Browsing by Author "Niyogi, S K"
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Item Association of enterotoxigenic Bacteroides fragilis with childhood diarrhoea.(1997-04-01) Niyogi, S K; Dutta, P; Mitra, U; Pal, D KThis study was conducted in a hospital setting to determine whether enterotoxigenic strains of Bacteroides fragilis (ETBF) were associated with childhood diarrhoea. ETBF was isolated from 6 (2.6%) of 226 patients and 3 (1.7%) of 172 controls and was found mostly in children between 1-5 yr of age. The syndrome associated with ETBF was secretory in nature with watery diarrhoea and of mild severity. ETBF may be associated with diarrhoeal illness in children but is not a major problem in this part of the country.Item Clinical manifestation of Clostridium difficile enteritis in Calcutta.(1991-09-01) Bhattacharya, M K; Niyogi, S K; Rasaily, R; Bhattacharya, S K; Dutta, P; Nag, A; Pal, S C233 cases with acute diarrhoea investigated, Clostridium difficile was isolated as a sole pathogen from 17 (7.3%) cases. The Major clinical features of these cases were watery diarrhoea (82.4%), bloody stool (17.6%), vomiting (64.8%), fever (17.6%) and abdominal pain (2.5%). Fourteen (82.4%) of 17 C difficile isolates were found to produce cytotoxin as detected by Verocell assay.Item Clostridium difficile and its cytotoxin in hospitalized children with acute diarrhea.(1991-10-01) Niyogi, S K; Dutta, P; Dutta, D; Mitra, U; Sikdar, SA total of 498 children, aged 0-14 years, admitted at the B.C. Roy Memorial Hospital for Children, Calcutta, were investigated for the occurrence of Clostridium difficile and its cytotoxin. Of the children in the investigation, 369 suffered from acute diarrhea. Only 8.4% of these children had C. difficile in fecal samples and in vitro cytotoxin was demonstrated in 7%. In 27 (7.3%) of the patients with acute diarrhea C. difficile was isolated as the only pathogen. In contrast, among 129 control children not suffering from acute diarrhea, only 4 (3.1%) harboured C. difficile. Isolation of C. difficile was significantly higher in children under one year of age. None of these patients had any history of prior antibiotic therapy.Item Clostridium difficile in antibiotic associated pediatric diarrhea.(1994-02-01) Dutta, P; Niyogi, S K; Mitra, U; Rasaily, R; Bhattacharya, M K; Chakraborty, S; Mitra, AA case control study was carried out at the medical wards of Dr. B.C. Roy Memorial Hospital for Children, Calcutta, between January and September 1989. One hundred eleven hospitalized children up to the age of 5 years, receiving antibiotics for different medical problems, developed antibiotic associated diarrhea. Isolation of Clostridium difficile as sole pathogen was very low (3.6%) from these patients. Fecal samples of 111 case matched control children were also screened for C.difficile. Only 2.7% fecal samples of control children were positive for C.difficile. All the strains of C.difficile isolated from antibiotic associated diarrhea cases showed neutralisable cytotoxin in in vitro test. In contrast none of the strains isolated from control children showed cytotoxicity. This study suggests that C.difficile is not an important pathogen related to antibiotic associated diarrhea in children at this hospital.Item Clostridium difficile--associated diarrhoeal diseases: an overview.(1995-03-01) Niyogi, S KItem Comparison between the multiplex PCR, sensitivity to biotype specific phages & polymyxin B for biotyping of Vibrio cholerae O1.(1997-12-24) Basu, A; Mukhopadhyay, A K; Chakrabarti, A K; Niyogi, S K; Saha, M R; Yamasaki, S; Takeda, Y; Nair, G BA total of 196 Vibrio cholerae O1 strains isolated between 1970 and 1996 were biotyped by multiplex PCR, susceptibility to polymyxin B and sensitivity to biotype specific phages. We modified the multiplex PCR by increasing the primer concentration of tcpA to improve the results. Comparison of the results of modified multiplex PCR and sensitivity to biotype specific phages and to polymyxin B showed that multiplex PCR was as efficient as phage typing for biotyping of V. cholerae O1. All the strains of V. cholerae O1 could be accurately distinguished based on polymyxin B sensitivity. Thus our results show that susceptibility of strains of V. cholerae O1 to polymyxin B is the easiest method to biotype V. cholerae O1 and is feasible in most laboratories when compared with multiplex PCR and sensitivity to biotype specific phages.Item Comparison of selective media for optimal recovery of Clostridium difficile from diarrhoeal stools.