Assessment of Conventional Insecticides against Common Bed Bugs Cimex Hemipterus (Hemiptera: Cimicidae) in Jeddah Province, Saudi Arabia

Bed bugs, Cimex hemipterus (Hemiptera: Cimicidae) are small insects that are considered public health pests and cause many health and economic problems. The efficacy of Organophosphorus insecticides (Safrotin and Actikill) and pyrethroids (Project and Cyper Safe) in controlling C. hemipterus adults and nymphs were investigated using contact and dipping methods. The WHO protocol was followed for insecticides application. The results of the current study showed that the project pesticide from the pyrethroids group gave the highest effectiveness against bed bugs, as the value of the concentration that killed 50% (LC50) of insects was of the adults (264.8, 337.5 ppm) when using dipping and contact methods, respectively. while the LC50 value when applying the two methods of the same insecticide against nymphs was 254.7 and 329.3ppm, respectively. However, Safrotin the more effective organophosphorus insecticide. The dipping method was more effective than the contact method for all insecticides, and the nymphs were more susceptible than the adults (LC50= 1502.6 and 1065.28ppm). The pesticides can be arranged in descending order according to their effect as follows: Project> Cyper Safe > Safrotin > Actikill. Our findings suggest that bed bugs in Jeddah Province may have developed resistance to common pesticides used in public health pest management programs. For this reason, this study recommends a periodic evaluation of the effectiveness of pesticides to be used during emergency pest outbreaks

Behavioural responses of juvenile Daphnia magna to two organophosphorus insecticides

In this study, the behaviour of Daphnia magna was studied under equipotent and sub-lethal concentrations of two pesticides congeners: chlorpyrifos (CPF; 5 ng L-1 to 50 ng L-1) and chlorpyrifos-methyl (CPF-m; 30 ng L-1 to 300 ng L-1) with aims to assess and compare the behavioural swimming responses (BSRs) of the cladocerans elicited by both compounds at different concentrations and exposure times. A video tracking analysis after 24 h and 48 h of exposure allowed us to evaluate different behavioural responses (distance moved, average velocity, active time, and average acceleration). The results indicate that BSRs are sensitive indicators of sub-lethal stress. Highly concentration- and time-response changes for both compounds were observed during the experiments. In particular, in the first 24 h of exposure, both compounds elicited a similar decreasing trend in swimming behaviour, in which CPF induced the highest decline. Further, hypoactivity was associated with the narcotic effects of both compounds. Conversely, after 48 h of exposure, we observed an increasing tendency in the swimming parameters, particularly at the highest tested concentrations. However, the compounds did not exhibit the same trend. Rather, CPF-m induced high variations from the control groups. This reversal trend could be due to the activation of compensatory mechanisms, such as feeding, searching, or avoidance behaviours. These results suggest that BSRs are measurable active responses of organisms, which are controlled by time.

"In-vitro Effects of Chlorpyrifos and Monocrotophos on the Activity of Acetylcholinesterase (AChE) in Different Tissues of Apple Snail Pila globosa (Swainson, 1822)"

The impact of two organophosphorus insecticides [Chlorpyrifos (CPF) and Monocrotophos (MCP)] on non-target wild natural gastropod, Pila globosa (apple snail) from the paddy fields was studied. The activity of acetylcholinesterase (AChE) was monitored on foot-muscle and hepatopancreas tissues of control and exposed snails. In the foot- muscle AChE inhibition progressed and reached 54.19% and 63.13% of the control, whereas, the AChE inhibition in the hepatopancreas reached 46.96% and 53.67% over control after 48 hours of exposure to 1.5 mL.L-1 and 2.5 mL.L-1 CPF respectively. After 48 hours of MCP exposure at 1.5 mL.L-1 and 2.5 mL.L-1 separately, the AChE inhibition of foot muscle was 49.07% and 57.59% respectively while in hepatopancreas it was 44.65% and 48.84% respectively. Our results show more inhibition of AChE activities on the foot-muscle than hepatopancreas in a concentration and time-dependent manner with greater severity by CPF in comparison to MCP. AChE inhibition increased with the increasing exposure time.

Biodegradable properties of organophosphorus insecticides by the potential probiotic Lactobacillus plantarum WCP931 with a degrading gene (opdC)

An organophosphorus (OP) insecticide-mineralizing strain, Lactobacillus plantarum WCP931, harboring a new OP hydrolase (opdC) gene, was isolated during kimchi (Korean traditional food) fermentation. Strain WCP931 exhibited a significant survival rate of 51 to 96% under artificial gastric acid conditions at pH 2 to 3 after 3 h. The opdC gene, consisting of 831 bp encoding 276 amino acids, was cloned from strain WCP907. Recombinant Escherischia coli harboring the opdC gene depleted 77% chlorpyrifos (CP) in M9 minimal medium after 6 days of incubation. The OpdC enzyme represents a novel member of the GHSQG family of esterolytic enzymes or a new Opd group. The OpdC molecular mass was estimated to be approximately 31 kDa by SDS-PAGE and showed maximum activity at pH 6 and 35 °C. The mutated OpdC (Ser116 → Ala116) enzyme had no activity towards OP insecticides and ρ-nitrophenol-β-butyrate. Importantly, the relative activity of OpdC protein against chlorpyrifos, coumafos, diazinon, fenamifos, methyl parathion, and parathion was higher than that against cadosafos, dyfonate, and ethoprofos insecticides. These results suggested the involvement of OpdC in the biodegradation of OP insecticide-contaminated cabbage during fermentation. The new OpdC enzyme expands the heterogeneity of the lactic acid bacterial Opd enzyme group in nature.

