Browsing by Author "S.C. Sanyal"

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A community study on the aetiology of childhood diarrhoea with special reference to Campylobacter jejuni in a semiurban slum of Varanasi, India.
(1993) G. Nath; B.N. Shukla; D.C. Reddy; S.C. Sanyal
In a community study of 607 diarrhoeal and 529 non-diarrhoeal (control) patients less than 5 years old carried out between August 1988 and July 1989, the Campylobacter jejuni isolation rate was 4% in the diarrhoeal and 0.9% in the control group. It was the second most common bacterial enteropathogen isolated after Escherichia coli. Its incidence was more common among 1-2 year old children (4.8%) and during rainy season (July-October). Features of dysentery were absent in C. jejuni diarrhoea. Findings strongly suggest its aetiological role in childhood diarrhoea. Among other enteropathogens in diarrhoeal specimens, rotavirus was the commonest (16.4%) followed by enterotoxigenic E. coli (13.8%), G. lamblia (10.3%), enteropathogenic E. coli (7.0%), E. histolytica (5.0%), Cryptosporidium (3.8%), H. nana spp. (1.5%), NAG vibrios (0.5%), P. shigelloides (0.5%), V. mimicus and Salmonella spp. (0.3%). Approximately one quarter of the stool specimens (22.6%, 256/1136) tested were positive for the ova of A. lumbricoides.
A profile of diarrhoea in an urban slum area.
(1990) A.K. Mandal; I.C. Tiwari; S.C. Sanyal
Researchers followed 90 households (445 people) in Sunderpur slum in Varanasi in Upper Pradesh, India for 1 year and collected stool samples when people were ill with diarrhea to determine diarrhea incidence and causes of diarrheal disease. The water supply consisted of a well, public tap, or house tap with 30 households in each group. They noted 106 diarrheal episodes for an incidence of around 23%. Incidence decreased significantly with age (p.001). For example, it was 62.9% for children 5 years old, 34% in the school age population, and 8.7% in people =or 15 years old. Improved resistance to infection and/or improved personal hygiene could have accounted for this difference. Diarrheal incidence was considerably lower in the autumn (9.3%) and winter months (11.1%) than the spring (49.1%) and summer months [rainy season] (30.5%) (p.001). Researchers found at least 1 parasite in the stool sample of 81.5% of cases. The leading causative agents included Ascaris lumbricoides (42.1%), Entamoeba histolytica (35.2%), hookworm (7.9%), and Escherichia coli (5.7%). Diarrhea incidence was much higher in persons whose water supply was a well (35.8%) compared to 23.2% for those with a public tap, and 12.8% for those with a private tap. These results concerning the water supply corroborated those of the Planning Research and Action Institute's (Upper Pradesh) pilot piped water supply program in the areas of Banki, Parendra, and Mokhampur in which incidence was highest in Banki where the water supply was an open well. The next highest and the lowest incidences were among those whose water supply consisted of public taps and private taps respectively.
Adherence of haemagglutinating and non-haemagglutinating clinical and environmental isolates of Aeromonas.
(1993) D.V. Singh; R.S. Dubey; S.C. Sanyal
Twelve haemagglutinating and non-haemagglutinating isolates of Aeromonas spp., comprising 6 each of clinical and environmental origin, were examined for their ability to adhere to rabbit intestinal epithelium, for inhibition of adhesion with sugars, and for delineation of the portion of intestine, jejunum, or ileum that is most susceptible to adhesion. Although the environmental isolates of Aeromonas haemagglutinated human erythrocytes that were inhibited by D-mannose and/or L-fucose, the majority of the clinical isolates of Aeromonas adhered to rabbit intestinal epithelium in almost equal proportions regardless of their haemagglutination (HA) properties, species designation, and source of isolation. Adhesion of both haemagglutinating and non-haemagglutinating isolates of Aeromonas was inhibited by sugars; however, the ability of sugar inhibition to adhere was similar to that observed with HA. This study suggests that adhesion is probably mediated by a variety of pilus or non-pilus colonisation factors which may or may not be a haemagglutinin. The jejunum was found to be more susceptible to adhesion than the ileum. However, no appreciable difference was observed in the number of adhered bacteria to adjacent loops.
