Open Access Original Research Article

Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

I. A. Adesina, A. O. Ojokoh, D. J. Arotupin

Journal of Advances in Microbiology, Page 1-8
DOI: 10.9734/JAMB/2017/31386

Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products.

Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid bacterial isolates were determined by the dual agar overlay method and well diffusion method.

Results: Eleven isolates (79%) out of the fourteen lactic acid bacterial strains screened showed antifungal activity against one or more of the moulds when the method used was dual agar overlay method. When agar well diffusion assay was used to check the antifungal activity of the cell-free culture supernatants of these eleven LAB isolates after excluding inhibition due to organic acids and hydrogen peroxide, only four LAB strains (BE1, IO1, PO4 and PO9) continued to show antifungal activity against the moulds. The selected bacteriocin-producing LAB strains (BE1, IO1, PO4, and PO9) were identified as Lactobacillus cellobiosus, Pediococcus pentosaceus, Lactobacillus rhamnosus, and Tetragenococcus halophilus respectively using API 50 CHL system. The cell-free culture supernatant of P. pentosaceus IO1, T. halophilus PO9, and L. cellobiosus BE1 sprayed on bread surface inhibited the growing of moulds during 14 days of storage in polythene bags.

Conclusion: These LAB isolates from fermented products capable of inhibiting the moulds have potential that could be used as biopreservative agents in bakery products.


Open Access Original Research Article

In vivo Studies of Antiviral Effect of Tetrapleura tetraptera Extracts on Newcastle Disease Virus

G. Ezeifeka, P. Nwiyi, C. Azuonye, I. Erumaka, A. Onyeabor, I. O. Oguoma, I. Ukwueni

Journal of Advances in Microbiology, Page 1-8
DOI: 10.9734/JAMB/2017/34521

Newcastle disease (ND) is an economically important disease of poultry. Vaccination had been the only way of prevention in Nigeria and indeed many countries of the world. Possible therapy is presently lacking. Drugs developed from medicinal chemistry, plant natural products constitute major sources of innovative therapeutic agents for various infectious diseases. Here we studied the in-vivo antiviral effect of Tetrapleura tetraptera (Tt) pods on ND virus in Birds. The aim of this study is to test the ability of this plant to prevent death in Birds. The study employed one (1) phase experimental design. Two concentrations of Tt extract (1.0%, 0.1%) and control were used for treatment in phase 1. All test birds were treated at pre-exposition prophylaxis, at time of prophylaxis after exposure and beginning of clinical signs. Clinical signs of greenish diarrhea, dyspnea, increase in temperature and paralysis were observed. All birds (100%) died, while mortality in treated birds was slightly delayed. There was 20% more lesion in untreated group than in treated groups at post-mortem. There was necrosis of intestinal mucosa and depletion of lymphocytes in the treated group while there was erosion of trachea, duodenum and mononuclear infiltration of muscle fiber in the untreated group. There was 14.3% mortality on the second day post-infection, followed by 71.4% and 14.3% mortality on the 6th and 9th day in treated birds that were infected directly in phase 1. Treatment of ND virus with T. tetraptera extracts was not significant.


Open Access Original Research Article

Antimicrobial Activity of Pleurotus squarrosulus on Clinical Pathogenic Bacteria and Fungi

Akpi U. Kalu, Odoh C. Kenneth

Journal of Advances in Microbiology, Page 1-9
DOI: 10.9734/JAMB/2017/34644

Aim: To evaluate the antimicrobial activities of Pleurotus squarrosulus mushroom extracts on bacterial and fungal isolates.

Study Design: Pleurotus squarrosulus was obtained from different sources in Umuahia North Local Government, Abia state, Nigeria and identified in the Department of botany, University of Nigeria, Nsukka.

Place and Duration of Study: Antimicrobial activities of Pleurotus squarrosulus was carried out in the department of microbiology between January 2016 and August 2016

Methodology: Pleurotus squarrosulus was extracted using ethanol, methanol and aqueous. Antimicrobial susceptibility tests were carried out by agar disc diffusion technique using National Committee of Clinical Laboratory Standard. Qualilative phytochemical analysis was carried out using standard methods.

