A survey of coccidian infection (Apicomplexa: Eimeriidaea) of freshwater fish in South Africa

Fish coccidia, especially Goussia and Eimeria spp., are common and frequent parasites of fish. The majority of the known species has been described from the Eurasian continent. Little is known, however, of the coccidian infections of South African freshwater fish. In September 2003, 77 specimens from 7 freshwater fish species were harvested at 4 sites from rivers and ponds in the Gauteng, North West and Limpopo provinces in South Africa. The fish were surveyed for coccidian infections. Two fish species were infected with apicomplexans belonging to Goussia. In banded tilapia (Tilapia sparrmanii Smith) unsporulated oocysts of Goussia vanasi Landsberg and Paperna, 1987 were found. These sporulated in tap water within 24 hours. Another species in the gut of the chubbyhead barb (Barbus anoplusWeber) harboured sporulated oocysts in the faeces and in the intestinal epithelium. The latter species has been described as Goussia anopli. This short survey suggests that more thorough studies might reveal the occurrence of further coccidian species in South African fishes

Description of a new actinosporean type from South African freshwater

The 1st report on actinospores described these organisms as parasites related to myxosporeans. For a long time this group of parasites was believed to represent an independent taxonomic entity. Research on actinosporeans became more intensive after it was shown that they corresponded to the intraoligochaete developmental stages of fish-parasitic myxosporeans. The relevant research includes earlier surveys, as well as studies of actinospore infection of oligochaetes in natural waters and fish farms in connection with the life cycle of myxosporeans. Relatively little data areavailable on myxosporean infections of African freshwater fishes and only a single paper appeared in Africa on their actinosporean alternative stages infecting oligochaetes. In September 2003, actinospore infection of oligochaetes collected from the mud of 2 freshwater biotopes in South Africa was studied. Using the ‘cell-well plate method’, a new aurantiactinomyxon type was found in 1.1 % of the examined Branchiura sowerbyi oligochaete specimens from Rietvlei River northwards to Johannesburg, Gauteng. In 1.5 % of Branchiura sowerbyi collected in a pond (Padda Dam), near the Rand Afrikaans University, Johannesburg, the same aurantiactinomyxon type was found. Infected oligochaetes were found only after collection, no actinosporean release was recorded in Branchiura specimens kept alive for several weeks. Actinospore infection showed high intensity in oligochaetes in both positive cases. Until now, no actinosporean stages of myxosporeans have been described from South Africa. The aurantiactinospore type presented in this paper differs from the already known types described in the special literature

Identifying flies used for maggot debridement therapy

To the Editor: The use of maggots to clean necrotic wounds, known as maggot debridement therapy (MDT), has long been known to the scientific world. Its use has been recorded since the 1500s when soldiers’ wounds were often infested with maggots. Napoleon’s surgeon, Baron Dominic Larrey, reported that wounds that were infested with maggots appeared to heal faster than those without maggots.1 William Baer is considered to be the founder of modern MDT. While treating soldiers in World War I, he noted the good condition of wounds that had been infested with maggots, and was the first doctor on record to experiment with the use of maggots in treating infections.1 MDT even featured in the recent version of the film ‘Spartacus’. Various species of flies have been used for MDT,1 the most commonly used being Lucilia sericata, a greenbottle blowfly (Figs 1 and 2). This fly is closely related to another greenbottle, L. cuprina, but L. cuprina feeds on live as well as necrotic tissue, which is undesirable in MDT. L. cuprina is commonly named the ‘sheep blowfly’ because it is responsible for fly-strike in sheep, a form of massive, usually rectal myiasis that can kill sheep. A recent article2 suggested that L. cuprina was being used successfully for MDT at the Eugene Marais Hospital Wound Care Centre (EMHWCC). As this would be inconsistent with international experience in MDT and at odds with the usual biology of L. cuprina, it was decided to check the identity of these flies

The Small and the Dead: A Review of Ancient DNA Studies Analysing Micromammal Species

The file attached is the Published/publisher’s pdf version of the article

Molecular mechanism of action of the glucocorticoid receptor:Role of ligand-dependent receptor phosphorylation and half-life in determination of ligand-specific transcriptional activity. : Contents Pages

