34th Annual Conference Nigerian Society Of Microbiology, Gabriel-Ajobiewe R.A.O, Ifesan B.O.T And Thomas D.

 Conference

 Involvement Of Bacteria In The Spontaneous Fermentation Of Mucuna Ghana AndMucuna Rajada.

 Gabriel-Ajobiewe R.A.O, Ifesan B.O.T And Thomas D.

 2010

NIL

 

 J Foodborne Pathogen Diseases 6:699-704.

 Journal

 Effect Of Eleutherine Americana Extract On Enzymatic Activity And Enterotoxin Production Of Staphylococcus Aureus In Broth And Cooked Pork

 (12) Ifesan, B.O.T. And Voravuthikunchai, S.P. 2009

 2009

Crude ethanolic extract from the bulb of Eleutherine americana was investigated for its inhibitory activities against lipase and protease enzymes and enterotoxin production by Staphylococcus aureus. Eleven isolates that demonstrated high enzyme activity with three reference strains were selected to study the effect of extract on enzyme production. Exposure of the isolates to subminimal inhibitory concentrations, ½ minimum inhibitory concentration (MIC) (125 mg=mL), and ¼MIC (62.5 mg=mL) of the crude extract resulted in both partial and total inhibition of lipase and protease enzymes. About 15% of the 106 isolates were positive for enterotoxin production with staphylococcal enterotoxin A (11.3%), enterotoxin B (3.7%), and enterotoxin C (10.3%), and no enterotoxin D was produced. The production of staphylococcal enterotoxins A–D in the presence or absence of the crude extract was carried out. In the broth system, the extract reduced enterotoxin production at subminimal inhibitory concentrations compared with the control. At MIC, total enterotoxin inhibition was observed for enterotoxin C production, whereas synthesis of enterotoxins A, B, and D was totally eliminated at 2MIC. The food system study revealed that the extract could delay production of enterotoxins A, B, and C compared with the control. The extract at 2mg=mL delayed production of toxins A and C for 8 and 4 h, while toxin B was not detected in the pork at 48 h. The ability of E. americana extract to inhibit lipase and protease enzymes and to delay enterotoxin production in food could present it as a novel food additive to combat the growth of S. aureus in food. 

 Ph.D, Dr.B.O.T.Ifesan.

 Disertations

 Effect Of Eleutherine Americana Merr. Extracts On Food Poisoning Staphylococcus Aureus And Its Application In Food Systems.

 Dr.B.O.T.Ifesan.

 2009

NIL

 

 J. Food Protect.

 Journal

 Assessment Of Antistaphylococcal Activity Of Partially-Purified Fractions And Pure Compounds From Eleutherine Americana.

 Ifesan, B.O.T., Hamtasin, S., Mahabusarakam, W. And Voravuthikunchai, S.P.

 2009

Ready-to-eat foods were investigated for contamination with methicillin-resistant Staphylococcus aureus (MRSA), and the partially purified fractions from the bulb of Eleutherine americana were evaluated for their anti-MRSA activity. Partially purified fractions Ea6.3 and Ea9 demonstrated good antibacterial activity with a MIC of 125 to 500 ?g/ml and MBC of 250 to ?1,000 ?g/ml against all the food isolates. Fraction Ea6.3 produced a MIC and MBC of 250 and 500 ?g/ml, respectively, whereas fraction Ea9 yielded MIC and MBC of 125 and ?1,000 ?g/ml, respectively, against the enterotoxin-producing reference strains. Growth curves in the presence of fraction Ea6.3 at 4× MIC resulted in total elimination of all the test strains between 20 and 24 h, while fraction Ea9 reduced bacterial population by at least 6 log relative to the control. The partially purified fractions were further purified to obtain pure compounds identified as eleutherol, eleutherin, isoeleutherin, hongconin, two anthraquinones, and elecanacin. The antibacterial activities of these compounds were also investigated; they produced MICs ranging from 31.25 to ?1,000 ?g/ml. This study suggests that E. americana crude extract or its partially purified fractions have potentials for application as natural food preservatives.

 

 Journal Of Food Protection

 Journal

 Application Of Eleutherine Americana Crude Extract In Homemade Salad Dressing.

 Ifesan, B.O.T., Siripongvutikorn, S. And Voravuthikunchai, S.P.

 2009

Crude extract from the herb Eleutherine americana was investigated for its antistaphylococcal activity both in vitro and in a food system. The extract activity against Staphylococcus aureus was better during incubation at 35 degrees C than at 10 and 4 degrees C. The extract exhibited excellent stability in response to heat and pH treatments. The extract was incorporated into homemade salad dressing and evaluated for its antibacterial, physical, chemical, and sensory properties. A more than 1-log reduction in S. aureus counts was observed compared with the control. Examination of lipid oxidation revealed that the extract could retard the formation of thiobarbituric acid-reactive substances in the salad dressing. The magnitude of the storage changes were minimal, and there were no significant differences in the appearance, color, taste, and overall acceptability ranking between samples supplemented with E. americana extract and the control samples. Based on all sensory attributes, the sensory evaluation from 0 to 16 days indicated that products with each extract concentration were acceptable. The extract from E. americana is a promising novel additive that can be used to improve the quality and safety of homemade salad dressing.

