Potential of Bacillus cereus strain RS87 for partial replacement of chemical fertilisers in the production of Thai rice cultivars.

BACKGROUND: There is increasing interest in the development of technologies which can reduce the requirement for chemical fertilisers in rice production. The objective of this study was to investigate the efficacy of Bacillus cereus strain RS87 for the partial replacement of chemical fertiliser in rice production. A greenhouse experiment was designed using different fertiliser regimes, with and without strain RS87. Six Thai rice cultivars were tested separately. RESULTS: Maximum rice growth and yield were obtained in rice receiving the full recommended fertiliser rate in combination with the strain RS87. Interestingly, all rice cultivars which were treated with strain RS87 and 50% recommended fertiliser rate provided equivalent plant growth and yield to that receiving the full recommended fertiliser rate only. A paired comparison between rice treated with 50% of the recommended fertiliser rate with the bacterial inoculant and the full fertiliser rate alone was further examined in small experimental rice paddy fields. Growth and yield of all rice cultivars which received the 50% fertiliser rate supplemented with strain RS87 gave a similar yield to that receiving the full fertiliser rate alone. CONCLUSION: Bacterial strain RS87 showed the potential to replace 50% of the recommended fertiliser rate for yield production. Integration of plant growth-promoting rhizobacterial inoculants with reduced application rates of chemical fertiliser appears promising for future agriculture.

Dose-responses of Bacillus cereus RS87 for growth enhancement in various Thai rice cultivars.

To achieve the goal of reducing the levels of chemical fertilizers applied in rice production, there is a need to develop microorganisms with the capacity to enhance plant growth. Previous studies have demonstrated that Bacillus cereus RS87 promotes growth of various plants in greenhouse and field trials. The objectives of this study were to (i) evaluate the efficacy and determine the optimum concentration of B. cereus RS87 to enhance growth of various Thai rice cultivars, (ii) measure the chlorophyll content in leaves affected by strain RS87, and (iii) investigate the capacity of strain RS87 to solubilize phosphate and produce siderophores. Three concentrations of strain RS87 (log 6.0, log 7.0, and log 8.0 CFU/mL) were applied to each rice cultivar. Superior responses (i.e., enhanced development of roots and shoots of all rice cultivars) were observed using RS87 at log 8.0 CFU/mL compared with lower bacterial concentrations and the water-treated control treatment. In addition, log 8.0 CFU/mL of RS87 provided the greatest root length and plant height of all rice cultivars 45 days after planting in the greenhouse. Rice leaves treated with log 8.0 CFU/mL of RS87 yielded the highest total chlorophyll, specifically chlorophyll a and chlorophyll b, compared with the control. Strain RS87 also solubilized phosphate and produced siderophores. The results of these studies demonstrate that log 8.0 CFU/mL is the optimum concentration of strain RS87 for growth promotion of various Thai rice cultivars.

Physicians’ generic drug prescribing behavior in district hospitals: a case of Phitsanulok, Thailand / Comportamiento de los médicos en prescripción de genéricos en hospitales distritales: el caso de Phitsanulok, Tailandia

Generic prescribing is a sound approach to contain health care costs. However, little is known about physicians' prescribing patterns in the Thai context. Objective: To explore physicians' generic prescription patterns in district hospitals. Methods: Data was collected from three of the eight district hospitals between January and December 2008 (final response rate 37.5%). All participating hospitals were between 30 and 60-bed capacity. The researchers reviewed 10% of total outpatient prescriptions in each hospital. Results: A total of 14,500 prescriptions were evaluated. The majority of patients were under universal health coverage (4,367; 30.1%), followed by senior citizens' health insurance (2,734; 18.9%), and civil servant medical benefit schemes (2,419; 16.7%). Ten thousand six hundred and seventy-one prescriptions (73.6% of total prescriptions) had at least one medication. Among these, each prescription contained 2.85 (SD=1.69) items. The majority of prescriptions (7,886; 73.9%) were prescribed by generic name only. Drugs prescribed by brand names varied in their pharmacological actions. They represented both innovator and branded-generic items. Interestingly, a large number of them were fixed-dose combination drugs. All brand name prescriptions were off patented. In addition, none of the brand-name drugs prescribed were categorized as narrow therapeutic range or any other drug that had been reported to have had problems with generic substitution. Conclusion: The majority of prescriptions in this sample were written by generic names. There is room for improvement in brand name prescribing patterns (AU)

