Immune roles of a rhamnose-binding lectin in the colonial ascidian Botryllus schlosseri.

The present paper describes the immune role played by a recently identified (Gasparini et al. 2008) member of the rhamnose-binding lectin (RBL) family from the colonial ascidian Botryllus schlosseri. B. schlosseri RBL (BsRBL) can activate phagocytes through: (i) induction of their directional movement towards the source of the molecule; (ii) modification of cytoskeleton, required for shape changes; (iii) stimulation of the respiratory burst, and consequent production of reactive oxygen species (ROS) with microbicidal activity, including superoxide anions and peroxides; and (iv) increase in the ability to phagocytose foreign particles. RBL also induces the synthesis and release, by cytotoxic morula cells (MCs), of cytokines recognised by anti-IL1α and anti-TNFα antibodies. At high concentrations, BsRBL induces degranulation of MCs and the consequent release of the cytotoxic enzyme phenoloxidase into the medium. Results are consistent with the existence of cross-talk between B. schlosseri immunocytes (phagocytes and MCs). In addition, a three-dimensional model for BsRBL is presented.

In vitro effects of glycyrrhetinic acid on the growth of clinical isolates of Candida albicans.

Compounds derived from Glycyrrhiza glabra L. root have been used widely for centuries for their numerous therapeutic properties. The present study aimed to test the in vitro activity against Candida albicans strains of the compound 18-beta glycyrrhetinic acid (18-beta GA), derived from the root of Glycyrrhiza species. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on C. albicans strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). The in vitro growth of the C. albicans strains was markedly reduced, in a pH-dependent manner, by relatively low doses (6.2 microg/mL) of 18-beta GA. The results demonstrate that 18-beta GA is a promising biological alternative for the topical treatment of recurrent vulvovaginal candidiasis (RVVC).

Substitution of the arginine/leucine residues in apidaecin Ib with peptoid residues: effect on antimicrobial activity, cellular uptake, and proteolytic degradation.

Several aspects of the mechanism of action of Pro-rich antimicrobial peptides, together with their low toxicity in mammalian cells, make them good candidates for the development of new antibiotic agents. We investigated the effect induced in the insect antimicrobial peptide apidaecin Ib by the replacement of a single arginine/leucine residue with a N-substituted glycine. The resulting peptoid-peptide hybrids are more resistant to proteolysis and devoid of any significant cytotoxic activity, but moving the [NArg]residue from the N- to the C-terminal end of the molecule progressively reduces the antibacterial activity. Cell uptake experiments in E. coli cells suggest that the loss of antibacterial activity of [NArg(17)]apidaecin is a consequence of its inability to translocate into bacterial cells. Conversely, apidaecin and its peptoid-peptide hybrids are able to cross the plasma membrane in eukaryotic cells and to diffuse in the cytosol, although their translocating ability is far less effective than that of other known cell permeant peptides.

Genital tract infections and infertility.

Infectious agents can impair various important human functions, including reproduction. Bacteria, fungi, viruses and parasites are able to interfere with the reproductive function in both sexes. Infections of male genito-urinary tract account for about 15% of the case of male infertility. Infections can affect different sites of the male reproductive tract, such as the testis, epididymis and male accessory sex glands. Spermatozoa themselves subsequently can be affected by urogenital infections at different levels of their development, maturation and transport. Among the most common microorganisms involved in sexually transmitted infections, interfering with male fertility, there are the Chlamydia trachomatis and Neisseria gonorrhoeae. Less frequently male infertility is due to non-sexually transmitted epididymo-orchitis, mostly caused by Escherichia coli. In female, the first two microorganisms are certainly involved in cervical, tubal, and peritoneal damage, while Herpes simplex cervicitis is less dangerous. The overall importance of cervical involvement is still under discussion. Tubo-peritoneal damage seems to be the foremost manner in which microorganisms interfere with human fertility. C. trachomatis is considered the most important cause of tubal lacerations and obstruction, pelvic inflammatory disease (PID) and adhesions. N. gonorrhoeae, even though its overall incidence seems to decline, is still to be considered in the same sense, while bacterial vaginosis should not be ignored, as causative agents can produce ascending infections of the female genital tract. The role of infections, particularly co-infections, as causes of the impairment of sperm quality, motility and function needs further investigation. Tropical diseases necessitate monitoring as for their diffusion or re-diffusion in the western world.

A study on the inactivation of micro-organisms and enzymes by high pressure CO2.

This study addresses some microbial inactivation phenomena induced by high pressure CO2 over micro-organisms and enzymes. The activity of four selected enzymes was measured before and after treatment with CO2 under pressure in both buffer solutions and natural cellular environment (E. coli cells and tomato paste). Results are reported for acid phosphatase, alkaline phosphatase, ATPase, and pectinase at different conditions of temperature, CO2 pressure, and treatment time (32-40 degrees C, 85-150 bar, 30-70 min). The results obtained show that the high pressure CO2 treatment induces an inactivation of cellular enzymatic activity higher than the one caused on the same enzymes in solution. However, the measured activity difference is not caused by a damage at the enzymes molecular level but is a consequence of the permeabilization of the cellular envelopes which leads to a release of unmodified enzymes from the cells with simultaneous drop of enzymatic cellular activity. The reported data suggest that the bacterial cell death is probably due not to a selective effect of high pressure CO2 treatment but to simultaneous detrimental action of CO2 on cellular membrane and cell wall.

Laterally transferred elements and high pressure adaptation in Photobacterium profundum strains.

