73 research outputs found
Exploring differentially expressed genes of Staphylococcus aureus exposed to human tonsillar cells using RNA sequencing
Background - The nose and the throat are the most predominant colonizing sites of Staphylococcus aureus, and colonization is a risk factor for infection. Nasal colonization is well described; however, we have limited knowledge about S. aureus throat colonization. The main objective of this study was to explore differentially expressed genes (DEGs) in S. aureus throat isolate TR145 exposed to human tonsil epithelial cells (HTEpiC) by using RNA sequencing (RNA-seq) and pathway analysis. DEGs in S. aureus at 1 or 3 hours (h) interaction with its host were explored.
Results - S. aureus was co-cultured in absence and presence of tonsillar cells at 1 or 3 h. Over the 3 h time frame, the bacteria multiplied, but still caused only minor cytotoxicity. Upon exposure to tonsillar cell line, S. aureus changed its transcriptomic profile. A total of 508 DEGs were identified including unique (1 h, 160 DEGs and 3 h, 78 DEGs) and commonly shared genes (1 and 3 h, 270 DEGs). Among the DEGs, were genes encoding proteins involved in adhesion and immune evasion, as well as iron acquisition and transport. Reverse transcription qPCR was done on selected genes, and the results correlated with the RNA-seq data.
Conclusion - We have shown the suitability of using HTEpiC as an in vitro model for investigating key determinants in S. aureus during co-incubation with host cells. Several DEGs were unique after 1 or 3 h exposure to host cells, while others were commonly expressed at both time points. As their expression is induced upon meeting with the host, they might be explored further for future targets for intervention to prevent either colonization or infection in the throat
In vitro acaricidal activity of Azadirachta indica and Phytolacca dodecandra leaves and their combination on Rhipicephalus (boophilus) decoloratus
Rhipicephalus (boophilus) decoloratus (ticks) are causing great economic loss among the cattle rearers from cattle mortalities and costs during the treatments. Synthetic acaricides have been used for a long time in the management of ticks, however chemical resistance from multiple uses of acaricides as well as contamination of dairy products from these acaricides has caused the urgent need for alternative herbal drugs. This study evaluated in vitro activity of the combination of Phytolacca dodecandra L’Her and Azardirachta indica A. Juss against R. (boophilus) decoloratus (ticks) with a view to developing active, less toxic and non-resistant acaricides. P. dodecandra and A. indica were collected, dried after authentication, pulverised mechanically and extracted with cold water. Ticks were treated with the herbal extracts singly and then in combination with concentrations ranging between 50-100mg/mL of distilled water. The anti-tick activity of P. dodecandra and A. indica was compared with Duodip and Ametix which are synthetic acaricides currently being used by farmers in Western Uganda. Results showed that P. dodecandra extract gave the highest mortality of ticks (65%) compared with A. indica (50%), Duodip (40%) and Ametix (5%) within a period of 12– 48 hours after exposure to the treatment. A combination of the two medicinal plant extracts (50%) did not show any significant difference in tick mortality compared to P. dodecandra. Phytolacca dodecandra has potential benefits thus may be used to obtain a natural eco-friendly acaricide for the management of ticks, however, a combination of the two medicinal herbal extracts has little synergistic effect compared to when P. dodecandra is used alone
LAXATIVE ACTIVITIES OF CASSIA SIEBERIANA AND SENNA OBTUSIFOLIA
Background: The root and stem bark of Cassia sieberiana DC. (Caesalpiniaceae) and the root of Senna obtusifolia (Linn) Irwin and Barneby (Caesalpiniaceae), used for constipation in Nigeria, were assayed for laxative properties in male albino rats using the official senna leaf (Senna alexandrina Mill. family Caesalpiniaceae) as the reference standard. This is with a view to finding alternative laxative drug to official senna which is presently being imported into Nigeria from the United Kingdom.
Materials and Methods: The mean percentage of wet faeces in rats, an indication of laxative activity, were obtained using established methods. The laxative activity was established at 500 mg/kg after the infusion of the drug was orally administered on male albino rats following established methods while a set of data was analyzed at 95 % confidence level.
Results: At 500 mg/kg, Senna obtusifolia root gave about 45 % wet faeces while Cassia sieberiana root gave about 40 % wet faeces while at the highest dose of 700 mg/kg, they produced 60 % and 38 % wet faeces, respectively. At these two doses, the official Senna gave 50.6 % and 66 % wet faeces, respectively. Thus, S. obtusifolia and C. sieberiana roots exhibited 89 % and 80 % of the potency of S. alexandrina (the official drug), respectively. The analysis of variance revealed a significant statistical difference in the levels of wet faeces produced by rats dosed with C. sieberiana root.
