Schweiz Monatsschr Zahnmed, 1991, 101(8), 993 - 6 {The determination of caries risk in schoolchildren based on microbiological-chemical analyses of the saliva and on the clinical dental status}; Brandle CR et al.; In a feasibility study for the determination of the caries risk in children by whole school class, the number of the colony forming units of mutans streptococci and lactobacilli in the stimulated saliva, the buffer capacity of the saliva and some chosen clinical indicators of increased caries risk were determined and evaluated in 103 schoolchildren (7 to 10 years old) in the city of Zurich . Mutans streptococci in the saliva were found in 73% of the children and lactobacilli in 77% . In 11% of the children, neither of the microorganisms were found . Sixty-three percent of the children showed a strong buffer capacity of the saliva and 12% a small one . On the basis of these results and some selected clinical factors, 30% of the children were classified as patients with a high caries risk and are now following an intensive prophylaxis program. Folia Microbiol (Praha), 1991, 36(3), 246 - 8 Effect of age, amount of inoculum and inoculation medium composition on lactic acid production from glucose by Lactobacillus casei subsp . rhamnosus; Martinkova L et al.; Effect of composition of the medium used for the inoculum cultivation, of the age and amount of the inoculum was investigated using a 3-L glass fermentor with a working volume of 1 L . The highest productivity of the culture was obtained when using a 20% (V/V) 1-d inoculum grown in the MRS medium . Yields of lactic acid were 88-97%, while the L(+)-isomer represented about 80% of the total product. Arch Oral Biol, 1991, 36(7), 549 - 52 Effects of low-dose oral contraceptives on female whole saliva; Laine M et al.; The composition and flow rate of paraffin-stimulated whole saliva were analysed in 22 women, of whom 11 used oral contraceptives and 11 did not . Ten men served as the controls . The salivary samples were collected during one month (oral contraceptive users and men), or during one menstrual cycle (non-users) . The saliva analyses included flow rate, pH, buffer effect, sialic acid, thiocyanate, peroxidase, lysozyme, amylase, immunoglobulins A, G and M, total protein, mutans streptococci, lactobacilli, yeasts and total numbers of aerobic bacteria . The salivary buffer effect of oral contraceptive users was significantly (p less than 0.005) higher than that of non-users . All the other constituents showed intra- and interindividual variation in all groups, but with no apparent hormone-dependencyPIP: The flow rate and composition of whole saliva were analyzed in 11 women using low dose oral contraceptives in comparison with 11 menstruating women and 10 men . Paraffin-stimulated whole saliva samples were collected Monday, Wednesday and Friday mornings for 1 cycle or 1 month in all subjects, checked for pH and buffer effect (Dentobuff method, Orion Diagnostics, Espoo, Finland, a measure of bicarbonate content) immediately, and frozen for later assay of salivary lysozyme, amylase, peroxidase, thiocyanate, sialic acid, total protein, IgA, IgG, IgM, Mutans streptococci, Lactobacilli, yeasts and aerobic bacteria . The oral contraceptives taken were Marvelon (Organon, Holland) by 4 subjects, Microgynon (Leiras, Finland) by 1, and Trikvilar (Leiras) by 6 . The only significant differences between subject groups of cycle phases was a higher salivary buffer effect in oral contraceptive users than that seen in non-users, who resembled male controls . There was a wide individual variation in most values, but less variation in pH and buffer effect . Salivary buffer effect, which is correlated with HCO3-content and salivary flow, is also higher in late pregnancy . Proc Finn Dent Soc, 1991, 87(4), 659 - 70 Experience and views of caries research and oral health; Luoma H; The main clinical and theoretical studies on caries etiology and prevention and on general health published by the author and his coworkers since the beginning of the 1960s are briefly reviewed . Among the caries prevention methods published by previous authors, the Finnish trials on fissure sealing and fluoride varnishing showed distinct preventive effects . On the basis of these and later supporting findings, these methods were rapidly and widely adopted in the dental health care of Finnish children and adolescents . A chlorhexidine-fluoride mouthrinsing solution, developed by the author, exhibited simultaneous reduction of both caries and gingivitis among high -risk children and this preparation or chlorhexidine-fluoride gels have been widely prescribed for risk subjects, especially those with a caries risk . Despite the good caries prevention results obtained through fluoridation of sugar products and in respective model studies, this procedure has not been passed for commercial use in Finland . The translocation of phosphorus, potassium and fluoride between microbes of dental plaque origin and their environment, including the respective elements of enamel origin, were presented as a partial explanation for the role of phosphates and fluoride in caries etiology and/or prevention . Animal experiments elucidated the killing mechanism of a high single fluoride intake and its prevention by magnesium with explanatory changes in cardiac calcium . On the other hand, experiments on prolonged intakes of low dietary fluoride by rats confirmed earlier findings on the potential of fluoride in preventing calcium salt imbalances in internal organs . This was accomplished with a fluoride intake sufficient for caries reduction . The ability of two strains of the mutans streptococci and a Lactobacillus to invade enamel and dentine and to destory these structures from the inside before the cavitation phase of caries was demonstrated with gnotobiotic rats . The marked caries reduction among Finnish children and adolescents within the past 20 years appears to be due to a number of factors. Proc Finn Dent Soc, 1991, 87(4), 515 - 25 Sugar, fluoride, pH and microbial homeostasis in dental plaque; Marsh PD; Factors that may contribute to the maintenance or breakdown of the oral microflora have been studied in the laboratory using a mixed culture chemostat system . Carbohydrate type had relatively little influence of the proportions of individual species at neutral pH . In contrast, when the pH was allowed to fall following carbohydrate metabolism, the stability of the microflora was markedly perturbed . The proportions of Streptococcus mutans, Lactobacillus casei and Veillonella dispar increased and they became the predominant species, while levels of other Gram-negative organisms and S . gordonii declined . Low levels (1 mmol/l) of sodium fluoride (NaF) had little effect on the microflora at neutral pH . However, when the pH fell following carbohydrate metabolism, 1 mmol/l of NaF slowed acid production and, in so doing, reduced the inhibition of acid-sensitive species, and suppressed the selection of S . mutans under otherwise favourable conditions . These data (and others) suggest that the mode of action of fluoride in human beings might include a subtle but clinically significant antimicrobial effect . These findings have also led to the proposal of a modified hypothesis (the "ecological plaque hypothesis") to explain the role of the resident oral microflora in dental disease . The hypothesis also has implications for treatment and prevention strategies. Klin Khir, 1991, (9), 50 - 2 {Surgical treatment of acute bacteroid purulent cholangitis}; Panov VA et al.; The results of treatment of 40 patients with acute purulent cholangitis developed against the background of choledocholithiasis are presented . Bacteroid of the kind B . fragilis (67.5% of cases), Fusobacterium, Lactobacillus sp . (30%) are the leading etiological factor of cholangitis . The indications for external and internal drainage of the bile ducts are substantiated . The ineffectiveness of internal drainage in this disease is demonstrated. Gynakol Rundsch, 1991, 31(3), 153 - 60 {Vaccination against nonspecific bacterial vaginosis . Double-blind study of Gynatren}; Siboulet A; 167 patients suffering from nonspecific bacterial vaginoses were vaccinated in a double-blind, randomized, placebo-controlled trial . It appeared, during the study period of 14 months, that the vaccination with Gynatren, a lactobacillus vaccine, was significantly better than the placebo as concerns its therapeutical effect, but mainly as concerns its preventive effect (less reinfections) . The vaccine was very well tolerated . We conclude that vaccination with Gynatren is an effective measure to prevent recurrences of nonspecific vaginosis. Caries Res, 1991, 25(5), 377 - 84 Factors associated with active and inactive root caries in patients with periodontal disease; Ravald N et al.; The aim of this study was to analyze a number of microbial, salivary, and dietary factors in patients with clinically active and inactive root caries . 147 patients, aged 30-78 years, referred for specialist treatment of periodontal disease, were randomly selected . 645 decayed and 539 filled root surfaces were found . Out of the carious lesions, 372 (58%) were recorded as clinically active and 273 (42%) as inactive . 30 patients showed no lesions (group 1), 46 had only fillings or inactive lesions (group 2), and 35 showed 1-2 (group 3) and 36 greater than or equal to 3 active lesions (group 4) . The lactobacillus count differed significantly between all groups, except group 1 vs . 2, and the mutans streptococcus count between groups 1 vs . 4 and 2 vs . 3 and 4 . Group 4 differed in plaque score from the other groups, and the salivary buffer effect differed between the inactive groups 1 and 2 and the active group 4 . By stepwise multiple regression analysis, it was shown that lactobacillus count, plaque index, salivary buffer effect, dietary habit index, and number of exposed root surfaces contributed significantly to the coefficient of determination. Lab Delo, 1991, (3), 78 - 9 {A nutrient medium for isolating Lactobacilli}; Abrosimova NA et al.; The composition of and method for preparation of nutrient medium for the isolation of Lactobacilli from biologic material are described . The medium is simple to prepare, consists of only Soviet reagents, this making it available for laboratories in this country. Biomed Mater Eng, 1991, 1(2), 115 - 25 Rapid counting method of living cells by fluorescent enzyme substrates; Sugata K et al.; The 5(and 6)-carboxyfluorescein diacetate (C-FDA) is used for a rapid and continuous counting of living cells . Nonfluorescent C-FDA is converted into fluorescent 5(and 6)-carboxyfluorescein (C-F) by the reaction with esterase, which is an enzyme of living cells . The conversion makes it possible to count the number of living cells by detecting fluorescence . Experimental results show that the living cells of beer's yeast, E . coli, and Lactobacillus bulgaricus can be detected by fluorescence . The flow cell system was used to experiment a continuous detection of living cells, so that the number of living cells of beer's yeast can be detected continuously . The proposed method can be applied to the on-line counting in the food plants. J Biol Chem, 1990 Dec 25, 265(36), 22561 - 8 Molecular cloning and DNA sequence of lacE, the gene encoding the lactose-specific enzyme II of the phosphotransferase system of Lactobacillus casei . Evidence that a cysteine residue is essential for sugar phosphorylation; Alpert CA et al.; The gene coding for the lactose-specific Enzyme II of the Lactobacillus casei phosphoenolpyruvate-dependent phosphotransferase system, lacE, has been isolated by molecular cloning and expressed in Escherichia coli . The DNA sequence of the lacE gene and the deduced amino acid sequence are presented . The putative translation product comprises a hydrophobic protein of 577 amino acids with a calculated molecular mass of 62,350 Da . The deduced polypeptide has a high degree of sequence similarity with the corresponding lactose-specific enzymes II of Staphylococcus aureus and Lactococcus lactis . The sequence surrounding cysteine 483 was strongly conserved in the three proteins . The identity of the lacE product as the Enzyme IIlacL.casei was demonstrated by in vitro lactose phosphorylation assays using the protein expressed in E . coli . Single replacement of each of the histidine and cysteine residues by site-directed mutagenesis pointed to cysteine 483 as an amino acid residue essential for the phosphoryl group transfer reaction. J Biol Chem, 1990 Dec 25, 265(36), 22554 - 60 Characterization of the lactose-specific enzymes of the phosphotransferase system in Lactococcus lactis; de Vos WM et al.; The plasmid-encoded lactose genes of the Lactococcus lactis phosphotransferase system encoding Enzyme IIIlac (lacF) and Enzyme IIlac (lacE) have been identified and cloned in Escherichia coli and L . lactis . Nucleotide sequence and transcription analysis showed that these genes are organized into a lactose-inducible operon with the gene order lacF-lacE-lacG-lacX, the latter two genes encoding phospho-beta-galactosidase and a 34-kDa protein with an unknown function, respectively . The lac-operon is immediately followed by an IS element that is homologous to ISS1 . Enzyme IIIlac was purified from L . lactis and determination of its NH2-terminal sequence demonstrated that the lacF gene starts with a TTG codon and encodes a 105 amino acid protein (Mr = 11416) . Cross-linking studies with the purified enzyme showed that Enzyme IIIlac is active as a trimer . A mutant lacF gene was identified in strain YP2-5 and appeared to encode Enzyme IIIlac containing the missense mutation