Deoxyribonucleic acid base composition of Micrococcus roseus

Drug sensitivity and clinical impact of members of the genus Kocuria

Organisms in the genus Kocuria are Gram-positive, coagulase-negative, coccoid actinobacteria belonging to the family Micrococcaceae, suborder Micrococcineae, order Actinomycetales. Sporadic reports in the literature have dealt with infections by Kocuria species, mostly in compromised hosts with serious underlying conditions. Nonetheless, the number of infectious processes caused by such bacteria may be higher than currently believed, given that misidentification by phenotypic assays has presumably affected estimates of the prevalence over the years. As a further cause for concern, guidelines for therapy of illnesses involving Kocuria species are lacking, mostly due to the absence of established criteria for evaluating Kocuria replication or growth inhibition in the presence of antibiotics. Therefore, breakpoints for staphylococci have been widely used throughout the literature to try to understand this pathogen's behaviour under drug exposure; unfortunately, this has sometimes created confusion, thus higlighting the urgent need for specific interpretive criteria, along with a deeper investigation into the resistance determinants within this genus. We therefore review the published data on cultural, genotypic and clinical aspects of the genus Kocuria, aiming to shed some light on these emerging nosocomial pathogens.

Kocuria aegyptia sp. nov., a novel actinobacterium isolated from a saline, alkaline desert soil in Egypt

A coccoid, non-motile actinobacterium, designated strain YIM 70003T, was isolated from a saline, alkaline, desert-soil sample from Egypt. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism formed a distinct phyletic line within the genusKocuriaand was most closely related toKocuria polarisDSM 14382T(98·6 % sequence similarity) andKocuria roseaDSM 20447T(98·2 %). Chemotaxonomic data, including the Lys–Ala3peptidoglycan type, the presence of phosphatidylglycerol and diphosphatidylglycerol as the predominant phospholipids, the presence of MK-8(H2) and MK-9(H2) as the major menaquinones, the predominance of fatty acids ai-C15 : 0and i-C15 : 0and the DNA G+C content, also supported the affiliation of the isolate to the genusKocuria. The low DNA–DNA relatedness withK. polarisDSM 14382T(56·6 %) andK. roseaDSM 20447T(15·5 %) in combination with phenotypic data show that strain YIM 70003Tshould be classified as a novel species of the genusKocuria. The nameKocuria aegyptiasp. nov. is proposed, with strain YIM 70003T(=CCTCC AA203006T=CIP 107966T=KCTC 19010T=DSM 17006T) as the type strain.

Kocuria marina sp. nov., a novel actinobacterium isolated from marine sediment

An actinobacterial strain was isolated from marine sediment taken from the Troitsa Bay of the Gulf of Peter the Great, East Siberian Sea, and subjected to a taxonomic investigation. The isolate, designated KMM 3905T, was Gram-positive, aerobic, non-motile and coccoid. The strain tolerated up to 15 % NaCl in growth media, although its presence was not essential for growth. Chemotaxonomic and phylogenetic properties of the strain were consistent with its classification in the genus Kocuria. The strain formed an independent phylogenetic line in the 16S rRNA gene tree encompassed by members of Kocuria. Comparison of phenotypic characteristics also supported its assignment to a novel species within Kocuria. The name Kocuria marina sp. nov. (type strain KMM 3905T=KCTC 9943T) is proposed for this halotolerant actinobacterium from the marine environment.

Rapid distinction between micrococci and staphylococci with furazolidone agars

Furazolidone agar proved to be a suitable medium for separating strains of the genera Micrococcus and Staphylococcus. 720 isolates (including 24 type strains) of gram- and catalase-positive cocci were tested for growth on tryptone soya and peptone agar with the addition of 50 microgram/ml furazolidone. The results were compared with the classification obtained by the standard-O/F-test and by the test system of Schleifer and Kloos. For routine identification and separation of staphylococci from micrococci a peptone agar with 20 microgram furazolidone/ml is recommended.

Neutral lipids in the study of relationships of members of the family micrococcaceae

The organisms studied were those of the family Micrococcaceae which cannot participate in genetic exchange with Micrococcus luteus and those whose biochemical and physiological characteristics appear to bridge the genera Staphylococcus and Micrococcus. The hydrocarbon compositions of M. luteus ATCC 4698 and Micrococcus sp. ATCC 398 were shown to be similar to those previously reported for many M. luteus strains, consisting of isomers of branched monoolefins in the range C25 to C31. However, Micrococcus sp. ATCC 398 differed somewhat by having almost all C29 isomers (approximately 88% of the hydrocarbon composition). Micrococcus spp. ATCC 401 and ATCC 146 and M. roseus strains ATCC 412, ATCC 416, and ATCC 516 contained the same type of hydrocarbon patterns, but the predominant hydrocarbons were within a lower distribution range (C23 to C27), similar to Micrococcus sp. ATCC 533 previously reported. The chromatographic profile and carbon range of the hydrocarbons of an atypical strain designated M. candicans ATCC 8456 differed significantly from the hydrocarbon pattern presented above. The hydrocarbons were identified as branched and normal olefins in the range C16 to C22. Studies of several different strains of staphylococci revealed that these organisms do not contain readily detectable amounts of aliphatic hydrocarbons. The members of the family Micrococcaceae have been divided into two major groups based on the presence or absence of hydrocarbons. With the exception of M. candicans ATCC 8456, this division corresponded to the separation of these organisms according to their deoxyribonucleic acid compositions.