RESUMO
Influenza D virus has been detected predominantly in cattle from several countries. In the United States, regional and state seropositive rates for influenza D have previously been reported, but little information exists to evaluate national seroprevalence. We performed a serosurveillance study with 1,992 bovine serum samples collected across the country in 2014 and 2015. We found a high overall seropositive rate of 77.5% nationally; regional rates varied from 47.7% to 84.6%. Samples from the Upper Midwest and Mountain West regions showed the highest seropositive rates. In addition, seropositive samples were found in 41 of the 42 states from which cattle originated, demonstrating that influenza D virus circulated widely in cattle during this period. The distribution of influenza D virus in cattle from the United States highlights the need for greater understanding about pathogenesis, epidemiology, and the implications for animal health.
Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Infecções por Orthomyxoviridae/veterinária , Thogotovirus , Animais , Bovinos , Doenças dos Bovinos/história , Feminino , Genes Virais , História do Século XXI , Masculino , Filogenia , Estudos Soroepidemiológicos , Thogotovirus/classificação , Thogotovirus/genética , Thogotovirus/imunologia , Estados Unidos/epidemiologiaRESUMO
The objective of this study was to determine the prevalence and characteristics of Salmonella spp. isolated from feces of cattle in feedlots in the United States. Fecal samples were collected from up to three pens of cattle in each of 68 feedlots in 12 states. Samples included up to 25 individual fecal pats from the pen floors and up to five composite samples from the floors of the same pens. The prevalence of Salmonella-positive samples was 9.1% (460/5050) and 11.3% (114/1009) for individual and composite samples, respectively. The prevalences of Salmonella at the pen level were 35.6% (72/202) and 22.8% (46/202) for individual and composite samples, respectively. Dietary factors, including inclusion of cottonseed hulls, coccidiostats, and antimicrobial drugs, were associated with differences in prevalence of Salmonella isolation. Overall, 32 serotypes of Salmonella were identified, but six serotypes accounted for 69.1% (495/716) of the isolates. Nearly two-thirds (64.7%, 44/68) of feedlots had at least one positive sample. All isolates were evaluated for susceptibility to a panel of 15 antimicrobial drugs. Most isolates (74.4%, 533/716) were susceptible to all antimicrobial drugs in the panel. When resistance was detected, it was most commonly to tetracycline (21.7%, 155/716 of isolates) or sulfisoxazole (12.4%, 89/716 of isolates). Less than 10% of the isolates were resistant to any other antimicrobials in the panel. The results of this study indicate that the prevalence of Salmonella in individual fecal samples was less than 10%, but that Salmonella is widely distributed among feedlot cattle. Furthermore, when Salmonella is present in feedlot cattle, there is a low occurrence of antimicrobial resistance with the exception of tetracycline and sulfisoxazole. More research is indicated to understand the ecology of Salmonella and antimicrobial resistance, when present, in cattle-feeding operations.
Assuntos
Antibacterianos/farmacologia , Doenças dos Bovinos/epidemiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Salmonelose Animal/epidemiologia , Salmonella/isolamento & purificação , Animais , Antibacterianos/classificação , Bovinos , Doenças dos Bovinos/microbiologia , Fezes/microbiologia , Modelos Logísticos , Testes de Sensibilidade Microbiana/veterinária , Fenótipo , Prevalência , Salmonella/classificação , Sorotipagem , Estados Unidos/epidemiologiaRESUMO
Salmonella is a major cause of foodborne illness and can cause clinical disease in animals. Understanding the on-farm ecology of Salmonella will be helpful in decreasing the risk of foodborne transmission. An objective of this study was to determine the prevalence of Salmonella among fecal samples collected on sheep operations in the United States. Another objective was to compare the use of composite fecal samples with fecal samples collected from individual sheep as a tool for screening sheep flocks for Salmonella. Sheep fecal samples (individual and composite) were collected on operations in 22 states. Salmonella isolates were characterized with regard to species, serotype, and antimicrobial susceptibility profile. Most operations (72.1%) had at least one positive sample and overall 26.9% of samples were positive. The percentage of positive samples varied by animal age class. Composite and individual samples gave similar results. The majority of the isolates (94%) were Salmonella enterica subspecies diarizonae serotype 61:-:1,5,7. Nearly all of the isolates (91.2%) tested for antimicrobial susceptibility were susceptible to all antimicrobials in the panel. The findings suggest that salmonellae typically associated with foodborne disease transmission are infrequently found on sheep operations in the United States.
