Potential of the plant Thespesia populnea in the treatment of ulcerative colitis

CONTEXT

Thespesia populnea Sol. ex Correa (Malvaceae), an indigenous tree species in India, is of interest to researchers because traditionally its heartwood is used in the treatment of ulcer and colic pain.

OBJECTIVE

To validate its folk use in the treatment of ulcerative colitis (UC).

MATERIALS AND METHODS

Mice were administered intrarectal DNBS and then treated with different plant extracts (100 and 200 mg/kg), 30 min before and 24 and 48 h after DNBS infusion. Colonic mucosal injury was assessed by macroscopic and histological examination. Furthermore, malondialdehyde (MDA), myeloperoxidase (MPO), protease, and hemoglobin (Hb) contents were measured in tissue and blood samples.

RESULTS

Administration of various extracts ameliorated macroscopic and microscopic scores which were altered due to DNBS treatment in mice. Hb concentration in blood was restored significantly by the aqueous extract to 17.20 ± 0.5, which was reduced to 13.80 ± 0.5 after treatment with DNBS. MDA level was increased to 10.82 nm/mg and 10.25 nm/ml in tissue and blood, respectively, due to DNBS treatment which was reduced to 2.69 nm/mg and 3.59 nm/ml in tissue and blood, respectively, by aqueous extract treatment. Similarly, MPO level was increased to 412 U/mg and 404 U/ml in tissue and blood, respectively, which was significantly reduced to 205 U/mg and 219 U/ml in tissue and blood, respectively, by aqueous extract treatment. Aqueous extract significantly reduced protease activity which was markedly increased in DNBS-treated animals.

DISCUSSION AND CONCLUSION

Aqueous extract of heartwood of T. populnea is effective in the treatment of UC.

Antinociceptive activity of Sesbania sesban (Linn) wood extracts, a preliminary study

The wood of the plant Sesbania sesban, is reported to have antinociceptive activity. To validate its folk use in the treatment of pain, wood was extracted successively with petroleum ether, chloroform, ethyl acetate, ethanol, and water to produce respective extracts. The extracts (50 and 100 mg/kg, ip) were screened for antinociceptive activity using hot plate test and acetic acid-induced writhing test in mice. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose-dependent activity in both the tests. In order to find out the involvement of opioid receptors, effect of naloxone (1 mg/kg, sc) on the action of extracts was checked in hot plate test. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose dependant antinociceptive activity. The antinociceptive action of the extracts was blocked by naloxone, suggesting involvement of opioid receptors in the action.

Report: quantitative estimation of beta-sitosterol, lupeol, quercetin and quercetin glycosides from leaflets of Soymida febrifuga using HPTLC technique

Soymida febrifuga (Meliaceae) dried leaflets (10 gm) were extracted with petroleum ether. Unsaponifiable matter quantitatively used for sample preparation, labeled as SF-U. Another 10 gm leaflet powder was extracted with methanol and quantitatively used for sample preparation labeled as SF-A. Sample and standard solution were dosage on three different plates and developed in its respective mobile phase plates were scanned using TLC scanner III and estimated using integration software CATs 4.05. Calculations for percentage were done considering standard and sample R(f), AUC and dilution factor. Estimation of beta Sitosterol, Lupeol, Quercetin, Quercetin-3-O-galactoside, Quercetin-3-O-xyloside and Quercetin-3-O-rutinoside were determined as 0.02146% w/w, 0.0377% w/w, 0.4079% w/w, 0.6197% w/w, 2.974% w/w and 3.235% w/w respectively with the help of HPLC techniques.

Survival, nodulation and N2 fixation ability of root nodule bacteria under different nutritional regimes

Eleven strains of Rhizobium and five strains of Bradyrhizobium were examined for their viability as well nodulation and nitrogen fixation ability after storage under different conditions for two years. The storage conditions comprised lateritic soil, lateritic soil plus 1% mannitol, lateritic soil plus 0.1% yeast extract, lateritic soil plus 1% mannitol and 0.1% yeast extract, organic soil, organic soil plus 1% mannitol, organic soil plus 0.1% yeast extract, organic soil plus 1% mannitol and 0.1% yeast extract, and sterile distilled water. All the slow growing strains showed better viability than the fast growing strains in any of these conditions. The survived strains maintained their nodulation ability about 50-60% after one year and 40-50% after two years of preservation as compared to control, but the nodulation ability in sterile distilled water was very poor. Acetylene reduction activity in the nodules was found to be 70-90% and 50-70% after 12 and 24 months of preservation, respectively. The strains retained their phenotypic characters like antibiotic resistance and salt tolerance up to their highest survivability in respective nutritional condition.

