Biofilm bacteria: formation and comparative susceptibility to antibiotics   总被引：17，自引：0，他引：17       下载免费PDF全文

Merle E. Olson  Howard Ceri  Douglas W. Morck  Andre G. Buret    Ronald R. Read 《Canadian journal of veterinary research》2002,66(2):86-92

The Calgary Biofilm Device (CBD) was used to form bacterial biofilms of selected veterinary gram-negative and gram-positive pathogenic bacteria from cattle, sheep, pigs, chicken, and turkeys. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of ampicillin, ceftiofur, cloxacillin, oxytetracycline, penicillin G, streptomycin, tetracycline, enrofloxacin, erythromycin, gentamicin, tilmicosin, and trimethoprim-sulfadoxine for gram-positive and -negative bacteria were determined. Bacterial biofilms were readily formed on the CBD under selected conditions. The biofilms consisted of microcolonies encased in extracellular polysaccharide material. Biofilms composed of Arcanobacterium (Actinomyces) pyogenes, Staphylococcus aureus, Staphylococcus hyicus, Streptococcus agalactiae, Corynebacterium renale, or Corynebacterium pseudotuberculosis were not killed by the antibiotics tested but as planktonic bacteria they were sensitive at low concentrations. Biofilm and planktonic Streptococcus dysgalactiae and Streptococcus suis were sensitive to penicillin, ceftiofur, cloxacillin, ampicillin, and oxytetracycline. Planktonic Escherichia coli were sensitive to enrofloxacin, gentamicin, oxytetracycline and trimethoprim/ sulfadoxine. Enrofloxacin and gentamicin were the most effective antibiotics against E. coli growing as a biofilm. Salmonella spp. and Pseudomonas aeruginosa isolates growing as planktonic populations were sensitive to enrofloxacin, gentamicin, ampicillin, oxytetracycline, and trimethoprim/sulfadoxine, but as a biofilm, these bacteria were only sensitive to enrofloxacin. Planktonic and biofilm Pasteurella multocida and Mannheimia haemolytica had similar antibiotic sensitivity profiles and were sensitive to most of the antibiotics tested. The CBD provides a valuable new technology that can be used to select antibiotics that are able to kill bacteria growing as biofilms.  相似文献   

Observations of aphids on potatoes in Northern Wisconsin, 1947     

C. M. Voss  Floyd Andre 《American Journal of Potato Research》1948,25(7):266-272

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Thromboelastography in wild Florida manatees (Trichechus manatus latirostris)          下载免费PDF全文

Ashley Barratclough  Ruth Francis Floyd  Roger L. Reep  Ray L. Ball  Bobbi J. Conner 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2018,47(2):227-232

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Breed-related expression patterns of Ki67, γH2AX,and p21 during ageing in the canine liver     

Hardwick  Laura J. A.  Kortum  Andre J.  Constantino-Casas  Fernando  Watson  Penny J. 《Veterinary research communications》2021,45(1):21-30

Veterinary Research Communications - Cellular senescence is a molecular hallmark of ageing that is associated with multiple pathologies, and DNA damage marker γH2AX, together with cell cycle...  相似文献   

From killer to carer: steroid hormones and paternal behaviour     

Ruan de Bruin  Andre Ganswindt  Aliza le Roux 《African Zoology》2016,51(4):173-182

Mammalian parental investment (i.e. care of descendant offspring) is largely biased towards maternal contributions due to the specific feeding needs of mammalian offspring; however, varying degrees of paternal investment have been reported in about 10% of all mammalian species. Within the order Carnivora, paternal contribution to rearing offspring is particularly high: an estimated 32% of all studied carnivore species exhibit direct paternal care. Despite the prominence of paternal investment in carnivores, the endocrine basis of this behaviour is not well understood. This review examines the current – highly constrained – state of knowledge about the endocrine basis of carnivore paternal investment. We attempt to link changes in androgen and glucocorticoid levels with variation in direct and indirect paternal care behaviour making specific predictions regarding the way forward. Well-studied species, such as bat-eared foxes (Otocyon megalotis), dwarf mongoose (Helogale parvula) and meerkats (Suricata suricatta), where social dynamics are relatively well understood, can act as ideal model systems through which we may further investigate the endocrine basis of paternal investment in carnivores.  相似文献   

Assessment of hemostatic changes in a model of acute hemorrhage in dogs          下载免费PDF全文