BACKGROUND: Oceans cover approximately 70% of the Earth's surface with an average depth of 3800 m and a pressure of 38 MPa, thus a large part of the biosphere is occupied by high pressure environments. Piezophilic (pressure-loving) organisms are adapted to deep-sea life and grow optimally at pressures higher than 0.1 MPa. To better understand high pressure adaptation from a genomic point of view three different Photobacterium profundum strains were compared. Using the sequenced piezophile P. profundum strain SS9 as a reference, microarray technology was used to identify the genomic regions missing in two other strains: a pressure adapted strain (named DSJ4) and a pressure-sensitive strain (named 3TCK). Finally, the transcriptome of SS9 grown under different pressure (28 MPa; 45 MPa) and temperature (4 degrees C; 16 degrees C) conditions was analyzed taking into consideration the differentially expressed genes belonging to the flexible gene pool. RESULTS: These studies indicated the presence of a large flexible gene pool in SS9 characterized by various horizontally acquired elements. This was verified by extensive analysis of GC content, codon usage and genomic signature of the SS9 genome. 171 open reading frames (ORFs) were found to be specifically absent or highly divergent in the piezosensitive strain, but present in the two piezophilic strains. Among these genes, six were found to also be up-regulated by high pressure. CONCLUSION: These data provide information on horizontal gene flow in the deep sea, provide additional details of P. profundum genome expression patterns and suggest genes which could perform critical functions for abyssal survival, including perhaps high pressure growth.

HPV genotype prevalence in cervical specimens with abnormal cytology: a report from north-east Italy.

We have investigated the prevalence of HPV DNA in cervical samples collected from 1335 women with abnormal Pap test and analysed the degree of association of HPV genotype with cervical cytological abnormality and also with patient age. The study was principally aimed at providing some cross-sectional figures on the epidemiology of HPV in our area, where the ethnic background is expected to rapidly evolve due to extensive immigration from overseas. 471 (35.3%) of the 1335 patients screened were positive for HPV DNA. A clear association was observed between cytological findings and the proportion of patients with positive HPV PCR, namely 24.0% HPV positivity in the ASCUS group (atypical squamous cells of undetermined significance), 48.7% in LSIL group (low grade squamous intraepithelial lesions), and 71.9% in HSIL group (high grade squamous intraepithelial lesions) (p-value < 0.001). High-risk (HR) HPV prevalence appeared to be different from other areas of the world; we have detected a high prevalence rate of HPV-16, 31, and 58 and a low prevalence rate of HPV-18 and 11. The prevalence of both HR and low risk (LR) genotype groups was clearly related to age (p-value < 0.001), since the prevalence of LR group had a nadir between 41 and 50 y of age and 2 peaks at 15-20 y and at over 60 y, while the curve of prevalence of HR genotypes displayed an almost inverse trend.

Determination of extracellular and intracellular pH of Bacillus subtilis suspension under CO2 treatment.

In this study, we consider the effect of carbon dioxide (CO(2)) on the intracellular and extracellular pH of a saline solution of a test-microorganisms Bacillus subtilis. The cytoplasmatic pH was determined by means of a flow cytometry with the fluorescent probe 5(and 6-)-carboxyfluorescein ester (cFSE). The physiological suspension of cells with the addition of the probe was first exposed to high pressure CO(2) for 5 min at different temperatures. The flow cytometry analysis indicated an intracellular depletion inside the cell caused by the action of CO(2), down to 3, the depletion being dependent on inactivation ratio. In addition, the extracellular pH was determined theoretically by means of the statistical associated fluid theory equation of state (SAFT EOS): it was demonstrated that CO(2) under pressure dissolves into liquid phase and acidifies the medium down to 3 at 80 bar and 303.15K. The results show a strong influence between extracellular and intracellular pH, and lead to the conclusion that a strong reduction of the pH homeostasis of the cell can be claimed as one of the most probable cause of inactivation of CO(2) pasteurization.

Pressure effects on Clostridium strains isolated from a cold deep-sea environment.

Three Clostridium strains were isolated from deep-sea sediments collected at a depth of 6.3-7.3 km in the Japan Trench. Physiological characterization and 16S rDNA analysis revealed that the three isolates were all closely related to Clostridium bifermentans. The spores of all three isolates were resistant to inactivation at high pressure and low temperature. However, despite the fact that the vegetative cells were halotolerant and eurythermal they did not appear to be adapted for growth or viability under the conditions prevailing in the deep-sea sediments from which they were obtained. The results suggest that the isolates had survived as spores in the deep-sea sediments and that the marine benthos could be a source of clostridia originating in other environments.

Rapid detection of Paenibacillus larvae from honey and hive samples with a novel nested PCR protocol.

The bacterial pathogen Paenibacillus larvae is the causative agent of American foulbrood disease in honeybees (Apis mellifera). A touchdown nested PCR protocol was developed to detect the presence of P. larvae spores directly in honey and hive samples. This approach allows early discovery of the bacteria even at concentrations below pathogenic levels, opening the door to new prophylactic approaches against American foulbrood and real-time epidemiological studies.

Photoinactivation of bacterial strains involved in periodontal diseases sensitized by porphycene-polylysine conjugates.

Selected bacterial strains that are responsible for periodontal diseases are efficiently inactivated by visible light irradiation in the presence of porphycene-polylysine conjugates. Repeated photosensitization of surviving cells does not induce the selection of resistant bacterial strains and does not modify their sensitivity to antibiotic treatment.