Publications

diversity in the arrangement of the ctx prophages in classical strains of vibrio cholerae o1.	this study reports the results of a molecular analysis of the ctx prophages in classical biotype strains of vibrio cholerae o1 of clinical origin isolated between 1970 and 1979 in india. all strains were sensitive to group iv classical phage and polymyxin b but resistant to group 5 el tor phage. these phenotypic traits are consistent to that exhibited by the classical biotype. pcr studies reconfirmed their biotype assignment and showed the presence of intact ctx prophages and the presence of the ...	2000	10612727
inorganic polyphosphate is required for motility of bacterial pathogens.	the ppk gene encodes polyphosphate kinase (ppk), the principal enzyme in many bacteria responsible for the synthesis of inorganic polyphosphate (polyp) from atp. a null mutation in the ppk gene of six bacterial pathogens renders them greatly impaired in motility on semisolid agar plates; this defect can be corrected by the introduction of ppk gene in trans. in view of the fact that the motility of pathogens is essential to invade and establish systemic infections in host cells, this impairment i ...	2000	10613886
affinity purification and partial characterization of the zonulin/zonula occludens toxin (zot) receptor from human brain.	the intercellular tight junctions (tjs) of endothelial cells represent the limiting structure for the permeability of the blood-brain barrier (bbb). although the bbb has been recognized as being the interface between the bloodstream and the brain, little is known about its regulation. zonulin and its prokaryotic analogue, zonula occludens toxin (zot) elaborated by vibrio cholerae, both modulate intercellular tjs by binding to a specific surface receptor with subsequent activation of an intracell ...	2000	10617135
development and evaluation of a phage typing scheme for vibrio cholerae o139.	the scenario of cholera that existed previously changed in 1992 and 1993 with the emergence of toxigenic vibrio cholerae o139 in india. the genesis of the new serogroup formed the impetus to search for o139 phages in and around the country. a total of five newly isolated phages lytic to v. cholerae o139 strains were used for the development of this phage typing scheme. these phages differed from each other and also differed from the existing o1 phages in their lytic patterns, morphologies, restr ...	2000	10618061
pulsed-field gel electrophoresis-based molecular comparison of vibrio cholerae o1 isolates from domestic and imported cases of cholera in japan.	sixty-seven vibrio cholerae o1 el tor isolates (36 domestic and 31 imported) were classified into 19 subtypes by noti- and sfii-digested pulsed-field gel electrophoresis. twenty-five of 36 domestic and 4 imported isolates were assigned to a noti-a1-sfii-a1 subtype, suggesting that this pulse type is widely distributed in asia and japan.	2000	10618132
genetic diversity of vibrio cholerae in chesapeake bay determined by amplified fragment length polymorphism fingerprinting.	vibrio cholerae is indigenous to the aquatic environment, and serotype non-o1 strains are readily isolated from coastal waters. however, in comparison with intensive studies of the o1 group, relatively little effort has been made to analyze the population structure and molecular evolution of non-o1 v. cholerae. in this study, high-resolution genomic dna fingerprinting, amplified fragment length polymorphism (aflp), was used to characterize the temporal and spatial genetic diversity of 67 v. chol ...	2000	10618215
genetic diversity of clinical and environmental isolates of vibrio cholerae determined by amplified fragment length polymorphism fingerprinting.	vibrio cholerae, the causative agent of major epidemics of diarrheal disease in bangladesh, south america, southeastern asia, and africa, was isolated from clinical samples and from aquatic environments during and between epidemics over the past 20 years. to determine the evolutionary relationships and molecular diversity of these strains, in order to understand sources, origin, and epidemiology, a novel dna fingerprinting technique, amplified fragment length polymorphism (aflp), was employed. t ...	2000	10618216
the type 4 prepilin peptidases comprise a novel family of aspartic acid proteases.	type 4 prepilins or prepilin-like-proteins are secreted by a wide range of bacterial species and are required for a variety of functions including type 4 pilus formation, toxin and other enzyme secretion, gene transfer, and biofilm formation. a distinctive feature of these proteins is the presence of a specialized leader peptide that is cleaved off by a cognate membrane-bound type 4 prepilin peptidase (tfpp) during the process of secretion. in this report we show that the tfpps represent a novel ...	2000	10625704
a region of the transmembrane regulatory protein toxr that tethers the transcriptional activation domain to the cytoplasmic membrane displays wide divergence among vibrio species.	the virulence regulatory protein toxr of vibrio cholerae is unique in that it contains a cytoplasmic dna-binding-transcriptional activation domain, a transmembrane domain, and a periplasmic domain. although toxr and other transmembrane transcriptional activators have been discovered in other bacteria, little is known about their mechanism of activation. utilizing degenerate oligonucleotides and pcr, we have amplified internal toxr gene sequences from seven vibrio and photobacterium species and s ...	2000	10629204
molecular cloning and transcriptional regulation of ompt, a toxr-repressed gene in vibrio cholerae.	in pathogenic vibrio cholerae, at least 17 genes are co-ordinately regulated by toxr. most of these genes, including those that encode cholera toxin (ct), toxin co-regulated pilus (tcp), accessory colonization factor (acf) and ompu, are positively regulated. ompt is the only identified protein under negative regulation of toxr. to understand the molecular mechanism by which toxr represses ompt expression, we cloned ompt and characterized the ompt promoter and its interaction with toxr. sequence ...	2000	10632889
two regions of epsl involved in species-specific protein-protein interactions with epse and epsm of the general secretion pathway in vibrio cholerae.	extracellular secretion of proteins via the type ii or general secretion pathway in gram-negative bacteria requires the assistance of at least 12 gene products that are thought to form a complex apparatus through which secreted proteins are translocated. although this apparatus is specifically required only for the outer membrane translocation step during transport across the bacterial cell envelope, it is believed to span both membranes. the epse, epsl, and epsm proteins of the type ii apparatu ...	2000	10633109
an endogenous retrovirus and exogenous scrapie in a mouse model of aging.	as we enter the post-genomic era, there is an increasing need for accurate methods of identifying host and pathogen factors that contribute to bacterial, viral and fungal disease. in addition, there is a requirement for fast and precise techniques to evaluate potential therapies for the prevention of infectious diseases. the development of useful and cost-effective model systems will be crucial in advancing our knowledge of all aspects of microbial pathogenesis. in this series, we will learn of ...	2000	10637643
