Observation of Rayleigh-Lamb waves generated by the 2022 Hunga-Tonga volcanic eruption with the POLA detectors at Ny-Ålesund.

The eruption of the Hunga-Tonga volcano in the South Pacific Ocean on January 15, 2022, at about 4:15 UTC, generated a violent explosion, which created atmospheric pressure disturbances in the form of Rayleigh-Lamb waves detected all over the globe. Here we discuss the observation of the Hunga-Tonga shock-wave performed at the Ny-Ålesund Research Station on the Spitsbergen island, by the detectors of the PolarquEEEst experiment and their ancillary sensors. Online pressure data as well as the results of dedicated offline analysis are presented and discussed in details. Results include wave arrival times, wave amplitude measurements and wave velocity calculation. We observed five passages of the shock wave with a significance larger than 3 [Formula: see text] and an amplitude up to 1 hPa. The average propagation velocity resulted to be (308 ± 0.6) m/s. Possible effects of the atmospheric pressure variation associated with the shock-wave multiple passages on the cosmic-ray rate at ground level are also investigated. We did not find any significant evidence of this effect.

In vitro and in vivo immune stimulating effects of a new standardized Echinacea angustifolia root extract (Polinacea).

Polinacea is a new standardized hydroethanolic extract obtained from Echinacea angustifolia roots containing echinacoside (>4%), the high molecular weight polysaccharide IDN 5405 (>5%) and a isobutylamide fraction (<0.1%). For in vitro tests, a bacterial lipopolysaccharide-free (LPS-free) Polinacea has been prepared in order to avoid non-specific responses of immunocompetent cells. LPS-free Polinacea enhanced the immune functions as highlighted by the proliferation rate and gamma-interferon production in murine T-lymphocyte cell cultures stimulated by anti-CD3. LPS-free Polinacea did not have a direct role on macrophage response as measured in the nitric oxide production test using the J774 macrophage cells line. In vivo, Polinacea showed an immune stimulating activity by reducing the Candida albicans induced mortality both in normal and in cyclosporin A-treated mice.

Genetic diversity of Pneumocystis carinii isolated from human immunodeficiency virus-positive patients in Turin, Italy.

By DNA sequence analysis we identified two new strain types and five novel sporadic variations among 25 isolates of Pneumocystis carinii f. sp. hominis obtained from 19 human immunodeficiency virus-positive patients. Of these, 13 were infected with a single strain and 6 were coinfected. Fifteen different combination types were identified among the 18 strains for which complete molecular typing was accomplished.

In vitro activity of propolis against Streptococcus pyogenes.

Propolis, a multifunctional substance used by bees to maintain the safety of their hives, is popular for its therapeutic potential against some micro-organisms. Ethanolic extracts of two propolis specimens, collected from different areas within a region in the north-west of Italy, were examined to evaluate their antimicrobial activity against 46 Streptococcus pyogenes strains. By both agar dilution and agar diffusion methods, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were

Macrolide resistance in group A streptococci.

Two hundred and twenty one Streptococcus pyogenes isolates collected from throat swabs of untreated children with uncomplicated pharyngotonsillitis living in two centres situated in the north of Italy were tested to evaluate their macrolide resistance phenotype. Isolates were also typed for T protein and assayed for opacity factor (OF) and protease production. Resistance to macrolides was found to be similar in the two centres. Fifty-one point two per cent of Torino strains and 43.5% of Pinerolo strains were not inhibited by erythromycin. Resistant strains belonged to one of three phenotypes: CR, constitutive resistance (37.9 and 42.5% in Torino and Pinerolo, respectively); IR, inducible resistance (40.9 and 17. 5%); NR, new resistance phenotype (21.2 and 40%). All the resistant and some of the susceptible strains were analysed by pulsed-field gel electrophoresis and genomic patterns were defined on the basis of band size and number. Five DNA profiles were found among erythromycin-resistant strains: three patterns characterized the NR resistance phenotype and one each the IR and CR phenotypes. The distribution of resistant strains according to their genomic patterns appears to be related to the resistance phenotype and only in some cases to the T serotype of bacteria. We conclude that the S. pyogenes strains analysed are genetically heterogeneous and therefore the high rate of erythromycin resistance observed is not caused by the spread of a single clone nor is it related to a particular serotype.

Streptococcus pyogenes collected in Torino (northwest Italy) between 1983 and 1998: survey of macrolide resistance and trend of genotype by RAPD.

We surveyed macrolide resistance in 1,086 isolates of Streptococcus pyogenes, collected between 1983 and 1998, from throat swabs of children with untreated pharyngotonsillitis living in Torino (northwest Italy). In 1983 and 1985, the frequency of erythromycin resistance was 10%, and from 1990 to 1992 it was 4%. However, it rose to 16.6% in 1994 and reached 51% in 1996 before decreasing to 38.5% in 1998. Characterization of the phenotype of resistant isolates revealed the prevalence of constitutive resistance (CR) in 1996, whereas the M phenotype, characterized by resistance to 14- and 15-membered macrolides with susceptibility to clindamycin and streptogramin B, prevailed in 1998. Moreover, in 1997 we observed an increase in the frequency of autoagglutinating bacteria and, in 1998, of OF-negative S. pyogenes. Meanwhile, penicillin tolerance, assessed in the isolates collected from 1990 to 1996, decreased and disappeared. Random amplification of polymorphic DNA (RAPD) was used to obtain the genomic profile of 32 S. pyogenes strains. Four main DNA profiles were demonstrated, generally related to the macrolide-resistance phenotype and for the major part to the T serotype. These results indicate that RAPD is reliable as a first screening method in the epidemiological characterization of resistant S. pyogenes.