Recurrent aseptic meningitis for 24 years: diagnosis and treatment of an associated lesion

Recurrent meningitis in the absence of an identifiable causative organism or anatomical source is a difficult diagnostic challenge for any infectious disease consultant. We evaluated a 49-year-old woman with episodes of meningitis which occurred on at least nine separate occasions for over 24 years. No causative organism, physical agent, or underlying disease process was identified as the source of this patient's recurrent lymphocytic meningitis. When computerized tomographic head scanning was first performed in 1977, a prominence of the left lateral ventricle was evident. It was not until the area was subsequently evaluated with magnetic resonance imaging techniques 13 years later that a lesion could be clearly identified, removed, and evaluated at pathology. Time alone will tell whether the lesion, a cavernous hemangioma, was truly the cause of this patient's recurrent aseptic meningitis for 24 years.     

The effect of mixtures of Lactobacillus spp. on the survival of enterotoxigenic Escherichia coli in in vitro continuous culture of porcine intestinal bacteria

Mixtures of strains of Lactobacillus spp., two of strains inhibitory to growth of the porcine enteropathogen Escherichia coli O149: K88ac: K91 in a co-culture screen, and one of strains with no effect on this pathogen, were examined to determine their effects on the retention of this pathogen in an in-vitro continuous culture system designed to maintain a representation of the porcine ileal microflora. Strains effective in co-culture also increased the rate of decline of the pathogen in the continuous culture. The inhibitory effect exceeded the displacement effect observed with non-inhibitory strains.     

Conserving biodiversity efficiently: what to do, where, and when

Conservation priority-setting schemes have not yet combined geographic priorities with a framework that can guide the allocation of funds among alternate conservation actions that address specific threats. We develop such a framework, and apply it to 17 of the world's 39 Mediterranean ecoregions. This framework offers an improvement over approaches that only focus on land purchase or species richness and do not account for threats. We discover that one could protect many more plant and vertebrate species by investing in a sequence of conservation actions targeted towards specific threats, such as invasive species control, land acquisition, and off-reserve management, than by relying solely on acquiring land for protected areas. Applying this new framework will ensure investment in actions that provide the most cost-effective outcomes for biodiversity conservation. This will help to minimise the misallocation of scarce conservation resources.     

Sinorhizobium fredii HH103 rkp-3 genes are required for K-antigen polysaccharide biosynthesis, affect lipopolysaccharide structure and are essential for infection of legumes forming determinate nodules

The Sinorhizobium fredii HH103 rkp-3 region has been isolated and sequenced. Based on the similarities between the S. fredii HH103 rkpL, rkpM, rkpN, rkpO, rkpP, and rkpQ genes and their corresponding orthologues in Helicobacter pylori, we propose a possible pathway for the biosynthesis of the S. fredii HH103 K-antigen polysaccharide (KPS) repeating unit. Three rkp-3 genes (rkpM, rkpP, and rkpQ) involved in the biosynthesis of the HH103 KPS repeating unit (a derivative of the pseudaminic acid) have been mutated and analyzed. All the rkp-3 mutants failed to produce KPS and their lipopolysaccharide (LPS) profiles were altered. These mutants showed reduced motility and auto-agglutinated when early-stationary cultures were further incubated under static conditions. Glycine max, Vigna unguiculata (determinate nodule-forming legumes), and Cajanus cajan (indeterminate nodules) plants inoculated with mutants in rkpM, rkpQ, or rkpP only formed pseudonodules that did not fix nitrogen and were devoid of bacteria. In contrast, another indeterminate nodule-forming legume, Glycyrrhiza uralensis, was still able to form some nitrogen-fixing nodules with the three S. fredii HH103 rifampicin-resistant rkp-3 mutants tested. Our results suggest that the severe symbiotic impairment of the S. fredii rkp-3 mutants with soybean, V. unguiculata, and C. cajan is mainly due to the LPS alterations rather than to the incapacity to produce KPS.     

