RESUMO
UNLABELLED: The movement of influenza A viruses (IAVs) from wild bird reservoirs to domestic animals and humans is well established, but the transmission mechanisms that facilitate efficient movement across and within these host populations are not fully defined. Although predominant routes of transmission vary between host populations, the extent of environmental stability needed for efficient IAV transmission also may vary. Because of this, we hypothesized that virus stability would differ in response to varied host-related transmission mechanisms; if correct, such phenotypic variation might represent a potential marker for the emergence of novel animal or human influenza viruses. Here, the objective was to evaluate the ability of eight swine and six human IAV isolates to remain infective under various pH, temperature, and salinity conditions using a preestablished distilled water system. Swine and human viruses persisted longest at near-neutral pH, at cold temperatures, or under "freshwater" conditions. Additionally, no significant differences in persistence were observed between pandemic and nonpandemic IAVs. Our results indicate that there have been no apparent changes in the environmental stability of the viruses related to host adaptation. IMPORTANCE: This study assessed the environmental stability of eight swine and six human influenza A viruses (IAVs), including viruses associated with the 2009 H1N1 pandemic, in a distilled water system. The important findings of this work are that IAV persistence can be affected by environmental variables and that no marked changes were noted between human and swine IAVs or between pandemic and nonpandemic IAVs.
Assuntos
Vírus da Influenza A/fisiologia , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Salinidade , Temperatura , Microbiologia da Água , Água/química , Animais , Humanos , Concentração de Íons de Hidrogênio , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/efeitos da radiação , SuínosRESUMO
Runting-stunting syndrome (RSS) in poultry has been known for more than 40 years, but the precise etiology remains unknown and a licensed vaccine is consequently not currently available. In order to mitigate the symptoms associated with RSS, a series of experiments was performed to investigate whether a combined bacteriotherapeutic treatment consisting of probiotics, prebiotics, and organic acids could influence the outcome of this disease. Initially two groups of commercial broiler chickens were either left uninoculated or inoculated with filtrate from homogenized intestines of RSS-affected broiler chickens. One group from each of these two challenge groups was treated, with a bacteriotherapeutic regimen. After 12 days chickens were euthanatized, the body weight was measured, and duodenal lesions were enumerated. Five consecutive broiler chicken flocks were then raised either on litter from RSS-affected birds or on fresh wood shavings. Treatment had no beneficial effect on the number and severity of intestinal lesions. There appeared to be a significant build-up of RSS agent(s) in poultry litter, with each consecutive flock placement, independent of bacteriotherapeutic treatment, as more individuals exhibited intestinal lesions on built-up litter in RSS-affected houses (28.9% vs. 44%). While treatment did not appear to consistently reduce intestinal lesions, it did significantly improve the mean body weights (P<0.05) and uniformity of 12-day-old chickens placed on reused litter in houses in which RSS-infected birds were previously raised. A combination of litter management and bacteriotherapy may be needed to ameliorate the adverse effects of RSS on intestinal health and body weight in broiler chickens.
Assuntos
Galinhas , Transtornos do Crescimento/veterinária , Doenças das Aves Domésticas/prevenção & controle , Prebióticos/microbiologia , Probióticos/uso terapêutico , Animais , Peso Corporal , Transtornos do Crescimento/prevenção & controleRESUMO
Preweaning respiratory disease continues to have a substantial effect on the current and future productivity of dairy replacement animals. Establishing an effective treatment plan for the preweaned calf may have a significant effect on well-being and lifetime productivity by limiting any early development of chronic disease. The primary objective of this study was to examine the efficacy of treatment with tulathromycin (TUL) or enrofloxacin (ENR) on the risk of re-treatment, with a secondary objective of investigating the effect of disease and subsequent treatment choice on average daily gain (ADG). A total of 1,141 Holstein heifers from 4 farms were observed and systematically scored for evidence of respiratory disease from birth through weaning or the time of death. At the time of diagnosis, calves were randomly and blindly allocated into 2 treatment groups. The overall incidence of respiratory disease was 60.9%. In the univariable analysis, the incidence of re-treatment between 7 and 10d of initial therapy for calves treated with ENR was greater than that in calves treated with TUL (27.6 vs. 21.2%). After adjusting for farm ID, clinical score at first treatment, and weight at first treatment, the odds of re-treatment were 1.5 times higher for calves treated with ENR than with TUL. The percentage of calves that required more than one re-treatment was higher for calves that received ENR compared with those that received TUL (9.3 vs. 4.1%). We observed no difference in ADG between calves treated with ENR or TUL, and no difference in ADG between calves that were treated for respiratory disease and those that were not treated for respiratory disease. Appropriate drug therapy for preweaning respiratory disease may have an important role in reducing the odds of re-treatment during the preweaning period.
