Worm Damage Research Articles

Considering ivermectin for treatment of schistosomiasis.

Because of recent reports of praziquantel resistance in schistosome infections, there have been suggestions to employ ivermectin as a possible alternative, especially as its chemical composition is different from that of praziquantel, so cross-resistance is not expected. In order to ascertain possible damage and elimination of worms, we used ivermectin by oral gavage in infected mice, at a high dose (30.1 mg/kg, bordering toxicity). We also tested the efficacy of the drug at various times postinfection (PI), to check on possible effect on young and mature stages of the parasites. Thus, we treated mice on days 21 and 22 or on days 41 and 42 and even on days 21, 22, 41, and 42 PI. None of the treatment regimens resulted in cure rates or signs of lessened pathology in the mice. We also compared the effect of ivermectin to that of artemisone, an artemisinin derivative which had served us in the past as an effective anti-schistosome drug, and there was a stark difference in the artemisone's efficacy compared to that of ivermectin; while ivermectin was not effective, artemisone eliminated most of the worms, prevented egg production and granulomatous inflammatory response. We assume that the reported lack of activity of ivermectin, in comparison with praziquantel and artemisinins, originates from the difference in their mode of action. In wake of our results, we suggest that ivermectin is not a suitable drug for treatment of schistosomiasis.

FARMER FIRST PROGRAMME: AN EFFECTIVE EXTENSION APPROACH FOR DISSEMINATION OF SUSTAINABLE COTTON PRODUCTION TECHNOLOGIES

Field experiments were conducted during 2019-20 on 160 farmer's field of the villages Mav Jinjava, Hadala, Deri Pipaliya and Nava Vaghaniya of Bagasara Taluka of Amreli District of Gujarat on intensification and pink bollworm management in cotton under the Farmers First Project. The technological intervention of the study comprised of improved Bt. cotton hybrid GTHH-49, closer planting technology (90 cm x30 cm), de topping of cotton plant at 75 DAS, pink bollworm management with 16 pheromone traps/acre, spraying of Spinosad 45 EC @ 2ml/10 liter water and four spray of bio pesticide Beauveria bassiana. The technological intervention was compared with the farmer's practice. The results revealed that the technological intervention registered 18.82 % significantly higher seed cotton yield than farmer's practice, additional net return of `10417/ha with ICBR of 2.37 over the farmer's practice. The pink boll worm damage was significantly decreased under technological intervention and recorded 16.76% over the farmer's practice. The pink bollworm incidence under technological intervention was decreased up to 60.94 % over the farmer's practice.

A single oral dose of celecoxib-loaded solid lipid nanoparticles for treatment of different developmental stages of experimental schistosomiasis mansoni

Schistosomiasis, a neglected tropical parasitic disease, is associated with severe pathology, mortality and economic loss. The treatment and control of schistosomiasis depends mainly on a single dose of praziquantel (PZQ). Drug repurposing and nanomedicine attract great attention to improve anti-schistosomal therapy. Previously, we reported that celecoxib (CELE), the non-steroidal anti-inflammatory drug, showed potent anti-schistosomal efficacy in an oral dose of 20 mg/kg/day for five days against different developmental stages of Schistosoma mansoni (S. mansoni) infection in mice. The aim of the current study was to shorten the duration of CELE treatment to reach an effective single oral dose against different developmental stages of S. mansoni infection using solid lipid nanoparticles (SLNs) as nano-carriers. The latter enhance the solubility, bioavailability and drug delivery and hence can decrease the frequency of administration which is of great clinical value. CELE-loaded SLNs showed good colloidal properties, high entrapment efficiency and drug loading, sustained biphasic release pattern with excellent storage stability. The used regimen was efficient against different developmental stages of S. mansoni infection with the most pronounced effect against the juvenile stage where the worm load, the hepatic egg count and the intestinal egg count were reduced by 86.39%, 91.45% and 90.11%, respectively. Meanwhile, when targeting the invasive and the adult stages, it induced reduction in the worm load by 73.55% and 78.22%, the hepatic egg count by 69.99% and 75.39% and the intestinal egg count by 77.57% and 79.89%, respectively. Additionally, CELE-loaded SLNs caused extensive tegumental damage of adult worms and marked improvement in the liver pathology.