Secreted frizzled-related protein disrupts PCP in eye lens fiber cells that have polarised primary cilia

Planar cell polarity (PCP) signaling polarises cells along tissue axes. Although pathways involved are becoming better understood, outstanding issues include; (i) existence/identity of cues that orchestrate global polarisation in tissues, and (ii) the generality of the link between polarisation of primary cilia and asymmetric localisation of PCP proteins. Mammalian lenses are mainly comprised of epithelial-derived fiber cells. Concentrically arranged fibers are precisely aligned as they elongate along the anterior-posterior axis and orientate towards lens poles where they meet fibers from other segments to form characteristic sutures. We show that lens exhibits PCP, with each fiber cell having an apically situated cilium and in most cases this is polarised towards the anterior pole. Frizzled and other PCP proteins are also asymmetrically localised along the equatorial-anterior axis. Mutations in core PCP genes Van Gogh-like 2 and Celsr1 perturb oriented fiber alignment and suture formation. Suppression of the PCP pathway by overexpressing Sfrp2 shows that whilst local groups of fibers are often similarly oriented, they lack global orientation; consequently when local groups of fibers with different orientations meet they form multiple, small, ectopic suture-like configurations. This indicates that this extracellular inhibitor disrupts a global polarising signal that utilises a PCP-mediated mechanism to coordinate the global alignment and orientation of fibers to lens poles.     

Development and validation of a TaqMan PCR assay for the Australian abalone herpes-like virus

The recent emergence of a herpes-like virus in both farmed and wild populations of abalone in Victoria, Australia, has been associated with high mortality rates in animals of all ages. Based on viral genome sequence information, a virus-specific real-time TaqMan assay was developed for detection and identification of the abalone herpes-like virus (AbHV). The assay was shown to be specific as it did not detect other viruses from either the Herpesvirales or the Iridovirales orders which have genome sequence similarities. However, the TaqMan assay was able to detect DNA from the Taiwanese abalone herpes-like virus, suggesting a relationship between the Taiwanese and Australian viruses. In addition, the assay detected < 300 copies of recombinant plasmid DNA per reaction. Performance characteristics for the AbHV TaqMan assay were established using 1673 samples from different abalone populations in Victoria and Tasmania. The highest diagnostic sensitivity and specificity were 96.7 (95% CI: 82.7 to 99.4) and 99.7 (95% CI: 99.3 to 99.9), respectively, at a threshold cycle (C(T)) value of 35.8. The results from 2 separate laboratories indicated good repeatability and reproducibility. This molecular assay has already proven useful in confirming presumptive diagnosis (based on the presence of ganglioneuritis) of diseased abalone in Victorian waters as well as being a tool for surveillance of wild abalone stocks in other parts of Australia.     

Lacaziosis in bottlenose dolphins Tursiops truncatus along the coastal Atlantic Ocean, Florida, USA

This study represents the first systematic study of lacaziosis (lobomycosis) in bottlenose dolphins Tursiops truncatus in the Atlantic Ocean along the east-central coast of Florida, USA. Lacaziosis is a chronic infection of the skin caused by the fungus Lacazia loboi, which affects only dolphins and humans. Previous studies have shown a high prevalence (6.8 to 12.0%) of lacaziosis in resident dolphins from the adjacent Indian River Lagoon Estuary (IRL), where the disease is endemic. We examined the prevalence of lacaziosis in this coastal area using photo-identification data collected between 2002 and 2008 to determine the prevalence of lacaziosis in coastal dolphins using photographic methodology shown to have high sensitivity and specificity in prior research. The prevalence of skin lesions compatible with lacaziosis estimated from photographic data was 2.1% (6/284), approximately 3 times lower than that described for the estuarine population using similar methods. To exclude potential bias introduced by differences in study duration and survey effort among areas, an 18 mo period when effort was most equal (January 2006 to June 2007) was chosen for statistical comparison. The prevalence of lacaziosis estimated from photographic data was significantly lower (3.8%: n = 6/160) in the Atlantic Ocean compared to the IRL (12.0%: n = 20/167) (risk ratio = 3.19, 95% CI 1.32 to 7.75, p < 0.01 by chi-square analysis). The lower prevalence of lacaziosis in dolphins found in the Atlantic Ocean and the overall lack of movement of dolphins between these habitats suggests that environmental conditions within the estuary may favor viability of L. loboi, and/or that immune compromise in resident estuarine dolphins is a precursor to the disease.