MOSP - Macao Scientific Publishers

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Isolation of Legionella pneumophila from surface and ground waters in Osogbo, Nigeria

O. A. Terry Alli*, Ogbolu D. Olusoga, S. A. Adedokun and O. E. Ogundare

Abstract: Legionella is a ubiquitous water environmental organism. Isolation/detection of Legionellae has been reported worldwide. However, there is no reported isolation of Legionellae in countries in Africa with the exception of South Africa. The aim of this study was to survey the surface, ground waters and air conditioner water systems (ACWs) in Osogbo, Nigeria for the presence of Legionella pneumophila by cultural isolation method. A total of 313 water samples from the streams (surface water), wells (groundwater) and ACWS were cultured on buffered charcoal yeast extract (BCYE) medium. The isolates were identified by Gram staining techniques, biochemical tests and demonstration of pore forming activity. Polymerase chain reaction for amplification of 0.52 kb fragment of the part of dot/icm region of L. pneumophila was used for the final identification. The results obtained showed that the prevalence of L. pneumophila from streams (8%) was statistically significant when compared to wells (1%) (Chi square, P < 0.05). L. pneumophila was not isolated from any of the water samples taken from air-conditioner water systems. The study concludes that L. pneumophila is present in natural aquatic environment in Nigeria.[...] Read More.

Keywords: Cultural isolation, Legionella pneumophila, Nigeria.

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Nano theoretical studies of fMet-tRNA structure in protein synthesis of prokaryotes and its comparison with the structure of fAla-tRNA

F. Mollaamin*, M. Noei, M. Monajjemi and R. Rasoolzadeh

Abstract: In this paper, we performed quantum mechanic calculations on structures of fMet-tRNA and fAla-tRNA. Comparing the results structure design was done by formalizing the amino acid and attaching in to the adenine nucleotide of tRNA. The performed calculations are Opt, SCRF, NBO and NMR.[...] Read More.

Keywords: Natural bond orbital (NBO), fMet-tRNA, NMR, Opt, SCRF, fAla-tRNA.

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Antibiotic susceptibility and toxins production of Staphylococcus aureus isolated from clinical samples from Benin

Sina H., Baba-Moussa F., Ahoyo T. A., Mousse W., Anagonou S., Gbenou J. D., Prévost G., Kotchoni S. O. and Baba-Moussa L.*

Abstract: A wide range of clinical samples were screened for identification of Staphylococcus aureus, their antibiotic sensitivity profile and the production of different leucotoxin and epidermolysins was evaluated. Out of 2,040 biological samples (collected from pus, urine, sperms, genital, catheter and blood of hospitalized and extra-hospital patients) screened, 123 pure cultures of S. aureus colonies were isolated. 48.78% of S. aureus were resistant to methicillin (MRSA), while 78% of them were isolated from extra-hospital patients. The S. aureus isolated from urines, pus and blood produced Panton and Valentine leukocidin (PVL) toxin, while the leucotoxin lukE-lukD was exclusively encountered by S. aureus isolated from pus samples. None of the bacterial colony isolated produced epidermolysin toxins A and B. In addition, 3.25% of MRSA and 8.13% of methicillin sensitive S. aureus (MSSA) produced PVL respectively. Our results indicated high frequency rate of MRSA in extra-hospital screened samples isolated from various types of infection. This high resistance rate combined with toxin production increases the virulence of S. aureus colonies and put therefore at risk the life of the patients in developing countries where auto-medication is not controlled. There is the need to instruct the population in order to avoid further widening of MRSA territory.[...] Read More.

Keywords: Staphylococcus aureus, Panton-Valentine leukocidin (PVL), antibiotic, infection, methicillin-resistant Staphylococcus aureus (MRSA), Benin.

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Outer membrane vesicle of Neisseria meningitidis serogroup B as an adjuvant in immunization of rabbit against Neisseria meningitidis serogroup A

Seyed Davar Siadat, Saied Reza Naddaf , Mehrangiz Zangeneh, Arfa Moshiri , Seyed Mehdi Sadat, Mehdi Shafiee Ardestani, Mohammad Hassan Pouriayevali, Safieh Amini and Mohammad Reza Aghasadeghi*

