Temporal study of staphylococcal species on healthy dogs

During a 1-year period, specimens were obtained monthly from 5 hair coat and 7 mucous membrane sites of 11 healthy dogs. Among 804 isolates of staphylococci, 13 species were identified. Staphylococcus intermedius was the most frequently isolated (40.2% of total isolates) coagulase-positive species, and S xylosus was the most frequently isolated (17.3%) coagulase-negative species. Moreover, S intermedius was the most frequently isolated species from the 12 sites evaluated and was isolated persistently from 8 of the 9 dogs that completed the 1-year study. On the basis of a commercial identification system, 14 profile numbers were identified for isolates of S intermedius. However, 2 profile numbers accounted for a majority (70.9%) of the isolates. Specific S intermedius biotypes identified on the basis of hemolysis, coagulase production, beta-lactamase activity, and antimicrobial susceptibility patterns were found repeatedly in 3 dogs. Seemingly, S intermedius was a resident of the normal bacterial microflora of these dogs; however, the inability to isolate S intermedius from 1 dog during the study year indicated that not all dogs harbor S intermedius as a resident microorganism.     

Specific binding of dl-cloprostenol and d-cloprostenol to PG F2α receptors in bovine corpus luteum and myometrial cell membranes

Prostaglandin F_2α receptors (PGF_2α Rs) were measured in bovine corpus luteum and myometrial cell membranes using a radiometric method. The inhibition of labelled PGF_2α binding exerted by d-cloprostenol, dl-cloprostenol, PGF_2α and PGE₁ (l0–¹¹ M to 10^–4 M) was evaluated in vitro. Results strongly suggest that cloprostenol binding to PGF_2αRs is stereospecific. d-Cloprostenol and PGF_2α were equipotent, about 150 times more potent than d-cloprostenol (P < 0.05) and approximately 280 times more potent than PGE, (P < 0.05) in inhibiting [3H]PGF_2α binding to corpus luteum cell membranes. Such differences were less evident in myometrial cell membranes, where d-cloprostenol and PGF_2α were about 10 times more potent than d-cloprostenol (P < 0.05) and approximately 95 times more potent than PGE_l (P < 0.05).     

Pharmacokinetics of oxolinic acid in sea-bass, Dicentrarchus labrax (L., 1758), after a single rapid intravascular injection

The pharmacokinetics of oxolinic acid was studied in sea-bass ( Dicentrarchus labrax ). The fish were kept in seawater at 15.2°C with a 12 h/12 h photoperiod. Oxolinic acid was injected in the caudal vein of anaesthetized sea-bass in a single rapid intravascular administration at a dose of 10 mg/kg of body weight. Plasma concentrations of oxolinic acid were determined using two analytical methods, a classic plate diffusion bioassay using Escherichia coli and a high performance liquid chromatography (HPLC) using solid phase extraction with an internal standard and a U.V. detection. The mean recoveries were 99.6% and 110.8% and determination limits were 0.04 μg/mL and 0.02 μg/mL, for the bioassay and the HPLC respectively. Compared to other fish species, the oxolinic acid was rapidly (absorption half life, t_a1/2= 0.69 h) distributed to body tissues outside the blood volume (volume of central compartment, V_c= 0.4 L/kg) and presented a large volume of distribution (V_dss= 2.55 L/kg). Considering its disappearance from the central compartment (rate constant: central-eliminated, k ₁₀= 0.16 h^–1) and its total body clearance ( Cl _t= 0.066 L/kg.h), the elimination phase of the oxolinic acid in sea-bass was shorter than in trout kept in freshwater, and longer than in salmon in seawater. Consequently, the area under the concentration–time curve ( AUC = 157 μg.h/mL) and the mean residence time ( MRT = 42 h) were relatively low and short, respectively.     