Anxiolytic and antiemetic activity of Zingiber officinale

The benzene fraction (BF) of a petroleum ether extract of dried rhizomes of ginger, which contained anticonvulsant principle(s), was screened for anxiolytic and antiemetic activity. Motor coordination was not affected by BF per se, but diazepam-induced motor incoordination was potentiated. Animals treated with BF showed decreased occupancy in the closed arm of the elevated plus maze suggesting the presence of anxiolytic principles in the BF. BF also blocked lithium sulphate-induced conditioned place aversion indicating antiemetic activity. These findings suggest that the fraction (BF) possesses anticonvulsant, anxiolytic and antiemetic activity.

Antimicrobial activity of extracts of Terminalia catappa root

The effect against bacteria of petroleum ether (60-80 degrees C), chloroform and methanolic extract of dried root of Terminalia catappa Linn. (combrataceae) was employed by cup plate agar diffusion method. The chloroform extract showed prominent antimicrobial activity against S. aureus and E. coli as compared to other tested microorganisms, while petroleum ether extract was devoid of antimicrobial activity. The methanolic: extract exhibited MIC of 0.065 mg/ml against E. coli. and chloroform extract exhibited MIC of 0.4 mg/ml against S. aureus The chloroform has well as methanolic extracts showed good antimicrobial activity against Gram positive and Gram negative microorganisms.

Nootropic and anxiolytic activity of saponins of Albizzia lebbeck leaves

The effect of saponin containing, n-butanolic fraction (BF), extracted from dried leaves of Albizzia lebbeck, was studied on cognitive behavior and anxiety in albino mice. The elevated plus maze was used for assessment of both nootropic and anxiolytic activity. The nootropic activity was evaluated by recording the effect of BF (0, 10, 25, and 50 mg/kg) on the transfer latency, whereas anxiolytic activity was assessed by studying its effect on the duration of occupancy in the closed arm. Results showed significant improvement in the retention ability of the normal and amnesic mice as compared to their respective controls. Animals treated with BF (25 mg/kg) spent more time in the open arm in a dose-dependent manner. The BF was without any significant effect on motor coordination. However, it significantly inhibited passivity and hypothermia induced by baclofen (10 mg/kg), a GABA(B) agonist. The data emanated in the present study suggests involvement of gamma-aminobutyric acid (GABA) in the nootropic and anxiolytic activity of saponins obtained from A. lebbeck.

Characterisation and identification of broad spectrum antibiotic producing Streptomyces hygroscopicus D 1.5

A streptomycete strain D1.5 capable of producing broad spectrum antiobiotic was isolated from soil. The morphological, cultural, physiological and biochemical characters were studied, compared to known species and identified as Streptmoyces hygroscopicus. Antibiotic activity of the strain was tested against both Gram positive and negative bacteria as well as fungi. It exhibited complete resistance to beta-lactum antibiotics.

Multi-drug resistant typhoid fever in hospitalised children. Clinical, bacteriological and epidemiological profiles

A total of 592 children with clinical diagnosis of typhoid fever admitted to the Dr B. C. Roy Memorial Hospital for Children, Calcutta, India during the period between February 1990 and January 1992, were screened for Salmonella typhi by blood culture. S. typhi was isolated from 221 (37.3%) cases. The majority of the strains (92.3%) showed multi-drug resistant (MDR). They were resistant to chloramphenicol, ampicillin, tetracycline and trimethoprim-sulphamethoxazole. However, all the strains were uniformly (100%) susceptible to gentamicin, amikacin, furazolidone, norfloxacin and ciprofloxacin. Minimum inhibitory concentration of the antimicrobial agents against the resistant strains of S. typhi ranged between 200 and > 1600 micrograms/ml. Phage type 0 was most frequently encountered. The rate of isolation of S. typhi was more or less the same in all the pediatric age groups. The majority of the cases came from lower socio-economic classes with poor personal hygiene. Fever was the main presenting feature in all the cases. Other associated features of the MDR typhoid fever cases, who were uncomplicated during admission, were headache (36.0%), chill and rigor (23.2%), diarrhea (37.2%), anorexia (26.2%), vomiting (23.8%), cough (18.0%) and abdominal pain (19.8%). Hepatosplenomegaly was present in 42.4% cases. However, complications were less frequently encountered among the MDR typhoid fever cases who were uncomplicated during admission and treated as in-patients. Fourteen bacteriologically-confirmed MDR typhoid fever cases had jaundice and another 18 cases had an abnormal state of consciousness during admission. Four (2.0%) bacteriologically-confirmed MDR typhoid fever patients died during the period of observation.

Alpha-amylase production in lactose medium by Bacillus circulans ACB

Alpha-amylase production by Bacillus circulans ACB was studied in various cultural conditions. During nutrient optimisation, it was found that 2% lactose can be utilized by the strain as source of carbon providing better growth and enzyme yields than starch. Ammonium sulfate of the basal medium can be replaced by ammonium nitrate for better growth and alpha-amylase activity. The strain demonstrated significant enhancement in alpha-amylase production when grown at pH 6.6.

