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Staphylococcus pseudintermedius is the most common opportunistic pathogen in dogs and methicillin resistance (MRSP) has been identified as an emerging problem in canine pyoderma. Here, we evaluated the antimicrobial resistance (AMR) features and phylogeny of S. pseudintermedius isolated from canine pyoderma cases in Argentina (n = 29) and the United States (n = 29). 62% of isolates showed multi-drug resistance. The AMR genes found: mecA, blaZ, ermB, dfrG, catA, tetM, aac(6')-aph(2â³), in addition to tetK and lnuA (only found in U.S. isolates). Two point mutations were detected: grlA(S80I)-gyrA(S84L), and grlA(D84N)-gyrA(S84L) in one U.S. isolate. A mutation in rpoB (H481N) was found in two isolates from Argentina. SCCmec type III, SCCmec type V, ΨSCCmec57395 were identified in the Argentinian isolates; and SCCmec type III, SCCmec type IVg, SCCmec type V, and SCCmec type VII variant in the U.S. cohort. Sequence type (ST) ST71 belonging to a dominant clone was found in isolates from both countries, and ST45 only in Argentinian isolates. This is the first study to comparatively analyze the population structure of canine pyoderma-associated S. pseudintermedius isolates in Argentina and in the U.S. It is important to maintain surveillance on S. pseudintermedius populations to monitor AMR and gain further understanding of its evolution and dissemination.
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Doenças do Cão , Pioderma , Infecções Estafilocócicas , Cães , Animais , Estados Unidos/epidemiologia , Antibacterianos/farmacologia , Infecções Estafilocócicas/epidemiologia , Argentina , Farmacorresistência Bacteriana/genética , Genômica , Pioderma/veterinária , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Shorter inpatient stays have resulted in greater patient acuity, making it difficult for patients to heal and challenging for staff to manage. OBJECTIVE: To improve the milieu for psychiatric inpatients using evidence-based practices. DESIGN: A thorough literature review suggested 18 basic principles to improve patient outcomes while reducing violence, seclusion, restraint, and 1:1 observation. Interventions were multiple, including intensive multi-modal staff education based on the literature review and starting in orientation, introduction of comfort rooms, changes in debriefing practices, careful review of all seclusion and restraint episodes, introduction of integrative modalities, and careful review of all 1:1 observation and review of unit structure. RESULTS: Multiple interventions resulted in favorable outcomes in the following: rates of seclusion and restraints; time devoted to 1:1 observation, patient and staff satisfaction; violent incidents; and staff and patient injury. CONCLUSIONS: Long-term culture change toward a more therapeutic milieu can occur as a result implementing evidence-based practices.
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Prática Clínica Baseada em Evidências/métodos , Hospitais Psiquiátricos , Humanos , Cultura Organizacional , Inovação Organizacional , Psiquiatria/métodos , Psiquiatria/normas , Resultado do TratamentoRESUMO
BACKGROUND: Bacteriologic culture remains one of the most important methods to diagnose bovine tuberculosis despite the lengthy incubation time, significant decontamination and media expense, and high biocontainment requirements. Media selection is an important determination of culture sensitivity, and the planned discontinuation of the BACTEC 460 TB culture system has challenged veterinary diagnostic laboratories to evaluate alternatives. At the National Veterinary Services Laboratories the BACTEC MGIT 960 and 4 solid media formulations were compared with the BACTEC 460 TB system on 6,795 veterinary diagnostic specimens submitted for Mycobacterium bovis culture. RESULTS: M. bovis was isolated from 2.6% of the samples and atypical mycobacteria from 4.4% of the samples. The BACTEC 12B media isolated significantly more M. bovis (93.1% of positive samples) than MGIT 960 media (81.9%). However, contamination rates were much higher for the MGIT media, 17-24%, compared to 7% for BACTEC, suggesting that contamination was a major cause of MGIT reduced sensitivity. Time to signal positive was 2.37 weeks (95% CI 2.24-2.5) for the MGIT, and 3.2 weeks (95% CI 3.07-3.3) for the BACTEC, both earlier than any solid media. Mycobactosel LJ failed to isolate M. bovis from primary culture. An in-house 7H11 media supplemented with calf sera, hemolyzed blood, malachite green and pyruvate recovered more M. bovis (80.6%) with the least amount of contamination of any other solid media evaluated. CONCLUSION: Decontamination methods may have to be optimized and or MGIT media may have to be altered to reduce contamination in veterinary samples. Despite these issues, the MGIT 960 system is still favored over the use of solid media due to decreased time to recovery and the potential for higher sensitivity.
