Attempts to isolate wall-defective microbial variants from clinical specimens

Benign lymphoepithelial lesion of salivary gland in a patient with AIDS

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Acinetobacter spp L-form infection of a cemented Charnley total hip replacement

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Controlled evaluation of hypertonic sucrose medium at a 1:5 ratio of blood to broth for detection of bacteremia and fungemia in supplemented peptone broth

The value of hypertonic media in the detection of bacteremia and fungemia is controversial, since prior clinical trials have yielded conflicting results with different media. Earlier, we showed that the addition of 10% sucrose to supplemented peptone broth at a 1:10 ratio of blood to broth yielded better recovery of Staphylococcus epidermidis, the Enterobacteriaceae, Pseudomonas aeruginosa, and yeasts. To evaluate the effect of 10% sucrose on blood cultured at a 1:5 ratio, we compared the yield and speed of detection of clinically important microorganisms from adult patients in 5,839 blood samples cultured in supplemented peptone broth with 0.03% sodium polyanetholesulfonate with and without 10% sucrose. The atmosphere of incubation (open venting units), 1:5 ratio of blood to broth, and methods of processing were the same for both bottles. Recovery of facultative gram-positive (P less than 0.02) and gram-negative (P less than 0.02) bacteria was improved, but the recovery of anaerobic gram-negative bacteria was both reduced (P less than 0.01) and delayed (P less than 0.02) by sucrose. The total yield of microorganisms including fungi, however, was increased with sucrose. The effect of sucrose on blood cultures appears to depend on the ratio of blood to broth as well as on the medium used and strains of microorganisms encountered.

Controlled evaluation of hypertonic sucrose medium for detection of bacteremia and fungemia in supplemented peptone broth

Because the value of hypertonic media in detection of bacteremia and fungemia is controversial, we evaluated supplemented peptone broth (SPB) with 0.03% sodium polyanetholsulfonate with and without 10% sucrose in 5,439 paired blood cultures from adult patients. The aerobic atmosphere, 1:10 ratio of blood to broth, and methods for processing blood cultures were identical. Only cultures with adequate blood samples (greater than or equal to 4 ml) were compared statistically. More clinically important bacteria were recovered from SPB with sucrose (P less than or equal to 0.001), including Staphylococcus epidermidis, Enterobacteriaceae, and Bacteroidaceae. However, only one of nine isolates of Neisseria gonorrhoeae grew in SPB with sucrose. Staphylococci (P less than 0.001), Enterobacteriaceae (P less than 0.01), Pseudomonas aeruginosa (P less than 0.01), and yeasts (P less than 0.05) were detected 1 or more days earlier in SPB with sucrose. The effect of sucrose on blood cultures appears to be medium dependent, based on comparisons of our results with those of published reports.

Infective endocarditis associated with cell wall-deficient bacteria. Electron microscopic findings in four cases

Although cell wall-deficient bacteria have been isolated in vitro from cases of endocarditis, no pathogenic role has been established for these forms in human disease. One criterion difficult to satisfy is the demonstration of these variants in human tissue, and electron microscopic documentation has not been reported. Cardiac valvular vegetations from four cases of endocarditis were examined by electron microscopy because of unusual histologic features of minimal inflammation and organization and small organisms that stained poorly by Gram stain. Although cell wall-complete bacteria were identified in the specimens, each showed the presence of cell wall-deficient forms within the vegetations; these variants predominated in three cases. Since manifestations of infective endocarditis were present in three cases and conventional cultures were negative, the evidence indirectly suggests a pathogenic role for these aberrant bacteria in human disease.

The role of the bacterial L form in urinary tract infection

The relationship between the bacterial L form and chronic relapsing urinary tract infection was evaluated, using septicaemic cases as the basis of assessment. The results of this study supported the theory that chronic relapsing pyelonephritis is associated with L form infection. The antibiotic treatment of L form infection is discussed.

Study on the usefulness of hypertonic culture media

Specimens from 300 patients were studied using five to nine aerobic and anaerobic culture media, including five that were hypertonic, Groups studied included fever of unknown origin, suspected endocarditis, endocarditis during therapy, bacteremia during therapy, abscess and cellulitis, presumed infectious arthritis, renal transplantation during rejection, collagen disease, sarcoidosis, lymphoma, and colitis. Isolates in hypertonic media were reverted to parent form by agar passage. In only 5% of these selected cases were organisms found in hypertonic, but not conventional, media that appeared on the basis of repeated isolation and/or serological studies to come from the patient. Nine of the 16 appeared to be of major significance. The two groups in which use of highly enriched, hypertonic media seemed most helpful were suspected endocarditis and undefined meningitis with negative cultures using standard media. The most effective of the hypertonic media used was 0.3 M sucrose in brain heart infusion with 20% horse serum. In most instances, the organism grew only in the hypertonic sucrose, and in most cases it appeared in conventional rather than aberrant form. Hypertonic media, especially 0.3 M sucrose, are of substantial helpin a small number of carefully selected cases.