Professor, Laboratory of Microbiology, Department of Botany, University of Dhaka, Dhaka 1000, Bangladesh

Biograph
Prof. Dr. M A Karim has above 22 years of teaching and research experience at University level. He has completed his PhD in 2003 from Ehime University, Japan where he worked on enhancement of heterotrophic activities in eutrophic bottom environments by indigenous bacteria.

In Bangladesh, current research efforts of Prof. Karim and his team are directed towards monitoring the water quality of drinking water, lake water and river water for ensuring safe water supply. He has extended the research with focused on developing a basic understanding of how to evaluate and control microbial activity in eutrophic environments, how pathogenic bacteria can survive longer period in adverse condition in association with other microorganisms and their interrelationship. He has own grants from different donor organizations for pursuing his research. Prof. Karim has supervised/co-supervised over 25 postgraduates and PhD. Prof. Karim is a writer of chapters of 12 text books of biological sciences and 3 thesis books. He has published over 60 research articles in national and international scientific Journals.

Prof. Karim has represented his university in different countries at various international and national forums in various capacities. He is executive editor of Bangladesh Journal of Botany (BJB) and member of editorial board of Asiatic Society of Bangladesh, Science; Science International; World Journal of Applied Sciences; International Journal of Biosciences; Journal of Biodiversity and Environmental Sciences; Microbiology Research International and NOAMI newsletter. He was awarded by University Grants Commission in the recognition of his outstanding performance in his field. Dr. Karim is a life member of 12 scientific associations in Bangladesh and a general member of American Society for Microbiology.

Presently he is Professor, Laboratory of Microbiology, Department of Botany, University of Dhaka, Dhaka 1000, Bangladesh.

Speech Title: SURVIVAL OF VIBRIO VULNIFICUS IN ASSOCIATION WITH BLUE GREEN ALGA ANABAENA VARIABILIS IN LABORATORY MICROCOSMS

Abstract: Vibrio vulnificus causes disease in individuals who eat contaminated seafood or have an open wound that is exposed to seawater. Ingestion of V. vulnificus can cause vomiting, diarrhea, and abdominal pain. The present investigation was aimed to determine the role of blue green alga in the persistence of V. vulnificus in laboratory microcosms. In the present study, the survival of V. vulnificus with association of a blue-green alga Anabaena variabilis in laboratory microcosm was assessed using conventional culture method. The microcosm study has been conducted with two types of water. One is laboratory-based microcosm water (pH 7.0 and salinity 10‰) and other is environmental source that is sea water from Cox’s bazar sea beach (pH 7.5 and salinity 28.8‰).

Viable but non-culturable (VBNC) state of the bacterium was examined using fluorescent antibody (FA) and polymerase chain reaction (PCR) technique. The test bacterium remained culturable for 27, 20 and 32 days in control water, water with algae and within algae, respectively in microcosm water. However, in sea water, it was culturable for 32 days in control water, 27 days in water with algae and 40 days within algae. V. vulnificus was found in VBNC state for 45, 40 and 70 days in control water, water with algae and within algae, respectively in microcosm water and 50, 45 and 70 days in control water, water with algae and within algae, respectively in sea water. In the microcosm water, where the alga was floating, pH has changed rapidly but in sea water it was changed slowly. Salinity and conductivity were increased with advent of time. The changes of TDS were random.

Both fluorescent antibody and PCR results were shown that V. vulnificus survived better as VBNC state with A. variabilis than in control and in water with algae. Association of V. vulnificus with A. variabilis was also longer period in sea water. Therefore, A. variabilis can act as a long-term reservoir of V. vulnificus in an aquatic environment.

Key words: Vibrio vulnificus, association, Anabaena variabilis, microcosm