Effect of oral administration of 3,3',4,4',5-pentachlorobiphyenl on the intestinal microbiota of Sprague–Dawley rats

The effect of the endocrine-disrupting chemical 3,3',4,4',5-pentachlorobiphyenl (PCB 126) on intestinal microbiota after oral administration, and the improvement of intestinal microbiota and feces quantity by the subsequent administration of Lactobacillus acidophilus or Lactobacillus reuteri was investigated. All the rats were given 100 μg/kg bodyweight of PCB 126. The changes in bacterial counts were confirmed using a culture method. The administration of PCB 126 tended to decrease the bacterial counts of lactobacilli (10^9.6−10^10.2 to 10^8.8−10^9.2) and bifidobacteria (10^5.3−10^6.1 to 10^3.6−10^4.2), and to increase those of Enterobacteriaceae (10^8.2−10^9.1 to 10^9.4−10^10.3) and staphylococci (10^6.6−10^7.4 to 10^7.2−10^8.4) compared to no PCB 126 administration. After administration of PCB 126, L. acidophilus or L. reuteri orally administered to rats caused Enterobacteriaceae and staphylococci counts to decrease, suggesting that the intestinal microbiota was improved by the lactobacilli. The administration of L. acidophilus and L. reuteri improved the balance of intestinal microbiota, and defecation volume returned to its normal level. L. acidophilus and L. reuteri have a remedial effect on intestinal microbiota affected by PCB 126 and can function to lessen accumulated PCB 126 volume.     

Frequency and antimicrobial susceptibility of Staphylococcus species isolated from canine pyodermas

Specimens obtained from pyogenic skin lesions of 210 dogs were culturally examined for staphylococci. A total of 215 isolates of staphylococci were biotyped, using the biochemical tests contained in a commercial staphylococcal identification system. Of 201 coagulase-positive isolates, 197 were identified as Staphylococcus intermedius, 3 as S aureus, and 1 as S hyicus. Of 14 coagulase-negative isolates, 5 were identified as S epidermidis, 5 as S xylosus, 3 as S simulans, and 1 as S hominis. Antimicrobial susceptibility tests were done on all staphylococcal isolates, using the standard disk-diffusion method. Staphylococcus intermedius isolates were susceptible to cephalothin, methicillin, and gentamicin. Resistance to ampicillin, penicillin G, and tetracycline was frequent. Antibiotic resistance was not associated with the depth of skin infection. Resistance to ampicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole was not associated with previous antibiotic use. Increased resistance to chloramphenicol, clindamycin, and erythromycin was associated with previous antibiotic therapy. Antimicrobial susceptibilities of the other Staphylococcus species isolated are reported, but the small numbers of these species precluded making meaningful comparison with S intermedius.     

Bioavailability of levamisole administered by subcutaneous and oral routes in rabbits

The bioavailability of levamisole in rabbits was determined after subcutaneous and oral administration at three dose levels of 12.5, 16.0 and 20.0 mg/kg. After non-compartmental analysis the mean values obtained were: C _max=3.54, 4.51 and 5.39 μg/ml; t _max= 12.0, 22.0 and 20.0 min; F = 134.8, 105.4 and 124.1% after subcutaneous administration for each dose, respectively, and C _max= 0.71, 1.32 and 1.77 μg/ml; t _max= 46.0, 96.0 and 84.0 min; F = 53.0, 62.0 and 80.7% after oral administration. The extent and rate of absorption from the two routes differed significantly, except for t _max at the 12.5 mg/kg dose. After compartmental analysis the pharmacokinetics of levamisole was characteristic of a two-compartment open model in 13 rabbits and of a one-compartment open model in two rabbits after subcutaneous administration, while it was two compartmental in nine and one compartmental in six rabbits after oral administration. The k_a values were 0.321, 0.145 and 0.145 min^-1 after subcutaneous administration and 0.054, 0.023 and 0.027 min¹ after oral administration. There were no significant differences between the values of C _max, t _max and AUC calculated by compartmental and non-compartmental analysis.     

