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1.
Genet Mol Res ; 13(3): 5840-8, 2014 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-25117342

RESUMEN

In this study, we estimated the heritability (h(2)) of earnings in the Quarter Horse in order to evaluate the inclusion of this trait in breeding programs. Records from 14,754 races of 2443 horses from 1978-2009 were provided by Sorocaba Hippodrome, São Paulo, Brazil. All ancestors of the registered horses were included in the pedigree file until the 4th generation. Log-transformed performance measures (LPM) were analyzed for animals aged 2, 3, and 4 years and during their entire career. The h(2) estimates were obtained using a multi-trait model and Gibbs sampling that included the effects of sex, year of race, and animal in all analyses. Five analyses were performed: 1 in which LPM was divided by the number of prizes, 1 in which LPM was divided by the number of race starts, and 3 analyses that included the number of prizes, number of race starts, and both (LPM_cNPS) as covariates. Analysis was performed with and without inclusion of the maternal effect. Models were compared based on the deviance information criterion and LPM_cNPS including maternal effects was found to be the best model. The h(2) estimates and standard deviation obtained using model LPM_cNPS were 0.19 ± 0.08, 0.21 ± 0.08, 0.22 ± 0.09, and 0.21 ± 0.07 for earnings at 2, 3, and 4 years of age and total career, respectively. Our analyses indicate that earnings are subject to selection and can be included in breeding programs to improve the racing performance of Quarter Horses.


Asunto(s)
Carácter Cuantitativo Heredable , Carrera , Factores de Edad , Animales , Brasil , Cruzamiento , Estudios de Asociación Genética , Caballos , Modelos Estadísticos
3.
J Fr Ophtalmol ; 36(10): 820-9, 2013 Dec.
Artículo en Francés | MEDLINE | ID: mdl-24119454

RESUMEN

Cavernous hemangioma is the most frequent benign orbital tumor in adults. The purpose of this study was to examine its clinical features, to define surgical indications, and to determine the roles of the various surgical approaches praticed in ophthalmology: transconjunctival (increasingly utilized), anterior transcutaneous, and lateral orbitotomy. The records of all patients treated for orbital cavernous hemangioma (OCH) since 2004 at the Fondation Rothschild (Paris, France) were retrospectively reviewed. Forty-three patients were treated for orbital cavernous hemangioma. Fifty-eight percent were women, mean age 50.2; 79 % of the tumors were intraconal. Among those patients, 36 underwent surgical removal, 5 were followed periodically, and 2 were lost to follow-up. The main surgical indications were: optic nerve compression (26 patients), proptosis (24 patients) and diplopia (3 patients). Transconjunctival, anterior transcutaneous and Kronlein approaches were used in 16, 12 and 4 patients respectively. Four patients had intrapalpebral hemangiomas easily reached transcutaneously. Two patients demonstrated transient partial 3rd nerve palsy (one with the lateral orbitotomy approach and one with the transconjunctival approach), one patient with the lateral orbitotomy approach developed a palsy of the superior branch of the 3rd nerve, and one patient with the transcutaneous anterior approach developed mydriasis. Surgical excision of OCH's is required in the presence of clinical complications. The transconjunctival approach is a safe technique which can lead to complete resection of the tumor in most cases.


Asunto(s)
Hemangioma Cavernoso/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos , Neoplasias Orbitales/cirugía , Adulto , Anciano , Estudios de Cohortes , Conjuntiva/cirugía , Femenino , Hemangioma Cavernoso/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Órbita/cirugía , Neoplasias Orbitales/epidemiología , Estudios Retrospectivos
4.
Animal ; 6(12): 1925-30, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23031384

