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1.
Fifty-one isolates of Corynebacterium equi recovered from pigs and horses belonging to two capsular serotypes were tested for susceptibility to antimicrobial agents. No clear differences were detected in sensitivity between isolates of different sources or serotypes. All isolates were sensitive to <0.25 μg/ml of erythromycin and gentamicin. The following minimum inhibitory concentrations (MICs) of antimicrobial agents were determined for ≤90% of isolates: methicillin >16 μg/ml, clindamycin 1–2 μg/ml, tobramycin ≤1 μg/ml, cephalothin 8–64 μg/ml, kanamycin 2–8 μg/ml, amikacin ≤1–2 μg/ml, penicillin 2–≤4 μg/ml, ampicillin 2–8 μg/ml, trimethoprim-sulfa 4/76–32/608 μg/ml tetracycline 1–4 μg/ml and chloramphenicol 8–16 μg/ml. 相似文献
2.
Ninety-nine isolates of obligate anaerobic bacteria obtained from clinical material were tested for susceptibility to ten antimicrobial agents. Regardless of the species of animal from which the isolates were obtained 90–95% were inhibited by ≤4 μg of ampicillin/ml, ≤4 μg of chloramphenicol/ml, ≤1 μg clindamycin/ml, ≤2 μg metronidazole/ml, ≤8 μg minocycline/ml, ≤16 μg penicillin Gyml, and ≤16 μg tetracycline/ml. All the aminoglycoside antibiotics tested (gentamicin, kanamycin, neomycin, and streptomycin) were shown to be relatively ineffective requiring ≥128 μg/ml for the inhibition of >50%of the isolates. The minimal inhibitory concentration of penicillin G and tetracycline tended to be higher for isolates from non-human primates (penicillin G) and ruminants (tetracycline). 相似文献
3.
OBJECTIVE: To determine the antibacterial activity of bovine lactoferrin hydrolysate (bLf-lysate) alone or in combination with other antimicrobials against antimicrobial-resistant Escherichia coli strains isolated from baby pigs. SAMPLE POPULATION: 3 clinical strains of E coli were isolated from baby pigs with severe diarrhea and designated as strains 9061, 9062, and 9065. PROCEDURE: The broth microdilution checkerboard and fractional inhibitory (or bactericidal) concentration index were used to evaluate the antibacterial effect elicited by bLf-lysate in combination with kanamycin, gentamicin, cephalothin, cefamandole, penicillin G, ampicillin, tetracycline, erythromycin, or rifampicin against the 3 strains of E coli. RESULTS: The 3 strains of E coli were susceptible to gentamicin and rifampicin but highly resistant to most of the other antimicrobials tested, except for strain 9061 that was also susceptible to cephalothin but intermediately inhibited by kanamycin and cefamandole. Synergistic growth-inhibitory activity was observed between bLf-lysate and gentamicin against 1 strain of E coli (strain 9062); synergistic bactericidal activity was found between bLf-lysate and rifampicin against all 3 strains of E coli. Moreover, partial synergy was observed between bLf-lysate and kanamycin, gentamicin, cephalothin, or cefamandole against the strains of E coli, but this partial synergistic activity was mostly seen against only 1 of the strains. Little interaction between bLf-lysate and tetracycline, ampicillin, penicillin G, or erythromycin was observed against the clinical strains of E coli. CONCLUSIONS AND CLINICAL RELEVANCE: A combination of bLf-lysate and certain antimicrobials may prove clinically effective against antimicrobial-resistant strains of E coli. 相似文献
4.