Plasma pharmacokinetics of ranitidine HCl in adult horses

Plasma pharmacokinetics of ranitidine HCl were investigated after intravenous (i.v.) and oral (p.o.) administration of 2.2 mg/kg drug to six healthy adult horses. Concentrations of ranitidine were determined using normal-phase, high-performance liquid chromatography. Plasma concentrations of ranitidine HCl declined from a mean of 5175 ng/mL at 5 min to 37 ng/mL at 720 min after i.v. administration. A three-exponent equation, C_p= A₁· e^–k1t+ A₂· e^–k2t+ A₃· e^–k3t, best described data for all horses. Mean values for model-independent values calculated from the last quantifiable time point were: apparent volume of distribution (Vd_ss) = 1.07 L/kg; area under the curve ( AUC ) = 231,000 ng · min/mL; area under the moment curve ( AUMC ) = 26,900,000 ng · min²/mL; mean residence time ( MRT ) = 113 min; and clearance (Cl) = 9.8 mL/min.kg. Following p.o. administration, a two-exponent equation, C_p= A₁· e^–k1t+ A₂· e^–k2t, best described the data for five horses; data for the remaining horse were best described by a three-exponent equation. Mean values of pharmacokinetic values from the p.o. study include: AUC = 59,900 ng · min/mL; AUMC = 10,600,000 ng · min²/mL; mean absorption time ( MAT ) = 58.9 min; T _max= 99.2 min; C _max= 237 ng/mL; and F = 27%.     

A Temporal Study Comparing the Carriage of Staphylococcus intermedius on Normal Dogs with Atopic Dogs in Clinical Remission

Résumé— Le portage de Staphylococcus intermedius dans les narines, le pourtour anal et la ligne blanche a été compare chez 10 chiens sains et 19 chiens atopiques cliniquement controlés, recevant de faibles doses, à jours alternés, de prednisone pendant une période six mois. Un test du x² n'a pas permis de mettre en évidence une différence significative du taux d'isolement de S. intermedius entre les deux groupes en aucune localisation ni en regroupant l'ensemble des localisations [Harvey, R. G., Noble, W. C. A temporal study comparing the carriage of Saphylococcus intermedius on normal dogs with atopic dogs in clinical remission (Etue comparative du portage de Staphylococcus intermedius chez les chiens sains et atopiques cliniquement guéris).
Abstract— A temporal study of the carriage of Staphylococcus intermedius from the nares, anal ring and ventral midline of 10 normal dogs was compared to that of 19 atopic dogs receiving low dose, alternate-day prednisolone over a period of six months and maintained in clinical remission.
Chi-squared comparison of the two groups revealed no difference between the groups in the recovery rate of S. intermedius at any single site and no significant difference when all sites were pooled.     

饲喂PRL抑制剂对燕山绒山羊毛囊发育的影响

旨在研究绒山羊毛囊生长期饲喂催乳素（PRL）抑制剂对毛囊发育的影响。本研究选择3月龄体重相近（（23.01±4.82） kg）、健康良好的燕山绒山羊公羊20只,随机分为两组,每组10只,分别为对照组和试验组,试验组饲喂PRL抑制剂（0.06 mg·kg^-1）,试验期90 d。试验结束时采集羊绒纤维、血液和皮肤样品,分析饲喂PRL抑制剂对山羊绒长度、细度、血液指标、毛囊性状及皮肤组织PRL、MTNR1a和RORα mRNA表达水平的影响。结果表明,饲喂PRL抑制剂显著提高了绒山羊初级毛囊数量、次级毛囊数量和S/P值（P<0.05）,并显著提高了活性初级毛囊占比和活性次级毛囊占比（P<0.05）,对山羊绒伸直长度和细度无显著影响（P>0.05）。饲喂PRL抑制剂3个月对绒山羊血清中PRL、MT、IGF-1、COR、GH、T₄和T₃均无显著影响（P>0.05）,但显著降低了皮肤中PRL和MTNR1a mRNA表达水平（P<0.05）,对RORα mRNA表达量无显著影响（P>0.05）。综上,在绒山羊毛囊生长期抑制PRL分泌可能是通过降低皮肤中PRL和MTNR1a基因的表达来促进毛囊发育。     

