Evidence of cross-contamination of waste workers and transmission of antimicrobial resistance genes by coagulase-negative Staphylococcus isolated from dental solid waste: an intriguing study.

The aim of this study was to phenotypically and genotypically identify coagulase-negative Staphylococcus (CoNS) recovered from the nostrils of waste workers and from dental waste; 135 strains were recovered and S. epidermidis was the prevailing species. Genetic similarity (100%) was observed between the two S. epidermidis isolated from different employees on the same shift and 85% similarity between the S. epidermidis recovered from an employee's nostril and from waste. The mecA gene was found in 20 CoNS, and 20% were also found to possess the vanA gene. The blaZ gene was detected in 46.7%, and the icaA (34.8%), B and C genes (11.8% each). Our findings emphasized the biological risk to which waste workers are exposed and unprecedently confirms that it was possible to recover genetically identical bacterial species from waste and from workers' nostrils. It is important to highlight that this risk is raised by the detection of relevant antimicrobial resistance genes. The results also suggest that effective measures to correctly manage waste and promote the rational use of antimicrobials should be adopted.

Th1 immune response to H. pylori infection varies according to the age of the patients and influences the gastric inflammatory patterns.

To compare children and adults in respect to the effect of H. pylori infection on the gastric concentrations of cytokines linked to innate and Th1 immune response, as well as to investigate the changes in the gastric concentrations of the studied cytokines according to the age. We studied 245 children (142 H. pylori-negative and 103 H. pylori-positive) and 140 adults (40 H. pylori-negative and 100 H. pylori-positive). The gastric concentrations of cytokines representative of the innate and Th1 response were higher in the H. pylori-positive than in the -negative children and adults. The gastric concentrations of IL-1α and TNF-α were significantly higher, while those of IL-2, IL-12p70 and IFN-γ were lower in the infected children than in the infected adults. In the infected children, the gastric concentration of IL-1α, IL-2, IL-12p70 and IFN-γ increased, whereas in adults, the gastric concentrations of IFN-γ and IL-12p70 decreased with the aging. Increased gastric concentration of Th1 associated cytokines correlated with increased degree of gastritis that is the background lesion for the development of the H. pylori associated severe diseases. Concluding, Th1 response to H. pylori infection varies according to the age and seems to have determinant implication in the H. pylori infection outcomes.