MOSP - Macao Scientific Publishers

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Quinolone resistance in Escherichia coli and Salmonella spp. isolates from diseased chickens during 1993-2008 in China

Xiang Chen, Weijuan Pan, Weiqiu Zhang, Zhiming Pan, Song Gao and Xinan Jiao,*

Abstract: A total of 363 Escherichia coli and 224 Salmonella spp. were isolated from diseased chickens during 1993-2008 in China. The susceptibility to eight quinolones and prevalence of plasmid-mediated quinolone resistance (PMQR) determinants was investigated in these isolates. Among the E. coli isolates obtained during 1993-1999, 65.2% were resistant to nalidixic acid, while more than 50% of the E. coli isolates collected during 2000-2008 were resistant to 7 quinolones. All 101 Salmonella spp. isolates obtained during 1993-1999 were susceptible to quinolones, while more than 50% of the Salmonella spp. isolates collected during 2000- 2008 were resistant to only nalidixic acid (82.9%) . Among the 363 E. coli isolates, 4 (1.1%) were positive for aac(6 )-Ib-cr, 3 (0.8%) for qepA and 1 (0.3%) for qnrB10. No PMQR gene was identified in 224 Salmonella spp. isolates. The resistance of E. coli and Salmonella spp. to quinolones has been increasing in the past twenty years and the resistance of Salmonella spp. was much lower than that of E. coli, although they were separated in the same period. There is a rising trend of avian isolates harboring PMQR genes in China.[...] Read More.

Keywords: Quinolone resistance, qnr; aac(6 )-Ib-cr; qepA, chicken.

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Bioaccumulation of cesium-137 and cobalt-60 from solid cellulosic-based radioactive waste simulates by Plurotus pulmonarius

Eskander S. B.*, Abdel Aziz S. M. and El-saayed H.

Abstract: Solid cellulose-based radioactive wastes (CBW) constitutes in some cases, about 70% of the total solid low and intermediate level organic wastes originated from peaceful applications of nuclear technology in various fields of our life. Cesium-137 and cobalt-60 represent two of the most important radioisotopes spiking these waste categories. Both are serious contamination concerns due to their high energy gamma ray emitting (Cs-137 = 0.662 MeV and Co-60 = 1.17 and 1.33 MeV), besides 137Cs is considered as one of long-lived isotopes (T1/2 = 30.5 years). In this part of work, laboratory scale attempts were performed to follow bioaccumulation of Cs-137 and/or Co-60, found separately or together in a mixture of some solid CBW simulates. The process is based on the capability of Pleurotus pulmonarius to biodegrade the solid CBW simulates achieving acceptable weight reduction for the waste as well as reasonable bioaccumulation of the two isotopes from the spiked mixture, within their cells. Up to 134.95 and 41.1 kBq/kg (based on the dry weight of mushroom) were accumulated from Cs-137 and Co-60 respectively within a period of 54±3 days. It is worth mentioning that more than 54% weight reduction percent for the solid CBW simulates was acquired only due to a single cultivation process. Based on the data so far obtained, the bioremediation process for solid CBW based on the P. pulmonarius bioactivity seems to be simple, effective, and economical and can work where the other process cannot be applied.[...] Read More.

Keywords: Biological treatment, mushroom, Pleurotus spp., cellulosic waste, radiocesium, radiocobalt, gamma irradiation.

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The domestic wastewater (DWW) influence on secondary metabolite in thyme (Thymus vulgaris L.) under field conditions

Hossein Hassanpour Darvishi and Hossein Aliabadi Farahani

Abstract: In order to study the domestic wastewater influence on secondary metabolite in thyme (Thymus vulgaris L.) under field condition, this experiment was carried out in Iran. In the field, 15 lysimeters having thyme (T. vulgaris L.) were used, where 1 to 5 lysimeters were irrigated by domestic wastewater and primary drainage water was accumulated. 6 to 9 lysimeters were irrigated by primary drainage water and then, were accumulated by secondary drainage water and we have irrigation 10, 11 and 12 lysimeters by secondary drainage water. In order to compare plants characteristics, in 13, 14 and 15 lysimeters were irrigated by agronomical water. The secondary metabolite in thyme 3.4% increased under irrigation by secondary drainage water into irrigation by agronomical water. The findings may give applicable advice to medicinal and aromatic plants researchers for management and concern on water strategy and estimate of irrigation carefully for increase of quantity and quality yields in medicinal and aromatic plants farming.[...] Read More.

Keywords: Domestic wastewater, essential oil yield, Thymus vulgaris.

