Effect of doxycycline and Lactobacillus probiotics on mRNA expression of ABCC2 in small intestines of chickens.

Probiotics and antibiotics are widely used in poultry and may alter drug bioavailability by affecting the expression of intestinal ATP-binding cassette (ABC) efflux transporters. Therefore the aim of the present investigation was to evaluate the effect of Lactobacilli probiotics, administered alone or in combination with doxycycline, on the expression of ABCB1 (gene, encoding P-glycoprotein), ABCC2 (gene, encoding multidrug resistance protein 2, MRP2) and ABCG2 (gene, encoding breast cancer resistance protein) mRNAs in chicken using RT-PCR. Duc one-day-old chicks (n=24) were divided equally in four groups: untreated control, probiotics supplemented group, probiotics plus doxycycline treated chickens and antibiotic administered group. Expression of ABCC2 mRNA was affected by doxycycline or by combination of Lactobacillus plantarum, L. brevis and L. bulgaricus and the antibiotic in the intestines. These results can be used as a basis for further functional studies to prove the beneficial effect on limitation of the absorption of toxins and improvement of efflux of endogenous substances and xenobiotics when the combination of doxycycline and Lactobacillus spp. probiotics are administered to poultry.

Effect of probiotics on enrofloxacin disposition in gastrointestinal tract of poultry.

Probiotics are routinely used in poultry husbandry due to health benefit on the host. The gut microbiota is now recognized to exert an important influence on the absorption and pharmacokinetics of many compounds. Therefore, this study was designed to evaluate the effect of candidate probiotics belonging to the species Lactobacillus brevis, L. plantarum and L. bulgaricus on pharmacokinetics of enrofloxacin in healthy chickens. The probiotic administration leads to higher degree of metabolism of enrofloxacin to ciprofloxacin in liver. The antibacterial drug was significantly faster absorbed (kab of 0.61 ± 0.54 h(-1) and Tmax 7.81 ± 3.52 h) at lower concentrations (Cmax of 1.34 ± 0.18 µg·g(-1)) during the first 24 h of treatment in the probiotic's group. The values of kab , Tmax , and Cmax for the group, treated solely with enrofloxacin, were 0.10 ± 0.065 h(-1), 15.42 ± 3.07 h, and 1.61 ± 0.24 µg·g(-1), respectively. A significantly higher concentration of enrofloxacin and its metabolite ciprofloxacin in the liver was observed in the group with the probiotic treatment. Disposition of both drugs was not significantly changed in the duodenum and in the jejunum. The selected dose is appropriate for treatment of infections caused by pathogens with MIC < 0.06 µg·mL(-1) irrespective of antibiotic administration alone or in combination with probiotics.

Influence of Lactobacillus brevis 15 and Lactobacillus plantarum 13 on blood glucose and body weight in rats after high-fructose diet.

In recent years, many authors have investigated the possible antidiabetic effect of lactic acid bacteria. Lactobacillus species constitute a major part of the lactic acid bacteria group and have been found to exhibit beneficial effects on the development of diabetes and its complications. In the current study, we investigated the effects of newly characterised Bulgarian Lactobacillus strains, Lactobacillus brevis 15 and Lactobacillus plantarum 13, on blood glucose levels and body weight of rats fed a fructose-enriched diet. An experiment was conducted over a period of 8 weeks with 24 2-month-old Wistar rats randomly assigned to receive a standard diet (Con, control group), fructose-enriched diet (Fr group), standard diet with probiotics given twice a week (Pro group), and fructose-enriched diet with probiotics given twice a week (Pro+Fr group). At the end of the experimental period, a statistically significant increase in body weight was observed in all experimental groups (P<0.0001). The highest rise was seen in the fructose group (Fr, 169±19 g), followed by the Pro+Fr group (153±15 g), Pro group (149±13 g), and Con group (141±5 g). Moreover, the final blood glucose levels had risen significantly in the groups receiving fructose either without (Fr; P<0.0001) or with lactobacilli (Pro+Fr; P=0.002), while the rise was insignificant in the group of rats given probiotic supplementation only (Pro, P=0.071) and inexistent in the Con group (P=0.999). The highest elevation of blood glucose levels was observed in the Fr group (3.18 mmol/l), followed by the Pro+Fr group (2.00 mmol/l) whereas the Pro group showed the lowest levels (0.60 mmol/l). The results of our study suggest that the newly characterised Bulgarian Lactobacillus strains, L. brevis 15 and L. plantarum 13, could be considered as possible probiotics and might be able to prevent some metabolic disturbances.