J. M. ENSINK W. R. KLEIN A. BARNEVELD A. G. VULTO† A.S.J.P.A.M. van MIERT‡J. J. TUKKER§ 《Journal of veterinary pharmacology and therapeutics》1996,19(6):439-444
The distribution of penicillins into a tissue chamber implanted subcutaneously in ponies was studied. Ampicillin sodium (equivalent to 15 mg/kg ampicillin) was administered intravenously. Pivampicillin, a prodrug of ampicillin, was administered by nasogastric tube to fed ponies at a dose of 19.9 mg/kg (equivalent to 15 mg/kg ampicillin). Procaine penicillin G was administered intramuscularly at a dose of 12 mg/kg (equivalent to 12 000 IU/kg). Six ponies were used for each medication. Antibiotic concentrations in plasma and tissue chamber fluid (TCF) were measured for 24 h after administration. Mean peak concentrations of ampicillin in TCF were 7.3 μg/mL, reached at 1.7 h, and 1.3 μg/mL, reached at 2.7 h, after administration of ampicillin sodium and pivampicillin respectively. The mean peak concentration of penicillin G of 0.3 μg/mL was reached 12.3 h after administration of procaine penicillin G. Concentrations in TCF remained above the minimum inhibitory concentration of Streptococcus zooepidemicus for the proposed dosing intervals of 8, 12 and 24 h for ampicillin sodium, pivampicillin and procaine penicillin G respectively. 相似文献
5.
M. P. BROWN SUSAN M. STOVER R. H. KELLY T. B. FARVER 《Journal of veterinary pharmacology and therapeutics》1982,5(2):119-122
Ten healthy adult mares were given a single intramuscular dose (2.2 mg/kg) of gentamicin sulfate. Over a 48-h period, gentamicin concentrations were measured serially in the serum of all ten mares and in synovial fluid, peritoneal fluid, and urine of six of the mares. The mean peak serum gentamicin concentration was 5.73 μg/ml at 1 h. Gentamicin was detected in synovial fluid and peritoneal fluid, with mean peak gentamicin concentrations of 2.41 μg/ml and 3.92 μg/ml, respectively, observed at 2 h. These concentrations declined in parallel with serum concentrations and were not measurable at 48 h. Urine gentamicin concentration was relatively high, with a mean peak concentration of 424.9 μg/ml at 1 h after drug administration. 相似文献
6.
Minimal concentrations of penicillin, ampicillin, cephalothin, chloramphenicol, tetracycline, erythromycin, nitrofurantoin, kanamycin and gentamicin inhibitory to Pasteurella haemolytica biotypes A and T were determined. They were found to be significantly higher for T than for A type strains in the case of all the antimicrobial drugs tested except the two aminoglycosides kanamycin and gentamicin, for which no differences were observed. In the case of penicillin the differences were so marked that they may be useful as a basis for biotyping P haemolytica isolates. The emergence of antibiotic-resistant strains observed in recent years, however, may limit such application. 相似文献
7.
为了解鲜牛奶中细菌的分布情况及其对抗生素的敏感状况,实验对30份采自河北张家口地区某养殖场的新鲜无菌牛奶进行细菌分离鉴定,并分别用青霉素(16μg/ml)、氯霉素(32μg/ml)、克林霉素(4μg/ml)、红霉素(8μg/ml)、四环素(16μg/ml)、庆大霉素(16μg/ml)、环丙沙星(4μg/ml)、头孢噻吩(32μg/m)l进行药敏实验。结果显示30份牛奶样品中共分离得到111株菌,分别为葡萄球菌31株、沙雷氏菌14株、假单胞菌12株、芽孢杆菌11株、肠杆菌5株、不动杆菌4株、奇异变形杆菌3株、微球菌3株、巨球菌3株、肠球菌4株、其它菌21株。其中耐青霉素16μg/ml的为50株,耐氯霉素32μg/ml的为23株,耐克林霉素4μg/ml的为46株,耐红霉素8μg/ml的为37株,耐四环素16μg/ml的为38株,耐庆大霉素16μg/ml的是7株,耐环丙沙星4μg/ml的为8株,耐头孢噻吩32μg/ml的为40株。通过实验可知,细菌类型主要有葡萄球菌、沙雷氏菌、假单胞菌等;8种抗生素中,庆大霉素、环丙沙星、氯霉素的抑菌效果较好,而青霉素、克林霉素、红霉素、四环素、头孢噻吩的抑菌效果相对较差。 相似文献
8.
