2017 "chryseobacterium yeoncheonense" hoang et al. 2013 chryseobacterium yonginense joung and joh 2011 chryseobacterium zeae kämpfer et al. 2014 "chryseobacterium zhengzhouense" wang et al. 2016