Open Access Original Research Article

Shiga Toxin Producing Strains of Escherichia coli (STEC) Associated with Beef Products and Its Potential Pathogenic Effect

Iyekhoetin Matthew Omoruyi, Eseosa Uwadiae, Gospel Mulade, Ejaromedoghene Omoruku

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/MRJI/2018/32959

Background: Contaminated beef products sold in Nigeria are widely consumed by all with little or no knowledge of the presence or occurrence of possible pathogen.

Methods: The current study investigated the presence of shiga toxin producing strains of E. coli (STEC) in beef products using selective and chromogenic media. Furthermore, the pathogenicity of STEC was determined in vivo using established methods.

Results: E. coli was isolated from all beef samples while 30 % (mean) were reported to be STEC. There was a dose-dependent increase in the levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase observed in the serum of all mice exposed to STEC. This was also confirmed by an obvious damage in the livers and kidneys of the affected mice.

Conclusion: By and large, the result of this study shows that beef products sold in Benin City, Edo State, Nigeria are loaded with STEC, which could pose grave problem for consumers. Hence, effort should be made to minimize their presence in beef, and to prevent possible outbreaks.


Open Access Original Research Article

Antimicrobial Susceptibility Profiles of Staphylococcus aureus Strains from Ear, Nose and Wound Swabs of Patients Attending Health Care Facilities, Ebonyi Sate, Nigeria

V. U. Olugbue, V. O. Nwaugo, M. C. Korie, M. O. Okata, I. Oko, N. U. Okoro

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2018/39731

Aim: This study assessed age group related level of infection and antimicrobial susceptibility profiles of Staphylococcus aureus strains from a clinical specimen.

Study Design: This is a prospective cross-sectional study conducted among in-patients and out- patients suspected of having a bacterial infection to determine the age group related level of infection and antimicrobial susceptibility profile of Staphylococcus aureus strains.

Place and Duration of Study: The study was conducted between May, 2015 and June, 2016 at the Microbiology Laboratory of Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria.

Methodology: A total of 723 clinical specimens including ear, nose and wound swabs were analysed for the presence of S. aureus. Standard microbiology laboratory tests were used to isolate and identify the strains. Antibiotic susceptibility testing of the strains was determined by the disc diffusion test (Kirby-Bauer method). Multidrug resistance was defined in this study as resistance to at least three different classes’ of antibiotics.

Results: A total of 215 (29.74%)  S. aureus strains were obtainedThe prevalence rate of S. aureus concerning types of specimen was 85 (51.52%) for wound swabs, 66 (33.33%) for nose swabs and 64 (17.78%) for ear swabs. There was no significant difference (P = 2.50) observed in the number of nose, ear and wound swabs that yielded S. aureus. Age group basis observation of S. aureus strains shows that the age group 21 – 30 years yielded the highest number of S. aureus strains representing 81 (37.67%).  In the tertiary hospital (MMH), almost all the strains showed high sensitivity to ofloxacin 101 (89.38%), followed by gentamycin 95 (84.07%). Antibiotic resistance was highest with cloxacillin 70 (61.95%) followed by cefuroxime 68 (60.18%). Also, in the teaching hospital (FETHA), a high level of sensitivity to ofloxacin 100 (98.04 %) and gentamycin 94 (92.16%) was recorded. Here, cloxacillin 61 (59.80%) followed by ceftazidime 57 (55.88%) showed the highest antibiotic resistance. A total of 76 (35.35%) of S. aureus strains were multidrug resistant (MDR).  Out of this total number of MDR S. aureus strains, 36 (42.35%), 24 (36.36%) and 16 (25.00%) were from wound, nose and ear swabs respectively. Constant antibiotic resistance monitoring is required in order guide physicians in choosing antibiotics against S. aureus.  


Open Access Original Research Article

Modeling the Effect of Natural Substances and Antibiotics Concentrations on the Variation of Inhibition Zone Diameter in Disc Diffusion Susceptibility Test

Gislaine Aurelie Kemegne, Ghislain Seuyim Kouogueu, Maximilienne Ascension Nyegue, Sylvain Leroy Sado Kamdem, Chantal Menut, Francois-Xavier Etoa

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/MRJI/2018/39218

Aims: The aim of this study was to propose a model describing the relationship between the antimicrobial concentration and the inhibition zone diameter during antimicrobial susceptibility testing.

Place and Duration of Study: Department of Microbiology of the University of Yaoundé I between June 2016 and December 2016 (6 months).

Methodology: Water, ethanol extracts and essential oils from plants as well as antibiotics were tested at different concentrations against five bacteria including both Gram+ and Gram-. The inhibition diameters obtained were plotted against the quantity of substance loaded on the disc. Data were divided into two groups and one was used for model construction (test data) while the other was combined to literature data and used for validation. The model construction begun with CurveExpert 1.4 software in order to search for the most suitable equation family fitting the data. The model family selected was modified accordingly to reduce the number of parameters.

