Enhancement of Cylindrocladium crotalariae Root Rot by Meloidogyne arenaria (Race 2) on a Peanut Cultivar Resistant to Both Pathogens

Two populations of Meloidogyne arenaria (race 2, incompatible on peanut) enhanced development of Cylindrocladium black rot (CBR) on CBR-resistant peanut cv. NC 3033 in greenhouse factorial experiments. Nematode populations 256 and 486 (0, 10³, 10⁴ eggs per 15-cm pot) were tested in all combinations with Cylindrocladium crotalariae (0, 0.5, 5, 50 microsclerotia per cm³ of soil). Root-rot index increased in the presence of either population. Positions but not slope values of inoculum density-disease curves were changed by both populations, indicating increased efficiency of microsclerotia when peanuts were grown in the presence of these nematodes. Although little or no reproduction occurred with either nematode population on NC 3033, larvae of 256 and 486 penetrated roots. Meloidogyne arenaria 486 did not induce root galls and was not snccessful in establishing feeding sites. Meloidogyne arenaria 256 produced a few very small eliptical galls and had a range of success in establishing a feeding site, varying from no giant cell development to large giant cell with production of a few eggs.     

The cost of tsetse control using ‘Tiny Targets’ in the sleeping sickness endemic forest area of Bonon in Côte d’Ivoire: Implications for comparing costs across different settings

BackgroundWork to control the gambiense form of human African trypanosomiasis (gHAT), or sleeping sickness, is now directed towards ending transmission of the parasite by 2030. In order to supplement gHAT case-finding and treatment, since 2011 tsetse control has been implemented using Tiny Targets in a number of gHAT foci. As this intervention is extended to new foci, it is vital to understand the costs involved. Costs have already been analysed for the foci of Arua in Uganda and Mandoul in Chad. This paper examines the costs of controlling Glossina palpalis palpalis in the focus of Bonon in Côte d’Ivoire from 2016 to 2017.Methodology/Principal findingsSome 2000 targets were placed throughout the main gHAT transmission area of 130 km² at a density of 14.9 per km². The average annual cost was USD 0.5 per person protected, USD 31.6 per target deployed of which 12% was the cost of the target itself, or USD 471.2 per km² protected. Broken down by activity, 54% was for deployment and maintenance of targets, 34% for tsetse surveys/monitoring and 12% for sensitising populations.Conclusions/SignificanceThe cost of tsetse control per km² of the gHAT focus protected in Bonon was more expensive than in Chad or Uganda, while the cost per km² treated, that is the area where the targets were actually deployed, was cheaper. Per person protected, the Bonon cost fell between the two, with Uganda cheaper and Chad more expensive. In Bonon, targets were deployed throughout the protected area, because G. p. palpalis was present everywhere, whereas in Chad and Uganda G. fuscipes fuscipes was found only the riverine fringing vegetation. Thus, differences between gHAT foci, in terms of tsetse ecology and human geography, impact on the cost-effectiveness of tsetse control. It also demonstrates the need to take into account both the area treated and protected alongside other impact indicators, such as the cost per person protected.     

Infection patterns of Myxobolus heterospora in two tilapia species (Teleostei: Cichlidae) and its potential effects

A Myxobolus heterospora (Baker, 1963) infection was found in 2 euryhaline tilapia species, Sarotherodon melanotheron melanotheron (Rüppel, 1853) and Tilapia zillii (Gervais, 1852), from a brackish water lake, Lake Nokoué (Benin, West Africa). The histology and ultrastructure of different levels of infection in intestinal connective tissues and wall tissues is described. A total of 391 S. melanotheron melanotheron and 222 T. zillii were examined from October 1987 to October 1989. M. heterospora was found throughout the study period, with a total prevalence of 42.19 and 26.57% for S. melanotheron melanotheron and T. zillii respectively. There was a statistically significant difference in occurrence as a function of season in S. melanotheron melanotheron but not in T. zilli, and there was a significant difference for size and sex in the former and for sex in the latter. M. heterospora induces total destruction of the intestine structure and probably leads to osmoregulatory disturbance. Further investigations of this myxosporean infection are necessary to determine its real effect on the host, since host survival and osmoregulatory rate have not yet been assessed.     

Comparison of serum HBsAg quantitation by four immunoassays, and relationships of HBsAg level with HBV replication and HBV genotypes

Background

The decline in hepatitis B virus surface antigen (HBsAg) may be an early predictor of the viral efficacy of Hepatitis B virus (HBV) therapy. The HBsAg levels obtained by different immunoassays now need comparing and the relationships between levels of HBsAg and HBV DNA alongside HBsAg and genotype must be evaluated.

