Vet Immunol Immunopathol, 1994 Dec, 44(1), 85 - 95 Genetic variation in the humoral immune response against Vibrio salmonicida and in antibody titre against Vibrio anguillarum and total IgM in Atlantic salmon (Salmo salar); Stromsheim A et al.; Total IgM level and antibody titre to Vibrio anguillarum O-antigen after bath-vaccination, and specific antibody response to V . salmonicida O-antigen at three different samplings were analysed in family material of Atlantic salmon (Salmo salar), consisting of 791 fish belonging to 34 maternal full-sib groups within 12 paternal half-sib groups . The fish were immunized twice, and blood samples collected three times . After the third blood sampling, the fish were challenged with V . anguillarum . Medium to low genetic variation was recorded in total IgM and in the antibody titres against V . anguillarum O-antigen and V . salmonicida O-antigen, with heritability estimates of 0.12, 0.18 and from 0.03 to 0.12, respectively . Moderate to high genetic and phenotypic correlations were found between the V . salmonicida O-antigen titres at different samplings . Genetic and phenotypic correlations between the initial titres were moderate to low . The effect of different immune traits, including Aeromonas salmonicida A-layer titres (previously described), on the ability to survive the challenge was examined . The likelihood of surviving the challenge was affected positively by the A . salmonicida A-layer titre at the second sampling, and almost significantly affected by the initial V . anguillarum O-antigen titre . Production traits, such as mean slaughter weight and mean proportion of survivors in a corresponding full-sib material, were obtained in the sea-rearing period . No significant full-sib correlation between immune parameters and production traits was detected. Int J Epidemiol, 1994 Dec, 23(6), 1292 - 9 Epidemic cholera during refugee resettlement in Malawi; Hatch DL et al.; BACKGROUND . In June 1988 a cholera epidemic occurred in a Mozambican refugee population resettling in southern Malawi . METHODS . A case-control study was conducted to determine possible risk factors for disease . The characteristics of 48 refugee households with any member(s) hospitalized for suspected cholera were compared to 441 randomly sampled refugee households without hospitalizations . RESULTS . Vibrio cholerae 01 was isolated from 50% (5/10) of case-patient stool cultures . Having any water containers with > or = 10 T capacity was associated with a significantly lower odds of suspected cholera in households (adjusted odds ratio {aOR} = 0.02, 95% confidence interval {CI} : 0.003-0.12), as was having metal cooking pots (aOR = 0.3, 95% CI : 0.12-0.7), after adjusting for length of residence and socioeconomic status (logistic regression model) . Households with two or more children < 5 years old were at markedly increased odds of suspected cholera (P < 0.0001) . These results suggest that water containers and cooking pots served important preventive functions during this cholera outbreak . Young children may have contributed to cholera transmission, but the reason(s) remains undetermined. Chem Pharm Bull (Tokyo), 1994 Dec, 42(12), 2449 - 51 Marine natural products . XXXIV . Trisindoline, a new antibiotic indole trimer, produced by a bacterium of Vibrio sp . separated from the marine sponge Hyrtios altum; Kobayashi M et al.; A new antibiotic indole trimer named trisindoline (1) was isolated, together with a known dioxopiperazine brevianamide F (2), from the culture of a bacterium of Vibrio sp., which was separated from the Okinawan marine sponge Hyrtios altum . The structure of trisindoline (1) has been determined on the bases of physicochemical evidence and chemical synthesis. Cell Biol Toxicol, 1994 Dec, 10(5-6), 345 - 51 Biochemiluminescence and biomedical applications; Champiat D et al.; Although used for analytical purposes for more than 40 years it is only recently that biochemiluminescence (BCL) has found widespread acceptance . Methods employing BCL reactions now play an important role in biomedical research and laboratory medicine . The main attractions for the assay technology include exquisite sensitivity (attomole-zeptomole), high selectivity, speed and simplicity . In biomedical research, the most important applications of BCL are: (1) to estimate microbial numbers and to assess cellular states (e.g., after exposure to antibiotic or cytotoxic agents) and in reporter gene studies (firefly luciferase gene); (2) NAD(P)H involved in redox/dehydrogenase studies using Vibrio luciferase complex; (3) BCL labels and CL detection of enzyme labels in immunoassays are the most widespread routine application for this technology . BCL enzyme immunoassays represent the most active area of development, e.g., enhanced BCL method for peroxidase and BCL assays for alkaline phosphatase labels using adamantyl 1,2-dioxetane. Glycoconj J, 1994 Dec, 11(6), 518 - 26 Chitovibrin: a chitin-binding lectin from Vibrio parahemolyticus; Gildemeister OS et al.; A novel 134 kDa, calcium-independent chitin-binding lectin, 'chitovibrin', is secreted by the marine bacterium Vibrio parahemolyticus, inducible with chitin or chitin-oligomers . Chitovibrin shows no apparent enzymatic activity but exhibits a strong affinity for chitin and chito-oligomers > dp9 . The protein has an isoelectric pH of 3.6, shows thermal tolerance, binds chitin with an optimum at pH 6 and is active in 0-4 M NaCl . Chitovibrin appears to be completely different from other reported Vibrio lectins and may function to bind V . parahemolyticus to chitin substrates, or to capture or sequester chito-oligomers . It may be a member of a large group of recently described proteins in Vibrios related to a complex chitinoclastic (chitinivorous) system. Asian Pac J Allergy Immunol, 1994 Dec, 12(2), 155 - 9 A monoclonal antibody-based dot-blot ELISA diagnostic kit for the detection of Vibrio cholerae 01 in stools of diarrheic patients and household contacts; Supawat K et al.; A "cholera diagnostic kit" was developed for sensitive, specific, rapid, and inexpensive detection of Vibrio cholerae 01 . The monoclonal antibody specific to antigen A of Vibrio cholerae 01 was used as an antigen detection reagent and the principle of dot-blot ELISA was adopted . The kits were used in seven Regional Medical Sciences Centres, Ministry of Public Health, located at various regions of Thailand where diarrhea occurs frequently . Diagnostic efficiency of the kits in the detection of Vibrio cholerae 01 from rectal swabs of the diarrheic patients and their household contacts was evaluated in comparison with the conventional culture method . The two methods were found to have excellent degree of agreement (kappa values > 95%) . The dot-blot ELISA has several advantages over the culture methods, ie rapid (dot-blot ELISA takes 1-2 hours while the culture method takes at least two days) and inexpensive . It requires no sophisticated equipment . The procedure is not complicated thus it is easy to train personnel . The diagnostic kits are recommended for use in the detection of severe diarrhea caused by V . cholerae 01 not only in hospitals and health centres where adequate treatment of the patients is required as a life-saving measure but also for early recognition of cholera cases and their contacts so that other action, ie prevention and control of outbreaks and surveillance can be promptly implemented. Rev Biol Trop, 1994 Dec, 42(3), 487 - 92 Extinction of Vibrio cholerae in acidic substrata: contaminated cabbage and lettuce treated with lime juice; Mata L et al.; Lime juice killed millions of Vibrio cholerae O1, El Tor, Inaba, present on cabbage and lettuce contaminated in the laboratory . The lethal effect was evident within 5 min of exposure to lime juice . No vibrios could be recovered at dilution 1:10 using alkaline peptone water (APW) and thiosulfate-citrate-bile salts-saccharose agar (TCBS) . More than 99.9% of the initial inoculum was effectively destroyed . The number of vibrios killed by lime juice was 2 to 6 logarithms greater than the maximum infecting dose, and 4 to 8 logs greater than the minimum infecting dose for cholera El Tor . The time interval needed for killing was smaller than the usual waiting time for serving food in homes and restaurants . The addition of lime juice to non-acidic foods, beverages and water, is strongly recommended to prevent infection with cholera vibrios and other acid-sensitive microorganisms . This measure is particularly important for rural and slum populations in the tropics and subtropics. Rev Biol Trop, 1994 Dec, 42(3), 479 - 85 Extinction of Vibrio cholerae in acidic substrata: contaminated fish marinated with lime juice (ceviche); Mata L et al.; Millions of Vibrio cholerae O1 El Tor were rapidly eliminated when added to commercial ceviche prepared by marination of mahi-mahi fish in lime juice . Likewise, large masses of viable vibrios present in laboratory contaminated fish, were readily eliminated after immersion in lime juice, during the preparation of ceviche . The killing effect was evident within 5 min of exposure of vibrios to lime juice, with reductions of more than 99.9% of the initial bacterial mass . After 2 h of marination of fish with lime juice (the minimum recommended), no vibrios were detected in the lowest working dilutions (1:10, 1:100) . The Vibrio mass eliminated by lime juice was 2 to 6 logarithms greater than the maximum infectious dose, and 4 to 8 logs greater than the minimum infectious dose to induce cholera El Tor . Also, the killing time was shorter than the elapsing time between preparing and serving food in homes or restaurants . The traditional marination of fish with lime juice or its addition to seafood and meals immediately before consumption, should be protected and promoted to prevent infection with cholera vibrios . In the face of an epidemic of cholera, consumption of ceviche prepared with lime juice would be one of the safest ways to avoid infection with V . cholerae. Biochem Biophys Res Commun, 1994 Nov 30, 205(1), 275 - 81 Stereospecificity of hydride transfer and substrate specificity for FMN-containing NAD(P)H-flavin oxidoreductase from the luminescent bacterium, Vibrio fischeri ATCC 7744; Inouye S et al.; The stereospecificity of the hydride transfer in NAD(P)H-flavin reductase reaction of V . fischeri ATCC 7744 was determined by 1H-NMR spectroscopy using stereospecifically labeled reduced beta-nicotinamide adenine dinucleotide (beta-NADH) . The recombinant flavoenzyme, purified from E . coli cells, selectively transferred the pro-R hydrogen at the C-4 position of the nicotinamide ring to flavin and is therefore classified as an A-side specific enzyme . Lumiflavin was used for the reductase reaction, but lumichrome and alpha-NADH were not utilized as electron acceptor and donor, respectively. Proc Natl Acad Sci U S A, 1994 Nov 22, 91(24), 11388 - 92 The Vibrio cholerae O139 serogroup antigen includes an O-antigen capsule and lipopolysaccharide virulence determinants; Waldor MK et al.; Vibrio cholerae serogroup O139 emerged on the Indian subcontinent in October 1992 to become the first non-O1 V . cholerae serogroup documented to cause epidemic cholera . Although related to V . cholerae El Tor O1 strains, O139 strains have unique surface structures that include a capsular surface layer and lipopolysaccharide (LPS) . Immunoblot analysis of either whole-cell lysates or LPS preparations revealed three electrophoretic forms of the O139 antigen: two slowly migrating forms and one rapidly migrating form that appeared identical to O139 LPS . All three forms of the antigen shared an epitope defined by an O139-specific monoclonal antibody . A serum-sensitive nonencapsulated mutant was isolated that lacks only the slow migrating forms . The slow migrating forms did not stain with silver whereas the rapidly migrating form did, suggesting that the former might constitute highly polymerized O-antigen side-chain molecules that were not covalently bound to core polysaccharide and lipid A (an "O-antigen capsule") . A single transposon insertion resulted in the loss of immunoreactivity of both the LPS and the O-antigen capsule, implying that there are genes common to the biosynthesis of both these macromolecules . The O139 LPS and O-antigen capsule were both important for colonization of the small intestine of the newborn mouse and for serum resistance, demonstrating that both of these forms of the O139 serogroup antigen are virulence factors. Biochim Biophys Acta, 1994 Nov 22, 1219(3), 701 - 5 Cloning and sequencing of a K+ transport gene (trk A) from the marine bacterium Vibrio alginolyticus; Nakamura T et al.; A gene has been cloned from the marine bacterium Vibrio alginolyticus that functionally complements a mutant strain of Escherichia coli, TK420, defective in K+ transport genes (kdpABC, trkD, trkA) . The cloned Vibrio gene allowed TK420 to grow in a synthetic medium containing less than 10 mM K+ and concomitantly led to an increase in K+ uptake activity . The nucleotide sequence of the cloned fragment revealed an open reading frame, which encodes a protein with a predicted 458 amino acid sequence and molecular mass of 50,122 Da . This gene has 71% homology to trkA gene at the DNA level from E . coli and the deduced amino acid sequence is 79% identical with E . coli TrkA, implying that V . alginolyticus has a trkA-like gene as a component of K+ transport systems. Gene, 1994 Nov 18, 149(2), 211 - 7 Insertion of a HIV-1-neutralizing epitope in a surface-exposed internal region of the cholera toxin B-subunit; Backstrom