Assuntos
Fezes/microbiologia , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Ovinos/microbiologia , Animais , Feminino , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana/veterinária , Gravidez , Salmonella/classificação , Intoxicação Alimentar por Salmonella/epidemiologia , Intoxicação Alimentar por Salmonella/transmissão , Salmonelose Animal/epidemiologia , Sorotipagem , Estados Unidos/epidemiologiaRESUMO
While efforts to control foodborne illness associated with the Shiga toxin-producing Escherichia coli (E. coli) O157 through processes and procedures implemented at harvest facilities have been very successful, there is concern about the burden of illness associated with other Shiga toxin-producing E. coli. The U.S. Department of Agriculture Food Safety and Inspection Service announced plans to classify an additional six non-O157 Shiga toxin-producing E. coli as adulterants. Little is known about the prevalence and distribution of these E. coli in the animal production environment. An investigation of the prevalence of O157 and the six major non-O157 E. coli serogroups was conducted in 21 feedlots over the period July 2011 to October 2011. Individual fecal swabs were collected from cattle approximately 60 days after their arrival in the feedlot and were pooled for evaluation using a polymerase chain reaction assay to identify the presence of seven E. coli O-types (O157, O45, O103, O121, O145, O26, and O111) and four virulence genes (stx1, stx2, eaeA, and ehxA). Overall, 1145 fecal pools were evaluated, with 506 (44.2%) being positive for one or more of the E. coli O-serogroups. The pool prevalences for E. coli O157, O45, O26, O103, O121, O145, and O111 were 19.7%, 13.8%, 9.9%, 9.3%, 5.5%, 1.1%, and 0.5%, respectively. Nearly all pools were positive for ehxA (99.7%) or stx2 (98.6%). The pool level prevalence for stx1 and eae was 65.5% and 69.3%, respectively. Pools that were positive for one or more of the other E. coli O-serogroups were 1.37 times more likely to be positive for E. coli O157. Conversely, pools that were positive for E. coli O157 were 1.43 times more likely to be positive for at least one of the other E. coli O-serogroups evaluated. These data will be useful to understand the expected prevalence of potential Shiga toxin-producing E. coli in cattle feedlots.
Assuntos
Bovinos/microbiologia , Escherichia coli O157/genética , Fezes/microbiologia , Toxina Shiga/genética , Escherichia coli Shiga Toxigênica/genética , Animais , DNA Bacteriano/genética , Escherichia coli O157/classificação , Escherichia coli O157/isolamento & purificação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Reação em Cadeia da Polimerase , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
Salmonella enterica is the leading cause of foodborne-related deaths and hospitalizations within the United States. Infections caused by antimicrobial-resistant (AMR) strains are associated with higher hospital costs and case fatality. The objective for this study was to determine the association of management practices with the recovery of Salmonella and AMR Salmonella on dairy herds. Individual adult cow fecal samples and/or composite fecal samples were collected from 265 dairy herds in 17 states. Samples were cultured for Salmonella, and the MIC was determined for 15 antimicrobials. Herds were classified as Salmonella positive if at least one isolate was recovered, and AMR Salmonella positive if at least one resistant isolate was recovered. Questionnaires regarding management practices were administered to herd operators, and a subset of practices was selected based on subject knowledge and prior research. Data on preventive and therapeutic antimicrobial usage were included in the analysis. Logistic regression models were used to determine which practices were significantly (p<0.05) associated with each herd classification. A total of 124 and 25 herds were classified as Salmonella positive and AMR Salmonella positive, respectively. Variables significantly associated with Salmonella-positive herds included using sprinklers or misters for heat abatement (OR=2.8; CI: 1.6-4.9), feeding anionic salts to cows (OR=1.9; CI: 1.1-3.5), and feeding ionophores to cows (OR=2.1; CI: 1.2-3.7). Herds that used a broadcast/solid spread had lower odds (OR=0.26; CI: 0.11-0.63) of being Salmonella positive. Herds with at least one resistant isolate were more likely to have used composted/dried manure for bedding relative to herds with only susceptible isolates (OR=3.6; CI: 1.2-11.0). These results can be useful to focus additional research aimed at decreasing the prevalence of Salmonella and AMR Salmonella on U.S. dairy herds.
