ISSN 2736-1756
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Current Rhizoctonia solani anastomosis groups in Egypt and their pathogenic relation to cotton seedlings
Maurice S. Mikhail1, Kamel K. Sabet1, Moawad R. Omar2, Amal A. Asran3 and Khaled K. Kasem1,4*
1Plant Pathology Department, Cairo University, Egypt.
2Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt.
3Botany and Microbiology Department, College of Science, King Saud University, Saudi, P. O. Box 2455, Riyadh 1145, Saudi Arabia.
4Agricultural Research Centre, Hamah, General Commission for Scientific Agricultural Research, Syria.
Accepted 11 November, 2014
Abstract
Twenty eight isolates of Rhizoctonia solani were obtained from cotton seedlings and twenty three isolates from other hosts; eight from peanut, five from chickpea, two from each of flax, tomato and watermelon and one from each of potato, cantaloupe, pepper and lupine. Microscopic examination revealed that 17 isolates (33.33%) each belonged to AG-2- 2, 17 and AG-4 HG-I, while 7 isolates (13.73%) belonged to AG -4 HG-II and 10 isolates (19.61%) belonged to AG-5. Pathogenicity test on cotton cultivar Giza 86, under greenhouse conditions, showed that 19 isolates significantly induced pre- and post-emergence damping-off, while they significantly decreased survival, plant height and dry weight. However, the pathogenic isolates of AG-2-2 represented 19.61% of the total isolates as well as the highest percentage of the pathogenic isolates (52.63%). There were no significant differences between effects of different AGs on the cotton seedling variables. Cluster analysis suggested that grouping the isolates based on their virulence patterns was not related to their geographic origins, AG or host.
Key words: Rhizoctonia solani, anastomosis groups, cotton, pathogenicity.
Amal A. Asran and Khaled K. Kasem*, Moawad R. Omar, Kamel K. Sabet, Maurice S. Mikhail
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Isolation of marine Streptomyces and the evaluation of its bioactive potential
Selvakumar Dharmaraj1*, B. Ashokkumar2 and K. Dhevendaran1
1Department of Aquatic Biology and Fisheries, University of Kerala, Kariavattom campus, Trivandrum 695 581, India.
2Zoological Survey of India, Marine Biological Station, Santhome High Road, Chennai 600 028, India.
Accepted 12 November, 2014
Abstract
Nearly ten isolates of Streptomyces were found to be associated with two species of sponges namely Mycale mytilorum (Annandale) and Tendania anhelans (Lieberkuhn). Among the ten isolates, four strains of white series were selected and characterized by conventional methods and assessed for their antagonistic activity against fish pathogens like Aeromonas hydrophila and Vibrio sp. All the strains showed inhibitory activity against these fish pathogens. The screening of antibacterial substances by the Streptomyces isolates proved the production of highly polyene nature compounds which were observed using criteria like thin layer chromatography (TLC) and spectral analysis. The results of the present investigation revealed that the sponges associated Streptomyces were found to be promising source of antibacterial bioactive substances. It concludes that development of appropriate fermentation and downstream processing technologies would bring out new classes of antibiotic leads.
Key words: Antimicrobials, marine Streptomyces, marine sponges.
Selvakumar Dharmaraj*, B. Ashokkumar and K. Dhevendaran
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Assessment of synergistic efficacy of carvacrol and cymene against Edwardsiella tarda in vitro and in Tilapia (Oreochromis niloticus)
Pongsak Rattanachaikunsopon* and Parichat Phumkhachorn
Department of Biological Science, Ubon Ratchathani University, Warin Chamrap, Ubon Ratchathani 34190, Thailand.
Accepted 13 January, 2014
Abstract
Carvacrol, a major compound naturally present in oregano and thyme and its precursor, cymene, were tested in vitro for their antimicrobial activity against Edwardsiella tarda, a fish pathogenic bacteria causing edwardsiellosis. When used alone, carvacrol, but not cymene, inhibited the bacterium with the minimal inhibitory concentration (MIC) of 20 ppm. However, cymene was shown to be able to enhance the inhibitory ability of carvacol indicated by the reduction of MIC to 5 ppm when used with 2.5 ppm of cymene. Based on mortalities in 2 weeks after intraperitoneal E. tarda injection, the median lethal dose (LD50) of E. tarda for tilapia (Oreochromis niloticus) was 5.0 × 102 CFU/g of fish. Fish diets supplemented with carvacrol and cymene were also tested for their protective effect against E. tarda infection in tilapia. The results showed that carvacrol (200 ppm) but not cymene (200 ppm) when fed prophylactically decreased the mortality in E. tarda-challenged tilapia. However, carvacrol at the same concentration could cause no mortality of E. tarda infected fish when used in conjunction with 200 ppm of cymene.
