Anaerobic biotransformation of hexachlorocyclohexane isomers by <Emphasis Type="Italic">Dehalococcoides</Emphasis> species and an enrichment culture

The biotransformation of hexachlorocyclohexane isomers (HCH) by two Dehalococcoides mccartyi strains (195 and BTF08) and an enrichment culture was investigated and compared to conversion by the obligate anaerobic strain Clostridium pasteurianum strain DSMZ 525. The D. mccartyi strains preferentially transformed γ-HCH over α-HCH and δ-HCH isomers while β-HCH biotransformation was not significant. In case of the enrichment culture, γ-HCH was preferentially transformed over the δ-HCH, β-HCH and α-HCH isomers. Major observed metabolites in both cases were tetrachlorocyclohexene and as end products monochlorobenzene (MCB) and benzene. Dechlorination of the γ-HCH isomer was linked to an increase in cell numbers for strain 195. γ-HCH transformation was linked to considerable carbon stable isotope fractionation with the enrichment factor ε_c?=???5.5?±?0.8‰ for D. mccartyi strain 195, ε_c?=???3.1?±?0.4‰ for the enrichment culture and ε_c?=???4.1?±?0.6‰ for co-metabolic transformation by C. pasteurianum.     

Farmers’ knowledge,perception and management of mango mealy bug,Drosicha mangiferae Green (Hemiptera: Monophlebidae), on Mangifera indica in Punjab,Pakistan

In 2004–05, during the December to February about 141 mango farmers were interviewed during peak activity of mango mealy bug in southern Punjab, Pakistan. The objective was to know the farmers’ knowledge, perceptions and practices in the management of mango mealy bug. Most of the farmers (94.33%) reported that Chaunsa variety (king of all mango varieties) was susceptible to mango and irrigation water was the major source of flare up of this pest. Basudin and Supracide were the most commonly used insecticides as 72.92 and 51.77 percent farmers gave positive response and grease bands were applied for the control of mango mealy bug by the majority of the respondents. Hundred percent yield losses was told by 22.7 percent respondents whereas 75 percent, 50 percent and 25 percent losses were reported by 39.7, 31.9 and 14.2 insecticidal spray did not show satisfaction to the respondents for the control of fertilized females of mango mealy bug coming down from the trees. Lack of knowledge about the pest, lack of money, adulterated and shortage of pesticides, lack of unity amongst farmers Further the growers’ views were tested in the field for confirmation and small land holdings were the main constraints for the control of mango mealy bug.     

Nutrient use preferences among soil Streptomyces suggest greater resource competition in monoculture than polyculture plant communities

Background an aims

Nutrient use overlap among sympatric Streptomyces populations is correlated with pathogen inhibitory capacity, yet there is little information on either the factors that influence nutrient use overlap among coexisting populations or the diversity of nutrient use among soil Streptomyces.

Methods

We examined the effects of plant host and plant species richness on nutrient use of Streptomyces isolated from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Growth on 95 carbon sources was assessed over 5d.

Results

Cumulative growth was significantly greater for polyculture vs. monoculture isolates, and for Lc vs. Ag isolates. Isolates from monocultures, but not polycultures, exhibited a drop in growth rates between 24 h and 72 h post-inoculation, suggesting resource allocation to non-growth functions. Isolates from high-carbon (polyculture) or high-nitrogen (Lc) soils had larger niche widths than isolates from low-C (monocultures) or low-N (Ag) soils. Sympatric isolates from polycultures were significantly more differentiated from one another in preferred nutrients for growth than sympatric isolates from monocultures.

Conclusions

These results suggest that Streptomyces populations respond to selection imposed by plant host and plant community richness and that populations from polyculture but not from monoculture, mediate resource competition via niche differentiation.

     

Effect of herbal melanin on IL-8: a possible role of Toll-like receptor 4 (TLR4)

The production of IL-8 can be induced by LPS via TLR4 signaling pathway. In this study, we tested the effect of a herbal melanin (HM) extract, from black cumin seeds (Nigella sativa L.), on IL-8 production. We used HM and LPS in parallel to induce IL-8 production by THP-I, PBMCs, and TLR4-transfected HEK293 cells. Both HM and LPS induced IL-8 mRNA expression and protein production in THP-1 and PBMCs. On applying similar treatment to HEK293 cells that express TLR4, MD2, and CD14, both HM and LPS significantly induced IL-8 protein production. We have also demonstrated that HM and LPS had identical effects in terms of IL-8 stimulation by HEK293 transfected with either TLR4 or MD2-CD14. Melanin extracted from N. sativa L. mimics the action of LPS in the induction of IL-8 by PBMC and the other used cell lines. Our results suggest that HM may share a signaling pathway with LPS that involves TLR4.     