M et al.; The non-toxic B-subunit of cholera toxin (CTB) is a powerful immunogen and has been investigated as a carrier for foreign peptide epitopes, with peptides genetically fused to either the N- or C terminus of CTB . In the present study, we have constructed a plasmid encoding a novel intrachain CTB fusion protein with a peptide epitope inserted into an internal region of CTB: eight amino acids (aa) in CTB (56-63) were substituted with a 10-aa peptide from the third variable (V3) loop of the HIV-1 envelope protein gp120 . The resulting chimeric protein retained important functional characteristics of the native CTB including pentamerization and GM1 ganglioside receptor binding . The internal hybrid protein was also shown to be resistant to proteolytic degradation during production in Vibrio cholerae, whereas a terminal hybrid protein, where the same gp120-epitope was fused to the N terminus of CTB, was rapidly cleaved during culture . The inserted epitope, which is known to give rise to HIV-1 neutralizing Ab, could be detected with a V3 loop-specific monoclonal Ab when the chimeric protein was analyzed in ELISA and immunoblot, indicating that the epitope inserted at this site is presented on the surface of the protein . Consistent with these observations, immunization of mice with the CTB::HIV hybrid protein elicited a high titered serum Ab response to the CTB moiety and also, in some but not all animals, a detectable response to the inserted gp120 epitope. Virology, 1994 Nov 15, 205(1), 7 - 16 Identification of a 40- to 42-kDa attachment polypeptide for canine parvovirus in A72 cells; Basak S et al.; The attachment of canine parvovirus (CPV) to different cell lines was quantitated by a fluorescence-activated cell sorter assay . The viral attachment was observed to both permissive A72 and nonpermissive ST cells but not to nonpermissive MDBK cells . The binding of and infectivity for CPV to A72 cells was reduced upon prior treatment of cells with Vibrio cholerae neuraminidase or lectins, specific for sialic acid . Similarly, treatment of cells with any of several proteases reduced virus binding; however, phospholipase treatment had no effect indicating that one or more membrane glycoproteins were involved in virus binding . These proteins were characterized with a virus overlay protein blot assay . Virus bound to a protein with a molecular mass of 40 to 42 kDa in membranes prepared from A72 and ST cells and not from MDBK cells . The binding to this polypeptide was specific since increasing amounts of unlabeled virions competitively inhibited binding of radiolabeled virions in a dose-dependent manner . A polypeptide of similar molecular mass was immunoprecipitated from radiolabeled octyl glucoside (OG) extract of A72 cells using purified virions, virion-specific antiserum, and protein A . The binding to this polypeptide was decreased but not abolished upon prior treatment of the membrane with V . cholerae neuraminidase . CPV preferentially recognized a polypeptide of similar molecular size in the OG extract prepared from the biotinylated basolateral surface of polarized MDCK monolayer . Hence, we propose that the 40- to 42-kDa glycoprotein represents a specific attachment molecule for CPV in A72 cells. Lancet, 1994 Nov 5, 344(8932), 1273 - 6 Protective efficacy of oral whole-cell/recombinant-B-subunit cholera vaccine in Peruvian military recruits; Sanchez JL et al.; The cholera epidemic in South America has reinforced the need for safe and effective oral vaccines . In a randomised, double-blind, placebo-controlled efficacy trial among 1563 Peruvian military recruits we have investigated the protective efficacy of an oral inactivated whole-cell/recombinant-B-subunit (WC/rBS) cholera vaccine . Participants were given two oral doses of cholera vaccine or Escherichia coli K12 placebo, with an interval of 7-14 days . 1426 (91%) subjects received the two prescribed doses and were followed up for a mean of 18 weeks (median 21 weeks) . After vaccination, Vibrio cholerae O1 El Tor Ogawa was isolated from 17 subjects with diarrhoea . 16 of the cholera cases occurred 2 weeks or longer after the second dose of vaccine (14 placebo recipients, 2 vaccinees) . We also detected 14 symptomless infections (11 {7 placebo recipients, 4 vaccinees}) 2 weeks or longer after the second dose . The vaccine had significant protective efficacy against cholera (86% {95% CI 37-97}, p < 0.01) but not against symptomless infection (42% {-96 to 85}) . All cholera cases were in people of blood group O, who made up 76% of the study population (p < 0.01) . Two doses of WC/rBS vaccine, given 1 to 2 weeks apart, provide rapid, short-term protection against symptomatic cholera in adult South Americans, who are predominantly of blood group O . Long-term efficacy studies in Peruvian adults and children are under way. J Bacteriol, 1994 Nov, 176(22), 6986 - 91 Effect of transposon-induced motility mutations on colonization of the host light organ by Vibrio fischeri; Graf J et al.; Vibrio fischeri is found both as a free-living bacterium in seawater and as the specific, mutualistic light organ symbiont of several fish and squid species . To identify those characteristics of symbiosis-competent strains that are required for successful colonization of the nascent light organ of juvenile Euprymna scolopes squids, we generated a mutant pool by using the transposon Mu dI 1681 and screened this pool for strains that were no longer motile . Eighteen independently isolated nonmotile mutants that were either flagellated or nonflagellated were obtained . In contrast to the parent strain, none of these nonmotile mutants was able to colonize the juvenile squid light organ . The flagellated nonmotile mutant strain NM200 possessed a bundle of sheathed polar flagella indistinguishable from that of the wild-type strain, indicating that the presence of flagella alone is not sufficient for colonization and that it is motility itself that is required for successful light organ colonization . This study identifies motility as the first required symbiotic phenotype of V . fischeri. J Bacteriol, 1994 Nov, 176(22), 6885 - 91 A plasmid-encoded prepilin peptidase gene from enteropathogenic Escherichia coli; Zhang HZ et al.; Enteropathogenic Escherichia coli, a leading agent of infantile diarrhea worldwide, adheres to tissue culture cells in a pattern called "localized adherence." Localized adherence is associated with bundle-forming pili encoded by the plasmid bfpA gene, the product of which is homologous with the major structural subunit proteins of type IV fimbriae in other bacteria . Several of these proteins have been shown to be processed from a precursor by a specific prepilin peptidase . We cloned restriction fragments downstream of the bfpA gene into an E . coli-Pseudomonas aeruginosa shuttle vector and mobilized them into a P . aeruginosa prepilin peptidase (pilD) mutant . A plasmid containing a 1.3-kb PstI-BamHI fragment was able to complement the pilD mutation, as demonstrated by restoration of sensitivity to the pilus-specific bacteriophage PO4 . The DNA sequence of this fragment revealed an open reading frame, designated bfpP, the predicted product of which is homologous to other prepilin peptidases, including TcpJ of Vibrio cholerae (30% identical amino acids), PulO of Klebsiella oxytoca (29%), and PilD of P . aeruginosa (28%) . A bfpA::TnphoA mutant complemented with a bfpA-containing DNA fragment only partially processes the BfpA protein . When complemented with a larger fragment containing bfpP as well as bfpA, the mutant expresses the fully processed BfpA protein . P . aeruginosa PAK, but not a pilD mutant of PAK, expresses mature BfpA protein when the bfpA gene is mobilized into this strain . Thus, as in other type IV fimbria systems, enteropathogenic E . coli utilizes a specific prepilin peptidase to process the major subunit of the bundle-forming pilus . This prepilin petidase contains sequence and reciprocal functional homologies with the PilD protein of P . aeruginosa. J Bacteriol, 1994 Nov, 176(22), 6812 - 8 Purification and characterization of a novel enzyme, alpha-neoagarooligosaccharide hydrolase (alpha-NAOS hydrolase), from a marine bacterium, Vibrio sp . strain JT0107; Sugano Y et al.; A novel enzyme, alpha-neoagarooligosaccharide hydrolase (EC 3.2.1.-), which hydrolyzes the alpha-1,3 linkage of neoagarooligosaccharides to yield agaropentaose (O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro-alpha-L-galactopyranosyl (1-->3)-D-galactose}, agarotriose {O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro- alpha-L-galactopyranosyl (1-->3)-D-galactose}, agarobiose {O-beta-D-galactopyranosyl(1-->4)-3,6-anhydro-L-galactose}, 3,6-anhydro-L-galactose, and D-galactose was isolated from the marine bacterium Vibrio sp . strain JT0107 and characterized . This enzyme was purified 383-fold from cultured cells by using a combination of ammonium sulfate precipitation, successive anion-exchange column chromatography, gel filtration, and hydroxyapatite chromatography, gel filtration, and hydroxyapatite chromatography . The purified protein gave a single band (M(r), 42,000) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Estimation of the M(r) by the gel filtration method gave a value of 84,000, indicating that the enzyme is dimeric . Amino acid sequence analysis revealed it to have a single N-terminal sequence that has no sequence homology to any other known agarases . The optimum temperature and pH were 30 degrees C and 7.7, respectively . The Km and maximum rate of metabolism for neoagarobiose were 5.37 mM and 92 U/mg of protein, respectively. Biochim Biophys Acta, 1994 Nov 1, 1188(1-2), 69 - 74 F0F1-ATPase of Vibrio parahaemolyticus: purification using new detergents and characterization; Ogawa W et al.; Previous attempts to isolate a stable F0F1-ATPase complex (H(+)-translocating ATPase) from Vibrio parahaemolyticus have been unsuccessful . Using new non-ionic detergents (alkyl thiomaltosides), a stable F0F1 complex with a high specific activity (15-25 units/mg protein) was purified and characterized . The purified F0F1-ATPase consists of eight subunits (alpha, beta, gamma, delta, epsilon, a, b and c) . The new detergents, in combination with sucrose (or glycerol), lipid, dithiothreitol and phenylmethylsulfonyl fluoride, effectively stabilized the F0F1 complex . The ATPase activity of the F0F1 complex was greatly increased by anions, such as SO4(2-) and SO3(2-) . Sodium ion increased the activity by about 2-fold . Dicyclohexylcarbodiimide, Zn2+, 4-acetamido-4'-isothiocyanostilben-2,2'disulfonate and tetrachlorosalicylanilide inhibited F0F1-ATPase activity . Ethanol, which stimulated F1-ATPase activity, inhibited F0F1-ATPase activity . Methanol, Na3VO4 and bafilomycin A1 did not have any significant effect on F0F1-ATPase activity, although methanol, like ethanol, stimulated F1-ATPase activity. Biochim Biophys Acta, 1994 Nov 1, 1188(1-2), 101 - 7 The effect of pH on the growth and motility of Rhodobacter sphaeroides WS8 and the nature of the driving force of the flagellar motor; Packer HL et al.; Rhodobacter sphaeroides WS8 grew, and swam vigorously, over the pH range 6 to 9 . Sustained motility was, however, observed in populations of cells resuspended at pH values between 4.9 and 10.4, although the mean run speed was reduced at the extremes of pH . The ability of R . sphaeroides to swim in strong alkaline conditions prompted the question of whether motility at alkaline pH was powered by a sodium motive force, as has been found in the facultative alkalophilic Bacillus and Vibrio species, particularly as motility was found to be sensitive to the sodium channel inhibitor amiloride . The nature of the driving force of the flagellar motor was therefore investigated . It was found that R . sphaeroides was motile over the same pH range in the absence and presence of sodium ions . The protonophore CCCP was found to inhibit motility under all conditions, whereas monensin, an inhibitor of sodium pumps, had no effect upon motility in the presence or absence of sodium . It was concluded that the delta p is the driving force for the flagellar motor in R . sphaeroides at all values of pH . Amiloride, a specific inhibitor of the sodium-driven flagellar motor in alkalophilic Bacillus and Vibrio was shown to act non-specifically on the proton driven motor of R . sphaeroides, reducing the swimming speed of this organism in media with and without sodium to the same extent and over the complete pH range . Measurement of the delta p by using the electrochromic absorbance change of the carotenoid pigments to measure delta psi and 31P-NMR to measure delta pH showed that the maximum delta p was about -215 mV . At pH 10 the cells swam more slowly and the delta p was about -90 mV . These data suggest that the flagellar motor of R . sphaeroides is proton-driven under all conditions with a threshold for motor rotation below -90 mV and saturation at above -90 mV and below -215 mV. Infect Immun, 1994 Nov, 62(11), 5120 - 5 Vibrio cholerae iron transport systems: roles of heme and siderophore iron transport in virulence and identification of a gene associated with multiple iron transport systems; Henderson DP et al.; Vibrio cholerae iron transport mutants were tested for their ability to cause disease in an infant mouse model . The mice were challenged with either the wild-type strain, a vibriobactin synthesis mutant, a heme utilization mutant, or double mutants containing both the vibriobactin synthesis defect and the heme utilization defect . When mice were challenged with 