A study of five bacteriophages of the Myoviridae family which replicate on different gram-positive bacteria

A comparative study is reported on five phages of the Myoviridae family which propagate on Bacillus subtilis, B. thuringiensis, Enterococcus sp., Lactobacillus plantarum, or Staphylococcus aureus. The phages are morphologically identical and characterized by isometric heads with conspicuous capsomers and by contractile tails with complex base plates. The phages show similar protein profiles, but vary considerably in burst size. Phage DNAs are about 95-166 kb in size and are unrelated by DNA-DNA hybridization and restriction endonuclease analysis. Therefore the phages are unrelated at species level. Implications of these data for our understanding of the development of phage species are discussed.

The effect of exogenous administration of Lactobacillus reuteri R2LC and oat fiber on acetic acid-induced colitis in the rat

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

Long-term treatment with rifaximin and lactobacilli in post-diverticulitic stenoses of the colon

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

Prevalence of dental caries in 4- to 5-year-old children partly explained by presence of salivary mutans streptococci

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

Cytolytic vaginosis: a common cause of cyclic vulvovaginitis

Cytolytic vaginosis (CV) infection is a little recognized but common cause of cyclic vulvovaginal complaints in women of reproductive age. Often misdiagnosed as candidiasis, most women have tried myriad antifungal medications to little or no avail. The history and physical examination is often similar to that seen in women with vaginal candidiasis. However in CV infection there is a luteal phase pattern of symptom recurrence. An astute clinician can make this diagnosis on vaginal microscopic examination and by meticulously ruling out other infections. Management consists of discontinuing all antifungal agents, using pads instead of tampons with menses, and taking baking soda sitz baths. Baking soda douches may also be helpful. As clinicians become familiar with CV infection, more women will be diagnosed and managed appropriately, leading to a long awaited resolution of their chronic vaginal complaints.

A multivariate model to predict caries increment in Montreal children aged 5 years

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

Two-year longitudinal observations of salivary status and dental caries in children with insulin-dependent diabetes mellitus

Salivary status and caries incidence were studied in 28 young, Type 1 diabetics from the onset of the disease and during a two-year period. Flow rate, buffer capacity, glucose content, total protein concentration and levels of mutans streptococci and lactobacilli were determined in stimulated whole saliva every third month. Dental caries was recorded at onset and then once a year. Forty-six per cent of the children developed caries during the observation period. Caries incidence was significantly higher (P less than 0.05) during the first year of diabetes, compared with the second. Caries-active children displayed significantly higher HbA1c levels (P less than 0.001), compared with caries-inactive diabetics. The number of salivary lactobacilli dropped significantly (P less than 0.05) during the first six months of the disease, while mutans streptococci levels remained unchanged during the study period. Salivary glucose concentration showed a considerable individual variation, but tended to be lower during the second year. The results suggest a possible relationship between Type 1 diabetes treatment and caries.

[Biological characteristics of strains of lactobacilli, promising for use as eubiotics]

In the course of in vitro studies 3 Lactobacillus strains with pronounced antagonistic activity against some pathogenic and opportunistic bacteria (shigellae, enteropathogenic Escherichia, Proteus, staphylococci) were selected. In experiments on germ-free rats faint colonization by L. plantarum 37 was observed in the small intestine, as well as in the large intestine when low doses of these bacilli were introduced into the gastrointestinal tract of the animals. In vitro experiments demonstrated the decreased growth rate of this strain. The prophylactic administration of two eubiotic strains, L. plantarum 37 and L. fermentum 39, simultaneously with chloramphenicol to primates inhibited the growth of opportunistic bacteria, though L. fermentum 39 excessively suppressed the content of Escherichia coli in the enterobacterial population. The optimum biological effect was achieved with the therapeutic use of these three strains for the correction of dysbiotic disturbances caused by the administration of tetracycline in volunteers.

Could bacterial vaginosis be due to the competitive suppression of lactobacilli by aerobic microorganisms?

Bacterial vaginosis (BV) is characterized by lack of lactobacilli and predominance of anaerobic species. Ciprofloxacin is active against a great number of aerobic bacteria. The effect of ciprofloxacin on the vaginal microbial flora was studied both in healthy subjects and in patients with BV in order to test if BV may be due to competitive suppression of lactobacilli by aerobic species. About half of the patients were relieved of their symptoms. No adverse effects on the microbial profile or colonization by lactobacilli were produced by the drug. Lactobacilli known to be able to produce hydrogen peroxide were found to be significantly more common in healthy women than in women with BV. The species most frequently related to vaginal health were Lactobacillus jensenii and Lactobacillus rogosae.

Influence of three-day antimicrobial therapy and lactobacillus vaginal suppositories on recurrence of urinary tract infections

Forty-one adult women with acute lower urinary tract infections (UTI) were randomly treated for three days with norfloxacin or trimethoprim/sulfamethoxazole (TMP/SMX). Infection was eradicated in 100% of norfloxacin-treated patients and in 95% of TMP/SMX-treated patients. UTI recurred in 29% of patients treated with norfloxacin and in 41% of those treated with TMP/SMX. Post-therapy vaginal administration of lactobacillus suppositories resulted in a recurrence rate of UTI of only 21%, while in patients given sterilized skim-milk suppositories the recurrence rate was 47%. This study indicates that lactobacillus vaginal suppositories are safe and may be effective in reducing the recurrence of UTI following antimicrobial therapy.

