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Dear Editor, I Sarcoptes scabiei i is an astigmatid mite of the genus I Sarcoptes i with high morphological variability in relation to its host.[1] In humans, I S. scabiei i var. I hominis i causes common and crusted scabies.[1] The latter typically occurs in patients with immunological, neurological and metabolic disorders.[2] We report a nosocomial outbreak of crusted scabies as a result of I S. scabiei i var. I canis i in immunosuppressed patients. Moreover, 1 month before our observation, when the patient's dog was already completely healed, the patient's wife and two sons presented recurrent, self-limiting and itchy erythemato-papular lesions without burrows, compatible with the diagnosis of pseudo-scabies. [Extracted from the article]

Linked article: L. Tognetti et al. J Eur Acad Dermatol Venereol 2020; 34: e27–e28. https://doi.org/10.1111/jdv.15869. [ABSTRACT FROM AUTHOR]

The cryptic behavior that characterizes bed bugs (Cimex lectularius L.) makes them one of the most difficult indoor pests to control. Thus, the use of products with long residual efficacy is a key component of successful bed bug management. Aprehend is a biopesticide for bed bug control, whose active ingredient is the entomopathogenic fungus, Beauveria bassiana. This product shows promise for extended bed bug control against pyrethroid-resistant bed bugs, causing mortality days after contact with the treated surface. However, it is unclear how surface type and distance traveled by bed bugs over a treated surface impact efficacy. Therefore, we evaluated the efficacy of different Aprehend band widths applied to different substrates commonly encountered by bed bugs, looking specifically at average time to mortality and overall mortality. Our findings indicate that exposure to fresh applications of Aprehend resulted in high mortality when bed bugs traveled very short distances (1 cm) over some Aprehend-treated surfaces (vinyl tile and cotton jersey fabric), while exposure to other treated surfaces (unfinished pinewood and painted drywall) resulted in comparatively lower mortality even over longer distances (5 cm). Furthermore, we found that bed bugs crawling on cotton jersey fabric picked up a significantly higher number of spores compared to unfinished pinewood. These results indicate that applications of Aprehend as 5 cm (2 inches) bands according to label recommendations can be effective, although surface type is an important determinator of efficacy. This information will help guide pest management professionals in their use of B. bassiana for bed bug control., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Protein self-assembling nanoparticles (NPs) can be used as carriers for antigen delivery to increase vaccine immunogenicity. NPs mimic the majority of invading pathogens, inducing a robust adaptive immune response and long-lasting protective immunity. In this context, we investigated the potential of NPs of different sizes and shapes-ring-, rod-like, and spherical particles-as carriers for bacterial oligosaccharides by evaluating in murine models the role of these parameters on the immune response. Oligosaccharides from Neisseria meningitidis type W capsular polysaccharide were conjugated to ring-shape or nanotubes of engineered Pseudomonas aeruginosa Hemolysin-corregulated protein 1 (Hcp1cc) and to spherical Helicobacter pylori ferritin. Glycoconjugated NPs were characterized using advanced technologies such as High-Performance Liquid Chromatography (HPLC), Asymmetric Flow-Field Flow fractionation (AF4), and Transmission electron microscopy (TEM) to verify their correct assembly, dimensions, and glycosylation degrees. Our results showed that spherical ferritin was able to induce the highest immune response in mice against the saccharide antigen compared to the other glycoconjugate NPs, with increased bactericidal activity compared to benchmark MenW-CRM 197 . We conclude that shape is a key attribute over size to be considered for glycoconjugate vaccine development.

