The potential of biochar and nanoparticles to serve as effective delivery agents for beneficial bacteria to crops was investigated. Application of nanoparticles and biochar as carriers for beneficial bacteria improved not only the amount of nitrogen-fixing and phosphorus-solubilizing bacteria in soil, but also improved chlorophyll content (1.2–1.3 times), cell viability (1.1–1.5 times), and antioxidative properties (1.1–1.4 times) compared to control plants. Treatments also improved content of phosphorus (P) (1.1–1.6 times) and nitrogen (N) (1.1–1.4 times higher) in both tomato and watermelon plants. However, the effect of biochars and nanoparticles were species-specific. For example, chitosan-coated mesoporous silica nanoparticles with adsorbed bacteria increased the phosphorus content in tomato by 1.2 times compared to a 1.1-fold increase when nanoclay with adsorbed bacteria was applied. In watermelon, the situation was reversed: 1.1-fold increase in the case of chitosan-coated mesoporous silica nanoparticles and 1.2 times in case of nanoclay with adsorbed bacteria. Our findings demonstrate that use of nanoparticles and biochar as carriers for beneficial bacteria significantly improved plant growth and health. These findings are useful for design and synthesis of novel and sustainable biofertilizer formulations.
Endemic and tropical human bot infestations are relatively uncommon or unreported in the United States. We report two cases in Connecticut: an unusual furuncular and respiratory myiasis by the rabbit bot Cuterebra buccata (Fab.) (Diptera: Oestridae) in a 74-yr-old male and a case of human bot fly, Dermatobia hominis (L.) (Diptera: Oestridae), myiasis in a 4-yr-old female with a tropical travel history with her family. Identification of C. buccata was based morphologically, in part, on spinal armature and further corroborated by DNA sequencing of the mitochondrial COI gene and comparison to the National Center for Biotechnology Information GenBank DNA sequence database. The resulting annotated sequence data were deposited into the National Center for Biotechnology Information GenBank. The unique medical aspects, and limitations and specifics on bot fly larval habits and identification are discussed.
The common bed bug Cimex lectularius L. (C. lectularius) is a hematophagous ectoparasite that has recently resurged in many western industrialized nations, in part due to pesticide resistance. Using a laboratory feeding system, we found that the antiparasitic drugs ivermectin and moxidectin did not show higher incapacitation rates in pyrethroid-resistant strains of C. lectularius compared to a pyrethroid-susceptible strain. Additionally, we developed a high-performance liquid chromatography (HPLC) and mass spectroscopy (MS) assay to measure the concentrations of ivermectin inside C. lectularius and found that ivermectin persists in the insects for up to one month. HPLC/MS will be useful in understanding the pathophysiology behind the long-term morbidity observed in C. lectularius that consumes a sublethal dose of ivermectin.
Aims To investigate the immunoglobulin (Ig) G response after being fed upon byCimex lectulariusL. Methods and Results Participants were fed upon by three maleC lectulariusinsects weekly for a month. Blood was obtained before the feeding and at the last feeding, which was used for immunoblots against bed bug salivary gland extract, with antihuman Immunoglobulin G (IgG) secondary antibodies. No consistent IgG changes developed in 11 humans serially fed upon byC lectularius. Two participants had new IgG responses to proteins at molecular weights of approximately 12-13 kDa, and one had an IgG response to a protein at approximately 40 kDa. At the last study visit, more intense IgG bands to proteins at molecular weights of 12-13 kDa had developed in 55% of participants (6/11) and at molecular weights of approximate to 30, approximate to 40 and approximate to 70 kDa in 45% (5/11) compared with the first study visit. Nitrophorin and apyrase were the most commonC lectulariusproteins identified with liquid chromatography-tandem mass spectrometry in both crushed bed bug salivary gland extract and post-bed bug feeding extract. Conclusions Human participants did not have consistent IgG responses to crushedC lectulariussalivary gland extract.
Human bed bug infestations have undergone a recent global resurgence. The human antiparasitic drug ivermectin has been proposed as a strategy to help control bed bug infestations, but in vivo data are lacking. We allowed separate populations of the common bed bug, Cimex lectularius L., to feed once on a rabbit before and after it was injected subcutaneously with 0.3 mg/kg of ivermectin, and bed bug morbidity and mortality were recorded. Ivermectin levels in the rabbit were measured using high-performance liquid chromatography and mass spectroscopy. Ivermectin blood levels of ∼2 ng/mL caused reductions in bed bug fecundity, and levels of >8 ng/mL caused bed bug death and long-term morbidity including reductions in refeeding, mobility, reproduction, and molting. Gut bacterial cultures from the fed bed bugs showed that ivermectin altered the bed bug gut microbiome.
