Lactobacillus

J Reprod Med, 1993 Jul, 38(7), 543 - 8
Microbial invasion of the amniotic cavity during term labor . Prevalence and clinical significance; Romero R et al.; The purpose of this study was to determine the prevalence and clinical significance of microbial invasion of the amniotic cavity during spontaneous parturition at term . Amniotic fluid was retrieved by transabdominal amniocentesis from 90 women in spontaneous term labor with intact membranes . Fluid was cultured for aerobic and anaerobic bacteria, including Mycoplasma . The prevalence of positive amniotic fluid cultures was 18.8% (17/90) . The most common microbial isolates were Ureaplasma urealyticum, Streptococcus agalactiae, Lactobacillus species and Mycoplasma hominis . Clinical signs of chorioamnionitis were present in three patients, and only one of them had a positive amniotic fluid culture . Five patients (5.5%) had puerperal endometritis; three of them had an amniotic fluid culture positive for microorganisms . All neonates were free of clinical signs of infection . The data indicate that microbial invasion of the amniotic cavity occurs frequently during spontaneous labor at term, and it may be both the cause and the consequence of labor.

Int J Food Microbiol, 1993 Jul, 19(2), 135 - 43
Microbiological and aromatic characteristics of fermented maize doughs for kenkey production in Ghana; Halm M et al.; A very uniform microflora was demonstrated in 15 samples of fermented maize dough from different larger commercial production sites . At the advanced stage of fermentation, more than 96% of the bacteria present were morphologically and biochemically uniform, obligatively heterofermentative lactobacilli occurring in concentrations about 10(9) cfu/g . Yeast occurred in levels of about 10(6) cfu/g, dominated by Candida and Saccharomyces spp . Studies on microbial successions indicated a selection towards a micropopulation dominated by lactic acid bacteria . The Gram-negative bacteria, catalase-positive Gram-positive bacteria and moulds underwent three to four decimal reductions during the early phase of the process . The aroma components detected were dominated by lactic acid, acetic, butyric and propionic acids . Volatile aroma components demonstrated by gas chromatography and mass spectrometry were characteristic for lactic acid bacteria with acetoin and related products as typical examples.

Plasmid, 1993 Jul, 30(1), 14 - 29
Characterization and sequence analysis of a small cryptic plasmid from Lactobacillus curvatus LTH683 and its use for construction of new Lactobacillus cloning vectors; Klein JR et al.; Lactobacillus curvatus LTH683, a strain originally isolated from raw sausage, contains the single cryptic plasmid called pLC2 . The sequence and genetic organization of the complete 2489-bp plasmid pLC2 was determined and used as the basis for construction of a series of vectors useful in Lactobacillus strains . The major parts of pLC2 nucleotide sequence could be aligned with other plasmids from gram-positive bacteria replicating by a rolling circle mechanism of replication (RCR) . Direct evidence for a RCR mechanism was obtained by showing the accumulation of single-stranded plasmid intermediates in the presence of rifampicin . Three protein-coding sequences could be predicted and the corresponding proteins were detected after in vitro transcription/translation of pLC2 plasmid DNA . ORFs 1 and 3 showed minor homologies to plasmids of gram-positive bacteria . The replication protein coded by ORF2 and its corresponding target sequence, the plus origin, were similar to replication regions of other gram-positive bacteria plasmids like pLS1, pWV01, and pE194 . Upstream of the ori+ site, in a noncoding region, which was nonessential for replication, strong homology to other Lactobacillus plasmids like pC30i1, pLP1, pLJ1, and pLAB1000 could be detected . A palindromic sequence predicted to be the minus origin of replication was localized there . Small vectors (3213 bp) suitable for cloning in lactobacilli were constructed based on a 1635-bp DNA fragment of pLC2, containing the region necessary for replication, marked with the chloramphenicol resistance gene and a multiple cloning site.

J Gen Microbiol, 1993 Jul, 139 ( Pt 7), 1441 - 8
Two cell-wall-associated aminopeptidases from Lactobacillus helveticus and the purification and characterization of APII from strain ITGL1; Blanc B et al.; Lactobacillus helveticus ITGL1 is able to hydrolyse many amino-acyl and dipeptidyl-p-nitroanilides . Analysis of heat inactivation kinetics, metal ion and protease inhibitor effects, and the subcellular location of aminopeptidase activities in both the parental strain and mutants deficient in lysyl-p-nitroanilide hydrolysis, led to the characterization of two cell-wall-associated aminopeptidases, APII and APIV . APII, which catalysed L-lysine p-nitroanilide hydrolysis, was purified about 28-fold to homogeneity from cell-wall extracts of L . helveticus ITGL1 and characterized . The purified enzyme appeared to be monomeric, with a molecular mass of 97 kDa . Aminopeptidase activity was greatest at pH 6.5 and 50 degrees C . APII was completely inhibited by bestatin, chelating agents such as EDTA or 1,10-phenanthroline and the divalent cations Zn2+ and Cu2+ . The activity of the EDTA-treated enzyme was restored by Co2+, Ca2+ or Mn2+ . Although APII was able to degrade several dipeptides and tripeptides with hydrophobic N-terminal amino acid (Leu, Ala), it was inactive on peptides containing Pro or Gly, and may thus contribute to the development of cheese flavour by processing bitter peptides.

Appl Environ Microbiol, 1993 Jul, 59(7), 2326 - 8
Brochocin-C, a new bacteriocin produced by Brochothrix campestris; Siragusa GR et al.; Brochotrix campestris ATCC 43754 produces a bacteriocin inhibitory towards Brochothrix thermosphacta, lactobacilli, Listeria spp., and other gram-positive bacteria . This antimicrobial agent is heat stable, sensitive to proteases, catalase insensitive, and free of organic acids . No phage particles were detected by transmission electron microscopy . Muramidase activity was not detected in the preparations . On the basis of established criteria, the antimicrobial agent was classified as a bacteriocin and named brochocin-C.

FEMS Microbiol Lett, 1993 Jul 1, 110(3), 299 - 305
Inhibition of adhesion of enteroinvasive pathogens to human intestinal Caco-2 cells by Lactobacillus acidophilus strain LB decreases bacterial invasion; Coconnier MH et al.; Salmonella typhimurium and enteropathogenic Escherichia coli (EPEC) were found to adhere to the brush border of differentiated human intestinal epithelial Caco-2 cells in culture, whereas Yersinia pseudotuberculosis and Listeria monocytogenes adhered to the periphery of undifferentiated Caco-2 cells . All these enterovirulent strains invaded the Caco-2 cells . Using a heat-killed human Lactobacillus acidophilus (strain LB) which strongly adheres both to undifferentiated and differentiated Caco-2 cells, we have studied inhibition of cell association with and invasion within Caco-2 cells by enterovirulent bacteria . Living and heat-killed Lactobacillus acidophilus strain LB inhibited both cell association and invasion of Caco-2 cells by enterovirulent bacteria in a concentration-dependent manner . The mechanism of inhibition of both adhesion and invasion appears to be due to steric hindrance of human enterocytic pathogen receptors by whole-cell lactobacilli rather than to a specific blockade of receptors.

FEMS Microbiol Lett, 1993 Jul 1, 110(3), 249 - 56
Identification and sequence analysis of the replication region of the phage resistance plasmid pCI528 from Lactococcus lactis subsp . cremoris UC503; Lucey M et al.; The replication region of the phage resistance plasmid pCI528 from Lactococcus lactis subsp . cremoris UC503 was localised to within a 10-kb HindIII restriction fragment . A 6.3-kb BglII-HindIII subclone of this fragment, cloned into a replication probe vector, allowed replication in Lactococcus but not in Bacillus or Lactobacillus . Sequence analysis revealed an ORF of 1152 bp preceded by a putative ori region containing a 22-bp sequence tandemly repeated three and three-quarter times, a second smaller direct repeat and two inverted repeats . Extensive homology was observed with the well characterised replication region of the small cryptic plasmid pCI305 (Hayes, F., Vos, P., Fitzgerald, G.F., deVos, W . and Daly, C . Plasmid 25, 16-26).

J Dairy Sci, 1993 Jul, 76(7), 1902 - 7
Improving survival of culture bacteria in frozen desserts by microentrapment; Sheu TY et al.; Lactobacillus bulgaricus cells were entrapped in beads of calcium alginate and evaluated for their ability to survive freezing processes . Cells survived freezing (without agitation) in ice milk mix much better than in distilled water, and more entrapped cells survived than did cells that were not entrapped . Glycerol and mannitol were cryoprotective, but glucose was not, when each was added (6%) separately to the beads . Entrapment protected the lactobacilli in batch frozen and continuously frozen ice milk mixes . The percentage of survival for entrapped and unentrapped cells in continuously frozen ice milk approximated 90 and 40%, respectively . Lactobacilli survived better in beads with mean diameters > 30 microns than in those averaging 15 microns . Addition of entrapped lactobacilli had no measurable effect on the sensory characteristics of the ice milk.

Plant Foods Hum Nutr, 1993 Jul, 44(1), 45 - 62
The fermentation of trahanas: a milk-wheat flour combination; Lazos ES et al.; The fermented food, trahanas (a milk-wheat flour combination prepared in Greece), was studied to determine the microbiological and chemical changes that occur during fermentation . It is a lactic acid bacterial fermentation in which Streptococcus lactis, Streptococcus diacetylactis, Leuconostoc cremoris, Lactobacillus lactis, Lactobacillus casei, Lactobacillus bulgaricus and Lactobacillus acidophilus play the major acid- and aroma-producing role . The whole fermentation lasts about 50 hours . The pH of the final dried trahanas was 4.07-4.75, the acidity 0.60-1.00%, the moisture content 8.6-11.5% and the protein content 10.4-13.6% . The product offers possibilities as an increased nutritive value or high-protein food.

Fiziol Zh, 1993 Jul-Aug, 39(4), 62 - 8
{Protective effect of Lactobacillus acidophilus on development of infection, caused by Klebsiella pneumoniae}; Kostiuk OP et al.; The mechanisms of protective action of Lactobacillus have been studied during development of the generalized infection induced by Klebsiella pneumoniae in CBA mice after weaning . The mice were infected intragastrically during the first day after weaning (1 x 10(9) bacterias per mice) . Suspensions of Lactobacillus were introduced before and after infection during 10 days (1 x 10(6) bacterias per mice) . It has been shown that introduction of Lactobacillus substantially decreased the level of the gut contamination by Klebsiella, prevented generalization of infection and death of animals . Significant higher levels of IgA in the blood serum, IgA and IgM in the gut content, percentage of splenocytes, expressing surface IgM and IgG were observed on the 7th day as compared with those in animals without Lactobacillus . Significantly lower percentage of splenocytes, expressing CD4 antigen was also observed . On the 11th day after infection the mice receiving lactobacillus have shown a tendency to an increase of IgA in the gut content, significantly lower concentrations of IgM in the gut content and a higher level of IgA to the blood serum as compared with the control . Other characteristics were comparable to those of the control group . A conclusion is made that introduction of Lactobacillus prevents development of the Klebsiella infection and protects the immune system from excessive antigenic action.

Gen Pharmacol, 1993 Jul, 24(4), 905 - 10
Isolation and characterization of the substance isolated from Streptosporangium species which inhibits lactic acid production by oral bacteria; Ikeda T et al.; 1 . The tentatively named MLI, which inhibits lactic acid production in mutants streptococci, was isolated from Streptosporangium species and purified by solvent extraction followed by chromatography, and then powdered . 2 . MLI greatly inhibited pH-decline and lactic acid production in glucose-containing reaction mixture by mutans streptococci or Lactobacillus species . 3 . These inhibitory mechanisms were not caused by an anti-bacterial effect, since the addition of a sufficient concentration of MLI to inhibit lactic acid production to the culture, recovery of cells in culture was not affected, excluding L . acidophilus . 4 . MLI directly affected lactate dehydrogenase (LDH) activity . 5 . These results indicate that MLI may represent a new anti-cariogenic substance.

Eur J Biochem, 1993 Jun 15, 214(3), 889 - 96
Purification and characterization of glyoxylate synthetase from greening potato-tuber chloroplasts; Janave MT et al.; Glyoxylate synthetase catalyzing the condensation of two formate molecules into glyoxylate was purified to homogeneity by AcA-34, Sepharose CL-6B and DEAE-Sepharose CL-6B chromatography . A 150-fold purification with a specific activity of 25 mumol . mg protein-1 x 5 min-1 was obtained by this procedure . The reaction product was identified as glyoxylate . The enzyme was a tetramer having a molecular mass of 160 kDa with a subunit molecular mass of 40 kDa . The enzyme could be activated 3-4-fold by the addition of 0.3 mM Fe2+ and 0.4 mM tetrahydrofolic acid to the reaction mixture . The requirement for Fe2+ and tetrahydrofolic acid was confirmed from the inhibition of enzyme by O-phenanthroline and alpha-aminopterin, respectively . The presence of a bound folate in the enzyme was indicated by the fluorescence emission at 450 nm and turbidity development in a Lactobacillus casei growth test . Fluorescence emission at 450 nm upon excitation at 280 nm indicated that the bound folate and the aromatic amino-acid residues of the enzyme were in close vicinity . The enzyme was maximally active at 25 degrees C and exhibited a pH optimum at 7.0 . The concentration of substrate was optimal at 5.0 mM and Km for substrate was found to be 1.4 mM . Activation by Fe2+ did not alter the Km but caused an increase in Vmax . The enzyme contained about 14-16 disulfide linkages, of which two were found to be reduced by treatment with 2-mercaptoethanol . The presence of excess 2-mercaptoethanol in the enzyme was inhibitory, indicating that the two disulfide linkages reduced by 2-mercaptoethanol were essential for activity . This was also confirmed by the inhibition of enzyme activity when reduced enzyme was treated with O-phthalaldehyde, which formed a thioisoindole derivative with reduced thiol groups at the active site.

J Med Microbiol, 1993 Jun, 38(6), 401 - 5
Sensitisation of cariogenic bacteria to killing by light from a helium-neon laser; Burns T et al.; Suspensions of the cariogenic bacteria Streptococcus mutans, S . sobrinus, Lactobacillus casei and Actinomyces viscosus were exposed to light from a 7.3-mW helium-neon laser in the presence of toluidine blue O . A substantial killing rate (c . 10(6) cfu) of all four species was achieved with a dye concentration of 50 micrograms/ml and a light energy dose of 33.6 J/cm2 . This was achieved in 60 s, an exposure time that is clinically acceptable . Exposure to laser light in the absence of the dye did not significantly affect the viability of any of the organisms . This approach may be useful in dentistry to sterilise a carious lesion prior to its repair.

J Virol, 1993 Jun, 67(6), 3061 - 8
Molecular comparison of the structural proteins encoding gene clusters of two related Lactobacillus delbrueckii bacteriophages; Vasala A et al.; Virulent phage LL-H and temperate phage mv4 are two related bacteriophages of Lactobacillus delbrueckii . The gene clusters encoding structural proteins of these two phages have been sequenced and further analyzed . Six open reading frames (ORF-1 to ORF-6) were detected . Protein sequencing and Western immunoblotting experiments confirmed that ORF-3 (g34) encoded the main capsid protein Gp34 . The presence of a putative late promoter in front of the phage LL-H g34 gene was suggested by primer extension experiments . Comparative sequence analysis between phage LL-H and phage mv4 revealed striking similarities in the structure and organization of this gene cluster, suggesting that the genes encoding phage structural proteins belong to a highly conservative module.

Pediatr Res, 1993 Jun, 33(6), 548 - 53
Diet during rotavirus enteritis affects jejunal permeability to macromolecules in suckling rats; Isolauri E et al.; We studied the influence of diet during diarrhea on gut mucosal barrier in a suckling rat model . Rat pups were inoculated with IDIR virus (a group B rotavirus) at 10 d of age . Beginning 2 d postinfection, in addition to maternal milk, group CM received a daily gavage of cow milk and group GG received Lactobacillus casei strain GG, a human strain previously shown to survive the passage through the gastrointestinal tract and temporarily colonize the gut . Group CMGG received a combination of these, and control animals were gavaged with tap water . At 21 d of age, jejunal absorption of intact and degraded horseradish peroxidase (HRP) in Ussing chamber was markedly higher in IDIR virus-infected than in noninfected controls . In the two groups gavaged with cow milk, group CM and group CMGG, the numbers of specific antibody-secreting cells (enumerated by the solid-phase enzyme-linked immunospot assay) against beta-lactoglobulin were significantly higher than in the groups that had not received cow milk . In parallel with immune system activation, a statistically significant increase in the absorption of intact HRP (mean and 95% confidence interval, ng x h-1 x cm-2) was detected: group CM, 302 (155, 586); group CMGG, 174 (56, 545); infected controls, 121 (57, 257); and group GG, 44 (8, 254) . A decrease in the uptake of intact HRP (F = 3.64, p = 0.06) and degraded HRP (F = 9.50, p = 0.004) was associated with the introduction of L . casei GG to the diet, irrespective of coexposure to cow milk.(ABSTRACT TRUNCATED AT 250 WORDS)

J Appl Bacteriol, 1993 Jun, 74(6), 649 - 51
A note on lactobacilli and beta-glucuronidase activity in the intestinal contents of mice; McConnell MA et al.; A comparison was made of caecal beta-glucuronidase activity in the caecal contents of mice with or without lactobacilli as members of the normal microflora . Male mice that did not have lactobacilli as intestinal inhabitants had approximately 52% more caecal beta-glucuronidase activity than their female counterparts . Colonization of male mice by lactobacilli reduced the beta-glucuronidase activity to that of female mice.

Community Dent Oral Epidemiol, 1993 Jun, 21(3), 136 - 42
Transmission of mutans streptococci to infants following short term application of an iodine-NaF solution to mothers' dentition; Dasanayake AP et al.; In a randomized clinical trial, six applications of an I2-NaF or a placebo solution were administered to the mothers' dentition at the time of tooth emergence of her infant, to evaluate its effect on transmission of mutans streptococci (MS) to the infant . MS and other bacterial levels were periodically monitored in 48 mother-infant pairs until the child's third birthday . There were significant reductions in maternal salivary MS (P = 0.04), lactobacilli (P = 0.04), total streptococci (P = 0.002), and total cultivable organisms (P = 0.004) immediately following treatment . In children, 3-yr incidence of MS colonization and the time of acquisition of MS or the caries experience did not differ significantly between the two groups . We conclude that short-term application of I2-NaF to the maternal dentition of predentate infants significantly lowers MS, lactobacilli, total streptococci, and total cultivable bacteria in mothers' saliva, but does not influence the incidence and the time of acquisition of MS or the caries experience in children.

Int J Food Microbiol, 1993 Jun 1, 18(4), 321 - 32
Changes in the microflora on commercial beef trimmings during their collection, distribution and preparation for retail sale as ground beef; Gill CO et al.; A commercial process for ground meat production, from the collection of meat plant trimmings to the retailing of consumer packs of ground beef, was examined . The selected process compiled with current concepts of Good Manufacturing Practice . During storage for up to 18 days before grinding, most trimming developed a flora of lactobacilli, of up to 10(7) CFU/g . Numbers of coliforms and of Escherichia coli on stored trimmings increased little and not at all, respectively . Increased total counts, and numbers of both coliforms and E . coli in displayed product indicated loss of control of the temperature of the displayed packaged product . It appears that the need to store a product, taking into account the unpredictable fluctuations in supply and demand, will inevitably result in much ground beef carrying large numbers of spoilage bacteria . Furthermore, currently accepted Good Practice in the retail handling of ground beef does not adequately control either spoilage or the growth of pathogenic bacteria.

Int J Food Microbiol, 1993 Jun 1, 18(4), 305 - 20
Characteristics and antagonistic activity of lactic acid bacteria isolated from chilled fish products; Jeppesen VF et al.; In fish products, contrary to other foods, the commercial use of starter cultures is relatively unexploited . In this study, 61 isolates of lactic acid bacteria from lightly preserved, chilled fish products were characterized with special emphasis on their antagonistic activity and their possible use as starter cultures . The strains were phenotypically identified and characterized with regard to gas production, carbohydrate fermentations, production of off odours, H2O2-production, antagonistic activity and growth at 2, 5 and 10 degrees C . Growth at 10 degrees C was detected for all strains within 4 days . At 5 degrees C, 90% of the isolates were growing within 3-9 days . At 2 degrees C only 33% of the strains were growing within 9 days . Fourteen strains were selected for further testing of antagonistic activity against spoilage- and pathogenic bacteria at different pH in a disc assay . Two strains, a Leuconostoc spp . (V 6) and a Lactobacillus plantarum (LKE 5), differed from the other lactic acid bacteria by a very wide inhibitory spectrum for V 6 and by very distinct inhibition zones for LKE 5 . The mechanisms of their inhibitory effects are discussed.

Int J Food Microbiol, 1993 Jun 1, 18(4), 279 - 87
Characterization and frequency distribution of species of lactic acid bacteria involved in the processing of mawè, a fermented maize dough from Benin; Hounhouigan DJ et al.; Lactic acid bacteria involved in the natural fermentation of both home-produced and commercial mawe were investigated during a 72 h fermentation period . Lactobacillus spp . constitute the majority (94%) of the strains of the lactic acid bacteria isolated, among which 89% represent the Betabacterium group . They include L . fermentum (biotype cellobiosus) (41%), L . fermentum or L . reuteri (19%), L . brevis (26%), L . confusus (less than 2%), L . curvatus (less than 1%) and L . buchneri (less than 1%) . Other isolated lactic acid bacteria were L . salivarius, Lactococcus lactis, Pediococcus pentosaceus, Pediococcus acidilactici and Leuconostoc mesenteroides . Several species were detected at the early stage of fermentation, but the final stage was dominated by L . fermentum (biotype cellobiosus) and L . fermentum or L . reuteri totalling 90% of the isolated strains . The trend was the same for both home-produced and commercial mawe . No strains of L . plantarum, generally reported as dominating lactic acid bacteria at the final stage of fermentation of most plant foods, were isolated.

Antimicrob Agents Chemother, 1993 Jun, 37(6), 1364 - 6
In vitro activity of ramoplanin against vancomycin-resistant gram-positive organisms; Collins LA et al.; In vitro activity of ramoplanin, a cyclic lipoglycopeptide, against 92 vancomycin-resistant gram-positive organisms was evaluated . Ramoplanin demonstrated potent activity against many highly vancomycin-resistant organisms including enterococci (MICs for 90% of strains tested of 0.5 micrograms/ml) and against Lactobacillus spp., Leuconostoc spp., and Pediococcus spp., all of which were inhibited at concentrations of < or = 0.25 micrograms/ml . This drug or a derivative compound merits further investigation as a potential therapeutic agent for infections due to vancomycin-resistant enterococci.

J Anim Sci, 1993 Jun, 71(6), 1503 - 9
Effect of galactan on selected microbial populations and pH and volatile fatty acids in the ileum of the weanling pig; Mathew AG et al.; Studies were conducted to determine the effect of galactan on the colonization of E . coli and lactobacilli and ileal pH and volatile fatty acid production in the digestive tract of the weanling pig . In each of two replicate trials, eight 21-d-old nursing pigs were cannulated in the terminal ileum . After a 7-d recovery period, the pigs were weaned and randomly assigned to two test diets: 1) a corn-soybean meal-based control diet and 2) a similar diet containing 1% galactan . On d 1 after weaning, all pigs were orally subjected to K88+ E . coli (2 x 10(9) colony forming units) . Ileal digesta samples were collected on d 0, 2, 4, 6, 8, and 10 after weaning and assayed for total E . coli, K88+ E . coli, lactobacilli, pH, and VFA . At the end of the trials, the pigs were killed and digesta samples were collected from the stomach, duodenum, cecum, and colon . Assays similar to those performed on the digesta samples collected from ileal cannulas were performed . Pigs fed 1% galactan had lower (P < .10) ileal pH, lower (P < .05) total E . coli on d 6 and 8, and lower (P < .05) K88+ E . coli concentrations in the ileum than pigs fed the control diet . There were no differences in ADG or gain:feed ratio between diets . The VFA concentrations were not different in the ileum between diets . The VFA were higher (P < .10) on d 0 than on any other day of the study . Acetate and isobutyrate concentrations were lower (P < .10) in the cecum in pigs fed 1% galactan.(ABSTRACT TRUNCATED AT 250 WORDS)

Clin Infect Dis, 1993 Jun, 16 Suppl 4, S273 - 81
The normal vaginal flora, H2O2-producing lactobacilli, and bacterial vaginosis in pregnant women; Hillier SL et al.; In this study of the vaginal flora of 171 pregnant women in labor at term, the flora was categorized as normal (Lactobacillus predominant), intermediate, or representative of bacterial vaginosis (BV) on the basis of a vaginal smear . BV was diagnosed in 39 women (23%); the vaginal flora was classified as normal in 50% of cases and as intermediate in 27% . H2O2-producing lactobacilli were recovered from 5% of women with BV, 37% of those with an intermediate flora, and 61% of those with a normal flora . H2O2-negative lactobacilli were equally frequent (57%-65%) in all three groups . The microorganisms most frequently recovered from women with BV included Gardnerella vaginalis, Prevotella bivia/disiens, Bacteroides ureolyticus, Prevotella corporis/Bacteroides levii, Fusobacterium nucleatum, Mobiluncus species, Peptostreptococcus prevotii, Peptostreptococcus tetradius, Peptostreptococcus anaerobius, viridans streptococci, Ureaplasma urealyticum, and Mycoplasma hominis (P < .05 for each) . The presence of all but three of these organisms was inversely related to vaginal colonization by H2O2-producing lactobacilli; the exceptions were B . ureolyticus, F . nucleatum, and P . prevotii . Other microorganisms were equally frequent among women with and without BV . We conclude that specific groups of anaerobes are associated with BV in this population and that a strong association exists between species associated with BV and those inhibited by H2O2-producing lactobacilli.

Clin Infect Dis, 1993 Jun, 16 Suppl 4, S181 - 7
Lactobacilli and the normal human anaerobic microflora; Lidbeck A et al.; The normal human microflora is a complex and usually stable ecosystem . The intestinal microflora is important to the host with regard to many metabolic functions and in resistance to bacterial infections . Administration of antimicrobial agents may disrupt the normal microflora, leading to a decrease in colonization resistance and alterations in metabolic activities of the intestinal bacteria . Antimicrobial therapy may also be accompanied by gastrointestinal disturbances and a reduction or elimination of lactobacilli in the intestinal microflora . Lactobacilli are part of the normal gram-positive anaerobic microflora . Through the production of lactic and acetic acids, hydrogen peroxide, and antimicrobial substances, these microorganisms possibly contribute to the maintenance of colonization resistance . Several studies have indicated a protective effect of lactobacilli against potential pathogens in the gastrointestinal tract . In view of these beneficial properties, it is considered important to maintain or increase the levels of lactobacilli in the intestinal microflora.

Biosci Biotechnol Biochem, 1993 Jun, 57(6), 978 - 81
Mechanism for the antihypertensive effect of a polysaccharide-glycopeptide complex from Lactobacillus casei in spontaneously hypertensive rats (SHR); Furushiro M et al.; Pharmacological studies on the antihypertensive effect of a polysaccharide-glycopeptide complex (SG-1) isolated from Lactobacillus casei were carried out by using spontaneously hypertensive rats (SHR) . An antihypertensive effect of SG-1 was observed by oral, but not by intravenous or intraperitoneal administration, and the effect was attenuated by orally pre-treating with indomethacin . A single oral administration of SG-1 (20 mg/kg) decreased the peripheral vascular resistance (PR) . The daily oral administration of SG-1 (10 mg/kg) for 14 days had no effect on either the urine volume or urinary electrolytes (Na+, K+, and Cl-), but it did increase the excretion of 6-keto-PGF1 alpha, a metabolite of PGI2, in the urine . Moreover, a single oral administration of SG-1 (20 mg/kg) also increased the biliary 6-keto-PGF1 alpha excretion . These results suggest that the antihypertensive effect of orally administered SG-1 resulted from an enhancement of PGI2 biosynthesis and the subsequent decrease in PR.

J Biol Chem, 1993 May 15, 268(14), 10102 - 8
Studies of 5-fluorodeoxyuridine 5'-monophosphate binding to carboxypeptidase A-inactivated thymidylate synthase from Lactobacillus casei; Cisneros RJ et al.; The binding of 5-fluorodeoxyuridylate (FdUMP) to carboxypeptidase-inactivated thymidylate synthase obtained from methotrexate-resistant Lactobacillus casei was investigated using {3H}FdUMP in a trichloroacetic acid precipitation assay and by 19F nuclear magnetic resonance spectroscopy . The cleavage of 1 valine residue from the carboxyl terminus of one of the identical subunits of the enzyme dimer correlates with complete loss of thymidylate synthesis (Aull, J . L., Loeble, R . B., and Dunlap, R . B . (1974) J . Biol . Chem . 249, 1167-1172) . We have further investigated the phenomenon of carboxypeptidase A-dependent inactivation of thymidylate synthase by employing immobilized carboxypeptidase A in order to facilitate the isolation and characterization of the inactivated enzyme . The time course of carboxypeptidase treatment of thymidylate synthase has been profiled by the spectrophotometric assay, tritium release assay, trichloroacetic acid precipitation assay (covalent adduct analysis), 19F nuclear magnetic resonance spectroscopy, and amino acid analysis . The techniques utilized in this study yielded results which showed that the completely inactivated enzyme (failure to catalyze thymidylate formation) continued to catalyze both covalent FdUMP-enzyme interactions and the formation of the covalent inhibitory ternary complex with the cofactor, 5,1O-methylenetetrahydrofolate, although to a reduced extent, thus effectively uncoupling these processes from thymidylate synthesis activity.

Biochim Biophys Acta, 1993 May 13, 1163(2), 165 - 75
Characterization of the covalent chromatography of thymidylate synthase on thiopropyl-Sepharose 6B; Bradshaw TP et al.; We have examined the covalent chromatography of Lactobacillus casei thymidylate synthase on thiopropyl-Sepharose 6B resin . This enzyme is a dimer of identical subunits, each of which contains one active site that features a catalytic sulfhydryl group (Cys-198) . Reversible coupling was achieved via the attack of one of the enzyme's two catalytic cysteine residues, causing displacement of 2-thiopyridone, the reactive moiety of the resin . To establish the usefulness of this matrix for immobilization and the conditions required for chromatography, model studies were conducted with 2,2'-dithiodipyridine . The chemical modification of thymidylate synthase with 2,2'-dithiodipyridine was shown to be specific for the catalytic sulfhydryl groups of the native dimer, titrating 1.51 sulfhydryl groups, while 2.93 cysteines were modified in the GnHCl-denatured protein . The former reaction, which resulted in total loss of enzyme activity, was reversible with complete recovery of control activity within 30 min after addition of 100 mM 2-mercaptoethanol . Characterization of the protein pools generated in the covalent chromatography procedure indicated that the enzyme fraction washing through the column without attachment had substantially lower catalytic and ligand binding activities than the original protein stock; conversely, the enzyme fraction eluted from the column by 2-mercaptoethanol exhibited higher levels of these activities . Gel electrophoresis studies further illustrated that the unique application of the covalent chromatography technique described herein fractionated homogeneous thymidylate synthase protein into enzyme pools exhibiting distinct biochemical properties . As immobilization reaction times were increased beyond 6 h, the coupling of thymidylate synthase was demonstrated to occur through more than one enzymic sulfhydryl group . Interestingly, no covalent coupling was detected in attempts using activated thiol-Sepharose 4B, a result underlining the importance of the structure of the resin linker arm in enzyme immobilization.

Biochemistry, 1993 May 11, 32(18), 4943 - 8
Site-directed alteration of three active-site residues of a pyruvoyl-dependent histidine decarboxylase; Pishko EJ et al.; The active site of histidine decarboxylase (HDC) from Lactobacillus 30a contains a pyruvoyl cofactor sitting at the interface of two molecules in a trimer . Although exhibiting hyperbolic kinetics at pH 4.8, near its optimum, HDC is cooperative at pH 7.6, indicating that the units of the trimer communicate . A Hill plot analysis shows that HDC, at pH 7.6, can be described by a two-state model . The tense (T) state has an apparent Km for histidine of 50 mM, while the relaxed (R) state has a Km of 5 mM . To explore the catalytic mechanism, three of the cross-boundary active-site residues were altered by site-directed mutagenesis and their effects observed . Ile-59 is known to act as lid on the substrate binding pocket; it was converted to Ala (I59A) and to Val (I59V) . The former was inactive, attesting to the importance of this residue in the mechanism . The I59V mutant showed a decrease in Km and in kcat at pHs 4.8 and 7.6 . Ile-59 appears to help orient substrate properly for catalysis; decreasing its size expands the binding site . This may allow the substrate to bind more readily, but in a number of conformations which are not optimal for catalysis . Conversion of Tyr-62 to Phe (Y62F) had no effect on catalysis but raised the Km 7-fold at pH 4.8 . Asp-63 appears to form an ion pair to the substrate imidazolium . Conversion to the neutral amide (D63N) had no effect on the kcat, but raised the Km 240-fold at pH 4.8 . This is consistent with the notion that the ion pair is up to 3 kcal/mol stronger than a simple hydrogen bond with the substrate . The mutant had no detectable activity at pH 7.6.