Chronic and transgenerational effects of polyethylene microplastics at environmentally relevant concentrations in earthworms

Microplastics are introduced into the agroecosystem through the application of wastewater and biosolids, plastic mulch films, greenhouse materials, and soil conditioners. Microplastics accumulation can alter the soil ecosystem and cause adverse effects on soil organisms. Therefore, this study for the first time evaluated the acute and chronic effects of pure and commercial polyethylene microplastics (PEMP) at environmentally relevant concentrations (0.01–0.5%) on earthworms ( Eisenia fetida ). Exposure to PEMP in the soil at 0.5 % concentration caused ≥ 70% reduction in earthworm reproduction for both parents (F0) and first filial (F1) generations compared to PEMP unamended control soil. Moreover, significant DNA damage was observed in F0 generations after 28 days. Also, this study demonstrated the release of phthalates used as additives in plastic and their accumulation by earthworms exposed to PEMP-amended soils. Thus the findings of this study have great implications for the risk assessment of PEMPs in the environment. • Assessed acute & chronic toxicity of polyethylene microplastics (PEMP) on earthworm. • PEMP at 0.5% caused 70% reduction in earthworm reproduction. • PEMP caused DNA damage in worms even at environmental concentrations. • PEMP released phthalates into soil. • PEMP exhibited transgenerational effects in earthworms.

Effects of multiple doses of simvastatin and artesunate monotherapy on SCHISTOSOMA MANSONI adult worms during infection in hyperlidemic mice

A single dose of simvastatin and of artesunate monotherapy cause damage to the reproductive system of schistosomes as well as severe tegumental damage in male worms recovered from mice fed high-fat chow. This study aims to investigate whether treatment with multipledose regimes may offer more antischistosomal activity advantages than single daily dosing in mice fed high-fat chow. For this purpose, nine weeks post-infection, Swiss Webster mice were gavaged with simvastatin (200 mg/kg) or artesunate (300 mg/kg) for five consecutive days and euthanized two weeks post-treatment. Adult worms were analyzed using brightfieldmicroscopy, confocal microscopy and scanning electron microscopy, presenting damages caused by simvastatin and artesunate to the reproductive system of males and females as well as tegument alterations, including peeling, sloughing areas, loss of tubercles, tegumental bubbles and tegument rupture exposing subtegumental tissue. The overall findings in this study revealed the potential antischistosomal activity of simvastatin and artesunate against Schistosoma mansoni adult worms, in addition to showing that multiple doses of either monotherapy caused severe damage to the tegument.KEY WORDS: Schistosoma mansoni; hyperlipidemia; simvastatin; artesunate; microscopy.

Elucidating the pathogenic potential of Enterobacter cloacae SBP-8 using Caenorhabditis elegans as a model host

Enterobacter cloacae, an opportunistic nosocomial pathogen, is reported to possess different virulence factors that could potentially influence its pathogenesis. Generally, the E. cloacae infections are of endogenous origin occurring in immunocompromised patients. The mechanisms of pathogenicity remain elusive, possibly due to the absence of established model hosts. Thus, we explored the utility of Caenorhabditis elegans as a model host to test the pathogenicity of E. cloacae SBP-8, a soil isolate. E. cloacae SBP-8 progressively colonized the intestine of C. elegans. It induced cell death (as assessed through DNA damage), reproductive defect and reduction of lifespan, comparable to a clinical isolate, E. cloacae (MTCC 509). Observation with Nomarski microscopy revealed significant anterior pharyngeal distention, and altered egg arrangement with internal egg hatching in 70% infected worms. The internal egg hatching was observed as early as 48 h post infection. E. cloacae SBP-8 infection reduced the brood size by 16%. A 2′,7′-dichlorodihydrofluorescein diacetate staining confirmed the 10-fold induction of reactive oxygen species implicating either mitochondrial damage or septic shock in infected worms. Expression analysis through RT-PCR indicated stimulation of immune response by E. cloacae SBP-8 in worms by upregulating tol-1, a Toll-like receptor, within 6 h of exposure. During the initial phase of infection (up to 24 h) the nematodes exhibited protective immune response by upregulating antimicrobial peptide genes, lys-1, clec-60, clec-85, and clec-87. However, these genes were downregulated at later hours (48 h), indicating the nematodes surrendered to the infection. A similar trend was observed for reproductive genes (lin-29 and let-23), suggesting a struggle to maintain functional reproduction by the nematodes. These results clearly demonstrate the pathogenic potential of E. cloacae SBP-8 and suggest the suitability of C. elegans as a model organism to study its pathogenesis. This is the first study indicating that E. cloacae infections could potentially originate from an exogenic source (here soil).

