Marina Cubeddu

Evaluation of the Antimicrobial Properties of the Essential Oil of Myrtus communis L. against Clinical Strains of Mycobacterium spp.

Mycobacterium tuberculosis is the etiological agent of tuberculosis. The World Health Organization has estimated that 8 million of people develop active TB every year and the situation is complicated by an increase of Mycobacterium tuberculosis strains resistant to drugs used in antitubercular therapy: MDR and XDR-TB. Myrtle leaf extracts, used as an antiseptic in Sardinian traditional medicine, have strong antibacterial activity as several investigations showed. In this study we investigated the antimicrobial properties of the essential oil of Myrtus communis against clinical strains of M. tuberculosis and M. paratuberculosis.

Tuberculosis patients are characterized by a low–IFN-γ/high–TNF-α response to methylated HBHA produced in M. smegmatis

Whole blood from Mycobacterium tuberculosis-infected subjects was stimulated with heparin-binding hemagglutinin (HBHA). Tuberculosis (TB) patients showed an HBHA-specific T-cell response characterized by low-IFN-γ/high-TNF-α secretion, while asymptomatic subjects with latent infection (LTBI) and TB patients under therapy showed a pattern with high IFN-γ/low TNF-α. These results underscore the usefulness of HBHA in helping to distinguish LTBI subjects versus TB patients.

Tuberculosis screening among asylum seekers in Sardinia.

Background In Italy, the guidelines for preventing Tuberculosis (TB) include X-ray screening and application of the Mantoux test for migrants from TB-endemic countries as soon as possible after admission to Italy. This article describes a screening survey conducted in the reception center for asylum seekers in Northern Sardinia. Methods The screening tests of Mantoux, chest X-ray, QuantiFERON TB Gold and Inducible-protein-10 were carried out on 109 subjects came from Africa and Asia. Results Mantoux was positive in 40 subjects and negative in 69. Chest X-rays were performed in all of the 40 Mantoux-positive subjects, and it was negative. QuantiFERON was positive in 16 refugees, negative in 92 and indeterminate in 1. A positive Inducible-protein-10 response was observed in 29 subjects, while a negative result was detected in 80 subjects. Conclusions Our results showed that the Mantoux may not be a suitable screening test in the migrant population considering its low specificity. QFT may be more suitable to identify subjects with tubercular infection may to receive preventive therapy, although its sensitivity could be increased by the Inducible-protein-10.

Could inducible protein-10 and heparin-binding hemagglutinin improve the detection of Mycobacterium tuberculosis-infected subjects in a country with low incidence of tuberculosis ?

Abstract Background: This study aimed to evaluate inducible protein-10 (IP-10) as a biomarker besides interferon-gamma (IFN-γ) to improve the identification of active tuberculosis (TB) and latent tubercular infection (LTBI) in a country with a low incidence of TB. Methods: Whole blood from Mycobacterium tuberculosis-infected subjects was stimulated with region-of-difference-1 (RD1)-specific peptides and with heparin-binding hemagglutinin (HBHA) to determine the release of IP-10 and IFN-γ. Results: No statistically significant difference was observed between positive rates of IP-10 and IFN-γ after RD1-specific peptide stimulation in the TB and LTBI groups; a different response was detected in QuantiFERON TB-gold test-negative (QFT–) subjects. A significantly different proportion of positive responses was observed between IP-10 and IFN-γ following HBHA stimulation in the TB group and in the QFT– group but not in the LTBI group. Conclusions: The IP-10 test seemed to identify false-negative QFT results in some subjects with a positive IFN-γ/IP-10/HBHA pattern.

Tuberculosis in Sardinia: An investigation into the relationship between natives and immigrants

Objective/background: Tuberculosis (TB) has had a recrudescence in the last few decades in Italy as a result of many factors, among which migration from countries where TB is endemic is one of them. In Sardinia, a major island of Italy, there was no knowledge of the mechanisms of transmission of TB in the immigrant subpopulation and the impact it may have on the native subpopulation and on the community as a whole. Therefore, a molecular epidemiological study was carried out to get a clearer picture of the number and genetic features of Mycobacterium tuberculosis strains isolated from immigrants and from natives in Sardinia. Methods: Two groups of clinical isolates of M. tuberculosis, one collected from immigrants and the other one from Sardinians, were analyzed in this study. The genotyping was executed through the variable number tandem repeat-mycobacterial interspersed repetitive units technique and a first-line antimycobacterial drug-susceptibility test was also carried out. Results: Thirty-six clinical isolates from immigrants and 25 from Sardinians were analyzed. Variable number tandem repeat-mycobacterial interspersed repetitive units technique showed that all of them belonged to different strains and there was a quite high allelic diversity among them. Moreover, data collected allowed the finding of, with a good approximation, the phylogenetic relations among the strains isolated and the best-known phylogenetic groups. Conclusion: The study pointed out that since every strain is different, there was no TB transmission in any of the subpopulations and between immigrants and natives. This showed that the presence of immigrants was not a risk factor for contracting TB in the community.

Comparison of two molecular methods for diagnosis of Chlamydia trachomatis

Chlamydia trachomatis is an obligate intracellular microorganism responsible for several diseases. It is considered the most common bacterial sexually transmitted infection (STI) worldwide. The World Health Organization (WHO) estimates that 92 million new cases of C. trachomatis occur globally every year. An estimated 3 to 4 million new cases are diagnosed every year in the United States, 5 million in Western Europe, and 16 million in sub-Saharan Africa. According to estimates from the Centers for Disease Control and Prevention (CDC), 75% of new cases in the United States are diagnosed in asymptomatic women. The sequelae of chlamydial infection in women are severe and can lead to serious complications, including pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain. Chlamydial genital infections have also been reported to increase human immunodeficiency virus transmission and influence the development of human papillomavirus-induced adenocarcinoma. In addition, pregnant women infected with C. trachomatis put their children at risk for conjunctivitis and pneumonitis through mother-to-child transmission. In men C. trachomatis is associated with non-gonococcal urethritis and epididymitis. In the male high-risk group, 50% are asymptomatic with mild symptoms. Today, sexually transmitted diseases are major and ever-expanding public health and social problems because of an increased rate of C. trachomatis infection in both the female and male population within the sexually active 20- to 30-year-old group . Several hypotheses may explain the rise of chlamydial infections, including changes in sexual behavior and insufficient knowledge of sexual life and sexual health. Moreover, the use of more sensitive tests may contribute to the rising rates. In Northern Sardinia as well, the problem is rising among young people. For this reason, screening programs must be implemented to prevent morbidity. Furthermore, a rapid diagnosis of the microorganism is essential to reduce the transmission of infection, most of all in young people.

Epidemic of tuberculosis in a high school in Northern Sardinia

The aim of this study was to investigate the Mycobacterium tuberculosis transmission among high school student and teacher populations in a high school in Northern Sardinia. Tuberculin skin-test screening, chest-X-rays, QuantiFERON-TB Gold, microbiological examination, spoligotyping and variable numbers of tandem repeats (VNTR) analysis of M. tuberculosis isolates were performed. This study indicates the effectiveness of the epidemiological investigation.

USEFULNESS OF THE QUANTIFERON-TB-GOLD IN TUBE IN A POPULATION AT RISK OF BOVINE TUBERCULAR INFECTION

The effectiveness of the QuantiFERON-TB-Gold in tube was compared with PPD to detect tuberculosis infection in the staff of cattle-farms, as a consequence of an outbreak of bovine tuberculosis in livestock. The data revealed the advantage of the immunological test for the specific detection of subjects infected by Mycobacterium tuberculosis complex.