10(7) bacteria, the ability of the double mutant to survive in the intestines was greatly reduced and that of the heme utilization mutant was slightly reduced compared with that of the wild type or the vibriobactin synthesis mutant . When the inoculum size was reduced 10-fold, all of the iron transport mutants failed to colonize the intestines and failed to cause diarrhea in the mice, whereas the wild-type strain was not cleared and elicited a diarrheal response . These data indicate that disruption of either the heme utilization or the vibriobactin uptake system reduces the ability of V . cholerae to cause disease . One of the heme utilization mutants, DHH1, was found to be defective also in utilization of vibriobactin and ferrichrome, mimicking the Escherichia coli TonB- phenotype . This mutant was the least virulent of the iron transport mutants tested . Transformation of DHH1 with the recombinant plasmid pHUT4 restored the abilities to use hemin, vibriobactin, and ferrichrome as iron sources, suggesting that pHUT4 encodes a gene(s) involved globally in the iron transport systems . Hybridization of Vibrio DNA with the V . cholerae heme utilization genes demonstrated the presence of DNA homologous to the genes encoding the outer membrane protein HutA and the inner membrane protein HutB in all the V . cholerae strains tested . The probe containing hutA, but not that containing hutB, also hybridized to DNA from Vibrio parahaemolyticus. Infect Immun, 1994 Nov, 62(11), 4781 - 8 The maltose regulon of Vibrio cholerae affects production and secretion of virulence factors; Lang H et al.; The effects of maltose on production and secretion of virulence factors of Vibrio cholerae in strain X28214, classical biotype, and in maltose-defective transposon mutants constructed from this strain were characterized . Maltose was found to inhibit secretion of cholera toxin and to reduce production of the mannose-sensitive hemagglutinin and the soluble hemagglutinin-protease . In contrast, the amount of toxin-coregulated pilus was increased in the presence of maltose . The maltose effect was apparently mediated by genes of the maltose regulon, since inactivation of the malQ or malF gene of V . cholerae by transposon insertion was found to affect production and secretion of the same virulence factors that were responsive to maltose . The malQ and malF mutants showed, in addition, reduced virulence in an infant-mouse model . These results suggest that maltose may have a significant regulatory role in the production of virulence factors and that an intact maltose regulon is needed for full virulence of V . cholerae. Rev Invest Clin, 1994 Nov-Dec, 46(6), 495 - 8 {Vibrio vulnificus in Mexico: a case report and review of the literature}; Porras-Cortes G et al.; Vibrio vulnificus is an etiologic agent of septicemia and skin lesions . Patients with chronic diseases, and more frequently chronic liver disease, are specially susceptible to this infection . The main risk factor is shellfish ingestion . In this report we present a patient with chronic liver disease who suffered fulminant sepsis and necro-hemorrhagic bullaes secondary to a V . vulnificus infection . The patient had ingested shrimps two days before . A review of the recent literature on the subject is also presented. Vaccine, 1994 Nov, 12(15), 1384 - 8 Comparative efficacy of biodegradable liposomes and microspheres as carriers for delivery of Vibrio cholerae antigens in the intestine; Chandrasekhar U et al.; The effect of the encapsulated antigens of Vibrio cholerae and their route of administration in induction of immune response was studied in experimental cholera . The antigenic proteins of V . cholerae El Tor strain KB207 were obtained by fractionation of cell-free lysate by high-performance liquid chromatography . The antigenic proteins were pooled and encapsulated in biodegradable liposomes and poly(D,L) lactic co-glycolic acid microspheres . Rabbits were immunized with free as well as encapsulated antigens by different routes . Liposome-encapsulated antigens delivered intraintestinally offered maximum protection . Orally or intraintestinally delivered antigens in microspheres failed to elicit a significant immune response, although as a carrier microspheres were comparable to liposomes when judged by the subcutaneous route . The results suggested that liposomes and microspheres could be used as carriers of protective antigens of V . cholerae for effective immunization. Toxicon, 1994 Nov, 32(11), 1397 - 412 Aspects of the haemolytic reaction induced by Kanagawa haemolysin of Vibrio parahaemolyticus; Huntley JS et al.; Vibrio parahaemolyticus, an important enteric pathogen, produces toxin (Kanagawa haemolysin, KH), the presence of which correlates well with pathogenicity . KH induced lysis of human red blood cells (HRBC); the kinetics were strongly dependent on KH concentration (0-1 HU/ml) and rather independent of target cell concentration {0.5 < or = haematocrit (%) < or = 6} and the ratio KH:HRBC . The suggestion that KH-induced haemolysis is due to colloid osmosis is supported by results indicating: (1) osmotic protection (by suspension in iso-osmotic choline chloride, D-sorbitol or L-valine, or MOPS-buffered saline with added sucrose), (2) a cell volume increase prior to lysis, and (3) an increase in HRBC cation (86Rb+) influx after KH addition, indicating raised passive cation permeation . The effect of temperature on KH-induced haemolysis indicates the importance of processes other than the action of a simple water-filled pore, because of the high activation energy {53.30 +/- 2.79 kJ (mol.)-1} involved . Although haemolytic rate was attenuated by washout after 5 min KH exposure, the KH-induced lesion itself was not susceptible to washout by either extracellular volume expansion (at constant osmolarity) or centrifugation/resuspension . This suggests that HRBC binding of KH from aqueous solution still continues after 5 min exposure at 37 degrees C . Pre-vortexing KH with dibutyl phthalate (DBP) dramatically reduced the haemolytic activity of the aqueous toxin preparation, suggesting a protein-lipid interaction, which may support the contention that KH can move from a hydrophilic to a hydrophobic environment . Two features were identified that are characteristic of highly purified TDH preparations: (1) thermostability of haemolysin, and (2) monovalent cation selectivity series of lesion: Cs+ > Li+ > K+ > Rb+ > Na+, confirming that TDH is the important leak-inducing agent of KH. Mol Biol (Mosk), 1994 Nov-Dec, 28(6), 1299 - 307 {A kinetic method of determining the frequency of homologous recombination of plasmids in Escherichia coli cells}; Zavil'gel'skii GB et al.; To test the frequency of recombination by the RecF pathway the hybrid plasmids have been constructed which allow the bioluminescence recombination assay in the transformed E . coli cells . pF2(+) and pF6(+) are derivatives of pUC18 and pACYC184 respectively, with the luxA and luxB genes of Vibrio fischeri cloned downstream of the lac promoter . The luxA genes in pF2(+) and pF6(+) were mutated at the XhoI site and the HindIII site, accordingly, pF8 is a pACYC184 derivative with two copies luxA and luxB genes . The one copy of luxA gene was mutated at the XhoI site and another copy of the luxA gene was mutated at the HindIII site . A kinetic analysis of the population of the replicating and recombinating plasmids has been carried out . Experimental values of the frequency of recombination per one generation (P) were determined for the different E . coli strains. Vaccine, 1994 Nov, 12(14), 1330 - 4 Immunogenicity of Vibrio cholerae ghosts following intraperitoneal immunization of mice; Eko FO et al.; The immunogenic potential of Vibrio cholerae ghosts (VCG) in comparison with heat-killed whole-cell vibrios (WCV) was evaluated after intraperitoneal immunization of adult mice . Swiss white mice received four doses of VCG or WCV intraperitoneally, consisting of 500 micrograms of lyophilized material in 200 microliters of phosphate-buffered saline (PBS), pH 7.4 . The control group received 200 microliters of PBS . Serum samples were collected from all mice on the day of immunization and on days 14, 24, 35 and 62 postimmunization . Sera were examined for vibriocidal antibodies by the microtitre and tube-dilution methods and Vibrio-specific serum IgG antibodies were assessed by ELISA . IgG antibodies to intact WCV were detected in sera from all animals immunized with VCG or WCV . The response was specific and of high magnitude . Significantly higher antibody responses were obtained when sera from both VCG- and WCV-immunized mice were titrated against VCG . The immunogenicity of VCG in evoking serum IgG responses was higher than that of WCV . However, the immunogenicity of the two antigen preparations was comparable in terms of seroconversion for vibriocidal antibodies . These results demonstrate that VCG administered intraperitoneally evoke Vibrio-specific serum IgG responses as well as vibriocidal antibody activity in mice. J Nat Prod, 1994 Nov, 57(11), 1587 - 90 Vibrindole A, a metabolite of the marine bacterium, Vibrio parahaemolyticus, isolated from the toxic mucus of the boxfish Ostracion cubicus; Bell R et al.; The EtOAc extract of the whole culture medium of Vibrio parahaemolyticus, which inhabits the toxic mucus of the box fish Ostracion cubicus, afforded a new indole-derived natural product, vibrindole A {1}, along with some known cyclic dipeptides and indoles . The structure of 1 was determined by analysis of its physicochemical characteristics. J Clin Microbiol, 1994 Nov, 32(11), 2775 - 9 Characterization of phenotypic, serological, and toxigenic traits of Vibrio cholerae O139 bengal; Nair GB et al.; Biochemical and physiological traits of a collection of strains of Vibrio cholerae O139 Bengal isolated from India, Bangladesh, and Thailand showed that these strains formed a phenotypically homogeneous group with identical characteristics that were essentially similar to those of the O1 serogroup . Resistance to 150 micrograms of the vibriostatic agent O/129 (2,4-diamino-6,7-diisopropylpteridine) and Mukherjee's El Tor phage 5 and classical phage IV and the nonagglutinability of the strains with O1 antiserum were the only discernible differences between the O139 and O1 serogroups . Extensive serological characterization further revealed the O139 serogroup to be distinct from the existing 138 serogroups of V . cholerae . Antiserum raised against the O139 serogroup required absorption with the R reference strain CA385 and with the reference strain representing serogroup O22 to remove cross-reacting agglutinins . All of the 223 representative strains of V . cholerae O139 examined hybridized with DNA probes specific for the cholera toxin (CT) gene, zonula occludens toxin gene, and El Tor hemolysin gene but not with the probe specific for the heat-stable enterotoxin gene . The amount of CT present in stool samples of patients infected with the O139 serogroup was higher than that found in stools of patients infected with O1 El Tor, and this echoed findings that the amount of CT produced by O139 strains in vitro was higher than that produced by the O1 El Tor strains . The nucleotide sequences of the genes encoding the A and B subunits of CT of the O139 serogroup were identical to the sequences reported for the CT gene of O1 El Tor . The CT gene of O139 strains could be amplified by using primers developed for detection of the CT gene of the O1 serogroup by a PCR assay, which could also be used to detect the CT gene in stool samples of patients infected with strains of the O139 serogroup. APMIS, 1994 Nov, 102(11), 874 - 6 The first fatal case of Vibrio vulnificus infection in Denmark; Bock T et al.; Vibrio vulnificus can cause severe infections in humans and persons with preexisting liver disorders are especially at risk . In this paper we report what is to our knowledge the first fatal case of V . vulnificus infection in Denmark . The patient was a 68-year-old man with a history of chronic lymphatic leukemia and hepatic cirrhosis . Physicians should be aware of the clinical manifestations of this disease and should be especially attentive to patients at risk of acquiring the infection if there has been possible exposure to V . vulnificus by contact with seawater or contaminated material such as eels. Indian J Med Res, 1994 Nov, 100, 217 - 8 Outbreak of cholera due to Vibrio cholerae 01 in Orissa state; Niyogi SK et al.; During May-June 1993, an outbreak of acute diarrhoea resulting in deaths primarily in adults was reported in two districts of Orissa state . Epidemiological and microbiological investigations revealed that this outbreak was caused by V . cholerae 01 biotype EITor . V . cholerae 01 strains were uniformly resistant to furazolidone. Indian J Med Res, 1994 Nov, 100, 213 - 6 Epidemic of Vibrio cholerae 0139 in Calcutta; Bhattacharya SK et al.; As one of large outbreaks of cholera-like illness in the Indian subcontinent, Calcutta and its neighbouring areas experienced an unprecedented epidemic due to a new strain of V . cholerae non-01, designated as V . cholerae 0139 Bengal, since January 1993 . This epidemic predominantly affected the adult population of Calcutta as evidenced by the hospitalization of more adults at the Infectious Disease Hospital, Calcutta (IDH), which bore the main brunt of the epidemic in and around Calcutta . During the peak of the epidemic about 180 to 300 diarrhoea patients were admitted daily at the IDH . Of the 807 patients screened, 407 were positive for V . cholerae 0139 and majority (82.8%) of the