1
|
Comprehensive assessment of nutritional and functional status of patients with ulcerative colitis and their impact on quality of life. Indian J Gastroenterol 2024; 43:254-263. [PMID: 38396280 DOI: 10.1007/s12664-024-01539-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/22/2024] [Indexed: 02/25/2024]
Abstract
INTRODUCTION Patients with ulcerative colitis (UC) are likely to have poor nutritional intake and increased gut losses. This study was designed to study the prevalence and predictors of nutritional deficiencies in patients with UC and their impact on the quality of life (QOL). METHODS A prospective study was conducted among consenting patients with UC (cases) and healthy relatives of the cases (controls) visiting a university teaching hospital. They were assessed for clinical, demographic, endoscopic (Mayo score) and histological profile (Robart's score). They were assessed for the presence of macronutrient and micronutrient deficiency, anthropometry, functional status (muscle strength by dynamometer and sit-to-stand test) and the quality of life (short inflammatory bowel disease questionnaire [SIBDQ]). A SIBDQ score of ≤ 50 was considered poor QOL. RESULTS We studied 126 cases and 57 healthy controls (age [mean ± SD] 37.7 ± 13.2 years vs. 34.40 ± 11.05 years; [p = 0.10] females [38.1% vs. 38.7%]; p = 0.94). Cases more often were underweight (28% vs. 3.5%; p < 0.001), had low mid arm circumference (45% vs. 12%; p < 0.0001), lower functional status in the form of weaker hand grip strength (67% vs. 45.6%; p = 0.007) and weaker lower limb strength (80% vs. 42%; p < 0.0001). Cases more often had the evidence of macronutrient deficiencies: total serum protein deficiency (31% vs. 3.5%; p < 0.0001), serum albumin deficiency (25.4% vs. 0.00%; p < 0.0001) and cholesterol deficiency (63% vs. 28%; p < 0.0001). Micronutrient deficiencies were highly prevalent among cases: calcium (44%), phosphate (21%), magnesium (11%), zinc (76%), iron (87%), folate (16%), vitamin B12 (10%) and vitamin D (81%). Most cases had a poor quality of life (85/126; 67.5%). Factors associated with poor QOL were low hemoglobin, serum albumin, zinc and vitamin D levels and histologically active disease. On multi-variate analysis, low vitamin D levels (odds ratio [OR] = 6.1; 95% confidence interval [CI]: 1.9-19.7) and histologically active disease (OR = 4.0; 95% CI: 1.6-9.9) were identified as independent predictors of poor QOL. CONCLUSIONS Macronutrient deficiency, micronutrient deficiency, lower functional status and poorer QOL are highly prevalent among patients with UC. The independent predictors of poor QOL were histologically active disease and low serum vitamin D levels. Identifying and correcting the deficiencies may help in improving the QOL of patients with UC.
Collapse
|
2
|
Resveratrol restores the level of key inflammatory cytokines and RANKL/OPG ratio in the femur of rat osteoporosis model. J Women Aging 2018; 31:540-552. [PMID: 30239309 DOI: 10.1080/08952841.2018.1522126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Resveratrol's effect on bone mineral density (BMD) and expression of cytokines in ovariectomized rats (postmenopausal osteoporosis model) was studied. The study was conducted on 3-month-old Sprague-Dawley rats that were (a) sham-operated, (b) ovariectomized, (c) ovariectomized and treated with β-estradiol (487.5 µg/kg weight/day), and (d) ovariectomized and treated with resveratrol (625 µg/Kg body weight/day). The treatment was for 4 weeks. After sacrifice BMD and gene expression (RANKL, OPG, IL-23, and IL-17A, IL-1β, and TNFα) were measured in tibia and femur respectively. Resveratrol could restore RANKL/OPG ratio, slightly increase BMD, and moderately but significantly reduce IL-23, IL-17A, IL-1β, and TNF-α cytokine expression levels.
