Br J Obstet Gynaecol, 1994 Dec, 101(12), 1048 - 53 A longitudinal study of bacterial vaginosis during pregnancy; Hay PE et al.; OBJECTIVE: To determine the longitudinal changes in the incidence of vaginosis in pregnancy . DESIGN: A prospective study of women during pregnancy . SETTING: A District General Hospital in North-West London . SUBJECTS: Seven hundred and eighteen pregnant women attending antenatal clinics . At their first attendance and subsequently, Gram-stained vaginal smears were examined and Mycoplasma hominis and Gardnerella vaginalis were sought by culture . RESULTS: Initially, 87 (12%) women had bacterial vaginosis diagnosed on Gram-stained reading of the vaginal smears . Examination of further smears, obtained from 176 women at 36 weeks of gestation, showed that those whose vaginal flora was normal initially, and who went to term, rarely developed vaginosis (three of 127, 2.4%) . Samples were obtained at 36 weeks gestation from 32 women who had bacterial vaginosis initially, and went to term . In almost 50% (15 of 32) of these a normal lactobacillus-dominated flora had regenerated . Thirty-five women (5%) had initial vaginal smears graded as intermediate . From this group, six of the 17 (35%) women from whom samples were obtained at 36 weeks gestation still had flora of an intermediate pattern; 10(59%) now had normal flora and only one (6%) had developed bacterial vaginosis . Women with bacterial vaginosis were more likely to be culture-positive for M . hominis than those with normal flora (34/78 versus 10/563, odds ratio 42.73 (18.9 to 102.3) P < 0.001), or to be culture-positive for G . vaginalis than those with normal flora (35/78 versus 21/563, odds ratio 21.0 (10.75 to 41.2) P < 0.001) . CONCLUSION: Pregnant women do not commonly develop bacterial vaginosis after 16 weeks gestation, and if present, it remits spontaneously in approximately half of those who reach term . As bacterial vaginosis is associated with increased rates of second trimester miscarriage and preterm delivery, any treatment aimed at its eradication in pregnancy should be given no later than the beginning of the second trimester of pregnancy. Appl Environ Microbiol, 1994 Dec, 60(12), 4487 - 94 Factors involved in adherence of lactobacilli to human Caco-2 cells; Greene JD et al.; A quantitative assay performed with bacterial cells labelled with {3H}thymidine was used to investigate factors involved in the adherence of human isolates Lactobacillus acidophilus BG2FO4 and NCFM/N2 and Lactobacillus gasseri ADH to human Caco-2 intestinal cells . For all three strains, adherence was concentration dependent, greater at acidic pH values, and significantly greater than adherence of a control dairy isolate, Lactobacillus delbrueckii subsp . bulgaricus 1489 . Adherence of L . acidophilus BG2FO4 and NCFM/N2 was decreased by protease treatment of the bacterial cells, whereas adherence of L . gasseri ADH either was not affected or was enhanced by protease treatment . Putative surface layer proteins were identified on L . acidophilus BG2FO4 and NCFM/N2 cells but were not involved in adherence . Periodate oxidation of bacterial cell surface carbohydrates significantly reduced adherence of L . gasseri ADH, moderately reduced adherence of L . acidophilus BG2FO4, and had no effect on adherence of L . acidophilus NCFM/N2 . These results indicate that Lactobacillus species adhere to human intestinal cells via mechanisms which involve different combinations of carbohydrate and protein factors on the bacterial cell surface . The involvement of a secreted bridging protein, which has been proposed as the primary mediator of adherence of L . acidophilus BG2FO4 in spent culture supernatant (M.-H . Coconnier, T . R . Klaenhammer, S . Kerneis, M.-F . Bernet, and A . L . Servin, Appl . Environ . Microbiol . 58:2034-2039, 1992), was not confirmed in this study . Rather, a pH effect on Caco-2 cells contributed significantly to the adherence of this strain in spent culture supernatant.(ABSTRACT TRUNCATED AT 250 WORDS) Lett Appl Microbiol, 1994 Dec, 19(6), 438 - 41 Bacteriocin production by Enterococcus faecium NA01 from 'wara'--a fermented skimmed cow milk product from west Africa; Olasupo NA et al.; An Enterococcus faecium strain from Nigerian fermented skimmed cow milk ('wara') produced bacteriocin inhibitory towards Lactobacillus, Enterococcus and Listeria strains . The bacteriocin (designated enterocin 01) was inactivated by proteases, heat-stable at 100 degrees c and active at pH 2.0-6.0 . The Ent . faecium isolate harboured plasmids of ca 36.3 and 23.1 kb . Curing experiments with ethidium bromide resulted in a bacteriocin-negative mutant which had not lost immunity to the bacteriocin . Slight differences in plasmid profiles between wild-type and mutant indicated a possible plasmid-coded bacteriocin production. J Anim Sci, 1994 Dec, 72(12), 3163 - 8 Effect of creep feeding on selected microflora and short-chain fatty acids in the ileum of weanling pigs; Mathew AG et al.; Pigs cannulated at the ileum were used to investigate the effect of creep feeding on specific intestinal microflora and VFA and lactate concentrations . In two replicate trials performed 50 d apart, a total of 24 15-d-old nursing pigs from seven sows were cannulated in the terminal ileum and randomly assigned to two test groups . One group was allowed access to a creep diet, whereas the other group was denied access to the diet by removal from the farrowing crate . Ileal samples were collected at 19, 22, 26, and 29 d of age (preweaning) and at 33, 36, and 40 d of age (postweaning) . Samples were assayed for total and hemolytic E . coli, total lactobacilli, pH, acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, D(-), and L(+) lactate . Creep feeding did not affect lactobacilli or E . coli concentrations (P > .05), nor did it affect short-chain fatty acid concentrations (P > .05) . Most volatile fatty acid concentrations decreased (P < .05), total lactate increased (P < .05), and the proportion of E . coli that were hemolytic increased (P < .05) following weaning . Consumption of creep feed did not affect specific microbial populations or fermentative byproducts in the ileum of the young pig. J Nutr Sci Vitaminol (Tokyo), 1994 Dec, 40(6), 617 - 21 Effects of skim milk and its fermented product by Lactobacillus acidophilus on plasma and liver lipid levels in diet-induced hypertriglyceridemic rats; Oda T et al.; Effects of skim milk and its fermented product by Lactobacillus acidophilus on plasma and liver triglyceride and cholesterol levels were examined in diet-induced hypertriglyceridemic rats . Male Sprague-Dawley rats at 4 weeks of age were fed a hypertriglyceridemic diet that contained 20% coconut oil, 17.5% fructose, and 17.5% sucrose for 14 days . The test diet was supplemented with either 20% skim milk powder or 20% powder of skim milk fermented by L . acidophilus SBT 2062 . Hypertriglyceridemia was observed in the control group, but plasma cholesterol levels were not increased . Skim milk suppressed the elevation of plasma triglyceride levels, while its fermented product had no significant effect . Both dairy products prevented the elevation of liver triglyceride and cholesterol levels, but had no effect on plasma cholesterol levels. J Nutr Sci Vitaminol (Tokyo), 1994 Dec, 40(6), 613 - 6 Effect of Lactobacillus acidophilus on iron bioavailability in rats; Oda T et al.; The effect of Lactobacillus acidophilus on iron bioavailability in rats was examined by the hemoglobin regeneration method . For hemoglobin depletion, female Wistar rats were fed an iron-deficient diet at 3 weeks of age for 13 days . Rats were then assigned to one of four groups, such that average blood hemoglobin value and average body weight were similar among the groups . For hemoglobin regeneration, they were fed one of two ferrous sulfate-supplemented diets that contained the following iron levels (mg/kg): 13.7 for two groups; 21.7 for the other two groups . In the two groups fed the same diet, one group additionally received oral administration of 2 ml of skim milk fortified with 0.3% yeast extract once or twice a day for 7 days, and other rats were administered with skim milk fermented by L . acidophilus SBT 2062 in the same manner . Hemoglobin regeneration efficiency (HRE) was significantly higher in the fermented product-given rats than in the skim milk-supplied rats . There was no significant interaction in HRE between the dietary iron group and the oral administration group . These results indicate that L . acidophilus SBT 2062 is effective for increasing of iron bioavailability in rats. Bangladesh Med Res Counc Bull, 1994 Dec, 20(3), 129 - 38 Studies on the anaerobic (bacterial) vaginosis among the Bangladeshi women of reproductive age group; Naher A et al.; Vaginal swab from 190 patients aged between 15 to 45 years with the complaint of excessive and foul smelling vaginal discharge and 50 healthy controls of comparable age were studied . Different diagnostic techniques used for the detection of G.vaginalis were compared . Antibiogram of isolated G.vaginalis was also performed to determine the drug sensitivity pattern . G . vaginalis were isolated from 74 patients (38.9%) and from 6 controls (12%) . The rate of isolation of G . vaginalis in the vaginal swabs of patients is significantly higher (p < 0.001) as compared to controls . Vaginal flora in 91% of G . vaginalis positive patients were Gardnerella morphotype and clue cells were found in vaginal discharge in 85% of these cases . In contrast, vaginal flora of 92% control group were Lactobacilli morphotype N and no clue cell was detected . No pus cell was observed in the vaginal discharge of 66 (89.2%) of 74 patients infected with G . vaginalis . Amine test was positive in 81% G . vaginalis positive patients . The test was negative in all the control cases . Significance of these findings were discussed in detail. Can J Microbiol, 1994 Dec, 40(12), 1043 - 50 Cloning of promoter-like sequences from Lactobacillus paracasei subsp . paracasei CG11 and their expression in Escherichia coli, Lactococcus lactis, and Lactobacillus reuteri; Djordjevic G et al.; Fragments of chromosomal DNA from Lactobacillus paracasei subsp . paracasei CG11 (formerly Lactobacillus casei CG11) capable of functioning as promoters were isolated using the broad host range, promoter-probe vector pGKV210 . Five such fragments designated P61, P79, P80, P116, and P144 were completely sequenced and analyzed . Fragment P61 had the highest transcriptional efficiency in Escherichia coli and Lactobacillus reuteri whereas P80 was the most active in Lactococcus lactis . In general, the orders of the transcriptional strengths were almost identical in E . coli and Lactobacillus reuteri but different from that in Lactococcus lactis . Mapping of the 5' end of cat mRNA showed that different regions of fragments P79 and P144 were used as promoters in Lactococcus lactis than in E . coli and Lactobacillus reuteri . Analysis of these DNA sequences revealed that the putative -35 and -10 hexanucleotides resembled those of E . coli, Bacillus subtilis, and lactococci . The spacing between these two hexanucleotides and between the putative -10 hexanucleotide and the transcriptional start point (A residues predominated) ranged from 17 to 18 base pairs and from 5 to 7 base pairs, respectively . Each of the cloned Lactobacillus paracasei CG11 promoter-like fragments contained an AT-rich sequence upstream of the putative -35 region (from 60 to 73%). Int J Food Microbiol, 1994 Dec, 24(1-2), 321 - 7 Effect of three commercial starters on growth of Staphylococcus aureus and enterotoxins (A-D) and thermonuclease production in broth; Gonzalez-Fandos E et al.; The growth of four enterotoxigenic Staphylococcus aureus strains was partially inhibited by three commercial starters used in the meat sausage industry when grown in APT broth at 30 degrees C statically . Starter SP318 (a mixture of selected strains of Lactobacillus sake, Pediococcus pentosaceus and Staphylococcus xylosus) showed the most inhibitory activity . Staphylococcal enterotoxins (A, B, C1 and D) synthesis was totally inhibited by the growth of the three starters, whereas staphylococcal thermonuclease production was partially inhibited in mixed cultures. Int J Food Microbiol, 1994 Dec, 24(1-2), 315 - 9 Cellular fatty acids analysis in the identification of lactic acid bacteria; Gilarova R et al.; The main factors affecting the cellular fatty acid composition such as cultivation temperature, pH and NaCl content of cultivation medium, growth stage and the method of fat isolation are summarised . The effects of these factors on the fatty acids patterns are compared with those found after the cultivation of several strains of Lactobacillus sake and L . pentosus. Int J Food Microbiol, 1994 Dec, 24(1-2), 295 - 308 Scanning electron microscopy of target cells and molecular weight determination of a bacteriocin produced by Lactococcus lactis D53; McDougall LA et al.; A bacteriocin, lactococcin D53, from Lactococcus lactis strain D53 was partially purified by precipitation with ammonium sulfate and dialysis against deionized water, at which time it precipitated from solution . A native molecular weight was determined by gel filtration, where bacteriocin was detected in two fractions which were measured at 104 and 6.7 kDa . A molecular weight of 7.0 kDa under denaturing conditions was determined by Tricine-SDS-polyacrylamide gel electrophoresis . The molecular weight determinations implied that lactococcin D53 complexed with other macromolecules in its native state in solution . Scanning electron micrographs of Lactobacillus D17 target cells treated with