G18E . The lacF gene could be expressed under control of vector-located promoter sequences resulting in overproduction of Enzyme IIIlac in E . coli and complementation of the L . lactis lacF mutant YP2-5 . The deduced amino acid sequence of Enzyme IIlac consists of 586 amino acids (Mr = 61562) and shows the characteristics of a hydrophobic, integral membrane protein . The deduced primary structures of the L . lactis Enzyme IIIlac and Enzyme IIlac are homologous to those of Staphylococcus aureus (72 and 71% identity, respectively) and Lactobacillus casei (48 and 47% identity, respectively) . In contrast, the organization of the lactose genes differs significantly between those Gram-positive bacteria . Heterogramic homology in specific domains was observed between the derived amino acid sequences of the lactose-specific enzymes and that of E . coli Enzyme IIIcel and Enzyme IIcel, which suggest a common function in the transport and phosphorylation of these structurally related beta-glucosides. Semin Dermatol, 1990 Dec, 9(4), 300 - 4 Microbiology of specialized skin: the vulva; Elsner P et al.; Human vulvar skin is an example of specialized skin . This is not only true for its gross and microscopic anatomy and physiology, but also for its microbiology . To the microbiologist, the vulva consists of several distinct ecotopes . These are defined by the physical factors, especially occlusion, nutrient factors, and by the close proximity to the vagina, the urethra, and the anus, which may result in contamination with the flora typical for those sites . Of the vulva ecotopes, only the labia majora have been seriously studied . The microbial flora of the labia majora is characterized by a high density of microorganisms, as is typical for occluded areas of the body, by the presence of organisms common for intertriginous skin such as gram-negative rods, and by the carriage of organisms unique for the vulva and probably related to urethral and vaginal flora such as the nonpathogenic neisseria, lactobacilli, and Gardnerella vaginalis . Finally, the labia majora skin is a preferred site of Staphylococcus aureus carriage that can be of clinical and epidemiological relevance. J Clin Microbiol, 1990 Dec, 28(12), 2621 - 6 Coaggregation of oral Candida isolates with bacteria from bone marrow transplant recipients; Hsu LY et al.; In vitro coaggregation between Candida species isolated from immunosuppressed bone marrow transplant recipients and oral bacteria was investigated . Each Candida strain showed a different pattern of coaggregation with the 22 bacterial strains studied . Two strains of Lactobacillus amylovorus isolated from separate bone marrow transplant patients and Fusobacterium nucleatum (VPI 10197) coaggregated with all Candida strains . Ten bacterial strains showed no coaggregation with the Candida strains . A variety of inhibition patterns were observed when coaggregating strains were first incubated with various sugars or subjected to heat treatment . Positive and negative results were generally consistent with all Candida strains . On the basis of the culture characteristics of the oral rinse specimens, relationships between the colonization of bacteria and yeasts and in vitro coaggregation were suggested. Am J Gastroenterol, 1990 Dec, 85(12), 1646 - 8 Liver abscess complicating intratumoral ethanol injection therapy for HCC; Isobe H et al.; We report a patient who developed multiple liver abscesses and sepsis caused by lactobacilli after the percutaneous intratumoral injection of ethanol for hepatocellular carcinoma . We diagnosed the liver abscess at an early stage because of a the finding of gas on ultrasound and computed tomography . Blood cultures grew Gram-positive rods, which were of the Lactobacillus species . The patient responded to the administration of antibiotics, and his hepatic tumors have not recurred in the 7 months since treatment . This is the first report of liver abscess following percutaneous ethanol injection therapy. An Fac Odontol, 1990 Dec, (26), 43 - 8 {Evaluation of a new colorimetric test (VIP) to determine the presence of lactobacillus in saliva}; Yorio VP et al.; This techniques using Rogosa agar modificated with green of bromocresol, placed into tubes (10 ml) containing 4 ml, was developed for qualitative estimation in saliva of lactobacilli in a quick form . We spotted with a pipette 0.1 ml of saliva dilution into different tubes with the culture medium previously mentioned . The tubes were incubated at 37 degrees C for 24 and 48 hours . The results obtained showed a great agreement with the number of latobacilli in the agar. An Fac Odontol, 1990 Dec, (26), 27 - 31 {Comparative study of the adherence test and the Petry plaque count test of Streptococcus mutans in saliva}; Pivel L et al.; The Streptococcus mutans counts--added to lactobacili depicting test--are an useful instrument in cariology when determining the risk groups . In studies concerning a large number of patients the S . Mutans count in saliva test are the most accesible . Nevertheless, they are very expensive and also complicate to carry out . Simplified techniques which depict S . Mutans on the basis of adherence tests have been perfected . The most suitable from them, taking into account our working conditions, is the Matsukubo test . We deemed it interesting to correlate this test and the Gold medium count . The study has been carried out with three different populations using both techniques at the same time . As per the correlation indices obtained we conclude that the Matsukubo technique and the count have a significant correlation between them . Due to its low cost, the simplicity of its realization, as well as its easy reading it can be effectively used as a primary procedure when studying populations large in number . Through this method selection will be made of the patients to be studied applying more precise microbiological techniques. Nichidai Koko Kagaku, 1990 Dec, 16(4), 429 - 40 {Microflora around the bracket by direct bonding system}; Abe M; The purpose of the present study is to clarify the influence of microflora in plaque of the brackets edge by direct bonding system and the cause of caries that is induced around the bracket during orthodontic treatment . The subjects were selected from the patients undergoing direct bonded orthodontic treatment and from the non-orthodontic patients . They were divided into four groups: those having no orthodontic treatment (control group), those having no caries around the bracket (group A) and those having caries around the bracket (groups B and C) . Sample plaques were collected from the initial tooth surface with control group, from the tooth surface around the bracket with group A, from the carious cavity around the bracket with group B and from the non-carious tooth surface around the bracket with group C . The isolation rates of microflora in dental plaque of the four groups were compared, and the following conclusions were obtained . 1 . Group A had almost same level with control group as to the proportion of each bacterium examined by shape and gram stain of microbiota . Group B had higher level of gram positive cocci than the other groups . 2 . Group A and control group had no difference as to the isolation rates of genera Streptococcus, Actinomyces and Lactobacillus . 3 . Group A had low level of S . mutans, was the same as control group . 4 . The isolation rate of each genus: 1) The isolation rate of genus Streptococcus was almost same in groups A, C and control group . Group B had higher than the other groups . 2) The isolation rate of genus Actinomyces was the highest in all groups . 3) The isolation rate of genus Lactobacillus was exceedingly low . 4) Groups B and C had significantly higher level of S . mutans group than group A and control group . Group B had significantly lower level of S . mitior than group A and control group . 5 . All four groups showed high level of biotype I, and biotype IV was observed in groups B and C . Biotype I was identified as S . mutans serotype c, biotype IV was observed as S . sobrinus serotype d. J Dent Assoc S Afr, 1990 Dec, 45(12), 503 - 6 Preservation of the quantity of lactobacilli in samples from the oral cavity; Botha SJ; Transport media for the preservation of streptococci from oral samples have been described, but a suitable transport medium for the preservation of lactobacilli in oral samples is yet to be established . In this study MRS, ROGOSA, and modifications of these media were evaluated as transport media for the quantitative preservation of oral lactobacilli . Results indicated a survival of ca . 100 per cent oral lactobacilli for both media when stored at 4 degrees C for up to 72 h . A decrease in the survival rate was obtained upon storage at -196 degrees C and growth occurred upon storage at 20 degrees C . It was evident throughout that carbohydrate-free modifications of both media best supported the quantitative survival of oral lactobacili . Carbohydrate-free modifications of both MRS and ROGOSA are therefore recommended as preservative transport media for the quantity of oral lactobacilli in oral samples for limited time periods. Oral Microbiol Immunol, 1990 Dec, 5(6), 346 - 51 Association of selected bacteria with the lesions of root surface caries; Bowden GH et al.; Plaque from the root surfaces of 165 subjects (mean age 65.5 years, 22-26 teeth/subject) was analysed for specific bacteria . Five subject groups were defined: A (DMFS 16.4), B (DMFS 55.9), C1 (DMFS 55.6), C2 (DMFS 57.0) and C3 (DMFS 48.1) . Groups C1 and C2 had unrestored root surface lesions; Group A, B and C3 were free of unrestored root caries and differed in their coronal caries experience . Streptococcus mutans was isolated more frequently from the root lesions in Groups C1 and C2 than from intact root surfaces in Group A . Streptococcus oralis, Streptococcus mitis 1 and Streptococcus sanguis were isolated more frequently from Group A . The percentage contribution that S . mutans made to plaque from lesions in Groups C1 and C2 was higher than that from plaque in Group A and Actinomyces viscosus serovar 2 contributed more to plaque in Group C1 than in samples from Group A . The percentage counts of Lactobacillus in plaque from lesions in Groups C1 and C2 were higher than those from intact roots in Groups A, B, and C3 . Subjects were also grouped on the presence of Lactobacillus and S . mutans in plaque samples . Samples with both organisms (n = 17) showed significantly higher isolation frequencies of specific strains of S . mitis 1 and also A . viscosus serovar 2 compared with samples of plaque containing S . mutans or Lactobacillus . Actinomyces naeslundii serovar 1 was not isolated from samples containing both S . mutans and Lactobacillus . The results confirm an association of S . mutans and Lactobacillus with root surface lesions and suggest a relationship between lesions and A . viscosus serovar 2. Indian J Med Res, 1990 Dec, 92, 431 - 2 Preliminary observations on effect of Lactobacillus sporogenes on serum lipid levels in hypercholesterolemic patients; Mohan JC et al.; Short term hypolipidemic effects of oral L . sporogenes therapy (360 million spores/day in tablet form) were studied in 17 patients with type II hyperlipidemia in an open label fixed dose trial . Total serum cholesterol (330 +/- 55 mg/dl vs 226 +/- 46 mg/dl, P less than 0.001), LDL-cholesterol (267 +/- 58 mg/dl vs 173 +/- 54 mg/dl, P less than 0.001) and total cholesterol to HDL cholesterol and LDL-cholesterol to HDL-cholesterol ratios (P less than 0.001) were reduced significantly over a period of three months . HDL-cholesterol was marginally increased (43.6 +/- 7 mg/dl vs 46.8 +/- 8.9 mg/dl, P less than 0.05); however there was no change in serum triglyceride levels. Agric Biol Chem, 1990 Dec, 54(12), 3211 - 9 Purification and characterization of an antihypertensive compound from Lactobacillus casei; Sawada H et al.; Antihypertensive compounds were purified from an extract of autologous Lactobacillus casei cell lysates . The most effective compounds were polysaccharide-glycopeptide complexes, found in the cell wall . The average molecular weight was estimated as 180,000 from gel filtration using Sephacryl S-300 . The polysaccharide moiety of the complexes consisted of glucose, rhamnose, and galactose, whereas the glycopeptide moiety consisted of N-acetylglucosamine, N-acetylmuramic acid, asparagine, glutamine, alanine, and lysine . The varieties of the components of these moieties were constant and independent of complex molecular size . When these complexes were orally administered to spontaneously hypertensive rats (SHR) and renal hypertensive rats (RHR) at doses of 1 mg/kg-body weight, systolic blood pressure (SBP) decreased by 10-20 mmHg 6 to 12 hr after administration without any change in heart rate . Appreciable hypotensive activity was lost by treating the complexes with hydrofluoric acid, which hydrolytically cleaves the phosphodiester bond between the polysaccharide and glycopeptide moiety. J Biol Chem, 1990 Nov 5, 265(31), 18776 - 9 Saturation site-directed mutagenesis of thymidylate synthase; Climie S et al.; We have subjected 12 different codons of a synthetic Lactobacillus casei thymidylate synthase (TS) gene to saturation site-directed mutagenesis to create amino acid "replacement sets" at each of those positions . The target residues were chosen because they are highly conserved and because they are important for the structure and function of the protein as indicated by solution and structural studies . The mutagenesis procedure involved excision of a fragment of the synthetic gene containing the target codon, followed by its replacement