Role of antioxidant activity of essential oils in their acaricidal activities against Rhipicephalus annulatus.

Essential oils of Origanum majorana and Satureja thymbra as well as carvacrol are natural products that are known to have potent antioxidant activities. The current study was designed to investigate the role of the antioxidant properties of these natural products in their acaricidal activities against Rhipicephalus annulatus larvae. The synergistic and/or antagonistic effects of the addition of vitamins E and C and hydrogen peroxide (H2O2) to these natural products were also evaluated. Larval packet tests were used to evaluate the acaricidal activities against the larvae of R. annulatus. The antioxidant effectiveness of these products was determined by a DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay. The addition of vitamin E at 100 mg/mL to O. majorana and S. thymbra decreased the concentrations required to achieve the death of half of the larvae (LC50) to 0.44 and 0.47%, respectively. The combination of O. majorana and S. thymbra attained the LC50 at 1.54% which was decreased to 0.69% after addition of vitamin E. Also, the addition of vitamin E to carvacrol reduced the LC50 to 0.27%. The total antioxidant activity of these natural products increased significantly in presence of vitamin E. The addition of H2O2 inhibited the acaricidal activity of all tested materials, especially at low concentrations. All treatments induced an increase in lipid peroxidation, whereas carvacrol-treated larvae revealed the lowest values for the superoxide dismutase. Glutathione peroxidase and catalase activity decreased in larvae treated with S. thymbra combined with vitamin E. In conclusion, the addition of vitamins E and C increased the acaricidal activities of the tested compounds, whereas the addition of H2O2 decreased these activities. The antioxidant activities of essential oils and their active components may play an important role in mediating their acaricidal activities.

Benzoate Derivatives Toxicity to Musca domestica Results in Severe Muscle Relaxation and Body Distortion.

The house fly, Musca domestica (Linnaeus) (Diptera: Muscidae), is a significant threat to human and animal health and is also resistant to a variety of insecticides. Plant-derived benzoates are known to have insecticidal activities against various insects. In this study, the larvicidal, pupicidal, and adulticidal activities of benzoate derivatives (benzyl alcohol BA, benzyl benzoate BB, and methyl benzoate MB) were assessed and investigated for their effects on larval structure and acetylcholinesterase activity. Six concentrations (2.5 to 100 mg/mL) of benzoate derivatives were applied to larvae and pupae through the residual film method and topical application, respectively. Meanwhile, concentrations from 0.625 to 50 mg/L air were applied to adult flies through a fumigation assay. BA and MB achieved promising results against larvae with LC50 values of 10.90 and 11.53 mg/mL, respectively. Moreover, BA killed 100% of the larvae at a concentration of 25 mg/mL, and MB achieved the same effect at a concentration of 50 mg/mL. Regarding the pupicidal activity, MB showed a percentage inhibition rate (PIR) of 100% at a concentration of 100 mg/mL, while the same effect was achieved by BA at a concentration of 50 mg/mL. Meanwhile, BB did not show any effect on the larvae or pupae at any of the tested concentrations. Moreover, the scanning microscopy observations on the treated larvae by BA and MB estimated flaccid and deformity in the larva body with a shrunken cuticle. Additionally, both BA and MB suppress nerve signal transmission by inhibiting acetylcholinesterase. In conclusion, the results of this study indicate that BA and MB may be useful in control housefly populations. These substances cause severe muscular relaxation and deformities in insects.

Potential of Marava arachidis, a Newly Recorded Earwig Species in Egypt as a Biological Control Agent of Rhipicephalus annulatus Tick in Laboratory.

In Egypt, only five species of Dermaptera (earwigs) have been reported. Based on both the morphological and molecular data of the earwig samples collected from a bakery in Beni-Suef, Egypt, we identified the species as Marava arachidis (Spongiphoridae), a cosmopolitan species with no prior records in Egypt. The current study was designed to analyze its predation capability on newly emerged eggs and larvae of the Rhipicephalus annulatus tick. A laboratory functional response study was set up by applying a predation test with various predator-prey ratios as treatments. This experiment was applied using the undefined mix of collected earwigs and the laboratory-collected eggs and the larvae of R. annulatus. The laboratory results showed that the mean number of predated tick eggs was 18.64 ± 11.18 in 24 h under the highest predator-prey ratio (1:10) examined, accompanied by 12.04 ± 4.38 broken but unconsumed eggs. Moreover, M. arachidis predated an average of 12.32 ± 9.07 tick larvae per day. In contrast, the mean dead larvae increased to 38.4 ± 2.30 per day with the highest predator density (1:10). The number of eggs and larvae consumed increased with the predator density. A linear relationship was detected between earwig density and the consumption rates of tick eggs (R2 = 0.99; p = 0.0001) and larvae (R2 = 0.96; p = 0.003). In conclusion, M. arachidis was first recorded in Egypt. This earwig has predation capability on R. annulatus tick eggs and larvae.