(1992-07-01) Niyogi, S K; Pal, S CFive selective media were compared for their efficacy in the recovery of C. difficile from stool specimens. Of 341 diarrhoeic stool samples, 38 (11%) yielded C. difficile. Eighty per cent of the isolates were detected on modified taurocholate cycloserine cefoxitin fructose agar (MTCCFA) and 73 per cent were detected on taurocholate cycloserine cefoxitin fructose agar (TCCFA). MTCCFA was also found superior to the other four media as it supported better growth of C. difficile colonies, by effectively suppressing the competing microflora. These results suggest that the recovery rate of C. difficile could be enhanced when routine media, incorporated with taurocholate and lower concentration of cycloserine and cefoxitin, is used for the isolation of C. difficile from diarrhoeic stool.Item Decreasing trend in the occurrence of Salmonella enterica serotype Typhi amongst hospitalised children in Kolkata, India during 1990-2000.(2002-02-26) Saha, M R; Dutta, P; Niyogi, S K; Dutta, S; Mitra, U; Ramamurthy, T; Manna, B; Bhattacharya, S KIn a prospective hospital based surveillance, 1454 children clinically diagnosed as typhoid fever were enrolled during the period between 1990 to 2000. Of them 336 (23.1%) children were positive for Salmonella enterica serotype Typhi by blood culture. A declining trend of hospitalization and identification of the pathogen was observed from 1992 to 2000 as compared to 1990-1991. A declining trend of resistance to the commonly used anti-typhoid drugs was seen in the S. enterica serotype Typhi isolates. Recently in 2000, nine strains were detected as ciprofloxacin resistant. Misuse and overuse of ciprofloxacin for the treatment of typhoid fever influenced the development of ciprofloxacin resistant strains of S. enterica serotype Typhi in and around Kolkata.Item Detection of faecal leucocytes & erythrocytes from stools of cholera patients suggesting an evidence of an inflammatory response in cholera.(2000-07-28) Saha, D R; Niyogi, S K; Nair, G B; Manna, B; Bhattacharya, S KBACKGROUND & OBJECTIVES: Detection of faecal leucocytes and RBCs in stool samples of cholera patients has been reported in a small number of studies. This study extends these observations by examining stool samples of cholera patients in Calcutta. METHODS: Out of 1562 diarrhoeal stool samples, Vibrio cholerae was isolated in 266 cases. Stool samples obtained were examined microscopically within two hours of collection. RBCs and faecal leucocytes were examined by normal saline and methylene blue stain. Stool culture was performed using selective and differential media for isolation of V. cholerae. RESULTS: Among 266 cholera patients, RBCs was detected in 58 per cent and faecal leucocytes in 88 per cent respectively. The extent of the changes correlated with clinical severity. INTERPRETATION & CONCLUSION: This study showed the presence of RBCs and faecal leucocytes in stools of patients of cholera caused by V. cholerae 01 and 0139 which indicates some inflammatory changes in the gut mucosa. Further study is required to elucidate the inflammatory mechanism involved in the underlying process(es).Item Distribution of phage type of Vibrio cholerae O1 biotype ElTor in Indian scenario (1991-98).