PREVALENCE AND SEVERITY OF SKUNK CRANIAL WORM (SKRJABINGYLUS CHITWOODORUM) DAMAGE INCREASE WITH PRECIPITATION IN SPOTTED SKUNKS (SPILOGALE SPP.).

Eastern and western spotted skunks (Spilogale putorius and Spilogale gracilis) serve as definitive hosts for skunk cranial worm (Skrjabingylus chitwoodorum), a metastrongylid nematode that spends its adult stage inhabiting the frontal sinuses of the host cranium. Skunk cranial worm can cause severe damage to the skull of spotted skunks, and this damage is identifiable in preserved specimens. We visited six mammal collections between 2016 and 2018 and used 578 spotted skunk skull specimens to identify patterns in prevalence and severity of skunk cranial worm damage in spotted skunks. Specimens were collected between 1895 and 1981 from across the US. We assessed effects of host genetic clade, collection year, precipitation, and sex on prevalence and severity rates. We hypothesized that the midwestern genetic clade (plains spotted skunk, Spilogale putorius interrupta), which experienced a range-wide population decline in the mid-1900s, would experience the highest infection and severity rates. We expected precipitation, but not sex to influence infection and severity. Our top models indicated that host genetic clade, precipitation in the year prior to specimen collection, and the year prior to specimen collection best predicted prevalence and severity of skunk cranial worm. We suggest the positive association with precipitation is a result of local availability of gastropods, the intermediate host for skunk cranial worm. There was a negative association between prior year and prevalence, but the severity of damage increased over time for all clades. Given concerns over population declines of spotted skunks as well as observations of increasing damage over the past century, there is a need for further research on the impacts of cranial worm infection on individual-scale behavior, reproduction and survival, and on population-scale demographics.

Radix Tetrastigma flavonoid ameliorates inflammation and prolongs the lifespan of Caenorhabditis elegans through JNK, p38 and Nrf2 pathways

The main flavonoid components of Radix Tetrastigma (RTF) were extracted and identified by UPLC-TOF/MS. In vitro, RTF prevented inflammation in RAW 264.7 cells by suppressing morphological (both cell and nucleus) changes, and decreasing nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) contents. Exposure to LPS also leads to oxidant damage, and RTF alleviated damage to mitochondria, decreased O2− accumulation, and restored the glutathione level. RTF intervention decreased the expression of c-Jun N-terminal kinase (JNK) and p38 phosphorylation, accompanied by downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and forkhead box protein O1 (FoxO1). In vivo, aging of Caenorhabditis elegans (C. elegans) by paraquat (PQ) was observed through lifespan, lipofuscin, and enzyme analysis. RTF protected against damage in N2 worms but not in daf-16 mutants. Gene expression was further assessed, and p38/PMK-1 and Nrf2/SKN-1 expression in worms was suppressed by PQ, which was reversed by RTF treatment. Together, these results suggested that RTF could help ameliorate inflammation-induced damage through JNK, p38 and Nrf2 pathways.

Chronic exposure to copper and zinc induces DNA damage in the polychaete Alitta virens and the implications for future toxicity of coastal sites

Copper and zinc are metals that have been traditionally thought of as past contamination legacies. However, their industrial use is still extensive and current applications (e.g. nanoparticles and antifouling paints) have become additional marine environment delivery routes. Determining a pollutant's genotoxicity is an ecotoxicological priority, but in marine benthic systems putative substances responsible for sediment genotoxicity have rarely been identified. Studies that use sediment as the delivery matrix combined with exposures over life-history relevant timescales are also missing for metals. Here we assess copper and zinc's genotoxicity by exposing the ecologically important polychaete Alitta virens to sediment spiked with environmentally relevant concentrations for 9 months. Target bioavailable sediment and subsequent porewater concentrations reflect the global contamination range for coasts, whilst tissue concentrations, although elevated, were comparable with other polychaetes. Survival generally reduced as concentrations increased, but monthly analyses show that growth was not significantly different between treatments. The differential treatment mortality may have enabled the surviving worms in the high concentration treatments to capture more food thus removing any concentration treatment effects for biomass. Using the alkaline comet assay we confirm that both metals via the sediment are genotoxic at concentrations routinely found in coastal regions and this is supported by elevated DNA damage in worms from field sites. However, combined with the growth data it also highlights the tolerance of A. virens to DNA damage. Finally, using long term (decadal) monitoring data we show stable or increasing sediment concentrations of these metals for many areas. This will potentially mean coastal sediment is a significant mutagenic hazard to the benthic community for decades to come. An urgent reappraisal of the current input sources for these ‘old pollutants’ is, therefore, required.