Acaricidal activity of Foeniculum vulgare against Rhipicephalus annulatus is mainly dependent on its constituent from trans-anethone.

Globally, the economic losses due to hard ticks infestation and the control of the associated diseases have been calculated at USD $13.9-18.7 billion per year. The economic impact is related to its direct damage to the skins, blood loss, anemia, severe immunological reactions and indirect losses that related to the effects of hemoparasites, cost of treatment for clinical cases and expenses incurred in the control of ticks. The current study evaluated the acaricidal activities of fennel Foeniculum vulgare essential oil and its main components; trans-anethole and fenchone; against R. annulatus. GC-MS analysis revealed that this oil contained 16 components representing 99.9% of the total identified compounds with E-anethole being the predominant component(64.29%), followed by fenchone (9.94%). The fennel oil and trans-anethole showed significant acaricidal activities. The LC50 of the fennel oil was attained at concentrations of 12.96% for adult ticks and 1.75% for tick larvae meanwhile the LC50 of trans-anethole was reached at concentrations of 2.36% for adult tick and 0.56% for tick larvae. On the contrary, fenchone showed no any significant adulticidal activities and its LC50 attained at a concentration of 9.11% for tick larvae. Regarding repellence activities, trans-anethole achieved 100% repellency at the concentration of 10% while fennel showed 86% repellency at the same concentration. Fenchone showed no repellency effect. Treatment of larvae with fennel, trans-anethole, and fenchone LC50 concentrations significantly inhibited the acetylcholinesterase activity. Meanwhile, glutathione s-transferase activity was significantly decreased in fennel treated larvae but no significant effect was found in the larvae of trans-anethole and fenchone groups. These results indicate that the acaricide effect of fennel oil may attributed to its high content of trans-anethole. This was supported by potent adulticidal, larvicidal, and repellency effects of trans-anethole against Rhipeciphalus annulatus tick and therefore it could be included in the list of acaricide of plant origin.

Prebiotic supplementation effect on Escherichia coli and Salmonella species associated with experimentally induced intestinal coccidiosis in rabbits.

BACKGROUND: Coccidian infection may enhance the proliferation of gut Enterobacteriaceae. Bacterial infections in rabbits can negatively affect the body condition and cause high mortality, especially at young ages. Therefore, the effect of prebiotic supplementation on the presence of Escherichia coli and Salmonella species in rabbits experimentally infected with intestinal coccidiosis was investigated. METHODS: Thirty male rabbits aged 35-40 days were divided into three equal groups. These groups were; prebiotic supplemented (PS), positive control (PC), and negative control (NC) groups. The prebiotic group was supplemented with 2 g/L of Bio-Mos® until the end of the experiment. At day ten post prebiotic supplementation; the PS and PC groups were inoculated orally with 5.0 × 104 sporulated oocysts of mixed species of rabbit Eimeria. The daily fecal examination was carried out from the day 4 post-infection (PI) until the day 8 PI. At day 5 and day 8 PI, 5 rabbits from each group (PS, PC, and NC) were humanely slaughtered and parts of intestinal tissue were collected for microbiological analysis. RESULTS: There was a significant decrease (P≤ 0.05) in the oocyst count in the PS group (25.12 × 104 ± 10.36) when compared with the PC group (43.43 × 104 ± 11.52) and this decrease was continued till the end of the experiment. Eleven E. coli isolates were detected in the collected samples with an overall prevalence of 24.4%. The highest prevalence of E. coli was in the PC group (13.33%) while the lowest one was in the PS group (4.44%). Meanwhile, four Salmonella serovars were isolated with an overall prevalence of 8.89%. The NC group showed one serovar (2.22%) and PC revealed three serovars (6.67%) while the prebiotic supplemented group didn't show any salmonella isolate. Of E. coli isolates, five isolates (O78, O125, O152, O115 and O168) showed high resistance to florfenicol and neomycin (100%). Also, of salmonella serovars, thee serovars (Salmonella entrica subsp. enterica serovar Macclesfield, Salmonella entrica Subsp. enterica serovar Canada and Salmonella entrica Subsp. enterica serovar Kisangani) showed high resistance to sulphamazole, amoxicillin and flumequin (75%) while it was sensitive to levofloxacin and ciprofloxacine (75%). The bacterial colony in this study was the same results at days 5 and 8 PI. CONCLUSION: The use of prebiotic as prophylaxis in this experiment significantly reduced the prevalence of E. coli and salmonella associated with the intestinal coccidiosis in rabbits.