lactococcin D53 showed considerable differences from untreated control cells . The bacteriocin-treated cells had rougher, more granular-looking outer surfaces than untreated cells, which appeared smooth . Counts of viable cells in buffer solution rapidly declined by about one log in target cells treated with bacteriocin. Int J Food Microbiol, 1994 Dec, 24(1-2), 191 - 8 Influence of pH, salt and nitrite on the heme-dependent catalase activity of lactic acid bacteria; Mares A et al.; A screening of commercial starter cultures used for the production of dry sausage showed a maximum heme-dependent catalase activity in the range of 60 mumol/l hematin for Lactobacillus sake, Lactobacillus plantarum, Lactobacillus pentosus and Pediococcus acidilactici . Pseudocatalase activity was not detected . In standard dry sausage production, 2-3% (w/w) nitrite salt (0.6% sodium nitrite per 100 g NaCl) is normally added, which corresponds to 4-6% salt in the water phase . In vitro experiments with L . sake and L . plantarum have shown that such a high concentration of salt caused a significant reduction of catalase activity and bacterial growth . In the case of P . acidilactici, the catalase activity remained constant at a salt concentration up to 6% (w/w); at 7% (w/w) the activity decreased sharply . The pH also affected the catalase activity, which remained constant up to pH 5.1 and decreased dramatically at lower values . The effect of nitrite has also been investigated . L . pentosus and P . acidilactici were not affected by the addition of 160 ppm nitrite (NO2-); L . plantarum, on the other hand, showed a significantly reduced catalase activity . In practice, optimum fermentation characteristics combined with an optimum catalase activity which are not inhibited by salt concentrations higher than 6% (w/v) and a residual nitrite content of about 160 ppm (w/v), are of the utmost importance in screening and selection of lactic acid bacteria for starter cultures. Int J Food Microbiol, 1994 Dec, 24(1-2), 179 - 89 Pathogenic potential of lactobacilli; Harty DW et al.; Lactobacilli are often considered to be commensal or beneficial participants in human microbial ecology and considerable research is being carried out into the effects of the use of lactobacilli as additives in both human and animal diets . However, lactobacilli also cause some human diseases (e.g . dental caries, rheumatic vascular disease, septicaemia and infective endocarditis (IE)), and have recently been identified as potential emerging pathogens in elderly and immunocompromised patients, particularly those receiving broad spectrum antibiotic therapy . The identification of potential pathogenic traits amongst lactobacilli will therefore facilitate the use of the organisms for probiotic purposes . The ability to aggregate human platelets is considered to be a possible pathogenic trait in the progression of IE . A comparison of bacterial cell surface properties amongst L . rhamnosus strains showed that platelets were aggregated by 5/5 IE strains and 8/16 laboratory strains . For the L . paracasei subsp . paracasei strains the respective numbers were 2/5 and 2/9 . However two strains, morphological mutants of a non-aggregating strain, which had been re-isolated after passaging through rats were found to aggregate platelets . No loss of aggregating function occurred on extensive subculturing of IE strains . Aggregation also occurred with 11/14 strains for five other species, namely, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus oris, Lactobacillus plantarum and Lactobacillus salvivarius, with each species being represented indicating that the property is not uncommon in the genus . A comparison of IE and oral isolates of L . rhamnosus and L . paracasei subsp . paracasei and seven other Lactobacillus species, has shown that the binding of both fibronectin and fibrinogen by lactobacilli is greatly increased, up to 50 fold, when the pH is reduced from 7.0 to 5.0 . Re-exposing the lactobacilli to a neutral pH environment releases most of the bound proteins, but the amount still remaining bound to the cell is several times more than is bound at neutral pH . Lactobacilli will also bind to the proteins that make up the extracellular matrix of endothelial cells . Lactobacilli bound significantly better to collagen types I and V than to types III and IV (p < 0.01) . Further, strains isolated from IE cases, particularly L . rhamnosus strains, bound significantly better to types I and V than did 'normal' strains (p < 0.02) . Type V collagen has been demonstrated at the sites of endothelial damage . Thus the binding of lactobacilli, particularly L . rhamnosus to these collagen types may be of importance in the early stages of colonization of the damaged heart valve.(ABSTRACT TRUNCATED AT 400 WORDS) Int J Food Microbiol, 1994 Dec, 24(1-2), 103 - 12 Mathematical modelling of the combined effect of water activity, pH and redox potential on the heat destruction; Reichart O et al.; Heat destruction of seven foodborne microorganisms (Lactobacillus plantarum, Lactobacillus brevis, Saccharomyces cerevisiae, Zygosaccharomyces bailii, Yarrowia lipolytica, Paecilomyces varioti and Neosartoria fischeri) as a function of the temperature, pH, redox potential and water activity was studied in synthetic heating media . Several mathematical models were developed for describing the heat destruction rate, most of them resulted in a good correlation between the fitted and measured values . The determination coefficients of the model-fitting were the best in case of lactobacilli and moulds (0.96-0.99) and the worst in case of the yeasts (0.81-0.88). Eur J Biochem, 1994 Nov 15, 226(1), 211 - 8 31P-NMR studies of NADPH, NADP+ and the complex of NADPH and methotrexate with Lactobacillus casei dihydrofolate reductase in the solid state; Gerothanassis IP et al.; 31P-NMR spectra on solid samples of NADP+, NADPH and NADPH bound to Lactobacillus casei dihydrofolate reductase have been recorded using the techniques of cross polarisation, magic angle spinning and high power proton decoupling . The isotropic chemical shifts, the principal components of the shielding tensors and the asymmetry parameters for the 31P nuclei in the 2'-phosphate and pyrophosphate groups have been measured . The isotropic shifts show similar trends to the chemical shifts measured in solution . The isotropic shifts and the shielding tensors for the dianionic and monoanionic states of the 2'-phosphate group have been determined and the presence of both ionisation states has been detected in a solid sample of the lyophilised complex of L . casei dihydrofolate reductase with NADPH and methotrexate . This contrasts with the behaviour in solution, where only the dianionic form is bound to the enzyme . The signals from the two pyrophosphates 31P nuclei in bound NADPH were resolved and identified . The asymmetry parameters in the different ionisation states and the orientations of the shielding tensors within the molecular framework are considered in the context of previous 31P studies on phosphate-containing compounds. Biochemistry, 1994 Nov 15, 33(45), 13373 - 81 Heterodimeric deoxyguanosine kinase/deoxyadenosine kinase of Lactobacillus acidophilus R-26: heterotropic activation of deoxyadenosine kinase subunit implicated by limited proteolysis and affinity labeling; Ikeda S et al.; The deoxyguanosine (dGuo) kinase/deoxyadenosine (dAdo) kinase complex of Lactobacillus has been purified to homogeneity by using a newly constructed dATP-Sepharose column as a final step (2700-fold purification) . A heterodimeric structure for the complex has recently been established {Ikeda et al . (1994) Biochemistry 33, 5328-5334} . On the basis of the kinetic and structural data accumulated so far, a model for the heterotropic activation of the dAdo kinase subunit by dGuo or dGTP is proposed: (1) there is an intrinsic difference in the enzyme conformation of the two subunits, with the dAdo kinase subunit being in a constrained (closed) state and the counterpart dGuo kinase subunit being in a relaxed (open) state, as reflected in their relative Vmax values and in the presence or absence of heterotropic activation, and (2) the conformational change induced by the binding of dGuo or dGTP to the active site of the dGuo kinase subunit causes the activation of the dAdo kinase subunit through subunit--subunit interactions . These proposed mechanisms are strongly supported by the following new findings made in this work: (1) low concentrations of chaotropic agents such as guanidine--HCl were found to increase the Vmax of dAdo kinase up to 2-fold--in the same kinetic fashion, apparently, as the activation by dGuo--while showing no effect on dGuo kinase; (2) the proteolytic inactivation of dAdo kinase by trypsin is significantly slower than that of dGuo kinase, but its rate of inactivation is stimulated by dGTP to the same level as for dGuo kinase; (3) the activating effect of dGuo on dAdo kinase was abolished in the course of differential proteolytic inactivation of the dGuo kinase by trypsin in the presence of dATP; and (4) photoaffinity labeling with {8-14C}-8-azido-Ade produces a new species of kinase heterodimer in which the dAdo kinase subunit is permanently activated as a result of specific labeling of the dGuo kinase active site. J Dent Res, 1994 Nov, 73(11), 1727 - 34 The predominant cultivable flora of sound and carious human root surfaces; van Houte J et al.; Little detailed knowledge exists about the composition of the human root flora . Therefore, the predominant cultivable flora (PCF) was determined for samples of: (1) plaque from sound root surfaces (SRS) in eight subjects without root caries, (2) plaque from incipient root lesions (IRL) in eight subjects with root caries, and (3) carious material from advanced root lesions (ARL) in nine other subjects with root caries . Generally, one root surface was sampled per subject, and organisms-358, 512, and 389 for SRS, IRL, and ARL, respectively-were identified by standard methods . It was found that: (1) streptococci, actinomyces, and veillonellae constituted 84.2, 57.8, and 65.7% of the PCF of SRS, IRL, and ARL samples, respectively; (2) a wide variety of other Gram-positive cocci and Gram-positive and -negative rods was also present; (3) the PCF of many samples was often dominated by few organisms, the identity of which differed from sample to sample; (4) a negative and no association with root caries existed for the PCF levels of the non-mutans streptococci (non-MS) and the actinomyces; and (5) mutans streptococci (MS) and lactobacilli (L) were not always present among the PCF of IRL and ARL, respectively, and non-MS were isolated from the PCF of most lesions and actinomyces from all lesions . Our findings illustrate the complexity of the root surface flora and suggest that root caries development involves organisms other than MS and L. Arch Biochem Biophys, 1994 Nov 1, 314(2), 344 - 50 Mutagenesis of the Lactobacillus casei folylpolyglutamate synthetase gene at essential residues resembling an ATP binding site; Toy J et al.; Site-directed mutagenesis studies were performed on a region of the Lactobacillus casei folylpoly-gamma-glutamate synthetase (FPGS) protein (residues 49 to 52), which is highly conserved when compared to the Escherichia coli and human FPGS proteins . The amino acid sequence of this region, GKGS/T, is similar to the consensus sequence for the A region of a nucleotide binding site, a motif which encodes a phosphate-binding loop . Mutation G49A or K50R, with substitution to amino acids of similar size and charge, resulted in decreases in Vmax/Km of 40- to over 100-fold, depending on the variable substrate . Alteration of G51 to S or T resulted in a large increase in the Km for glutamate . The Km for ATP was not affected more than 4-fold by any of the mutations . Our studies indicate that the conserved region is essential for FPGS function, since many of the mutations resulting in functionally conservative substitutions produced inactive enzymes . However, the mutations affected binding of all three substrates, so there is no direct evidence for involvement of the region in ATP binding. Am J Obstet Gynecol, 1994 Nov, 171(5), 1215 - 20 Desquamative inflammatory vaginitis: a new subgroup of purulent vaginitis responsive to topical 2% clindamycin therapy; Sobel JD; OBJECTIVE: Desquamative inflammatory vaginitis is an uncommon clinical syndrome of unknown cause characterized by diffuse exudative vaginitis, epithelial cell exfoliation, and a profuse purulent vaginal discharge . The purpose of this report is to describe 51 patients with desquamative inflammatory vaginitis, the majority of whom were treated with 2% topical clindamycin in an open observational study . STUDY DESIGN: A retrospective chart review found 51 patients seen in a referral university vaginitis clinic between 1987 and 1993 who met the case definition of desquamative inflammatory vaginitis . All patients had diffuse exudative purulent vaginitis, signs of epithelial cell exfoliation (increased parabasal cells), elevated vaginal pH, and Gram stain findings of complete or relative absence of the normal long gram-positive bacilli and their replacement by gram-positive cocci . RESULTS: No consistent microbiologic pathogen was identified except for the absence of lactobacilli and an overall increase in prevalence of group B streptococci . Intravaginal treatment with 2% clindamycin suppositories resulted in clinical improvement in > 95% of patients and, although relapse occurred in 30%, overall antimicrobial cure was accomplished in all patients . Postmenopausal patients with desquamative inflammatory vaginitis