Glucocorticoids mediate their effects by binding to the glucocorticoid receptor (GR), resulting in modulation of transcription of target genes via direct binding to DNA or tethering via proteinprotein interactions. A central question is what determines the rank order of ligand-selective transcription with different GR ligands for the same gene in the same cell. Using a panel of twelve GR ligands, including agonists, partial agonists and antagonists, the relationship between the extent of GR phosphorylation at S226, GR turnover and transcriptional response, was investigated using a variety of biochemical approaches. Using a phospho-S226-specific GR antibody, ligand-selective S226 phosphorylation was shown to occur in both COS-1 and U2OS cells, while GR phosphorylation at S226 was shown to inhibit maximal transactivation and transrepression efficacy. Attempts to identify the kinases responsible for this interaction were inconclusive but suggested a combination of kinases is responsible for the in vivo phosphorylation of the hGR in these cells. Similarly the rate of GR degradation was different for the different ligands. Interestingly, both ligand-selective GR phosphorylation and half-life were found to correlate with efficacy for transactivation and transrepression of model synthetic reporter genes, where agonists resulted in the greatest extent of phosphorylation and the fastest vii rate of GR turnover, suggesting a link between these functions. Furthermore experiments where transcription was blocked suggest that GR turnover does not require transcription. However, using a S226A GR mutant, as well as in experiments where GR turnover was blocked, it was established that neither phosphorylation of the GR at S226 nor GR degradation rate determines the rank order of ligand-selective GR transactivation. The mechanisms whereby GR phosphorylation influence GR-mediated transcription was further investigated using a triple phosphorylation deficient mutant. It was shown that phosphorylation at one or more of residues S203/S211/S226 is required for transactivation of a MMTV promoter but does not affect unliganded or agonist-induced GR degradation and acetylation. Additionally, it was shown that phosphorylation at S203/S211/S226 is not the sole determinant of co-activator p300 recruitment to the GR. Interestingly, GR-mediated transrepression via AP-1 is less sensitive to GR phosphorylation than GR-mediated transactivation, indicating different mechanisms in the role of GR phosphorylation on transactivation vs. transrepression. Pull-down and chromatin immunoprecipitation assays showed that phosphorylation of the GR at one or more of these residues are required for interaction of the GR with the co-activator GRIP-1 in vitro and for maximal recruitment of GR and GRIP-1 to the MMTV promoter in intact cells. Cellular fractionation showed that phosphorylation at these residues is not however required for GR nuclear localisation. Taken together these results support the conclusion that phosphorylation at one or more of S203/S211/S226 of the hGR is required for maximal transactivation response to enable GRIP-1 recruitment to the hGR

Insights into prey handling and feeding strategies by ghost crabs on sea turtle eggs and hatchlings

The feeding behaviour on sea turtle eggs and hatchlings by the golden ghost crab Ocypode convexa, a species endemic to the west coast of Australia, was observed in field and laboratory settings using infrared videography. On beaches where ghost crab densities are high, multiple crabs can feed on nests over several nights, often resulting in destruction of clutches. Crabs appear to anticipate the emergence of hatchlings, often congregating near nests in the moments prior to emergence. When feeding on eggs crabs rupture eggshells using the sharp tips of their claws, with tissue subsequently moved to the mouthparts for ingestion using the minor claw while the broken shell is held with the major claw. When feeding on hatchlings crabs generally restrain hatchlings using the large claw to grip them around the neck, while the small claw cuts through the soft skin around the neck to partially or fully sever the head before feeding from the cavity. Infrared videography was successfully used to observe cryptic prey handling and feeding behaviours that may be compromised by more traditional observational methods

Water Footprint of Table Grape Production Systems: A Review of South African and Global Studies

Being a water-scarce country, South Africa (SA) faces several water challenges, including drought andother effects of climate change. Therefore, there is a need to improve water-use efficiency (WUE) by accuratelyquantifying the water use and WUE of table grape vineyards. The objective of this review is to (i)provide an overview of water footprint (WF) studies conducted on table grape production systems in SAand globally; (ii) identify limitations in current WF assessments of table grape production systems; and(iii) establish a range of WF values for table grape production systems as an indicator of WUE and for usein decision-making regarding sustainable freshwater use. The review has demonstrated that only a limitednumber of detailed WF studies have been undertaken on table grapes in SA and globally. Region-specificlookup tables for quantifying blue, green and grey water use in table grape production systems are availablefor three table grape production regions of SA and could be used for future WF assessments. Mostglobal studies conducted on grape WF and WUE were desktop studies and did not include actual fieldrecords from production units, nor did they distinguish between different grape types (table, raisin andwine grapes). WF values must be interpreted in context, specifically regarding the water used versus yield,quality and income, as well as the region, climatic conditions, soil characteristics, irrigation and cultivationpractices. For future WF and WUE assessments, a more detailed breakdown of water use is recommended,both during the production process and postharvest