with a mixture of oligonucleotides which code for all 20 amino acids and the amber stop codon . TS mutants were identified by DNA sequencing, and catalytically active mutants were identified by genetic complementation using a Thy- strain of Escherichia coli . Only 3 of the 12 target amino acids examined were essential for TS activity; and of the 125 total mutants identified, 57 were catalytically active . These results point to a high degree of plasticity of TS in accommodating function with structural change. J Dairy Sci, 1990 Nov, 73(11), 3050 - 8 Factors controlling histamine production in Swiss cheese inoculated with Lactobacillus buchneri; Sumner SS et al.; Swiss cheese was made from raw milk inoculated with various concentrations of a histamine-producing strain of Lactobacillus buchneri . Histamine production in these cheeses was proportional to the initial number of L . buchneri present in the raw milk . The highest inoculum level tested was 10(5) L . buchneri/ml . This cheese contained 80 mg of histamine/100 g of cheese after 90 d of storage . Only 15 mg of histamine/100 g of cheese were detected after 90 d at the lowest inoculum level, 10(2) L . buchneri/ml . No histamine was detected in any of the Swiss cheese samples until after the brining stage . Perceptible growth of L . buchneri also did not occur until after the warm room treatment . Therefore, control of histamine formation in Swiss cheese requires control of the number of histamine-producing bacteria in the raw milk . A 5.5% NaCl concentration in DeMan, Rogosa, Sharpe (MRS) broth inhibited the production of histamine by L . buchneri, but the concentrations of NaCl typically found in Swiss cheese were not inhibitory . The histamine-producing isolate of L . buchneri survived heating at 49 to 80 degrees C for 10 min, suggesting that this organism would easily survive the normal heating process applied to raw milk used prior to making Swiss cheese. ASDC J Dent Child, 1990 Nov-Dec, 57(6), 428 - 32 Occlusal hidden caries: a bacteriological profile; Weerheijm KL et al.; Eleven teeth from nine patients with occlusal caries lesions beneath an apparently intact enamel surface were treated . Two dentine samples, one from the dentinoenamel junction (Sample A) and one just before all the caries appeared to be removed clinically (Sample B), were taken under aseptic conditions and examined for bacteria . In all cases, the A samples and in ten cases the B samples contained mutans streptococci, lactobacilli or both, while in ten cases the dentine after opening was soft with a light color . This suggests that we are dealing with active caries lesions, which should be treated as such . The salivary data of the patients group were compared with the salivary data of the control group . Although the buffer capacity of the groups were not significantly different (chi-square), further analysis revealed that a significant relationship could be found between the group and the buffer capacity (Kendall's Tau C) . While the other salivary components (numbers of mutants streptococci per ml saliva and the secretion rate) showed no significant differences . Unfortunately these occlusal caries lesions are not detected with the present criteria used in epidemiological surveys. J Dent Res, 1990 Nov, 69(11), 1712 - 6 An intra-oral appliance study of the plaque microflora associated with early enamel demineralization; Macpherson LM et al.; An intra-oral appliance model was used to investigate the composition of the plaque microflora associated with early enamel demineralization . Enamel sections, with exposed windows, were mounted on lower removable appliances, and the devices were worn by volunteers for three-week periods under three experimental conditions . These were: (1) "normal" plaque conditions, (2) extra-oral sucrose applications nine times daily, and (3) inoculation of each volunteer's own mutans streptococci onto the test sites and sucrose applications as described for (2) . After 21 days, the plaque overlying each window was removed, and the bacterial composition was determined . Changes in mineral content of the associated enamel were measured by microradiography and microdensitometry, and the total mineral loss (delta z) that had occurred at each site was calculated . The 144 sites studied were divided into four demineralization groups by delta z value, with an increase in mineral loss from group 1 to group 4 . A progressive and significant increase in the isolation frequency of mutans streptococci occurred from delta z group 1 to group 4 sites . These organisms were isolated from the plaque of every location with enamel mineral loss of over 1000 delta z units, but were not detected in 27% of the group 3 sites . Lactobacilli comprised 2% to 3% of the total cultivable microflora in groups 1-3 sites, but were found in significantly higher proportions (18%) at those enamel sites experiencing the most extensive mineral loss (group 4) . No significant relationship was found between demineralization and the levels of Actinomyces species or Veillonella.(ABSTRACT TRUNCATED AT 250 WORDS) J Dent Res, 1990 Nov, 69(11), 1706 - 11 The effect of sucrose application and implantation of mutans streptococci on the microbial composition of three-week experimental plaque--an in situ study; Macpherson LM et al.; This study describes the predominant cultivable microflora of three-week-old plaque samples obtained from human enamel sites, on the basis of microbial identification of over 9000 fresh isolates . Lower removable appliances, on which were mounted enamel sections and slabs, were worn by five young adult subjects under three experimental protocols . These were (1) 'normal' plaque conditions, (2) extra-oral sucrose applications nine times daily, and (3) inoculation of each subject's own mutans streptococci onto the enamel test sites and sucrose applications, as described above . With the exception of slightly higher proportions of Gram-negative bacilli associated with slab plaque following sucrose application, no significant differences in percentage or absolute counts of organisms were found between normal and sucrose plaques . The inoculation of mutans streptococci, combined with extra-oral sucrose applications, was associated with significantly higher percentages and absolute mean counts of both mutans streptococci and lactobacilli, and lower proportions of S . sanguis and S . oralis . Although the isolation frequency of mutans streptococci increased in all subjects and the overall mean proportion rose following inoculation, considerable inter-subject variation was seen in mean percentage counts of these organisms isolated from the three-week plaque samples. J Bacteriol, 1990 Nov, 172(11), 6339 - 47 Cloning, expression, and nucleotide sequence of the Lactobacillus helveticus 481 gene encoding the bacteriocin helveticin J; Joerger MC et al.; Lactobacillus helveticus 481 produces a 37-kDa bacteriocin called helveticin J . Libraries of chromosomal DNA from L . helveticus were prepared in lambda gt11 and probed for phage-producing fusion proteins that could react with polyclonal helveticin J antibody . Two recombinant phage, HJ1 and HJ4, containing homologous inserts of 350 and 600 bp, respectively, produced proteins that reacted with antibody . These two phage clones specifically hybridized to L . helveticus 481 total genomic DNA but not to DNA from strains that did not produce helveticin J or strains producing unrelated bacteriocins . HJ1 and HJ4 lysogens produced beta-galactosidase fusion proteins that shared similar epitopes with each other and helveticin J . The intact helveticin J gene (hlv) was isolated by screening a library of L . helveticus chromosomal DNA in lambda EMBL3 with the insert DNA from phage HJ4 as a probe . The DNA sequence of a contiguous 3,364-bp region was determined . Two complete open reading frames (ORF), designated ORF2 and ORF3, were identified within the sequenced fragment . The 3' end of another open reading frame, ORF1, was located upstream of ORF2 . A noncoding region and a putative promoter were located between ORF1 and ORF2 . ORF2 could encode an 11,808-Da protein . The L . helveticus DNA inserts of the HJ1 and HJ4 clones reside within ORF3, which begins 30 bp downstream from the termination codon of ORF2 . ORF3 could encode a 37,511-Da protein . Downstream from ORF3, the 5' end of another ORF (ORF4) was found . A Bg/II fragment containing ORF2 and ORF3 was cloned into pGK12, and the recombinant plasmid, pTRK135, was transformed into Lactobacillus acidophilus via electroporation . Transformants carrying pTRK135 produced a bacteriocin that was heat labile and exhibited an acitivity spectrum that was the same as that of helveticin J. Zh Mikrobiol Epidemiol Immunobiol, 1990 Nov, (11), 6 - 9 {The effect of a preparation made from Solco lactobacteria on the survival rate and intestinal microflora of irradiated animals}; Bossart V et al.; Lactobacillus acidophilus strain Lat 11/83 Solco has been used for the normalization of intestinal microflora in experimental post-irradiation intestinal dysbacteriosis in mice . The results of these experiments indicate that live Solco lactobacteria, introduced intragastrically, facilitate the enhancement of the survival rate of irradiated animals and the normalization of microflora in their gastrointestinal tract . The strain can be used as bacterial preparation for the regulation of intestinal microbiocenosis. Poult Sci, 1990 Nov, 69(11), 1966 - 73 Influence of a dried Bacillus subtilis culture and antibiotics on performance and intestinal microflora in turkeys; Jiraphocakul S et al.; Two experiments, each involving a 3 x 2 factorial design, were conducted with Large White Nicholas turkeys . The first experiment involved three antibiotic treatments: an unmedicated control diet, the diet plus 44 ppm of penicillin-streptomycin (1:3), and the diet plus 44 ppm of Zn bacitracin; each diet was fed in the presence and absence of a dried Bacillus subtilis culture to females 0 to 16 wk of age . Antibiotic supplements increased body weight at 12 (P less than .05) and 16 (P less than .001) wk of age . Body weight and feed efficiency were not significantly affected by feeding the B . subtilis culture in this experiment . The dietary B . subtilis culture significantly increased B . subtilis counts in the crop and cecum but failed to influence intestinal Lactobacillus or Escherichia coli counts . The second experiment also involved three antibiotic treatments: an unmedicated control diet, 44 ppm of Zn-bacitracin, and 2.2 ppm of bambermycins, and each diet was fed in the presence and absence of the dried B . subtilis culture to male birds from 0 to 20 wk of age . Increased body weight gain was observed in birds receiving the B . subtilis culture at 12 wk (P less than .01) . Feed efficiency of birds receiving the B . subtilis culture was improved (P less than .05) at 20 wk . Birds receiving bambermycins had greater body weights (P less than .05) at 12 and 16 wk of age than birds receiving Zn bacitracin or the control diet . Livability was not affected by the B . subtilis culture or the antibiotic treatments in either experiment. J Appl Bacteriol, 1990 Nov, 69(5), 648 - 54 Antimicrobial activity of Leuconostoc gelidum against closely related species and Listeria monocytogenes; Harding CD et al.; A newly isolated strain of Leuconostoc gelidum was evaluated for its ability to inhibit a wide spectrum of lactic acid bacteria, meat spoilage bacteria and food-related human pathogens, including Listeria monocytogenes . It was inhibitory to most of the lactobacilli, all the leuconostocs, and three strains of L . monocytogenes when tested both by direct and well diffusion methods . Cell-free extract retained activity after 60 min at 100 degrees C but was sensitive to protease . Dialysis suggested a molecular weight in excess of 10(4) daltons . The inhibitory effect was bactericidal and rapid. Czas Stomatol, 1990 Nov-Dec, 43(11-12), 666 - 71 {Quantitative and qualitative characteristics of the bacterial flora of saliva and dental plaque in artificially fed children}; Szczepanska J et al.; Stomatological and bacteriological studies were carried out in 66 children aged 1-5 years divided into two groups: I--without caries, II--with carietic lesions typical of the so called "bottle caries", that is with carietic defects on the vestibular surfaces of upper incisors and on masticating surfaces of first molars . No differences of qualitative character were found in the bacterial flora of the saliva and the dental plaques in children with "bottle caries" in relation to those without caries . A significant correlation was noted between the quantity of S . mutans and Lactobacillus in the saliva or dental plaque and the intensity of caries . These results confirm the suggestions of other authors that Str . mutans plays an important role in caries and that it is the prevailing species among acid-producing flora in children with bottle caries. Biochemistry, 1990 Oct 16, 29(41), 9561 - 72 Properties of bacteriophage T4 thymidylate synthase following mutagenic changes in the active site and folate binding region; LaPat-Polasko L et al.; Amino acid replacements have been introduced in specific sites of bacteriophage T4 thymidylate synthase (T4-TS) to assess the role that these changes have on enzyme activity . Each of the conserved amino acids in the active-site region of T4-TS was modified, and the effects that these changes had on the kinetic and physical properties of this enzyme were measured . The mutations introduced were Pro-155-Ala (P155A), Cys-156-Ser (C156S), and His-157-Val (H157V) with the resulting synthases possessing kcat's of 10.3, 0.008, and 2.70 s-1, respectively, relative to that of the wild-type enzyme of 11.8 s-1 . Equilibrium dialysis was performed on the wild-type and mutant enzymes to determine the binding constants for 2'-deoxyuridylate and 5-fluoro-2'-deoxyuridylate, and while in most cases the extent of binding of these nucleotides to the mutant proteins was reduced when compared with wild-type TS, the number of binding sites involved remained about 1 or less for the binary complex and almost 2 for the ternary complex . Heat and urea stability studies revealed that the mutant with the highest enzyme activity, P155A, was the most unstable, while spectrofluorometric analyses revealed that the structures of P155A and H157V were perturbed relative to the C156S and wild-type TSs . These studies are in agreement with others implicating the phylogenetically conserved active-site cysteine as playing an essential mechanistic role in the catalytic process promoted by TS . The proximal amino acids on either side of this cysteine, although also highly conserved, do not appear to affect the catalytic mechanism directly, but may do so indirectly through their influence on the conformation at the active site as well as other regions of the enzyme . Amino acids replacements were introduced also into the folate and deoxynucleotide 5'-phosphate binding sites of the T4-phage TS to ascertain the potential role that these amino acids play in the catalytic process . These positions were selected on the basis of previous chemical modification and X-ray crystallographic studies on Lactobacillus casei TS . Amino acid residues 48 and 49, which are in the putative folate binding site, were converted from lysines to arginines; in the former case, the mutated enzyme had less than 7% of the wild-type activity while in the latter, the mutated enzyme still retained about 60% of its activity.