Identification of a peptide sequence targeting mammary vasculature via RPLP0 during lactation

To find novel targeting moieties to lactating mammary gland, in vivo phage display screening was conducted with lactating rats and a peptide ligand, CLHQHNQMC (designated as MG1), which specifically homes to the mammary tissue during lactation, was identified through the consecutive in vivo biopannings. MG1 peptide ligand showed specific binding affinity to lactating mammary tissue without any preference to other organs tested in ex vivo and in vivo validation, and microscopy analysis revealed that systemically introduced MG1 could be specifically localized in the lactating mammary gland associated with mammary epithelia and alveolar vasculature. Based on the observation that binding of MG1-encoding phage to lactating mammary gland was competitively inhibited by synthetic MG1 peptide ligand, we attempted to identify a counterpart molecule corresponding to specific recognition of the MG1 and the acidic Ribosomal Protein Large P0 (RPLP0) was selected as a candidate receptor for MG1 by peptide affinity pull-down assay with protein extracts from lactating mammary tissue. We demonstrated specific expression of RPLP0 in mammary tissue, especially during lactation, by immunoblotting assays and also demonstrated that MG1 peptide ligand could be bound to, and internalized into, the cells effectively via specific interaction with RPLP0 by analysis using an in vitro endothelial cell model. The overall results suggest that the MG1 has a specific affinity with RPLP0 which are dominantly expressed on the mammary vasculature during lactation and this specific affinity enables the MG1 would be served as an effective homing ligand to deliver functional molecules to the lactating mammary gland.

Complete genome sequence of a newly isolated lytic bacteriophage, EFAP-1 of Enterococcus faecalis, and antibacterial activity of its endolysin EFAL-1

AIMS

In this work, we aimed to identify an effective treatment of infections caused by Enterococcus spp. strains resistant to conventional antibiotics.

METHODS AND RESULTS

We report the isolation and characterization of a new lytic bacteriophage, designated bacteriophage EFAP-1, that is capable of lysing Enterococcus faecalis bacteria that exhibit resistance to multiple antibiotics. EFAP-1 has low sequence similarity to all known bacteriophages. Transmission electron microscopy confirmed that EFAP-1 belongs to the Siphoviridae family. A putative lytic protein of EFAP-1, endolysin EFAL-1, is encoded in ORF 2 and was expressed in Escherichia coli. Recombinant EFAL-1 had broad-spectrum lytic activity against several Gram-positive pathogens, including Ent. faecalis and Enterococcus faecium.

CONCLUSIONS

The complete genome sequence of the newly isolated enterococcal lytic phage was analysed, and it was demonstrated that its recombinant endolysin had broad lytic activity against various Gram-positive pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Bacteriophage EFAP-1 and its lytic protein, EFAL-1, can be utilized as potent antimicrobial agents against Enterococcus spp. strains resistant to conventional antibiotics in hospital infections and also as environmental disinfectants to control disease-causing Enterococcus spp. in dairy farms.

Cloning and characterization of a novel tuf promoter from Lactococcus lactis subsp. lactis IL1403

Genetic engineering of lactic acid bacteria (LAB) requires a reliable gene expression system. Especially, a stable promoter is an important genetic element to induce gene expression in such a system. We report on a novel tuf promoter (Ptuf) of Lactococcus lactis subsp. lactis IL1403 that was screened and selected through analysis of previously published microarray data. Ptuf activity was examined and compared with three other known lactococcal promoters (PdnaJ, PpfkA, and Pusp45) using different bacteria as expression hosts. Each promoter was, respectively, fused to the promoterless and modified bmpB gene as a reporter, and we estimated promoter activity through BmpB expression. All promoters were active in IL1403, and Ptuf activity was strongest among them. The activity of each promoter differed by host bacteria (Lactobacillus plantarum Lb25, Lactobacillus reuteri ATCC23272, and Escherichia coli Top10F'). Ptuf had the highest activity in IL1403 when growth reached late log phase. The activity of each promoter correlated with the expression of each cognate gene in the microarray data (R (2) = 0.7186, P = 0.06968). This study revealed that novel food-grade promoters such as IL1403 Ptuf can be selected from microarray data for food-grade microorganisms and Ptuf can be used to develop a reliable gene expression system in L. lactis.

Isolation and characterization of potential probiotic lactobacilli from pig feces

This study examined four lactobacilli isolated from pig feces. Two hundred lactic acid bacteria strains were obtained from pig feces using selective culture media (with vancomycin and bromocresol green; termed LAMVAB agar). Microscopy, the catalase test, Gram-staining, and RAPD-PCR analysis were used to group the bacteria into 20 related clusters. Phenotypic analysis using the API 50 CH test and genotypic analysis of 16S rDNA sequences identified these clusters as representing single strains of each of Lactobacillus fermentum, Lactobacillus salivarius, Lactobacillus plantarum, and Lactobacillus reuteri. Bacterial survival under the conditions of low pH (2.0) and high concentration (5.0%, w/v) of bile salt was much better than that of the reference strain (Lactobacillus acidophilus ATCC 33199). The isolated bacteria were quite capable of inhibiting the growth of two pathogens, Escherichia coli K88 and Salmonella typhimurium. The high acid-resistance, bile resistance and antagonism against pathogens, suggest that the four lactic acid bacteria isolated from pig feces could prove useful as piglet probiotics.