Abstract: Neisseria meningitidis serogroup B outer membrane vesicle (OMV) was revealed to be an efficient carrier for polysaccharide antigens such as capsular antigens. Also, OMV of N. meningitidis was shown to be able to induce high levels of antibodies when applied as an adjuvant for T-independent antigens. In this study OMV was used as an adjuvant with group A meningococcal capsular polysaccharide (GAMP) and tested in New zealand white rabbits to evaluate bactericidal antibody response and opsonophagocytosis activity against serogroup A meningococci. Non- covalent combination of OMV and GAMP and three controls including GAMP, OMV and normal saline were injected intramuscularly into groups of four female New Zealand rabbits with boosters on days 14 and 28 after primary immunization. The serum samples were collected on days 0, 14, 28 and 42 and tested by complement mediated bactericidal assay and opsonophagocytosis activity against serogroup A meningococci according to the world health organization protocol. The results indicate that the combination of OMV with GAMP, in noncovalent form, would be able to induce a high level of bactericidal antibody and opsonophagocytosis activity response in comparison with GAMP alone after 42 days (P< 0.05) . The OMV of N. meningitidis showed to be a potent carrier protein in the induction of immune system but in this article the role of OMV is studied as an adjuvant to promote immune system in non-covalent form and without any conjugation process in order to induce immune response against three prevalent serogroups of N. meningitidis.[...] Read More.

Keywords: OMV, Adjuvant, Neisseria meningitidis serogroup A, Bactericidal activity.

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Cloning and characterization of a female gametophyte-specific gene in GRACILARIA LEMANEIFORMIS (Gracilariales, Rhodophyte)

Full Length Research Paper

Abstract: In this study, forward and reverse suppression subtractive hybridization (SSH) libraries were constructed between female and male gametophyte of GRACILARIA LEMANEIFORMIS to isolate genes differentially expressed between gametophytes. Dot-blots were performed to screen 384 colonies randomly selected from each subtracted libraries. Partial gene (designated as GMF-01) which is female gametophyte-specific was selected to isolate its cDNA full length sequences and to be characterized. Then we got its cDNA full length sequences using SMART-RACE technic. Sequence analysis showed that the open reading frame (ORF) of GMF-01 is 1002 bp long with a GC content of 47.7%, encoding 333 amino acids. GMF-01 does not have significant match in the databases when examined on NCBI website. Amino acid sequence analysis showed that the theoretical pI of this translated protein is 7.92, while the instability index is computed to be 43.61, which has classified the protein as unstable. Results of prediction showed 45.05% of its secondary structure has random coil and sub-cellular location prediction indicated that it is probably a extracellular protein.[...] Read More.

Keywords: Gracilaria lemaneiformis, suppression subtractive hybridization (SSH), sex determination, gametophyte.

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Isolation and identification of Bacillus strains with antimycobacterial activity

Souraya El Guendouzi, David Suzanna, Mohammed Hassi, Abdellatif Haggoud, Saad Ibn souda, Abdellah Houari and Mohammed Iraqui*

Abstract: Tuberculosis is the principal cause of death worldwide due to an infectious disease. The resurgence of tuberculosis, followed by the increase in prevalence of infections caused by nontuberculous mycobacteria (NTM), as well as the multi-drug resistance of mycobacteria to the majority of currently available antibiotics, have encouraged research for new antimycobacterial agents. Soil and water samples from different Moroccan biotopes, have led to the isolation of four bacterial strains (M, R, G and S), showing an inhibitory effect on mycobacterial growth. This effect was shown to be due to secreted substances in the growth medium. From subsequent analysis it was concluded that these strains produced different active substances. Sequencing of the 16S rRNA showed that these isolates belong to the genus Bacillus. The active substance from isolate M, showed the more important inhibitory effect on mycobacterial growth. It precipitated with ammonium sulfate and lost all activity when treated with Proteinase K, revealing its protein nature.[...] Read More.

Keywords: Tuberculosis, mycobacteria, antimycobacterial agents, Bacillus.

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Biodegradation of Panicum repens residues by Pleurotus ostreatus for its use as a non conventional feedstuff in diets of Oreochromis niloticus

Elsayed B. Belal and Khalafalla, M. M. E

Abstract: Biological degradation of torpedo grass, Panicum repens L. residues by Pleurotus ostreatus and suitability of using the highly digestible, protein-enriched, as a non conventional feedstuff in diets of Nile tilapia, Oreochromis niloticus, fingerlings were investigated. The optimal pH and temperature for growth Pleurotus ostreatus and its cellulase production were 6 and 25°C, respectively. The cellulase was induced in submerged culture with presence of the carboxymethyl cellulose and Torpedo grass residues in MSL, while the presence of additional carbon sources such as glucose, dextrose or a complex media (Potato Dextrose) suppressed enzyme production. The amount of reducing sugar present in the biodegraded biomass by cellulase after 30 min incubation time was 2.5 (U/ml/min) but was 2.1 (U/ml/min) by Pleurotus ostreatus after 14 days incubation time under optimum growth conditions. The solid substrate fermentation (SSF) was carried out at pH 6 and 25°C for 32 days. Protein contents of the biodegraded biomass increased from 7.52 to 8.91% and crude fiber contents decreased from 23.27 to 11.28. This biodegraded biomass was used as non conventional feedstuff in diets of Oreochromis niloticus fingerlings. The results showed that Nile tilapia fingerlings received diets containing 25% treated torpedo grass showed the best results in growth parameters, feed efficiency and economic efficiency.[...] Read More.

