Recent Advances in Biological Research Vol. 3

The causative agent of banana streak disease (BSD) is Banana streak virus (BSV). In tropical countries such as Kenya, the virus causes considerable damage to the banana crop besides lowering banana production yields. Several mealy-bug species have been reported as vectors of BSV. The latent and retention time of the BSV in the oleander mealy-bug (Paracoccus burnerae) is however unknown. The latent and retention times of viruses in disease vectors are important characteristics in the determination of the mode of transmission of viruses by their vectors. The purpose of this study was to determine the latent and retention time of the BSV in its vector, P. burnerae. We employed both the Immuno-capture Polymerase Chain Reaction (IC-PCR) and Rolling Circle Amplification (RCA) techniques to select diseased and healthy plantlets for transmission trials. RCA assays were performed on the deoxyribonucleic acid (DNA) samples of viruliferous mealy-bug instars of P. burnerae and on the DNA of virus-inoculated plantlets. The findings of the study indicated that BSV has no latent period in P. burnerae during transmission at ambient conditions (9-30°C). However, the vector can retain and transmit BSV for a period of four days under ambient temperatures (9-30°). The results revealed that the vector P. burnerae, transmits BSV semi-persistently which is an indication of a non-circulative mode of transmission of the virus. The results of this study contribute to the elucidation of the mode of transmission of BSV by P. burnerae and impetus for the development of novel control strategies of BSD. Further studies are recommended to determine the specific BSV and vector proteins involved in the transmission process. Such studies have the potential to contribute to development of novel disease management strategies based on the use of viral genes that encode for proteins that are defective to prevent vector inoculation and successful transmission of BSV by its vectors. From our results, we also recommend further screening studies for banana plant encoding molecules (e.g. peptides) that are able to bind to cuticle protein receptors in the vector mouthparts which may provide innovative virus management strategies by interfering with the process of virus retention.

The concept of metabolic Syndrome was first introduced as Syndrome X by Gerald Reaven He delivered the Banting Lecture in 1988 at the American Diabetes Association national meeting. He stated that Syndrome X is aggregation of independent, risk factors present in the same individual which are seen in coronary heart disease (CHD). The various risk factors included in the syndrome were insulin resistance, defined as the inability of insulin to optimally stimulate the transport of    glucose into the body’s cell (hyperinsulinemia or impared glucose tolerance, hypertension, hypertriglyceridemia, and low, high-density lipotrotein cholesterol (HDL) [1]. Syndrome X is referred as,the deadly quartet by Kaplan [2] and Foster described it as,a secret killer [3]. Reaven in his Banting Lecture described the point that insulin resistance/hyperinsulinemia might be the underlying cause of the syndrome. Reaven also suggested that insulin resistance/hyperinsulinemia was an underlying risk factor for T2D, which, at the time, was referred to as noninsulin-dependent diabetes mellitus. In 1991, Ferrannini et al. [4] in his article published entitled,’ Hyperinsulinemia: the key feature of a cardiovascular and metabolic syndrome,’ described Reaven’s point of view about insulin resistance and metabolic syndrome. Furthermore, use of the term MS acknowledges that this array of factors is associated with abnormal carbohydrate and lipid metabolism. These authors emphasized that insulin resistance was the underlying factor and, once acquired, those with a genetic predisposition would develop all the other aspects of the disorder. Haffner et al. [5] coined the term “insulin resistance syndrome” for the disorder to highlight the fact that insulin resistance preceded other aspects of the syndrome. Some individuals still use the term insulin resistance syndrome but now the term “metabolic syndrome” is more commonly used to describe the aggregation of multiple CHD and T2D risk factors.

Metabolic syndrome is a pathophysiological process, meaning that it is either caused by a disease or represents a dysregulation of normal physiological mechanisms occurring due to long standing insulin resistance. The baseline cause of metabolic syndrome is obesity which is mainly due to accumulation of fat. Thus cluster of condition seen in metabolic syndrome are mainly due to fat storage condition and insulin resistance is feature of fat storage condition.