Selective glucocorticoid receptor properties of GSK866 analogs with cysteine reactive warheads

Synthetic glucocorticoids (GC) are the mainstay therapy for treatment of acute and chronic inflammatory disorders. Due to the high adverse effects associated with long-term use, GC pharmacology has focused since the nineties on more selective GC ligand-binding strategies, classified as selective glucocorticoid receptor (GR) agonists (SEGRAs) or selective glucocorticoid receptor modulators (SEGRMs). In the current study, GSK866 analogs with electrophilic covalent-binding warheads were developed with potential SEGRA properties to improve their clinical safety profile for long-lasting topical skin disease applications. Since the off-rate of a covalently binding drug is negligible compared to that of a non-covalent drug, its therapeutic effects can be prolonged and typically, smaller doses of the drug are necessary to reach the same level of therapeutic efficacy, thereby potentially reducing systemic side effects. Different analogs of SEGRA GSK866 coupled to cysteine reactive warheads were characterized for GR potency and selectivity in various biochemical and cellular assays. GR-and NF kappa B dependent reporter gene studies show favorable anti-inflammatory properties with reduced GR transactivation of two non-steroidal GSK866 analogs UAMC-1217 and UAMC-1218, whereas UAMC-1158 and UAMC-1159 compounds failed to modulate cellular GR activity. These results were further supported by GR immuno-localization and S211 phospho-GR western analysis, illustrating significant GR phosphoactivation and nuclear translocation upon treatment of GSK866, UAMC-1217, or UAMC-1218, but not in case of UAMC-1158 or UAMC-1159. Furthermore, mass spectrometry analysis of tryptic peptides of recombinant GR ligand-binding domain (LBD) bound to UAMC-1217 or UAMC-1218 confirmed covalent cysteine-dependent GR binding. Finally, molecular dynamics simulations, as well as glucocorticoid receptor ligand-binding domain (GR-LBD) coregulator interaction profiling of the GR-LBD bound to GSK866 or its covalently binding analogs UAMC-1217 or UAMC-1218 revealed subtle conformational differences that might underlie their SEGRA properties. Altogether, GSK866 analogs UAMC-1217 and UAMC-1218 hold promise as a novel class of covalent-binding SEGRA ligands for the treatment of topical inflammatory skin disorders

A new species of Argulus (Crustacea: Branchiura) from a bony fish in Algoa Bay, South Africa

The new species is characterized by the unique shape of the antennule, antenna and maxilla. In addition, huge scales are present on the mouth tube and smaller scales are present on the base of the mouth tube. A row of small spines is present inside the sucker rim of the maxillule. A round dimpled structure occurs ventral to the male gonopore and the unique accessory copulatoiy structures are described

Ripening Trends of Vitis vinifera L. cv Sugrasixteen (SABLE SEEDLESS®) Table Grapes at Different Crop Loads and Bunch Sizes

Crop load and bunch size manipulation are two prominent viticultural practices used in the production of Vitis vinifera L. cv. Sugrasixteen table grapes. However, their respective effects on berry ripening are unknown and were investigated in this study. A split-plot vineyard block design with three different crop loads (low, medium, and high) as the main treatments and two bunch size treatments (small and large) as the subplot factors were used. Weekly berry samples from veraison to harvest from each treatment were analysed for mass, total soluble solids (TSS), titratable acidity (TA), and pH. Data mining established the ripening trends and explored the possibility of estimating optimal harvest dates using EC50 values. Results showed that berries of large bunches had higher average mass than small bunches during ripening. Increased crop loads resulted in berries with lower mass, TSS and TSS: TA ratio, and delayed berry ripening. Conversely, berries from the low crop load increased in mass and accumulated TSS faster during ripening than higher crop loads, reaching EC50 two to four days earlier with accumulation starting to slow down at higher values.  EC50 could be used to estimate harvest dates for low to medium crop loads, but not for high crop loads. This study provides the first in-depth analysis of SABLE SEEDLESS® ripening trends concerning crop load and bunch size management. The results have implications for the grape’s overall eating quality. The statistical prediction of optimal harvest dates for lower crop loads could have practical benefits for the industry