RESUMEN

The files for ultrasound diagnosis of gestating mares belonging to the French equine herd recorded for 3 consecutive years were joined with the files for foal birth of these same mares, allowing the statistical analysis of factors of pregnancy loss. For 28 872 positive diagnoses of gestation, 2898 losses were recorded, that is, a global rate of gestation interruption of 9.12%. The etiology of these interruptions is mainly extrinsic: the year and month of insemination, as well as region for climatic reasons. The intrinsic causes that are implicated are breed of the father (heavy breeds except the hypermetric ones lose fewer pregnancies than warm-blooded breeds), age of the mother (losses are lower in mares of 7 to 10 years of age) and status (mares with foals have fewer pregnancy losses than mares not having foaled the previous year), as well as fetuses with consanguinity (when this increases, the pregnancy losses increase as well). However, the additive genetic effect is extremely low; it corresponds to heritability below 5% and few effects of the environment, common to the offspring of the same mare, were identified. This therefore gives little hope of being able to select against the 'gestation loss' trait.


Asunto(s)
Aborto Veterinario/epidemiología , Pérdida del Embrión/veterinaria , Muerte Fetal/veterinaria , Enfermedades de los Caballos/epidemiología , Resultado del Embarazo/veterinaria , Aborto Veterinario/etiología , Aborto Veterinario/genética , Factores de Edad , Animales , Pérdida del Embrión/epidemiología , Pérdida del Embrión/etiología , Pérdida del Embrión/genética , Femenino , Muerte Fetal/epidemiología , Muerte Fetal/etiología , Muerte Fetal/genética , Francia/epidemiología , Geografía , Enfermedades de los Caballos/etiología , Enfermedades de los Caballos/genética , Caballos , Endogamia , Incidencia , Modelos Logísticos , Oportunidad Relativa , Paridad , Embarazo , Factores de Riesgo , Estaciones del Año
5.
J Fr Ophtalmol ; 35(9): 667-77, 2012 Nov.
Artículo en Francés | MEDLINE | ID: mdl-22999254

RESUMEN

PURPOSE: To describe the management of orbital exenterations and the surgical techniques for the reconstruction of orbital exenteration cavities. PATIENTS AND METHODS: This retrospective study includes 56 patients who underwent orbital exenteration between 2000 and 2009. Patients' age at the time of exenteration, diagnoses, complications and reconstructive techniques were studied. RESULTS: Fifty-six patients - 31 male and 25 female patients - who underwent orbital exenteration between 2000 to 2009 were included in the study. The mean age was 62.5 years at the time of exenteration. Average follow-up was 23 months. The principal diagnoses were basal cell carcinoma of the eyelids (25%) and conjunctival melanoma (20%). For orbital reconstruction, 18 patients (32%) had a muscle flap, and 24 patients (43%) underwent secondary reconstruction by bone-anchored implants after spontaneous epithelialisation of the orbit. Approximately 50% of the patients received postoperative radiation therapy. DISCUSSION: Surgical reconstruction using muscle flaps may mask recurrent tumor. Epithelialisation and bone-anchored implants supporting the prosthesis allow for recurrent cancer surveillance while providing better stabilization of the prosthesis. Radiation therapy seems to render the orbit more fragile and thus less stable for implants. CONCLUSION: Orbital exenteration is a mutilating technique. Rehabilitation techniques have been improved, in particular the bone-anchored implants which allow adaptation of the prosthesis with satisfactory cosmetic results.


Asunto(s)
Evisceración Orbitaria , Procedimientos de Cirugía Plástica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
6.
Pathol Biol (Paris) ; 57(7-8): 548-54, 2009.
Artículo en Francés | MEDLINE | ID: mdl-19233571