Increased plasma free fatty acid concentrations are typically associated with many insulin-resistant states. It is demonstrated in the animal experimental study that fatty acids compete with glucose for substrate oxidation in heart muscle and diaphragm muscle.

It is speculated that increased fat oxidation causes the insulin resistance associated with obesity [6-8]. The mechanism proposed to explain the insulin resistance was that an increase in fatty acids caused an increase in the intra mitochondrial acetyl CoA/CoA and NADH/NAD+ ratios, with sub- sequent inactivation of pyruvate dehydrogenase. This in turn would cause intracellular citrate concentrations to increase, leading to inhibition of phosphofructokinase, a key rate-controlling enzyme in glycolysis. Subsequent accumulation of glucose-6-phosphate would inhibit hexokinase II activity, resulting in an increase in intracellular glucose concentrations and decreased glucose uptake.

The increase in plasma fatty acid concentrations initially induce insulin resistance by inhibiting glucose transport or phosphorylation activity, and that causes reduction in muscle glycogen synthesis and glucose oxidation resp. The reduction in insulin-activated glucose transport and phosphorylation activity in normal subjects is observed at high plasma fatty acid levels and leading to accumulation of intramuscular fatty acids (or fatty acid metabolites). This appears to play an important role in the pathogenesis of insulin resistance seen in obese patients and patients with type 2 diabetes. Moreover, fatty acids seem to interfere with a very early step in insulin stimulation of GLUT4 transporter activity or hexokinase II activity.

Increasing intracellular fatty acid metabolites, such as diacylglycerol, fatty acyl CoA’s, or ceramides activates a serine/threonine kinase cascade (possibly initiated by protein kinase), leading to phosphorylation of serine/threonine sites on insulin receptor substrates. Serine-phosphorylated forms of these proteins fail to associate with or to activate PI 3-kinase, resulting in decreased activation of glucose transport and other downstream events, Any perturbation in these events results in accumulation of intracellular fatty acyl CoA’s or other fatty acid metabolites in muscle and liver, either through increased delivery or decreased metabolism, might be expected to induce insulin resistance.

Introduction: Salmonella infections remain a veterinary and public health problem of major importance. Poultry birds are known to be one of the major reservoirs of Salmonella and could consequently act as a vehicular transmission route to humans. Rare Salmonella serovars, whose epidemiological and serological patterns are not well understood, are becoming increasingly common in Nigeria and other parts of the world. We report the isolation of Salmonella enterica serovars Wangata and Penarth, two serovars that had not been previously reported in chicken in Nigeria.

Materials and Methods: A total of 300 chickens comprising of 150 intensively reared and 150 free range chickens, from selected farms and live bird markets, were sampled via cloacal vent using sterile cotton swab tips according to the International Office of Epizootics (OIE) standards. Following standard bacteriological techniques, samples were pre-enriched in buffered peptone water, before transferring into Rappaport Vassiliadis medium and finally streaked onto Salmonella-Shigella agar (SSA). Salmonella spp. were identified biochemically and serotyped based on reaction with somatic (O), flagella (H), and capsular (Vi) antisera. Antibiotic susceptibility testing was performed following Kirby-Bauer (disk-diffusion) method.

Results: Out of the 300 samples, 4% (n = 12) were positive for salmonellae. The isolates comprise of 6 isolates of S. enterica ser Wangata, 5 S. enterica ser Enteritidis and 1 S. enterica ser Penarth. All the rare serotypes S. Wangata and S. Penarth were isolated from free range chickens, while S. Enteritidis was isolated from both intensively reared and free range chickens. There was no difference in the sensitivity pattern between the rare serovars and serovar Enteritidis to the antibiotics tested. S. Penarth had a higher MIC to Cotrimoxazole, but lower MBC for gentamicin and tetracycline.

Conclusions: Free range chickens could be vehicles for the transmission and/or reservoirs of the rare salmonellae serotypes in Nigeria. Any prophylactic program aimed at controlling these agents in poultry farms in Nigeria, must take into account the free range local chickens.