(ABSTRACT TRUNCATED AT 400 WORDS) Biochemistry, 1990 Oct 16, 29(41), 9660 - 7 NMR studies of multiple conformations in complexes of Lactobacillus casei dihydrofolate reductase with analogues of pyrimethamine; Birdsall B et al.; 1H and 19F NMR signals from bound ligands have been assigned in one- and two-dimensional NMR spectra of complexes of Lactobacillus casei dihydrofolate reductase with various pyrimethamine analogues (including pyrimethamine {1, 2,4-diamino-5-(4'-chlorophenyl)-6-ethylpyrimidine}, fluoropyrimethamine {2, 2,4-diamino-5-(4'-fluorophenyl)-6-ethylpyrimidine}, fluoronitropyrimethamine {3, 2,4-diamino-5-(4'-fluoro-3'-nitrophenyl) -6-ethylpyrimidine}, and methylbenzoprim {4, 2,4-diamino-5-{4'- (methylbenzylamino)-3'-nitrophenyl}-6-ethylpyrimidine}) . The signals were identified mainly by correlating signals from bound and free ligands by using 2D exchange experiments . Analogues (such as 1 and 2) with symmetrically substituted phenyl rings give rise to 1H signals from four nonequivalent aromatic protons, clearly indicating the presence of hindered rotation about the pyrimidine-phenyl bond . Analogues containing asymmetrically substituted aromatic rings (such as 3 and 4) exist as mixtures of two rotational isomers (an enantiomeric pair) because of this hindered rotation and the NMR spectra revealed that both isomers (forms A and B) bind to the enzyme with comparable, though unequal, binding energies . In this case two complete sets of bound proton signals were observed . The phenyl ring protons in each of the two forms experience essentially the same protein environment (same shielding) as that experienced by the corresponding protons in bound pyrimethamine: this confirms that forms A and B correspond to two rotational isomers resulting from approximately 180 degrees rotation about the pyrimidine-phenyl bond, with the 2,4-diaminopyrimidine ring being bound similarly in both forms . The relative orientations of the two forms have been determined from NOE through-space connections between protons on the ligand and protein.(ABSTRACT TRUNCATED AT 250 WORDS) Scand J Dent Res, 1990 Oct, 98(5), 391 - 400 Root surface caries and associated factors; Fure S et al.; The prevalence of root surfaces caries in 208 randomly selected 55, 65, and 75-yr-old Swedes was related to the frequency of coronal caries, the number of remaining teeth and to bacteriologic, salivary, and dietary variables . At least one decayed or filled root surface was found in 89% of the individuals and all of those had also experienced coronal caries . The frequency of root surface caries was positively correlated to the frequency of coronal decay and negatively correlated to the number of remaining teeth and exposed root surfaces . The study shows that the same factors which are associated with enamel caries seem to be of importance in determining the development of root surface caries . The variation in the frequency of root surface caries was best explained by the salivary levels of mutans streptococci and lactobacilli, the percentage of surfaces harboring plaque and the frequency of carbohydrate intake . Other contributory factors were the saliva secretion rate and the buffer capacity. J Biochem (Tokyo), 1990 Oct, 108(4), 568 - 71 Structure of polysaccharide-peptidoglycan complex from the cell wall of Lactobacillus casei YIT9018; Nagaoka M et al.; The isolation and analysis of the polysaccharide-peptidoglycan complexes of Lactobacillus casei YIT9018 are presented . Two polysaccharide-peptidoglycan complexes, PS-PG1 and PS-PG2, were solubilized from the heat-killed cell by treatment with N-acetylmuramidase . PS-PG1 was composed of glucose, rhamnose, and small amount of galactose and glucosamine . PS-PG2 was composed of glucose, rhamnose, galactosamine, and glucosamine . The ratio by weight of these fractions was about 1:8 . PS-PG2 was analyzed in detail . Smith degradation and deamination of this complex yielded oligosaccharide units . The results of methylation analysis of these units and intact PS-PG2 led to the most probable structure of PS-PG2: (formula; see text) Int J Food Microbiol, 1990 Oct, 11(2), 127 - 34 Immunofluorescence microscopic studies on distribution of Lactobacillus kefiranofaciens and Lactobacillus kefir in kefir grains; Arihara K et al.; Immunofluorescence staining was applied to observe distribution of two Lactobacillus species in kefir grains with cauliflower floret forms . Kefiran-producing, encapsulated Lactobacillus kefiranofaciens was located all over the grain and increased toward the center, while Lactobacillus kefir populated only a small region at the surface layers. Community Dent Oral Epidemiol, 1990 Oct, 18(5), 249 - 52 Dental caries, mutans streptococci, lactobacilli, and saliva secretion rate in adults; Klock B et al.; In 718 Swedish patients, equally divided into four age groups (19-25, 26-45, 46-60, greater than 60 yr), salivary levels of mutans streptococci and lactobacilli, saliva secretion rate, and DMFS were registered . No significant differences were found between the various age groups either in salivary factors or in caries (D) . Number of missing (M) and filled (F) surfaces increased with age . Prevalence of root caries, which increased with age, was significantly correlated to number of exposed root surfaces independent of age . Of the total study group, 50% had greater than or equal to 10(6) mutans streptococci and 40% had greater than or equal to 10(5) lactobacilli per mL saliva . Three percent had a saliva secretion rate of less than or equal to 0.5 mL/min . Correlation analyses showed that both mutans streptococci and lactobacilli significantly correlated to the caries prevalence but the r-value never exceeded 0.34. Clin Microbiol Rev, 1990 Oct, 3(4), 335 - 44 Is there a role for lactobacilli in prevention of urogenital and intestinal infections? Reid G, Bruce AW, McGroarty JA, Cheng KJ, Costerton JW. This review describes the importance of microbial adhesion in the ecology of the urogenital and intestinal tracts and the influence of host and microbial factors in bacterial interference . In a recent revival of interest in bacterial interference, lactobacillus administration has been studied as a means of treating and preventing disease . Although evidence is conflicting, Lactobacillus acidophilus appears to be involved in beneficial antagonistic and cooperative reactions that interfere with establishment of pathogens in the gastrointestinal tract . The mechanisms of action are believed to involve competitive exclusion and production of inhibitory substances, including bacteriocins . These characteristics, as well as demonstrated adherence abilities in vitro, led to selection of certain Lactobacillus strains for clinical studies of cystitis . Weekly intravaginal Lactobacillus therapy reduced the recurrence rate of uncomplicated lower urinary tract infections in women . Use of Lactobacillus strains resistant to Nonoxynol-9, a spermicide that kills members of the protective normal vaginal flora, may have potential for use in women with recurrent cystitis using this contraceptive agent . In veterinary studies, bacterial interference by administration of probiotics has also been beneficial in disease prevention in animals . Carefully selected bacterial mixtures integrate with the gastrointestinal flora of the animals and can confer disease resistance and improve physiological function . Additional human and animal trials are needed to determine the practical, long-term usefulness of bacterial interference as a protective mechanism against infectious diseases. J Anim Sci, 1990 Oct, 68(10), 3392 - 8 Effects of microbial supplements containing yeast and lactobacilli on roughage-fed ruminal microbial activities; Dawson KA et al.; Effects of two microbial feed supplements on microbial activities in rumen-stimulating cultures and the rumens of steers fed a fescue hay-based roughage diet were evaluated . The yeast culture supplement contained Saccharomyces cerevisiae (1.4 to 4.2 x 10(9) colony-forming units {cfu}/g), whereas the mixed microbial supplement contained yeast, lactobacilli and enterococci (1.4 to 2.7 x 10(9) cfu/g, 1.2 to 2.3 x 10(9) cfu/g, and 1.5 to 2.6 x 10(10) cfu/g, respectively) . Concentrations of viable yeast cells were increased consistently in continuous cultures and rumens of steers receiving either supplement (1 g/kg of feed) . However, neither supplement consistently altered the relative concentrations of volatile fatty acids or ammonia in continuous cultures and rumens of steers . The pH tended to be greater (P = .13) in continuous cultures receiving yeast culture supplement than in cultures receiving the unsupplemented diet (6.50 vs 6.36), but pH in the rumens of steers was not affected by the supplements . Concentrations of cellulolytic microorganisms in cultures and the rumens of steers receiving supplements containing only yeast were from 5 to 40 times greater than those observed in cultures or steers receiving the unsupplemented diet . Supplements that had been treated with heat (121 degrees C for 15 min) to inactive yeast cells did not alter the concentrations of cellulolytic bacteria in rumen-stimulating cultures . These results suggest that live yeast culture supplements stimulate growth of cellulolytic microorganisms in the rumen. J Bacteriol, 1990 Oct, 172(10), 5670 - 6 Spontaneous deletion formation within the beta-galactosidase gene of Lactobacillus bulgaricus; Mollet B et al.; To investigate the genetic stability of the dairy organism Lactobacillus bulgaricus, we have analyzed 107 spontaneous mutations of the beta-galactosidase gene of this organism . Ten of these mutations were DNA rearrangements giving rise to different deletions, located predominantly within a small hot spot area . The DNA sequences of the different deletion junctions have been determined . The analysis showed that the deletions can be divided into two classes, depending on the presence of short direct-repeat sequences at the deletion endpoints and on the length of the deleted sequences . Possible mechanisms of these deletion formations and the involvement of inverted-repeat sequences that may enhance slipped DNA mispairing are discussed. Oral Microbiol Immunol, 1990 Oct, 5(5), 288 - 97 A IIIman protein is involved in the transport of glucose, mannose and fructose by oral streptococci; Bourassa S et al.; We show in this article that the transport of glucose, mannose and fructose by the phosphoenolpyruvate: mannose phosphotransferase system of oral streptococci requires the participation of a protein component that we have called IIIman . This protein was purified from Streptococcus salivarius by chromatography on DEAE-cellulose, DEAE-TSK, hydroxyapatite, and Dyematrex Green A . The purified protein migrated as a 38,900 molecular weight protein on a sodium dodecyl sulfate polyacrylamide gel . However, electrophoretic analysis of phosphoproteins and Western blot experiments indicated the presence in membrane-free cellular extracts of S . salivarius of 2 different forms of IIIman having molecular weights of 38,900 and 35,200 . The presence of the high-molecular-weight form of IIIman was observed by immunodiffusion, Western blot and phosphorylation by {32}PEP in S . salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus lactis but not in Streptococcus faecium, Staphylococcus aureus, Bacillus subtilis and Lactobacillus casei . Antibodies directed against the IIIman of S . salivarius did not react with the IIIman of Escherichia coli. Cesk Pediatr, 1990 Oct, 45(10), 587 - 90 {Immunobiologic properties of lactobacilli}; Mihal V et al.; The authors investigated in experiments on mice immunobiological properties of selected strains of lactobacilli (Lbc . acidophilus, Lbc . casei and Lbc . delbruecki) . Their immunostimulating action was evaluated from the migrating