Alex M. Lynch BVSc  DACVECC  Armelle M. deLaforcade DVM  DACVECC  Dawn Meola BS  Andre Shih DVM  DACVAA  DACVECC  Carsten Bandt DVM  DACVECC  Natalia Henao Guerrero DVM  MS  DACVAA  Carolina Riccó DVM  MS  DACVAA 《Journal of Veterinary Emergency and Critical Care》2016,26(3):333-343

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Infection studies in kittens, using feline infectious peritonitis virus propagated in cell culture   总被引：4，自引：0，他引：4  

N C Pedersen  J F Boyle  K Floyd 《American journal of veterinary research》1981,42(3):363-367

The propagation of feline infectious peritonitis virus (NW1-FIPV strain) in cell culture is described. Tissue culture-propagated virus was used to inoculate specific-pathogen-free kittens intraperitoneally, intratracheally, or orally. Intraperitoneal inoculation caused seroconversion and effusive peritonitis in 100% of the kittens. Intratracheal inoculation produced disease in 60% of the kittens, and oral inoculation in only 20%. Seroconversions without production of disease occurred in 10% of the kittens inoculated by either the intratracheal or the oral route. The remainder of the kittens inoculated by the intratracheal (30%) and oral (70%) routes did not develop serum antibodies or disease.  相似文献   

Use of a polymerase chain reaction assay to detect bovine herpesvirus type 2 DNA in skin lesions from cattle suspected to have pseudo-lumpy skin disease     

d'Offay JM  Floyd JG  Eberle R  Saliki JT  Brock KV  D'Andrea GH  McMillan KL 《Journal of the American Veterinary Medical Association》2003,222(10):1404-7, 1366-7

Beef cattle from a herd in north Alabama were examined because of an outbreak of nonfatal skin disease characterized by discrete circumscribed areas of inflammation that developed on the skin from the neck to the hips. Areas of inflammation, which tended to be superficial, underwent necrosis and scabbed over. The scabs eventually dropped off leaving discrete, round, whitish, hairless lesions that were 1.2 to 2.5 cm diameter. Because clinical signs were consistent with those expected with pseudo-lumpy skin disease (PLSD) caused by bovine herpesvirus type 2 (BHV-2), samples from 16 representative animals were submitted for BHV-2 testing. All 16 animals were seropositive for BHV-2, but the virus could not be isolated from skin biopsy specimens or buffy coat samples. Results of a polymerase chain reaction assay incorporating primers designed to amplify 2 DNA sequences from BHV-2 were positive for 3 of the 10 cattle, suggesting that skin lesions in these cattle were a result of PLSD. Our findings suggest that PLSD may be more common and widespread in the United States than suggested by the frequency with which BHV-2 has been isolated from cattle with PLSD-like skin lesions.  相似文献   

Effects of organic and mineral fertilizer inputs on maize yield and soil chemical properties in a maize cropping system in Meru South District, Kenya     

Monicah Mucheru-Muna  Daniel Mugendi  James Kung’u  Jayne Mugwe  Andre Bationo 《Agroforestry Systems》2007,69(3):189-197

Soil nutrient depletion as a result of continuous cultivation of soils without adequate addition of external inputs is a major challenge in the highlands of Kenya. An experiment was set up in Meru South District, Kenya in 2000 to investigate the effects of different soil-incorporated organic (manure, Tithonia diversifolia, Calliandra calothyrsus, Leucaena leucocephala) and mineral fertilizer inputs on maize yield, and soil chemical properties over seven seasons. On average, tithonia treatments (with or without half recommended rate of mineral fertilizer) gave the highest grain yield (5.5 and 5.4 Mg ha⁻¹ respectively) while the control treatment gave the lowest yield (1.5 Mg ha⁻¹). After 2 years of trial implementation, total soil carbon and nitrogen contents were improved with the application of organic residues, and manure in particular improved soil calcium content. Results of the economic analysis indicated that on average across the seven seasons, tithonia with half recommended rate of mineral fertilizer treatment recorded the highest net benefit (USD 787 ha⁻¹) while the control recorded the lowest (USD 272 ha⁻¹). However, returns to labor or benefit-cost ratios were in most cases not significantly improved when organic materials were used.  相似文献   

Two‐Stage Rumen Cannulation Technique in Dairy Cows          下载免费PDF全文

Roger Martineau DVM  PhD  Julien G. Proulx DVM  Cristiano Côrtes DVM  PhD  Andre F. Brito DVM  PhD  Todd F. Duffield DVM  DVSc 《Veterinary surgery : VS》2015,44(5):551-556

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