High performance liquid chromatography and pharmacokinetics of the non-steroidal anti-inflammatory drug oxindanac in calves

A high-performance liquid chromatographic method for the determination of the non-steroidal anti-inflammatory drug, oxindanac, in calf plasma is described. Recoveries over the concentration range 0.3 75 to 62.5 μg/ml were 90.2–107.8% with interassay coefficients of variation of 2.1–22.3%. The limit of detection was estimated as 0.10 μg/ml and the limit of quantification calculated to be 0.24 pg/ml in a 1 ml plasma sample. This method was used to establish the pharmacokinetics following intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administration to calves of oxindanac at a dose rate of 2 mg/kg. The elimination t ¹/₂, was long ( t 1/2 21.2 h after i.v. injection) and absorption was rapid (t¹/_2B 0.072 h) and complete ( F > 100%) following i.m. administration. Bioavailability was incomplete ( F = 66.6%) following p.o. administration to calves that had been fed on milk, and Wagner-Nelson analysis revealed twoabsorption phases ( t ¹/₂'s 0.20 and 1.9 h). Oxindanac produced long-lasting inhibition of serum TxB₂ production, with mean k_max values (% inhibition) of 96.8, 94.1 and 81.3 following i.v., i.m. and p.0. administration, respectively. A single i.v. or i.m. injection of 2 mg/kg oxindanac will probably be active in calves for at least 36–48 h.     

Association of the amino acid motifs of BoLA-DRB3 alleles with mastitis pathogens in Japanese Holstein cows

The association of the polymorphism of bovine leukocyte antigen ( BoLA-DRB3 ) genes, identified by the polymerase chain reaction sequence-based typing (PCR-SBT) method, with resistance and susceptibility to mastitis caused by Streptococci , coagulase-negative Staphylococci, Escherichia coli and Staphylococcus aureus was investigated. Blood samples for DNA extraction were collected from 170 Holstein cows (129 mastitis and 41 healthy cows) from 5 districts in Chiba prefecture, Japan. Susceptibility or resistance to the mastitis-causing pathogens was thought to vary by the presence of amino acid substitutions at the 9, 11, 13, and 30 positions. DRB3*0101 and DRB3*1501 had amino acid motifs of Glu⁹, Ser¹¹, Ser¹³, and Tyr³⁰, and they were considered to have susceptibility to all 4 mastitis pathogens. In contrast, DRB3*1101 and DRB3*1401 had amino acid motifs of Gln⁹, His¹¹, Gly¹³, and His³⁰ in these positions, and they also had Val⁸⁶, so these alleles were considered to have resistance to Streptococcal and coagulase-negative Staphylococcal mastitis. However, in the case of Escherichia coli mastitis, amino acid substitutions at the 9, 11, 13, and 30 positions had little effect, but rather substitutions at the 47, 67 positions of pocket 7, and at the 71, 74 positions of pocket 4, Tyr⁴⁷, Ile⁶⁷, Ala⁷¹, and Ala⁷⁴, were associated with resistance. This motif was present in DRB3*1201 .     