New phage typing scheme for Vibrio cholerae O1 biotype El Tor strains

The conventional phage typing scheme proposed by S. Basu and S. Mukerjee (Experientia 24:299-300, 1968) has been used routinely for identification of the strains at the Vibrio Phage Reference Laboratory since 1968. However, because of limitations of this scheme, a new phage typing scheme using five newly isolated phages was incorporated into the conventional scheme. A different definition of routine test dilution (almost confluent lysis) was found to be more useful than the one previously used (confluent lysis). The 1,000 strains tested could be clustered into 27 types with the five new phages. With the new scheme of 10 phages (5 new phages and 5 phages of Basu and Mukerjee), the 1,000 strains could be grouped into 146 types. The new phages were different from each other and also from those of Basu and Mukerjee, as revealed by lytic pattern, electron microscopy, restriction endonuclease digestion, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and antiphage antiserum studies. With the new typing scheme, 99.6% of the strains were typeable. Phage type 115 was the most common and includes 119 (11.9%) of the 1,000 strains tested. Next most common were phage types 142 (9.4%), 143 (7.0%), 104 and 116 (both 5.4%), 3 (5.3%), 5 (4.1%), 4 (3.9%), 24 (2.1%), and 100 (1.7%). The larger number of types would be useful for further classification of the strains for epidemiological purposes. This newly developed scheme is highly applicable to, and could be widely adopted for, phage typing of Vibrio cholerae O1 biotype El Tor strains.

Value of a single Widal test in the diagnosis of typhoid fever

Results of a single Widal test in patients with bacteriologically confirmed typhoid fever (116), clinically suggestive but culture negative fever (170) and non-typhoidal febrile illness (98) and in normal control children (54) were analysed. Positive Widal test (antibody titre against S. typhi O antigen of 1:160) was recorded in 61.2 per cent of patients with bacteriologically confirmed typhoid fever and in 58.8 per cent with culture negative but clinically suggestive typhoid fever. In contrast, the same titre was observed in 10.2 per cent patients with other febrile illnesses of known etiology and in 1.8 per cent of normal children. Differences in the positivity of Widal test in patients with bacteriologically confirmed typhoid fever and clinically suggestive but culture negative fever were highly significant (P < 0.000001) when compared to that of patients with non-typhoidal febrile illnesses and normal controls. High specificity and positive predictive value in 1:160 dilution makes the Widal test acceptable as a diagnostic tool.

Significance of Cryptosporidium as an aetiologic agent of acute diarrhoea in Calcutta: a hospital based study

The significance of Cryptosporidium as a causative agent of acute diarrhoea has been assessed in a year long hospital based study. A significantly higher detection of Cryptosporidium (P < 0.01) was observed in cases as compared to controls. Cryptosporidium was detected alone from 3% of acute diarrhoeal patients and from 5.5% in combination with other enteric pathogens. However, only 1.1% of control subjects were positive for Cryptosporidium. The highest detection rate of Cryptosporidium oocysts was in the first two years of life, in both cases and controls. No sex specific predilection for Cryptosporidium was observed in either the cases or controls.

Biochemical and immunological studies on soluble antigens of Entamoeba histolytica

The soluble antigens of Entamoeba histolytica trophozoites were analysed in detail by biochemical and immunochemical methods. The antigen was highly complex and heterogeneous as revealed by Sephacryl S-300 column chromatography, which showed four distinct fractions. The molecular mass of fractions FI, FII, FIII and FIV was 660, 170, 65 and 13 kDa, respectively. Protein was the major constituent in crude soluble antigen (CSA) and fractions FI and FII (67%, 80% and 90%, respectively). Polysaccharide was predominant in the FIII fraction (59%). Antigenic activity observed after different physico-chemical treatments revealed that CSA and FI antigens were predominantly glycoprotein in nature. However, the antigenicity of FIII antigen was greatly reduced after sodium meta-periodate treatment, whereas no alteration in reactivity was discerned after trypsin treatment. Sodium dodecyl sulphate-polyacryl-amide gel electrophoresis (SDS-PAGE) analysis demonstrated nearly 28 Coomassie blue bands for CSA and 20, 16, 15 and 3 polypeptide bands for the FI, FII, FIII and FIV fractions, respectively. The molecular mass of the polypeptides of these bands ranged from 210 to 20 kDa. Antigenic activity was observed in CSA and in the first three fractions, both in counter immunoelectrophoresis (CIEP) and in enzyme-linked immunosorbent assay (ELISA). However, the highest antigenic activity was noted in fraction FI. Major immunoreactive polypeptides of CSA and FI antigens against whole trophozoite antibody were observed in the 10- to 170-kDa regions. However, major differences in the immunoreactivity of the two antigens were noted at 116 and 14 kDa for FI antigen and at 84, 30 and 20 kDa for CSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of admission weight on neonatal mortality amongst hospitalised neonates in Calcutta