Mol Gen Genet, 1993 May, 239(1-2), 33 - 40
Cloning and expression of the manganese superoxide dismutase gene of Escherichia coli in Lactococcus lactis and Lactobacillus gasseri; Roy DG et al.; The Escherichia coli sodA gene encoding the antioxidant enzyme Mn-containing superoxide dismutase (MnSOD), was cloned in the expression vector pMG36e . This vector has a multiple cloning site downstream of a promoter and Shine-Dalgarno sequences derived from Lactococcus . The protein-coding region of sodA from E . coli was amplified by the polymerase chain reaction, using a thermocycler and Taq DNA polymerase before cloning into pMG36e . When introduced into E . coli, the recombinant plasmid expressed the predicted fusion protein, both in the presence and absence of oxygen . The expression of the fusion protein in E . coli was verified by SOD assays, activity gels and Western blots . The recombinant plasmid was also introduced into Lactococcus lactis, which contains a resident SOD, and into Lactobacillus gasseri, which is devoid of SOD . Transformed lactococci expressed an active SodA fusion protein plus an active hybrid protein composed of subunits of the Lactococcus and the recombinant E . coli enzymes . Transformants of L . gasseri expressed only the fusion SodA protein, which was enzymatically active.

Mol Gen Genet, 1993 May, 239(1-2), 269 - 72
Gene disruption in Lactobacillus plantarum strain 80 by site-specific recombination: isolation of a mutant strain deficient in conjugated bile salt hydrolase activity; Leer RJ et al.; A chloramphenicol-resistance gene (cml) was introduced into the Lactobacillus plantarum gene encoding conjugated bile acid hydrolase (cbh) on a ColE1 replicon . This plasmid which is nonreplicative in Lactobacillus was used to transform L . plantarum strain 80 . A homologous double cross-over recombination event resulted in replacement of the chromosomal cbh gene by the cml-containing cbh gene . The transformants obtained were unable to synthesize active conjugated bile acid hydrolase (Cbh) . The Cbh- CmlR phenotype was stably maintained for more than 100 generations under nonselective conditions.

Plant Foods Hum Nutr, 1993 May, 43(3), 273 - 8
Alcohol production in submerged cashew pomace; Aderiye BI et al.; The variations in the total titratable acidity, hydrogen ion concentration, reducing sugar, soluble solids and alcohol contents of the supernatant of the submerged cashew pomace in a non-aseptic condition were investigated . The crude fibre content of the pomace was also determined during fermentation . At intervals, the changes in microbial load in both the pomace and its supernatant were examined during the 14-day study . Fifty four percent of the total soluble solids (TSS) was utilised within 7 days of degradation while an increase of about 91% in the total titratable acidity occurred in the cashew pomace within the same period bringing its pH to 3.24 . Acid hydrolysis of the pomace accounted for the relative high value of 2.15% TSS on the 8th day . Isolates of the genera Leuconostoc, Lactobacillus, Pediococcus, Aspergillus, Rhizopus and some yeast strains were obtained from the fresh pomace . The fungal colonies constituted about 76% of the population in the cashew pomace . The 86% drop in microbial population of the 8th day biodegraded pomace could be attributed to a decrease in nutrients of the substrate and the inhibitory effect of the organic acids produced during fermentation.

J Dairy Sci, 1993 May, 76(5), 1253 - 9
Influence of bile on cellular integrity and beta-galactosidase activity of Lactobacillus acidophilus; Noh DO et al.; The influence of bile on beta-galactosidase activity, cellular integrity, cellular retention of beta-galactosidase, and cellular permeability of five strains of Lactobacillus acidophilus was investigated . The five strains were also compared for bile tolerance . Two strains, 223 and 4356, were significantly less resistant to bile than the others (107, NCFM, and 606) . beta-Galactosidase activity of all five strains was significantly higher in the presence of .3% oxgall than in its absence . Strain 107 showed the highest increase of enzyme activity in the presence of oxgall . Cells were not lysed in the presence of .3% oxgall, and beta-galactosidase was retained inside the cell even after extended incubation (60 min) in the presence of .3% oxgall . However, material that absorbed light at 260 nm leaked from the cells in the presence of oxgall . We concluded that, in the presence of bile, the permeability of cells of L . acidophilus increased, permitting more substrate to enter the cells, thus increasing the beta-galactosidase activity of whole cells.

FASEB J, 1993 May, 7(8), 662 - 70
Lysine 2,3-aminomutase: is adenosylmethionine a poor man's adenosylcobalamin?
Frey PA.
The interconversion of lysine and beta-lysine, which is catalyzed by lysine 2,3-aminomutase, is formally similar to the isomerization reactions catalyzed by adenosylcobalamin-dependent aminomutases . However, lysine 2,3-aminomutase is activated by S-adensoylmethionine and not by adenosylcobalamin . Lysine 2,3-aminomutase also contains {FeS} clusters, Co(II), and pyridoxal 5'-phosphate, all of which are required for maximum activity . Lysine 2,3-aminomutase acts through a mechanism akin to that of the adenosylcobalamin-dependent enzymes in which substrate radicals are intermediates . However, the 5'-deoxyadenosyl moiety of S-adenosylmethionine mediates hydrogen transfer in place of the 5'-deoxyadenosyl moiety of adenosylcobalamin . 5'-Deoxyadenosine is an intermediate in adenosylcobalamin-dependent reactions and in the reaction of lysine 2,3-aminomutase . The 5'-deoxyadenosyl radical, derived either from adenosylcobalamin or S-adenosylmethionine, appears to participate in these reactions . Similarly, the ribonucleotide reductase from Lactobacillus leichmanii is activated by adenosylcobalamin, whereas the ribonucleotide reductase from anaerobically grown Escherichia coli is activated by S-adenosylmethionine and an activating enzyme . The 5'-deoxyadenosyl radical seems to participate in the activation of both reductases . Therefore, both adenosylcobalamin and S-adenosylmethionine appear to serve as sources of 5'-deoxyadenosyl radicals in nature . S-Adenosylmethionine is not as chemically elegant a molecule as adenosylcobalamin, so it may be regarded as "a poor man's adenosylcobalamin."

Int J Food Microbiol, 1993 May, 18(3), 191 - 200
Sugar uptake and involved enzymatic activities by yeasts and lactic acid bacteria: their relationship with breadmaking quality; Antuna B et al.; The uptake kinetics of sugars present in wheat doughs and alpha-glucosidase as well as beta-fructosidase activities were determined in different strains of yeasts and lactic acid bacteria . These strains were previously selected according to their breadmaking quality . Saccharomyces cerevisiae (P6), Candida guilliermondii (P40), Lactobacillus plantarum (B31 and La18) and L . brevis (B21) showed good performance, while Sacch . fructuum (P43), L . cellobiosus (B37) and Enterococcus faecium (B11) yielded bread of lower quality . Leuconostoc mesenteroides (B10), when used in combination with other strains led also to high quality starters . All yeast strains used assimilated glucose, fructose and maltose, exhibiting saturable kinetics . Lactic acid bacteria showed saturable kinetics only for hexoses, whereas disaccharide uptake was linear . Sacch . cerevisiae, Leuconostoc mesenteroides, L . brevis and L . plantarum (B31) displayed better sugar uptake properties . For all the strains used alpha-glucosidase and beta-fructosidase activities were detected . The highest specific activities were found for Sacch . cerevisiae, C . guilliermondii and L . plantarum (B31) . These results indicate good correlation between the parameters evaluated and the breadmaking potential of the microorganisms.

J Prosthet Dent, 1993 May, 69(5), 524 - 8
Influence of salivary levels of mutans streptococci on colonization of crown margins: a longitudinal study; Kohler B et al.; Initial colonization of mutans streptococci in 36 crown margins of 21 patients was studied . Before cementation, salivary concentrations of mutans streptococci and Lactobacillus sp, microorganisms associated with dental caries, were determined . Within 1 week 25% of the selected crown margins in subjects with low salivary levels of mutans streptococci and 89% in subjects with high salivary levels were colonized . High salivary counts of lactobacilli seemed to reflect conditions that enhanced the risk of colonization of mutans streptococci . The results suggest that, before cementation of fixed prosthodontics, measures should be taken to control the salivary concentrations of these organisms to reduce the susceptibility to recurrent caries.

J Bacteriol, 1993 May, 175(10), 2864 - 70
Generation of a proton motive force by histidine decarboxylation and electrogenic histidine/histamine antiport in Lactobacillus buchneri; Molenaar D et al.; Lactobacillus buchneri ST2A vigorously decarboxylates histidine to the biogenic amine histamine, which is excreted into the medium . Cells grown in the presence of histidine generate both a transmembrane pH gradient, inside alkaline, and an electrical potential (delta psi), inside negative, upon addition of histidine . Studies of the mechanism of histidine uptake and histamine excretion in membrane vesicles and proteoliposomes devoid of cytosolic histidine decarboxylase activity demonstrate that histidine uptake, histamine efflux, and histidine/histamine exchange are electrogenic processes . Histidine/histamine exchange is much faster than the unidirectional fluxes of these substrates, is inhibited by an inside-negative delta psi and is stimulated by an inside positive delta psi . These data suggest that the generation of metabolic energy from histidine decarboxylation results from an electrogenic histidine/histamine exchange and indirect proton extrusion due to the combined action of the decarboxylase and carrier-mediated exchange . The abundance of amino acid decarboxylation reactions among bacteria suggests that this mechanism of metabolic energy generation and/or pH regulation is widespread.

Clin Exp Rheumatol, 1993 May-Jun, 11 Suppl 9, S3 - 6
Can we prevent long term cardiac damage in Kawasaki disease? Lessons from Lactobacillus casei cell wall-induced arteritis in mice; Lehman TJ; A single intraperitoneal injection of sonicated cell walls from group B Lactobacillus casei (LC) produces an acute inflammatory coronary arteritis in mice that closely resembles the coronary arteritis found in children with Kawasaki Disease (KD) . The coronary arteritis is accompanied in its early stages by pancarditis and valvulitis, and in its later stages by coronary artery aneurysms, stenoses, and myocardial infarctions . The importance of this model is two-fold . First, it provides the opportunity to study the natural history of coronary artery disease over a relatively short life span . Second, it provides a model system in which the effects of immunological and pharmacological interventions may be tested without putting human life at risk . Studies to date indicate that inflammatory coronary arteritis such as occurs in this model and in children with KD is associated with the accelerated development of coronary artery insufficiency and premature death from cardiovascular disease . The use of immunomodulators or other agents early in the disease course to reduce the frequency and severity of the coronary arteritis appears to reduce the incidence of premature death in this mouse model and may reduce the consequences of KD as well.

J Nurse Midwifery, 1993 May-Jun, 38(3), 146 - 51
The vagina as an ecologic system . Current understanding and clinical applications; Overman BA; Recent advances in understanding the mechanisms of dominance of the healthful microecology by Lactobacillus acidophilus through microbicidal enzyme systems has led to renewed interest in ecologic approaches to vaginal health maintenance and treatment of vaginosis and vaginitis . Review of pertinent research suggests that due to inadequate adherence of lactobacilli from dairy sources, contaminants in commercial sources, and lack of evidence of effectiveness in sparse clinical trials, intravaginal applications of L . acidophilus cannot be recommended . Bacterial vaginosis is described in this article as a microecologic shift in the dominant organism of the microecology from L . acidophilus to Gardnerella vaginalis . This results in conditions favorable to vaginal establishment of many anaerobic organisms . The ability to identify and nurture healthful lactobacilli in the vaginal microflora is suggested as a future direction for health-enhancement-oriented research, practice, and screening.

Arzneimittelforschung, 1993 May, 43(5), 622 - 5
In vitro anti-human immunodeficiency virus activity of 2',3'-dideoxynucleosides and their effect on clonal growth of hemopoietic cells from human bone marrow; Cinatl J Jr et al.; Seven 2',3'-dideoxynucleosides synthesized by substitution of nucleosides using nucleoside deoxyribosyltransferase from Lactobacillus leichmanii were tested for their anti-human immunodeficiency virus (HIV) activity . Two of them, including 2,6-diaminopurine-2',3'-dideoxyriboside (DAPDDR) and 6-chlorpurine-2',3'-dideoxyriboside (CPDDR) demonstrated high antiviral activity against several strains of HIV-1 and one strain of HIV-2 . The selectivity index of the drugs (SI; ratio of the drug concentration required for 50% of cell killing to drug concentration required to inhibit 50% of virus-induced cell killing) was established by application of tetrazolium (MTT) colorimetric assay . SI ranged for different HIV strains from 501 to 850 and from 60 to 118 for DAPDDR and CPDDR, respectively . Both DAPDDR and CPDDR retained their antiviral activity against HIV-1 strain D148/88 which was resistant to Zidovudine (3'-azido-3'-deoxythymidine, AZT) . Assays for clonal growth of human bone marrow cells in semisolid fibrin clot culture medium demonstrated that DAPDDR possesses significantly lower inhibitory activity for erythroid (BFU-E), multipotent (GEMM-CFC) and granulocyte-monocyte (GM-CFC) bone marrow progenitor cells than CPDDR or AZT . These results suggest that DAPDDR is a nucleoside analog which should be further tested as an anti-HIV compound especially in combination with other anti-retroviral drugs.

J AOAC Int, 1993 May-Jun, 76(3), 682 - 90
Potential application of LASER/microbe bioassay technology for determining water-soluble vitamins in foods; Anderson EM et al.; A microbiological technique was developed for quantitating niacin by determining microbial growth rates in response to the amount of vitamin available . Unlike the current official AOAC method, the new procedure for niacin measured the growth rates during the early exponential growth phase rather than during the stationary phase . Lactobacillus plantarum was used to determine niacin to a lower limit of 100 pg/mL . The assay time was approximately 6 h, compared with 16-24 h for the current AOAC method . The extent of microbial growth was determined by differential light scattering of a LASER beam . Multiple photodetectors were integrated with a computer system to collect and analyze the data . The use of differential light scattering to determine 8 water-soluble vitamins under stationary phase conditions demonstrated the potential application of the new technology for microorganisms and foods.

J Appl Bacteriol, 1993 May, 74(5), 549 - 56
Strain characterization, genome size and plasmid content in the Lactobacillus acidophilus group (Hansen and Mocquot); Roussel Y et al.; Chromosomal DNA of nine strains of the Lactobacillus acidophilus (Hansen and Mocquot) group in which heterogeneity had previously been revealed by biochemical characteristics and DNA-DNA hybridization studies were further investigated by restriction analysis, Southern hybridization, conventional and pulsed-field gel electrophoresis (PFGE) analyses . Industrial strains were characterized and identified as Lact . acidophilus . For this species, the number of rRNA gene clusters was estimated to be at least four from analyses of rRNA gene restriction patterns . The chromosome size of type-strains of Lact . acidophilus and Lact . gasseri was estimated from PFGE analysis to be 1.85 and 2.02 Mb respectively and Lact . gasseri strains were found to contain large-sized linear plasmids.

J Biotechnol, 1993 May, 29(1-2), 157 - 75
Shear stress effects on growth and activity of Lactobacillus delbrueckii subsp . bulgaricus; Arnaud JP et al.; Cells are frequently submitted to shear stresses during industrial processes . Shear stress can be either beneficial or detrimental to the cells depending on the organism and on the level of intensity . The present work was designed to study the effect of shear stress on cell activity of a widely used lactic acid bacterium, Lactobacillus delbrueckii subsp . bulgaricus (L . bulgaricus) . A constant shear stress bioreactor, based on Couette device, was developed and used to control shear stress from 0 to 72 Pa during a 4-h cultivation of a supplemented whey permeate medium with L . bulgaricus at 42 degrees C . In order to reach high shear stresses and to perform experiments within the laminar flow range where hydrodynamic conditions are accurately defined, the medium was thickened with carboxymethylcellulose (CMC) . pH, cell counts, optical density, lactose and lactic acid concentrations were monitored during culture, and cell activity was evaluated after culture and after a freezing treatment at -80 degrees C, using a standardized activity test based on optical density measurement . Cell metabolism was significantly improved by intermediate shear stress levels (36 and 54 Pa) during culture . Furthermore, biomass concentration, evaluated by optical density, was clearly higher at 36 Pa . Cell lengthening was observed, which was mainly related to the presence of CMC and partly to shear stress level, especially at 36 Pa . Hydrodynamic conditions during culture could affect the membrane permeability of the cell and its resistance to freezing . Cells cultivated at 72 Pa were certainly weakened by shearing forces, and these cultures exhibited lag times twice as long after freezing as those grown at 36 Pa . Furthermore, after freezing, cultures grown at 36 Pa had shorter lag times than at 0 Pa (1.1 and 1.3 h, respectively) and higher specific growth rates (1.24 and 0.99 h-1, respectively).

J Appl Bacteriol, 1993 May, 74(5), 532 - 41
Phylogenetic analysis of some leuconostocs and related organisms as determined from large-subunit rRNA gene sequences: assessment of congruence of small- and large-subunit rRNA derived trees; Martinez-Murcia AJ et al.; The large-subunit ribosomal RNA gene sequences of Leuconostoc carnosum, Leuc . mesenteroides, Leuc . oenos, Leuc . paramesenteroides and Lactobacillus confusus were determined by direct sequencing of enzymatically-amplified DNA . Comparative analysis of the large-subunit rDNA sequences revealed that the leuconostocs form three distinct lines of descent: Leuconostoc sensu stricto, Leuc . paramesenteroides group of organisms, and Leuc . oenos . The distance matrix tree constructed from the large-subunit sequence data was in excellent agreement with that derived from small-subunit sequences, and demonstrates the 'synchrony' of the two chronometers . The results of the present and earlier sequence analyses indicate the taxonomy of the genus Leuconostoc is in need of revision, and that the Leuc . paramesenteroides group of organisms and the species Leuc . oenos represent distinct phylogenetic units, separate from Leuconostoc sensu stricto.

Biochemistry, 1993 Apr 20, 32(15), 3998 - 4006
Isotope effects and the identification of catalytic residues in the reaction catalyzed by glutamate racemase; Tanner ME et al.; Primary kinetic isotope effects on Vmax were observed in both reaction directions upon racemizing samples of {2-2H}glutamate with the cofactor-independent glutamate racemase from Lactobacillus . This supports a deprotonation/protonation mechanism for racemization in which the breaking of the carbon-hydrogen bond at C-2 is partially rate-determining . Substantial "overshoots" were observed when the time course of racemization of either enantiomer of glutamate was monitored using circular dichroism spectroscopy . This is consistent with a "two-base" mechanism accompanied by a kinetic isotope effect . "Competitive deuterium washout" experiments were used to measure kinetic isotope effects on Vmax/Km of 2.5 for (S)-glutamate and 3.4 for (R)-glutamate . The ratio of the notably different isotope effects was confirmed by "double competitive deuterium washout" experiments . Site-directed mutagenesis was used to generate the mutant C73A and C184A enzymes . In each case the mutant enzymes were inactive as racemases . The two mutant enzymes are, however, capable of catalyzing the elimination of HCl from opposite enantiomers of threo-3-chloroglutamic acid, a process that presumably requires only one enzymic base . This finding indicates that the active sites of the mutant enzymes are intact and that the two cysteines flank the bound substrate molecule . It appears that cysteine-73 is responsible for the abstraction of the C-2 hydrogen from (R)-glutamate and cysteine-184 abstracts the proton from (S)-glutamate in the racemization reaction of the wild-type enzyme.

Biochemistry, 1993 Apr 20, 32(15), 3991 - 7
Mechanism of the reaction catalyzed by glutamate racemase; Gallo KA et al.; The mechanism of the cofactor-independent glutamate racemase from Lactobacillus has been studied . The possible formation of an acylenzyme intermediate during catalysis has been investigated using 18O-carboxyl labeled glutamate . The absence of any washout of label during racemization argues against intermediate formation . The observation of the enzyme-catalyzed incorporation of deuterium at the C-2 position of glutamate upon racemization in D2O provides evidence for a deprotonation/protonation mechanism . Further experiments have been performed in order to determine the number of enzymic bases responsible for racemization . Solvent deuterium is efficiently incorporated into the product enantiomer but not into the recovered substrate enantiomer in each reaction direction . This finding is consistent with a "two-base" mechanism in which one enzymic base deprotonates the substrate, and the conjugate acid of a second enzymic base protonates the resulting intermediate from the opposite face . It also suggests that the two bases are monoprotic . The possibility that the two enzymic forms, which differ at the very least by the protonation states of the active-site bases, are kinetically significant has been examined by measuring the entire time course of the approach to equilibrium at various concentrations of glutamate . An "oversaturated" regime {Fisher, L . M., Albery, W . J., & Knowles, J . R . (1986) Biochemistry 25, 2529-2537} was not observed using glutamate concentrations as high as 100 mM, indicating that the two enzyme forms are rapidly interconverting under physiological conditions.

Gene, 1993 Apr 15, 126(1), 61 - 6
Genetic organization and sequence of the region encoding integrative functions from Lactobacillus gasseri temperate bacteriophage phi adh; Fremaux C et al.; A 2.0-kb fragment from the Lactobacillus gasseri temperate bacteriophage phi adh contained the essential genetic determinants for site-specific integration . The nucleotide sequence of this fragment was determined . An open reading frame (intG), which adjoined the phage attachment site (attP), encoded a deduced protein related to the integrase family . The organization of this region was comparable to other phage site-specific recombination systems.

New Microbiol, 1993 Apr, 16(2), 177 - 80
Isolation and partial characterization of three rumen Lactobacillus plantarum bacteriophages; Nemcova R et al.; The first isolation of Lactobacillus plantarum bacteriophages from ruminal fluid is reported . Three bacteriophages were characterized on the basis of plaque morphology, host ranges, stability, electron microscopic morphology and DNA restriction endonuclease digestion patterns . They formed clear plaques and are placed in group A of Bradley's scheme and have identical host ranges . Bacteriophages were stable to urea and chloroform . They were relatively thermostable but partially inactivated by rumen fluid and by acetate . DNA restriction analysis showed that phage L20 had different numbers of cleavage sites in comparison with the next two phages.

Int J Food Microbiol, 1993 Apr, 18(2), 107 - 13
Biochemical characterization of lactobacilli from dry fermented sausages; Hugas M et al.; The characterization of 254 strains of lactobacilli isolated from dry spontaneously fermented sausages from 15 different producers at two different stages of ripening time is reported . The species identified were Lactobacillus sake 55%, L . curvatus 26%, L . bavaricus 11% and L . plantarum 8% . The main criteria for the identification of isolates to species level were: production of lactic acid isomers, presence of mDpm acid in cell walls, deamination of arginine and fermentation of mannitol and melibiose . The composition of the populations of lactobacilli were the same for the two stages of ripening . The deamination of arginine was tested in aerobic and anaerobic cultures and in different media by checking the production of ammonia and detecting the production of citrulline . In 94% of strains tested both methods gave identical results . In two L . sake strains arginine catabolism was dependent on culture media; for two other L . sake strains the deamination of arginine only occurred when oxygen was scarce.

J Dairy Sci, 1993 Apr, 76(4), 956 - 61
Relationship among bile tolerance, bile salt deconjugation, and assimilation of cholesterol by Lactobacillus acidophilus; Walker DK et al.; The relationships among growth in the presence of bile, deconjugation of sodium taurocholate, and assimilation of cholesterol by 19 cultures of Lactobacillus acidophilus were examined . Cultures of L . acidophilus were grown at 37 degrees C in lactobacilli MRS broth supplemented with sodium thioglycollate, sodium taurocholate, and cholesterol (cholesterol phosphatidyl choline micelles) . Deconjugation activity was maximum in the late exponential phase of growth, which also coincided with maximum assimilation of cholesterol . Considerable variation existed among cultures in their ability to grow in the presence of bile, to deconjugate sodium taurocholate, and to assimilate cholesterol . However, statistical analyses revealed no significant correlations.

J Dairy Sci, 1993 Apr, 76(4), 1083 - 90
In vitro effects of a thiopeptide and monensin on ruminal fermentation of soluble carbohydrates; Tung RS et al.; Using a purified diet and a mixed culture of ruminal microorganisms, we studied the in vitro effects of a sulfur-containing peptide (A10255) and monensin on ruminal VFA and lactic acid concentrations . After 22 h of fermentation, total VFA concentration was greater in cultures with A10255 and monensin (2.5 ppm each) than in untreated controls (84.1, 91.9, and 65.2 mM for cultures with A10255, monensin, and control, respectively) . The molar proportions of propionate were more than 40% greater, and the molar proportions of acetate were about 15% less, in treated than in untreated cultures . The molar proportions of the remaining VFA were lowest in monensin-treated cultures, intermediate in A10255-treated cultures, and greatest in untreated cultures . Addition of A10255 or monensin also prevented the accumulation of lactate and maintained higher pH than in untreated cultures . In pure culture, growth of Streptococcus bovis was slowed by A10255 at pH 5.5 and 6.5 . Growth of S . bovis was reduced markedly with addition of monensin at pH 6.5 and inhibited at pH 5.5 . Growth of Lactobacillus acidophilus was inhibited more at pH 5.5 than 6.5 with monensin but was unaffected by A10255 . The thiopeptide A10255 and monensin inhibited ruminal lactate production, but sensitivities of lactate-producing bacteria differed between compounds.

J Appl Bacteriol, 1993 Apr, 74(4), 372 - 9
Mesenterocin 52, a bacteriocin produced by Leuconostoc mesenteroides ssp . mesenteroides FR 52; Mathieu F et al.; One hundred and sixty-five isolates of Leuconostoc spp . were tested for bacteriocin production . Only one strain, Leuc . mesenteroides ssp . mesenteroides FR 52, isolated from a raw milk, produced a bacteriocin which was named Mesenterocin 52 . This bacteriocin inhibited other Leuconostoc strains and several strains of Enterococcus and Listeria spp . No activity was found against lactococci and lactobacilli . The antibacterial spectrum differed from that of previously described Leuconostoc bacteriocins . Mesenterocin 52 was secreted into the medium during the growth phase . It was inactivated with protease treatments . At pH 7.0 it had a relative stability after heating at 100 degrees C (15 min), but it had a greater stability at pH 4.5 than at pH 7.0 after 6 h at 80 degrees C . The apparent molecular mass was estimated to be less than 10 kDa by ultrafiltration . Mesenterocin 52 showed a bactericidal effect on Leuconostoc paramesenteroides DSM 20288.

J Bacteriol, 1993 Apr, 175(8), 2475 - 8
Cloning and sequence determination of the valS gene, encoding valyl-tRNA synthetase in Lactobacillus casei; Taylor BV et al.; The DNA sequence of the valS gene from Lactobacillus casei and the predicted amino acid sequence of its valyl-tRNA synthetase product have been determined . An open reading frame coding for a protein of 901 amino acids was found . A clone containing the intact L . casei valS gene functionally complemented the temperature-sensitive growth of the valS mutant strain 236c of Escherichia coli . The valS gene and the downstream folylpolyglutamate synthetase gene are transcribed in the same direction but are separated by a putative transcription terminator.

Scand J Dent Res, 1993 Apr, 101(2), 87 - 91
Periodontopathic bacteria and salivary microbes before and after extraction of partly erupted third molars; Rajasuo A et al.; This study examines the effect of extraction of third molars on suspected periodontopathogenic microbes, salivary acidogenic bacteria, and yeasts . The subjects were 39 healthy conscripts aged 20.2 yr, with symptom-free, partly erupted mandibular third molars . Microbial samples were taken from the mandibular third molar pericoronal space and from the adjacent gingival pocket of the second molar . The samples were stained by Gram's and Giemsa's methods and studied under a light microscope . Stimulated saliva was collected for assessing mutans streptococci, lactobacilli, and yeast counts by chair-side kits . All partly erupted third molars were extracted from 20 test subjects; 19 control subjects were left untreated . Microbial samplings were repeated 2 and 5 months postoperatively . Results showed that at base line the total number of Gram-negative bacteria, Gram-negative rods, and spirochetes was significantly higher at the third molar than at the second molar sites . The extraction of the third molars caused a significant decrease in the percentage of these bacteria at the second molar sites . High counts of salivary mutans streptococci (CFU > or = 10(6)) and lactobacilli (CFU > or = 10(5)) were also significantly less frequent after the operations . Yeast counts were not affected by the extractions . Thus, partly erupted third molars may harbor a periodontally pathogenic microflora and increase the number of salivary acidogenic microbes.

Indian J Biochem Biophys, 1993 Apr, 30(2), 89 - 97
Studies on cinnamic acid-4-hydroxylase from wounded potato tissue: isolation and characterization of cinnamic acid-4-hydroxylase activation factor; Pendharkar MB et al.; Cinnamic acid-4-hydroxylase activation factor has been found to be located in the supernatant fraction of wounded potato tissue homogenate in phosphate buffer . The factor has been purified to homogeneity as judged by SDS polyacrylamide gel electrophoresis, by heat treatment on boiling water-bath for 7.5 min followed by dialysis with cut off limit of 8 kDa and final separation by gel filtration on Sephadex G-50 column . Gel filtration resolved this into three active fractions of molecular mass 12500, 10000 and 8500 Da conjugated to a fluorescent compound and subsequently identified as a folate derivative . The amino acid analysis of polypeptide chains of these fractions revealed that the polypeptides were rich in glutamic and aspartic acids . The fluorescent moiety of the complex released from polypeptide chain of molecular weight 10000 by mild acid hydrolysis was able to support the growth of Lactobacillus casei ATCC 7469 which requires folic acid for its growth . On storage, this compound degraded into a number of fluorescent products identified as p-amino benzoic acid, p-amino benzoyl glutamic acid, pteroic acid and 6-methyl pterin indicating that the activation factor is a folic acid derivative conjugated with the polypeptide chain.

Indian J Biochem Biophys, 1993 Apr, 30(2), 103 - 10
Ternary complex formation with 5-fluoro-2'-deoxyuridylate and the kinetic properties of thymidylate synthase from Lactobacillus leichmannii; Rao KN; Lactobacillus leichmannii thymidylate synthase (5,10-CH2-H4PteGlu:dUMP C-methyltransferase, EC 2.1.1.45) forms a tight and stable covalently bonded ternary complex with the inhibitor 5-FdUMP in the presence of the cofactor 5,10-CH2-H4-PteGlu . 'Filter assay' employing the radioactive nucleotide ligand showed that 2 moles of FdUMP are bound per mole enzyme during the ternary complex formation with the L . leichmannii dTMP synthase . This is in line with our earlier observation on the Streptococcus faecium thymidylate synthase {Narasimha Rao, K & Kisliuk R L (1983), Proc Natl Acad Sci USA, 80, 916-920} . The enzyme has Km values of 6.3 x 10(-6) M, 8.2 x 10(-5) M and 1.0 x 10(-4) M for dUMP, (dl)-L-H4PteGlu and Mg2+ respectively; Vmax for dUMP, (dl)-L-H4PteGlu and Mg2+ are; 0.55, 0.5 and 1.1 respectively . It has K(i) values of 6.7 x 10(-6) M, 2.2 x 10(-6) M, 5.0 x 10(-5) M and 2.0 x 10(-4) M for FdUMP, dTMP, MTX and Ca2+ respectively . The type of enzyme inhibition with FdUMP, dTMP, MTX and Ca2+ was competitive . dTMP Studies clearly show the 'end product' inhibition of the enzyme.

Biotechnol Appl Biochem, 1993 Apr, 17 ( Pt 2), 139 - 53
Microbial reduction of 1-(4-fluorophenyl)-4-{4-(5-fluoro-2-pyrimidinyl)-1- piperazinyl}butan-1-one; Patel RN et al.; Among various micro-organisms screened for the stereoselective reduction of 4-chloro-1-(4-fluorophenyl)butan-1-one (1), Hansenula polymorpha {American Type Culture Collection (A.T.C.C.) 26012 and 86014}, Nocardia salmonicolor {Squibb Culture (S.C.) 6370}, Arthobacter simplex (A.T.C.C . 6949), Mycobacterium vaccae (A.T.C.C . 29678), Candida boidinii (A.T.C.C . 13821) and Saccharomyces cerevisiae (A.T.C.C . 13792) reduced compound 1 to the corresponding (R)-(+)-alcohol (2) . In contrast, Lactobacillus kefir (A.T.C.C . 35411), Pullularia pullulans (A.T.C.C . 16623), Trigonopsis variabilis (A.T.C.C . 10679) and Cunninghamella echinulata (A.T.C.C . 26269) reduced compound 1 to the (S)-(-)-alcohol (2) . When 1-(4-fluorophenyl)-4-(1-piperazinyl)butan-1-one (3) was used as substrate for the reduction, only Nocardia globerula (A.T.C.C . 12505) and Saccharomyces cerevisiae (A.T.C.C . 13792) converted compound 3 into the corresponding (R)-(+)-alcohol (4) . Organisms which reduced compound 1 were inactive for the reduction of compound 3 . 1-(4-Fluorophenyl)-4-{4-(5-fluoro-2- pyrimidinyl)butan-1-one (5) was reduced to the corresponding (R)-(+)-alcohol (6) by Mortierella ramanniana (A.T.C.C . 38191) and to the (S)-(-)-alcohol (6) by Pullularia pullulans (A.T.C.C . 16623) . (R)-(+)-compound 2 and compound 4 are key chiral intermediates in the total chemical synthesis of (R)-(+)-compound 6, an effective antipsychotic agent under development at Bristol-Myers Squibb . A single-stage (fermentation/biotransformation) process and two-stage (fermentation and subsequent biotransformation by cell suspensions) process were developed for the stereoselective reduction of compound 5 to (R)-(+)-compound 6 by Mortierella ramanniana (A.T.C.C . 38191) . In both processes, the reaction yield of 98% and the optical purity of 99.4% were obtained for (R)-(+)-compound 6 . The enzyme which catalysed the reduction of compound 5 to (R)-(+)-compound 6 was purified to homogeneity . The purified protein consisted of a single polypeptide of 29 kDa.

