2,075 research outputs found
Expressed centromere specific histone 3 (CENH3) variants in cultivated triploid and wild diploid bananas (Musa spp.)
Open Access JournalCentromeres are specified by a centromere specific histone 3 (CENH3) protein, which exists in a complex environment, interacting with conserved proteins and rapidly evolving satellite DNA sequences. The interactions may become more challenging if multiple CENH3 versions are introduced into the zygote as this can affect post-zygotic mitosis and ultimately sexual reproduction. Here, we characterize CENH3 variant transcripts expressed in cultivated triploid and wild diploid progenitor bananas. We describe both splice- and allelic-[Single Nucleotide Polymorphisms (SNP)] variants and their effects on the predicted secondary structures of protein. Expressed CENH3 transcripts from six banana genotypes were characterized and clustered into three groups (MusaCENH-1A, MusaCENH-1B, and MusaCENH-2) based on similarity. The CENH3 groups differed with SNPs as well as presence of indels resulting from retained and/or skipped exons. The CENH3 transcripts from different banana genotypes were spliced in either 7/6, 5/4 or 6/5 exons/introns. The 7/6 and the 5/4 exon/intron structures were found in both diploids and triploids, however, 7/6 was most predominant. The 6/5 exon/introns structure was a result of failure of the 7/6 to splice correctly. The various transcripts obtained were predicted to encode highly variable N-terminal tails and a relatively conserved C-terminal histone fold domain (HFD). The SNPs were predicted in some cases to affect the secondary structure of protein by lengthening or shorting the affected domains. Sequencing of banana CENH3 transcripts predicts SNP variations that affect amino acid sequences and alternatively spliced transcripts. Most of these changes affect the N-terminal tail of CENH3
Prevalence and Antibiotic Resistance Patterns of Escherichia coli among Hospitalised Patients at Thika District Hospital
Background: Emerging resistance to antimicrobial drugs increases morbidity and mortality by hampering the provision of effective chemotherapy, and makes treatment more costly. The emergence of resistance to antimicrobial agents is a global public health problem, especially in pathogens causing nosocomial infections.Objectives: To determine the carriage of E. coli from wounds and urine in catheterised inpatients at Thika District Hospital (TDH) and to determine antimicrobial resistance patterns to β-lactams, aminoglycosides and (fluoro) quinolones.Design: A cross-sectional study.Setting: Thika District Hospital among hospitalised patients.Subjects: A total of 450 specimens were collected and forty two (42) Escherichia coli isolated. Pus swabs were collected from wounds and urine was collected aseptically from the inpatients with catheters. Escherichia coli were identified by culture methods and biochemical tests. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method and interpreted according to Clinical Laboratory Standards Institute recommendations.Results: Susceptibility results in aminoglycosides were, resistance for amikacin, gentamicin and kanamycin was 20%, 39% and 51% respectively. Resistance in penicillin was ampicillin 85% and piperacillin 83%. Resistance for sulfamethoxazole was 83%, tetracycline 66 %, nalidixic acid 44 % and chloramphenicol 39%. In amoxicillin/clavulanic acid, resistance was 68%. Cephalosporins’ resistance was ceftazidime 22 %, cefotaxime 56 %. Resistance for imipenem and tazobactam was 7% and 12 % respectively.Conclusion: Due to observations on resistance to antimicrobial agents commonly used in Thika District Hospital, this shows that there is need to revise antimicrobial policy in this region in the treatment of E. coli infections
Molecular Characterisation and Antimicrobial Resistance Patterns of Escherichia coli Isolates from Goats Slaughtered in Parts of Kenya
Objective: To determine the antibiotic resistance patterns of pathogenic Escherichia coli on goat meat carcass at Huruma and Kiserian abattoirs in Kenya.Design: Laboratory based study.Setting: Huruma and Kiserian abattoirs in Kenya,Subjects: 400 slaughtered goats inspected by veterinary health officers and approved for human consumption.Methods: A Total of 400 slaughtered goats which were inspected by veterinary health officers and approved for human consumption were sampled from Huruma and Kiserian abattoir. Goat carcass swabs were collected by passing each swab tissue on four parts of the carcass mainly neck , right and left forelimbs, right and left hind limbs, and brisket.Results: A total of 54 E. coli isolates were isolated and confirmed to be pathogenic. The percentage of isolates resistant to various microbial agents was recorded as follows: ampicillin (26 %), amoxycillin-clavulanic acid (17%), tetracycline (15%), chroramphenicol (4%), and ceftrixone (2% each). All Escherichia coli isolates were susceptible to gentamicin sulphamethaxazole-trimethomprin, kanamycin, cetriazididine (CAZ,30ìg), ciproxacin, nalidixic acid and chloramphenicol. Isolates were resistant to one or more of the antibiotics tested. Among the drugs tested, resistance was more frequently observed against