Identification of repellent odorants to the body louse, Pediculus humanus corporis, in clove essential oil

In vitro activity of essential oils against adult and immature stages of Ctenocephalides felis felis

Essential oils (EOs) are considered a new class of ecological products aimed at the control of insects for industrial and domestic use; however, there still is a lack of studies involving the control of fleas. Ctenocephalides felis felis, the most observed parasite in dogs and cats, is associated with several diseases. The aim of this study was to evaluate the in vitro activity, the establishment of LC50 and toxicity of EOs from Alpinia zerumbet (Pers.) B. L. Burtt & R. M. Sm, Cinnamomum spp., Laurus nobilis L., Mentha spicata L., Ocimum gratissimum L. and Cymbopogon nardus (L.) Rendle against immature stages and adults of C. felis felis. Bioassay results suggest that the method of evaluation was able to perform a pre-screening of the activity of several EOs, including the discriminatory evaluation of flea stages by their LC50. Ocimum gratissimum EO was the most effective in the in vitro assays against all flea stages, presenting adulticide (LC50 = 5.85 μg cm-2), ovicidal (LC50 = 1.79 μg cm-2) and larvicidal (LC50 = 1.21 μg cm-2) mortality at low doses. It also presented an excellent profile in a toxicological eukaryotic model. These findings may support studies involving the development of non-toxic products for the control of fleas in dogs and cats.

Empirical "integrated disease management" in Ferrara during the Italian plague (1629-1631)

Plague, a highly infective disease caused by Yersinia pestis (Proteobacteria: Enterobacteriales), ravaged Europe from 1347 over the course of more than 450 years. During the Italian Plague (1629-1631), the disease was rampaging in the entire Northern Italy down to Tuscany, but the city of Ferrara was relatively spared, in spite that the economic activities were maintained with highly affected cities, such as Milan, through the relevant salt commerce. The aim of the study is to evaluate the hygiene rules that were effective in preventing the spread of the plague in Ferrara in 1630, by examining historical documents and reports. According to these documents, a kind of empirical "integrated disease management" was carried out, using remedies including compounds with bactericidal, anti-parasite and repellent activity, and by technical strategies including avoidance of possible plague carriers. The anti-plague remedies and technical strategies used in ancient Ferrara are critically analysed using a multidisciplinary approach (pharmaceutic, medical, epidemiologic and entomological) and compared to current prevention protocols.

Scalp microbiota alterations in children with pediculosis

Pediculosis is a disease caused by the insect Pediculus humanus capitis that mainly occurs in childhood. A comparative study was carried out evaluating groups of schoolchildren with (group A) and without pediculosis (group B) to analyse the characteristics of the scalp microbiota. Samples were collected by swab using Stuart transport medium and incubate in Sabouraud dextrose agar with tetracycline to analyse the fungal microbiota and in blood agar to assess the bacterial microbiota. The isolates identity was confirmed by sequencing of the 16S and 18S regions of the ribosomal DNA gene for bacteria and fungi, respectively. The analysis of the 186 isolates led to the identification of 35 bacteria and 40 fungi in group A and 47 bacteria and 64 fungi in group B. The results indicate differences in bacterial and fungal species in the groups analysed. In the observed bacterial microbiota, Staphylococcus capitis occurred more frequently than Staphylococcus epidermidis in group A vs B. Among fungal isolates, Debaryomyces sp. was more frequent in group B vs A. Our findings showed scalp microbiota alterations in children with pediculosis, meriting future studies to analyse the relationship between these agents and their impact on human health.

Primary Screening of Plant Essential Oils as Insecticides, Fumigants, and Repellents Against the Health Pest Paederus fuscipes (Coleoptera: Staphylinidae)

The contact and fumigant toxicity as well as repellent activity of 10 plant essential oils were evaluated against Paederus fuscipes Curtis adults. Essential oils were identified through gas chromatography-mass spectrometry analysis. Results showed that wintergreen oil exhibited optimal contact and fumigant toxicity but had no significant repellent activity against P. fuscipes. The LC50 values of fumigant toxicity of wintergreen oil were 2.680 and 1.591 µL/L air after 1 and 8 h of exposure, respectively. The LC50 values of contact toxicity of wintergreen oil were 0.086 and 0.060 µL/adult after 1 and 8 h of exposure, respectively. Cinnamon oil exhibited the highest repellent activity. In particular, 0.1 µL/cm2 cinnamon oil showed 100% repellency against P. fuscipes even for 6 h. Moreover, 0.01 and 0.005 µL/cm2 cinnamon oil conferred 80% repellency against P. fuscipes for 8 and 4 h, respectively. Overall, wintergreen oil is the best candidate insecticide and fumigant, and cinnamon oil is optimal as a repellent. The low-dose, rapid action of wintergreen oil and the low-dose, persistent repellency of cinnamon oil are important factors that suggest their use as insecticides, fumigants, and repellents against P. fuscipes.