occasionally required supplementary estrogen therapy to maintain remission . CONCLUSION: Desquamative inflammatory vaginitis responsive to topical clindamycin 2% therapy represents an uncommon cause of purulent vaginitis with unique clinical and laboratory characteristics . Evidence suggests a microbial, possibly gram-positive coccal, cause for this syndrome, although a specific bacterial species responsible for all cases has not been identified . The majority of cases occurred in patients in whom estrogen deficiency may have played a role in pathogenesis. J Infect Dis, 1994 Nov, 170(5), 1209 - 15 Effects of H2O2-producing lactobacilli on Neisseria gonorrhoeae growth and catalase activity; Zheng HY et al.; In the vagina and endocervix, Neisseria gonorrhoeae must interact with complex microflora . Among these are lactobacilli, which may inhibit the growth of gonococci . Lactobacillus acidophilus, which produce H2O2 (LB+), and L . acidophilus and Lactobacillus casei, which do not produce H2O2 (LB-), were coincubated with catalase-positive and -deficient strains of N . gonorrhoeae . When the incubation medium was maintained at pH 7.3, neither LB+ nor LB- affected gonococcal growth . However, LB+ caused a significant increase in expression of gonococcal catalase, which could be offset by exposure of the bacteria to exogenous catalase . When coincubation medium was at lower pH (4.8-5.0), there was a significant decrease in gonococcal survival and catalase activity, which was only partly reversed by exogenous catalase . Lysates of LB+ also effectively inhibited gonococcal catalase . This inhibition was retained upon heating of the lysate to 100 degrees C for 15 min but was lost with proteinase K treatment . Thus, LB+ may inhibit growth of gonococci by acidification of the environment, secretion of H2O2, and production of protein inhibitors. Plasmid, 1994 Nov, 32(3), 245 - 53 Sequence of a 2.6-kb cryptic plasmid from a marine cyanobacterium Synechococcus sp; Kawaguchi R et al.; We have shown previously that the copy number of plasmid pSY10 from the marine cyanobacterium Synechococcus sp . NKBG 042902 is dependent on the salinity of the growth medium . We report here the complete nucleotide sequence (2561 bp) of this plasmid . The longest open reading frame, ORF-B (1.08 kb), occurs on a 1.6-kb EcoRI fragment . This ORF encodes a putative protein which is 360 aa residues in length and is 37.8% homologous to the replication protein of plasmid pCA2.4 from Synechocystis sp . strain PCC 6803, 35.8% homologous to an ORF from the Nostoc plasmid pGL2, and 33.2% homologous to the ORF of a plasmid from Lactobacillus plantarum, pC30il . Highly conserved regions of amino acid sequence were also found between ORF-B and other bacterial plasmids. Sex Transm Dis, 1994 Nov-Dec, 21(6), 338 - 44 Effects of Cetyltrimethylammonium naproxenate on the adherence of Gardnerella vaginalis, Mobiluncus curtisii, and Lactobacillus acidophilus to vaginal epithelial cells; Catalanotti P et al.; BACKGROUND AND OBJECTIVES: A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina constitutes a frequent observation in bacterial vaginosis . GOAL OF THE STUDY: Cetyltrimethylammonium naproxenate has been evaluated in vitro to detect antiadhesive properties at subinhibitory concentrations for Gardnerella vaginalis and Mobiluncus curtisii to vaginal epithelial cells (VEC) . STUDY DESIGN: Bacterial strains 14C- and or 3H-labeled were tested for adherence and competition to binding sites in VECs before and after treatment at sub-MIC with cetyltrimethylammonium naproxenate . RESULTS: In control tests of adherence, G . vaginalis and M . curtisii had their maximal adhesion at pH 5.4, L . acidophilus at pH 4.4 . Preincubation of G . vaginalis and M . curtisii with cetyltrimethylammonium naproxenate 2.5 mg/mL (subinhibitory concentration) at pH 5.4 reduced adherence to VECs respectively by 48.3% and 34.1% . The same treatment of L . acidophilus showed no statistically significant difference . Treatment of VECs alone did not modify adherence . Competition tests between L . acidophilus and G . vaginalis and between L . acidophilus and M . curtisii showed that, in small quantities, L . acidophilus could compete with G . vaginalis and M . curtisii for binding sites in VECs at pH 4.4, when pretreated with cetyltrimethylammonium naproxenate . At a higher pH (4.8 and 5.4), L . acidophilus in higher quantities did not compete for binding sites occupied by G . vaginalis and M . curtisii . CONCLUSIONS: Cetyltrimethylammonium naproxenate at subinhibitory concentrations modifies the adhesiveness of G . vaginalis and M . curtisii to VECs, reducing it by 48.3% and 34.1%, respectively . Adhesion of L . acidophilus to VECs is not impaired by pretreatment with cetyltrimethylammonium naproxenate at pH 4.4, even if they are in low number and compete for binding sites against pathogens . At higher pH levels, L . acidophilus did not compete for binding sites occupied by G . vaginalis and M . curtisii. Poult Sci, 1994 Nov, 73(11), 1712 - 23 Performance of single comb White Leghorn layers fed corn-soybean meal and barley-corn-soybean meal diets supplemented with a direct-fed microbial; Nahashon SN et al.; An experiment was conducted with Single Comb White Leghorn (SCWL) layers to determine the effect of feeding either corn-soybean meal (C-S) or barley-corn soybean meal (B-C-S) diets with or without condensed cane molasses solubles (CCMS) or with or without CCMS-1,100 mg Lactobacillus (Lacto)/kg (ppm) diet on performance, nutrient retentions, digesta passage rate, and histological changes of the gastrointestinal (GI) tracts . Six dietary treatments were fed for eight 28-d periods and consisted of C-S (control), C-S + CCMS, C-S + CCMS-1,100 ppm Lacto (4.4 x 107 cfu/mg Lacto), B-C-S (control), B-C-S + CCMS, and B-C-S + CCMS-1,100 ppm Lacto . The CCMS served as the carrier for the Lacto, and the CCMS-Lacto premix (55 g Lacto/kg) was incorporated at 2% of the diet . Lactobacillus supplementation in C-S diets improved (P < .05) egg weight, egg mass, egg size, and body weight gains, and in B-C-S diets improved body weight gains . There were no differences in feed consumption, feed conversion, internal egg quality, and egg specific gravity among the dietary treatments . Passage rates of digesta were increased (P < .05) when either C-S or B-C-S layer diets were supplemented with Lacto . Lactobacillus supplementations of the C-S and B-C-S diets increased (P < .05) fat and calcium, and fat, phosphorus, copper, and manganese retentions, respectively . Increased cellularity of Peyer's patches in the ileum indicated a stimulation of the mucosal immune system that responds to antigenic stimuli by secreting immunoglobulin (IgA). Poult Sci, 1994 Nov, 73(11), 1699 - 711 Production variables and nutrient retention in single comb White Leghorn laying pullets fed diets supplemented with direct-fed microbials; Nahashon SN et al.; Two experiments were carried out for six and seven 28-d periods, respectively, with DeKalb XL Single Comb White Leghorn laying pullets to ascertain the effect of feeding 1,100 mg Lactobacillus (Lacto)/kg diet (ppm) and 2,200 ppm Lacto diets, and the supplementation of these diets with 1 and 3% fat, on layer performance and nitrogen, calcium, and phosphorus retention . The dietary treatments were corn-soybean meal (C-S) control, C-S plus condensed cane molasses solubles (CCMS)-1,100 ppm Lacto (4.4 x 10(7) cfu/mg Lacto), and C-S plus CCMS-2,200 ppm Lacto (8.8 x 10(7) cfu/mg Lacto) without fat (Experiment 1) and without and with 1 and 3% supplemental fat to each Lacto level (Experiment 2) . In both experiments, layers fed the 1,100 ppm Lacto diets had better (P < .05) hen-day production, daily feed consumption, egg mass, egg weight, egg size, and feed conversion than layers fed diets without Lacto . Egg mass, interior egg quality, and feed conversion (Experiment 1), mean body weight gains, and nitrogen, calcium, and phosphorus retention (Experiment 2) were further improved (P < .05) with feeding 2,200 ppm Lacto diets . Feeding Lacto diets with 1% fat provided (P < .05) larger eggs and better (P < .05) nitrogen and phosphorus retention, whereas 3% fat decreased (P < .05) feed consumption and nutrient retention and improved (P < .05) feed conversion and body weight gain . Positive correlations between Lacto diets and nitrogen and calcium retentions, daily feed consumption, and egg size were observed . Feeding 1,100 ppm Lacto diets to layers stimulated appetite and improved egg production, egg mass, egg weight, egg size, and feed conversion . Addition of fat to Lacto diets reduced daily feed consumption and provided better feed conversion, egg masses, egg sizes, body weight gains, and nutrient retentions. Int J STD AIDS, 1994 Nov-Dec, 5(6), 405 - 8 Bacterial vaginosis in a district genitourinary medicine department: significance of vaginal microbiology and anaerobes; Saidi SA et al.; The aim of this study was to correlate the significance of vaginal microbiology, in particular its anaerobic component, to the presence of bacterial vaginosis (BV), and to review the clinical criteria used in the diagnosis of this condition . Ninety-two female patients who received routine STD screening were studied . After routine history, presence and character of vaginal discharge and vaginal pH were noted, an amine test performed, and a wet stain observed microscopically . Routine Gram stain smears and cultures were prepared . BV was diagnosed clinically in 28 (30%) of our sample, and Gardnerella vaginalis was cultured in 41 patients (45%) . Both clue cells and anaerobes were closely associated with each other and both mutually exclusive with the presence of lactobacilli on Gram stain (P < 0.001) . BV was found to be strongly associated with the presence of clue cells on the wet film, anaerobes and G . vaginalis . In conclusion, bacterial vaginosis is not only strongly associated with the presence of G . vaginalis in the vaginal flora, but more strongly with the presence of anaerobes . The study suggests that the microaerophile G . vaginalis is a commensal organism in a significant proportion of sexually active women . If the aerobic status of the healthy vagina is disrupted, anaerobes (including Gardnerella) will flourish, producing the clinical picture of bacterial vaginosis. Oral Surg Oral Med Oral Pathol, 1994 Nov, 78(5), 577 - 82 Cariogenic microflora in patients with Hodgkin's disease before and after mantle field radiotherapy; Keene HJ et al.; Because mantle field radiotherapy is associated with partial xerostomia in patients with Hodgkin's disease, the purpose of this study was to evaluate their cariogenic microflora before and after completion of radiotherapy . We obtained samples of oral saline solution rinse from 40 patients with Hodgkin's disease before radiotherapy and from 31 patients with Hodgkin's disease who had survived 1 to 24 years after radiotherapy . We also evaluated caries experience and history of fluoride gel use for caries prevention in these patients . Mutans streptococci and lactobacilli levels were significantly higher in the postradiotherapy patients with carious teeth, particularly in those with limited home use of fluoride gels . In the postradiotherapy group, caries parameters were significantly higher (p < 0.05) than in the preradiotherapy group . Within the postradiotherapy group, both caries and microbial parameters tended to be higher in patients who were less compliant about using the recommended 0.4% stannous fluoride "brush-in" technique than in those who used the gel regularly at home . This study indicates that for patients with Hodgkin's disease who receive mantle field irradiation during the management of their disease, a sustained brush-in program with stannous fluoride gel can be of benefit for caries prevention and for limitation of oral levels of cariogenic mutans streptococci. Mol Gen Genet, 1994 Nov 1, 245(3), 334 - 8 ISL2, a new mobile genetic element in Lactobacillus helveticus; Zwahlen MC et al.; Spontaneous, phenotypically stable mutations at the beta-galactosidase locus (lacL-lacM) in Lactobacillus helveticus were identified and analyzed . We found that a significant number of mutations were caused by integration of a new IS element, ISL2, into these lac genes . ISL2 is 858 bp long, flanked by 16-bp perfect inverted repeats and generates 3-bp target duplications upon insertion . It contains one open reading frame, which shows significant homology (40.1% identity) to the putative transposase of IS702 from Cyanobacterium calothrix . ISL2 is present in 4-21 copies in the L . helveticus genome, but it is not found in other lactic acid bacteria . Its divergence in copy number and genomic locations in different L . helveticus strains makes it useful as a tool for strain identification by genetic fingerprinting. Appl Microbiol Biotechnol, 1994 Nov, 42(2-3), 280 - 6 Purification and characterization of X-prolyl dipeptidyl peptidase from Lactobacillus casei subsp . casei LLG; Habibi-Najafi MB et al.; X-Prolyl dipeptidyl peptidase, which hydrolysed X-Pro-Y almost specifically, has been purified to homogeneity from crude cell-free extracts of Lactobacillus casei subsp . casei LLG using fast protein liquid chromatography equipped with preparative and analytical anion exchange columns . The enzyme was purified to 274-fold by ammonium sulphate fractionation, and by two successive ion-exchange chromatographies with a recovery of 34% . The purified enzyme appeared as a single band on both native-polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulphate (SDS)-PAGE and had a molecular mass of 79 kDa . The pH and the temperature optima by the purified enzyme were 7.0 