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Flooding in Dhaka in July 2004 caused epidemics of diarrhea. Enterotoxigenic Escherichia coil (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools. ETEC that produced heat-stable enterotoxin [...]

Abstract With more than 1.4 million of the 9 million child deaths being attributed to diarrhoea in 2008 and 49% of them occurring in five countries namely, India, Nigeria, Democratic Republic of the Congo, Pakistan and China, there is an urgent need for intervention to prevent and control diarrhoeal diseases. Of the various interventions, probiotics offer immense potential. The past decade has witnessed the validation of their utility for the prevention, treatment and management of a variety of infective and non infective disorders. The most investigated field continues to remain infectious diarrhoea and compelling evidence comes from randomized placebo controlled trials. While results from these studies are encouraging most of them reflect the outcomes of the developed world. Developing countries like India continue to struggle with nutritional and health challenges and bear the greatest burden of diarrhoea. A paucity of data from the developing countries limits the definite recommendation of probiotics. In these countries curd, often confused for a probiotic, is practiced as an integral part of the culture. While the nutritional benefits of these products cannot be understated, it is still uncertain whether these products can be classified as a probiotic. The emergence of probiotic foods which are scientifically validated for their efficacy and impart defined health benefits offer an excellent opportunity to improve public health. A recent randomized controlled trial conducted by the National Institute of Cholera and Enteric Diseases in Kolkata, India demonstrated a protective efficacy of 14% in preventing diarrhoea among children who received a probiotic. For the developing world however the vision for probiotics would mean a fundamental change in perception and developing a well planned strategy to allow interventions like probiotics to permeate to impoverished settings, where the assault of micro organisms is on a daily basis. This would mean that probiotics are ingrained into the public health system without being seen as a medicine.

Background & objectives: Bacillus cereus is one of the pathogens responsible for human diarrhoea, mainly due to consumption of contaminated food. The present study was undertaken to determine the occurrence of B. cereus among diarrhoeal patients and its phenotypic and genetic characteristics that determine the virulence and clonal features. Methods: Stool specimens were collected for two years from acute diarrhoeal patients attending the two referral hospitals in Kolkata. Presence of virulence genes in B. cereus was determined by PCR. Clonality was assessed by pulsed-field gel analysis (PFGE) by restriction digestion with SmaI and NotI enzymes. Enterotoxins were detected by haemolysin assay and using BCET-RPLA kit. Invasion assay was done on Hep-2 cell line. Antimicrobial susceptibility was tested by disc diffusion method. Results: B. cereus was identified in 54 (3.5%) of the 1536 diarrhoeal cases studied. Majority of the isolates were susceptible to many antibiotics but showed resistant to amoxyclav and cephalosporins. Six genes covering the two different enterotoxic complexes determining the pathogenicity of B. cereus have been characterized by PCR. The nhe genes were detected in a higher proportion than hbl. Except in two, clonal diversity was noticed among 21 B. cereus isolates. Haemolytic enterotoxin was detected in 76 per cent of the isolates. Majority of the isolates (67%) produced in vitro enterotoxin (BCET) confirming its involvement in the infection. Interpretation & conclusions: Though the presence of B. cereus was not high in patients with diarrhoea, several virulence factors confirm their association with diarrhoea. Distinct clonality was identified in majority of the isolates indicating their origin from different sources. [ABSTRACT FROM AUTHOR]

Chronological analysis of 125 Vibrio cholerae O139 strains isolated during 1993–2005 in Kolkata revealed the prevalence of two new genotypes of cholera toxin (CT) and novel combinations of ctxB and rstR alleles resulting in variant CTX prophages. One of the new genotypes of ctxB, which first appeared in 1996 with the re-emerged V. cholerae O139 strains that had CTX Calcutta phage, was designated as genotype 4. In 1998, another new genotype, designated as genotype 5, was detected that prevailed mostly in CTX phages with El Tor rstR. The prototype El Tor CTX phage with genotype 3 gradually disappeared in O139, and since 2002 the predominant CTX prophages in O139 are Calcutta phages with genotype 4 and El Tor phages with genotype 5. Results showed that V. cholerae O139 strains of Kolkata, isolated over a decade, harboured CTX prophages in the large chromosome having no RS1 downstream of CTX prophage. During the course of its intermittent incidence over a decade, five types of O139 strains were detected based on CT genotypes. Such abrupt genetic changes in O139 strains might not favour its continued prevalence in human cases in Kolkata, India. [ABSTRACT FROM AUTHOR]

Flooding in Dhaka in July 2004 caused epidemics of diarrhea. Enterotoxigenic Escherichia coli (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools. ETEC that produced heat-stable enterotoxin alone was most prevalent, and 78% of strains had colonization factors. Like V. cholerae 01, ETEC can cause epidemic diarrhea. [ABSTRACT FROM AUTHOR]

Climate change and its negative impacts on health are now globally recognized. A wide variety of diseases and health conditions - ranging from heat and radiation-related illnesses to water and vector-borne diseases, under-nutrition, respiratory and cardiac problems, drowning, injuries and mental stress arising from extreme and sudden weather events and their resultant population displacements - all have been associated with various components of changing climate. However, the exact nature and extent of such impacts are yet to be firmly established since many other non-climate factors also produce or affect similar outcomes. This calls for more research specially from the underdeveloped countries, where such impacts are disproportionately more but reliable data are remarkably less. Recognizing the importance of human influences on global warming, almost all countries in the world have undertaken some kind of policies and measures to mitigate adverse climatic changes. Unfortunately, even without further addition of greenhouse gases (GHGs) in our climate, the amount of GHGs already released has the potential to continue the damages for many more decades to come. Thus, all countries should also place priorities in assessing their own vulnerabilities from climate change and take adaptive measures accordingly. As climate change exerts its impact simultaneously in many non-health sectors as well, this would require strong intersectoral cooperation at various levels.

From 300 stool samples, 58 Campylobacter strains were isolated by standard microbiological and biochemical methods. Of these, 40 strains were identified as Campylobacter jejuni and 5 as Campylobacter coli. The presence of flaA (100%), cadF (100%), racR (100%), dnaJ (100%), pldA (100%), ciaB (95%), virB11 (0%), ceuE (82.5%), cdtA (97.5%), cdtB (97.5%), cdtC (97.5%), and wlaN (7.5%) genes was detected in C. jejuni by PCR. All C. jejuni strains but one produced cytolethal distending toxin in a HeLa cell assay.