Open Access Original Research Article

Antiplasmodial Activity of Ethanolic Leaf Extract of Cymbopogon citratus (DC) Stapf in Swiss Albino Mice Infected with Plasmodium berghei NK 65

E. O. Dada, R. O. Adebayo

South Asian Journal of Research in Microbiology, Page 27-38
DOI: 10.9734/sajrm/2020/v8i330193

The study assessed the antiplasmodial activity of the ethanolic leaf extract of Cymbopogon citratus on chloroquine sensitive Plasmodium berghei in mice. Standard methods were used to determine the bioactive components of the leaf extract, acute toxicity test and antiplasmodial activity.  Mice obtained (of body weight 20-25 g) were housed and acclimatized for seven days at room temperature before the commencement of the experiment. A total of 16 albino mice were randomized into four groups of four mice each for acute toxicity while 35 were grouped into five groups of seven mice each for antiplasmodial activity. All the groups 1-5 were infected with P. berghei and were treated for six consecutive days with leaf extract dosage of 200, 400 and        800 mg/kg, standard antimalarial drug (chloroquine) as positive control and normal saline as negative control respectively.

Phytochemical screening/ bioactive compounds of the leaf extract reveals the presence of saponins (10.3 mg/g), tannins (2.38 mg/g), flavonoids (1.87 mg/g), terpenoids (19.12 mg/g), steroids (6.21 mg/g) and glycosides (19.9 mg/g) as secondary metabolites. The leaf extract revealed decrease in body weight of the infected mice and did not show any toxicity at all dosage levels used.

The antiplasmodial investigation revealed a decrease in percentage parasitaemia level in mice of extract treated groups compared with mice infected and not treated. The parasitaemia reduction was higher in 800 mg/kg than 200 mg/kg and 400 mg/kg. This significant decrease (P<0.05) in percentage parasitaemia level in the study was dose and time-dependent. The extract showed significant (p<0.05) antiplasmodial activity and could serve as possible candidates for the development of new effective drugs for the treatment of malaria.

Open Access Original Research Article

Effect of Optimization Factors on the Production of Bacillus subtilis and Escherichia coli Synthesized Silver Nanoparticles

C. Chi-Nwankwo, J. N. Ogbulie, C. O. Akujobi

South Asian Journal of Research in Microbiology, Page 39-47
DOI: 10.9734/sajrm/2020/v8i330195

The recent discovery of silver nanoparticles and their production from Bacillus subtilis and Escherichia coli have enhanced optimization attempts. Extracellular biosynthesis of silver nanoparticles using the Bacillus subtilis and Escherichia coli cultured supernatants was done according to standard procedures. Optimization of the production of silver nanoparticles was done in a 3 X 3 (three factors) design involving temperature (25, 30 and 35 degrees), pH (6, 7 and 8), and time of incubation (24, 48 and 72 Hours) in a total of 15 non-randomized runs. The result showed a sharp decline in the synthesis of B. subtilis silver nanoparticles (BNP) within the first 40 hours but attained steady optimization between 40 – 60 mins. An exponential increase in BNP synthesis was observed between pH 6 – 7 with a slight decline observed between pH 7 – 8. An increase in temperature from 25-300C resulted in a decrease in the production of BNP while the production of BNP increased over 30-350C. An initial lag in Escherichia coli synthesized silver nanoparticle (ENP) synthesis was observed with temperature variations. ENP synthesis maintained an exponential increase up to pH 7 but decreased with 7>pH≤8. The results showed that the increase in temperature resulted in a gradual decrease in production of ENP producing a negative slope. Therefore, the variations in optimization factors of silver nanoparticles produced from both B. subtilis and E. coli led to improved production.

Open Access Original Research Article

Optimization of Pectinase and Protease Produced from Bacillus subtilis Isolated from Market Waste

C. Anab-Atulomah, E. Nwachukwu

South Asian Journal of Research in Microbiology, Page 48-57
DOI: 10.9734/sajrm/2020/v8i330196

Aims: The objective of the study was to produce and optimize protease and pectinase from Bacillus subtilis isolated from market waste.

Place and Duration of Study: Department of Microbiology (laboratory unit), Michael Okpara University of Agriculture Umudike, Abia State Nigeria.

Methodology: The production and optimization of protease and pectinase from bacteria isolated from solid market waste was investigated. Isolated bacteria from the waste were screened for protease and pectinase production using skim milk agar and pectin agar respectively. Using morphological, biochemical and molecular technique the enzymes producing isolate was confirmed as Bacillus subtilis. Protease and Pectinase were produced by Bacillus subtilis using submerged fermentation in gelatin broth and pectin broth respectively. The enzymes were purified using ammonium sulphate precipitation, dialysis and ion-exchange chromatography. Optimization using different temperatures, pH and nutrient sources was done. Enzyme activity was measured.