Conclusion: The results have shown that the roots of the two species could be developed as mild laxative drugs for children and pregnant women for whom the official senna will be contraindicated
Bacterial Cell Envelope Lysis and Hemotoxicity of Peptides Previously isolated From African Catfish, Clarias gariepinus
Background: The skin mucus layer of fish is endowed with biologics including, Antimicrobial peptides (AMPs) that offer a first line of defence against pathogens. Such peptides can either inhibit bacterial growth or completely kill the bacteria and hence are regarded as a viable alternative to traditional antibiotics, in addressing the ever-increasing incidences of antimicrobial resistance. However, one of the major hurdles to AMPs use is their poor haemolytic profile. As a result, a thorough evaluation of prospective AMPs’ bacterial cell membrane disruption and hemolytic potentials in the early phases of drug discovery is critical. The current study presented cell membrane destruction as well as hemo-compatibility of antimicrobial peptides previously isolated from skin mucus of African catfish, Clarias gariepinus.Methods: A previously isolated antimicrobial peptide in the skin mucus of African catfish, C. gariepinus were profiled using 15% Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The electrical conductivity and alkaline phosphatase assays were utilised to measure bacterial cell envelope lysis activity as a classical mode of action of the antimicrobial peptides. Afterwards, fresh Rabbit blood cells were then utilised for in vitro hemolytic assay.Results: The peptides were found to be about 5 kDa molecular weight with, ability to damage the bacterial cell envelope causing significant leakage in periplasmic alkaline phosphatase enzyme and cytoplasmic electrolytes. Even at the highest peptide extract concentration of 100 μg/mL, no significant hemolysis was observed on the fresh rabbit blood cells [3.63%;P>.05], signifying their safety on normal mammalian cells.Conclusion: The findings of this study pointed out that antimicrobial peptides in skin mucus of C. gariepinus are potentially safe source of antimicrobial drug leads; however, further studies are still required to search for possibly maximum dose that is safe to host cells but still effective against infecting bacteria
The interaction between Staphylococcus aureus SdrD and desmoglein 1 is important for adhesion to host cells
ADMET profiling and molecular docking of potential antimicrobial peptides previously isolated from African catfish, Clarias gariepinus
Amidst rising cases of antimicrobial resistance, antimicrobial peptides (AMPs) are regarded as a promising alternative to traditional antibiotics. Even so, poor pharmacokinetic profiles of certain AMPs impede their utility necessitating, a careful assessment of potential AMPs’ absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties during novel lead exploration. Accordingly, the present study utilized ADMET scores to profile seven previously isolated African catfish antimicrobial peptides (ACAPs). After profiling, the peptides were docked against approved bacterial protein targets to gain insight into their possible mode of action. Promising ACAPs were then chemically synthesized, and their antibacterial activity was validated in vitro utilizing the broth dilution method. All seven examined antimicrobial peptides passed the ADMET screening, with two (ACAP-IV and ACAP-V) exhibiting the best ADMET profile scores. The ACAP-V had a higher average binding energy (−8.47 kcal/mol) and average global energy (−70.78 kcal/mol) compared to ACAP-IV (−7.60 kcal/mol and −57.53 kcal/mol), with the potential to penetrate and disrupt bacterial cell membrane (PDB Id: 2w6d). Conversely, ACAP-IV peptide had higher antibacterial activity against E. coli and S. aureus (Minimum Inhibitory Concentration, 520.7 ± 104.3 μg/ml and 1666.7 ± 416.7 μg/ml, respectively) compared to ACAP-V. Collectively, the two antimicrobial peptides (ACAP-IV and ACAP-V) are potential novel leads for the food, cosmetic and pharmaceutical industries. Future research is recommended to optimize the expression of such peptides in biological systems for extended evaluation
Ethnobotanical survey of medicinal plants used in the management of cancer in Uganda
Introduction: Patients with cancer in Africa embrace the use of herbal medicine more than anywhere else in the world. This study identified and documented medicinal plant species used to manage cancer in ten (10) districts of Uganda.
Methods: An ethnobotanical survey was conducted between October 2021 and January 2022. In total, 18 (out of 55) traditional medicine practitioners (TMPs) having more than 10 years of experience in managing patients with cancer were interviewed using a semi-structured questionnaire.
Data were analysed using descriptive statistics. The Relative frequency of citation (RFC) and Family importance value (FIV) indices were also computed.