RESUMEN

Extensive proteolytic remodeling processes constitute a critical step during tumor progression. The endocytic receptor low-density lipoprotein receptor-related protein-1 (LRP-1), by its function in the clearance of multiple extracellular proteases involved in metastatic spreading, has long been considered as a putative tumor suppressor. Moreover, the receptor is likely to control the peritumoral microenvironment by internalization of growth factors and matricial proteins and could therefore participate to the control of signaling events involved in survival and proliferation of cancer cells. Nevertheless, recent data lead to reconsider the initially attributed antitumor properties of LRP-1. A more complex model seems to emerge in which LRP-1 could constitute a sensor of pericellular environment and regulate the membrane proteome dynamics. By its control of focal adhesions composition and turn-over, regulation of the cytoskeleton organization and integrin endocytic recycling, LRP-1 appears as a crucial actor of the epithelial-mesenchymal transition, thereby reinforcing the aggressive phenotype of malignant cells. LRP-1 partitioning into rafts and association with tissue-type and tumor grade specific intracellular scaffold proteins appear crucial to determine its function in tumor progression. Those emerging aspects present numerous promising perspectives in oncology and allow envisaging the development of innovative strategies of control of tumor progression through the targeting of LRP-1.


Asunto(s)
Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/fisiología , Metástasis de la Neoplasia/patología , Neoplasias/patología , Neoplasias/prevención & control , Proteínas Supresoras de Tumor/fisiología , División Celular , Supervivencia Celular , Citoesqueleto/patología , Citoesqueleto/ultraestructura , Progresión de la Enfermedad , Endocitosis , Células Epiteliales/citología , Humanos , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/efectos de los fármacos , Modelos Biológicos , Metástasis de la Neoplasia/prevención & control
7.
J Anim Breed Genet ; 124(3): 124-32, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17550353

RESUMEN

The aim of this study was to detect Thoroughbred mare families and sire lines, in France, in the United Kingdom and Ireland, whose offspring may be successful in steeplechase races and can be recommended therefore for sport horse breeding. Race results were collected from all steeplechase races in these countries between 1998 and 2003, which contained the results of 17,355 horses from 12,861 dams and 2452 sires. In France, non-Thoroughbred horses were also included in the analysis because they race and mate together with Thoroughbreds. Performance was measured with two criteria: earnings and ranks after mathematical transformation. The effects of year, sex, age and race were considered as fixed, animal, permanent environment and maternal environment as random. Precorrection for the effect of race was done to avoid computational difficulties. Maternal environmental components for ranks were 0.02 in France and zero in the United Kingdom and Ireland. Estimated heritabilities for the ranking criteria were 0.18 (repeatability 0.33) in France and 0.06 (repeatability 0.19) in the United Kingdom and Ireland. The high genetic correlation between the two criteria of measurement (0.94 and 0.97 respectively) gives the opportunity to choose the most suitable criteria for breeding value estimation. The ranking value, after statistical normalization has a great advantage for comparison between the countries.


Asunto(s)
Caballos/genética , Caballos/fisiología , Selección Genética , Deportes , Animales , Cruzamiento , Femenino , Francia , Irlanda , Masculino , Reino Unido
8.
Equine Vet J Suppl ; (34): 319-24, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12405708

RESUMEN

Dressage is one of the Olympic equestrian sports practiced in several countries using different horse breeds. Specific characteristics of the walk, trot and canter are required for dressage. It has been assumed that some of these traits could be selected for genetically and contribute to dressage performance. The purpose of this study was to compare the walk, trot and conformation characteristics in young horses of different breeds used for dressage. A total of 142 horses age 3 years were classified into 3 groups of breeds (German, French and Spanish saddle horses) and tested using the same procedure. The skeletal conformation measurements were made by image analysis. Gait variables of the walk and trot were measured by the accelerometric gait analysis system Equimetrix. Discriminant analysis could explain the variability between the groups by taking into account the walk (P<0.0003), trot (P<0.0001) and conformation variables (P<0.0001). Many gait and conformation variables were significantly different between the breeds. In summary, the German horses had gait characteristics more adapted for dressage competition, and the results of this group could be used as a reference for early evaluation in dressage. Purebred Spanish horses could be considered as a reference for collected gaits used for farm work and old academic dressage. The gait and conformation tests could be applied in a breeding or crossing plan to detect more accurately young horses with good dressage ability.