cloning and characterization of vuua, a gene encoding the vibrio vulnificus ferric vulnibactin receptor.	the ability of vibrio vulnificus to acquire iron from the host has been shown to correlate with virulence. many iron transport genes are regulated by iron, and in v. vulnificus, transcriptional regulation by iron depends on the fur gene. the n-terminal amino acid sequence of a 72-kda iron-regulated outer membrane protein purified from a v. vulnificus fur mutant had 53% homology with the first 15 amino acids of the mature protein of the vibrio cholerae vibriobactin receptor, viua. in this report, ...	2000	10639413
molecular characterization of a new variant of toxin-coregulated pilus protein (tcpa) in a toxigenic non-o1/non-o139 strain of vibrio cholerae.	a toxigenic non-o1/non-o139 strain of vibrio cholerae (10259) was found to contain a new variant of the toxin-coregulated pilus (tcp) protein gene (tcpa) as determined by pcr and southern hybridization experiments. nucleotide sequence analysis data of the new tcpa gene in strain 10259 (o53) showed it to be about 74 and 72% identical to those of o1 classical and el tor biotype strains, respectively. the predicted amino acid sequence of the 10259 tcpa protein shared about 81 and 78% identity with ...	2000	10639469
optimizing the germfree mouse model for in vivo evaluation of oral vibrio cholerae vaccine and vector strains.	the germfree mouse model of vibrio cholerae infection can be used to judge immune responses to v. cholerae vaccine and vector strains. in the original model, a single oral inoculation was administered on day 0, a booster oral inoculation was administered on day 14, and immune responses were analyzed with samples collected on day 28. unfortunately, immune responses in this model frequently were low level, and interanimal variability occurred. in order to improve this model, we evaluated various p ...	2000	10639476
use of lambda phage s and r gene products in an inducible lysis system for vibrio cholerae- and salmonella enterica serovar typhimurium-based dna vaccine delivery systems.	novel methods for adapting dna vaccine technology to the prevention of mucosal diseases are greatly needed. here we show that regulated expression of phage lambda lysis genes s and r causes dramatic lysis of both vibrio cholerae and salmonella enterica serovar typhimurium cells with concomitant release of plasmid dna into the surrounding media. we also used single and double dnase mutant strains to show that secreted v. cholerae dnases can adversely affect the integrity of dna molecules released ...	2000	10639478
climate and infectious disease: use of remote sensing for detection of vibrio cholerae by indirect measurement.	it has long been known that cholera outbreaks can be initiated when vibrio cholerae, the bacterium that causes cholera, is present in drinking water in sufficient numbers to constitute an infective dose, if ingested by humans. outbreaks associated with drinking or bathing in unpurified river or brackish water may directly or indirectly depend on such conditions as water temperature, nutrient concentration, and plankton production that may be favorable for growth and reproduction of the bacterium ...	2000	10677480
in vitro and in vivo analyses of constitutive and in vivo-induced promoters in attenuated vaccine and vector strains of vibrio cholerae.	the optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. we therefore introduced plasmids expressing the b subunit of cholera toxin (ctxb) under the control of a number of promoters into v. cholerae vaccine strain peru2. we evaluated the tac promoter, which is constitutively expressed in v. cholerae, as well as the ...	2000	10678922
iha: a novel escherichia coli o157:h7 adherence-conferring molecule encoded on a recently acquired chromosomal island of conserved structure.	the mechanisms used by shiga toxin (stx)-producing escherichia coli to adhere to epithelial cells are incompletely understood. two cosmids from an e. coli o157:h7 dna library contain an adherence-conferring chromosomal gene encoding a protein similar to iron-regulated gene a (irga) of vibrio cholerae (m. b. goldberg, s. a. boyko, j. r. butterton, j. a. stoebner, s. m. payne, and s. b. calderwood, mol. microbiol. 6:2407-2418, 1992). we have termed the product of this gene the irga homologue adhes ...	2000	10678953
the virulence regulatory protein toxr mediates enhanced bile resistance in vibrio cholerae and other pathogenic vibrio species.	the transmembrane regulatory protein toxr is required for expression of virulence factors in the human diarrheal pathogen vibrio cholerae, including cholera toxin (ct) and the toxin coregulated pilus (tcp). toxr is necessary for transcription of the gene encoding a second regulatory protein, toxt, which is the direct transcriptional activator of ct and tcp genes. however, toxr, independent of toxt, directly activates and represses transcription of the outer membrane porins ompu and ompt, respect ...	2000	10678965
infectious ctxphi and the vibrio pathogenicity island prophage in vibrio mimicus: evidence for recent horizontal transfer between v. mimicus and v. cholerae.	vibrio mimicus differs from vibrio cholerae in a number of genotypic and phenotypic traits but like v. cholerae can give rise to diarrheal disease. we examined clinical isolates of v. mimicus for the presence of ctxphi, the lysogenic filamentous bacteriophage that carries the cholera toxin genes in epidemic v. cholerae strains. four v. mimicus isolates were found to contain complete copies of ctxphi. southern blot analyses revealed that v. mimicus strain pt5 contains two ctx prophages integrated ...	2000	10678967
cytotoxic cell vacuolating activity from vibrio cholerae hemolysin.	a vibrio cholerae cytotoxin, designated vcvac, was found to cause vacuolation in vero cells. it was originally detected in the pathogenic o1 amazonia variant of v. cholerae and later shown to be produced in environmental strains and some el tor strains. comparison of vcvac production in various strains suggested that hemolysin was responsible for the vacuolating phenotype. genetic experiments established a firm correlation between vacuolation and hemolysin production. the mammalian cell vacuolat ...	2000	10678992
novel approaches to monitor bacterial gene expression in infected tissue and host.	elucidating the complex and dynamic host-microbe interactions during infection requires, among other things, detailed knowledge of microbial gene expression in vivo. recently, advances in fluorescence and bioluminescence detection techniques, as well as recombinase-based in vivo expression technology, have rendered monitoring virulence gene expression in vivo a feasible task. these techniques have been adapted by several laboratories to study the spatial and temporal patterns of virulence gene e ...	2000	10679414