An outbreak of infection in neurosurgery ward
(1980) L. Das; S. Mohanty; S.C. Sanyal; K.C. Mukherjee
[No abstract available]
Antibiotic resistance in clinical and environmental isolates of aeromonas spp
(1994) D.V. Singh; S.C. Sanyal
[No abstract available]
Antibiotic resistance in Shigella
(1979) R.S. Rao; S.C. Sanyal; P.C. Sen
82 strains of Shigella isolated at Varanasi were tested for their susceptibility to 12 currently used antibiotics by the disc agar-diffusion technique. A maximum number of strains (56.1%) were resistant to demeclocycline and the resistance to doxycycline was detected in 52.4% of strains. Resistance to chlorotetracycline, oxytetracycline, demeclocycline and doxycycline was detected in 19.5% of strains. Streptomycin-resistance was found in 29.3% of strains and 50% of these were Sh.dysenteriae. A few strains were resistant to chloramphenicol, ampicillin, furazolidone, co-methoxazole and gentamycin. No resistance to kanamycin or neomycin was found.
Attachment of non-culturable toxigenic Vibrio cholerae O1 and non-O1 and Aeromonas spp. to the aquatic arthropod Gerris spinolae and plants in the River Ganga, Varanasi
(1995) B.N. Shukla; D.V. Singh; S.C. Sanyal
Non-cultivable, pathogenic O1 and non-O1 Vibrio cholerae and Aeromonas spp. were resuscitated from aquatic arthropods and plant homogenate respectively, by rabbit ileal loop (RIL) assay. These organisms adhered to the aquatic arthropod Gerris spinolae and various species of phytoplankton in the River Ganga, but failed to grow after direct inoculation on artificial media except for only 10 homogenates of the arthropod. The number of non-O1 V. cholerae and Aeromonas recovered on direct inoculation of G. spinolae homogenates were in the order of 105-106 whereas those of the Ganga water were 102-103 ml-1. A total of 119 strains of O1 and non-O1 V. cholerae and Aeromonas spp. (69 isolates from G. spinolae and 50 from aquatic plants) were recovered from the loop contents. The results indicate that production of the enzyme chitinase by O1 and non-O1 V. cholerae and Aeromonas spp. might facilitate their adsorption and multiplication on different species of zoo- and phyto-plankton. Most of the isolates were enterotoxic, haemolytic and resistant to different antibiotics. This study suggests that species of zoo- and phyto-planktons, until now not reported to be associated with O1 and non-O1 V. cholerae, may act as reservoirs of these organisms as well as different species of Aeromonas in a fresh-water riverine ecosystem. © 1995.
Bacterial flora in acute small bowel obstruction
(1980) S. Gupta; K.R.R.M. Reddy; S.C. Sanyal
The bacterial flora has been studied by direct sampling techniques at various levels in 25 cases of acute small bowel obstruction. The presence of coliform bacteria in the distal ileum below the level of obstruction and progressive increase of bacterial counts from the jejunum towards the distal ileum above the obstruction suggest that ingestion may not be the only factor of bacterial growth in the small bowel in acute intestinal obstruction. Moreover, indirect peritoneal contamination in 8 cases of long-standing acute small bowel obstruction indicates that possibly a combination of multiple factors like ingestion of food, retrograde spread from the large bowel, lymphatic and/or hematogenous spread are responsible for bacterial dissemination in and around the obstructed bowel.
Bacteriology of weaning foods in some areas of Varanasi
(1982) D.K. Agarwal; S. Chandra; B.D. Bhatia; S.C. Sanyal
Mothers of 106 children of 6 to 24 months of age (37 urban, 39 urban slum and 30 rural), were interviewed to find out the weaning foods being used for their children. One hundred and fifty samples of actual weaning food being fed to children were collected in sterile containers for bacteriological studies. Dal, rice or mixture of rice and dal were the most commonly used weaning foods (35.3, 19.8 and 33.6% respectively). Fifty-eight per cent of the weaning food samples yielded positive cultures for E. coli indicating high fecal contamination. The other organisms isolated were K. pneumonae, Ps. aeruginosa, S. fecalis and Citrobacter.
Better preservation of Campylobacter jejuni/C. coli in a defined medium
(1991) S.K. Saha; S.C. Sanyal
[No abstract available]
Biochemical characterisation, enteropathogenicity and antimicrobial resistance plasmids of clinical and environmental Aeromonas isolates
(Microbiology Society, 1996) A. Chaudhury; G. Nath; B.N. Shukla; S.C. Sanyal
One hundred and eight strains of Aeromonas from clinical and environmental samples were speciated. Seven species were identified, the most prevalent of which was A. hydrophila. Experimental studies in an animal model with 36 representative strains of different species revealed that all strains could cause significant fluid accumulation in rabbit ileal loops. Of 107 strains showing single or multiple antimicrobial resistance, the highest incidence of resistance was shown for β-lactam antibiotics other than cefotaxime. Transferable resistance plasmids, encoding resistance to ampicillin, cephalexin, cefoxitin, erythromycin and furazolidone, either alone or in combination, were detected in 35 strains. A further proportion of strains could be cured of one or more resistance markers, including resistance to nalidixic acid, and this was accompanied by the loss of plasmid DNA. The plasmids ranged in size between 85.6 and >150 kb.