Assuntos
Dissacarídeos/farmacologia , Fluoroquinolonas/farmacologia , Compostos Heterocíclicos/farmacologia , Doenças Respiratórias/tratamento farmacológico , Doenças Respiratórias/veterinária , Animais , Anti-Infecciosos/farmacologia , Técnicas de Tipagem Bacteriana , Peso Corporal , Bovinos , Enrofloxacina , Feminino , Modelos Lineares , Modelos Logísticos , Doenças Respiratórias/microbiologia , Resultado do Tratamento , DesmameRESUMO
Rhodococcus equi (R. equi), a pneumonia-causing intracellular bacterium, results in significant morbidity and mortality in young foals, while healthy adult horses rarely develop disease. Survival and replication within alveolar macrophages (AMφ) are the hallmarks of R. equi's pathogenicity. The vitamin D receptor (VDR) and its ligand, the active vitamin D metabolite 1,25(OH)2D, are important in immune responses to intracellular bacteria. The vitamin D/VDR pathway regulates the downstream production of cytokines in infected human AMφ. The immunomodulatory role of the vitamin D/VDR pathway in equine leukocytes is unknown. The objective of the current study was to determine the impact of R. equi infection and age on synthesis of 1,25(OH)2D, VDR expression, and cytokine production in an ex vivo model of R. equi infection in equine AMφ. AMφ were collected from ten healthy foals at 2-, 4- and 8-weeks old and from nine healthy adult horses once via bronchoalveolar lavage. AMφ were mock infected (CONTROL) or infected with a virulent laboratory strain of R. equi for 7 days (INFECTED). VDR expression was determined via RT-qPCR from cell lysates. 1,25(OH)2D and cytokines were measured in cell supernatant by immunoassays. VDR expression was impacted by age (P = 0.001) with higher expression in AMφ from 8-week-old foals than from 2-week-old foals and adults. There was no significant effect of infection in foal AMφ, but in adults, relative VDR expression was significantly lower in INFECTED AMφ compared to CONTROL AMφ (P = 0.002). There was no effect of age or infection on 1,25(OH)2D concentration (P > 0.37). Mean TNFα production was significantly higher from INFECTED compared to CONTROL AMφ from 4- and 8-week-old foals and adults (P < 0.005). Mean IFNγ production was significantly higher from AMφ from foals at 8-weeks-old compared to 2-weeks-old (P = 0.013) and higher from INFECTED AMφ than from CONTROL AMφ in foals at 4-weeks-old and in adults (P < 0.027). The proportion of samples producing IL-1ß and IL-10 was also significantly higher from INFECTED compared to CONTROL AMφ isolated from 4-week-old foals (P < 0.008). Similarly, in adult samples, IL-17 was produced from a greater proportion of INFECTED compared to CONTROL samples (P = 0.031). These data document age-associated changes in VDR expression and cytokine production in equine AMφ in response to R. equi infection. This preliminary investigation supports the need for further research to fully elucidate if the vitamin D pathway has an immunomodulatory role in the horse.
Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Rhodococcus equi , Animais , Infecções por Actinomycetales/veterinária , Citocinas/metabolismo , Cavalos , Macrófagos Alveolares/metabolismo , Receptores de Calcitriol , Vitamina DRESUMO
Domestic cats are susceptible to infection with highly pathogenic avian influenza virus H5N1, resulting in pneumonia and in some cases, systemic spread with lesions in multiple organ systems. Recent transmission of the 2009 pandemic H1N1 influenza virus from humans to cats also resulted in severe pneumonia in cats. Data regarding the susceptibility of cats to other influenza viruses is minimal, especially regarding susceptibility to low pathogenic avian influenza viruses from wild birds, the reservoir host. In this study, the authors infected 5-month-old cats using 2 different North American shorebird avian influenza viruses (H1N9 and H6N4 subtypes), 3 cats per virus, with the goal of expanding the understanding of avian influenza virus infections in this species. These viruses replicated in inoculated cats based on virus isolation from the pharynx in 2 cats, virus isolation from the lung of 1 cat, and antigen presence in the lung via immunohistochemistry in 2 cats. There was also seroconversion and lesions of patchy bronchointerstitial pneumonia in all of the cats. Infection in the cats did not result in clinical disease and led to variable pharyngeal viral shedding with only 1 of the viruses; virus was localized in the alveolar epithelium via immunohistochemistry. These findings demonstrate the capacity of wild bird influenza viruses to infect cats, and further investigation is warranted into the pathogenesis of these viruses in cats from both a veterinary medical and public health perspective.
Assuntos
Doenças do Gato/virologia , Vírus da Influenza A/patogenicidade , Influenza Aviária/transmissão , Infecções por Orthomyxoviridae/veterinária , Pneumonia Viral/veterinária , Animais , Animais Selvagens , Aves , Doenças do Gato/patologia , Gatos , Reservatórios de Doenças , Suscetibilidade a Doenças , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/patologia , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/transmissão , Pneumonia Viral/patologia , Saúde Pública , Eliminação de Partículas ViraisRESUMO
The vitamin D receptor (VDR)-vitamin D axis modulates pulmonary immunity in people but its role in equine immunity is unknown. Bacterial pneumonia causes high morbidity/mortality in foals and alveolar macrophages (AMφ) are important for pulmonary defenses. Age-related variations in vitamin D-mediated function of AMφ might contribute to the foal's susceptibility to pneumonia. Our aim was to assess the impact of age on equine vitamin D metabolism and VDR expression in AMφ. AMφ and plasma was collected from healthy foals (2, 4 and 8 weeks old) and adult horses (once). AMφ VDR expression was determined via RT-qPCR and plasma vitamin D metabolites quantified via immunoassays. Data were analyzed with linear mixed models. Inactive-vitamin D metabolite concentrations were lowest in foals at 2 weeks and lower at 2 and 4 weeks compared to adults (P < 0.001). Active-vitamin D metabolite concentrations were higher in foals than adults (P < 0.05). VDR expression was detected in AMφ in all animals and was highest in 2-week-old foals. Vitamin D metabolism and AMφ VDR expression are impacted by age in horses. This may have immunological consequences in foals given the key role that the VDR-vitamin D axis has in pulmonary immunity in other species.