 

 Journal Of Food Science, U.S.A.

 Journal

 Inhibitory Effect Of Eleutherine Americana Merr. Extract On Staphylococcus Aureus Isolated From Food.

 Ifesan, B. O. T, Hamtasin, C., Mahabusarakam, W., Voravuthikunchai, S.P.

 2009

About 106 samples of ready-to-eat foods were purchased over a period of 3 mo out of which 76 (71.69%) were contaminated with Staphylococcus aureus. S. aureus isolated from the food samples were characterized phenotypically using traditional biochemical methods. Ninety-four percent of the isolates were mannitol fermenters, 86% positive for coagulase test, while 80% produced lipase enzyme. Antibiotic susceptibility test revealed that 21% and 63% of the food isolates were resistant to oxacillin and penicillin, respectively. The antibacterial activity of the bulb of Eleutherine americana used in Thai cuisine was investigated by agar disc diffusion using 2.5 mg of the crude extract and produced inhibition zone between 14.5 and 15.7 mm, while the minimum inhibitory concentration (MIC) value ranged from 0.06 to 1.00 mg/mL on both food isolates and reference strains. Growth curve in the presence of the crude ethanol extract at 4 MIC showed bacteriostatic effect by 5 log reduction relative to the control. Partially purified fractions tentatively identified by column chromatography were suspected to be responsible for the antibacterial property. This study suggests that E. americana bulb has potential for application as a natural preservative in foods. 

 Journal Of Food Science, U.S.A.

 Journal

 Evaluation Of The Ability Of Eleutherine Americana Crude Extract As Natural Food Additive In Cooked Pork.

 Ifesan, B.O.T., Siripongvutikorn, S., Hutadilok-Towatana, N. And Voravuthikunchai, S.P.

 2009

Crude ethanolic extract from the bulb of Eleutherine americana was investigated for its inhibitory activities against lipase and protease enzymes and enterotoxin production by Staphylococcus aureus. Eleven isolates that demonstrated high enzyme activity with three reference strains were selected to study the effect of extract on enzyme production. Exposure of the isolates to subminimal inhibitory concentrations, (1/2) minimum inhibitory concentration (MIC) (125 microg/mL), and (1/4)MIC (62.5 microg/mL) of the crude extract resulted in both partial and total inhibition of lipase and protease enzymes. About 15% of the 106 isolates were positive for enterotoxin production with staphylococcal enterotoxin A (11.3%), enterotoxin B (3.7%), and enterotoxin C (10.3%), and no enterotoxin D was produced. The production of staphylococcal enterotoxins A-D in the presence or absence of the crude extract was carried out. In the broth system, the extract reduced enterotoxin production at subminimal inhibitory concentrations compared with the control. At MIC, total enterotoxin inhibition was observed for enterotoxin C production, whereas synthesis of enterotoxins A, B, and D was totally eliminated at 2MIC. The food system study revealed that the extract could delay production of enterotoxins A, B, and C compared with the control. The extract at 2 mg/mL delayed production of toxins A and C for 8 and 4 h, while toxin B was not detected in the pork at 48 h. The ability of E. americana extract to inhibit lipase and protease enzymes and to delay enterotoxin production in food could present it as a novel food additive to combat the growth of S. aureus in food. 

 FEMS Immunol Med Microbiol. 57: 193-201, Ifesan, B.O.T, Joycharat, N. And Voravuthikunchai, S.P.

 Journal

 The Mode Of Antistaphylococcal Action Of Eleutherine Americana.

 Ifesan, B.O.T, Joycharat, N. And Voravuthikunchai, S.P.

 2009

NIL

 

 Bioresource Management And Utilization. Studium Press LLC, Houston, Texas, USA, Pp 1-138, Voravuthikunchai S.P., Ifesan B., Chusri S., Saising J.

 Others

 Bioactive Natural Products As Anti-staphylococal Infections.

 Voravuthikunchai S.P., Ifesan B., Chusri S., Saising J.

 2008

NIL

 

 Clin. Microbiol. Infect. 14 (Suppl. 7): P580, Voravuthikunchai, S.P., Ifesan, B.O.T., Mahabusarakam, W., And Hamtasin, C.

 Journal

 Antistaphylococcal Activity Of Semi-purified Fractions From Eleutherine Americana.

 Voravuthikunchai, S.P., Ifesan, B.O.T., Mahabusarakam, W., And Hamtasin, C.

 2008

NIL