Do bacteria have an electric permanent dipole moment?

In the scientific literature in the last 40 years, some data for the permanent dipole moment and the electric polarizability of Escherichia coli can be found [S.P. Stoylov, Colloid Electro-Optics - Theory, Techniques and Application, Academic Press, London, 1991]. In this paper the data based mainly on electro-optic investigation is considered as much as some dipolophoretic (most often called dielectrophoretic) studies. Serious grounds are found to doubt the conclusions made for the electric dipole moments of bacteria by one of the authors of this paper (SPS) and by some other researchers. This concerns both the permanent dipole moment and the electric charge dependent polarizabilities of E. coli. Here, along with the discussion of the old experimental data, new experimental data are shown for a strain of E. coli HB101. The conclusions from the analysis of the old and the new experimental data is that they do not provide correct evidence for the presence of a permanent dipole moment. It seems that all statements for the existence of electric permanent dipole moment in bacteria [S.P. Stoylov, Colloid Electro-Optics - Theory, Techniques and Application, Academic Press, London, 1991; S.P. Stoylov, S. Sokerov, I. Petkanchin, N. Ibroshev, Dokl. AN URSS 180 (1968) 1165; N.A. Tolstoy, A.A. Spartakov, A.A. Trusov, S.A. Schelkunova, Biofizika 11 (1966) 453; V. Morris, B. Jennings, J. Chem. Soc. Faraday Trans. II 71 (1975) 1948; V. Morris, B. Jennings, J. Colloid Interface Sci. 55 (1978) 313; S.P. Stoylov, V.N. Shilov, S.S. Dukhin, S. Sokerov, I. Petkanchin, in: S.S. Dukhin (Ed.), Electro-optics of Colloids, Naukova Dumka, Kiev, 1977 (in Russian).] based on electro-optic studies are result of incorrect interpretation. Therefore, they should be further ignored.

Probiotic properties of Lactococcus lactis ssp. lactis HV219, isolated from human vaginal secretions.

AIMS: To determine the resistance of Lactococcus lactis ssp. lactis HV219 to acids, bile, antibiotics, inflammatory drugs and spermicides, compare adsorption of the strain to bacteria and Caco-2 cells under stress, and evaluate the antimicrobial activity of bacteriocin HV219. METHODS AND RESULTS: Bacteriocin HV219 activity against Gram-positive and Gram-negative bacteria was confirmed by leakage of DNA and beta-galactosidase, and atomic force microscopy. Adsorption of bacteriocin HV219 to bacteria is influenced by pH, temperature, surfactants and salts. Initially, only 3% of HV219 cells adhered to Caco-2 cells. However, after 2 h, adherence increased to 7%. Strain HV219 and Listeria monocytogenes ScottA did not compete for colonization. Strain HV219 is sensitive to most antibiotics tested, but resistant to amikacin, ceftazidime, nalidixic acid, metronidazole, neomycin, oxacillin, streptomycin, sulphafurazole, sulphamethoxazole, sulphonamides, tetracycline and tobramycin. Ibuprofen, ciprofloxacin, diklofenak and nonoxylol-9 inhibited the growth of strain HV219. CONCLUSION: Strain HV219 is resistant to hostile conditions in the intestinal tract, including therapeutic levels of specific antibiotics and binds to Caco-2 cells, but not in competition with L. monocytogenes. SIGNIFICANCE AND IMPACT OF THE STUDY: Strain HV219 will only be effective as probiotic if taken with specific antibiotics and not with anti-inflammatory drugs and spermicides.

