Antibacterial compounds from the flowers of Alangium salviifolium

1-Methyl-1H-pyrimidine-2,4-dione and 3-O-beta-D-glucopyranosyl-(24beta)-ethylcholesta-5,22,25-triene, isolated from the flowers of Alangium salviifolium, showed remarkable antibacterial activities against a number of Gram-positive and Gram-negative bacterial species.     

Characterization of <Emphasis Type="Italic">Pectobacterium carotovorum</Emphasis> causing a new soft rot disease on okra in Malaysia

Dark brown, necrotic pods with extensive water-soaked lesions caused by plant pathogenic bacteria were found on okra plants in different fields in Malaysia in 2010. PCR amplification of the pectate lyase (pel) gene and amplification of the 16S–23S rRNA (ITS) with G₁ and L₁ primers produced 434-, 535- and 570-bp fragments, respectively. From the similarity between the results of biochemical tests and their equivalency with standard bacteriological sources, PCR-based pel gene, and RFLP analysis of the ITS-PCR products, all isolates were identified as Pectobacterium carotovorum. This is the first report of P. carotovorum in okra from Malaysia.     

Cross‐infectivity of oil palm by Phytophthora spp. isolated from perennial crops in Malaysia

Bud rot disease or “Pudricion del cogollo” (PC) of oil palm is a major constraint on production in Colombia and neighbouring countries such as Brazil, Costa Rica, Ecuador, Nicaragua, Panama, Peru and Surinam. To date, there are no documented reports of Phytophthora disease of oil palm in South‐East Asia. This research, therefore, was conducted to determine the pathogenic potential of Phytophthora palmivora and Phytophthora nicotianae on oil palm using both in vitro and nursery inoculation experiments. In vitro inoculation of both P. palmivora and P. nicotianae on immature oil palm leaflets caused discoloration within 2 days of inoculation and incubation at 25 ± 1.5°C, 100% RH. Similarly, in nursery trials, lesions formed on the buds (unopened leaflets) 3 days after inoculation with P. palmivora or P. nicotianae zoospore suspensions. No lesions developed on untreated leaflets in either in vitro or nursery inoculation experiments. Phytophthora spp. were re‐isolated from leaflet lesions and confirmed as the inoculated pathogens.     

Influence of sheep grazing on soil chemical properties and growth of rubber (Hevea brasiliensis) in Malaysia

In a rubber estate in Kelantan, Malaysia, sheep grazing increased N, P, Ca and Mg levels and soil pH. Foliar N, P, Ca, Mg and Na also increased with grazing, but K decreased. The girth of rubber trees under grazing had a higher increment than in the ungrazed areas.     

Assessment of growth condition for a candidate probiotic, <Emphasis Type="Italic">Shewanella algae</Emphasis>, isolated from digestive system of a healthy juvenile <Emphasis Type="Italic">Penaeus monodon</Emphasis>

To conquer disease problem in shrimp industries, probiotic biocontrol is a well-known remedy now. The antagonistic ability of separated isolates from different parts of juvenile P. monodon was screened against shrimp Vibrio pathogens, V. parahaemolyticus and V. alginolyticus. The most antagonistic effect was observed for an isolate that primarily identified as Shewanella algae using conventional method followed by Biolog GN and GP microplates. Since adaptability to the host optimum cultural condition of the target organism is of the great importance, response surface methodology, with central composite design, was applied to assess log cell count response of S. algae in different incubation conditions. Therefore, four independent variables were assumed as: temperature (10–50°C), pH (6–10), NaCl concentration (0–50‰) and time (12–60 h). The coefficients of multiple determinations (R ²) for the responses log cell count of S. algae being 0.827. Temperature was the merely significant independent variable that affected the log cell count of the candidate probiotic. The candidate probiotic was revealed a reasonable growth response in quite wide range of temperature, pH and NaCl concentration in which the maximum levels were in same range of optimum shrimp culture.     

The study of seroprevalence of hepatitis E virus and an investigation into the lifestyle behaviours of the aborigines in Malaysia

Malaysia is a non‐endemic country for hepatitis E virus (HEV) infection. However, seroprevalence as high as 50% among samples of aboriginal people were reported over two decades ago. A total of 207 samples collected from seven aboriginal villages in rural settlements across two states in Malaysia were analysed for anti‐HEV IgG and IgM by an enzyme‐linked immunoassay. Following the detection of anti‐HEV seroprevalence, we organized health outreach to inform and educate the community. Qualitative interviews were conducted with individuals tested positive for anti‐HEV antibodies. Data derived from interviews and observations were used to investigate possible lifestyle behaviours associated with HEV infection. Anti‐HEV IgG was detected in six samples (5.9%) from the village of Dusun Kubur. Qualitative inquiry and observation study revealed poor dietary and household hygiene, contaminated food and water, contact with animal faeces, unsanitary and domestic waste disposal, and wildlife reservoirs could be the contributing factors for transmission and acquisition of HEV infection. Investigation during health outreach is important to provide insights for future empirical research and implementation for improvement of lifestyle behaviours among the aborigines. Managing the risk of HEV infection in the aborigines may reduce the risk of HEV transmission to the local communities.     

Characterization of Malaysian Pectobacterium spp. from vegetables using biochemical, molecular and phylogenetic methods

In August 2011, vegetable crops showing symptoms of maceration and water soaked lesions on their tuber, leaf, and fruit were collected from four major vegetable growing states in Malaysia including Pahang, Johor, Melaka and Selangor. The majority of the causal organisms isolated from infected tissues (52 strains) were identified as Pectobacterium spp. based on PCR amplification of the pectate lyase (pel) gene and amplification of the 16S-23S rRNA (ITS) with G1 and L1 primers. Physiological and biochemical assays divided Malaysian Pectobacterium species into two main groups: Pectobacterium wasabiae and Pectobacterium carotovorum subsp carotovorum. Partial sequence of PCR product from reaction of putative Pectobacterium spp. with 16S rRNA confirmed the results obtained from physiological and biochemical assays used for identification of the bacterium. Application of specific primers such as Eca1F/Eca2r, Br1f/L1r, EXPCCF/EXPCCR, and also ITS-PCR following by RFLP by restriction enzyme (RsaI) successfully differentiated Malaysian P. wasabiae and P. carotovorum subsp carotovorum isolates from other species and subspecies of Pectobacterium. Phylogenetic analysis of Malaysian isolates with housekeeping genes (mdh, gapA) grouped Malaysian P. carotovorum subsp carotovorum and P. wasabiae in the same cluster with P. carotovorum subsp carotovorum (Ecc380) and P. wasabiae (SCRI488) respectively.