No abstract

Background Several inactivated enterovirus-A71 (EV-A71) vaccines are currently licensed in China; however, the development of additional EV-A71 vaccines is ongoing, necessitating extensive analysis of the molecular epidemiology of the virus worldwide. Until 2012, laboratory confirmation of EV-A71 for hand, foot, and mouth disease (HFMD) and other associated diseases had not occurred in the Philippines. Because EV-A71 has been linked with cases of acute flaccid paralysis (AFP), AFP surveillance is one strategy for documenting its possible circulation in the country. To expand current knowledge on EV-A71, molecular epidemiologic analysis and genetic characterization of EV-A71 isolates were performed in this study. Methods A retrospective study was performed to identify and characterize nonpolio enteroviruses (NPEVs) associated with AFP in the Philippines, and nine samples were found to be EV-A71–positive. Following characterization of these EV-A71 isolates, the complete viral protein 1 (VP1) gene was targeted for phylogenetic analysis. Results Nine EV-A71 isolates detected in 2000 ( n = 2), 2002 ( n = 4), 2005 (n = 2), and 2010 ( n = 1) were characterized using molecular methods. Genomic regions spanning the complete VP1 region were amplified and sequenced using specific primers. Phylogenetic analysis of the full-length VP1 region identified all nine EV-A71 Philippine isolates as belonging to the genogroup C lineage, specifically the C2 cluster. The result indicated a genetic linkage with several strains isolated in Japan and Taiwan, suggesting that strains in the C2 cluster identified in the Asia-Pacific region were circulating in the Philippines. Conclusion The study presents the genetic analysis of EV-A71 in the Philippines. Despite some limitations, the study provides additional genetic data on the circulating EV-A71 strains in the Asia-Pacific region, in which information on EV-A71 molecular epidemiology is incomplete. Considering that EV-A71 has a significant public health impact in the region, knowledge of its circulation in each country is important, especially for formulating vaccines covering a wide variety of strains.

The antibacterial activities of mangrove species, Avicennia marina, Sonneratia caseolaris (collected from Teluk Payo, Banyuasin, South Sumatera), Ceriops tagal, Rizhopora apiculata, and Sonneratia alba (collected from Sadai, South Bangka) were screened against Salmonella typhi and Listeria monocytogenes by agar disk diffusion assays. Extractions were conducted using organic solvents (methanol, ethyl acetate, and acetone, subsequently). Most of the extracts tested showed potential antibacterial activity against both pathogens. The methanol extracts of the bark from S. alba and the fruit from A. marina showed particularly large inhibition zones (15 mm) against S. typhi. The acetone extract of S. alba leaves showed the largest inhibition zone (14 mm) when tested against L. Monocy-togenes. Further partial purifications of selected extracts which showed strong inhibition were performed by silica gel column chromatography using various eluent compositions with different polarities. The third fraction of methanol extract from S.alba leaves eluted with chloroform:methanol (1:5) resulted in a remarkably large inhibition zone (23 mm) against S. typhi. The third and seventh fractions of acetone extract from S. alba leaves eluted with ethyl acetate:methanol (7:3) resulted in a large inhibition zones (15 mm) against L. monocytogenes. In addition, the sixth fraction of methanol extract from A. marina fruit eluted with chloroform : methanol (6:4) resulted in the largest inhibition zone (17 mm) against L. monocytogenes. These results indicated that mangrove extracts could be developed as potential biomaterials for biopharmaceutical as well as biopreservation industries.Keywords: antibacterial activity, mangrove, column chromatography

Lactobacillus plantarum S34 dilaporkan mempunyai aktivitas antibakteri yang terkait dengan produksi bakteriosin. Bagian dari gen yang menyandikan salah satu lokus bakteriosin yang diproduksi oleh L. plantarum S34, disebut dengan plantarisin W (plnW), diamplifikasi dari plasmid dan dikloning menggunakan sistem vektor pGEM®-T Easy ke dalam Escherichia coli DH5?. Sekuens nukleotida plnW (± 405 pb) diidentifikasi sebagai protein integral membran. Lebih lanjut, plnW diekspresikan secara heterologus sebagai fusi protein dengan His(6)-tag tioredoksin menggunakan vektor ekspresi pET-32a(+) ke dalam E. coli BL21 (DE3) pLysS. Protein fusi rekombinan plnW terdapat dalam sitoplasma sel, tetapi selain fraksi terlarut terdapat juga fraksi tidak terlarut berupa badan inklusi. Purifikasi parsial dilakukan menggunakan kromatografi afinitas ligan Co2+ untuk fraksi terlarut dan metode elektroelusi gel poliakrilamid untuk fraksi tidak terlarut. Massa molekul berukuran kurang lebih 33 kDa terdeteksi berdasarkan pemisahan SDS-PAGE dan dikonfirmasi dengan Western blot sebagai protein fusi rekombinan plnW. Protein yang sudah terpurifikasi bermanfaat untuk mengetahui kaitan antara struktur dan fungsi bakteriosin.