Gonococcus infection probably acquired from bathing in a natural thermal pool: a case report.

BACKGROUND: Authorities need to recognize that, while rare, gonorrhea can be transmitted nonsexually, and should not be presumed definitive evidence of abuse. We report the unusual case of a girl diagnosed with Neisseria gonorrhoeae after bathing in a heavily frequented hot pool at the edge of the crater lake Specchio di Venere ("Mirror of Venus") on Pantelleria Island, Italy. CASE PRESENTATION: Two days after bathing in the pool, this 11-year-old Austrian girl developed vulvovaginitis that partially settled with antifungal cream. Subsequent swabs cultured positive for Neisseria gonorrhoeae. Family members tested negative. The child adamantly denied any sexual contact, and no opportunities for sexual exposure could be identified. It was therefore concluded that she must have acquired the infection from pool water contaminated by gonococcus after a 2-day incubation period. The infection was successfully treated with ceftriaxone and azithromycin with no adverse effects. CONCLUSIONS: The pools are shallow, close to body temperature, isotonic, slightly acidic from CO2 bubbles, and contain organic particles, all potentially supporting survival of gonococcus. There are historical case reports in the literature of gonococcal epidemics in children's hospitals being traced to common baths. It is imperative that all cases of gonococcal infection in children are fully investigated, including examining all other relevant family members, to determine whether sexual assault has occurred. This is not a diagnosis to be missed. However, both sexual and nonsexual transmission are possible. A presumption that a gonococcal infection is diagnostic of sexual abuse can be dire, with children wrongfully removed from their parents' care, and their caregivers facing false charges of sexual crimes. Our case serves to illustrate that the very uncommon diagnosis of gonorrhea in a child may be the result of nonsexual transmission of the infection, and that contaminated hot pools are a very rare source of infection that should be considered.

Tracking the marine migration routes of South Pacific silver eels.

Three catadromous Pacific eels (2 Anguilla marmorata, 1 A. megastoma) from the Archipelago of Vanuatu were tagged with pop-up satellite archival transmitters and their migration tracks towards their presumed spawning area approximately 870 km northeast of the point of release were reconstructed in order to evaluate their movements in relation to oceanographic conditions. We used the timing of diel vertical migrations to derive the eels' positions. Two A. marmorata exhibited steep-angled turns resulting in a zig-zag migration path along the east-west axis, while one A. megastoma took a relatively straight course towards the presumed spawning area. They migrated with a speed over ground of 21-23 km day-1. In this region, the eastward flow of the South Equatorial Counter Current (SECC, ∼ 5-10°S) separates the westward flowing South Equatorial Current (SEC; ∼0-5°S and 10-18°S) into two branches. During shallower nighttime migration depths around 150 m eels crossed a variable flow field through the southern branch of the westward SEC with westward propagating mesoscale eddies and the eastward SECC, but stayed south of the stronger northern branch of SEC possibly increasing retention time of larvae within this area. The eels headed towards a tongue of high-salinity Subtropical Underwater (STUW) that may have provided cues for orientation. The eels did not move beyond a salinity front of 35.9-36.0 at a depth of 100-200 m, which may have provided cues for orientation towards the spawning area. These 3 tracks may represent the movements of mature silver eels all the way to where they spawn.

Distribution of anguillid leptocephali and possible spawning areas in the South Pacific Ocean.

Seven South Pacific anguillid eel species live from New Guinea to French Polynesia, but their spawning areas and life histories are mostly unknown despite previous sampling surveys. A July-October 2016 research cruise was conducted to study the spawning areas and times, and larval distributions of South Pacific anguillid eels, which included a short 155°E station-line northeast of New Guinea and five long transects (5-25°S, 160°E-140°W) crossing the South Equatorial (SEC) and other currents. This survey collected nearly 4000 anguilliform leptocephali at 179 stations using an Isaacs-Kidd Midwater Trawl accompanied by 104 CTD casts. Based on mor-phometric observations and DNA sequencing, 74 anguillid leptocephali were collected, which in the southern areas included 29 larvae of six species: Anguilla bicolor pacifica, A. marmorata, A. australis, A. reinhardtii, A. megastoma, and A. obscura (all anguillid species of the region were caught except A. dieffenbachii). Small A. australis (9.0-16.8 mm) and A. reinhardtii (12.4, 12.5 mm) leptocephali were collected south of the Solomon Islands, other A. australis (10.8-12.0 mm) larvae were caught northwest of Fiji along with an A. obscura (20.0 mm) larva, and an A. marmorata (7.8 mm) larva was collected near Samoa. Considering collection sites, larval ages from otolith analysis, and westward SEC drift, multiple spawning locations occurred from south of the Solomon Islands and the Fiji area (16-20 days old larvae) to near Samoa (19 days old larva) during June and July in areas where high-salinity Subtropical Underwater (STUW, ~150 m depth) and the warm, low-salinity surface Fresh Pool were present. Five long hydrographic sections showed the strong Fresh Pool in the west and the STUW formation area in the east.

