Carriage of Staphylococcus aureus among food handlers: An ongoing challenge in public health

Staphylococcus aureus is a commensal bacterium known to colonize the skin, nares, and gastrointestinal tract of humans. Asymptomatic workers can contaminate food via manual contact or through respiratory secretions thus becoming the source of staphylococcal food poisoning. This gastrointestinal intoxication occurs after the ingestion of food contaminated by enterotoxin-producing Staphylococcus aureus. Although most individuals overcome the infection without medical assistance and make a full recovery, in rare cases the infection can be life-threatening. Hence, Staphylococcus aureus food contamination represents a serious problem for both the food industry and healthcare systems. In the last few decades, many studies have investigated the prevalence of carriers among food handlers. We present an overview of all investigations carried out on nasal carriers working in different food industry settings highlighting the risk associated with cross-contamination

Comparison of UV, Peracetic Acid and Sodium Hypochlorite Treatment in the Disinfection of Urban Wastewater

One source of water contamination is the release of wastewater that has not undergone efficient treatment. The aim of this study was to evaluate the reduction obtained with sodium hypochlorite (NaClO), UV and peracetic acid disinfection treatment of Salmonella spp., pathogenic Campylobacter, STEC and bacterial indicators in three full-scale municipal wastewater plants. A general reduction in Salmonella was observed after disinfection, but these bacteria were detected in one UV-treated sample (culture method) and in 33%, 50% and 17% of samples collected after NaClO, UV and PAA disinfection treatments, respectively (PCR method). A better reduction was also observed under NaClO disinfection for the microbial indicators. Independent of the disinfection treatment, E. coli O157:H7 was not detected in the disinfected samples, whereas some samples treated with UV and PAA showed the presence of the stx1 gene. No reduction in the presence of stx2 genes was verified for any of the disinfection treatments. Campylobacter was not detected in any of the analysed samples. The overall results highlight a better reduction in microbiological parameters with a NaClO disinfection treatment in a full-scale municipal wastewater plant compared with UV and PAA. However, the results indicate that a complete and specific monitoring program is necessary to prevent a possible risk to public health

Antitumoral Efficacy of Two Turmeric Extracts According to Different Extraction Methods in Hepatocellular Carcinoma Cell Lines

Curcuminoids, bioactive molecules contained in turmeric, have been reported to exert anticancer effects in several human cancers, including hepatocellular carcinoma (HCC). However, the extraction method can significantly affect the structural characteristics of curcuminoids and their biological properties. On this basis, in the present study we investigated the content of curcuminoids and the anticancer activity of two turmeric powders extracted according two different methodologies: solvent extraction with ethyl acetate vs an ancient Indian extraction method of boiling of rhizomes in water followed by dehydration at the sun. Results obtained showed that extraction with ethyl acetate resulted in a significant recovery of curcuminoids and anticancer activity both in terms of cell cytotoxicity and migration/invasiveness inhibition in HCC cell lines, compared to common Indian practice. Overall these findings suggest that turmeric powders could have different efficacy, depending on the extraction method. This aspect should be taken into account when choosing the best product to be employed in the prevention and treatment of human diseases, including cancer

Assessment of hygienic conditions of recreational facility restrooms: an integrated approach

Introduction. Microbiological quality of recreational environ- ments included restrooms, is generally assessed by water and surface monitoring. In this study, an environmental monitoring, conducted in spring, of swimming pool restrooms of a recreation center located in the Marche region has been carried out. Seven water samples and seven surface swabs were collected. Moreover, six air samples have been included. The aim of this study was to evaluate if air microbiological monitoring, along with molecular detection in real-time PCR, could give additional useful information about the hygienic conditions of the facility. Methods. Heterotrophic Plate Count (HPC) both at 22°C (psy- chrophilic) and 37°C (mesophilic) was determined by separate cultures in all samples. The presence of Legionella pneumophila and Pseudomonas aeruginosa was evaluated by both culture and real-time PCR. Results. The analysis of shower water recorded a HPC load of mesophilic bacteria (37°C) more than 10-fold higher in men restroom, respect to women’s one (> 100 vs < 10 CFU/ml), while in air samples was between < 100 and > 500. Concerning pathogen presence, both species Legionella pneumophila and Pseudomonas aeruginosa were detected only in men restroom, but in different sample types by using different methods (culture and real-time PCR). Conclusions. Air sampling may offer the advantage of giving more representative data about microbial presence in restrooms, including bacterial species transmitted through aerosol, like Legionella. Moreover, the concurrent use of molecular and micro- biological detection in an integrated approach could offer the advantage of greater sensitivity

The Inhibitory Effect of ddC on Human Immunodeficiency Virus Replication Diminishes in Cells that are Chronically Exposed to the Drug

One possible explanation for the failure of human immunodeficiency virus type 1 (HIV-1) antiretroviral inhibitors to block the clinical progression of the infection may be a failure to maintain adequate drug levels at the site of viral replication. We have previously found that exposure of human monoblastoid cells (U937) for several months to a therapeutically relevant concentration (0.1 μM) of 2′,3′-dideoxycytidine (zalcitabine, ddC) allowed the isolation of a drug-resistant cell line characterized by a normal drug transport but a reduced ability to accumulate 2′,3′-dideoxycytidine 5′-triphosphate (the active antiretroviral form of the drug). In this paper we show that the drug-resistant cells were indistinguishable from normal cells in terms of surface CD4 receptors. The susceptibility of parental and ddC-resistant U937 cells to infection by HIV-1 was similar, as measured by proviral DNA formation. However, HIV-1 p24 production and the number of infectious virus particles produced were significantly lower in the drug-resistant compared to control cells. Addition of 0.1 μM ddC inhibited viral production by up to 92% in the control cells but had no effect on ddC-resistant cells. Thus, human cells exposed to therapeutically relevant ddC concentrations for several months show a reduced ddC anabolism and allow ddC-sensitive HIV-1 to replicate in the presence of inhibitory ddC concentrations

Modulation of Stat-1 in human macrophages infected with different species of intracellular pathogenic bacteria.

none6The infection of human macrophages by pathogenic bacteria induces different signaling pathways depending on the type of cellular receptors involved in the microorganism entry and on their mechanism(s) of survival and replication in the host cell. It was reported that Stat proteins play an important role in this process. In the present study, we investigate the changes in Stat-1 activation (phosphorylation in p-tyr(701)) after uptake of twoGram-positive (Listeria monocytogenes and Staphylococcus aureus) and two Gram-negative bacteria (Salmonella typhimurium and Legionella pneumophila) characterized by their varying abilities to enter, survive, and replicate in human macrophages. Comparing the results obtained with Gram-negative and Gram-positive bacteria, Stat-1 activation in macrophages does not seem to be related to LPS content. The p-tyr(701) Stat-1 expression levels were found to be independent of the internalized bacterial number and IFN-gamma release. On the contrary, Jak/Stat-1 pathway activation only occurs when an active infection has been established in the host macrophage, and it is plausible that the differences in the expression levels of p-tyr(701) Stat-1 could be due to different survival mechanisms or to differences in bacteria life cycles within macrophages.openSchiavano, Giuditta Fiorella; Dominici, Sabrina; Rinaldi, Laura; Cangiano, Alfonsina Mariarosaria; Brandi, Giorgio; Magnani, MauroSchiavano, GIUDITTA FIORELLA; Dominici, Sabrina; Rinaldi, Laura; Cangiano, ALFONSINA MARIAROSARIA; Brandi, Giorgio; Magnani, Maur