The Genus Hafnia

Abstract

The genu s Hafnia wa s recogn i zed by Møller (1954) wh i le s tudy i ng am i no ac i d decarboxyla s e pattern s among Enterobacter i aceae . Member s of th is taxon are Gram-negat i ve, facultat i vely anaerob i c rod s that are typ i cally methyl red and Voge s -Pro s kauer po si t i ve, po si t i ve for ly si ne and orn i th i ne decarboxyla s e, and nega- t i ve for arg i n i ne d i hydrola s e . The taxonom i c po si t i on of the s e organ is m s ha s been the s ub- j ect of s ome controver s y, and over the year s they have been referred to a s Bacillus asiaticus (c i ted by Ew i ng and F i fe, 1968), Bacterium cadaveria (Gale and Epp s , 1943), Aerobacter s pec i e s b i otype 32011 (Stuart et al . , 1943b), Enterobacter alvei (Sakazak i , 1961), Entero- bacter aerogenes s ub s p . hafniae (Ew i ng, 1963), and Enterobacter hafniae (Ew i ng and F i fe, 1968) . However, DNA hybr i d i zat i on s tud i e s have s hown that the s e organ is m s are d is t i nct from Enterobacter (Ste i gerwalt et al . , 1976), and Hafnia alvei (the only recogn i zed s pec i e s of the genu s ) is a leg i t i mate taxon . Barbe de s cr i bed two H. alvei b i otype s , wh i ch can be d is t i ngu is hed by hydroly sis of arbut i n and e s cul i n and fermentat i on of s al i c i n and D- arab i no s e (c i ted i n Introduct i on to the Fam i ly Enterobacter i aceae i n the s econd ed i t i on) . Janda et al . (2002) s ub s equently i dent i fied is o- late s that fell i nto two add i t i onal b i ogroup s (Table 1) . The s e author s reported that is olate s belong i ng to b i ogroup 2 were le ss common than is olate s belong i ng to b i ogroup 1 and that is o- late s belong i ng to b i ogroup s 3 and 4 were rare (Janda et al . , 2002) . Both DNA relatedne ss (Ste i gerwalt et al . , 1976) and 16S r i bo s omal RNA gene s equenc i ng (Janda et al . , 2002) i nd i - cate that there are at lea s t two d is t i nct genomo- s pec i e s of H. alvei . Becau s e the genomo s pec i e s cannot be clearly d is t i ngu is hed by phenotyp i c character is t i c s , they rema i n cla ssi fied a s a si ngle heterogeneou s s pec i e s. It ha s been s ugge s ted that genomo s pec i e s 1, wh i ch i nclude s the ma j or- i ty of is olate s a s well a s the type s tra i n (ATCC 13337), s hould be con si dered H. alvei s en s u s tr i cto (Janda et al . , 2002) .