MOSP - Macao Scientific Publishers

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Biodegradation of 2,2,6,6-Tetramethyl-4-piperidone by three soil bacteria strains and their isolation and identification

Q. F. Li*, L. F. Wang, C. J. Hao, G. M. Zhao and J. H. Wang

Abstract: In order to isolate and characterize 2,2,6,6-Tetramethyl-4-piperidone (TMPD)- degrading bacteria and to select the optimal degrading conditions, different bacterial types which can degrade TMPD were isolated from soil samples. Three strains (LF-1, LF-2 and LF-3) showed strong biodegradation ability by UV-visible spectrophotometer analysis. Morphological and biochemical analyses, as well as 16S rRNA gene sequence comparisons of three strains were further carried out. They were identified as Klebsiella oxytoca, Staphylococcus pasteur and Bacillus flexus, respectively. K. oxytoca, S. pasteur and B. flexus had degrading capabilities for TMPD in mineral salt medium of 80.9, 69.8 and 64.9%, respectively, during 24 days of incubation. Maximum degrading rates were obtained by an initial concentration of the TMPD of 200 mg/L, an incubation temperature of 30°C, and constant aeration (180 rev/min). In conclusion, K. oxytoca, S. pasteur and B. flexus show their potentials in TMPD detoxifying and in protecting the TMPD contaminated environment.[...] Read More.

Keywords: 2,2,6,6-Tetramethyl-4-piperidone (TMPD), biodegradation, Klebsiella oxytoca, Staphylococcus pasteur, Bacillus flexus.

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Potential of Beauveria bassiana as a biological control agent against two important and destructive stored pestsâ€™ C. maculatus and S. granarius adults

Full Length Research Paper

Abstract: This research was carried out to evaluate the suppressive efficacy of entomopathogenic fungi Beauveria bassiana against adults of Callosobruchus maculatus (F.) and Sitophilus granarius (L.) on stored grains in darkness (27±2°C and 65±5% RH) . The insects were inoculated by following immersion in five aqueous suspensions with concentrations determined with preliminary tests and compared with untreated wheat and cowpea as control. Probit analysis showed that the lowest LT 50 values in suspensions with highest concentrations (2.3 × 107 conidia ml-1) were 6.63 and 10.45 days for C. maculatus and S. granarius, respectively. On the other hand, the LC50 values on day 9 post-treatment were 3.17 × 106 and 6.08 × 107 con.ml-1 for C. maculatus and S. granarius, respectively. Comparison of Lc50, LT 50 values and mortalities indicated that in both assays, B. bassiana was consistently more virulent for C. maculatus than S. granarius. The overall results showed that these two pests were controlled successfully with entomopathogenic fungi Beauveria bassiana.[...] Read More.

Keywords: Callosobruchus maculatus, Beauveria bassiana, Sitophilus granarius, stored grain.

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Optimization of bacteriocin production by Lactobacillus plantarum YJG, isolated from the mucosa of the gut of healthy chickens

Bing Han, Zhanqiao Yu, Baosheng Liu, Qingshan Ma and Rijun Zhang*

Abstract: The objective was to develop an optimal, albeit low-cost medium for bacteriocin production, thereby facilitating industrial production. Soybean meal and peptide, two low-cost nitrogen sources often applied in industrial fermentation, were used to replace their expensive counterparts in De Man Rogosa and Sharpe (MRS). Two factors were first chosen from the 11 considered in the Plankett-Burman (PB) design. Then, the path of steepest ascent and central composite design (CCD) were used to approach the optimum region of the response and determine the maximum activity of the bacteriocin. Optimal concentration of glucose (36.3 g/l) and NaCl (1.41 g/l) stimulated the production of bacteriocins. And the optimal equation was then verified by 50 L fermentor. Under optimized conditions, Lactobacillus plantarum YJG produced a 1.4 fold higher production of bacteriocin than the common MRS, with 40.6% cost savings relative to non-optimized conditions.[...] Read More.

Keywords: Lactobacillus plantarum YJG, bacteriocin, response surface methodology, central composite design, optimization.

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Pollen germination, tube growth and longevity in some cultivars of Vitis vinifera L.

Yavar Sharafi* and Ali Bahmani

Abstract: The grapevines (Vitis vinifera, L.) are cultured widely in Maragheh and are made one of the most important commercial fruit crops of its regions. Most of the cultivars are growing with their fruits or are used in rasine, juice and fresh fruits forms. However, pollination is the main factor affecting fruit set and knowledge about pollen traits of cultivars is necessary to plan the vineyards establishment and breeding programs. This study was accomplished to investigate pollen traits of 15 main grape cultivars ('Fakhri', 'Hosaini', 'Khalili', 'Keshmeshi' ('Sefide bidaneh), 'Lale bidaneh', 'Garmian', 'Gizil uzum', 'Sahebi', 'Jigh jigha', 'Shahani', 'Soltanin', 'Rish baba', 'Syahe malahi', 'Razeghi' ('Peikami') and 'Tabarzeh') which are grown in Maragheh. Pollens of cultivars gathered and cultured in the in vitro medium contained sucrose, boric acid and agar. Pollen germination percentage and tube growth were studied by light microscope. Experiment was carried out based on completely randomized design was (CRD) and data were analyzed with SAS software. Pollen germination percentage and tube growth rate showed significant differences among all of the studied cultivars. Finally, cultivars 'Fakhri', 'Khalili', 'Keshmeshi' 'Lale bidane' and 'Rish baba' showed the highest range of pollen germination, tube growth rate, longevity and selected for vineyards establishment and breeding programs.[...] Read More.