capacity of lymphocytes into the interepithelial spaces and lamina propria mucosae of the gut . The most marked changes were observed in the group of animals to whom Lbc . acidophilus and Lbc . casei was administered for two weeks by a gastric tube . The protective properties of lactobacilli on the course and development of model infections (virus of encephalomyocarditis) was greatest in mice given Lbc . casei and Lbc . acidophilus by the intraperitoneal route four days before infection . At the end of the two-week period in the Lbc . casei group 66% mice survived and in the Lbc . acidophilus group 34% . The ability of lactobacilli to influence the interferon producing activity was investigated in vitro on a model of peritoneal cells obtained from premedicated mice . The lactobacilli strains themselves did not have interferon inducing properties . However, when the interferon producing capacity of peritoneal cells was assessed after administration of the viral inducer (virus of Newcastle disease) the capacity was much higher, when compared with controls. Lett Appl Microbiol, 1990 Oct, 11(4), 214 - 9 Cloning and expression of alpha-amylase from Bacillus amyloliquefaciens in a stable plasmid vector in Lactobacillus plantarum; Jones S et al.; Lactobacillus plantarum is used in a wide range of agricultural and food fermentations . In this paper we report the introduction of alpha-amylase into the organism from Bacillus amyloliquefaciens on a stable recombinant plasmid . The genetically manipulated organism grew on MRSB medium supplemented with starch and it may be a prototype for the development of lactobacilli able to use an increased range of substrates in commercial fermentations. Gene, 1990 Sep 28, 94(1), 61 - 7 Cloning, expression and sequence analysis of an endolysin-encoding gene of Lactobacillus bulgaricus bacteriophage mv1; Boizet B et al.; The lysA gene specifying an endolysin of Lactobacillus delbrueckii subsp . bulgaricus bacteriophage mv1, was cloned and expressed in Escherichia coli . The 4.05-kb restriction fragment containing this gene was analysed by restriction and deletion mapping, and by subcloning . The nucleotide sequence of a 1150-bp fragment coding for an active lysin was determined . The lysA gene consists of 585 bp and codes for a protein of a deduced Mr of 21,120, which agrees with the size based on in vivo transcription/translation studies . The deduced amino acid sequence of the mv1 lysin (LysA) was compared to that of other known lytic enzymes . Significant homology was observed with the N-terminal portion of the muramidase of the fungus Chalaropsis and that of the muramidase of the Streptococcus pneumoniae phage Cp-1, suggesting that LysA might be a muramidase . In E . coli, the cloned lysA gene was able to complement the muramidase-defective bacteriophage lambda Ram5, proving that the products of these two genes are interchangeable . The lysA gene is preceded by an open reading frame with unknown function and no characteristic prokaryotic promoter sequences could be detected upstream from lysA, suggesting that this gene is part of an operon. Biochemistry, 1990 Sep 4, 29(35), 8063 - 9 Role of lysine-54 in determining cofactor specificity and binding in human dihydrofolate reductase; Huang S et al.; Lysine-54 of human dihydrofolate reductase (hDHFR) appears to be involved in the interaction with the 2'-phosphate of NADPH and is conserved as a basic residue in other species . Studies have suggested that in Lactobacillus casei dihydrofolate reductase Arg-43, the homologous residue at this position, plays an important role in the binding of NADPH and in the differentiation of Km values for NADPH and NADH . A Lys-54 to Gln-54 mutant (K54Q) of hDHFR has been constructed by oligodeoxynucleotide-directed mutagenesis in order to study the role of Lys-54 in differentiating Km and Kcat values for NADPH and NADH as well as in other functions of hDHFR . The purpose of this paper is to delineate in quantitative terms the magnitude of the effect of the Lys-54 to Gln-54 replacement on the various kinetic parameters of hDHFR . Such quantitative effects cannot be predicted solely on the basis of X-ray structures . The Km for NADPH for the K54Q mutant enzyme is 58-fold higher, while the Km for NADH for K54Q is only 3.9-fold higher than that of the wild type, indicating that the substitution of Lys-54 with Gln-54 decreases the apparent affinity of the enzyme for NADPH dramatically, but has a lesser effect on the apparent affinity for NADH.(ABSTRACT TRUNCATED AT 250 WORDS) Biochim Biophys Acta, 1990 Sep 3, 1040(2), 287 - 93 Purification and characterization of uridine and thymidine phosphorylase from Lactobacillus casei; Avraham Y et al.; Uridine and thymidine phosphorylases have been purified to homogeneity from crude extracts of Lactobacillus casei . Both enzymes had an apparent molecular mass of about 80 kDa . Uridine phosphorylase consisted of four identical subunits while thymidine phosphorylase was composed of two identical ones . The sequence of 23 amino-acid residues from its N-terminal end was analyzed . Uridine phosphorylase had a Km of 5.0 x 10(-3) M for uridine and 1.24 x 10(-1) M for phosphate, while thymidine phosphorylase had a Km of 1.32 x 10(-1) M for thymidine and 1.0 x 10(-1) M for phosphate . Uridine phosphorylase was equally active with uridine and 5-methyluridine, but had a low activity towards thymidine . Its activity was inhibited competitively by 3-O-methyl-alpha D-glucopyranoside, on the other hand thymidine phosphorylase activity was not affected by this compound . Thymidine phosphorylase showed specificity towards the deoxyribosyl moiety of the substrate . In addition, it required a nonsubstituted pyrimidine moiety or one which was substituted in position 5 . The pattern of the double-reciprocal plots of the initial velocities vs . the concentrations of either one of the substrates, and the product inhibition kinetics, indicated that the catalytic mechanism of both enzymatic reactions is sequential rather than Ping-Pong and that the sequence of the addition of the substrates is random (rapid equilibrium) . In the case of the uridine phosphorylase-catalyzed reaction, the products are also released randomly, while in the thymidine phosphorylase-catalyzed reaction deoxyribose 1-phosphate is released after thymine. Obstet Gynecol, 1990 Sep, 76(3 Pt 1), 407 - 13 Microbiologic efficacy of intravaginal clindamycin cream for the treatment of bacterial vaginosis; Hillier S et al.; Bacterial vaginosis is characterized by replacement of the normal Lactobacillus-predominant vaginal flora with Gardnerella vaginalis, anaerobic bacteria, and Mycoplasma hominis . The present study evaluated the vaginal flora of women with bacterial vaginosis before and after treatment with intravaginal clindamycin cream . Sixty-seven nonpregnant women with symptoms and signs of bacterial vaginosis, and without other genital tract infections, were randomly assigned to receive placebo cream or 0.1, 1, or 2% clindamycin cream . Quantitative vaginal cultures for facultative and anaerobic bacteria and genital mycoplasmas were performed at enrollment and at 4-7 days and 4-5 weeks after completion of therapy . At enrollment, G vaginalis was recovered from 99%, Bacteroides sp from 94%, Peptostreptococcus sp from 81%, and M hominis from 58% of the 67 women with bacterial vaginosis . The vaginal cultures yielded a median of 12 isolates per specimen, with equal numbers of aerobic and anaerobic species . The mean log concentration was 1.2 X 10(9) cfu/mL for aerobic and 2.6 X 10(8) cfu/mL for anaerobic bacteria . After treatment, the frequency and concentration of bacteria per milliliter of vaginal fluid decreased for G vaginalis, Bacteroides sp, Peptostreptococcus sp, and M hominis . The 2% clindamycin cream had the greatest effect on the bacterial vaginosis-associated flora and resulted in clinical resolution of bacterial vaginosis in 15 (94%) of 16 women . Treatment with lower concentrations of clindamycin cream had less effect on the vaginal flora and resulted in clinical cure in 25 (71%) of 35 women . Therapy was associated with an increase in the frequency and concentration of Lactobacillus, and a probably transient increase in the frequency of Escherichia coli and Enterococcus.(ABSTRACT TRUNCATED AT 250 WORDS) FEMS Microbiol Rev, 1990 Sep, 7(1-2), 103 - 11 Uncommon pathways of metabolism among lactic acid bacteria; London J; A small number of lactic acid bacteria possess the ability to derive energy from organic molecules not utilized by the vast majority of representatives of this large group of microorganisms . Thus, strains of Lactobacillus casei and enterococci readily grow at the expense of substrates such as gluconate, malate and pentitols . Transport of gluconate and pentitols is catalysed by phosphotransferase systems unique to these bacteria . Similarly, the initial steps in pentitol dissimilation are mediated by enzymes found only in Lb . casei and Streptococcus avium. J Appl Bacteriol, 1990 Sep, 69(3), 326 - 31 Comparison of quantitative and qualitative methods of detecting hydrogen peroxide produced by human vaginal strains of lactobacilli; Fontaine EA et al.; A quantitative method was developed for the measurement of micromolar quantities of H2O2 produced in Rogosa broth and peptonized milk broth by vaginal strains of lactobacilli isolated from women . The production of substantial amounts reproducibly was dependent on the growth of the organisms in acid media (pH less than or equal to 6.0) under anaerobic or micro-aerophilic conditions with continuous agitation . The addition to the media of the enzyme inhibitor, 3-amino-1,2,4-triazole, with or without catalase sometimes induced the production of H2O2 especially in non-agitated cultures . However, other agents such as concanavalin and o-dianisidine had no enhancing effect, and catalase or peroxidase alone completely inhibited H2O2 production . The H2O2 produced in the acid media was stable for more than a month at 5 degrees C but not in media at pH greater than or equal to 7.0 . Of five strains of lactobacilli tested by the quantitative method and by a chromogenic qualitative method (Rogosa-catalase or -per-oxidase agar), three consistently produced H2O2 measurable by the former method, but none did so after growth of the organisms on Rogosa-catalase/peroxidase agar which suggested that the qualitative method was unreliable . The fact that H2O2 was produced in substantial quantities by some strains and not at all by others enabled H2O2-producers and non-producers to be distinguished easily. J Appl Bacteriol, 1990 Sep, 69(3), 311 - 20 Lactobacilli isolated from sugary kefir grains capable of polysaccharide production and minicell formation; Pidoux M et al.; Homo- and heterofermentative species of Lactobacillus have been isolated from sugary kefir grains . Most of the homofermentative strains fermented tagatose and aldonitol and presented 48-54% of homology with Lactobacillus paracasei ssp . paracasei NCDO 151 (ex Lactobacillus casei) . The two variants of a hetero-fermentative species, although fermenting arabinose, were related to Lactobacillus hilgardii NCDO 264 (type strain) with 88% of homology . One of them produced polysaccharide from sucrose at pH 4.8 and 30 degrees C; the best glucose conversion into polysaccharide was obtained from 3% of sucrose (81.8%), and the maximum production occurred about 35 hours after the end of the log phase of growth, in MRS sucrose broth . Polysaccharide formation did not occur above 40 degrees C, a temperature at which no growth was observed . The two variants were forming minicells by abnormal divisions. Rev Infect Dis, 1990 Sep-Oct, 12(5), 856 - 72 Emerging role of lactobacilli in the control and maintenance of the vaginal bacterial microflora; Redondo-Lopez V et al.; The vaginal microflora of healthy asymptomatic women consists of a wide variety (two to five isolates at any one time) of anaerobic and aerobic bacterial genera and species dominated by the facultative, microaerophilic, anaerobic genus Lactobacillus . That the vaginal flora forms part of a dynamically changing ecosystem is evident from the variable prevalence and population levels of each bacterial species detected with repetitive longitudinal sampling, with pregnancy, and with stage in the menstrual cycle . This review emphasizes the role that vaginal lactobacilli may play in control of the vaginal microflora and maintenance of the normal state . Lactobacilli possess many antagonistic properties and produce many metabolites that may be important in maintaining dominance in the vagina . Contradictory data from previous studies regarding the impact of factors such as contraception, catamenial products, and physiologic elements on the vaginal microflora are due in part to poor study design and differences in methodology . Well-designed and controlled investigations with large numbers of individuals in each group are needed, and the limitations of the methodology for such investigations must be considered . Studies of the normal flora, exploring the interaction of lactobacilli and other bacterial species, must be performed before the pathologic processes resulting in vaginitis or systemic sequelae are investigated. FEMS Microbiol Rev, 1990 Sep, 7(1-2), 43 - 60 In vivo genetic systems in lactic acid bacteria; Gasson MJ; A review of in vivo genetic systems covers the key features of transduction and conjugation but emphasises the intramolecular and intermolecular DNA interactions that are often associated with these processes . As well as the transfer of many lactose plasmids, conjugal transfer of nisin genes and the use of conjugation to construct