Asunto(s)
Marcha/fisiología , Caballos/genética , Caballos/fisiología , Condicionamiento Físico Animal , Animales , Fenómenos Biomecánicos , Cruzamiento , Análisis Discriminante , Femenino , Miembro Anterior , Marcha/genética , Miembro Posterior , Caballos/anatomía & histología , Masculino , Fotograbar/veterinaria , Deportes
9.
J Org Chem ; 66(14): 4826-30, 2001 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-11442412

RESUMEN

In the presence of enolizable carbonyl compounds, hemiaminals of fluoral and related polyfluoroaldehydes behave as equivalents of fluoroalkyl iminium compounds and provide beta-polyfluoroalkyl beta-dialkylamino ketones, which are easily transformed, under acidic conditions, into beta-polyfluoroalkylenones.

10.
Mamm Genome ; 12(6): 450-5, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11353392

RESUMEN

Coat color genetics, when successfully adapted and applied to different mammalian species, provides a good demonstration of the powerful concept of comparative genetics. Using cross-species techniques, we have cloned, sequenced, and characterized equine melanocortin-1-receptor (MC1R) and agouti-signaling-protein (ASIP), and completed a partial sequence of tyrosinase-related protein 1 (TYRP1). The coding sequences and parts of the flanking regions of those genes were systematically analyzed in 40 horses and mutations typed in a total of 120 horses. Our panel represented 22 different horse breeds, including 11 different coat colors of Equus caballus. The comparison of a 1721-bp genomic fragment of MC1R among the 11 coat color phenotypes revealed no sequence difference apart from the known chestnut allele (C901T). In particular, no dominant black (ED) mutation was found. In a 4994-bp genomic fragment covering the three putative exons, two introns and parts of the 5'- and 3'-UTRs of ASIP, two intronic base substitutions (SNP-A845G and C2374A), a point mutation in the 3'-UTRs (A4734G), and an 11-bp deletion in exon 2 (ADEx2) were detected. The deletion was found to be homozygous and completely associated with horse recessive black coat color (Aa/Aa) in 24 black horses out of 9 different breeds from our panel. The frameshift initiated by ADEx2 is believed to alter the regular coding sequence, acting as a loss-of-function ASIP mutation. In TYRP1 a base substitution was detected in exon 2 (C189T), causing a threonine to methionine change of yet unknown function, and an SNP (A1188G) was found in intron 2.


Asunto(s)
Proteínas Portadoras , Moléculas de Adhesión Celular , Proteínas del Helminto/genética , Glicoproteínas de Membrana/genética , Mutación , Receptores de la Hormona Hipofisaria/genética , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Proteínas Adaptadoras Transductoras de Señales , Alelos , Animales , Secuencia de Bases , Proteínas de Ciclo Celular , Clonación Molecular , Color , Análisis Mutacional de ADN , Exones , Mutación del Sistema de Lectura , Genotipo , Proteínas del Helminto/química , Caballos , Intrones , Glicoproteínas de Membrana/química , Metionina/química , Modelos Genéticos , Datos de Secuencia Molecular , Fenotipo , Reacción en Cadena de la Polimerasa , Receptores de la Hormona Hipofisaria/química , Análisis de Secuencia de ADN , Treonina/química
11.
J Food Prot ; 62(7): 797-9, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10419275

RESUMEN

Loading pigs onto trucks and transporting them for 30 min resulted in a significant increase in proportion of antimicrobial resistance of gram-negative enteric bacteria in fecal material. Similarly, the mean number of antimicrobial agents in the resistance patterns of these bacteria increased during loading and transportation. However, the increases were of a transient nature, as resistance values were similar to those of a nontransported control group 1 day after the pigs had been transported.