The study was conducted on 785 neonates aged up to 28 days to evaluate the influence of admission weight on mortality. It was observed that there were 200 (25.5%) cases of septicaemia, 134(17.1%) of diarrhoea, 120(15.3%) each of prematurity related conditions and neonatal jaundice, 117(14.9%) of respiratory diseases and 94 (11.9%) cases of convulsion. There were total 182(23.18%) deaths comprising 70(38.5%) from prematurity related conditions, 40(22%) from diarrhoea, 35(19.2%) from respiratory diseases, 26(14.3%) from septicaemia, 8(4.4%) from neonatal jaundice and 3(1.6%) deaths from convulsion. The incidence of deaths among neonates weighing less than 2500 g on admission was 59.2% in diarrhoeal diseases, 53.4% in respiratory diseases and 44.6% in other conditions compared to those of 10%, 8.2% and 7.1% respectively in neonates having admission weight more than 2500 g. The findings are statistically significant. The results of the study indicate that low admission weight should be considered as a predictor of mortality among neonates.

Prevalence of diarrhoeal diseases amongst tribals of Car Nicobar Island, India

In a cross sectional study of total 14514 tribal Nicobarese people of Car Nicobar Island, an union territory of India, situated in Bay of Bengal, morbidity, mortality and treatment practices of diarrhoeal diseases of under-five children were surveyed. The incidence of diarrhoea (0.2 episode/ch.year), Crude death rate (3.6/1000) and IMR (31/1000 live births) were exceedingly low as compared to SouthEast Asian Countries including mainland of India. ORS utilisation rate was high (41%) as compared to the National figure (12.0%). This is the first study of it's kind carried out in this island and amongst the Nicobarese tribe in India. A preliminary study carried out among the mothers of the hospitalised children indicated that protective behaviours like breast feeding, hand washing, use of chlorinated water and proper disposal of stool were regularly being practiced by the community traditionally. An in-depth study on risk factors of diarrhoea in this island can yield useful clue for describing the same.

Detection of specific anti-Giardia antibodies in the serodiagnosis of symptomatic giardiasis

The roles of circulating anti-Giardia IgM and IgG antibodies were assayed by the Enzyme linked immunosorbent assay (ELISA) using axenic Giardia lamblia whole trophozoites as antigen for routine serodiagnosis of Giardia infection. Detection of anti-Giardia IgM antibody was found to be useful in the early detection of symptomatic giardiasis, whereas IgG detection was not, since the latter could not discriminate between present infection and previous exposure. A mean optical density (OD) +/- 2 standard deviation (SD) value of 0.088 at 1:100 serum dilution was found optimal for the detection of anti-Giardia IgM antibodies as it completely separated out the acute Giardia cases from the Giardia-free controls. The same sera did not reveal any marked differences when tested for anti-Giardia IgG antibodies. Detection of IgM antibodies correlated with high sensitivity and specificity (96%) in an evaluation of a large number of sera collected from Giardia cases and controls.

Efficacy of norfloxacin for shigellosis: a double-blind randomised clinical trial

In a double-blind, randomised, clinical trial on 122 adults with acute Shigella dysentery, 60 patients were treated with norfloxacin and 62 with nalidixic acid. Of these, 32 patients in the norfloxacin group and 28 patients in the nalidixic acid group had Shigella in their stool. Patients of the two treatment groups were clinically comparable on admission. No significant differences in clinical responses were observed in the two groups among the Shigella-positive cases, Shigella-negative cases and among the total cases. All isolates of Shigella were susceptible to norfloxacin, whereas 13.8% of the strains were resistant to nalidixic acid.

Shigellosis in children: a prospective hospital based study

From 1985 to 1988, fecal samples of 950 hospitalized children suffering from diarrhea or dysentery were screened for Shigella species using standard methods. Shigella species were isolated as sole pathogen from 192 (20.2%) cases and S. flexneri type 2 was the predominant serotype. Shigella infection was prevalent throughout the year with high isolation rate during the summer and early monsoon months. Shigella strains isolated during the period were resistant to most of the commonly used drugs for the treatment of shigellosis. Nearly 16% of the Shigella strains were also resistant to nalidixic acid. Presence of blood and mucus in stools (dysentery) was the common clinical presentation of shigellosis cases. Malnutrition was associated with longer duration of illness. High cases fatality rate (16.7%) was observed among hospitalized children infected with Shigella.

Screening and identification of antibiotic producing strains of Streptomyces

About 450 actinomycetes were isolated from nearly 100 soil samples collected from different parts of West Bengal. The isolates were screened on the basis of their inhibitory effect against test organisms. Finally two potent antibiotic producers were chosen having maximum inhibitory effect on both gram positive and gram negative test bacteria. On the basis of morphological, structural, physiological and biochemical characters, the two potent antibiotic producers were identified as Streptomyces violaceus-niger and S. antibioticus.