Direct comparison of optical frequency combs using a comb-injection-lock technique

This paper demonstrates a direct comparison of optical frequency combs (OFCs) with different repetition rates without a stable intermediate laser using a single-mode comb-injection-lock technique. Two OFCs based on Ti:Sapphire mode-locked lasers were compared utilizing a single-mode diode laser for the selection and the amplification of one mode of an OFC by comb-injection, which makes the direct comb comparison possible. The frequencies of the two combs were found to agree within 0.019 Hz at 352 THz with the uncertainty of 0.25 Hz (7.1 x 10(-16) ). This is one of the best results among the comparisons of combs referenced to a microwave frequency. This technique simplifies the comb comparison utilities and can be applied even when repetition rates differ.

Coherent multi-frequency optical source generation using a femto-second laser and its application for coherent population trapping

We present a coherent multi-frequency source generated from a mode-locked femto-second laser. The key concept for the coherent multi-frequency source generation is using the mode-locked femto-second laser as many continuous wave (CW) optical sources. We simultaneously selected and amplified the desired modes of the optical frequency comb using femto-second laser injection-locking (FSLIL). Using two coherent sources generated by the mode-locked femto-second laser, we have demonstrated a coherent spectroscopy in a Lambda-type system of the Cs D2 line. The proposed coherent multi-frequency source generation technique will be a useful technique for optical frequency standards based on multi-photon schemes.

Sweep optical frequency synthesizer with a distributed-Bragg-reflector laser injection locked by a single component of an optical frequency comb

A sweep optical frequency synthesizer is demonstrated by using a frequency-stabilized optical frequency comb and injection-locked distributed-Bragg-reflector (DBR) laser diode. The injection-locked DBR laser acts as a single-frequency filter and, simultaneously, a high-gain amplifier of the optical frequency comb. The frequency instability of the heterodyne beat signal between two independently injection-locked DBR lasers is measured to be 2.3 x 10(-16) at 1 s averaging time. The output frequency of the sweep optical frequency synthesizer can be precisely tuned over 1 GHz, and a saturated absorption spectrum of the Cs D2 line at 852 nm is recorded by the injected DBR laser.

Defect structure around two colloids in a liquid crystal

This Letter investigates the defect structures that arise between two colloidal spheres immersed in a nematic liquid crystal. Molecular simulations and a dynamic field theory are employed to arrive at molecular-level and mesoscopic descriptions of the systems of interest. At large separations, each sphere is surrounded by a Saturn ring defect. However, at short separations both theory and simulation predict that a third disclination ring appears in between the spheres, in a plane normal to the Saturn rings. This feature gives rise to an effective binding of the particles. The structures predicted by field theory and molecular simulations are consistent with each other.

Biodegradation of toluene by a lab-scale biofilter inoculated with Pseudomonas putida DK-1

The biodegradation of toluene by biofiltration inoculated with Pseudomonas putida DK-1 was investigated with variation of the several environmental parameters, such as temperature, bed length, gas flow rate and optimal humidity zone. The optimal temperature range to treat toluene gas was found to be 32-35 degrees C. Increasing the gas flow rate showed an inverse effect on the elimination capacity and the removal efficiency. The optimal gas flow rate was obtained at 65 ml min(-1) from the relation between the removal efficiency and the elimination capacity. The biodegradation rate of the toluene with respect to the bed lengths (3, 6, 9, 12 and 15 cm) increased up to 80 h but was then independent of the bed lengths after 80 h except for the 3 cm bed length. The elimination capacity was improved by about 70% compared with that reported in other literature and was also in agreement with theoretical models.

Cold resistance estimated on the basis of fetal hemoglobin changes during acute general cooling

In order to find a criterion for human cold resistance and adaptability we studied the reaction of hematological indices to acute general cooling of the whole organism (12 degrees C, 1 h) in 60 male volunteers 19-25 years old living in Norilsk (69 degrees N) for about 2 1/2 years. The first group of subjects comprised of cold adapted individuals whose professional activity was associated with 4-5 hrs daily work outdoor in cold environment. The volunteers of the second group regularly worked indoor and are considered a priori cold unadapted. Our results indicate that fetal hemoglobin (HbF) concentration shows the most remarkable reaction to acute cooling in comparison with other parameters studied (erythrocyte count, hematocrit, total hemoglobin level). Cold exposure of unadapted young males was accompanied by a marked increase of HbF concentration in venous blood (from 1.27 +/- 0.13% to 2.04 +/- 0.02%, p less than 0.01), whereas the same procedure in the adapted subjects was followed by practically unchanged HbF levels. These findings lead us to the conclusion, that the change of the HbF level under acute general cooling can be considered a satisfactory criterion of human cold resistance.

[Lipid peroxidation reactions to the administration of various doses of zymosan]

The results have been presented of the zymosan (Z) effect mechanism in the reaction of the lipid peroxidation and the parts' separation of the protection antioxidant. The experiments were made on 32 Wistar rats. At the experimental series 25 mg/kg and 100 mg/kg of Z were injected. Control rats were injected with physiological saline alone.

Transformation of horse skin cells by type-C sarcoma viruses

A horse skin cell line (E. Derm, NBL-6, CCL-57) was susceptible to focus formation by the Kirsten mouse sarcoma virus, feline sarcoma virus (ST stain) and the MSV pseudotypes with woolly monkey, gibbon monkey, RD-114, AT-124, baboon placenta and murine xenotropic (BALB/c 3T3 and C57L/JD) type-C viruses. Foci were detected within 5 days after infection and the transformed cells continued to produce infectious virus and group-specific antigen of their respective type-C leukemia viruses. The transformation efficiency of various type-C sarcoma viruses in horse cells was also very high.