Chromobacterium haemolyticum sp. nov., a strongly haemolytic species

Abstract

A Gram-negative bacterium, strain MDA0585(T), isolated from a sputum culture, was characterized by a polyphasic approach. The 16S rRNA gene and a conserved portion of the DNA gyrase A gene were sequenced and analysed phylogenetically. Strain MDA0585(T) showed the closest relationships with Chromobacterium violaceum ATCC 12472(T) and Chromobacterium subtsugae PRAA4-1(T) (96.1 % and 96.3 % 16S rRNA gene sequence similarity, respectively). The cellular fatty acids of strain MDA0585(T) consisted mainly of C(16 : 0), C(16 : 1)omega7c and C(16 : 1)omega6c (summed feature 3) and C(18 : 1)omega7c and C(18 : 1)omega6c (summed feature 8), a profile that was similar to, but distinguishable from, those of C. violaceum ATCC 12472(T) and C. subtsugae PRAA4-1(T). In culture, strain MDA0585(T) differed from C. violaceum and C. subtsugae in several ways: lack of violet pigmentation, the ability to haemolyse sheep blood, differences in several biochemical reactions and higher resistance to antibiotics. The culture supernatant of strain MDA0585(T) also caused remarkable haemolysis of human erythrocytes. These results suggest that strain MDA0585(T) represents a novel species within the genus Chromobacterium, for which the name Chromobacterium haemolyticum sp. nov. is proposed. The type strain is MDA0585(T) (=CCUG 53230(T)=JCM 14163(T)=DSM 19808(T)).