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A novel poly (L-lactide) degrading thermophilic actinomycetes, Actinomadura keratinilytica strain T16-1 and pla sequencing

Full Length Research Paper

Abstract: An actinomycete strain T16-1 demonstrated the maximum poly (L-Lactide)-degrading activity when cultured in basal liquid medium at 50°C. According to 16S rDNA sequence analysis, chemotaxonomic and DNA-DNA hybridization revealed that strain T16-1 belong to the family Thermomonosporaceae, genus Actinomadura. On the basis of phenotypic and phylogenic data, strain T16-1 which is a novel PLA-degrading thermophilic actinomycete was identified as Actinomadura keratinilytica, but the color of its colony on ISP plates, NaCl tolerant and utilization of mannitol, raffinose and arabinose were different. Partial sequence of poly (L-lactide) depolymerase gene from strain T16-1 was demonstrated. The gene consisting of 222 amino acids was related to serine protease from Streptomyces sp. with 43 to 46% identity.[...] Read More.

Keywords: Actinomadura keratinilytica, cloning, identification, poly (L-lactide).

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Influence of bispyribac sodium on nitrogenase activity and growth of cyanobacteria isolated from paddy fields

Gulten Okmen* and Aysel Ugur

Abstract: The goal of this study was to determine the effect of bispyribac-sodium on the nitrogenase activities and growth of cyanobacteria isolated from paddy fields. Ten cyanobacterial species were used in this study. Cyanobacterial species were isolated from soil and water samples obtained from rice fields in Corum, Turkey. Among all Anabaena strains, the maximum activity was determined in Anabaena sp. O-22 (2.26 µl ethylene/mg.h) whereas; the lowest activity was shown in Gloeothece sp. O-Y (0.04 µl ethylene/mg.h). The maximum inhibition was seen in Anabaena sp. O-22, Synechocystis sp. O-X and Anabaena sp. O-16 in 100 µg/ml bispyribac-sodium concentration. Although low bispyribac-sodium concentrations somewhat stimulated growths of Anabaena sp. O-X2, O-Ç, O-4, O-16, O-8 and Synechocystis sp. O-X, the biomass of all cultures were severely inhibited at higher concentrations. The growths of Anabaena sp. O-22 and Synechocystis sp. O-X completely repressed at 100 µg/mL and at higher bispyribac-sodium concentrations, whereas, Anabaena O-X2, O-6, O-4 and O-16 completely suppressed at 500 µg/mL bispyribac-sodium concentration. The end of the study Anabaena sp. O-22 has been proposed as biofertilizer. The results obtained may be useful for the production of rice.[...] Read More.

Keywords: Cyanobacteria, nitrogenase activity, herbicide.

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Bacteriological analysis of drinking water sources

Solomon Abera*, Ahmed Zeyinudin, Biruktawit Kebede , Amare Deribew, Solomon Ali, and Endalew Zemene

Abstract: The quality of potable water and treatment of waterborne diseases are critical public health issues. Bacterial contamination of drinking water sources is the most common health risk. The research determines bacteriological quality of drinking water sources in Serbo town, south west Ethiopia. A Cross-sectional study design on bacteriological analysis of drinking water was conducted in Serbo town from September to October, 2010. 100 ml of water specimen was collected from each water sources and transported for testing to the department of medical laboratory sciences and pathology laboratory by cold chain. The water samples were tested using the multiple tube technique on OXOID MacConkey Broth, (Oxoid Ltd, Basingstoke, Hampshire, England) for presumptive coliform count followed by ESCHERICHIA COLI confirmation. A total of twenty four drinking water samples were analyzed. Eighteen (75%) were from unprotected wells and the remaining six (25%) were from protected wells. Twenty three out of the total (87.5%) have presumptive bacteria count above the permissible limits for drinking water. Majority of the water sources were not safe for drinking. Hence, regular disinfection of drinking water sources needs to be run.[...] Read More.

Keywords: Potable water, most probable number, fecal coliform, protected well and unprotected well.