Asunto(s)
Crianza de Animales Domésticos/métodos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/aislamiento & purificación , Intestinos/microbiología , Porcinos/microbiología , Animales , Farmacorresistencia Microbiana , Heces/microbiología , Transportes
12.
Appl Environ Microbiol ; 65(4): 1501-5, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10103243

RESUMEN

This study was designed to determine whether isolates from chicken carcasses, the primary source of Campylobacter jejuni and Campylobacter coli in human infections, commonly carry the cdt genes and also whether active cytolethal distending toxin (CDT) is produced by these isolates. Campylobacter spp. were isolated from all 91 fresh chicken carcasses purchased from local supermarkets. Campylobacter spp. were identified on the basis of both biochemical and PCR tests. Of the 105 isolates, 70 (67%) were identified as C. jejuni, and 35 (33%) were identified as C. coli. PCR tests amplified portions of the cdt genes from all 105 isolates. Restriction analysis of PCR products indicated that there appeared to be species-specific differences between the C. jejuni and C. coli cdt genes, but that the restriction patterns of the cdt genes within strains of the same species were almost invariant. Quantitation of active CDT levels produced by the isolates indicated that all C. jejuni strains except four (94%) had mean CDT titers greater than 100. Only one C. jejuni strain appeared to produce no active CDT. C. coli isolates produced little or no toxin. These results confirm the high rate of Campylobacter sp. contamination of fresh chicken carcasses and indicate that cdt genes may be universally present in C. jejuni and C. coli isolates from chicken carcasses.


Asunto(s)
Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Campylobacter/aislamiento & purificación , Pollos/microbiología , Animales , Campylobacter/genética , Campylobacter/metabolismo , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/aislamiento & purificación , Cartilla de ADN , Desoxirribonucleasa EcoRI/metabolismo , Genes Bacterianos , Células HeLa , Humanos , Reacción en Cadena de la Polimerasa/métodos , Mapeo Restrictivo
13.
J Clin Microbiol ; 37(5): 1646-50, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10203548

RESUMEN

Campylobacter jejuni produces a toxin called cytolethal distending toxin (CDT). Knowledge of the prevalence and homogeneity of Campylobacter sp. cdt genes is incomplete. In this work, we identified four PCR primer pairs that collectively amplified cdt genes in all of the C. jejuni and Campylobacter coli strains tested. Restriction analyses of the cdt PCR products showed clear differences between the cdt genes of these two species, yet there were few heterogeneities noted between members of the same species. Consequently, it may be possible to speciate C. jejuni and C. coli isolates on the basis of restriction patterns within their cdt genes.


Asunto(s)
Toxinas Bacterianas/genética , Campylobacter coli/patogenicidad , Campylobacter jejuni/patogenicidad , Genes Bacterianos , Reacción en Cadena de la Polimerasa , Toxinas Bacterianas/toxicidad , Campylobacter coli/genética , Campylobacter jejuni/genética , Células HeLa , Humanos
14.
Equine Vet J Suppl ; (30): 289-92, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10659270

RESUMEN

The purpose of this study was to determine the percentage of fast myosin heavy chains (fast MHCs = MHC 2A + 2B) in 2 propelling muscles to estimate the heritability and to identify any relationship with performance. The gluteus medius and the biceps femoris muscles were biopsied in 100 related French Anglo-Arabian horses. The percentages of slow and fast myosin heavy chains were measured using an ELISA technique. The heritability (s.e.) of the fast MHCs percentage was estimated at 13% (0.1) using a restricted maximum likelihood resolution of a mixed animal model. There were significant (P < 0.05) correlations between the performance level and the fast MHCs percentage of the gluteus medius and biceps femoris muscles: 0.47 and 0.34 respectively. An analysis of variance revealed a significant (P < 0.05) effect of performance level in gallop racing and show jumping on the fast MHCs percentage of the gluteus medius muscle. The good performers in gallop racing (75.5 > 69.6% fast MHCs) and show jumping (74.1 > 67.8% fast MHCs) had a higher percentage of fast MHCs in the gluteus medius than poor performers (P < 0.05). This muscular analysis could be one of the interesting physiological traits to measure for early selection of gallop racing and show jumping horses.