Antibiot Khimioter, 1993 Apr-May, 38(4-5), 40 - 2
{Various approaches to treatment of dysentery in children}; Iushkevich SB et al.; The clinical process, etiological pattern and results of antibacterial therapy of dysentery in 1105 children were analyzed by hospital records for the last 25 years . Significant changes in the etiology of dysentery were revealed . In the 1960s Shigella flexneri prevailed (56.3 per cent) and in the 1970-1990s Shigella sonnei prevailed (69.9 to 74.6 per cent) whereas the percentage of Newcastle dysentery was low and stable (1.5 to 8.7 per cent) . Simultaneously, there were changes in antibiotic sensitivity of the Shigella strains . In the 1960s the Shigella strains were mainly sensitive to tetracyclines, in the 1970s they were mainly sensitive to levomycetin and polymyxin and in the 1980-1990s they were mainly sensitive to gentamicin, polymyxin, carbenicillin and ampicillin . Accordingly, the antibacterial therapy allowed for the sensitivity of the pathogen at the particular period . Biological preparations such as bifidum bacterin, bificol, lactobacterin, etc . should be used in the complex therapy of Shigella infection due to frequent affection of intestinal biocenosis.

J Mol Biol, 1993 Mar 20, 230(2), 516 - 28
Refined structure of the pyruvoyl-dependent histidine decarboxylase from Lactobacillus 30a; Gallagher T et al.; The crystal structure of the pyruvoyl-dependent histidine decarboxylase from Lactobacillus 30a has been refined to an R-value of 0.15 (for the 5.0 to 2.5 A resolution shell) and 0.17 (for the 10.0 to 2.5 A resolution shell) . A description of the overall structure is presented, focusing on secondary structure and subunit association . The enzyme is a hexamer of alpha beta subunits . Separate alpha and beta-chains arise from an autocatalytic cleavage reaction between two serine residues, which results in the pyruvoyl cofactor . The central core of the alpha beta subunit is a beta-sandwich which consists of two face-to-face three-stranded antiparallel beta-sheets, flanked by alpha-helices on each side . The beta-sandwich creates a stable fold that allows conformational strain to be introduced across an internal cleavage region between the alpha and beta chains and places the pyruvoyl cofactor in a position for efficient electron withdrawal from the substrate . Three alpha beta subunits are related by a molecular three-fold symmetry axis to form a trimer whose interfaces have complementary surfaces and extensive molecular interactions . Each of the interfaces contains an active site and a solvent channel that leads from the active site to the exterior of the molecule . The trimers are related by a crystallographic two-fold symmetry axis to form the hexamer with an overall dumbbell shape . The interface between trimers has few molecular interactions.

Science, 1993 Mar 5, 259(5100), 1445 - 50
Structure-based discovery of inhibitors of thymidylate synthase; Shoichet BK et al.; A molecular docking computer program (DOCK) was used to screen the Fine Chemical Directory, a database of commercially available compounds, for molecules that are complementary to thymidylate synthase (TS), a chemotherapeutic target . Besides retrieving the substrate and several known inhibitors, DOCK proposed putative inhibitors previously unknown to bind to the enzyme . Three of these compounds inhibited Lactobacillus casei TS at submillimolar concentrations . One of these inhibitors, sulisobenzone, crystallized with TS in two configurations that differed from the DOCK-favored geometry: a counterion was bound in the substrate site, which resulted in a 6 to 9 angstrom displacement of the inhibitor . The structure of the complexes suggested another binding region in the active site that could be exploited . This region was probed with molecules sterically similar to sulisobenzone, which led to the identification of a family of phenolphthalein analogs that inhibit TS in the 1 to 30 micromolar range . These inhibitors do not resemble the substrates of the enzyme . A crystal structure of phenolphthalein with TS shows that it binds in the target site in a configuration that resembles the one suggested by DOCK.

J Antimicrob Chemother, 1993 Mar, 31(3), 363 - 72
Comparative susceptibility of the Bacteroides fragilis group species and other anaerobic bacteria to meropenem, imipenem, piperacillin, cefoxitin, ampicillin/sulbactam, clindamycin and metronidazole; Goldstein EJ et al.; The in-vitro activity of meropenem, imipenem, piperacillin, cefoxitin, ampicillin/sulbactam, clindamycin and metronidazole was determined against 395 strains of strict and facultative anaerobes, including Gardnerella vaginalis, Lactobacillus spp . and Mobiluncus spp . The activities of meropenem and imipenem were within one dilution of their MIC50 and MIC90 values . One isolate of Bacteroides fragilis, two of Bacteroides distasonis, and two of Bacteroides ovatus showed resistance or diminished susceptibility to meropenem and imipenem . Metronidazole was active against almost all obligate anaerobic isolates . Some non-spore-forming Gram-positive bacilli and lactobacilli were resistant . Ampicillin/sulbactam inhibited almost all isolates at < or = 16/8 mg/L . The activity of clindamycin and cefoxitin was relatively good, but some strains of non-fragilis B . fragilis group species were resistant . Piperacillin was the least active agent tested.

Rev Fr Gynecol Obstet, 1993 Mar, 88(3 Pt 2), 211 - 4
{Bacterial vaginosis: what risks for the mother and child?}; Zana J; Bacterial vaginosis are characterized by a polymicrobial proliferation of anaerobic organisms and the disappearance of the commensal lactobacilli, which can cause ascending utero-adnexitis and endanger ongoing pregnancy . The role of anaerobes in utero-adnexitis and tubal abscess was first raised in 1973 par Eschenbach . Several authors have since established correlations between bacterial vaginosis and both pain from the uterine appendages and gynecologic infections, particularly post-abortum . Bacterial vaginosis is a major problem in pregnant women, given its high prevalence (15-20 p . cent) and significant relationship with premature delivery and premature rupture of the membranes (at less than 37 weeks of amenorrhea) in epidemiological case-control and cohort studies taking into account demographic and concomitant obstetric characteristics . In particular, histological lesions indicative of chorioamniotitis have been correlated with prematurity and with the presence of bacteria (usually those involved in vaginosis) in the amniochorial space . Bacterial vaginosis can give rise to ascending infections which reach the amniochorial space and cause uterine contractions or alter the amniochorial membrane, leading to premature rupture of the membranes . These epidemiological data must, however, be confirmed by controlled trials of antibiotics active in bacterial vaginosis and their preventive effect on prematurity and premature rupture of the membranes . Finally, bacterial vaginosis can play a role in endometritis following both natural and caesarean delivery; this has been shown in multivariate analyses with adjustment for maternal age, duration of labor and rupture of the membranes, and isolation of bacteria associated with bacterial vaginosis from the endometrium.

Rev Fr Gynecol Obstet, 1993 Mar, 88(3 Pt 2), 207 - 10
{Recent bacteriologic data: from physiopathology to treatment}; Lefevre JC; Bacterial vaginosis is characterized by a change in the vaginal ecosystem in which Lactobacillus spp, the dominant members of the normal flora, are replaced by an association of various bacterial species including Gardnerella vaginalis, anaerobes (Bacteroides spp, Prevotella spp, Porphyromonas spp, Peptostreptococcus spp and Mobiluncus spp) and Mycoplasma hominis . The reasons for this imbalance are unknown, although the loss of lactobacilli that produce hydrogen peroxide (which is toxic for G . vaginalis and numerous anaerobes) may be an essential element . The introduction of one or several of these species into the vagina (they can occasionally be isolated in small numbers even in the absence of vaginosis) following intercourse or from the intestinal tract may also play a role . G . vaginalis itself is not considered to cause vaginosis, but is almost always present and multiplies rapidly; in addition, it has a high capacity for adherence to epithelial cells both in vivo and in vitro . It is now agreed that the concomitant growth of one or several anaerobic species is required for bacterial vaginosis to develop . Our knowledge of the bacteriology of bacterial vaginosis has implications for diagnosis and treatment . It is now possible to obtain a precise bacteriologic diagnosis, not by culturing G . vaginalis (a costly and low-yield procedure), but by direct examination of the vaginal flora after Gram staining, which shows the replacement of lactobacilli by a characteristic polymorphic flora . Therapy is based on the use of antibiotics such as the imidazoles, which are active against G . vaginalis and anaerobes, but not against the commensal lactobacilli.(ABSTRACT TRUNCATED AT 250 WORDS)

Rev Fr Gynecol Obstet, 1993 Mar, 88(3 Pt 2), 203 - 6
{The bacteriologic diagnosis of bacterial vaginosis in an urban practice}; Askienazy-Elbhar M; The term "bacterial vaginosis" carries both bacteriologic and clinical connotations . Indeed, it implies that the vagina is uninflamed (as shown by the absence of polymorphonuclear neutrophils), but that potential pathogens (particularly Gardnerella vaginalis) are present . Many studies conducted over the last 10 years have shown that a tentative diagnosis is simple to make, based on the sniff test, the aspect of the vaginal discharge, the presence of clue cells, and the absence of polymorphonuclear cells and lactobacilli on fresh smears . However, classical treatment with metronidazole can be insufficient given the innumerable microbial associations, and a more thorough bacteriological diagnosis is required . The presence of anaerobes is suggested by a positive sniff test . Direct examination reveals small Gram-negative rods in clue cells, but cannot differentiate between commensal atypical lactobacilli and Gram-positive anaerobes . Culture with CO2 supplementation or in anaerobic conditions yields Bacteroides and Mobiluncus spp, frequently associated with Gardnerella vaginalis and pathogenic Fusobacterium spp . Culture in appropriate conditions will detect metronidazole-resistant Propionibacteria and pathogenic anaerobic cocci . Antibiotic susceptibility testing of these organisms is costly and time-consuming, but can avoid therapeutic failures . Gardnerella vaginalis is also frequently associated in bacterial vaginosis with endogenous (mainly E . coli and group B streptococci) and Ureaplasma . Antibiotic susceptibility testing is useful if the predominant members of the flora are Gram-negative aerobes, group D streptococci or pathogenic anaerobes . Bacterial vaginosis is simple to diagnose but poses a real therapeutic problem since some cases call for a simple readjustment of the commensal flora while others require full chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Rev Fr Gynecol Obstet, 1993 Mar, 88(3 Pt 2), 195 - 7
{The definition and epidemiology of bacterial vaginosis}; Mardh PA; Bacterial vaginosis is a condition with a flora change in the vaginal where a lactobacilli-dominated flora is exchanged with an abundant complex flora dominated by strict and facultative anaerobic bacteria . The condition seldom occurs in prepubertal girls and post-menopausal women, suggesting an hormonal component in its etiology . Recurrent episodes of bacterial vaginosis are frequent . Three out of four criteria should be fulfilled for establishing the diagnosis of bacterial vaginosis, i.e., an increased (often homogeneous) vaginal discharge, a positive amine test, the presence of a great number of clue cells, a vaginal pH > or = 4.5 . There are no hard data supporting that bacterial vaginosis is a sexually transmitted disease . Cytological changes (CIN I, II, III) have been found more often in women with bacterial vaginosis than in those without this condition . It has been proposed that nitrosamines from the abundant vaginal bacterial flora may be oncogenic, a correlation which, however, needs to be proved . The reservoir for one or more of the bacterial vaginosis-associated organism, e.g., some Bacteroides and Mobiluncus spp., Gardnerella vaginalis and Mycoplasma hominis, is probably the distal intestinal tract and the mouth . Sparse or even a moderate number of clue cells are present in many women who do not have bacterial vaginosis . A vaginal pH of 4.7 seems to be a better cut-off level than 4.5 . There is a statistical correlation between bacterial vaginosis and obstetrical complications.

J Appl Bacteriol, 1993 Mar, 74(3), 314 - 23
Numerical taxonomy of Lactobacillus spp . associated with healthy and diseased mucosa of the human intestines; Molin G et al.; Two-hundred and fifty Lactobacillus strains isolated from healthy and diseased mucosa of human intestines of 75 individuals and 49 reference strains were phenotypically classified using 49 unit characters . Data were processed by the Jaccard (SJ) and Simple Matching (SSM) coefficients, and unweighted pair group algorithm with arithmetic averages . Seventeen major clusters were defined at the 76% SJ-similarity level which approximately correspond to the SSM-level of 91% . Seven clusters could be identified: Lactobacillus plantarum (isolates recovered from 5% of the patients), Lact . casei subsp . rhamnosus (17% of the patients), Lact . casei subsp . pseudoplantarum (5% of the patients), Leuconostoc mesenteroides subsp . mesenteroides (3% of the patients), Lact . buchneri (4% of patients), Lact . reuteri (4% of the patients) and Lact . salivarius subsp . salivarius (9% of the patients) . Unassigned clusters 1 and 3 both contained homofermentative Lactobacillus strains . Cluster 1 included the type strains of Lact . crispatus, Lact . acidophilus, Lact . jensenii and Lact . gasseri, and cluster 3, the type strains of Lact . delbrueckii subsp . lactis, Lact . agilis and Lact . casei subsp . tolerans . Clusters 1 and 3 were found in 15% and 25% of the patients, respectively . Unassigned clusters 2, 6, 7, 8 and 10 contained homofermentative Lactobacillus strains but no reference strains . Clusters 11, 12, 15 and 17 were made up of heterofermentative Lactobacillus strains but no reference strains . Phenotypical characteristics of the clusters are given . No obvious trends in species (cluster) composition between different intestinal locations could be noted . Most clusters contained isolates from both diseased and healthy mucosa . Exceptions were cluster 15 and cluster 17 which only included isolates from healthy mucosa, and cluster 11 which only included isolates from diseased mucosa . Cluster 15 was isolated in 12% of the patients, and cluster 11 in 8%.

J Appl Bacteriol, 1993 Mar, 74(3), 295 - 300
Molecular characterization of Lactobacillus curvatus and Lact . sake isolated from sauerkraut and their application in sausage fermentations; Vogel RF et al.; Lactobacillus curvatus and Lact . sake are best adapted to meat fermentations and dominate the flora during the whole process . In fermenting sauerkraut, Leuconostoc mesenteroides subsp . mesenteroides is the major organism only during the early phase . In this environment Lact . curvatus and Lact . sake provide up to 50% of the microbial flora especially of the later phase, depending on the process conditions . Strains of Lact . curvatus and Lact . sake isolated from fermenting sauerkraut were identified by hybridization with species specific 23S rRNA-targeted oligonucleotide probes and further characterized . In 59 of 72 strains, plasmid DNA was detected . Small cryptic plasmids of 20 strains were found to be homologous with pLc2, a 2.6 kb plasmid from Lact . curvatus LTH683, which was originally isolated from meat . The ability to compete was investigated in fermenting sausages of two strains each of Lact . curvatus and Lact . sake isolated from sauerkraut . One strain each of Lact . curvatus and Lact . sake was found to outnumber the meat-borne flora and govern the process.

J Appl Bacteriol, 1993 Mar, 74(3), 290 - 4
Adhesion of Lactobacillus acidophilus to avian intestinal epithelial cells mediated by the crystalline bacterial cell surface layer (S-layer); Schneitz C et al.; Lactobacillus acidophilus was isolated from washed and homogenized walls of the crop and caecum of an adult fowl . A strain that adhered well in the Fuller adhesion test was subcultured until colonies on Lactobacillus Selective agar changed from rough to smooth . This coincided with a change from aggregate to planktonic growth in liquid medium and a marked loss of ability to adhere . ultrastructure of cells from both types of culture was studied by electron microscopy . An S-layer formed the outermost part of the cell wall in the strongly-adherent strain, whereas this layer was covered with polymerized material or was absent in strains that lacked the ability to adhere, or those with reduced adherence.

J Dent Res, 1993 Mar, 72(3), 623 - 9
A microbiological study of primary root-caries lesions with different treatment needs; Beighton D et al.; Samples of altered or carious dentin for microbiological culture were obtained from 301 primary root-caries lesions in 59 patients by means of a standardized sampling procedure . This involved the cleansing of each root surface of extraneous supragingival plaque by means of a hand-held toothbrush and distilled water and the collection of the sample with a sterile dental excavator passed through the entire vertical dimension of each lesion . The total number of colony-forming units (cfu) in each sample and the numbers of mutans streptococci (primarily Streptococcus mutans), lactobacilli, yeasts, and Gram-positive pleomorphic rods (GPPR) were determined . Individual bacterial counts were expressed as log10 (cfu per sample), as a percentage of the total number of bacteria per sample, and as a frequency of isolation from lesions with different clinical diagnostic criteria . Clinical measurements of each lesion were made for color, texture, position relative to the gingival margin, and treatment need . Lesions classified as soft yielded significantly more bacteria, mutans streptococci, lactobacilli, and GPPR than leathery lesions, which yielded more bacteria than hard lesions . Lesions were classified into 5 treatment categories: soft and restore, leathery and restore, leathery and debride of caries; leathery and treat therapeutically; and hard no treatment . The total numbers of bacteria, mutans streptococci, lactobacilli, GPPR, and yeasts decreased significantly with decreasing treatment need . The frequency of isolation of mutans streptococci, lactobacilli, and yeasts was significantly greater from lesions requiring restoration and from lesions situated within 1 mm of the gingival margin . We suggest that the majority of root caries is initiated adjacent to the gingival margin.

FEBS Lett, 1993 Mar 1, 318(2), 177 - 80
Stereospecific assignments of the leucine methyl resonances in the 1H NMR spectrum of Lactobacillus casei dihydrofolate reductase; Ostler G et al.; A general method is described for the stereospecific assignment of methyl resonances in protein NMR spectra based on selective deuteration procedures . A selectively deuterated dihydrofolate reductase from L . casei was prepared by incorporating stereoselectively deuterated L-leucine, (2S,4R){5,5,5-2H3}leucine . By comparing the COSY spectra of the dihydrofolate reductase-methotrexate complexes formed using deuterated and non-deuterated enzyme the stereospecific assignments for resonances of all 13 leucine residues were obtained by noting the absence of cross-peaks in spectra from the deuterated proteins.

J Clin Microbiol, 1993 Mar, 31(3), 689 - 91
Biochemical characteristics and fatty acid composition of Gilardi rod group 1 bacteria; Moss CW et al.; Fifteen strains of eugonic, nonoxidative, gram-negative rods isolated primarily from human wounds of the extremities and blood formed a distinct group which was designated Gilardi rod group 1 . The phenotypic characteristics of Gilardi rod group 1 were most similar to those of CDC group M-5, with the major difference that nitrite reduction was observed with CDC group M-5 . All 15 strains of Gilardi rod group 1 possessed a distinct fatty acid profile which was characterized by large amounts (> 15%) of cis-vaccenic (18:1 omega 7c), palmitic (16:0), myristic (14:0), and lactobacillic (19:0 cyc11,12) acids and moderate amounts (3 to 5%) of lauric (12:0), 3-hydroxylauric (3-OH-12:0), and palmitoleic (16:1 omega 7c) acids . This fatty acid profile is unique compared with the profiles of CDC group M-5 and other bacteria we have tested and is useful for the rapid identification of Gilardi rod group 1 isolates.

Int J Paediatr Dent, 1993 Mar, 3(1), 17 - 21
The use of a concentrated oral rinse culture technique to sample oral candida and lactobacilli in children, and the relationship between candida and lactobacilli levels and dental caries experience: a pilot study; Coulter WA et al.; The purpose of this study was to test the suitability of a concentrated rinse culture technique, previously applied to adults, as a method for sampling the oral cavity of children on a community basis . The technique was used to assess the levels of oral candida and lactobacilli in the mouths of a group of 32 14- to 15-year-old children and to relate this to their past caries experience . Caries experience was assessed by means of a DMFS count . Each subject rinsed with 10 ml of buffered saline for 1 minute for microbial sampling . The oral rinse was concentrated by centrifugation and cultured on to selective media for candida and lactobacilli . The rinse technique proved simple and effective as a means of sampling the oral flora in children . The level of candida was more easily assessed and appeared to be a more useful indicator of microbial risk factors in caries than the lactobacilli count.

J Gen Microbiol, 1993 Mar, 139 ( Pt 3), 513 - 7
Identification and classification of Lactobacillus acidophilus, L . gasseri and L . johnsonii strains by SDS-PAGE and rRNA-targeted oligonucleotide probe hybridization; Pot B et al.; Thirty-two strains originally identified as Lactobacillus acidophilus and L . gasseri were screened for their taxonomic homogeneity by SDS-PAGE of whole-cell proteins . After numerical comparison of the resulting protein electrophoretic fingerprints, two well-delineated clusters were detected . The majority of the strains grouped in one electrophoretic cluster, which contained the type strain of L . acidophilus and corresponds to DNA group A1 of Johnson, J . L., Phelps, C . F., Cummins, C . S., London, J . & Gasser, F . (1980; International Journal of Systematic Bacteriology 30, 53-68) . Another cluster corresponded to DNA group B . It contained two subclusters, which agreed perfectly with DNA subgroups B1 (L . gasseri) and B2 (L . johnsonii), respectively . The 23S rRNA genes were partially sequenced and 23S-rRNA-targeted oligonucleotide probes were designed for identification of DNA groups A1, B1 and B2 . Probe Lbg reacted with all strains of electrophoretic cluster B1 (L . gasseri), probe Lbj hybridized with strains of cluster B2 (L . johnsonii) and probe Lba with strains of cluster A1 (authentic L . acidophilus) . The probes were successfully used for the identification of strains belonging to the respective species . The phylogenetic relationship of a representative of L . johnsonii was determined by comparative sequence analysis of the 16S rRNA genes . It is very closely related to L . gasseri.

Science, 1993 Feb 12, 259(5097), 965 - 7
Structure of the thiamine- and flavin-dependent enzyme pyruvate oxidase; Muller YA et al.; Pyruvate oxidase from Lactobacillus plantarum is a tetrameric enzyme that decarboxylates pyruvate, producing hydrogen peroxide and the energy-storage metabolite acetylphosphate . Structure determination at 2.1 angstroms showed that the cofactors thiamine pyrophosphate (TPP) and flavin adenine dinucleotide (FAD) are bound at the carboxyl termini of six-stranded parallel beta sheets . The pyrophosphate moiety of TPP is bound to a metal ion and to a beta alpha alpha beta unit corresponding to an established sequence fingerprint . The spatial arrangement of TPP and FAD suggests that the oxidation of the oxyethyl intermediate does not occur by hydride displacement but rather by a two-step transfer of two electrons.

Microbiologia, 1993 Feb, 9 Spec No, 37 - 48
{Utilization of lactic bacteria in the control of pathogenic microorganisms in food}; Hernandez PE et al.; The lactic acid bacteria have the potential to inhibit the growth of pathogenic and spoilage bacteria and the possibility exists of using them to improve the hygienic quality and to extend the shelf-life of different foods . Among the many inhibitory substances produced by the lactic acid bacteria, the bacteriocins are of particular interest . It has been the objective of this work to review the bacteriocins produced by lactic acid bacteria from the genera Lactococcus, Lactobacillus and Pediococcus, as well as Leuconostoc and Carnobacterium to understand their relevant biochemical, immunological and genetic characteristics . The lactic acid bacteria may also express foreign genes codifying metabolites with antimicrobial activities against foodborne pathogens of interest, and this will also permit hypothesize about theoretical and experimental models of microbial antagonism mediated by the lactic acid bacteria.

Int J Food Microbiol, 1993 Feb, 17(4), 311 - 20
Inhibition of the growth of yeasts in fermented salads; Bonestroo MH et al.; Salads composed of vegetables and/or meat in an oil-in-water emulsion were prepared by fermentation for 7 h at 42 degrees C or 45 degrees C with strains of Lactobacillus spp . Their stability towards spoilage yeasts was studied using Saccharomyces cerevisiae, Saccharomyces exiguus and Torulaspora delbrueckii, isolated from salads, as well as Pichia membranaefaciens and Zygosaccharomyces bailii . Salads fermented with good lactic starters usually had pH values of < or = 4.2 and lactic acid concentrations of 0.28 to 0.43% (w/w) . High numbers of spoilage yeasts (and production of large volumes of CO2) were not attained in these salads, provided the initial concentration of spoilage yeasts was sufficiently low (< or = 100 CFU/g) . Inhibition of spoilage yeasts in lactic fermented salads is probably due to lactic acid, the low storage temperature and the low residual oxygen concentration.

Int J Food Microbiol, 1993 Feb, 17(4), 303 - 9
Effects of gluconodeltalactone and Lactobacillus plantarum on the production of histamine and tyramine in fermented sausages; Buncic S et al.; Fermented sausages were made experimentally with addition of 0.3% (w/w) gluconodeltalactone (GDL) or a starter culture of Lactobacillus plantarum, unable to produce histamine or tyramine . Controls were produced without GDL and starter culture . During 15 days preparation and storage periods, number of bacteria and lactobacilli, pH, and levels of histamine, tyrosine and tyramine were monitored, and organoleptic evaluations were carried out . Maximal histamine levels were 19.41 micrograms/g of dry matter in the GDL-added sausages, 18.64 micrograms/g in the control, and 17.20 micrograms/g in the starter sausages . Maximal tyramine levels were 1249.16 micrograms/g in the GDL sausages, 1101.16 micrograms/g in the control, and 906.35 micrograms/g in the starter sausages . Sausages produced with GDL proved less acceptable in organoleptic evaluation due to an unpleasant sour flavour.

Antimicrob Agents Chemother, 1993 Feb, 37(2), 366 - 70
In vitro activity of CP-99,219, a new fluoroquinolone, against clinical isolates of gram-positive bacteria; Eliopoulos GM et al.; The in vitro activity of the fluoroquinolone CP-99,219 against gram-positive bacteria was compared with those of five other antimicrobial agents . Against ciprofloxacin-susceptible staphylococci and against streptococci, MICs were < or = 0.12 and < or = 0.5 microgram/ml, respectively . CP-99,219 was also more active than ciprofloxacin against ciprofloxacin-resistant staphylococci, most enterococci, Leuconostoc spp., and lactobacilli.

Acta Odontol Scand, 1993 Feb, 51(1), 31 - 7
Intra- and inter-individual variation in salivary flow rate, buffer effect, lactobacilli, and mutans streptococci among 11- to 12-year-old schoolchildren; Tukia-Kulmala H et al.; Both intra- and inter-individual variation in salivary flow rate, buffer effect, and the levels of salivary mutans streptococci and lactobacilli were analyzed in 128 11-year-old children . The follow-up period was 9 months, with six saliva samplings done at regular intervals . Inter-individual variation was relatively large in paraffin-stimulated salivary flow rate: low (< 1.0 ml/min) and high (> or = 2.0 ml/min) flow rates were measured in 18% and 13% of the children, respectively . Intraindividual variation during the follow-up period was found in 63% of the boys and in 73% of the girls . The buffer effect stayed stable in all samplings in 59% of the boys and in 42% of the girls . Buffer effect was significantly (p < 0.001) lower in girls than in boys . Mutans streptococci were analyzed by a chair-side method (Strip mutans test) and by cultivation on mitis-salivarius-bacitracin (MSB) agar plates . The results of the two methods correlated highly significantly (r = 0.79, p < 0.001) . With the Strip mutans test no variation in test scores occurred in 49% of all subjects in all six samplings, whereas the respective percentage for MSB scores was only 19% . No variation in salivary lactobacilli occurred in only 18% of the subjects, and in 13% the intraindividual variation was as high as > or = 3 logs . These results show that in young teenagers with a developing dentition, simultaneous changes in behavioral, hormonal, and dietary factors make single-point measurements of salivary factors too unreliable for caries-diagnostic or predictive purposes.

Scand J Dent Res, 1993 Feb, 101(1), 40 - 3
Salivary stimulation by chewing gum and lozenges in rheumatic patients with xerostomia; Risheim H et al.; The effect of chewing gum and lozenges in relieving the signs and symptoms of xerostomia was studied in a 2-wk cross-over clinical trial in 18 rheumatic patients with dry mouth symptoms and low salivary flow rates . Resting flow was measured before (PRESTIM) a chewing stimulated flow rate test (STIM), and also 5 min after (POSTSTIM) . STIM flow (mean 1.0 ml/min) was not affected by the test regimens . In the lozenge regimen, mean PRESTIM flow in the group increased from 0.11 to 0.14 ml/min and POSTSTIM from 0.10 to 0.13 . In the chewing gum regimen, PRESTIM flow (mean 0.13 ml/min) did not change, whereas POSTSTIM flow increased from 0.13 to 0.16 ml/min . In terms of patients' preferences, chewing gum and lozenges were ranked equal . Both these physiologic stimuli had few side-effects . Subjective symptoms were relieved in about one-third of the subjects, but relief was not always verified by improved flow rates . The regimens were not found to influence buffering capacity; salivary counts of mutans streptococci, lactobacilli, and candida; or oral sugar clearance time.

J Clin Periodontol, 1993 Feb, 20(2), 124 - 9
Root caries susceptibility in periodontally treated patients . Results after 12 years; Ravald N et al.; The aim of the investigation was to study the individual susceptibility to root caries in periodontally treated patients in a long-term follow-up of 12 years . Age, plaque score, salivary counts of lactobacilli and mutans streptococci, salivary secretion rate and buffer effect, oral sugar clearance time and dietary habit index were tested as possible predictors for root caries incidence . During the whole observation period of 12 years, new root caries lesions were recorded in 24 of a total of 27 patients . In 8 of these, the root caries incidence was between 1 and 5, in 7 between 6 and 9 and in 9, 12 or more new DFS . However, the annual mean number of new DFS was rather low . 13 patients with > 5 new DFS% during the 3rd 4-year period (years 9-12) differed significantly from 14 patients with < or = 5 new DFS% in salivary mutans streptococcus counts (p < 0.01), plaque scores (p < 0.001) and new DFS% during the 2nd 4-year period (years 5-8) (p < 0.001) . Simultaneously, risk values among the variables tested at the 8-year examination were about 3 x more prevalent in patients that developed > 5 new DFS% in years 9-12 than in those with < or = 5 new DFS% . During the whole 12-year observation period, smokers had significantly more root caries than non-smokers (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

J Dent Res, 1993 Feb, 72(2), 529 - 37
Caries risk assessment by a cross-sectional discrimination model; Leverett DH et al.; Although the prevalence of dental caries is continuing to decline, it still affects a majority of the US population and can be a serious problem for those afflicted . The objective of this project was to develop and perfect a model for assessment of risk of dental caries onset in children . In the first study, reported herein, a set of clinical, microbiological, biochemical, and socio-demographic variables was identified that distinguished, with an acceptable level of sensitivity and specificity, between children who had no previous caries experience and children who had high caries levels . A total of 313 children--age 12-15 years, 140 from a fluoridated community and 173 from a fluoride-deficient community--was selected on the basis of previous caries experience, either zero DMFS or high DMFS (> or = 6 in the fluoridated or > or = 8 in the fluoride-deficient community) . Clinical exams for DMFS, dental fluorosis, and plaque were conducted . Stimulated whole saliva was collected for analysis of mutans streptococci, lactobacilli, total viable flora, and fluoride concentration . A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices . By means of discriminant analyses, with use of seven key clinical and laboratory variables, it was possible for zero-DMFS subjects to e classified correctly (specificity) in 77.6% of cases in the fluoridated community and in 86.1% of cases in the fluoride-deficient community . High-caries subjects were classified as such (sensitivity) in 79.3% and 88.1% of cases, respectively.

J Dent Res, 1993 Feb, 72(2), 508 - 16
The association of mutans streptococci and non-mutans streptococci capable of acidogenesis at a low pH with dental caries on enamel and root surfaces; Sansone C et al.; Coronal dental plaque from each of 12 caries-positive subjects (Group I) was pooled from "white spot" tooth surface areas and, separately, from sound surface areas; sound surface areas in each of 18 caries-free subjects (Group II) were sampled similarly . Two samples, one consisting of material from a root-surface lesion and another of plaque from a sound root-surface area, were obtained from each of another 10 subjects (Group III) . The samples from Groups I and II were evaluated for: (1) pH-lowering potential in vitro with dispersed plaque suspensions, excess glucose supply, and a 60-minute test; (2) the levels of mutans streptococci (MS) and lactobacilli; and (3) the distribution of the predominant non-mutans streptococci (non-MS) according to their final pH in glucose broth; only microbial analysis was done for the Group III samples . The levels of the MS were generally positively associated with caries . A weaker positive association was found for the levels of those non-MS capable of acidogenesis at low pH (final pH < 4.4) . The latter generally far outnumbered the MS in all types of samples . The levels of lactobacilli were nearly always very low . The pH-lowering potential (final pH and pH drop rate) was higher for plaque from "white spot" areas than for plaque from sound surface areas (Group I) . The samples from caries-free subjects (Group II), however, exhibited a pH-lowering potential which was not significantly different from that of both types of samples from the caries-active subjects (Group I).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagn Microbiol Infect Dis, 1993 Feb, 16(2), 111 - 8
Antimicrobial activity and spectrum of rifaximin, a new topical rifamycin derivative; Hoover WW et al.; Rifaximin, a rifamycin derivative, was evaluated in vitro to assess its spectrum and potency against a wide variety of bacteria, yeasts, viruses, and parasites . High concentrations of rifaximin were often used to reflect topically achieved levels since this compound is poorly absorbed by oral route . Like rifampin, rifaximin possessed best activity against Staphylococcus spp . (MIC50 < or = 0.015 microgram/ml), Streptococcus spp . (MIC50s, < or = 0.03-0.12 microgram/ml), Enterococcus spp . (MIC50s, 0.25-2 micrograms/ml), Bacillus cereus (MIC50, 0.06 microgram/ml), Moraxella catarrhalis (MIC50, < or = 0.03 microgram/ml), and Haemophilus influenzae (MIC50, 0.25 microgram/ml) . Rifaximin demonstrated potential use as a topical agent for bacterial vaginosis by inhibiting Bacteroides bivius-disiens, Gardnerella vaginalis, Lactobacillus spp., and Mobiluncus spp . strains (all MICs < or = 1 microgram/ml) . Strains of Haemophilus ducreyi and Neisseria gonorrhoeae (MIC50s, 0.25 microgram/ml) were also inhibited . However, some organisms associated with genital tract infections were rifaximin resistant, for example, Candida spp., herpes virus, mycoplasmas, Trichomonas vaginalis, and Ureaplasma urealyticum . Clinical trials appear warranted using rifaximin topical concentrations that will minimize mutations to rifamycin resistance.