Rational MD simulations for improvement the affinity of nanobody against PlGF (placenta growth factor): mutagenesis based on electrostatic interactions

Abbreviations COM center of mass distance

MD molecular dynamics

MM-PBSA Molecular Mechanics Poisson–Boltzmann Surface Area

Nb nanobody

PlGF placenta growth factor

Rg radius of gyration

RMSD root mean-square deviation

SASA solvent-accessible surface area

VEGF vascular endothelial growth factor

     

Safety and Immunogenicity Study of Multiclade HIV-1 Adenoviral Vector Vaccine Alone or as Boost following a Multiclade HIV-1 DNA Vaccine in Africa

Background

We conducted a double-blind, randomized, placebo-controlled Phase I study of a recombinant replication-defective adenovirus type 5 (rAd5) vector expressing HIV-1 Gag and Pol from subtype B and Env from subtypes A, B and C, given alone or as boost following a DNA plasmid vaccine expressing the same HIV-1 proteins plus Nef, in 114 healthy HIV-uninfected African adults.

Methodology/Principal Findings

Volunteers were randomized to 4 groups receiving the rAd5 vaccine intramuscularly at dosage levels of 1×10¹⁰ or 1×10¹¹ particle units (PU) either alone or as boost following 3 injections of the DNA vaccine given at 4 mg/dose intramuscularly by needle-free injection using Biojector® 2000. Safety and immunogenicity were evaluated for 12 months. Both vaccines were well-tolerated. Overall, 62% and 86% of vaccine recipients in the rAd5 alone and DNA prime - rAd5 boost groups, respectively, responded to the HIV-1 proteins by an interferon-gamma (IFN-γ) ELISPOT. The frequency of immune responses was independent of rAd5 dosage levels. The highest frequency of responses after rAd5 alone was detected at 6 weeks; after DNA prime - rAd5 boost, at 6 months (end of study). At baseline, neutralizing antibodies against Ad5 were present in 81% of volunteers; the distribution was similar across the 4 groups. Pre-existing immunity to Ad5 did not appear to have a significant impact on reactogenicity or immune response rates to HIV antigens by IFN-γ ELISPOT. Binding antibodies against Env were detected in up to 100% recipients of DNA prime - rAd5 boost. One volunteer acquired HIV infection after the study ended, two years after receipt of rAd5 alone.

Conclusions/Significance

The HIV-1 rAd5 vaccine, either alone or as a boost following HIV-1 DNA vaccine, was well-tolerated and immunogenic in African adults. DNA priming increased the frequency and magnitude of cellular and humoral immune responses, but there was no effect of rAd5 dosage on immunogenicity endpoints.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00124007","term_id":"NCT00124007"}}NCT00124007     

Gender differences in the expression of genes involved during cardiac development in offspring from dams on high fat diet

Previously we have demonstrated that maternal high fat diet (HF) during pregnancy increase cardiovascular risk in the offspring, and pharmacological intervention using statins in late pregnancy reduced these risk factors. However the effects of maternal HF-feeding and statin treatment during pregnancy on development of heart remain unknown. Hence we measured expression of genes involved in cell cycle progression (cyclin G1), ventricular remodelling brain natriuretic peptide (BNP), and environmental stress response small proline-rich protein 1A (SPRR 1A) in the offspring left ventricle (LV) from dams on HF with or without statin treatment. Female C57 mice were fed a HF diet (45 % kcal fat) 4 weeks prior to conception, during pregnancy and lactation. From the second half of the pregnancy and throughout lactation, half of the pregnant females on HF diet were given a water-soluble statin (Pravastatin) in their drinking water (HF + S). At weaning offspring were fed HF diet to adulthood (generating dam/offspring dietary groups HF/HF and HF + S/HF). These groups were compared with offspring from dams fed standard chow (C 21 % kcal fat) and fed C diet from weaning (C/C). LV mRNA levels for cyclin G1, BNP and SPRR 1A were measured by RT-PCR. Heart weights and BP in HF/HF offspring were higher versus C/C group. Maternal Pravastatin treatment reduced BP and heart weights in HF + S/HF female offspring to levels found in C/C group. LV cyclin G1 mRNA levels were lower in HF/HF versus both C/C and HF + S/HF offspring. BNP mRNA levels were elevated in HF/HF females but lower in males versus C/C. BNP gene expression in HF + S/HF offspring was similar to HF/HF. SPRR 1A mRNA levels were similar in all treatment groups. Statins given to HF-fed pregnant dams reduced cardiovascular risk in adult offspring, and this is accompanied by changes in expression of genes involved in adaptive remodelling in the offspring LV and that there is a gender difference.     

