A promising biological control agent for the invasive alien plant,Pereskia aculeata Miller (Cactaceae), in South Africa

Pereskia aculeata Miller (Cactaceae) is an invasive alien plant from Central and South America that has become a problematic environmental weed in South Africa. A potential biological control agent, the stem-wilter, Catorhintha schaffneri Brailovsky & Garcia (Coreidae), was collected in southern Brazil and imported into quarantine in South Africa. Field host range data suggested that C. schaffneri has a host range restricted to P. aculeata. No-choice nymph survival tests were then conducted on 27 test plant species in 9 families. Survival to the adult stage was only recorded on P. aculeata and the closely related Pereskia grandifolia Haw. (Cactaceae). Mortality was significantly higher on P. grandifolia with only 3% of the nymphs reaching the adult stage compared with 74% on P. aculeata indicating that P. aculeata is the primary host plant. P. grandifolia is native in South America and is of no agricultural importance in South Africa so any feeding on P. grandifolia in South Africa would have no negative environmental or economic consequences. In other tests, adult survival on P. aculeata [25.8 days (SE ± 3.74)] was significantly longer than on other test plant species [4.3 days (SE ± 0.36)] further confirming the host specificity of the species. Impact studies conducted in quarantine indicated that C. schaffneri is damaging to P. aculeata, significantly reducing the number of leaves and the shoot lengths of plants, even at relatively low insect densities. C. schaffneri is safe for release in South Africa and is likely to be a damaging and effective agent.     

Feasibility of Performing Multiple Point of Care Testing for HIV Anti-Retroviral Treatment Initiation and Monitoring from Multiple or Single Fingersticks

Background

Point of Care testing (POCT) provides on-site, rapid, accessible results. With current South African anti-retroviral treatment guidelines, up to 4 fingersticks /patient/clinic visit could be required if utilizing POC. We determined the feasibility and accuracy of a nurse performing multiple POCT on multiple fingersticks followed by simplification of the process by performance of multiple POC on a single fingerstick.

Method and Findings

Random HIV positive adult patients presenting at a HIV treatment clinic in South Africa, for ART initiation/ monitoring, were approached to participate in the study between April-June 2012. Phase I: n=150 patients approached for multiple POCT on multiple fingersticks. Phase II: n=150 patients approached for multiple POCT on a single fingerstick. The following POC tests were performed by a dedicated nurse: PIMA (CD4), HemoCue (hemoglobin), Reflotron (alanine aminotransferase, creatinine). A venepuncture specimen was taken for predicate laboratory methodology. Normal laboratory ranges and Royal College of Pathologists Australasia (RCPA) allowable differences were used as guidelines for comparison. In 67% of participants, ≥3 tests were requested per visit. All POCT were accurate but ranged in variability. Phase I: Hemoglobin was accurate (3.2%CV) while CD4, alanine aminotransferase and creatinine showed increased variability (16.3%CV; 9.3%CV; 12.9%CV respectively). PIMA generated a misclassification of 12.4%. Phase II: Hemoglobin, alanine aminotransferase and creatinine showed good accuracy (3.2%CV, 8.7%CV, 6.4%CV respectively) with increased variability on CD4 (12.4%CV) but low clinical misclassification (4.1%). No trends were observed for the sequence in which POC was performed on a single fingerstick. Overall, PIMA CD4 generated the highest error rate (16-19%).

Conclusions

Multiple POCT for ART initiation and/or monitoring can be performed practically by a dedicated nurse on multiple fingersticks. The process is as accurate as predicate methodology and can be simplified using a single fingerstick.     

Nyasol and 1,3(5)-diphenyl-1-pentene related glycosides from Hypoxis angustifolia

From the rhizomes of Hypoxis angustifolia, nyasol, (Z)-1-(4′-hydroxyphenyl)-3-(4′-hydroxyphenyl)-l,4-pentadiene, has been isolated and identified, together with hypoxoside, nyasoside, nyaside and mononyasine A and B.