Assuntos
Macrófagos Alveolares , Receptores de Calcitriol , Animais , Cavalos , Receptores de Calcitriol/genética , Vitamina D , PulmãoRESUMO
We studied the effect of different routes of inoculation on the infectivity and duration of viral shedding in mallards (Anas platyrhynchos) infected with wild bird-origin low pathogenic avian influenza viruses (LPAIVs). One-month-old mallards were inoculated with 10(6) median embryo infectious doses of either A/mallard/MN/199106/99 (H3N8) or A/mallard/MN/355779/00 (H5N2) via 1 of 5 different routes: intranasal (IN), intratracheal (IT), intraocular (IO), intracloacal (IC), or intra-ingluvial (II). Birds in all routes of inoculation groups became infected with LPAIV as detected by virus isolation, real time reverse transcription polymerase chain reaction, and serology. Mallards in different route of inoculation groups had similar viral shedding through oropharynx and cloaca from 1 day postinoculation (dpi). The peak of oropharyngeal (OP) viral shedding was reached between 2 and 3 dpi in all routes of inoculation groups infected with either virus. The peak of cloacal (CL) viral excretion was reached between 2 and 3 dpi in all routes of inoculation groups infected with H3N8 LPAIV and in the IO-, IC-, and II-inoculated groups infected with H5N2 LPAIV, with a delayed and shorter peak for the IN- and IT-inoculated groups. The birds inoculated via the II route had more productive OP and CL viral shedding after infection with either LPAIV, as evidenced by higher number of swabs testing positive over the study period. In conclusion, mallards can be infected with LPAIV by various routes of inoculation, and this corroborates their high susceptibility to infection by these viruses.
Assuntos
Patos , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Eliminação de Partículas Virais/fisiologia , AnimaisRESUMO
Dietary bacteriophages potentially can serve as a step to reduce Salmonella contamination of feed through direct lysis of the bacteria. However, poultry producers commonly vaccinate with live Salmonella vaccines, which could potentially be lysed by dietary bacteriophages. The objective of this study was to evaluate if dietary bacteriophages impacted the colonization of a live Salmonella vaccine. A total of 210 day-of-hatch Ross male broiler chicks were divided into 3 treatments consisting of 2 replicate per treatment. Each replicate contained 35 birds. T1 was the challenge control, given no Salmonella vaccine, T2 was challenged and given Salmonella vaccine and T3 was challenged, given Salmonella vaccine as well as dietary bacteriophage. Salmonella vaccine was administered day of hatch. On d 3, four birds/pen were sampled for Salmonella vaccine colonization of ceca and liver/spleen. The remaining birds were challenged with 5 × 107 CFU of nalidixic acid- resistant Salmonella enteritidis (S.E.). On d 28, ten birds/replicate were sampled via cloaca swabs to culture for S.E. On d 42, the trial was terminated, birds were weighed, and performance was calculated. In addition, 15 birds/replicate were sampled for cecal cultures of S.E. On d 3, T1 had 0% vaccine strain isolated, and significantly lower (P = 0.009) cecal prevalence compared with T2 (75%) and T3 (38%) being intermediate. T1 (0%) had significantly lower liver/spleen vaccine strain prevalence (P = 0.002) compared with T3 (88%) and T2 (63%) being intermediate. No significant differences (P > 0.05) were observed among treatments in Salmonella prevalence in d 28 cloacal swabs. No significant differences (P > 0.05) were observed in d 42 cecal Salmonella prevalence between all treatments. No significant differences in bird weight were observed between treatments d 0 to 42 (P > 0.05). However, T2 and T3 had lower mortality and adjusted feed conversion ratio (FCR; P < 0.05) compared with T1. Therefore, the dietary bacteriophage did not interfere with colonization or protection afforded by the live Salmonella vaccine.