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Mycobacterium bovis/isolamento & purificação , Kit de Reagentes para Diagnóstico/veterinária , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Meios de Cultura , Histocitoquímica/veterinária , Estudos Prospectivos , Tuberculose Bovina/patologia , Estados UnidosRESUMO
BACKGROUND: Mycobacteria other than M. bovis may interfere with current bovine tuberculosis diagnostic tests resulting in false positive test results. As the prevalence of M. bovis decreases in the United States, interference from other mycobacteria play an increasingly important role in preventing the eradication of M. bovis. To identify mycobacteria other than M. bovis that may be interfering with current diagnostic tests, a retrospective study was performed to identify mycobacteria isolated from clinical tissues at the National Veterinary Services Laboratories between 1 January 2004 and 9 October 2011. RESULTS: During the study period, 2,366 mycobacteria other than M. bovis were isolated from samples submitted for clinical diagnosis of M. bovis. Fifty-five mycobacterial species were isolated during this time period. In cattle, M. avium complex, M. fortuitum/fortuitum complex, M. smegmatis, M. kansasii, and M. terrae complex were the predominate species other than M. bovis isolated from tissues submitted for culture. Mycobacteria other than M. bovis isolated from deer were predominantly M. avium complex, M. terrae/terrae complex, and M. fortuitum/fortuitum complex. CONCLUSIONS: These data provide information characterizing the species and relative prevalence of mycobacteria other than M. bovis that may interfere with current diagnostic tests.
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Doenças dos Bovinos/microbiologia , Infecções por Mycobacterium/veterinária , Mycobacterium/isolamento & purificação , Matadouros/estatística & dados numéricos , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Coinfecção/microbiologia , Coinfecção/veterinária , Bases de Dados Factuais , Cervos/microbiologia , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/microbiologia , Mycobacterium bovis/isolamento & purificação , Prevalência , Estudos Retrospectivos , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/microbiologia , Estados Unidos/epidemiologiaRESUMO
Understanding the microbial genomic contributors to antimicrobial resistance (AMR) is essential for early detection of emerging AMR infections, a pressing global health threat in human and veterinary medicine. Here we used whole genome sequencing and antibiotic susceptibility test data from 980 disease causing Escherichia coli isolated from companion and farm animals to model AMR genotypes and phenotypes for 24 antibiotics. We determined the strength of genotype-to-phenotype relationships for 197 AMR genes with elastic net logistic regression. Model predictors were designed to evaluate different potential modes of AMR genotype translation into resistance phenotypes. Our results show a model that considers the presence of individual AMR genes and total number of AMR genes present from a set of genes known to confer resistance was able to accurately predict isolate resistance on average (mean F1 score = 98.0%, SD = 2.3%, mean accuracy = 98.2%, SD = 2.7%). However, fitted models sometimes varied for antibiotics in the same class and for the same antibiotic across animal hosts, suggesting heterogeneity in the genetic determinants of AMR resistance. We conclude that an interpretable AMR prediction model can be used to accurately predict resistance phenotypes across multiple host species and reveal testable hypotheses about how the mechanism of resistance may vary across antibiotics within the same class and across animal hosts for the same antibiotic.
