The effects of supplemental chromium (Cr) from high-Cr yeast were investigated with steer calves fed corn silage diets. One hundred eight Charolais-crossed calves, weighing 245 kg after marketing and transport, were allotted to one of four treatments during the initial 28-d stress period: control,.4 ppm of Cr in the diet, long-acting injectable oxytetracycline (LAOTC), and Cr + LAOTC. Those fed Cr received 4 mg of Cr/d for the first 3 d sprinkled onto a small amount of hay over the silage. Chromium without LAOTC increased (P less than .05) ADG by 30%(.61 vs .79 kg/d) and ADG/DMI by 27%(.123 vs .156). Oxytetracycline alone increased (P less than .05) ADG by 30% and DMI by 15%. Chromium had no effect on morbidity. However, LAOTC tended (P less than .14) to reduce morbidity (26.0 vs 14.0%) after its administration. After d 28, steers were processed. Two weeks later, they were rerandomized within Cr groups to urea-corn vs soybean meal supplementation of corn silage during a 70-d growing period. Level of Cr was reduced to .2 ppm. Jugular blood was collected from eight steers on each treatment on two occasions. Chromium had no effect on ADG or ADG/DMI. However, Cr decreased (P less than .05) serum cortisol (75.0 vs 55.6 nmol/L). Furthermore, Cr increased (P less than .05) serum immunoglobulin M and total immunoglobulins in calves fed diets with soybean meal but had no effect in calves with urea-corn supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

A 6-year multicenter therapeutic study was performed on 1100 children with brucellosis in order to compare several antibiotic combinations and duration of treatment. The patients were randomized to receive oral therapy with oxytetracycline, doxycycline, rifampin and trimethoprim-sulfamethoxazole (TMP/SMX) either alone or in combination with each other or combined with streptomycin or gentamicin injections. The patients were also randomized into three groups based on the duration of oral therapy: 500 patients were treated for 3 weeks; 350 for 5 weeks; and 250 for 8 weeks. When intramuscular aminoglycosides were used, streptomycin was given for 2 weeks and gentamicin for 5 days. In oral monotherapy oxytetracycline, doxycycline and rifampin showed comparable results with low relapse rates (less than or equal to 9%) and no statistically significant differences were found among 3-, 5- or 8-week durations of therapy. TMP/SMX alone showed an unacceptably high relapse rate (30%) with all durations of therapy. In combined oral therapy rifampin plus oxytetracycline, rifampin plus TMP/SMX and oxytetracycline plus TMP/SMX showed comparable results with low relapse rates ranging from 4 to 8% in patients receiving therapy for 3 or 5 weeks, no relapses occurred in patients treated for 8 weeks. When oral monotherapy was combined with either streptomycin or gentamicin, very few relapses were seen, irrespective of the duration of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Edwardsiella tarda, an enteric, gram-negative bacterium, causes gas-filled, malodorous lesions in muscle tissue of channel catfish. Incidence and epizootiology of the disease are presented.

BACKGROUND We investigated the efficacy and cost-effectiveness of five antimicrobial regimens for mild to moderate facial acne and whether propionibacterial antibiotic resistance affects treatment response. METHODS In this randomised, observer-masked trial, 649 community participants were allocated one of five antibacterial regimens. Primary outcomes were patients' self-assessed improvement and reduction in inflamed lesions at 18 weeks. Analyses were by intention to treat. FINDINGS Moderate or greater improvement at 18 weeks was reported in 72 (55%) of 131 participants assigned oral oxytetracycline plus topical placebo, 70 (54%) of 130 assigned oral minocycline plus topical placebo, 78 (60%) of 130 assigned topical benzoyl peroxide plus oral placebo, 84 (66%) of 127 assigned topical erythromycin and benzoyl peroxide in a combined formulation plus oral placebo, and 82 (63%) of 131 assigned topical erythromycin and benzoyl peroxide separately plus oral placebo. Most improvement occurred in the first 6 weeks. Treatment differences for the proportion of people with at least moderate improvement were: minocycline versus oxytetracycline -1.2%(unadjusted 95% CI -13.3 to 10.9); combined erythromycin and benzoyl peroxide versus oxytetracycline 11.1%(-0.7 to 22.9) and versus minocycline 12.3%(0.4 to 24.2); erythromycin and benzoyl peroxide separately versus combined formulation -3.5%(-15.2 to 8.2); benzoyl peroxide versus oxytetracycline 5.0%(-7.0 to 17.0), versus minocycline 6.2%(-5.8 to 18.2), and versus combined formulation -6.1%(-17.9 to 5.7). Benzoyl peroxide was the most cost-effective treatment. Efficacy of both tetracyclines was reduced by pre-existing tetracycline resistance. INTERPRETATION Topical benzoyl peroxide and benzoyl peroxide/erythromycin combinations are similar in efficacy to oral oxytetracycline and minocycline and are not affected by propionibacterial antibiotic resistance.

The prophylactic administration of injectable tilmicosin for pneumonia in weaned beef calves was investigated in 1,806 animals. Comparisons were made among calves receiving an "on-arrival" injection of tilmicosin, calves receiving a single injection of long-acting oxytetracycline, and calves receiving no prophylaxis. Morbidity and mortality attributable to pneumonia, morbidity and mortality attributable to all causes, and case fatality were significantly lower in the group of calves that received tilmicosin, compared with calves that received long-acting oxytetracycline and calves that received no prophylactic antibiotic. Mean time to initial pneumonia treatment was significantly extended in calves that received prophylaxis, compared with those that received no antibiotic on arrival at the feedlot. Calves that received tilmicosin gained significantly more weight than calves that received oxytetracycline. Calves that were not treated for pneumonia during the trial period gained significantly more weight than did those calves that were treated for pneumonia regardless of experimental group. The majority of mortalities were attributable to fibrinous pneumonia (31/34). Important bacterial isolates (Pasteurella spp, Haemophilus somnus, Actinomyces pyogenes) obtained at necropsy did not have resistance to tilmicosin in association with administration of tilmicosin as prophylaxis for pneumonia. However, bacterial resistance to trimethoprim/sulfonamide and to oxytetracycline were commonly found in these postmortem isolates.

In a randomized double-blind trial fifty-one patients with rosacea were treated for 2 months with either I% metronidazole cream and placebo tablets or with 250 mg oxytetracycline tablets taken twice daily, and placebo cream (the cream base). The patients were assessed before and at the end of the trial, using the following criteria:(1) overall clinical assessment,(2) lesion counts,(3) degree of erythema,(4) independent photographic evaluation,(5) patients' opinion. An improvement was shown in 90% of the patients of both groups, and there was no significant difference between the two treatments.