- Volume 25, Issue 1, 1975

The type species (ATCC 13637) and one other strain (ATCC 17444) of Pseudomonas maltophilia have been examined for their ability to use the disaccharide lactose for growth. These organisms lack the usual high levels of β-galactosidase found in most lactose-positive bacteria, although both strains were found to have high levels of the enzyme lactose dehydrogenase. If this latter enzyme is responsible for all lactose splitting, P. maltophilia is unlike other pseudomonads, which have lactose dehydrogenase but which apparently cannot use lactose as a source of carbon and energy for growth.

Three hundred and eighty-four strains of bacteria representing the genera of the Enterobacteriaceae were examined over a wide range of biochemical, physiological, and morphological characters. The data were subjected to numerical analysis, and the resulting 33 clusters were equated as far as possible with established taxa within the Enterobacteriaceae. The clusters formed three groups. Group A corresponded to the tribe Klebsielleae and consisted of the genera Enterobacter, Klebsiella, and Serratia. The data suggest that Enterobacter and Klebsiella, could be combined into a single genus, whereas Hafnia alvei should be retained in a genus separate from Enterobacter. Group B comprised the tribes Edwardsielleae, Salmonelleae, and Escherichieae. Strains of Edwardsiella species fell into two clusters, suggestive of possible biotype differences or perhaps two separate species. Many of Kauffmann’s biochemical subgroup 1 salmonellae could be combined into a single species, which on grounds of priority should be designated Salmonella enteritidis (Gaertner) Castellani and Chalmers. However, there are other subgroup 1 serotypes which clearly do not belong in this species. Further study is suggested. Three species of Shigella, i.e., S. boydii. S. flexneri, and S. dysenteriae, were not separated by the analyses performed in this study. Either the three species cannot be identified on the basis of the biochemical characters employed or their identification requires considerable modification. Also included in group B were members of the genus Yersinia. Group C, representing the tribe Proteae, requires considerable revision, if a classification reflecting both molecular genetic and phenetic taxonomic relationships is to be attained.

One hundred and seven strains of Vibrio and Spirillum were examined for 175 morphological, physiological, biochemical, and nutritional characteristics. The results were analyzed by the method of numerical taxonomy. The deoxyribonucleic acid base composition of the Spirillum strains was also determined. Marked phenetic differences were found between Vibrio and Spirillum, with species of the genus Vibrio demonstrating more versatile biochemical capabilities. The numerical taxonomy and molecular genetic data are in agreement with the recently suggested assignment of selected Spirillum strains to the genera Oceano-spirillum and Aquaspirillum.

ATCC strain no. 27731 (VPI 7953) is described and designated as the neotype strain of Peptococcus niger (Hall) Kluyver and van Niel 1936. This strain conforms in all respects to the original description of the single isolate of Micrococcus niger Hall 1936. Additional strains from eight people are also described.

Staphylococci were isolated from human skin and subjected to a taxonomic study. As a result of this study, three new species are being proposed in this paper: Staphylococcus cohnii, S. haemolyticus, and S. xylosus. The type strains of these species are DSM (Deutsche Sammlung von Mikroorganismen) 20260, DSM 20263, and DSM 20266, respectively. Amended descriptions of S. epidermidis and S. saprophyticus are also given. The main characters for the distinction of staphylococci and micrococci are mentioned. Staphylococci were classified on the basis of cell wall composition, lactic acid configuration, and a variety of morphological and physiological characters. There are some key differential characters of these species which can be determined by simple laboratory procedures. The failure to ferment trehalose and mannitol is typical for S. epidermidis. The fermentation of xylose and/or arabinose is a characteristic of S. xylosus. The failure to ferment sucrose and turanose is typical for S. cohnii. Strains of S. saprophyticus do not reduce nitrate, but most of them produce acetylmethylcarbinol and ferment xylitol. S. haemolyticus is usually hemolysis positive, like S. aureus, but it does not produce coagulase, does not have strong phosphatase and deoxy-ribonuclease activities, and does not ferment mannose.

Staphylococci were isolated from the skins of people living in North Carolina and New Jersey and were studied in an attempt to resolve their natural relationships. As a result of this study, four new species are proposed in this paper: Staphylococcus warneri, S. capitis, S. hominis, and S. simulans. The type strains of these species are ATCC 27836, ATCC 27840, ATCC 27844, and ATCC 27848, respectively. The new species were established on the basis of a variety of morphological, physiological, biochemical, and antibiotic characters. Cell wall composition was particularly useful in resolving species and correlated well with other characters. Characteristic pigment production was useful in distinguishing several of the different species. A summary of the character variation found in the species and a scheme for the classification of human cutaneous staphylococci are included in this paper. The predominant staphylococci found on human skin were S. epidermidis and S. hominis.

Amino acid and vitamin requirements were determined for 215 natural auxotrophic strains of micrococci isolated from human skin. Requirement parameters were distinctly different for each of the seven Micrococcus species studied.