and 50 degrees C, respectively . X-PDP was a serine-dependent enzyme, as both diisopropylfluorophosphate and phenylmethylsulphonylfluoride caused complete inhibition of the enzyme activity . The Michaelis constant (Km) and maximum reaction velocity (Vmax) values were 0.2 mM and 43 mM per milligram, respectively. Biosci Biotechnol Biochem, 1994 Nov, 58(11), 2084 - 6 Plasmid-associated bacteriocin production by a Lactobacillus plantarum strain; Kanatani K et al.; A Lactobacillus plantarum strain, LTF154, isolated from a fermented sausage, produces a bacteriocin, designated plantacin 154 . Plantacin 154 was stable to heat treatment, and its activity was sensitive to proteolytic enzymes . The molecular mass, as indicated by activity detection after SDS-PAGE, was estimated to be 3.0 kDa or less . A plasmid-curing experiment and transformation analysis indicated that a 9.5-MDa plasmid, pLP1542, may be involved in the production of plantacin 154. Lett Appl Microbiol, 1994 Nov, 19(5), 345 - 8 Expression of Lactobacillus casei ATCC 393 beta-galactosidase encoded by plasmid pLZ15 in Lactococcus lactis CNRZ 1123; Hemme D et al.; Lactococcus lactis subsp . lactis CNRZ 1123, a Lac- derivative of CNRZ 1122 was transformed by electroporation with the Lactobacillus casei ATCC 393 plasmid pLZ15, which bears a beta-galactosidase gene . The transformants expressed a constitutive beta-galactosidase activity at a higher level than in Lact . casei, and in the cell-free extract two additional protein bands were detected by SDS-PAGE which could correspond to lactose metabolism enzymes . Both plasmid and beta-gal activity were stable in Lactococcus after 100 generations in glucose-containing medium. Minerva Stomatol, 1994 Nov, 43(11), 501 - 5 Lack of correlation between salivary Streptococcus mutans and lactobacilli counts and caries in IDDM children; Canepari P et al.; In a previous clinical study regarding the incidence of caries and the periodontal health, a group of young patients with various levels of glyco-metabolic control was studied and the results showed that the decayed-missing-filled teeth (DMFT) index was higher in insulin dependent diabetes mellitus (IDDM) type 1 patients with a poor glyco-metabolic balance than in a control group or in IDDM patients with sufficient glyco-metabolic balance . In light of these results, the purpose of this study was to find an explanation for these clinical observations by searching at a microbiological level . The results indicate that salivary counts of Streptococcus mutans and lactobacilli were higher in patients with active caries whether or not they be diabetic, than in people with no active caries, but the count of S . mutans was not directly correlated to the DMFT index . No significant alterations were found in salivary flow, pH, buffer capacity and glucose concentration in all the groups in this study . We conclude that the salivary count of S . mutans is not sufficient alone to account for the higher susceptibility to active caries of young IDDM patients with poor glyco-metabolic control. J Mol Biol, 1994 Oct 28, 243(3), 413 - 24 Transcription of the xyl operon is controlled in Bacillus subtilis by tandem overlapping operators spaced by four base-pairs; Dahl MK et al.; The expression of xylose utilization in Bacillus subtilis is regulated at the level of transcription by xylose dependent Xyl repressor-xyl operator interaction . We have structurally and functionally characterized the binding sites of Xyl repressor in the xyl regulatory region . Methylation and hydroxyl radical protection and ethylation interference of binding suggests tandem overlapping xyl operators spaced by four base-pairs . A mutational inactivation of each and both operators was performed . DNA retardation experiments with these mutants confirmed the existance of two binding sites . They can be simultaneously occupied, despite their overlapping, intertwined organization . In vivo repressor titration and regulation of indicator gene expression by the xylO mutants confirmed that both binding sites contribute to regulation of the xyl operon . The protection and interference patterns of both sites are identical and indicate binding of a repressor oligomer to one side of B-form DNA of each operator . A tandem overlapping arrangement of two operators is also found in the xyl regulatory sequences of Bacillus megaterium, Staphylococcus xylosus and Lactobacillus pentosus . The xyl operon of Bacillus licheniformis contains a similar element in which the second operator is more diverged . This high degree of conservation among bacteria of different genera supports the conclusion that a tandem overlapping arrangement of xyl operators contributes to efficient regulation. Biochemistry, 1994 Oct 25, 33(42), 12676 - 85 Coenzyme B12-dependent ribonucleotide reductase: evidence for the participation of five cysteine residues in ribonucleotide reduction; Booker S et al.; Ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the conversion of ribonucleotides to 2'-deoxyribonucleotides and requires adenosylcobalamin (AdoCbl) as a cofactor . Recent cloning, sequencing, and expression of this protein {Booker, S., & Stubbe, J . (1993) Proc . Natl . Acad . Sci . U.S.A . 90, 8352-8356} have now allowed its characterization by site-directed mutagenesis . The present study focuses on the role of five cysteines postulated to be required for catalysis . The choice of which of the ten cysteines of RTPR were to be mutated was based on extensive studies on the Escherichia coli ribonucleoside diphosphate reductase . Despite the differences between these two reductases in primary sequence, quaternary structure, and cofactor requirements, their mechanisms are strikingly similar . The mutagenesis studies reported herein further suggest that the complex role of the five cysteines is also very similar . A variety of single and double mutants of RTPR were prepared (C731S, C736S, C731 and 736S, C119S, C419S, C408S, and C305S), and their interaction with the normal substrate (CTP) was characterized under several sets of conditions . Mutants C731S, C736S, and C731 and 736S all catalyzed the formation of dCTP at rates similar to those of the wild-type (wt) enzyme in the presence of the artificial reductant DTT . In the presence of the in vivo reducing system (thioredoxin, thioredoxin reductase, and NADPH), however, each of these mutants catalyzed the formation of only 0.6-0.8 dCTPs per mole of enzyme . The inability of these mutants to catalyze multiple turnovers with respect to the in vivo reducing system suggests that their function might be to transfer reducing equivalents from thioredoxin into the active site disulfide of the reductase . Mutants C119S and C419S were targeted as being the active site cysteines, the ones which directly reduce the ribonucleotide substrate . As expected, neither of these mutants catalyzed the formation of dCTP . However, they did catalyze a time-dependent formation of cytosine, destruction of the cofactor, and the appearance of a chromophore associated with the protein--all phenotypes previously observed for the corresponding active site cysteines of the E . coli reductase . Mutant C408S was unable to catalyze dNTP production or cytosine release . Moreover, it was ineffective in catalyzing two additional reactions which are unique to this enzyme: the exchange of tritium from the 5' hydrogens of AdoCbl with H2O and the destruction of AdoCbl under anaerobic conditions to give 5'-deoxyadenosine and cob(II)alamin . These results are consistent with the role of this cysteine as the protein radical responsible for initiating catalysis. J Biol Chem, 1994 Oct 21, 269(42), 26116 - 20 Interactions of 2'-modified azido- and haloanalogs of deoxycytidine 5'-triphosphate with the anaerobic ribonucleotide reductase of Escherichia coli; Eliasson R et al.; The anaerobic Escherichia coli ribonucleotide reductase (class III reductase) responsible for the synthesis of the deoxyribonucleotides required for anaerobic DNA replication contains an oxygen-sensitive glycyl radical (Gly-681) suggesting involvement of radical chemistry in catalysis . The amino acid sequence of this enzyme completely differs from that of earlier described aerobic class I (prototype, aerobic E . coli) and class II (prototype, Lactobacillus leichmanii) reductases that use radical chemistry but employ other means for radical generation . Here, we study the interaction between the anaerobic E . coli reductase with the 5'-triphosphates of 2'-chloro-2'-deoxycytidine, 2'-fluoro-2'-deoxycytidine, and 2'-azido-2'-deoxycytidine (N3CTP), which are mechanism-based inhibitors of class I and II reductases and, on interaction with these enzymes, decompose to base, inorganic di(tri)phosphate and 2'-methylene-3(2H)-furanone . Also, with the anaerobic E . coli reductase, the 2'-substituted nucleotides act as mechanism-based inhibitors and decompose . N3CTP scavenges the glycyl radical of the enzyme similar to the interaction of N3CDP with the tyrosyl radical of class I enzymes . However, we found no evidence for a new transient radical species as is the case with class I enzymes . Our results suggest that the chemistry at the nucleotide level for the reduction of ribose by class III enzymes is similar to the chemistry employed by class I and II enzymes. Biochemistry, 1994 Oct 18, 33(41), 12416 - 26 Solution structure of bound trimethoprim in its complex with Lactobacillus casei dihydrofolate reductase; Martorell G et al.; Two- and three-dimensional (2D and 3D) NMR techniques have been used to assign the signals from nearly all of the protons in Lactobacillus casei dihydrofolate reductase (DHFR) (M(r) 18,300) in its 1:1 complex with the antibacterial drug trimethoprim . A sample of uniformly 15N-labeled protein was examined using 3D 15N/1H experiments {nuclear Overhauser, heteronuclear multiple quantum coherence (NOESY-HMQC) and total correlation, heteronuclear multiple quantum coherence (TOCSY-HMQC) experiments} . Twenty-two intermolecular NOEs between trimethoprim and protein protons and four intramolecular NOEs in the ligand have been detected . Some were obtained by using heteronuclear editing and 2D HMQC-NOESY experiments on complexes formed with 15N-and 13C-labeled trimethoprim molecules ({1,3-15N2,2-amino-15N}-and {7-13C,4'-methoxy-13C}trimethoprim) bound to unlabeled protein . The ligand-protein NOEs were used as distance constraints in conjunction with minimum energy and simulated annealing calculations (carried out with X-PLOR) to dock the trimethoprim ligand into dihydrofolate reductase, using as a starting structure the crystal coordinates from a related complex with a similar overall protein structure . The restrained minimum energy calculations and the simulated annealing calculations gave 83 calculated structures with distance violations of < 0.1 A . In all of these, the two aromatic rings of trimethoprim occupied essentially the same region of conformational space in the binding site (RMSD = 0.63 A) . The protein residues nearest to the bound trimethoprim were found to be very similar in all of the structures and agreed well with corresponding contact residues observed in the X-ray crystal studies on trimethoprim complexes formed with Escherichia coli and chicken liver DHFRs. Mol Gen Genet, 1994 Oct 17, 245(1), 117 - 25 Promoter analysis and transcriptional regulation of Lactobacillus pentosus genes involved in xylose catabolism; Lokman BC et al.; The xyl genes in Lactobacillus pentosus are induced by xylose and repressed by glucose, ribose, and arabinose . Northern blot analysis showed that regulation is mediated at the transcriptional level . Under inducing conditions, two xylA transcripts were detected, a major transcript of 1.5 kb and a minor transcript of 3 kb . The 3 kb transcript also comprises sequences from xylB, suggesting that xylA and xylB are transcribed together . A 1.2 kb xylR transcript was found under inducing and non-inducing conditions . In the presence of xylose, a second xylR transcript (> 7 kb) was detected, which includes sequences from two upstream genes, xylQ and xylP . The transcription start sites for xylA and xylR were mapped by primer extension and S1 nuclease experiments at 42 and 83 nucleotides, respectively upstream of the translation start sites . Induction by xylose of the chloramphenicol acetyltransferase (CAT) gene under control of the xylA promoter, on a multicopy plasmid, was 60 to 80-fold, but only 3 to 10-fold in the presence of glucose and xylose . Expression of CAT under control of the xylR promoter was constitutive at a level tenfold less than that observed under control of the xylA promoter . Sequence analysis suggests the presence of two operator-like elements, one overlapping with the promoter -35 region of xylA and controlling the expression of xylA by binding factors involved in catabolite repression, and a second operator downstream of the promoter -10 region of xylA, which may bind the product of xylR, the repressor.