Occurrence and molecular genotyping of Cryptosporidium spp. in surface waters in Northern Ireland

AIMS: To investigate the incidence and genotype of Cryptosporidium parvum oocysts in drinking water sources in Northern Ireland for the period 1996-1999, and to compare conventional and molecular methods of detection. METHODS AND RESULTS: Four hundred and seventy-four waters were investigated by conventional methods, namely immuno-fluorescent antibody detection (IFA; 380) and immuno-magnetic separation-IFA (IMS-IFA; 94), of which 14/474 (3%) were positive. Two hundred and fourteen samples (214/474) were also investigated by PCR techniques, targeting both the 18S rRNA and TRAP-C2 genes, of which 11/214 (5.1%) were positive. These 11 samples were classified as genotype II following sequence analysis of the TRAP-C2 amplicon. CONCLUSIONS: This study demonstrated the low incidence of oocysts of C. parvum in water sources in Northern Ireland. SIGNIFICANCE AND IMPACT OF THE STUDY: Such molecular-based techniques offer a number of advantages over conventional detection methodologies, namely greater sensitivity and specificity as well as the ability to provide accurate genotyping data rapidly, which may be valuable in directing operational management in potential outbreak situations.     

Life on the edge: the demography of short-season populations of deer mice

We documented populations of deer mice in the Kananaskis Valley, southwestern Alberta, Canada from 1979 to 1997 to determine whether these short-season populations were more, or less, variable than populations in more temperate environments. We then examined patterns of reproduction, age-specific survival, and immigration to explain variation in summer population growth. Population densities showed no multi-annual periodicity and were generally low. At maximum, numbers doubled over the breeding season, but declined over the breeding season in 4 of 16 yr. Variability in population density was low, and similar to that of Peromyscus populations in more temperate environments. No demographic parameters were related to spring population densities, and immigration rates were low when conditions for survival of nestlings and adults were favorable. Variation in summer population growth was attributed primarily to variation in nestling survival among years.     

Asaia sp., an Unusual Spoilage Organism of Fruit-Flavored Bottled Water

A gram-negative bacillus was isolated from a batch of fruit-flavored bottled water, which had spoiled as a result of bacterial overgrowth (>10⁶ CFU/ml). The spoilage organism was extremely difficult to identify phenotypically and was poorly identified as Pasturella sp. (78.7% identification profile) employing the API 20NE identification scheme, which gave the profile 5040000. Molecular identification through PCR amplification of a partial region of the 16S rRNA gene followed by direct automated sequencing of the PCR amplicon allowed identification of the organism. Due to the sequence identity (100%) between the spoilage organism and a reference strain in GenBank, the spoilage isolate was considered to be an Asaia sp., a recently described genus and member of the acetic acid bacteria. This is the first report of Asaia sp. causing spoilage of a foodstuff and highlights the benefits of molecular identification techniques based on 16S rRNA gene sequences in the identification of unusual spoilage organisms.     

Influence of the larval environment on performance and adult body size of the wood-boring beetle Phoracantha semipunctata

Large body size confers a reproductive advantage to adults of the wood‐boring beetle Phoracantha semipunctata (F.) (Cerambycidae: Cerambycinae: Phoracanthini). Larvae of this species feed subcortically in stressed and dying eucalypt trees and logs. We evaluated the influence of the larval environment on larval performance and adult body size by manipulating the post‐felling age of host logs (from freshly cut to 2‐weeks‐old) and the density of colonizing neonates (low density with minimal competition for resources vs. high density with intense competition). Adult beetles emerged in greater numbers from logs that had been subjected to the aging treatment which reduced bark moisture content and favored colonization by neonates. Survival was greatest in larger logs having lower densities of neonates, but was greatly diminished in all treatments by mortality during pupation. Development time varied from 2 months to more than a year and was shortest in smaller logs having high densities of larvae. The size of adult beetles emerging from a log was not influenced by larval density, but was positively correlated with the age of logs when the neonates colonized, and log size. These findings suggest that the optimal developmental conditions for P. semipunctata larvae, in terms of larval performance and adult body size, are available in large, aged host logs having low densities of larvae. Manipulation of the larval environment in this study resulted in a considerable variation in adult body size, but large individuals were relatively more common in the wild population that was the source of neonates for the experiment. Potential body size may have been constrained by our use of only one host species and a narrow range of log dimensions.     

Landholder participation in native vegetation management in irrigation areas

Summary Landholder adoption of conservation practices has been extensively researched in dryland areas, but there has been less research into the adoption of biodiversity conservation practices in irrigation areas. The Murray Catchment Management Authority (MCMA) and Murray Irrigation Limited (MIL) in south‐west New South Wales offer landholders monetary incentives to enhance native vegetation management. However, uptake of the incentives and recommended practices has been slower in the irrigation areas than in dryland areas serviced by the MCMA. We explored landholder participation in native vegetation management in the MIL area using semistructured interviews with landholders and extension staff. Our findings suggest there are important differences between irrigation and dryland contexts. Landholders in irrigation districts face higher opportunity costs and are more likely to mistrust government intentions. Other constraints to adoption include lack of financial resources, restricted time to carry out works and a high turnover of extension staff. Landholders adopted recommended vegetation management practices because those practices matched their values and goals. The importance of regular contact with a positive and enthusiastic extension officer was also evident. These findings have important implications for conservation policies and programs. Extension should move beyond arousing interest and include substantial follow‐up contact to maintain landholder motivation and confidence, as well as provide recognition for past landholder efforts. Incentive programs should be designed to provide wider landholder support with different entry points allowing participants to adapt, learn and build confidence. Incentives should address the constraints experienced by landholders, particularly at times of peak workloads and during drought. Work targets set for field staff can be too high and result in program staff focusing on accomplishing on‐ground work, rather than developing irrigators’ longer‐term commitment to vegetation conservation.     

Measles and Other Virus-specific Immunoglobulins in Multiple Sclerosis

Immunoglobulins M and G specific for meales, herpes simplex, and rubella viruses were assayed by the fluorescent antibody method in sera and cerebrospinal fluids (C.S.F.) obtained simultaneously from 30 patients with multiple sclerosis, 30 patients with other neurological diseases, and 30 “normal” control subjects. Sera of 11 out of 30 patients with multiple sclerosis had IgM which reacted specifically with measles virus-infected cells, compared with 2 out of 30 of the patients with other neurological diseases and none of the 30 normal controls. Virus-specific IgM was not found in C.S.F. by this method.The geometric mean titre of measles virus-specific IgG in serum was significantly higher in the multiple sclerosis group than in either control group, and while IgG specific for all three viruses was found in C.S.F., suggesting transfer across the blood-brain barrier, measles IgG predominated.     

Immunoglobulin M. Specific for Measles and Mumps in Multiple Sclerosis

Sera from 43 patients with multiple sclerosis were tested by immunofluorescence. Sera from patients with active multiple sclerosis included four with measles virus-specific immunoglobulin M (measles IgM) and two with mumps virus-specific IgM (mumps IgM). In one case each mumps IgM and measles IgM seem to have persisted for two and a half years and three years respectively. In a comparable group of 43 patients with other nervous diseases measles IgM was found in only one serum, and among 43 normal patients no measles or mumps IgM was found.Herpes simplex virus-specific IgM (herpes simplex IgM) was distributed among all three groups. Anticellular IgM was also found, predominantly in active multiple sclerosis, and persisted in two sera for two and a half years.