Prevalence and Identity of Translocating Bacteria in Healthy Dogs

Bacterial translocation is characterized by the passage of intestinally derived bacteria across the intestinal mucosa to local or regional tissues. This phenomenon is believed to be important in the pathogenesis of gram-negative bacteremia and septicemia; however, the pathway or route of translocation remains unclear. To define the route of translocation better, mesenteric lymph nodes from 50 apparently healthy dogs undergoing elective ovariohysterectomies were cultured aerobically and anaerobically. The aims of this study were to determine the prevalence of bacterial translocation and to quantify and identify types of organisms found in mesenteric lymph nodes. Peripheral blood and portal blood samples were similarly cultured to rule out hematogenous organisms as a source of lymph node contamination. Bacteria were isolated from mesenteric lymph nodes of 26 dogs (52%). The number of bacteria varied from 50 to > 10⁵ organ-isms/g of tissue. Bacteria isolated included Staphylococcus intermedius (n = 3), coagulase-negative Staphylococcus (n = 2), nonhemolytic Streptococcus (n = 4), Bacillus species (n = 5), Escherichia coli (n = 6), Salmonella species (n = 3), Pseudomonas species (n = 2), Enterococcus species (n = 2), Clostridium sordelli (n = 1), Micrococcus species (n = 1), Lactobacillus species (n = 1), and Propionibacterium acnes (n = 1). One of 50 peripheral blood samples yielded an unidentified gram-positive coccus and a coagulase-negative Staphylococcus. No bacteria were isolated from portal blood samples of any dog. Further studies of this type on sick dogs are warranted before clinical recommendations can be made to culture mesenteric lymph nodes routinely.     

Occurrence of Staphylococcus intermedius on the hair and skin of normal dogs.

Aerobic bacterial populations were studied on the distal hair coat and at the skin surface of the shoulder, rump and abdomen of 10 healthy dogs. Coagulase negative staphylococci (CNS) were more frequently isolated from the hair than the skin at the shoulder and rump. There was no difference in the isolation rate of coagulase positive staphylococci (CPS) (Staphylococcus intermedius) between the hair and skin. Total skin counts were greatest on the abdomen whereas CNS counts from the hair were least at this site. There were no differences between CPS counts at the three sites on either hair or skin. The populations on the relatively unfavourable microenvironment of the distal hair may represent contamination rather than colonisation. The low populations of CPS at the skin surface also indicate contamination or transient colonisation rather than true resident status.     

Pharmacokinetics, bioavailability and dosage regimen of sulphadiazine (SDZ) in camels (Camelus dromedarius)

The pharmacokinetics of sulphadiazine (SDZ) (100 mg/kg, body weight) were investigated in six camels ( Camelus dromedarius ) after intravenous (i.v.) and oral (p.o.) administration. Following i.v. administration, the overall elimination rate constant (β) was 0.029±0.001/h and the half-life ( t _½β) was 23.14±1.06 h. The apparent volume of distribution ( V d_(area)) was 0.790±0.075 L/kg and the total body clearance ( Cl _B) was 23.29±2.50 mL/h/kg. After p.o. administration, SDZ reached a peak plasma concentration ( C _max(cal.)) of 62.93±2.79 μg/mL at a post injection time of ( T _max(cal.)) 22.98±0.83 h. The elimination half-life was 19.79±1.22 h, not significantly different from that obtained by the i.v. route. The mean absorption rate constant (K_a) was 0.056±0.002 h⁻¹ and the mean absorption half-life ( t _½Ka) was 12.33±0.37 h. The mean availability ( F ) of sulphadiazine was 88.2±6.2%.
  To achieve and maintain therapeutically satisfactory plasma SDZ levels of 50 μg/mL, the priming and maintenance doses would be 80 mg/kg and 40 mg/kg intravenously and 90 mg/kg and 45 mg/kg orally, respectively, to be repeated at 24 h intervals.     

Coagulase-negative, novobiocin-resistant staphylococci on the skin of animals and man, on meat and in milk.