Effect of enterococcin A 2000 on biological and synthetic phospholipid membranes.

Lactic acid bacterium isolated from Bulgarian cheese and identified as Enterococcus faecium produces a small hydrophobic peptide substance (enterococcin A 2000) with broad spectrum of antimicrobial activity. The wide range of enterococcin antibacterial activity of this compound against Gram-positive, as well as against some Gram-negative bacteria, suggests a single mechanism of action. The mode of action of enterococcin A 2000 was studied in intact liver mitochondria and synthetic phospholipid liposomes used as model systems. Enterococcin A 2000 stimulated the ATPase activity in intact mitochondria. The kinetic curve of ATP hydrolysis differed from that obtained in presence of dinitrophenol (DNP) and showed a character similar to the ATP hydrolysis in the presence of classic ionophores. Enterococcin A 2000, when bound to synthetic phospholipid liposomes, permeabilized liposomes liberating the marker carboxyfluorescein (CF).

Effects of nitrogen sources on bacteriocin production by Enterococcus faecium A 2000.

The production of a novel broad-spectrum antimicrobial peptide enterococcin A 2000, active against Gram-positive and Gram-negative microorganisms including Listeria subsp. and Escherichia coli, by Enterococcus faecium strain A 2000 isolated from the surface of traditional Bulgarian yellow cheese "kash-kaval" is considerably influenced by complex nitrogen sources in the production medium. Medium components, especially peptone and yeast extract, and their concentration contributed to the increase in bacteriocin production during the stationary phase (16-46 h) of cultivation even in the absence of one of the components present in the basal cultivation MRS medium.

[Calcium ions and the differentiation of Streptomyces hygroscopicus 155, a producer of an antibiotic complex]. / Iony kal'tsiia i differentsiatsiia Streptomyces hygroscopicus 155, produtsenta antibioticheskogo kompleksa.

The effect of Ca2+ on differentiation of Streptomyces hygroscopicus 155 and its inactive variant 155-0 was studied. Addition of Ca2+ to the medium induced formation of the aerial mycelium in the inactive variant and accelerated formation of the aerial mycelium in the parent strain. The inhibitory effect of EGTA, verapamil, nifedipin, chlorpromazine and dilthiazeme on the aerial mycelium formation demonstrated the physiological role of Ca2+ in the process. Addition of pandavir (nigericin) and azalomycin B, the antibiotics produced by the streptomycete, induced formation of the aerial mycelium in the inactive variant. The effect was higher in the presence of Ca2+. Streptomyces hygroscopicus 155 and its inactive variant synthesized a proteolytic complex containing metalloproteases and trypsin-like proteases. The total proteolytic activity of the inactive variant was lower than that of the parent strain. Addition of Ca2+ to the medium stimulated their proteolytic activity. The inducing action of the antibiotics produced by the parent strain on differentiation of S.hygroscopicus 155-0 and the increase of their action in the presence of Ca2+ suggested that they controlled the differentiation and that such a function of the antibiotics expressed itself through the Ca2+ signal system.

Stereotyped behaviours in blind children.

Stereotyped behaviours occur frequently in blind children. Most authors attribute stereotyped mannerisms to factors such as hospitalisation, motor limitations, and reduced capacity for exploration. There seems to be a specific association between blindness and behavioural mannerisms, such as eye pressing and eye poking, which have been observed in children with peripheral blindness. We studied the prevalence of stereotyped motor behaviours in a sample of congenitally blind children with and without other neurodevelopmental disabilities in order to assess the types and features of such stereotyped behavioural traits. Twenty-six congenitally blind children (11 male and 15 female) were assessed through videotape recording and through a questionnaire focusing on the type, frequency, form of manifestation and duration of the children's stereotyped behaviours. Stereotyped behavioural traits were observed in 19 (73%) of the patients. Stereotyped behaviours most frequently observed were body rocking (8; 30.7%), repetitive handling of objects (8; 30.7%), hand and finger movements (7; 26.9%), eye pressing and eye poking (8; 30.7%), and lying face downwards (6; 22.8%) and jumping (3; 11.4%). We found that a reduction in stereotyped behavioural traits could be obtained by stimulating appropriate adaptive behaviour in children, while these behaviours were increased by restricted environmental conditions, reduced sensory stimulation and reduced motility.