cases were > 10 yr of age . Severe dehydration was recorded in 85.5 per cent of the cases. J AOAC Int, 1994 Nov-Dec, 77(6), 1492 - 9 Identification of Vibrio vulnificus by cellular fatty acid composition using the Hewlett-Packard 5898A Microbial Identification System: collaborative study; Landry WL; A gas chromatographic method using a capillary column for rapid identification of Vibrio vulnificus was examined in a collaborative study . Identifications were performed by analysis of cellular fatty acid profiles which were automatically searched against reference profiles stored in a computer-generated library . Each of the 13 collaborators was sent 15 unknown isolates, which included 10 V . vulnificus isolates and 5 negative control isolates . Each collaborator was furnished with a computer-generated library, developed by the Dallas U.S . Food and Drug Administration laboratory, which contained entries for V . vulnificus, V . cholerae, V . fluvialis, V . parahaemolyticus, V . mimicus, and Aeromonas hydrophila . Of the 195 isolates sent to the collaborators, results for 190 isolates were received . The other 5 isolates were nonviable before analyses began . Of the 126 V . vulnificus isolates analyzed, 118 (93.7%) were correctly identified . Of the 65 negative control isolates sent, one was nonviable, one was misidentified as V . vulnificus, and 2 were misidentified as V . parahaemolyticus . Of the 64 negative controls analyzed, 95.3% were correctly identified . Statistical analysis shows a sensitivity rate of 0.872, specificity rate of 0.982, false positive rate of 0.010, and false negative rate of 0.206 . The gas chromatographic method for identification of Vibrio vulnificus by microbial fatty acid profile has been adopted first action by AOAC INTERNATIONAL. Microbiology, 1994 Nov, 140 ( Pt 11), 3117 - 24 Cloning and nucleotide sequence of the carboxynorspermidine decarboxylase gene from Vibrio alginolyticus; Yamamoto S et al.; The gene (nspC) encoding carboxynorspermidine decarboxylase (CANS DC), the last enzyme in norspermidine biosynthesis, in Vibrio alginolyticus was isolated by immuno-screening and its complete nucleotide sequence was determined . Sequence analysis of the subcloned fragment (2.0 kb) revealed an ORF of 1131 bp encoding a protein of 377 amino acids with a calculated molecular mass of 42,008 Da . The sequence of 20 N-terminal amino acids of purified CANS DC was found to be identical to that predicted from the nspC gene . A putative ribosome binding sequence was observed 8 bp upstream from the translation start site (ATG), and promoter- and terminator-like sequences were detected upstream and downstream of the ORF, respectively . Database searches identified no similar proteins, but the deduced amino acid sequence contained a putative pyridoxal 5'-phosphate binding region similar to those of the bacterial meso-2,6-diaminopimelate decarboxylases and eukaryotic ornithine decarboxylases . Another full ORF was found on the opposite strand downstream from the nspC gene . It encoded a protein of 69 amino acids with a calculated molecular mass of 7441 Da, which exhibited some weak similarity to ScrR, a repressor protein of V . alginolyticus, in the helix-turn-helix DNA binding domain, but did not appear to be expressed in the host cells. Zentralbl Bakteriol, 1994 Nov, 281(4), 475 - 80 Antigenicity and antigenic cross-reactivity of outer membrane proteins of Vibrio parahaemolyticus; Biswas T et al.; Antigenicity of outer membrane proteins was studied and compared between Kanagawa positive (clinical) and negative (environmental) strains of Vibrio parahaemolyticus . Murine antibodies recognized a wide range of outer membrane proteins of Kanagawa negative strains as antigens with molecular masses ranging between 102 kDa to 14 kDa . However, only a few of the total outer membrane proteins of clinical isolates were antigenic and comprised a 55kDa protein as the major antigen . Although a marked difference in antigenicity was found, molecular masses of outer membrane proteins of Kanagawa positive and negative strains migrated similarly in SDS-PAGE . Several outer membrane proteins of Kanagawa-positive strains were found to be antigenic and ubiquitous in a cross-reactivity study indicating that the ubiquitous proteins which could not be recognized by anti-KP antibodies were buried in the outer membrane. Microb Pathog, 1994 Nov, 17(5), 339 - 46 Expression and mutagenesis of recombinant cholera toxin A subunit; Vadheim KL et al.; ADP-ribosylating protein exotoxins from Vibrio cholerae (CT) and Escherichia coli (LT-I) share two short regions of sequence similarity with Bordetella pertussis toxin (PT) . Previous studies have indicated that substitution of arginine for lysine 7 within the first region of CT drastically decreases ADP ribosyltransferase activity . We have more closely defined the role of other amino acids in this region by generating modified proteins in which arginine 7 was replaced with lysine (R7K), aspartate 9 was replaced with arginine (D9R), glycine was substituted for proline 12 (P12G), amino acids 6 to 13 were deleted (delta 613) or the C-terminal KDEL sequence was changed to NEDL . The modified proteins R7K, D9R and delta 613 exhibited undetectable ADP ribosyltransferase activity . Comparison of the tryptic digest of R7K with native CT suggested that changes in protein conformation may be responsible for the loss of ADP-ribosylation activity. FEMS Microbiol Lett, 1994 Nov 1, 123(3), 289 - 98 Monoclonal antibodies against Vibrio anguillarum O2 and Vibrio ordalii identify antigenic differences in lipopolysaccharide O-antigens; Mutharia LM et al.; Monoclonal antibodies (mAbs) that recognize distinct species-specific antigenic epitopes in O-antigens from Vibrio anguillarum O2, O2a and certain O2b strains (mAb 7B4) and from Vibrio ordalii strains (mAbs A16 and 7D11) were generated . Western immunoblot analysis using these mAbs revealed that vibrio strains grown in the presence of fresh rainbow trout blood expressed lipopolysaccharide (LPS) with longer (high molecular mass) O-antigens and extracellular capsular layers when compared to strains grown without rainbow trout blood . We also generated mAbs that react with O-antigens from V . anguillarum serotype O1 (mAbs 7B8, 7B5 and 1C3) and serotype O3 (mAbs 13A1 and 14C5) strains . These mAbs provide rapid and accurate diagnostic reagents for serological differentiation of V . ordalii from serotype O2 strains of V . anguillarum, and for serotyping of these pathogenic vibrios. Eur J Biochem, 1994 Nov 1, 225(3), 1029 - 39 Isolation and structural analysis of oligosaccharide phosphates containing the complete carbohydrate chain of the lipopolysaccharide from Vibrio cholerae strain H11 (non-O1); Bock K et al.; For the first time, an oligosaccharide has been prepared comprising the lipid A backbone, the core oligosaccharide and one repeating unit of the O-specific polysaccharide (O-chain) of a lipopolysaccharide . Lipopolysaccharide from Vibrio cholerae strain H11 (non-O1) was deacylated and the products were separated by high-performance anion-exchange chromatography . Major fractions were a hexadecasaccharide trisphosphate 1, representing the core-lipid A oligosaccharide substituted by one modified repeating unit of the O-antigenic polysaccharide, a dodecasaccharide trisphosphate 2 and an undecasaccharide trisphosphate 3, representing the core-lipid A region . Oligosaccharide 1 originated from beta-elimination upon alkaline hydrolysis of alpha-galacturonic acid of the O-chain; oligosaccharides 2 and 3 were most likely obtained from naturally occurring lipopolysaccharide species carrying no O-chain . The structures of these compounds were elucidated on the basis of monosaccharide composition, and NMR investigations comprising correlation spectroscopy, total correlation spectroscopy and nuclear Overhauser enhancement spectroscopy experiments, as well as heteronuclear 13C, 1H correlation spectroscopy . The structures are as follows: {formula: see text} where R is beta-L-threo-hex-4-enuronopyranosyl-(1-4)-alpha-Neu-(2-3)-beta-Gal A-(1-3)- beta-QuiN-(1-4)-beta-Sedf-(2- in 1, beta-Sedf-(2- in 2, and H in 3 . Where not stated otherwise, sugars are pyranoses of the D-series . Hep is L-glycero-D-manno-heptose, QuiN is 2-amino-2,6-dideoxy-glucose, Kdo is 3-deoxy-D-manno-2-octulosonic acid, Sed is D-altro-heptulose and GalA is galacturonic acid. JAMA, 1994 Oct 19, 272(15), 1203 - 5 Diagnosis and treatment of cholera in the United States . Are we prepared? Besser RE, Feikin DR, Eberhart-Phillips JE, Mascola L, Griffin PM. OBJECTIVE--To assess cholera recognition and treatment by US health care workers in the largest cholera outbreak in the United States this century . DESIGN--We reviewed the medical records of passengers from a flight on which a cholera outbreak occurred . To determine the availability of oral rehydration solutions, we surveyed treatment facilities and referral pharmacies . SETTING--On February 14, 1992, more than 100 passengers on a flight from South America to Los Angeles, Calif, were infected with toxigenic Vibrio cholerae O1 . SUBJECTS--Fifty-four of 67 passengers who sought care in California and Nevada . RESULTS--We reviewed the records of 54 passengers, including 39 with diarrhea and 15 without symptoms . All 17 persons who sought treatment before the outbreak was widely reported by the media had diarrhea . For 12 of these persons, recent travel to South America was noted, but only those four whose records listed cholera as a possible diagnosis were immediately hospitalized . Seven sought care again within 3 days; three were dehydrated, two of these three were hospitalized, and one of these two died . None of the 26 patients suspected to have cholera received appropriate fluids; severely dehydrated patients did not receive Ringer's lactate solution and those not severely dehydrated did not receive an oral rehydration solution . None of the facilities and pharmacies involved stocked World Health Organization oral rehydration salts solution, the preferred solution for treating cholera and other diarrheal diseases . CONCLUSIONS--Treatment of cholera in the United States was suboptimal . Oral fluids appropriate for the treatment of cholera and other diarrheal diseases were generally unavailable . Widespread cholera in the developing world means that US physicians should be prepared to treat "imported" cases . Physicians evaluating patients with diarrhea should obtain a travel history, should consider cholera in patients returning from countries with endemic or epidemic cholera, and should instruct patients in appropriate use of World Health Organization oral rehydration salts solution or other oral rehydration solutions containing 75 to 90 mmol/L of sodium . Pharmacies and medical facilities should stock these solutions. FEMS Microbiol Lett, 1994 Oct 15, 123(1-2), 185 - 91 Cloning and sequencing of the gene encoding Vibrio cholerae O1 fimbrial subunit (fimbrillin); Ehara M et al.; The gene encoding an 18 kDa fimbrial subunit of Vibrio cholerae O1 was identified in a fimbriate strain Bgd17 . Mixed oligoprimers were prepared based on the amino acid sequence of the N-terminus and that from a cyanogen bromide-cleaved fragment of the fimbrillin . A PCR-amplified 185 bp DNA fragment was sequenced . This 185 bp fragment was further extended to 540 bp to 3' and 5' termini by RNA-PCR using a primer containing a random hexamer at its 3' end . This fragment did not contain the stop codons . It was further extended by a gene walking method using Eco RI cassette and its primers . Finally a 660 bp fragment was obtained and sequenced . This fragment contained the complete open reading frame of the structural subunit of the fimbriae, composed of 169 amino acids with a molecular mass of 17435.65 and a leader sequence of 6 or 9 amino acids . The deduced amino acid sequence of the polypeptide encoded by the gene, designated fimA, displayed a highly conserved sequence of MKXXXGFTLI EL of type 4 fimbriae. FEMS Microbiol Lett, 1994 Oct 15, 123(1-2), 179 - 84 Morphology of the viable but nonculturable Vibrio cholerae as determined by the freeze fixation technique; Kondo K et al.; The morphology of the nonculturable Vibrio cholerae strain TSI-4 was examined by the freeze fixation technique of electron microscopy and subsequently four unique structures were found in the fine structure s of this bacterium . The size of the cell was about 2/3 of the growing cell . Although the cell was observed to have an outer membrane as well as the cell membrane and cytoplasm, the outer membrane was undulated and had a surface layer of fine fibers . The peptidoglycan layer was thick and more electron dense than that of normal cells. Biochemistry, 1994 Oct 11, 33(40), 12194 - 201 Probing the Vibrio harveyi luciferase beta subunit functionality and the intersubunit domain by site-directed mutagenesis; Xin X et al.; While the critical role of the bacterial luciferase alpha subunit in catalysis has been amply documented, the beta subunit was only known to be involved in thermal stability and substrate binding . Two conserved histidyl residues at position 81 and 82 of the beta subunit of Vibrio harveyi luciferase were each mutated to an alanine, aspartate, or lysine to probe further the beta functionality . These mutations resulted in higher Km values for reduced riboflavin 5'-phosphate, less efficient oxidations of the aldehyde substrate, and decreased light-emitting activities . beta His82 appears to be significantly more critical than beta His81 . For the beta His82-mutated luciferases, the maximal light intensities and total light outputs were reduced to 19-4% of that for the wild-type enzyme, and the values of Vmax/Km,flavin were decreased by 2-3 orders of magnitude . The reduced light emission activities for these mutated luciferases can be correlated to lower yields of the flavin 4a-hydroperoxide intermediate, reduced productions of the excited flavin emitter, and/or enhanced quenching of the emitter . The beta subunit and the conserved beta His82 in particular have thus been shown to be critical not only to flavin binding but also to catalytic characteristics of luciferase . The dimeric structure of luciferase is essential to its high catalytic efficiency . To characterize the intersubunit domain, three sets of single/double mutants were constructed, and the additivities of mutational effects were tested to screen for residues that could interact across the subunit interface.