In vitro antimicrobial sensitivity of 12 Hungarian isolates and the type strain ATCC 33144 of Actinobaculum suis to different antimicrobial compounds was determined both by the agar dilution and by the disc diffusion method. By agar dilution, MIC50 values in the range of 0.05-3.125 micrograms/ml were determined for penicillin, ampicillin, ceftiofur, doxycycline, tylosin, pleuromutilins, chloramphenicol, florfenicol, enrofloxacin and lincomycin. The MIC50 value of oxytetracycline and spectinomycin was 6.25 and 12.5 micrograms/ml, respectively. For ofloxacin, flumequine, neomycin, streptomycin, gentamicin, nalidixic acid, nitrofurantoin and sulphamethoxazole + trimethoprim MIC50 values were in the range of 25-100 micrograms/ml. With the disc diffusion method, all strains were sensitive to penicillin, cephalosporins examined, chloramphenicol and florfenicol, tetracyclines examined, pleuromutilins, lincomycin and tylosin. Variable sensitivity was observed for fluoroquinolones (flumequine, enrofloxacin, ofloxacin), most of the strains were susceptible to marbofloxacin. Almost all strains were resistant to aminoglycosides but most of them were sensitive to spectinomycin. A strong correlation was determined for disc diffusion and MIC results (Spearman's rho 0.789, p < 0001). MIC values of the type strain and MIC50 values of other tested strains did not differ significantly. Few strains showed a partially distinct resistance pattern for erythromycin, lincomycin and ampicillin in both methods. 相似文献
9.
The effects of probenecid on serum ampicillin and amoxycillin concentrations were investigated in 1–5 week old calves after oral and parenteral drug administration. Ampicillin trihydrate was administered orally at 250mg/calf, after an overnight fast, alone and with 1.5g probenecid. Peak serum ampicillin concentrations were elevated from 0.60 to 1.22 μg/ml by the co-administration of probenecid. In calves given 0.5 g amoxycillin trihydrate with the milk replacer, peak serum drug concentration increased from 1.74 to 3.16 μg/ml when 1.5 g probenecid was given too. Maximal effect of probenecid administered orally was with the 1.5 g/calf dose with considerably lesser increase in peak serum amoxycillin being observed with doses of 0.5 g, 1 g and 2 g/calf. After parenteral injection of probenecid solution at 1 g and 2 g/calf serum ampicillin concentrations peaked at more than twice the concentrations measured after equal doses of the two antibiotics were injected alone. The co-administration of 2 g probenecid and 1 g sodium ampicillin or 0.5 g sodium amoxycillin parenterally resulted in peak antibiotic concentrations considered to be effective against some of the more resistant pathogenic Gram-negative bacteria associated with diseases in calves and serum antibiotic concentrations 5 μg/ml were maintained during 5–6 h as opposed to 2–3 h after the antibiotics were injected alone. Oral administration of 1.5 g probenecid at three consecutive milk feeding times did not alter serum urea or serum creatinine concentrations. 相似文献
10.
Pharmacokinetics of erythromycin in foals and in adult horses 总被引：1，自引：0，他引：1
J. F. PRESCOTT D. J. HOOVER I. R. DOHOO 《Journal of veterinary pharmacology and therapeutics》1983,6(1):67-73
The pharmacokinetic parameters of erythromycin in foals were determined following intravenous administration of 5.0 mg/kg to animals aged 1, 3, 5 and 7 weeks. The distribution of the drug was described by a two-compartment open model, and no significant differences were observed between coefficients on which the parameters were based. Pharmacokinetic values were also determined for four mares given 5.0 mg/kg intravenously and for six 10–12 week-old foals given 20.0 mg/kg intravenously. The half-life of erythromycin for all groups of animals (foals less than 7 weeks, mares, foals 10–12 weeks) was 1.0–1.1 h; the apparent volume of distribution was between 2.3 and 7.2 l/kg, and the clearance of the drug from the body was between 1.9 and 5.0 mg/kg/h. No drug could be detected in the serum following oral administration of 5.0 mg/kg erythromycin estolate; detectable levels were found for 5 h in mares given 12.5 mg/kg, and for 8 h in foals given 20.0 mg/kg orally. Peak levels in foals given the drug orally were 0.42 μg/ml at 120 min after administration. Foals given 10.0 mg/kg of erythromycin base intramuscularly had serum concentrations detectable 12 h later, the peak level achieved was 1.44 μg/ml serum 90 min after administration and concentrations exceeded 0.25 μg/ml for 6 h. In the mares the milk concentrations were approximately twice those in serum. Recommendations were made for drug dosage to be used in the treatment of Corynebacterium equi pneumonia of foals. 相似文献
11.