Results: We propose a model where the inhibition diameter (Id) = aXb where “a” and “b” are parameters estimated using nonlinear regression, X is the quantity of antimicrobial deposited on the disc. Validation of the model on new set data gave R2 values ranging between 0.96 and 0.98. Moreover the proposed model described three inhibition patterns already discussed theoretically in literature.

Conclusion: This work proposes for the first time a simple and direct mathematical relationship between the antimicrobial concentration and inhibition diameter in the disc diffusion susceptibility test. This may be used in comparing the level of activity of antimicrobials and contribute in classifying natural substances according to their activity pattern.


Open Access Original Research Article

Microbial Synthesis of Polyhydric Alcohol by Saccharomyces cerevisiae

Simiat Olanike Jimoh, Lawal Aminat Olajumoke, Ashorobi Abdul Adisa, Oyekanmi Ezekiel Abiodun, Bakare Rashidat Ikeoluwa, Adefioye Nafisat Adesola, Ibrahim Ramon Adegboyega

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/MRJI/2018/34852

Aim: Synthesis of polyhydric alcohol from agricultural residue using Saccharomyces cerevisiae.

Study of Design: Submerged fermentation process, biomass yield and reducing sugar analysis, non-reducing sugar analysis, extraction and quantification of sugar monomers and polyhydric alcohols.

Place and Duration of Study: Microbiology Unit, Department of Biological Sciences, College of Natural and Applied Sciences, Fountain University Osogbo, Osun State, Nigeria between October 2015 and July 2016.

Methodology: Synthetic route for the production of polyhydric alcohol through sugar reduction under submerged fermentation using Saccharomyces cerevisiae MP2 isolated from fermented beverages was investigated. Biomass yield, reducing sugar concentration (DNS method) and non-reducing sugar (Anthrone method) were analysed. The crude extract obtained after fermentation period was subjected to derivatisation; thus sugars (reducing and non-reducing sugars) and polyhydric alcohol were quantified using Gas Chromatography Flame Ionization Detector.

Results: Biomass yield and reducing sugar concentration decreased as fermentation period increased. Sugar monomers (ribose, sucrose, xylose, rhamnose, lactose, maltose, glucose, arabinose and fructose) and polyhydric alcohol (glycerol, erythritol, arabitol, sorbitol, xylitol, galactitol, ribitol, maltitol and mannitol) with varying concentrations were obtained. The total sugar monomer concentrations obtained from pineapple peel, banana peel and orange peel media were 1612.25, 1534.79 and 1475.56 mg/100 g with corresponding polyhydric alcohol concentrations of 286.42, 250.71 and 247.94 mg/100 g respectively.

Conclusion: Based on the sugar monomers and polyhydric alcohol profile obtained in the research, Saccharomyces cerevisiae MP2 was able to overcome the challenging biological processes such as; delignification in order to release free cellulose and hemicellulose from the lignocellulosic material, depolymerization of the carbohydrate polymers from the cellulose and hemicellulose to generate free sugars, and fermentation of mixed hexose and pentose sugars to finally produce polyhydric alcohol.


Open Access Original Research Article

Effect of Different Fermentation Methods on the Microbial and Proximate Composition of Pigeon Pea (Cajanus cajan)

E. Odion-Owase, A. O. Ojokoh, V. O. Oyetayo

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/MRJI/2018/33604

Pigeon pea (Cajanus cajan) was subjected to different fermentation methods and treatments for 72 hr. The raw (control) and fermented samples were analyzed for microbial and proximate composition. The pH ranged from 6.8 to 4.5 after 72 hr fermentation. The microbial evaluation results showed that there was increase in microbial counts from 0hr to 48hr and reduction at 72 hr. Sodium bicarbonate treated fermented pigeon pea had the highest bacterial counts at 0 hour, (3.2+0.04) and the least counts at 72hr, (3.1+0.05) Solid state fermented pigeon pea had the highest bacterial count at 72hr, (4.9+0.02) Sodium bicarbonate treated fermented pigeon pea had the lowest fungal counts at 72hr, (2.8+0.02), while hot water treated fermented pigeon pea had the highest fungal counts, (3.6+0.05). Bacillus subtilis, Bacillus megatarium, Staphylococcus aureus, Lactobacillus plantarum, Streptococcus lactis, Saccharomyces cerevisae, Aspergillus flavus, Aspergillus niger and Candida albican were found to be associated with the fermentation of pigeon pea. At the end of 72 hr of fermentation, Bacillus subtilis, Bacillus megatarium, Lactobacillus plantarum, Streptococcus lactis and Saccharomyces cerevisae were isolated. The proximate analysis showed that back slope fermented sample had the highest fat content of 10.12% and least carbohydrate value of 57.84%, potassium bicarbonate treated fermented pigeon pea had the least fat value of 7.23% and the highest value of carbohydrate content of 65.3%. Cold water treated fermented pigeon pea had the highest protein content of 14.21%, hot water treated fermented pigeon pea had the highest energy value of 6,762 Kcal/g, while the non fermented (control) pigeon pea had the least energy value of 4, 296 Kca/g.