Showing papers by "Myron S. Cohen published in 1984"

Serum Sensitivity of Neisseria gonorrhoeae: The Role of Lipopolysaccharide

Abstract: A lipopolysaccharide (LPS) mutant (FA5100) of a serum-resistant strain of Neisseria gonorrhoeae (FA19) was found to be highly sensitive to the bactericidal activity of normal human serum (NHS). Both strain FA5100 and an unrelated serum-sensitive clinical isolate (F62) were killed by NHS via the classical complement pathway since killing required C2 and Ca++. However, the fact that only strain FA5100 was sensitive to human hypogammaglobulinemic and cord serum suggested that this strain might activate the classical complement pathway in the absence of antibody. Anticomplementary concentrations of LPS from strain FA5100 inhibited the bactericidal activity of NHS against either strain FA5100 or strain F62. However, concentrations of LPS from strain FA5100 that exhibited marginal anticomplementary behavior also inhibited the killing of strain F62 by NHS. The ability of LPS from strain FA5100 to inhibit the bactericidal activity of NHS against strain FA5100 and to activate complement was reduced by treatment with mild alkali. However, alkali-treated LPS from strain FA5100 still inhibited the bactericidal activity of NHS against strain F62.

A Bacterial Respiratory Burst: Stimulation of the Metabolism of Neisseria gonorrhoeae by Human Serum

Abstract: Exposure of Neisseria gonorrhoeae to human serum causes an immediate increase in metabolism, including a fourfold increase in O2 consumption and [14C]adenine uptake and a threefold increase in glucose consumption. These effects were detected at a serum concentration of 1.0% and were maximal at 20%. Serum-stimulated gonococcal metabolism was inhibited by KCN but was not affected by heating or boiling of serum. Dialysis of serum with membrane tubing having a molecular weight exclusion of 3,500 eliminated stimulation of O2 consumption and reduced incorporation of [14C]adenine. Addition of lactate, pyruvate, or cysteine to dialyzed serum had no effect on bacterial metabolism. One in vitro ramification of this observation was demonstrated when gonococci, serum, and polymorphonuclear neutrophils (PMNs) were incubated in an O2 monitor. Under these conditions O2 consumption by bacteria stimulated by serum confounded interpretation of results and would be expected to reduce the O2 concentration in the suspension available for microbicidal metabolism by PMNs.

Pyogenic otorhinologic infections in acquired immune deficiency syndrome.

Abstract: • A 25-year-old homosexual man with acquired immune deficiency syndrome had CNS toxoplasmosis, mucosal candidiasis, acute otitis media, and sinusitis. These problems persisted despite multiple courses of antibiotic therapy. Surgical drainage proved to be the only effective means of controlling his otorhinologic infections. We recommend early surgical intervention for this type of patient when standard antibiotic therapy for sinusitis and otitis media proves ineffective. (Arch Otolaryngol1984;110:130-131)

Gonococcal osteomyelitis: a case report and review of the literature.

Abstract: Osteomyelitis is a rare complication of disseminated gonoccal infection. We report a case of gonococcal osteomyelitis and review the other eight proved or probable cases that have been described in the English-language literature since the introduction of antibiotics. Two cases were caused by beta-lactamase-producing strains. The single common characteristic of patients with gonococcal osteomyelitis was a substantial delay (mean 37 days) between the onset of joint symptoms and the institution of appropriate antibiotic therapy. The duration of antibiotic therapy varied from 12 days to six weeks and did not correlate with outcome. Only three patients enjoyed complete resolution of both symptoms and roentgenographic abnormalities.

Treatment of Gonococcal Osteomyelitis

Abstract: To the Editor— We refer to the article by Drs Tindall and Regan-Smith 1 on gonococcal osteomyelitis We have recently reported an additional case 2 and reviewed three other cases not described in their article Although gonococci that produce disseminated infections are usually exquisitely sensitive to penicillin, two of these additional cases of gonococcal osteomyelitis were caused by β-lactamase-producing strains 3,4 This observation calls attention to two points: (1) The setting of acute, asymmetric pauciarticular arthritis in a sexually active patient is complex While the response of patients with gonococcal arthritis to penicillin is usually dramatic, failure to respond may not absolutely exclude the diagnosis (2) Empiric therapy with cefoxitin or cefotaxime 5 may be indicated for patients with presumed gonococcal arthritis or osteomyelitis who do not respond rapidly to penicillin and who may have had sexual exposure in areas where β-lactamase-producing gonococci have been isolated

The great cephalosporin wars.

Abstract: The Great Cephalospotin Wars are the results of nearly two decades of investment in antibiotic research. With the availability of six or more new cephalosporin antibiotics, intense competition has arisen for the attention of the hospital pharmacist, the microbiology laboratory and most importantly, the practicing physician. The pharmaceutical industry has allocated enormous resources for this war (1) commensurate with the profits that can be generated on the battlefield. However, as has recently been pointed out by Sanders (2): \"Our ability to produce new enzyme-stable antibiotics has outstripped the science necessary to understand and adequately evaluate them.\" New second and third generation cephalosporins are now or soon will be available in the United States. It is certainly beyond the scope of this editorial to compare and contrast these agents, as several comprehensive reviews and comparisons have recently been published (3-6), but it is important to identify the issues around which the Cephalosporin Wars ought to be fought, as well as to make suggestions for the future. It is of critical importance to separate those issues Which are likely to affect clinical outcome from those that have become the focus of the marketing departments of the various pharmaceutical companies. I propose that physicians can make satisfactory choices on the basis of a very few criteria: spectrum and pharmacology of the drugs involved, distinctive data from clinical trials, and toxicity and cost.