Erratum: Saeed, E.-A.; Shawky, M.A.; El-Sayed, M.A.-K.; Shymaa, A.H.; Lilian, N.M.; Eman, M.F.; Asmaa, A.K. Investigation of Pre- and Post-Weaning Mortalities in Rabbits Bred in Egypt, with Reference to Parasitic and Bacterial Causes. Animals 2020, 10, 537.

The authors wish to make the following correction to their paper [...].

Investigation of Pre- and Post-Weaning Mortalities in Rabbits Bred in Egypt, with Reference to Parasitic and Bacterial Causes.

This study was conducted to investigate the causes of mortality in young rabbits. A total of 110 V-Line breed female rabbits aged 5 m were used in this study. Rabbit kits were examined daily in pre- and postweaning stages to detect clinical disorders that caused death. The postmortem examination was carried out on dead kits. Furthermore, rabbits were examined for the probable bacteriological and parasitological causes of death. Fecal samples were collected from each dead kit and examined by standard microbiological procedures for bacterial pathogens and macroscopically and microscopically for the presence of endo- and ectoparasites. Throughout two breeding seasons, 2238 newborns were obtained, of which 1736 died, accounting for a 77.57% mortality rate. During preweaning (1st month of age) and postweaning (up to 3 months of age), 1501 (67.10%) and 235 (31.90%) deaths were recorded, respectively. A postweaning fecal examination revealed that 198 out of 229 (86.50%) were diarrheic rabbits due to Eimeria infection. Cittotaenia spp. eggs were detected in 4.37% of fecal samples, and mites (Sarcoptis scabiei) were present in 6.55%. E. coli was detected in 100% of examined animals during pre- and postweaning periods; however, Salmonella spp. were 97.22% and 43.67, respectively. Managemental risk factors were the main causes in preweaning mortality, including insufficient milk supply (37.37%), cannibalism (26.38%), mange infestation of a rabbit doe (22.20%), mastitis (4.30%), lack of doe care (5.00%), bronchopneumonia (2.13%), and enteritis (1.80%). However, risk factors in postweaning mortality included sudden death with general septicemia (13.80%), enteritis (9.63%), bronchopneumonia (5.43%), mange infestation (2.04%), and malnutrition (0.81%). In conclusion, the etiology of preweaning mortality in kits was related mainly to the doe, especially managemental risk factors. However, a combination of multiple pathogenic agents (parasites and bacteria) and managemental factors was reported in the postweaning stage. Careful attention must be paid to avoid these causes.

Docosahexaenoic acid-flurbiprofen combination ameliorates metaflammation in rats fed on high-carbohydrate high-fat diet.

OBJECTIVE: Potential benefits of combining docosahexaenoic acid (DHA), an omega-3 fatty acid with flurbiprofen (Flu), a non-steroidal anti-inflammatory drug in ameliorating obesity remain to be elucidated. This study aimed to investigate the possible protective effects of DHA and Flu, either alone or in combination, against obesity-induced metaflammation and to clarify the underlying molecular mechanisms. METHODS: Seventy-five male Wistar rats were divided into five groups: normal diet (ND) group, high-carbohydrate high-fat diet (HCHFD) control group, DHA group (HCHFD + 200 mg/kg DHA), Flu group (HCHFD + 10 mg/kg Flu), and DHA + Flu group (HCHFD + DHA + Flu). Treatments were administered orally daily for 8 consecutive weeks, parallel with the start of diets. RESULTS: Plasma levels of glucose, insulin, and TGs were significantly reduced in DHA, Flu, and DHA + Flu treated groups, while HDL-C concentrations were significantly elevated in the same groups, compared to HCHFD control group. Only Flu and DHA + Flu groups showed a significant decrease in plasma levels of leptin, TC, and LDL-C, relative to HCHFD control group. Concentrations of phosphorylated adenosine monophosphate-activated protein kinase (pAMPK) and resolvin D1 (RvD1) in epididymal adipose tissue (EAT) were significantly increased in the three treated groups, compared with HCHFD control group. Expression of AMPK-α1 subunit in EAT was significantly increased, whereas expression of nuclear factor kappa B (NF-κB) was significantly decreased in EAT of the three treated groups, relative to HCHFD control group. CONCLUSIONS: Docosahexaenoic acid-flurbiprofen combination showed an ameliorative effect on obesity-associated metaflammation and its consequences in rats.

