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91.
Prevalence of Clostridium perfringens in commercial broiler hatcheries.   总被引:1,自引:0,他引:1  
Clostridium perfringens, a cause of human foodborne and poultry disease, has been isolated from the intestinal tract of poultry and from the processed carcass. Little is known about the incidence and sources of this pathogen in the poultry production environment. To determine if the broiler hatchery is a possible source of C. perfringens, we collected samples from three hatcheries, each operated by a different poultry integrator, and the presence of C. perfringens in these samples was determined. For each sampling period, eggshell fragments, chick fluff from the hatcher, and paper pads stored in the hatchery before use with chicks and after placement beneath chicks for 1 hr were evaluated. Clostridium perfringens was found in eggshell fragments, fluff, and paper pads in each of the three hatcheries. The percentages of C. perfringens-positive samples from the three hatcheries ranged from 13% to 23%, with an overall incidence of 20%. Positive samples were consistently found, i.e., detected on each of the nine sampling days (three sampling days for each of three hatcheries). These results suggest that the hatchery is a potential source/reservoir for C. perfringens in the integrated poultry operation.  相似文献   
92.
Flow cytometry sorting of spermatozoa using fluorescence dye Hoechst 33342 is the only effective sex selection methodology validated in numerous laboratories. This study was carried out to determine the effect of Hoechst 33342 on the motility and fertility of stained boar spermatozoa. Experiment 1 evaluated motility parameters (percentage of motile spermatozoa, velocity, angularity and oscillation) of boar spermatozoa stained with Hoechst 33342 by a computer‐aided sperm analysis (CASA) instrument. Spermatozoa (30 million/ml) were divided into five treatment groups and stained during 1 h at 35°C with 9, 18, 27, 60 and 90 μM of H33342. There were no differences in sperm motility patterns nor percentages of motile spermatozoa incubated in the presence of 9, 18 or 27 μM. Percentage of motile spermatozoa and motility parameters decreased significantly (p < 0.05) at 60 μM of Hoechst 33342. Spermatozoa were immotile at concentration of 90 μM. In experiment 2, pregnancy rates, farrowing rates and litter size from sows (n = 275) artificially inseminated (AI) with either Hoechst 33342 stained (27 μM) or unstained (control) spermatozoa were determined. Sows inseminated with stained spermatozoa had no significant lower pregnancy rate (88.33%) as compared with controls (90.32%). Staining neither affected farrowing rates (85.0 vs 87.7%) nor total number of piglets born (10.56 ± 0.32 vs 10.47 ± 0.24, stained and controls, respectively). No phenotypical abnormalities were registered among the newborn piglets. The data suggest that incubating spermatozoa with Hoechst 33342 at levels required for X‐ and Y‐bearing chromosome sperm sorting, does not impair sperm viability or their fertility after AI.  相似文献   
93.
Surgery, chemotherapy, and irradiation have been used singly or in combination to treat dogs with cutaneous grade-2 mast cell tumors (MCT). However, optimal treatment has not been established. At The Animal Medical Center, 32 dogs with grade 2, stage 0 MCT received cobalt radiation treatment to a dose of 54 Gy; 94% had a disease-free interval of 1 year. The 2–,3–,4–, and 5–year disease-free intervals were 86%. Survival rates were 100% for 1 year and 96% for 2 to 5 years, with only 1 death caused by MCT. Primary site was not a prognostic factor for survival in this study. Minimal toxicity was observed and was limited to acute cutaneous reactions. Late-term reactions to radiation therapy were mild and considered acceptable in all cases. No deaths occurred due to treatment, and no dog was eliminated from the study because of radiation therapy toxicity. Radiation therapy appears to be an effective treatment for dogs with grade 2, stage 0 MCT.  相似文献   
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A two-step semen-extending protocol was compared to a one-step protocol in its efficiency in inhibiting growth of Haemophilus somnus, Campylobacter fetus ssp. venerealis, Mycoplasma bovis , and Ureaplasma diversum in experimentally infected semen. In both protocols, the effect of an antibiotic mixture of 500 μg gentamycin, 100 μg tylosin, 300 μg lincomycin, and 600 μg spectinomycin (GTLS) was compared to a mixture of 500 IU penicillin, 500 IU streptomycin, 150 μg lincomycin, and 300 μg spectinomycin (PSLS). The one-step extending method was as effective as the two-step extending method. Both antibiotic mixtures were equally effective in controlling C. fetus . For H. somnus and U. diversum , the PSLS mixture was more effective than the GTLS mixture. It was striking that both antibiotic mixtures had no effect in decreasing the numbers of M. bovis .  相似文献   
97.