Assuntos
Bacteriófagos , Doenças das Aves Domésticas , Salmonelose Animal , Vacinas contra Salmonella , Ração Animal/análise , Animais , Ceco/microbiologia , Galinhas , Masculino , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/epidemiologia , Salmonella enteritidis , Vacinas AtenuadasRESUMO
The objective was to compare clinical protection [evaluated through health scoring, endoscopy score of the upper respiratory tract (URT-ES), leukocyte count, viremia, and virus shedding in nasal secretions] following Bovine viral diarrhea virus 2 (BVDV2) and Bovine herpes virus 1 (BHV1) challenge among calves submitted to modified-live virus (MLV) booster vaccination (either intranasal or subcutaneous) concurrent with injectable trace minerals (ITM) or saline. Forty-eight dairy calves received an MLV intranasal (IN) vaccine containing BHV1, BRSV, and BPI3V and subcutaneous (SC) ITM (Se, Cu, Zn & Mn; ITM, n = 24) or saline (SAL, n = 24). Ten weeks later, calves received a second dose of ITM, or saline, according to previous groups and were randomly assigned to receive the same IN vaccine [ITM-IN (n = 12), SAL-IN (n = 12)] or a SC MLV vaccine containing BHV1, BRSV, BPI3V, BVDV1 & 2 [ITM-SC (n = 12), SAL-SC (n = 12)]. Additionally, 12 calves did not receive vaccine or treatment and served as a control group (UNVAC, n = 12). Forty-nine days after booster, calves were challenged with BVDV2; and seven days later with BHV1. Health scores indicated disease in UNVAC on days 6, 10 and 12 compared to the vaccinated groups. Unvaccinated calves had the highest URT-ES after BHV1 challenge. Calves that received SC booster had lower URT-ES after BHV1 challenge than UNVAC calves. Calves in ITM-IN had significantly lower URT-ES after BHV1 infection than SAL-IN and UNVAC calves. In conclusion, IN or SC MLV vaccination was similarly effective in protecting calves from BVDV2 + BHV1 challenges (reducing clinical and endoscopy scores, preventing leukopenia, and viremia), compared to unvaccinated calves. Endoscopic evaluation of the URT allowed visualization of the inflammation and damage at multiple depths in the URT caused by a serial BVDV2 + BHV1 challenge. Calves that received SC vaccination had significantly lower URT-ES after BHV1 challenge than the UNVAC calves. Administration of ITM concurrent with IN vaccination was associated with reduced URT inflammation after BVDV2 + BHV1 challenge.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Doenças dos Bovinos , Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina Tipo 2 , Herpesvirus Bovino 1 , Oligoelementos , Vacinas Virais , Animais , Bovinos , Oligoelementos/uso terapêutico , Viremia/veterinária , Anticorpos Antivirais , Vacinas Atenuadas/uso terapêutico , Vacinação/veterinária , Doenças dos Bovinos/prevenção & controle , Endoscopia/veterinária , Sistema Respiratório , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controleRESUMO
Necrotic enteritis (NE) is a common disease that causes great economic loss to the broiler industry due to mortality and reduced performance. Although Clostridium perfringens (CP) is a necessary component of this disease, coccidia species are a well-defined predisposing factor that exacerbates the condition. Different Eimeria species have been reported to influence NE to different degrees. In a pair of experiments, six different Eimeria species were evaluated in the presence and absence of C. perfringens. Male broiler chicks were housed in battery cages for the duration of both experiments. Feed conversion, body weight gain, and NE mortality were reported in both experiments. Experiment 1 challenged birds with E. maxima, E. acervulina, E. tenella, E. necatrix, and E. brunetti at day 13 and subsequently inoculated birds with CP on days 18, 19, and 20. In the second experiment, E. maxima, E. acervulina, E. tenella, and E. praecox were inoculated on day 15 and challenged with CP on days 17, 18, 19, 20, 21, and 22 of the experiment. In the first experiment, E. acervulina, E. brunetti, E. maxima, and E. necatrix with the addition of CP all stimulated necrotic enteritis mortality. In the second experiment, E. praecox had minimal impact on performance during the challenge (14-23 days) while E. maxima + CP decreased body weight gain and increased mortality compared to the CP alone control. Eimeria maxima had the highest mortality (21.9%) in this experiment followed by E. acervulina (6.3%). The remaining Eimeria with added CP in the second experiment did not induce NE mortality. While the challenge with CP alone did not induce mortality, feed conversion was increased compared to the unchallenged control group. When using isolated Eimeria species in these experiments, disturbances created by E. brunetti and E. maxima resulted in the most-severe challenges. These experiments highlight the NE risk of these species of Eimeria and give insight into how other species interact with the host in a controlled CP challenge model.