A total of 522 strains belonging to streptococci, enterococci and staphylococci isolated from sub-clinical and clinical cases of bovine mastitis from the west littoral region of Uruguay were analysed for their susceptibility to several antimicrobial agents. The susceptibility patterns were studied by agar disk diffusion methods (ADDM) and broth micro-dilution to determine the minimum inhibitory concentration (MIC). The concentration that inhibits 90% (MIC90) of the analysed strains reported in micrograms per millilitre, for Staphylococcus aureus were > 8, 8, < or = 0.5, < or = 4, < or = 1, < or = 0.5, > 64, < or = 0.25, 0.5, < or = 1 and < or = 1 to penicillin, ampicillin, oxacillin, cephalotin, gentamicin, erythromycin, oxitetracycline, enrofloxacin, trimethoprim/sulfamethoxazole, neomycin, and clindamycin, respectively. Coagulase-negative staphylococci (CNS) had different values for penicillin (4) and ampicillin (2), while the other antimicrobial agents had the same MIC90 values as reported for S. aureus. The MIC90 values for streptococci were 0.12, 0.25, < or = 4, 16, < or = 0.25, 0.5, 0.25 for penicillin, ampicillin, cephalotin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, whereas MIC90 for enterococci were 4, 4, 4, < or = 0.5, 2, > 8 for penicillin, ampicillin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, respectively. Of 336 strains of S. aureus, 160 (47.6%) were resistant to penicillin. For 41 CNS strains, 10 (27%) presented penicillin-resistance. All the streptococcal strains were susceptible to penicillin, while 3 (7%) of the 43 enteroccocal strains were resistant. Non significant statistical differences were found between the results obtained by ADDM and broth micro-dilution for classifying bacterial isolates as susceptible or resistant according to the National Committee of Clinical Laboratory Standards. 相似文献
12.
Treatment of Corynebacterium equi pneumonia of foals: a review 总被引：4，自引：0，他引：4
J F Prescott C R Sweeney 《Journal of the American Veterinary Medical Association》1985,187(7):725-728
Combined antimicrobial drug treatment was recommended for foals with Corynebacterium equi pneumonia. The preferred combination is orally administered erythromycin estolate (25 mg/kg of body weight, QID) plus rifampin (10 mg/kg, BID). Erythromycin estolate also can be combined for synergistic effect with sodium benzyl penicillin given IV (100,000 IU/kg, QID) or with ampicillin given IV (11 to 15 mg/kg, QID). A third choice is sodium benzyl penicillin IV with gentamicin IM (2.2 mg/kg, TID) or with kanamycin IM (10 mg/kg, QID). Gentamicin should be combined with penicillin G or ampicillin and not used for longer than one week without monitoring for nephrotoxicosis. Rifampin should be used only in combination with erythromycin or penicillin. Erythromycin or rifampin and gentamicin give antagonistic interactions in vitro. Chloramphenicol or trimethoprim-sulfamethoxazole may be effective if given in high doses but are not preferred drugs. Treatment response should be monitored clinically and radiographically and treatment should be continued for 2 weeks after the foal is clinically and radiographically normal. 相似文献
13.