Carbohydr Res, 1993 Feb 1, 239, 209 - 26
Structural characterisation of the exopolysaccharide produced by Lactobacillus delbrückii subspecies bulgaricus rr grown in skimmed milk; Gruter M et al.; The exopolysaccharide of Lactobacillus delbruckii subsp . bulgaricus rr, isolated from skimmed milk, is a heteropolymer of D-galactopyranosyl, D-glucopyranosyl, and L-rhamnopyranosyl residues in the molar ratio 5:1:1 . The structure was established by linkage analysis and 1D and 2D NMR spectroscopy of the native polysaccharide, in combination with characterisation of oligosaccharide fragments, obtained by Smith degradation and partial acid hydrolysis, using methylation analysis, EIMS, and 1D and 2D 1H NMR spectroscopy . The polysaccharide has a branched heptasaccharide repeating unit with the following structure: -->2)-{beta-D-Galp-(1-->3)}-alpha-D-Galp-(1-->3)- beta-D-Glcp-(1-->3)-{beta-D-Galp-(1-->4)}-beta-D-Galp-(1-->4)-{alpha-L- Rhap-(1-->3)}-alpha-D-Galp-(1-->.

Scand J Gastroenterol, 1993 Feb, 28(2), 155 - 62
The effect of exogenous administration of Lactobacillus reuteri R2LC and oat fiber on acetic acid-induced colitis in the rat; Fabia R et al.; The potential beneficial effect of exogenous administration of Lactobacillus on acetic acid-induced colitis was evaluated in the rat . Colitis was induced by instillation of 4% acetic acid for 15 sec in an exteriorized colonic segment . This produced uniform colitis with a threefold increase in myeloperoxidase (MPO) activity of the colonic tissue (an index of neutrophil infiltration) and a sixfold increase in plasma exudation into the lumen of the colon (mucosal permeability) as evaluated 4 days after acetic acid administration . Intracolonic administration of L . reuteri R2LC immediately after acetic acid administration, at a dose of 5 ml of 7 x 10(7) colony-forming units (CFU)/ml in two forms: either as pure bacterial suspension or as fermented oatmeal soup, prevented the development of colitis . Thus, the morphologic score, MPO activity, and mucosal permeability were almost normalized by Lactobacillus treatment . Initiating the treatment 24 h after acetic acid administration or using lower doses of 1 ml for 3 consecutive days resulted in a smaller protective effect . We conclude that exogenous administration of L . reuteri R2LC prevents the development of acetic acid-induced colitis in the rat.

J Periodontol, 1993 Feb, 64(2), 89 - 94
The distribution and interrelationship of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and BANA scores among older adults; Drake CW et al.; In a random sample of subgingival dental plaque samples from 375 blacks and 300 whites aged 65 and older, immunofluorescence assays for 3 target pathogens including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, and BANA enzyme analysis were carried out . Blacks had significantly greater proportions of P . gingivalis and P . intermedia in their subgingival plaque and had significantly higher BANA scores . These assay results were investigated for concordance with each other and with 2 cariogenic salivary bacteria, Streptococcus mutans and lactobacilli . In general for both races, the periodontal pathogens were more likely to occur in combination with each other than with either S . mutans or lactobacilli . P . gingivalis and P . intermedia were more frequently associated with each other than with A . actinomycetemcomitans . There was a significant negative concordance between BANA and A . actinomycetemcomitans in whites and a significant positive concordance between BANA and P . intermedia in blacks.

J Dent Res, 1993 Feb, 72(2), 538 - 43
Caries risk assessment in a longitudinal discrimination study; Leverett DH et al.; Our objective was to develop and perfect a model for the assessment of risk of dental caries onset in children . Even though dental caries prevalence in children is continuing to decline, there is still a significant minority for whom it is a problem . In this study, we sought to ascertain whether a set of variables selected in a previous cross-sectional study could be used to differentiate between caries-free six-year-olds who would or would not subsequently present with clinically-detectable caries . A total of 472 caries-free six-year-olds--286 from a fluoridated community and 186 from a fluoride-deficient community--was selected . Clinical examinations for DMFS, dental fluorosis, and plaque were conducted . Stimulated whole saliva was collected for analysis of mutants streptococci, lactobacilli, total viable flora, and fluoride, calcium, and phosphate concentrations . A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices . By means of linear discriminant analyses, it was possible to predict correctly which children would develop caries within six to 12 months (sensitivity) in 82.8% of cases and which children would not develop caries during that period (specificity) in 82.4% of cases.

J Rheumatol, 1993 Feb, 20(2), 362 - 7
In vitro correlates of the L . casei animal model of Kawasaki disease; Tomita S et al.; The induction of coronary arteritis in mice by Lactobacillus casei cell wall (CW) is thought to represent an animal model of Kawasaki disease . Treatment of vascular endothelial cells (EC) in vitro with supernatants from CW stimulated human mononuclear cells (MNC) enhanced adherence of human polymorphonuclear leukocyte (PMN) to human EC, and EC expression of intercellular adhesion molecule-1 (ICAM-1) but not HLA-DR . Supernatants contained high concentrations of tumor necrosis factor-alpha (TNF-alpha) and PMN adherence correlated directly with the concentration of TNF-alpha . Intravenous human gamma globulin (IVGG) preparations did not block the effect of cytokine containing MNC supernates upon EC, ICAM-1 expression by EC, or PMN adherence to prestimulated EC . However, both EC ICAM-1 expression and enhanced PMN adherence to EC by CW induced MNC supernatants were blocked by anti-TNF-alpha treatment . The initial coronary inflammatory reaction in the mouse model appears to involve PMN adherence to vascular EC that have been activated by TNF-alpha released by MNC after stimulation with CW.

Indian J Biochem Biophys, 1993 Feb, 30(1), 26 - 35
Purification, relative molecular mass and subunits of thymidylate synthase from Lactobacillus leichmannii; Rao KN; Thymidylate synthase (5, 10-methylenetetrahydrofolate: dUMP C-methyltransferase, EC 2.1.1.45) from crude cell extracts of Lactobacillus leichmannii has been purified 190-fold to homogeneity by chromatography on hydroxylapatite, DEAE-cellulose and Sephadex G-100 columns . It has UV absorption maxima at 280 nm . The crude extracts, however, have RNA associated with the native enzyme . This is in line with our earlier observation on the Streptococcus faecium thymidylate synthase {Narasimha Rao K & Kisliuk R L, (1983) Proc Natl Acad Sci USA, 80, 916-920} . Optimal conditions for dTMP synthase activity are: 275 microM (dl)-L-H4PteGlu, 13 mM HCHO, 13 mM MgCl2, 100 microM dUMP and 75 mM 2-mercaptoethanol at pH 7.4 using Tris-HCl buffer . The enzyme has M(r) of 74 kDa, Stokes radius of 1.24 nm and a sedimentation coefficient value of 0.45 S . The enzyme is a dimer composed of 2 identical subunits each with M(r) of 37 kDa.

Caries Res, 1993, 27(3), 195 - 200
Effects of a 12-month prophylactic programme on selected oral bacterial populations on root surfaces with active and inactive carious lesions; Emilson CG et al.; In 15 caries-active patients, with a total of 770 exposed root surfaces, the effect of fluoride therapy and professional tooth cleaning was studied during a 1-year period . Dental plaque from 92 of the root surfaces and whole saliva samples were analysed at baseline and after 12 months for the presence of specific bacteria . The results showed that the number of active carious lesions had decreased from 99 to 46, while the inactive lesions had increased from 69 to 124 . Of the active lesions which had been converted into inactive lesions, most were on the buccal and fewest were located on the distal surfaces . Lower plaque scores were found on sound and inactive root surfaces compared to active surfaces . The salivary concentrations of mutans streptococci and lactobacilli remained constant during the 12-month observation period . There was a tendency for higher levels of Streptococcus mutans in plaque from active lesions compared with sound root surfaces, whereas an inverse relationship was noted for the Streptococcus oralis group . No significant differences in the Actinomyces naeslundii counts were detected . In conclusion, the 12-month prophylactic programme had an effect on the clinical surface characteristics of root caries, but the components of the oral microflora selected for study seemed to be relatively unaffected during the observation period.

Biol Neonate, 1993, 63(4), 236 - 45
Influence of the destabilisation of the maternal digestive microflora on that of the newborn rat; Brunel A et al.; By destabilising the digestive flora of pregnant rats by antibiotic treatment, it was shown that part of the digestive microflora of the neonate originated from the maternal faeces . A mixture of ampicillin, bacitracin neomycin and streptomycin associated with nystatin were administered ad libitum at three different times, 1-3, 3-5, and more than 5 days before the estimated date of littering . For each treatment, samples were taken from the faeces, teats, and vagina of dams and from the digestive tracts of neonates aged between 6 and 120 h, and analysed for the presence of staphylococci, enterococci, lactobacilli and coliform bacteria . Antibiotic treatment reduced digestive flora populations to levels lower than 10(2) g-1 but had less effect on the vaginal and cutaneous mammary flora . In the digestive microflora of the neonate, the enterococci were unevenly affected, whereas the staphylococci were considerably decreased and the lactobacilli almost completely eliminated; coliform bacteria were found sporadically and in small numbers . The traces of antibiotics found in milk are not sufficient to explain these modifications . Counts made in control animals on media fed the same antibiotic concentrations were not modified . This work underlined the awful consequences for the newborn of a serious perturbation of the mother flora and the necessity of its presence for a normal installation of the digestive microflora of the newborn.

Caries Res, 1993, 27 Suppl 1, 68 - 71
Salivary counts of mutans streptococci and lactobacilli and past caries experience in caries prediction; Alaluusua S; Clinical and salivary factors were compared with each other for the ability to predict 3-year caries increment in a group of 122 teenagers . The group was screened according to two levels of salivary mutans streptococci and lactobacilli and comparable levels of baseline caries experience (DFS) . The risk for caries was validated at three different levels . Sensitivity, specificity, and the positive and negative prediction values were calculated for each level . The results showed that the baseline caries experience was better or as powerful as the salivary tests in predicting future caries increment at comparable screening and validation levels.

Caries Res, 1993, 27(1), 38 - 42
Effect of sucrose rinses on the oral microflora and on salivary sucrase activity; Karjalainen S et al.; The effect of sucrose rinses on the salivary microflora and on bacterial sucrose cleaving, i.e., sucrase activity, was studied in 11 dental students with high salivary counts of mutans streptococci (> or = 10(5) CFU/ml) . The subjects rinsed for 1 min with a 10% (w/v) sucrose solution every 4-h during waking hours on 2 consecutive days . Four paraffin-stimulated saliva samples were collected as follows: one before the rinses and then 12 h and 5 and 8 days after the rinses . Commercial dip-slide methods were used to determine viable counts of mutans streptococci, lactobacilli, and yeasts; mutans streptococci were also enumerated using MSB agar, while blood agar was used to recover the total facultative and anaerobic bacteria . The sucrase activity was determined using both whole (mainly cell-associated) and centrifuged (extracellular) saliva samples . The proportions of facultative bacteria (p = 0.007) and mutans streptococci (p = 0.001) increased as a result of the sucrose rinses . No changes were detected in the number of lactobacilli or yeasts . The sucrose rinses increased both the cell-associated (p = 0.049) and the extracellular (p = 0.011) sucrase activities . The measurement of sucrase activity may be of value in assessing dietary habits and sucrose consumption.

Appl Environ Microbiol, 1993 Jan, 59(1), 34 - 9
Inhibition of adhesion of Escherichia coli K88 to piglet ileal mucus by Lactobacillus spp; Blomberg L et al.; Enteropathogenic Escherichia coli K88 colonizing the piglet ileum adhere to the mucosa by K88 fimbrial appendages . A recent study in our laboratory has implicated indigenous lactobacilli in the suppression of the colonization potential of enteropathogenic E . coli as measured by adhesion to ileal mucus . The aim of this study was to investigate the effect of Lactobacillus spp . of porcine origin on the adhesion of K88 fimbriae of E . coli . With an in vitro assay, the adhesion of E . coli K88ab strain G1108E and E . coli K88ac strain 1107 to 35-day-old piglet ileal mucus was studied in the presence of spent culture fluid of Lactobacillus spp . Detailed studies focused specifically on culture fluid of Lactobacillus fermentum 104R . Subsequently, the ileal mucus was exposed to the retentate of the spent culture fluid after dialysis and fractionation . Adhesion was confirmed to be attributable to K88 fimbriae when K88-specific monoclonal antibodies and isogenic mutants of E . coli K-12 with and without the plasmid containing the K88 gene were used . The active component was characterized by pretreatment of dialysis retentate with heat, periodate, pronase, and centrifugation, as well as by growth of the lactobacillus in various media and by assays at both 0 and 37 degrees C . All three lactobacilli of porcine origin reduced adhesion of E . coli K88 by approximately 50% . Inhibition occurred when mucus was pretreated with either spent culture dialysis retentate or the void volume (fraction of > 250,000 molecular weight) after gel filtration . The activity of the dialysis retentate was sensitive to pronase, but there was still activity at 0 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1993 Jan, 59(1), 274 - 80
Molecular analysis of the rolling-circle replicating plasmid pA1 of Lactobacillus plantarum A112; Vujcic M et al.; Lactobacillus plantarum A112 has four different plasmids . Plus-origin-specific probes were used to determine that the smallest, cryptic plasmid, pA1 (2,820 bp), showed homology to the pE194 plasmid family . This subclass of plasmids uses the rolling-circle mode of replication . Subsequent analysis of plasmid pA1 demonstrated that it generates single-stranded DNA intermediates, and sequence analysis revealed that it contains three putative open reading frames (ORFs): ORF1, ORF2, and ORF3, which could encode proteins designated RepA (47 amino acids {aa}) and RepB (196 aa) and a protein of 103 aa, respectively . Two of these proteins, RepA (5.6 kDa) and RepB (26 kDa), were identified in in vitro transcription translation assays . The RepA protein contains a characteristic alpha-helix-turn-alpha-helix motif typical of DNA-binding proteins that act as DNA-binding repressors . The RepB protein shows a significant similarity with replication initiation proteins of the pE194 family of plasmids that use the rolling-circle mode of replication . Plasmid pA1 is able to replicate in Escherichia coli and Lactobacillus lactis subsp . lactis as well as in other L . plantarum strains.

Int J Immunopharmacol, 1993 Jan, 15(1), 25 - 37
Stimulating effect of DEODAN (an oral preparation from Lactobacillus bulgaricus "LB51") on monocytes/macrophages and host resistance to experimental infections; Popova P et al.; DEODAN is a lysozyme lysate from Lactobacillus bulgaricus for oral administration which has shown antitumor activity in mice and humans . The effects of this preparation on some functions of monocytes/macrophages and on host resistance to experimental infections were examined . The oral administration to mice of DEODAN-150 mg/kg daily (the recommended dose in humans) caused an increase of the spreading ability and phagocytic activity of peritoneal macrophages, which showed morphological signs of cell activation . The level of Interleukin-1 (IL-1) secreted in the culture supernatant of peritoneal macrophages of DEODAN-treated mice was found to be slightly increased only when the mice were treated with 150 mg/kg DEODAN for 10 days . However, the in vitro incubation of human blood monocytes with DEODAN resulted in induction of membrane-bound and cytoplasmic IL-1 and Tumor Necrosis Factor (TNF)-alpha . The oral treatment of mice with DEODAN also caused a decrease in mortality after experimental infections with Klebsiella pneumoniae and Listeria monocytogenes . These results indicate that DEODAN activates the phagocytic and secretory functions of mononuclear cells and increases host resistance to bacterial infections.

J Appl Bacteriol, 1993 Jan, 74(1), 36 - 40
Distribution of pathogen inhibition in the Lactobacillus isolates of a commercial probiotic consortium; Chateau N et al.; Pure strains of Lactobacillus ssp . isolated from a commercial probiotic consortium were checked in a double layer solid medium for their inhibition activities against selected pathogenic bacteria including serotypes of Listeria monocytogenes, Escherichia coli and Salmonella . The antagonistic properties of the Lactobacillus strains may be related to the production of bacteriocin-like compounds . All the pathogens tested were inhibited by one or a few strains of Lactobacillus, the best inhibition was observed against L . monocytogenes but the inhibition was also satisfactory against E . coli, Salm . typhimurium and Salm . enteritidis.

J Dent Res, 1993 Jan, 72(1), 37 - 45
Initial acquisition of mutans streptococci by infants: evidence for a discrete window of infectivity; Caufield PW et al.; Oral bacterial levels of 46 mother-child pairs were monitored from infant birth up to five years of age so that the acquisition of mutans streptococci (MS) by children could be studied . The initial acquisition of MS occurred in 38 children at the median age of 26 months during a discrete period we designated as the "window of infectivity" . MS remained undetected in eight children (17%) until the end of the study period (median age of 56 mo) . The levels of both MS and lactobacilli in saliva of mothers of children with and without MS were not significantly different . Comparisons between a caries-active cohort colonized by MS (nine of 38) and children without detectable MS revealed similar histories in terms of antibiotic usage, gestational age, and birth weight . Interestingly, half of the children between the ages of one and two years who were not colonized by MS were attended by caretakers other than the mother, while all of the caries-active children during this same time period were cared for by their mothers; the difference was statistically significant . Here we report for the first time that MS is acquired by infants during a defined period in the ontogeny of a child . Support for the notion of a discrete window of infectivity comes from other sources, including animal models.

J Clin Microbiol, 1993 Jan, 31(1), 66 - 70
Prevalence of dental caries in 4- to 5-year-old children partly explained by presence of salivary mutans streptococci; Granath L et al.; The correlation between dental caries and the number of oral mutans group streptococci (ms) present has been shown to be weak . The aim of this investigation was to study associations between caries experience (decayed, missing, and filled surfaces {dmfs}) and the number of ms in stimulated saliva, with emphasis on the level of disease and the confounding effect of regular intake of sweets, the presence of salivary lactobacilli, and oral hygiene . In some 2,700 4- to 5-year-old South African children of different ethnic origins, caries was diagnosed on the basis of World Health Organization criteria and saliva samples were analyzed for ms after cultivation on mitis salivarius-bacitracin agar and for lactobacilli by using the Dentocult kit . Oral hygiene was scored on the basis of the Greene and Vermillion simplified debris index, while data on intake of sweets were derived from extensive interviews . Pearson's coefficient of correlation was computed, and multiple regression analysis was performed to correct for confounding factors . The distribution of the children in the eight caries classes was strongly associated with the ms class (P < 0.001), with those in the lower ms classes generally having low dmfs scores and those in the higher ms classes having dmfs scores distributed over the whole range . The r value for the two variables was 0.25 for the total material; this was reduced to 0.18 by correction for confounding factors . The corresponding values for children with caries were 0.21 and 0.17, for those in the 1 to 6 dmfs interval they were 0.07 and 0.03, and for those in the 7 to 81 dmfs interval they were 0.16 and 0.14 . The data imply that the explanatory values for ms, those for the lower caries interval not counted, ranged from 6 to 2% . The unexpected results for children with caries might be due to their distribution pattern . It is concluded that there is a need for reevaluation of ms as a risk factor in dental caries.

Microbios, 1993, 75(303), 117 - 23
Detection of bacteriocins produced by Lactobacillus plantarum strains isolated from different foods; Atrih A et al.; Bacterial strains (106 in toto) isolated from different foods and identified as Lactobacillus plantarum were screened for antagonistic activities against other bacteria under conditions which eliminated the effects of organic acids and hydrogen peroxide . Five isolates were shown to be bacteriocin producers, and the bacteriocins, on the basis of their host range inhibition and cross inhibition were all different . The bacteriocins were preliminarily characterized by temperature stability, sensitivity to proteolytic, lipolytic and glycolytic enzymes and precipitation with ammonium sulphate.

Caries Res, 1993, 27(4), 285 - 91
Effects of a lactoperoxidase system-containing toothpaste on levels of hypothiocyanite and bacteria in saliva; Lenander-Lumikari M et al.; Lactoperoxidase (LPO)/H2O2/SCN(-)-system-generated hypothiocyanite ions (OSCN-) and hypothiocyanous acid (HOSCN) are inhibitory against a number of oral bacteria, including mutans streptococci . A commercially available toothpaste (Biotene) comprises the complete LPO system . Generation of HOSCN/OSCN- by Biotene was studied in vitro both in sterilized and nonsterilized saliva of 10 healthy subjects . The HOSCN/OSCN- yield ranged from 100 to 300 microM with Biotene, while the salivary levels of HOSCN/OSCN- before the addition of Biotene were 30.1 +/- 25.1 microM . Two in vivo trials were carried out . In the first study, resting saliva was collected from 12 individuals before, immediately after, and 2, 5, 10 and 20 min after brushing with Biotene to evaluate the in vivo generation and decomposition of HOSCN/OSCN- . In the second study, 26 healthy individuals attended a 1-month crossover trial with Biotene and a control toothpaste, Vademecum (no LPO system), both containing F- and xylitol . The salivary counts of total streptococci, mutans streptococci (MS), lactobacilli and the total flora (TF), as well as the peroxidase, thiocyanate ion and HOSCN/OSCN- levels were determined before and after 2 and 4 weeks daily use of the toothpastes . Twice-a-day use of Biotene for 1 month resulted in an elevation of 'resting levels' of HOSCN/OSCN- . No such effect was found with the control toothpaste . No significant changes were found in the salivary levels of total streptococci, MS, lactobacilli or TF after 1-month use of either toothpaste . The results show the capability of the LPO-system-containing toothpaste to elevate the salivary levels of HOSCN/OSCN-, although no bactericidal effect was observed.

Caries Res, 1993, 27(4), 280 - 4
In situ anticariogenic potential of glass ionomer cement; Benelli EM et al.; The purpose of this study was to compare the amount of fluoride in plaque formed on glass ionomer cement or composite and to evaluate the effects of fluoride released on growth of cariogenic microflora, fluoride uptake, and secondary caries formation under in situ conditions of a high cariogenic challenge . Ten adult volunteers took part in this crossover study performed in two phases of 28 days . Eighty enamel blocks were randomly restored with glass ionomer cement (Chelon-Fil-Espe) or composite (Silux) . During each phase of the study, an acrylic resin appliance, containing four enamel blocks restored with the same material, was constructed for each of the volunteers . During the experimental period, all subjects used fluoride-free dentifrice, refrained from brushing the restored enamel blocks, and immersed the appliances into 20% sucrose solution eight times a day . Fluoride levels, mutans streptococci, and lactobacilli were assessed in dental plaque . Fluoride uptake and microhardness profiles were determined in enamel around the restorations . Statistical analyses indicated a significantly higher level of fluoride (p < 0.05) and a lower level of mutans streptococci plaque formed on glass ionomer cement . Analysis of variance in a split-plot model indicated that in the enamel around the glass ionomer restoration the fluoride uptake was significantly greater (p < 0.025) and the mineral loss significantly lower (p < 0.01) . The results show that glass ionomer cement presents a broad anticariogenic effect and may be of value in preventing secondary caries, even under conditions of a high caries risk.

Microb Pathog, 1993 Jan, 14(1), 23 - 31
The binding of Pneumococcal lipoteichoic acid to human erythrocytes; McCloskey JJ et al.; Previous studies have evaluated the binding characteristics of lipoteichoic acids (LTA) composed of polyglycerol phosphate to mammalian cell membranes . This present study was performed to evaluate the binding characteristics of Pneumococcal LTA, a polyribitol phosphate containing LTA, to human erythrocytes . Binding was found to be specific, reversible, and dependent on temperature and time . Maximum binding was achieved within 2 h at 37 degrees C . Scatchard plot analysis of the binding revealed a biphasic plot which suggests two receptor sites with different affinities . Competitive inhibition studies with LTA composed of polyglycerol phosphate and isolated from Streptococcus pyogenes and Lactobacillus fermentum revealed significant inhibition of Pneumococcal LTA-binding to the erythrocyte membrane by these heterologous LTAs . These results demonstrate that Pneumococcal LTA binds specifically to human erythrocytes and that the receptor site is similar for other structurally different LTAs.

Acta Obstet Gynecol Scand, 1993 Jan, 72(1), 17 - 9
Bacterial vaginosis in pregnancy treated with yoghurt; Neri A et al.; As various drugs might have an effect on the fetus during pregnancy, the use of drugs should be minimized in the pregnant woman . Since bacterial vaginosis (BV) can be associated with prematurity and postpartum complications, we searched for alternative therapy for its cure during pregnancy . Commercial yoghurt incorporates both factors necessary for maintaining the protective mechanism of the vagina, vaginal pH and lactobacillus . A total of 32 women with BV in the first trimester of pregnancy were treated with intravaginal application of yoghurt . The result was favorable indicating that the continuous correction of vaginal pH and lactobacillus flora is crucial for normal vaginal ecology . During pregnancy, a local treatment restoring the normal acidity and vaginal flora, without systemic effect, may be preferable to any other treatment.

Arch Virol, 1993, 132(3-4), 321 - 30
Characterization of a prolate-headed bacteriophage of Lactobacillus delbrueckii subsp . lactis, and its DNA homology with isometric-headed phages; Forsman P; A new Lactobacillus delbrueckii subsp . lactis bacteriophage, JCL 1032, was characterized . JCL 1032 had a small, elongated prolate head, and a long non-contractile tail with cross-bars . The restriction map of JCL 1032 genome was constructed with five endonucleases . The genome was 45.8 kb in size, and it had cohesive ends (cos) . Molecular masses of the phage structural proteins were also determined . JCL 1032 showed DNA homology with morphologically dissimilar, isometric-headed phages of Lb . delbrueckii (subsp . lactis and subsp . bulgaricus) when analyzed by Southern hybridization . Although in general JCL 1032 was only distantly related to isometric-headed phages, there were also a few short highly homologous (minimal homology 84%) DNA regions.

Microbios, 1993, 75(302), 57 - 65
Adhesion of three Lactobacillus strains to human urinary and intestinal epithelial cells; Reid G et al.; Three strains of urogenital lactobacilli were found to adhere in phosphate buffered saline to human uroepithelial cells in vitro according to thermodynamic principles, and to adhere in culture medium to intestinal cells with no such correlation . The most hydrophilic strain (water contact angle 54 degrees) L . casei RC-17 was the most adherent to uroepithelial (118 bacteria per cell) and intestinal cells (165 bacteria per cell) . A direct correlation was found between bacterial hydrophilicity and adhesion to uroepithelial cells for the three strains tested . An extracellular adhesin, which appeared to be proteinaceous, and a trypsin-insensitive cell wall adhesin were identified . It was evident that high levels of bacterial retention could be reproduced in vitro, perhaps indicating the potential colonizing capacity of these strains in vivo.

J Basic Microbiol, 1993, 33(3), 169 - 77
Taxonomy of lactic acid bacteria from spoiled, vacuum packaged vienna sausages by total soluble protein profiles; Dykes G et al.; To resolve the taxonomic status of sixty-one lactic acid bacteria isolated from spoiled, vacuum packaged vienna sausages, a computer assisted analysis of total soluble protein profiles was undertaken . Sixty-two% of the strains in the study were recovered in fourteen clusters at the 72% similarity level, indicating high degree of heterogeneity among the strains examined . Two clusters representing Leuconostoc species were the largest and most homogeneous, containing twenty strains between them . One cluster contained both typical Lactobacillus sake and Lactobacillus curvatus strains, indicating the inability of protein profiles to consistently differentiate between all strains of these two species . The presence of an independent Lactobacillus curvatus grouping and the clustering of some atypical strains with Lactobacillus sake isolates, however, indicated that the atypical strains may be closely related to Lactobacillus sake.

Med Dosw Mikrobiol, 1993, 45(2), 249 - 52
{Candida parapsilosis in reproductive organ infections}; Pawlik B et al.; Frequency of occurrence of strains of C . parapsilosis, their susceptibility to drugs and importance in pathogenesis of vaginal mycosis, was evaluated . Strains of C . parapsilosis were isolated in 44 cases which comprises 1.34% of a total number of 3275 tested Candida-like strains . Vaginal mycoses occurred in presence of Lactobacillus sp., normal pH values of vaginal contents, whereas leukocytosis was differing . Following drugs were used for testing susceptibility of C . parapsilosis: nystatin, pimaricin, amphotericin B, flucytosine, cotrimoxazole, miconazole, ketoconazole, tioconazole, fluconazole and itraconazole . It has been demonstrated that 38.3% strains of C . parapsilosis were exhibiting lowered activity toward amphotericin B, nystatin (23.5% resistant) and flucytosine (11.7% resistant) . Tested strains were susceptible to remaining drugs within 94.1% and 100%.

Med Dosw Mikrobiol, 1993, 45(2), 195 - 8
{Characteristics of lactobacillus species strains isolated from reproductive organs in various clinical cases}; Kasprowicz A et al.; The study was aimed at detection of presence of Lactobacillus species bacteria in 167 samples of material derived from vagina of patients with cervix uteri (22 samples), chronic vaginosis (100 samples) and from women after treatment of inflammatory diseases (45 samples) . Out of 100 isolated strains of Lactobacillus only 13 belonged to L . acidophilus . They were mainly present (10 strains) in patients after effective treatment of inflammatory diseases of reproductive organs . Remaining strains belonged to L . jensenii (18 strains) and Lactobacillus sp . (69 strains) and did not cleave glycogen . This was detected by quantitative determinations of lactic acid in cultures of these bacteria in the fluid media containing 0.25% of glycogen . It seems that treatment of bacterial infections of reproductive organs should be concentrated on not only elimination of pathogenic bacteria, but also on noneffective strains from Lactobacillus species (strains unable to cleave glycogen with production of lactic acid).

Swed Dent J, 1993, 17(5), 191 - 9
A longitudinal study of dental caries and cariogenic microflora in a group of young adults from Göteborg; Bjarnason S et al.; Caries and cariogenic microorganisms were assessed in a group of young adults over a 3-year period . A 30% random sample comprising 101 individuals aged 18-19 years was re-examined under conditions consistent with the baseline survey 3 years earlier . The means for DFS prevalence and increment were 8.9 and 2, respectively . Continuing polarization of the disease was observed, with mean DFS score reaching 19.9 in the upper 15% of the frequency distribution . Highest caries activity was observed approximally where the increment of manifest and incipient lesions averaged 1.3 and 1.6 surfaces, respectively, as compared to 0.5/0.6 occlusally and 0.2/0.5 bucco-lingually . While the occlusal component continued to dominate DF score with 5.7 surfaces, the prevalence of approximal lesions increased by 48%, averaging 2.7 surfaces . Frequency distribution showed a shift to the right and increasing skewness . The proportion without manifest lesions/restorations had declined by 3% . While only 6% of the dentin lesions/restorations were found in the lowest quartile, 15% of the individuals with highest caries levels accounted for 40% of the total DFS and 58% of the D component . Among the 88 subjects who were saliva sampled, salivary mutans streptococci were detected in 89.7% and lactobacilli in 83% . Forty-one percent of the 18-19-year-olds had high numbers of mutans streptococci (> 5 x 10(5) cfu per ml) as compared to 33% at the age of 15-16-years, while high numbers of lactobacilli (> 10(5) cfu per ml) were recovered in 21.8% as compared to 14.3% . The stability within each range of microorganisms varied depending on the baseline level.(ABSTRACT TRUNCATED AT 250 WORDS)

Postgrad Med J, 1993, 69 Suppl 3, S49 - 57
Study on the usefulness of povidone-iodine obstetric cream with special reference to the effect on the thyroid functions of mothers and the newborn; Sakakura K et al.; The effect of povidone-iodine obstetric cream (OAD cream) on the thyroid functions of mothers and the newborn was investigated in 56 patients . Effects on labour and on the neonatal course of the newborn were also studied . OAD cream was used for disinfection of the vulva and vagina during prenatal obstetric examinations (1-10 times) and at parturition . Bacteriological specimens were obtained before and after use of the OAD cream, and the total iodine, thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels were measured in the maternal blood and umbilical cord blood . The overall bacterial eradication rate for the vulva was 74.7% although the eradication rate for coagulase negative staphylococci was low (23.1%) . The overall bacterial eradication rate for the vagina was 56.1% although the eradication rates for Candida albicans and Lactobacillus spp . were low (9.1% and 29.4% respectively) . There was no significant difference in the types of delivery or complications of labour and delivery between the group treated with OAD cream and the control group, but the duration of labour was prolonged in the former group . There were no malformations among the newborn, and no difference between the group treated with OAD cream and the control group in regard to body weight and length of the newborn at birth, Apgar score, postnatal gain in body weight, or bilirubin level . The maternal blood levels of total iodine, TSH, and T4 were within the normal ranges both during pregnancy and at delivery, but the level of T3 was slightly elevated at delivery . The umbilical cord blood levels of the total iodine, TSH, and T4 were within normal ranges both during pregnancy and at delivery, but the level of T3 was somewhat elevated . At age six days, the T4 level was normal in all the newborn . TSH was higher than 15 microU/ml in two newborns, but returned to normal levels three week later.