Importance of pesticides for lethal poisoning in India during 1999 to 2018: a systematic review

Background Poisoning is a major problem in India. However, there is little systematic information on the key poisons responsible for most deaths by geographical area and over time. We aimed to review the literature to identify the poison classes causing the greatest number of deaths in India over the last 20 years. Methods We performed a systematic literature review in Medline, Embase and Google Scholar (1999–2018), and Indian online medical journals, to find papers that reported deaths from all forms of poisoning in India, with last search 20 April 2020. We included epidemiological studies, observational studies, randomised trials, interventional studies, and case series published from 1999 to 2018 that showed the number of deaths and autopsy studies indicating the specific poisons or poison classes. Studies providing the case fatality for specific poisons or classes, which enabled calculation of the number of deaths, were also included. We excluded deaths due to animal bites and stings, ethanol or methanol poisoning, and gas inhalation as well as papers reporting a single death (case study of single patient). We grouped the papers into 5-year intervals and identified the two most common poison classes in each paper. We used descriptive statistics to summarise the findings over time based on the causative poison and the location of the study. Results We identified 186 papers reporting 16,659 poisoning deaths between 1999 and 2018. The number of publications per 5-year interval showed no clear trend over the period (48, 38, 67, and 36 for consecutive periods). Half of the deaths (n = 8338, 50.0%) were reported during the first 5 years of the study (1999–2003), the number of deaths declining thereafter (to n = 1714 in 2014–2018). Deaths due to pesticide poisoning (94.5%) were dominant across the study period compared to other classes of poison [hair dye paraphenylenediamine poisoning (2.6%), medicine overdose (1.4%) or plant poisoning (1.0%)]. Among the pesticides, aluminium phosphide was the most important lethal poison during the first 10 years before declining markedly; organophosphorus insecticides were important throughout the period, becoming dominant in the last decade as aluminium phosphide cases declined. Unfortunately, few papers identified the specific organophosphorus insecticide responsible for deaths. Conclusion Use of the published literature to better understand the epidemiology of lethal poisoning in India has clear limitations, including secular variation in publishing practices and interest in poisoning. Unfortunately, there are no long-term detailed, combination hospital and community studies from India to provide this information. In their absence, our review indicates that pesticides are the most important poison in India, with organophosphorus insecticides replacing aluminium phosphide as the key lethal poison after government regulatory changes in 2001 reduced the latter’s lethality. Plant and hair dye poisoning and medicines overdose caused few deaths. Aluminium phosphide deaths mostly occurred in northern Indian states, whereas deaths from organophosphorus insecticide poisoning occurred throughout India. Paraquat poisoning has become a clinical problem in the last 10 years. Lethal pesticide poisoning remains alarmingly common, emphasising the need for additional regulatory interventions to curtail the burden of pesticide poisoning deaths in India. More detailed reporting about the specific pesticide involved in lethal poisoning will be helpful to guide regulatory decisions.

Study the Protective Effect of Ginger against the Toxicity of Dimethoate on Hormones in Rabbits

Organophosphorus insecticides have been widely classified as a health dangerous and high toxicity compounds due to their widespread use and release into the environment. Ginger (Zingiber officinale) has been used as a medicinal plant since antiquity and is known to play diverse biological roles including anti oxidation, anti-inflammation, hyperlipidemia, anti-carcinogenesis, anti-nausea, anti-thrombosis, and antibacterial process. The purpose of these experiments was to study decreasing the toxicity effect of Dimethoate by ginger. All animals in this study were assigned to one of four treatment groups: 0 mg ginger and 0 mg dimethoate /kg BW (control); 100 mg ginger/kg BW; 43.2 mg dimethoate /kg BW; and 43.2 mg dimethoate plus 100 mg ginger/kg BW. Rabbits were orally managed the particular measurements each other day for 12 weeks. Results indicated that treatment with ginger alone caused significant (P<0.05) increase in body weight (BW) and relative weight of testes compared to control animals. Whereas the rabbits treated with dimethoate showed significant (P<0.05) decrease in BW and relative weight of testes compared with control. Results showed that treatment with DM caused significant (P<0.05) decrease activity of testosterone, T3 and T4. While, increase the levels of FSH and LH in plasma. Ginger caused significant (P<0.05) increase in the activity of testosterone, T3 and T4 in plasma compared to control. While, decrease the levels of FSH and LH in plasma. The presence of ginger with DM caused significant (P<0.05) decrease in the reduction of T3 and T4, while caused an improvement in the levels of testosterone as compared to control and the presence of ginger with DM caused increase in the levels of FSH and LH as compared to control, and this means that ginger counteracted the toxic effects of DM.