Minimum inhibitory concentration determinations for various antimicrobial agents against 1570 bacterial isolates from turkey poults 总被引：3，自引：0，他引：3
Minimum inhibitory concentrations (MICs) were determined for 1570 bacteria from eight geographic locations (1204 Escherichia coli, 231 other enteric gram-negative bacilli [including Citrobacter spp., Enterobacter spp., Klebsiella spp., Proteus spp., and Salmonella spp.], 31 Pseudomonas spp., 18 coagulase-positive staphylococci, 26 coagulase-negative staphylococci, and 55 streptococci and enterococci) by the National Committee for Clinical Laboratory Standards broth microdilution procedure. Antimicrobial agents tested included ampicillin, ceftiofur, enrofloxacin, erythromycin, florfenicol, gentamicin, neomycin, spectinomycin, sulfamethazine, tetracycline, and trimethoprim/sulfadiazine. Against the E. coli strains tested, ceftiofur, enrofloxacin, gentamicin, and trimethoprim/sulfadiazine were the most active compounds with MIC at which 50% of the strains are at or below (MIC50) = 0.5, < or = 0.03, 0.5, and 0.13 microg/ml, respectively, and MIC at which 90% of the strains are at or below (MIC90) = 1.0, 0.13, 32.0, and 2.0 microg/ml, respectively. Ampicillin, florfenicol, neomycin, and spectinomycin were the next most active compounds against the E. coli strains, with MIC50 = 4.0, 4.0, 16.0, and 16.0 microg/ml, respectively. MIC90 values for these compounds against E. coli strains were > 32.0, 8.0, 512.0, and > 128.0 microg/ml, respectively. The remaining compounds exhibited limited, strain-dependent activity against the E. coli strains tested. As with the E. coli, enrofloxacin, ceftiofur, and trimethoprim/sulfadiazine were also the most active compounds against the 231 other enteric organisms tested, with MIC50 < or = 1.0 microg/ml for all of these genera. The remaining compounds exhibited limited activity against these genera. Against the gram-positive cocci tested, ampicillin, enrofloxacin, ceftiofur, and trimethoprim/sulfadiazine were most active, whereas the remaining compounds exhibited strain-dependent activity. When MIC data for E. coli were summarized separately, differences were observed between the geographic locations for the various antimicrobial agents. In conclusion, ceftiofur, enrofloxacin, and trimethoprim/sulfadiazine were the most active of the compounds tested against all of the bacterial strains. 相似文献
14.
Murchie TA Macpherson ML LeBlanc MM Luznar S Vickroy TW 《Equine veterinary journal》2006,38(6):520-525
REASONS FOR PERFORMING STUDY: Most current treatments for placentitis in mares are empirical with few control studies to evaluate their effectiveness. OBJECTIVE: To monitor drug concentrations in allantoic fluid of pregnant pony mares using in vivo microdialysis and establish if this method would be useful for determining allantoic concentrations of drugs in normal mares and those with placentitis. METHODS: Five late gestational pony mares had microdialysis probes inserted into the allantoic fluid using transabdominal ultrasound-guided allantocentesis. Single injections of penicillin G (22,000 u/kg), gentamicin (6.6 mg/kg bwt) and flunixin meglumine (1 mg/kg bwt) were administered i.v. and dialysate samples collected continuously for 24 h. In a separate study, drug concentrations were monitored in allantoic fluid of 2 mares with experimental placentitis induced by intracervical inoculation with Streptococcus equi ssp. zooepidemicus. Drug concentrations were measured by high performance liquid chromatography (penicillin G, flunixin meglumine) or enzyme-linked immunosorbent assay (gentamicin). RESULTS: Penicillin G and gentamicin achieved average peak concentrations of 9.8+/-2.2 and 8.5+/-3.1 microg/ml, respectively, in allantoic fluid of noninfected mares. Pharmacokinetic comparisons indicate that penicillin G persists much longer in allantoic fluid than blood, whereas gentamicin exhibited similar profiles in the 2 compartments. Flunixin meglumine was not detected in allantoic fluid. In infected mares, penicillin G achieved a similar peak concentration in allantoic fluid (11.2 microg/ml) whereas peak gentamicin concentration (3.9 microg/ml) appeared to be reduced relative to drug concentrations in noninfected mares. CONCLUSIONS: Microdialysis is a useful technique for continuous in vivo monitoring of drugs in equine allantoic fluid. Our results indicate that penicillin G and gentamicin undergo effective placental transfer in pregnant mares and in 2 mares that transplacental drug transfer may be altered selectively if active placental infection is present. POTENTIAL RELEVANCE: Further studies are needed to evaluate the feasibility of using increased dose intervals for penicillin G and an increased dose rate of gentamicin to effectively combat placental infections in mares. 相似文献
15.