J Endod, 1993 Jan, 19(1), 26 - 30
Correlation between thermal sensitivity and microorganisms isolated from deep carious dentin; Hahn CL et al.; The correlation between thermal sensitivity and the microorganisms present in 29 deep carious lesions was studied . The numbers of lactobacilli and total Gram-positive rods in the carious lesions were found to be negatively related to the length of pain triggered by cold and heat stimulants . The presence of Gram-positive cocci and non-black-pigmented Bacteroides were positively associated with both cold and heat sensitivities . Black-pigmented Bacteroides, Streptococcus mutans, and total anaerobic colony counts were positively related to the heat sensitivity . Recovery of Fusobacterium nucleatum, Actinomyces viscosus, and enterics on the selective plates was associated with cold sensitivity . Total counts of Gram-positive cocci and Gram-negative rods on the anaerobic nonselective medium were positively related to the cold sensitivity . It appeared that teeth with low numbers of lactobacilli in the carious lesions usually responded to thermal tests with longer duration of pain . Conversely, teeth with high numbers of lactobacilli in the carious lesions usually responded with shorter duration of pain.

Caries Res, 1993, 27(6), 505 - 10
Caries prevalence in 2.5-year-old children; Grindefjord M et al.; The prevalence of caries and gingivitis was determined clinically in 2.5-year-old children (n = 832) living in the southern suburbs of Stockholm . The occurrence of mutants streptococci and lactobacilli was determined in samples taken from the tongue and the buffer capacity of the saliva was measured . The parents answered a structured questionnaire concerning their children's dietary habits, oral hygiene, fluoride exposure and their social and ethnic background . Initial or manifest caries was diagnosed in 11.7 and 6.4% of the subjects, respectively . Seventy-two percent of the total number of caries lesions were localized to the maxillary incisors . Caries prevalence in children with an immigrant background was significantly higher (p < 0.001) than in children without . In the multivariate analysis, the variables significantly associated with caries were: colonization with mutans streptococci (p < 0.001), lactobacilli (p < 0.01) and children with immigrant background (p < 0.01) . The study demonstrates an association between early colonization of cariogenic microflora and an increased risk of developing dental caries in very young children.

Biochimie, 1993, 75(9), 797 - 802
Pyruvate kinase from Lactobacillus bulgaricus: possible regulation by competition between strong and weak effectors; Le Bras G et al.; The pyruvate kinase from Lactobacillus bulgaricus has been purified to homogeneity . The native enzyme is composed of four probably identical subunits of relative molecular mass M(r) 72,000 +/- 4,000 . The unique N-terminal amino acid sequence is homologous to those of other pyruvate kinases, especially of type I and II enzymes from Escherichia coli . The saturation of the pyruvate kinase from Lactobacillus bulgaricus is hyperbolic for ADP and cooperative for the other substrate phospho-enol-pyruvate . The enzyme is strongly activated by glucose-6-phosphate, ribose-5-phosphate, and fructose-6-phosphate, which increase the affinity for phospho-enol-pyruvate . These activators seem to stabilize the same state of the enzyme, since their maximum activations are not additive, but their partial activations can be cumulated . Pyruvate kinase is also weakly activated by AMP and inhibited by fructose-1,6-bisphosphate . However, both AMP and fructose-1,6-bisphosphate act as strong inhibitors in the presence of a strong activator, because these weak effectors suppress the activation by glucose-6-phosphate, ribose-5-phosphate, or fructose-6-phosphate . This mutual exclusion of strong and weak effectors, which appears as an original regulatory mechanism, could reflect either the binding of different effectors to different interacting sites or their competition for a unique polyvalent regulatory site in the pyruvate kinase from Lactobacillus bulgaricus.

Agents Actions, 1993, 39 Spec No, C198 - 200
Pathogenesis of Lactobacillus casei-induced polyarthritis in Lewis rats: 2 . Time related changes in organ weights and liver enzymes; Wilson D et al.; Hepatic enzymes and organ weights were measured in LEW/N female rats during the acute and the chronic phases of L . casei-induced arthritis on day 3 and days 30 and 59, respectively . In the acute phase, day 3, adrenal and spleen weights were increased and thymus weights were decreased in L . casei arthritic rats as compared to normal control rats . Adrenal, liver, kidney, spleen and thymus weights of arthritic rats were in the normal range on days 30 and 59 . Liver cytochrome P450, aminopyrine N-demethylase and analine hydroxylase were reduced in livers of L . casei-treated rats on day 3 as compared to normal controls . On days 30 and 59 hepatic enzymes in L . casei-arthritic rats were in the normal range . Unlike adjuvant arthritis in which changes in liver enzymes alter drug metabolism; after the acute onset of L . casei-induced arthritis, hepatic enzymes return to the normal range.

Agents Actions, 1993, 39 Spec No, C183 - 5
Pathogenesis of Lactobacillus casei-induced polyarthritis in Lewis rats: 1 . Time related changes in histopathological scores and hematology; Blancuzzi V et al.; Intraperitoneal injection of cell wall fragments from L . casei (ATCC 11578) induces an acute and a chronic inflammatory arthritis of the distal joints of LEW/N female rats . Histopathological changes in four distal joints and hematologic changes were analyzed on days 3, 10, 20, 30, 40, 50 and 59 . All joints were scored for changes in inflammation, pannus, cartilage and bone . The acute inflammatory response consisted of fluid exudate, fibrin, neutrophils and some macrophages concentrated along the periosteum of the longer bones . The disease progressed with synovial fibroblast proliferation and infiltration of lymphocytes and macrophages . On day 10, cartilage changes were associated with pannus formation and subchondral fibrosis . Both localized bone resorption and periosteal new bone formation were features of the chronic phase . Lymphocytes were elevated above normal (p < 0.05) on day 3, 10, 20, 30 and 40; returning to the normal range on day 50 and 59 . Neutrophils were elevated on days 10, 20, 30, 40 and 59 . L . casei-induced polyarthritis in Lewis rats appears to be a fibroblast-, macrophage-mediated disease with a prominent lymphoid component.

Akush Ginekol (Mosk), 1993, (5), 39 - 41
{The treatment of bacterial vaginosis}; Kira EF; A two-staged procedure involving creation of a physiologic vaginal environment and formation of normal microbiocenosis is suggested for correction of dysbiotic conditions of the vagina . Biologic preparations lactobacterin, acilact, bifidumbacterin, bifidin are used at the final stages of vaginitis therapy . Altogether 88.4% of patients were cured after the first eubiotic course, 6.8% after 2-3 courses . In 4.7% of patients the treatment was hardly effective . The results demonstrate a high efficacy of eubiotic therapy of bacterial vaginosis.

Caries Res, 1993, 27(5), 431 - 7
Dental caries and cariogenic factors in pre-school urban Icelandic children; Holbrook WP; Caries prevalence and several caries-related factors were measured in 158 pre-school children in Reykjavik, initially aged 4 years and followed longitudinally for 2 years . The mean dmfs at 4 years was 3.3 and rose to 5.8 at 6 years although 34% remained caries-free throughout the study . Caries was very unevenly distributed . Children with dmfs > or = 5 at 4 years were significantly more likely to have caries in their permanent dentition at 6 years than those with a lower caries score at 4 years . Almost all children carried Streptococcus mutans but only 58% carried lactobacilli at 4 years . Lactobacilli declined in numbers at 5 and 6 years as the number of open carious lesions decreased but the mean count of S . mutans remained fairly static (> 10(5) cfu/ml) . There were strong associations between high counts of S . mutans or lactobacilli and caries . Salivary parameters were not as strongly associated with caries although a low salivary pH and low salivary flow rate were significantly associated with high caries scores . The misuse of sugar as determined by dietary questionnaire was strongly associated with a high caries score and low caries prevalence was found in those children that took fluoride tablets regularly.

Caries Res, 1993, 27(5), 424 - 30
Prediction of dental caries in pre-school children; Holbrook WP et al.; Data obtained in a longitudinal study of caries incidence and caries-related factors were analysed with a view to producing a model for the prediction of caries . In direct correlations, caries incidence was significantly associated with bacterial, dietary and salivary variables; but when the data were examined by stepwise regression the strongest variables were the baseline caries score and misuse of sugar . Counts of Streptococcus mutans entered into the analysis but only as a relatively minor component . Similar significant relationships were seen with the determination of odds ratios . A caries activity test was formulated combining the following caries-associated variables: high counts of S . mutans, or lactobacilli, or the misuse of sugar, or frequent consumption of paediatric medicines . Regular use of fluoride tablets could compensate for paediatric medicine use or misuse of sugar . Such a caries activity test if it had been applied to the children at baseline would have had a positive predictive value of 0.76, a negative predictive value of 0.82, a sensitivity of 0.8 and a specificity of 0.78 . Combining tests made the prediction of caries more accurate and in the population for which it was intended gave a reliable means of detecting those children most in need of enhanced caries prevention.

Caries Res, 1993, 27(5), 402 - 8
Microbiological validation of assessments of caries activity during cavity preparation; Kidd EA et al.; The operative management of primary and secondary caries assumes that all discoloured tissue at the enamel-dentine junction (EDJ) represents active disease and this is removed to arrest the carious process . This study aims to establish clinical criteria to differentiate between active and arrested caries at the EDJ using microbiological assessment of dentine samples to verify its clinical status . Radiographs were available for posterior teeth . Cavities (n = 205) were prepared under rubber dam . After gaining access, areas of the EDJ were chosen and assessments made of consistency (soft, medium, hard), colour (dark brown, mid-brown, pale) and moisture content (wet, dry) . Dentine was removed by using a No . 3 round burr and placed in 1 ml of bacteriological culture broth . This sampling procedure was repeated at the same site once during cavity preparation and again when the cavity was judged as fully prepared . Samples were vortexed, diluted and cultured to give viable counts of the total anaerobic microflora, mutans streptococci and lactobacilli; viable counts were expressed as log10 (CFU per sample +1) . Results showed no significant differences between the microflora of primary and secondary caries . The number of bacteria recovered diminished significantly as cavities were completed . Initial samples from soft and wet lesions harboured significantly more bacteria, lactobacilli and mutans streptococci than samples from medium, hard or dry lesions . Lesions visible on radiographs harboured more bacteria, including lactobacilli and mutans streptococci, while dentine colour was not discriminatory.(ABSTRACT TRUNCATED AT 250 WORDS)

Arch Virol, 1993, 133(1-2), 75 - 84
A study of five bacteriophages of the Myoviridae family which replicate on different gram-positive bacteria; Jarvis AW et al.; A comparative study is reported on five phages of the Myoviridae family which propagate on Bacillus subtilis, B . thuringiensis, Enterococcus sp., Lactobacillus plantarum, or Staphylococcus aureus . The phages are morphologically identical and characterized by isometric heads with conspicuous capsomers and by contractile tails with complex base plates . The phages show similar protein profiles, but vary considerably in burst size . Phage DNAs are about 95-166 kb in size and are unrelated by DNA-DNA hybridization and restriction endonuclease analysis . Therefore the phages are unrelated at species level . Implications of these data for our understanding of the development of phage species are discussed.

Schweiz Monatsschr Zahnmed, 1993, 103(9), 1107 - 12
{The germ colonization of the oral cavity in small children with the nursing bottle syndrome}; Wetzel WE et al.; 46 infants, aged 23 to 77 months, presenting with the nursing bottle syndrome, were examined clinically {dmf(t)} and microbiologically . Saliva and carious tooth substance was analysed for the presence of Streptococcus mutans, Lactobacilli and Candida albicans, using in part commercial tests . For comparative reasons, a group of caries-free children, aged 37 to 77 months, was examined as well . Increased numbers of specific caries bacteria (mutans streptococci and lactobacilli) and of Candida albicans were found in saliva and in the carious material of children with diseased teeth . The results confirm that excessive drinking from nursing bottles over a period longer than the first 12 months of life does not only lead to problematic tooth decay and its consequences but also to pathological changes in the entire oral flora . The invasion of candida forces us to reconsider the development of caries in infants.

Riv Eur Sci Med Farmacol, 1993 Jan-Feb, 15(1), 29 - 34
Long-term treatment with rifaximin and lactobacilli in post-diverticulitic stenoses of the colon; Giaccari S et al.; The authors report their endoscopic experience in the treatment of intestinal inflammatory complications and their prevention with cyclic antibiotic treatment (rifaximin 400 mg b.i.d . for 7 days/month), followed by recolonizing treatment with lactobacilli (2 capsules in the morning for 7 days/month), for an overall period of 12 months . In all 79 cases (45 males and 34 females, mean age 63 years, range 55-75 years), the treatment proved capable of controlling the symptoms and averting the onset of the complications which follow attacks of acute diverticulitis . These complications include uncontrollable sepsis, free perforation of a hollow viscus, evolutive fistulation, intestinal occlusion, abscesses not drained percutaneously, all factors which necessitate urgent elective surgery . Rifaximin, together with lactobacillus treatment, proved to be effective, well-tolerated and safe, and can thus be considered an indispensable aid in the treatment of diverticular disease and in the prevention of its complications.

Folia Microbiol (Praha), 1993, 38(6), 441 - 6
Caseicin, a bacteriocin from Lactobacillus casei; Muller E et al.; The intracellular bacteriocin caseicin 80 was purified from cell extracts of Lactobacillus casei strain B80 . It is a thermolabile protein with an apparent molar mass of 42 kDa . As no plasmids were observed in the bacteriocinogenic strain it is assumed that caseicin is encoded by the bacterial chromosome . Using 14C-labelled precursors it was found that biosynthesis of DNA and proteins was influenced by caseicin but this inhibition is probably not the primary effect . The incorporation of fructose but not of glucose into cellular material was inhibited by caseicin.

Nahrung, 1993, 37(6), 583 - 91
Biochemical changes during the preservation stage of ripe olive processing; Garrido A et al.; The influences of initial sodium chloride (6% and 0% w/v in tap water) and acetic acid concentrations (0.3%, and 0.6% v/v), use of starter culture, and aerobic versus anaerobic conditions on the biochemical changes that take place throughout the preservation stage of ripe olive processing were investigated . Glucose, fructose and sucrose were completely consumed during preservation . Mannitol and malic acid were metabolized only in the presence of lactic acid bacteria or oxidative yeast (aerobic treatment) . The main metabolites produced were lactic and acetic acid in aerobic or anaerobic treatments inoculated with Lactobacillus plantarum . Methanol and ethanol were present in all the brines although in a lower concentration when conditions were aerobic . Thus, induced lactic fermentation led to the most efficient utilization of carbohydrates and yielded the most suitable physicochemical characteristics for ripe olive preservation.

Nutr Cancer, 1993, 20(3), 271 - 81
Antigenotoxic properties of lactic acid bacteria in vivo in the gastrointestinal tract of rats; Pool-Zobel BL et al.; In view of the high incidence of dietary-related tumors, one important research goal is to identify the participating genotoxic carcinogens and the nutritional factors that may counteract their activities . We therefore have further developed a method to assess DNA damage in tumor target tissues of the gastrointestinal tract . Subsequently the prevention of this inducible DNA damage by lactic acid bacteria and by milk products fermented with probiotics was studied as well . The microgel electrophoresis technique was applied to cells of the esophageal, gastric, duodenal, and colonic mucosa . Cells were grouped according to their degree of DNA damage, the simplest measure of which is to discriminate between those with damage (comets) and those without damage . When these cells were isolated from animals treated with a genotoxic carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and exposed to MNNG for 1-24 hours, it was possible to follow the course of genotoxicity throughout the gastrointestinal tract . After the animals were treated with the lactic acid bacteria under study, it was possible to detect antigenotoxic properties as well . The gavage of 10(10) viable Lactobacillus casei cells in 10 ml of 0.9% NaCl per kilogram body weight immediately before the oral administration of MNNG (5 mg/kg body wt) resulted in a reduction of induced DNA damage in gastric and colonic mucosa cells . A sequential treatment schedule was even more effective: when the animals were treated orally with lactic acid bacteria or yogurt (10 ml/kg body wt) in the morning followed by MNNG (7.5 mg/kg body wt) eight hours later and the colon cells were isolated 16 hours later, the percentages of cells remaining intact were distinctly higher in the combination groups (68 +/- 10 and 68 +/- 19 for L . casei and a "Bio" yogurt, respectively) than in the group receiving only MNNG (45 +/- 17) . The effect of heating L . casei was studied and was found to yield less clear-cut effects in preventing genotoxicity . The method is an efficient tool to elucidate antigenotoxic properties of food components in vivo in those target tissues actually afflicted by dietary-related tumors.

Antonie Van Leeuwenhoek, 1993-94, 64(2), 85 - 107
Genetics of lactobacilli: plasmids and gene expression; Pouwels PH et al.; This paper reviews the present knowledge of the structure and properties of small (< 5 kb) plasmids present in Lactobacillus spp . The data show that plasmids from Lactobacillus spp., like many plasmids from other Gram-positive bacteria, display a modular organization and replicate by a mechanism of rolling circle replication . Structurally, plasmids from lactobacilli are closely related to plasmids from other Gram-positive bacteria . They contain elements (plus- and minus origin of replication, element(s) for control of plasmid replication, mobilization function) showing extensive similarity to analogous elements in plasmids from these other organisms . It is believed that lactobacilli have acquired such elements by intra- and/or intergenic transfer mechanisms . The first part of the review is concluded with a description of plasmid vectors with a Lactobacillus replicon and integrative vectors, including data concerning their structural and segregational stability . In the second part of this review we describe the progress that has been made during the last few years in identifying and characterizing elements that control expression of genetic information in lactobacilli . Based on the sequence of eleven identified and twenty presumed promoters, some preliminary conclusions can be drawn regarding the structure of Lactobacillus promoters . A typical Lactobacillus promoter shows significant similarity to promoters from E . coli and B . subtilis . An analysis of published sequences of seventy genes indicates that the region encompassing the translation start codon AUG also shows extensive similarity to that of E . coli and B . subtilis . Codon usage of Lactobacillus genes is not random and shows interspecies as well as intraspecies heterogeneity . Interspecies differences may, in part, be explained by differences in G+C content of different lactobacilli . Differences in gene expression levels can, to a large extent, account for intraspecies differences of codon usage bias . Finally, we review the knowledge that has become available concerning protein secretion and heterologous gene expression in lactobacilli . This part is concluded with a compilation of data on the expression in Lactobacillus of heterologous genes under the control of their own promoter or under control of a Lactobacillus promoter.

Chin J Biotechnol, 1993, 9(4), 263 - 71
Biocompatibilities of organic solvents with Lactobacillus delbrueckii; Fan X et al.; In the search for biocompatible extractants for extractive fermentation of lactic acid, the effect of twelve organic solvents on the activity of L . delbrueckii were studied at different concentration levels . On this basis, the compatibilities of twelve solvents with L . delbrueckii were summarized into four classes: completely compatible, compatible at molecular level, partially compatible and non-compatible . The characteristics were described qualitatively for each class in terms of relative values between the solubility of organic solvent in water (Cs) and the toxicity of organic solvent, which is indicated by a newly defined concentration parameter (Cm) . The classification was helpful for the selection of extractant in extractive fermentation.

J Appl Bacteriol, 1992 Dec, 73(6), 480 - 3
In vitro studies on the growth of Shigella sonnei by Lactobacillus casei and Lact . acidophilus; Apella MC et al.; The inhibitory effect of lactobacilli on growth of Shigella sonnei was studied . The effect was not due to pH alone, as addition of hydrochloric, lactic or acetic acids to culture media did not inhibit the normal growth of the shigellas . The degree of inhibition was measured by disc assay and showed that the inhibitory substance(s) can be extracellular and diffusible, varying the degrees of inhibition depending on the media tested . When broth was inoculated with mixed cultures of Lactobacillus and Shigella strains, the inhibition began at 6 h and the death phase at 9 h . The higher inhibition was produced by the mixture of lactobacilli (35.5 +/- 2.5% at 6 h culture, 57.4 +/- 1.9% at 9 h and 91.2 +/- 1.2% at 14 h) . The degree of inhibition was higher when the relationship pathogen : lactobacilli was 1:10(3) . The specific growth rate of lactobacilli and shigella was different in pure or mixed cultures . When the lactobacillus alone was grown for 12 h and the shigellas then added, the numbers of shigellas began to decrease immediately at 37 degrees C . This work shows that the Lactobacillus strains employed in fermented milk can be used to inhibit the growth of Sh . sonnei.

J Gen Microbiol, 1992 Dec, 138 ( Pt 12), 2715 - 20
Purification and amino acid sequence of sakacin A, a bacteriocin from Lactobacillus sake Lb706; Holck A et al.; Sakacin A, a bacteriocin produced by Lactobacillus sake Lb706 and which inhibits the growth of Listeria monocytogenes, was purified to homogeneity by ammonium sulphate precipitation and ion-exchange, hydrophobic-interaction and reversed-phase chromatography . The complete amino acid sequence of sakacin A was determined by Edman degradation . The bacteriocin consisted of 41 amino acid residues and had a calculated M(r) of 4308.7, which is in good agreement with the value determined by mass spectrometry . The structural gene encoding sakacin A (sakA) was cloned and sequenced . The gene encoded a primary translation product of 59 amino acid residues which was cleaved between amino acids 18 and 19 to yield the active sakacin A . Sakacin A shared some sequence similarities with other bacteriocins.

J Gen Microbiol, 1992 Dec, 138 ( Pt 12), 2657 - 61
Adhesion to porcine squamous epithelium of saccharide and protein moieties of Lactobacillus fermentum strain 104-S; Henriksson A et al.; The mechanism by which Lactobacillus fermentum strain 104-S adheres to porcine squamous epithelium was investigated by studying the adsorption to epithelial cells, and control surfaces, of radioactively labelled material released from the bacterial cells by water extraction . The released material was fractionated by gel filtration and the adsorption of pronase-sensitive and -resistant material in the various fractions to porcine gastric tissue and the control surfaces of polystyrene and immobilized bovine serum albumin (BSA) was determined . The fraction with affinity for the epithelium was characterized by enzymic degradation, periodate oxidation, lipid extraction, and protein and carbohydrate analyses . The adsorption pattern of radioactively labelled crude released material mimicked the adhesion of whole labelled cells to polystyrene and to gastric squamous tissue pieces . On fractionation, the pattern of adsorption to polystyrene and BSA was different from that obtained for the tissue pieces . Considerably less labelled pronase-stable material bound to surfaces of polystyrene and BSA, as compared with the tissue, suggesting that the pronase-resistant component has a tissue-specific affinity . After pronase treatment of the fraction of M(r) about 20,000 (20 K) containing labelled components with affinity for the epithelium, only saccharides were detected . Radioactivity was lost after hydrolysis with HCl, and therefore this pronase-resistant labelled component must be a saccharide . It is concluded that protein moieties in the extract have an affinity for several surfaces, including polystyrene, and that saccharide moieties have a specific affinity for the gastric squamous epithelium.

Appl Environ Microbiol, 1992 Dec, 58(12), 4086 - 8
Analysis of exopolysaccharide production by Lactobacillus casei CG11, isolated from cheese; Kojic M et al.; Exopolysaccharide-producing Lactobacillus casei CG11 was isolated from soft, white, homemade cheese . In basal minimal medium, it produces a neutral heteropolysaccharide consisting predominantly of glucose (about 75%) and rhamnose (about 15%) . Plasmid curing experiments revealed that exopolysaccharide production by strain CG11 is linked to a plasmid approximately 30 kb in size.

Appl Environ Microbiol, 1992 Dec, 58(12), 3792 - 8
Cloning and expression of a conjugated bile acid hydrolase gene from Lactobacillus plantarum by using a direct plate assay; Christiaens H et al.; The conjugated bile acid hydrolase gene from the silage isolate Lactobacillus plantarum 80 was cloned and expressed in Escherichia coli MC1061 . For the screening of this hydrolase gene within the gene bank, a direct plate assay developed by Dashkevicz and Feighner (M . P . Dashkevicz and S . D . Feighner, Appl . Environ . Microbiol . 53:331-336, 1989) was adapted to the growth requirements of E . coli . Because of hydrolysis and medium acidification, hydrolase-active colonies were surrounded with big halos of precipitated, free bile acids . This phenomenon was also obtained when the gene was cloned into a multicopy shuttle vector and subsequently reintroduced into the parental Lactobacillus strain . The cbh gene and surrounding regions were characterized by nucleotide sequence analysis . The deduced amino acid sequence was shown to have 52% similarity with a penicillin V amidase from Bacillus sphaericus . Preliminary characterization of the gene product showed that it is a cholylglycine hydrolase (EC 3.5.1.24) with only slight activity against taurine conjugates . The optimum pH was between 4.7 and 5.5 . Optimum temperature ranged from 30 to 45 degrees C . Southern blot analysis indicated that the cloned gene has similarity with genomic DNA of bile acid hydrolase-active Lactobacillus spp . of intestinal origin.

Scand J Dent Res, 1992 Dec, 100(6), 310 - 3
Caries and saliva in 12-18-year-old diabetics and controls; Swanljung O et al.; Eighty-five 12-18-yr-old adolescents suffering from insulin-dependent diabetes mellitus (IDDM) and their healthy age- and sex-matched controls were investigated with respect to dental caries, salivary flow rate, pH and buffering capacity of saliva, counts for lactobacilli and mutans streptococci, and salivary glucose content . The diabetics had their disease well controlled according to the HbA1 levels . The results showed no statistically significant difference between diabetics and controls in DMF and DMFS indexes and the number of initial caries lesions . Mean number of initial caries lesions was 3.2 in diabetics, 2.3 in controls . Mean stimulated salivary flow rate was 1.2 ml/min in the patients, 1.4 ml/min in the controls . The pH and buffering capacity values were 7.3 and 4.8 in the patients, 7.4 and 5.1 in the controls, respectively . High counts of mutans streptococci (> 10(6) CFU/ml) and lactobacilli (> 10(5) CFU/ml) were observed more often, but not significantly so, among the patients than in the controls . The mean concentration of glucose in saliva was 10.3 micrograms/ml in the patients, 9.7 1 microgram/ml in the controls . Thus, if the patients' IDDM is well controlled, their salivary and caries data does not differ from that of healthy controls.

Community Dent Oral Epidemiol, 1992 Dec, 20(6), 338 - 42
Dental caries and its determinants among recent immigrants from rural Ethiopia; Sgan-Cohen HD et al.; Adults (35-45 yr old) and children (5 and 12 yr old) recently arrived in Israel from rural areas in Ethiopia were examined . Caries levels were low: e.g . DMFT = 0.31 among 12-yr-olds, and 1.27 amongst adults . The 5-yr-olds were 86.8% caries-free, while 12-yr-olds were 81.8% and adults 54% caries-free respectively . According to interview data, the diet in Ethiopia had been based on local agricultural products and was almost sugar-free . The mean total count of salivary bacteria, as determined on blood agar, was 3.4 x 10(8); mean count of Streptococcus viridans, on mitis salivarius, was 6.7 x 10(7); and mean count of S . mutans, as determined on mitis salivarius with bacitracin, was 1.7 x 10(7) . These levels were all high and were not significantly different from a control group of 20 Israelis . The mean number of lactobacilli, on Rogosa agar, was 2.75 x 10(4), which was significantly higher than among the controls (3.6 x 10(3) . Salivary pH levels were generally similar between the Ethiopian group and the controls . Salivary flow was significantly higher for the Ethiopians (1.93 ml/min) than for controls (1.16 ml/min) . Low levels of caries in this population can be attributed to an almost sugar-free diet and high salivary flow, but not to the composition of oral microflora.

Protein Sci, 1992 Dec, 1(12), 1710 - 8
Characterization of the stabilizing effect of point mutations of pyruvate oxidase from Lactobacillus plantarum: protection of the native state by modulating coenzyme binding and subunit interaction; Risse B et al.; Point mutations in the gene of pyruvate oxidase from Lactobacillus plantarum, with proline residue 178 changed to serine, serine 188 to asparagine, and alanine 458 to valine, as well as a combination of the three single point mutations, lead to a significant functional stabilization of the protein . The enzyme is a tetrameric flavoprotein with tightly bound cofactors, FAD, TPP, and divalent metal ions . Thus, stabilization may be achieved either at the level of tertiary or quaternary interactions, or by enhanced cofactor binding . In order to discriminate between these alternatives, unfolding, dissociation, and cofactor binding of the mutant proteins were analyzed . The point mutations do not affect the secondary and tertiary structure, as determined by circular dichroism and protein fluorescence . Similarly, the amino acid substitutions neither modulate the enzymatic properties of the mutant proteins nor do they stabilize the structural stability of the apoenzymes . This holds true for both the local and the global structure with unfolding transitions around 2.5 M and 5 M urea, respectively . On the other hand, deactivation of the holoenzyme (by urea or temperature) is significantly decreased . The most important stabilizing effect is caused by the Ala-Val exchange in the C-terminal domain of the molecule . Its contribution is close to the value observed for the triple mutant, which exhibits maximum stability, with a shift in the thermal transition of ca . 10 degrees C . The effects of the point mutations on FAD binding and subunit association are interconnected . Because FAD binding is linked to oligomerization, the stability of the mutant apoenzyme-FAD complexes is increased . Accordingly, mutants with maximum apparent FAD binding exhibit maximum stability . Analysis of the quaternary structure of the mutant enzymes in the absence and in the presence of coenzymes gives clear evidence that both improved ligand binding and subunit interactions contribute to the observed thermal stabilization.

Protein Sci, 1992 Dec, 1(12), 1699 - 709
Stability and reconstitution of pyruvate oxidase from Lactobacillus plantarum: dissection of the stabilizing effects of coenzyme binding and subunit interaction; Risse B et al.; Pyruvate oxidase from Lactobacillus plantarum is a homotetrameric flavoprotein with strong binding sites for FAD, TPP, and a divalent cation . Treatment with acid ammonium sulfate in the presence of 1.5 M KBr leads to the release of the cofactors, yielding the stable apoenzyme . In the present study, the effects of FAD, TPP, and Mn2+ on the structural properties of the apoenzyme and the reconstitution of the active holoenzyme from its constituents have been investigated . As shown by circular dichroism and fluorescence emission, as well as by Nile red binding, the secondary and tertiary structures of the apoenzyme and the holoenzyme do not exhibit marked differences . The quaternary structure is stabilized significantly in the presence of the cofactors . Size-exclusion high-performance liquid chromatography and analytical ultracentrifugation demonstrate that the holoenzyme retains its tetrameric state down to 20 micrograms/mL, whereas the apoenzyme shows stepwise tetramer-dimer-monomer dissociation, with the monomer as the major component, at a protein concentration of < 20 micrograms/mL . In the presence of divalent cations, the coenzymes FAD and TPP bind to the apoenzyme, forming the inactive binary FAD or TPP complexes . Both FAD and TPP affect the quaternary structure by shifting the equilibrium of association toward the dimer or tetramer . High FAD concentrations exert significant stabilization against urea and heat denaturation, whereas excess TPP has no effect . Reconstitution of the holoenzyme from its components yields full reactivation . The kinetic analysis reveals a compulsory sequential mechanism of cofactor binding and quaternary structure formation, with TPP binding as the first step . The binary TPP complex (in the presence of 1 mM Mn2+/TPP) is characterized by a dimer-tetramer equilibrium transition with an association constant of Ka = 2 x 10(7) M-1 . The apoenzyme TPP complex dimer associates with the tetrameric holoenzyme in the presence of 10 microM FAD . This association step obeys second-order kinetics with an association rate constant k = 7.4 x 10(3) M-1 s-1 at 20 degrees C . FAD binding to the tetrameric binary TPP complex is too fast to be resolved by manual mixing.

Zentralbl Bakteriol, 1992 Dec, 277(4), 519 - 28
Binding of Lactobacillus reuteri to fibronectin immobilized on glass beads; Lindgren SE et al.; Human fibronectin was immobilized on glass beads . The beads were used to evaluate binding of Lactobacillus reuteri to fibronectin . Organisms bound to the glass beads were detected using fluorescence microscopy after treatment with acridine orange . This binding was confirmed and quantified with the use of {3H}-labelled organisms . Three strains of Lactobacillus reuteri, three strains of Lactobacillus acidophilus and one strain of Lactobacillus fermentum were tested for binding capacity . L . reuteri strain 1063 exhibited a strong binding to the immobilized fibronectin, and L . acidophilus 1754 showed a slight binding . The binding of L . reuteri to the fibronectin was mediated by a protein as judged by the absence of binding after treatment of the bacteria with proteolytic enzymes . Treatment of the bacteria with urea, SDS and heat (80 degrees C) also reduced binding . Treatment of the bacterial cells prior to the assay with fibronectin interfered with binding . Albumin did not show this interaction.

Eur J Clin Microbiol Infect Dis, 1992 Dec, 11(12), 1166 - 9
In vitro antibacterial activity of antiseptics against vaginal lactobacilli; Juliano C et al.; The results of investigations carried out to evaluate the inhibitory activity in vitro of seven vaginal antiseptic douche solutions against several strains of vaginal lactobacilli isolated from asymptomatic women are reported . Some of the products examined showed marked antibacterial activity even at high dilutions and for short exposure times . The post-antibiotic effect of two of these antiseptics on vaginal lactobacilli was also evaluated . The results of these investigations suggest that uncontrolled use of antiseptic products could cause changes in the normal vaginal flora.