Historical demographic profiles and genetic variation of the East African Butana and Kenana indigenous dairy zebu cattle

Butana and Kenana breeds from Sudan are part of the East African zebu Bos indicus type of cattle. Unlike other indigenous zebu cattle in Africa, they are unique due to their reputation for high milk production and are regarded as dairy cattle, the only ones of their kind on the African continent. In this study, we sequenced the complete mitochondrial DNA (mtDNA) D‐loop of 70 animals to understand the maternal genetic variation, demographic profiles and history of the two breeds in relation to the history of cattle pastoralism on the African continent. Only taurine mtDNA sequences were identified. We found very high mtDNA diversity but low level of maternal genetic structure within and between the two breeds. Bayesian coalescent‐based analysis revealed different historical and demographic profiles for the two breeds, with an earlier population expansion in the Butana vis a vis the Kenana. The maternal ancestral populations of the two breeds may have diverged prior to their introduction into the African continent, with first the arrival of the ancestral Butana population. We also reveal distinct demographic history between the two breeds with the Butana showing a decline in its effective population size (N_e) in the recent past ~590 years. Our results provide new insights on the early history of cattle pastoralism in Sudan indicative of a large ancient effective population size.     

Synthesis of tentacle-type magnetic beads as immobilized metal-chelate affinity support for cytochrome c adsorption

Magnetic poly(2-hydroxyethylmethacrylate) (mPHEMA) beads with an average diameter of 100-140 microm were produced by suspension polymerization in the presence of magnetite particles (i.e. Fe3O4). Specific surface area and average pore size of the magnetic beads was found to be 50 m2/g and 819 nm, respectively. Ester groups in the mPHEMA structure were converted to imine groups by reacting with poly(ethyleneimine) (PEI) in the presence of NaH. Amino (-NH2) content of PEI-attached mPHEMA beads was determined as 102 mg PEI/g. Then, Cu2+ ions were chelated on the magnetic beads in the range of 20-793 micromol Cu2+/g. Cytochrome c (cyt c) adsorption was performed on the metal chelating beads from aqueous solutions containing different amounts of cyt c at different pHs, Cu2+ loadings and temperatures. Cyt c adsorption on the mPHEMA/PEI beads was 4.6 mg/g. Cu2+ chelation increased the cyt c adsorption significantly (40.1 mg/g). Adsorption capacity increased with Cu2+ loading and then reached a saturation value. Cyt c adsorption decreased with increasing temperature. Cyt c molecules could be reversibly adsorbed and eluted ten times with the magnetic adsorbents without noticeable loss in their cyt c adsorption capacity. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium capacity and correlation coefficients. Results suggest that chemisorption processes could be the rate-limiting step in the adsorption process. In the last part of this article, cyt c adsorption experiments were performed in a magnetically stabilized fluidized bed (MSFB) system at optimum conditions determined from the batch experiments. The adsorption capacity decreased significantly from 46.8 to 15.4 mg/g polymer with the increase of the flow-rate from 0.5 to 4.0 ml/min. The resulting magnetic chelator beads possessed excellent long-term storage stability.     

Climate‐driven changes to the spatio‐temporal distribution of the parasitic nematode,Haemonchus contortus,in sheep in Europe

Recent climate change has resulted in changes to the phenology and distribution of invertebrates worldwide. Where invertebrates are associated with disease, climate variability and changes in climate may also affect the spatio‐temporal dynamics of disease. Due to its significant impact on sheep production and welfare, the recent increase in diagnoses of ovine haemonchosis caused by the nematode Haemonchus contortus in some temperate regions is particularly concerning. This study is the first to evaluate the impact of climate change on H. contortus at a continental scale. A model of the basic reproductive quotient of macroparasites, Q₀, adapted to H. contortus and extended to incorporate environmental stochasticity and parasite behaviour, was used to simulate Pan‐European spatio‐temporal changes in H. contortus infection pressure under scenarios of climate change. Baseline Q₀ simulations, using historic climate observations, reflected the current distribution of H. contortus in Europe. In northern Europe, the distribution of H. contortus is currently limited by temperatures falling below the development threshold during the winter months and within‐host arrested development is necessary for population persistence over winter. In southern Europe, H. contortus infection pressure is limited during the summer months by increased temperature and decreased moisture. Compared with this baseline, Q₀ simulations driven by a climate model ensemble predicted an increase in H. contortus infection pressure by the 2080s. In northern Europe, a temporal range expansion was predicted as the mean period of transmission increased by 2–3 months. A bimodal seasonal pattern of infection pressure, similar to that currently observed in southern Europe, emerges in northern Europe due to increasing summer temperatures and decreasing moisture. The predicted patterns of change could alter the epidemiology of H. contortus in Europe, affect the future sustainability of contemporary control strategies, and potentially drive local adaptation to climate change in parasite populations.