The antibiotic sensitivity patterns of Bacillus anthracis isolated from the Kruger National Park 总被引：3，自引：0，他引：3
M W Odendaal P M Pieterson V de Vos A D Botha 《The Onderstepoort journal of veterinary research》1991,58(1):17-19
Forty-four isolates of Bacillus anthracis made from carcasses and soil in different localities of an endemic anthrax area in the Kruger National Park, South Africa, were tested by standard disc diffusion for their susceptibility to 18 different antibiotics. These were ampicillin, penicillin G, sulphatriad, streptomycin, clindamycin, gentamicin, fusidic acid, trimethoprim, sulphamethoxazole, chloramphenicol, erythromycin, methicillin, tetracycline (2 different concentrations), novobiocin, cefotaxime, netilmicin, cefamandole and cefoxitin. All the isolates were susceptible to ampicillin, streptomycin, chloramphenicol, erythromycin, tetracycline, methicillin and netilmicin. More than 90% of the isolates were sensitive to clindamycin, gentamicin and cefoxitin, whereas only 84.1% of the isolates were sensitive to penicillin G, 86.4% to novobiocin and 68.18% to cefamandole. Complete resistance in 100% of the isolates was encountered with trimethoprim and sulphamethoxazole, with 95.45% for sulphatriad. Moderate sensitivity occurred with penicillin G (15.9% of the isolates), clindamycin (6.8%), novobiocin (13.6%), fusidic acid (84.1%), cefotaxime (100%), cefamandole (31.8%) and cefoxitin (6.8%). The relevance of the findings to the therapeutic uses of different types of antibiotic in human clinical cases referred to in the literature is discussed. 相似文献
16.
Baljinder Kumar Bansal Navdeep S. Bajwa S. S. Randhawa Rakesh Ranjan P. S. Dhaliwal 《Tropical animal health and production》2011,43(2):323-329
Elimination of erythromycin in milk following intramammary therapy of specific mastitis in cows was studied. Five cows received
therapy in one quarter (G1), and eight in two quarters with five milked twice (G2) and three thrice a day (G3). Dose infused
was 300 mg/quarter 12 h × 5 times. The drug concentrations in milk were determined using microbial assay technique with Micrococcus luteus as the test organism. Considerable variations occurred in the excretion of drug; levels for treated quarters being 8.25 to
37.61 μg/ml at first milking that declined rapidly at 24 h and no drug activity was observed beyond 36 h post treatment. In
total, about 6–25% of the last infused dose appeared in the milk. Drug crossed to 1/15 quarter (G1), 6/10 quarters (G2) and
all the six untreated quarters (G3). Crossover levels were significantly higher in mastitic quarters and for G3 cows, but
duration of excretion remained same in all cases. It seems that crossover of erythromycin to untreated quarters is related
to the udder health and dose infused. 相似文献
17.