J Chemother, 1992 Dec, 4(6), 342 - 6
Antibacterial, antimycotic and trichomonicidal activity of a new nitroimidazole (EU 11100); Dubini F et al.; The antimicrobial profile of a new nitroimidazole derivative (5-nitro-1-methyl-imidazolyl-2-hydroxy-3 terbutylphenyl carbinol) has been studied . The in vitro activity of the new molecule has been evaluated against both aerobic and anaerobic bacteria, Trichomonas vaginalis, and mycetes, under suitable experimental conditions . The new compound was compared with ampicillin against aerobic bacteria; with metronidazole against anaerobic bacteria, lactobacilli and T . vaginalis; with nistatin and econazole against candida and with econazole and bifonazole against filamentous fungi . The new nitroimidazole derivative has been shown to be moderately active against some anaerobic bacteria belonging to both the Gram-positive and Gram-negative groups . Its inhibitory activity against T . vaginalis was similar to that of metronidazole.

FEBS Lett, 1992 Nov 9, 312(2-3), 147 - 51
13C NMR studies of complexes of Escherichia coli dihydrofolate reductase formed with methotrexate and with folic acid; Cheung HT et al.; 13C NMR studies of 13C-labelled ligands bound to dihydrofolate reductase provide (DHFR) a powerful means of detecting and characterizing multiple bound conformations . Such studies of complexes of Escherichia coli DHFR with {4,7,8a,9-13C}- and {2,4a,6-13C}methotrexate (MTX) and {4,6,8a-13C}- and {2,4a,7,9-13C}folic acid confirm that in the binary complexes, MTX binds in two conformational forms and folate binds as a single conformation . Earlier studies on the corresponding complexes with Lactobacillus casei DHFR indicated that, in this case, MTX binds as a single conformation whereas folate binds in multiple conformational forms (both in its binary complex and ternary complex with NADP+); two of the bound conformational states for the folate complexes are very different from each other in that there is a 180 degrees difference in their pteridine ring orientation . In contrast, the two different conformational states observed for MTX bound to E . coli DHFR do not show such a major difference in ring orientation and bind with N1 protonated in both forms . The major difference appears to involve the manner in which the 4-NH2 group of MTX binds to the enzyme (although the same protein residues are probably involved in both interactions) . Addition of either NADP+ or NADPH to the E . coli DHFR-MTX complex results in a single set of 13C signals for bound methotrexate consistent with only one conformational form in the ternary complexes.

Ital J Gastroenterol, 1992 Nov-Dec, 24(9 Suppl 2), 4 - 9
Non-absorbable antibiotics and small bowel bacterial overgrowth; Corazza GR et al.; The normal gastrointestinal flora includes no more than 10(3) organisms/ml of gastric aspirate and no more than 10(5) organisms/ml of duodenal or jejunal juice . The organisms are primarily gram-positive and aerobic bacteria . In particular anatomical or functional predisposing conditions, an abnormal colonization takes place in the small bowel with microbial concentrations > or = 10(7)/ml of aspirate and with a predominance of anaerobes and coliforms . At times this small bowel bacterial overgrowth remains asymptomatic, but more often leads to a true malabsorption syndrome with symptoms, such as diarrhoea, weight loss and megaloblastic anemia . The most accurate procedure for confirming the presence of this condition is represented by the bacterological analysis of the jejunal aspirate . The routine use of this method is, however, notably hindered by the need for intubation of the patient and by the lack of laboratories suitably equipped for anaerobe culture . As an alternative to this complex procedure, numerous non-invasive tests have been perfected over the last few years, including the glucose- or lactulose- H2 breath test . The main aim of the treatment of the small bowel bacterial overgrowth is the suppression of the bacterial colonization using antimicrobial therapy . Among the local-action non-absorbable antibiotics, rifaximin, was shown to have bactericidal activity against aerobes and anaerobes bacteria, such as bacteroides, lactobacilli and clostrides . In controlled clinical trials the antibiotic has demonstrated therapeutic efficacy in bacterial origin diarrhoea, in porto-systemic encephalopathy, in diverticulosis and, finally, in small bowel bacterial overgrowth.

Minerva Ginecol, 1992 Nov, 44(11), 573 - 84
{Benzidamine in the topical treatment of vaginitis caused by Gardnerella vaginalis}; Bracco PL et al.; The present clinical trial has been carried out in order to evaluate the efficacy of benzydamine in treatment of vaginitis caused by Gardnerella vaginalis . Fifty women affected by this specific pathology have been submitted to topical treatment with 0.5% benzydamine vaginal cream . The treatment has been carried out for 9 consecutive days using a local application of benzydamine twice a day . The clinical result was evaluated after 12 and 60 days . The following parameters were taken into consideration: symptoms (leucorrhea, itching, burning), clinical signs (oedema, hyperemia, vaginal secretion), instrumental data (pH, colposcopy, sniff test) and microbiological findings (searching of clue cells, Lactobacillus and Gardnerella vaginalis) . At the first check point after 12 days 84% of patients have been considered healed; at the second check the percentage of healing rose to 92% . Therefore benzydamine was considered highly effective in 92% of vaginitis caused by Gardnerella vaginalis.

Int J Immunopharmacol, 1992 Nov, 14(8), 1429 - 36
Determination of cytokine release after in vivo and in vitro administration of Deodan (a preparation from Lactobacillus bulgaricus "LB51") by the rabbit pyrogen test; Guencheva G et al.; We investigated the in vivo and in vitro cytokine inducing effects of Deodan, an oral preparation from Lactobacillus bulgaricus "LB-51", using the rabbit pyrogen test . In the first experimental approach we administered Deodan, or its chromatographically purified fraction, via the i.m . or i.v . routes . Low doses of Deodan i.m . caused the formation of a single temperature peak, whereas large doses produced a biphasic temperature curve . Intravenous injection of Deodan produced a monophasic fever in all tested doses . Chromatographically purified Deodan injected i.v . to rabbits caused a febrile response with a dose-dependent pattern, strikingly similar to that of lipopolysaccharide . LAL-testing of Deodan, however, showed that the preparation does not contain endotoxin . In in vivo neutralization studies we demonstrated that IL-1, TNF alpha, and IL-6 mediate the rabbit febrile response to Deodan . Interestingly, the effects of Deodan on the production of TNF alpha and IL-6 were more pronounced than its IL-1 inducing activity . In the second approach, we injected supernatants from mononuclear cells incubated with nonpyrogenic doses of Deodan, intravenously to rabbits ("monocyte type" of pyrogen test) . Rapid-onset monophasic fevers were observed, typical for the rabbit pyrogen reaction to i.v . administration of exogenous IL-1 and TNF . Finally, we demonstrated the presence of pyrogenic cytokines in the supernatants from macrophages of Deodan-treated mice . Together, these results indicate that Deodan induces the production of cytokines with endogenous pyrogenic activity.

Int J Immunopharmacol, 1992 Nov, 14(8), 1355 - 62
Endogenous production of tumor necrosis factor in normal mice orally treated with Deodan--a preparation from Lactobacillus bulgaricus "LB51"; Davidkova G et al.; The ability of orally administered Deodan, a product from the cell wall of Lactobacillus bulgaricus strain "I . Bogdanov patent strain tumoronecroticance B51" ATCC #21815, shortly called "LB51", to induce endogenous tumor necrosis factor-alpha (TNF alpha) production in normal mice was evaluated . The priming and triggering activities of the preparation were investigated in combination with lipopolysaccharide (LPS) and live BCG vaccine . Deodan was applied at a dose of 150 mg/kg and various treatment schedules were employed . The serum levels of TNF alpha in treated mice were quantified by ELISA . Oral administration of Deodan at a dose of 150 mg/kg for 1, 3, 10 or 20 consecutive days only enhanced serum TNF alpha levels in treated mice . Maximal TNF alpha levels were reached 6 h after the last application of Deodan . Deodan was effective in priming TNF alpha in mice triggered intravenously (i.v.) with LPS . Deodan triggered the production of TNF alpha in BCG-primed mice . The preparation, however, was not an effective trigger of mice primed intradermally (i.d.) with 1 microgram/mouse LPS . These findings suggest that Deodan is both a primer and trigger of endogenous TNF alpha . The advantages of treatment of neoplastic disease with agents which induce endogenous TNF alpha is discussed.

FEMS Microbiol Lett, 1992 Nov 1, 77(1-3), 71 - 4
Lectin-like activity of Lactobacillus acidophilus strain JCM 1026; Mukai T et al.; The lectin-like activity of the Lactobacillus acidophilus strain JCM 1026 was studied by hemagglutination and hemagglutination-inhibition assays . L . acidophilus strain JCM 1026 was found to hemagglutinate human and animal erythrocytes . Neuraminidase-treatment of human-type O erythrocytes enhanced the activity . Treatment of the bacterial cells with proteinase K reduced hemagglutinating activity significantly . Although several mono- and disaccharides did not inhibit hemagglutination, several different glycoproteins did . These data indicate that a proteinaceous lectin-like component(s) recognizing carbohydrate-containing molecules is located on the cell surface of L . acidophilus.

J Dairy Res, 1992 Nov, 59(4), 543 - 9
Studies on antimutagenic effect of milk cultured with lactic acid bacteria on the Trp-P2-induced mutagenicity to TA98 strain of Salmonella typhimurium; Hosoda M et al.; The inhibitory effects of cultured milk using 76 strains of lactic acid bacteria isolated from milk products were investigated on the mutagenicity of 3-amino-1-methyl-5H-pyrido{4,3-b}indole (Trp-P2), a tryptophan pyrolysate for Salmonella typhimurium TA98 . Each cultured milk sample displayed its characteristic antimutagenic effect against the mutagenicity of Trp-P2 . The milk cultured with Lactobacillus acidophilus LA106 (LA2) showed the highest inhibition of 82.1% among the strains used . Milk samples cultured with Lactococcus lactis subsp . lactis, Lll103 (10-3) and Lll102 (KM) also exhibited higher inhibition percentages.

J Appl Bacteriol, 1992 Nov, 73(5), 407 - 11
Inhibition of Shigella sonnei by Lactobacillus casei and Lact . acidophilus; Nader de Macias ME et al.; The protective effect of feeding milk fermented with a mixture of Lactobacillus casei and Lact . acidophilus against Shigella sonnei was studied . There was a 100% survival rate in mice fed for 8 d with fermented milk and then dosed orally with Sh . sonnei . The survival rate in control mice was approximately 60% after 21 d . Colonization of the liver and spleen with Sh . sonnei was markedly inhibited by pretreatment with fermented milk . Differences in cell counts of 2-3 log units between treated and control mice were always obtained, shigellas were not detected in these organs by the 10th day in treated mice, while high levels were maintained in the controls . Higher levels of anti-shigella antibodies were found both in sera and in small intestinal fluid of mice treated with fermented milk, suggesting that the protective immunity could be mediated by the mucosal tissue . These results suggest that milk fermented with Lact . casei and Lact . acidophilus could be used as a prophylactic against gastrointestinal infections by shigellas.

J Bacteriol, 1992 Nov, 174(22), 7419 - 27
S-layer protein gene of Lactobacillus brevis: cloning by polymerase chain reaction and determination of the nucleotide sequence; Vidgren G et al.; The surface (S)-layer protein of Lactobacillus brevis was isolated, purified, and characterized . The S-layer protein is the major protein of the cell, with an apparent molecular mass of 46 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) . Immunogold electron microscopy with polyclonal antiserum against the isolated 46-kDa protein was used to confirm the surface location of this protein . N-terminal amino acid sequences of the intact 46-kDa protein and its tryptic peptides were determined . The gene of the S-layer protein was amplified from the genome of L . brevis by polymerase chain reaction with oligonucleotides, synthesized according to the N-terminal amino acid sequences, as primers . The polymerase chain reaction fragments containing the entire S-layer gene and its regulatory regions were sequenced . Nucleic acid sequence analysis revealed one open reading frame with a capacity to encode a protein of 48,159 Da . From the regulatory region of the gene, two subsequent promoters and a ribosome binding site, showing typical features of prokaryotic consensus sequences, were found . The coding region contained a characteristic gram-positive-type signal peptide of 30 amino acids . Removal of the signal peptide results in a polypeptide of 435 amino acids, which is in excellent agreement with the size of the S-layer protein determined by SDS-PAGE . The size and the 5' end analyses of the S-layer transcripts confirmed the monocistronic nature of the S-layer operon and the functionality of the two promoters found.

J Bacteriol, 1992 Nov, 174(22), 7217 - 20
Multiple forms of bile salt hydrolase from Lactobacillus sp . strain 100-100; Lundeen SG et al.; Four isozymes of bile salt hydrolase (BSH) have been purified from the cytosol of cells of Lactobacillus sp . strain 100-100 . The four proteins were designated BSH A, B, C, and D . They eluted from anion-exchange high-pressure liquid chromatography columns at 0.15, 0.18, 0.21, and 0.25 M NaCl, respectively . They are catalytically similar, except that the Vmax of BSH D is about 10-fold lower than those of the other three isozymes . All four proteins consist of one or two polypeptides . The peptides have molecular weights of 42,000 and 38,000 and are designated alpha and beta, respectively . The approximate native molecular weights of BSH A, B, C, and D are 115,000, 105,000, 95,000, and 80,000, respectively . The native proteins are probably trimers; the four isozymes are the array of possible subunit combinations alpha 3, alpha 2 beta 1, alpha 1 beta 2, and beta 3 for A, B, C, and D, respectively . The two subunits are antigenically distinct . Polyclonal antibodies raised against BSH A (all alpha peptide) react in Western blots (immunoblots) only with proteins containing the alpha peptide; such antibodies raised against BSH D (all beta peptide) react only with proteins containing the beta peptide . The amino acid compositions of the two peptides differ . This is the first report of a bacterium that makes four BSH isozymes.

Eur J Biochem, 1992 Nov 1, 209(3), 993 - 8
Unusual amino acid substitution in the anion-binding site of Lactobacillus plantarum non-allosteric L-lactate dehydrogenase; Taguchi H et al.; In Lactobacillus plantarum non-allosteric L-lactate dehydrogenase (L-LDH), the highly conserved His188 residue, which is involved in the binding of an allosteric effector, fructose 1,6-bisphosphate {Fru(1,6)P2}, in allosteric L-LDH is uniquely substituted by an Asp . The mutant L . plantarum L-LDH, in which Asp188 is replaced by a His, showed essentially the same Fru(1,6)P2-independent catalytic activity as the wild-type enzyme, except that the Km and Vmax values were slightly decreased . However, the addition of Fru(1,6)P2 induced significant thermostabilization of the mutant enzyme, as in the case of many allosteric L-LDHs, while Fru(1,6)P2 showed no significant effect on the stability of the wild-type enzyme, indicating that only the single-point mutation, G-->C, sufficiently induces the Fru(1,6)P2-binding ability of L . plantarum L-LDH . The mutant enzyme showed higher thermostability than the wild-type enzyme in the presence of Fru(1,6)P2 . In the absence of Fru(1,6)P2, on the other hand, the mutant enzyme was more labile below 65 degrees C but more stable above 70 degrees C.

Biosci Biotechnol Biochem, 1992 Nov, 56(11), 1859 - 62
Calcium requirement for protoplast transfection mediated by polyethylene glycol of Lactobacillus casei by PL-1 Phage DNA; Watanabe K et al.; The effects of some divalent cations on protoplast transfection mediated by polyethylene glycol of Lactobacillus casei ATCC 27092 by PL-1 phage DNA in 50 mM Tris-maleate buffer (pH 6.0) were investigated . The efficiency of transfection increased about 30 times in the presence of 10 mM Ca2+ . Sr2+ increased the transfection rate as well, but Ba2+, Mn2+, and Mg2+ did not . Co2+ and Zn2+ inhibited transfection . The simultaneous use of Ca2+ and Mg2+ increased the transfection efficiency . Impairment of transfection caused by lack of Ca2+ could not be reversed by the addition of Ca2+ later . A decrease in the Ca2+ concentration to an ineffective level before transfection ended immediately inhibited transfection . Protoplasts were transfected with a phage adsorption mutant resistant to PL-1, also, and these metal ions had the same effect . Multiplication of phages in the transfected protoplasts was independent of the presence or absence of calcium ions . Calcium ions seemed to be involved in the entry of PL-1 DNA into the host protoplasts.

Eur J Obstet Gynecol Reprod Biol, 1992 Oct 23, 47(1), 41 - 5
The relationship between prior cervical conization, cervical microbial colonization and preterm premature rupture of the membranes; Svare JA et al.; The occurrence of prior cervical conization and the cervical microbial colonization was investigated in 38 women with idiopathic preterm labor, 35 women with preterm premature rupture of the membranes (PPROM) and 75 normal pregnant women at 26-34 weeks of gestation . Data were analyzed by Fisher's exact test (two-tailed) . The frequency of prior cervical conization was significantly higher in PPROM patients compared to normal pregnant women (P < 0.001) and to patients in preterm labor (P < 0.01) . Lactobacilli occurred with a lower frequency in patients with PPROM compared to patients in preterm labor (P < 0.05) and control patients (P = 0.0543)-and with a lower frequency in patients with prior cervical conization (P < 0.05) . All other microorganisms occurred with the same frequencies in all groups . The absence of lactobacilli may indicate changes in the cervical flora, which could increase the risk of PPROM . Prior cervical conization may impair the antimicrobial defense-mechanisms in the cervix, which could facilitate ascending microbial colonization . This may lead to a release of prostaglandins and proteolytic enzymes and subsequently preterm labor and rupture of the membranes.

J Biol Chem, 1992 Oct 5, 267(28), 20298 - 301
Glutamate 264 modulates the pH dependence of the NAD(+)-dependent D-lactate dehydrogenase; Kochhar S et al.; Recently, we amplified the Lactobacillus bulgaricus NAD(+)-dependent D-lactate dehydrogenase gene by the polymerase chain reaction, cloned and overexpressed it in Escherichia coli (Kochhar, S., Chuard, N., and Hottinger, H . (1992) Biochem . Biophys . Res . Commun . 185, 705-712) . Polymerase chain reaction-amplified DNA fragments may contain base changes resulting in mutant gene products . A comparison of specific activities of D-lactate dehydrogenase in the crude extracts of 50 recombinant clones indicated that one of the clones had drastically reduced enzyme activity . Nucleotide sequence analysis of the insert DNA showed an exchange of A to G at position 795 resulting in substitution of Glu264 to Gly in the D-lactate dehydrogenase . The purified mutant D-lactate dehydrogenase showed a shift of 2 units in its optimum pH toward the acidic range . The dependence of kcat/Km on the pH of the mutant enzyme showed that the pKa of the free enzyme was around 4, at least 2 pH units lower than that of the wild-type enzyme . Both the wild-type and the mutant enzyme at their respective optimum pH values showed similar kcat and Km values . The data suggest that the highly conserved Glu264 is not critical for enzyme catalysis, but it must be situated within hydrogen bonding distance to amino acid residue(s) involved in substrate binding as well as in catalysis.

Microbiologica, 1992 Oct, 15(4), 413 - 7
Serum cholesterol levels in axenic mice colonized with Enterococcus faecium and Lactobacillus acidophilus; Zacconi C et al.; Hypocholesterolemic effect was shown in axenic, mono, bicolonized and conventional mice: the effect was different depending on probiotic properties of intestinal microorganisms . Contamination by Enterococcus faecium CX determined the highest effect: haematic cholesterol level decrease was 16.9% in females and 7.8% in males . In mice contaminated by Lactobacillus acidophilus N5 the decrease of haematic cholesterol levels was less and not relevant in mice contaminated by conventional microflora . Enterococcus faecium CX and Lactobacillus acidophilus N5 strains were able to grow in presence of bile salts, to colonize intestinal tract, to survive at gastric conditions and to assimilate cholesterol (E . faecium more than L . acidophilus) . The authors consider the possibility to associate probiotic strains with these characteristics for the health of consumers.

Mol Microbiol, 1992 Oct, 6(19), 2833 - 44
The glucose kinase gene of Streptomyces coelicolor A3(2): its nucleotide sequence, transcriptional analysis and role in glucose repression; Angell S et al.; Mutants (glk) of Streptomyces coelicolor A3(2) that are resistant to the non-utilizable glucose analogue 2-deoxyglucose are deficient in glucose kinase activity, defective in glucose repression, and usually unable to utilize glucose . A 2.9 kb BclI fragment, previously shown to restore a wild-type phenotype to a glk deletion mutant that lacks the entire segment, contains two complete open reading frames that would encode proteins of 20.1 kDa (ORF2) and 33.1 kDa (ORF3) . ORF3 is transcribed from its own promoter, and also from a promoter that initiates transcription upstream of ORF2 . A derivative of the temperate phage phi C31 containing ORF3 alone restored a wild-type phenotype when used to lysogenize the deletion mutant . The product of ORF3 is homologous to members of a family of repressor proteins encoded by xylR in Bacillus subtilis and Lactobacillus pentosus, and by nagC in Escherichia coli . Although this might suggest that ORF3 encodes a positive activator for glucose kinase, rather than the enzyme itself, ORF3 restored the ability to metabolize glucose to an E . coli glk mutant, and activity gels of cell extracts of E . coli containing ORF3 cloned in the pT7-7 expression vector demonstrated that the ORF3 product has glucose kinase activity.

J Appl Bacteriol, 1992 Oct, 73(4), 349 - 54
M13 DNA fingerprinting, a new tool for classification and identification of Lactobacillus spp; Miteva VI et al.; The optimal conditions for the application of M13 DNA fingerprinting to the genus Lactobacillus were determined . Comparative fingerprint analysis of representative strains of Lactobacillus delbrueckii subsp . delbrueckii, Lact . delbrueckii subsp . lactis, Lact . delbrueckii subsp . bulgaricus, Lact . helveticus and Lact . casei permitted the differentiation of species, subspecies and individual strains and the quantitative determination of their genetic relatedness . The results confirm the high specificity of M13 DNA fingerprinting and indicate that it might be used in the classification of Lactobacillus spp.

J Appl Bacteriol, 1992 Oct, 73(4), 309 - 16
Isolation and properties of a bacteriocin-producing Carnobacterium piscicola isolated from fish; Stoffels G et al.; A facultative psychrotrophic lactic acid bacterium isolated from fresh fish was identified as Carnobacterium piscicola on the basis of carbohydrate utilization, G + C content and 16S RNA analysis . Its bacteriocin, designated carnocin UI49, is produced during the mid-exponential phase of growth at temperatures between 15 degrees C and 34 degrees C . Carnocin UI49 is active against a large number of closely-related lactic acid bacteria including carnobacteria, lactobacilli, pediococci and lactococci . Furthermore, the bacteriocin has a bactericidic mode of action which results in lysis of sensitive cells . Maximum bactericidal activity is observed at 34 degrees C with a decrease in activity down to 15 degrees C where it is completely abolished.

J Appl Bacteriol, 1992 Oct, 73(4), 299 - 308
Identification and characterization of helveticin V-1829, a bacteriocin produced by Lactobacillus helveticus 1829; Vaughan EE et al.; Lactobacillus helveticus 1829 produced an antimicrobial agent, designated helveticin V-1829, that demonstrated antagonistic activity against closely-related species . The agent was excreted into MRS agar, and was present in the supernatant fluids from both overnight broth and clotted milk cultures . It was heat labile (inactivated by 50 degrees C for 30 min) and was stable over the pH range 2.5 to 6.5 . Production of the substance was pH-dependent and maximum yields were obtained in MRS broth cultures maintained at pH 5.5 . Helveticin V-1829 was partially purified following growth of the producing strain in a semi-defined MRS medium and precipitating the cell-free filtrate with ammonium sulphate to 30% saturation . The cleared supernatant fluid was then brought to 60% saturation and the resulting precipitate pelleted and dialysed in 0.3 mol/l phosphate buffer . The partially purified inhibitor was sensitive to several proteolytic enzymes, and it was bactericidal in its mode of action against indicator cells of Lact . helveticus 1844 and Lact . delbrueckii subsp . bulgaricus 1489, indicating that it was a bacteriocin . A DNA probe specific for the helveticin J structural gene failed to hybridize to total genomic DNA of Lact . helveticus 1829, indicating that helveticin V-1829 is not significantly related to helveticin J.

Community Dent Oral Epidemiol, 1992 Oct, 20(5), 261 - 4
Relationship of microbial and salivary parameters with dental caries in Brazilian pre-school children; Bretz WA et al.; Caries examination and collection of paraffin wax-stimulated saliva samples were performed in 37 children, 3-6 years old, in a child-care facility at the Vidigal slum, Rio de Janeiro, Brazil . The levels of mutans streptococci and lactobacilli in saliva were estimated by the Cariescreen and by the Dentocult tests and the saliva secretion rate was determined . Statistical analysis was performed on surface-based and patient-based caries prevalence rates (SBCPR and PBCPR), and related to bacterial and salivary parameters . The results show that 31 of the 37 children were caries active . The SBCPR for the primary dentition was 6.7% +/- 1.0% . Occlusal surfaces were the most affected by decay . Regression analysis revealed that mutans streptococci salivary levels were significantly associated with the SBCPR (P = 0.0001) . Similarly, lactobacilli salivary levels were significantly associated with the SBCPR (P = 0.0001) . No significant association could be found between the saliva secretion rate and the SBCPR . When regression analysis was used to model dependence of the SBCPR on both organisms, the mutans streptococci and lactobacilli salivary levels were significantly associated with the SBCPRs (P = 0.0021 and 0.0118, respectively), and salivary levels of these organisms accounted for 57% of the SBCPR variability . These findings indicate that the levels of mutans streptococci and lactobacilli in saliva are significantly related to the SBCPRs on the primary dentition of these children.

Proc Natl Acad Sci U S A, 1992 Oct 1, 89(19), 9151 - 5
Expression cloning of a human cDNA encoding folylpoly(gamma-glutamate) synthetase and determination of its primary structure; Garrow TA et al.; A human cDNA for folypoly(gamma-glutamate) synthetase {FPGS; tetrahydrofolate:L-glutamate gamma-ligase (ADP forming), EC 6.3.2.17} has been cloned by functional complementation of an Escherichia coli folC mutant . The cDNA encodes a 545-residue protein of M(r) 60,128 . The deduced sequence has regions that are highly homologous to peptide sequences obtained from purified pig liver FPGS and shows limited homology to the E . coli and Lactobacillus casei FPGSs . Expression of the cDNA in E . coli results in elevated expression of an enzyme with characteristics of mammalian FPGS . Expression of the cDNA in AUXB1, a mammalian cell lacking FPGS activity, overcomes the cell's requirement for thymidine and purines but does not overcome the cell's glycine auxotrophy, consistent with expression of the protein in the cytosol but not the mitochondria.

J Bacteriol, 1992 Oct, 174(19), 6159 - 70
Nucleotide and deduced amino acid sequences of the lacR, lacABCD, and lacFE genes encoding the repressor, tagatose 6-phosphate gene cluster, and sugar-specific phosphotransferase system components of the lactose operon of Streptococcus mutans; Rosey EL et al.; The complete nucleotide sequences of lacRABCDF and partial nucleotide sequence of lacE from the lactose operon of Streptococcus mutans are presented . Comparison of the streptococcal lac determinants with those of Staphylococcus aureus and Lactococcus lactis indicate exceptional protein and nucleotide identity . The deduced polypeptides also demonstrate significant, but lower, sequence similarity with the corresponding lactose proteins of Lactobacillus casei . Additionally, LacR has sequence homology with the repressor (DeoR) of the Escherichia coli deoxyribonucleotide operon, while LacC is similar to phosphokinases (FruK and PfkB) from E . coli . The primary translation products of the lacRABCDFE genes are polypeptides of 251 (M(r) 28,713), 142 (M(r) 15,610), 171 (M(r) 18,950), 310 (M(r) 33,368), 325 (M(r) 36,495), 104 (M(r) 11,401), and 123 (NH2-terminal) amino acids, respectively . As inferred from their direct homology to the staphylococcal lac genes, these determinants would encode the repressor of the streptococcal lactose operon (LacR), galactose-6-phosphate isomerase (LacA and LacB), tagatose-6-phosphate kinase (LacC), tagatose-1,6-bisphosphate aldolase (LacD), and the sugar-specific components enzyme III-lactose (LacF) and enzyme II-lactose (LacE) of the S . mutans phosphoenolpyruvate-dependent phosphotransferase system . The nucleotide sequence encompassing the S . mutans lac promoter appears to contain repeat elements analogous to those of S . aureus, suggesting that repression and catabolite repression of the lactose operons may be similar in these organisms.

Protein Expr Purif, 1992 Oct, 3(5), 380 - 5
Purification methods for recombinant Lactobacillus casei thymidylate synthase and mutants: a general, automated procedure; Kealey JT et al.; General procedures for the rapid, large-scale purification of recombinant Lactobacillus casei thymidylate synthase and its mutants have been established . An effective method employs sequential phosphocellulose and hydroxylapatite chromatography . Crude cell extracts are directly applied to phosphocellulose, and the enzyme is obtained in a nearly pure state by stepwise elution with KCl . The eluate is directly applied to hydroxylapatite, and the homogeneous enzyme is eluted with a gradient of potassium phosphate . The method has been successful for the purification of recombinant wild-type enzyme and all mutants thus far examined . The entire purification procedure has been automated using a commonly available FPLC system and can be performed in several hours with minimal operator time.

Gene, 1992 Sep 21, 119(1), 123 - 6
Isolation and complete sequence of the purL gene encoding FGAM synthase II in Lactobacillus casei; Gu ZM et al.; The purL gene from Lactobacillus casei, encoding phosphoribosylformylglycinamidine synthase II involved in the de novo synthesis of purines, was cloned and sequenced . The putative purL product of 741 amino acids (M(r) of 79,575) shows 25% and 53% identity to the homologous enzymes from Escherichia coli and Bacillus subtilis, respectively . In addition, partial sequences of two other pur genes (purQ and purF) and a possible third gene (purC) were obtained . All these genes are organized in an operon similar to that of B . subtilis . In contrast, the corresponding genes from E . coli and Salmonella typhimurium are scattered through the genome.

Eur J Biochem, 1992 Sep 15, 208(3), 799 - 805
Cloning and overexpression of Lactobacillus helveticus D-lactate dehydrogenase gene in Escherichia coli; Kochhar S et al.; NAD(+)-dependent D-lactate dehydrogenase from Lactobacillus helveticus was purified to apparent homogeneity, and the sequence of the first 36 amino acid residues determined . Using forward and reverse oligonucleotide primers, based on the N-terminal sequence and amino acid residues 220-215 of the Lactobacillus bulgaricus enzyme {Kochhar, S., Hunziker, P . E., Leong-Morgenthaler, P . & Hottinger, H . (1992) J . Biol . Chem . 267, 8499-8513}, a 0.6-kbp DNA fragment was amplified from L . helveticus genomic DNA by the polymerase chain reaction . This amplified DNA fragment was used as a probe to identify two recombinant clones containing the D-lactate dehydrogenase gene . Both plasmids overexpressed D-lactate dehydrogenase (greater than 60% total soluble cell protein) and were stable in Escherichia coli, compared to plasmids carrying the L . bulgaricus and Lactobacillus plantarum genes . The entire nucleotide sequence of the L . helveticus D-lactate dehydrogenase gene was determined . The deduced amino acid sequence indicated a polypeptide consisting of 336 amino acid residues, which showed significant amino acid sequence similarity to the recently identified family of D-2-hydroxy-acid dehydrogenases {Kochhar, S., Hunziker, P . E., Leong-Morgenthaler, P . & Hottinger, H . (1992) Biochem . Biophys . Res . Commun . 184, 60-66} . The physicochemical and catalytic properties of recombinant D-lactate dehydrogenase were identical to those of the wild-type enzyme, e.g . alpha 2 dimeric subunit structure, isoelectric pH, Km and Kcat for pyruvate and other 2-oxo-acid substrates . The kinetic profiles of 2-oxo-acid substrates showed some marked differences from that of L-lactate dehydrogenase, suggesting different mechanisms for substrate binding and specificity.

J Bacteriol, 1992 Sep, 174(17), 5584 - 92
Site-specific integration of the temperate bacteriophage phi adh into the Lactobacillus gasseri chromosome and molecular characterization of the phage (attP) and bacterial (attB) attachment sites; Raya RR et al.; The temperate bacteriophage phi adh integrates its genome into the chromosomal DNA of Lactobacillus gasseri ADH by a site-specific recombination process . Southern hybridization analysis of BclI-digested genomic DNA from six relysogenized derivatives of the prophage-cured strain NCK102 displayed phage-chromosomal junction fragments identical to those of the lysogenic parent . The phi adh attachment site sequence, attP, was located within a 365-bp EcoRI-HindIII fragment of phage phi adh . This fragment was cloned and sequenced . DNA sequence analysis revealed striking features common to the attachment sites of other site-specific recombination systems: five direct repeats of the sequence TGTCCCTTTT(C/T) and a 14-bp inverted repeat . Oligonucleotides derived from the sequence of the attP-containing fragment enabled us to amplify predicted junction fragment sequences and thus to identify attL, attR, and attB . The core region was defined as the 16-bp sequence TACACTTCTTAGGAGG . Phage-encoded functions essential for site-specific insertion of phage phi adh were located in a 4.5-kb BclI fragment . This fragment was cloned in plasmid pSA34 to generate the insertional vector pTRK182 . Plasmid pTRK182 was introduced into L . gasseri NCK102 by electroporation . Hybridization analysis showed that a single copy of pTRK182 had integrated at the attB site of the NCK102 erythromycin-resistant transformants . This is the first site-specific recombination system described in lactobacilli, as well as the first attP-based site-specific integration vector constructed for L . gasseri ADH.