La prescripción genérica es algo que podría contener los costes sanitarios. Sin embargo, se sabe poco de los hábitos de prescripción genérica de los médicos tailandeses. Objetivo. Explorar los hábitos de prescripción genérica de los médicos en hospitales distritales. Métodos. Se recogieron datos de tres de los ocho hospitales de distrito entre enero y diciembre de 2008 (tasa final de respuesta 37,5%). Todos los hospitales participantes estaban entre 30 y 60 camas de capacidad. Los investigadores revisaron el 10% del total de las prescripciones ambulatorias de cada hospital. Resultados. Se evaluó un total de 14500 prescripciones. La mayoría de los pacientes estaban bajo la cobertura sanitaria universal (4367; 30,1%) seguidos del seguro de ciudadanos mayores (2734; 18,9%) y de los sistemas de funcionarios civiles (2419; 16,7%). 10671 prescripciones (73,6% del total de prescripciones) tenían al menos un medicamento. Entre estas, cada prescripción contenía 2,85 (DE=1,69) ítems. La mayoría de las prescripciones (7886; 73,9%) estaban escritas en nombre genérico solamente. Los medicamentos prescritos por marca comercial variaban en sus acciones farmacológicas. Estos representaban tanto ítems innovadores como genéricos con marca. Curiosamente, un gran número de ellos eran combinaciones a dosis fijas. Todas las prescripciones por marca eran medicamentos con patente caducada. Además, ninguna de las marcas prescritas estaba calificada de estrecho margen terapéutico u otros medicamentos que hayan comunicado problemas con la sustitución genérica. Conclusión. La mayoría de las prescripciones en esta muestra estaban escritas en nombres genéricos. Existe espacio para mejorar los patrones de prescripción por marcas (AU)

Physicians' generic drug prescribing behavior in district hospitals: a case of Phitsanulok, Thailand.

UNLABELLED: Generic prescribing is a sound approach to contain health care costs. However, little is known about physicians' prescribing patterns in the Thai context. OBJECTIVE: To explore physicians' generic prescription patterns in district hospitals. METHODS: Data was collected from three of the eight district hospitals between January and December 2008 (final response rate 37.5%). All participating hospitals were between 30 and 60-bed capacity. The researchers reviewed 10% of total outpatient prescriptions in each hospital. RESULTS: A total of 14,500 prescriptions were evaluated. The majority of patients were under universal health coverage (4,367; 30.1%), followed by senior citizens' health insurance (2,734; 18.9%), and civil servant medical benefit schemes (2,419; 16.7%). Ten thousand six hundred and seventy-one prescriptions (73.6% of total prescriptions) had at least one medication. Among these, each prescription contained 2.85 (SD=1.69) items. The majority of prescriptions (7,886; 73.9%) were prescribed by generic name only. Drugs prescribed by brand names varied in their pharmacological actions. They represented both innovator and branded-generic items. Interestingly, a large number of them were fixed-dose combination drugs. All brand name prescriptions were off patented. In addition, none of the brand-name drugs prescribed were categorized as narrow therapeutic range or any other drug that had been reported to have had problems with generic substitution. CONCLUSION: The majority of prescriptions in this sample were written by generic names. There is room for improvement in brand name prescribing patterns.

Pesticide use patterns among small-scale farmers: a case study from Phitsanulok, Thailand.

In this study, 130 small-scale farmers were surveyed regarding pesticide use patterns in rural Phitsanulok, northern Thailand using a structured questionnaire administered via personal interviews and an observational checklist of farmer pesticide storage practices. The survey was conducted during December 2007-January 2008. The results indicate pesticides are readily available and widely used in crop production. This includes the use of endosulfan which has been banned by the Thai government since 2004. Overall, pesticide use was inappropriate. Farmers did not wear suitable personal protection, apply pesticides in an appropriate fashion, or discard the waste safely. They frequently relied on commercial advertisements for the best pesticide to use. Pesticide use patterns among small-scale farmers in Thailand need improvement. Educational interventions are essential for promoting safety during all phases of pesticide handling. Public policies should be developed to encourage farmers to change their pest management methods from chemical based to methods that are healthier and more environmentally friendly.

Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement.

The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P < or = 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.

Stability studies of saponins in Bacopa monnieri dried ethanolic extracts.

