Members of the genus Brucella infect many domesticated and wild animals and cause serious zoonotic infection in humans. The availability of discriminatory molecular typing tools to inform and assist conventional epidemiological approaches would be invaluable in controlling these infections, but efforts have been hampered by the genetic homogeneity of the genus. We report here on a molecular subtyping system based on 21 variable-number tandem-repeat (VNTR) loci consisting of 13 previously unreported loci and 8 loci previously reported elsewhere. This approach was applied to a collection of 121 Brucella isolates obtained worldwide and representing all six classically recognized Brucella species. The size of repeats selected for inclusion varied from 5 to 40 bp giving VNTR loci with a range of diversities. The number of alleles detected ranged from 2 to 21, and Simpson's diversity index values ranged from 0.31 to 0.92. This assay divides the 121 isolates into 119 genotypes, and clustering analysis results in groups that, with minor exceptions, correspond to conventional species designations. Reflecting this, the use of six loci in isolation was shown to be sufficient to determine species designation. On the basis of the more variable loci, the assay could also discriminate isolates originating from restricted geographical sources, indicating its potential as an epidemiological tool. Stability studies carried out in vivo and in vitro showed that VNTR profiles were sufficiently stable such that recovered strains could readily be identified as the input strain. The method described here shows great potential for further development and application to both epidemiological tracing of Brucella transmissions and in determining relationships between isolates worldwide.Brucellosis is a zoonotic disease of major public health, animal welfare, and economic significance worldwide. In humans, infection with Brucella can lead to a chronic debilitating infection; in domesticated animals, the main symptom is reproductive failure. Disease in humans usually reflects occupational exposure or the consumption of unpasteurized dairy products. Brucellosis remains a major problem in many parts of the world, particularly Mediterranean regions, western Asia, and parts of Africa and Latin America (11), although in many developed countries it has been eradicated or severely curtailed by a combination of strict veterinary hygiene measures, monitoring programs, and improved food safety measures. Brucella species have also long been considered potential biological warfare agents, and in 1954 Brucella became the first biological agent to be treated as a weapon and field tested on animals under the old U.S. offensive biological weapons program. Recent history has raised awareness in this area (28), and the organism remains on the list of Centers for Disease Control and Prevention category B potential biological warfare agents (25).Classical Brucella taxonomists developed a classification system that recognized six species based on subtle phenotypi...

Amplified fragment length polymorphism (AFLP) is a whole-genome fingerprinting method that relies on the selective PCR amplification of restriction fragments. The potential of this approach for the discrimination of Brucella isolates at the species and intraspecies level was assessed. A number of different combinations of restriction enzymes and selective primers were examined, and one, using EcoRI and MseI with additional selective TC bases on the MseI primer, was selected for full assessment against a panel of Brucella isolates. The technique could readily differentiate Brucella spp. from all Ochrobactrum spp. representing the group of organisms most closely related to Brucella spp. Application of AFLP highlighted the genetic homogeneity of Brucella. In spite of this determination of AFLP profiles of large numbers of isolates of human and animal origin, including Brucella abortus, B. melitensis, B. ovis, B. neotomae, marine mammal isolates (no species name), B. canis, and B. suis, confirmed that all but the latter two species could be separated into distinct clusters based on characteristic and conserved differences in profile. Only B. suis and B. canis isolates clustered together and could not be distinguished by this approach, adding to questions regarding the validity of species assignments in this group. Under the conditions examined in the present study only limited intraspecies genomic differences were detected, and thus this AFLP approach is likely to prove most useful for identification to the species level. However, combination of several of the useful restriction enzyme-primer combinations identified in the present study could substantially add to the discriminatory power of AFLP when applied to Brucella and enhance the value of this approach.Brucella spp. comprise a closely related group of organisms that classical taxonomists divided into six species based on subtle phenotypic and antigenic differences and host specificity: Brucella abortus (bovine), B. melitensis (caprine and ovine), B. ovis (ovine), B. canis (canine), B. suis (porcine), and B. neotomae (only seen in the desert wood rat). The situation has recently been complicated by the identification of Brucella isolates in marine mammals that do not fit into any of the recognized species and themselves show intragroup diversity (4,14). Some of the species are classically divided into biovars such that several B. abortus, B. melitensis, and B. suis biovars are recognized. In addition, host specificity is not absolute; thus, B. melitensis and B. suis are important causes of bovine disease in some countries, and B. suis biovars 2, 4, and 5 have been associated with hares, reindeer, and rodents, respectively. The traditional view on Brucella taxonomy was challenged some time ago on the basis of the high degree of homology indicated by DNA hybridization experiments (26) and the inability to differentiate Brucella spp. by 16S rRNA sequencing. Although these findings conform better with the view of a single species within which the six classical spec...

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This is a follow-up study of people who were involved in bomb explosions in two Birmingham public houses in November 1974, but were not seriously injured. One hundred and sixteen people were conveyed to hospital, registered, given casualty treatment and allowed home that evening. A small sub-sample of these survivors were visited at home two years after the disaster and the clinical characteristics were observed; the social and symptomatic disturbances were greater than expected. Work records of these survivors before and after the explosion were compared with matched outpatient casualties. On comparing disturbance to employment for the two groups, the bomb victims showed much greater incapacity.

This paper reports the initial findings of a survey (N=388) conducted in Winter 1991 focusing on the quality of the academic experience for Arts and Science students at a medium size post-secondary institution in eastern Canada. Our purposes are: 1) to set out the context in which undergraduates conduct their academic work, 2) to document what their experience entails, and 3) to present some of their perceptions of the higher education process. While most students have vocational goals in mind, they are also keenly interested in acquiring a solid general education. Undergraduates attend most of their classes, are heavily committed to completing their programs, and work quite diligently in pursuit of their goals in the face of what many of them consider to be heavy workloads. They are not, however, completely satisfied with the services that they receive in return for their tuition fees and for Canadians' tax dollars. While satisfaction levels vary with the type of services provided, it is clear that there does exist substantial room in which institutions can make improvements. Specifically, our data suggest that the primary goals of universities seeking to better the undergraduate experience should be to encourage more effective teaching and its evaluation, to reduce class sizes, to increase formal and informal interaction among faculty members and students, to improve the quality of academic advising, and to support the creation of more equitable financial assistance programs for students.