Assessment of microbial pollution and diversity of E. coli and Shigella in
freshwater resources in Bangladesh (NUFUPRO-2007/10063)
Department of Microbiology, University of Dhaka (coordinator: Sirajul Islam Khan) and
Department of Biology, University of Bergen (coordinator: Nils-Kåre Birkeland)
• Other researchers: Prof. Chowdhury Ahsan, Prof. Humaira Akhter, Prof. Anowara
Begum, Dr. Ziaur Rahman (all in Dhaka)
• Three PhD students: Ms Nafisa Azmuda, Ms Selina Akter and Ms Fatema Moni
Chowdhury (all in sandwich model but enrolled at UoD)
• In addition to the main project, we have received Supplementary Activities (NUFUSA)
funding for:
1) Academic writing course and
2) Dissemination of results
• Scientific focus on the diversity, distribution and survivability of enteropathogenic
bacteria, e.g. Shigella spp. and E. coli in surface water
• Diarrheal diseases are responsible for up to 100, 000 deaths (mostly children) annually
in Bangladesh, with Shigella and E. coli as major disease-causing agents.
• Shigellosis (bacillary dysentery) is a particularly dreadful diarrheal disease, with heavy
excretions of blood and mucus. Pathogenic types of E. coli usually causes milder forms
of diarrhea, but certain pathogenic types can causer severe diarrheal disease
• Normally, Shigella is not found in healthy humans, while E. coli is a normal component
of the gut flora of human and animals, but a number of disease-causing E. coli strains
exist. Both organisms are mainly disseminated by contaminated food and water.
• Shigella is extremely difficult to detect and recover from surface water while E. coli is
easily recovered and is being used as a fecal indicator. The two organisms are closely
related.
Shigella invading the mucosal epithelium
E. coli
Main goals:
• Infrastructure: Improve the research facilities at the environmental/molecular
laboratory in Dhaka
• Education: Train PhD and Master students in environmental and molecular
microbiology as related to health
• Science: Improve the knowledge of the environmental biology of Shigella and E. coli in
surface waters of Bangladesh
Main results:
• An advanced and functional microbiology lab established
• 12 Master students graduated, 4 still in progress
• 3 PhD students in thesis writing stage
Highlights from scientific results:
1. Through design of novel culture media and isolation procedures we have succeeded
in isolation of a number of Shigella-like strains from surface waters (by resuscitation
from a dormant state). Some of these isolates are “atypical” (i.e. different from
clinical strains) and do not possess pathogenic properties. This is a breakthrough in
the study of the environmental biology of Shigella. Extensive transfer of “Shigella
genes” between bacterial species has also been demonstrated.
2. We have monitored the seasonal and geographic distribution
pattern of all the pathogenic E. coli types (EHEC, ETEC, EIEC etc.)
in surface waters covering a large part of Bangladesh (46 sites).
This has provided a better understanding of the fluctuations and
possible influence of abiotic factors.
3. Through molecular bacterial community analyses we have
determined the near-complete composition and seasonal
variation of bacteria in a few sites. The work includes “stateof-the-art” deep sequencing. This is the first time such an indepth analyses have been performed in tropical surface
waters.
4. A non-pathogenic “Shigella-like” isolate is being
evaluated as a possible vaccine candidate.
Immunization with a non-pathogenic strain provides
protection against virulent strains in guinea pig eye
tests (Sereny tests), which is a test for invasiveness.
Challenges/ problems:
•Since this is a sandwich model, students taking courses in Bergen should be given course
credit in Dhaka. Too rigid regulations at DU made this a problem.
•Very time-consuming (lengthy) procedures for PhD admission in Dhaka (a bureaucratic
process that may take more than 9 months)
•A bottle neck: Lack of adequate academic/ scientific writing capability among students and
staff
•Many prospective students prefer a foreign PhD degree. Joint North-South degrees should
be developed. Joint degrees would strengthen the relationship at the institutional level.
Most of the best students will not join because they want a “foreign” degree.
•Logistics problems:
 It is often difficult to procure special scientific consumables from abroad, and its customs
clearing is too time-consuming
Housing of foreign PhD students in Bergen was sometimes a problem. SiB does not
generally regard PhD students as “students”. Negotiations required.