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Antibacterianos , Gado , Animais , Humanos , Antibacterianos/farmacologia , Animais de Estimação , Farmacorresistência Bacteriana/genética , Escherichia coli/genéticaRESUMO
A variable-number tandem repeat (VNTR) protocol targeting 10 loci in the Brucella abortus genome was used to assess genetic diversity among 366 field isolates recovered from cattle, bison, and elk in the Greater Yellowstone Area (GYA) and Texas during 1998 to 2011. Minimum spanning tree (MST) and unweighted-pair group method with arithmetic mean (UPGMA) analyses of VNTR data identified 237 different VNTR types, among which 14 prominent clusters of isolates could be identified. Cattle isolates from Texas segregated into three clusters: one comprised of field isolates from 1998 to 2005, one comprised of vaccination-associated infections, and one associated with an outbreak in Starr County in January 2011. An isolate obtained from a feral sow trapped on property adjacent to the Starr County herd in May 2011 clustered with the cattle isolates, suggesting a role for feral swine as B. abortus reservoirs in Starr County. Isolates from a 2005 cattle outbreak in Wyoming displayed VNTR-10 profiles matching those of strains recovered from Wyoming and Idaho elk. Additionally, isolates associated with cattle outbreaks in Idaho in 2002, Montana in 2008 and 2011, and Wyoming in 2010 primarily clustered with isolates recovered from GYA elk. This study indicates that elk play a predominant role in the transmission of B. abortus to cattle located in the GYA.
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Brucella abortus/classificação , Brucella abortus/isolamento & purificação , Brucelose/veterinária , Tipagem Molecular , Ruminantes/microbiologia , Animais , Brucella abortus/genética , Brucelose/epidemiologia , Brucelose/microbiologia , Análise por Conglomerados , Surtos de Doenças , Variação Genética , Epidemiologia Molecular , Estados Unidos/epidemiologiaRESUMO
The atmosphere hosts multiple sources of electric charge that influence critical processes such as the aggregation of droplets and the removal of dust and aerosols. This is evident in the variability of the atmospheric electric field. Whereas these electric fields are known to respond to physical and geological processes, the effect of biotic sources of charge has not hitherto been considered. Here, we combine theoretical and empirical evidence to demonstrate that honeybee swarms directly contribute to atmospheric electricity, in proportion to the swarm density. We provide a quantitative assessment of this finding, by comparing the electrical contribution of various swarming insect species with common abiotic sources of charge. This reveals that the charge contribution of some insect swarms will be comparable with that of meteorologically induced variations. The observed transport of charge by insects therefore demonstrates an unexplored role of biogenic space charge for physical and ecological processes in the atmosphere.
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Antimicrobial resistance (AMR) is a global problem facing human, animal, plant, and environmental health by threatening our ability to effectively treat bacterial infections with antimicrobials. In the United States, robust surveillance efforts exist to collect, analyze, and disseminate AMR data in human health care settings. These tools enable the development of effective infection control methods, the detection of trends, and provide the evidence needed to guide stewardship efforts to reduce the potential for emergence and further spread of AMR. However, in veterinary medicine, there are currently no known equivalent tools. This paper reviews efforts in the United States related to surveillance of AMR in veterinary medicine and discusses the challenges and opportunities of using data from veterinary diagnostic laboratories to build a comprehensive AMR surveillance program that will support stewardship efforts and help control AMR in both humans and animals.
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Extraintestinal pathogenic Escherichia coli (ExPEC) cause urinary tract and potentially life-threatening invasive infections. Unfortunately, the origins of ExPEC are not always clear. We used genomic data of E. coli isolates from five U.S. government organizations to evaluate potential sources of ExPEC infections. Virulence gene analysis of 38,032 isolates from human, food animal, retail meat, and companion animals classified the subset of 8142 non-diarrheagenic isolates into 40 virulence groups. Groups were identified as low, medium, and high relative risk of containing ExPEC strains, based on the proportion of isolates recovered from humans. Medium and high relative risk groups showed a greater representation of sequence types associated with human disease, including ST-131. Over 90% of food source isolates belonged to low relative risk groups, while >60% of companion animal isolates belonged to medium or high relative risk groups. Additionally, 18 of the 26 most prevalent antimicrobial resistance determinants were more common in high relative risk groups. The associations between antimicrobial resistance and virulence potentially limit treatment options for human ExPEC infections. This study demonstrates the power of large-scale genomics to assess potential sources of ExPEC strains and highlights the importance of a One Health approach to identify and manage these human pathogens.