New particle formation in a tropical marine boundary layer setting was characterized during NASA's Pacific Exploratory Mission-Tropics A program. It represents the clearest demonstration to date of aerosol nucleation and growth being linked to the natural marine sulfur cycle. This conclusion was based on real-time observations of dimethylsulfide, sulfur dioxide, sulfuric acid (gas), hydroxide, ozone, temperature, relative humidity, aerosol size and number distribution, and total aerosol surface area. Classic binary nucleation theory predicts no nucleation under the observed marine boundary layer conditions.  相似文献   
98.
Objective To describe the clinical presentation, ultrasound findings, management and outcome in horses with muscle tear injuries of the hindlimbs. Design Retrospective case series Procedure Medical records of eight horses were reviewed and information on signalment, history, presenting complaint, physical examination findings and further diagnostic tests were recorded. Diagnosis of muscle injury was determined by the presence of abnormal ultrasound findings, compared with the contralateral limb, and, when required, nuclear scintigraphy. Follow-up information was obtained via telephone interviews with owners, trainers and referring veterinarians. Results Muscle tears causing lameness were identified in the middle gluteal (3), semitendinosus (1), semimembranosus (2) and gracilis (2) muscles. Tears were classified by ultrasound imaging as partial (6) or complete (2). The degree of lameness did not appear to be indicative of the extent of injury or of completion of healing. Long-term follow-up was available for seven horses and the outcome was favourable in six cases. Conclusions and clinical relevance Ultrasonography is useful in the diagnosis and assessment of moderate to severe muscle strain injuries. The prognosis appears to be favourable in most cases, although recurrence of injury and lameness can delay the return to athletic activity and an inferior outcome with persistent gait abnormality may occur.  相似文献   
99.
OBJECTIVE: To compare clinical information obtained from medical records of cats with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S aureus (MSSA) infections, evaluate antibiograms of MRSA and MSSA for multiple-drug resistance (MDR), and characterize the strain type and staphylococcal chromosome cassette (SCC)mec type of each MRSA. SAMPLE POPULATION: 70 S aureus isolates obtained from 46 cats. PROCEDURES: Clinical information obtained from medical records, including signalment, clinical signs, histologic examination of affected tissues, and outcomes, was compared between the 2 groups. Composite antibiograms of MRSA and MSSA were compared statistically. The MRSA strains were characterized by use of pulsed-field gel electrophoresis and SCCmec typing. RESULTS: No statistical differences in signalment or subjective differences in clinical signs or outcomes were detected between groups with MRSA or MSSA infection. Significant differences in antimicrobial resistance were detected, with MRSA having complete resistance to fluoroquinolone and macrolide antimicrobials, whereas MSSA maintained a high frequency of susceptibility. Seven pulsed-field patterns were observed in 15 MRSA strains; all but 1 were highly related. All MRSA isolates contained a type II SCCmec element. CONCLUSIONS AND CLINICAL RELEVANCE: Because MDR cannot be predicted in staphylococcal infections in cats on the basis of clinical signalment, culture and susceptibility testing are recommended whenever initial empirical treatment is unsuccessful. Molecular characterization of MRSA strains suggests that there has been reverse-zoonotic transmission from humans. IMPACT FOR HUMAN MEDICINE: The SCCmec type II element is typically associated with nosocomial MRSA infections of people. Cats may serve as reservoirs for MRSA infections in humans.  相似文献   
100.
Cardiac troponin I (cTnI) and T (cTnT) have a high sequence homology across phyla and are sensitive and specific markers of myocardial damage. The purpose of this study was to evaluate the Cardiac Reader, a human point-of-care system for the determination of cTnT and myoglobin, and the Abbott Axsym System for the determination of cTnI and creatine kinase isoenzyme MB (CK-MB) in healthy dogs and in dogs at risk for acute myocardial damage because of gastric dilatation-volvulus (GDV) and blunt chest trauma (BCT). In healthy dogs (n = 56), cTnI was below detection limits (<0.1 microg/L) in 35 of 56 dogs (reference range 0-0.7 microg/L), and cTnT was not measurable (<0.05 ng/mL) in all but 1 dog. At presentation, cTnI, CK-MB, myoglobin, and lactic acid were all significantly higher in dogs with GDV (n = 28) and BCT (n = 8) than in control dogs (P < .001), but cTnT was significantly higher only in dogs with BCT (P = .033). Increased cTnI or cTnT values were found in 26 of 28 (highest values 1.1-369 microg/L) and 16 of 28 dogs (0.1-1.7 ng/mL) with GDV, and in 6 of 8 (2.3-82.4 microg/L) and 3 of 8 dogs (0.1-0.29 ng/mL) with BCT, respectively. In dogs suffering from GDV, cTnI and cTnT increased further within the first 48 hours (P < .001). Increased cardiac troponins suggestive of myocardial damage occurred in 93% of dogs with GDV and 75% with BCT. cTnI appeared more sensitive, but cTnT may be a negative prognostic indicator in GDV. Both systems tested seemed applicable for the measurement of canine cardiac troponins, with the Cardiac Reader particularly suitable for use in emergency settings.  相似文献   
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