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Clinical management of infective endocarditis (IE) is expected to become more difficult with the emergence of Staphylococcus aureus with reduced susceptibility to vancomycin (SARV) in the United States and worldwide. We report the strain characterization and treatment of a patient with SARV IE.

The hemolysin of Escherichia coli has been concentrated 23-fold by ethanol and ammonium sulfate precipitation. Further evidence has been presented that the hemolysin is a protein or peptide. Kinetic studies of the hemolytic reaction reveal a complex curve which consists of a lag, an area of accelerated reaction rate, and a plateau. Kinetic studies also show that the hemolytic reaction can be best demonstrated at a pH of 7.9 and a temperature of 30 °C using a 1% suspension of sheep erythrocytes.

Pseudomonas alcaligenes is a common soil and water inhabitant that has rarely been proven a human pathogen. We describe a fatal case of Pseudomonas alcaligenes endocarditis. The need for accurate identification of unusual organisms isolated in a clinical setting are discussed.

SUMMARYThe amount of haemolysin produced by Escherichia coli grown under various gas phases was determined by the amount of growth obtained under these conditions. Calcium or strontium was required for activation of haemolysin. The haemolytic reaction was stopped by sodium citrate. The loss of haemolytic activity after incubation with trypsin and chymotrypsin indicated that at least the active group of the haemolytic molecule is protein or a peptide. I N T R O D U C T I O NSeveral studies have shown discordant results about the production and assay of Escherichia coli haemolysins. This paper attempts to clarify the effects of various gas phases on the production of haemolysin and to demonstrate a cation requirement for activation of the haemolysin. METHODS Organism.A haemolysin-producing strain of Escherichia coli type 06 (Iowa Stock Culture, ISC, no. 447), originally obtained from a patient with pyelonephritis, was used. A standard inoculum was obtained as previously described (Snyder & Koch, I 966).Measurement of haemolytic activity. Total haemolysin content of the cultures was obtained by two-fold dilution of whole cultures. Filterable haemolysin was determined in the same manner with culture filtrates passed through a Millipore filter (0.45 mp porosity). The amount of haemolysin/ml. culture or filtrate was determined as previously described (Snyder & Koch, 1966).Measurement of growth andpH value. Turbidometric measurements of growth were obtained with a Spectronic 20 spectrophotometer at a wavelength of 625 mp. The pH value of the culture was determined with a Beckman Zeromatic II pH meter. Preparation of media.Beef heart for infusion medium (BHI) was prepared from Difco Beef Heart for infusion as described by the manufacturer. When glucose was added to the media, I ml. of a Millipore-filtered solution 20 % (w/v) glucose was added to IOO ml. autoclaved media. In media buffered with phosphate, 0.23 g. KBHPOl and 0.078 g. KHBPOI were added to each IOO ml. of medium before sterilization.Alkaline meat-extract broth was prepared as described by Smith (1963).Incubation of cultures. Anaerobic growth was obtained by using Brewer jars. The jars were flushed with nitrogen three times and filled with hydrogen, a palladium catalyst being used for removal of residual oxygen. Incubation in a COB atmosphere

Two criteria must be met before mycobacterial specimens can be tested by DNA amplification methods: (i) the sample must be rendered noninfectious, and (ii) the organisms must be lysed to free the DNA. Previous publications reporting DNA amplification of mycobacteria have concentrated on lysis and amplification procedures and have not addressed the issue of sample safety. We have shown that heating of samples below 100°C may not consistently kill mycobacteria; however, heating at 100°C in a boiling-water bath or a forced-air oven for a minimum of 5 min kills mycobacteria, including Mycobacterium thermoresistibile. Furthermore, heating at 100°C for 30 min consistently lyses mycobacteria to produce short fragments of DNA that are suitable for amplification by PCR and strand displacement amplification. This procedure works with clinical samples digested by the n-acetyl cysteine-NaOH method as well as with suspensions of organisms in phosphate buffer. This paper also demonstrates the feasibility of using strand displacement amplification with clinical

The Difco ESP and Organon Teknika BacT/Alert (BTA) systems were evaluated in a clinical study of 5,421 aerobic and 5,035 anaerobic blood cultures. Of 405 clinically significant positive cultures evaluated, 272 grew in both systems, 86 grew in ESP only, and 47 grew in BTA only (P < 0.005). Of 320 organisms detected in aerobic bottles, 208 grew in both systems, 68 grew in ESP only and 45 grew in BTA only (P < 0.05), with

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