TB treatment using family members, treatment supporters and self-administered therapies in rural Papua New Guinea

SETTING

Papua New Guinea (PNG) has one of the world's highest TB incidence rates. It is difficult for patients to access TB care in remote provinces due to insufficient infrastructure and challenging terrain, making varied, targeted delivery models for treating TB necessary.

OBJECTIVE

To assess treatment outcomes using self-administered treatment (SAT), family-supported treatment and community-based directly observed therapy (DOT) via treatment supporter (TS) in the PNG context.

DESIGN

A retrospective, descriptive analysis of routinely collected data from 360 patients at two sites in 2019-2020. All patients were assigned a treatment model based on risk factors (adherence or default) and offered patient education and counselling (PEC), family counselling and transportation fees. End-of-treatment outcomes were assessed for each model.

RESULTS

Treatment success rates among drug-susceptible TB (DS-TB) were good overall: 91.1% for SAT, 81.4% for family-supported treatment and 77% for DOT patients. SAT was strongly associated with favourable outcomes (OR 5.7, 95% CI 1.7-19.3), as were PEC sessions (OR 4.3, 95% CI 2.5-7.2).

CONCLUSION

By considering risk factors when determining their treatment delivery model, strong outcomes were seen in all three groups. Multiple modes of treatment administration, tailored to individuals' needs and risk factors, is a feasible, effective, patient-centred care model for hard-to-reach, resource-limited settings.

Adverse events using shorter MDR-TB regimens: outcomes from Port Moresby, Papua New Guinea

Evidence increasingly indicates that standardised, shorter regimens (SR) for multidrug-resistant TB (MDR-TB) is effective in treating this global disease, but there is little published data on associated adverse events. We report outcomes from a cohort treated with the SR in Port Moresby, Papua New Guinea (PNG). Among 26 patients treated with a TB SR from September 2017 to September 2018, 10 (39%) were successful treatments, 12 (46%) were failures, 2 died, and 2 were lost to follow-up. Of those whose treatment failed, most (n = 10) changed their regimen due to adverse events, including seven from ototoxicity, suggesting this SR may not be suited to all patients in PNG and similar settings.

The HIV-1 Pr55 gag polyprotein binds to plastidial membranes and leads to severe impairment of chloroplast biogenesis and seedling lethality in transplastomic tobacco plants

Chloroplast genetic engineering has long been recognised as a powerful technology to produce recombinant proteins. To date, however, little attention has been given to the causes of pleiotropic effects reported, in some cases, as consequence of the expression of foreign proteins in transgenic plastids. In this study, we investigated the phenotypic alterations observed in transplastomic tobacco plants accumulating the Pr55(gag) polyprotein of human immunodeficiency virus (HIV-1). The expression of Pr55(gag) at high levels in the tobacco plastome leads to a lethal phenotype of seedlings grown in soil, severe impairment of plastid development and photosynthetic activity, with chloroplasts largely resembling undeveloped proplastids. These alterations are associated to the binding of Pr55(gag) to thylakoids. During particle assembly in HIV-1 infected human cells, the binding of Pr55(gag) to a specific lipid [phosphatidylinositol-(4-5) bisphosphate] in the plasma membrane is mediated by myristoylation at the amino-terminus and the so-called highly basic region (HBR). Surprisingly, the non-myristoylated Pr55(gag) expressed in tobacco plastids was likely able, through the HBR motif, to bind to nonphosphorous glycerogalactolipids or other classes of lipids present in plastidial membranes. Although secondary consequences of disturbed chloroplast biogenesis on expression of nuclear-encoded plastid proteins cannot be ruled out, results of proteomic analyses suggest that their altered accumulation could be due to retrograde control in which chloroplasts relay their status to the nucleus for fine-tuning of gene expression.

Co-existence of different host-adapted forms of the Myzus persicae group (Hemiptera: Aphididae) in southern Italy

Multivariate morphometric analysis (method of canonical variates) was used to compare 38 parthenogenetic lineages and three field collections of aphids of the Myzus persicae (Sulzer) group sampled on peach and tobacco in the Caserta region of southern Italy. Comparisons were also made with the morphology of lineages collected on peach in Lehonia, in central eastern Greece away from tobacco-growing regions, and on tobacco in Naphplion, in southern Greece. The lineages were measured after parthenogenetic rearing for one to three generations on the same host (potato) under constant conditions. As in previous work, the multivariate morphometric approach separated the aphids from peach from those feeding on tobacco. The life cycle category of the lineages was also examined. Almost all the lineages from peach in Caserta were holocyclic, yet the lineages from tobacco in the same region were unable to produce sexual morphs. The results suggest that tobacco-adapted and non-tobacco-adapted forms co-exist in the same region in southern Italy, not only because they colonize different host plants, but also because they have different life cycles. This is in complete contrast to the situation in peach-growing areas of northern Greece, and shows that the ecology and population structure of M. persicae is different in neighbouring counties of the Mediterranean area, even where climatic conditions and cultivated crops are similar.

Behaviour of Listeria monocytogenes during the traditional manufacture of water-buffalo Mozzarella cheese

The behaviour of a four-strains mixture of Listeria monocytogenes (strains Scott A, V7, OH and Cal) during the traditional manufacture of water-buffalo Mozzarella cheese was investigated at two levels of inoculation: ca 10(5) and 10(3) cfu ml-1 of vat milk. No significant change in Listeria counts was observed during the curd ripening (4.0-4.5 h), at the end of which the pH ranged between 4.83 and 4.91. A decrease of about 2 log was observed after stretching of the curd in hot water (95 degrees C), followed by complete elimination of Listeria after 48 and 24 h of storage of the final cheese in the conditioning liquid (skim water resulting from the stretching, pH ca 4.0) with initial high and low contamination of the cheese milk respectively. Results also indicated that a 1.7 log reduction of L. monocytogenes could be achieved during the preparation of the natural whey culture utilized as starter in cheesemaking.