Guarana (Paullinia cupana Mart.) protects against amyloid-β toxicity in Caenorhabditis elegans through heat shock protein response activation

Alzheimer disease (AD) is a progressive neurodegenerative brain disorder that causes significant disruption in normal brain functioning, representing the most common cause of dementia in the elderly. The main hallmark of AD is the presence of amyloid plaques in the brain formed by the deposition of insoluble amyloid protein (Aβ) outside of neurons. Despite intensive investigation of the mechanisms of AD pathogenesis during the past three decades, little has been achieved in terms of effective treatments or ways to prevent the disease. Paullinia cupana, known as guarana, is a plant endemic to the Amazon region in Brazil with several beneficial effects reported, including delayed aging. In this study, we investigated the effects of chronic consumption of guarana ethanolic extract (GEE) on Aβ toxicity using a C. elegans model of AD. We analyzed the behavioral phenotype, oxidative damage and Aβ protein expression in worms treated with GEE. In addition, we investigated the possible role of the heat shock response on the beneficial effects induced by GEE. Overall, our data demonstrate that chronic GEE treatment decreased the formation of Aβ aggregates in C. elegans, preventing the behavioral deficits and the oxidative damage inducible by Aβ expression, due to activation of the heat shock protein (HSP) response. This finding provides a new alternative against amyloidogenic neurodegenerative diseases and other diseases caused by protein accumulation during aging.

Effects of C-Glycosides from Apios americana Leaves against Oxidative Stress during Hyperglycemia through Regulating Mitogen-Activated Protein Kinases and Nuclear Factor Erythroid 2-Related Factor 2.

Main components of Apios americana leaves extract (ALE) were flavonoid C-glycosides, including vitexin (46.7%), schaftoside (18.9%), and orientin (4.32%). In vitro, ALE restored glucose consumption, glucose uptake, and glycogen content in glucose-induced hepatic cells. Exposure of HepG2 cells to high glucose resulted in reactive oxygen species and O2- accumulation, while ALE alleviated these increases by 47 ± 0.68 and 68 ± 0.74%, respectively. Glucose increased c-Jun N-terminal kinase (JNK) and decreased extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 phosphorylation, while ALE reduced p-JNK and p-p38 but not p-ERK1/2, accompanied by nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, and NAD(P)H quinine oxidoreductase 1 downregulation. In vivo, the lifespan of Caenorhabditis elegans was more violently shortened by paraquat under hyperglycemia, while ALE protected this damage in N2 worms (2.6 times extension) but not in daf-16 mutants. Furthermore, p38/PMK-1 and Nrf2/SKN-1 expressions in worms were suppressed by glucose, which were reversed by ALE treatment. These results suggest that ALE prevents glucose-induced damage via regulating specific mitogen-activated protein kinases and Nrf2 pathways.

A software assignment algorithm for minimizing worm damage in networked systems

Homogeneous networked systems are at high risk of being compromised by malicious attacks that exploit a single weakness common to all. Following the survivability through heterogeneity philosophy, we present a novel approach to improving survivability of networked systems via software diversity. In this work, we propose an algorithm for assigning a number of software packages over a network of systems in an intelligent way such that machines running identical software are isolated into small “islands”, hence restricting the worm-like attacks from propagation. While developing the algorithm, we take into consideration not only practical constraints, including host functionality and software availability, but also weight, severity and impact range of vulnerability, well balancing and effectively minimizing the potential damage by an single attack. We also introduce possible enhancements by taking advantage of topological features of the network. Finally, we present a comparative analysis of our algorithm using simulation over various network structures. The results not only confirm the effectiveness and scalability of our algorithm, but also show its capability in creating moving attack surface. The level of heterogeneity our algorithm can actually create depends on the ratio of the number of installed software to the total number of available software.

