ISSN 2736-1756
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Characterization of selected strains from Lactobacillus acidophilus and Bifidobacterium bifidum
Kamila Goderska* and Zbigniew Czarnecki
The August Cieszkowski Agricultural University of Poznan, Institute of Food Technology of Plant Origin, Wojska Polskiego 31, 60-624 Poznan, Poland.
Accepted 31 March, 2012
Abstract
The presented study aims to characterize Lactobacillus acidophilus DSM 20079 and DSM 20242 and Bifidobacterium bifidum DSM 20082, DSM 20215, DSM 20239 and DSM 20456 strains. Within the framework of the performed investigations, the author evaluated their biochemical properties, resistance to antibiotics, antagonism towards selected pathogens as well as the effect on their survivability of different environmental conditions with special emphasis on the conditions prevailing in the human gastrointestinal tract. The performed experiments revealed significant differences between the examined bacterial species as well as between strains of the same species. All the examined strains were characterized by diverse biochemical properties, resistance to antibiotics and showed antagonistic action against Helicobacter pylori bacteria. The tested strains of the L. acidophilus bacteria were found to exhibit antagonistic activity against Escherichia coli and Salmonella enteritidis bacteria, although the observed activity was smaller in comparison with the antagonistic activity against H. pylori. These data confirm reports about the antagonistic effect of probiotic bacteria on the growth of pathogenic bacteria. All the examined bacterial strains fulfil the basic criterion expected from probiotic strains, that is, are capable of surviving in the ‘in vitro’ conditions of the gastrointestinal tract, at low pH and in the presence of bile salts.
Key words: Bifidobacterium bifidum, Lactobacillus acidophilus, probiotic, antibiotic resistance, acidity resistance, bile tolerance, antagonistic activity.
Zbigniew Czarnecki, Kamila Goderska*
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Antibiotic resistance profile of Escherichia coli from clinically healthy pigs and their commercial farm environments
Chikwendu C. I.*, Nwabueze R. N. and Anyanwu B. N.
Department of Microbiology, School of Science, Federal University of Technology, P. M. B. 1526 Owerri, Imo State, Nigeria.
Accepted 5 February, 2012
Abstract
The study was conducted to determine the antibiotic resistance profile of Escherichia coli isolated from clinically healthy pigs and their commercial farm environments. Differential and selective media were used to isolate a total of 142 E. coli strains from 202 samples. These were tested against 16 antibiotics using the disc diffusion method. The isolates showed high resistance rates to Cefuroxime (89.4%), Nitrofurantoin (89.4%), Tetracycline (74.6%), Ceftazidime (73.9%), Cefotaxime (72.5%) and Cephalexin (53.5%). Rates of resistance to Septrin and Chloramphenicol were moderate (12.7 to 39.4%), while low rates were recorded for Gentamycin (0.09%), Ciprofloxacine (0.08%), Perfloxacine (0.05%), Augumentine (0.06%), Nalidixic acid (0.07%), Streptomycin (0.05%) and Ofloxacine (0.05%). A total of 78 resistance patterns were identified. The high rates of resistance, as well as the large number of resistant patterns recorded in the absence of the use of antibiotics for growth promotion or as prophylactics suggested that antibiotics are not the only selective factors for antibiotic resistance.
Key words: Escherichia coli, antibiotics, resistance, clinically healthy, prophylaxis
Nwabueze R. N. and Anyanwu B. N., Chikwendu C. I.*
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
A survey of Salmonella enterica contamination of camel milk in Kenya
Matofari, J. W., Shitandi, A.*, Shalo, P. L., Nanua, N. J., Younan, M.
Guildford Dairy Institute, Egerton University Njoro, P.O. Box 536 Egerton 20107 Kenya.
Accepted 3 May, 2012
Abstract
This study was undertaken to conduct a baseline risk analysis of raw camel milk with special emphasis on Salmonella enterica serovars. Cross-sectional studies were designed to investigate the prevalence of S. enterica serovars in a major camel milk production zone of Kenya. A total of 196 samples were assessed for possible presence of S. enterica. The samples included composite milk from the individual camel udders, bulk milk from collection and market centres, faeces, soil and water samples. Of the 196 samples tested, 43% (84/196) were found to contain Salmonella species. Out of the 84, only 31% (26/84) was positively identified as S. enterica. S. enterica was found in all the sample categories that repre-sented the camel milk production environment. The results suggest that raw camel milk contamination by S. enterica was influenced by post-harvest handling of the product rather than camel infection by the pathogen. It was concluded that a need exists to formulate better regulation strategies for the safe handling of camel milk on rural Kenyan farms.
Key words: Camel milk; Salmonella enterica, Milk safety, Kenya.
