Browsing by Author "Haiyambo, Daniel H."
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Item Effects of plant growth-promoting rhizobacteria and biocontrol bacteria isolated from Kavango on Pennisetum Glaucum and Sorghum Bicolor(2015) Haiyambo, Daniel H.As a result of the ever increasing population growth, the demand on food is expected to rise significantly. In order to meet this increase in food demand, alternatives (PGPR and biocontrol bacteria) to environmentally damaging chemical augmenters can be utilized for the production of agricultural crops. This study was conducted to isolate and screen rhizospheric bacteria from grasses along the Kavango River for plant growth promoting and biocontrol abilities. Once validated, bacteria possessing these abilities were used as peat-based inoculants to evaluate their effects on the growth of Pennisetum glaucum and Sorghum bicolor. The bacteria were isolated from rhizospheres of P. australis, Sporobolus sp., V. nigritana, P. glaucum, S. bicolor and a grass known locally as ngwena. The isolates were screened for NH3 production, protease activity, phosphate solubilisation, siderophore production, indole-3-acetic acid production, nifH-gene presence and antifungal-activity. Up to 14 bacteria considered as possessing plant growth enhancing (11) or biocontrol (3) traits were isolated from grasses located at Mashare and surrounding areas. The majority of the isolates exhibited more than one trait and were classified as follows; 3 phosphate solubilizers, 4 siderophore producers, 8 IAA producing isolates, 5 N2-fixers, and 3 isolates with antifungal-activity. S. maltophilia LCS2-11 as single treatment and in combination treatment with B. amyloliquefaciens LSM1-61 and P. stutzeri ACM2-32, enhanced P. glaucum biomass statistically similarly to the commercial fertilizer’s growth effects. The combination treatment T9 (B. amyloliquefaciens LSM1-61: E. cloacae FCM2-50: P. stutzeri ACM2-32) enhanced S. bicolor biomass significantly (p = 0.032) compared to the water control. Single inoculants S. maltophilia LCS2-11, E. cloacae FCM2-50, and B. amyloliquefaciens LSM1-61 and combination inoculants T7, T8 and T9, enhanced S. bicolor root biomass as well as the commercial fertilizer. The results indicate that PGPR and biocontrol bacteria can be used as efficient plant growth enhancing agents.Item Molecular detection of P. vivax and P. ovale foci of infection in asymptomatic and symptomatic children in Northern Namibia(PLOS, 2019) Haiyambo, Daniel H.Knowledge of the foci of Plasmodium species infections is critical for a country with an elimination agenda. Namibia is targeting malaria elimination by 2020. To support decision making regarding targeted intervention, we examined for the first time, the foci of Plasmodium species infections and regional prevalence in northern Namibia, using nested and quantitative polymerase chain reaction (PCR) methods. We used cross-sectional multi-staged sampling to select 952 children below 9 years old from schools and clinics in seven districts in northern Namibia, to assess the presence of Plasmodium species. The median participant age was 6 years (25–75%ile 4–8 y). Participants had a median hemoglobin of 12.0 g/dL (25–75%ile 11.1–12.7 g/dL), although 21% of the cohort was ane- mic, with anemia being severer in the younger population (p<0.002). Most of children with Plasmodium infection were asymptomatic (63.4%), presenting a challenge for elimination. The respective parasite prevalence for Plasmodium falciparum (Pf), Plasmodium vivax (Pv) and Plasmodium ovale curtisi (Po) were (4.41%, 0.84% and 0.31%); with Kavango East and West (10.4%, 6.19%) and Ohangwena (4.5%) having the most prevalence. Pv was localized in Ohangwena, Omusati and Oshana, while Po was found in Kavango. All children with Pv/ Pf coinfections in Ohangwena, had previously visited Angola, affirming that perennial migrations are risks for importation of Plasmodium species. The mean hemoglobin was lower in those with Plasmodium infection compared to those without (0.96 g/dL less, 95%CI 0.40–1.52 g/dL less, p = 0.0009) indicating that quasi-endemicity exists in the low transmission setting. We conclude that Pv and Po species are present in northern Namibia. Additionally, the higher number of asymptomatic infections present challenges to the efforts at elimination for the country. Careful planning, coordination with neighboring Angola and execution of targeted active intervention, will be required for a successful elimination agenda.Item Molecular detection of P. vivax and P. ovale foci of infection in asymptomatic and symptomatic children in Northern Namibia(2019) Haiyambo, Daniel H.; Uusiku, Petrina; Mumbengegwi, Davis R.; Pernica, Jeff M.; Bock, Ronnie; Malleret, Benoit; Renia, Laurent; Greco, Beatrice; Quaye, Isaac K.Knowledge of the foci of plasmodium species infections is critical for a country with an elimination agenda. Namibia is targeting malaria elimination by 2020. To support decision making regarding targeted intervention, we examined for the first time, the foci of Plasmodium species infections and regional prevalence in northern Namibia, using nested and quantitative polymerase chain PRC methods.