acetyl-coa synthetase from the amitochondriate eukaryote giardia lamblia belongs to the newly recognized superfamily of acyl-coa synthetases (nucleoside diphosphate-forming).	the gene coding for the acetyl-coa synthetase (adp-forming) from the amitochondriate eukaryote giardia lamblia has been expressed in escherichia coli. the recombinant enzyme exhibited the same substrate specificity as the native enzyme, utilizing acetyl-coa and adenine nucleotides as preferred substrates and less efficiently, propionyl- and succinyl-coa. n- and c-terminal parts of the g. lamblia acetyl-coa synthetase sequence were found to be homologous to the alpha- and beta-subunits, respectiv ...	2000	10681568
vibrio cholerae in victoria.		2000	10682025
gene replacement in gram-negative bacteria: the pmaksac vectors.		2000	10683723
evaluation of antibacterial activity of asparagus racemosus willd. root.	different concentrations (50, 100, 150 microg/ml) of the methanol extract of the roots of asparagus racemosus willd. showed considerable in vitro antibacterial efficacy against escherichia coli, shigella dysenteriae, shigella sonnei, shigella flexneri, vibrio cholerae, salmonella typhi, salmonella typhimurium, pseudomonas putida, bacillus subtilis and staphylococcus aureus. the effects produced by the methanol extract were compared with chloramphenicol.	2000	10685109
epidemic cholera in guinea-bissau: the challenge of preventing deaths in rural west africa.	an epidemiologic investigation was conducted to identify factors associated with cholera mortality in a rural african setting and interventions likely to prevent deaths in future epidemics.	2000	10689208
double-blind, randomized, placebo controlled pilot study evaluating efficacy and reactogenicity of an oral etec b-subunit-inactivated whole cell vaccine against travelers' diarrhea (preliminary report).	diarrhea caused by enterotoxigenic e.coli (etec) is an important health problem in developing countries and in travelers to these areas. in previous trials formulations of etec vaccines containing the b-subunit of cholera toxin, which is antigenically similar to the heat labile enterotoxin of etec, and the most prevalent colonization factor antigens of etec, were shown to stimulate relevant mucosal immune responses in volunteers from sweden and egypt.	2000	10689236
phosphorylation of the flagellar regulatory protein flrc is necessary for vibrio cholerae motility and enhanced colonization.	the human pathogen vibrio cholerae specifically expresses virulence factors within the host, including cholera toxin (ct) and the toxin co-regulated pilus (tcp), which allow it to colonize the intestine and cause disease. v. cholerae is a highly motile organism by virtue of a polar flagellum, and motility has been inferred to be an important aspect of virulence, yet the exact role of motility in pathogenesis has remained undefined. the two-component regulatory system flrb/flrc is required for po ...	2000	10692152
delineation of pilin domains required for bacterial association into microcolonies and intestinal colonization by vibrio cholerae.	the toxin-co-regulated pilus (tcp), a type 4 pilus that is expressed by epidemic strains of vibrio cholerae o1 and o139, is required for colonization of the human intestine. the tcp structure is assembled as a polymer of repeating subunits of tcpa pilin that form long fibres, which laterally associate into bundles. previous passive immunization studies have suggested that the c-terminal region of tcpa is exposed on the surface of the pilus fibre and has a critical role in mediating the colonizat ...	2000	10692166
vibrio cholerae vibf is required for vibriobactin synthesis and is a member of the family of nonribosomal peptide synthetases.	a 7.5-kbp fragment of chromosomal dna downstream of the vibrio cholerae vibriobactin outer membrane receptor, viua, and the vibriobactin utilization gene, viub, was recovered from a sau3a lambda library of o395 chromosomal dna. by analogy with the genetic organization of the escherichia coli enterobactin gene cluster, in which the enterobactin biosynthetic and transport genes lie adjacent to the enterobactin outer membrane receptor, fepa, and the utilization gene, fes, the cloned dna was examine ...	2000	10692380
ctxphi infection of vibrio cholerae requires the tolqra gene products.	ctxphi is a lysogenic filamentous bacteriophage that encodes cholera toxin. filamentous phages that infect escherichia coli require both a pilus and the products of tolqra in order to enter host cells. we have previously shown that toxin-coregulated pilus (tcp), a type iv pilus that is an essential vibrio cholerae intestinal colonization factor, serves as a receptor for ctxphi. to test whether ctxphi also depends upon tol gene products to infect v. cholerae, we identified and inactivated the v. ...	2000	10692381
neonatal septicemia caused by vibrio cholerae o:139.		2000	10694008
lowering of the electric potential on the membrane as a possible signal modulating the expression of virulence factors in vibrio cholerae.		2000	10652109
pandemic spread of an o3:k6 clone of vibrio parahaemolyticus and emergence of related strains evidenced by arbitrarily primed pcr and toxrs sequence analyses.	vibrio parahaemolyticus o3:k6 strains responsible for the increase in the number of cases of diarrhea in calcutta, india, beginning in february 1996 and those isolated from southeast asian travelers beginning in 1995 were shown to belong to a unique clone characterized by possession of the tdh gene but not the trh gene and by unique arbitrarily primed pcr (ap-pcr) profiles (j. okuda, m. ishibashi, e. hayakawa, t. nishino, y. takeda, a. k. mukhopadhyay, s. garg, s. k. bhattacharya, g. b. nair, an ...	2000	10655349
helicobacter pylori and epidemic vibrio cholerae o1 infection in peru.	in a cross-sectional study of the 1991 peruvian cholera epidemic, vibrio cholerae o1 infection was associated with helicobacter pylori infection, particularly in young children. these data support the hypothesis that hypochlorhydria induced by h. pylori is important in the pathogenesis of diarrhoeal disease.	2000	10665561
genomic diversity among vibrio cholerae o139 strains isolated in bangladesh and india between 1992 and 1998.	in order to assess the extent of genomic diversity among vibrio cholerae o139 strains, restriction fragment length polymorphisms in two genetic loci, rrn and ctx, were studied. analysis of 144 strains isolated from different regions of bangladesh and india between 1992 and 1998 revealed the presence of at least six distinct ribotypes (b-i through b-vi) of which three were new ribotypes, and one of these was represented by a nontoxigenic o139 strain. strains of ribotypes b-i through b-v shared 11 ...	2000	10713434
isolation and characterization of vich, encoding a new pleiotropic regulator in vibrio cholerae.	during the last decade, the hns gene and its product, the h-ns protein, have been extensively studied in escherichia coli. h-ns-like proteins seem to be widespread in gram-negative bacteria. however, unlike in e. coli and in salmonella enterica serovar typhimurium, little is known about their role in the physiology of those organisms. in this report, we describe the isolation of vich, an hns-like gene in vibrio cholerae, the etiological agent of cholera. this gene was isolated from a v. cholerae ...	2000	10715012