Mycobacterium ulcerans (MU), the causative agent of Buruli ulcer (BU), skin disease, is considered to be an environmental pathogen. The pathogenic virulence of MU is being linked to the expression of toxin called Mycolactone. The ketoreductase (KR) gene, is one of the synthesis genes of mycolactone enzymes previously found in M. ulcerans. Genetic analyses using variable number tandem repeats (VNTR) and mycobacterial interspersed repetitive units (MIRU) have shown high diversity in M. ulcerans and in mycolactone producing Mycobacteria (MPMs).

Aim: The purpose of this study is to detect ketoreductase gene in the genome of environmental mycobacteria strain, apart the M. ulcerans, from aquatic environments in Côte d’Ivoire.

Place and Duration of the Study: The analysis of the samples took place in the laboratories of Institut Pasteur de Côte d’Ivoire in Abidjan City between June 2014 and December 2015. Sampling was done in some hypoendemic and hyperendemic sites of Buruli Ulcer of Côte d’Ivoire.

Methodology: A total of 473 samples were collected comprising of 251 waters and 222 sediments based on sampling sites. PCR diagnostics using IS2404 and KR were performed on strains.

Results: 20% fast growing isolated mycobacteria species including Mycobacterium mucogenicum, Mycobacterium peregrinum and Mycobacterium sp. was found carrying the IS2404 gene previously found in M. ulcerans. 9.23% of strains carried the ketoreductase (KR) genes, one of the synthesis of mycolactone enzyme.

Conclusion: The results of this study proved the existence of ketoreductase (KR) genes in rapidly- growing mycobacteria. This study is one of the steps taken in order to understand different skin infections encountered in Côte d’Ivoire. Cutaneous ulceration is a public health problem in Côte d'Ivoire. This work showed a probable involvement of non ulcerans mycobacteria in the spread of this disease. Investigations must therefore continue in order to confirm this observation in clinical practice. All of which could help to determine the likely prevalence of skin ulcers due to Mycobacterium other than M. ulcerans to better adapt treatment in Côte d'Ivoire.This study will help to better diagnose patients suffering from skin infections other than Buruli ulcer and to consider strategies and means of protection of the population against all mycobacterioses by breaking the epidemiological chain.

The population dynamics of Periophthalmus barbarus in the mangrove swamp of Iko River estuary, southeast of Nigeria were obtained from a twenty four month length composition data ranging 4.6 – 14.5 cm total length (TL) (mean 9.1841± 1.6346: n = 2,876) corresponding to 1.16 – 50.6 g total weight (TW) (mean = 9.9626 ± 5.4796) the growth was exponential. The asymptotic length (L∞) of the Powell-Wetheral plot (L∞ = 15.03 cm) was seeded into FSAT II (FAO-ICLARM Stock Assessment Tools II) software to obtain best estimates of vonBertalanfy growth parameters as L∞ = 16.22 cm TL, growth coefficient (K) = 1.2 year^-1, age of fish at zero length, t_o = 0.071; longevity, t_max = 2.5 years. The estimated growth performance index, φ' = 2.449. Other FISAT II growth parameters were the amplitude of growth oscillation, C = 0.6 and the winter point, WP = 0.6, Rn = 0.3127. Mortality parameters were total mortality, Z = 479 year^-1, natural mortality, M = 2.39 year^-1 and fishing mortality, F was 2.40 year^-1. Result indicate the fishery is optimally exploited with current exploitation rate, Ecur = 0.50 < Emax = 0.668 > Eopt = 0.5 which suggests stock optimal exploitation; corroborated by Z/K ration (3.184).  Ecur (0.5) means that 50% of the available stock is being fished annually. The length-at-first capture Lc = 7.33 cm TL and Lc/L∞ was 0.45, indicating the fish was yet to complete 55% of growth as at the time of capture at Lc; hence P. barbarus in the ecosystem is at the optimal level of exploitation as well as the presence of growth overexploitation. Thus to circumvent the consequences of growth overfishing, sustainable fisheries measures such as monitoring of fishing effort, use of selective gears and increase in mesh size should be encouraged, implemented and enforced. The study has revealed that P. barbarus population residing in the mangrove swamp of Iko River Estuary is experiencing exploitation rate close to the maximum sustainable yield amidst the presence of heavy fishing pressure. Moreover, the mudskipper fishery in this ecosystem is currently exhibiting growth overexploitation signs which could lead to severe implications on the population size and food security within vulnerable fishing households in the future. Therefore, urgent management interventions in the form of monitoring fishing efforts, return of captured juveniles back to the water body from the non-selective fishing gear and use of selective gear with large mesh size (to increase length at first capture) are needed to safeguard this important fish species from possible collapse in the future.

