53 research outputs found

    Rhodococcus opacus strain RW, a resorcinol-degrading bacterium from the gut of Macrotermes michaelseni

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    The population of resorcinol degrading bacteria in the intestinal tract of fungi-cultivating termite, Macrotermes michaelseni, was estimated to be 6.8 × 102 cells/ml. A gram-positive bacterium designated RW, capable of degrading resorcinol, was isolated from the highest positive dilution. Isolate RW could also degrade phenol and benzoic acid aerobically, and anaerobically using nitrate as an electron acceptor. The isolate is a rod-shaped bacterium that exhibited evolutionary relatedness with the genus Rhodococcus, as determined by phenotypic traits and physiological tests, and a 16S rRNA gene sequence similarity value of 99.6% to the closest Rhodococcus opacus strain. On the basis of these results isolate RW is proposed as a new strain in the species R. opacus. The ability of the isolate to degrade resorcinol, phenol and benzoic acid makes it a potential candidate for use in bioremediation of environments contaminated by such or related compounds.African Journal of Biotechnology Vol. 4 (7), pp. 639-645, 200

    Isolation and characterization of Escherichia colipathotypes and factors associated with well and boreholes water contamination in Mombasa County

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    Introduction: Safe water for human consumption is important, but there is a limited supply. Mombasa County has water shortages making residences rely on other sources of water including boreholes and wells. Microbiological evaluation of drinking water is important to reduce exposure to water borne enteric diseases. This cross sectional study aimed at determining the frequency and characterization of Escherichia coli (E. coli) pathotypes from water samples collected from wells and boreholes in Mombasa County. Methods: One hundred and fifty seven (157) water samples were collected from four divisions of the county and a questionnaire administered. The samples were inoculated to double strength MacConkey broth and incubated at 370C for up to 48 hours. Positive results were compared to the 3 tube McCrady MPN table. The E. coli were confirmed by Eijkman's test and antibiotic susceptibility carried out. Using polymerase chain reaction (PCR), the E. coli were characterized to establish pathotypes. Results: One hundred and thirty one (n=131; 83.4%) samples had coliform bacteria with only 79 (60.3%) samples having E. coli. Significant values (<0.05) were noted when coliforms were compared to variables with E. Coli showing no significance when compared to similar variables. E. coli (n = 77; 100%) tested were sensitive to Gentamicin, while all (n = 77; 100%) isolates were resistant to Ampicillin. PCR typed isolates as enteroinvasive E. Coli (EIEC). Conclusion: Findings suggest that coliforms and E. coli are major contaminants of wells and boreholes in Mombasa County. The isolates have a variety of resistant and sensitivity patterns to commonly used antibiotics.Pan African Medical Journal 2016; 2

    Physical and Chemical Characteristics of Five Hot Springs in Eritrea

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    Eritrea has a number of hot springs whose physicochemical characteristics are not documented. This study examined the thermal and chemical features of five hot springs located in the eastern escarpment of Eritrea. Field data and water samples were collected from five hot springs namely; Akwar and Maiwooi near Gahtelai, Garbanabra and Gelti near Irafayle at the Gulf of Zula and Elegedi in Alid volcanic center. The water temperatures at source varied from 49.5°C to 100°C while pH levels ranged from 6.97 to 7.54. Elegedi had significantly higher temperature (p < 0.05) than the other four hot springs. Strong correlation was observed between electrical conductivity (EC), total dissolved solid (TDS), salinity, sodium, potassium, calcium and chloride (R2 > 0.9) as well as between temperature and sulphate levels (R2 = 0.96). Evident clustering was noted at p < 0.05, using Non-metric multidimensional scaling (NMDS), between the three locations of the hot springs. Akwar and Maiwooi, situated close to each other, clustered together, Garbanabra and Gelti, which were characterized by higher salinity levels, formed a separate cluster. Elegedi, characterized by high temperature (100°C), sulphate (979.7 mg/l) and NH4+ (196.33 mg/l) levels, clustered separately. Akwar and Maiwooi had high bicarbonate (345 mg/l and 393 mg/l) and fluoride (8.20 mg/l and 6.48 mg/l) levels which are above WHO limits. Electrical conductivity (23,133 mS/cm), total dissolved solid (15,552 mg/l), sodium (3,800 mg/l), potassium (198 mg/l), calcium (1,653 mg/l) and chloride (5,946 mg/l) levels in Garbanabra and Gelti hot springs exceeded WHO limits. Bromine (74.8 mg/l in Garbanabra and 45.2 mg/l in Gelti) and boron (2.21 mg/l in Garbanabra and 1.55 mg/l in Gelti) levels were also above standard limits set for potable water. Maiwooi (1.20) and Elegedi (1.10) were depositional while Akwar water (-0.71) was slightly corrosive. The corrosive nature of the water sample from Akwar, is a public health concern. The waters from the five Eritrean hot springs are thus not fit for human consumption. In addition, the use of thermal spring water for recreational purposes should be closely monitored. Keywords: key words, hot springs, physicochemical, Eritre

    Bacteria and Archaea diversity within the hot springs of Lake Magadi and Little Magadi in Kenya

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    Active diversity relative abundance of microbial taxa at family level in various samples collected from the three hot springs (83.6, 81 and 45.1 °C) of L. Magadi and Little Magadi. ‘No blast hit/Others’ represent unclassified sequences in both data sets. (XLSX 32 kb

    p16INK4a/Ki-67 dual stain cytology for cervical cancer screening in Thika district, Kenya