Int J Food Microbiol, 1992 Sep, 17(1), 67 - 70
Effect of tomato juice addition on the growth and activity of Lactobacillus acidophilus; Babu V et al.; Addition of tomato juice to skimmed milk stimulated the growth of Lactobacillus acidophilus . It resulted in higher viable counts, shorter generation time and improved sugar utilization with more acid produced and lower pH for the strains tested . Varying results were obtained for the five strains examined.

Int J Food Microbiol, 1992 Sep, 17(1), 27 - 35
Ropy slime-producing lactic acid bacteria contamination at meat processing plants; Makela PM et al.; At three Finnish meat processing plants the processing rooms, meat trimmings and carcasses were examined for the presence of ropy slime-producing lactic acid bacteria . Bacterial isolates similar to ropy slime-producing lactobacilli strains able to produce ropy slime on meat products, were recovered from the processing rooms and meat trimmings, indicating that these rooms and raw materials are a source of contamination for ropy bacteria . The ability to produce ropy slime would appear to be a common characteristic of lactobacilli, since altogether 10 different ropy lactobacilli groups were isolated in this study.

Community Dent Health, 1992 Sep, 9(3), 273 - 81
A multivariate model to predict caries increment in Montreal children aged 5 years; Demers M et al.; A study was carried out in Montreal (Canada) to predict caries development over the period of one year in primary teeth of kindergarten children (mean age 5 years 8 months +/- 4 months) living in a non-fluoridated area . The 302 children were examined at school on two occasions, one year apart . At the first examination selected predictors were collected: caries experience, salivary S . mutans and lactobacilli, buffer capacity, debris index, parents' education, fluoride consumption and family structure (one or two parents) . Regression analysis was performed to select the significant factors . A total of 143 children developed new caries over the study period; the mean increment for the whole group was 2.1 dmfs . Sensitivity (Sn) and specificity (Sp) were calculated for each predictor and for the final model . The best model comprised only two factors, caries experience and lactobacillus . This could identify 81.8 per cent of children who would develop new caries during the next 12 months (Sn) and 77.4 per cent of those who would not (Sp) . Among the single predictors caries experience alone reached 78.3 per cent for sensitivity and 77.4 per cent for specificity . None of the other predictors, except parents' education, was very good at predicting caries increment over one year.

Community Dent Health, 1992 Sep, 9(3), 261 - 71
A comparison between commercial kits and conventional methods for enumeration of salivary mutans streptococci and lactobacilli; Davenport ES et al.; Mutans streptococci (ms) and lactobacilli levels were determined by conventional and commercial dip-slide methods in three groups of young subjects, aged 5-6 years (93 subjects), 12-13 years (78 subjects) and 18-20 years (81 subjects) . Using the same paraffin-stimulated saliva samples, ms and lactobacilli were estimated by conventional viable counts on modified mitis-salivarius agar (MSB) and Rogosa agar plates, and by inoculation of Dentocult SM and Dentocult LB dip-slides (Orion Diagnostica, Finland) . The salivary ms and lactobacilli counts obtained from conventional agar plates were significantly correlated (P < 0.0001) with the dip-slide estimates of these organisms (Kendal Tau = 0.56, 0.71 respectively) . Subjects in Group 2 showed the highest proportion (77 per cent) of individuals with salivary ms levels above 2.5 x 10(5) cfu/ml saliva; 99 per cent of that group had detectable levels of lactobacilli . Significantly different median salivary ms and lactobacilli levels were demonstrated between all groups except for lactobacilli levels between Groups 2 and 3 . These dip-slide tests provided suitable and simple methods for screening salivary lactobacilli and ms levels which may have a useful role in the assessment of caries risk.

J Gen Microbiol, 1992 Sep, 138 ( Pt 9), 1985 - 90
Purification and amino acid sequence of a bacteriocin produced by Pediococcus acidilactici; Nieto Lozano JC et al.; A bacteriocin produced by Pediococcus acidilactici has been purified to homogeneity by a rapid and simple four-step purification procedure which includes ammonium sulphate precipitation, chromatography with a cation-exchanger and Octyl Sepharose, and reverse-phase chromatography . The purification resulted in an approximately 80,000-fold increase in the specific activity and about a 6-fold increase in the total activity . The amino acid composition and sequencing data indicated that the bacteriocin contained 43-44 amino acid residues . The predicted M(r) and isolectric point of the bacteriocin are about 4600 and 8.6, respectively . Comparing the amino acid sequence of this bacteriocin with the sequences of leucocin A-UAL 187, sakacin P and curvacin A (bacteriocins produced by Leuconostoc gelidum, Lactobacillus sake and Lactobacillus curvatus, respectively) revealed that all four bacteriocins had in their N-terminal region the sequence Tyr-Gly-Asn-Gly-Val-Xaa-Cys, indicating that this concensus sequence is of fundamental importance for this group of bacteriocins . The bacteriocin from P . acidilactici and sakacin P were very similar, having at least 25 common amino acid residues . The sequence similarity was greatest in the N-terminal half of the molecules--17 of the first 19 residues were common--indicating the fundamental importance of this region . Leucocin A-UAL 187 and curvacin A had, respectively, at least 16 and 13 amino acid residues in common with the bacteriocin from P . acidilactici.

J Appl Bacteriol, 1992 Sep, 73(3), 203 - 9
Microbiological events during commercial meat fermentations; Marchesini B et al.; Microbiological developments during industrial meat fermentations (salami), made with and without commercial starter cultures, were followed at two factories in Germany and Italy . In the German product microbial growth was evident only for the first 48 h, followed by a gradual decline in numbers of most micro-organisms . The pH fell from 5.8 to 4.8 in the 28 d required for production . In Italy a similar situation was seen, except that a second period of bacterial growth began around 15 d, coincident with the appearance of intentional surface mould growth which reversed the pH fall, the final pH being 6.2 . The German starter culture was a mixture of Lactobacillus plantarum and Staphylococcus carnosus, whereas in Italy only Staph . carnosus was used . The strain of Lact . plantarum used did not grow in the German product whereas the Staph . carnosus grew well in both products to form a substantial proportion of the final microflora.

Enzyme Microb Technol, 1992 Sep, 14(9), 715 - 24
Counter-diffusion of lactose and lactic acid in kappa-carrageenan/locust bean gum gel beads with or without entrapped lactic acid bacteria; Arnaud JP et al.; The effective diffusion coefficient (De) and equilibrium partition factor (Kp) for lactose and lactic acid in k-carrageenan (2.75% w/w)/locust bean gum (0.25% w/w) (LBG) gel beads (1.5-2.0 mm diameter), with or without entrapped Lactobacillus casei subsp . casei (L . casei), were determined at 40 degrees C . Results were obtained from transient concentration changes in well-stirred solutions of finite volume in which the beads were suspended . Mathematical models of unsteady-state diffusion into and/or from a sphere and appropriate boundary conditions were used to calculate effective diffusion coefficients of lactose and lactic acid from the best fit of the experimental solute concentration changes . The effective diffusivities of lactose and lactic acid were 5.73 x 10(-10) and 9.96 x 10(-10) m2 s-1, respectively . Furthermore, lactic acid was found to modify gel structure since lactose diffusion characteristics (De and Kp) differed significantly from an earlier study and in the literature . In gel beads heavily colonized with L . casei, the effective diffusion coefficients of lactose and lactic acid were respectively 17% and 24% lower than for cell-free beads . Partition coefficients also confirmed the obstruction effect due to the cells, and decreased from 0.89 to 0.79, and from 0.98 to 0.87, for lactose and lactic acid, respectively . External mass transfer was estimated by an unsteady-state model in infinite volume using the Biot number . The effect of external mass transfer resistance on De results and the data reported in the literature are discussed.

Gene, 1992 Sep 1, 118(1), 39 - 46
Nonidentity between plasmid and chromosomal copies of ISS1-like sequences in Lactococcus lactis subsp . lactis CNRZ270 and their possible role in chromosomal integration of plasmid genes; Huang DC et al.; The nucleotide sequence of an insertion sequence (IS) observed during mating experiments using the lactose-protease plasmid, pUCL22, of Lactococcus (Lc.) lactis subsp . lactis CNRZ270, was found to be similar to that of ISS1 from Lc . lactis subsp . lactis ML3 . The IS was named ISS1RS . The chromosome of this strain contains several copies of ISS1-like IS as assessed by hybridization . One of these copies was cloned and named ISS1CH . Its sequence differs from that of the plasmid-borne copy, and appears to be more closely related to ISS1N from Lc . lactis subsp . cremoris SK11 . This suggests independent introduction of both ISS1 elements . Moreover, the observation of plasmid genes integrated in the CNRZ270 chromosome near ISS1CH suggests that their presence is the result of integration by a Campbell mechanism using both IS homologies . ISS1-like sequences were also found on plasmids of numerous Lc . lactis strains, as well as one out of seven Lactobacillus (Lb.) casei and one out of three Lb . plantarum strains examined.

Cancer Epidemiol Biomarkers Prev, 1992 Sep-Oct, 1(6), 491 - 7
Characteristics of women by smoking status in the San Francisco Bay Area; Holly EA et al.; To better understand why smokers are more likely to develop cervical cancer than nonsmokers, we investigated laboratory and demographic differences between the two groups . Women between the ages of 18 and 49 who attended eleven community clinics in the San Francisco Bay Area were studied to investigate differences between smokers and nonsmokers . The 332 smokers and 365 nonsmokers were queried about smoking habits, sexual and reproductive history, and recent diet . Cervical mucus specimens were cultured for yeast, lactobacillus, and other microorganisms . Results showed that white Hispanic women were less likely to smoke than white non-Hispanic women . Smokers, when compared to nonsmokers, consumed larger quantities of coffee, soft drinks, liquor, and beer in the 24 h prior to the interview . Women who smoked were more likely than those who did not smoke to have had first sexual intercourse before age 16, had a greater number of lifetime sexual partners, and were more likely than nonsmokers to have been pregnant . After controlling for number of sexual partners, smokers reported a history of chlamydia, gonorrhea, and/or pelvic inflammatory disease more often than did nonsmokers, and cervical mucus of smokers was more likely than that from nonsmokers to contain greater than 8500 microorganisms/ml.

FEMS Microbiol Lett, 1992 Aug 15, 74(2-3), 169 - 73
Selective isolation of bacteria with dipeptidyl aminopeptidase type I activity from the sheep rumen; McKain N et al.; Five-hundred-and-six fresh isolates of rumen bacteria were tested for their ability to hydrolyse the synthetic substrate for dipeptidyl aminopeptidase type I, GlyArg-4-methoxy-2-naphthylamide (GlyArg-MNA), using a gel overlay technique . Twelve positive isolates were small Gram-negative rods which resembled Bacteroides ruminicola in their biochemical and morphological properties . SDS-PAGE of whole cell extracts indicated that two were similar to B . ruminicola strain B14, six resembled B . ruminicola strain M384, and four were similar to B . ruminicola GA33 . All hydrolysed GlyArg-MNA, Ala2 and Ala5, and showed no activity against Leu-MNA . Ala3 and Ala2, but no Ala4, was produced from Ala5 . The different groups had different, distinctive activity profiles . The two remaining positive isolates were Lactobacillus spp . with an exceptionally high Leu-MNA activity . It was concluded that, although different strains may only be distantly related, B . ruminicola forms the most important group of bacteria in the rumen to possess a dipeptidyl aminopeptidase type I activity.

FEMS Microbiol Lett, 1992 Aug 15, 74(2-3), 235 - 40
Comparative sequence analyses of the 16S rRNA genes of Lactobacillus minutus, Lactobacillus rimae and Streptococcus parvulus: proposal for the creation of a new genus Atopobium; Collins MD et al.; 16S rRNA gene sequencing was performed on the species Lactobacillus minutus, Lactobacillus rimae and Streptococcus parvulus in order to clarify their taxonomic position . Based on comparative sequence analyses these organisms represent a hitherto unknown line of descent within the lactic acid group of bacteria for which a new genus, Atopobium gen . nov., is proposed.

J Gen Microbiol, 1992 Aug, 138 ( Pt 8), 1689 - 96
Adhesion of human Lactobacillus acidophilus strain LB to human enterocyte-like Caco-2 cells; Chauviere G et al.; Twenty-five strains of lactobacilli were tested for their ability to adhere to human enterocyte-like Caco-2 cells in culture . Seven Lactobacillus strains adhered well to the Caco-2 cells, of which three possessed calcium-independent adhesion properties . A high level of calcium-independent adhesion was observed with the human stool isolate Lactobacillus acidophilus strain LB . Scanning electron microscopy revealed that this strain adhered to the apical brush border of the cells . Adhesion increased in parallel with the morphological and functional differentiation of the Caco-2 cells . Two Lactobacillus components were involved in this adhesion . One was protease-resistant and bacterial-surface-associated; the other was heat-stable, extracellular and protease-sensitive.

Clin Infect Dis, 1992 Aug, 15(2), 250 - 5
Two cases of endocarditis due to Lactobacillus species: antimicrobial susceptibility, review, and discussion of therapy; Griffiths JK et al.; Endocarditis caused by lactobacilli may lead to death or to relapse of infection, despite antimicrobial treatment . We report two cases of lactobacillus endocarditis in individuals with native bicuspid aortic valves who survived without relapse and review the 39 other cases reported in the literature . In only 15 previously reported cases have patients been cured with medical therapy alone . One of our patients, who was infected with Lactobacillus acidophilus, was cured by medical therapy alone, and our other patient, who was infected with Lactobacillus casei subspecies rhamnosus, required surgical replacement of his aortic valve . L . acidophilus was tolerant and L . casei subspecies rhamnosus was resistant to many antibiotics tested . Combinations of penicillin or daptomycin and gentamicin were synergistic by time-kill assay . Synergistic therapy with a penicillin and an aminoglycoside was effective clinically and appears to provide optimal medical treatment on the basis of microbiological data.

Can J Microbiol, 1992 Aug, 38(8), 774 - 8
Prevention of 5-fluorouracil-induced infection with indigenous Escherichia coli in tumor-bearing mice by nonspecific immunostimulation; Nomoto K et al.; We have previously reported that the lethal toxicity of 5-fluorouracil (5-FU) in specific-pathogen-free mice is due to an indigenous infection with Escherichia coli (K . Nomoto, T . Yokokura, Y . Yoshikai, et al . Can . J . Microbiol . 37:244-247, 1991) . In the present study, we demonstrate that nonspecific immunostimulation augments host resistance against the lethal toxicity of 5-FU in tumor-bearing mice . Intravenous administration of a preparation of heat-killed Lactobacillus casei (LC 9018), a nonspecific immunostimulant, at a dose of 20 mg/kg to BALB/c mice augmented their resistance against the lethal toxicity of 5-FU if the preparation was injected into the mice 10-40 days before administration of 5-FU . Injection of LC 9018 into BALB/c mice bearing Meth A fibrosarcoma also enhanced their resistance against the lethality of 5-FU . Systemic infection with E . coli was induced in all of the 5-FU-treated tumor-bearing mice 10 days or more after administration of the drug at a lethal dose of 500 mg/kg, and it was accompanied by an overgrowth of the bacteria in the intestine . Treatment of tumor-bearing mice with LC 9018 resulted in decreased rates of occurrence of systemic infection with E . coli and inhibition of overgrowth of the bacteria in the intestine after administration of 5-FU . A single administration of either LC 9018 or 5-FU significantly inhibited the growth of Meth A cells in vivo, and a combined antitumor effect was shown in the mice treated with both 5-FU and LC 9018.

Int J Food Microbiol, 1992 Aug, 16(4), 313 - 22
Accelerated natural lactic fermentation of cereal-based formulas at reduced water activity; Nout MJ; Energy required to dehydrate fermented cereal-based food formulas plays a significant part in the production cost . Therefore the effect of reduced moisture content on the fermentation was investigated . Generally, lactic fermentation at reduced moisture content resulted in increased final pH . Significant acidification still occurred at 0.33 kg water/kg dry matter corresponding to either aW = 0.925 in a sorghum-maize-soya (SMS) mixture, or aW = 0.950 in a sorghum-maize-milk powder (SMM) mixture . Acidification adequate for microbiological safety (pH < or = 4.5) was achieved at 0.54 kg water/kg dm in SMS (aW = 0.950) and 0.43 kg/kg dm in SMM (aW = 0.965) . In stable accelerated natural lactic fermentations obtained by inoculum recycling ('back-slopping') at 30 degrees C, dominant lactic acid bacteria included Lactobacillus plantarum, L . brevis, L . acidophilus and Lactococcus lactis . Dominating yeasts were Saccharomyces cerevisiae and Candida krusei . L . plantarum isolated from high-moisture (1.5 kg/kg dry matter) SMS fermentations had higher specific growth rates than L . plantarum isolated from reduced moisture (0.54 kg/kg dm) SMS fermentations, when tested under similar aW conditions . This effect was not caused by previous culturing conditions; probably different strains of L . plantarum having different aW-optima dominate at high or reduced moisture conditions.

Jpn J Antibiot, 1992 Aug, 45(8), 1065 - 70
Comparisons of the bacterial flora in genital regions at non-pregnancy; Chimura T et al.; In the development of infectious diseases at non-pregnancy and at pregnancy, correlations between bacterial flora in the vagina and portio vaginalis and the ascending infections of those bacteria have recently been discussed . To clarify the cause of those infectious diseases, we studied the localization of microorganisms in genital regions . Patients undergone abdominal total hysterectomy (n = 172) were employed as subjects, and microorganisms isolated from 4 genital regions were studied . In addition, the preventive effect of cefmetazole (CMZ) against postoperative infections was analyzed in 479 cases including the hysterectomy cases mentioned above . The results obtained are summarized as follows: 1 . The isolation rate of microorganisms at non-pregnancy, from subjects of 30 to 69 years old, was 65.6% (82/125) in the vagina and portio vaginalis, 52.1% (25/48) in the cervical mucus, 7.3% (9/124) in the uterine cavity and 0% (0/47) in the ovarian surface . 2 . Numbers of microorganisms isolated in each region were 99 strains in the vagina and portio vaginalis, 28 in the cervical mucus, 10 in the uterine cavity and none in the ovarian surface . Isolation of aerobic Gram-positive bacteria (60-89.3%) and anaerobic Gram-positive bacteria (7.1-30%) were varied in each region . Lactobacillus spp . (38 strains), Staphylococcus epidermidis (20 strains) and Propionibacterium acnes (10 strains) were isolated from vagina and portio vaginalis, and Lactobacillus spp . (17 strains) were the most often isolated bacteria from the cervical mucus.(ABSTRACT TRUNCATED AT 250 WORDS)

Int Dent J, 1992 Aug, 42(4), 199 - 208
Saliva and dental caries: diagnostic tests for normal dental practice; Larmas M; Salivary diagnostics is now entering the surgery of the modern dentist, although no test yet available is so specific and sensitive that caries can be diagnosed from saliva samples only . The present tests are useful for estimating the caries activity due to bad dietary habits (salivary lactobacilli), establishing the presence of infection (salivary mutans streptococci), and identification of salivary yeasts for the determination of the medical condition of the patient . Buffer capacity reveals the most important host response factor acting against caries, while measures of flow rate form the diagnostic basis for treatment planning . These tests, alone or in combination, are now so easy to perform that they should be used in every dental practice.

Mol Gen Genet, 1992 Aug, 234(2), 265 - 74
Structural and functional analysis of two cryptic plasmids from Lactobacillus pentosus MD353 and Lactobacillus plantarum ATCC 8014; Leer RJ et al.; The DNA sequences of a 2.4 kb plasmid (p353-2) from Lactobacillus pentosus MD353 and a 1.9 kb plasmid (p8014-2) from Lactobacillus plantarum ATCC 8014 show 81.5% overall similarity . Both plasmids carry elements (replication protein gene, plus-origin and minus-origin of replication), which are typical of plasmids that replicate via a rolling-circle mechanism of replication (RCR) . Direct evidence for an RCR mechanism was obtained by showing the accumulation of single-stranded plasmid intermediates in the presence of rifampicin . A minus-origin of replication was defined for plasmids p353-2 and p8014-2 based on DNA sequence analysis and on its ability to convert single-stranded into double-stranded plasmid DNA . Plasmids pLPE323, pLPE350 and pLPC37 that are derived from the p353-2 or p8014-2 replicon are structurally and segregationally stable in L . pentosus MD353, L . plantarum ATCC 8014 and in Lactobacillus casei ATCC 393 . The presence of Escherichia coli or lambda DNA fragments in vectors derived from p353-2 or p8014-2 does not affect the structural stability but results in segregational instability of the vectors . The instability increases with increasing size of the inserted DNA fragment . Since vectors based on these replicons can be efficiently propagated in a wide variety of Lactobacillus species, they are highly suitable for cloning and expression of foreign DNA in Lactobacillus, provided that selective pressure is applied.

Appl Microbiol Biotechnol, 1992 Aug, 37(5), 599 - 603
Transformation of N epsilon-CBZ-L-lysine to CBZ-L-oxylysine using L-amino acid oxidase from Providencia alcalifaciens and L-2-hydroxy-isocaproate dehydrogenase from Lactobacillus confusus; Hanson RL et al.; Biotransformations were developed to oxidize N epsilon-carbobenzoxy(CBZ)-L-lysine and to reduce the product keto acid to L-CBZ-oxylysine . Lysyl oxidase (L-lysine: O2 oxidoreductase, EC 1.4.3.14) from Trichoderma viride was relatively specific for L-lysine and had very low activity with N epsilon-substituted derivatives . L-Amino acid oxidase (L-amino acid: O2 oxidoreductase {deaminating}, EC 1.4.3.2) from Crotalus adamanteus venom had low activity with L-lysine but high activity with N epsilon-formyl-, t-butyoxycarbonyl(BOC)-, acetyl-, trifluoroacetyl-, or CBZ-L-lysine . L-2-Hydroxyisocaproate dehydrogenase (EC 1.1.1.-) from Lactobacillus confusus catalyzed the reduction by NADH of the keto acids from N epsilon-acetyl-, trifluoroacetyl-, formyl- and CBZ-L-lysine but was inactive with the products from oxidation of L-lysine, L-lysine methyl ester, L-lysine ethyl ester or N epsilon-t-BOC-L-lysine . Providencia alcalifaciens (SC9036, ATCC 13159) was a good microbial substitute for the snake venom oxidase and also provided catalase (H2O2:H2O2 oxidoreductase EC 1.11.1.6) . N epsilon-CBZ-L-Lysine was converted to CBZ-L-oxylysine in 95% yield with 98.5% optical purity by oxidation using P . alcalifaciens cells followed by reduction of the keto acid using L-2-hydroxyisocaproate dehydrogenase . NADH was regenerated using formate dehydrogenase (formate: NAD oxidoreductase, EC 1.2.1.2) from Candida boidinii . The Providencia oxidase was localized in the particulate fraction and catalase activity was predominantly in the soluble fraction of sonicated cells . The pH optima and kinetic constants were determined for the reactions.

Biosci Biotechnol Biochem, 1992 Aug, 56(8), 1212 - 5
Purification and some properties of acidocin 8912, a novel bacteriocin produced by Lactobacillus acidophilus TK8912; Tahara T et al.; Acidocin 8912, a bacteriocin produced by Lactobacillus acidophilus TK8912, was purified by ammonium sulfate fractionation and successive chromatographies on CM-cellulose, Sephadex G-50, Sephadex G-25, and reversed-phase HPLC on Aquapore RP-300 . The purified acidocin 8912 migrated as a single band on SDS-PAGE . The molecular weight was estimated to be 5200 by SDS-PAGE, and 5400 by HPLC gel filtration on TSKgel G3000PWXL . Both the amino acid composition and the N-terminal amino acid sequence analysis indicated that acidocin 8912 was a peptide composed of presumably 50 amino acids containing a Lys residue at the N-terminus . The purified acidocin 8912 showed a bactericidal effect on sensitive cells but not a bacteriolytic effect.

Pediatr Res, 1992 Aug, 32(2), 141 - 4
Enhancement of the circulating antibody secreting cell response in human diarrhea by a human Lactobacillus strain; Kaila M et al.; Human Lactobacillus sp strain GG (Lactobacillus GG) administered during acute rotavirus diarrhea has been shown to promote clinical recovery . To elucidate the immune mechanisms behind such a favorable outcome, the ELISPOT (solid phase enzyme-linked immunospot) assay of Ig- and specific antibody-secreting cells among circulating lymphocytes was used, giving indirect evidence of the immunologic events in the gut . After rehydration, 39 children with acute rotavirus diarrhea, mean age 16 (SD 6) mo, randomly received either a Lactobacillus GG fermented milk product (study group) or a pasteurized yogurt (placebo group) . The duration of diarrhea was significantly shorter in the study group than in the placebo group {mean 1.1 (SD 0.6) versus 2.5 (SD 1.4)d, p = 0.001} . Lactobacillus GG therapy was associated with a significantly enhanced nonspecific humoral response during the acute phase of the infection, reflected in the IgG, IgA, and IgM Ig-secreting cell numbers . At convalescence, 90% of the study group versus 46% of the placebo group had developed an IgA specific antibody-secreting cell response to rotavirus (p = 0.006) . The results indicate that Lactobacillus GG promotes recovery from rotavirus diarrhea via augmentation of the local immune defense . Furthermore, specific IgA response to rotavirus is endorsed, which is possibly relevant in protection against reinfections.

Thorax, 1992 Aug, 47(8), 666 - 7
Fatal lung abscess due to Lactobacillus casei ss rhamnosus; Namnyak SS et al.; A fatal case of community acquired pneumonia due to Lactobacillus casei ss rhamnosus is reported . Clinicians should be aware of this type of pneumonia.

J Mol Biol, 1992 Jul 20, 226(2), 549 - 54
Nuclear magnetic resonance detection of bound water molecules in the active site of Lactobacillus casei dihydrofolate reductase in aqueous solution; Gerothanassis IP et al.; Proton nuclear magnetic resonance spectroscopy has been used to detect two water molecules bound to residues in the active site of the Lactobacillus casei dihydrofolate reductase (DHFR) . Their presence was detected by measuring nuclear Overhauser effects between NH protons in protein residues and protons in the individual bound water molecules in two-dimensional nuclear Overhauser effect spectroscopy (NOESY), in nuclear Overhauser effect spectroscopy in the rotating frame (ROESY) and three-dimensional 1H-15N ROESY-heteronuclear multiple quantum coherence spectra recorded on samples containing appropriately 15N-labelled DHFR . For the DHFR-methotrexate-NADPH complex, two bound molecules were found, one close to the Trp5 amide NH proton and the other near to the Trp21 indole HE1 proton: these correspond to two of the water molecules (Wat201 and Wat253) detected in the crystal structure studies described by Bolin and co-workers . However, the nuclear magnetic resonance experiments did not detect any of the other bound water molecules observed in the X-ray studies . The nuclear magnetic resonance results indicate that the two bound water molecules that were detected have lifetimes in the solution state that are longer than approximately two nanoseconds . This is of considerable interest, since one of these water molecules (Wat253) has been implicated as the likely proton donor in the catalytic reduction of dihydrofolate to tetrahydrofolate.

Biochemistry, 1992 Jul 7, 31(26), 6038 - 44
Thymidylate synthase with a C-terminal deletion catalyzes partial reactions but is unable to catalyze thymidylate formation; Carreras CW et al.; The V316Am mutant of Lactobacillus casei thymidylate synthase has a single amino acid deletion at the C-terminus which abolishes catalysis of dTMP formation . However, V316Am catalyzes two partial reactions which require covalent catalysis: a CH2H4folate-dependent exchange of the 5-hydrogen of dUMP for protons in water and a thiol-dependent dehalogenation of 5-bromo- and 5-iodo-dUMP . These reactions proceed with kcat and Km values similar to those of the wild-type TS-catalyzed reactions . dUMP, dTMP, and FdUMP are competitive inhibitors of the debromination reaction with Ki values similar to those obtained with wild-type enzyme . These results show that removal of the terminal valine does not alter the ability of the enzyme to bind to or form covalent bonds with nucleotide ligands . V316Am also forms a covalent ternary complex with FdUMP and CH2H4folate . However, the affinity of the TS-FdUMP complex for the cofactor is reduced, and the rate of covalent ternary complex formation and its stability are significantly lower than with wild-type TS . These results allow us to place the major defects of the mutation on steps that occur subsequent to initial CH2H4folate binding.

Biochemistry, 1992 Jul 7, 31(26), 6032 - 8
Complete replacement set of amino acids at the C-terminus of thymidylate synthase: quantitative structure-activity relationship of mutants of an enzyme; Climie SC et al.; The C-terminal residue of thymidylate synthase (TS) is highly conserved and has been implicated in cofactor binding, catalysis, and a conformational change . The codon for the C-terminal valine of Lactobacillus casei TS has been replaced with those for 19 other amino acids and the amber stop codon . Fourteen of the resulting mutant proteins were active by genetic complementation using a Thy- strain of Escherichia coli, and 18 mutants were active by in vitro assay . Only the aspartate and amber mutations had undetectable activity . All of the mutants were expressed at high levels (5-30% of soluble protein) and were purified by phosphocellulose chromatography . In general, the alterations at position 316 led to little effect on the Km for dUMP, an increase in Km for the folate cofactor, and a decrease in kcat . The observations show that TS can tolerate the substitution of most amino acids for valine at the C-terminus without a complete loss of activity, that hydrophobic substitutions are preferred, and that the C-terminal side chain is involved in both cofactor binding and catalysis . There was an excellent correlation between log kcat and hydrophobicity of the side chain at position 316 and an inverse correlation between log Km and the hydrophobicity of this residue . Kinetic parameters of the cofactor-independent TS-catalyzed dehalogenation of BrdUMP showed no variation with the side chain at position 316 . In context of the structure of TS, it is proposed that binding of the cofactor triggers a conformational change in which the C-terminal side chain undergoes hydrophobic interactions that stabilize a rate-limiting transition state of the TS reaction.

Appl Environ Microbiol, 1992 Jul, 58(7), 2315 - 20
Monoclonal antibody-colony immunoblot method specific for isolation of Pediococcus acidilactici from foods and correlation with pediocin (bacteriocin) production; Bhunia AK et al.; BALB/c mice were immunized with broken, heat-killed cells of Pediococcus acidilactici H . After murine cell fusions, one monoclonal antibody (MAb), Ped-2B2, was selected on the basis of its positive reaction with seven of seven strains tested in an enzyme-linked immunosorbent assay with whole cells of P . acidilactici . The MAb Ped-2B2 did not show any cross-reactions with other lactic-acid bacteria or other gram-positive or gram-negative organisms . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) analysis of surface proteins of P . acidilactici indicated that Ped-2B2 reacted with a protein of 116 kDa . MAb Ped-2B2 was used as a probe to isolate Pediococcus species from fermented-meat products by colony immunoblotting . A total of 18 Ped-2B2-reactive Pediococcus spp . isolates were isolated from eight food samples and assayed for bacteriocin production . All of the isolates produced bacteriocins which were heat stable, proteinaceous, and inhibitory to Lactobacillus plantarum NCDO 955 . Biochemical characterization of these isolates indicated that they were all P . acidilactici.

J Med Microbiol, 1992 Jul, 37(1), 38 - 42
Fibronectin binding of Lactobacillus species isolated from women with and without bacterial vaginosis; Nagy E et al.; Lactobacilli isolated from the vaginas of healthy women (39 strains) and from the vaginal discharge of women with bacterial vaginosis (15 strains) were investigated for their binding to 125I-fibronectin . Nine of the 54 strains bound fibronectin at pH 7.2 . The binding capacity of these nine strains was about the same as that observed with Staphylococcus aureas Cowan 1 . The binding was specific; an excess of unlabelled fibronectin or its amino-terminal 29-kDa fragment effectively competed for binding, whereas bovine serum albumin, human IgG and orosomucoid did not . Incubation of lactobacilli with fibronectin for different periods revealed a time-dependent increase in binding . Lowering the pH to 4.0 increased the binding capacity of all of the lactobacilli tested; binding occurred with strains that had previously failed to bind at pH 7.2 . The increased binding of lactobacilli to fibronectin at a low pH may play a role in the maintenance of the ecological balance of the vagina.

FEMS Microbiol Lett, 1992 Jul 1, 73(1-2), 121 - 6
Characterization of an extracellular factor that stimulates bile salt hydrolase activity in Lactobacillus sp . strain 100-100; Lundeen SG et al.; Bile salt hydrolase activity in Lactobacillus sp . strain 100-100 is strictly intracellular . The strain produces an extracellular factor that stimulates the intracellular hydrolase activity . The factor is inducible by conjugated bile salts, has an apparent molecular mass over 12 kDa but less than 25 kDa, is stable in air, and resistant to pronase and heat . It is partially extractable into organic solvents and inactivated by a sulphydryl group inhibitor . We postulate that the factor functions by a novel mechanism to facilitate entry of conjugated bile salts into the bacterial cells.