Tomato is one of the most widely grown and extensively consumed horticultural crops in the world. Isolation, identification and pathogenicity of fungal organisms causing postharvest spoilage of tomato fruits during storage was carried out. Tomato fruits showing symptoms of rot were collected from the store house. Small sizes were cut and surface sterilized in 1% of Sodium hydrochloride and rinsed in several changes of sterile distilled water. They were plated on Potato Dextrose Agar (PDA) and observed for fungal growth. Identification was done macroscopically and microscopically. For pathogenicity, healthy tomato fruits were plugged with pure cultures of the fungal isolates and disease incidence and severity were evaluated. Five fungi namely Aspergillus flavus, Penicillium waksmanii, Botryodiplodia theobromae, Fusarium oxysporum and Colletotrichum asianum were isolated. Incidence of decay on healthy tomato fruits was 100% for all fungal isolates while the control was 0%. T-test revealed significant differences between the inoculated and the controls at 1% and 5% levels of probability. Severity of decay ranged from 51–53% for all fungal isolates, while the controls showed 0%. T-test revealed significant differences between the inoculated and the control at 1% and 5% levels of probability. Pathogenic microorganisms on tomato are a potential health hazard to man and animals following ingestion.

Aims: To highlight whether metabolites of Alcaligenes faecalis BW1 extract can be administered orally for their possible antimycobacterial effects.

Study Design: Study of the influence of certain parameters on the extract of Alcaligenes faecalis by using either discs or well diffusion methods against M. smegmatis.

Place and Duration of Study: Laboratory of Microbial Biotechnology, Department of Biology, Faculty of Sciences and Technical, University Sidi Mohamed Ben Abdellah, BP 2202, Road of Immouzer, Fez, Morocco From April to August, 2012.

Methodology: The impact of acidic pH of gastric juice, bile, hydrogen peroxide, pancreatic enzymes and lysozyme on the antimycobacterial activity of Alcaligenes faecalis BW1 extract was evaluated by agar diffusion method. Detection whether or not antibacterial metabolites having a synergistic effect with rifampicin against M. smegmatis was also explored.

Results: Antibacterial metabolites of Alcaligenes faecalis BW1 extract resist to the action of gastric pH, gallbladder bile and hydrogen peroxide. In addition, they are not affected by pancreatic enzymes and lysozyme. Moreover, they have a synergistic effect with rifampicin against M. smegmatis.

Conclusion: Anti-mycobacterial metabolites of Alcaligenes faecalis BW1 extract are compatible with rifampicin and could be administered orally as antitubercular agents after their purification, identification in further work.

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) is defined as the resistant to penicillinase-stable penicillin’s, thus the acronym MRSA is still under use even though methicillin is no longer the agent of choice for treatment. The use of vancomycin for MRSA remains as the treatment of choice but concerns with rising resistance to glycol peptides call for the restrictive use of these drugs. The resistance mechanism and the genes that mediate resistance have presumably evolved in organism that produce antibiotics such that the antibiotic produced is not effective against the producing organism.

Aims: To assess the antibacterial property of seed crude extracts of Pongamia pinnata Linn and isolated flavonoids component from crude extract against Methicillin resistant Staphylococcus aureus obtained from clinical isolates.

Study Design: Observational study.

Place and Duration of the Study: Department of Allied health sciences, Department of Biochemistry and Department of Microbiology in Sri Devaraj Urs Academy Of Higher Education and  Research, Tamaka, Kolar, between February 2014 and march 2015.