The occurrence of coagulase-negative, novobiocin-resistant staphylococci, i.e. Staphylococcus cohnii, Staphylococcus saprophyticus, Staphylococcus sciuri and Staphylococcus xylosus, on the skin of animals and man has been studied. On cultures from cats, cows, dogs, guinea pigs, mice, rabbits and sheep studied, such organisms were predominant among the coagulase-negative staphylococci. From the skin of the hands of 21 of 38 persons whose professions brought them into contact with animals, e.g. inséminât ors, slaughterhouse workers and veterinarians, coagulase-negative, novobiocin-resistant staphylococci were isolated. This finding contrasted with that regarding 50 persons lacking such contacts, of whom only 1 harboured such bacteria. S. saprophyticus was isolated only from those slaughterers presenting with wounds on their hands. Coagulase-negative, novobiocin-resistant staphylococci were also isolated from every second specimen collected from the surface of meat at a slaughterhouse. No difference in the culture results could be demonstrated from specimens collected before and after cutting-up of the carcasses. Of 26 strains of coagulase-negative, DNase-negative staphylococci isolated from milk with pathological CMT, all but 5 were novobiocin-resistant. Fifteen were classified as S. xylosus, 4 as S. sciuri and 1 as S. cohnii. Of another 15 DNase-positive strains, 3 were resistant to novobiocin. Finally, clinical infections with coagulase-negative, novobiocin-resistant staphylococci in man, e.g. urinary tract infections caused by S. saprophyticus, are considered in relation to possible contagious reservoirs and modes of spread.     

Antimicrobial resistance of feline staphylococci in south-eastern England

Staphylococcus aureus is reported as the predominant feline staphylococcal pathogen. There is concern that cats may transfer resistant staphylococci to humans. In this study, staphylococci were obtained from skin and mucosae of 20 domestic cats, 9 with lesions, and 10 healthy feral cats. Species were identified by DNase and API ID32 Staph tests. Of 187 isolates, 21.4% were coagulase-positive and predominately from lesional cats; 90% of these were Staphylococcus intermedius . Coagulase-negative species were isolated equally in all three groups. All isolates were susceptible to coamoxiclav, cephalexin and bacitracin. Twenty-two, including 18 coagulase-negative isolates, showed some resistance to cotrimoxazole, lincomycin, enrofloxacin or oxytetracycline. Two isolates were resistant to more than one antibiotic. More resistant isolates were obtained from feral cats ( P < 0.01). The results suggest that S. intermedius is the principal coagulase-positive species. Antibiotic resistance is generally low amongst feline staphylococci. Higher resistance amongst feral cats suggests exposure to environmental antibiotics.     

Der Einfluß von Pseudomonas aeruginosa, Escherichia coli und Staphy-lococcus aureus auf die metabolischen Prozesse und die Vitalität von Bullenspermien

Es wurde der Einfluβ von Pseudomonas aeruginosa, Staphylococcus aureus und Escherichia coli auf Bullensperma untersucht, und zwar auf den O ₂ -Verbrauch, den GOT-Gehalt sowie den Anteil lebender und toter Spermien. Die Bakterien wurden in zwei verschiedenen Konzentrationen, 3 bzw. 30 × 10⁶ Zellen pro ml, dem in 2,9 %iger Natriumzitratlösung verdünnten Sperma zugesetzt. Die Inkubationszeit betrug 60 Mi-nuten bei 37°C. Nach der Inkubation war in den Samenproben rnit 30 Mill. Bakterien eine deutliche Senkung des Prozentsatzes lebender Spermien zu sehen. Die Diffrenz in Bezug auf die Kontrollprobe betrug bei Pseudomonas aeruginosa 6,9 % (P < 0,05), bei Staphylococcus aureus 9,7 % und bei E. coli 6,5 % (beide P < 0,01). Eine deutliche Abnahme des Sauerstoffverbrauches trat in den Samenproben mit 30 Mill. Staphylococcus aureus nach 15 Minuten Inkubation auf. Nach 60 minütiger Inkubation war das Volumen des verbrauchten Sauerstoffs in allen mit 30 × 10⁶ Bakterien pro ml konta-minierten Samenproben deutlich niedriger als in den Kontrollproben (Diffrenz P < 0,01). Samenproben mit 30 Mill. Pseudomonas aeruginosa und Staphylococcus aureus pro ml wiesen auch einen erhöhten GOT-Gehalt auf (Differenz zu den Kontrol-len P<0,01 ).     