Collapse
|
3
|
Resveratrol regulates body weight in healthy and ovariectomized rats. Nutr Metab (Lond) 2017; 14:30. [PMID: 28413432 PMCID: PMC5391549 DOI: 10.1186/s12986-017-0183-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/30/2017] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE The elevated body weight in post-menopausal state attributes to the reduced estrogen levels which is alleviated by resveratrol (RES) but its role in control rats is not well understood. The main objective of the study was to explore the effects of RES on the body weight of ovariectomized (OVX) female rats with controls and to relate their biochemical parameters. METHODS Female Wistar rats weighing 200-300 g underwent bilateral ovariectomy (OVX) and were fed soya free diet (n = 8 rats per group). In all groups: (Control, Control + Resveratrol, OVX and OVX + Resveratrol) resveratrol was administered orally at a dose of 5 mg/kg/day for 1 month. Glucose and other biochemical parameters were examined. RESULTS Significant reduction in the gain of body weight was observed in the control rats treated with resveratrol. Ovariectomy caused an escalation in gain of body weight due to loss of estrogen which was brought down with resveratrol. There was a slight dip in the blood glucose levels after resveratrol treatment. CONCLUSION Resveratrol significantly reduced the gain of body weight in the control rats and in OVX rats showing its antiobesogenic effects.
Collapse
|
4
|
Telomere mean length in patients with diabetic retinopathy. Sci Rep 2015; 5:18368. [PMID: 26670612 PMCID: PMC4680942 DOI: 10.1038/srep18368] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/16/2015] [Indexed: 01/01/2023] Open
Abstract
Telomere regression has been shown to be associated with several complex disorders like diabetes mellitus, cancer, cataract etc. Diabetic retinopathy develops as a complication of chronic hyperglycemia leading to increased oxidative stress that may potentially lead to shortening of telomeres. We sought to determine whether there is any association between telomere mean length (TML) of peripheral blood monocytes with the presence and severity of diabetic retinopathy. The study involved 120 subjects, comprising 27 non-insulin dependent diabetes mellitus (NIDDM) without any diabetic retinopathy (NDR), 45 NIDDM subjects with non-proliferative diabetic retinopathy (NPDR), 12 NIDDM subjects with proliferative diabetic retinopathy (PDR) and 36 healthy controls. Determination of TML of the study subjects was performed by Southern hybridization using telomere probe. Among the biochemical parameters, HBA1c showed a negative correlation with shortened telomeres in the PDR subjects. However, telomere length was positively correlated with high density lipo protein (HDL) in the control subjects. The control group had significantly greater TML as compared to the rest of the groups and the NDR subjects with NPDR and PDR had substantially decreased TML than the NIDDM subjects without retinopathy.
Collapse
|
5
|
Safety and immunogenicity of a live oral recombinant cholera vaccine VA1.4: a randomized, placebo controlled trial in healthy adults in a cholera endemic area in Kolkata, India. PLoS One 2014; 9:e99381. [PMID: 24983989 PMCID: PMC4077646 DOI: 10.1371/journal.pone.0099381] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/08/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND A live oral cholera vaccine VA 1.4 developed from a non-toxigenic Vibrio cholerae O1 El Tor strain using ctxB gene insertion was further developed into a clinical product following cGMP and was evaluated in a double-blind randomized placebo controlled parallel group two arm trial with allocation ratio of 1∶1 for safety and immunogenicity in men and women aged 18-60 years from Kolkata, India. METHOD A lyophilized dose of 1.9×109 CFU (n = 44) or a placebo (n = 43) reconstituted with a diluent was administered within 5 minutes of drinking 100 ml of a buffer solution made of sodium bicarbonate and ascorbic acid and a second dose on day 14. RESULT The vaccine did not elicit any diarrhea related adverse events. Other adverse events were rare, mild and similar in two groups. One subject in the vaccine group excreted the vaccine strain on the second day after first dose. The proportion of participants who seroconverted (i.e. had 4-folds or higher rise in reciprocal titre) in the vaccine group were 65.9% (95% CI: 50.1%-79.5%) at both 7 days (i.e. after 1st dose) and 21 days (i.e. after 2nd dose). None of the placebo recipients seroconverted. Anti-cholera toxin antibody was detected in very few recipients of the vaccine. CONCLUSION This study demonstrates that VA 1.4 at a single dose of 1.9×109 is safe and immunogenic in adults from a cholera endemic region. No additional benefit after two doses was seen. TRIAL REGISTRATION Clinical Trials Registry-India, National Institute of Medical Statistics (Indian Council of Medical Research) CTRI/2012/04/002582.
