Dihydrostreptomycin sulfate

Dry cow therapy, administered at the end of lactation, is aimed at eliminating current and preventing future intramammary (IMM) bacterial infections and typically involves intramammary administration of antibiotics. Certified organic dairies in the United States are restricted from using antibiotics and must consider an alternative therapy or no dry cow therapy. The current study compared 2 herbal products to conventional dry cow therapy and no treatment for a total of 5 treatments over 2 trials. Trial 1 was conducted over 3 yr on 1 research farm and trial 2 included 4 commercial farms plus the research herd over 2 yr. Treatments included (1) a conventional IMM antibiotic and internal teat sealant (penicillin-dihydrostreptomycin and bismuth subnitrate; CON); (2) an herbal IMM product purported to act as a teat sealant (Cinnatube, New AgriTech Enterprises, Locke, NY; CIN); (3) an herbal IMM product (Phyto-Mast, Bovinity Health LLC, Narvon, PA; P-M); (4) Phyto-Mast and Cinnatube (PC); or (5) no dry cow therapy (NT).

OBJECTIVE: To develop a method for simultaneous determination of streptomycin and dihydrostreptomycin residues in tomato ketchup by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

The study objective was to compare the efficacy of 3 commercial dry cow mastitis formulations regarding quarter-level prevalence of intramammary infections (IMI) postcalving, cure of preexisting infections over the dry period, prevention of new infections during the dry period, and risk for a clinical mastitis case between calving and 100d in milk (DIM). A total of 1,091 cows (4,364 quarters) from 6 commercial dairy herds in 4 different states (California, Iowa, Minnesota, and Wisconsin) were enrolled and randomized to 1 of the 3 treatments at dry-off: Quartermaster (QT; 1,000,000 IU of procaine penicillin G and 1 g of dihydrostreptomycin; Pfizer Animal Health, New York, NY), Spectramast DC (SP; 500 mg of ceftiofur hydrochloride; Pfizer Animal Health), or ToMorrow Dry Cow (TM; 300mg of cephapirin benzathine; Boehringer Ingelheim Vetmedica Inc., St. Joseph, MO). Quarter milk samples were collected for routine bacteriological culture before dry cow therapy treatment at dry-off, 0 to 6 DIM, and 7 to 13 DIM and an on-farm record-keeping system was used to retrieve data on clinical mastitis cases.

To determine and compare the extent of contamination caused by antimicrobial-resistant lactic acid bacteria (LAB) in imported and domestic natural cheeses on the Japanese market, LAB were isolated using deMan, Rogosa and Sharpe (MRS) agar and MRS agar supplemented with six antimicrobials. From 38 imported and 24 Japanese cheeses, 409 LAB isolates were obtained and their antimicrobial resistance was tested. The percentage of LAB resistant to dihydrostreptomycin, erythromycin, and/or oxytetracycline isolated from imported cheeses (42.1%) was significantly higher than that of LAB resistant to dihydrostreptomycin or oxytetracycline from cheeses produced in Japan (16.7%; P=0.04). Antimicrobial resistance genes were detected in Enterococcus faecalis (tetL, tetM, and ermB; tetL and ermB; tetM) E. faecium (tetM), Lactococcus lactis (tetS), Lactobacillus (Lb.), casei/paracasei (tetM or tetW), and Lb. rhamnosus (ermB) isolated from seven imported cheeses.