Reassessment of the prevalence of heat-stable enterotoxin (NAG-ST) among environmental Vibrio cholerae non-O1 strains isolated from Calcutta, India, by using a NAG-ST DNA probe

A collection of 521 environmental isolates of Vibrio cholerae which were previously examined by the suckling mouse assay and found to be negative for the heat-stable enterotoxin NAG-ST were reassessed by a recently developed DNA probe for NAG-ST. A total of 12 (2.3%) of the isolates hybridized with the NAG-ST probe. By using a cholera toxin (CT) DNA probe, the CT gene was detected in six of the strains in the collection, although none of the isolates of V. cholerae non-O1 hybridized with both of the toxin probes. All of the NAG-ST and CT probe-positive strains were hemolysin positive. Thirty-fold-concentrated supernatants of the three representative NAG-ST DNA probe-positive V. cholerae non-O1 strains gave positive fluid accumulation ratios in the suckling mouse assay even after heating (100 degrees C for 5 min) and also inhibited the binding of a NAG-ST monoclonal antibody to the bound NAG-ST in a competitive enzyme-linked immunosorbent assay (ELISA). Likewise, all six CT probe-positive V. cholerae non-O1 strains produced in vitro CT when examined by the CT bead ELISA. HindIII digest patterns of chromosomal DNA from the representative NAG-ST gene-positive strains were visually indistinguishable. Between the groups of NAG-ST probe-positive strains examined, there was a variation in the hybridizable fragments, with one group of strains exhibiting a hybridizable fragment similar to that of the NRT 36 reference strain; a smaller HindIII fragment hybridized with the NAG-ST probe in the other group of strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the bead enzyme-linked immunosorbent assay for detection of cholera toxin directly from stool specimens

A highly sensitive bead enzyme-linked immunosorbent assay (bead ELISA) for detection of cholera toxin (CT) was evaluated for direct detection of CT from stool specimens of patients with acute secretory diarrhea. Of the 75 stool samples examined, 59 yielded biochemically, and serologically confirmed strains of Vibrio cholerae O1. The bead ELISA was positive for CT in stool supernatants in 50 (84.7%) of the 59 samples from which V. cholerae O1 was isolated. In addition, the bead ELISA was positive for three stool specimens which were negative by culture. The free CT present in 48 of the 50 stool samples positive by culture for V. cholerae O1 and for CT by bead ELISA was completely absorbed by anti-CT immunoglobulin G. All of the 59 strains of V. cholerae O1 biotype eltor isolated in this study produced in vitro CT. The concentration of CT present in the bead ELISA-positive stool samples ranged between 26 pg/ml and greater than 100 ng/ml. This evaluation study demonstrates that the bead ELISA is a sensitive and simple method for direct detection of CT in nonsterile stool samples, and we recommend routine use of this assay for detection of CT in stool samples and culture supernatants in clinical and reference laboratories.

Comparison of selective media for optimal recovery of Clostridium difficile from diarrhoeal stools

Five 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.

Occurrence of multi-drug resistant Salmonella typhi in Calcutta

Blood and faecal samples were collected from 122 hospitalised patients of Calcútta clinically suspected to have enteric fever, for isolation of S. typhi. It was isolated from 34.4, 4.9 and 4.1 per cent patients by blood culture, stool culture and by both respectively. The in vitro drug susceptibility testing showed that all the isolates were resistant to chloramphenicol, ampicillin and trimethoprim-sulphamethoxazole, but were uniformly susceptible to ciprofloxacin, norfloxacin and furazolidone. In view of the appearance of multi-drug resistant S. typhi in Calcutta, great care should be exercised in the use of newer quinolone derivatives.

Entero-adherent Escherichia coli is an important diarrhoeagenic agent in infants aged below 6 months in Calcutta, India

Escherichia coli adherent to HEp-2 and HeLa cells were isolated from the faeces of 43 (19.7%) of 218 hospitalised infants aged below 6 months with acute diarrhoea. No conventional virulence factors, including enterotoxin production--heat-labile (LT) or heat-stable (ST), the verotoxin (VT) or shiga-like toxin (SLT)--or the invasive phenotype (determined by the Sereny test) could be detected among these isolates. Out of the 43 isolates, 16 (37.2%) were of the known enteropathogenic O:K serogroups--enteropathogenic E. coli (EPEC). The remaining 27 (62.8%) isolates showed different types of adherence to HEp-2 and HeLa cells which was diffuse (40.7%), localised (37.0%), or both (22.3%); they were identified as entero-adherent E. coli (EAEC). The EAEC isolates adhered to HEp-2 and HeLa cells in the presence of mannose, lactose, fucose, galactose, and fetuin, indicating that adhesion was not specific for these sugars or glycoprotein. Haemagglutination and the salt aggregation test (SAT) did not correlate with patterns of adherence. The results of this study indicate that LA-EAEC is an important aetiological agent of acute diarrhoea in infants aged below 6 months in Calcutta.

