Tama | mrc unit, the gambia newsletter | vol. 12 | issue 01 | 2013

inactivated rdxA in Mtz(r) strains were identified and explained using RdxA protein's structure. All of the strains were sensitive to clarithromycin and erythromycin. Amoxicillin and tetracycline resistance was rare. Sequence analysis indicated that most tetracycline resistance, when found, was not due to 16S rRNA gene mutations. These data suggest caution in the use of Mtz-based therapies in The Gambia. The increasing use of macrolides against respiratory infections in The Gambia calls for continued antibiotic susceptibility monitoring. The rich variety of rdxA mutations that we found will be useful in further structure-function studies of RdxA, the enzyme responsible for Mtz susceptibilityin this important pathogen.
Secka O, Berg DE, Antonio M, Corrah T, Tapgun M, Walton R, Thomas V, Galano JJ, Sancho J, Adegbola RA, Thomas JE. Antimicrob Agents Chemother. 2013 Mar;57(3):1231-7. Epub 2012 Dec 21.
Development of odour-baited flytraps for sampling the African latrine fly, Chrysomya putoria, a putative vector of enteric diseases.
African pit latrines produce prodigious numbers of the latrine fly, Chrysomya putoria, a putative vector of diarrhoeal pathogens. The investigators set out to develop a simple, low-cost odour-baited trap for collecting C. putoria in the field. A series of field experiments was carried out in The Gambia to assess the catching-efficiency of different trap designs. The basic trap was a transparent 3L polypropylene box baited with 50 g of fish, with a white opaque lid with circular entrance holes. Variations of the number, diameter, position and shape of the entrance holes were tested, the height of the trap above ground, degree of transparency of the box, its shape, volume, colour, and the attractiveness of gridded surfaces on or under the trap. Traps were rotated between positions on different sampling occasions using a Latin Square design. The optimal trapping features were incorporated into a final trap that was tested against commercially available traps. Features of the trap that increased the number of flies caught included: larger entrance holes (compared with smaller ones, p<0.001), using conical collars inside the holes (compared with without collars, p = 0.01), entrance holes on the top of the trap (compared with the side or bottom,p<0.001), traps placed on the ground (compared with above ground, p<0.001), the box having transparent sides (compared with being opaque, p<0.001), and with no wire grids nearby (compared with those with grids, p = 0.03). This trap collected similar numbers of C. putoria to other common traps for blow flies. The optimum trap design was a transparent box, with a white plastic lid on top, perforated with 10 conical entrance holes, placed on the ground. This simple trap provides a cheap, low-maintenance and effective method of sampling C. putoria in the field.
Lindsay TC, Jawara M, D'Alessandro U, Pinder M, Lindsay SW. PLoS One. 2012;7(11):e50505. doi: 10.1371/journal.
Interferon-γ ELISPOT as a Biomarker of Treatment Efficacy in Latent Tuberculosis Infection: A Clinical Trial.
Biomarkers that can be used to evaluate new interventions against latent tuberculosis infection (LTBI) and predict reactivation TB disease are urgently required. The objective of this study was to evaluate ESAT-6 and CFP-10 (EC) IFN-γ ELISPOT as a biomarker for treatment efficacy in LTBI. This was a randomized, blinded, and placebo-controlled trial of INH in EC ELISPOT and Mantoux test positive participants. Participants received a 6-month course of 900 mg INH twice weekly or a matching placebo. INH acetylator genotypes were determined and urine tested for INH metabolites to confirm adherence. The proportion of positive responders for CFP-10 and ESAT-6 between treatment arms was compared using mixed effects logistic regression models. A Tweedie (compound Poisson) model was fitted to allow for zero inflation and overdispersion of quantitative response. The proportions of EC ELISPOT-positive subjects reduced over time (P < 0.001) but did not differ by study arm (P = 0.36). Median spot-forming units for ESAT-6 and CFP-10 also declined significantly with time (P < 0.001) but did not differ by study arm (P = 0.74 and 0.71, respectively). There was no evidence of an interaction between acetylator status and INH reatment with respect to ELISPOT results over time.

Source: http://www.mrc.gm/enewsletter/files/assets/downloads/page0017.pdf