Asunto(s)
Caballos/genética , Fibras Musculares Esqueléticas/fisiología , Músculo Esquelético/fisiología , Cadenas Pesadas de Miosina/genética , Análisis de Varianza , Animales , Biopsia , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Caballos/fisiología , Masculino , Cadenas Pesadas de Miosina/fisiología
15.
J Food Prot ; 61(10): 1352-7, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9798154

RESUMEN

Aerobic, microaerophilic, coliform, and mold populations of Botrytis cinerea-inoculated strawberry fruit not exposed (control) or exposed to low and high quantities of four volatile compounds during storage at 2 degrees C were determined after storage for 7 days and after removal of the volatile and transfer to 22 degrees C for 3 days. Fruit harvested at the ripe stage were inoculated with 10(6) conidia B. cinerea per ml and were placed in plastic containers containing no volatile compound (control) or two quantities of (E)-2-hexenal (10 or 100 microliters), (E)-2-hexenal diethyl acetal (30 or 300 microliters), benzaldehyde (30 or 300 microliters), or methyl benzoate (12 or 60 microliters). The fruit containers were overwrapped with a low-density polyethylene film, sealed, stored at 2 degrees C for 7 days, and then transferred to 22 degrees C for 3 days. Aerobic, microaerophilic, and coliform populations of fruit exposed to volatile compounds tended to be lower than the controls after storage at 2 degrees C for 7 days and, depending on the volatile compound, similar, lower, or higher than the controls after transfer and storage at 22 degrees C. However, due to variability in initial aerobic, microaerophilic, and coliform populations of the fruit used in the different trials (P < 0.05), none of the differences between control and treatment and between treatments within a sample time were significant (P > 0.05). Strawberry fruit exposed to 100 microliters of (E)-2-hexenal was the only treatment that did not show a significant increase in mold populations after transfer and storage at 22 degrees C for 3 days. Additional studies are needed to determine if (E)-2-hexenal can be used in combination with other postharvest storage conditions, such as low temperature and controlled/modified atmosphere, to delay mold spoilage and extend the shelf life of the strawberry.


Asunto(s)
Bacterias/aislamiento & purificación , Botrytis/aislamiento & purificación , Manipulación de Alimentos , Frutas/microbiología , Hongos/aislamiento & purificación , Aldehídos/farmacología , Bacterias/efectos de los fármacos , Bacterias Aerobias/efectos de los fármacos , Bacterias Aerobias/aislamiento & purificación , Benzaldehídos/farmacología , Benzoatos/farmacología , Botrytis/efectos de los fármacos , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/aislamiento & purificación , Hongos/efectos de los fármacos , Temperatura
16.
Lett Appl Microbiol ; 21(5): 334-5, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7576528

RESUMEN

Staphylococcus aureus produces one or more enzymes with lipolytic activity, but differences between strains have been reported (Owens and John 1975; O'Toole 1987; Rollof et al. 1987). The biological and biochemical properties of these enzymes have been investigated and results were recently reviewed (Kötting et al. 1984). Baird-Parker medium (Baird-Parker 1962) is a selective medium commonly used for the isolation of Staph. aureus. The presence of egg yolk in this medium permits the detection of two reactions due to lipolytic activity of staphylococci: (1) Lecithinase reaction, a zone of precipitate in the medium surrounding the colonies; and (2) Lipase reaction or 'pearly layer', an iridescent film in and immediately surrounding colonies, visible by reflected light (iridescent sheen or 'oil in water'). In this study, human and bovine strains, previously biotyped according to the scheme of Devriese et al. (1984), were compared for production of a zone of precipitation, lecithinase reaction, on Baird-Parker medium. Bovine and human strains of Staph. aureus were compared for production of the egg yolk reaction (lecithinase reaction) on Baird-Parker medium and the results were related to their biotypes and site of origin of the sample. Human strains and strains biotyped as human biotypes had higher percentage of positive results than bovine isolates and/or biotypes. However, all strains isolated from body sites of heifers produced a positive reaction regardless of the biotype.