Assuntos
Antibacterianos/farmacologia , Derrame de Bactérias , Bovinos/microbiologia , Indústria de Laticínios/métodos , Farmacorresistência Bacteriana , Salmonella/efeitos dos fármacos , Animais , Antibacterianos/uso terapêutico , Estudos Transversais , Farmacorresistência Bacteriana Múltipla , Fezes/microbiologia , Feminino , Fertilizantes/microbiologia , Modelos Logísticos , Testes de Sensibilidade Microbiana , Vigilância da População , Salmonella/crescimento & desenvolvimento , Salmonella/isolamento & purificação , Intoxicação Alimentar por Salmonella/prevenção & controle , Salmonelose Animal/tratamento farmacológico , Salmonelose Animal/prevenção & controle , Microbiologia do Solo , Inquéritos e Questionários , Estados UnidosRESUMO
OBJECTIVES: The primary objective was to evaluate differences in antimicrobial resistance among enteric bacteria recovered from feedlot cattle that were being raised without exposure to antimicrobial drugs (AMDs) and those reared using conventional practices. MATERIALS: Forty pens of feedlot cattle (4557 total animals) that were being fed without AMD exposures were selected for enrollment as were 44 pens of cattle (4913 total animals) being fed for production of conventional beef products at the same feedlots. Fecal samples were collected from the floors of pens approximately biweekly through the middle of the feeding period and again prior to slaughter. Samples were cultured to recover nontype-specific Escherichia coli (NTSEC) and Salmonella enterica, and isolates were evaluated for susceptibility to a panel of AMDs. RESULTS: Cattle enrolled in the study did not differ between groups in entry weight or finish weight, but cattle with restricted AMD and hormone exposures were fed for an average of 50 days longer than conventionally reared cattle (p < 0.001). Resistance among NTSEC isolates was most common to tetracycline, streptomycin, and sulfamethoxazole, and there were slightly higher prevalence of resistance among NTSEC isolates recovered from conventionally reared cattle. Therapeutic AMD exposures did not have a detectable impact on the prevalence of resistance among NTSEC. Although there were detectable temporal trends through the feeding period for resistance to tetracycline, naladixic acid, chloramphenicol, and cephalothin, the direction of trends differed among drugs and these trends were not associated with study groups. S. enterica was recovered rarely (0.73%) but at similar prevalences from cattle with both rearing methods. CONCLUSIONS: These findings suggest that conventional feedlot production methods (including parenteral and in-feed use of AMDs) do not predictably or uniformly increase the prevalence of antimicrobial resistance among fecal NTSEC when compared with rearing methods that restrict exposure to AMDs.
Assuntos
Criação de Animais Domésticos/métodos , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fezes/microbiologia , Ração Animal , Animais , Antibacterianos/administração & dosagem , Bovinos , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Estudos Longitudinais , Testes de Sensibilidade Microbiana , Estudos Prospectivos , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificaçãoRESUMO
Contamination can occur at a number of stages during farm-to-fork processing. Preharvest intervention is an ongoing area of interest in reduction of risk of foodborne illness. This study examined risk factors associated with detection of Salmonella from cattle in U.S. feedlots. During two visits to 73 feedlots, 25 fresh fecal samples were collected from each of three pen floors. Associations between management and demographic factors and culture status were evaluated using logistic regression. Factors positively associated with culture-positive status included brewers' grains (odds ratio [OR] = 26.35; confidence interval [CI], 10.33-67.20), corn gluten (OR = 10.35; CI, 5.98-17.91), or cottonseed hulls (OR = 8.34; CI, 3.58-19.42) in the ration, and sourcing animals in a pen from multiple herds of origin (OR = 5.17; CI, 2.32-11.51). Factors negatively associated with positive culture status included urea (OR = 0.27; CI, 0.16-0.44), alfalfa, clover, or sorghum silage (OR = 0.31; CI, 0.12-0.79), and antimicrobials of the tetracycline class in the ration (within 2 weeks before sampling, OR = 0.04 and CI, 0.02-0.09; more than 2 weeks before sampling, OR = 0.23 and CI, 0.06-0.80). Since 18.3% of positive samples were on a single operation, a second model was constructed after excluding data from this operation. Three additional variables were retained in the second model, including grain-processing method (OR for dry roll, cracked, or unprocessed grain = 2.99; CI, 1.55-5.75), soybean meal (OR = 2.74; CI, 1.58-4.75), and use of a coccidiostat in the ration (OR for no coccidiostat = 4.50; CI, 2.03-10.01). Considering the increasing use of by-products of the biofuel industry as feeds, further investigation of the association between feeding brewers' grains and corn gluten and Salmonella recovery is warranted.
Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Derrame de Bactérias , Bovinos/microbiologia , Salmonella/isolamento & purificação , Agricultura , Ração Animal/análise , Ração Animal/economia , Animais , Antibacterianos/administração & dosagem , Biocombustíveis , Coccidiostáticos/administração & dosagem , Fezes/microbiologia , Abrigo para Animais , Resíduos Industriais/análise , Resíduos Industriais/economia , Modelos Logísticos , Fatores de Risco , Salmonella/classificação , Intoxicação Alimentar por Salmonella/prevenção & controle , Sorotipagem , Tetraciclinas/administração & dosagem , Estados UnidosRESUMO
There is a growing demand for information about the health and well-being of animals on farms. Such information has many uses. In some instances such information is used locally by livestock owners and producers to gauge their position relative to their peers. In other instances the information can be used at a national or international level by policy makers and trade negotiators. Animal health companies use such information to target research and product development. Academicians and other educators use information on animal health to teach future members of the agricultural industries. In addition, consumers are asking more questions about the manner in which animals are raised and cared for on farms. With so many stakeholders with an interest in such information there is a need for objective data collected with credible methods covering a substantial proportion of the population of interest. Such efforts are unlikely to be accomplished by entities other than a nationally focused unit in the government. The United States Department of Agriculture's National Animal Health Monitoring System (NAHMS) has been providing management and health-related data on the United States livestock and poultry populations for nearly 20 years.
Assuntos
Doenças dos Animais/prevenção & controle , Criação de Animais Domésticos/métodos , Animais Domésticos , Animais , Estados Unidos , United States Department of AgricultureRESUMO
Dairy operations in states representing 86% of the United States' national dairy herd were surveyed regarding the occurrence of common dairy diseases or disorders (digestive, respiratory, gastrointestinal, lameness, mastitis, navel infection) in specified production groups (weaned heifers, unweaned heifers, adult cows), and the most common antimicrobial preparation used to treat these conditions. Within disease and production group, disease frequency and characteristics of primary antimicrobial (drug class, availability, spectrum of activity, extra-label usage, withdrawal times) were compared among herd sizes (30-99, 100-499, and >/=500 cows) using chi-square or t-tests that accounted for the sampling design. The most common diseases were mastitis and lameness in cows, and gastrointestinal disease in unweaned calves, affecting 16, 11, and 15% of the target populations, respectively. Herd-level disease prevalence tended to increase as herd size increased, whereas within-herd prevalence tended to decrease as herd size increased. Broad-spectrum antimicrobials were selected as primary treatments by a majority of operations for nearly all diseases surveyed. When treating gastrointestinal disease, navel infection, or reproductive disorders, a majority of operations selected primary treatments not specifically labeled for that condition. Selection of over-the-counter preparations tended to decrease as herd size increased, whereas selection of broad-spectrum preparations tended to increase with herd size.
Assuntos
Antibacterianos/uso terapêutico , Doenças dos Bovinos/tratamento farmacológico , Indústria de Laticínios/métodos , Animais , Animais Recém-Nascidos , Bovinos , Doenças dos Bovinos/epidemiologia , Estudos Transversais , Feminino , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/epidemiologia , Gastroenteropatias/veterinária , Coxeadura Animal/tratamento farmacológico , Coxeadura Animal/epidemiologia , Mastite Bovina/tratamento farmacológico , Mastite Bovina/epidemiologia , Densidade Demográfica , Prevalência , Estados Unidos/epidemiologia , DesmameRESUMO
A body of evidence exists that suggests that antimicrobial use in food animals leads to resistance in both pathogenic and commensal bacteria. This study focused on the impact of three different antimicrobial regimes (low-level continuous, pulse, and no antimicrobial) for two antimicrobials (chlortetracycline and tylosin) on the presence of Salmonella spp. and on the prevalence of antimicrobial resistance of both Salmonella spp. and nonspecific Escherichia coli in fecal samples from feeder swine. The prevalence of fecal samples positive for Salmonella spp. significantly decreased between the samples taken at feeder placement compared to samples taken when the animals were close to market weight. Differences in resistance of Salmonella spp. did not appear to be influenced by dosing treatment including the control. Analysis of antimicrobial resistance examining both susceptibility and resistance, as well as MIC outcomes, demonstrated that only resistance to cephalothin increased in E. coli under the pulse chlortetracycline treatment. These results suggest that the dosing regimes examined in this study did not lead to an increase in either the prevalence of Salmonella spp. or the prevalence of antimicrobial resistance in isolates of Salmonella spp. or E. coli.
Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Fezes/microbiologia , Salmonella/efeitos dos fármacos , Animais , Cefalotina/farmacologia , Clortetraciclina/farmacologia , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Testes de Sensibilidade Microbiana , Salmonella/crescimento & desenvolvimento , Salmonella/isolamento & purificação , Suínos , Tilosina/farmacologiaRESUMO
Antimicrobial resistance is a growing concern for public and animal health. Threats to public health could come from the transfer of pathogens from animals to people via indirect contact such as through food or by direct contact with animals. In addition, concern has been raised for the potential transfer of resistance determinants from animals to humans through commensal bacterial flora such as Escherichia coli. Isolates of E. coli and Salmonella spp. from dairy cows on farms in 21 states were evaluated for resistance to a panel of 16 antimicrobial drugs. Resistance patterns for E. coli were compared to those of Salmonella spp. when they were isolated concurrently on the same farm or from the same fecal sample. Overall, most of the E. coli isolates (85.3%) and Salmonella spp. isolates (87.2%) were susceptible to all antimicrobials in the panel. The resistance profiles for E. coli with and without concurrent isolation of Salmonella were comparable with the exception of tetracycline resistance, which was more common among the E. coli isolated with Salmonella spp. The resistance patterns for E. coli and Salmonella spp. isolated concurrently were not significantly different for any of the antimicrobials evaluated. The data from this study demonstrate that the majority of commensal E. coli and Salmonella spp. recovered from feces of dairy cows harbored no resistance to a broad range of antimicrobial drugs. Further studies are indicated to better understand the factors that influence the frequency of resistance in commensal E. coli and Salmonella spp. on dairy operations.
Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Contaminação de Alimentos/análise , Salmonella/efeitos dos fármacos , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Indústria de Laticínios/métodos , Indústria de Laticínios/normas , Reservatórios de Doenças/veterinária , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Feminino , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Humanos , Testes de Sensibilidade Microbiana , Salmonelose Animal/tratamento farmacológico , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Estados UnidosRESUMO
The incidence of initial respiratory disease was followed for 12 weeks in 122 pens of feedlot cattle, based on producer-collected daily morbidity counts. Weekly incidence density was calculated based on the number of new cases and the population at risk. Incidence density was greatest in the 1st week after arrival and decreased in following weeks. Weekly incidence rate varied between pens and over time from 0 to 27.7 cases per 100 animal weeks at risk. A negative binomial model controlling for multiple events within pens and over time was used to model effects on the number of new cases. Mixed gender groups, cattle from multiple sources and increasing distance shipped were associated with increased risk for initial respiratory morbidity. Heavier entry weight was associated with decreased morbidity risk. These factors may be useful in categorizing groups of calves into risk groups for targeted purchase and management decision making.
Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Bovinos/epidemiologia , Doenças Respiratórias/veterinária , Animais , Peso Corporal , Bovinos , Doenças dos Bovinos/mortalidade , Feminino , Abrigo para Animais , Incidência , Masculino , Densidade Demográfica , Dinâmica Populacional , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/mortalidade , Fatores de Risco , Meios de Transporte , Estados Unidos/epidemiologiaRESUMO
OBJECTIVE To identify geographic areas in the United States where food animal veterinary services may be insufficient to meet increased needs associated with the US FDA's Veterinary Feed Directive. DESIGN Cross-sectional study. SAMPLE Data collected between 2010 and 2016 from the US Veterinary Medicine Loan Repayment Program, the National Animal Health Monitoring System Small-Scale US Livestock Operations Study, and the USDA's National Veterinary Accreditation Program. PROCEDURES Each dataset was analyzed separately to identify geographic areas with greatest potential for veterinary shortages. Geographic information systems methods were used to identify co-occurrence among the datasets of counties with veterinary shortages. RESULTS Analysis of the loan repayment program, Small-Scale Livestock Operations Study, and veterinary accreditation datasets revealed veterinary shortages in 314, 346, and 117 counties, respectively. Of the 3,140 counties in the United States during the study period, 728 (23.2%) counties were identified as veterinary shortage areas in at least 1 dataset. Specifically, 680 counties were identified as shortage areas in 1 dataset, 47 as shortage areas in 2 datasets, and 1 Arizona county as a shortage area in all 3 datasets. Arizona, Kentucky, Missouri, South Dakota, and Virginia had ≥ 3 counties identified as shortage areas in ≥ 2 datasets. CONCLUSIONS AND CLINICAL RELEVANCE Many geographic areas were identified across the United States where food animal veterinary services may be inadequate to implement the Veterinary Feed Directive and meet other producer needs. This information can be used to assess the impact of federal regulations and programs and help understand the factors that influence access to food animal veterinary services in specific geographic areas.