Serovar, biotype, phage type, toxigenicity & antibiotic susceptibility patterns of Vibrio cholerae isolated during two consecutive cholera seasons (1989-90) in Calcutta

Characteristics of V. cholerae isolated from patients of acute secretory diarrhoea admitted to the Infectious Diseases Hospital, Calcutta during two consecutive cholera seasons (1989 and 1990), with special emphasis on biotyping and toxigenicity, were investigated. The isolation rates of V. cholerae during 1989 and 1990 were 78 and 85.1 per cent respectively, with Inaba serotype dominating in 1989 and Ogawa in 1990. All the V. cholerae 01 strains isolated in this study belonged to biotype Eltor with phage type 4 dominating (48.8%). Most of the strains of V. cholerae were resistant to 10 and 150 micrograms/ml of 0/129 vibriostatic agent. Similarly, majority of the V. cholerae strains were resistant to furazolidone (95.7%), cotrimoxazole (83%) and tetracycline (63.1%) and several resistance patterns were encountered. All the V. cholerae 01 strains examined produced cholera toxin (CT) in amounts ranging between greater than 70 pg/ml and greater than 2.5 ng/ml. In contrast, all but one of the non-01 strains isolated in this study did not produce CT. Further studies are required to elucidate the mechanism involved in the pathogenesis of non-01 V. cholerae mediated diarrhoea.

Taxonomical implications of the emergence of high frequency of occurrence of 2,4-diamino-6,7-diisopropylpteridine-resistant strains of Vibrio cholerae from clinical cases of cholera in Calcutta, India

Of the 110 consecutive isolates of Vibrio cholerae recovered from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India, between July 1989 and October 1990, 90 and 82.7% were resistant to 10 and 150 micrograms of 2,4-diamino-6,7-diisopropylpteridine (O/129), respectively. Additionally, all O/129-resistant strains of V. cholerae were multiply resistant to antimicrobial agents. Except in the cases of four strains, resistance to O/129 was invariably linked with resistance to co-trimoxazole. Although O/129 susceptibility is still a useful test for Vibrio identification, resistance of V. cholerae to this compound in local areas might occasionally pose a problem.

Occurrence of multi-resistant Salmonella typhimurium infection in a pediatric hospital at Calcutta

Salmonella typhimurium was isolated from 55 (15.9%) of the 347 hospitalized diarrheal children and 14 (11.1%) of the 126 non-diarrheal controls. All the 98 asymptomatic children attending hospital outpatients were negative. Six (3.7%) of the 162 samples of different categories examined from the hospital were positive for S. typhimurium. Finger washing of one female food handler, feces of two cats of the wards, surface of wash basin, lavatory seat and shelf yielded positive isolations. In vitro antibiotic sensitivity testing showed majority of the strains were resistant against commonly used antimicrobial agents while they were uniformly sensitive to norfloxacin and ciprofloxacin. The present study points to cross-infection by multi-resistant S. typhimurium strains in the hospital wards.

Virulence traits of Aeromonas strains in relation to species and source of isolation

The virulence traits of 39 well-defined clinical (29 strains) and environmental (10 strains) isolates of Aeromonas (16 A. hydrophila, 12 A. sobria and 11 A. caviae) were examined by a variety of assays to delineate differences, if any, in the enteropathogenic potential in relation to species and the source of isolation. The distribution of enterotoxin (ent), cytotoxin (cyt) and haemolysin (hae) producing strains of Aeromonas did not correlate to species and source of isolation. The extracellular virulence phenotype Ent+ Cyt+ Hae+ was the most common one among all the three species although unique phenotypes associated prominently with either A. hydrophila or A. sobria were also discernible. None of the cytotoxin or haemolysin producing strains hybridized with the vt1/vt2 or the tdh/trh gene probes, respectively, indicating that these two factors of Aeromonas were distinct. Haemagglutination of human O group erythrocytes was not related to the source of isolation or production of enterotoxin, cytotoxin or haemolysin but appeared to be related to species. The strains which did not exhibit cell-associated haemagglutination belonged to either A. hydrophila or A. caviae. Haemagglutination unaffected by fucose, mannose and galactose was the dominant inhibition pattern exhibited mainly by the clinical haemagglutinating strains of the three species. Only one clinical strain of A. caviae showed a diffuse pattern of adherence to HeLa cells. Expression of the 5 bacterial enzymes by strains of Aeromonas did not fall into a readily discernible pattern in relation to species or source of isolation. From this study, it is clear that the mechanism of the pathogenesis of Aeromonas is a multifactorial one.

Campylobacter species as a cause of diarrhoea in children in Calcutta

From 1985 to 1988, 857 children (aged between 1 day and 60 months) admitted to hospital with diarrhoea and 241 controls (aged between 5 days and 60 months) were examined for campylobacters and other enteric pathogens by means of conventional methods. The difference between the isolation rates of campylobacters in those cases in which no other enteric pathogen was found (4.8%) and controls (6.2%) was not significant (P greater than 0.05). Strains of Campylobacter jejuni/coli were isolated throughout the year with higher isolation rates during the summer and monsoon months. Mixed infections were very common. Watery diarrhoea (97.6% cases) was the most common clinical presentation of patients found to be infected solely by C. jejuni/coli. Most patients infected with campylobacters were mildly to moderately dehydrated. Biotype I of C. jejuni and C. coli was the dominant biotype associated with cases and controls. All strains of C. jejuni/coli, regardless of their source, were found to be sensitive to erythromycin. From this study, it appears that enteric infections with campylobacters among children in Calcutta are common but often asymptomatic.