Characterization of a bacteriocin produced by Streptococcus thermophilus 81.

A new bacteriocin, produced by Streptococcus thermophilus 81 has been isolated, purified and characterized. By its heat sensitivity and broad inhibitory spectrum it does not resemble any other S. thermophilus bacteriocin. The mode of action is bacteriostatic. This peptide of 32 amino acids is efficient against several Bacillus species, Listeria monocytogenes, Salmonella typhimurium, Escherichia coli, Yersinia pseudotuberculosis and Yersinia enterocolitica. This bacteriocin is heat labile but its activity was not altered by pH variation from 3 to 10. Six months of storage at 40 degrees C did not influence the activity. The inactivation by detergents and the inability to resolve the protein in SDS-PAGE supposes a more complex structure or a possible stabilizing effect of other molecules. The low sensitivity of Lactobacillus delbrueckii subsp. bulgaricus to the isolated bacteriocin suggests that S. thermophilus 81 may be used in yoghurt starters.

Detection and characterization of a novel antibacterial substance produced by a Lactobacillus delbrueckii strain 1043.

A novel antibacterial substance produced by a strain isolated from Bulgarian yellow cheese was characterized. The producer strain was identified by molecular typing to belong to the species Lactobacillus delbrueckii, which is a rare producer of bacteriocins. The inhibitory agent was heat stable and active against lactic acid bacteria species and several food-borne pathogens: Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Yersinia enterocolitica and Y. pseudotuberculosis. Its sensitivity to amylolitic enzymes and lipase suggested that a lipid and carbohydrate moiety could be important for the activity. The amino acid content of the purified bacteriocin was estimated to 29 amino acids. The bacteriocin was shown to be small (3.6-6 kDa) by three different methods: HPLC gel-filtration, SDS-PAGE and amino acid contents.

Cerebral visual impairment in periventricular leukomalacia.

Infants with cerebral palsy (CP) frequently present cerebral visual impairment (CVI) often caused by damage to retrochiasmatic pathways. This is particularly true of subjects with damage to the periventricular white matter. Thirty-eight preterm infants with periventricular leukomalacia (PVL) diagnosed by MRI were examined to correlate binocular visual acuity with neuroradiological findings. Binocular visual acuity was evaluated using Teller Acuity Cards and a complete ophthalmological examination was also performed. Three infants with ROP III were excluded from the sample. The age of observation ranged from 20 months to 5 and a half years (mean 42 months). The possible involvement of the optic radiations and/or of the calcarine cortex was detected by brain MRI. Twenty-three infants (66%) presented visual impairment. Of these, 9 (26%) were totally or nearly totally blind and 14 (40%) were low vision children. The other 12 (34%) had normal (2) or near normal (9) vision. MRI findings correlated with visual acuity; a relationship was detected between the degree of visual acuity and the reduction of the peritrigonal white matter, and also between the degree of visual acuity and the extent of calcarine atrophy. This report clearly establishes a relationship between visual impairment and specific MRI findings in children with PVL. Teller Acuity Cards and MRI are useful for detecting potential visual impairment and for improving both the clinical diagnosis of these disorders and the therapeutic approach to these subjects.

Cerebral cavernous angiomas: an atypical case in infancy.