Biochemical characteristics and enterotoxicity of Aeromonas species isolated from man and environment.
(1992) D.V. Singh; S.C. Sanyal
A total of 147 isolates of Aeromonas spp., of which 54 were isolated from children and adults with diarrhoea, 44 from variety of water sources and 49 from environmental sources, were tested for enterotoxin production and its correlation with biochemical characters. Lysine was decarboxylated by 38% of A. hydrophila, 35% of A. sobria and 20% of A. caviae. Majority strains were unable to utilise citrate as the sole source of carbon except one of A. hydrophila, 8 of A. sobria and 6 of A. caviae. Beta-haemolysis was shown by 108 isolates that included 79% of A. hydrophila, 76% of A. sobria and 70% A. caviae. About 56% of Aeromonas strains including A. caviae caused fluid accumulation in the rabbit ileal loop in the initial tests and the remaining did so after 1-3 consecutive passages. Enterotoxin production did not correlate with the positive biochemical characters such as Voges-Prauskauer reaction, lysin decarboxylation, haemolysin production, citrate utilisation and failure to ferment arabinose either singly or in combination. This study indicates that enterotoxicity of Aeromonas may not be correlated with any of the biochemical characters either singly or in combination.
Biological similarity of enterotoxins of Vibrio cholerae serotypes other than type 1 to cholera toxin and Escherichia coli heat-labile enterotoxin
(1982) A. Lahiri; R.K. Agarwal; S.C. Sanyal
Vibrio cholerae serotypes other than type 1, the so-called NAG vibrios, have been recognised as an important cause of diarrhoea. A few of them have been shown to produce an enterotoxin similar, immunologically and physiologically, to cholera toxin; and cholera toxin has been shown to be structurally, functionally and immunologically identical with Escherichia coli heat-labile toxin (LT). The present investigation has demonstrated biological similarities among cholera toxin, E. coli LT and enterotoxins produced by strains of V. cholerae of 59 serotypes other than 1, in the biological models, rabbit ileal loops and rabbit skin. Culture filtrates of almost all the strains were neutralised completely and all filtrates showed some neutralisation, in enterotoxic action and increase of permeability, by cholera antitoxin and E. coli LT antiserum. The partial neutralisation observed in a few strains was probably due to high concentrations of identical toxin rather than the presence of other toxic substances.
Candidate live oral cholera vaccine strains produce a new cholera toxin
(1996) D.V. Singh; Anjali Tikoo; S.C. Sanyal
When six candidate live oral cholera vaccine strains deleted for one or all known virulence factors are tested for enterotoxin production, two of them caused fluid accumulation in the initial rabbit ileal loop (RIL) test, the others did so after 1-3 serial passages through RIL. Culture filtrates also showed similar secretory response. Ten times concentrated culture filtrates of these strains gave precipitin band against anti-new cholera toxin showing reaction of identity. These observations clearly indicate that vaccine strains produce a secretogen antigenically similar to the new cholera toxin.
Characterisation and neutralisation of Aeromonas hydrophila enterotoxin in the rabbit ileal-loop model
(1979) R.S. Dubey; S.C. Sanyal
[No abstract available]
Childhood diarrhoea due to rotavirus in a community
(1992) G. Nath; S.P. Singh; S.C. Sanyal
The etiologic role of rotavirus in acute diarrhoeal illness in children under five years of age was studied over a period of one year in an urban slum community. Rotavirus was detected in 17.7 per cent-of 376 children with diarrhoea and 4 per cent of 299 healthy children with maximum prevalence at 19-24 months of age with statistically comparable detection in 0-6 months of age. The overall prevalence was significantly higher in children below 2 yr as compared to those between 2-5 yr of age. Girls (24.1%) were more susceptible amongst the diarrhoeal group in comparison to boys (13.8%). Diarrhoea due to rotavirus was more prevalent during the cooler months (November-February) of the year and no correlation was observed with rainfall and relative humidity. Rotavirus as the sole pathogen was observed in 9 per cent children with diarrhoea and in the rest, association of Cryptosporidium (3%) was observed for the first time with this virus along with other known enteropathogenic bacteria and parasites, enterotoxigenic Escherichia coli being the commonest organism.