Bacopa monnieri (L.) Wettst. (Brahmi) is currently used as a drug and food supplement for memory improvement. However, studies on the physical and chemical stability of the extract components, especially on the lead compound important for pre-formulation, have not yet been reported. In this study, the stabilities of the crude extract and the diluted crude extract were investigated at various temperatures using saponin glycosides, bacopaside I and bacoside A3 as markers for quantitative analysis. The stability testing of bacopaside I and bacoside A3 standard solution was performed at various temperatures and pH values. The quantity of both compounds under all conditions was analyzed using HPLC techniques. The moisture adsorption of the crude extract was determined at 5, 40, 60 and 80 degrees C at 75 % relative humidity using gravimetric methods. The results revealed that the crude extract quickly adsorbed moisture up to 54 % w/w at both 40 and 80 degrees C, while it only slowly adsorbed moisture at 5 degrees C. The amounts of intact bacopaside I and bacoside A3 in the crude extract decreased drastically at 80 degrees C, slowly at 40 and 60 degrees C, and remained unchanged at 5 degrees C during the period of investigation. Moreover, the amount of both compounds in the standard solution dropped sharply at a pH of 1.2 but slowly at pH 6.8 and 9.0, respectively. The pre-formulation data could be further used for improvement of the final product quality.

Determination of pseudojujubogenin glycosides from Brahmi based on immunoassay using a monoclonal antibody against bacopaside I.

Bacopa monnieri (L.) Wettst. (Brahmi) is an Ayurvedic medicinal plant used for centuries as a memory enhancer. Dammarane-type triterpenoid saponins classified as pseudojujubogenin and jujubogenin glycosides are reported as the active components in this plant. In this study, the monoclonal antibody (MAb) against bacopaside I, a major pseudojujubogenin glycoside found in Brahmi, was produced and characterised. Bacopaside I was conjugated with bovine albumin serum to prepare an immunogen. Hybridomas secreting a monoclonal antibody against bacopaside I was produced by fusing splenocytes from an immunised mouse and SP2/0-Ag14 myeloma cells. The results showed that the antibodies were raised specifically against pseudojujubonin glycosides. An enzyme-linked immunosorbant assay (ELISA) using anti-bacopaside I MAb was performed in the range of 1.95-62.5 ng/mL of bacopaside I, with a limit of detection of 0.5 ng/mL. The method was validated and the practical use of the ELISA for analysing saponin glycosides from Brahmi was demonstrated.

An enzyme-linked immunosorbant assay using polyclonal antibodies against bacopaside I.

Bacopa monnieri (L.) Wettst. (Brahmi) is a medicinal plant used as a memory enhancer in Ayurvedic medicines. Its active components are triterpenoid glycosides namely pseudojujubogenin and jujubogenin glycosides. In order to analyze these saponin glycosides, an enzyme-linked immunosorbant assay (ELISA) was developed using polyclonal antibodies against bacopaside I, one of the pseudojujubogenin glycosides found in the plant. Bacopaside I was conjugated with a bovine albumin serum (BSA) to prepare an immunogen. The bacopaside I-BSA conjugate was immunized to a rabbit for producing polyclonal antibodies (PAbs). The results showed that the antibodies were raised specifically against pseudojujubogenin glycosides. An ELISA using anti-bacopaside I PAbs was performed in the range of 1.95-62.5 ng mL(-1) of bacopaside I and the limit of detection was 0.1 ng mL(-1). The method was validated and the applicability of the ELISA for analyzing saponin glycosides from Brahmi was demonstrated.

Broad-Spectrum Protection Against Several Pathogens by PGPR Mixtures Under Field Conditions in Thailand.

Prior greenhouse experiments showed that four mixtures of plant growth-promoting rhizobacteria (PGPR) strains (all Bacillus spp.) elicited induced systemic resistance in several plants against different plant pathogens. Based on these findings, we sought to determine if systemic resistance induced by these PGPR would lead to broad-spectrum protection against several pathogens under field conditions in Thailand. Experiments were conducted during the rainy season (July to October 2001) and winter season (November 2001 to February 2002) on the campus of Naresuan University, Phitsanulok, Thailand. The specific diseases and hosts tested were southern blight of tomato (Lycopersicon esculentum) caused by Sclerotium rolfsii, anthracnose of long cayenne pepper (Capsicum annuum var. acuminatum) caused by Colletotrichum gloeosporioides, and mosaic disease of cucumber (Cucumis sativus) caused by Cucumber mosaic virus (CMV). Results showed that some PGPR mixtures suppressed disease more consistently than the individual PGPR strain IN937a. One PGPR mixture, Bacillus amyloliquefaciens strain IN937a + B. pumilus strain IN937b, significantly protected (P = 0.05) plants against all tested diseases in both seasons. Further, cumulative marketable yields were positively correlated with some treatments.