Assuntos
Educação em Veterinária , Área Carente de Assistência Médica , United States Food and Drug Administration/legislação & jurisprudência , Médicos Veterinários/provisão & distribuição , Animais , Estudos Transversais , Humanos , Gado , Serviços de Saúde Rural , Estados UnidosRESUMO
Antimicrobial resistance is a serious threat to animal and human health worldwide, requiring a collaborative, holistic approach. The U.S. Government has developed a national strategy to address antimicrobial resistance, with one component being to monitor antimicrobial resistance in agricultural settings. We developed a survey to collect information about antimicrobial susceptibility testing (AST) from the veterinary diagnostic laboratory community in the United States, assessing current practices and technologies and determining how AST information is shared. Of the 132 surveys administered, 52 (39%) were returned. Overall, responding laboratories conducted susceptibility tests on 98,788 bacterial isolates in 2014, with Escherichia coli being the most common pathogen tested across all animal species. The 2 most common AST methods employed were the disk diffusion method (71%) and the Sensititre platform broth microdilution system (59%). Laboratories primarily used the Clinical Laboratory Standards Institute (CLSI) VET-01 standard (69%) and the automatically calculated interpretations provided by the commercial AST systems (61%) for interpreting their AST data. Only 22% of laboratories published AST data on a periodic basis, usually via annual reports published on the laboratory's website or through peer-reviewed journals for specific pathogens. Our results confirm that disk diffusion and broth microdilution remain the standard AST methods employed by U.S. veterinary diagnostic laboratories, and that CLSI standards are commonly used for interpreting AST results. This information will help determine the most efficient standardized methodology for future surveillance. Furthermore, the current infrastructure within laboratories, once harmonized, will help provide a mechanism for conducting national surveillance programs.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Laboratórios/normas , Testes de Sensibilidade Microbiana/veterinária , Medicina Veterinária/métodos , Animais , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Estados UnidosRESUMO
Infection with bovine leukemia virus (BLV) results in economic loss because of reduced productivity, especially reduced milk production, and early culling. In the United States, studies in 1996, 1999, and 2007 showed BLV infection to be widespread, especially in dairy herds. We updated information herein on BLV seroprevalence in the United States, using samples submitted for testing and found negative for antibodies for Brucella by the Kentucky Eastern Regional Federal Brucellosis Laboratory. From October 2014 through August 2015, 2,000 samples from all regions of the contiguous United States were selected and tested for BLV antibodies by enzyme-linked immunosorbent assay. The overall percentage of samples positive for BLV antibody was 38.6%. Based on the animal's origin, the percent positive by region ranged from 32.5% (Mountain West region) to 54.3% (Northeast region; p < 0.05). The positive rate for slaughter plants that processed mainly dairy animals (dairy plants; 47.6%) was higher than the positive rate at slaughter plants that processed mainly beef animals (beef plants; 33.6%; p < 0.05). The results suggest that BLV infection remains widespread in all regions of the United States and that rates may differ between beef and dairy cattle.