Methodology: Confirmed clinical isolates for MRSA were collected from Microbiology department to test the efficacy of crude extracts of seeds from Pongamia pinnata L. Methanolic crude extract has been preferably used for isolation of flavonoid content using Dimethyl Sulfoxide [DMSO] and methanol as ideal solvents during extraction process by column chromatography technique. Agar well diffusion method was performed to determine the antibacterial activity of crude seed extracts of Pongamia pinnata and isolated flavonoids by using quercitin as positive control for flavonoids. Vancomycin a glycopeptide powder used as gold standard for comparing bactericidal activity of quercitin, flavonoids and crude extracts of P. pinnata on MRSA.

Results: The highest antibacterial activity (75-89%) was observed in crude extract of Pongamia pinnata in comparison to vancomycin considered as cent percent. Extracted flavonoids showed activity (66-92%) with respect to crude extract and (50-84%) with vancomycin and the activity (71-92%) with respect to quercitin when tested with concentration ranging from 25-400 µg/ml.

Conclusion: This study showed that seed extracts of Pongamia pinnata L and its phytochemical compound flavonoids showed potential antibacterial activity against MRSA using quercitin and vancomycin. Flavonoids occupy the first grade antimicrobials in combating methicillin resistant staphylococcus aureus infections. These infections which are prominent in ICU units and HICU units can be drastically controlled without any side effects.

The history of nosocomial infections can be traced to the origin of hospitals themselves and have been defined by the WHO as infections that develop in a patient during his/her stay in a hospital or other types of clinical facilities which were not present at the time of admission. Nosocomial infections are a major public health problem globally and are on the increase despite efforts in hospital infection control measures and contribute significantly to morbidity and mortality. Naturally, any micro-organism has the potential to cause infection in hospitalized patients however, only a few including Staphylococci, Escherichia coli, Pseudomonas aeruginosa, Enterococci, fungi and to a lesser extent, viruses and parasites are responsible for the majority of nosocomial infections. In sub-Saharan Africa, data available show that the incidence of nosocomial infections ranges from 2-49% with patients in intensive care units having the   highest rate ranging from 21.2-35.6%. The prevalence of nosocomial infections have  been reported  to vary  between 1.6%-28.7% in Burkina Faso, United Republic of Tanzania, Ghana, Mali, Cameroon, Gabon, Uganda, Burundi, Democratic republic of Congo and Senegal. In Nigeria and Ethiopia, the total accruing occurrence in surgical wards has been reported to vary from 5.7%-45.8% with the later having an incidence as high as 45.8% and an incidence density equal 26.7 infections per 1000 patient days in paediatric surgical patients. In addition, 3.4 -10.9% of hospital-associated infections often  result to mortality in most developed countries though these figures are suspected to be higher in developing countries of sub-Saharan Africa including Nigeria. However, simple and effective control programmes together with effective training of healthcare workers will go a long way in reducing the endemic nature of nosocomial infections in sub Saharan Africa. This paper highlights the natural history, distribution, risk factors of nosocomial infections especially in sub Saharan Africa as well as its contributory factors. Nosocomial infections are endemic in sub Saharan Africa and are further enhanced by emerging and re- emerging resistant agents. Simple and effective control programme together with computer-based epidemiological surveillance carried out as a global project with considerable inputs from developing countries for monitoring will enable the development of nosocomial infections to be halted if not eliminated. In addition, it is necessary to review the current infection control practices in all hospitals particularly in developing countries including Nigeria so as to incorporate molecular techniques which have been proven to be effective in keeping the spread of nosocomial infections under check. The training and re-training of health care givers on principles of infection control is strongly recommended. Also, the principles of infection control should be incorporated into student nurses, medical students, and other paramedical curriculum as well as employment of adequately competent health workers to avoid over labour which sometimes cause workers to be inefficient resulting in disease outbreaks. Finally, hand washing and other standard infection control practices should be adhered to so that nosocomial infections can be controlled effectively.

