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SUMMARYMenaquinones were the only isoprenoid quinones found in 48 corynebacteria and actinomycete strains examined. Dihydromenaquinones having nine isoprene units were the main components isolated from Gordona, Mycobacterium, Corynebacterium bovis, Corynebacterium glutamicum and a strain labelled Nocardia farcinica, but dihydromenaquinones having eight isoprene units were characteristic of other Corynebacterium species and representatives of the ' rhodochrous' complex. Tetrahydromenaquinones having six and eight isoprene units were found in Nocardia strains and in a single strain of Micropolyspora brevicatena, which also contained mycolic acids similar in chain length to those of Nocardia. Menaquinones having nine isoprene units with from one to five double bonds hydrogenated were the main Components in Actinomadura madurae, Actinomadura pelletieri, Micropolyspora faeni, Oerskovia turbata and Streptomyces strains. Actinomadura dassonvillei strains had a characteristic pattern of di-, tetra-and hexahydromenaquinones with 10 isoprene units which was slightly different from the pattern in mixtures of similar quinones from Actinomyces israelii and A c t inom y ces viscosus .

Strains representing the mycolic acid-containing taxa Nocard ia , Mycobacterium, Gordona, Corynebacterium, Bacterionema, and the "rhodochrous" complex were analysed for polar lipids by two-dimensional, thin-layer chromatography; diphosphatidylglycerol and phosphatidylinositol were found in all strains and phosphatidylethanolamine was absent only in extracts of Coryne bacterium and Bacterionema. Mono-and diacyl phosphatidylinositol dimannosides were present in all Nocardia, Mycobacterium, Corynebacterium, and rhodochrous strains and in the single strain of Gordona aurantiaca examined; Bacterionema and strains of the other Gordona species had only a monoacyl phosphatidylinosito1 dimannoside. Phosphatidylglycerol was present in substantial amounts in extracts of two strains of Bacterionema matruchotii and in reduced proportions in strains of several other species. Unidentified glycolipids were detected in the lipids of a majority of the organisms investigated.Lipids can provide good characters for the classification and identification of bacteria (10, 31, 42). In mycobacteria and coryneform and nocardioform bacteria the distribution of longchain components, in particular the mycolic acids, has diagnostic value (1, 2, 3, 12, 25, 26, 31). Less attention has been paid to the value of polar lipids as taxonomic markers. Inconsistencies between various reports (17, 19, 21, 22, 37, 48-50) on the distribution of polar lipids in nocardioform and related taxa require clarification. The most characteristic polar lipids of actinomycetes are the phosphatidylinositol mannosides (PIMs); a few mycobacteria contain major amounts of phosphatidylinositol dimannosides (PIDMs) with three or four fatty acid residues in each molecule co-occurring with lipids having up to five mannose units (6, 35). Phosphatidylinositol monomannosides have been reported from Nocardia leishmanii (501, Nocardia coeliaca (49), Nocardia polychromogenes (17, 481, Nocardia asteroides, Nocardia caviae, and strains labeled Nocardia erythropolis and Nocardia farcinica (37). However, another report (19) highlighted the presence of PIDMs in strains of N . coeliaca and N . potychromogenes. In a more extensive investigation (22) of the value of phospholipids in the taxonomy of coryneform and nocardioform bacteria, the number of mannose units in the PIMs was not determined. In the present study, the polar lipid patterns of strains of Corynebacterium, Mycobacterium, Nocardia, Gordona, and the "rhodochrous" complex (11) were compared and the PIMs of representative nocardiae were examined in more detail. Two strains of Bacterionema matruchotii, recently shown to contain fatty and mycolic acids (la) similar t o those of Corynebacterium, were also studied. MATERIALS AND METHODSStrains and growth conditions. Details of the strains and their sources are given in Table 1. All cultures were maintained routinely on yeast extract agar a t room temperature.The mycobacteria, nocardiae, and gordonae were grown in shake culture at 30°C for 2 to 5 days in modified Sauton medium (33) a...

Strains representing the taxa Cellulomonas, Oerskovia, Brevibacterium fermentans, Corynebacterium manihot and Nocardia cellulans were degraded by acid methanolysis and the non‐hydroxylated fatty acid esters released examined by thin‐layer and gas chromatography. The major fatty acid in all strains was 12‐methyltetradecanoic acid (anteiso C15) which occurred together with other anteiso acids, iso and straight‐chain acids. The fatty acid profiles of the cellulomonads were distinguished by the presence of 13‐carbon acids and significantly higher proportions of straight‐chain acids than found in the other test strains whose profiles were closely similar to one another. Two‐dimensional thin‐layer chromatography showed that almost identical and very characteristic polar lipid patterns were given by all the organisms under study: the only major components were diphosphatidylglycerol, phosphatidylinositol and two phospho‐glycolipids chromatographing similarly to, but distinguishable from, the mono‐ and diacyl phosphatidylinositol dimannosides characteristic of Nocardia and other actinomycetes. The accumulated lipid data support the reclassification of B. fermentans, Cor. manihot and N. cellulans in the genus Oerskovia.

Leprosy: Ancient and Modern In medieval Europe, leprosy was greatly feared: Sufferers had to wear bells and were shunned and kept isolated from society. Although leprosy largely disappeared from Europe in the 16th century, elsewhere in the world almost a quarter of a million cases are still reported annually, despite the availability of effective drugs. Schuenemann et al. (p. 179 , published online 13 June; see the 14 June News story by Gibbons , p. 1278 ) probed the origins of leprosy bacilli by using a genomic capture-based approach on DNA obtained from skeletal remains from the 10th to 14th centuries. Because the unique mycolic acids of this mycobacterium protect its DNA, for one Danish sample over 100-fold, coverage of the genome was possible. Sequencing suggests a link between the middle-eastern and medieval European strains, which falls in line with social historical expectations that the returning expeditionary forces of antiquity originally spread the pathogen. Subsequently, Europeans took the bacterium westward to the Americas. Overall, ancient and modern strains remain remarkably similar, with no apparent loss of virulence genes, indicating it was most probably improvements in social conditions that led to leprosy's demise in Europe.