Artículo regularEfecto de diferentes especies de Eimeria con Clostridium perfringens sobre los parámetros de rendimiento y la inducción de enteritis necrótica clínica en pollos de engorde. La enteritis necrótica (NE) es una enfermedad común que causa grandes pérdidas económicas a la industria del pollo de engorde debido a la mortalidad y a la reducción del rendimiento. Aunque Clostridium perfringens (CP) es un componente necesario de esta enfermedad, las especies de coccidia son un factor predisponente bien definido que agrava la enfermedad. Se ha informado que diferentes especies de Eimeria influyen en la enteritis necrótica en diferentes grados. En un par de experimentos, se evaluaron seis especies diferentes de Eimeria en presencia y ausencia de C. perfringens. Pollos de engorde machos se alojaron en jaulas en batería durante la duración de ambos experimentos. En ambos experimentos se analizaron la conversión alimenticia, el aumento de peso corporal y la mortalidad por enteritis necrótica. En el Experimento 1 se desafió a las aves con E. maxima, E. acervulina, E. tenella, E. necatrix y E. brunetti en el día 13 y posteriormente se inoculó a las aves con C. perfringens en los días 18, 19 y 20. En el segundo experimento, E. maxima, E. acervulina, E. tenella y E. praecox se inocularon en el día 15 y se desafiaron con C. perfringens en los días 17, 18, 19, 20, 21 y 22 del experimento. En el primer experimento, E. acervulina, E. brunetti, E. maxima y E. necatrix junto con C. perfringens estimularon la mortalidad por enteritis necrótica. En el segundo experimento, E. praecox tuvo un impacto mínimo en el rendimiento durante el desafío (14 a 23 días) mientras que el tratamiento de E. maxima + C. perfringens disminuyó el aumento de peso corporal y aumentó la mortalidad en comparación con el control con solamente C. perfringens. Eimeria maxima tuvo la mayor mortalidad (21.9%) en este experimento seguida por E. acervulina (6.3%). El resto de las especies de Eimeria junto con C. perfringens en el segundo experimento no indujeron mortalidad por enteritis necrótica. Si bien el desafío con C. perfringens no solo no indujo mortalidad, sino que la conversión alimenticia aumentó en comparación con el grupo de control no desafiado. Cuando se utilizaron especies de Eimeria aisladas en estos experimentos, los problemas creados por E. brunetti y E. maxima resultaron en los desafíos más severos. Estos experimentos destacan el riesgo por enteritis necrótica con estas especies de Eimeria y dan una idea de cómo otras especies interactúan con el hospedador en un modelo de desafío con C. perfringens controlado.
Assuntos
Galinhas , Infecções por Clostridium/veterinária , Coccidiose/veterinária , Eimeria/fisiologia , Enterite/veterinária , Necrose/veterinária , Doenças das Aves Domésticas , Animais , Infecções por Clostridium/microbiologia , Clostridium perfringens/fisiologia , Coccidiose/parasitologia , Enterite/microbiologia , Enterite/parasitologia , Masculino , Necrose/microbiologia , Necrose/parasitologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/parasitologia , Distribuição Aleatória , Especificidade da EspécieRESUMO
The integrated commercial poultry system is a highly connected network in which routine activities keep farms within a geographic area in constant contact. Consequently, biosecurity practices designed to minimize the transmission of infectious diseases between and within farms are an important component of modern flock health programs. A survey of Georgia poultry growers was conducted in order to assess the level of adoption of standard biosecurity measures by farm personnel and visitors. The results showed that compliance with recommended biosecurity practices did not significantly vary by company, farm size, or number of farms owned by the same grower. However, biosecurity was higher in the northern part of the state, where the density of farms is higher, and where there was an ongoing outbreak of infectious laryngotracheitis at the time of the study. The survey found that growers place more emphasis on biosecurity measures targeting farm visitors than those targeting farm personnel. Most growers reported that all visitors to the farm were required to wear shoe covers, although visitors were not typically required to park outside the farm entrance or to wash tires on their vehicles. No visitor type was reportedly excluded from poultry houses during grow out on all farms. The results highlight the need to evaluate the comparative efficacy of specific biosecurity measures in order to set priorities and attain feasible rates of implementation of targeted biosecurity practices.
Assuntos
Criação de Animais Domésticos , Abrigo para Animais , Doenças das Aves Domésticas/prevenção & controle , Roupa de Proteção/veterinária , Agricultura , Animais , Galinhas , Coleta de Dados , Georgia , Aves Domésticas , Eliminação de Resíduos , Inquéritos e QuestionáriosRESUMO
The objective of this study was to determine the effect of an injection of 10% butaphosphan and cyanocobalamin (Catosal, Bayer, Shawnee Mission, KS) on the day of calving and 1 d later on the prevalence of subclinical ketosis in dairy cattle in the early postpartum period. Cows from 4 herds (n=1,122) were randomized to receive either 25mL of 10% butaphosphan and cyanocobalamin or 25mL of sterile water subcutaneously on both days. Each milliliter of Catosal contained 0.05mg of cyanocobalamin and 100mg of butaphosphan, which provided 17.3mg of P in the form of [1-(butylamino)-1-methylethyl]-phosphonic acid. Serum was sampled for beta-hydroxybutyrate (BHBA) concentration at calving (pretreatment) and again between 3 and 10 d in milk. A subset of samples from mature cows was also evaluated for serum Ca and P concentrations. When cows from all age groups were included in the analysis, there was no difference between the median serum BHBA concentrations of cows in the 2 treatment groups, and no difference in the proportion of hyperketonemic cows (serum BHBA >or=1,200micromol/L) during the first week postpartum. When the analysis was restricted to mature cows (lactation >or=3), both the median BHBA concentration and the proportion of hyperketonemic cows were significantly lower in the treatment group than in the placebo group. Serum Ca and P concentrations did not differ between treatment groups. Our results suggest that injection of butaphosphan and cyanocobalamin on the day of calving and 1 d later may decrease the prevalence of subclinical ketosis during the week after calving in mature dairy cows, but not in first- and second-lactation animals.