(ABSTRACT TRUNCATED AT 250 WORDS) Biochem J, 1994 Oct 15, 303 ( Pt 2), 401 - 5 3H-n.m.r . studies of multiple conformations and dynamic processes in complexes of folate and methotrexate with Lactobacillus casei dihydrofolate reductase; Curtis N et al.; {7,3',5'-3H3}- and {7,9-3H3}-folic acid and {7,3',5'-3H3}methotrexate (MTX) have been prepared and 3H-n.m.r . spectra obtained for their complexes with Lactobacillus casei dihydrofolate reductase (DHFR) . The 3H results confirm the presence of three pH-dependent different conformational forms in the complex DHFR.NADP+.folate . The folate benzoyl ring could be shown to be in essentially the same environment in the different forms, with the major differences being associated with the pterin ring . The appearance of a single resonance for the 3',5'-tritons showed that the benzoyl ring is flipping rapidly in all three forms . In contrast, the MTX complex was shown to exist as a single conformational state with the benzoyl ring flipping rate being too low to give a single averaged signal for the 3',5'-nuclei over the temperature range 283-313 K. Microbiology, 1994 Oct, 140 ( Pt 10), 2859 - 65 Permeabilization of mycolic-acid-containing actinomycetes for in situ hybridization with fluorescently labelled oligonucleotide probes; Macnaughton SJ et al.; The application of whole-cell hybridization using labelled oligonucleotide probes in microbial systematics and ecology is limited by difficulties in permeabilizing many Gram-positive organisms . In this investigation paraformaldehyde treatment, acid methanolysis and acid hydrolysis were evaluated as a means of permeabilizing mycolic-acid-containing actinomycetes prior to hybridization with a fluorescently labelled oligonucleotide probe designed to bind to a conserved sequence of bacterial 16S rRNA . Methods were evaluated on stationary-phase cultures of Gordona bronchialis, Mycobacterium fortuitum, Nocardia asteroides, N . brasiliensis, Rhodococcus equi, R . erythropolis, R . fascians, R . rhodochrous and Tsukamurella paurometabola, none of which could be probed following 4% (w/v) paraformaldehyde fixation . For comparison and to test the general applicability of mild acid pretreatments, Bacillus subtilis, Lactobacillus plantarum, Escherichia coli and Pseudomonas putida were also studied . The data showed that most of the mycolic-acid-containing organisms were successfully permeabilized by mild acid hydrolysis in 1 M HCl at 37 degrees C . Cells were treated for different lengths of time . In general, the mycolic-acid-containing organisms required between 30 and 50 min hydrolysis, whereas B . subtilis, E . coli and P . putida were rendered permeable in only 10 min . Interestingly, L . plantarum could not be permeabilized using acid hydrolysis even after 60 min exposure to 1 M HCl. Microbiology, 1994 Oct, 140 ( Pt 10), 2601 - 10 A Lactococcus lactis gene encodes a membrane protein with putative ATPase activity that is homologous to the essential Escherichia coli ftsH gene product; Nilsson D et al.; A gene, encoding a protein homologous to an essential Escherichia coli protein, FtsH, was identified adjacent to the hpt gene and the trnA operon in the Gram-positive bacterium Lactococcus lactis . The deduced amino acid sequence of the gene product showed full-length similarity to FtsH of E . coli, Yme1p of Saccharomyces cerevisiae and a conserved region found in a new family of putative ATPases . In-frame fusions of L . lactis ftsH and phoA1 in E . coli, and immunodetection of the L . lactis FtsH protein in cell fractions using anti-E . coli FtsH serum showed that L . lactis ftsH was expressed and encodes a membrane protein . When contained on a high copy number plasmid, the L . lactis ftsH gene complemented the lethality of a delta ftsH3::kan mutation in E . coli at 37 degrees C and below, indicating that the L . lactis ftsH gene can functionally replace the E . coli ftsH gene to some extent . The resulting E . coli strain showed temperature sensitivity and salt sensitivity . A L . lactis mutant with an insertion into ftsH was salt-, heat- and cold-sensitive . These results suggest that FtsH is somehow involved in stress responses . Southern hybridization analysis indicated that genes homologous to ftsH of L . lactis were also present in Bacillus subtilis, and several Lactobacillus and Leuconostoc species, suggesting high conservation of ftsH in bacterial species. Am J Dent, 1994 Oct, 7(5), 271 - 4 Fluoride, remineralization and root caries; Featherstone JD; This paper reviews the probable mechanism of dental caries and the role of fluoride in the inhibition or reversal of that process . The initial stages of root caries are comparable to enamel caries, being the acid dissolution of mineral resulting from acids generated by bacterial metabolism . The fermentation of carbohydrates by oral bacteria including mutans streptococci and lactobacilli initiate the root caries process, removing mineral from among the organic matrix which is primarily composed of collagen . Subsequent to this demineralization, the organic material can be further broken down by bacterial enzymes . Fluoride inhibits mineral loss during the acid dissolution process and enhances remineralization in a similar manner to that which occurs in dental enamel. Appl Environ Microbiol, 1994 Oct, 60(10), 3529 - 35 Development of an amylolytic Lactobacillus plantarum silage strain expressing the Lactobacillus amylovorus alpha-amylase gene; Fitzsimons A et al.; An amylolytic Lactobacillus plantarum silage strain with the starch-degrading ability displayed by Lactobacillus amylovorus was developed . An active fragment of the gene coding for alpha-amylase production in L . amylovorus was cloned and integrated into the chromosome of the competitive inoculant strain L . plantarum Lp80 at the cbh locus . The alpha-amylase gene fragment was also introduced into L . plantarum Lp80 on an autoreplicative plasmid . Both constructions were also performed in the laboratory strain L . plantarum NCIB8826 . All four recombinant strains secreted levels of amylase ranging from 23 to 69 U/liter, compared with 47 U/liter for L . amylovorus . Secretion levels were higher in L . plantarum NCIB8826 than in L . plantarum Lp80 derivatives and were higher in recombinant strains containing autoreplicative plasmids than in the corresponding integrants . The L . plantarum Lp80 derivative containing the L . amylovorus alpha-amylase gene fragment integrated into the host chromosome secreted alpha-amylase to a level comparable to that of L . amylovorus and was stable over 50 generations of growth under nonselective conditions . It grew to a higher cell density than either the parent strain or L . amylovorus in MRS medium containing a mixture of starch and glucose as the fermentable carbohydrate source . This recombinant alpha-amylolytic L . plantarum strain would therefore seem to have considerable potential as a silage inoculant for crops such as alfalfa, in which water-soluble carbohydrate levels are frequently low but starch is present as an alternative carbohydrate source. Appl Environ Microbiol, 1994 Oct, 60(10), 3522 - 8 Identification and purification of a protein that induces production of the Lactobacillus acidophilus bacteriocin lactacin B; Barefoot SF et al.; Lactacin B is a heat-stable bacteriocin produced by Lactobacillus acidophilus N2 that is active against closely related lactobacilli, including Lactobacillus delbrueckii subsp . lactis (formerly Lactobacillus leichmannii) ATCC 4797 . Pure producer cultures propagated in MRS broth (initial pH 6.5) contain no lactacin B; it is detected only in cultures maintained at pH 5.0 to 6.0 and produced optimally at pH 6.0 S . F . Barefoot and T . R . Klaenhammer, Antimicrob . Agents Chemother . 26:328-334, 1984) . Associative growth of producer and indicator, L . delbrueckii subsp . lactis ATCC 4797, resulted in production of an inhibitor identical to lactacin B . Associative growth increased lactacin B production from nondetectable levels (< 100 activity units {AU}/ml) to between 3,200 and 6,400 AU/ml in MRS broth (initial pH 6.5) and resulted in early but equal production of lactacin B (approximately 25,600 AU/ml) in broth maintained at pH 6.0 . Indicator cells, but not spent culture filtrates, induced lactacin B production . Indicator cells disrupted by a French pressure cell yielded cell-free filtrates containing inducing activity . Chromatofocusing and gel filtration high-performance liquid chromatography of cell-free filtrates yielded a protein with a pI of 4.1 and a molecular size of approximately 58 kDa that induced lactacin B production . Analytical isoelectric focusing yielded a single protein band . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels contained a 28-kDa protein suggesting a two-subunit structure . Protein sequencing identified an N-terminal serine and 18 additional amino acids . To our knowledge, there are not previous descriptions of proteins that induce bacteriocin production in lactic acid bacteria. FEMS Microbiol Rev, 1994 Oct, 15(2-3), 217 - 37 Genetics of lactose utilization in lactic acid bacteria; de Vos WM et al.; Lactose utilization is the primary function of lactic acid bacteria used in industrial dairy fermentations . The mechanism by which lactose is transported determines largely the pathway for the hydrolysis of the internalized disaccharide and the fate of the glucose and galactose moieties . Biochemical and genetic studies have indicated that lactose can be transported via phosphotransferase systems, transport systems dependent on ATP binding cassette proteins, or secondary transport systems including proton symport and lactose-galactose antiport systems . The genetic determinants for the group translocation and secondary transport systems have been identified in lactic acid bacteria and are reviewed here . In many cases the lactose genes are organized into operons or operon-like structures with a modular organization, in which the genes encoding lactose transport are tightly linked to those for lactose hydrolysis . In addition, in some cases the genes involved in the galactose metabolism are linked to or co-transcribed with the lactose genes, suggesting a common evolutionary pathway . The lactose genes show characteristic configurations and very high sequence identity in some phylogenetically distant lactic acid bacteria such as Leuconostoc and Lactobacillus or Lactococcus and Lactobacillus . The significance of these results for the adaptation of lactic acid bacteria to the industrial milk environment in which lactose is the sole energy source is discussed. J Med Microbiol, 1994 Oct, 41(4), 272 - 8 Genetic modification of a vaginal strain of Lactobacillus fermentum and its maintenance within the reproductive tract after intravaginal administration; Rush CM et al.; Many micro-organisms cause important diseases of the female genital tract . Because systematic vaccination does not usually provide a good immune response at mucosal sites, commensal lactobacilli from the female genital tract were developed as vehicles to deliver continued doses of foreign antigen directly to the genital mucosal surface with the aim of stimulating strong local mucosal immune responses . Lactobacilli were shown to be common inhabitants of the genital tract of the animal model studied, the guinea-pig . One species, Lactobacillus fermentum, was found in all guinea-pigs studied and was chosen for genetic manipulation . Improved methods of electroporation were developed to enable the routine transformation of L . fermentum BR11 strain with the broad host range plasmid pNZ17 . This recombinantly modified Lactobacillus strain was shown to possess good segregational stability over 120 generations in the absence of antibiotic selection . When this recombinant L . fermentum strain was administered to the vaginal tract of three guinea-pigs it persisted for only 5 days . Despite the relatively short period of persistence in these initial experiments, this novel vaccine approach could provide an effective means of stimulating mucosal immunity in the female genital tract. J Nutr Sci Vitaminol (Tokyo), 1994 Oct, 40(5), 491 - 8 Agar plate method using Lactobacillus plantarum for biotin determination in serum and urine; Fukui T et al.; An improved agar plate method of biotin bioassay using Lactobacillus plantarum ATCC 8014 and bromocresol purple was established to determine biotin levels in human serum and urine . Samples were treated with 4.5 N H2SO4 to liberate free biotin, autoclaved for 1 h and neutralized by 4.5 N NaOH, then 10 microliters was added to wells in each plate . The biotin levels were measured in 190 serum and 59 urine samples, and the means were 2.7 +/- 0.53 ng/ml and 12.4 +/- 5.56 ng/mg of creatinine, respectively . The intra-assay coefficient varience (CV) were 3.2 (n = 20) and 1.3% (n = 23), respectively . The recovery of biotin added (10 ng/ml) to serum was 110.7%, and to urine was 99.6% . These findings suggest that this assay is sufficiently accurate and reproducible for routine use in the clinical laboratory . The excretion of orally administered biotin was also demonstrated by the method. J Biochem (Tokyo), 1994 Oct, 116(4), 818 - 25 Isolation and characterization of the prolyl aminopeptidase gene (pap) from Aeromonas sobria: comparison with the Bacillus coagulans enzyme; Kitazono A et al.; The Aeromonas sobria pap gene encoding prolyl aminopeptidase (PAP) was cloned . It consists of 425 codons and encodes a homotetrameric enzyme of 205 kDa . The purified enzyme showed an almost absolute specificity for amino-terminal proline . Proline and hydroxyproline residues from many peptide and amide substrates could be easily removed, while no activity was detected for substrates having other amino terminals . The enzyme was very similar to that from Bacillus coagulans in many aspects, such as the strong inhibition caused by PCMB and the weak or no inhibition caused by DFP and chelators, respectively . However, these enzymes show only 15% identity in their amino acid sequences . Differences were also observed in their molecular weight, stability and activity toward some peptide substrates . When aligning the deduced amino acid sequence with known sequences from other microorganisms, conserved sequences were found at the amino-terminal region; the significance of these conserved regions is discussed . Based on the results of