Recognition of Oerskovia Species in the Clinical Laboratory: Characterization of 35 Isolates

Abstract

Fifty-seven clinical isolates of previously unidentified gram-positive, fermentative, nonsporeforming rods were studied and compared to the type strains of Oerskouia turbata and 0 . xanthineolytica. Thirty-five of the isolates were identified as Oerskouia species: 9 were identified as 0. turbata, and 26 were identified as 0. xanthineolytica. The Oerskouia cultures could be differentiated from the other isolates on the basis of the development of filamentous colonies. The genus Oerskouia, described by Prauser et al. (€9, Sukapure et al. (ll), and emended by Lechevalier (61, consists of yellow-pigmented organisms with branched hyphae. These hyphae break up into motile, rodlike elements that "appear bacterial" in smears. These rods are gram positive and non-acid fast. Previously described sources of the organisms are soil, aluminum hydroxide gel antacid, and dry grass cuttings (6). During the last 20 years, the Special Bacteriology Section (SBS), Bacteriology Division, Center for Disease Control (CDC), has received for identification a number of motile, gram-positive, nonsporeforming, yellow pigment-producing organisms isolated from clinical sources. These organisms were not recognized as belonging to any established species and were arbitrarily designated as group A Corynebacterium sp. Later, this group was divided into five subgroups, primarily on the basis of carbohydrate reactions. When these isolates were observed to have characteristics similar to those reported for the genus Oerskovia, a collaborative study between the Actinomycete Laboratory of CDC's Mycology Division and the SBS was initiated to further characterize and classify them. Listeria denitrificans was included in this study because two of our colleagues, D. Hollis and G. Wiggins, had noted during earlier work on the genus Listeria that many biochemical characteristics of this species were similar to those of the group A strains.

Characterization of clinical isolates previously identified as Oerskovia turbata: proposal of Cellulosimicrobium funkei sp. nov. and emended description of the genus Cellulosimicrobium

“…All colonies were smooth, convex and entire-edged. All isolates studied were motile, with lateral or polar flagella or both (Sottnek et al, 1977). Description of Cellulosimicrobium funkei sp.…”

“…Aesculin, adenine, casein, gelatin, hypoxanthine, urea and xanthine are decomposed. Nitrate is not reduced to nitrite (Sottnek et al, 1977). Acid is produced from L-arabinose, cellobiose, fructose, D-galactose, Dglucose, glycerol, lactose, maltose, mannose, salicin, sucrose, D-trehalose and D-xylose.…”

“…Strain W6122 T was isolated from the blood of an endocarditis patient and identified in 1975 as O. turbata (Reller et al, 1975;Sottnek et al, 1977). Recently, the clonality of W6122 T and three additional blood isolates (strains W2622, W2728 and W2729) from the same patient, as well as six homograft valve isolates (strains W2732, W2734, W2736, W2739, W6120 and W6121), was confirmed (McNeil et al, 2004).…”

The medically important aerobic actinomycetes: epidemiology and microbiology

“…On the basis of DNA-DNA relatedness studies, supported by comparative analyses of 1 6S rRNAs, Stackebrandt et al (558,561) have proposed that the oerskoviae be removed to the genus Cellulomonas. The basis for this proposal is that Cellulomonas cellulans is more closely related to members of the genus Oerskovia than to other members of the genus Cellulomonas (558,561 (555) reported on the characteristics of 35 clinical isolates of the genus Oerskovia that were formerly included in group A-1 and A-2 Corynebacterium spp. Nine of the isolates were identified as 0. turbata, and 25 were identified as 0. xanthineolytica.…”

“…Nine of the isolates were identified as 0. turbata, and 25 were identified as 0. xanthineolytica. These were all isolates submitted to a reference laboratory, and no clinical histories of the patients were available (555). Nine were blood isolates, five were from heart valves or cardiac tissue, one was from cerebrospinal fluid, and the remainder were from sources such as urine, sputum, wounds, eye drainage, liver, and lung biopsy.…”