Aims: The focus of this study was to evaluate the antimycobacterial activity of Alcaligenes faecalis BW1 extract and to purify it partially.

Study Design: Partial purification of A. faecalis BW1 extract was performed by using thin layer chromatography and active substances responsible for the biological activity were localized.

Place and Duration of Study: The study was carried out at laboratory of Microbial Biotechnology, Department of Biology, Faculty of Sciences and Technical, University Sidi Mohamed Ben Abdellah, BP 2202, Road of Immouzer, Fez, Morocco, during the period from January 2011 to July 2011.

Methodology: Crude extract of A. faecalis BW1 was obtained by using ethyl acetate as an organic solvent and its antimycobacterial effect was investigated by agar discs diffusion method. The extract was then fractionated by thin layer chromatography and the bioactivity was assessed with a bioautography technique followed by spots elution tests.

Results: The results showed that A. faecalis BW1 produced compounds with antimycobacterial activity. All the detected spots by thin layer chromatography inhibited the growth of M. smegamtis.

Conclusion: Various metabolites of A. faecalis BW1 are responsible for the sought effect or they could act synergistically to inhibit mycobacterial growth. These compounds could be used after their total purification in further work against mycobacterial infections.

Gongronema latifolium is a plant that has a wide range of nutritional and ethnomedical uses in different tropical African communities. Scientific reports on the chemical composition and bioactivity (anti-inflammatory, antimicrobial, antidiabetic, antioxidant, anticancer and allelopathic properties) of the plant material by different authors are discussed in this review. Future prospects of the plant extracts in the areas of herbal formulations, food preservation, alcoholic fermentation and beer production, drug discovery and allelopathy are also highlighted.

The bacterial pathogenicity phenomenon is the poly-functional biological potency of germs that are realized by factors (determinants) of pathogenicity (PF) in multi-cellular organism.  

Biological functions are responsible for bacterial pathogenicity in a multi-cellular host organism: the adhesive function, the function of invasion and penetration into the cell, the function of evasion of host defense, and the damage function. Factors of pathogenicity are representative bio-molecules possessed different functional activity. The ligand - receptor interaction of bacterial PF and receptors on eukaryotic cells is the basis of specific lesions caused by the pathogen.