ampicillin, amoxycillin-clavulanic acid, tetracycline, ceftrixone and chroramphenicol antibiotics.Among the isolates 26(48%) were positive for the stx1 gene, 19(35%) had the eae gene, 10(19%) possessed est gene, while 8(15%) harboured elt gene. Overall five isolates (10%) possessed aspu gene and two (4%) had aggR gene. No isolate possessed ipah gene.Conclusion: This study demonstrated that there is a significant level of antimicrobial resistance in pathogenic E. coli isolated from goat meat from Huruma and Kiserian abattoir. This indicates that goat meat from abattoirs could pose a risk of transmission of pathogenic antibiotic resistant strains to human. Poor hygienic standards and indiscriminate use of antimicrobials are the two main reasons for the presence of resistant pathogens in goat carcasses. Recommendations: Implemention of appropriate hygiene measures to control contamination of meat with pathogenic E. coli.Key words: Escherichia. coli pathotypes, Antibiotic resistance, Goat meat, Abattoir
Factors Affecting Sustainability Of Wetland Agriculture Within Lake Victoria Basin In Uganda
In recent years, the high rate of conversion of wetlands for agriculture has raised environmental concerns in Uganda. A study was therefore conducted to identify issues that need to be addressed if communities are to continue deriving livelihoods from wetland agriculture, without causing stress to the wetlands of Lake Victoria basin. This was done by conducting household surveys and focus group discussions in two of the districts that border Lake Victoria. Wetland agriculture was found to be a significant source of livelihoods for resource poor communities, contributing over 60% of the household income. Farming was mainly done at a subsistence level. The study found that socio economic factors, poor farming practices and weak policies were contributing to the rapid conversion of wetlands. Concerted efforts need to be made by government institutions to sensitize communities on conservation of wetlands. Some of the policies need to be harmonized to avoid
contradictions. Alternative sources of livelihoods must be created to ensure socio economic benefits and environmental conservation. Keywords: Wetland agriculture; Sustainability; Livelihoods; Uganda.Journal of Agriculture and Social Research Vol. 8 (1) 2008: pp. 78-8
The Dantu blood group prevents parasite growth in vivo: Evidence from a controlled human malaria infection study
Background: The long co-evolution of Homo sapiens and Plasmodium falciparum has resulted in the selection of numerous human genetic variants that confer an advantage against severe malaria and death. One such variant is the Dantu blood group antigen, which is associated with 74% protection against severe and complicated P. falciparum malaria infections in homozygous individuals, similar to that provided by the sickle haemoglobin allele (HbS). Recent in vitro studies suggest that Dantu exerts this protection by increasing the surface tension of red blood cells, thereby impeding the ability of P. falciparum merozoites to invade them and reducing parasite multiplication. However, no studies have yet explored this hypothesis in vivo. Methods: We investigated the effect of Dantu on early phase P. falciparum (Pf) infections in a controlled human malaria infection (CHMI) study. 141 sickle-negative Kenyan adults were inoculated with 3.2 × 103 aseptic, purified, cryopreserved Pf sporozoites (PfSPZ Challenge) then monitored for blood-stage parasitaemia for 21 days by quantitative polymerase chain reaction (qPCR)analysis of the 18S ribosomal RNA P. falciparum gene. The primary endpoint was blood-stage P. falciparum parasitaemia of ≥500/μl while the secondary endpoint was the receipt of antimalarial treatment in the presence of parasitaemia of any density. On study completion, all participants were genotyped both for Dantu and for four other polymorphisms that are associated with protection against severe falciparum malaria: α+-thalassaemia, blood group O, G6PD deficiency, and the rs4951074 allele in the red cell calcium transporter ATP2B4. Results: The primary endpoint was reached in 25/111 (22.5%) non-Dantu subjects in comparison to 0/27 (0%) Dantu heterozygotes and 0/3 (0.0%) Dantu homozygotes (p=0.01). Similarly, 49/111 (44.1%) non-Dantu subjects reached the secondary endpoint in comparison to only 7/27 (25.9%) and 0/3 (0.0%) Dantu heterozygotes and homozygotes, respectively (p=0.021). No significant impacts on either outcome were seen for any of the other genetic variants under study. Conclusions: This study reveals, for the first time, that the Dantu blood group is associated with high-level protection against early, non-clinical, P. falciparum malaria infections in vivo. Learning more about the mechanisms involved could potentially lead to new approaches to the prevention or treatment of the disease. Our study illustrates the power of CHMI with PfSPZ Challenge for directly testing the protective impact of genotypes previously identified using other methods
Pathogenic E.coli and other pathogenic gram negative enteric strains from foecal samples of children without diarrhoea living in Mukuru slums, Nairobi