Assuntos
Ácido 3-Hidroxibutírico/sangue , Cálcio/sangue , Doenças dos Bovinos/prevenção & controle , Cetose/veterinária , Compostos Organofosforados/administração & dosagem , Fósforo/sangue , Período Pós-Parto , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Indústria de Laticínios , Feminino , Cetose/epidemiologia , Cetose/prevenção & controle , Modelos Logísticos , Organofosfonatos , Gravidez , Prevalência , Distribuição AleatóriaRESUMO
Bovine respiratory disease (BRD) is the most common cause of morbidity and mortality in North American beef cattle. Mannheimia haemolytica is the bacterial pathogen most often isolated from cattle with BRD, and the prevalence of antimicrobial resistance (AMR) in this organism has increased in recent years. Antimicrobials are commonly used to prevent BRD in cattle at high risk of developing BRD; however, recent work would suggest that this practice might be one factor contributing to the increased prevalence of AMR in M. haemolytica. We hypothesized that the administration of the short-acting fluoroquinolone, enrofloxacin, would be just as effective as the long-acting triamilide, tulathromycin, in preventing BRD but would be less likely to select for AMR M. haemolytica in stocker calves at high risk of developing BRD. Three hundred forty-one stocker calves were enrolled in the study with 172 calves in 4 pens being randomly assigned to treatment with enrofloxacin and 169 calves in 4 pens randomly assigned to treatment with tulathromycin. Calves within each treatment group were allocated to one of 4 replicate pens based on the week of enrollment. Of calves receiving enrofloxacin, 33.7% required treatment for BRD at least once within 45 d after arrival, compared with 18.3% of calves receiving tulathromycin (P = 0.040). The percentages of calves that required more than one treatment for BRD within 45 d after arrival did not differ statistically for those receiving enrofloxacin compared with those receiving tulathromycin (10.5% and 4.7%, respectively; P = 0.107) Likewise, the percentages of calves that died during the 45-d follow-up period did not differ for those receiving enrofloxacin compared with those receiving tulathromycin (12.2% and 10.1%, respectively; P = 0.592). Mannheimia haemolytica was cultured from 11% of calves sampled at arrival and from 50% of calves sampled at revaccination 14 to 17 d later. There was a significanst effect of sampling time on the proportion of calves carrying multidrug-resistant (MDR) isolates, with calves having a higher prevalence of MDR isolates at revaccination than arrival (100% vs. 13%; P < 0.001). Future research evaluating the impact of MDR on response to antimicrobial therapy is necessary.
Assuntos
Antibacterianos/farmacologia , Complexo Respiratório Bovino/microbiologia , Dissacarídeos/farmacologia , Farmacorresistência Bacteriana , Fluoroquinolonas/farmacologia , Compostos Heterocíclicos/farmacologia , Mannheimia haemolytica/efeitos dos fármacos , Animais , Complexo Respiratório Bovino/epidemiologia , Complexo Respiratório Bovino/prevenção & controle , Bovinos , Método Duplo-Cego , Enrofloxacina , Georgia/epidemiologia , Incidência , Masculino , Prevalência , Distribuição AleatóriaRESUMO
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in North American beef cattle. () is the bacterial pathogen most frequently isolated from cattle with BRD and the prevalence of antimicrobial resistance in this pathogen has been increasing. Administration of antimicrobials to prevent BRD is commonplace in stocker cattle, but the impact of this practice on emergence of resistance in is unknown. High risk, sale barn origin bull and steer calves ( = 169) were transported to a stocker facility in central Georgia and sampled via deep nasopharyngeal swab (NPS) at arrival processing. All calves received the macrolide antimicrobial tulathromycin (2.5 mg/kg subcutaneously) at arrival processing. A second NPS was collected from each calf 10 to 14 d after arrival. The occasional calves diagnosed and treated for BRD prior to 10 to 14 d were swabbed and cultured prior to treatment. Swabs were submitted for culture and antimicrobial susceptibility testing using the Kirby-Bauer disk diffusion method. Of the 169 cattle enrolled, 27 (16.0%) were culture positive for at arrival processing and of these, a multi-drug resistant (MDR) strain of was detected in 1 (3.7%). In contrast, 123 (72.8%) cattle were culture positive for at second sampling and of these, a MDR strain of was detected in 122 (99.2%). The proportions of cattle culture positive for and positive for MDR at arrival processing and at second sampling were significantly different ( < 0.001). At the level of the individual bacterial isolate, 366 individual isolates were collected from the calves at the time of the second sampling. Of these isolates, 361 (98.6%) were intermediate or resistant to all macrolides tested (tilmicosin, gamithromycin, tulathromycin) and the fluoroquinolone enrofloxacin. In addition, 254 isolates (69.4%) were intermediate or resistant to florfenicol and 4 (1.1%) were intermediate or resistant to ceftiofur. There was a significant difference in the proportion of isolates resistant to all of the drug classes except cephalosporins at arrival processing versus second sampling ( < 0.001). Our results show that there was an increase in the proportion of calves positive for from arrival processing to second sampling, and that there was an increase in the proportion of calves that had MDR strains of detected from arrival processing to second sampling. More research is needed to understand the role of metaphylaxis on MDR in and the impact of MDR on morbidity and mortality in stocker cattle.