Cerebral cavernous angiomas (CCA) are rare, reportedly accounting for only 1% of all intracranial vascular lesions and 15% of all cerebral vascular malformations. Forms are sporadic or familial, and the mode of inheritance is probably autosomal dominant. We report an unusual case of an infant born at 37 weeks of gestational age following a normal pregnancy. Her birth-weight was 1560 g. The family history was negative. At 10 months of age, the child presented with the sudden onset of muscular hypotonia, motility and strength deficits, and absence of osteotendinous reflexes in the right arm. The psychomotor development of the child was normal. MRI revealed the presence of a cavernous angioma in the paramedian pontine region. The child's monoparesis quickly disappeared. This case is interesting because of the age at onset and the way in which the clinical manifestations developed.

[Calcium ions in the life cycle of Streptomyces albogriseolus 444]. / Iony kal'tsiia v zhiznennom tsikle Streptomyces albogriseolus 444.

The influence of Ca2+ on the growth, antibiotic production and differentiation of Streptomyces albogriseolus 444 was studied. Consumption of the calcium ions by the strain was followed up. It was shown that Ca2+ changed the dynamics of the biomass accumulation and had no significant effect on the antibiotic production. Calcium present in the medium was assimilated more intensively during the first 24 hours of the strain growth. The own antibiotic nigericin exogenously added to the medium increased the calcium assimilation. In the presence of Ca2+ the nigericin stimulation of the strain differentiation was higher.

[Isolation and partial characterization of NAD+ kinase from Streptomyces albogriseolus 444]. / Vydelenie i chastichnaya kharakteristika NAD+ kinazy Streptomyces albogriseolus 444

NAD+ kinase was isolated from the culture of Streptomyces albogriseolus 444. an organism producing an antibiotic complex. The enzyme was partially characterized. Its molecular weight is 141219 Da.

[Physiological role of extracellular proteases and calcium ions in the processes of differentiation and antibiotic production by Streptomyces albogriseolus 444]. / Fiziologicheskaia rol' vnekletochnykh proteaz i ionov kal'tsiia v protsessakh differentsiatsii i antibiotikoobrazovaniia Streptomyces albogriseolus 444.

The extracellular proteolytic activity of Streptomyces albogriseolus 444 was investigated. S. albogriseolus 444 was shown to synthesize an extracellular proteolytic complex with metal-protease and trypsin-like activity defining differentiation of the substrate mycelium to the aerial one as well as the spore formation. The synthesis of the complex proceeded in the absence of the inductor in the medium i.e. constitutively. The complex heterogeneity was confirmed chromatographically. Low concentration of calcium ions (1.5 mM) stimulated the total caseinolytic activity and suppressed the activity of the trypsin-like proteases.

[Effect of calcium ions on the differentiation of actinomycetes]. / Vliianie ionov kal'tsiia na differentsiatsiiu aktinomitsetov.

The influence of Ca2+ on the formation of the aerial mycelium in 23 actinomycete strains was studied. It was shown that in concentrations up to 5 mM exogenous Ca2+ induced the formation of the aerial mycelium in 11 out of the 23 actinomycete strains tested. The Ca2+ channel blockers (verapamil and nifedipine), calmodulin inhibitor (chlorpromazine) and Ca2+ chelator (EGTA) inhibited the aerial mycelium formation in 3 streptomycete strains out of the 23 actinomycetes. Chlorpromazine and nifedipine proved to be the most active inhibitors when used in concentrations of 0.2 to 2.5 mumol/disk. The Ca2+ concentrations of 5 mM were found to stimulate the formation of the submerged spores in S. hygroscopicus 155. The activity of ATP synthase was stimulated in the aerial and submerged spores after the Ca2+ uptake.

[Nitrate content in the soils and vegetable crops in the villages of one district]. / Prouchvane sudurzhanieto na nitrati v pochvi i zelenchukovi kulturi v niakoi selishta na edin okrug.

The authors determine the content of nitrates in soil samples and the vegetables grown on them (lettuce, spinach, onion, garlic) via sensitive spectrophotometric methods with phenodisulphonic acid and reduction with cadmium column. The lowest nitrates content was established in the soil samples and vegetables grown by AIC, followed by the private arms, and the highest - in the green-horse vegetables and soil samples, owing mainly to the technology of production.