bacteriophage-resistant dairy starter cultures are discussed . The discovery and characterization of insertion sequences in Lactobacillus and Lactococcus and the exploitation of heterologous conjugation and transposition systems in the lactic acid bacteria are described. Arch Latinoam Nutr, 1990 Sep, 40(3), 408 - 25 {Preparation of microbial silage from fish of underutilized species}; Ottati M et al.; Fish silage was produced by microbial means from a mixture of several fish species which are not used for human consumption, and form part of the shrimp by-catch . The fish was mixed with a carbohydrate source (molasses) and a starter culture of Lactobacillus plantarum 8014 . The mixture was fermented at 30 +/- 2 degrees C . Several tests were undertaken to determine the optimal conditions and concentration of molasses (5, 10 and 15%) and Lactobacillus (0.5, 1.0, 2.5, 5.0 and 10.0%) . Results indicated that 1% of microorganisms and 15% of molasses were the optimal proportions to produce a stable fish silage . The production process and stability study of fish silage were followed through chemical, physical and microbiological tests . As findings revealed, the first six days of the process are related to acid production, pH reduction and microbial control, while after this period the process is basically related to protein hydrolysis . In addition, sensory tests of flavor and color were performed . The results of this study suggest the feasibility of utilizing this marine resource at present discarded, through a technological scheme, to produce fish silage for animal feed. FEMS Microbiol Rev, 1990 Sep, 7(1-2), 149 - 63 Antagonistic activities of lactic acid bacteria in food and feed fermentations; Lindgren SE et al.; Many factors contribute to a successful natural fermentation of carbohydrate-rich food and feed products . Metabolic activities of lactic acid bacteria (LAB) play a leading role . Their ability to rapidly produce copious amounts of acidic end products with a concomitant pH reduction is the major factor in these fermentations . Although their specific effects are difficult to quantitate, other LAB metabolic products such as hydrogen peroxide and diacetyl can also contribute to the overall antibiosis and preservative potential of these products . The contribution of bacteriocins is also difficult to evaluate . It is suggested that they may play a role in selecting the microflora which initiates the fermentation . Bacteriocins are believed to be important in the ability of LAB to compete in non-fermentative ecosystems such as the gastrointestinal tract . During the past few decades interest has arisen in the use of the varied antagonistic activities of LAB to extend the shelf-life of protein-rich products such as meats and fish . Recent findings indicate that the newly discovered Lactobacillus reuteri reuterin system may be used for this purpose. Zh Mikrobiol Epidemiol Immunobiol, 1990 Sep, (9), 3 - 6 {The determination of the antagonistic activity of Solco lactobacteria (Lactobacillus acidophilus Lat 11/83) using gnotobiotic technology}; Popova-Barzashka S et al.; Lactobacillus acidophilus strain Lat 11/83 has been used for the study of its antagonistic activity with respect to pathogenic microorganisms in experiments on conventional germ-free animals . The results of these experiments indicate that the above strain may be recommended as a highly active antagonist for the treatment and prophylaxis of intestinal dysbacteriosis of different etiology. J Appl Bacteriol, 1990 Sep, 69(3), 321 - 5 Microbiology of 'obiolor': a Nigerian fermented non-alcoholic beverage; Achi OK; Obiolor is an acidic non-alcoholic beverage prepared by fermenting sorghum and millet malts . The traditional process for the production and microbiological characteristics of the beverage were investigated . Bacillus spp., Lactobacillus plantarum and Streptococcus lactis were the associated micro-organisms most actively involved . Yeasts were present in low numbers towards the end of the fermentation . Other micro-organisms isolated did not appear to play a role in the fermentation process . Variations in the important microbial groups involved and their metabolic products were studied . Titratable acidity increased gradually until the end of the fermentation while the total soluble solids and pH declined . Acetobacter spp . were probably responsible for the unacceptability of the product after 24 h. J Appl Bacteriol, 1990 Sep, 69(3), 302 - 10 Antibacterial activity of lactic acid bacteria isolated from vacuum-packaged meats; Ahn C et al.; Lactic acid bacteria isolated from vacuum-packaged fresh meat stored at 4 degrees C were shown to produce antagonistic substances active against closely related bacteria . Growth medium, pH and growth temperature all affected the production of the inhibitory substances . Ten strains including aciduric Lactobacillus-type organisms, Carnobacterium spp . and Leuconostoc spp . were selected that produced protein-aceous substances that caused inhibition of indicator strains . These were considered to be bacteriocins or bacteriocin-like compounds based on their inactivation with protease, generally narrow spectra of antibacterial activity and bactericidal or bacteriostatic modes of action . Activity was not lost from supernatant fluids as a result of heat treatment at 62 degrees C for 30 min, except for the Leuconostoc strains . Inhibitory spectra of some strains included Enterococcus spp . and Listeria monocytogenes . Some strains were of interest because their inhibitory substances were detected in the supernatant fluid early in the growth cycle . The inhibitory substances differed in characteristics between strains and there is evidence that more than one bacteriocin-like substance may be produced by some strains. Res Microbiol, 1990 Sep-Oct, 141(7-8), 955 - 62 Oral administration of TNP-Lactobacillus conjugates in mice: a model for evaluation of mucosal and systemic immune responses and memory formation elicited by transformed lactobacilli; Gerritse K et al.; Safe live vector systems are being developed for oral delivery of antigens . A transformation system for indigenous Lactobacillus species of the gastrointestinal tract is described . Model systems were set up to evaluate immune responses . Orally administered trinitrophenylized (TNP) Lactobacillus were examined for their ability to induce immunological memory formation via determination of specific antibody titres in serum . We demonstrate a direct correlation between the level of systemic memory formation, as revealed by specific anti-TNP IgG serum antibodies, and the TNP substitution ratio of the Lactobacillus suspension used for oral priming . The specific IgG anti-TNP serum titres were comparable to or even higher than the titres of parental intraperitoneally primed animals . These results demonstrate the feasibility of using orally administered antigen-Lactobacillus as a future approach to vaccination. Br J Clin Pract Suppl, 1990 Sep, 71, 65 - 9 Bacterial vaginosis; Sobel JD; In the western world, bacterial vaginosis is now being recognised as the commonest cause of vaginitis . Bacterial vaginosis represents a major disturbance in vaginal microbiology with the massive overgrowth of predominantly anaerobic bacteria normally found in the vagina . Accordingly, high population levels of non-fragilis Bacteroides sp., peptostreptococci, Gardnerella vaginalis and Mobiluncus sp . are found, with a corresponding decline in Lactobacillus sp . Excessive polyamine production by anaerobes is responsible for the offensive vaginal discharge, and G . Vaginalis adherent to epithelial cells produces pathognomonic clue cells, which together with elevated vaginal pH constitute the hallmark of diagnosis . The pathogenesis of bacterial vaginosis remains poorly understood and the role of sexual transmission is controversial . Bacterial vaginosis may cause symptoms but is frequently asymptomatic . It is more than a nuisance vaginal infection in that (a) many patients have recurrent episodes, and (b) it has recently been associated with post-partum and post-operative fever, upper genital tract infection, amnionitis and prematurity . Therapy for symptomatic bacterial vaginosis is currently dominated by metronidazole; however, clindamycin and a host of new agents may enjoy similar success . Women with recurrent bacterial vaginosis constitute a major therapeutic problem, as do pregnant women . The cause of frequently recurring bacterial vaginosis remains obscure . New data are presented here indicating that early recurrences are due to relapse and not reinfection . No evidence has emerged that suggests that relapse is due to antimicrobial resistance. Indian Heart J, 1990 Sep-Oct, 42(5), 361 - 4 Short term hypolipidemic effects of oral lactobacillus sporogenes therapy in patients with primary dyslipidemias; Mohan JC et al.; Short term hypolipidemic effects of oral Lactobacillus sporogenes (360 million spores/day) were studied in 17 patients (mean age 45.6 years; males 15, females 2) with type II hyperlipidemia in an open label fixed dose trial . Over a period of 3 months, significant reductions were observed in total cholesterol (330 +/- 55 mg% to 226 +/- 46 mg%, p less than 0.001) and LDL-cholesterol (267 +/- 58 mg% to 173 +/- 54 mg%, p less than 0.001) . The HDL-cholesterol was marginally increased (43.6 +/- 7 mg% to 46.8 +/- 8.9 mg%, p less than 0.05) . There was no change in serum triglyceride concentration . Total cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol ratios were significantly reduced after treatment (p less than 0.001) . No adverse effect was noted . While the change in serum lipid levels on treatment was consistent with regard to total and LDL-cholesterol, it was not so in case of serum triglycerides and HDL-cholesterol . Oral Lactobacillus sporogenes therapy may prove to be an important hypolipidemic therapy after confirmation in larger trials. Am J Dent, 1990 Sep, 3 Spec No, S27 - 34 Effect of a triclosan/copolymer/fluoride dentifrice on the oral microflora; Zambon JJ et al.; Eighty-one human subjects completed a double-blind study which examined the effects of a 0.3% triclosan/2% Gantrez copolymer/0.243% sodium fluoride dentifrice on the microflora of supragingival dental plaque . Subjects were divided into an experimental group which performed normal oral hygiene with the triclosan/copolymer/fluoride dentifrice and a control group which also performed normal oral hygiene with the same dentifrice minus the triclosan/copolymer . At baseline, 10 weeks, and 28 weeks, supragingival dental plaque was collected from buccal and lingual surfaces of the four first molar teeth and assayed for: 1) bacterial morphotypes by phase contrast microscopy, 2) Actinobacillus actinomycetemcomitans, Actinomyces species, Bacteroides forsythus, Bacteroides gingivalis, Bacteroides intermedius, Streptococcus mutans, Streptococcus sanguis, and Wolinella recta by immunofluorescence microscopy, and 3) Lactobacillus, yeast, enterics, Staphylococcus, aerobes and anaerobes by bacterial culture . After 28 weeks' use of their respective dentifrices, changes in the supragingival plaque microflora of the subjects were similar between the triclosan/copolymer/fluoride dentifrice group and the control dentifrice group, except for statistically significant reductions in fusiforms, spirochetes and staphylococci and significant increases in S . sanguis in the triclosan/copolymer/fluoride dentifrice group, as compared to the control dentifrice group . The subject population was unusual in the presence of enteric species and anaerobes found in supragingival plaque sites . This study indicates that the use of a dentifrice containing 0.3% triclosan and 2% Gantrez copolymer over an extended period of time (28 weeks) does not result in shifts in the microflora of supragingival plaque favoring the growth of either opportunistic or pathogenic bacterial species. Eur J Biochem, 1990 Aug 17, 191(3), 659 - 68 The 1H-NMR assignments of the aromatic resonances in complexes of Lactobacillus casei dihydrofolate reductase and the origins of their chemical shifts; Birdsall B et al.; All the aromatic proton resonances in the 500-MHz NMR spectra of Lactobacillus casei dihydrofolate reductase have been assigned for several of its complexes with inhibitors . For the complexes with methotrexate and trimethoprim this was achieved by using a combination of NMR techniques in conjunction with a selectively deuterated protein designed to simplify the spectra such that nuclear Overhauser effect (NOE) connections could be detected with greater ease and certainty . By correlating these NOE data with crystal structure data on related complexes it was possible to assign all the aromatic resonances and to extend these assignments to spectra of other complexes of dihydrofolate reductase . The conformation-dependent chemical shifts observed for many of the resonances could be explained qualitatively, but not quantitatively, in terms of ring-current shifts . The discrepancies between calculated ring-current shifts and the observed conformation-dependent shifts could not in general be accounted for satisfactorily in terms of carbonyl-group anisotropic shielding contributions calculated using presently available models . In the case of the H delta 1, delta 2 protons of Phe30 some of the discrepancy probably results from a difference in the conformation of the Phe ring between the solution and crystal states. Scand J Dent Res, 1990 Aug, 98(4), 305 - 12 Comparative study on mineralization-related intraoral parameters in periodontitis-affected and periodontitis-free adults; Sewon L et al.; The parameters related to an intraoral mineralization