Assuntos
Antibacterianos/farmacologia , Doenças dos Bovinos/microbiologia , Farmacorresistência Bacteriana Múltipla , Mannheimia haemolytica/efeitos dos fármacos , Infecções por Pasteurellaceae/veterinária , Animais , Bovinos , Masculino , Infecções por Pasteurellaceae/microbiologiaRESUMO
BACKGROUND: Four sampling techniques commonly are used for antemortem identification of pathogens from cattle with bovine respiratory disease (BRD): the nasal swab (NS), guarded nasopharyngeal swab (NPS), bronchoalveolar lavage (BAL), and transtracheal wash (TTW). Agreement among these methods has not been well characterized. OBJECTIVE: To evaluate agreement among TTW and NS, NPS, or BAL for identification of viral and bacterial pathogens in dairy calves with BRD. ANIMALS: One hundred dairy calves with naturally acquired BRD. METHODS: Calves were sampled by all 4 methods. Viral agents were identified by real-time RT-PCR, bacteria were identified by aerobic culture, and Mycoplasma bovis (M. bovis) isolates were speciated by PCR. Agreement among TTW and NS, NPS, or BAL was evaluated by calculating the kappa statistic and percent positive agreement. McNemar's exact test was used to compare the proportions of positive results. RESULTS: Agreement among TTW and NS, TTW and NPS, and TTW and BAL, was very good for identification of P. multocida, M. haemolytica, and M. bovis. For bovine respiratory syncytial virus (BRSV), agreement with TTW was moderate for NS, good for NPS, and very good for BAL. For bovine coronavirus (BCV), agreement with TTW was moderate for NS and NPS, and good for BAL. McNemar's test was significant only for BCV, indicating that for this pathogen the proportion of positive results from NS and NPS could not be considered comparable to TTW. CONCLUSIONS AND CLINICAL IMPORTANCE: This study provides guidance for veterinarians selecting diagnostic tests for antemortem identification of pathogens associated with BRD.
Assuntos
Doenças dos Bovinos/diagnóstico , Infecções Respiratórias/veterinária , Doença Aguda , Animais , Lavagem Broncoalveolar/veterinária , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/virologia , Coronavirus , Feminino , Mycoplasma bovis , Mucosa Nasal/microbiologia , Nasofaringe/microbiologia , Vírus Sincicial Respiratório Bovino , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Traqueia/microbiologiaRESUMO
Environmental samples collected from each of 3 locations on 23 large California dairies were cultured to evaluate the utility of this approach for identifying herds infected with Mycobacterium avium ssp. paratuberculosis. Results were compared with concurrent ELISA testing of > or = 60 animals in each herd, and with previously performed individual and pooled fecal cultures of 60 animals. The estimated proportions of infected herds did not differ significantly among the testing methods (environmental sampling, 74%; previous fecal culture, 70%; and concurrent ELISA testing, 65%). Measures of agreement between environmental sampling and the results of previous fecal cultures were 70% (observed agreement), 85% (positive agreement), 62% (negative agreement), and 0.47 (kappa), whereas agreement between environmental sampling and concurrent ELISA testing was 65, 75, and 43%, and 0.19, for the same measures, respectively. The proportion of positive environmental samples on each farm was significantly correlated with the proportion of seropositive animals (r = 0.53), suggesting that environmental sampling may also provide a qualitative estimate of within-herd prevalence. Of the sampling locations that were evaluated, samples of lagoon water (15/23; 65%) were significantly more likely to yield a positive result than were composite manure samples (8/22; 36%) collected from the sick/fresh cow pen or from the alleyway (9/23; 39%) where cows exited from the milking parlor. Environmental sampling was an effective and inexpensive method of identifying herds infected with Mycobacterium avium ssp. paratuberculosis.
Assuntos
Bovinos/microbiologia , Indústria de Laticínios , Microbiologia Ambiental , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Animais , Anticorpos Antibacterianos/sangue , California , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Abrigo para Animais , Mycobacterium avium subsp. paratuberculosis/genética , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/microbiologia , Paratuberculose/prevenção & controle , Reação em Cadeia da Polimerase , Densidade Demográfica , Microbiologia da ÁguaRESUMO
Allergic asthma, a Th2 cell driven response to inhaled allergens, has classically been thought of as predominantly mediated by IgE antibodies. To investigate the role of other immunoglobulin classes (e.g., IgG and IgA) in the immunopathogenesis of allergic asthma, levels of these allergen-specific immunoglobulins were measured in serum and mucosal fluids. Bermuda grass allergen (BGA)-specific IgG and IgA ELISAs in serum and bronchoalveolar lavage fluid (BALF) were developed and optimized in an experimental model of BGA-induced feline asthma. Levels of BGA-specific IgG and IgA significantly increased over time in serum and BALF after allergen sensitization. Additionally, these elevated levels of BGA-specific IgG and IgA were seen in conjunction with the development of an asthmatic phenotype indicated by positive intradermal skin tests, enhanced airways hyperreactivity, and increased eosinophil percentages in the BALF.