Effects of Straw Volume and Equex-STM® on Boar Sperm Quality after Cryopreservation

The present experiments were designed to study the effect of adding the detergent Equex-STM^® to freezing extender, and of straw volume (0.25 ml vs 0.5 ml), on boar sperm quality after cryopreservation. Three ejaculates from each of four purebred boars (three Landrace and one Yorkshire) were collected and frozen with a lactose-egg yolk extender containing glycerol with or without 1.5% Equex-STM^®. The extended semen was loaded into either 0.25- or 0.5-ml straws. The straws were placed in liquid nitrogen (LN₂) vapour approximately 3 cm above the level of LN₂ for 20 min and then were plunged into LN₂. Thawing was achieved in warm water at 50°C for 12 s and then was incubated in a 38°C water-bath for 30 min before evaluating sperm quality. Results showed that the individual motility, viability and acrosomal normal apical ridge (NAR) were improved (p < 0.001) when Equex-STM^® was added to the freezing extender. There was no difference (p   =   0.48) in sperm motility between 0.25- and 0.5-ml straws when Equex-STM^® was added. The percentages of viable and of NAR sperm in 0.5-ml straws were higher than those in 0.25-ml straws (p   =   0.02, p   =   0.0003 respectively). The percentages of membrane intact sperm evaluated using the short hypo-osmotic swelling test were not affected by straw volume or the adding of Equex-STM^® (p   >   0.05). The results of these investigations suggested that Equex-STM^® exerts a beneficial effect on the quality of cryopreserved boar semen and this cryopreservation protocol was favourable for a 0.5-ml straw.     

Frequency and antimicrobial susceptibility of Staphylococcus spp isolated from feline skin lesions

Swab specimens obtained from skin lesions of 45 cats were cultured bacteriologically for staphylococci. Thirty-two staphylococcal isolates were recovered from 30 cats and were biotyped, using biochemical tests contained in a staphylococcal identification system. Of 23 isolates considered coagulase-positive, 16 were identified as Staphylococcus aureus, 5 as S intermedius, and 2 as S hyicus. Of 9 isolates considered coagulase-negative, 6 were identified as S simulans, 2 as S epidermidis, and 1 as S xylosus. Antimicrobial susceptibility tests were done on all staphylococcal isolates, using a disk-diffusion method. Staphylococcal isolates were susceptible to clavulanic acid-amoxicillin, cloxacillin, cephalothin, chloramphenicol, gentamicin, erythromycin, and trimethoprim-sulfamethoxazole. Resistance to penicillin G, ampicillin, and tetracycline was frequent.     

The effect of age on phenylbutazone pharmacokinetics, metabolism and plasma protein binding in goats

Phenylbutazone (PBZ) was administered intravenously as a single dose (10 mg/ kg) to adult male and 1-day-, 10-day-, 4-week- and 6 week-old male goats. The plasma concentration of PBZ and its major metabolites oxyphenbutazone (OPBZ) and γ-hydroxyphenbutazone (γ-OHPBZ) was measured over time. The elimination half-life (t_½β) of PBZ decreased from 120 h in the 1-day-old to 16 h in the adult goats. Although the volume of distribution ( V _d) did not change significantly during maturation, the total body clearance ( Cl B) increased from 2 ml.h^-1.kg^-1 in I-day-old t o 13 ml.h^-1.kg^-1 in the adult goats; the increase was 2-fold in the first 10 days of life. Oxyphenbutazone was detectable in the plasma of adult and 6-week-old goats as early as 15 min after PBZ administration. Its peak concentration occurred at 1.5 h (1.6 μg/ml) in adults and at 6 h (0.95 μg/ml) and 12 h (0.36 μg/ml) in 6- and 4-week-old goats respectively. The highest plasma concentration of γ-OHPBZ was achieved in 4-week-old followed by 6-week-old and adult animals.