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BACKGROUND: Culture of M. bovis from diagnostic specimens is the gold standard for bovine tuberculosis diagnostics in the USA. Detection of M. bovis by PCR in tissue homogenates may provide a simple rapid method to complement bacterial culture. A significant impediment to PCR based assays on tissue homogenates is specificity since mycobacteria other than M. bovis may be associated with the tissues. RESULTS: Previously published IS6110 based PCR diagnostic assays, along with one developed in house, were tested against environmental mycobacteria commonly isolated from diagnostic tissues submitted to the National Veterinary Services Laboratory. A real-time PCR assay was developed (IS6110_T) that had increased specificity over other IS6110 based assays. Of the 13 non-tuberculous mycobacteria tested with IS6110_T only M. wolinskyi was positive. Thirty M. bovis infected tissue homogenates and 18 control tissues were used to evaluate the potential for the assay as a diagnostic test. In this small sample, IS6110_T detected 20/30 samples from M. bovis infected animals and 0/18 control tissues. CONCLUSIONS: The IS6110_T assay provides a PCR based assay system that is compatible with current diagnostic protocols for the detection of M. bovis in the USA and compliments current testing strategies.
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Mycobacterium bovis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Tuberculose Bovina/microbiologia , Animais , Bovinos , Elementos de DNA Transponíveis/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Mycobacterium bovis/genética , Sensibilidade e Especificidade , Análise de Sequência de DNA , Tuberculose Bovina/diagnósticoRESUMO
Two adult female bontebok (Damaliscus pygarus dorcas) were euthanized because of signs of pneumonia and weakness (case 1), and a nonresponsive lameness with draining fistula (case 2). Necropsy findings were similar in both cases and consisted of disseminated granulomatous lesions in the liver, kidneys, spleen, lungs, pleural surfaces, and multiple lymph nodes. Mycobacterium kansasii was isolated from both cases after multiple attempts on a variety of samples by two laboratories. The remaining four animals in the herd were tested for antibody responses using the Chembio ElephantTB STAT-PAK, DPP VetTB kits, and multi-antigen print immunoassay (MAPIA), for immune reaction using the intradermal tuberculin test, and by tracheal wash cultures, and thoracic radiographs. Banked serum samples collected in 2005 and obtained from the original institution, revealed 1/9 (11.11%) seropositive animals using the three immunoassays. Retesting the current herd in 2008 showed 2/6 (33.33%) seropositive animals by the three tests, with MAPIA demonstrating antibody reactivity to MPB83 and MPB70 proteins. Inconsistent intradermal tuberculin test results, cross-reactivity in serologic assays designed for tuberculosis detection, difficulty in obtaining definitive identification by culture, and inability to identify a source of infection created challenges in distinguishing the atypical mycobacteriosis due to M. kansasii from the initially suspected tuberculous infection in this herd. Owing to regulatory considerations, differences in host-to-host transmission, and source of infection between Mycobacterium tuberculosis complex and nontuberculous mycobacteria, correct diagnosis is crucial for management of these diseases in wildlife species.
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Antílopes , Infecções por Mycobacterium não Tuberculosas/veterinária , Mycobacterium kansasii/classificação , Mycobacterium kansasii/isolamento & purificação , Mycobacterium tuberculosis/classificação , Animais , Técnicas Bacteriológicas , Feminino , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/microbiologiaRESUMO
Hourly rounds are becoming more popular on inpatient medical wards and are known to be beneficial to patients and nurses. However, there is little evidence about their impact in psychiatry and what hourly rounds would look like on inpatient mental health units. This article examines the introduction of hourly nurse rounds on inpatient mental health wards in an American hospital, and how they were adapted to the needs of psychiatric patients. The positive effects on patient care and staff are reported.