Keywords: Biodegradation, Pleurotus ostreatus, torpedo grass, Panicum repens L., Nile tilapia, growth parameters.

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Biodegradation of free-gossypol by a new fungus isolated from cotton planted soil

Xia Yang, Jianlin Guo and Jianyi Sun*

Abstract: A new fungal strain isolated from a soil microcosm was investigated due to the finding that it could biodegrade free-gossypol on agar plates. Benzyl chloride was used for extracting fungal genomic DNA which was isolated from mycelium grown in liquid culture, then 18S rDNA was specifically polymerase chain reaction (PCR) amplified using a pair of primers EF4/EF3 (1.4 kb). The strain was further identified as a member of the genus Aspergillus through the morphological and molecular biological methods. The isolated strain had a high tolerance of free-gossypol and 2 g/L was chosen as the best addition amount. Furthermore, the dry weight method was employed to determine the growth curve and optimum temperature of the gossypol-degrading fungus in different carbon sources. The results showed that it was best to be researched after incubation for 72 h at 30°C. To the extent of our knowledge, this is the first report on biodegradation of gossypol on solid plates without other carbon sources and this might help in decomposing some anti-nutritional factors in feed resources.[...] Read More.

Keywords: Free-gossypol, fungus, biodegradation, isolation, growth characteristics.

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Advances in microbial heterologous production of flavonoids

Fangchuan Du, Fangkai Zhang, Feifei Chen, Anming Wang*, Qiuyan Wang, Xiaopu Yin and Shuling Wang

Abstract: Flavonoids are important plant specific secondary metabolites that are synthesized from the general phenylpropanoid pathway and have many pharmaceutical and nutraceutical functions. Separation of pure flavonoids from plants material is very difficult and chemical syntheses of flavonoids require extreme reaction conditions and toxic chemicals. However, in the past decades, engineered microbes are becoming increasingly important as recombinant production platforms. Cultivation of the recombinant strains in rich medium offers another choice for the production of flavonoids. In the present review, we cover the main achievements that the multi-gene pathway of phenylpropanoid is introduced as microorganisms to heterologously produce flavonoids, analyze the key factors affecting heterologous production of flavonoids in microbes, and discuss the new research prospect.[...] Read More.

Keywords: Flavonoids, metabolic engineering, natural products, synthetic biology.

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Quick isolation and characterization for the confirmation of a novel Bacillus thuringiensis strains from chicken manure samples

Suguna Muniady, Xavier Rathinam and Sreeramanan Subramaniam*

Abstract: Bacillus thuringiensis (Berliner) (Bt) based pesticides has become the greatest successes among the microbial pesticides. This research was focused on the isolation and characterization of Bt from chicken manure samples as a comprehensive effort to contribute to the establishment of native Bt strains from various types of habitats in Malaysia. Initially, selection was done mainly based on colony morphology, Gram staining and phase contrast microscopy. Total of 85 colonies were identified and isolated based on colony morphology, in which off-white, matte and creamy appearance showed the characteristics of the genus Bacillus. The number reduced to 35 colonies after Gram staining was done. Subsequently, total of 8 isolates were confirmed to be B. thuringiensis after Coomassie Brilliant Blue staining was carried out. The presence of B. thuringiensis strain was confirmed when a blue cap -like structure and a darkly stained oval structure, insecticidal crystal proteins (ICP) appeared in the sporulation phase. An isolate was chosen out of the 8 isolates in order to generate the growth curve of B. thuringiensis bacteria. The similarity of the aspects above confirms that the selected isolate was a Bt strain. Isolates were further characterized by SDS-PAGE analysis to determine the molecular masses of the Bt proteins. These isolates produced two major ranges of polypeptides, the Cry protein which corresponds to a range of 70-150kDa and the Cyt protein profile which corresponds to the range of 18-40kDa. The protein profile obtained correlates the strains to the typical Bt strain. A total of 6 isolate yielded SDS-PAGE products that demonstrated major protein bands of approximately 135kDa and 140kDa, possibly encoded by the genes cryI and cryIV, respectively.[...] Read More.

Keywords: Bacillus thuringiensis, chicken manure, protein analysis.

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