this work, and on the studies available to date, the occurrence of at least two types of PAPs is postulated . One group would be formed by the Bacillus, Neisseria, and Lactobacillus enzymes, and the other by enzymes such as the Aeromonas PAP. Indian J Med Res, 1994 Oct, 100, 172 - 6 A quantitative microbiological study of bacterial vaginosis; Roy S et al.; A quantitative microbial study of vaginal secretions from 100 women with bacterial vaginosis (BV) and 50 healthy women matched for age, was undertaken . This was aimed at comparing the bacterial flora colonising the vagina of sexually active asymptomatic women with those with BV and correlating bacterial counts with presence of symptoms . Of the total 475 bacteria isolated anaerobes were predominant among controls and among patients aerobes and anaerobes had equal prevalences . The increased viable counts of all anaerobes (> 10(7) cfu/g) were related with symptoms . Mobiluncus mulieris could be isolated from one patient and Chlamydia trachomatis antigen was absent in all samples tested . Bacteroides, G . vaginalis and Ureaplasma urealyticum were found to be the most commonly occurring group in women with BV . Lactobacillus, and probably Coryneforms have a protective role in health, preventing disease. Int J Food Microbiol, 1994 Oct, 23(2), 179 - 96 Characterisation of lactic acid bacteria isolated from naturally fermented Greek dry salami; Samelis J et al.; A total of 348 lactic acid bacteria isolated from five batches of naturally fermented dry salami at various stages of ripening were characterised . The majority of the strains were assigned to two main phylogenetic groups of species: (i) the psychrotrophic, formerly called atypical, meat streptobacteria (169 strains) and (ii) a new genus Weissella (120), which was recently proposed (Collins et al., 1993) to include Leuconostoc paramesenteroides and some other closely related species . Meat streptobacteria were identified as Lactobacillus curvatus (88 strains) and L . sake (76), whereas 5 strains were indistinguishable and, thus designated L . sake/curvatus . Non-psychrotrophic streptobacteria were also isolated and identified as L . plantarum (34 strains), L . farciminis (10), L . coryniformis (1) and L . casei subsp . pseudoplantarum (1) . The majority of the Weissella strains (86) were leuconostoc-like bacteria; four of them were identified as W . viridescens, 11 belonged to the newly described W . hellenica (Collins et al., 1993), another 11 resembled W . paramesenteroides, whereas 60 isolates were not classified to any species . The latter group comprised strains that produced D(L)-lactate . The remaining Weissella were gas-forming, arginine-positive rods assigned to W . minor (31) and W . halotolerans (3) . Other species identified were Enterococcus faecium (10), Leuconostoc mesenteroides (1), L . brevis (1) and Pediococcus sp . (1) . The main criteria used to distinguish between above species as well as their distribution on the five salami batches in relation to their succession with time and suitability as starters were discussed. G Chir, 1994 Oct, 15(10), 429 - 32 {Immune evaluations in cancer patients after colorectal resection}; Losacco T et al.; The authors report a protocol of immunomodulation and monitoring of the intestinal function in coloresected patients using fermented milk (yoghurt) . Intestinal immunity was evaluated with respect to CD4+ cells armed with secretory intestine-derived IgA, and to CD8+ cells armed with IgG aiming to an additional effect in the host protection against Gram-negative strains, such as Salmonella typhi, whose particularly high incidence in Apulia accounts for an increased immunitary activity . Ten patients (six females, four males), age ranging from 44 to 85 years, who underwent surgery between 1989 and 1992, each of whom had been prescribed a daily ration of 500 gr skimmed yoghurt for one month, were observed . The authors suggest that yoghurt may determine a higher release of gamma-IFN with activation of CD4+ and CD8+ cells . The Lactobacillus stimulation of the B lymphocytes of the Peyer plates seems to induce an increased production of secretory IgA that bind to the CD4+ surface, and of IgG (as an anamnestic response to challenge with yoghurt lactobacilli) . Coloresected patients show an immunitary deficiency related to the Gram+ bacterial flora reduction and consequently a decrease in the physiological stimuli . Although these date concern a limited sample, the authors stress the importance of the restoration of bacterial flora in coloresected patients. Minerva Ginecol, 1994 Oct, 46(10), 583 - 6 {Cetyltrimethylammonium naproxenate as vaginal lavage in the therapy of vulvovaginal dystrophies in the postmenopause}; Plotti G et al.; A peculiar aspect of the postmenopausal period is atrophy of the lower genital tract, vagina and vulva . This is due to estrogen deficiency and is accompanied by vaginal pH elevation, lower number of lactobacilli and increased incidence of aspecific vulvovaginitis . We tested a new vaginal douche with an antibacterial-anti-inflammatory (non antibiotic-nonsteroidal) principle, cetyltrimethylammonium naproxenate 0.223% as an adjunct to classical estrogen topical replacement therapy . We treated 34 menopausal patients (mean age 67 yrs) in a double parallel controlled (15 A only estrogen topical therapy vs 19 B topical estrogen plus cetyltrimethylammonium naproxenate douches uid) study for 30 days . A significant reduction of symptoms was obtained in both groups although a faster reduction has been seen in the group treated with both drugs (= B) . In conclusion a better replacement of physiological pH with reappearance of lactobacilli, a selective action on vaginal pathogens, a faster symptom remission and an higher psychophysical welfare can be attributed to the vaginal douche used in adjunct to classical estrogen topical therapy. Ethiop Med J, 1994 Oct, 32(4), 223 - 9 Inhibition of spoilage and food-borne pathogens by lactic acid bacteria isolated from fermenting tef (Eragrostis tef) dough; Nigatu A et al.; A study was carried out at the Department of Biology, Addis Abeba University, in 1991 to determine the inhibitory potential of fermenting tef and the lactic acid bacteria isolated from fermenting tef dough on Salmonella spp., Pseudomonas aeruginosa, Klebsiella spp., Bacillus cereus and Staphylococcus aureus . The test bacteria grew in the fermenting tef uptill 30 hr or till the pH dropped to 4.7 . Thereafter, growth was inhibited and decreases in population were apparent . The results showed that the spent media from all of the four lactic acid bacterial isolates, namely, Lactobacillus spp., Pediococcus spp., Leuconostoc spp . and Streptococcus spp . inhibited the test bacteria . Acidity on its own was not responsible for the inhibition of the test bacteria . The spent medium from Streptococcus spp . showed the best inhibitory activity amongst the lactic acid bacteria. Poult Sci, 1994 Oct, 73(10), 1552 - 62 Phytase activity, phosphorus and calcium retention, and performance of single comb White Leghorn layers fed diets containing two levels of available phosphorus and supplemented with direct-fed microbials; Nahashon SN et al.; The presence of phytase activities in condensed cane molasses solubles (CCMS) and CCMS-Lactobacillus (Lacto) were determined . Single Comb White Leghorn layers were fed .25 and .45% available P (AP) diets supplemented with CCMS and CCMS-Lacto for nine 28-d periods to determine phytase activities of the gastrointestinal (GI) tract contents and intestine, liver, and pancreatic tissues, the GI tract pH, the P and Ca retention, and layer performance . Six dietary treatments were corn-soybean (C-S) control, C-S+CCMS, and C-S+CCMS-1,100 mg Lacto/kg diet (ppm) {4.4 x 10(7) cfu/mg Lacto} each with .25 and .45% AP . The CCMS were used as a carrier for the Lacto, and the CCMS and CCMS-Lacto premix were incorporated at 2% of the diets . Phytase activity was much higher in CCMS-Lacto premix than in CCMS . Phytase activities of the crop contents were higher with the CCMS-Lacto diets regardless of the AP level . Intestinal phytase activity was higher with the .45% AP CCMS-Lacto diet than the unsupplemented .45% AP diets . Lactobacillus supplementation did not stimulate phytase activities in the intestinal contents or liver and pancreatic tissues . The pH of the crop and intestinal contents were much lower for the Lacto-fed layers than the layers fed unsupplemented diets regardless of dietary AP levels . No differences in Ca retentions were observed with Lacto supplementation regardless of the dietary AP levels . However, higher P retentions were observed with the Lacto supplementation in the .25% AP diet . Layers fed .25 and .45% AP Lacto-supplemented diets had lower hen-day egg production, poorer feed conversion value, consumed slightly more feed, produced less egg mass, and laid larger eggs than the layers fed .25 and .45% AP unsupplemented diets . Lacto supplementation to .25% AP diet produced eggs with higher specific gravity than the unsupplemented .45% AP diet, but not different from unsupplemented .25% AP diet . Layers fed the .25% AP diets had lower BW gains then layers fed the .45% AP diets regardless of lacto supplementation . Phytase activity was present in the lacto source, and the presence of phytase and Lacto supplementation to a .25% AP diet improved P retention in layers. Appl Microbiol Biotechnol, 1994 Oct, 42(1), 108 - 15 Expression of a chitinase gene from Serratia marcescens in Lactococcus lactis and Lactobacillus plantarum; Brurberg MB et al.; A chitinase gene from the Gram-negative bacterium Serratia marcescens BJL200 was cloned in Lactococcus lactis subsp . lactis MG1363 and in the silage inoculum strain Lactobacillus plantarum E19b . The chitinase gene was expressed as an active enzyme at a low level in Lactococcus lactis, when cloned in the same transcriptional orientation as the gene specifying the replication protein of the vector pIL253 . Using the expression vectors pMG36e and pGKV259 with lactococcal promoter fragments p32 and p59, the expression in L . lactis was increased nine- and 27-fold, respectively . An additional twofold increase was obtained after cloning the gene under the control of p59 in the high-copy number replicon pIL253 . In Lactobacillus plantarum, chitinase activity was expressed from p32, and the activity was at the same level as under p32 control in L . lactis. Appl Microbiol Biotechnol, 1994 Oct, 42(1), 100 - 7 Characterization and evaluation of a pta (phosphotransacetylase) negative mutant of Escherichia coli HB101 as production host of foreign lipase; Hahm DH et al.; In order to evaluate the pta(phosphotransacetylase) (-) mutant of Escherichia coli as a potential host of foreign lipase expression, the pta(-) mutant HB101 was constructed for the purpose of blocking the acetate synthetic pathway . Since acetate is known as a major inhibitory by-product of cell growth and foreign protein production, the growth characteristics and expression kinetics of the microbial lipase of the pta(-) E . coli mutant were investigated . The growth rate was considerably decreased (about 30%) when grown on M9 minimal media containing glucose, mannose or glycerol . Growth retardation was not observed when a gluconeogenic carbon source (acetate, malate or succinate) was utilized . It should be noted that the growth rate of the mutant was enhanced (about 20%) in modified M9 media including a gluconeogenic carbon source and NZ-amine . Growth inhibition of the pta(-) mutant by menadione, a representative redox-cycling drug, was more pronounced than that of the parental type of E . coli . Furthermore, the inhibition effect was more pronounced in glucose minimal medium, whereas the menadione sensitivity was not observed when a gluconeogenic carbon source was used as a sole carbon source or the lactate dehydrogenase gene from Lactobacillus casei was introduced in the pta(-) mutant . Therefore, it is suggested that the growth deficiency of the pta(-) mutant is closely related to the intracellular redox balance . When the pseudomonad lipase was expressed in the pta(-) mutant, a comparable expression rate and yield to the parental type strain was observed . High-cell-density culture of the mutant was easy to achieve even under the fluctuating conditions of residual glucose concentration. Lett Appl Microbiol, 1994 Oct, 19(4), 188 - 91 Evidence for the presence of plasmids in four therapeutically important strains of Lactobacillus acidophilus; Kumar R et al.; Four therapeutically important strains of Lactobacillus acidophilus designated as R, 301, 1899 and NCFM were screened for the presence of plasmids . Two lysis methods were used for the isolation of plasmid DNA: an alkaline method and a more gentle technique . It was found that the gentle lysis method yielded better plasmid DNA both quantitatively and qualitatively . All four strains studied apparently possess plasmids . The strains 301 and NCFM possessed one plasmid each, with a size of 4.2 kb, whereas R possessed three plasmids (3.5, 2.4 and 2.1 kb) and 1899 possessed two plasmids (4.1 and 4.2 kb) . Restriction analysis revealed that the plasmid DNA from strain R was cleaved by Bam HI but not by Hind III and Eco RI . The plasmid DNA from the remaining three strains was cleaved by all three restriction enzymes used. Arch Oral Biol, 1994 Oct, 39(10), 907 - 11 Influence of caries-preventive measures in mothers on cariogenic bacteria and caries experience in their children; Kohler B et al.; Preventive measures, which reduced the salivary level of mutans streptococci in mothers, delayed colonization by these organisms in their children . The preventive