Asunto(s)
Fosfolipasas/metabolismo , Staphylococcus aureus/enzimología , Animales , Bovinos , Medios de Cultivo , Yema de Huevo , Humanos
17.
Appl Environ Microbiol ; 59(5): 1467-72, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8517740

RESUMEN

A total of 114 gram-negative fecal isolates from domestic pigs in herds with different histories of antimicrobial agent exposure were screened for the presence of plasmid DNA and specific tetracycline resistance determinants. More than 84% of the isolates harbored plasmid DNA, which ranged in size from 2.1 to 186 kb. A total of 78 isolates (68.4%) were resistant to tetracycline at concentrations greater than 4 micrograms/ml. Plasmid DNAs from about 56% of the tetracycline-resistant isolates hybridized with DNA probes for class A, B, C, and D tetracycline resistance determinants. The class B determinant was the most common determinant (35% of the isolates), followed by the class C determinant (12%) and the class A determinant (1%). About 9% of the isolates contained two determinants on plasmids. None of the plasmids from isolates hybridized with the class D determinant probe. The class C determinant was the most prevalent determinant on plasmids in isolates from pigs not exposed to antimicrobial agents for more than 146 months, while the class B determinant was more prevalent on plasmids in isolates from pigs exposed to either subtherapeutic or therapeutic levels of antimicrobial agents. Most tetracycline resistance determinants were localized on plasmids which were more than 30 kb long. A great number of wild-type tetracycline-resistant Escherichia coli strains were found with the class E determinant on their chromosomes. This study revealed a high prevalence of tetracycline resistance determinants in the fecal flora of pig herds whether or not they were fed with antibiotics.


Asunto(s)
Bacterias Gramnegativas/aislamiento & purificación , Porcinos/microbiología , Animales , Antibacterianos/administración & dosificación , Sondas de ADN , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/genética , Factores R , Salmonella enteritidis/genética , Salmonella enteritidis/aislamiento & purificación , Resistencia a la Tetraciclina/genética
18.
J Clin Microbiol ; 30(8): 2113-7, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1500519

RESUMEN

Research has shown that various percentages of fecal Escherichia coli isolates obtained from healthy subjects may be beta-glucuronidase negative. The ability to detect beta-glucuronidase activity among fecal E. coli isolates from healthy subjects may be affected by assay conditions. A study was conducted in which agar and broth media containing 4-methylumbelliferyl-beta-D-glucuronide (MUG) were used to examine beta-glucuronidase activities of fecal isolates from healthy swine. Rectal swabs were plated on MacConkey agar plus 100 mg of MUG per liter (MAC-MUG) and incubated at 35 degrees C for 24 h. Each of 986 isolates picked from MAC-MUG was inoculated into duplicate tubes of lauryl tryptose broth plus 50 mg of MUG per liter (LT-MUG). One set of tubes was incubated at 35 degrees C and the other set of tubes was incubated at 44.5 degrees C. Gas production and hydrolysis of MUG, indicated by fluorescence when observed with UV light with a wavelength of 360 nm, were determined after incubation for 24 and 48 h. A higher percentage (P less than 0.01) of isolates was MUG positive at 44.5 degrees C than at 35 degrees C after 24 h of incubation in LT-MUG. A higher percentage (P less than 0.01) of isolates was MUG positive after 48 h than after 24 h of incubation at both 35 and 44.5 degrees C. A lower percentage of isolates (P less than 0.05) was observed to be MUG positive on MAC-MUG agar compared with their MUG reactions in LT-MUG at 35 and 44.5 degrees C. Approximately 89% of the isolates identified were beta-glucuronidase-positive E. coli. The largest proportion of MUG-positive E. coli was detected with LT-MUG at 35 degrees C after 48 h of incubation.