Assuntos
Alérgenos/imunologia , Asma/veterinária , Doenças do Gato/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Animais , Asma/imunologia , Hiper-Reatividade Brônquica , Testes de Provocação Brônquica/veterinária , Líquido da Lavagem Broncoalveolar/imunologia , Gatos , Cynodon/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Cloreto de Metacolina/imunologia , Testes de Função Respiratória/veterináriaRESUMO
Serum samples from six cats with experimentally induced asthma were used to purify feline IgE using gel filtration and affinity chromatography. The resultant IgE, evaluated for purity by immunoelectrophoresis (IEP) and reactivity by Prausnitz-Kustner (PK) testing, was used to develop polyclonal rabbit anti-feline IgE antisera. Using reverse cutaneous anaphylaxis (RCA), the antisera were determined to be specific for feline IgE. The polyclonal rabbit anti-feline IgE antiserum was then validated in an allergen-specific ELISA. Serum samples from an additional five asthmatic cats sensitized with Bermuda grass allergen (BGA) were evaluated prior to sensitization, after parenteral sensitization, and after aerosol sensitization and challenge. A significant increase in serum BGA-specific IgE was noted over time.
Assuntos
Asma/veterinária , Doenças do Gato/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Imunoglobulina E/imunologia , Alérgenos/imunologia , Animais , Anticorpos Anti-Idiotípicos/biossíntese , Asma/sangue , Asma/imunologia , Gatos , Cromatografia em Gel/veterinária , Cynodon/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Soros Imunes/imunologia , Imunoeletroforese/veterinária , Imunoglobulina E/sangue , Imunoglobulina E/isolamento & purificaçãoRESUMO
OBJECTIVE: To identify risk factors associated with dysautonomia in dogs. DESIGN: Case-control study. ANIMALS: 42 dogs with dysautonomia examined between October 1988 and January 2000 and 132 control dogs examined during the same period for an unrelated problem. PROCEDURE: Information was gathered from medical records and surveys mailed to owners of case and control dogs. RESULTS: 42 case and 132 control dogs were included; completed surveys were returned by owners of 30 case and 103 control dogs. Dogs with dysautonomia were significantly younger (median, 18 months) than control dogs (median, 60 months) and more likely to come from rural areas and to spend > or =50% of their time outdoors. Compared with rural control dogs that spent at least some time outdoors, affected dogs were more likely to have access to pasture land, farm ponds, and cattle, and to have consumed wildlife, at least occasionally. The largest numbers of dogs with dysautonomia were identified during February and April, with relatively few dogs identified during the summer and early fall. CONCLUSION AND CLINICAL RELEVANCE: Although the cause of dysautonomia is unknown, results suggest that dogs with dysautonomia were significantly more likely to live in rural areas and spend > or =50% of their time outdoors than were control dogs examined for unrelated diseases.
Assuntos
Doenças do Sistema Nervoso Autônomo/veterinária , Doenças do Cão/etiologia , Fatores Etários , Animais , Doenças do Sistema Nervoso Autônomo/etiologia , Estudos de Casos e Controles , Coleta de Dados , Cães , Feminino , Masculino , Fatores de Risco , População Rural , Estações do AnoRESUMO
REASONS FOR PERFORMING STUDY: Incisional complications following exploratory celiotomy increase morbidity, extend hospitalisation and increase cost. Retrospective studies seek to identify risk factors and measures for prevention of surgical site infection. The relatively high incidence of incisional complications following exploratory laparotomy necessitates identification of ideal surgical closure methods. OBJECTIVES: The study sought to identify the incidence of incisional drainage within our hospital population, and to identify risk factors for incisional complications while determining surgical practices that reduce the incidence of incisional drainage. STUDY DESIGN: Retrospective cohort study. METHODS: A retrospective study, with telephone follow-up, was performed on 199 horses that underwent exploratory laparotomy at the University of Georgia from 2 January 2008 to 31 December 2010, examining associations between case background, lesion type, access to the lumen of the bowel, and closure methods and incisional draining. The linea alba incisions were closed by the primary surgeon and junior house officers closed the subcutaneous tissues and skin. RESULTS: The incidence of purulent or persistent serosanguinous incisional drainage in 142 horses with complete follow-up information was 21.8%. Background, lesion type, and enterotomy or enterectomy were not associated with a significantly increased likelihood of incisional drainage. However, closure of the subcutaneous tissues and skin in a 2-layer, modified subcuticular pattern was associated with a significantly lower incidence of post operative incisional drainage. Follow-up information identified subsequent episodes of colic in 28.9% of horses. However, 80.3% of horses had returned to their previous level of work. CONCLUSIONS AND POTENTIAL RELEVANCE: Incisional drainage is common following ventral midline laparotomy. The use of a 2-layer, modified subcuticular closure was associated with a significant reduction in the incidence of incisional drainage compared with closure performed with skin sutures, but not closure performed with staples.