Assuntos
Leucose Enzoótica Bovina/epidemiologia , Vírus da Leucemia Bovina/isolamento & purificação , Matadouros , Animais , Anticorpos Antivirais/sangue , Bovinos , Estudos Transversais , Leucose Enzoótica Bovina/virologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Prevalência , Estudos Soroepidemiológicos , Estados Unidos/epidemiologiaRESUMO
Four species of ruminant pestivirus are currently circulating in the United States: Bovine viral diarrhea virus 1 and 2 (BVDV-1, -2; predominant host: cattle), Border disease virus (BDV; predominant host: sheep), and pronghorn virus (sporadically detected in wild ruminants). A third bovine pestivirus called HoBi-like virus has been detected in cattle and water buffalo in South America, Asia, and Europe. To date, no isolations of HoBi-like viruses from U.S. cattle have been reported. To assess exposure, 2,000 cattle sera, collected between 2014 and 2015 as part of the U.S. brucellosis surveillance program, were tested for antibodies against BVDV-1, BVDV-2, and HoBi-like viruses. In addition, RNA was extracted and tested by reverse transcription-polymerase chain reaction for the presence of pestiviruses; all samples tested negative. The percent of VN-positive samples was 91.3% for BVDV-1, 89.3% for BVDV-2, and 84.9% for HoBi-like viruses. Because the 3 bovine pestiviruses are antigenically cross-reactive, the comparative level of antibody against each pestivirus species was determined. Based on comparative titers, samples were segregated into 6 categories: no titers (7.6%), titers clearly higher against BVDV-1 (22.2%), titers substantially higher against BVDV-2 (9.1%), BVDV-1 and BVDV-2 titers equivalent but substantially higher than HoBi titers (25.7%), titers substantially higher against HoBi-like viruses (0%), and equivocal (35.4%). Titers tended to be higher against BVDV-1 than BVDV-2. However, the overall percentage of animals with titers below levels considered protective against acute bovine pestivirus infection were ~11% for BVDV-1, 12% BVDV-2, and 18% for HoBi-like virus.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Brucelose Bovina/epidemiologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Brucelose Bovina/sangue , Bovinos , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Vírus da Diarreia Viral Bovina Tipo 2/imunologia , Vírus da Diarreia Viral Bovina Tipo 2/isolamento & purificação , Vírus da Diarreia Viral Bovina/imunologia , Vigilância da População , Estados Unidos/epidemiologiaRESUMO
Bovine abortions due to Neospora caninum infection have been reported worldwide and its economic impact on the beef industry has been acknowledged as a problem. Uruguay has the largest export value of beef per acre in South America. However, no data on the prevalence of N. caninum infection have been available in this country. The objective of this study was to estimate the prevalence and distribution of N. caninum infection in beef cattle in Uruguay through a nationwide survey. A two stage sampling design was used with farms being selected in stage one and animals being selected in stage two. A brief questionnaire was administered on each farm. Seroprevalence of N. caninum in 4444 beef cattle from 229 farms in all the counties, except Montevideo, of Uruguay was determined by an ELISA. The data were then analyzed to identify associations between infection and variables such as type of animal (cow or heifer), herd size, use of veterinary advice, productivity of the soil in relation to the national average, use of improved grass, use of mineral salts, use of supplemental feed, and presence of a dog(s) on the farm. The estimated proportion of positive farms for all the beef cattle operations was 69.2% (95% confidence interval [CI], 53.7-84.7). The overall cattle seroprevalence was estimated as 13.9% (95% CI, 11.6-16.3). The prevalence estimation by animal category was 14.3% (95% CI, 11.4-17.2) for beef cows and 12.9% (95% CI, 10.0-15.8) for beef heifers. There was no significant difference in the estimated prevalence between the two animal types. There was no significant difference in the animal level prevalence of N. caninum infection among different herd sizes. None of the herd demographic or management variables was significantly associated with the seropositivity to N. caninum infection. In conclusion, these results show that N. caninum infection is common among beef herds across Uruguay. Since the beef industry is one of the key industries in Uruguay, the economic effect and risk factors of N. caninum infection among beef cattle in this country should be further evaluated in the near future.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Bovinos/epidemiologia , Coccidiose/veterinária , Neospora/imunologia , Aborto Animal/parasitologia , Criação de Animais Domésticos/métodos , Animais , Bovinos , Coccidiose/epidemiologia , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Masculino , Estudos Soroepidemiológicos , Uruguai/epidemiologiaRESUMO
The first step in assessing the risk of water contamination by Cryptosporidium parvum oocysts from feedlot cattle (Bos taurus) production systems is to quantify the number of C. parvum oocysts present in the fecal material deposited by feedlot cattle. Our primary objective for this project was to estimate the daily environmental load of C. parvum oocysts in fecal material deposited by feedlot cattle from across the central and western USA. Our secondary goal was to genotype isolates of C. parvum from feedlot cattle to help facilitate proper identification of mammalian sources of waterborne C. parvum. Based on 5274 fecal samples from 22 feedlots in seven states (California, Washington, Colorado, Oklahoma, Texas, Nebraska, and South Dakota), we estimated a point prevalence of C. parvum of 0.99 to 1.08% in fecal material from feedlot pens from a wide range of climates and a diverse range of feedlot management systems. On average, fresh fecal material from throughout feedlot systems (recent arrivals to nearing slaughter) contained about 1.3 to 3.6 oocysts/g feces, which roughly translates to about 2.8 x 10(4) to 1.4 x 10(5) oocysts/animal per day.