(ABSTRACT TRUNCATED AT 250 WORDS) Gene, 1994 Oct 11, 148(1), 91 - 5 Identification of a ToxR-activated gene, tagE, that lies within the accessory colonization factor gene cluster of Vibrio cholerae O395; Kovach ME et al.; The nucleotide (nt) sequence has been determined for a Vibrio cholerae ToxR-activated gene designated tagE that is located within a cluster of genes required for efficient intestinal colonization . The tagE gene encompasses 909 nt and is predicted to encode a 303-amino-acid (aa) protein with an estimated molecular mass of 34,468 Da . Computer-assisted similarity searches revealed that TagE possesses aa sequence similarity with Escherichia coli OrfU and Staphylococcus simulans lysostaphin, two proteins that are involved in cell-wall biosynthesis and peptidoglycan degradation, respectively . The role, if any, that TagE plays in the accessory colonization factor phenotype is currently under investigation. Arthritis Rheum, 1994 Oct, 37(10), 1553 - 4 Systemic lupus erythematosus presenting as a non-O:1 Vibrio cholerae abscess; Nedunchezian D et al.; The usual presentations and manifestations of systemic lupus erythematosus (SLE) are well known . We describe a patient with SLE that was discovered in the course of evaluation of an abscess, found to be associated with non-O:1 Vibrio cholerae. J Trop Med Hyg, 1994 Oct, 97(5), 317 - 20 Vibrio cholerae 0139 'Bengal' in Singapore; Tay L et al.; Vibrio cholerae 0139 was isolated from five patients with cholera-like illness . All were imported cases . Laboratory investigations found our five isolates in show similar morphological, biochemical and serological characteristics to the V . cholerae 0139 strains causing epidemics in Bangladesh and India . Our isolates were toxin producers resistant to streptomycin and co-trimoxazole . No local transmission was known to have occurred following introduction of these imported cases. J Bacteriol, 1994 Oct, 176(20), 6199 - 206 Molecular evolution of the seventh-pandemic clone of Vibrio cholerae and its relationship to other pandemic and epidemic V . cholerae isolates; Karaolis DK et al.; Genetic variation and molecular evolution within the seventh-pandemic clone of Vibrio cholerae O1 and its relationship to other V . cholerae isolates were examined by studying 58 clinical isolates that were epidemiologically unassociated and isolated from patients in different countries over 62 years (1931 to 1993) . The sample consisted of 45 isolates from the seventh cholera pandemic (1961 to the present), 3 from the sixth pandemic, 3 from sporadic El Tor outbreaks prior to the seventh pandemic, 2 from the U.S . Gulf Coast, and 5 O139 Bengal isolates . Ribotyping detected 11 polymorphic restriction sites within the seventh-pandemic isolates and showed major differences in ribotypes in comparison with sixth- and pre-seventh-pandemic isolates . O139 isolates were very similar to isolates from the start of the seventh pandemic, differing at only two sites . The majority of seventh-pandemic isolates fall into two groups, the first present from 1961 to the present and found only in Asia and the second arising in 1966 and spreading worldwide . Both groups underwent change over time, allowing a provisional estimate for the nucleotide substitution rate within the seventh pandemic clone. J Bacteriol, 1994 Oct, 176(19), 5988 - 98 MotX, the channel component of the sodium-type flagellar motor; McCarter LL; Thrust for propulsion of flagellated bacteria is generated by rotation of a propeller, the flagellum . The power to drive the polar flagellar rotary motor of Vibrio parahaemolyticus is derived from the transmembrane potential of sodium ions . Force is generated by the motor on coupling of the movement of ions across the membrane to rotation of the flagellum . A gene, motX, encoding one component of the torque generator has been cloned and sequenced . The deduced protein sequence is 212 amino acids in length . MotX was localized to the membrane and shown to interact with MotY, which is the presumed stationary component of the motor . Overproduction of MotX, but not that of a nonfunctional mutant MotX, was lethal to Escherichia coli . The rate of lysis caused by induction of motX was proportional to the sodium ion concentration . Li+ and K+ substituted for Na+ to promote lysis, while Ca2+ did not enhance lysis . Protection from the lethal effects of induction of motX was afforded by the sodium channel blocker amiloride . The data suggest that MotX forms a sodium channel . The deduced protein sequence for MotX shows no homology to its ion-conducting counterpart in the proton-driven motor; however, in possessing only one hydrophobic domain, it resembles other channels formed by small proteins with single membrane-spanning domains. J Bacteriol, 1994 Oct, 176(19), 5949 - 57 Stringent control during carbon starvation of marine Vibrio sp . strain S14: molecular cloning, nucleotide sequence, and deletion of the relA gene; Flardh K et al.; In order to evaluate the role of the stringent response in starvation adaptations of the marine Vibrio sp . strain S14, we have cloned the relA gene and generated relaxed mutants of this organism . The Vibrio relA gene was selected from a chromosomal DNA library by complementation of an Escherichia coli delta relA strain . The nucleotide sequence contains a 743-codon open reading frame that encodes a polypeptide that is identical in length and highly homologous to the E . coli RelA protein . The amino acid sequences are 64% identical, and they share some completely conserved regions . A delta relA::kan allele was generated by replacing 53% of the open reading frame with a kanamycin resistance gene . The Vibrio relA mutants displayed a relaxed control of RNA synthesis and failed to accumulate ppGpp during amino acid limitation . During carbon and energy starvation, a relA-dependent burst of ppGpp synthesis concomitant with carbon source depletion and growth arrest was observed . Also, in the absence of the relA gene, there was an accumulation of ppGpp during carbon starvation, but this was slower and smaller than that which occurred in the stringent strains, and it was preceded by a marked decrease in the {ATP}/{ADP} ratio . In both the wild-type and the relaxed strains, carbon source depletion caused an immediate decrease in the size of the GTP pool and a block of net RNA accumulation . The relA mutation did not affect long-term survival or the development of resistance against heat, ethanol, and oxidative stress during carbon starvation of Vibrio sp . strain S14. J Bacteriol, 1994 Oct, 176(19), 5897 - 903 Glucose upshift of carbon-starved marine Vibrio sp . strain S14 causes amino acid starvation and induction of the stringent response; Flardh K et al.; The physiological status of carbon-starved cells of the marine Vibrio sp . strain S14 has been investigated by the analysis of their immediate response to carbon and energy sources . During the first minute after glucose addition to 48-h-starved cells, the pools of ATP and GTP increased rapidly, and the {ATP}/{ADP} ratio reached the level typical for growing cells within 4 min . The total rates of RNA and protein synthesis increased initially but were inhibited 4 to 5 min after glucose addition by the induction of the stringent response . A mutation in the relA gene abolished stringent control during the recovery and significantly prolonged the lag phase, before the starved cells regrew, after the addition of a single source of carbon . However, both the wild-type and the relA cells regrew without a significant lag phase when given glucose supplemented with amino acids . On the basis of these results, it is suggested that carbon-starved cells are deficient in amino acid biosynthesis and that ppGpp and the stringent response are involved in overcoming this deficiency, presumably by depressing the synthesis of amino acid biosynthetic enzymes . Furthermore, the data suggest that the starved cells primarily are starved for energy, and evidence is presented that the step-up in the rate of protein synthesis after refeeding is partially dependent on de novo RNA synthesis. Infect Immun, 1994 Oct, 62(10), 4176 - 85 Importance of ADP-ribosylation in the morphological changes of PC12 cells induced by cholera toxin; Glineur C et al.; Cholera toxin (CTX) is composed of two subunits, subunit A, which possesses ADP-ribosyltransferase activity, and subunit B, which is responsible for receptor binding . It has previously been shown that agents that increase cyclic AMP (cAMP) levels in cells induce differentiation of PC12 cells into neurite-like cells . In this report, we show that as little as 100 pg of CTX per ml induces such changes . CTX was found to ADP-ribosylate at least four membrane proteins of PC12 cells in vitro and in vivo and to increase intracellular cAMP levels . We have developed an inducible ctx gene expression system in Vibrio cholerae by using the tac promoter . The culture medium of the CTX-producing bacteria was able to induce the morphological changes and the ADP-ribosylation of the PC12 cell membrane proteins . We have constructed two CTX-cross-reactive mutant proteins (CTX-CRM) by site-directed mutagenesis . The choice of glutamic acid 29 as the target amino acid was based on sequence similarities with other bacterial toxins . CTX-CRM-E29 delta, in which the Glu-29 of the A subunit was deleted, showed strongly reduced ADP-ribosyltransferase activity and did not induce significant morphological changes of PC12 cells . In contrast, CTX-CRM-E29D, in which the Glu-29 was replaced by an aspartic acid, was as active as the wild-type protein . We conclude that the ADP-ribosylation activity of CTX is important for the toxin-induced differentiation of PC12 cells . Pertussis toxin, which had no visible effect on PC12 cell morphology, was also able to ADP-ribosylate a membrane-bound protein(s) in vitro and in vivo . Pertussis toxin alone did not significantly increase cAMP levels in PC12 cells, but it acted synergistically with CTX. Protein Sci, 1994 Oct, 3(10), 1670 - 86 Protein crystallography and infectious diseases; Verlinde CL et al.; The current rapid growth in the number of known 3-dimensional protein structures is producing a database of structures that is increasingly useful as a starting point for the development of new medically relevant molecules such as drugs, therapeutic proteins, and vaccines . This development is beautifully illustrated in the recent book, Protein structure: New approaches to disease and therapy (Perutz, 1992) . There is a great and growing promise for the design of molecules for the treatment or prevention of a wide variety of diseases, an endeavor made possible by the insights derived from the structure and function of crucial proteins from pathogenic organisms and from man . We present here 2 illustrations of structure-based drug design . The first is the prospect of developing antitrypanosomal drugs based on crystallographic, ligand-binding, and molecular modeling studies of glycolytic glycosomal enzymes from Trypanosomatidae . These unicellular organisms are responsible for several tropical diseases, including African and American trypanosomiases, as well as various forms of leishmaniasis . Because the target enzymes are also present in the human host, this project is a pioneering study in selective design . The second illustrative case is the prospect of designing anti-cholera drugs based on detailed analysis of the structure of cholera toxin and the closely related Escherichia coli heat-labile enterotoxin . Such potential drugs can be targeted either at inhibiting the toxin's receptor binding site or at blocking the toxin's intracellular catalytic activity . Study of the Vibrio cholerae and E . coli toxins serves at the same time as an example of a general approach to structure-based vaccine design . These toxins exhibit a remarkable ability to stimulate the mucosal immune system, and early results have suggested that this property can be maintained by engineered fusion proteins based on the native toxin structure . The challenge is thus to incorporate selected epitopes from foreign pathogens into the native framework of the toxin such that crucial features of both the epitope and the toxin are maintained . That is, the modified toxin must continue to evoke a strong mucosal immune response, and this response must be directed against an epitope conformation characteristic of the original pathogen. Immunology, 1994 Oct, 83(2), 288 - 94 Effect of injected yeast glucan on the activity of macrophages in Atlantic salmon, Salmo salar L., as evaluated by in vitro hydrogen peroxide production and phagocytic capacity; Brattgjerd S et al.; A prepared polysaccharide from