programme was discontinued when the children were 3 years old . These children, at the age of 7 years, and their mothers were now examined to determine the effect of the earlier caries-preventive approach . The control mothers had significantly higher levels of salivary mutans streptococci and lactobacilli than the test mothers (p < 0.05) . The median level of salivary mutans streptococci was 0.6 x 10(6) c.f.u . (colony-forming units) per ml in the test mothers and 1.3 x 10(6) c.f.u . in the control mothers . The median level of salivary lactobacilli was 10 times higher in control than test mothers (80 x 10(3) and 7 x 10(3) c.f.u . per ml, respectively) . Significantly more children of control than test mothers carried mutans streptococci (95 versus 46%) (z-test; p < 0.01) . Children of test mothers had lower salivary levels of mutants streptococci and lactobacilli (p < 0.05) . Twenty three % of the test children were caries-free, compared with 9% of the control children (z-test; p < 0.01) . The mean caries experience of the test children was also significantly lower than that of the control children (defstot 5.2 and 8.6, respectively; p < 0.05) . The results show that reduction of the mutans streptococci in the mother during the emergence of the primary teeth in her child has a long-term influence on colonization by these bacteria and the caries experience in the child. Microbiology, 1994 Oct, 140 ( Pt 10), 2591 - 600 Cloning and nucleotide sequence analysis of pepV, a carnosinase gene from Lactobacillus delbrueckii subsp . lactis DSM 7290, and partial characterization of the enzyme; Vongerichten KF et al.; Cell extracts of Lactobacillus delbrueckii subsp . lactis DSM 7290 were found to exhibit unique peptolytic ability against unusual beta-alanyl-dipeptides . In order to clone the gene encoding this activity, designated pepV, a gene library of strain DSM 7290 genomic DNA, prepared in the low-copy-number plasmid pLG339, was screened for heterologous expression in Escherichia coli . Recombinant clones harbouring pepV were identified by their ability to allow the utilization of carnosine (beta-alanyl-histidine) as a source of histidine by the E . coli mutant strain UK197 (pepD, hisG) . Complementation was observed in a colony harbouring a recombinant plasmid (pKV101), carrying pepV . A 2.4 kb fragment containing pepV was subcloned and its nucleotide sequence revealed an open reading frame (ORF) of 1413 nucleotides, corresponding to a protein with predicted molecular mass of 51998 Da . A single transcription initiation site 71 bp upstream of the ATG translational start codon was identified by primer extension . No significant homology was detected between pepV or its deduced amino acid sequence with any entry in the databases . The only similarity was found in a region conserved in the ArgE/DapE/CPG2/YscS family of proteins . This observation, and protease inhibitor studies, indicated that pepV is of the metalloprotease type . A second ORF present in the sequenced fragment showed extensive homology to a variety of amino acid permeases from E . coli and Saccharomyces cerevisiae. J Dent, 1994 Oct, 22(5), 273 - 8 Killing of cariogenic bacteria by light from a gallium aluminium arsenide diode laser; Burns T et al.; Suspensions of Streptococcus mutans, S . sobrinus, Lactobacillus casei and Actinomyces viscosus were exposed to light from a gallium aluminium arsenide laser in the presence of aluminium disulphonated phthalocyanine and the numbers of survivors determined . Exposure to the laser light in the absence of the dye, or the dye in the absence of the laser light, had no significant effect on the viability of the organisms . However, a light-dose-related decrease in the viable count of all four target organisms was found on exposure to the laser light in the presence of the dye . The kills attributable to lethal photosensitization amounted to approximately 10(6) CFU in the case of each organisms . As appreciable kills were achieved within clinically convenient exposure times (30-90 s), these results imply that lethal photosensitization may be a useful technique for eliminating bacteria from carious lesions prior to restoration. Cancer Lett, 1994 Sep 30, 85(1), 93 - 103 Non-immunologically-mediated cytotoxicity of Lactobacillus casei and its derivative peptidoglycan against tumor cell lines; Fichera GA et al.; Lactobacillus casei, which shows antitumoral activity mediated by the stimulation of cellular defence mechanisms, and its peptidoglycan were tested for their ability to inhibit in vitro the viability of various murine (Yac-1, P815, Ehrlich ascites tumor, mammary carcinoma) and human (K562, KB) tumor cell lines through primary cytotoxic activity . Treatment of these tumor line with L . casei or its peptidoglycan at different doses and for different times demonstrated a decrease in viability by 25-30% . This cytotoxic activity was revealed by 51Cr release, succinate dehydrogenase (SDH) activity, ATP assays and morphological alterations in the treated tumor cells . Immunoenzymatic assays (ELISA) showed a precise ratio of binding between Ehrlich ascites or YAC-1 cell membranes and peptidoglycan . This binding is discussed with regard to the structure of the peptidoglycan molecule . The results suggest that L . casei and its derivative peptidoglycan have both a stimulating activity in normal cells and an inhibiting activity in tumor cells, as has been found for other immunomodulatory complexes. FEMS Microbiol Lett, 1994 Sep 15, 122(1-2), 145 - 51 Cloning and expression of the plasmid encoded beta-D-galactosidase gene from a Lactobacillus plantarum strain of dairy origin; Mayo B et al.; The beta-galactosidase (beta-Gal) gene from Lactobacillus plantarum C3.8 was cloned and expressed in Lactococcus lactis and Escherichia coli . Hybridization experiments indicated that the gene is located on a plasmid and is present in other strains of Lactobacillus plantarum . Its sequence is very similar to a Leuconostoc lactis beta-Gal gene . Expression of the gene, both in Lactobacillus plantarum and in Lactococcus lactis, was four-fold higher in cells growth in lactose compared to those grown in glucose . The presence of the beta-Gal gene in Lactococcus lactis allowed this bacterium to be efficient in clotting milk. FEMS Microbiol Lett, 1994 Sep 15, 122(1-2), 121 - 8 Determination and comparison of Lactobacillus delbrueckii ssp . lactis DSM7290 promoter sequences; Matern HT et al.; The transcriptional start points of ten Lactobacillus delbruckii ssp . lactis DSM7290 genes were determined by primer extension . The upstream located promoter regions, including potential -35 and -10 regions and the spacing between them were compared to the well-known Escherichia coli and Bacillus subtilis promoters . The Lb . delbruckii -35 consensus sequence (TTGACA) seems to be less conserved then the E . coli sequence . The nucleotides TGC were often found upstream of the -10 region (TATAAT) . The most frequently observed spacing between the two core promoter regions was 17 nt and the main distance between the -10 region and the transcriptional start point was mostly determined to be 6 nt in contrast to 7 nt, as described for E . coli promoters . The preferred initiation nucleotides in Lb . delbruckii were shown to be definitely purines (A or G) . The ribosome binding sites located downstream of the promoters revealed the consensus sequence 3'-UCCUCCU-5', being the predicted 3'-OH end of the Lactobacillus 16S rRNA with a high degree of homology to known 16S rRNAs. Experientia, 1994 Sep 15, 50(9), 846 - 9 Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones; Tsuchiya H et al.; Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro . Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml. Eur J Biochem, 1994 Sep 15, 224(3), 991 - 7 Characterization and expression of the Lactobacillus helveticus pepC gene encoding a general aminopeptidase; Vesanto E et al.; An aminopeptidase C gene (pepC) was detected by nucleic acid hybridization from an industrially important Lactobacillus helveticus strain . Three hybridization positive clones were isolated from a gene library of this L . helveticus strain, and one of them was characterized in more detail . Deletion mapping localized the hybridization positivity into a 2.8-kb fragment, which also encoded aminopeptidase activity . This fragment was sequenced and two open reading frames (ORF1 and 2) of 1347 and 840 base pairs were identified . The ORF1 was preceded by a typical prokaryotic promoter region, and an inverted repeat structure with delta G of -49.0 kJ mol-1 was found downstream of the coding region . The deduced amino acid sequence of ORF1, with an encoding capacity for a 51.4-kDa protein, was shown to share 48.3% and 98.0% identities with the PepC proteins from Lactococcus lactis and L . helveticus CNRZ32, respectively, thus confirming that ORF1 codes for an aminopeptidase C . mRNA size analyses revealed 1.7-kb and 2.7-kb transcripts in Northern blot with the pepC-specific probe . A further analysis with the pepC- and ORF2-specific probes showed that downstream ORF2 is co-transcribed with the pepC gene at the exponential phase of growth whereas, at the stationary growth phase, transcripts derived from the pepC promoter were below the detection limit, and the ORF2 was expressed by its own promoter . The 5' end mapping of the pepC transcripts with primer extension revealed one transcription start site suggesting a new position for the pepC promoter region when compared to that predicted for the L . helveticus CNRZ32 pepC gene . Expression of pepC was also studied in L . helveticus as the function of growth in a bioreactor study . Transcription of pepC was typical to exponential growth phase expression . The level of total thiol-aminopeptidase activity, however, remained nearly constant throughout the stationary growth phase. J Gen Virol, 1994 Sep, 75 ( Pt 9), 2537 - 41 Restriction map of the genomic DNA of Lactobacillus casei bacteriophage PL-1 and nucleotide sequence of its cohesive single-stranded ends; Nakashima Y et al.; A restriction map of the genomic DNA of Lactobacillus casei phage PL-1 was constructed using the restriction endonucleases BamHI, EcoRI, HindIII, KpnI, NruI and XhoI . The PL-1 genome was 42.2 kb in size and had complementary cohesive ends forming a ring-like monomer . The cohesive ends, analysed with exonuclease III and S1 nuclease, were 3'-terminated single strands protruding from both ends . The nucleotide sequence of the cohesive ends, determined by the dideoxynucleotide method, comprised four A + T and 10 G + C pairs: 5' GAGGCCGACCGTTC 3'/3' CTCCGGCTGGCAAG 5' . Thus, the cohesive ends of PL-1 DNA were higher in G + C content than those of other known bacteriophage DNAs. J Bacteriol, 1994 Sep, 176(17), 5330 - 40 Isolation of a novel IS3 group insertion element and construction of an integration vector for Lactobacillus spp; Walker DC et al.; An insertion sequence (IS) element from Lactobacillus johnsonii was isolated, characterized, and exploited to construct an IS-based integration vector . L . johnsonii NCK61, a high-frequency conjugal donor of bacteriocin production (Laf+) and immunity (Lafr), was transformed to erythromycin resistance (Emr) with the shuttle vector pSA3 . The NCK61 conjugative functions were used to mobilize pSA3 into a Laf- Lafs EMs recipient . DNA from the Emr transconjugants transformed into Escherichia coli MC1061 yielded a resolution plasmid with the same size as that of pSA3 with a 1.5-kb insertion . The gram-positive replication region of the resolution plasmid was removed to generate a pSA3-based suicide vector (pTRK327) bearing the 1.5-kb insert of Lactobacillus origin . Plasmid pTRK327 inserted randomly into the chromosomes of both Lactobacillus gasseri ATCC 33323 and VPI 11759 . No homology was detected between plasmid and total host DNAs, suggesting a Rec-independent insertion . The DNA sequence of the 1.5-kb region revealed the characteristics of an IS element (designated IS1223): a length of 1,492 bp; flanking, 25-bp, imperfect inverted repeats; and two overlapping open reading frames (ORFs) . Sequence comparisons revealed 71.1% similarity, including 35.7% identity, between the deduced ORFB protein of the E . coli IS element IS150 and the putative ORFB protein encoded by the Lactobacillus IS element . A putative frameshift site was detected between the overlapping ORFs of the Lactobacillus IS element . It is proposed that, similar to IS150, IS1223 produces an active transposase via translational frameshifting between two tandem, overlapping ORFs. Berl Munch Tierarztl Wochenschr, 1994 Sep, 107(9), 302 - 7 {Protein fingerprinting as a method for strain-specific differentiation of technologically useful Lactobacillus strains from clinical isolates}; Klein G et al.; Lactobacilli are often used in products of animal origin because of their technological properties and as protective cultures against pathogenic microorganisms, however they are supposed to be related to human infections as well . Therefore 39 strains of species that are in biotechnological usage, including the type strains, and some clinical isolates were investigated . 