RDG Conference Report of Cynthia T. Hedreyda

Write up about the Conference

The American Society for Microbiology (ASM) has more than 39,000 members with more than one third of its members located outside the United States. Members belong to 26 disciplines of microbiology plus a division for microbiology educators. ASM holds its annual meeting in the late spring to bring together microbiologists from different countries with a program to educate participants in fields such as diagnostic microbiology, epidemiology, pathogenesis, host response mechanisms, general and applied microbiology, molecular microbiology, physiology, and virology. There are also hands-on workshops organized before or after the meeting. The programs include oral paper presentation by experts in different fields and several poster paper presentations on all fields of specializations enumerated above.Students, researchers, and professors in microbiology (members and non-members alike) participate in all activities. This meeting is a venue to share ideas, research outputs, and learn from the work and experiences of colleagues. Only registered participants have access to poster papers and oral presentations, including exhibits by different companies selling equipment, kits, and chemicals for microbiological research.

In this ASM meeting NIMBB has two poster papers. One is my paper summarizing the work done in the Molecular Microbiology Laboratory for the last 6 years, at generating about 5 ISI publications and one is an on-going project to isolate a gene for oil degradation from bacteria.

Feedback on paper presented

One major feedback from a researcher working at the CDC Atlanta Georgia was the possible application of the gene sequence analysis of four genes presented in the poster in addressing proper identification of Vibrio isolates they encounter. Their laboratory experience a similar problem of ambiguous classification of environmental strains of Vibrios.

Some Filipino graduate students from different universities were glad to know that molecular microbiology research was being conducted in the Philippines. They are happy to see papers from the Philippines being presented in this big meeting of microbiologists. They take their time to visit poster papers from the country, an admirable trait of our future scientists and mentors. Consequently, if they see that decent research in the field can be done in the Philippines, they may be inspired to go home and contribute to local scientific effort.

Future directions of research presented

The successful isolation and complete gene sequencing of genes reported for the first time in the species studied provides enough reason for continued gene sequence analysis of important genes in other species to address different problems…identification or classification, determine role in pathogenicity, isolation of genes for specific industrially significant proteins or enzymes for cloning and expression

Potential foreign collaborators

In previous ASM meetings, and in this one, discussions with other researchers working on Vibrios were made. Data sharing have contributed a lot to the completion of the research presented.

Other important contacts and insights

While in the US, communication with NIMBB alumni (graduate students in the US) who have agreed to visit NIMBB to present their work in seminars and classes. Two NIMBB alumni are coming this semester to present their research.

Short write-up of one’s participation (to be used to feature/publicize the grantee’s participation in the conference)

The paper presented described the work on detecting and Identifying bacteria that kills black tiger shrimp. In the late 1990’s, the production of black tiger shrimp experienced a state of decline and major economic losses and the bacterium Vibrio harveyi and its close relative Vibrio campbellii were implicated in shrimp disease. The initial research conducted at the Molecular Microbiology Laboratory of NIMBB was to identify markers that could be used to detect the presence of these bacterial species using PCR. This search for detection markers led to the work on two genes, the gene for the ToxR protein and hemolysin which were present in both bacteria.

Complete gene sequences for toxR were reported for the first time for type strains of V.harveyi and V. campbellii. Complete gene sequence for the hemolysin gene in V.campbellii was also published. Variable regions of the toxR and hemolysin genes that could distinguish type strains of these two shrimp pathogens were successfully identified and used in designing PCR primers for detection.

Conventional approach for identifying V. harveyi and V. campbellii used the ornithine decarboxylase assay and luminescence where V. harveyi is positive and V campbellii is negative for both tests. Interest in determining the molecular basis for these assay results led to the studies that generated the complete sequence of the ornithine decarboxylase gene in V. harveyi and the luxA and B genes in V.campbellii.

Complete gene sequences revealed significant sequence difference (with only 79% sequence similarity) of toxR and hemolysin genes between type strain V. harveyi and V. campbellii. Gene for ornithine decarboxylase was sequenced from V. harveyi but could not be detected from V.campbellii. A full length type strain V. campbellii luxB gene homologous tothe V. harveyi luxB but a much shorter 225-bp luxA gene compared to the 1,068-bp full length luxA of type strain V. harveyi) were obtained for V. campbellii.

These work generated complete gene sequences for ToxR, hemolysin, ornithine decarboxylase, and luciferase A and B that were also subjects of several published paper. Moreover, the paper presentation was able to show examples of molecular microbiology work done in the country.