Stable species boundaries despite ten million years of hybridization in tropical eels.

Genomic evidence is increasingly underpinning that hybridization between taxa is commonplace, challenging our views on the mechanisms that maintain their boundaries. Here, we focus on seven catadromous eel species (genus Anguilla) and use genome-wide sequence data from more than 450 individuals sampled across the tropical Indo-Pacific, morphological information, and three newly assembled draft genomes to compare contemporary patterns of hybridization with signatures of past introgression across a time-calibrated phylogeny. We show that the seven species have remained distinct for up to 10 million years and find that the current frequencies of hybridization across species pairs contrast with genomic signatures of past introgression. Based on near-complete asymmetry in the directionality of hybridization and decreasing frequencies of later-generation hybrids, we suggest cytonuclear incompatibilities, hybrid breakdown, and purifying selection as mechanisms that can support species cohesion even when hybridization has been pervasive throughout the evolutionary history of clades.

High genetic diversity and lack of pronounced population structure in five species of sympatric Pacific eels.

Understanding the population structure of tropical anguillids residing in the Pacific is vital for their conservation management. Here, the population genetic structure of five sympatric freshwater eels (Anguilla marmorata Quoy & Gaimard, A. megastoma Kaup, A. obscura Steindachner, A. reinhardtii Günther and A. australis Richardson) across 11 western South Pacific (WSP) islands was investigated based on partial nucleotide sequences of the mtDNA control region and the nuclear GTH2b genes of 288 newly collected samples jointly with existing sequences. WSP anguillids are characterised by overall high levels of genetic diversity. Both mtDNA and nuclear sequences provided no evidence for distinct geographic clines or barriers in any of the species across the WSP. The occurrence of admixed individuals between A. marmorata and A. megastoma was confirmed, and a new possible occurrence of a further species was revealed (A. interioris Whitley on Bougainville Island). All species showed evidence for demographic population growth in the Pleistocene, and a subsequent population reduction for A. megastoma. Common spawning grounds and mixing of larvae by ocean currents could promote the lack of pronounced isolation by distance, a finding that has significant implications for the future management of anguillids in the area.

First Limnological Characterization of Crater Lake Billy Mitchell (Bougainville Island, Papua New Guinea)1.

In this study we present a first limnological characterization of Lake Billy Mitchell [1,013 m above sea level (a.s.l.), 88.3 m depth, 3 km2 surface area] in central Bougainville Island, Papua New Guinea. Physicochemical depth profiles indicated mixis of the entire water body with oxygen saturation reaching 55% in the deepest layers. A shallow thermocline was eroded at night, indicating atelomixis. HCO 3 - , Cl - , SO 4 2 - and Na+, Ca2+, Mg2+ were the dominant anions and cations, respectively, leading to a conductivity of around 1,230 µS cm-1. The pH was close to neutral throughout the water column, and no accumulation of CO2 was observed at greater depths. With a total phosphorus concentration of around 25 µg liter-1 the lake can be considered as meso-to eutrophic. The phytoplankton community consisted of 18 taxa. The dinophyte Peridiniopsis cf. penardii and the filamentous green alga Planctonema lauterbornii dominated in the uppermost layer and reached a total biovolume around 16 mm3 liter-1. Six macrophyte taxa were found (three Spermatophyta/three Bryophyta), with the water chestnut Eleocharis dulcis covering the shoreline and Ceratophyllum demersum spreading to at least 3 m depth. Seven ciliate species were detected (<5 individuals ml-1) with bacterivorous scuticociliates and the prostomatid Coleps hirtus hirtus dominating the assemblage. The micrometazoan plankton community comprised the rotifer Anuraeopsis fissa, the copepod Mesocyclops cf. affinis, and a cladoceran species with-in the Ceriodaphnia cornuta group all concentrating in the upper water column. The only fish species found in the lake was the eel Anguilla megastoma, whereas in the effluent river this species occurred together with Anguilla marmorata.

The hydrographic features of anguillid spawning areas: potential signposts for migrating eels.