Detection of cholera toxin by a highly sensitive bead-enzyme linked immunosorbent assay

A bead-enzyme linked immunosorbent assay (bead-ELISA) for detection and quantification of cholera toxin (CT) in broth cultures of Vibrio cholerae O1 has been developed. Under optimal buffer and pH conditions the bead-ELISA could consistently detect 40 pg/ml of CT. None of the ingredients of commonly used media for in vitro culture of V. cholerae O1 hindered the performance of the bead-ELISA. Evaluation of the sensitivity and specificity of the bead-ELISA against the commonly used reversed passive latex agglutination (RPLA) test for detection of CT was performed using a collection of 239 strains of V. cholerae O1 (including both biotypes and serotypes) which were examined by a gene probe encoding for the A1 subunit of CT. Although both the assays were highly specific, the bead-ELISA was more sensitive than the RPLA. Quantification of CT by the bead-ELISA revealed that the concentration of CT produced by the strains of V. cholerae O1 which were negative by the RPLA was lower than 1 ng/ml and therefore below the minimum detection ability of the RPLA. The bead-ELISA is a simple, specific and highly sensitive assay for routine detection of CT and is recommended for routine use in clinical microbiology laboratories.

Randomized clinical trial of norfloxacin for shigellosis

In a randomized clinical trial, norfloxacin was compared with nalidixic acid in the treatment of acute invasive diarrhea, with particular reference to shigellosis in adults. Of 104 patients studied, 40 were positive for Shigella in stool cultures, of which 22 received norfloxacin and 18 received nalidixic acid. The patients in these two groups were comparable on admission. In the treatment of culture-positive shigellosis cases, the responses to therapy with both drugs were similar, except that the duration of fever, anorexia, and abdominal pain were less in those who received norfloxacin. Norfloxacin appeared to be superior to nalidixic acid in the treatment of shigellosis cases caused by Shigella strains resistant to nalidixic acid.

Polymerase chain reaction for detection of the cholera enterotoxin operon of Vibrio cholerae

We report a set of oligonucleotide primers and amplification conditions for the polymerase chain reaction to detect the ctx operon of Vibrio cholerae. The results of this assay on strains of V. cholerae and related organisms were identical with those obtained by the DNA colony hybridization test with the polynucleotide probe. The detection limit of this system was 1 pg of chromosomal DNA or broth culture containing three viable cells. The polymerase chain reaction method could directly detect the ctx operon sequences in rice-water stool samples from patients with cholera.

Acute diarrhoeal diseases in infants aged below six months in hospital in Calcutta, India: an aetiological study

In a prospective 2-year study, 218 infants aged less than 6 months admitted to a children's hospital in Calcutta with acute diarrhoea and 102 infants (control group) from the out-patient department of the same hospital with similar age, sex and socio-economic composition as the diarrhoea patients, were concurrently investigated for enteropathogenic agents in the faeces. Enteropathogenic Escherichia coli, enterotoxigenic E. coli, and enteroadherent E. coli constituted the 3 types of diarrhoeagenic E. coli most frequently (57.4%) detected in the faeces of diarrhoeic infants either as a sole pathogen or in association with other microorganisms. Other enteropathogens detected were rotavirus, Campylobacter jejuni, Salmonella typhimurium and Aeromonas hydrophila. The frequency of detection of various aetiological agents was 72%; in the remaining 28% an infectious aetiology could not be determined. The study suggests that diarrhoeagenic E. coli plays a major role in the causation of acute diarrhoea in infants aged under 6 months in Calcutta.

A polyclonal-monoclonal antibody based sensitive sandwich enzyme linked immunosorbent assay for specific detection of cholera toxin

A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for specific detection of prototype cholera toxin (CT) elaborated by Vibrio cholerae serovar O1 has been developed. The use of a high affinity monoclonal antibody (MAb) for capturing of CT epitopes permitted a high efficiency. Using this ELISA, we sought in vitro production of CT from clinical strains of V. cholerae O1, Non-O1 and from LT-producing E. coli. All culture supernatants of V. cholerae O1 were positive for CT whereas V. cholerae non-O1 and LT producing E. coli were found negative for CT. This ELISA will be particularly useful in specifically designed studies where detection of CT and not of related labile toxins is mandatory.

Clinical manifestation of Clostridium difficile enteritis in Calcutta

233 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.

