The tropical bloom-forming cyanobacterium Cylindrospermopsis raciborskii (Woloszynska) Seenaya et Subba Raju is causing increasing concern because of its potential toxicity and invasive behavior at midlatitudes. This species has recently been identified in several temperate areas and was first reported in France in 1994, but the mechanisms underlying this acclimation process remain to be elucidated. We performed a range of laboratory experiments in an attempt to identify the physiological characteristics that could account for this behavior. We investigated the three following hypotheses: 1) clones of C. raciborskii adapted to temperate climate have been selected as it advanced north, 2) C. raciborskii has high physiological tolerance that allows it to prosper in a wide range of conditions, and 3) changes in climate (global warming) have favored the development of C. raciborskii in mid-latitudes. Ten strains of C. raciborskii from Australia n 5 1), Brazil (2), France (2), Germany (1), Hungary (1), Mexico (1), and Senegal (2) were cultured at different temperatures and light intensities. The in vitro growth parameters (l and T opt ) were the same for the tropical and temperate strains. All 10 strains displayed positive net growth in a wide range of temperatures (from 20 to 351 C) and light intensities (from 30 to 400 lmol photons . m À 2 . s À 1 ), with maximum growth rates at around 301 C and 80 lmol photons . m À 2 . s À 1 . This suggests that the colonization of mid-latitudes by C. raciborskii may result from a combination of its ability to tolerate a rather wide range of climatic conditions and the global warming phenomenon, which provides this species with better environmental conditions for its growth.

To characterize the clinical and bacteriologic characteristics of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections, we reviewed 14 cases that were diagnosed in previously healthy patients during an 18-month period in France. Eleven patients had skin or soft-tissue infections. Two patients died of CA-MRSA necrotizing pneumonia. A case of pleurisy occurred in a child who acquired CA-MRSA from his mother, who had a breast abscess. The Panton-Valentine leukocidin genes and the lukE-lukD leukocidin genes were detected in all 14 isolates. The clonal origin of all of the isolates was demonstrated on the basis of their pulsotypes and antibiotic resistance profiles. All isolates had an agr3 allele. The combination of the Panton-Valentine leukocidin determinant (which encodes a virulence factor for primary skin infection and pneumonia) with the mecA gene (which confers antibiotic resistance and epidemicity) appears to have created a superadapted S. aureus strain that is spreading in the community.

Because of polyploidy and large genome size, deletion stocks of bread wheat are an ideal material for physically allocating ESTs and genes to small chromosomal regions for targeted mapping. To enhance the utility of deletion stocks for chromosome bin mapping, we characterized a set of 84 deletion lines covering the 21 chromosomes of wheat using 725 microsatellites. We localized these microsatellite loci to 94 breakpoints in a homozygous state (88 distal deletions, 6 interstitial), and 5 in a heterozygous state representing 159 deletion bins. Chromosomes from homoeologous groups 2 and 5 were the best covered (126 and 125 microsatellites, respectively) while the coverage for group 4 was lower (80 microsatellites). We assigned at least one microsatellite in up to 92% of the bins (mean 4.97 SSR/bin). Only a few discrepancies concerning marker order were observed. The cytogenetic maps revealed small genetic distances over large physical regions around the centromeres and large genetic to physical map ratios close to the telomeres. As SSRs are the markers of choice for many genetic and breeding studies, the mapped microsatellite loci will be useful not only for deletion stock verifications but also for allocating associated QTLs to deletion bins where numerous ESTs that could be potential candidate genes are currently assigned.