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    Background: The identification of suited early detection tests is one among the multiple requirements to reduce cervical cancer incidence in developing countries. Methods: We evaluated p16INK4a/Ki-67 dual-stain cytology in a screening population in Thika district, Kenya and compared it to high-risk human papillomavirus (HR-HPV) DNA testing and visual inspection by acetic acid (VIA) and Lugol’s iodine (VILI). Results: Valid results for all tests could be obtained in 477 women. 20.9 % (100/477) were tested positive for HR-HPV DNA, 3.1 % (15/477) had positive VIA/VILI and 8.2 % (39/477) positive p16INK4a/Ki-67 cytology. Of 22 women that showed up for colposcopy and biopsy, 6 women were diagnosed with CIN3 and two with CIN2. All women with CIN2/3 were negative in VIA/VILI screening and positive by HR-HPV DNA testing. But HPV was also positive in 91.7 % (11/12) of women with normal histology. p16INK4a/Ki-67 cytology was positive in all 6 women with CIN3, in one of the two CIN2 and in only 8.3 % (1/12) of women with normal histology. Conclusions: p16INK4a/Ki-67 cytology is an interesting test for further studies in developing countries, since our findings point to a lower fraction of false positive test results using p16INK4a/Ki-67 cytology compared to HPV DNA testing in a Kenyan screening population. VIA/VILI missed all histology-proven CIN2/3

    Compatibility between Calpurnia aurea leaf extract, attraction aggregation, and attachment pheromone and entomopathogenic fungus Metarhizium anisopliae on viability, growth, and virulence of the pathogen

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    Metarhizium anisopliae sensu stricto (ss) (Metsch.) Sorok. isolate ICIPE 07 is being developed as biopesticide for the control of ticks. In addition, leaf extracts of Calpurnia aurea Benth, and the attraction aggregation and attachment pheromone (AAAP) are being used as ticks’ attractant. The three agents are being considered for use in combination in an autodissemination approach, whereby ticks that are attracted to semiochemicals are infected with the inoculum. Experiments were therefore conducted to evaluate in vitro the compatibility between C. aurea, AAAP, and the M. anisopliae on vegetative growth, conidial production, and spore viability. Calpurnia aurea leaf extract was compatible with the fungus at all the concentrations tested, whereas AAAP inhibited all the fungal growth parameters. The virulence of M. anisopliae formulated in emulsifiable extracts of C. aurea was also tested against different developmental stages of Rhipicephalus appendiculatus in laboratory bioassays. No significant differences in virulence were observed between M. anisopliae applied alone and M. anisopliae formulated in different concentrations of C. aurea leaf extracts. These results suggest that C. aurea leaf extracts is compatible with M. anisopliae and could be mixed together for “spot-spray” treatments as low-cost and environmental-friendly technology to control ticks in grazing field, while AAAP should be used separately.Bioscience Eastern and Central Africa Network (BecANet) and the Canadian International Development Agency (CIDA).http://link.springer.com/journal/10340hb2013mn201

    The soil microbiomes of forest ecosystems in Kenya : their diversity and environmental drivers

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    DATA AVAILABILITY : The demultiplexed high-quality sequence reads has been deposited in the National Centre for Biotechnology Information (NCBI) Sequence Read Archive (SRA), as Bio Project ID: PRJNA851255 and study accession numbers available for download at http://www.ncbi.nlm.nih.gov/biopr oject/851255. This Whole Genome Shotgun project has been deposited at DDBJ/EMBL/GenBank under the Bioproject PRJNA291812. The metadata, soil chemistry data, input files for Qiime and R analysis scripts were deposited at https://zenodo.org/ and a DOI-10.5281/zenodo.7827433 available using the link; https://doi.org/10.5281/zenodo.78274 32.Soil microbiomes in forest ecosystems act as both nutrient sources and sinks through a range of processes including organic matter decomposition, nutrient cycling, and humic compound incorporation into the soil. Most forest soil microbial diversity studies have been performed in the northern hemisphere, and very little has been done in forests within African continent. This study examined the composition, diversity and distribution of prokaryotes in Kenyan forests top soils using amplicon sequencing of V4-V5 hypervariable region of the 16S rRNA gene. Additionally, soil physicochemical characteristics were measured to identify abiotic drivers of prokaryotic distribution. Different forest soils were found to have statistically distinct microbiome compositions, with Proteobacteria and Crenarchaeota taxa being the most differentially abundant across regions within bacterial and archaeal phyla, respectively. Key bacterial community drivers included pH, Ca, K, Fe, and total N while archaeal diversity was shaped by Na, pH, Ca, total P and total N. To contextualize the prokaryote diversity of Kenyan forest soils on a global scale, the sample set was compared to amplicon data obtained from forest biomes across the globe; displaying them to harbor distinct microbiomes with an over-representation of uncultured taxa such as TK-10 and Ellin6067 genera.USAID, The Oppenheimer Foundation and the University of Pretoria.https://www.nature.com/srepam2024BiochemistryGeneticsMicrobiology and Plant PathologySDG-15:Life on lan

    Multilateral benefit-sharing from digital sequence information will support both science and biodiversity conservation

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    Open access to sequence data is a cornerstone of biology and biodiversity research, but has created tension under the United Nations Convention on Biological Diversity (CBD). Policy decisions could compromise research and development, unless a practical multilateral solution is implemented.This workwas funded by the German Federal Ministry of Education and Research (BMBF) WiLDSI 031B0862 (A.H.S., J.O., and J.F.) and Horizon Europe EVA-GLOBAL 871029 (A.H.S.). I.K.M. was supported by the National Center for Biotechnology Information of the National Library of Medicine, National Institutes of Health
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