mobilization of plasmids and chromosomal dna mediated by the sxt element, a constin found in vibrio cholerae o139.	the vibrio cholerae sxt element encodes resistance to multiple antibiotics and is a conjugative, self-transmissible, and chromosomally integrating element (a constin). excision and self-transfer of the sxt element require an element-encoded integrase. we now report that the sxt element can also mobilize the plasmids rsf1010 and clodf13 in trans as well as chromosomal dna in an hfr-like manner. sxt element-mediated mobilization of plasmids and chromosomal dna, unlike its self-transfer, is not dep ...	2000	10715015
food handlers and foodborne diseases: knowledge, attitudes, and reported behavior in italy.	the purpose of this study was to evaluate knowledge, attitudes, and behavior concerning foodborne diseases and food safety issues among food handlers in italy. face-to-face interviews were conducted within a random sample using a structured questionnaire. of the 411 food handlers responding, 48.7% knew the main foodborne pathogens (salmonella spp., staphylococcus aureus, vibrio cholerae or other vibrio spp., clostridium botulinum, hepatitis a virus), and this knowledge was significantly greater ...	2000	10716569
[bacteremia by vibrio cholera no 01, two cases].		2000	10721567
the role of probiotic cultures in the control of gastrointestinal health.	the use of probiotics to enhance intestinal health has been proposed for many years. probiotics are traditionally defined as viable microorganisms that have a beneficial effect in the prevention and treatment of specific pathologic conditions when they are ingested. there is a relatively large volume of literature that supports the use of probiotics to prevent or treat intestinal disorders. however, the scientific basis of probiotic use has been firmly established only recently, and sound clinic ...	2000	10721914
molecular evidence of clonality amongst vibrio cholerae o1 biotype el tor during an outbreak in malaysia.	forty-three clinical strains of v. cholerae o1 biotype e1 tor were isolated between 3 may and 10 june 1998 during an outbreak in the metropolitan area of kuala lumpur and its suburbs. with the exception of three inaba strains that were restricted to three members of a family, all the others belonged to the ogawa serotype. the strains were analysed for clonality using ribotyping and pulsed-field gel electrophoresis (pfge). two ribotypes, v/b21a and b27, were identified among 40 ogawa isolates usi ...	2000	10722126
cell vacuolation, a manifestation of the el tor hemolysin of vibrio cholerae.	culture supernatants of nontoxigenic nonepidemic clinical strains of vibrio cholerae belonging to diverse serogroups were found to induce vacuolation of nonconfluent hela cells. the vacuoles became prominent 18 h after introduction of culture supernatant, and vacuolated cells survived for 48 h and then died. only a fraction of the vacuolated cells took up neutral red dye, implying that there were differences in the vacuolar microenvironment. further tests showed that the factor responsible for v ...	2000	10722584
mutations in the extracellular protein secretion pathway genes (eps) interfere with rugose polysaccharide production in and motility of vibrio cholerae.	vibrio cholerae is the causal organism of the diarrheal disease cholera. the rugose variant of v. cholerae is associated with the secretion of an exopolysaccharide. the rugose polysaccharide has been shown to confer increased resistance to a variety of agents, such as chlorine, bioacids, and oxidative and osmotic stresses. it also promotes biofilm formation, thereby increasing the survival of the bacteria in the aquatic environments. here we show that the extracellular protein secretion system ( ...	2000	10722590
high-efficiency passive elution of bacterial lipopolysaccharides from polyacrylamide gels.	we recently described a method for recovering polyacrylamide-gel-separated bacterial lipopolysaccharides (lps) based on the sensitive on-gel lps detection (1-10 ng/band) with zinc-imidazole followed by passive elution from 32 microm average size gel microparticles into water. with this procedure, the recovery of rough- or semismooth-type lps after 3 h elution is about 70-80%, while that of smooth lps is only about 10%. here we evaluated whether a simple replacement of water with other eluents wo ...	2000	10726753
antibodies (igg) to lipopolysaccharide of vibrio cholerae o1 mediate protection through inhibition of intestinal adherence and colonisation in a mouse model.	an antiserum raised against purified lipopolysaccharide (lps) of a vibrio cholerae o1 strain (co366) induced passive protection against challenge with the parent as well as other o1 organisms but not against o139 or non-o1/non-o139 organisms. a considerable level of protection against o1 strains was also observed with the igg fraction of the antiserum which inhibited intestinal adherence and colonisation. the monovalent fab(igg) fragment, on the other hand, showed only a low level of protection. ...	2000	10731603
identification of an operon required for ferrichrome iron utilization in vibrio cholerae.	mutagenesis of vibrio cholerae with tnphoa, followed by screening for fusions that were activated under low-iron conditions, led to the identification of seven independent fusion strains, each of which was deficient in the ability to utilize ferrichrome as a sole iron source for growth in a plate bioassay and had an insertion in genes encoding products homologous to escherichia coli fhua or fhud. expression of the gene fusions was independent of irgb but regulated by fur. we report here a map of ...	2000	10735886
effect on systemic antibody concentrations of topical application of choleratoxin to skin of sheep.	to examine the ability of a vaccine formulation combining choleratoxin with an experimental antigen to induce a systemic antibody response when applied topically on unbroken skin of sheep.	2000	10736674
surveillance of bacterial pathogens associated with acute diarrhea in lima, peru.	a study was conducted in lima, peru, from january to april 1995, to determine the bacterial pathogens associated with acute diarrhea in adults, their susceptibility to common antimicrobials, the risk factors involved in cholera transmission, and the best clinical predictors of cholera.	2000	10737846
efficacy trial of single-dose live oral cholera vaccine cvd 103-hgr in north jakarta, indonesia, a cholera-endemic area.	a randomized, double-blind, placebo-controlled efficacy trial of one dose of cvd 103-hgr live oral cholera vaccine was performed in indonesia from 1993 to 1997. 67,508 persons aged 2-41 years ingested vaccine or placebo and were followed for four years, detecting cholera cases using hospital-based surveillance. a nested reactogenicity study (538 vaccinees, 535 controls) revealed no vaccine-attributable side effects. a nested immunogenicity study (n=657) showed vibriocidal seroresponses in 64-70% ...	2000	10738097