Results: Purified protease exhibited maximum activity of 8.72U/ml at 40oC while pectinase exhibited maximum activity of 8.98U/ml at 50oC. Glucose as a carbon source and peptone as a nitrogen source gave optimum activity for both enzymes. Both pectinase and protease exhibited optimum activity at pH 9. There was significant difference (P=.05) in enzyme activity at different temperatures, pH and nitrogen sources for both protease and pectinase. There was no significant difference in pectinase activity at P=.05 for the different carbon sources while there was significant difference for protease activity for the different carbon sources at P=.05.

Conclusion: Production of microbial enzymes such as protease and pectinase from waste material is an eco-friendly process and cheaper option for large scale use of enzymes in industry.

Open Access Original Research Article

Assessment of Bacteria and Parasite Contamination of Dried Sliced Beef (Kilishi) Sold within Birnin Kebbi Metropolis, Kebbi State, Northern Nigeria

R. D. Jabaka, Queen Ododife, Attah D. Daniel, U. D. Nuhu, E. J. Doro, R. J. Jibo, G. K. Tanko

South Asian Journal of Research in Microbiology, Page 58-66
DOI: 10.9734/sajrm/2020/v8i330197

Kilishi is a version of jerky that originated in Hausa land Nigeria. It is made from deboned cow, sheep or goat meat. The dried sliced beef (kilishi) is often left open in a basin thereby exposing it to flies, dust and other effects of the environment by so doing the product can be contaminated. This study was carried out to investigate the bacteria and parasite contaminants of dried slice beef (kilishi) sold in different locations within Birnin Kebbi metropolis. The samples were analyzed using pour plate method. The bacterial species were characterized and identified on the basis of their colonial morphology; gram’s staining reaction and biochemical characteristics. The protozoans and helminthes cyst/eggs morphology were identified using microscopy techniques. The total bacteria plate count for each sample ranges from the highest (8x109) to the lowest (3.5x103) CFU/g from Birnin Kebbi Kalgo, Jega and Aliero samples respectively. The organisms isolated include; Staphylococcus aureus (35.2%), Escherichia coli showed 30(21.1%) percentage of occurrence, Bacillus species occurred 17(12%) Klebsiella spp 16(11.3%), Pseudomonas spp 13(9.2%), Shigella spp 10(7.04%) and the least was P. vulgaris 6(4.2%). The kilishi meat product was also contaminated with some Protozoans and helminthes contaminants which include; Acaris lumbricoides (14.2%), Entamoeba histolytica (35%), Girdia lambila (42.8%), and Taenia spp. (7.1%). It was concluded that the high bacteria count and frequency of isolates from the kilishi samples tested is an indication of high contamination of the meat by potential pathogens due to poor handling and sanitary conditions which may pose a potential source of food borne diseases.

Open Access Review Article

Global Trends of Emerging Infectious Diseases and the Impacts on Biodiversity: Spillover, Diversity and the Role of Bats in Evolutionary Relationships as Zoonotic Virus Reservoirs

Diniz Pereira Leite Júnior, Elisangela Santana de Oliveira Dantas, Gisela Lara da Costa, Ronaldo Sousa Pereira, Mário Mendes Bonci, Regina Teixeira Barbieri Ramos, Rodrigo Antônio Araújo Pires, Marcia de Souza Carvalho Melhem, Paulo Anselmo Nunes Felippe, Claudete Rodrigues Paula

South Asian Journal of Research in Microbiology, Page 1-26
DOI: 10.9734/sajrm/2020/v8i330192

Introduction: It is possible that the evolution of man is associated with manifestations of microscopic beings that have accompanied him since ancient times. Emerging infectious diseases have been warning for decades that habitat fragmentation and degradation, antropization effects, animal trafficking increase the risk of diseases spreading from wildlife to human populations.

Aims: The purpose of this study was to review the current events about the pandemics that occurred on the planet and the current situation of bat involvement, their high degree of ecological plasticity that these beings present with the emergence and spread of viruses.

Methodology: Review the current knowledge about viral diversity, host condition and possible mammalian reservoirs in the face of pandemics and the close relationship of bats with humans and other possibly incriminated species. Given the epidemics of the last century, it is possible to observe that the increased interaction between humans and wild animals has facilitated the emergence of viral strains of importance for public health.

Results: Given the reports argued by the scientific community, bats may be responsible for the air cycle of viral diseases, being considered of great importance in the study of epidemiology. Conclusion: The SARS-CoV-2 epidemic has come to test the ability of humans to face a threat that may be repeated in the future. As part of nature, bats cannot be framed as precursors of viral agents. The knowledge obtained, associated with investment in science, research and education, will put us one step ahead of future pandemic events.