Enzyme immunoassay for macrolide antibiotics: characterization of an antibody to 23-amino-O-mycaminosyltylonolide

An enzyme-linked immunosorbent assay was developed for the detection of macrolide antibiotics by using a polyclonal antibody generated in rabbits immunized with 23-amino-O-mycaminosyltylonolide (23-amino-OMT) covalently linked to keyhole limpet hemocyanin. The specificity and sensitivity of this antibody were characterized by using 23-amino-OMT coupled to alkaline phosphatase as an enzyme-linked label in a direct competitive enzyme-linked immunosorbent assay. The assay sensitivity was as low as 0.3 ng/ml for 23-amino-OMT, with a 50% inhibitory concentration of 8 ng/ml. This antibody exhibited good reactivity with 12-, 14- or 16-membered macrolides possessing amino-substituted sugar moieties, regardless of the presence of neutral sugar residues. Little or no cross-reactivity was observed with the macrocyclic lactone ring structure (tylactone) or macrolides containing only neutral sugars. No cross-reaction was observed with polyenes or nonmacrolide antibiotics. Known macrolide-producing cultures grown in fermentation broth also showed good reactivity, indicating that this assay is useful in detecting this class of metabolites in fermentation.

[Immunologic aspects of macrolide antibiotics]

The authors investigated in an experimental and clinical study the part played by the macrolide antibiotic, tylosine, in the elevated immunological reactivity of the present population to Erythromycin. The first assembled results justify the statement that tylosine used in veterinary practice (sometimes without control) may indice acrossed immunological reactivity against Erythromycin. The authors discuss also other undesirable manifestations after Erythromycin administration. The assembled data confirm the need of an aimed and controllable administration of antimicrobial preparations in human as well as in veterinary medicine.

[Antigenicity study of rokitamycin]

The antigenicity of rokitamycin (TMS-19-Q, TMS) was studied. Rabbits and mice were repeatedly challenged with TMS emulsified with adjuvant to be strongly immunized. Neither IgG nor IgE antibodies were, however, detected in serum from these animals when assayed by PCA and PHA reactions. Furthermore, guinea pigs immunized with TMS together with Freund's complete adjuvant did not exhibit any systemic anaphylactic reactions when elicited with TMS alone. In contrast, specific antibody production against TMS was confirmed in animals immunized with chemically introduced antigen of TMS-carrier protein conjugate, where TMS had antigenic nature as hapten.

Tiamulin in drinking water for treatment and development of immunity to swine dysentery

The diarrhea of swine dysentery receded in swine treated with 60 or 45 mg of tiamulin/L of drinking water (60 or 45 ppm). However, within 2 to 10 days (average 4.1 days) after drug withdrawal, diarrhea recurred. Tiamulin (22.5 mg/L in drinking water) did not markedly reduce the diarrhea during medication, and tylosin (66 mg/L in the drinking water) was not effective. In swine treated with 120 mg of dimetridazole/L of drinking water, there was no recurrence of diarrhea. After the recurrence of diarrhea in swine, repeated medication with tiamulin in drinking water reduced the severity of diarrhea and prevented deaths. After 1 to 3 retreatments, swine were immune to exposure with swine dysentery inoculum, and there was a significant (P less than 0.05) increase in their serum anti-Treponema hyodysenteriae antibodies. Seemingly, drug withdrawal permitted the occurrence and recurrence of diarrhea that was necessary to stimulate immunity.

Asthma due to inhaled chemical agents--the macrolide antibiotic Spiramycin

One year after starting work in the pharmaceutical industry a 35-year-old non-atopic maintenance engineer developed attacks of sneezing, coughing and breathlessness. These occurred at home during the evening and early morning, never at work during the day. His employment involved contact with a wide variety of chemical agents including the macrolide antibiotic spiramycin. Inhalation challenge tests carried out in hospital with gradually increasing quantities of spiramycin reproduced his symptoms and led to the development of late asthmatic reactions, during which the FEV1 fell by 25% and the FEV1/FVC ratio by 15%. No change occurred in the single breath CO transfer factor nor were crepitations heard over the lung fields which remained normal on chest X-ray. The patient showed positive immediate skin prick tests to spiramycin and developed blood eosinophilia during the late asthma attacks. Inhalation of sodium cromoglycate either before, or before and hourly after the provocation challenge for 6 hr, failed to prevent the late asthma, although its onset was further delayed. On leaving the pharmaceutical industry the patient's symptoms improved but did not finally clear until his wife, who had worked in a clerical capacity in the same factory also ceased her employment.