determination of biological toxins using capillary electrokinetic chromatography with multiphoton-excited fluorescence.	we report a highly sensitive and rapid strategy for characterizing biological toxins based on capillary electrokinetic chromatography with multiphoton-excited fluorescence. in this approach, aflatoxins b1, b2, and g1 and the cholera toxin a-subunit are fractionated in approximately 80 s in a narrow-bore electrophoretic channel using the negatively charged pseudostationary phase, carboxymethyl-beta-cyclodextrin. the aflatoxins--highly mutagenic multiple-ringed heterocycles produced by aspergillus ...	2000	10740883
evidence for specificity in type 4 pilus biogenesis by enteropathogenic escherichia coli.	type 4 fimbriae (pili) are surface appendages that are expressed by many species of gram-negative bacteria. previous studies have demonstrated that pseudomonas aeruginosa can express and assemble pilin subunits from several unrelated species, indicating a common mechanism for biogenesis of type 4 pili whereby structural subunits from one system may be interchanged with those of another. in this study, an isogenic mutant of enteropathogenic escherichia coli (epec) was constructed containing the e ...	2000	10746776
distribution of vibrio cholerae virulence genes among different vibrio species isolated in sardinia, italy.	the members of the genus vibrio include harmless aquatic strains as well as strains capable of causing epidemics of cholera. diarrhoea caused by vibrio cholerae is attributed to cholerae enterotoxin (ct) codified by the ctx operon and regulated by a number of virulence genes such as toxt, toxr and toxs. fifty-two vibrio strains were isolated from different aquatic environments in and around sardinia and searched by pcr for the presence of ctxa, zot, ace, toxr, toxs, toxt, tcpa and vpi virulence ...	2000	10747228
mucosal and systemic antibody responses after peroral or intranasal immunization: effects of conjugation to enterotoxin b subunits and/or of co-administration with free toxin as adjuvant.	the mucosa-binding molecules cholera toxin (ct) from vibrio cholerae and heat-labile enterotoxin (lt) from escherichia coli have previously been used as mucosal adjuvants and carriers for many types of antigen. however, since these molecules are toxic and cannot be used in human vaccines, it is important to study whether their non-toxic mucosa-binding b subunits, ctb and ltb, can be used as alternative safe mucosal adjuvants and/or carrier molecules. we have as a model protein antigen used human ...	2000	10752686
the suckling mouse model of cholera.	vibrio cholerae colonization of the suckling mouse intestine is a commonly used animal model for the human diarrheal disease cholera. this model has a number of advantages as well as disadvantages, and has been extremely useful in the identification and characterization of proven and putative virulence factors involved in human cholera.	2000	10754579
vibrio cholerae o139 in calcutta, 1992-1998: incidence, antibiograms, and genotypes.	we report results of surveillance for cholera caused by vibrio cholerae o139 from september 1992, when it was first identified, to december 1998. v. cholerae o139 dominated as the causative agent of cholera in calcutta during 1992-93 and 1996- 97, while the o1 strains dominated during the rest of the period. dramatic shifts in patterns of resistance to cotrimoxazole, neomycin, and streptomycin were observed. molecular epidemiologic studies showed clonal diversity among the o139 strains and conti ...	2000	10756147
vibrio cholerae o2 as a cause of a skin lesion in a tourist returning from tunisia.	isolates of vibrio cholerae other than o1 and o139 (non o1 vibrio cholerae) are associated with sporadic diarrheal disorders, and limited outbreaks of diarrhea, and have often been reported in association with extraintestinal infections. the majority of cases of non o1 vibrio cholerae infection involve immunocompromised patients with hematologic malignancies or cirrhosis. in italy, very few cases of gastrointestinal and extraintestinal infections due to non o1 vibrio cholerae have been described ...	2000	10759577
convergence of the secretory pathways for cholera toxin and the filamentous phage, ctxphi.	virulence of vibrio cholerae depends on secretion of cholera toxin (ct), which is encoded within the genome of a filamentous phage, ctxphi. release of ct is mediated by the extracellular protein secretion (eps) type ii secretion system. here, the outer membrane component of this system, epsd, was shown to be required for secretion of the phage as well. thus, epsd plays a role both in pathogenicity and in horizontal transfer of a key virulence gene. genomic analysis suggests that additional filam ...	2000	10764646
classical and el tor biotypes of vibrio cholerae differ in timing of transcription of tcpph during growth in inducing conditions.	two protein pairs in vibrio cholerae, toxrs and tcpph, are necessary for transcription from the toxt promoter and subsequent expression of cholera virulence genes. we have previously shown that transcription of tcpph in classical strains of v. cholerae is activated at mid-log-phase growth in toxr-inducing conditions, while transcription of tcpph in el tor strains is not. in this study, we showed that while transcription of tcpph differs at mid-log-phase growth in toxr-inducing conditions between ...	2000	10769005
[radiosensitivity of vibrio cholerae o1 incorporated in oysters, to (60)co].	evaluate the effect of ionizing irradiation by 60co on vibrio cholerae o1, el-tor, ogawa, non-toxigenic, incorporated in live oysters crassostrea brasiliana.	2000	10769357
novel beta-lactamase genes from two environmental isolates of vibrio harveyi.	two ampicillin-resistant (amp(r)) isolates of vibrio harveyi, w3b and hb3, were obtained from the coastal waters of the indonesian island of java. strain w3b was isolated from marine water near a shrimp farm in north java while hb3 was from pristine seawater in south java. in this study, novel beta-lactamase genes from w3b (bla(vhw-1)) and hb3 (bla(vhh-1)) were cloned and their nucleotide sequences were determined. an open reading frame (orf) of 870 bp encoding a deduced protein of 290 amino aci ...	2000	10770767
distribution and content of class 1 integrons in different vibrio cholerae o-serotype strains isolated in thailand.	in this study, 176 clinical and environmental vibrio cholerae strains of different o serotypes isolated in thailand from 1982 to 1995 were selected and studied for the presence of class 1 integrons, a new group of genetic elements which carry antibiotic resistance genes. using pcr and dna sequencing, we found that 44 isolates contained class 1 integrons harboring the aadb, aada2, blap1, dfra1, and dfra15 gene cassettes, which encode resistance to gentamicin, kanamycin, and tobramycin; streptomyc ...	2000	10770768
survival of vibrio cholerae o1 in ceviche and its reduction by heat pretreatment of raw ingredients.	the survival of vibrio cholerae o1 serotypes inaba and ogawa was determined in ceviche prepared from inoculated ground fish. ground mackerel purchased from a seafood distribution center was inoculated with v. cholerae and stored at 8 or 20 degrees c. counts of v. cholerae decreased in 2.6 to 2.7 log10 cfu/g during 96 h of storage at 8 degrees c or 2.5 to 2.6 log10 cfu/g during 24 h at 20 degrees c. survival studies indicated that serotype inaba decreased its number following a linear or retarded ...	2000	10772208