Collapse
|
6
|
Abstract
Rhizopus oryzae is the most frequent causative agent of zygomycosis. Although zygomycosis causes considerable morbidity and mortality in immunocompromised patients, the epidemiology of the disease is not well studied and no standard molecular typing method has been described for any of the causative agents. Here we describe a multilocus microsatellite typing (MLMT) method for R. oryzae. R. oryzae genome sequences were downloaded from the Fungal Genome Initiative database (Broad Institute). The intergenic regions and ORFs of approximately 5.7 Mb were screened for repeat regions with the help of the online repeat search tool Repeat Masker. Of the 30 microsatellite loci identified, 3 microsatellites [RO3, (CCT)(n); RO4, (TA)(n); and RO8, (GAA)(GGA)(n)] were selected after validation of the ability to amplify them and their size variation in 8 randomly selected clinical isolates of R. oryzae. Nucleotide sequence analysis of these loci demonstrated polymorphism in the microsatellite repeat number. The capabilities of these microsatellite loci were assessed for strain differentiation on 30 clinical isolates, based on fragment size determination in an automated capillary electrophoresis using fluorescent labelled primers. These three polymorphic microsatellite loci were found to have good discriminatory power (D) (RO3, D=0.846; RO4, D=0.747; RO8, D=0.742; with a combined D=0.986) and stability for seven subcultures. It was also confirmed that the MLMT method may be applied to both R. oryzae and Rhizopus delemar (a proposed new species), although MLMT analysis could not differentiate them into two clusters. The MLMT system, described here for what is believed to be the first time for a zygomycotic fungus, holds promise as a powerful tool for the strain typing of R. oryzae.
Collapse
|
7
|
Decreased myocardial expression of dystrophin and titin mRNA and protein in dilated cardiomyopathy: possibly an adverse effect of TNF-alpha. J Clin Immunol 2010; 30:520-30. [PMID: 20373002 DOI: 10.1007/s10875-010-9388-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 03/12/2010] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND AIMS While the molecular basis of dilated cardiomyopathy (DCM) remains uncertain, concrete evidence is emerging that sarcomeric and cytoskeleton gene expression of myocardium isolated from failing versus non-failing patients differ dramatically. The central aim to this work was to find out the possible role of dystrophin and titin along with the TNF-alpha in the pathogenesis of cardiomyopathy. PATIENTS AND METHODS mRNA levels and protein expression of a cytoskeletal protein, dystrophin and a sarcomeric protein, titin in endomyocardial biopsies of DCM patients were examined using RT-PCR and immunohistochemistry, respectively. Further, we examined the effect of TNF-alpha on myocardial expression of titin and dystrophin in vitro in rat cardiac myoblast cell line (H9c2). RESULTS We observed significantly decreased mRNA and protein levels of dystrophin and titin in endomyocardial biopsy of DCM patients as compared to control group. The decreased levels of these proteins correlated with the severity of the disease. Plasma levels of both TNF-alpha and its soluble receptors TNFR1 and TNFR2 were found to be significantly higher in patients as compared to control group. Treatment of H9c2 cells with TNF-alpha resulted in a dose- and time-dependent decrease in mRNA levels of dystrophin and titin. Pretreatment of these cells with MG132, an inhibitor of nuclear factor kappa B (NF-kappaB) pathway, abolished TNF-alpha-induced reduction in mRNA levels of dystrophin and titin. CONCLUSION Our results suggest that reduced expression of dystrophin and titin is associated with the pathophysiology of DCM, and TNF-alpha may modulate the expression of these proteins via NF-kappaB pathway.
Collapse
|
8
|
Randomized placebo controlled human volunteer trial of a live oral cholera vaccine VA1.3 for safety and immune response. Vaccine 2009; 27:4850-6. [DOI: 10.1016/j.vaccine.2009.05.065] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 05/11/2009] [Accepted: 05/21/2009] [Indexed: 11/24/2022]
|
9
|
Expression of toxin co-regulated pilus subunit A (TCPA) of Vibrio cholerae and its immunogenic epitopes fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum). PLANT CELL REPORTS 2008; 27:307-318. [PMID: 17962948 DOI: 10.1007/s00299-007-0464-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 09/30/2007] [Indexed: 05/25/2023]
Abstract
For protection against cholera, it is important to develop efficient vaccine capable of inducing anti-toxin as well as anti-colonizing immunity against Vibrio cholerae infections. Earlier, expression of cholera toxin B subunit (CTB) in tomato was reported by us. In the present investigation, toxin co-regulated pilus subunit A (TCPA), earlier reported to be an antigen capable of providing anti-colonization immunity, has been expressed in tomato. Further, to generate more potent combinatorial antigens, nucleotides encoding P4 or P6 epitope of TCPA were fused to cholera toxin B subunit gene (ctxB) and expressed in tomato. Presence of transgenes in the tomato genome was confirmed by PCR and expression of genes was confirmed at transcript and protein level. TCPA, chimeric CTB-P4 and CTB-P6 proteins were also expressed in E. coli. TCPA protein expressed in E. coli was purified to generate anti-TCPA antibodies in rabbit. Immunoblot and G(M1)-ELISA verified the synthesis and assembly of pentameric chimeric proteins in fruit tissue of transgenic tomato plants. The chimeric protein CTB-P4 and CTB-P6 accumulated up to 0.17 and 0.096% of total soluble protein (TSP), respectively, in tomato fruits. Whereas expression of TCPA, CTB-P4 and CTB-P6 in E. coli can be utilized for development of conventional vaccine, expression of these antigens which can provide both anti-toxin as well as anti-colonization immunity, has been demonstrated in plants, in a form which is potentially capable of inducing immune response against cholera infection.