Keywords: Grapevine, vineyards, pollen germination, pollen tube growth, pollen longevity, breeding programs

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Prevalence and antibiotics susceptibility patterns of some bacterial isolates from a street vended fruit product

Kalsoom Farzana*, Muhammad Rouf Akram and Seema Mahmood

Abstract: The study is aimed to evaluate the food safety status of a street vended fruit product locally known as fruit chat. Sample collection was carried out from four groups of vendors which were discriminated based on their mobility, vending practice and storage facility. The extent of prevalence for Enterobacter species, Escherichia coli, Klebsiella species, Salmonella species, Staphylococcus aureus and S. epidermidis was assessed in fruit chat samples. Bacterial isolates were identified through biochemical characterization. The degree of susceptibility of these isolates was evaluated against six different antibiotics that is, amikacin, ampicillin, ciprofloxacin, gentamycin, ceftriaxone and co-trimoxazol using disc diffusion method. Results indicated a higher (105 to 1010 CFU/g) total plate count (TPC) and total coliforms count (TCC) ranged from 104 to 109 CFU /g in samples collected from mobile vendors without covering. Mobility of vendors and, use of no covering, resulted in significant (P≤0.05) contamination. However, fruit chat samples collected from stationary vendors with refrigeration facilities exhibited considerably lower bacterial count. The study clearly indicated that consumption of fruit chats from street vendors can be a potential risk for food borne outbreaks because of their contamination level by pathogenic bacteria. Bacterial species had shown variable susceptibility and resistance patterns in response to different antibiotics used in the study. However, all bacterial species had shown greater sensitivity for amikacin, whereas, bacterial strains appeared to develop resistance against other commonly used antibiotics. The mounting resistance against antibiotics is currently one of the foremost challenges to treat food borne infections. Therefore, both preventative and effective curative measures should be adopted. Firstly, the safety status of street vended food products can be enhanced by improving hygienic conditions during the preparation of food stuff. Secondly, the use of effective antibiotics will be of significant importance to cure food borne infections as well as to avoid growing resistance in pathogenic bacteria.[...] Read More.

Keywords: Safety status, street vended fruit product, bacterial prevalence, antibiotics susceptibility.

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Species distribution and antibiotic sensitivity pattern of coagulase-negative Staphylococci other than Staphylococcus epidermidis isolated from various clinical specimens

O. Bouchami*, W. Achour, and A. Ben Hassen

Abstract: This study was undertaken to determine the species distribution and antibiotic resistance patterns of coagulase-negative Staphylococci (CoNS) other than Staphylococcus epidermidis. A total of 142 CoNS (except S. epidermidis) strains were isolated from a variety of clinical specimens in neutropenic patients at the Bone Marrow Transplant Centre of Tunisia between 2002 and 2004. All CoNS isolates were further identified by Api ID32 STAPH and ITS-PCR and antibiotic sensitivity was performed by disc diffusion method. Staphylococcus haemolyticus was the commonest species (38%) followed by Staphylococcus hominis (36%). All isolates were sensitive to vancomycin and 8 (6%) strains showed a reduced sensitivity to teicoplanin. Resistance to penicillin G and methicillin was 84 and 60%, respectively. Methicillin-resistant CoNS strains were determined to be more resistant to antibiotics than methicillin-susceptible CoNS strains. The mecA gene was detected by PCR in 65% (92/142) CoNS isolates. Out of 92 mecA-positive isolates, 90 were phenotypically methicillin-resistant and two were methicillin-susceptible. Phylogenetic analysis, carried out to study the evolution of mecA genes between different Staphylococcal species, revealed a high homology for such genes among Staphylococci.[...] Read More.

Keywords: Coagulase-negative Staphylococci, methicillin-resistance, mecA gene.