the cell wall of yeast, M-Glucan, has previously been demonstrated to have immunostimulatory effects in salmonids as observed by enhanced in vivo non-specific disease resistance in Atlantic salmon, Salmo salar L., and increased in vitro bactericidal activity of rainbow trout, Oncorhynchus mykiss (Walbaum), macrophages . In the present study M-Glucan was injected intraperitoneally into Atlantic salmon and the effect on core components in the non-specific part of the immune system was observed . The hydrogen peroxide (H2O2) production of isolated head kidney macrophages from glucan-injected fish was measured 3 and 6 weeks after M-Glucan treatment and was increased at both time-points upon phorbol myristate acetate-(PMA) triggering . Without PMA triggering the difference was only significant 3 weeks after glucan injection when compared to a control group injected with saline . In a phagocytic assay with macrophages and Vibrio salmonicida the initial uptake of bacteria was elevated at both 3 and 6 weeks after glucan treatment . There was no significant difference when uptake of another fish pathogenic bacteria, Renibacterium salmoninarum, was studied . Treatment of Atlantic salmon with M-Glucan also resulted in enhanced serum lysozyme activity in week 3 of the experimental period . The results indicate that M-Glucan elevates the activity of the non-specific part of the immune system and the use of M-Glucan as an immunostimulant is discussed. Mol Microbiol, 1994 Oct, 14(2), 255 - 62 Proximal and distal sites bind LuxR independently and activate expression of the Vibrio harveyi lux operon; Miyamoto CM et al.; The LuxR regulatory protein of Vibrio harveyi as well as the autoinducer molecule, N-(3-hydroxybutanoyl) homoserine lactone, are known to be required for expression of luminescence . Although LuxR has been implicated in the activation of the promoter of the lux operon of V . harveyi, and can bind to two distinct sites upstream of the transcription initiation start site, its mode of action is unknown . In the present experiments, mobility shift assays were used to demonstrate that LuxR bound to the distal and proximal sites in an independent rather than co-operative interaction with a much tighter binding to the distal site . Deletion mutation analyses of DNA upstream of the lux promoter followed by transconjugation into V . harveyi in trans using the chloramphenicol acetyltransferase (cat) gene as a reporter demonstrated, however, that the proximal site for LuxR was absolutely critical for promoter activation while the distal LuxR site was only necessary for maximum activation . This result was confirmed by mutation of the proximal site which blocked activation of the lux promoter and binding of LuxR to this site, but did not prevent LuxR binding to the distal site. Mol Microbiol, 1994 Oct, 14(1), 17 - 29 Transcriptional control of toxT, a regulatory gene in the ToxR regulon of Vibrio cholerae; Higgins DE et al.; Co-ordinate expression of many virulence genes in Vibrio cholerae is under the control of the ToxR and ToxT proteins . These proteins function in a regulatory cascade in which ToxR is required to activate toxT, and ToxT activates virulence genes . The precise mechanism for ToxR activation of toxT is unknown, but data presented in this report suggest a direct involvement of ToxR . Primer extension and gene fusion analyses identified a ToxR-regulated promoter directly upstream of toxT, immediately following a region of inverted repeats capable of terminating transcription . Gel mobility shift studies indicate that ToxR binds DNA within the inverted repeat region, yet preliminary evidence suggests that ToxR binding alone is not sufficient for activation of toxT . Possible mechanisms of ToxR-dependent toxT expression are discussed. J Fla Med Assoc, 1994 Oct, 81(10), 676 - 8 Non 0-1 Vibrio cholerae septicemia and culture negative neutrocytic ascites in a patient with chronic liver disease; Poulos JE et al.; Non 0-1 Vibrio cholerae infection is often associated with ingestion of contaminated seafood and its common presentation is gastroenteritis . Septicemia may be found in immunocompromised hosts resulting in mortality approaching 50% . A case is reported of non 0-1 Vibrio cholerae infection presenting with septicemia in a patient with neutrocytic ascites suggestive of spontaneous bacterial peritonitis. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 295 - 306 {Polymerase chain reaction (PCR) for the identification of toxigenic Vibrio cholerae O1 in oysters}; Rodriguez-Angeles MG et al.; PCR was made with ctx2 (CGG GCA GAT TCT AGA CCT CCT G) y ctx3 (CGA TGA TCT TGG AGC ATT CCC AC) primers for subunit A of cholera toxin, 30 cycles of temperature on samples of 50 g of oysters added in 450 ml of peptone alcaline water that were inoculated with 15 x 10(6), 0.75 x 10(6) and 0.15 x 10(6) CFU/ml of toxigenic 6707 V . cholerae O1 reference strain . The samples were tested by three microbiological methods: INDRE's method uses 1 x 10(-1) dilution of sample, two fold pass to peptone alcaline water pH 9 incubated 18 h and 6 h at 37 degrees C, the Food and Drugs Administration (FDA) method uses 10(-1) to 10(-6) dilutions of sample, 6 h incubation and reincubation for 18 h at 37 and 42 degrees C and the Mexican laboratories (LMD) with 10(-4) to 10(-3) dilutions, the samples were incubated for 6 h and then reincubated for 18 h at two temperatures 37 and 42 degrees C . The PCR by INDRE's method was positive with 3 x 10(2) CFU/ml/g oyster . In the FDA's method the PCR detected DNA in 10(-4) dilution with 3 x 10(1) CFU/ml/g oyster and in LMD's method the PCR was positive in 10(-3) with 3 CFU/ml/g oyster . The results of the PCR were obtained between 5-6 h, and later V . cholerae O1 was isolated by three microbiological methods . The PCR reproducibility was better on DNA sample diluted 1:4 and 10 microliters of sample increased from 1:1000 to 1:10000 the sensitivity of PCR. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 283 - 93 {Identification of Vibrio cholerae O1 by flow cytometry}; Alvarado-Aleman FJ et al.; A total of 72 peptonated water samples suspected of carrying Vibrio cholerae were assessed by laser flow cytometry (LFC) and compared with positive culture . We used a direct fluorescence technique using polyclonal (PolAb) and monoclonal antibodies (MoAb) conjugated to fluorescein . The PolAb were able to detect 33 positive samples . A clear difference among the 20 positive samples was found with only three V . cholerae O1 false negatives when MoAb were used whereas all 13 V . cholerae Non O1 samples were detected . The correlation index comparing control autofluorescence with peptonated water samples show a R = 0.69, versus 0.96 with pure V . cholerae O1 strains . Our data suggest that the LFC technique is able to recognize V . cholerae O1 from a mixture of microorganisms with high sensitivity and specificity in a few hours. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 277 - 81 {Cytotoxic effect of Vibrio cholerae non-O1 on Vero cells}; Figueroa-Arredondo P et al.; At the present time there is still in Mexico a diarrhoeal outbreak due to Vibrio cholerae O1 . In INDRE we have isolated from the same outbreak last year (jan-apr), 70 strains of Vibrio cholerae Non-O1 . These were isolated from patients with a diarrhoeal illness different from cholera . Patients were of different ages and sex, and from various geographic areas . The isolated strains were confirmed by serological agglutination test with polyclonal antisera, and they neither belong to O1 serogroup or O139 . We assayed all the 70 strains in Vero cells, searching for cytotoxic effect, probably attributed to cholera toxin, or any other toxin . The strains were screened by PCR for cholera toxin gene detection, and negative results were obtained . We have found only one CT-producer strain, but it was a rough one so, we are not able to affirm that is not a V . cholerae O1 serotype . Vibrio cholerae Non-O1 strains, tested in Vero cells assay, produced cytotoxic effect within 24 h . It was found that 48/70 strains (66.6%), had cytotoxic activity, showing rounding and then lysis of cells . From our results we concluded that this cytotoxic effect, is not cholera toxin related, instead we propose it could be due to an unknown virulence factor, probably a different toxin in mexican Vibrio cholerae Non-O1 strains. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 273 - 6 {Evaluation of the ELISA method for cholera toxin determination in Vibrio cholerae cultures}; Gonzalez-Bonilla C et al.; ELISA test was evaluated in 503 cultures of Vibrio cholerae O1 y 303 Non-O1 . The cultures were isolated from sewage from different states of Mexico between june 1991 and october 1992 . The sensitivity was 100% and specificity was 96% . Only 12 strains of V . cholerae Non-O1 were positive for CT toxin . When these cultures were confirmed by polymerase chain reaction (PCR) for cholera toxin, the results were negative . ELISA test is a good alternative to be used for toxin production in cultures of V . cholerae, it needs confirmation only with O1 negative and Non-O1 positive reactions. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 263 - 71 {Cytotonic and cytotoxic effect of cholera toxin on Vero cells and its relation to PCR}; Rodriguez-Angeles MG et al.; We studied 40 Vibrio cholerae strains: 16 from stool, 16 from sewage and 8 from food . The serotypes were Inaba in 21 strains, 8 Ogawa strains and 11 V . cholerae non-O1 . PCR was made with ctx2 and ctx3 primers with 25 cycles of temperature: 1 min at 94 degrees C, 1 min at 60 degrees C and 1 min at 72 degrees C . 24 V . cholerae strains were positive: 18/24 Inaba y 6/24 Ogawa . PCR was negative for 16 strains: 3 Inaba serotype, 2 Ogawa y 11 V . cholerae non-O1 . In Vero culture cells 18 strains were cytotonic, 21 cytotoxic and 1 strain was negative . ELISA was positive for 11 strains with PCR positive . The PCR sensitivity was 95.83% compared with culture cells . V . cholerae O1 produced cytotoxic effect on Vero culture cells, maybe related to ACE factor . Colony blot was made with a specific probe labeled with digoxigenin and it could detect 4 Vibrio cholerae toxigenic strains with PCR negative . All V . cholerae Non O1 strains were PCR negative. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 253 - 6 {Seroepidemiology of cholera in Mexico}; Gonzalez-Bonilla C et al.; Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera . Samples from their contacts and from healthy people living in the same communities were also analyzed . Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples . An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera . Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year. Rev Latinoam Microbiol, 1994 Oct-Dec, 36(4), 243 - 51 {Phenotypic and genotypic characterization of Vibrio cholerae O1}; Giono-Cerezo S et al.; We made 52180 tests for isolation and identification of toxigenic V . cholerae O1 from rectal swabs and reference strains . We isolated 17.6% V . cholerae O1 strains in 1991, 43.5% in 1992 and 38.9% in 1993 . The main serovar in 1991 was Inaba, whereas in 1993 a similar percentage was serovar Ogawa . The phenotype of V . cholerae strains was determined by hemolysis test, Voges-Proskauer test, polymyxin B resistance and phages 4 and 5 resistance . All of the mexican strains were El Tor . There were 2.9-0.75% hemolytic strains from 1991 to 1993, but they were negative when the test was made in tube with human erythrocytes . The resistotypes were performed in 24526 selected strains by Kirby-Bauer method and MIC tests . All of the strains were sensitive, except more than 100 strains isolated in Veracruz that were resistant to tetracycline and doxycycline . Detection of cholera toxin was made by ELISA and on culture of Vero and CHO cells . All the V . cholerae O1 strains were toxigenic . The genotype was determined by PCR and ribotyping . The PCR amplified one 564 pb fragment on V . cholerae O1 . The ribotypes of mexican strains were 5 and 6a. Vaccine, 1994 Oct, 12(13), 1231 - 7 Production of Vibrio cholerae ghosts (VCG) by expression of a cloned phage lysis gene: potential for vaccine development; Eko FO et al.; The protein E-specific lysis mechanism of the Escherichia coli-specific bacteriophage PhiX174 was employed to produce Vibrio cholerae ghosts (VCG) . VCG consist of both rounded and collapsed cells that have lost their cytoplasmic contents through an E-specific hole in the cell envelope . These ghosts are proposed as non-living material for immunization against cholera . A specific membrane anchor sequence was used to insert the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) fusion protein into the cell envelope of V . cholerae . The identity of the expression products was confirmed by Western blot analysis employing an RT-specific monoclonal antibody . HIV-1 RT was chosen as a model for the purpose of evaluating heterologous gene expression in V . cholerae and the carrier potential of VCG . Intraperitoneal immunization of mice was used to evaluate the immunogenic potential of VCG . Preliminary results showed significant seroconversions to intact whole-cell vibrio antigens in mice immunized with VCG or a heat-killed whole-cell vibrio preparation. J Biotechnol, 1994 Sep 15, 37(1), 33 - 7 A model system for the continuous production of a heterologous protein using a novel secretion promoting factor which operates in Escherichia coli; Tokugawa K et al.; The 'PAS factor' whose gene has been cloned from a species of Vibrio, is a novel protein secretion factor which is