Cholera toxin gene-positive Vibrio cholerae O1 Ogawa and Inaba strains produce the new cholera toxin
(1988) Setarunnahar Saha; S.C. Sanyal
Two strains of cholera toxin (CT) gene-positive Vibrio cholerae O1, Ogawa, isolated from patients with diarrhoea and the hypertoxigenic V. cholerae O1, Inaba (569B), were found to produce the new cholera toxin that has earlier been demonstrated to be elaborated by CT gene-negative human and environmental isolates of V. cholerae O1. The CT gene-positive strains produce the new cholera toxin simultaneously with CT, indicating that they contain the gene coding for the new cholera toxin in addition to that of CT. © 1988.
Cloning of enterotoxin gene from Aeromonas hydrophila provides conclusive evidence of production of a cytotonic enterotoxin
(1984) T. Chakraborty; M.A. Montenegro; S.C. Sanyal; R. Helmuth; E. Bulling; K.N. Timmis
Culture filtrates of two Aeromonas hydrophila strains which were isolated from patients with diarrhea and assumed to be causative agents of the infections were shown to contain enterotoxic, cytotoxic, and hemolytic activities. Modest heat treatment of the filtrates inactivated the cytotoxic and cytolytic activities, but not the enterotoxic activity. The construction of cosmid gene banks in Escherichia coli of DNA from both A. hydrophila strains demonstrated that the determinants of the three activities are located on three different segments of the A. hydrophila chromosome. Both heated culture filtrates of A. hydrophila and nonheated filtrates of an E. coli clone containing the A. hydrophila enterotoxin gene provoked fluid accumulation in the rabbit ileal loop and suckling mouse models and caused elongation of Chinese hamster ovary cells. Differences in the responses of the models to the A. hydrophila enterotoxin and to the heat-labile and heat-stable toxins of E. coli indicated that the former is distinct from the latter two types of toxin. These results constitute conclusive evidence for the production by A. hydrophila of a cytotonic enterotoxin that is distinct from the A. hydrophila cytotoxin and hemolysin and known E. coli enterotoxins.
Development of an improved synthetic medium for a better production of the new cholera toxin and its immunological relationship with the toxin produced by Vibrio cholerae O139 strains
(Blackwell Publishing Ltd, 1996) Anjali Tikoo; D.V. Singh; B.N. Shukla; S.C. Sanyal
An improved synthetic medium (M4) comprising syncase medium supplemented with sodium chloride (1%) and sucrose (0.5%) pH adjusted to 7.4 was developed for a better production of the new cholera toxin (NCT). The culture filtrates prepared in the M4 medium caused significantly (P < 0.05) more fluid accumulation than that in syncase medium. Crude toxin, prepared in the M4 medium with V. cholerae O1 strains (X-392 and 2740-80) caused a reaction similar to that of the same amount of NCT (32 μg) prepared in the syncase medium. The neutralization of the optimal loop reacting dose of the NCT prepared in the M4 medium by anti-NCT raised against syncase prepared toxin indicates the release of the same kind of toxin in both media. These observations indicate that the modified M4 medium may be used for NCT preparation and further characterization All the strains of Vibro cholerae O139 used in this study produced a toxin-antigenically similar to NCT.
Elevation of adenosine 3' 5' cyclic monophosphate level by Aeromonas hydrophila enterotoxin
(1981) R.S. Dubey; A.K. Bhattacharya; S.C. Sanyal
Culture filtrates and partially purified enterotoxin preparations from A. hydrophila caused 3-fold increase in the level of cyclic 3' 5' adenosine monophosphate (cAMP) in epithelial cells of rabbit ileal loops. Toxin treated epithelial cells showed 104.6-143.1 picomoles/mg of tissue protein whereas normal epithelial cells had 34.6-40.0 picomoles/mg. Crude enterotoxin treated epithelial cells showed comparatively lesser cAMP level (85.10 ± 1.06 picomoles/mg) than cells treated with culture filtrates (122.70 ± 2.67 picomoles/mg). When graded doses of enterotoxin preparations were inoculated in the ligated ileal loops and cAMP levels of epithelial cells were measured after 6 hr of inoculation there was no significant change observed in cAMP level (105.45 ± 2.29 = 137.87 ± 9.26) with respect to the various doses. These data indicate the possible role of cAMP in the action of A. hydrophila enterotoxin.