Assuntos
Ração Animal , Cryptosporidium parvum/isolamento & purificação , Fezes/parasitologia , Oocistos/isolamento & purificação , Animais , Bovinos , Estados UnidosRESUMO
Objective-To evaluate antimicrobial susceptibility of commensal Escherichia coli strains isolated from the feces of horses and investigate relationships with hospitalization and antimicrobial drug (AMD) administration. Design-Observational study. Animals-68 hospitalized horses that had been treated with AMDs for at least 3 days (HOSP-AMD group), 63 hospitalized horses that had not received AMDs for at least 4 days (HOSP-NOAMD group), and 85 healthy horses that had not been hospitalized or treated with AMDs (community group). Procedures-Fecal samples were submitted for bacterial culture, and up to 3 E coli colonies were recovered from each sample. Antimicrobial susceptibility of 724 isolates was evaluated. Prevalence of resistance was compared among groups by use of log-linear modeling. Results-For 12 of the 15 AMDs evaluated, prevalence of antimicrobial resistance differed significantly among groups, with prevalence being highest among isolates from the HOSP-AMD group and lowest among isolates from the community group. Isolates recovered from the HOSP-AMD and HOSP-NOAMD groups were also significantly more likely to be resistant to multiple AMDs. Resistance to sulfamethoxazole and resistance to trimethoprim-sulfamethoxazole were most common, followed by resistance to gentamicin and resistance to tetracycline. Use of a potentiated sulfonamide, aminoglycosides, cephalosporins, or metronidazole was positively associated with resistance to 1 or more AMDs, but use of penicillins was not associated with increased risk of resistance to AMDs. Conclusion and Clinical Relevance-Results suggest that both hospitalization and AMD administration were associated with prevalence of antimicrobial resistance among E coli strains isolated from the feces of horses.
Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Doenças dos Cavalos/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Infecção Hospitalar/veterinária , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Feminino , Doenças dos Cavalos/microbiologia , Cavalos , Hospitalização , Masculino , Testes de Sensibilidade Microbiana/veterináriaRESUMO
OBJECTIVE: To evaluate bacterial and protozoal contamination of commercially available raw meat diets for dogs. DESIGN: Prospective longitudinal study. SAMPLE POPULATION: 240 samples from 20 raw meat diets for dogs (containing beef, lamb, chicken, or turkey), 24 samples from 2 dry dog foods, and 24 samples from 2 canned dog foods. PROCEDURE: Each product was purchased commercially on 4 dates approximately 2 months apart. Three samples from each product at each sampling period were evaluated via bacterial culture for non-type-specific Escherichia coli (NTSEC), Salmonella enterica, and Campylobacter spp. Antimicrobial susceptibility testing was performed on selected isolates. Polymerase chain reaction assays were used to detect DNA from Cryptosporidium spp, Neospora spp, and Toxoplasma spp in samples obtained in the third and fourth sampling periods. RESULTS: One hundred fifty-three of 288 (53%) samples were contaminated with NTSEC. Both raw and prepared foods contained NTSEC during at least 1 culture period. Salmonella enterica was recovered from 17 (5.9%) samples, all of which were raw meat products. Campylobacter spp was not isolated from any samples. In 91 of 288 (31.6%) samples, there was no gram-negative bacterial growth before enrichment and in 48 of 288 (16.7%) samples, there was no aerobic bacterial growth before enrichment. Susceptibility phenotypes were variable. Cryptosporidium spp DNA was detected in 3 samples. CONCLUSIONS AND CLINICAL RELEVANCE: Bacterial contamination is common in commercially available raw meat diets, suggesting that there is a risk of foodborne illness in dogs fed these diets as well possible risk for humans associated with the dogs or their environments.