Halobacterium vallismortis sp. nov. An amylolytic and carbohydrate-metabolizing, extremely halophilic bacterium

The extremely halophilic bacterium (formerly designated as strain J.F. 54) isolated from salt pools of the Death Valley, California, is a motile, Gram-negative, extremely pleomorphic organism, aerobe, and facultative anaerobe. A variety of carbohydrates are assimilated with or without acid production; soluble starch is hydrolyzed. The organism is not proteolytic; catalase, oxidase, and DNase reactions are positive; Tween 20 is slightly hydrolyzed, but Tweens 40, 60, and 80 are not. Nitrates are reduced to nitrites with gas production; nitrites are not reduced. Optimum growth temperature is 40 degrees C. Growth is inhibited by bacitracin and by novobiocin. The type strain J.F. 54 differs from described species of the genus Halobacterium and is assigned to a new species, Halobacterium vallismortis sp. nov.

Comparative efficacy of chloramphenicol, ampicillin, and co-trimoxazole in the treatment of typhoid fever

Two clinical trials were conducted to compare the efficacy of 3 antimicrobial agents often recommended for the treatment of typhoid fever. Chloramphenicol was more effective than parenteral ampicillin or oral co-trimoxazole (trimethaprim/sulphamethoxazole) in reducing the duration of fever. Oral chloramphenicol was more effective than parenteral chloramphenicol probably because oral doses resulted in higher blood concentrations of the drug. However, parenteral chloramphenicol was given during the initial period of acute illness, without loss of efficacy.

Comparative properties of bacteriophage phi6 and phi6 nucleocapsid

Nonionic detergent treatments released a nucleocapsid from the enveloped bacteriphage phi6. The nucleocapsid sedimented at nearly the same rate as the whole phage in sucrose density gradients, but the buoyant density in Cs2S04 changed from 1.22 g/cm3 for the whole phage to 1.33 g/cm3 for the nucleocapsid. The detergent completely removed the lipid and 5 of the 10 proteins from the phage. Surface labeling of the phage and nucleocapsid with 125I revealed that protein P3 was on the outer surface of the whole phage and P8 was on the surface of the nucleocapsid. Both the phage and the nucleocapsid were stable between pH 6.0 and 9.5. Low concentrations of EDTA (10-4 M) dissociated the nucleocapsid but had no effect on the whole phage. The nucleocapsid contained all three double-stranded RNA segments, as well as RNA polymerase activity.

Bacteriologic flora of aspiration-induced pulmonary infections

The role of anaerobic and aerobic microorganisms in the genesis of pneumonia or lung abscess in patients with historical, clinical, and radiologic findings suggestive of aspiration was compared to their role in similar patients without these findings. Bacterial specimens were obtained by transtracheal aspiration or thoracentesis. Anaerobes were isolated in 100% of the patients who were aspiration-prone as contrasted with only 20% of those who were not. Isolation of a single species or no growth was more common in the nonaspiration group, whereas multiple isolates were more common in the aspiration group. Patients with lung abscesses were treated with penicillin and all of them responded clinically, despite occasional recovery from the culture specimen of penicillin-resistant organisms. This suggests that lung abscess may be the result of a synergistic bacterial infection.

Staphylococcal bacteremia and hexachlorophene bathing. Epidemic in a newborn nursery

An outbreak of staphylococcal bacteremia in healthy, full-term neonates occurred in the newborn nursery at a large county hospital not employing prophylactic hexachlorophene bathing. Seven infants had staphylococcal bacteremia and one had omphalitis. Two of the three isolates obtained for phage typing were type 86, and the other was 3c/71. Staphylococcal colonization rate in the nursery was 64% when the outbreak was recognized; 86% of these isolates were type 86. No predominant phage type was isolated from nursery personnel. The outbreak followed a six-month preliminary study that showed a rise in staphylococcal colonization rate from 2.2% with hexachlorophene bathing to 67% with a nonhexachlorophene-containing preparation. In a community survey of infants born during the two months prior to the epidemic, seven of eight babies with lesions were infected with Staphylococcus aureus type 86.

Staphylococcus aureus Protoplasting Induced by d -Cycloserine

Addition of sublethal doses of d -cycloserine to growing cells of Staphylococcus aureus induces the rupture of the cell wall along an equatorial ring, thus allowing the liberation of protoplasts.