tendency in periodontitis-affected (P+) and periodontitis-free (P-) study subjects (16 adults, 46-74 yr, matched for sex and age) were compared . For this purpose the calcium (Ca) and phosphate (P) concentration of both plaque and saliva, resting pH and the acidogenic response of interdental plaque, plaque wet weight, salivary flow rate, buffering capacity and sucrase activity, interdental plaque, plaque S . mutans levels as well as salivary lactobacilli and yeast levels were estimated . Plaque Ca (micrograms/mg protein, P less than 0.025) and P (micrograms/mg protein, P less than 0.05), saliva Ca (micrograms/ml, P less than 0.005) and the saliva Ca:P ratio (P less than 0.005) were higher in the P+ than in the P- group . The resting pH values were higher (P less than 0.025) and the acidogenic response of the interdental plaque was lower (P less than 0.025) in the P+ group than in the P- group . The P+ group had lower S . mutans levels in saliva and interdental plaque . No differences were found in the wet weight of plaque and in the flow rate, buffering capacity or sucrase activity of saliva between the groups . The findings of the mineralization-related parameters in the two "extreme" groups of periodontal status suggest a higher intraoral mineralization tendency in periodontitis-affected persons than in periodontitis-free subjects . Ca and P accumulation of supragingival plaque seem to be connected with low acidogenicity of plaque and high salivary Ca concentration. J Dent Res, 1990 Aug, 69(8), 1463 - 8 Association of the microbial flora of dental plaque and saliva with human root-surface caries; Van Houte J et al.; Dental plaque was obtained from one or two sound root surfaces of subjects with different degrees of root-surface caries experience . From subjects with root-surface caries, plaque samples were also obtained from either one incipient or one more advanced lesion . Proportions of the total flora were determined for total streptococci and different streptococcal species, total and different Actinomyces species, and lactobacilli . A sample of saliva was obtained from about one-third of the subjects for determination of the concentrations of mutans streptococci and lactobacilli . The main observations were: (1) Subjects without root-surface caries or restorations (group I), as compared with subjects with root-surface caries with or without restorations (group II), were characterized by having a lower prevalence and proportion of mutans streptococci and a higher prevalence and proportion of A . naeslundii in plaque on sound root surfaces; (2) subjects in group I also tended to have a lower salivary concentration of mutans streptococci and lactobacilli than subjects in group II; (3) dental plaque on sound surfaces in group II subjects contained a lower proportion of mutans streptococci than plaque associated with incipient or advanced lesions; and (4) the prevalence and proportion of lactobacilli in plaque associated with sound as well as carious root surfaces were very low . The data reinforce findings from other studies and indicate that, as for coronal caries, the plaque and saliva populations of mutans streptococci specifically are correlated positively with the presence of root-surface caries. J Bacteriol, 1990 Aug, 172(8), 4171 - 7 Characterization and purification of bile salt hydrolase from Lactobacillus sp . strain 100-100; Lundeen SG et al.; We have characterized and purified the bile salt hydrolase from Lactobacillus sp . strain 100-100 . Bile salt hydrolase from cells of the strain was purified with column and high-performance liquid chromatography . The activity was assayed in whole cells and cell-free extracts with either a radiochemical assay involving {14C}taurocholic acid or a nonradioactive assay involving trinitrobenzene sulfonate . The activity was detectable only in stationary-phase cells . Within 20 min after conjugated bile acids were added to stationary-phase cultures of strain 100-100, the activity in whole cells increased to levels three- to fivefold higher than in cells from cultures grown in medium free of bile salts . In cell-free extracts, however, the activity was about equal, 1.41 and 1.53 mumol/min per mg of protein, respectively, whether or not the cells have been grown with bile salts present . When supernatant solutions from cultures grown in medium containing taurocholic acid were used to suspend cells grown in medium free of the bile salt, the bile salt hydrolase activity detected in whole cells increased two- to threefold . Two forms of the hydrolase were purified from the cells and designated hydrolases A and B . They eluted from anion-exchange high-performance liquid chromatography in two sets of fractions, A at 0.15 M NaCl and B at 0.18 M NaCl . Their apparent molecular weights in nondenaturing polyacrylamide gel electrophoresis were 115,000 and 105,000, respectively . However, discrepancies existed in the apparent molecular weights and number of peptides detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the two forms . Both had similar substrate specificities, highest on taurodeoxycholic and glycocholic acid, and pH optima between 3.8 and 4.5 . The kinetic properties were also similar, with Vmaxs of 17 and 53 micromoles/min per mg of protein and Kms of 0.76 and 0.95 mM taurocholic acid for A and B, respectively . Therefore, whether the enzyme exists in two forms in the cells remains to be determined. Acta Odontol Scand, 1990 Aug, 48(4), 217 - 22 Effect of culture medium on acid production from sorbitol by oral bacteria; Kalfas S et al.; The fermentation of sorbitol or glucose and the acid production by strains belonging to the genera Actinomyces, Lactobacillus, and Streptococcus isolated from the predominant sorbitol-fermenting human dental plaque flora were studied in cultures in complex or defined bacteriologic broths and in saliva-based broth . The growth yields of Lactobacillus and Streptococcus in the saliva-based media and of Actinomyces in the defined broth were poor . Addition of fermentable carbohydrate to the saliva-based broth favored the growth of Streptococcus and Lactobacillus but not that of Actinomyces . The results showed obvious differences in the capacity of oral bacteria to ferment sorbitol between cultures in saliva-based and bacteriologic broths . Lactobacillus failed to utilize sorbitol when saliva was the only source of nutrients . Lower proportions of lactic and formic acids were formed from sorbitol by Actinomyces and Lactobacillus in the saliva-based than in the bacteriologic media . The findings illustrate some mechanisms possibly involved in the interactions between sorbitol and dental plaque flora. J Appl Bacteriol, 1990 Jul, 69(1), 80 - 5 Iron complexation as a tool to direct mixed clostridia-lactobacilli fermentations; Bruyneel B et al.; Iron complexation was investigated as a possible tool to give lactobacilli a competitive advantage over clostridia . The iron complexing substance tested, i.e . 2,2'-dipyridyl, was not toxic itself for clostridia, but its addition to a mixed culture of lactobacilli and clostridia resulted in a strong ecological advantage of the lactobacilli. Int J Syst Bacteriol, 1990 Jul, 40(3), 302 - 4 Lactobacillus intestinalis (ex Hemme 1974) sp . nov., nom . rev., isolated from the intestines of mice and rats; Fujisawa T et al.; The genetic and phenotypic properties of 10 strains identified as Lactobacillus intestinalis sp . nov . were examined . These strains constitute a distinct species which can be differentiated from all of the previously described homofermentative species in the genus Lactobacillus by their carbohydrate fermentation pattern . The guanine-plus-cytosine contents of their DNAs are 33 to 35 mol% . DNAs from 10 other Lactobacillus species did not exhibit significant levels of relatedness to representative strains of the new species . The name Lactobacillus intestinalis (ex Hemme) sp . nov., nom . rev . is proposed for these isolates, and strain Th4 (= ATCC 49335 = JCM 7548) is the type strain. Appl Environ Microbiol, 1990 Jul, 56(7), 2029 - 35 Isolation of a replication region of a large lactococcal plasmid and use in cloning of a nisin resistance determinant; von Wright A et al.; The replication region of a 28-kilobase-pair (kbp) cryptic plasmid from Lactococcus lactis subsp . lactis biovar diacetylactis SSD207 was cloned in L . lactis subsp . lactis MG1614 by using the chloramphenicol resistance gene from the streptococcal plasmid pGB301 as a selectable marker . The resulting 8.1-kbp plasmid, designated pVS34, was characterized further with respect to host range, potential cloning sites, and location of replication gene(s) . In addition to lactococci, pVS34 transformed Lactobacillus plantarum and, at a very low frequency, Staphylococcus aureus but not Escherichia coli or Bacillus subtilis . The 4.1-kbp ClaI fragment representing lactococcal DNA in pVS34 contained unique restriction sites for HindIII, EcoRI, XhoII, and HpaII, of which the last three could be used for molecular cloning . A region necessary for replication was located within a 2.5-kbp fragment flanked by the EcoRI and ClaI restriction sites . A 3.8-kbp EcoRI fragment derived from a nisin resistance plasmid, pSF01, was cloned into the EcoRI site of pVS34 to obtain a nisin-chloramphenicol double-resistance plasmid, pVS39 . From this plasmid, the streptococcal chloramphenicol resistance region was subsequently eliminated . The resulting plasmid, pVS40, contains only lactococcal DNA . Potential uses for this type of a nisin resistance plasmid are discussed. J Clin Microbiol, 1990 Jul, 28(7), 1506 - 8 Reproducibility of interpretation of Gram-stained vaginal smears for the diagnosis of bacterial vaginosis; Mazzulli T et al.; In the diagnostic microbiology laboratory, interpretation of Gram-stained slides of vaginal swab specimens is used to support the clinical diagnosis of bacterial vaginosis . The reproducibility with which technologists interpret these Gram-stained slides was evaluated by presenting, in coded fashion, 80 original slides and 80 duplicate slides of vaginal swab specimens to three technologists . They each interpreted the original slide twice and the duplicate slide from the same specimen once . Intraobserver and interobserver agreement was assessed by use of the weighted kappa statistic . Semiquantitation of Lactobacillus and Gardnerella morphotypes and a diagnosis of bacterial vaginosis showed the greatest intraobserver agreement, with kappa values ranging from 0.772 to 1.000 . Interobserver agreement was also high for rating Lactobacillus morphotypes and clue cells (kappa values between 0.735 and 0.869) but decreased slightly for Gardnerella morphotypes and a diagnosis of bacterial vaginosis (kappa values between 0.656 and 0.800) . These results indicate that there is good agreement for the interpretation of Gram-stained slides of vaginal swab specimens and that this method alone, without culture, can be used reliably to support the clinical diagnosis of bacterial vaginosis. Zh Mikrobiol Epidemiol Immunobiol, 1990 Jul, (7), 17 - 9 {The correction of dysbiotic disorders of the vaginal microflora by using a preparation made from highly adhesive lactobacteria}; Korshunov VM et al.; The effectiveness of a new bacterial preparation obtained from highly adhesive lactobacteria and intended for the correction of dysbiotic disturbances of vaginal microflora was studied in the treatment of 60 pregnant women with dysbacteriosis of the maternal passages . 30 pregnant women were simultaneously treated by the vaginal application of Lactobacterin . The study showed that the use of the preparation of highly adhesive lactobacteria caused the pronounced and stable correction of the microflora of the maternal passages . This correction was manifested by the domination of lactic acid bacterial flora and a decrease in the number of opportunistic microorganisms. Plant Foods Hum Nutr, 1990 Jul, 40(3), 167 - 73 Fermentation of pearl millet flour with yeasts and lactobacilli: in vitro digestibility and utilisation of fermented flour for weaning mixtures; Khetarpaul N et al.; Single as well as mixed culture fermentation by yeasts (S . diastaticus; S . cerevistiae) and lactobacilli (L . brevis; L . fermentum) at 30 degrees C for 72 h improved the starch and protein digestibility (in vitro) of pearl millet flour significantly . The flour fermented by Saccharomyces diastaticus, a starch hydrolysing yeast, had the highest starch digestibility whereas fermentation by Saccharomyces cerevisiae enhanced the in vitro protein digestibility of the flour significantly . Weaning mixtures prepared from the fermented flour were also found to be organoleptically acceptable. Clin Microbiol Rev, 1990 Jul, 3(3), 280 - 91 Resistance to vancomycin and teicoplanin: an emerging clinical problem; Johnson AP et al.; Vancomycin and teicoplanin are glycopeptides active against a wide range of gram-positive bacteria . For 30 years following the discovery of vancomycin in 1956, vancomycin resistance was not detected among normally susceptible bacteria recovered from human specimens . Since 1986, however, bacteria resistant to vancomycin or teicoplanin or both have been described . Strains of the genera Leuconostoc, Lactobacillus, Pediococcus, and Erysipelothrix seem inherently resistant to glycopeptides . Species and strains of enterococci and coagulase-negative staphylococci appear to have acquired or developed resistance . There are at least two categories of glycopeptide resistance among enterococci, characterized by either high-level resistance to vancomycin (MIC, greater than or equal to 64 mg/liter) and teicoplanin (MIC, greater than or equal to 8 