Role of mobile DNA in the evolution of vancomycin-resistant Enterococcus faecalis

The complete genome sequence of Enterococcus faecalis V583, a vancomycin-resistant clinical isolate, revealed that more than a quarter of the genome consists of probable mobile or foreign DNA. One of the predicted mobile elements is a previously unknown vanB vancomycin-resistance conjugative transposon. Three plasmids were identified, including two pheromone-sensing conjugative plasmids, one encoding a previously undescribed pheromone inhibitor. The apparent propensity for the incorporation of mobile elements probably contributed to the rapid acquisition and dissemination of drug resistance in the enterococci.     

Concurrent isolation from patient of two arboviruses, Chikungunya and dengue type 2

Chikungunya virus and dengue type 2 virus were isolated from a single blood specimen taken from a patient in the acute phase of a dengue-like illness seen at Christian Medical College Hospital, Vellore, South India, in October 1964. In serial blood specimens collected from this patient there was an increase in antibody to these same two viruses. The technique for unmasking an agent (such as dengue) with a long incubation period in mice in the presence of an agent with a short incubation period is described.     

Amyotrophic lateral sclerosis: effect of serum on anterior horn cells in tissue culture

A high proportion of diluted serums of patients with amyotrophic lateral sclerosis were toxic to the anterior horn cells of the mouse in tissue culture. This is not a general cytotoxicity, since apparently only the neurons were killed. Serums from other degenerative neurological diseases were inactive.     

A whole-genome assembly of Drosophila

We report on the quality of a whole-genome assembly of Drosophila melanogaster and the nature of the computer algorithms that accomplished it. Three independent external data sources essentially agree with and support the assembly's sequence and ordering of contigs across the euchromatic portion of the genome. In addition, there are isolated contigs that we believe represent nonrepetitive pockets within the heterochromatin of the centromeres. Comparison with a previously sequenced 2.9- megabase region indicates that sequencing accuracy within nonrepetitive segments is greater than 99. 99% without manual curation. As such, this initial reconstruction of the Drosophila sequence should be of substantial value to the scientific community.     

Catagonus, an "extinct" peccary, alive in paraguay

A third species of peccary, discovered in the Chaco of Paraguay, is added to the living members of family Tayassuidae. It is assigned to the genus Catagonus Ameghino, heretofore considered confined to the Pleistocene. The new peccary is conspecific with Catagonus wagneri (Rusconi), a species placed in the related extinct genus Platygonus LeConte when it was described from pre-Hispanic archeological deposits of Argentina.     

Pyogranulomatous panniculitis in a domestic cat associated with Pseudomonas luteola infection

Pseudomonas luteola, a pathogen causing disease in humans, has in animals been reported only in rainbow trout and ferrets. This case report describes pyogranulomatous panniculitis in a cat associated with P. luteola infection. Organisms were seen histologically and identified with PCR and sequencing. Lesions resolved after treatment with marbofloxacin.     

Long term effects of saline irrigation on the yield and growth of mature Williams pear trees

Salt tolerance of mature Williams Bon Cretien pear trees was assessed in a field trial on a duplex, slowly permeable clay loam. The trees were irrigated with a range of salinities; electrical conductivity of irrigation water (EC_w) of 0.2 to 1.4 dS/m by flood for seven years or 0.2 to 2.1 dS/m by microjet sprinklers for nine years. Water-table levels were maintained below 3 m by a groundwater pump. Yield and leaf ion content were assessed during the treatment period. Aspects of growth and physiology were monitored in the 0.2 and 2.1 dS/m microjet treatments during the seventh irrigation season.Soil profile salinities varied between 3.0 and 4.3 dS/m for the most saline flood treatment and from 1.5 to 2.6 dS/m for the most saline microjet treatment. Soil sodicity (sodium absorption ratio) increased during the experiment, reaching a maximum of 9 in the most saline treatments. The salinity treatments caused reduced yields after seven years. In the most saline treatment (EC_w = 2.1 dS/m, microjet-irrigated), yield decreased to about 60 and 50% of the control in the eighth and ninth years, respectively, and 40% of trees were dead in the ninth year. Leaf ion concentrations (in January) of the most saline treatment were at excess levels (>0.1% Cl and >0.02% Na) from 1982 to 1990. There were significant (P<0.01) negative linear relationships between yield in 1990 and leaf Na and Cl, measured both in 1990 and in 1989. During the seventh season of saline irrigation, lateral shoot growth was reduced, leaves and fruit were smaller and leaf fall was earlier in the 2.1 dS/m treatment compared with the control. Dawn and midday water potential and osmotic potential were not significantly affected by saline irrigation. Midday CO₂-assimilation rates (A) and leaf conductance to water vapour diffusion (g) were similar for 2.1 dS/m irrigated and control trees, however there was a trend towards a reduction in A and g of these salt-treated trees late in the irrigation season when leaf Na and Cl had increased to 250 and 240 mM (tissue water basis) respectively.     

The Seychelles Child Development Study: Results and New Directions Through Twenty-Nine Months

The Seychelles Child Development Study was hegun in 1986 to prospectively examine the association between child development and prenatal and postnatal methylmercury exposure from a high fish diet. Hair mercury levels from mothers and children are used as the index of exposure. A cross-sectional Pilot Study of 789 infants suggested that prenatal mercury exposure may affect development and that the effect decreased with age independently of exposure. A follow up of 217 Pilot Study children at 66 months of age also suggested that neurodevelopmental effects of prenatal exposure might be present, but the associations were dependent on outcomes in a small number of children. On the basis of the initial results of the Pilot Study a prospective, longitudinal Main Study, with more data on confounding variables and more extensive developmental testing, was hegun on a new cohort of 779 children. No association between prenatal exposure and primary neurodevelopmental outcomes was seen at 6 1/2, 19, or 29 months of age. There was an inverse relationship at 29 months in boys only between maternal hair mercury level and activity level, as judged by the examiner during the testing session (one of seven behavioral subscales of the Infant Behavior Record, of the Bayley Scales of Infant Development).In addition to an interaction between maternal hair level and gender, subsequent, secondary analyses are examining interactions between mercury level and a number of socioeconomic factors. Secondary analyses of developmental milestones, similar to those used in the Iraq study, are also under way. Although the association with activity suggests the need for further study of this cohort, no definite adverse neurodevelopmental effects from fetal mercury exposure have been detected through 29 months of age. In a related study, brains were obtained at autopsy from thirty-two Seychellois infants. Tissue from six different brain regions was examined histologically and analyzed for mercury. No definite histological abnormalities were found. Mercury levels ranged from about 50 ppb to 300 ppb and there was good correlation among brain regions. For 27 brains maternal hair from delivery was available and maternal hair mercury levels correlated well with levels in infant brain.