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Continuidade da Assistência ao Paciente , Transtornos Mentais/enfermagem , Cuidados de Enfermagem/organização & administração , Satisfação do Paciente , Humanos , New York , Projetos PilotoRESUMO
With the cost of next-generation sequencing (NGS) decreasing, this technology is rapidly being integrated into the workflows of veterinary clinical and diagnostic laboratories nationwide. The mission of the U.S. Department of Agriculture-National Animal Health Laboratory Network (NAHLN) is in part to evaluate new technologies and develop standardized processes for deploying these technologies to network laboratories for improving detection and response to emerging and foreign animal diseases. Thus, in 2018, the NAHLN identified the integration of NGS into the network as a top priority. In order to assess the current state of preparedness across NAHLN laboratories and to identify which have the capability for performing NGS, a questionnaire was developed by the NAHLN Methods Technical Working Group and submitted to all NAHLN laboratories in December 2018. Thirty of 59 laboratories completed the questionnaire, of which 18 (60%) reported having some sequencing capability. Multiple sequencing platforms and reagents were identified, and limited standardized quality control parameters were reported. Our results confirm that NGS capacity is available within the NAHLN, but several gaps remain. Gaps include not having sufficient personnel trained in bioinformatics and data interpretation, lack of standardized methods and equipment, and maintenance of sufficient computing capacity to meet the growing demand for this technology.
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Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Laboratórios/estatística & dados numéricos , Medicina Veterinária/estatística & dados numéricos , Estados UnidosRESUMO
Members of the Mycobacterium tuberculosis complex cause tuberculosis, infamous for enormous impacts on human health. As zoonoses, they also threaten endangered species like African/Asian elephants. We report the whole-genome sequences of Mycobacterium tuberculosis bv. tuberculosis and Mycobacterium tuberculosis bv. bovis from two zoo elephants in the United States.
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Multilocus variable number tandem repeat analysis (MLVA) has recently emerged as a genotyping method that is both robust and highly discriminatory for the differentiation of Mycobacterium tuberculosis complex (MTBC) strains, including Mycobacterium bovis. However, MLVA assessment of M. bovis isolates recovered from animals in North America has been limited. Using an epidemiologically diverse set of 41 North American M. bovis animal isolates, MLVA, based on 27 published variable number tandem repeat (VNTR) loci, was evaluated. Nineteen loci displayed polymorphism, which resulted in differentiation of 21 unique MLVA genotypes. A subset of 6 loci differentiated the isolates into 14 genetically related groups that displayed remarkable concordance with the epidemiological data gathered via traditional trace-back methods. In most cases, MLVA exhibited greater resolution than spoligotyping, which differentiated the isolates into 11 groups. MLVA genotyping of M. bovis shows great potential as a molecular typing tool for characterizing the epidemiology of M. bovis animal infections in North America. However, the greatest resolution was achieved by using a combination of both MLVA and spoligotyping.
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Mycobacterium bovis/isolamento & purificação , Sequências de Repetição em Tandem , Animais , Bovinos , Impressões Digitais de DNA , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Variação Genética , Genótipo , Mycobacterium bovis/classificação , Mycobacterium bovis/genética , América do Norte/epidemiologia , Polimorfismo Genético , Tuberculose Bovina/epidemiologiaRESUMO
Tuberculosis (TB) represents a barrier for free trade of livestock between Mexico and the United States of America (US). In spite of efforts from Mexico to export TB-free animals, some of those found with TB lesions in slaughterhouses in the US are traced back to that country. Therefore, the purpose of this study was to determine, through molecular epidemiology, the most probable source of infection for cattle found with TB lesions in the US. Ninety M. bovis isolates, 50 from Mexico obtained from cattle in 8 different states, and 40 from the US from cattle, deer, elk and feral pigs from 7 different states were included in the study. All samples were analyzed in both laboratories, Mexico and the US, following the same protocol for molecular analysis by spoligotyping. Twenty-seven clusters, ranging from 1 to 18 genetically similar strains were found. Some clustering by country was observed, strains from cattle and deer in Michigan in the US fell into the same cluster, suggesting transmission between species. These results, combined with epidemiological information suggest that despite of the possibility that some animals with lesions in the US come from Mexico as false negatives, the US has its own source of infection, must probably in dairy cattle and wildlife. Genetic diversity of isolates from Mexico was larger than that in the US, which could be a consequence of the endemic status of the disease and the indiscriminate movement of animals between regions.