Descriptive epidemiology of intravenous heroin users--a new risk group for transmission of HIV in India

India is considered to have a low incidence of HIV infection so far. Nevertheless, an epidemic of HIV infection has been reported recently among intra-venous drug users (IVDUs) in Manipur, a north-eastern state of India, bordering Myanmar (Burma). This report describes the epidemiology of intravenous drug abuse in the state of Manipur. Four hundred and fifty IVDUs were interviewed. Their age (median 24 years) and sex patterns (95% male) differ from those reported from western countries. It is estimated that there may be approximately 15,000 such addicts in a population of 1.8 million and 50% of them could be positive for HIV. Knowledge of AIDS and its transmission is significantly higher among the addicts than non-addict controls. Free availability of heroin was found to be the major factor responsible for the high rate of addiction. It is presumed that two other neighbouring States which are well-connected to Manipur and also have a common border with Myanmar (part of the 'Golden Triangle') may have a similar problem with HIV infection.

An operational study on implementation of oral rehydration therapy in a rural community of West Bengal, India

An operational study of a 3-tier strategy for implementation of oral rehydration therapy (ORT) was conducted in a block of West Bengal with 216,825 population through the existing health services facilities. All the grassroot level, health workers including their supervisors at various levels were trained regarding the management of patients of diarrhoea with mild to moderate degree of dehydration, by ORT. Another block in the same district with similar demographic features where this intervention was not provided served as control. After 22 months of observation, it was evident that despite adequate training, the performance of Community Health Guides (CHGs) and Anganwadi Workers (AWWs) was not encouraging because of the low utilization of both home available fluids (32.0%) and oral rehydration solution (18.0%) in the study area. Similarly, diarrhoea associated mortality could not be reduced significantly. Lack of motivation and failure to maintain sustained level of skill by the CHGs and AWWs constitute the major bottlenecks for the successful implementation of the programme at the community level.

Prospective hospital based study on persistent diarrhoea

A total of 383 children aged less than 5 years suffering from acute watery diarrhoea or dysentery were studied in hospital to determine the rate of persistent diarrhoea. Altogether 335 (87.5%) recovered within 13 days. Only in 48 (12.5%) did the diarrhoea continue for 14 days or more, and they were considered as having persistent diarrhoea. Children aged between 7 and 18 months had a significantly increased incidence of persistent diarrhoea. Children suffering from grade II-IV malnutrition constituted the majority (70.8%) of those with persistent diarrhoea. Higher rates of isolation of Shigella flexneri, Shigella dysenteriae 1, and Salmonella typhimurium were observed among patients with persistent diarrhoea than in those with diarrhoea of shorter duration. No positive correlations were observed between the clinical severity of disease at hospital admission and measles. Breast fed babies were not prone to persistent diarrhoea.

Oral rehydration solution containing 90 millimol sodium is safe and useful in treating diarrhoea in severely malnourished children

The safety and efficacy of standard oral glucose-electrolyte solution, containing 90 mmol of sodium per litre, was evaluated in the treatment of dehydrating diarrhoea among severely malnourished (marasmic) children. A total of 81 male children aged between 6 and 48 months were studied; 41 were in the malnourished group (study group: less than 60% of Harvard Standard weight-for-age) and 40 were in the well-nourished group (control group: 80% or more Harvard Standard weight-for-age). Children of both groups could be rehydrated with standard oral rehydration solution (ORS) without encountering any clinical or biochemical complications. The results of this study lend support to the World Health Organization's concept of a unified formula of ORS for the treatment of all cases of acute diarrhoea, including severely malnourished children.

Toxin production by atypical strains of Vibrio cholerae E1 Tor under different cultural conditions

It was observed that at 37 degrees C under in vitro conditions, aerobic culture filtrates of a few strains of Vibrio cholerae biotype El Tor isolated from diarrhoeal cases produced a minute amount of toxin which failed to elicit a positive ileal loop reaction like toxigenic strains. Thus, these strains showed an atypical behaviour in their toxin producing ability. At 25 degrees C and 30 degrees C under aerobic cultural conditions enhanced toxin production was noticed in toxigenic strains, but these temperatures did not affect the toxigenicity of the atypical strains. The atypical Vibrio cholerae El Tor strains exhibited enhanced toxin production only at 37 degrees C under anaerobic conditions and the amount of toxin produced was akin to those of the toxigenic strains. In comparison to aerobic conditions, growth was observed to be comparatively lower under anaerobiosis both in the toxigenic and atpyical V. cholerae strains. Moreover, in contrast to the toxigenic strains, the toxin did not remain membrane-bound in these atypical strains at 37 degrees C and aerobic cultural conditions.

Blood group and shigellosis

A study on the distribution of ABO blood groups was carried out on 85 patients with clinically and bacteriologically proven shigellosis. A significant association (P less than 0.01) of blood group B was observed with shigellosis cases in comparison to controls from whom no Shigella species or other enteropathogen could be isolated. Patients with isoagglutinin B or those who possess blood group B antigen may be at a relatively increased risk of shigellosis.