Results: Methanol, ethanol and aqueous extracts of Pleurotus squarrosulus were tested against E. coli, B. cereus, S. aureus, P. aeruginosa, C. albicans and C. glabrata. The different test microorganisms showed varied susceptibility to the test extracts. All the test organisms were inhibited by methanol, ethanol and aqueous extract at varied concentrations ranging between 500 mg/ml and 125 mg/ml. Statistically, inhibition of the antibacterial and antifungal control for the test organisms were significantly higher (P < 0.05) than that of the extracts. The phytochemical analysis revealed the presence of saponin, carbohydrates, tannins, flavonoids and proteins in all the extracts while glycoside and alkaloids, were found in some.

Conclusion: The finding of this result suggest that Pleurotus squarrosulus possess broad-spectrum antimicrobial activity. The potential of developing antimicrobials from plants appear rewarding.


Open Access Original Research Article

Diversity and Levels of Bacteriological Contamination in Orashi River, Mbiama Community, River State, Nigeria

Enetimi Idah Seiyaboh, Ebiotu Precious Kolawole

Journal of Advances in Microbiology, Page 1-6
DOI: 10.9734/JAMB/2017/34671

This study evaluated the level and diversity bacteria contamination in River Orashi in Mbiama community, Rivers state of Nigeria. Triplicate samples were obtained from three stations viz: upstream, downstream and midstream. Standard bacteriological methods were employed for the analysis. Total heterotrophic bacteria, total coliform and fecal coliform ranged from 3.00 to 7.00 x 106 cfu/ml, 12.00 to 15.67 MPN/100 ml and 7.00 to 14.00 MPN/100 ml respectively. Analysis of variance showed that there were no significance difference (P>0.05) among the various location apart from total heterotrophic bacteria that was significantly different (P<0.05) among the different location. The bacteria density exceeded the Standard Organization of Nigeria and World Health Organization/Food and Agricultural Organization allowable limit of 1.0 x 102 cfu/ml for potable water. The bacteria isolates identified include Pseudomonas, Proteus, Micrococcus, Shigella, Salmonella, Enterobacter species, Staphylococcus aureus and E. coli. The findings of this study showed that the water quality of Orashi River at Mbiama community is not suitable for consumption based on bacteriological analysis. As such the water should be treated through boiling and chlorination prior to consumption.

Open Access Original Research Article

Asymptomatic Carriers of Enteric Pathogens and the Risk Factors among Food Handlers in a Rural Setting in Nigeria

A. N. Umo, A. O. Okon

Journal of Advances in Microbiology, Page 1-6
DOI: 10.9734/JAMB/2017/34060

Introduction: Presence of enteric pathogens in humans has been described as one of the most common challenges of developing countries.

Materials and Methods: Stool samples were collected from 540 randomly selected workers in the hospitality industry in Etim-Ekpo and were subjected to microscopic and bacteriological examination to detect asymptomatic carriers of enteric pathogens. A structured questionnaire was used to collect additional data from the subjects. Each of these subjects aged between 18 and 56 years, gave informed oral consent before samples were collected.

Results: The results show presence of the following enteric bacterial pathogens: Salmonella sp, Shigella sp, Escherichia coli, Citrobacter sp and Campylobacter sp. Intestinal parasites detected were ova of Ascaris lumbricoides, Hookworm, Taenia sp and Trichuris trichuria, cysts of Entamoeba histolytica and Giardia lamblia. The distribution of the enteric pathogens was comparable among male and female subjects (p˃0.5). Putative risk factors that may have promoted transmission of these pathogens include poor personal hygiene habits, (OR 5.14, 95% CI 1.66-10.62, p = 0.01), use of local stream/river as source of domestic water supply (OR 2.52, 95% CI 1.20-4.2, p = 0.01) and poor sanitation with improper facility for sewage disposal (OR 4.49, 95% CI 2.61-4.21, p = 0.03).

Discussion and Conclusion: The findings in this study bring to light the evidence that food handlers in some hospitality outlets in Etim-Ekpo are asymptomatic carriers of enteric pathogens. It is therefore advocated that food handlers in this area should be screened regularly and treated if found to harbor enteric pathogens. Promulgation and implementation of appropriate policies should be enforced in order to check the excesses of some food handlers and vendors.