M. , A.* , Matofari , Nanua , Shalo , N. J., P. L., Shitandi , J. W., Younan
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Production of indole-3-acetic acid by Rhizobium isolates from Sesbania species
M. Sridevi and K. V. Mallaiah*
Department of Microbiology, Acharya Nagarjuna University, Nagarjuna Nagar-522 510, Andhra Pradesh, India.
Accepted 13 May, 2012
Abstract
Rhizobium isolates from root (Sesbania procumbens) and stem nodules (S. rostrata and S. procumbens) of Sesbania species were shown to produce indole-3-acetic acid (IAA) in culture supplemented with L-tryptophan. Production of IAA was maximal after 72 h of incubation when the bacteria reached stationary phase of growth. The cultural requirements were optimized for maximum IAA production. The effect of carbon (1%) and nitrogen sources (0.1%) revealed that glucose and potassium nitrate were best promoters for IAA production over controls. The effect of different concentrations of EDTA revealed that 0.2 gml-1 EDTA increased IAA production. Among the three isolates, maximum amount of IAA was produced by the Rhizobium isolate from S. procumbens. The IAA from this isolate was extracted, purified and identified by thin layer chromatography.
Key words: Rhizobium species, Indole acetic acid, Sesbania species, Rhizobium-legume symbiosis.
K. V. Mallaiah*, M. Sridevi
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Studies on the antibacterial activity of root extracts of Carica papaya L.
Doughari, J. H.*, Elmahmood, A. M. and Manzara, S.
Department of Microbiology, Federal University of Technology, P.M.B. 2076, Yola, Adamawa State, Nigeria.
Accepted 16 July, 2012
Abstract
The bioactive compounds of root extracts of Carica papaya L. were extracted, using water and organic solvents, and were investigated for antibacterial activity against some pathogenic bacteria using the cup plate agar diffusion method. The aqueous extracts did not show significant activity, but the organic extracts had significant activity with the methanol extracts demonstrating the highest activity against the test bacteria. The extracts demonstrated higher activities against all the gram-negative bacteria than the gram-positive bacteria tested, with the highest activity (14 mm zone of inhibition) demonstrated against Salmonella typhi. Increase in temperature enhanced the activity of the extracts, while alkaline pH decreased the activity. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts ranged between 50-200 mg/ml. Preliminary phytochemical analyses showed that the extracts contain alkaloids, tannins, saponins, glycosides and phenols. Carica papaya may be used for the treatment of gastroenteritis, uretritis, otitis media, typhoid fever and wound infections.
Key words: Carica papaya L., antibacterial activity, phytochemical analysis, antibiotics.
J. H.*, Elmahmood , A. M. and Manzara, S. , Doughari
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Effectiveness of trisodium phosphate, lactic acid, and acetic acid in reduction of E .coli and microbial load on chicken surfaces
F. M. Bin Jasass
King Abdulaziz City for Science and Technology, General Directorate of Research Grants, Riyadh 11442, P. O. Box 6086. Kingdom of Saudi Arabia. E-mail [email protected]. Tel: 966-1-4813373. Fax: 966-1-4813878.
Accepted 06 July, 2012
Abstract
Procedures for dipping of chicken carcasses in trisodium phosphate (TSP), lactic acid (LA) and acetic acid (AA) were evaluated to determine their effectiveness for reducing E. coli NCTC 10538 and aerobic total counts on the chicken meat surfaces. Chicken portions were dipped in a suspension of E. coli (7 log CFU/ml) for 20 s and kept for 90 min to allow E. coli to get attached to the chicken surface. The chicken portions were then dipped in 8, 10, and 12% concentration of TSP, 1, 2, and 3% concentration of LA, and 0.5, 1, and 1.5% concentration of AA for 20 s each followed by dipping in tap water for 20 s. A sterile template 4 x 4 cm was placed on the chicken surface and then swabbed by swab cotton. The number of E. coli and aerobic total counts were enumerated. The reduction of E. coli on chicken meat surfaces dipped in 8, 10 and 12% of TSP decreased E. coli by 0.5, 1.2 and 1.6 log CFU/ cm2, respectively. The reduction of E. coli on chicken meat surfaces dipped in 1, 2 and 3% LA was 0.5, 1.8 and 2.1 log CFU/cm2 respectively. The reduction of E. coli on chicken meat surface dipped in 0.5, 1.0 and 1.5% of AA had decreased the E. coli counts of 0.7, 1.1 and 1.4 log CFU/ cm2, respectively. The results showed that LA was more effective against E. coli and aerobic total counts than TSP and AA.
Key words: Trisodium phosphate, Lactic acid, Acetic acid, E. coli, Aerobic count, Quality, Chicken, Poultry.
F. M. Bin Jasass
Page: 1 - 10