9 strains of L . acidophilus, 7 of L . gasseri and 23 strains of L . rhamnosus were tested . Biochemical and physiological properties were proved by classical tests . Analysis of the total soluble cytoplasmatic protein patterns was performed with diamine silver staining, a technique not previously applied to lactobacilli . Classical tests were able to confirm all strains as belonging to one of the three species . Analysis of protein patterns allowed to differentiate between strains of the same species . In case of L . acidophilus biotechnologically used strains and clinical isolates were clustered separately . L . rhamnosus formed three clusters . SDS-PAGE of proteins together with diamine silver staining seems to be helpful to detect intra-species differences . It was stated, that technologically used strains of lactobacilli could clearly be differentiated from another and also from clinical isolates. Z Lebensm Unters Forsch, 1994 Sep, 199(3), 186 - 90 Regulation of acetic acid production by homo- and heterofermentative lactobacilli in whole-wheat sour-doughs; Martinez-Anaya MA et al.; The efficiency of sour-dough as a possible preservative agent of microbial spoilage of bread depends on its acetic acid content . As a secondary metabolite of sugar fermentation by lactic acid bacteria, acetic acid may be promoted in the presence of O2 or H+ acceptors . This paper studies the influence of O2 and high fructose content products (pure sugar, invert sugar, fructose syrup) addition on acetic acid production by hetero- (Lactobacillus brevis 25a, B-21, L-62; L . sanfrancisco L-99) and homofermentative (L . plantarum B-39) lactobacilli in whole-wheat sour-doughs {280 and 250 dough yield (DY)} . The pH and total titratable acidity (TTA) of sour-doughs after 44 h fermentation varied with DY and strain . As expected, the addition of O2 promoted greater increases in TTA with heterofermentative lactobacilli (15-42%) than with L . plantarum (15%) . Fructose addition was only effective for heterofermentative strains, but the overall effects were smaller than those observed for oxygenation . The ability of lactobacilli to produce acetic acid in sour-doughs without treatment varied from 0.16 g/100 g flour at 44 h (B-39, 280, 350 DY) to 0.47-0.65% (L-62, 280, 350 DY) . The production of acetic acid was positively promoted by all treatments . Oxygenation was again the most effective way of inducing acetic acid production; increases ranged from 54% (B-21) to 269% (L-99, 350 DY) . The addition of H+ acceptors had variable effects.(ABSTRACT TRUNCATED AT 250 WORDS) Microbiology, 1994 Sep, 140 ( Pt 9), 2263 - 9 Nucleotide sequence and structural organization of the small, broad-host-range plasmid pCI411 from Leuconostoc lactis 533; Coffey A et al.; The nucleotide sequence of the Leuconostoc lactis 533 cryptic plasmid pCI411 (2926 bp) was determined . Analysis revealed the presence of three open reading frames (ORFs) . ORF 1 was capable of encoding a 24.9 kDa peptide which shared homology with the replication initiation protein (RepB) from a number of Gram-positive rolling circle plasmids . ORF 2 could encode a peptide of 6.6 kDa which was homologous to the RepC protein of the lactococcal plasmid pWV01 . A function could not be assigned to ORF 3, which was capable of encoding a 12.1 kDa peptide . Transcription-translation analysis indicated the presence of three peptides of the predicted molecular masses . A putative double strand origin of replication (DSO) was identified which showed strong similarity with the DSO of a number of Gram-positive plasmids including pE194 from Staphylococcus . Structural analysis identified a number of direct and indirect repeats in addition to putative recombination-specific sites (RSA and RSB) in the non-coding region of pCI411 . The observed characteristics suggest that this plasmid replicates using the rolling circle mechanism . pCI411, which could be introduced into Leuconostoc, Lactococcus, Streptococcus, Lactobacillus and Bacillus is the first plasmid from the genus Leuconostoc to be characterized in such detail. Ann Thorac Surg, 1994 Sep, 58(3), 887 - 9 Transmission of Lactobacillus pneumonia by a transplanted lung; Jones SD et al.; Herein we report Lactobacillus pneumonia in a lung transplant recipient . The organism may have been normal flora in the donor but was a pathogen in the immunosuppressed recipient . Antibiotic therapy should include penicillin or clindamycin. Appl Environ Microbiol, 1994 Sep, 60(9), 3419 - 20 Deconjugation of bile acids by lactobacilli in the mouse small bowel; Tannock GW et al.; Conjugated and unconjugated bile acid concentrations in the small bowel contents and portal serum samples collected from mice with and without lactobacilli (RLFL and RLF, respectively) as gastrointestinal inhabitants were measured . The major portion of bile acids in the small bowel contents of RLFL mice was unconjugated (67.9%) in contrast to that of RFL animals in which a smaller portion of bile acids was unconjugated (23.5%) . This study demonstrated that bile salt hydrolase produced by lactobacilli is active under the conditions prevailing in the proximal small bowels of mice. Eur J Biochem, 1994 Sep 1, 224(2), 439 - 46 NAD(+)-dependent D-2-hydroxyisocaproate dehydrogenase of Lactobacillus delbrueckii subsp . bulgaricus . Gene cloning and enzyme characterization; Bernard N et al.; A genomic library from Lactobacillus delbrueckii subsp . bulgaricus was used to complement an Escherichia coli mutant strain deficient for both lactate dehydrogenase and pyruvate formate lyase, and thus unable to grow anaerobically . One recombinant clone was found to display a broad specificity NAD(+)-dependent D-2-hydroxyacid dehydrogenase activity . The corresponding gene (named hdhD) was subcloned and sequenced . The deduced amino acid sequence of the encoded enzyme indicates a 333-residue protein closely related to D-2-hydroxyisocaproate (i.e . 2-hydroxy-4-methyl-pentanoate) dehydrogenase (D-HO-HxoDH) of Lactobacillus casei and other NAD(+)-dependent D-lactate dehydrogenases (D-LDH) from several other bacterial species . The hdhD gene was overexpressed under the control of the lambda phage PL promoter and the enzyme was purified with a two-step method . The L . delbrueckii subsp . bulgaricus enzyme, like that of L . casei, was shown to be active on a wide variety of 2-oxoacid substrates except those having a branched beta-carbon. Urol Nefrol (Mosk), 1994 Sep-Oct, (5), 19 - 21 {The microbiocenosis of the intestinal mucosa during the treatment of infectious urogenital diseases with fluorinated quinolones}; Kisina VI; Intestinal microecology was studied in 52 patients (47 females and 5 males aged 18-61) with urogenital infections . Group 1 consisted of 35 patients with new-onset urogenital infections, group 2 of 17 patients had long-term recurrent urogenital infection . All the patients exhibited abnormal intestinal mucosal flora manifest more definitely in group 2 . The microfloral changes comprised reduced count of bifidal bacteria, E . Coli, lactobacteria, occurrence of atypical bacteria . Administration of fluorinated quinolones (abactal or maxaquine) affected aerobic intestinal microflora and insignificantly influenced anaerobic bacteria . It is thought valid to investigate intestinal flora in patients with urogenital infections for taking adequate corrective measures. Plant Foods Hum Nutr, 1994 Sep, 46(2), 117 - 26 Effect of roasting and fermentation on viscosity of cereal-legume based food formulas; Wanink JF et al.; With the view of preparing semi-liquid weaning foods of high energy content, the influence of roasting (stationary hot air treatment) and fermentation (with natural and pure culture inocula) on the viscosity of maize-sorghum-soya porridges was investigated . Roasting resulted in porridges of significantly higher viscosity (cooked porridge cooled to 40 degrees C) . Porridges made from the individual ingredients (maize, sorghum, soya) did not show this behaviour . Natural fermentation of mixed ingredients resulted in lower porridge viscosities (cooked porridge cooled to 40 degrees C, as well as hot-paste peak viscosity) when pH was 5.0-5.5 . At lower pH the viscosity of the final porridges increased . Fermentation experiments of individual ingredients inoculated with pure cultures of Lactobacillus plantarum and Candida famata lead to the conclusion that various factors contribute to the effect of fermentation on porridge viscosity . Porridges of minimum viscosity are obtained at pH 5.0-5.5 corresponding with a moderate extent of fermentation . From a consumer safety point of view, it would be preferable to acidify to lower pH values (pH < 4.5) . If necessary, viscosity adjustments could be made using malted cereals. J Radiat Res (Tokyo), 1994 Sep, 35(3), 147 - 56 Timing in administration of a heat-killed Lactobacillus casei preparation for radioprotection in mice; Tsuneoka K et al.; A single subcutaneous injection of a preparation of heat-killed Lactobacillus casei (LC 9018), given before or after irradiation, significantly increased the survival rate of mice that had received 8.5-Gy 137Cs whole-body gamma-irradiation . A similar radioprotective effect was observed when LC 9018 was administered within the period from 2 days before irradiation to 9 h after irradiation, the pre-irradiation treatment being slightly better than the post-irradiation treatment . Increases in the weight of the spleen and in the number of endogenous spleen colonies on days 8 and 12 after irradiation suggested that the radioprotective effect was based on enhanced recovery of hematopoietic tissues . The activity of macrophage colony-stimulating factor (M-CSF) in serum was rapidly increased by the treatment and was maintained at the elevated level for 13 days . At the same time, an increased level of M-CSF mRNA was detected in the livers of the treated mice . However, LC 9018 failed to save the lives of mice when administered 3 days after irradiation, although it increased serum M-CSF as effectively as noted above . The small advantage of the pre-irradiation over the post-irradiation treatment was not explained by the increases of metallothionein in the hematopoietic tissues of the treated mice. Nutrition, 1994 Sep-Oct, 10(5), 392 - 6 Diarrhea with enteral feeding: prospective reappraisal of putative causes; Heimburger DC et al.; Our objective was to test, in tube-fed patients whether treatment with antibiotics, the presence of hypoalbuminemia, or the use of hypertonic tube feeding is associated with a higher incidence of diarrhea; how often tube feeding actually causes diarrhea; and whether administration of a Lactobacillus preparation reduces the incidence of diarrhea . Our study design included a randomized, double-blind, placebo-controlled trial of patients on tube feeding for at least 5 days . Stool weights and clinical assessment of bowel function were used as outcome measures . Diarrhea was defined as > 200 g of stool, or three or more liquid stools, in any 24-h period . The tube feeding was considered responsible for diarrhea only when the latter resolved on discontinuation of the feeding . When diarrhea did not resolve, other causes were sought . Of 62 patients enrolled, 41 reached a trial end point . Of these, 34 completed 5 days of feeding without diarrhea, and 7 experienced diarrhea . Although diarrhea was associated with hypoalbuminemia and with protracted treatment with antibiotics, in only 1 subject who had a history of gastric surgery was it caused by tube feeding . The other 6 cases of diarrhea were caused by factors other than tube feeding, mainly drugs administered through the tube . Lactobacillus treatment did not alter the risk of diarrhea . Diarrhea occurs more commonly in tube-fed patients who have low serum albumin levels and have been treated with antibiotics for long periods, but these associations are generally not causal . Hypertonic feeding formulas are not associated with increased risk of diarrhea . Most cases of diarrhea in tube-fed patients are caused by factors extraneous to the tube feeding. Arch Oral Biol, 1994 Sep, 39(9), 753 - 7 Adsorption of {3H}-lipoteichoic acid to hydroxyapatite and its effect on crystal growth; Damen JJ et al.; 3H-labelled lipoteichoic acid was isolated from Lactobacillus casei cells cultured in the presence of {2-3H}-glycerol . The adsorption characteristics of both native and deacylated {3H}-lipoteichoic acid on to hydroxyapatite crystals were determined in 2.0 mM CaCl2, 50 mM Hepes, pH 7.2 . The maximum numbers of adsorption sites per unit surface area were 80 +/- 3 and 49 +/- 2 nmol/m2 for native and deacylated lipoteichoic acid, respectively . At low concentrations, which were previously found to stimulate hydroxyapatite growth in a supersaturated solution (1.0 mM CaCl2, 7.5 mM KH2PO4, 50 mM Hepes, pH 7.2), lipoteichoic acid appeared for a large part adsorbed to the crystals, while crystal growth was delayed when there was an excess of unbound lipoteichoic acid in solution . These results suggest that lipoteichoic acid released from plaque bacteria may have dual effects both on the precipitation of calcium phosphate in dental plaque and on the remineralization of lesions in the underlying hard tissues. Carbohydr Res, 1994 Aug 3, 261(1), 67 - 78 Structural study on an exocellular polysaccharide produced by Lactobacillus helveticus TY1-2; Yamamoto Y et al.; Lactobacillus helveticus TY1-2 produced an exocellular polysaccharide when it was cultured in reconstituted skim milk . This polysaccharide is a high molecular weight heteropolymer of D-glucopyranosyl, D-galactopyranosyl, and 2-acetamido-2-deoxy-D-glucopyranosyl residues in the molar ratio 3.0:2.8:0.9 . The primary structure of the polysaccharide was shown by glycose analysis, methylation analysis, Smith degradation, and NMR spectroscopy to be composed of branched heptasaccharide repeating units having the following structure: {formula: see text} J Can Dent Assoc, 1994 Aug, 60(8), 711 - 4 The effectiveness of three different strengths of chlorhexidine mouthrinse; Clark DC et al.; Dental caries in dentate elderly patients may be controlled with chlorhexidine . The purpose of this study is to establish the effectiven