(1999-06-24) Sarkar, B L; Roy, M K; Chakrabarti, A K; Niyogi, S KDuring the period 1991-98, distribution of biotype, serotype and phage type of V. cholerae O1 strains isolated from different parts of the country and referred to the National Institute of Cholera and Enteric Diseases, Calcutta were studied. Of the 8101 strains received, 5613 (69.2%) were subjected to phage typing. All these strains belonged to the biotype ElTor and Ogawa was the predominant serotype (96.08%). The strains were clustered into only two types--types 2 and 4 and around 10 per cent strains remained untypable. However, using the new scheme, all these strains were found to be typable and 8 major types were recognized of which type number 27 was the predominant type (66.12%). The distribution of a common type throughout the country suggests that a particular clone of V. cholerae O1 is probably circulating all over India. A constant monitoring through phage typing is necessary to observe the emergence of any new clone of V. cholerae O1 in India.Item Enteroaggregative Klebsiella pneumoniae in association with childhood diarrhoea.(2000-10-24) Niyogi, S K; Pal, A; Mitra, U; Dutta, PA total of 19 strains of Klebsiella pneumoniae isolated as sole pathogen from children with diarrhoea were used to study their virulence mechanism using different assays. Eith strains of K. pneumoniae exhibited aggregative adherence that was distinct from the stacked brick enteroaggregative pattern shown by Escherichia coli. The study suggests the presence of a new virulence mechanism in the pathogenesis of Klebsiella-associated diarrhoea.Item Enteropathogens associated with acute diarrhoeal diseases.(1994-04-01) Niyogi, S K; Saha, M R; De, S PItem Epidemiological, microbiological & electron microscopic study of a cholera outbreak in a Kolkata slum community.(2006-01-29) Sur, Dipika; Sarkar, B L; Manna, B; Deen, J; Datta, S; Niyogi, S K; Ghosh, A N; Deb, A; Kanungo, S; Palit, A; Bhattacharya, S KBACKGROUND & OBJECTIVE: Epidemics of cholera caused by Vibrio cholerae O1 or O139 have been reported from different parts of India. Factors such as unsafe water supply, poor environmental sanitation, indiscriminate defaecation and lack of personal hygiene are mainly responsible for continued transmission of this disease. We report here epidemiological and microbiological findings of a localized outbreak of cholera, which occurred during March and April 2004 in the eastern part of Kolkata city. METHODS: The affected slum area has a population of 4409, predominantly muslims. Patients suffering from acute watery diarrhoea attended the health outposts organized by National Institute of Cholera and Enteric Diseases, Kolkata and International Vaccine Institute, South Korea as part of a routine surveillance programme at the locality as well as the emergency medical camp organized by the Kolkata Municipal Corporation. Stool and water samples were collected and tested for diarrhoeagenic pathogens in the laboratory. Bacteriophages specific for V. cholerae were isolates and studied electron microscopically for morphology. RESULTS: A total of 89 diarrhoea cases were reported giving an attack rate of 2 per cent. V. cholerae O1 biotype ElTor, serotype Ogawa was isolated as a sole pathogen from 15 (15.8%) of 89 stool samples screened. Water samples (2 from tube wells, 3 from municipal taps and 1 from well) showed presence of coliform bacilli with high MPN (Most Probable Number) count. Bacteriophages specific to V. cholerae were isolated from 2 of 6 water samples examined. A leakage was detected in the main pipeline supplying drinking water to that area. INTERPRETATION & CONCLUSION: The outbreak was caused by V. cholerae O1 (Ogawa) biotype ElTor. The presence of phages in the water samples was an additional indicator for V. cholerae contamination in this community. Occurrences of such outbreaks support vaccination against cholera as an alternative strategy.Item Epidemiology of HIV infection among brothel-based sex workers in Kolkata, India.