functional in Escherichia coli cells . To demonstrate that practical use of the PAS factor gene is possible, we have constructed a model secretion vector 'pAS23' . Using this system, beta-lactamase was produced and secreted into the medium of a continuous culture system, after optimization of culture conditions. J Bacteriol, 1994 Sep, 176(18), 5631 - 8 Identification, cloning, and sequencing of a gene required for ferric vibriobactin utilization by Vibrio cholerae; Butterton JR et al.; Chromosomal DNA downstream of the Vibrio cholerae ferric vibriobactin receptor gene, viuA, was cloned and sequenced, revealing an 813-bp open reading frame encoding a deduced protein of 271 amino acids . In vitro transcription-translation of this DNA confirmed expression of a protein of the expected size . A deletion mutation of this gene, viuB, was created in the classical V . cholerae strain O395 by in vivo marker exchange . By cross-feeding studies, this mutant was unable to utilize exogenous ferric vibriobactin but synthesized the siderophore normally; synthesis of siderophore by the mutant was also confirmed by the Arnow assay . Complementation of the mutant with a plasmid encoding only viuB restored ferric vibriobactin utilization to normal . Unexpectedly, hydropathicity analysis of ViuB did not reveal a signal sequence or transmembrane domain, suggesting that ViuB is not a periplasmic or membrane protein but may be a cytoplasmic protein involved in ferric vibriobactin uptake and processing, perhaps analogous to the Escherichia coli protein Fes . ViuB was not, however, homologous to Fes or to other proteins in the database . Complementation studies revealed that the cloned V . cholerae viuB gene could complement an E . coli fes mutant but that the cloned E . coli fes gene could not complement a V . cholerae viuB mutant . Northern (RNA) blot analysis of RNA from wild-type V . cholerae grown in high- and low-iron media revealed a monocistronic viuB message that was negatively regulated by iron at the transcriptional level . The promoter of viuB was located by primer extension and contained a nucleotide sequence highly homologous to the E . coli Fur binding consensus sequence, suggesting that expression of viuB is under the control of the V . cholerae fur gene. J Infect Dis, 1994 Sep, 170(3), 701 - 4 The novel epidemic strain O139 is closely related to the pandemic strain O1 of Vibrio cholerae; Berche P et al.; A new Vibrio cholerae serogroup O139 strain of unknown origin recently emerged in India and Bangladesh, causing a major outbreak of cholera . The genetic relationship between this epidemic strain and the O1 strain responsible for the 7th pandemic of cholera was studied by analyzing the DNA polymorphism of V . cholerae by pulsed-field gel electrophoresis and arbitrarily primed polymerase chain reaction . The restriction patterns of the reference strain O139 Bengal and 10 wild O139 strains isolated early in the Indian outbreak strikingly resemble that of the pandemic O1 strain of V . cholerae El Tor, thus suggesting a close genetic relationship among these strains . This similarity contrasts with the genetic heterogeneity of sporadic non-O1 strains isolated in various parts of the world . Study results strongly suggest that the new epidemic O139 strain is closely related to and might be derived from the pandemic O1 strain of V . cholerae. J Bacteriol, 1994 Sep, 176(17), 5450 - 8 Identification of VCR, a repeated sequence associated with a locus encoding a hemagglutinin in Vibrio cholerae O1; Barker A et al.; We have determined the nucleotide sequence of a 6.3-kb BamHI fragment of the chromosome of Vibrio cholerae 569B that includes the sequence of the mannose-fucose-resistant hemagglutinin reported previously (V.L . Franzon, A . Barker, and P . A . Manning, Infect . Immun . 61:3032-3037, 1993) . This region contains nine copies of a 124-bp direct repeat, here named VCR, of imperfect dyad symmetry, that are shown by Southern hybridization to occur at least 60 to 100 times in the V . cholerae O1 chromosome . Large-scale chromosomal mapping suggests that the repeats are confined to about 10% of the chromosome . Related sequences are also found in non-O1 V . cholerae but not in other members of the family Vibrionaceae . However, VCR is unrelated to other previously described repetitive sequences. Infect Immun, 1994 Sep, 62(9), 3859 - 63 Vibrio cholerae non-O1 serogroup associated with cholera gravis genetically and physiologically resembles O1 E1 Tor cholera strains; Hall RH et al.; Until recently, only Vibrio cholerae strains of the O1 serogroup have been associated with epidemic cholera . In December 1992, an outbreak of cholera gravis in Vellore, India, was attributed to a new serogroup of V . cholerae recently designated O139 . Serogroup O139 cholera has since spread to 13 countries and has reached pandemic proportions . Serogroup O139 cholera evades immunity to O1 cholera and is not detected by the standard O1 antigen test . Understanding the origins of O139 cholera and determining the relatedness of O139 to O1 cholera are necessary to device strategies for detecting, reporting, and controlling this new pandemic . In order to determine the origins of this novel cholera serogroup, O139 was analyzed for virulence genes, for virulence proteins and their regulation, and for its genomic background . We found that O139 and O1 V . cholera strains of the E1 Tor biotype possess highly homologous virulence genes encoding cholera toxin and toxin-coregulated pili and that the regulation of virulence protein expression likewise was indistinguishable between O139 and O1 . Pulsed-field gel electrophoresis (PFGE) revealed the restriction digest pattern of O139 strains to be closely related to that of O1 serogroup E1 Tor biotype cholera strains from the Indian subcontinent . However, PFGE showed minor differences among individual O139 cholera isolates, suggesting that O139 V . cholerae is evolving. Vaccine, 1994 Sep, 12(12), 1078 - 82 Immunological memory after immunization with oral cholera B subunit--whole-cell vaccine in Swedish volunteers; Jertborn M et al.; The capacity of peroral immunization with either two or three doses of B subunit-whole cell (B-WC) cholera vaccine to induce immunological memory was examined in Swedish volunteers by testing the immune responses to a single dose of B-WC vaccine given 10 months after the initial immunization . Antibody responses in serum and antibody-secreting cell (ASC) responses in peripheral blood were studied, since these responses seem to reflect the gut mucosal IgA immune responses after oral immunization with B-WC vaccine . Previously immunized volunteers responded to a single dose of B-WC vaccine more frequently and with higher levels of IgA and IgG antitoxin antibodies as well as vibriocidal antibodies in serum than did previously unvaccinated controls . The IgA-ASC responses to cholera toxin B subunit were also higher in primed volunteers than in controls . Two doses of B-WC vaccine were as effective as three doses in inducing immunological memory for cholera immunity . A new B-WC cholera vaccine based on recombinant B subunit had the same capacity as the first generation of B-WC vaccine to induce immunological memory for cholera antitoxin immunity. Kansenshogaku Zasshi, 1994 Sep, 68(9), 1068 - 74 {Serotypes of urease producing Vibrio parahaemolyticus and their relation to possession of tdh and trh genes}; Suzuki N et al.; We analysed 467 isolates of Vibrio parahaemolyticus for possession of tdh/trh gene in comparison with urease production and serotypes . Strains possessing tdh+/trh-, tdh+/trh+, tdh-/trh-, and tdh-/trh- show positive urease production 2.1, 100, 65.7, 100%, respectively . Serotypes of O1:K69, O3:K6, O3:K72, O6:K18, O6:K46 and O1:KUT were frequently positive (100% except 91.7% of the latest one) in urease production . All isolates of O3:K6 prossessed trh, whereas all isolates of certain serotypes including O1:K69 and O3:K72 possessed both trh and trh and tdh genes . Among these, most of O1:K69 and O3:K72 were urease producer . From these results, we speculate that urease production is closely related to the presence of the trh gene or/and lesser production of TDH . We also found the new combination of serovar, O3:K25, O4:K37 and O13:K72 in Kanagawa phenomenon-positive strains. Indian J Med Res, 1994 Sep, 100, 95 - 7 Endemicity of cholera among rural areas of Loni, Ahmednagar district of Maharashtra; Jain RC et al.; A total of 130 Vibrio cholerae strains isolated during November 1989 to December 1992 from the rural population of Loni areas--Ahmednagar district of Maharashtra were characterised . Of these isolates, 124 were El tor vibrios serotype Ogawa, and 6 were El tor vibrios serotype Inaba . One hundred twenty two strains belonging to T4 phage, while 8 strains of El tor vibrio serotype Ogawa were untypable . All the strains isolated, showing haemolytic and non-haemolytic colony variants of El tor V . cholerae, and had resistance of one or more antibiotics . Maximum incidence was observed in November-December, the illness had a mild onset and no fatality was reported. Indian J Med Res, 1994 Sep, 100, 93 - 4 Changing bacteriological profile of cholera in Nagpur, 1991-93; Agarwal V et al.; In Nagpur (Maharashtra) during the period 1991-93, Vibrio cholerae serogroup 01 predominated in 1991 (94.7%) and 1992 (86.4%) but significantly declined in 1993 (10.7%) . Serogroups 02-0138 were infrequently encountered . A new strain V . cholerae serogroup 0139 emerged in 1993 and accounted for 89.3 per cent of the total vibrios isolated in the year . Replacement of the endemic 01 strain by the new 0139 strain was observed. Appl Environ Microbiol, 1994 Sep, 60(9), 3483 - 4 Effect of time and temperature on multiplication of Vibrio vulnificus in postharvest Gulf Coast shellstock oysters; Cook DW; After harvest, shellstock oysters stored under controlled temperatures of 10, 13, and 18 degrees C and at ambient outside air temperature (23 to 34 degrees C) were sampled after 12 and 30 h for Vibrio vulnificus . At 13 degrees C and below, V . vulnificus failed to multiply in the oysters . In oysters held at 18 degrees C for 30 h and under ambient conditions for 12 and 30 h, V . vulnificus numbers were statistically greater (P < 0.05) than those in oysters at harvest . These data indicate that endogenous V . vulnificus can multiply in unchilled shellstock oysters. Zh Mikrobiol Epidemiol Immunobiol, 1994 Sep-Oct, (5), 37 - 41 {A prognostic model of a cholera epidemic}; Boev BV et al.; A new model for the prognostication of cholera epidemic on the territory of a large city is proposed . This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat . The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons . The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state . The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833 . The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city. J Diarrhoeal Dis Res, 1994 Sep, 12(3), 222 - 4 Distribution of Zonula occludens toxin (zot) gene among clinical isolates of Vibrio cholerae O1 from Bangladesh and Africa; Faruque SM et al.; Seventy-two clinical isolates of Vibrio cholerae O1 from Bangladesh, and 12 and 9 isolates respectively from Tanzania and Nigeria were screened for sequences homologous to zonula occludens toxin (zot) and cholera toxin (ctx) genes . As observed previously, all isolates in the present study also possessed sequences for both toxins which suggested that zot does not occur independent of ctx . It appears that along with the virulence genes located in the "virulence cassette" region of the bacterial chromosome, zot may play a role in the pathogenesis of cholera. J Diarrhoeal Dis Res, 1994 Sep, 12(3), 214 - 8 Severity of cholera during concurrent infections with other enteric pathogens; Faruque AS et al.; In a clinic-based case-control study in Bangladesh we evaluated whether children with diarrhoea due to V . cholerae O1 in association with other enteric pathogen(s) are likely to manifest more severe disease as indicated by development of moderate or severe dehydration . Children with moderate or severe dehydration were defined as cases and those with no dehydration were controls; both cases and controls had acute diarrhoea . A systematic sample of 268 dehydrated cases and 699 nondehydrated controls aged 1-35 months with acute watery diarrhoea of 6 days or less was included . In a multivariate analysis it has been shown that infection with Vibrio cholerae O1 in association with another diarrhoea pathogen (odds ratio = 7.07) was strongly correlated with status of dehydration than those with the V . cholerae O1 infection as a single pathogen (odds ratio = 3.63) . Either group was associated with significant risk of dehydration . The results of the study suggest that more than one enteropathogen may be simultaneously involved in causing severe diarrhoea, and appropriate public health measures to reduce environmental contamination should be beneficia Mol Microbiol, 1994 Sep, 13(6), 1013 - 20 TcpA pilin sequences and colonization requirements for O1 and O139 vibrio cholerae; Rhine JA et al.; The distribution, characterization and function of the tcpA gene was investigated in Vibrio cholerae O1 strains of the El Tor biotype and in a newly emergent non-O1 strain classified as serogroup O139 . The V . cholerae tcpA gene from the classical biotype strain O395 was used as a probe to identify a clone carrying the tcpA gene from the El Tor biotype strain E7946 . The sequence of the E7946 tcpA gene revealed that the mature El Tor TcpA pilin has the same number of residues as, and is 82% identical to, TcpA of classical biotype strain O395 . The majority of differences in primary structure are either conservative or clustered in a manner such that compensatory changes retain regional amino acid size, polarity and charge . In a functional analysis, the cloned gene was used to construct an El Tor mutant strain containing an insertion in tcpA . This strain exhibited a colonization defect in the infant mouse cholera model similar in magnitude to that previously described for classical biotype tcpA mutants, thus establishing an equivalent role for TCP in intestinal colonization by El Tor biotype strains . The tcpA analysis was further extended to both a prototype El Tor strain from the Peru epidemic and to the first non-O1 strain known to cause epidemic cholera, an O139 V . cholerae isolate from the current widespread Asian epidemic . These strains were shown to carry tcpA with a sequence identical to E7946 . These results provide further evidence that the newly emergent non-O1 serogroup O139 strain represents a derivative of an El Tor biotype strain and, despite its different LPS structure, shares common TCP-associated antigens.