Objective To measure the population size and fecundity of the common bed bug Cimex lectularius L. (C. lectularius) after feeding it with the blood obtained from human subjects who have consumed a single dose of ivermectin. Methods Serial blood samples were obtained from two human subjects at hour 0 (control) and 4-96 hours after they received a single 0.2 mg/kg dose of ivermectin. The blood samples were then fed to 2,273 bed bugs. Bed bug incapacitation rates, fecundity, and population sizes were recorded over a 54-day period. Whole blood ivermectin levels were measured in the human subjects and the insects. Results The fold change in the size of the control group population over the course of the experiment was found to be 2.16. This was significantly greater (p: <.001) than for all the post-ivermectin feeding groups (range: -11.04-1.43). Two weeks after the experiment, the number of eggs laid per live adult female bed bug per day was 10.74 for controls, which was significantly different (p: <0.001) compared to all the post-ivermectin feeding groups (range: 0-4.28). Conclusions There were significant reductions in C. lectularius population size and fecundity in insects that fed on blood obtained from human study subjects up to 96 hours after they have consumed a single oral dose of ivermectin.
The common bed bug, Cimex lectularius L., is a hematophagous ectoparasite that preferentially feeds on humans. Pharmaceuticals present in a person’s blood may adversely affect C. lectularius when it feeds. We fed >10,000 C. lectularius on blood samples containing more than 400 different drug doses and drug combinations using an in vitro feeding system to determine insect mortality. The majority of drug doses approximated the peak plasma concentration in humans taking those drugs. Twenty-one drugs were found to cause >17% 12–14-day mortality compared to 8.5% mortality in the control (p < 0.05), but postliminary testing of three of the drugs, famotidine, ethambutol, and primaquine, did not demonstrate an increase in C. lectularius mortality. We also tested 23 drugs for their effects on C. lectularius fecundity. The results may have implications for understanding C. lectularius population dynamics in an infestation.
Ixodes scapularis Say 1821, the primary vector of several human pathogens in the northeastern and upper Midwestern United States, has considerable genetic and morphological variation throughout its range. Recently, developmental or teratological abnormalities have been observed in this species for the first time, further complicating morphological identification. Here, we report the first evidence of nanism (dwarfism) in I. scapularis, found parasitizing a human host. We used molecular methods and scanning electron microscopy to identify the specimen. Morphological identification confirmed that the specimen is substantially smaller, approximately half the size, than a typical I. scapularis female. Here we discuss the recent reports of teratological abnormalities in I. scapularis, particularly from the Hudson River valley region of the northeastern United States, and highlight the need for additional studies of teratology in this important species and its potential implications in disease transmission.
Little is known about cimicosis, the resultant dermal reaction from feeding activity by the common bedbug, Cimex lectularius L. We fed C. lectularius on human study subjects four times over four weeks and measured serum cytokine and antibody levels, and subjects recorded any cimicosis. The average time for subjects to develop cimicosis decreased with each feeding from 8.4, to 2.1, 1.5 and 1.3 days, respectively. There were no significant changes in total IgG, IgG1, IgG2, IgG4 or IgE levels between the first and fourth bedbug feedings, but there was a significant decrease in total IgG3 levels (P <.001). IgG4 was not required for cimicosis. Higher IgG2 and IgG4 levels at study visit 4 were associated with an increased duration of cimicosis (P=.04) and lower pruritis (P=.03), respectively. There were no significant changes in serum TNF-alpha, IL-1 beta, IL-4, IL-5, IL-6, IL-10, IFN-gamma and IL-17A levels before and one hour after the C. lectularius feeding. Lower post-C. lectularius feeding IL-6 levels were associated with increased pruritis (P=.001) and the time to maximum pruritis ( P=.04), respectively. Higher post-C. lectularius feeding IL-5 levels were associated with a longer duration of pruritis (P=.05).
Little is known about the epidemiology of bed bugs within the healthcare system, but nymphal stages predominate in natural infestations. This study determined the life stages of bed bugs captured within a medical centre, and found that older bed bugs were more likely to be captured than younger insects. The numbers of first instars, third–fifth instars and adult females captured were significantly different compared with the numbers of each life stage found in a natural infestation (P<0.01). A significant number of early-instar bed bugs introduced into the medical centre may go unnoticed by hospital staff.
Seafarers are traveling workers, subject to unique exposures and generally isolated from adequate medical care. This case report of paederus dermatitis diagnosed at sea highlights the importance of a multidisciplinary diagnostic approach and telecommunication in providing remote medical advice to isolated traveling workers such as seafarers.
The recent resurgence of the common bed bug Cimex lectularius L. throughout western industrialized nations has been facilitated in part by the insect becoming pesticide-resistant. Novel control strategies, including xenointoxication, should be considered to combat C. lectularius. Ivermectin, a U.S. Food and Drug Administration (FDA)-approved treatment for several human parasites, and the antiparasitic drug moxidectin, currently being explored in human clinical trials, were evaluated for efficacy against C. lectularius. Results showed that C. lectularius fed on ivermectin or moxidectin blood concentrations of >25 ng/mL and had significantly higher mortality (50–100 %) than controls (0–6 %) by day 13. Bed bugs that survived a blood meal containing >2.5 ng/mL of ivermectin suffered long-term sequelae including reduced fecundity, feeding difficulty, and incomplete ecdysis. Some insects that survived a blood meal containing ≤75 ng/mL moxidectin were able to feed and reproduce.