The minimal inhibitory concentrations (MIC) of 129 strains of genus Bacteroides, isolated from abscesses in pigs, for 13 different antimicrobial agents were determined by an agar-dilution method under anaerobic conditions. Clindamycin, the most active antibiotic tested, had a median MIC of 0.8 micrograms/ml. Penicillin G, talampicillin, minocycline, chloramphenicol, and cefoxitin also inhibited all isolates at lower concentrations. Some isolates of B pyogenes were susceptible to gentamicin (MIC, 0.4 micrograms/ml), erythromycin (MIC, 0.8 micrograms/ml), cephalexin (MIC, 0.8 micrograms/ml), and cefoxitin (MIC, 3.2 micrograms/ml). Erythromycin, at a concentration of 3.2 micrograms/ml, was active against 70% of B suis tested, but it was less active against the other Bacteroides species. Some strains tested were resistant to streptomycin and neomycin. 相似文献
18.
P J Adamson W D Wilson D C Hirsh J D Baggot L D Martin 《American journal of veterinary research》1985,46(2):447-450
In vitro antimicrobic susceptibility patterns of commonly isolated aerobic gram-positive and gram-negative bacterial pathogens of equine origin were determined, using the agar-plate dilution method. All organisms were recent clinical isolates and included Corynebacterium (Rhodococcus) equi, Corynebacterium pseudotuberculosis, (coagulase positive) Staphylococcus sp, Streptococcus equi, Streptococcus zooepidemicus, Actinobacillus sp, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella. In vitro susceptibility levels were outlined for 14 antimicrobics as follows: amikacin less than or equal to 4.0 micrograms/ml, ampicillin less than or equal to 1.0 microgram/ml, amoxicillin less than or equal to 1.0 microgram/ml, cefadroxil less than or equal to 8.0 micrograms/ml, chloramphenicol less than or equal to 8.0 micrograms/ml, erythromycin less than or equal to 1.0 microgram/ml, gentamicin less than or equal to 2.0 micrograms/ml, kanamycin less than or equal to 4.0 micrograms/ml, penicillin less than or equal to 1.0 microgram/ml, tetracycline less than or equal to 1.0 microgram/ml, sulfadimethoxine less than or equal to 10.0 micrograms/ml, ormetoprim/sulfadimethoxine less than or equal to 0.5/9.5 micrograms/ml, sulfadiazine less than or equal to 10.0 micrograms/ml, and trimethoprim/sulfadiazine less than or equal to 0.5/9.5 micrograms/ml. 相似文献
19.
The pharmacokinetics of erythromycin was studied in five lactating dairy cows following single intramammary infusion of 300
mg erythromycin in each of two quarters per cow with specific mastitis. Levels of erythromycin in plasma and quarter milk
samples were measured by agar plate diffusion assay using Micrococcus luteus (ATCC 9341) as the test organism. Erythromycin level in plasma reached a peak concentration value (C
max) of 0.07 ± 0.01 μg/ml at 30 min; thereafter, levels declined gradually to reach 0.05 ± 0.00 μg/ml 12 h post drug administration.
The pharmacokinetic profile of the drug revealed mean absorption half life (t
1/2ka) as 0.26 ± 0.05 h. The drug was eliminated slowly with elimination half-life (t
1/2β) of 13.75 ± 0.35 h and elimination rate constant (k
el) of 0.04 ± 0.00 h−1. The volume of distribution based on the zero-time plasma concentration intercept of the least-squares regression line of
the elimination phase (V
d(B)) was 0.032 L/kg. The drug crossed to untreated quarters also; mean drug levels of 0.20 ± 0.07, 0.23 ± 0.07, 0.17 ± 0.04,
and 0.17 ± 0.04 μg/ml were found at 3, 6, 8 and 12 h, respectively. The mean drug concentration for treated quarters was
measured as 22.97 ± 2.31 μg/ml milk at first milking (12 h) following drug infusion. No apparent adverse reaction was seen
in cows administered erythromycin. It is concluded that following intramammary infusion erythromycin diffuses readily and
extensively in various body fluids and tissues and adequate concentration is maintained in udder tissues for at least 12 h
post intramammary administration. Thus, erythromycin may be recommended for local therapy of acute mastitis caused by Gram-positive
bacteria in lactating dairy cows. 相似文献