Results: We identified 121 plant species, belonging to 55 families, with the most common families being the Fabaceae (20 species, FIV = 0.119), Asteraceae (13 species, FIV = 0.131), and Euphorbiaceae (eight species, FIV = 0.079). The plant parts most commonly used were leaves (39.3%) and roots (12.9%). The most frequently cited plants were: Hoslundia opposita Vahl (RFC = 0.44), followed by Aspilia africana (Pers.) C.D. Adams (RFC = 0.33), Spathodea nilotica Seem (RFC = 0.33), Annona muricata L. (RFC = 0.33, Prunus africana (Hook.f.) Kalkman (RFC = 0.28), Acacia hockii De Wild (RFC = 0.28), Bidens pilosa L. (RFC = 0.28), and Carica papaya L (RFC = 0.22). The most common method of plant preparation and administration was the decoction (69.2%) and oral (86.7%) route, respectively.
Conclusions: Although most plants used by TMPs have the potential to generate leads for chemo-preventive cancer medicines, they remain unexplored. This study provides a lead to explore the potential of traditionally used plants for the management of cancer through pre-clinical and clinical research
Co-culturing with Streptococcus anginosus alters Staphylococcus aureus transcriptome when exposed to tonsillar cells
IntroductionImproved understanding of Staphylococcus aureus throat colonization in the presence of other co-existing microbes is important for mapping S. aureus adaptation to the human throat, and recurrence of infection. Here, we explore the responses triggered by the encounter between two common throat bacteria, S. aureus and Streptococcus anginosus, to identify genes in S. aureus that are important for colonization in the presence of human tonsillar epithelial cells and S. anginosus, and further compare this transcriptome with the genes expressed in S. aureus as only bacterium.MethodsWe performed an in vitro co-culture experiment followed by RNA sequencing to identify interaction-induced transcriptional alterations and differentially expressed genes (DEGs), followed by gene enrichment analysis.Results and discussionA total of 332 and 279 significantly differentially expressed genes with p-value < 0.05 and log2 FoldChange (log2FC) ≥ |2| were identified in S. aureus after 1 h and 3 h co-culturing, respectively. Alterations in expression of various S. aureus survival factors were observed when co-cultured with S. anginosus and tonsillar cells. The serine-aspartate repeat-containing protein D (sdrD) involved in adhesion, was for example highly upregulated in S. aureus during co-culturing with S. anginosus compared to S. aureus grown in the absence of S. anginosus, especially at 3 h. Several virulence genes encoding secreted proteins were also highly upregulated only when S. aureus was co-cultured with S. anginosus and tonsillar cells, and iron does not appear to be a limiting factor in this environment. These findings may be useful for the development of interventions against S. aureus throat colonization and could be further investigated to decipher the roles of the identified genes in the host immune response in context of a throat commensal landscape
Simulation and Optimization of an Integrated Process Flow Sheet for Cement Production
In this study the process flow diagram for the cement production was simulated using Aspen HYSYS 8.8 software to achieve high energy optimization and optimum cement flow rate by varying the flow rate of calcium oxide and silica in the clinker feed. Central composite Design (C.C.D) of Response Surface Methodology was used to design the ten experiments for the simulation using Design Expert 10.0.3. Energy efficiency optimization is also carried out using Aspen Energy Analyser. The optimum cement flow rate is found from the contour plot and 3D surface plot to be 47.239 tonnes/day at CaO flow rate of 152.346 tonnes/day and the SiO2 flow rate of 56.8241 tonnes/day. The R2 value of 0.9356 determined from the statistical analysis shows a good significance of the model. The overall utilities in terms of energy are found to be optimised by 81.4% from 6.511 x 107Â kcal/h actual value of 1.211 x 107Â kcal/h with 297.4 tonnes/day the carbon emission savings
Energy and Economic Comparison of Different Fuels in Cement Production
Cement clinkerisation is the major energy-consuming process in cement manufacturing due to the high-temperature requirement. In this paper, energy data including specific energy consumption, forms, and types of energy used at different units of cement manufacturing processes were analyzed and compared for effectiveness, availability, cost, environmental, and health impact. Data from three different cement industries in Nigeria labeled as A, B, and C were used for the analysis in this study. The results of this research work established that coal is the cheapest energy source but environmental issues exonerate it from being the choice energy source. LPFO and Natural gas give better production output while minimizing pollution and health issues. When benchmarked against each other, Factory B was found to be the most energy-efficient in terms of output and cost of production. Although coal is cheaper compared to fuel oil and supposed to contribute a share of fuel used in cement industries, the industries are moving towards the use of alternative and conventional fuels to reduce environmental pollution. It is therefore recommended that deliberate effort to achieve appreciable energy-efficient levels should be the priorities of the cement industries in Nigeria
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