Catadromous anguillid eels (Genus Anguilla) migrate from their freshwater or estuarine habitats to marine spawning areas. Evidence from satellite tagging studies indicates that tropical and temperate eel species exhibit pronounced diel vertical migrations between 150 to 300 m nighttime depths to 600 to 800 m during the day. Collections of eggs and larvae of Japanese eels (A. japonica) show they may spawn at these upper nighttime migration depths. How anguillid eels navigate through the ocean and find their spawning areas remains unknown, so this study describes the salinity, temperature and geostrophic currents between 0 and 800 m depths within two confirmed and three hypothetical anguillid spawning areas during likely spawning seasons. Within all four ocean gyres many eels would encounter subducted 'Subtropical Underwater' during their nighttime ascents that could provide odor plumes as signposts. Four spawning areas are located near the western margins of where subducted water masses form cores of elevated salinities (~35.0 to 36.8) around 150 m depths, while one is found near the center of subduction. Low salinity surface waters and fronts are present in some of the areas above the high-salinity cores. Spawning may occur at temperatures between 16 to 24°C where the thermocline locally deepens. At spawning depths, weak westward currents (~0 to 0.1 m s-1) prevail, and eastward surface countercurrents are present. Anguillid eels possess acute sensory capabilities to detect these hydrographic features as potential signposts guiding them to where they spawn.

Differential diagnosis of Triaenophorus crassus and T. nodulosus experimental infection in Cyclops abyssorum praealpinus (Copepoda) from the Alpine Lake Grundlsee (Austria) using PCR-RFLP.

In 2005, an epidemic of the cestode Triaenophorus crassus in Arctic charr, Salvelinus umbla from Lake Grundlsee (Austria) was reported, resulting in the closure of the local fisheries. The parasite uses a copepod and a salmonid fish as intermediate hosts, and the European pike (Esox lucius) as definitive host. In Lake Grundlsee procercoids of T. crassus, T. nodulosus and Eubothrium salvelini use the copepod Cyclops abyssorum praealpinus as their first intermediate host. We report on the development of a PCR-RFLP assay for the specific differentiation between the procercoids of the three cestode species. Ban I restriction sites within a 207-bp 18S rRNA-amplified fragment yielded two and three species-specific products to unequivocally distinguish between T. crassus and T. nodulosus, respectively. The assay is sufficiently sensitive to characterise a single procercoid of both Triaenophorus species in their copepod host, enabling a direct measure of infection. This assay will be useful in monitoring the progress of the control methods currently in place.

Hang on or run? Copepod mating versus predation risk in contrasting environments.

Mating durations of copepods were found to differ significantly between fishless high-altitude waters and lowland lakes containing fish. In lowland species the whole mating process was completed within a few minutes, but it averaged over an hour in high-altitude species. Alpine copepods showed a prolonged post-copulatory association between mates, during which the male clasped the female for an extended period after spermatophore transfer, while in lowland species males abandoned their partner immediately after copulation. Prolonged associations also occurred after transfer of spermatophores to heterospecific females with shorter conspecific mating duration, suggesting that male interests largely dictate the time spent in tandem. The differences observed may be adaptations to environments with different predation pressure, as pairs in tandem are more conspicuous and less reactive than single animals. We argue that differences in mating behavior and mating duration evolved under sexual versus natural selection, reflecting trade-offs between enhancement of fertilization success and reduction of vulnerability to visual predation. In fishless mountain lakes with high intrasexual competition, guarding males can reduce the risk of spermatophore displacement or the risk that the female will accept sperm from rival males without increased risk of being eaten, thereby maximizing paternity. Populations from fishless alpine lakes further differed from lowland species by exhibiting higher female/male size dimorphism and more intense pigmentation. While these traits vary between populations according to predation pressure, mating duration appears to be more species-specific.

Trophic specialisations in alternative heterochronic morphs.

Polymorphisms are suspected of reducing competition among conspecifics in heterogeneous environments by allowing differential resource use. However the adaptive significance of alternative morphs has been poorly documented. The aim of this study is to determine food partitioning of two heterochronic morphs of the Alpine newt, Triturus alpestris, in mountain lakes. The morphs differ in the functional morphology of their feeding apparatus. Only paedomorphs are able to expel water during prey suction behind the mouth through gill slits. We observed a substantial trophic differentiation between morphs in all lakes. Paedomorphs preyed mainly on plankton, whereas metamorphs foraged on terrestrial invertebrates that fell upon the water surface. This resource partitioning may facilitate the coexistence of the alternative morphs in lakes devoid of vertebrate competitors. Food diversity may thus favour the evolutionary maintenance of facultative polymorphism in natural populations.