Essential Oil from Origanum vulgare Completely Inhibits the Growth of Multidrug-Resistant Cystic Fibrosis Pathogens.

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.

Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis.

In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris) to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc). These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF), and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris) were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients), suggesting that they might be used in the future to fight B. cepacia complex infections.

Sero-epidemiology of hepatitis B markers in the population of Tuscany, Central Italy, 20 years after the implementation of universal vaccination.

Italy was one of the first industrialized countries to introduce a program of universal vaccination against hepatitis B in 1991. Twenty years later we verified the impact of universal immunisation on the epidemiology of hepatitis B infection by analyzing the prevalence of specific viral markers (anti-HBs, anti-HBc and HBsAg). The ELISA tests were performed on residual blood samples collected by 0.05% of the resident population aged 1-50 years in Tuscany (Italy). About 63% of subjects aged < 30 years were anti-HBs positive compared to about 25% in older subjects, without differences between genders. About 22% of subjects over 40 years were anti-HBc-positive compared to 5% in the younger age groups. The number of HBsAg-positive subjects was almost 10 fold higher in the unvaccinated age groups than in the cohorts involved in the universal vaccination program. The results of our study show the persisting high anti-HBs reactivity in vaccinated cohorts, while HBV markers related to natural exposure or persistent infection remain remarkably higher in older age groups. This sero-epidemiological study supports with prevalence data the downward incidence trend of acute hepatitis B highlighted by epidemiological surveillance systems, and corroborates the forecast for elimination of hepatitis B in Italy in a few decades.

Progress towards measles and rubella elimination in Tuscany, Italy: the role of population seroepidemiological profile.

BACKGROUND: As a part of the National Plan for Measles and Congenital Rubella Elimination, a catch-up campaign targeting children aged 7-14 years with Measles-Mumps-Rubella (MMR) vaccine was conducted during 2004-05 in Tuscany, Central Italy. METHODS: To assess the profile of measles and rubella susceptibility, immunoglobulin G antibodies against measles (945 subjects) and rubella (1110 subjects) were detected using two commercial enzyme-linked immunosorbent assay tests in sera from a population aged 1-49 years. RESULTS: Overall immunity towards measles increased in the last years, but the WHO-Euro recommended threshold of susceptibility for elimination was attained only in 2- to 4-year-olds. All fertile women up to 29 years had rates of susceptibility clearly higher than those required by WHO-Euro (5%) to eliminate congenital rubella. Despite the reduction of susceptibility among subjects targeted by the catch-up campaign, continuous efforts to increase immunization coverage are needed to eliminate measles and rubella circulation. Our results are predictive of a high chance of measles and rubella outbreaks because of the accumulation of susceptible individuals. CONCLUSION: Additional catch-up vaccination strategies targeting the adult population (particularly fertile women) are strongly needed to eliminate the risk of measles and congenital rubella syndrome for future generations.

Primary Hepatitis A vaccination failure is a rare although possible event: results of a retrospective study.

A case of Hepatitis A occurred in a traveller in spite of a complete course of immunization with a combined HAV and HBV vaccine [Taliani G, Sbaragli S, Bartoloni A, Santini MG, Tozzi A, Paradisi F. Hepatitis A vaccine failure: how to treat the threat. Vaccine 2003;21(31):4505-6]. A retrospective study was performed to evaluate whether the failure was primary or could be attributed to a specific lot of vaccine or to its inadequate handling and/or storage. Two distinct populations of vaccinees were selected in a 1:2 proportion. The case group (N=31) included subjects who were vaccinated in the same period and with the same lot and batch of vaccine as the case. The control group (N=62) included subjects who received different lot and batch of the same vaccine as the case group. A persisting antibody response to HAV vaccine was found among all subjects (anti-HAV >20mIU/ml). The overall anti-HBs seropositivity rate (anti-HBs >10mIU/ml) was 74%, without significant difference between the case (77%) and the control group (73%; P>0.05). The reported Hepatitis A case can be attributed to a rare primary vaccine failure rather than to inefficacy of a specific lot of vaccine or to inappropriate vaccine handling or storage. Our study supports the indications for use of combined Hepatitis A+B immunization in travellers at risk for both infections, but stresses the need for information on correct hygienic behaviours while abroad.

Hofmeister effects in supramolecular and biological systems.

Specific ion effects, representative of near-universal Hofmeister phenomena, are illustrated in three different systems. These are the formation of supramolecular assemblies from cyclodextrins, the optical rotation of L-serine, and the growth rate of two kinds of microorganisms (Staphylococcus aureus and Pseudomonas aeruginosa). The strong specific ion effects can be correlated with the anion polarizabilities and related physico-chemical parameters. The results show the relevance of dispersion (non-electrostatic) forces in these phenomena.

Specific ion effects on the growth rates of Staphylococcus aureus and Pseudomonas aeruginosa.

Motivated by recent advances in the physical and chemical basis of the Hofmeister effect, we measured the rate cell growth of S. aureus--a halophilic pathogenic bacterium--and of P. aeruginosa, an opportunistic pathogen, in the presence of different aqueous salt solutions at different concentrations (0.2, 0.6 and 0.9 M). Microorganism growth rates depend strongly on the kind of anion in the growth medium. In the case of S. aureus, chloride provides a favorable growth medium, while both kosmotropes (water structure makers) and chaotropes (water structure breakers) reduce the microorganism growth. In the case of P. aeruginosa, all ions affect adversely the bacterial survival. In both cases, the trends parallel the specific ion, or Hofmeister, sequences observed in a wide range of physico-chemical systems. The correspondence with specific ion effect obtained in other studies, on the activities of a DNA restriction enzyme, of horseradish peroxidase, and of Lipase A (Aspergillus niger) is particularly striking. This work provides compelling evidence for Hofmeister effects, physical chemistry in action, in these organisms.

Impact of universal vaccination programmes on the epidemiology of hepatitis B: 10 years of experience in Italy.

Ten years have elapsed since routine vaccination of infants and of 12-year-old adolescent was implemented in Italy. In this period, evidence has accumulated on the epidemiological impact of universal immunisation. Coverage is on average >90% and is >or=95% in many areas of the country. Incidence of acute hepatitis B, that was already declining before 1991, was further decreased by routine vaccination programmes. This is particularly evident in adolescents and young adults (cohorts involved by mandatory vaccination), while incidence shows little changes in older subjects according to data of the last years. Prevalence of hepatitis B virus (HBV) markers detected by sero-epidemiological studies on anonymous sera confirms both the very high coverage with hepatitis B vaccination and the virtual absence of chronic HBsAg carriers in cohorts involved by routine vaccination programmes. The system of passive surveillance on adverse events following hepatitis B vaccination supports the excellent safety record of hepatitis B vaccines. In a hyperendemic area of Southern Italy, where a pilot programme was firstly implemented, it was also possible to document the decline of the involvement of hepatitis B in chronic liver pathologies (from 48% in 1982 to 18% in 1997). If coverage rates are maintained at the present levels, elimination of HBV transmission in Italy may be envisaged in few decades.