Characteristics of coagulase-negative staphylococci that help differentiate these species and other members of the family Micrococcaceae

Abstract

One hundred reference strains and 1,240 clinical isolates representing 26 species of the family Micrococcaceae were used to evaluate the potential of tests for synergistic hemolysis, adherence to glass, pyroglutamyl-II-naphthylamide hydrolysis, and susceptibility to a set of five antimicrobial agents for differentiating these species and strains within the species. Sixty-eight percent of the clinical isolates exhibited synergistic hemolysis; 69% of the clinical staphylococci but none of the micrococci or stomatococci were adherence positive, and 92% of the strong positive adherence reactions were produced by strains of Staphylococcus epidermidis. Strains from 15 of the species were pyroglutamyl-4-naphthylamide positive, but this test separated Staphylococcus xylosus from other novobiocin-resistant staphylococci and Staphylococcus intermedius from other coagulase-positive species. A polymyxin B disk helped differentiate S. epidermidis from most other coagulase-negative staphylococci, and a bacitracin disk (10 U) helped differentiate Staphylococcus haemolyticus from most other novobiocin-susceptible staphylococci. All strains that were susceptible to furazolidone and resistant to Taxo A disks (bacitracin, 0.04 U; BBL Microbiology Systems, Cockeysville, Md.) were staphylococci. We observed a 91% correlation between species identification obtained with the Staph-Ident system (Analytab Products, Plainview, N.Y.) and conventional methods; but the micrococci and stomatococci were incorrectly identified as staphylococci with Staph-Ident, and several isolates of S. epidermidis were misidentified as Staphylococcus hominis because they were alkaline phosphatase negative. Both these problems can be prevented by adding the simple tests we describe to those already recommended when the Staph-Ident system is used to identify isolates of gram-positive, catalase-positive cocci.

Molecular Characterization of Staphylococcus sciuri Strains Isolated from Humans

“…Two other reports also documented the isolation of this species from blood samples (11,31), and other authors mentioned the isolation of S. sciuri strains from other clinical sources, such as infected wounds of hospital patients (18,31) and umbilici of infants and the teats of their mothers (17). Furthermore, several strains of S. sciuri were reported to be adherence positive (10) or to produce slime (31), which is considered a potential factor for both colonization and virulence. Nevertheless, the paucity of reports of infections caused directly by S. sciuri indicates that it is probably a rare and opportunistic pathogen in humans.…”

“…Traditionally described as a commensal species of rodents, marsupials, cetaceans, artiodactyls, and perissodactyls, S. sciuri has also been isolated from healthy and sick domestic and husbandry animals, including household cats (4,12), domestic dogs (15), cattle, goats, poultry, sheep, horses, and pigs (3,7,8,13,27), and houseflies (9). Although S. sciuri is associated rarely with colonization or infection in humans (14), it has been occasionally isolated from human clinical samples (1,3,6,10,11,17,18,21,29,31).…”

Staphylococcus lugdunensis endocarditis

“…The staphylococci were identified by using a set of 39 biochemical tests, including ornithine decarboxylase (16), modified oxidase (8), tests for free coagulase using rabbit plasma and for bound coagulase using both rabbit and human plasma (16), production of thermonuclease by the microslide method (18), nitrate reduction (17), urea hydrolysis using Christensen's urea agar (2), pyrrolidonyl arylamidase (13), hydrolysis of Tween 80 (4), resistance to 0.02% furazolidone (1), and production of CAMP factor (12).…”

The amino acid sequences and activities of synergistic hemolysins fromStaphylococcus cohnii

“…Coagulase-negative staphylococci (CoNS) rarely produce a or b hemolysin (Hebert, 1990;Molnar et al, 1994). On the other hand, d-toxin, which can be detected by a simple test of synergistic hemolysis (Christie, Atkins, Munch and Petersen test, CAMP), was found in most species of CoNS (Bhakdi, 1985;Hebert & Hancock, 1985;Hebert et al, 1988;Gemmell, 2002).…”