Effects of PAHs and dioxins on the earthworm Eisenia andrei: A multivariate approach for biomarker interpretation

In this study, a battery of biomarkers was utilised to evaluate the stress syndrome induced in the earthworm Eisenia andrei by exposure to environmentally realistic concentrations of benzo[a]pyrene (B[a]P) and 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) in OECD soil. The set of tests was then employed to assess the toxicity of field soils contaminated with organic xenobiotic compounds (such as PAHs, dioxins and PCBs). The results highlighted an impairment of immune and metabolic functions and genotoxic damage in worms exposed also to lower bioavailable concentrations of toxic chemicals. Multivariate analysis of biomarker data showed that all different contaminated soils had a detrimental effect on the earthworms. A separation between temporal and concentration factors was also evident for B[a]P and TCDD treatments; and field contaminated soils were further differentiated reflecting a diverse contamination. Multivariate analysis also demonstrated that lysosomal membrane stability can be considered a prognostic indicator for worm health status.

Neutrophils prime a long-lived effector macrophage phenotype that mediates accelerated helminth expulsion (INC7P.423)

Abstract The innate immune cells mediating macroparasite clearance remain largely undefined. We examined their role in acquired resistance to the parasitic nematode, Nippostrongylus brasiliensis (Nb) hypothesizing that they may mediate the markedly accelerated CD4+ cell-independent worm clearance occurring after secondary inoculation. After secondary inoculation, parasitic larvae in the lung are surrounded by macrophages and showed reduced ATP, indicating impaired metabolism. As late as one month after Nb inoculation, lung macrophages, transferred to naïve recipients, accelerated parasite clearance. Primed macrophages adhered to larvae in vitro and triggered increased mortality through CD11b-dependent mechanisms. Neutrophil depletion impaired the recall response and depletion of neutrophils in primed mice abrogated the protective effects of transferred macrophages in recipient mice and inhibited their binding to L3. Global transcriptome analyses of sort-purified lung neutrophils from Nb inoculated mice revealed a markedly different expression pattern from lung neutrophils isolated from LPS inculated mice, indicating that neutrophils, like macrophages, develop a distinct alternatively activated phenotype (N2) after helminth infection. These data thus indicate that differentially activated neutrophils in the context of a type 2 immune response prime a long-lived effector macrophage phenotype that binds metazoan parasites and directly mediates rapid worm damage and clearance.

Primed effector macrophages mediate rapid worm expulsion after N. brasiliensis infection (P4247)

Abstract The innate immune cell populations that mediate macroparasite expulsion remain largely undefined. We examined the role of innate cells in the immune response to the nematode parasite, Nippostrongylus brasiliensis, hypothesizing that they may mediate the markedly accelerated CD4-independent worm expulsion occurring after secondary inoculation. By three days after secondary inoculation, immunofluorescence microscopy demonstrated a localized infiltrate of macrophages and eosinophils surrounding the L3 in the lung, and lung L3 showed reduced ATP, indicating impaired metabolism. Transfer of macrophages from N. brasiliensis primed WT mice to naïve recipients resulted in accelerated expulsion after primary inoculation, similar to WT mice given a secondary inoculation; this protective effect was blocked when primed macrophages were transferred from IL-4Rα-/- donor mice. Culture of L3 with sorted macrophages from primed WT, but not IL-4Rα-/-, mice resulted in macrophage adhesion to L3, decreased L3 metabolism and increased L3 mortality. Neutrophil (Ly6G+) depletion during priming blocked protective immunity after secondary inoculation and depletion of neutrophils in primed mice blocked protective effects of transferred macrophages in recipient mice and inhibited their in vitro binding to L3. These data indicate that neutrophils in the context of a type 2 cytokine environment prime effector macrophages that can directly bind parasites and mediate worm damage and expulsion.

The Research on Control Strategy of Worms Spread in Complex Network in Industry

Internet worms have been a severe threat to the Internet infrastructure and hosts recently. However, because of its outbreak of a sudden and massive make the worm’s research facing enormous challenges. This article describes a simulation system based on NS2 worm - WSS. First, by processing BGP routing table information to the Internet used for simulation of the abstract network, then the model-based epidemiological model of worm propagation, and finally in the two in NS2 combination to achieve the simulation of worm propagation. Experiments show that, WSS can get in a lab environment similar to actual worm outbreak statistics, in understanding the macroscopic behavior of the worm, the worm flow forecasting, transmission speed and damage have a wide range of applications.