Introduction: Plants are a limitless gift of nature to humans and they possess very appreciative values and roles. They have stood the test of time in the life of man since creation. All over the world, they are hugely exploited for food, fuel, timber, medicine etc. The natural endowment of plants with numerous metabolites and bioactive compounds makes them good sources of therapeutic agents capable of replacing synthetic antibiotics; For example, Salversan and Penicillin are synthetic drugs formerly used for the treatment of Syphilis and Staphylococcus aureus infections, respectively, but which became less preferred because these pathogens developed resistance to the drugs.
Aim: This study was aimed at evaluating Euphorbia abyssinica ( Desert Candle ) , a medicinal plant extensively used in folklore medicine among the Kendem people of South-west Cameroon for antibacterial activity and extracts analyzed for phytochemical composition.
Study Design: The completely randomized block design was used and data analyzed using of two way analysis of variance. Significant means were separated using Duncan’s New Multiple Range Test.
Place and Duration of Study: This study was carried out in the Department of Microbiology, University of Nigeria Nsukka, Enugu State, Nigeria, between April 2011 and August 2012.
Methodology: Extraction was done using absolute methanol, 50% methanol ( in water ) and water as solvents. Qualitative analysis methods were used to assay the phytochemical constituents. Agar-well diffusion, macro broth dilution and agar dilution and time-kill assay were the susceptibility test methods adapted.
Results: The phytochemical constituents detected were alkaloids, flavonoids, tannins, cardiac glycosides, carbohydrates and steroids, and saponins. The 50% methanol extract of the stem-bark was highly active against Staphyloccocus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa and compared favorably with the Gentamycin control drug. The inhibition zone diameters ( IZDs ) obtained with 50% methanol extract measured 23 mm for S. aureus and 19 mm for P. aeruginosa compared to 18 mm achieved with the absolute methanol extract for both S. aureus and P. aeniginosa. For the aqueous extract the overall IZD range of 10±1.60-13±2.16 mm. The susceptibility patterns obtained using both dilutions ( agar and macro-broth) methods were similar to that obtained with the agar diffusion method above. S. aureus ( with MIC, 10.93±1.00-; MBC, 25mg/mL, agar dilution or MIC, 3.9±1.60 -, MBC, 12.5-mg/mL, macro broth dilution methods, respectively ) . It was considered to be the most significantly susceptible bacteria strain tested ( significant mean value 3.933) , while E. coli was the least susceptible ( with MIC, 50±0.00-, MBC, 100mg/mL, in the agar dilution; MIC, 25±0.00-, MBC, 50-mg/mL in the broth dilution and a significant mean value of 14.70) . The stem-bark extracts was also significantly more active than the latex extracts P= .05 with significant mean values of 13.48 and 19.53 respectively. In the time-kill assay, all ( 100% ) the organisms tested were killed by 50% methanol extract of E. abyssinica at concentrations equivalent to 1MIC- 4MIC.
Conclusion: E. abyssinica extracts showed considerable antibacterial activity against the bacterial species tested. These findings authenticate the folklore use of Euphorbia abyssinica for broad spectrum treatment of bacterial infections. The determination of the antimicrobial activity of Euphorbia abyssinica stem ( bark and Latex extracts ) extract included the 50% methanol, absolute methanol and aqueous extracts of these plant parts. The antimicrobial activity variously exhibited by the 50% methanol extracts of all the two plant parts tested, is significant. This is because it validates the popular traditional uses of dilute alcohol concoctions of medicinal plant preparations in ethno medicinal practice in south-West region of Cameroon. Secondly, the results indicated that these herbs used in traditional medicine have selective antimicrobial activities. Thus, the microorganisms which were susceptible to these extracts are those often associated with wound and ear infections, urinary and gastrointestinal tract infections as well as pyrexia of unknown origin. This explains the discriminate uses of these plants in the treatment of particular ailments. These findings provide evidence that E. abyssinica is a strong candidate in microgram concentrations while the plant extracts were effective in milligram concentrations. Therefore actual comparison between the control drugs and the extracts would await isolation, purification and determination of molar concentrations of the pure active ingredients of these plants extracts.

Leaves of Hibiscus rosa-sinensis are processed using different methods depending on the intended application. Using three different processing methods, we investigated the effects of processing on the proximate constitution of the leaf. Result demonstrated that the fresh raw leaf had moisture content of 82.30 ± 0.42%, which were significantly (p<0.05) reduced by drying but not extraction and blanching. The protein content of the raw leaf was low (1.80 ± 0.10%). Extraction and blanching reduced the protein content, whereas drying increased the protein content significantly (p < 0.05) for raw dried leaf powder and blanched leaf products. The raw leaf contained vitamins A, B_2, C and E, which were significantly reduced by extraction and blanching, but were concentrated by drying. Anti-nutrient contents of the raw leaf were low and were reduced to negligible levels by the processing techniques employed. Comparing the nutrient and chemical constituents with recommended dietary allowance (RDA) values; we found that the leaves contain an appreciable amount of nutrients, minerals, vitamins, proteins and phytochemicals and low degree of toxicants. These findings suggested that the treatment method employed in processing this leaf affected the proximate composition, and this should be considered in utilization of this leaf (and other leaves) product in various food and pharmaceutical formulations. Various heat processing techniques applied during the preparation of the processed products from Hibiscus rosa-sinensis leaves; caused adverse effects on the chemical composition of the processed leaf products. This was evident especially for the vitamins and minerals constitution of the processed products. More so, blanching and drying caused a significant reduction in the nutrients and anti-nutrient composition of the formulated samples. While the best processed samples were the dried powdered products, especially the RDLP, whereas the worst processed samples were the extracts, notably B₂LE. It is recommended that other processing techniques such as freezing, solar and spray drying and ethanol extraction can also be applied in order to determine their effects on nutrient retention and anti-nutrient reduction on the plant leaves and compare it with the results of this study.