First Report of Cattle Tick Rhipicephalus (Boophilus) annulatus in Egypt Resistant to Ivermectin.

Tick control is mainly dependent on the application of acaricides, but resistance has developed to almost all classes of acaricides, including macrolactones. Therefore, we aimed to investigate ivermectin resistance among tick populations in middle Egypt. The larval immersion test was conducted using a commercial formulation of ivermectin (1%). Different concentrations of the immersion solution (0.0000625% (625 × 10-7%), 0.000125% (125 × 10-6%), 0.0005% (5 × 10-4%), 0.001% (1 × 10-3%), 0.0025% (2.5 × 10-3%), 0.005% (5 × 10-3), and 0.01% (1 × 10-2%)) were prepared by diluting a commercial ivermectin (1%) with distilled water containing 1% (v/v) ethanol and 2% (v/v) TritonX-100. Field populations of Rhipicephalus annulatus were collected from five different localities in Beni-Suef province, Egypt. Adult engorged female ticks were collected and assessed for oviposition and egg fertility. Eggs were collected, and hatched larvae were then used in the experiment. Application of acaricides was conducted on 10-day-old larvae. There was a significant difference in the LC50 (50% lethal concentration) among the examined localities on the log dose-response plot, where, the LC50 of tick populations from two localities (Emin elaros and Aldiabia) was higher than the other localities (Alhalabia, Alkom, and Beshnna). Besides, tick populations from Emin elaros and Aldiabia showed higher LC90 values with lower slope values compared to those from Alhalabia, Alkom, and Beshnna. According to these values (LC50, LC90, and slope values), as well as a history of acaricide failure to ticks in these areas, R. annulatus developed resistance to ivermectin. This study documents the first report of field populations of R. annulatus resistant to ivermectin in Egypt.

Diversity of Parasitic Diarrhea Associated with Buxtonella Sulcata in Cattle and Buffalo Calves with Control of Buxtonellosis.

The association between parasite isolates, including Buxtonella sulcata, in suckling and post-weaning calves and diarrhea was studied with the aim to control diarrhea caused by B. sulcata. A total of 1100 diarrheic fecal samples were collected from 609 suckling calves and 491 post-weaning calves with diarrhea. Salt floatation and modified Ziehl-Neelsen techniques were applied for the microscopic examination of the presence or absence of parasite eggs and oocysts/cysts. The microscopic findings revealed that 20.36% of the calves had parasitic diarrhea, with a prevalence rate of 19.54% in suckling calves and 21.38% in post-weaning calves. The most frequently detected parasites according to morphological characters were Eimeria species, Buxtonella sulcata, Toxocara vitulorum, Cryptosporidium species, and Moneizia species. In suckling calves, Eimeria species, B. sulcata, and T. vitulorum had the highest prevalence rates of infection, corresponding to about 37.14%, 32.86%, and 20.00%, respectively. However, in post-weaning calves, B. sulcata infection was more prevalent (30.15%) than infections with Eimeria species and T. vitulorum. The highest parasite score density was found in multiple infections with B. sulcata, Eimeria species, and T. vitulorum; however, the score density of B. sulcata when present alone in the fecal specimens was higher than in specimens co-infected with other parasites. The risk factors affecting the prevalence rate of parasitic diarrhea, such as sex, season, housing system, and feed stuff, are discussed. Concerning the treatment of diarrhea caused by B. sulcata in post-weaning cattle calves, 20 calves were divided into 4 equal groups. Group A was given sulphadimidine sodium (1.0 g/10 kg body weight) and metronidazole (500 mg/40 kg body weight); group B was treated with oxytetracycline hydrochloride (500 mg/45 Kg of body weight) and metronidazole (500 mg/40 kg body weight); group C was daily administered garlizine (allicin), 2 g/ L in drinking water; group D was the untreated control group. All medications were administered orally for four successive days. The results showed that the cyst count was significantly lower in the drug-treated groups, and the metronidazole + oxytetracycline hydrochloride and metronidazole + sulphadimidine combinations achieved 98.77% and 96.44% efficacy, respectively. Garlizine had 72.22% efficacy. Intriguingly, B. sulcata infection was associated with other parasitic infections, but B. sulcata mono-infection was the most common cause of diarrhea. Moreover, the combinations of oxytetracycline hydrochloride or sulphadimidine with metronidazole are recommended to control buxtonellosis in calves. Further studies are recommended to investigate the bacterial, viral, and fungal infections associated with B. sulcata infection.