susceptibility of vibrio cholerae o139 to antibody-dependent, complement-mediated bacteriolysis.	volunteer studies with vibrio cholerae o1 have shown that the best correlate of a vaccine's protective efficacy is its propensity to elicit serum bactericidal responses in its recipients. attempts to detect such responses following infection with v. cholerae o139, however, have met with varying success. using a tube-based assay which involves viable counting, we now report that strains of serogroup o139 can appear to be sensitive or resistant to a fixed concentration of complement in the presenc ...	2000	10799459
zonulin, a newly discovered modulator of intestinal permeability, and its expression in coeliac disease.	we identified zonulin, a novel human protein analogue to the vibrio cholerae derived zonula occludens toxin, which induces tight junction disassembly and a subsequent increase in intestinal permeability in non-human primate intestinal epithelia. zonulin expression was raised in intestinal tissues during the acute phase of coeliac disease, a clinical condition in which tight junctions are opened and permeability is increased.	2000	10801176
purification and characterization of n-acetylglucosamine-6-phosphate deacetylase from a psychrotrophic marine bacterium, alteromonas species.	a psychrotrophic bacterium, strain mct-9, which produced an n-acetylglucosamine-6-phosphate deacetylase, was isolated from a deep-seawater sample in the mariana trough. the mct-9 strain was identified as alteromonas sp. the native enzyme had a molecular mass of 164,000 da, and was predicted to be composed of four identical subunits with molecular masses of 41,000 da. the purified enzyme hydrolyzed n-acetylglucosamine (glcnac), glcnac-6-phosphate, and glcnac-6-sulfate. considering the low k(m) an ...	2000	10804240
the marine pathogen vibrio vulnificus encodes a putative homologue of the vibrio harveyi regulatory gene, luxr: a genetic and phylogenetic comparison.	vibrio vulnificus is an opportunistic pathogen that exhibits numerous virulence factors, including the secretion of a zinc metalloprotease and the production of a capsule. we have cloned and sequenced a gene from v. vulnificus that is a homologue of the positive transcriptional regulator, luxr, of the lux operon in vibrio harveyi. this gene encodes a putative, single complete open reading frame designated smcr, which shares greater than 75% nucleotide identity with luxr of v. harveyi. the deduce ...	2000	10806366
[the cultivation of vibrio cholerae with green algae in an experiment].	relationships between vibrio cholerae of different origin and some serogroups with green algae scenedesmus quadricauda in mineral medium at two temperatures have been experimentally studied. differences in the relationships of various strains with green algae under the above-mentioned experimental conditions have been established. the study has shown that a decrease in the concentration and the death of vct+ and vct- vibrios of all strains under study occur in the linear phase of the development ...	2000	10808566
[a dried nutrient medium for the isolation of vibrio cholerae].	a dried differential nutrient medium for the isolation of v. cholerae has been developed. the medium is sufficiently sensitive, has pronounced differentiating properties and greatly inhibits the appearance of microbial associations. during the cultivation of v. cholerae with the use of this medium the cultural, morphological and agglutination properties of the initial strains are retained.	2000	10808569
differential activation of the tcpph promoter by aphb determines biotype specificity of virulence gene expression in vibrio cholerae.	vibrio cholerae strains of the classical biotype express the genes encoding cholera toxin (ct) and toxin-coregulated pilus (tcp) under a variety of environmental conditions in vitro, whereas el tor biotype strains express these genes only under specialized culture conditions. we show here that a single base-pair difference at positions -65 and -66 of the classical and el tor tcpph promoters, respectively, is responsible for the differential regulation of virulence gene expression in these two di ...	2000	10809704
two-year study of the protective efficacy of the oral whole cell plus recombinant b subunit cholera vaccine in peru.	the protective efficacy of an oral inactivated whole cell vibrio cholerae plus recombinant b subunit cholera vaccine was determined against el tor cholera among peruvian children and adults (2-65 years old) in a randomized, double-blind manner. study subjects received 2 doses of vaccine or placebo 2 weeks apart, followed by a booster dose 10 months later. surveillance for cholera was performed actively, with 2 visits per week to each household, and passively, at a local hospital. stool samples w ...	2000	10823767
local and systemic immune responses to combined vibrio cholerae cvd103-hgr and salmonella typhi ty21a live oral vaccines after primary immunization and reimmunization.	the local and systemic antibody responses elicited following concomitant primary immunization and reimmunization with the live oral attenuated vibrio cholerae cvd103-hgr and salmonella typhi ty21a vaccine strains were determined in healthy adult volunteers. a more pronounced serum vibriocidal antibody response was generated after primary immunization compared to reimmunization 2.5 or 3.5 yr later. the seroconversion rate (> or =4-fold rise over baseline) was 81% subsequent to primary immunizatio ...	2000	10825607
health impairments arising from drinking water resources contaminated with vibrio cholerae.	the endemic and seasonal nature of cholera depends upon the survival of toxigenic vibrio cholerae in various niches of the aquatic environment. to understand the transmission and ecology of v. cholerae, it is necessary to know which component in the aquatic ecosystem can harbor it and thus contribute to the endemic presence. toxigenic v. cholerae is now recognized as an autochthonous member of the microflora in many aquatic environments based on its protracted survival and proliferation without ...	2000	10842790
identification of a novel gene, fimv, involved in twitching motility in pseudomonas aeruginosa.	transposon mutagenesis was used to identify a new locus required for twitching motility in pseudomonas aeruginosa. four tn5-b21 mutants which lacked twitching motility and a fifth which exhibited impaired motility were found to map to the same kpn:i restriction fragment at approximately 40 min on the p. aeruginosa genome. cloning and sequencing studies showed that all five transposon insertions occurred within the same 2.8 kb orf, which was termed fimv. the product of this gene has a putative pe ...	2000	10846211