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Trichosporon identification methods for isolates obtained from different clinical specimens

Noha El-Mashad*, Mohamed Taha Mahmoud and Heba allah El-Shewehy

Abstract: Trichosporon is a medically important genus that includes the causative agents of both deep- seated, mucosa-associated infection and superficial infection. In this study, we aimed to present data on the phenotypic and molecular identification of Trichosporon species recovered from various clinical specimens representing both superficial and systemic infections. 397 samples (65 blood cultures, 192 nail scrapings, 140 skin scrapings) were included for isolation, phenotypic and genotypic identification of Trichosporon species. Cases of hematological malignancies, onychomycosis, and Tinea pedis were positive for yeast isolates with percentage of 10.7, 16.6, 20.7%, respectively. Based on the morphologic characters of isolated colonies on Sabouraud dextrose agar (SDA), microscopic examination of colonies on rice agar, and stained smears, yeasts identified as Trichosporon were: 9(4.68%) from nail samples, and 5(3.6%) from skin samples and 0(0.0%) from blood cultures. Polymerase chain reaction (PCR) using Trichosporon genus specific primers for 68 yeast isolates was positive in 16 samples (14 were previously identified by morphology and 2 nail scrapings were falsely diagnosed negative) at 170 bp. We subsequently performed 2 PCR runs on the identified 16 samples using specific primers for each of T. asahii and T. mucoides. Their sequences included ITS1, ITS2. They yielded specific amplification of a DNA fragment at 430 bp in 13(16) samples, which is specific for Trichosporon asahii, and 0(0.0%) sample was positive for Trichosporon mucoides specific primers. Occurance of trichosporonosis is not rare in human. T. asahii species is common in our locality. Molecular methods for identification of Trichosporon are more precise. The standardization of laboratory methods for trichosporon identification and antifungal susceptibility tests are necessary to investigate for both superficial and systemic trichosporonosis.[...] Read More.

Keywords: Trichosporon asahii, polymerase chain reaction (PCR), Trichosporon mucoides.

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Streptomyces sannurensis sp. nov., a new alkaliphilic member of the genus Streptomyces isolated from Wadi Sannur in Egypt

Wael N. Hozzein,*, Mohammed I. A. Ali, Ola Hammouda, Ahmed S. Mousa and Michael Goodfellow

Abstract: The taxonomic position of an actinomycete isolated from a soil sample collected from Wadi Sannur in Egypt was established using a polyphasic approach. The isolate, which was designated WS 51T, was shown to have chemical and morphological properties typical of streptomycetes. An almost complete 16S rDNAgene sequence of the strain was generated and compared with corresponding sequences of representative streptomycetes. The resultant data confirmed the classification of the strain in the genus Streptomyces but also showed that it formed a distinct phyletic line within the 16S rDNAStreptomyces gene tree. The organism was most closely associated to the type strains of Streptomyces hygroscopicus, Streptomyces malaysiensis and Streptomyces yatensis but was readily separated from them using a range of phenotypic properties. It is proposed that strain WS 51T (= CCTCC 001032T = DSM 41834T) be classified in the genus Streptomyces as Streptomyces sannurensis sp. nov.[...] Read More.

Keywords: Streptomyces sannurensis sp. nov., polyphasic taxonomy, alkaliphilic streptomycete.

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Comparison of cELISA and IFA tests in the serodiagnosis of anaplasmosis in cattle

Full Length Research Paper

Abstract: This study was performed to compare indirect fluorescence antibody (IFA) test with competitive ELISA (cELISA) for detection of antibodies to Anaplasma marginale in cattle. In this study, a total of 484 cattle were examined on farms that had a positive history of anaplasmosis. Thin blood smears were prepared from each examined cattle and the cELISA and IFA tests were performed. Samples in which the results of microscopic examination and cELISA were compatible were used as a “gold standard” to define sensitivity and specificity of IFA test and these were used to give “real diagnosis”. According to the test result; 62 of 69 samples found positive in “real diagnosis” were positive in IFA test, and all of the 187 samples that were negative in the real diagnosis were defined as negative in IFA test. When compared to gold standard the sensitivity and specificity of the IFA test were 88.95 and 100%, respectively. In conclusion, both IFA and cELISA tests can be used in the diagnosis of A. marginale.[...] Read More.

Keywords: Anaplasma marginale, IFA test, cELISA.

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Evaluation of gastric ulcer model based on gray-scale image analysis

Wang Shuai, Bao Yong-rui, Diao Yun-Peng, Meng Xian-Sheng* and Kang Ting-Guo

Abstract: Absolute alcohol, stress, pyloric ligation and others are well-rounded experimental gastric ulcer models widely used to evaluate the anti-ulcer activity of drugs (Wang et al., 2007; Zhang et al., 2007; Huang et al., 2004; Oyagi et al., 2010). In the model evaluation process, ulcer index is a more important indicator. So in this experiment, the absolute alcohol gastric ulcer model is taken as an example to discuss a model of gastric ulcer index, which can be used as a new method to calculate the reduction of the systematic errors that exist in the experiment. The oral ethanol approach was used to establish an absolute alcohol gastric ulcer model, and impose certain medication, while traditional methods and the establishment of grayscale image analysis methods were used for calculating its ulcer index respectively, before comparing the differences between the two methods. Grayscale image analysis methods and traditional methods have significant correlation (r = 0.819, P＜0.01) and similarity (r = 0.951). A grayscale image analysis method not only proves to be a more scientific approach to measure rat gastric ulcer area, but also provide a new method to evaluate drug efficacy to some extent.[...] Read More.

Keywords: Gastric ulcer, ulcer index, gray-scale image analysis, image J.

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