Asunto(s)
Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , Heces/enzimología , Heces/microbiología , Glucuronidasa/análisis , Porcinos/microbiología , Animales , Técnicas Bacteriológicas , Escherichia coli/metabolismo , Estudios de Evaluación como Asunto , Femenino , Fermentación , Glucósidos/metabolismo , Himecromona/análogos & derivados , Himecromona/metabolismo , Lactosa/metabolismo , Masculino
19.
J Dairy Sci ; 75(7): 1835-9, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1500579

RESUMEN

During a 14-mo period, 77 multiparous and 36 primiparous cows were sampled to determine the prevalence of staphylococci during the periparturient period. Distal streak canal swabs were taken at 14 d prepartum, and foremilk was sampled the first 5 consecutive wk of lactation. Staphylococcus aureus was isolated from 7.6% of quarters of primiparous cows but from only .6% of quarters of multiparous cows at parturition. Prevalence in primiparous cows declined to 3.5% by the wk-1 sampling. Quarter prevalence of coagulase-negative Staphylococcus species prepartum, at parturition, and wk 1 to 5 in primiparous cows was 38.9, 27.8, 15.3, 14.6, 13.2, 15.3, and 14.6%, respectively. In multiparous cows, prevalence at these times was 50.3, 12.3, 6.2, 8.1, 10.7, 7.1, and 8.1%. Staphylococcus chromogenes was the predominant species isolated, accounting for over 50% of the staphylococci isolated at each sampling time. Results suggest that high prevalence of staphylococci isolated prepartum is a reflection of natural skin flora and that a higher postpartum prevalence of these organisms was observed in primiparous cows than in multiparous cows. These data suggest also that the peripartum heifer could be a source of Staphylococcus aureus in the lactating herd.


Asunto(s)
Portador Sano/microbiología , Mastitis Bovina/microbiología , Complicaciones Infecciosas del Embarazo/veterinaria , Infecciones Estafilocócicas/veterinaria , Staphylococcus/aislamiento & purificación , Animales , Portador Sano/epidemiología , Bovinos , Femenino , Trastornos de la Lactancia/epidemiología , Trastornos de la Lactancia/microbiología , Trastornos de la Lactancia/veterinaria , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/epidemiología , Paridad , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/microbiología , Prevalencia , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificación
20.
J Dairy Sci ; 74(6): 1855-9, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1894794

RESUMEN

Microbiological data from 1123 uninfected quarters and 216 quarters with preexisting coagulase-negative staphylococci infections were analyzed to determine the influence of infection status on subsequent new infection rate. Overall, prevalence of new infections in uninfected quarters was approximately two times that in quarters already harboring a coagulase-negative Staphylococcus infection. New infections by coagulase-negative staphylococci were greater in uninfected quarters than in quarters with preexisting coagulase-negative staphylococci infections. However, no differences were observed between uninfected and infected quarters in number of new infections by major pathogens (Staphylococcus aureus, streptococci, and coliforms). No differences were observed in uninfected or coagulase-negative Staphylococcus-infected quarters in infections with minor pathogens compared with major pathogens. The influence of individual coagulase-negative Staphylococcus species on new infections was also analyzed. However, numbers of existing infections by Staphylococcus species other than Staphylococcus chromogenes were limited. Therefore, the protective capacity of each coagulase-negative Staphylococcus species was difficult to assess. Overall, a significant restriction of bacterial invasion was observed in quarters with a preexisting infection. These results suggest that quarters harboring a coagulase-negative Staphylococcus infection suppress colonization of the mammary gland by mastitis-causing pathogens.


Asunto(s)
Glándulas Mamarias Animales/microbiología , Mastitis Bovina/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus/crecimiento & desarrollo , Animales , Bovinos , Coagulasa , Femenino , Infecciones Estafilocócicas/complicaciones , Infecciones Estafilocócicas/microbiología , Staphylococcus/enzimología , Staphylococcus/aislamiento & purificación , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/aislamiento & purificación
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