[The use of sporulating bacteria in treating patients with dysbacteriosis]

In the treatment of patients with different forms of dysbacteriosis routine bacterial preparations (coli-, lacto-, bifidumbacterin) were supplemented by sporeforming aerobic Bacillus bacteria. It was found that efficacy of treatment in patients receiving sporeforming bacteria was 20-30% higher than traditional bacterial agents.

Correlations between caries prevalence and potential etiologic factors in large samples of 4-5-yr-old children

A data base containing information on dental caries, oral hygiene, gingival state, Streptococcus mutans and lactobacillus counts, and salivary flow rate and buffer capacity in some 2800 4-5-yr-old South African children was created in 1984. The children were equally distributed in four groups; rural black, urban black, urban Indian, and urban white. In this study, the data were used for simple linear correlations between all the factors including caries as well as stepwise multiple regression analyses between caries prevalence and the independent factors in each of the four groups. The highest r value obtained in the single correlations was 0.56 for dmfs/lactobacillus count in the white group. The overall pattern of the groups did not vary much. In the stepwise multiple regression analyses, lactobacilli entered first in all groups. S. mutans and oral hygiene interchanged as Nos. 2 and 3, and gingival state or buffer capacity came out as No. 4. The highest percentage of caries variability explained by these regressions was 25%, in the urban black group, while the lowest was 12%, in the indian group. It was concluded that our generally accepted etiologic factors are unsatisfactory to explain variation in caries in observational studies, which among other things might be ascribed to the inadequate way these factors generally are measured or estimated.

[The efficacy of the use of lactic acid lactobacterin enriched with zinc in the treatment of patients with celiac disease]

Zinc sulfate-enriched lactic acid lactobacterin was used in the combined treatment of 23 children with celiac disease, aged from 1 to 10 years. A group of 23 children with celiac disease who received lactic acid lactobacterin without zinc were used as control. The patients treated with lactobacterin containing zinc showed a higher increase in body mass, total protein and zinc levels in the blood serum and elevated activity of metalloenzymes-ceruloplasmin and cytochrome oxidase.

Invasion of bacteria in enamel carious lesions

A review of recent findings concerning enamel carious lesions is presented. This lesion represents the initial phase of dental caries and is characterized by a demineralization of the subsurface enamel caused by acids of the plaque bacteria. Streptococcus mutans has been described as the etiologic agent of the dental caries and the most acidogenic plaque bacteria. Morphological studies have shown an invasion of microorganisms inside the enamel carious lesion. Unfortunately, several technical problems are associated with such studies. The identification of the invading bacteria has not yet been achieved. The future identification of bacteria inside the subsurface enamel lesions will represent an important step in the prevention of the carious progression.

Identification of a nucleotide sequence conserved in Lactococcus lactis bacteriophages

A genetic element which is conserved in the genomes of numerous Lactococcus lactis bacteriophage isolates has been identified and its nucleotide sequence determined. Approximately 95-99% of all L. lactis bacteriophages collected over a period of six years from two geographically distinct sources carry this conserved DNA fragment. Genetic variation in other regions of the genomes of these bacteriophages is exhibited by changes in the overall restriction patterns. The complete nt sequence for a 1.6-kb region from nine independent L. lactis bacteriophage isolates was determined and only five changes in the nt sequence were observed within a span of 1536 bp. This region has a single large 1356-bp open reading frame (ORF) coding for a 51-kDa protein. Three out of the five changes occur in a 187-bp region, 5' to this large ORF. The two additional changes are found within the 1356-bp ORF, which results in two amino acid substitutions that do not, however, change the net charge of the protein. The encoded protein is extremely charged and shares some homology with yeast translation initiation factor. In addition, there is a potential zinc-binding domain within this protein, similar to those observed in genes from bacteriophages T4 and T7.

[A comparative study of the immunological properties of peptidoglycans of different origins]

The action of peptidoglycans (PG) of different origin has been experimentally studied in vivo. In these experiments PG of bacterial origin, such as blastolysin (BL), and synthetic PG, viz. muramyldipeptide (MDP) and its analog glucosaminylmuramyldipeptide (GMDP) have been used. Their toxicity, allergenic action, their effect on the phagocytic activity of peritoneal exudate macrophages (PEM), the accumulation of antibody-producing cells in the spleen, antibody titer in the blood serum and delayed hypersensitivity to nonbacterial antigens have been determined. As revealed in this study, BL does not differ from MDP in its toxicity and allergenic action. The phagocytic activity of PEM under the influence of BL only insignificantly differs from their activity under the influence of MDP, but is lower than under the influence of GMDP. The adjuvant action of BL is somewhat higher than that of synthetic PG.

Preliminary observations on effect of Lactobacillus sporogenes on serum lipid levels in hypercholesterolemic patients

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.

Preservation of the quantity of lactobacilli in samples from the oral cavity

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.

[Quantitative and qualitative characteristics of the bacterial flora of saliva and dental plaque in artificially fed children]

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.