Methodology/Principal Findings

HBsAg levels were compared among 80 patients using the Abbott Architect assay, a commercial immunoassay approved for HBsAg detection and quantitation, and three other assays derived from immunoassays approved for HBsAg detection (manufactured by Diasorin, Bio-Rad and Roche). Good correlation was found between the Abbot vs. Diasorin, Bio-Rad and Roche assays with narrow 95% limits of agreement and small mean differences: −0.06 to 0.11, −0.09 log₁₀ IU/mL; −0.57 to 0.64, −0.04 log₁₀ IU/mL; −0.09 to 0.45, −0.27 log₁₀ IU/mL, respectively. These agreements were not affected by genotypes A or D. HBsAg was weakly correlated with HBV DNA, whatever the HBsAg assay used: Abbott, ρ = 0.36 p = 0.001, Diasorin ρ = 0.34, p = 0.002; Bio-Rad ρ = 0.37, p<0.001; or Roche ρ = 0.41, p<0.001. This relationship between levels of HBsAg and HBV DNA seemed to depend on genotypes. Whereas HBsAg (Abbott assay) tended to correlate with HBV DNA for genotype A (ρ = 0.44, p = 0.02), no such correlation was significant for genotypes D (ρ = 0.29, p = 0.15).

Conclusion/Significance

The quantitation of HBsAg in routine clinical samples is comparable between the reference assay and the adapted assays with acceptable accuracy limits, low levels of variability and minimum discrepancy. While HBsAg quantitation is not affected by HBV genotype, the observed association between levels of HBsAg and HBV DNA seems genotype dependent.     

Untreated human infections by Trypanosoma brucei gambiense are not 100% fatal

The final outcome of infection by Trypanosoma brucei gambiense, the main agent of sleeping sickness, has always been considered as invariably fatal. While scarce and old reports have mentioned cases of self-cure in untreated patients, these studies suffered from the lack of accurate diagnostic tools available at that time. Here, using the most specific and sensitive tools available to date, we report on a long-term follow-up (15 years) of a cohort of 50 human African trypanosomiasis (HAT) patients from the Ivory Coast among whom 11 refused treatment after their initial diagnosis. In 10 out of 11 subjects who continued to refuse treatment despite repeated visits, parasite clearance was observed using both microscopy and polymerase chain reaction (PCR). Most of these subjects (7/10) also displayed decreasing serological responses, becoming progressively negative to trypanosome variable antigens (LiTat 1.3, 1.5 and 1.6). Hence, in addition to the "classic" lethal outcome of HAT, we show that alternative natural progressions of HAT may occur: progression to an apparently aparasitaemic and asymptomatic infection associated with strong long-lasting serological responses and progression to an apparently spontaneous resolution of infection (with negative results in parasitological tests and PCR) associated with a progressive drop in antibody titres as observed in treated cases. While this study does not precisely estimate the frequency of the alternative courses for this infection, it is noteworthy that in the field national control programs encounter a significant proportion of subjects displaying positive serologic test results but negative results in parasitological testing. These findings demonstrate that a number of these subjects display such infection courses. From our point of view, recognising that trypanotolerance exists in humans, as is now widely accepted for animals, is a major step forward for future research in the field of HAT.     

Profil parasitologique de deux formes de schistosomiase (formes urinaire et intestinale) dans dix sites du Burkina Faso (pays d’Afrique sub-saharienne)

In spite of great progress in schistosomiasis control during the last decade in Burkina Faso, this disease remains a public health concern in the country. Indeed, our study consisted of the analysis of parasitological data related to Schistosoma haematobium and Schistosoma mansoni and in malacological investigations. The prevalence rate of Schistosoma haematobium varies from 3.3% to 50.4% and from 3.3% to 39.1% for Schistosoma mansoni, but only in the western part of Burkina Faso. Schoolboys are more infested than girls, but the phenomenon is reversed in adults. Biomphalaria pfeifferi, Bulinus truncatus, Bulinus senegalensis and Bulinus globosus were collected during this study. Thus, the behavioral factors as well as the dynamics and the distribution of the intermediate mollusks play a major role in the persistence of the disease.     

Biphenyl amide p38 kinase inhibitors 3: Improvement of cellular and in vivo activity

The biphenyl amides (BPAs) are a novel series of p38α MAP kinase inhibitor. The optimisation of the series to give compounds that are potent in an in vivo disease model is discussed. SAR is presented and rationalised with reference to the crystallographic binding mode.