stearates and Escherichia-coli-Infections

The experimental system utilized in investigating the correlation between the chemical structures of muramyl peptides and their protective activities in the sepsis type of systemic infections caused by Escherichia coli was applied in evaluating the enhancement of resistance to infection induced by 32 synthetic glycopeptide analogs, including 6-O-acyl derivatives and 1-alpha-O-benzyl derivatives of muramyl dipeptide (N-acetyl muramyl-L-alanyl-D-isoglutamine). In assessing the 6-O-acyl derivatives of muramyl dipeptide, we found that the degree of protective activity was attributable to the kinds of fatty acids introduced. Acylation of the 6-hydroxy group on the muramic acid moiety in muramyl dipeptide with natural mycolic acid or a synthetic fatty acid possessing either an alpha-branched or an alpha-branched, beta-hydroxylated group resulted in a decrease in or a disappearance of the protective activity of muramyl dipeptide. Acylation with a normal fatty acid or an iso fatty acid resulted in a retention or enhancement of muramyl dipeptide activity. The activity of acylated derivatives containing linear fatty acids was stimulated by increasing the chain length up to 18 carbon atoms. The highest degree of protective activity occurred with the derivatives acylated with straight-chain fatty acids, particularly with the derivatives acylated with palmitic acid and arachidic acid. Benzylation of the 1-hydroxy group of muramyl dipeptide resulted in a decrease in or a loss of protective activity.

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Acylation; Animals; Benzyl Compounds; Escherichia coli Infections; Fatty Acids; Glycopeptides; Immunity, Innate; Male; Mice; Mycolic Acids; Stearates; Structure-Activity Relationship

An open comparative study was carried out to assess the effectiveness of 4 antibiotic regimens in eradicating acute bacterial infections of the upper respiratory tract. Patients in each treatment group had similar physical parameters, severity of disease and bacterial pathogens, and were treated for 10 days with either erythromycin estolate, erythromycin stearate, ampicillin or oxytetracycline in the recommended dosage. Each patient was reviewed daily by physical examination and the bacteriological findings from throat swab and salivary washings. The results showed that erythromycin stearate produced more rapid bacterial eradication and clinical resolution of symptoms and fever than with the other antibiotic preparations, and was well tolerated by most patients.

Topics: Acute Disease; Ampicillin; Bacterial Infections; Erythromycin; Erythromycin Estolate; Escherichia coli Infections; Humans; Oxytetracycline; Penicillin Resistance; Respiratory Tract Infections; Stearates