Histamine is a biogenic amine that regulates multiple physiological functions in diverse organisms, specifically playing a central role in the mammalian immune response. The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), excretes histamine in large amounts in its feces as a component of its aggregation pheromone, which contaminates homes. The potential health risks associated with the presence of indoor histamine are unclear, but to predict future exposure risks, it is critical that we understand if other arthropods excrete histamine in any discernible phylogenetic pattern. In the present study, we evaluated histamine excretion by various arthropods; specifically those commonly found in large numbers indoors, other hematophagous species, and other species in the order Hemiptera. To evaluate arthropods for histamine excretion, rearing containers for each arthropod were swabbed and/or the harborage substrates were collected. Samples were then analyzed for the presence of histamine using gas chromatography-mass spectrometry. For those arthropods where histamine was present above the method detection limit, total histamine excretion was quantified over a period of 2 wk. Our results indicate that histamine excretion is limited to hematophagous hemipterans (bed bugs, bat bugs, tropical bed bugs, and kissing bugs), suggesting that indoor histamine contamination in the United States can be primarily linked to bed bugs., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The common bed bug (Cimex lectularius L.) is a hematophagous pest species that lives in close proximity to humans. Following a blood meal, bed bugs deposit fecal material indoors. The feces contain a variety of compounds, including histamine, which serves as a component of their aggregation pheromone. Histamine is a pivotal mammalian immune modulator, and recently it was shown to be present in high concentrations in household dust from homes infested with bed bugs. To better understand the dynamics of histamine excretion, we analyzed bed bug fecal material from different life stages and populations, along with fecal material collected at different post-feeding times and from bed bugs fed on different diets. Our analysis showed significant variation in histamine excretion among life stages, with mated females excreting the most histamine and first instar nymphs excreting the least histamine. However, when histamine excretion was normalized for blood consumption, males were found to excrete more histamine than the other life stages. There was no difference in histamine excretion among laboratory and recently home-collected bed bug populations. Further, we found histamine excretion continued for at least 14 d post-feeding, with the highest amount of histamine excreted 3-4 d after a bloodmeal. Overall, this work demonstrates that bed bugs excrete histamine across all feeding life stages, populations, and at various times after feeding, and that histamine excretion is directly related to blood feeding. These results will be used to better understand the health risks associated with histamine excretion and potential mitigation strategies of environmental histamine., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The biopesticide Aprehend, containing spores of the entomopathogenic fungus Beauveria bassiana , is a biological control agent for the management of the common bed bug ( Cimex lectularius L.) (Hemiptera: Cimicidae). The spores are applied in strategically placed barriers, which bed bugs walk across as they search for a bloodmeal. Application of chemical insecticides by the general public and professional pest managers is common, which means that Aprehend may be sprayed on existing insecticide residues. We evaluated the effect of chemical residues, of 22 different chemical insecticides on different household surface types. We found that residues from 12 chemical pesticides significantly reduced spore viability measured 5 weeks after application in comparison to the control. However, efficacy of Aprehend, as measured by bed bug mortality and mean survival time after exposure to sprayed surfaces, seven weeks after application was not impacted detrimentally. Furthermore, in some cases, efficacy of old chemical residues was enhanced by the combination of chemical and Aprehend seven weeks after application. Surface type also played a role in the relative efficacy of all products and combinations, particularly as the residues aged.

Factor H binding protein (fHbp) is a key virulence factor of Neisseria meningitidis and a main component of the two licensed vaccines against serogroup B meningococcus (Bexsero and Trumenba). fHbp is a surface-exposed lipoprotein that enables the bacterium to survive in human blood by binding the human complement regulator factor H (fH). When used as vaccine, the protein induces antibodies with potent bactericidal activity. While the fHbp gene is present in the majority of N. meningitidis serogroup B isolates, the expression level varies up to 15 times between different strains and more than 700 different sequence variants have been described. Antigenically, the protein has been divided into three variants or two subfamilies. The 3D structure of fHbp alone, in combination with fH or in complex with bactericidal antibodies, has been key to understanding the molecular details of the protein. In this article, we will review the biochemical and immunological properties of fHbp, and its key role in meningococcal pathogenesis, complement regulation, and immune evasion., (© 2020 Federation of European Biochemical Societies.)