Ultrastructural analysis of miltefosine-induced surface membrane damage in adult Schistosoma mansoni BH strain worms

Schistosomiasis is an infectious parasitic disease caused by helminths from the genus Schistosoma; it affects over 200 million people globally and is endemic in 70 countries. In Brazil, 6 million individuals are infected with Schistosoma mansoni. Furthermore, as the prevalence of S. mansoni infections is increasing, approximately 26 million citizens in 19 Brazilian states are at risk for infection. Schistosomiasis disease control involves predominately the administration of a single drug, praziquantel. Although praziquantel exhibits chemotherapeutic efficacy and safety, its massive use in endemic zones, the possibility of the emergence of drug-resistant Schistosoma parasites, and the lack of another efficacious antischistosomal drug demand the discovery of new schistosomicidal compounds. First developed as anti-tumor drug, miltefosine is an alkylphospholipid derivative that exhibits bioactivity against Leishmania and Trypanosoma parasites, free-living protozoa, bacteria, and fungi. With its anti-parasite activity, miltefosine was the first orally administered drug against visceral and cutaneous leishmaniasis approved. Previously, by means of the MTT cytotoxic assay and a DNA fragmentation test, we verified that, at doses of 100 and 200 μM (40 and 80 μg/mL), miltefosine exhibited in vitro schistosomicidal activity against adult S. mansoni worms. Here, we present ultrastructural evidence of rapid, severe miltefosine-induced surface membrane damage in S. mansoni following drug treatment. The number of dead parasites was concentration- and time-dependent following miltefosine treatment. At a miltefosine concentration of 200 μM (∼80 μg/mL), in vitro parasite killing was initiated as early as 3 h post-incubation, and it was maximal after 24 h of treatment. The parasite death was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. According to our present results, miltefosine is very effective at inducing membrane destruction of S. mansoni with a short onset of pharmacological action.

Assessment of the Toxicity of Artemisia inculta Extract on the Bone Marrow of Mice Infected with Schistosomiasis

The discovery of the crude extract of Artemisia inculta (an Egyptian species of the Artemisia plant) for the therapy of schistosomiasis has evoked the study of its long-term toxicity produced by antischistosomal doses. Hence, an assessment of the noxious effects on bone marrow was attempted in this study. Transmission electron microscopy of the bone marrow was conducted on infected mice receiving a crude ethanolic extract from Artemisia inculta by newly designed dose regimens (500 or 800 mg/kg body weight in the 7th, 14th and 21st weeks post infection). This regimen was found to produce an efficient therapeutic effect in decreasing worm load and causing tegumental damage of juvenile and adult worms. The ultrastructural features of all cell lines in the bone marrow were comparable in both treated (500 and 800 mg/kg body weight dose levels) and untreated groups showing normal cellularity, maturation and morphology. This denotes that the drug is non-toxic to the hemopoietic tissue. Electron microscopy has provided a direct and accurate evidence of the nontoxic property of the plant extract on bone marrow using therapeutic doses. However, this study should be extended to other vital organs such as the liver or brain to establish the safety of this drug.

Use of fluorescent probes as a useful tool to identify resistantSchistosoma mansoniisolates to praziquantel

The use of chemotherapy on a mass scale in endemic areas may lead to the appearance of resistant isolates through the mechanism of selective drug pressure. Studies have demonstrated that praziquantel (PZQ) is able to inhibit the excretory activity and to cause tegumental damage in Schistosoma mansoni adult worms. The use of the probe resorufin to evaluate excretory activity, as well as the probe Hoechst 33258 to detect tegumental damage in adult worms, may represent a method to identify resistant (or less susceptible) isolates. The purpose of the present work was to compare the changes caused by PZQ in the function of the excretory system and in the integrity of the tegument of adult worms from the LE isolate (susceptible to PZQ) and the LE-PZQ isolate (less susceptible to PZQ). Worms from the isolate LE-PZQ showed less severe tegumental lesions, in both in vitro and in vivo experiments, detected by labelling with Hoechst 33258 and continued to have a functional excretory system as shown by labelling with resorufin in vitro.

Worm damage minimization in enterprise networks

Attackers utilize many forms of intrusion via computer networks; currently, worms are an important vector with the potential for widespread damage. None of the strategies is effective and rapid enough to mitigate worm propagation. Therefore, it is extremely important for organizations to better understand worm behaviour and adopt a strategy to minimize the damage due to worm attacks. This paper describes an approach to minimize the damage due to worm infection in enterprise networks. The approach includes: (1) analyzing the effect of parameters influencing worm infection: openness, homogeneity, and trust, (2) predicting the number of infected nodes by fuzzy decision, and (3) optimizing the trust parameter to minimize the damage by fuzzy control. Experiments using real worm attacks show that the selected parameters are strongly correlated with actual infection rates, the damage prediction produces accurate estimates, and the optimization of the selected parameter can lessen the damage from worm infection.