a ganglioside-based assay for cholera toxin using an array biosensor.	a rapid assay for cholera toxin (ct) has been developed using a fluorescence-based biosensor. this sensor was capable of analyzing six samples simultaneously for ct in 20 min with few manipulations required by the operator. the biochemical assays utilized a ganglioside-"capture" format: ganglioside gm1, utilized for capture of analyte, was immobilized in discrete locations on the surface of the optical waveguide. binding of ct to immobilized gm1 was demonstrated with direct assays (using fluores ...	2000	10847619
evidence for a signaling system in helicobacter pylori: detection of a luxs-encoded autoinducer.	helicobacter pylori possesses a homolog of the luxs gene, initially identified by its role in autoinducer production for the quorum-sensing system 2 in vibrio harveyi. the genomes of several other species of bacteria, notably escherichia coli, salmonella enterica serovar typhimurium, and vibrio cholerae, also include luxs homologs. all of these bacteria have been shown to produce active autoinducers capable of stimulating the expression of the luciferase operon in v. harveyi. in this report, we ...	2000	10850976
antibacterial activity of a chitooligosaccharide mixture prepared by cellulase digestion of shrimp chitosan and its application to milk preservation.	the antibacterial activity of a chitooligosaccharide mixture prepared by digestion of shrimp chitosan with cellulase at 50 degrees c for 14 h was evaluated. sugars with 1 to 8 degrees of polymer (dp) were found in this chitooligosaccharide mixture, and the weight percentage of sugars with dp > or = 6 was 44.3%. minimal lethal concentrations of this mixture against aeromonas hydrophila, escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, salmonella typhimurium, shigella dysenteriae, ...	2000	10852568
vibrio vulnificus has the transmembrane transcription activator toxrs stimulating the expression of the hemolysin gene vvha.	in an attempt to dissect the virulence regulatory mechanism in vibrio vulnificus, we tried to identify the v. cholerae transmembrane virulence regulator toxrs (toxrs(vc)) homologs in v. vulnificus. by comparing the sequences of toxrs of v. cholerae and v. parahaemolyticus (toxrs(vp)), we designed a degenerate primer set targeting well-conserved sequences. using the pcr product as an authentic probe for southern blot hybridization, a 1.6-kb bglii-hindiii fragment and a 1.2-kb hindiii fragment con ...	2000	10852871
functional analysis of genes in the rfb locus of leptospira borgpetersenii serovar hardjo subtype hardjobovis.	lipopolysaccharide (lps) is a key antigen in immunity to leptospirosis. its biosynthesis requires enzymes for the biosynthesis and polymerization of nucleotide sugars and the transport through and attachment to the bacterial membrane. the genes encoding these functions are commonly clustered into loci; for leptospira borgpetersenii serovar hardjo subtype hardjobovis, this locus, named rfb, spans 36.7 kb and contains 31 open reading frames, of which 28 have been assigned putative functions on the ...	2000	10858186
use of rna arbitrarily primed-pcr fingerprinting to identify vibrio cholerae genes differentially expressed in the host following infection.	evidence suggests that a repertoire of vibrio cholerae genes are differentially expressed in vivo, and regulation of virulence factors in vivo may follow a different pathway. our work was aimed at characterization of in vivo-grown bacteria and identification of genes that are differentially expressed following infection by rna arbitrarily primed (rap)-pcr fingerprinting. the ligated rabbit ileal loop model was used. the motility of in vivo-grown bacteria increased by 350% over that of in vitro-g ...	2000	10858198
detection of dna via an ion channel switch biosensor.	detection of dna by an ion channel switch biosensor has been demonstrated in a model system, using single-stranded oligonucleotide sequences of 52-84 bases in length. two different biotinylated probes are bound, via streptavidin, either to the outer region of a gramicidin ion channel dimer or to an immobilized membrane component. the ion channels are switched off upon detection of dna containing complementary epitopes to these probes, separated by a nonbinding region, at nanomolar levels. the dn ...	2000	10860501
bacterial, viral and parasitic enteric pathogens associated with acute diarrhea in hospitalized children from northern jordan.	to determine the etiology of acute diarrhea in jordanian children under 5 years of age, we examined stool samples from 265 children admitted to the pediatric ward at princess rahma hospital for children, irbid, jordan, for parasites, rotavirus and enteric bacteria. using both traditional and molecular diagnostic techniques, we detected enteropathogens in 66.4% of patients with diarrhea. a single enteric pathogen was detected in 50.9% of the children, and multiple pathogens were detected in 15.5% ...	2000	10865179
cholera incidence and el niño-related higher ambient temperature.		2000	10865299
characterization of a putative virulence island in the chromosome of uropathogenic escherichia coli possessing a gene encoding a uropathogenic-specific protein.	this study was initiated to search for a homologue of the vibrio cholerae zot gene in uropathogenic escherichia coli (upec) using a specific dna probe. the faint signal obtained at low stringency with some upec strains associated with prostatitis cases prompted us to examine upec strains by pcr using primers designed from the conserved regions of the proteins of the zot group of putative ntpases containing the classical ntp binding motif. this led to the discovery of a dna fragment in upec strai ...	2000	10702359
distribution of is1358 and linkage to rfb-related genes in vibrio anguillarum.	the insertion sequence is1358 is linked to the rfb regions of both vibrio cholerae o1 and o139, and its location was suggestive of a role in generating new combinations of rfb genes. this provoked an examination of the distribution and localization of is1358 in vibrio anguillarum. s11358 was widely distributed in a number of v. anguillarum serogroups. in particular, when cosmid clones of v. anguillarum o1 were screened with is1358 and subsequently subcloned and sequenced, it was found that rfb-l ...	2000	10708371
nhaa, an na(+)/h(+) antiporter involved in environmental survival of vibrio cholerae.	vibrio cholerae, the agent of cholera, is a normal inhabitant of aquatic environments, in which it survives under a wide range of conditions of ph and salinity. in this work, we identified the nhaa gene in a wild-type epidemic strain of v. cholerae o1. nhaa encodes a protein of 382 amino acids that is very similar to the proteins nhaa of vibrio parahaemolyticus, vibrio alginolyticus ( approximately 87% identity), and escherichia coli (56% identity). v. cholerae nhaa complements an e. coli nhaa m ...	2000	10781565
bacteremic cellulitis caused by non-01, non-0139 vibrio cholerae: report of a case in a patient with hemochromatosis.	we report a case of bacteremia associated with hemorrhagic bullous skin lesions on the leg caused by non-01, non-0139 vibrio cholerae in a 66-year-old man with hemochromatosis developed in an inland region. the organism was isolated from blood and bullae fluid. the patient was treated successfully with cefotaxime and doxycycline. this report emphasizes the potential of this organism to produce bacteremic cellulitis in people with underlying illness in the absence of usual epidemiological risk fa ...	2000	10794945
