Ninety-nine clinical staphylococcal isolates (58 coagulase-negative Staphylococcus spp. [CoNS] and 41 Staphylococcus aureus isolates) were evaluated for susceptibility to oxacillin. The following susceptibility testing methods, media, and incubation conditions were studied: agar dilution by using Mueller-Hinton (MH) medium (Difco) supplemented with either 0, 2, or 4% NaCl and incubation at 30 o...

BACKGROUND Antimicrobial susceptibility testing (AST) of Clostridium difficile is increasingly important because of the rise in resistant strains. The standard medium for the AST of C. difficile is supplemented Brucella agar (sBA), but we found that the growth of C. difficile on sBA was not optimal. Because active growth is critical for reliable AST, we developed a new, modified C. difficile (m...

By sequence analysis of available group B streptococcus (GBS) genomes, we discovered a conserved putative operon involved in the catabolism of sialic acid, containing a tripartite transporter formed by two integral membrane components and a sugar-binding unit, named SAL0039. Expression analysis in the presence of different substrates revealed that SAL0039 was specifically upregulated by the pre...

which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Editorial Group B streptococci (GBS) are facultative anaerobic, gram-positive cocci that colonize the gastrointestinal and urogenital tracts of humans. GBS strains are serologically divided into 10 types (Ia, Ib, and II through IX) according to their capsula...

A cabinet for detecting the fluorescence of cultures on agar media is described. The use of fluorescence as a criterion for detection of Ps. pyocyanea is compared with that of the oxidase reaction. From a series of patients with burns, all colonies of Gram-negative bacilli which gave a positive oxidase reaction yielded fluorescent subcultures on 0.03% cetrimide agar; all fluorescent cultures on...

they were washed with wet swabs and suspended in 1 ml. of nutrient broth and inoculated on blood agar media and into mice. All tested slides failed to produce either culture or infection. A similar experiment was performed with the same type of slides from which mercuric chloride was removed. Both the medium and mice failed to show the presence of B. anthracis. Because unstained areas round the...

Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial media would relieve facilities of the cost of maintaining cell lines, permit isolation at fish cultur...

Presumptive identification of Gardnerella vaginalis from 48-h human blood agar cultures by using a Gram stain, hemolysis, and colonial morphology was highly accurate.

A new test for the presumptive identification of Clostridium perfringens, C. bifermentans, C. sordellii, and C. paraperfringens is described. The test is based on the synergistic haemolysis shown by the clostridia and group B streptococci on sheep and human and CaCl2-supplemented human blood agar. C. perfringens gave crescent-shaped synergistic lytic zones (7 to over 20 mm in length), and C. pa...