(ABSTRACT TRUNCATED AT 250 WORDS) Food Addit Contam, 1994 Sep-Oct, 11(5), 549 - 58 Antimicrobial action of some GRAS compounds against Vibrio vulnificus; Sun Y et al.; Vibrio vulnificus is a bacterium indigenous to estuarine waters and is known to be a significant human pathogen . Infections are generally associated with the consumption of raw oyster . In an attempt to identify possible antimicrobial agents against this organism that might be used in foods, ten compounds that are generally recognized as safe (GRAS) by the FDA were tested against both the opaque and translucent morphotypes of V . vulnificus . Eight of those compounds had a lethal effect for both morphotypes of this bacterium . Diacetyl had the lowest lethal concentration (50 ppm) of the GRAS compounds tested within 24 h . Lactic acid and butylated hydroxyanisole possessed lethal activities at 300 ppm and 400 ppm, respectively, within 3 h . The mode of action of lactic acid against V . vulnificus appears to be an effect primarily of pH, while the antimicrobial activities of diacetyl and BHA appeared not to be affected by pH . No significant differences were found for opaque to translucent, or from translucent to opaque switching, in examining the possible effects of the GRAS compounds on colonial morphology. Immunol Lett, 1994 Sep, 42(1-2), 67 - 73 Binding of serum autoantibodies to sialidase-treated tracheal epithelial cells . Determination of autoantibodies isotypes in normal and influenza virus infected guinea pig sera; Nahori MA et al.; Cultured epithelial cells isolated from guinea pig trachea were treated with Vibrio cholerae sialidase . The treatment was not cytotoxic and resulted in membrane desialylation as assessed by measurement of sialic acids released, along with an increased fixation of the galactose-specific lectin peanut agglutinin . After incubation in serum from normal guinea pigs, membrane-bound immunoglobulins were detected using peroxidase-labelled antibodies . Sialidase-treated cells bound significantly more IgM than controls (P < 0.0005), whereas binding of IgG was not significantly different between treated and untreated cells (0.1 < P < 0.375); IgA were never detected . In influenza-infected guinea-pigs, as assessed by reactivity with peanut agglutinin, the tracheal and lung epithelium, as well as alveolar cells were hyposialylated . In these animals, the level of serum IgG autoantibodies capable to bind sialidase treated cultured cells increased, while the level of IgM autoantibodies did not change . These autoantibodies may participate in cellular dysfunctions and modified bronchoreactivity that occur during infection of the respiratory tract by sialidase-producing microorganisms, either through activation of the complement system, or subsequently to their reaction with cells expressing membrane complement and/or Fc receptors. Rev Med Chil, 1994 Sep, 122(9), 986 - 92 {Characterization of a multiresistant strain of Vibrio cholerae O1, isolated from a case of cholera in Chile}; Castillo L et al.; This report characterizes a multiresistant Vibrio Cholerae O1 strain, isolated from a patient with cholera, and investigates the mechanism of resistance . The analyzed strain was resistant to tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole . The resistance was mediated by a 101 megadalton plasmid that was transferred to the resultant of a conjugation assay between the multiresistant V . Cholerae strain and E . coli C-600 used as receptor strain, that acquired the triple resistance of the parental strain . The resistant V . cholerae strain had a Ogawa serotype, El Tor biotype and toxigenic capacity, demonstrated by ELISA and latex agglutination techniques . The biochemical features of the strain were identical to those of susceptible strains, except for the resistance to 10 and 150 ug o 129 vibriostatic factor . The emergence of plasmid mediated resistance to drugs of choice in the treatment of cholera must alert Chilean and Latin American health authorities, considering the cholera will continue affecting the region. FEMS Microbiol Lett, 1994 Sep 1, 121(3), 321 - 5 Vibrio vulnificus may produce a metalloprotease causing an edematous skin lesion in vivo; Miyoshi S et al.; Vibrio vulnificus, an opportunistic human pathogen, secretes a metalloprotease which has been suspected of being the causative factor for edematous skin lesions . The antibody against alpha-macroglobulin, the sole plasma inactivator of V . vulnificus metalloprotease, delayed clearance of the protease administered into dorsal skin, and increased the edema-forming ability of living bacterial cells . The derivative of the protease, which is resistant to the inactivating action of alpha-macroglobulin, was not excluded from the dorsal skin . Furthermore, the vibrio inoculated into the mammalian serum was found to produce the protease in adequate amounts . These results suggest that V . vulnificus secretes a metalloprotease into the interstitial-tissue space, resulting in the development of an edematous skin lesion, and that the protease is immediately inactivated by alpha-macroglobulin and subsequently excluded. Biochim Biophys Acta, 1994 Aug 24, 1194(1), 166 - 70 Inhibitory mechanism of Ca2+ on the hemolysis caused by Vibrio vulnificus cytolysin; Park JW et al.; Calcium in millimolar concentrations protected mouse erythrocytes from hemolysis caused by Vibrio vulnificus cytolysin without affecting the release of intracellular K+ from the cells . This effect was maximal at 25 mM CaCl2 . The protection was not absolute and could be partially overcome by increased concentrations of cytolysin . Calcium failed to block both the binding and oligomer formation of cytolysins on the erythrocyte membrane . After pore formation, the continued presence of calcium is required for the prevention of hemolysis . There was hardly any inflow of calcium into the erythrocytes through pores as measured by 45Ca2+ uptake . The presence of calcium after the abolition of Ca2+ gradient by ionomycin cannot inhibit the hemolysis caused by cytolysin . These results suggest that calcium exerts its major inhibitory effect on V . vulnificus cytolysin-induced hemolysis as an osmotic protectant, and that cytolysin may become an useful tool for permeabilizing cells selectively for small ions such as potassium or sodium while preventing the Ca2+ flow. Biochemistry, 1994 Aug 16, 33(32), 9382 - 8 Structure of a myristoyl-ACP-specific thioesterase from Vibrio harveyi; Lawson DM et al.; The crystal structure of a myristoyl acyl carrier protein specific thioesterase (C14ACP-TE) from a bioluminescent bacterium, Vibrio harveyi, was solved by multiple isomorphous replacement methods and refined to an R factor of 22% at 2.1-A resolution . This is the first elucidation of a three-dimensional structure of a thioesterase . The overall tertiary architecture of the enzyme resembles closely the consensus fold of the rapidly expanding superfamily of alpha/beta hydrolases, although there is no detectable homology with any of its members at the amino acid sequence level . Particularly striking similarity exists between the C14ACP-TE structure and that of haloalkane dehalogenase from Xanthobacter autotrophicus . Contrary to the conclusions of earlier studies {Ferri, S . R., & Meighen, E . A . (1991) J . Biol . Chem . 266, 12852-12857} which implicated Ser77 in catalysis, the crystal structure of C14ACP-TE reveals a lipase-like catalytic triad made up of Ser114, His241, and Asp211 . Surprisingly, the gamma-turn with Ser114 in a strained secondary conformation (phi = 53 degrees, psi = -127 degrees), characteristic of the so-called nucleophilic elbow, does not conform to the frequently invoked lipase/esterase consensus sequence (Gly-X-Ser-X-Gly), as the positions of both glycines are occupied by larger amino acids . Site-directed mutagenesis and radioactive labeling support the catalytic function of Ser114 . Crystallographic analysis of the Ser77-->Gly mutant at 2.5-A resolution revealed no structural changes; in both cases the loop containing the residue in position 77 is disordered.(ABSTRACT TRUNCATED AT 250 WORDS) FEMS Microbiol Lett, 1994 Aug 15, 121(2), 181 - 8 Role of iron in the pathogenicity of Vibrio damsela for fish and mammals; Fouz B et al.; The ability to obtain iron of 14 isolates of Vibrio damsela with different degrees of virulence for mice and turbot (Scophthalmus maximus) has been evaluated in artificial and natural iron-restricted environments . All strains were capable of utilizing haemoglobin (Hb) and ferric ammonium citrate (FAC) as the sole iron sources in vitro . However, only virulent V . damsela strains were able to resist the bacteriostatic and bactericidal effects of human and turbot sera, their growth being enhanced by the addition of Hb and FAC . The inhibitory effect of these sera on the growth of the non-pathogenic strain (ATCC 35083), however, was reversed by heat treatment (56 degrees C for 60 min) . The role of iron-availability on the virulence was investigated in iron-overloaded animals . The iron-treatment before the infection resulted in a significant reduction in the LD50 of virulent strains . This fact demonstrates a positive correlation between iron availability in host fluids and degree of virulence in the species Vibrio damsela. J Mol Biol, 1994 Aug 12, 241(2), 283 - 7 Crystallization and preliminary crystallographic analysis of NADPH:FMN oxidoreductase from Vibrio harveyi; Tanner J et al.; Crystals of NADPH:FMN oxidoreductase from Vibrio harveyi have been obtained and characterized by X-ray diffraction . This enzyme plays a role in the generation of light in luminescent bacteria by providing reduced FMN to luciferase . Large, high quality crystals were grown using polyethylene glycol 6000 at pH 7.0 . They crystallize in the monoclinic space group P2(1) with cell dimensions a = 51.2 A, b = 85.9 A, c = 58.1 A, beta = 109.3 degrees, and diffract to 1.8 A . We expect two molecules per asymmetric unit . High resolution data sets have been recorded and a search is under way for heavy-atom derivatives. J Biol Chem, 1994 Aug 12, 269(32), 20785 - 90 Biosynthesis of poly-3-hydroxybutyrate in the luminescent bacterium, Vibrio harveyi, and regulation by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone; Sun W et al.; Poly-3-hydroxybutyrate (PHB), a biopolymer of important commercial applications, is found in a wide range of Gram-negative and Gram-positive bacteria and cyanobacteria . The present study has resulted in the identification of PHB in the luminescent marine bacteria, Vibrio harveyi, in spite of it being previously classified as PHB-negative . PHB granules with distinct membranes were detected by electron microscopy after fixation and staining of V . harveyi cells with malachite green . Analyses by gas chromatography, nuclear magnetic resonance, infrared, and ultraviolet spectroscopy clearly established the presence of PHB . The synthesis of PHB in V . harveyi was found to be under cell density regulation with the levels increasing from 0 (< 0.2) to 26 mg of PHB/g of dry cell weight during growth in a manner analogous to the induction of luminescence in this bacteria . Moreover, synthesis of PHB in V . harveyi was shown to be controlled by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone, providing not only a potential link between luminescence and PHB production but also showing that the lux autoinducer acts as a general signal transductant . These results have also extended the role of homoserine lactones in metabolic regulation to include the control of synthesis of potential energy reserves. Mol Gen Genet, 1994 Aug 2, 244(3), 295 - 302 Gene sequence of recA+ and construction of recA mutants of Vibrio cholerae; Stroeher UH et al.; The recA+ gene of Vibrio cholerae O1 has been cloned, its nucleotide sequence determined and the product characterized . A deletion mutation was constructed in the recA gene and mutants showed the typical sensitivity to UV and to DNA-damaging agents, as well as an inability to mediate homologous DNA recombination . The chromosomal recA deletion mutants in V . cholerae do not show altered virulence in the infant mouse cholera model and are thus ideal strains for use in complementation studies. Appl Environ Microbiol, 1994 Aug, 60(8), 3020 - 2 Urea hydrolysis can predict the potential pathogenicity of Vibrio parahaemolyticus strains isolated in the Pacific Northwest; Ka