Key words: Carvacrol, cymene, Edwardsiella tarda, tilapia.
Parichat Phumkhachorn, Pongsak Rattanachaikunsopon*
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Prevalence of job stress among primary school teachers in South-west, Nigeria
O. ’Lanre Olaitan*, O. O. Oyerinde, O. Obiyemi and O. O Kayode
Department of Human Kinetics and Health Education, University Of Ilorin, Ilorin, Kwara State, Nigeria.
Accepted 29 July, 2014
Abstract
The study determined the job stress among primary school teachers in South-west, Nigeria. A total of 624 teachers were chosen as subjects using a multistage sampling technique, and a structure questionnaire was used to gather information from the subjects. Research hypotheses were formulated and inferential statistics of test and analysis of variance ANOVA were employed to analyze significant differences at a = 0.05 level. The differences were significant only for age and gender. Majority of the teachers have headache as symptom of poor health and majority of them engage in watching TV as a strategy for coping with stress. The major source of stress for the subjects is the society. It was recommended among others that, teachers working condition should be improved by planning educational ergonomics and of some social facilities such as: satellite TV; computer connected with Internet; and that the school curriculum should take into cognizance, sporting activities especially for the teachers which should be given a bit of knowledge in health education so to be able to understand themselves and generate more coping techniques for job stress.
Key words: Job, stress, ergonomics.
O. O. Oyerinde, O. Obiyemi and O. O Kayode, O. ’Lanre Olaitan*
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Bacterial etiology of acute middle ear infections
G. Aydemir*, C. Meral, S. Suleymanoglu , F. Karademir and Tarık engör
Department of Pediatrics, GATA Haydarpasa Teaching Hospital, Istanbul, Turkey.
Accepted 9 November, 2014
Abstract
To determine the bacterial etiology of acute middle ear infections in preschool age children. This prospective descriptive clinical study was implemented in Marmaris town between November, 2008 and May, 2009 with 80 cases. Their age ranged from 2 - 6. One fourth of the cases were preschoolers. The diagnosis of acute middle ear infection was confirmed by an otolaryngologist following a pediatrician and paracentesis that was performed. Bacterial culture was done in regular conditions and antibacterial resistance was assessed with disk diffusion method. Streptococcus pneumoniae was the most frequent etiologic agent. It was followed by Haemophilus influenzae (15%) and Staphylococcus aureus (6%) in order of frequency. The penicillin resistance rate of pneumococci was 24%.
Key words: Child, infection, middle ear infection.
F. Karademir and Tarık engör, C. Meral, S. Suleymanoglu, G. Aydemir*
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
On the evolution of cell size distribution during bacterial growth cycle: Experimental observations and individual-based model simulations
Clara Prats1*, Jordi Ferrer1, Daniel López1, Antoni Giró1 and Josep Vives-Rego2
1Escola Superior d'Agricultura de Barcelona, Departament de Física i Enginyeria Nuclear, Campus del Baix Llobregat,
Universitat Politècnica de Catalunya, Av. del Canal Olímpic 15, 08860 Castelldefels, Barcelona, Spain. 2Departament de
Microbiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 645, 08028, Barcelona, Spain.
Accepted 19 January, 2014
Abstract
Individual-based modelling (IbM) has become a fully incorporated part of predictive microbiology methodologies in the last decade. Previous studies of bacterial culture growth cycle with the IbM simulator INDISIM analysed the evolution of bacterial biomass distribution during the different phases of growth. The predicted forward shift during lag, stability during exponential and backward shift when entering the stationary phase have been experimentally observed in an Escherichia coli batch culture by means of flow cytometry and particle size analysis measurements. In addition, the experimental results were analysed using the product distance, a mathematical tool developed to assess the evolution of cell size distribution. These results confirmed the assumptions about the bacterial lag phase made by INDISIM. Moreover, flow cytometry and particle analysis methods were shown to be useful experimental techniques in combination with IbM simulations when studying the evolution of individual properties during the bacterial growth cycle. This is essential in order to provide a new and consistent interpretation of the dynamics and heterogeneity of cell biomass during the growth cycle.
Key words: Bacterial cell cycle phases, biomass distribution, individual-based modelling, flow cytometry, particle size analysis.
Antoni Giró and Josep Vives-Rego, Jordi Ferrer, Daniel López, Clara Prats*
Page: 1 - 10