identification of a cho cell-elongating factor produced by vibrio cholerae o1.	vibrio cholerae strains with all known toxin genes deleted or inactivated still cause diarrhoea in some volunteers, suggesting the presence of an unknown virulence factor or factors. lysozyme-edta treated cells of jbk70, a genetically manipulated cholera toxin negative strain of vibrio cholerae o1, biotype el tor, release a factor that causes elongation of chinese hamster ovary (cho) cells. cho cell-elongating toxin (cef) was purified by fplc chromatography (anion exchange; q sepharose high perf ...	2000	10873485
detection and analysis of gene expression during infection by in vivo expression technology.	many limitations associated with the use of in vitro models for study of bacterial pathogenesis can be overcome by the use of technologies that detect pathogen gene expression during the course of infection within an intact animal. in vivo expression technology (ivet) accomplishes this with versatility: it has been developed with a variety of reporter systems which allow for either in vivo selection or ex vivo screening. selectable gene fusion systems generally allow for the complementation of a ...	2000	10874732
virulence gene regulation inside and outside.	much knowledge about microbial gene regulation and virulence is derived from genetic and biochemical studies done outside of hosts. the aim of this review is to correlate observations made in vitro and in vivo with two different bacterial pathogens in which the nature of regulated gene expression leading to virulence is quite different. the first is vibrio cholerae, in which the concerted action of a complicated regulatory cascade involving several transcription activators leads ultimately to ex ...	2000	10874738
ecological study of vibrio cholerae in vellore.	vellore is endemic for cholera due to vibrio cholerae o1 and o139. in a previous study the prevalence of vibrio cholerae in drinking water, lakes and sewage outfalls in a single 2-months period in vellore, india was determined. in addition water samples from three sites were also tested for the presence of v. cholerae o1 and o139 by fluorescent antibody staining. this follow on study has examined how the environmental distribution of v. cholerae at the same sites alters over a 12-month period an ...	2000	10813143
antibiotic resistance in the ecor collection: integrons and identification of a novel aad gene.	the 72 escherichia coli strains of the ecor collection were examined for resistance to 10 different antimicrobial agents including ampicillin, tetracycline, mercury, trimethoprim, and sulfonamides. eighteen strains were resistant to at least one of the antibiotics tested, and nearly 20% (14 of 72) were resistant to two or more. several of the resistance determinants were shown to be carried on conjugative elements. the collection was screened for the presence of the three classes of integrons an ...	2000	10817710
[the determination of the optimal conditions for the production of a number of pathogenicity factors in vibrio cholerae].	conditions for the cultivation of v. cholerae of different sero- and biovars on tryptone medium, ensuring the maximum production of cholera toxin (ct), dermonecrotic factor (dnf), hemorrhagic factor (hf) and new cholera toxin (nct) have been determined. the lack of coincidence in the optimum conditions ensuring the maximum production of ct, dnf and hf has been established, which may be indicative of different nature of these toxic substances. nct, produced by vct- strains, is similar to cn in bi ...	2000	10876885
[noncapsular mutants of vibrio cholerae serogroup o139: their isolation, identification and use for the preparation of an o139 diagnostic antiserum].	on the basis of v. cholerae strain p16064, serogroup o139, spontaneous and transposon mutants with the stable lose of the capacity for producing the polysaccharide capsule, but retaining antigen o139, have been obtained. as revealed in this study, capsular and noncapsular strains differ in their sensitivity to cholera phages 20 and inaba, as well as in agglutination with o139-antiserum. these data make it possible to use of bacteriophages for the differentiation of capsular and noncapsular strai ...	2000	10876889
crystal structure of an anti-carbohydrate antibody directed against vibrio cholerae o1 in complex with antigen: molecular basis for serotype specificity.	the crystal structure of the murine fab s-20-4 from a protective anti-cholera ab specific for the lipopolysaccharide ag of the ogawa serotype has been determined in its unliganded form and in complex with synthetic fragments of the ogawa o-specific polysaccharide (o-sp). the upstream terminal o-sp monosaccharide is shown to be the primary antigenic determinant. additional perosamine residues protrude outwards from the ab surface and contribute only marginally to the binding affinity and specific ...	2000	10880560
ctxphi contains a hybrid genome derived from tandemly integrated elements.	ctxphi is a filamentous, temperate bacteriophage whose genome includes ctxab, the genes that encode cholera toxin. in toxigenic isolates of vibrio cholerae, tandem arrays of prophage dna, usually interspersed with the related genetic element rs1, are integrated site-specifically within the chromosome. we have discovered that these arrays routinely yield hybrid virions, composed of dna from two adjacent prophages or from a prophage and a downstream rs1. coding sequences are always derived from th ...	2000	10880564
enterotoxin adjuvants have direct effects on t cells and antigen-presenting cells that result in either interleukin-4-dependent or -independent immune responses.	in an in vitro study, escherichia coli heat-labile toxin (lt) was shown to directly affect activated cd4(+) t cells and support interleukin (il)-5 production in il-4-deficient (il-4(-/-)) mice, whereas cholera toxin (ct) did not. both lt and ct enhanced b7-2 expression on b cells and macrophages. these effects were not influenced by cd40-cd40 ligand cosignaling. addition of lt- or ct-treated antigen-presenting cells to anti-cd3-triggered cd4(+) t cells resulted in the induction of t cell prolife ...	2000	10882596
host-pathogen interactions in emerging and re-emerging infectious diseases: a genomic perspective of tuberculosis, malaria, human immunodeficiency virus infection, hepatitis b, and cholera.	on exposure to a pathogen, a host may resist infection, become subclinically infected, or progress through several stages from mild to severe infection. chronic sequelae may or may not occur. host factors, particularly host genes, influence many of these stages. we have used a model of the continuum of pathogenesis of infectious diseases to consider the effect of host genes on five pathogens of significant public health burden: mycobacterium tuberculosis, plasmodium species, human immunodeficien ...	2000	10884944