Background: Diarrhoea remains a major public health problem among children and adults in developing nations such as Kenya. The risk of infection is higher in children due to their developing immunity, relatively poor hygiene and habits especially those living in informal settlements where water supply and sanitation are inadequate.Objectives: To determine the prevalence of selected enteric pathogens from children without diarrhoea attending two clinics in Mukuru as well as the anti-microbial resistance patterns, and pathogenicity of E. coli isolated.Design: A cross sectional study.Setting: Mukuru slum, Nairobi County.Subjects: Three hundred and twenty two children of ages five and below.Results: Mukuru Kwa Njenga; E. coli 34.6%, Salmonella spp. 1.3%, Shigella 0.7%, Citrobacter spp. 2.3%, Klebsiella spp. 5.3%, Proteus spp. 7.0%, No growth 2.3%. Mukuru Kwa Reuben; E. coli 63.4%, Salmonella 0.6%, Shigella 0.6%, Citrobacter spp. 1.2%,Klebsiella spp. 14.3%, Proteus spp. 16.1%, No growth 3.7%. No significant difference among the organisms isolated in both clinics (p = 0.982). Ampicillin, Amoxycillin/ Clavulanic, cefoxitin had high resistance, while gentamicin was 100% susceptible. 46.6% E. coli isolates were positive for at least one of the eight virulence genes tested.Conclusion: Salmonella, Shigella and pathogenic E.coli associated with diarrhoea and presence of resistance genes were identified in foecal samples of children without diarrhoea living in Mukuru informal settlements in Nairobi. The major concern from the findings of this study was the emerging high resistance of E.coli that was observed to cephamycin (Cefoxitin)
Rapid assembly of highly-functionalised difluorinated cyclooctenones via ring-closing metathesis
Building block methodology from trifluoroethanol and ringclosing metathesis using a Fürstner modification of Grubbs’ conditions allows the rapid synthesis of novel difluorinated cyclooctenones
Phytochemicals Present in Engleromyces goetzei and Antimicrobial Activity Against Phytopathogenic Bacteria
Interest in the extraction of bioactive compounds from natural sources has increased in recent years due to the potential applications of these compounds in food, chemical, and pharmaceutical industries. The methanolic extract of the fungus Engleromyces goetzei was investigated for the presence of phytochemicals and the antibacterial properties. The study shows that the extract has flavonoids, coumarins, saponins, terpenoids and steroids. Engleromyces goetzei has potential as a source of useful antibacterial compounds active against phytopathogenic bacteria. Disk diffusion assay was used to analyze the susceptibility of an organism which help in identifying the proper antibacterial biopesticide. In this experiment, this was done by placing the antimicrobial disks impregnated with E. goetzei on the NA plates swabbed with Xanthomonas campestris, Pseudomonas sryingae pv phaseolicola, Erwinia carotovora and Xanthomonas axonopodis pv. phaseoli. After twenty-four hours of incubation, there were areas around the antimicrobial disks with no bacterial growth. The MIC of E. goetzei against X. axonopodis pv. phaseoli, Ps. syringae pv phaseolicola and X. campestris was found to be 1mg/ml while that of E. carotovora was 10mg/ml. Keywords: Phytochemicals, Engleromyces goetzei, X. axonopodis pv. phaseoli, E. carotovora, Ps. syringae pv phaseolicola, X. campestri
Genotypic analysis of multidrug-resistant Salmonella enterica Serovar typhi, Kenya.
We report the emergence in Kenya during 1997-1999 of typhoid fever due to Salmonella enterica serovar Typhi resistant to ampicillin, tetracycline, chloramphenicol, streptomycin, and cotrimoxazole. Genotyping by pulsed-field gel electrophoresis of XbaI-digested chromosomal DNA yielded a single cluster. The multidrug-resistant S. Typhi were related to earlier drug- susceptible isolates but were unrelated to multidrug-resistant isolates from Asia
Effect of Inoculation with Mycorrhizae on Growth Parameters of Dombeya torrida, Leucaena leucocephala and Tephrosia vogelii
The present work evaluated the impact of arbuscular mycorrhizal (AM) fungus on growth. Three species of trees, Tephrosia vogelii, Leucaena leucocephala and Dombeya torrida were treated with fragments of arbuscular mycorrhizae and grown in greenhouse. The aim of the present work was to determine whether arbuscular mycorrhizal symbiotic association with these tree species would enhance their growth. Data on height, stem diameter and number of leaves were taken after every two weeks for a period of three months. Mycorrhizal plants demonstrated higher vigor with Tephrosia vogelii giving a mean height of 57.50 cm, 0.50 cm diameter and 9.33 number of leaves which were significantly different from the control plants at p ≤ 0.05 according to least significant difference (LSD). The biomass was also taken at the end of 90 days of growth and the same trend was exhibited. Mycorrhizal plants also showed root nodules with mycorrhizal arbuscles. This work contributes to our understanding of the effects of AM symbiosis on the accumulation of certain micronutrients in valuable woody tree species. Keywords: arbuscular mycorrhizae, Tephrosia vogelii, Leucaena leucocephala, plant growt
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