Collapse
|
10
|
Class I integrons and SXT elements in El Tor strains isolated before and after 1992 Vibrio cholerae O139 outbreak, Calcutta, India. Emerg Infect Dis 2003; 9:500-2. [PMID: 12702236 PMCID: PMC2957977 DOI: 10.3201/eid0904.020317] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We examined the distribution of class I integrons and SXT elements in Vibrio cholerae O1 El Tor strains, isolated in Calcutta, India, before and after the V. cholerae O139 outbreak in 1992. Class I integrons, with aadA1 gene cassette, were detected primarily in the pre-O139 strains; the SXT element was found mainly in the post-O139 strains.
Collapse
|
11
|
Occurrence of antibiotic resistance gene cassettes aac(6')-Ib, dfrA5, dfrA12, and ereA2 in class I integrons in non-O1, non-O139 Vibrio cholerae strains in India. Antimicrob Agents Chemother 2002; 46:2948-55. [PMID: 12183252 PMCID: PMC395331 DOI: 10.1128/aac.46.9.2948-2955.2002] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Molecular mechanisms of multidrug resistance in Vibrio cholerae belonging to non-O1, non-O139 serogroups isolated during 1997 to 1998 in Calcutta, India, were investigated. Out of the 94 strains examined, 22 strains were found to have class I integrons. The gene cassettes identified were dfrA1, dfrA15, dfrA5, and dfrA12 for trimethoprim; aac(6')-Ib for amikacin and tobramycin; aadA1 and aadA2 for streptomycin and spectinomycin; and ereA2 for erythromycin resistance. To our knowledge, this is the first report of the presence of dfrA5, dfrA12, aac(6')-Ib, and ereA2 cassettes in class I integrons of V. cholerae. Forty-three of 94 strains also had plasmids, and out of these, 14 contained both class I integrons and plasmids. Pulsed-field gel electrophoresis followed by Southern hybridization revealed that in the 14 plasmid-bearing strains, class I integrons resided either on chromosomes, on plasmids, or on both. Our results indicated that besides class I integrons and plasmids, a conjugative transposon element, SXT, possibly contributed to the multiple antibiotic resistance.
Collapse
|
12
|
Comparison of antibiogram, virulence genes, ribotypes and DNA fingerprints of Vibrio cholerae of matching serogroups isolated from hospitalised diarrhoea cases and from the environment during 1997-1998 in Calcutta, India. J Med Microbiol 2001; 50:879-888. [PMID: 11599737 DOI: 10.1099/0022-1317-50-10-879] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study identified 17 matching serogroups of Vibrio cholerae belonging to serogroups other than O1 and O139 isolated from human cases and from the environment during a concurrent clinical and environmental study conducted in Calcutta, a cholera endemic area. Isolates within these matching serogroups were compared by various phenotypic and genotypic traits to determine if the environment was the source of the organisms associated with the disease. Clinical strains of V. cholerae were resistant to a greater number of drugs and exhibited multi-drug resistance compared with their environmental counterparts. Except for the presence of the genes for the El Tor haemolysin and the regulatory element ToxR in most of the strains of V. cholerae examined, non-O1, non-O139 V. cholerae strains lacked most of the other known virulence traits associated with toxigenic V. cholerae O1 or O139. Restriction fragment-length polymorphism of virulence-associated genes, ribotypes and DNA fingerprints of strains of matched serogroups showed considerable diversity, although some gene polymorphisms and ribotypes of a few strains of different serogroups were similar. It is concluded that despite sharing the same serogroup, environmental and clinical isolates were genetically heterogeneous and were of different lineages.