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Epidemiologia Molecular , Mycobacterium bovis/genética , Tuberculose/veterinária , Animais , Bovinos , Comércio , Cervos , Internacionalidade , México/epidemiologia , Filogenia , Suínos , Tuberculose/epidemiologia , Estados Unidos/epidemiologiaRESUMO
A joint multiagency project was initiated in response to a Salmonella outbreak in San Diego County, California, in 2004. Samples of cheese were collected during four 1-day operations at the San Ysidro port of entry, along the United States-Mexico border. Surveyed participants were persons crossing the border as pedestrians or in vehicles who had a minimum of 2.27 kg of cheese, which may suggest a potential diversion to illegal marketing. In addition, data were collected about the cheese to identify risk factors for cheese contamination. Two hundred four cheese samples were submitted to the California Animal Health and Food Safety Laboratory System-San Bernardino Branch and analyzed for potential food pathogens. Ninety-four percent (190 of 203) of the samples tested positive for alkaline phosphatase. Salmonella was detected from 13% (27 of 204) of the samples comprising 11 serogroups and 28 serotypes. Pulsed-field gel electrophoresis DNA fingerprinting analysis, performed following standardized methods, determined that an isolate obtained from this study had an indistinguishable pattern from a recent Salmonella enterica serovar Typhimurium var. Copenhagen epidemic in the San Diego County that was linked to 14 illnesses. Listeria spp. were detected from 4% (8 of 204) of the samples, and of these, half were identified as L. monocytogenes. Escherichia coli O157:H7 was not detected from any of the samples. Mycobacterium bovis was detected from one panela-style cheese sample. Nine additional samples yielded Mycobacterium spp.
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Queijo/microbiologia , Comércio , Contaminação de Alimentos/análise , Listeria monocytogenes/isolamento & purificação , Mycobacterium bovis/isolamento & purificação , Salmonella/isolamento & purificação , Fosfatase Alcalina/metabolismo , California/epidemiologia , Surtos de Doenças , Microbiologia de Alimentos , Humanos , 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.
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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
The wildlife of the Greater Yellowstone Ecosystem carries brucellosis, which was first introduced to the area by cattle in the 19th century. Brucellosis transmission between wildlife and livestock has been difficult to study due to challenges in culturing the causative agent, Brucella abortus . We examined B. abortus transmission between American bison ( Bison bison ), Rocky Mountain elk ( Cervus elaphus nelsoni), and cattle ( Bos taurus ) using variable number tandem repeat (VNTR) markers on DNA from 98 B. abortus isolates recovered from populations in Idaho, Montana, and Wyoming, US. Our analyses reveal interspecies transmission. Two outbreaks (2007, 2008) in Montana cattle had B. abortus genotypes similar to isolates from both bison and elk. Nevertheless, similarity in elk and cattle isolates from the 2008 outbreak suggest that elk are the likely source of brucellosis transmission to cattle in Montana and Wyoming. Brucella abortus isolates from sampling in Montana appear to be divided in two clusters: one found in local Montana elk, cattle, and bison; and another found mainly in elk and a bison from Wyoming, which is consistent with brucellosis having entered Montana via migration of infected elk from Wyoming. Our findings illustrate complex patterns of brucellosis transmission among elk, bison, and cattle as well as the utility of VNTRs to infer the wildlife species of origin for disease outbreaks in livestock.