Prophylactic and Therapeutic Efficacy of Prebiotic Supplementation against Intestinal Coccidiosis in Rabbits.

This study was conducted to investigate the effect of prebiotic supplementation against intestinal coccidiosis in rabbits. Fifty male rabbits aged 35-60 days (1-1.5 kg) were divided into prophylactic and therapeutic experiments (five groups, 10 rabbits per group). Prophylactic experiment had prebiotic supplemented (PS-P), non-supplemented infected control (NI-P), and non-supplemented non-infected control (NN-P) groups. Ten days post-prebiotic supplementation (PPS), rabbits in groups PS-P and NI-P were infected orally with 5.0 × 104 sporulated oocysts of mixed Eimeria species. However, therapeutic experiment had prebiotic supplemented (PS-T) and untreated infected (UI-T) groups of naturally infected rabbits with Eimeria species. A significant reduction in oocyst count per gram feces (OPG) (p ≤ 0.05) was reported in the PS-P (57.33 × 103 ± 2.84) and NI-P (130.83 × 103 ± 43.38) groups during the experiment. Additionally, rabbits in groups (PS-P, 970.33 ± 31.79 g and NI-P, 870.66 ± 6.66 g) showed weight loss after infection. However, a significant (p ≤ 0.05) decrease in OPG was observed at day seven PPS in the PS-T group (4 × 103 ± 0.00) when compared with the UI-T group (32 × 103 ± 7.54). Furthermore, the PS-T group had a higher body weight than rabbits in the UI-T group. Histopathological findings of the intestinal tissues (duodenum, jejunum, and ileum) showed that the counts of the endogenous stages were significantly higher in the NI-P and UI-T groups than in the prebiotic-supplemented groups (PS-P and PS-T). Supplementation of the prebiotic did not have any adverse effects on biochemical parameters, such as AST, ALT, creatinine, total protein, and total cholesterol. In conclusion, prebiotic supplementation can be used to minimize the adverse effects of intestinal coccidiosis in rabbits, which in turn limits body weight loss, especially for the prophylaxis of coccidial infection.

Molecular detection of Rhipicephalus (Boophilus) annulatus resistance against deltamethrin in middle Egypt.

This study was designed to investigate the susceptibility/resistance of Rhipicephalus (Boophilus) annulatus to commercial deltamethrin 5%. The work was based on in vitro bioassays; adult immersion test (AIT) and larval packet test (LPT). Fully engorged female ticks were collected from 11 locations in Beni-Suef Governorate, Egypt (Alfashin, Eminelaros, Ehnasia, Smusta, Belifia, Aldiabia, Alhalabia, Beshnna, Alkom, Nasr and Beba). Two concentrations of commercial deltamethrin 5% (200 and 400 ppm) were tested by AIT on R. (B.) annulatus. The mortality of ticks at 400 ppm was higher than 200 ppm which was not reached to 100%. Ehnasia tick population was the least susceptible to deltamethrin while Alfashin population was the most susceptible one. Different deltamethrin concentrations (0.000625, 0.00125, 0.0025, 0.005, 0.010 and 0.020) were used in LPT to evaluate the larval mortality. The highest LC50 appeared in Ehanasia tick population (0.01) with 95% confidence interval (0.005 to 0.01) meanwhile, the lowest LC50 appeared in Alfashin (0.0006) with 95%CI (0.0005 to 0.0007). Thus, it is possible to deduce that one population was considered susceptible; seven populations were resistant level I and three populations were resistant level II. Additionally, PCR revealed that the resistant alleles (R) appeared in two localities (Ehnasia and Aldiabia). It was concluded that at least two tick populations of the investigated locations were of possible resistant to deltamethrin.