Collapse
|
13
|
Construction of a recombinant live oral vaccine from a non-toxigenic strain of Vibrio cholerae O1 serotype inaba biotype E1 Tor and assessment of its reactogenicity and immunogenicity in the rabbit model. Immunol Lett 1999; 68:219-27. [PMID: 10424424 DOI: 10.1016/s0165-2478(99)00076-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The disease cholera is an important cause of mortality in many developing countries. Though it can be controlled through improved sanitation, this goal is not easily attainable in many countries. Development of an efficacious vaccine offers the best immediate solution. A new oral candidate vaccine has been constructed from a non-toxigenic strain of Vibrio cholerae E1 Tor, Inaba, which is not only devoid of the cholera toxin (CT) virulence cassette but also is completely non-reactogenic in rabbit ileal loop assay. The strain, however, had toxR and tcpA genes. Through a series of manipulations, the ctxB gene of V. cholerae, responsible for the production of the 'B' subunit of the cholera toxin (CTB) was introduced into the cryptic hemolysin locus of the strain. The resulting strain, named vaccine attempt 1.3 (VA1.3), was found to be able to produce copious amounts of CTB. In the RITARD model this strain was found to be non-reactogenic and provided full protection against the challenge doses of both V. cholerae O1, classical and E1 Tor. In the immunized rabbit it invoked significant levels of anti-bacterial and anti-toxin immunity.
Collapse
|
14
|
Molecular analysis of non-O1, non-O139 Vibrio cholerae associated with an unusual upsurge in the incidence of cholera-like disease in Calcutta, India. J Clin Microbiol 1998; 36:756-63. [PMID: 9508308 PMCID: PMC104621 DOI: 10.1128/jcm.36.3.756-763.1998] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
There was an inexplicable upsurge in the incidence of non-O1, non-O139 Vibrio cholerae among hospitalized patients admitted to the Infectious Diseases Hospital, Calcutta, India, between February and March 1996. Of the 18 strains of V. cholerae isolated during this period, 15 belonged to the non-O1, non-O139 serogroups (4 belonged to O144, 3 belonged to O11, 1 each belonged to O6, O8, O12, O19, O39, and O58, and 2 strains could not be typed), 2 belonged to the O139 serogroup, and 1 belonged to the O1 serogroup. Cell-free culture supernatants of 13 representative non-O1, non-O139 V. cholerae strains evoked a distinct cytotoxic effect on CHO and HeLa cells, and the strains examined produced the nonmembrane-damaging cytotoxin. By several PCR assays, it was determined that none of the non-O1, non-O139 strains were positive for the ctxA, zot, ace, and tcpA genes and for the genes representing the heat-labile toxin, heat-stable toxin, and verotoxin of Escherichia coli and the various variants of these genes. Studies on the clonality of non-O1, non-O139 V. cholerae strains by restriction fragment length polymorphism (RFLP) analysis of rRNA genes and of other genes (hlyA, hlyU, hlx, toxR, and attRS1) and by pulsed-field gel electrophoresis (PFGE) collectively indicate that the upsurge which occurred in February and March 1996 was caused by strains belonging to different clones. Overall, there was an excellent correlation between the results of ribotyping, RFLP analysis of various genes, and PFGE, with strains belonging to a particular serogroup showing nearly identical restriction patterns and PFGE profiles. It is clear from this study that some serogroups of V. cholerae can cause diarrhea by a mechanism quite different from that of toxigenic V. cholerae O1 and O139, and we have proposed the nomenclature of enteropathogenic V. cholerae to include these serogroups.
Collapse
|
15
|
Strategies for production of a potential candidate vaccine for cholera. Indian J Med Res 1996; 104:60-75. [PMID: 8783508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
First attempt at cholera vaccination was made by Jaime Ferran in 1884. Since then, a variety of strategies and methods have been evolved to create a safe, efficacious vaccine against cholera. For the first few years emphasis was on the development of parenteral vaccines. However, as a result of accumulation of a tremendous amount of knowledge, not only on Vibrio cholerae-the causative agent, but also on its interaction with the host, emphasis has shifted towards the development of oral vaccines. Two such vaccines, one killed, a whole cell/B subunit combination vaccine and the other a live attenuated one, have shown promise. The combination vaccine in its present state of development confers only a transient protection in young children, while the live attenuated one produces adverse reaction. To combat these, various strategies are being evolved. In one attempt, a potential candidate vaccine strain has been constructed from a non-reactogenic clinical isolate of V. cholerae, which is devoid of all known major virulence genes and is also a good colonizer. In animal studies this construct has shown considerable promise. This review discusses the various strategies that have been employed so far in the quest for an ideal cholera vaccine.
Collapse
|