(2005-09-03) Sarkar, K; Bal, B; Mukherjee, R; Niyogi, S K; Saha, M K; Bhattacharya, S KA cross-sectional study was carried out during January-June 2004 to assess the status of HIV infection among brothel-based sex workers in Kolkata city, India. Six hundred and twenty-two sex workers, selected from six brothels, were included in the study to assess their HIV status, and 362 sex workers, a subset of the above population, were interviewed to study their risk behaviour and practices. Blood samples were collected from each sex worker for testing HIV by an unlinked anonymous method. The prevalence of HIV infection was 9.6%, but was much higher among younger sex workers aged 20 years or less (27.7%) compared to the older age group (8.4%). This difference was statistically significant, indicating an association of younger ages with HIV infection [p = 0.006 and odds ratio (OR) = 4.18; (95% confidence interval (CI) 1.2-13.8)]. HIV was not associated with duration of sex work, average number of clients entertained per day, condom use, practice of sex during menstruation, pre-coital examination of penis for visible ulcer/discharge, suffering from sexually transmitted infections, and entertaining clients outside the brothel. There was a big gap between the reported and the evaluated condom use by sex workers. The results suggest that there is a need to develop suitable HIV intervention strategies, considering the socioeconomic and cultural aspects of city sex workers, with a provision for continuous monitoring and evaluation.Item Etiological spectrum of acute diarrhoea in hospitalised patients in Calcutta.(1985-10-01) Sen, D; Saha, M R; Nair, G B; Das, P; Niyogi, S K; De, S P; Bhattacharya, S K; Datta, P; Dutta, D; Pal, S CItem Frequency of isolation of toxigenic Clostridium difficile from healthy adults.(1997-12-24) Niyogi, S K; Dutta, D; Bhattacharya, M K; Bhattacharya, S KAn attempt was made to isolate Clostridium difficile from 129 faecal specimens from 87 young and 42 elderly healthy adults. C.difficile was isolated using bacterial culture from 7 (5.4%) specimens and the frequency of isolation of toxigenic C. difficile as detected by cytotoxin (tissue culture) assay was 1.1 per cent and 2.4 per cent in healthy young and elderly adults respectively. The carrier rate of toxigenic C. difficile amongst healthy adults is relatively low in this part of our country.Item Isolation of a fluoroquinolone resistant Shigella dysenteriae 1 strain from Calcutta.(1997-12-24) Chunder, N; Bhattacharya, S K; Biswas, D; Niyogi, S K; Kumar, RFourteen strains of Shigella spp. were isolated from patients aged 5-12 yr, hospitalized with dysentery during 1995-1996. The strains isolated were Shigella dysenteriae 1, S. flexneri and S.sonnei. All but one of the 14 strains were sensitive to ciprofloxacin and norfloxacin. The MIC of both the fluoroquinolones was 15 micrograms/ml for the resistant S.dysenteriae 1 strain (NRM4). Therefore, the careful use of antimicrobials is required for therapy of Shigellosis.Item Multi-drug resistant non-typhoidal Salmonella spp. associated with acute diarrhoeal disease.(1999-12-04) Niyogi, S K; Dutta, D; Bhattacharya, M K; Bhattacharya, S KThe prevalence of different serotypes of non-typhoidal Salmonella spp. among patients suffering from acute diarrhoea admitted to the Infectious Diseases Hospital, Calcutta was investigated. The predominant serogroup was C and Salmonella infantis was the major serotype isolated followed by S. worthington, S. enteritidis, S. typhimurium, S. weltevereden and S. newport. All the Salmonella strains were isolated from adults. Multidrug resistance to various antimicrobial agents was observed in 37.5 per cent of the strains. All the strains were sensitive to ciprofloxacin, norfloxacin and gentamycin.Item Newer bacterial pathogens in relation to acute diarrhoeal diseases--an overview.(1996-05-01) Niyogi, S K; De, S PItem An outbreak of acute diarrhoeal disease amongst tribal population in Tripura.(1993-07-01) Niyogi, S K; Sircar, B K; Sarkar, B L; De, S P; Deb, B CA massive outbreak of acute diarrhoeal diseases occurred during March-April, 1992 in the north district of Tripura. Investigation of the outbreak revealed Vibrio cholerae 01 biotype ElT or as the main etiologic agent in 50 per cent of patients. The outbreak which started amongst the tribal population might have spread due to prevailing illiteracy, poverty, low personal and domestic hygiene and vulnerable water sources (chhara water).