mg/liter) or lower-level vancomycin resistance (MIC, 32 to 64 mg/liter) and teicoplanin susceptibility (MIC, less than or equal to 1 mg/liter) . The two categories appear to have similar resistance mechanisms, although genetic and biochemical studies indicate that they have arisen independently . Among coagulase-negative staphylococci, strains for which vancomycin MICs are up to 20 mg/liter or teicoplanin MICs are 16 to 32 mg/liter have been reported, but cross-resistance between these glycopeptides varies . The selective advantage accorded to glycopeptide-resistant bacteria and the observation that high-level resistance in enterococci is transferable suggest that such resistance may be expected to increase in incidence . Clinicians and microbiologists need to be aware of this emerging problem. Rev Fac Odontol Univ Chile, 1990 Jul-Dec, 8(2), 17 - 25 {Antimicrobial activity of orthodontic band cements}; Pavic J et al.; The prevalence of enamel decalcification and caries beneath orthodontic bands, has indicated the need for a new enamel binding adhesive orthodontic cement . The purpose of this study was to evaluate the antimicrobial activity, in vitro, on Streptococcus mutans and Lactobacillus, acidophillus, of three materials used to cements the orthodontic bands . The cements studied were: Zinc phosphate cement, Glass-ionomer cement, and Policarboxylate cement . Thirty petri plates were seeded with S . mutans, and thirty with L . acidophillus; on each plate three pellet were placed, one of each cement studied . Petri plates were incubated under microaerophilic conditions at 37 C, and checked at 72 hrs . for Streptococcus, mutans, and four days for Lactobacillus acidophillus to evaluate the inhibition zone . The results were tabulated for each material . It was demonstrated that exists important variations in the antimicrobial properties of the materials studied, as in the microbial sensitivity to these cements. Pract Odontol, 1990 Jul, 11(7), 37 - 9, 42-3, 45-6 {Prevention of caries with lactobacillus (final results of a clinical trial on dental caries with killed lactobacillus {streptococcus and lactobacillus} given orally)}; Bayona Gonzalez A et al.; Caries prevention with lactic bacteria . (Final results of a dental caries clinical trial using heat killed lactic bacteria {streptococci and lactobacilli} orally.) The results of a dental caries clinical trial in 245 seven-year-old children are reported . Chewable tablets of two different types were prepared: A) Containing pyridoxine (Vit . B6) and heat killed lactic bacteria . B) Placebo tablets with pyridoxine only . They were randomly given once a week for 16 weeks to experimental and control groups respectively . Four evaluation surveys were conducted during 24 months of follow up, using the "Decay, Missing, Filled, Surfaces" index (DMFS) for the clinical evaluation of the permanent teeth . A consistent reduction in the incidence of dental caries in the experimental group was observed in all 4 surveys . After 2 years of follow up a 42% reduction in the incidence rate of dental caries was observed in the experimental group compared to the control group . Summary tables and discussion of the clinical evaluation surveys are given . The potential use of these clinical findings as support for a future dental caries vaccine evaluation project is proposed. Zh Mikrobiol Epidemiol Immunobiol, 1990 Jul, (7), 14 - 7 {The effect of "Solco" lactobacteria (Lactobacillus acidophilus) on the survival and microflora of mice with a Salmonella infection}; Popova-Barzashka S et al.; The Solco lactobacterial strain L . acidophilus Lat 11/83 has been used for the normalization of intestinal microflora in experimental post-infectious intestinal dysbacteriosis in mice . The results of experiments indicate that the intragastric administration of live Solco lactobacteria contributes to an increase in the survival rate of infected animals and the normalization of their gastrointestinal microflora . This strain may be used as a bacterial preparation for the regulation of intestinal microbiocenosis. Kansenshogaku Zasshi, 1990 Jul, 64(7), 781 - 6 {The antitumor activity of Lactobacillus casei--the direct effects of L . casei to human tumor cell lines}; Katayama Y; The effects of somatic components of Lactobacillus casei (L . casei) were studied on cell growth in vitro . L . casei was able to suppress the growth of MT-2, MT-4 cells from adult T-cell leukemia, Molt-4 cells from acute lymphoblastic leukemia and U-937 cells from promonocytic leukemia . This effect was obviously different from the cytotoxicity of Vinbrastin, an anti-cancer drug . Flow cytometric experiments employing BrdU-anti BrdU antibody demonstrated an increase of cells in G1 + G0 phases (pre-DNA synthesis phases) by the treatment of L . casei, therefore L . casei maybe acts as a low grade inhibitor of the protein synthesis . PC-treated L . casei had no more inhibition on cell growth than the non-treated one. Int J Syst Bacteriol, 1990 Jul, 40(3), 224 - 30 16S rRNA sequence determination for members of the genus Carnobacterium and related lactic acid bacteria and description of Vagococcus salmoninarum sp . nov; Wallbanks S et al.; The phylogenetic interrelationships of members of the genus Carnobacterium and some atypical lactobacilli isolated from diseased salmonid fish were investigated by using reverse transcriptase sequencing of 16S rRNA . The four species Carnobacterium piscicola, Carnobacterium divergens, Carnobacterium gallinarum, and Carnobacterium mobile exhibited a high degree of sequence similarity with each other (ca . 96 to 98%) and formed a phylogenetically coherent group that was quite distinct from all other lactic acid bacteria . The sequence data clearly demonstrated that carnobacteria are phylogenetically closer to the genera Enterococcus and Vagococcus than to members of the genus Lactobacillus . The strains from fish were found to be phylogenetically related to the genus Vagococcus and represent a new species, Vagococcus salmoninarum . The type strain of Vagococcus salmoninarum is strain NCFB 2777. FEMS Microbiol Lett, 1990 Jun 15, 58(1), 73 - 83 A phylogenetic analysis of the genus Leuconostoc based on reverse transcriptase sequencing of 16 S rRNA; Martinez-Murcia AJ et al.; The phylogenetic interrelationships of members of the genus Leuconostoc and some heterofermentative lactobacilli, which phenotypically resemble leuconostocs, were investigated by comparative analysis of their 16 S rRNA sequences . The six species, Leuconostoc mesenteroides, Leu . carnosum, Leu . citreum, Leu . gelidum, Leu . lactis and Leu . pseudomesenteroides exhibited a high degree of sequence similarity with each other and formed a phylogenetically coherent group, quite separate from all other lactic acid bacteria investigated . The species Leu . paramesenteroides was found to be phylogenetically distinct from the Leu . mesenteroides group of species and formed a natural grouping with the heterofermentative lactobacilli, Lb . confusus, Lb . kandleri, Lb . minor and Lb . viridescens . The rRNA sequence of the acidophilic species, Leu . oenos, displayed exceptionally low levels of homology with all of the other taxa examined . The 16 S sequence of Leu . oenos showed major nucleotide differences in relatively highly conserved positions of the molecule indicating this species is phylogenetically distinct and warrants a separate genus. J Clin Microbiol, 1990 Jun, 28(6), 1348 - 55 Clinical and microbiologic characteristics of pediococci; Riebel WJ et al.; Over a 43-month period, 23 separate isolates of nonenterococcal alpha- and nonhemolytic streptococci were reported by our clinical microbiology laboratory to be resistant to vancomycin . This constituted 0.32% of nonenterococcal alpha- and nonhemolytic streptococci reported and 4.4% of such streptococci upon which susceptibility testing was performed . Of 13 isolates which were available for further study, all were highly resistant to vancomycin (MIC greater than or equal to 1,024 micrograms/ml), but none were actually streptococci . Three were clearly gram-positive rods by Gram stain and were found to be homofermentative lactobacilli . Two strains with elongated gram-positive cocci from colonies on agar showed small gram-positive rods when grown in thioglycolate broth and were physiologically identified as Lactobacillus confusus . Two isolates with lenticular gram-positive cocci appeared to be Leuconostoc mesenteroides subsp . mesenteroides . Six gram-positive isolates with round cells from growth on agar and from broth were arranged in tetrads in broth and closely resembled Pediococcus acidilactici . Twelve additional strains of pediococci that were not of human origin were also found to be highly resistant to vancomycin . These findings confirm published reports of clinical isolation of organisms resembling pediococci and suggest that clinically isolated, vancomycin-resistant bacteria which superficially resemble streptococci are probably other lactic acid bacteria. Acta Odontol Scand, 1990 Jun, 48(3), 183 - 7 Sucrase activity in relation to other salivary factors and DMFS values of dental students; Karjalainen S et al.; Samples of stimulated whole saliva were collected from 176 dental students, and their teeth were examined both clinically and radiographically . Salivary flow; buffering capacity; numbers of lactobacilli, yeasts, and Streptococcus mutans; and DMFS and DS values were correlated to sucrase activity . The high flow-rate group had a lower (p = 0.0201*) sucrase activity than the low flow-rate group . The proportion of high (greater than or equal to 10 mumol/min x mg x 10(-3} sucrase activities among the highest density category of lactobacilli was 67%, whereas the corresponding proportion in the whole material was only 28% . Men had significantly (p = 0.0169*) higher sucrase activities than women . The other variables measured did not seem to have any significant effect on the sucrase activity values . In addition to sucrose consumption, other factors like the rate of salivary flow and the density of lactobacilli seem to influence the level of salivary sucrase activity. Community Dent Oral Epidemiol, 1990 Jun, 18(3), 149 - 52 Longitudinal study of caries and cariogenic bacteria in an elderly disabled population; MacEntee MI et al.; A 2-yr longitudinal study was conducted among elderly disabled residents of a longterm care facility . Each of the 50 subjects examined at the beginning of the study had a mean of 14 teeth, with a mean of 6 carious and 6 restored teeth, per person . Most of the subjects had very poor oral hygiene, and 26 of them had dental plaque that produced cultures of mutans streptococci and lactobacilli in excess of 10(5) CFU/ml . At the end of the first year, 40 subjects were examined again and, apart from a decrease in the mean number of carious root lesions per person, there was very little change in their dental or microbial status . Although only 18 subjects were available at the end of the second year, they presented with fewer carious lesions after 2 yr . The reduction in caries appeared to result from the remineralization of tooth structure, but new lesions did appear in 33% of the 1-yr group, and in 78% of the 2-yr group . This dynamic environment around the teeth produced a mean net incidence of one lesion in the first year, and three lesions over 2 yr . There was a significant (P less than 0.05) association between large (greater than 10(5) CFU/ml) numbers of mutans streptococci and the development of new lesions, but there was no association between the dental status of the subjects and the dental treatment they received . Overall, the results indicate that caries is not rampant in this population. Community Dent Oral Epidemiol, 1990 Jun, 18(3), 120 - 5 Caries prevalence and microbiological and salivary caries activity tests in Scottish adolescents; Russell JI et al.; Salivary and microbiological caries activity tests were investigated on three occasions in a group of 372 Scottish adolescents . Counts of lactobacilli, mutans streptococci, and candida were consistently and significantly associated with caries prevalence, as either DS or DMFS score, and buffering capacity was consistently inversely related to DMFS score . However, veillonella counts and salivary flow rate were not correlated with caries prevalence . Significant improvements in the associations were obtained when the results of more than one test were included using stepwise regression analysis . On an individual basis, at most, stepwise discriminant analysis identified the DMFS group correctly in 49% of all subjects, and the DS group in 47%. Scand J Dent Res, 1990 Jun, 98(3), 197 - 210 Salivary conditions and cariogenic microorganisms in 55, 65, and 75-year-old Swedish individuals; Fure S et al.; Secretion rate, buffer capacity, and cariogenic microorganisms of resting and stimulated whole saliva were examined in 208 55-, 65-, and 75-yr-old Swedes . The secretion rate for both resting and stimulated saliva decreased with age . When the use of drugs was taken into account the difference in terms of age group was significant for resting saliva alone (P less than 0.01) . In 22% the resting saliva was less than 0.1 ml/min, and in 5% the stimulated saliva was less than 0.7 ml/min . Persons with subjective dryness in the mouth had a lower salivary flow . Men had higher secretion rates than women irrespective of medication (P less than 0.05) . The buffer capacity was strongly correlated to the secretion rate of both resting and stimulated saliva (r = 0.39 and r = 0.44, respectively) . The number of mutans streptococci and lactobacilli increased with age, although significant in terms