The classical complement pathway is triggered when antigen-bound immunoglobulins bind to C1q through their Fc region. While C1q binds to a single Fc with low affinity, a higher avidity stable binding of two or more of C1q globular heads initiates the downstream reactions of the complement cascade ultimately resulting in bacteriolysis. Synergistic bactericidal activity has been demonstrated when monoclonal antibodies recognize nonoverlapping epitopes of the same antigen. The aim of the present work was to investigate the synergistic effect between antibodies directed toward different antigens. To this purpose, we investigated the bactericidal activity induced by combinations of monoclonal antibodies (mAbs) raised against factor H-binding protein (fHbp) and Neisserial Heparin-Binding Antigen (NHBA), two major antigens included in Bexsero, the vaccine against Meningococcus B, for prevention from this devastating disease in infants and adolescents. Collectively, our results show that mAbs recognizing different antigens can synergistically activate complement even when each single Mab is not bactericidal, reinforcing the evidence that cooperative immunity induced by antigen combinations can represent a remarkable added value of multicomponent vaccines. Our study also shows that the synergistic effect of antibodies is modulated by the nature of the respective epitopes, as well as by the antigen density on the bacterial cell surface., (© 2020 GSK Vaccines SRL. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Objectives: In this study, we investigated the antimicrobial activity of resveratrol in combination with colistin, a last-resort agent for the treatment of severe infections caused by multidrug resistant Gram-negative pathogens. Methods: The synergistic activity and the bactericidal activity of colistin in combination with resveratrol was investigated by checkerboard assays and time-kill assays, respectively. A total of 21 strains were investigated, including 16 strains of different species ( Klebsiella pneumoniae, n = 6, Escherichia coli, n = 6; Citrobacter braakii, n = 1; Stenotrophomonas malthophilia, n = 1; Enterobacter cloaceae, n = 1 ; Acinetobacter baumannii, n = 1) with acquired colistin resistance, three colistin-susceptible K. pneumoniae precursors, and two strains of intrinsically colistin-resistant species ( Serratia marcescens, n = 1; Proteus mirabilis, n = 1). Mechanisms of acquired colistin resistance included chromosomal mutations (i.e., mgrB, pmrAB ) and plasmid genes ( mcr-1, mcr-1 .2). Results: Resveratrol did not show any significant intrinsic antimicrobial activity. Overall, a relevant synergistic antimicrobial activity of resveratrol in combination with colistin was observed with all tested strains, except for the three colistin-susceptible K. pneumoniae strains, and for two mcr-1 -positive E. coli strains. In time-kill assays, performed with 15 selected strains, the combination of colistin 2 mg/L plus resveratrol 128 mg/L was bactericidal with 11 strains, and bacteriostatic for the remaining ones. Conclusions: Resveratrol was found to potentiate colistin activity against a wide panel of colistin-resistant strains, regardless of species and resistance mechanisms, which would deserve further investigation for potential clinical applications.

Aging rooms of dry-cured ham and cheese are subject to the development of mold and arthropods, above all mites, which cause the erosion of the external part of these food products, reducing their surface to dust and determining their progressive degradation. This work is meant to give the results of an experiment carried out to test the level of protection supplied by Alistag TM , a coating agent based on Gluconodeltalactone, on a typical Sicilian cheese cosacavaddu ibleo . Alistag TM was applied by nebulization and by immersion. The two parameters took in consideration to evaluate their efficacy were the presence/absence of cracks and the level of dustiness on the surface of the cheese. Alistag TM turned out to be very efficient in protecting cheese both from the development of dust and from cracks; between the two kinds of application tested, immersion resulted to be the best one, for the protecting action lasts longer., Competing Interests: Conflict of interest: the authors declare no potential conflict of interest.

Objective: To describe bioelectrical impedance vector distribution in relation to BMI (body mass index; body weight/stature(2)) in a population of healthy children in order to detect possible changes in body composition status., Design: Observational study involving 464 healthy 8-year-old children. The subjects were divided into three groups based on their BMI: 218 normal weight (NW) children with BMI<18.4 for male and BMI<18.3 for female; 135 overweight (OW) children with BMI 18.4 to <21.6 for male and with BMI 18.3 to <21.6 for female; 111 obese (OB) children with BMI>/=21.6. Skinfold thickness was measured at the triceps using a Holtain caliper. Bioelectrical impedance analysis (BIA) measurements were performed. Total body water (TBW), fat-mass (FM), fat-free mass (FFM), body cell mass (BCM) and extra-cellular water (ECW) were estimated using conventional BIA regression equations. The resistance-reactance graph (RXc graph) method was used for vector BIA using as reference population the set of 353 children with BMI 14.0-21.5kg/m(2)., Results: Mean vector displacement followed a definite pattern, with progressive vector shortening in groups with increasing BMI class, and along a fixed phase angle. This pattern indicates an increase in TBW due to an increase in soft tissue mass with an average, normal hydration. In NW children, vectors out of the right and upper half of the 75% tolerance ellipse indicating leanness, and vectors falling out of the right and lower half of the tolerance ellipse indicating undernutrition, show a significantly reduced value of BCM but no significant differences in FM or triceps skinfold thickness (TST), respectively, compared to vectors falling within the 75% tolerance ellipse., Conclusions: Although BMI is a reliable measure to grade overweight, it cannot differentiate whether weight change is due to variation of FM, FFM or water. In our study a different impedance vector pattern has been associated with normal weight to obesity, and we have established the trajectory followed by the impedance vector of standardized age, healthy children grouped by BMI. This BIVA may be useful for clinical purposes due to ability to detect changes in hydration or body composition in children.