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Effect of AvidÂ® on the synnema-like formation of Aspergillus flavus grown on Czapek medium

Full Length Research Paper

Abstract: The effect of Avid® on the induction of synnema-like structure of Aspergillus flavus (61 strains) grown on various types of agar media was investigated. Other related species of Aspergillus within the section Flavi, A. parasiticus (14 strains), A. nomius (14 strains), A. psuedotamarii (2 strains), A. tamarii (20 strains) and A. oryzae (5 strains), were also evaluated for comparison. When Avid® was added into five different solid media (Czapek, V8, Aspergillus flavus and A. parasiticus, corn meal and potato dextrose agar) at 0.004% (v/v), only the A. flavus strains (all 61 tested) were able to produce synnema-like structures, and only in the Czapek agar medium containing Avid®. The effect of carbon (sucrose, glucose and starch) and nitrogen (NaNO3, urea and peptone) sources in Czapek medium containing Avid® on the induction of a synnema-like structure was also determined, with synnema-like structure induction being found in all three carbon sources but only in NaNO3 as the nitrogen source. All the three of the inert solvents in Avid® (mineral oil, butylated hydroxytoluene and n-methylpyrrolidone) did not induce synnema-like structure formation, indicating that abamectin, an active ingredient of Avid® together with NaNO3 likely play important roles in the induction of synnema-like structure of A. flavus.[...] Read More.

Keywords: Aspergillus flavus, Avid®, synnema-like structure.

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Epidemiology of Pseudomonas aeruginosa in Intensive Care Unit and Otolaryngology Department of a Tunisian hospital

Karim Ben Slama, Skander Gharbi, Ahlem Jouini , Meriem Maarouf, Chedlia Fendri, Abdellatif Boudabous and Maher Gtari*

Abstract: Ninety four clinical isolates of Pseudomonas aeruginosa cultured from patients admitted to the Intensive Care Unit (ICU) (N= 37) and Otolaryngology (ORL) (N= 57) during one year (2001-2002) at the Rabta hospital (Tunisia) have been investigated by using serotyping, pyocintyping, drug susceptibility, M13-PCR and PFGE typing. Result shown that most of the isolates at the ICU belonged to serotype O:12 (11/37) that showed high resistance to commonly used antimicrobials ( -lactamins, aminosids, and quinolone) and a predominance for pyocinotype P10. Despite the frequent occurrence of identical serotypes and pyocinotypes, most of the isolates represent unique RAPD-M13 genotype (88/94). PFGE typing detected three distinct clusters amongst the O12 isolates, suggesting a clonal relatedness among multiresistant O12 isolates. This study illustrates the importance of phenotypic and genotypic epidemiological surveillance of predominant O12 serotype clones in such service in local hospital.[...] Read More.

Keywords: Pseudomonas aeruginosa, epidemiology, clonal diffusion, multidrug resistance.

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Current understanding of de novo synthesis of bacterial lipid carrier (undecaprenyl phosphate): More enzymes to be discovered

Olabisi Oluwabukola Coker* and Prasit Palittapongarnpim

Abstract: An isoprenoid named undecaprenyl phosphate (Und-p) is the only known lipid carrier in bacteria. It is involved in the translocation of hydrophilic intermediates of cell wall components across the hydrophobic phospholipid bilayer of the cell membrane for subsequent polymerization in cell wall synthesis. Und-p is made available by both de novo synthesis and recycling. Evidences are emerging that in addition to dephosphorylation of undecaprenyl pyrophosphate (Und-pp), the phosphorylation of undecaprenol (Und-OH) into Und-p exists as an alternative pathway in Gram-positive bacteria but not in Gram-negative bacteria. This review gives an overview of the current knowledge in the synthesis of Und-p. It also hypothesizes the presence of yet to be identified Und-pp phosphatases at the inner cytoplasmic membrane that function in addition to a known phosphatase, named undecaprenyl pyrophosphate phosphatase (Upp-P) in de novo synthesis of Und-p. As the processes involved in cell wall synthesis remains the most promising antimicrobial therapeutic means, a more thorough understanding of the synthesis of the bacterial lipid carrier will not only improve the knowledge of cell wall synthesis but may also lead to the identification of potential drug targets and vaccine candidates.[...] Read More.

Keywords: Lipid carrier, undecaprenyl phosphate, undecaprenol, undecaprenol kinase, cell wall synthesis.

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Optimized antibacterial measures against Escherichia coli O157:H7 and Staphylococcus aureus

Raftari, M., Azizi Jalilian F., Abdulamir, A. S., Sobhan Ghafurian, Radu S., Sekawi Z., Abu Bakar F.*

Abstract: Varied mixtures of different concentrations 1, 1.5 and 2% of acetic (AA), lactic (LA), propionic (PA) and formic (FA) acids at 1:1 ratio were spray- washed on inoculated meat to evaluate their efficacy in reducing loads of Escherichia coli O157:H7 and Staphylococcus aureus on meat tissue. It was found that increasing the concentration of the used organic acids increased the bacterial lethality proportionally. And significant difference (P[...] Read More.

Keywords: Antibacterial, Escherichia coli, Staphylococcus aureus, organic acid, sterilization, meat.

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