Objective: Urine is the most frequent specimen received for culture/sensitivity by clinical laboratories. The microbiological performance of HiCrome UTI agar medium was compared with Blood agar and MacConkey agar for isolation and presumptive identification of bacteria from urine culture. Methods: A total of 443 consecutively collected midstream and/or catheter-catch urine samples from patients attending the Islami Bank Medical College Hospital, Rajshahi, Bangladesh during January to December, 2012 were cultured. Urine samples showing pus cells ≥ 5/HPF were inoculated on to Blood agar (BA), MacConkey agar (MAC) and HiCrome UTI agar (CA) media simultaneously and incubated overnight aerobically at 370C. Rate of isolation and presumptive identification of bacterial species were compared for different media. Results: Culture yielded a total of 199 bacterial isolates from 189 (42.67%) positive plates including 179 (40.40%) unimicrobial and 10 (2.26%) polymicrobial (mixed growth of pair of bacteria) growths. Both HiCrome UTI agar and Blood agar media supported 100% growths while 151 (75.88%) growths were observed on MacConkey agar. The rate of presumptive identification was found significantly higher on HiCrome UTI agar (97.49%) than MAC agar (67.34%) (P<0.001) as primary urine culture medium. Of 199 isolates, E. coli was found to be the leading uropathogen isolated from 118 (59.30%) samples with its presumptive identification rate of 95.76%, 93.22% and 5.93% on CA, MAC and BA respectively. All 10 (100%) polymicrobial growths were demonstrated distinctly on CA against only 01(10%) on each BA and MAC. Conclusion: HiCrome UTI agar was found to be more useful as primary urine culture medium in both higher rate of isolation and presumptive identification of uropathogens in comparison to conventional media. Its inherent characteristics in demonstrating polymicrobial growth and ease of rapid identification by distinct colony colour are unique.

HAQUE, RIAZ-UL (Ohio State University, Columbus), AND JACK N. BALDWIN. Purification and properties of staphylococcal beta-hemolysin. I. Production of beta-hemolysin. J. Bacteriol. 88:1304-1309. 1964.-Highest activity of f-hemolysin was observed when buffered saline (pH 7.0) containing 0.001 M magnesium sulfate was used as a diluent, and the tubes were incubated at 37 C for 80 min and then refrigerated for 30 min. Either Heart Infusion semisolid agar or a dialysate of Heart Infusion containing 0.3% agar was suitable for the production of large quantities of ,B-hemolysin. The concentration of ,B-hemolysin in semisolid and broth cultures was greatest after incubation for 24 hr. Continued incubation resulted in a loss of active hemolysin in broth cultures but not in semisolid agar cultures. Incubation in atmospheres containing 20% carbon dioxide greatly enhanced the production of fl-hemolysin. The presence of fermentable sugars inhibited the production of ,3-hemolysin. Highest yields of fl-hemolysin were obtained when the initial pH of the medium was 5.5 to 5.8. 3-Hemolysin is one of a variety of diffusible substances produced by Staphylococcus aureus. The only property of 3-hemolysin which is universally accepted is the "hot-cold" lysis of sheep or bovine red blood cells. Other properties of the culture filtrates of S. aureus were also ascribed to /-hemolysin. Thus, Bryce and Rountree (1936) found that f-hemolysin was toxic for guinea I Taken in part from a thesis submitted by R. Haque to the Graduate School of The Ohio State University in partial fulfillment of the requirements for M.S. degree.

Staphylococcal beta hemolysin from the 681 strain of Staphylococcus aureus grown in a Heart Infusion dialysate semisolid medium under 10% carbon dioxide was obtained in an immunoelectrophoretically pure form by a combination of procedures of precipitation with 2 volumes of acetone followed by chromatography on diethylaminoethyl cellulose at pH 6.0. The acetone precipitation procedure did not show any deleterious effect on the hemolytic activity of the beta hemolysin unless the precipitate was left in contact with the acetone for at least 4 hr. The crude preparations contained two types of beta hemolysin. One of these represented the major portion of the total activity of beta hemolysin and behaved as a cation. The other represented a minor (1/5,000) portion of the total beta hemolysin activity and behaved as an anion. These active principles were designated as cationic and anionic beta hemolysins, respectively. An unexpected increase in the total beta hemolysin activity of the crude preparations was noted when these were concentrated by dialysis against polyethylene glycol (20 M). This effect was probably due to polyethylene glycol. A further unexpected increase in the titer of the acetoneprecipitated preparations occurred when these were lyophilized. The reason for this incremental increase is not known. It may be due to fragmentation of the beta hemolysin. Certain strains of Staphylococcus aureus are capable of producing a hemolytic macromolecule with characteristic ability to cause "hot-cold" lysis of sheep erythrocytes. This hemolysin, designated beta hemolysin by Glenny and Stevens (5), is most readily identified by the characteristic zone of darkening or discoloration that it produces on sheep blood-agar plates. Until recently, "hot-cold" lysis of sheep erythrocytes was the only activity attributed to beta hemolysin. Chesbro et al. (2) have now shown that the beta hemolysin which they obtained in partially purified form was leukocidal for guinea pig macrophages and was able to liberate mucopolysaccharides from the rabbit erythrocyte stroma, polysaccharides and mucopeptides from staphylococcal cell walls, and rhamnose, glucose, N-acetyl glucosamine, and at least two polysac-1 Portions of this study were presented at the 63rd Annual Meeting of the American Society for Microbiology, Cleveland, Ohio, May 1963. This paper is based on portions of a dissertation submitted by R. Haque to the Graduate School of The Ohio State University, Columbus, in partial fulfillment of the requirements for the Ph.D. degree.

, AND JACK N. BALDWIN. Types of hemolysins produced by Staphylococcus aureus as determined by the replica plating technique.