J Gen Microbiol, 1992 Jul, 138 ( Pt 7), 1353 - 64
Cloning, sequencing and expression of the gene encoding the cell-envelope-associated proteinase from Lactobacillus paracasei subsp . paracasei NCDO 151; Holck A et al.; The gene encoding the cell-envelope-associated proteinase of Lactobacillus paracasei subsp . paracasei NCDO 151 (formerly Lactobacillus casei NCDO 151) was cloned and sequenced . The gene was located on the chromosome and encoded a polypeptide of 1902 amino acids . The proteinase is N-terminally cleaved upon maturation . It shows extensive homology to the Lactococcus lactis subsp . cremoris Wg2 proteinase . Similar to the situation in Lactococcus, a maturation gene was found upstream of the proteinase gene . The cloned proteinase gene was expressed in Lactobacillus plantarum . However, no expression was observed when the gene was cloned in Lactococcus lactis.

J Appl Bacteriol, 1992 Jul, 73(1), 60 - 2
A note on the use of a plasmid as a DNA probe in the detection of a Lactobacillus fermentum strain in porcine stomach contents; Tannock GW et al.; A plasmid (about 50 kb) was used as a DNA probe to enumerate, by colony hybridization, a strain of Lactobacillus fermentum in the stomach contents of eight piglets . The population sizes obtained by colony hybridization were in agreement with estimated levels calculated on the basis of plasmid profiling of colonies isolated at random from the total lactobacillus population.

Int J Syst Bacteriol, 1992 Jul, 42(3), 487 - 91
Taxonomic study of the Lactobacillus acidophilus group, with recognition of Lactobacillus gallinarum sp . nov . and Lactobacillus johnsonii sp . nov . and synonymy of Lactobacillus acidophilus group A3 (Johnson et al . 1980) with the type strain of Lactobacillus amylovorus (Nakamura 1981); Fujisawa T et al.; Biochemical properties and DNA-DNA reassociation studies of Lactobacillus acidophilus strains isolated from humans and animals indicate that these include six genomospecies . Two new species can be differentiated from the established species of the genus Lactobacillus: L . gallinarum sp . nov . (type strain, ATCC 33199) and L . johnsonii sp . nov . (type strain, ATCC 33200) . Furthermore, it was clarified that L . acidophilus group A3 (Johnson et al . 1980) is synonymous with L . amylovorus.

West Afr J Med, 1992 Jul-Sep, 11(3), 195 - 8
Bacteriological investigation of infected root canals in Benin City, Nigeria; Ufomata D et al.; Possible viable bacteria were isolated and determined through culture based on paper point inoculation from infected root canals of 50 patients who presented for endodontic therapy at the school of Dentistry, University of Benin Teaching Hospital and Central Hospital, Benin City . Eighty-one strains of bacteria were isolated from 50 patients . The bacterial isolates were Streptococcus species, (51), Klebsiella species (17), E . coll (5), Staphylococcus aureus (3), Micrococcus species (2), Neisseria spp . (2) and Lactobacillus . The isolation of Klebsiella spp from the study is particularly interesting, constituting 21% of all the isolated bacteria . The implications of these findings in root canal infections are presented.

Int J Food Microbiol, 1992 Jul, 16(3), 215 - 25
Sakacin M, a bacteriocin-like substance from Lactobacillus sake 148; Sobrino OJ et al.; The antagonistic activity of Lactobacillus sake 148 was evaluated during its growth on complex broth media and in a semisynthetic defined medium (SDM) with various supplements . The antagonistic activity was a growth-associated property, being detected and quantified when L . sake 148 was grown at either 4, 8, 16, 25 or 32 degrees C . The concentrated culture supernatant of L . sake 148 was subjected to purification by lyophilization and gel filtration . The purification procedure resulted in a small increase in its specific activity (7-fold) and in a low recovery of the original inhibitory activity (8%) . Gel filtration analysis of the partially purified activity on Sephadex G-50 revealed an apparent molecular weight of 4640 . The partially purified antagonistic activity of L . sake 148 was destroyed by treatment with proteolytic enzymes . However, the antagonistic activity was resistant to heat, having D-values at 121, 135 and 150 degrees C of 23.8, 17.4 and 15.2 min, respectively.

Spec Care Dentist, 1992 Jul-Aug, 12(4), 177 - 82
Dietary and salivary factors associated with root caries; Faine MP et al.; In this pilot study, dietary habits, microbial factors, and salivary factors in 20 older adults who had active decay on root surfaces were compared with those of 20 adults who had inactive or no root caries . In this case-control study, the groups were matched by sex and were of similar age . Subjects using medications known to induce dry mouth were excluded . Subjects completed a nutrition interview and a four-day food diary . Stimulated whole saliva flow rate, buffering capacity, levels of salivary lactobacilli with use of the Dentocult method, and S . mutans cultured on MSB agar were determined . The root caries group had a greater mean number of eating occasions per day (6.1 vs . 4.6), more frequent exposures to fermentable carbohydrates (5.8 vs . 4.2), and higher average daily sugars intake (133 g/day vs . 105 g/day) than the control group . Root caries subjects had significantly higher lactobacilli counts and less salivary buffering capacity . Within the root caries group, significant correlations were found with Root Caries Index and lactobacilli (r = 0.56) and S . mutans counts (rs = 0.50) . These results show that frequent intake of simple sugars, high lactobacilli counts, and low saliva buffering capacity may be risk factors associated with root caries in older adults.

Spec Care Dentist, 1992 Jul-Aug, 12(4), 149 - 52
Streptococcus mutans, lactobacilli, and caries experience in older adults; Hunt RJ et al.; This study investigated salivary levels of Streptococcus mutans, lactobacilli, and caries experience in a random sample of 448 black and 362 white older dentate adults living in North Carolina . Significant proportions of the participants had stimulated salivary flow rates less than 1.0 mL/min, salivary buffering capacity less than 4.0, S . mutans levels of 10(5) cfu/mL or more in stimulated whole saliva, or lactobacilli levels of 10(5) cfu/mL or more . Each of these factor levels could be considered, on a clinical basis, to increase caries risk . In general, people with higher levels of S . mutans or lactobacilli had more untreated coronal and root caries, but not greater total caries experience.

Nippon Saikingaku Zasshi, 1992 Jul, 47(4), 617 - 24
{Phosphoenolpyruvate:hexose phosphotransferase systems in Lactobacillus species}; Nagasaki H et al.; The substrate range of phosphoenolpyruvate:hexose phosphotransferase systems (hexose-PTSs) in Lactobacillus casei subsp . casei LAC3 and L . acidophilus LAC5 was examined . Strain LAC3 demonstrated PTS activities for glucose (Glc), mannose (Man), glucosamine (GcN), 2-deoxyglucose (2DG) and fructose (Fru), while strain LAC5 showed the activities only for Man and Fru . These activities were all constitutive . Growth of both strains was strongly inhibited by 2DG . 2DG-resistant mutants DG329 and DG504 were isolated, respectively, from strains LAC3 and LAC5 . Mutant DG329 grown on Glc was defective in all the above-described activities observed with strain LAC3, whereas no defect in PTS activities was found in mutant DG504 . Mutant DG329, however, showed some inducible activities for Man and Fru when grown on Man, Fru or Scr . These results strongly suggest that strain LAC3 has inducible PTS(s) specific for Man and/or Fru besides the well-known, broadly specific, constitutive Man-PTS, and also that strain LAC5 lacks the Man-PTS, but has other constitutive PTS(s) specific for Man and/or Fru . L . fermentum LAC12 had the Man-PTS as reported previously (Nagasaki et al., 1992), but had no inducible activities like those found in strain LAC3.

ASDC J Dent Child, 1992 Jul-Aug, 59(4), 263 - 8
Sealing of occlusal hidden caries lesions: an alternative for curative treatment?
Weerheijm KL, de Soet JJ, van Amerongen WE, de Graaff J.
The bacterial composition of the dentine of thirty molars with sealed occlusal surfaces (Delton tinted) was examined . Undiagnosed hidden caries was present at the time of treatment . Although clinically assessed as good (age 3.4 years, s.d . 2.1), 47 percent of the sealants had a marginal defect, when assessed with SEM . The dentine of the treated teeth was of a soft consistency . The median of the number of microorganisms was 400 (range 0-3.10(5)) cfu per sample . Mutans streptococci and lactobacilli were found in 53 percent of the samples . No relationship was found between the number of microorganisms and the marginal adaptation of the sealant, when examined under SEM; neither was a relationship found between the age of the sealant and the number of microorganisms (Kendall's Tau-C = 0.17, n.s . and -0.01, n.s., respectively) . At present, there are insufficient grounds for treating nonvisible lesions (with a radiolucency on the bitewing) with a resin sealant.

Appl Environ Microbiol, 1992 Jul, 58(7), 2287 - 91
Comparative acid tolerances and inhibitor sensitivities of isolated F-ATPases of oral lactic acid bacteria; Sturr MG et al.; pH activity profiles and inhibitor sensitivities were compared for membrane ATPases isolated from three oral lactic acid bacteria, Lactobacillus casei ATCC 4646, Streptococcus mutans GS-5, and Streptococcus sanguis NCTC 10904, with, respectively, high, moderate, and low levels of acid tolerance . Membranes containing F1F0 ATPases were isolated by means of salt lysis of cells treated with muralytic enzymes . Membrane-free F1F0 complexes were then isolated from membranes by detergent extraction with Triton X-100 or octylglucoside . Finally, F1 complexes free of the proton-conducting F0 sector were obtained by washing membranes with buffers of low ionic strength . The pH activity profiles of the membrane-associated enzymes reflected the general acid tolerances of the organisms from which they were isolated; for example, pH optima were approximately 5.5, 6.0, and 7.0, respectively, for enzymes from L . casei, S . mutans, and S . sanguis . Roughly similar profiles were found for membrane-free F1F0 complexes, which were stabilized by phospholipids against loss of activity during storage . However, profiles for F1 enzymes were distinctly narrower, indicating that association with F0 and possibly other membrane components enhanced tolerance to both acid and alkaline media . All of the enzymes were found to have similar sensitivities to Al-F complexes, but only F1F0 enzymes were highly sensitive to dicyclohexylcarbodiimide . The procedures described for isolation of membrane-free F1F0 forms of the enzymes from oral lactic acid bacteria will be of use in future studies of the characteristics of the enzymes, especially in studies with liposomes.

J Bacteriol, 1992 Jul, 174(14), 4707 - 17
Biosynthesis of D-alanyl-lipoteichoic acid: cloning, nucleotide sequence, and expression of the Lactobacillus casei gene for the D-alanine-activating enzyme; Heaton MP et al.; The D-alanine-activating enzyme (Dae; EC 6.3.2.4) encoded by the dae gene from Lactobacillus casei ATCC 7469 is a cytosolic protein essential for the formation of the D-alanyl esters of membrane-bound lipoteichoic acid . The gene has been cloned, sequenced, and expressed in Escherichia coli, an organism which does not possess Dae activity . The open reading frame is 1,518 nucleotides and codes for a protein of 55.867 kDa, a value in agreement with the 56 kDa obtained by electrophoresis . A putative promoter and ribosome-binding site immediately precede the dae gene . A second open reading frame contiguous with the dae gene has also been partially sequenced . The organization of these genetic elements suggests that more than one enzyme necessary for the biosynthesis of D-alanyl-lipoteichoic acid may be present in this operon . Analysis of the amino acid sequence deduced from the dae gene identified three regions with significant homology to proteins in the following groups of ATP-utilizing enzymes: (i) the acid-thiol ligases, (ii) the activating enzymes for the biosynthesis of enterobactin, and (iii) the synthetases for tyrocidine, gramicidin S, and penicillin . From these comparisons, a common motif (GXXGXPK) has been identified that is conserved in the 19 protein domains analyzed . This motif may represent the phosphate-binding loop of an ATP-binding site for this class of enzymes . A DNA fragment (1,568 nucleotides) containing the dae gene and its putative ribosome-binding site has been subcloned and expressed in E . coli . Approximately 0.5% of the total cell protein is active Dae, whereas 21% is in the form of inclusion bodies . The isolation of this minimal fragment without a native promoter sequence provides the basis for designing a genetic system for modulating the D-alanine ester content of lipoteichoic acid.

FEMS Microbiol Lett, 1992 Jul 1, 73(1-2), 101 - 4
Correlation between hydrophobicity and resistance to nonoxynol-9 and vancomycin for urogenital isolates of lactobacilli; Tomeczek L et al.; Seven clinical isolates of lactobacilli were found to be relatively hydrophobic with a mean water-contact angle of 66 +/- 15 degrees, and to be susceptible to 1% nonoxynol-9 and vancomycin . However, seven other strains were relatively hydrophilic with a mean water-contact angle of 32 +/- 13 degrees, and found to be resistant to 25% nonoxynol-9 and vancomycin . Thus, the surface properties of lactobacilli that influence susceptibility to antimicrobial agents may involve surface hydrophobicity . Possibly the penetration barrier posed by the cell surface towards these two nonionic antimicrobials is lower for hydrophobic cells than for hydrophilic cells.

Rev Argent Microbiol, 1992 Jul-Dec, 24(3-4), 136 - 44
{Effect of glucose and lactose on the utilization of citrate by Lactobacillus casei subsp . rhamnosus ATCC 7469}; Benito de Cardenas IL et al.; The utilization of citrate by Lactobacillus casei subsp . rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin) . This lactobacillus uses citrate as an energy source in the absence of carbohydrates . External pH and growth increases when citrate is added to complex medium . The presence of citrate does not affect glucose uptake . L . casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control . Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.

Am J Obstet Gynecol, 1992 Jul, 167(1), 16 - 9
Simplified gram stain interpretive method for diagnosis of bacterial vaginosis; Thomason JL et al.; OBJECTIVE: Two methods which only consider bacterial morphotypes and require counting various types of bacteria, for interpreting Gram stains of vaginal secretions for the purpose of diagnosing bacterial vaginosis were previously described . A new interpretative method, which combines clue cells with bacterial morphotypes as diagnostic markers, is offered . STUDY DESIGN: One hundred twenty patients were tested with the new interpretative method and clinical criteria of bacterial vaginosis as the reference standard . RESULTS: The new method was found comparable to older methods when all were compared with clinical diagnostic methods . The sensitivity of the clue cell method was 86.1% and the specificity was 92.8% . The predictive value of a positive test was 83.7% for a population with a prevalence of bacterial vaginosis of 30% . The negative predictive value was 94.0% . CONCLUSION: If clue cells are present and the nonlactobacilli morphotypes exceed lactobacilli morphotypes, bacterial vaginosis can be diagnosed without the need for exact bacterial counts.

Biochem Biophys Res Commun, 1992 Jun 15, 185(2), 705 - 12
Cloning and overexpression of the Lactobacillus bulgaricus NAD(+)-dependent D-lactate dehydrogenase gene in Escherichia coli:purification and characterization of the recombinant enzyme; Kochhar S et al.; The Lactobacillus bulgaricus NAD(+)-dependent D-lactate dehydrogenase gene was amplified by the polymerase chain reaction and cloned into an Escherichia coli expression plasmid pKK223.3 . Attempts to clone the full-length chromosomal DNA encoding D-lactate dehydrogenase from a partial Sau3AI lambda phage library or an enriched clone bank in E . coli were unsuccessful . The recombinant plasmid pKBULDH containing the amplified gene overexpressed D-lactate dehydrogenase (greater than 30% of total soluble protein) following induction of the tac promotor with isopropyl-beta-D-thiogalactopyranoside . The cloned gene product was purified to homogeneity by two chromatographic steps with 76% recovery of enzyme activity . All the properties of the recombinant protein, e.g., optimum pH and temperature, Km and k(cat) for pyruvate as well as for other 2-oxo acids and the subunit structure were identical to the wild-type enzyme.

Biochemistry, 1992 Jun 9, 31(22), 5100 - 4
Mutation of asparagine 229 to aspartate in thymidylate synthase converts the enzyme to a deoxycytidylate methylase; Liu L et al.; The conserved Asn 229 of thymidylate synthase (TS) forms a cyclic hydrogen bond network with the 3-NH and 4-O of the nucleotide substrate dUMP . The Asn 229 to Asp mutant of Lactobacillus casei thymidylate synthase (TS N229D) has been prepared, purified, and investigated . Steady-state kinetic parameters of TS N229D show 3.5- and 10-fold increases in the Km values of CH2H4folate and dUMP, respectively, and a 1000-fold decrease in kcat . Most important, the Asp 229 mutation changes the substrate specificity of TS to an enzyme which recognizes and methylates dCMP in preference to dUMP . With TS N229D the Km for dCMP is bout 3-fold higher than for dUMP, and the Km for CH2H4folate is increased about 5-fold; however, the kcat for dCMP methylation is 120-fold higher than that for dUMP methylation . Specificity for dCMP versus dUMP, as measured by kcat/Km, changes from negligible with wild-type TS to about a 40-fold increase with TS N229D . TS N229D reacts with CH2H4folate and FdUMP or FdCMP to form ternary complexes which are analogous to the TS-FdUMP-CH2H4folate complex . From what is known of the mechanism and structure of TS, the dramatic change in substrate specificity of TS N229D is proposed to involve a hydrogen bond network between Asp 229 and the 3-N and 4-NH2 of the cytosine heterocycle, causing protonation of the 3-N and stabilization of a reactive imino tautomer . A similar mechanism is proposed for related enzymes which catalyze one-carbon transfers to cytosine heterocycles.

J Appl Bacteriol, 1992 Jun, 72(6), 475 - 8
Hydrolysis of vicine and convicine from fababeans by microbial beta-glucosidase enzymes; McKay AM; The toxic glycosides vicine and convicine which are present in fababeans have been implicated in favism, an anaemic disease of humans . Vicine and convicine concentrations are reduced by growth of Lactobacillus plantarum on fababean suspensions . The glycosides are eliminated from the fababean substrate by the growth of the filamentous fungus Fusarium graminearum . Incubation of fababean suspension with concentrated culture filtrate of Aspergillus oryzae, induced for extracellular beta-glucosidase production, results in complete degradation of the glycosides . This study suggests a potential use of micro-organisms or microbial enzymes for detoxification of fababeans.

Scand J Dent Res, 1992 Jun, 100(3), 140 - 3
Caries associated microflora in plaque from orthodontic appliances retained with glass ionomer cement; Hallgren A et al.; The caries associated microflora in dental plaque adjacent to orthodontic brackets retained with a glass ionomer cement (GIC) and a resin based composite was investigated using the split-mouth technique . 3, 8, and 28 days after the onset of the appliances, 48-h-old plaque was sampled . An increasing prevalence of mutans streptococci and lactobacilli in plaque from both retaining materials was found . A tendency to colonize more frequently around the composite retained brackets was noticed for both types of bacteria . The proportion of mutans streptococci in relation to the total viable count was significantly higher in plaque samples from composite retained brackets compared to GIC retained 1 month after onset of treatment . The results suggest that a less caries inducing microflora may develop when GIC is used as luting agent in orthodontic dentistry.

Scand J Dent Res, 1992 Jun, 100(3), 137 - 9
Sweets and other sugary products tend to be the primary etiologic factors in dental caries; Sundin B et al.; The aim of this study was to analyze the relationships between caries incidence and each of seven caries-related factors in a group of 15- to 18-yr-olds as well as in single and combined subgroups representing favorable or less favorable fractions of six of the factors . Sixty-nine 18-yr-olds were interviewed about consumption of sweets and other sugar-containing products during the past 3 yr and examined for oral hygiene, salivary counts of mutants streptococci and lactobacilli, salivary flow rate and oral sugar clearance time at the ages of 15 and 18 . Simple linear correlations and a stepwise multiple regression analysis were used to compare ranks and explanatory values . The highest correlations were obtained for intake of sweets and intake of other sugary products, with r values increasing from 0.25 and 0.16, respectively, in the total material to 0.70 and 0.67 in less favorable fractions of oral hygiene, salivary flow rate and other sugary products in the former case, sweets in the latter . The stepwise multiple regression analysis revealed that sweets and other sugary products contributed 12 percentage points to the total explanatory value, which was as low as 19%.

Community Dent Oral Epidemiol, 1992 Jun, 20(3), 138 - 43
Effect of conventional dental restorative treatment on bacteria in saliva; Wright JT et al.; Dental caries results from the dissolution of mineralized dental tissues by the metabolic by-products of oral bacteria colonizing the surface of teeth . The principal modality for dealing with this infectious process is through restorative treatment which removes the pathologic tissue and replaces it with a variety of inert materials . The purpose of this study was to evaluate the effect of traditional restorative treatment on select oral bacterial populations . Fifty-two females demonstrating high levels of mutans streptococci (greater than or equal to 2.5 x 10(4) colony forming units (cfu) per ml saliva) with no more than four missing posterior teeth were recruited for this study . Salivary levels of mutans streptococci, lactobacilli, total streptococci, and total cultivable bacteria were evaluated before, during, and after restorative treatment . Initial DMFS scores were established by two standardized examiners using bitewing radiographs and clinical examination, which was conducted under optimal conditions . All restorative treatment was completed by faculty members of the University of Alabama School of Dentistry using treatment plans developed by the DMFS examiners . The participants received a mean of 16.4 restored surfaces, which resulted in significant reductions of all the bacterial populations tested . All microbial populations monitored were predicted to return to their baseline levels within 151 days after restorative treatment in 50% of the participants . This study shows that conventional restorative treatment results in a significant reduction of bacterial populations including those associated with the dental caries process, i.e., mutans streptococci and lactobacilli.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1992 Jun, 58(6), 2034 - 9
Protein-mediated adhesion of Lactobacillus acidophilus BG2FO4 on human enterocyte and mucus-secreting cell lines in culture; Coconnier MH et al.; The adhesion of Lactobacillus acidophilus BG2FO4, a human stool isolate, to two human enterocytelike cell lines (Caco-2 and HT-29) and to the mucus secreted by a subpopulation of mucus-secreting HT29-MTX cells was investigated . Scanning electron microscopy revealed that the bacteria interacted with the well-defined apical microvilli of Caco-2 cells without cell damage and with the mucus secreted by the subpopulation of HT29-MTX cells . The adhesion to Caco-2 cells did not require calcium and involved an adhesion-promoting factor that was present in the spent supernatant of L . acidophilus cultures . This factor promoted adhesion of poorly adhering human Lactobacillus casei GG but did not promote adhesion of L . casei CNRZ 387, a strain of dairy origin . The adherence components on the bacterial cells and in the spent supernatant were partially characterized . Carbohydrates on the bacterial cell wall appeared to be partly responsible for the interaction between the bacteria and the extracellular adhesion-promoting factor . The adhesion-promoting factor was proteinaceous, since trypsin treatment dramatically decreased the adhesion of the L . acidophilus strain . The adhesion-promoting factor may be an important component of Lactobacillus species that colonize the gastrointestinal tract.

Appl Environ Microbiol, 1992 Jun, 58(6), 2005 - 10
1,3-Propanediol:NAD+ oxidoreductases of Lactobacillus brevis and Lactobacillus buchneri; Veiga-da-Cunha M et al.; In the cofermentation of glycerol with a sugar by Lactobacillus brevis and Lactobacillus buchneri, a 1,3-propanediol:NAD+ oxidoreductase provides an additional method of NADH disposal . The enzyme has been purified from both L . brevis B22 and L . buchneri B190 and found to have properties very similar to those reported for the enzyme from Klebsiella pneumoniae . The enzymes required Mn2+ and are probably octamers with a molecular mass of 350 kDa . Although not absolutely specific for 1,3-propanediol when tested as dehydrogenases, the enzymes have less than 10% activity with glycerol, ethanol, and 1,2-propanediol . These properties contrast sharply with those of a protein isolated from another Lactobacillus species (L . reuteri) that ferments glycerol with glucose and previously designated a 1,3-propanediol dehydrogenase.

Appl Environ Microbiol, 1992 Jun, 58(6), 1992 - 5
Growth phase, cellular hydrophobicity, and adhesion in vitro of lactobacilli colonizing the keratinizing gastric epithelium in the mouse; Savage DC; Lactobacillus strains of numerous species isolated from several animal sources exhibited cellular hydrophobicities that differed from those expected on the basis of their abilities to colonize the keratinizing stratified squamous epithelium in the mouse stomach . Cells of Lactobacillus fermentum 100-33, grown to either exponential or stationary phase, were strongly hydrophilic . By contrast, cells of L . fermentum RI and six transformant derivatives of strain RI and 100-33, strains DM101 through DM106, were hydrophobic to various degrees in either growth phase . Most of them were less hydrophobic, however, when in the stationary phase than in the exponential phase . Cells of strains RI and 100-33 in the exponential phase adhered in the same number in vitro to disks of keratinized mouse gastric mucosa . By contrast, when in stationary phase, strain RI and two transformants, DM103 and DM104, adhered to the surface in higher numbers than 100-33 . In contrast to their cellular progenitor, 100-33, the transformant strains share with their DNA donor, RI, the capacity to colonize the keratinizing gastric epithelium in mice . These findings indicate that lactobacilli able to colonize the surface of the keratinocytes in the murine stomach can adhere to that surface by either hydrophilic or hydrophobic molecules.

Infect Immun, 1992 Jun, 60(6), 2375 - 9
Mouse intravaginal infection with Trichomonas vaginalis and role of Lactobacillus acidophilus in sustaining infection; McGrory T et al.; Recent work with a mouse model of Trichomonas vaginalis infection indicated that only 25% of mice harbor Lactobacillus spp . and that T . vaginalis infection rates fall rapidly after 7 days postinfection . In women infected with T . vaginalis, there is a disruption of the Lactobacillus population, which usually predominates . In an attempt to establish a better mouse intravaginal infection that resembles human disease, we established Lactobacillus acidophilus in estrogenized BALB/c mice . T . vaginalis was then inoculated intravaginally into mice previously infected with L . acidophilus and into mice in an untreated group . From 52 mice, 50-microliters vaginal washes were collected, cultured, and examined daily for live trichomonads after inoculation . Although initial infectivity in the two groups was comparable (79 to 83%), L . acidophilus-infected mice showed greater duration of infection . At day 24 postinfection, 69% of L . acidophilus-infected mice were still infected with T . vaginalis compared with only 11% of untreated mice (P = 0.002) . The addition of L . acidophilus did not significantly alter the resident mouse vaginal flora . By the addition of L . acidophilus, the mouse will be valuable for studying factors involved in T . vaginalis infectivity and pathogenicity.

APMIS, 1992 Jun, 100(6), 543 - 52
In vitro activity of teicoplanin and vancomycin against gram-positive bacteria from human clinical and veterinary sources; Jensen KT et al.; The minimum inhibitory concentration (MIC) of teicoplanin and vancomycin was determined by the agar dilution method for 186 Gram-positive bacteria from human clinical and veterinary sources . Teicoplanin MIC values were less than or equal to 4 micrograms/ml for 94% of staphylococci (group A, n = 52) and less than or equal to 2 micrograms/ml for all streptococci, enterococci, aerococci and pediococci (group B, n = 75) . Seventy-eight percent of Gram-positive rods, Rhodococcus and Leuconostoc spp . (group C, n = 59) were inhibited by 4 micrograms/ml . Teicoplanin resistance (MIC greater than or equal to 16 micrograms/ml) was demonstrated for all Nocardia strains and for some strains of Lactobacillus, E . rhusiopathiae, Leuconostoc, and S . haemolyticus . Cross-resistance between teicoplanin and vancomycin was observed for all Nocardia strains and for some strains of Lactobacillus, E . rhusiopathiae, and Leuconostoc . Three methicillin-resistant S . haemolyticus strains were either resistant or intermediately susceptible to teicoplanin and susceptible to vancomycin . Eight strains (motile enterococci four, E . rhusiopathiae three and Leuconostoc sp . one) were susceptible to teicoplanin and resistant to vancomycin . Teicoplanin disc diffusion on Danish Blood Agar with NeoSensitabs (Rosco), PDM AB Biodisc and locally prepared discs revealed a wide range of zone diameters in groups B and C . The relation between MIC values and zone diameters for teicoplanin was analysed by the error-rate bounded method . Zone size interpretive criteria as suggested by the manufacturers (greater than or equal to 15 mm) produced 2.7% (95% confidence limits 0.9-6.2%) and 1.6% (95% confidence limits 0.3-4.6%) very major errors for NeoSensitabs and PDM-disc, respectively . Using a zone size breakpoint for susceptibility of greater than or equal to 25 mm for NeoSensitabs and greater than or equal to 20 mm for PDM-disc, the proportions of very major errors were 0.5% (95% confidence limits 0.0-3.0%) at the expense of 5.9% (95% confidence limits 3.0-10.3%) indeterminate strains that belonged to E . rhusiopathiae, Leuconostoc, Lactobacillus and S . haemolyticus . However, using these zone size breakpoints five major errors (beta-haemolytic streptococci, group B three, S . aureus one, Leuconostoc sp . one) were observed for NeoSensitabs and two major errors (beta-haemolytic streptococcus, group B one, Leuconostoc sp . one) were observed for PDM-disc . Susceptibility testing against teicoplanin among these taxa should therefore include a determination of MIC.

Int J Food Microbiol, 1992 Jun, 16(2), 167 - 72
Classification of ropy slime-producing lactic acid bacteria based on DNA-DNA homology, and identification of Lactobacillus sake and Leuconostoc amelibiosum as dominant spoilage organisms in meat products; Makela P et al.; The classification of lactic acid bacteria able to cause ropy slime on vacuum-packed cooked meat products was carried out based on DNA-DNA homology . The ropy slime-producing lactobacilli were identified as strains of Lactobacillus sake and the ropy slime-producing leuconostocs, such as Leuconostoc amelibiosum and Leuconostoc mesenteroides.

Int J Food Microbiol, 1992 Jun, 16(2), 141 - 51
Identification and characterization of two bacteriocin-producing strains of Lactococcus lactis isolated from vegetables; Uhlman L et al.; Isolated from mixed salad and fermented carrots, 123 strains of lactic acid bacteria were screened for bacteriocin production . Two strains, D53 and 23, identified as Lactococcus lactis by DNA-DNA hybridizations, produced heat stable bacteriocins which were resistant to trypsin and pepsin, but were inactivated by alpha-chymotrypsin and proteinase K . The bacteriocins were active from pH 2 to 9 and inhibited species of Listeria, Lactobacillus, Lactococcus, Pediococcus, Leuconostoc, Carnobacterium, Bacillus and Staphylococcus . Strain D53 produced bacteriocin at pH values of 4.5-8.0 and from 10 to 37 degrees C.

Oral Surg Oral Med Oral Pathol, 1992 Jun, 73(6), 670 - 6
Effects of total body irradiation on salivary gland function and caries-associated oral microflora in bone marrow transplant patients; Jones LR et al.; Forty-one cancer patients who received chemoradiotherapy conditioning with bone marrow transplantation were examined for changes in salivary gland function and caries-associated oral microflora . Salivary flow rates (stimulated and unstimulated) and Streptococcus mutans levels decreased after pretransplant cytoreductive therapy and posttransplant prophylactic antibiotic therapy . Normal levels returned with time after the patients left the protected environment . Lactobacillus counts were not affected . Chronic graft-versus-host disease did not significantly influence saliva production . Results indicate that irradiation is probably the major factor responsible for the transient xerostomia.

Antibiot Khimioter, 1992 Jun, 37(6), 12 - 5
{Antibiotic resistance of Lactobacillus strains}; Kozlova EV et al.; One hundred and thirty six Lactobacillus strains isolated from poultry and 23 Lactobacillus strains isolated from long-living persons were tested for their antibiotic sensitivity . Occurrence of some type determinants of resistance to aminoglycoside antibiotics and tetracyclines in the Lactobacillus strains resistant to these antibiotics was studied . The majority of the strains from the both collections were resistant to aminoglycosides (73 and 79 per cent, respectively) . The isolates from the poultry were characterized by multiple resistance . The isolates from the long-living persons were most frequently resistant to one of two antibiotics . All the tested Lactobacillus strains isolated from the long-living persons were sensitive to tetracyclines . The species composition of the isolates was different . The antibiotic-resistant strains were detected in all the species involved in the study . By hybridization of Lactobacillus colonies with the probes containing various genes of the resistance it was shown that in 14 per cent of the antibiotic-resistant strains belonging to Lactobacillus the antibiotic resistance was controlled by the genes homologous to resistance genes widely distributed in gramnegative organisms . This indicated a possible wide exchange and heterologous expression of the antibiotic resistance determinants between microorganisms of various taxonomic groups.

Enferm Infecc Microbiol Clin, 1992 Jun-Jul, 10(6), 340 - 4
{Epidemiological factors and vaginal flora changes in vaginal bacteriosis (bacterial vaginosis)}; Munoz Bellido JL et al.; BACKGROUND: The aim of this study was to know the modifications of the vaginal bacterial flora that occurs in bacterial vaginosis and to know the involvement of these microorganisms and the influence of several epidemiologic factors in the etiology of this disease . METHODS: We studied, by using semiquantitative cultures and GLC, vaginal washings from 50 healthy women and 50 women with bacterial vaginosis . RESULTS: The most remarkable results were the high sensitivity of Amsel's criteria and their good correlation with GLC . Women with bacterial vaginosis showed a great increase of CFUs/ml of Gardnerella vaginalis, Mycoplasma hominis, Ureaplasma urealyticum and several species of anaerobic bacteria, and an important decrease of the amounts of aerobic lactobacilli . The main epidemiologic factor among those that were studied was the use of IUDs . CONCLUSIONS: The appearance of bacterial vaginosis is associated with the increase of the amounts of G . vaginalis, Bacteroides or related genera (Prevotella, Porphyromonas), and probably M . hominis and U . urealyticum, also being associated to a decrease of the amounts of aerobic lactobacilli . These facts are probably related with alteration in the ecologic relationship lactobacilli/G . vaginalis/anaerobic bacteria.

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