Epidemiological perspective associated with principal risk factors of Trichinella spiralis infection in pigs and humans in Egypt

Research (Published online: 11-06-2022)

5. Epidemiological perspective associated with principal risk factors of Trichinella spiralis infection in pigs and humans in Egypt

Eman Sayed Mohammed, Asmaa Gahlan Youseef, Asmaa Gaber Mubarak, Amany Sayed Mawas, Fatma Ahmed Khalifa and Wael Felefel

Veterinary World, 15(6): 1430-1437

ABSTRACT

Background and Aim: In Egypt, there is a scarcity of recent data on trichinellosis in pigs and humans. Therefore, this study aimed to determine the epidemiological profile and risk factors associated with Trichinella spiralis infection as well as to assess the effectiveness of the trichinoscope and digestion technique in diagnosing trichinellosis.

Materials and Methods: Data were collected on 33812 pigs slaughtered during a year at the Al-Basateen abattoir, Cairo Governorate, Egypt. The slaughtered pigs had already been examined by trichinoscope in the abattoir. The diagnostic effectiveness technique was randomly conducted on 170 pork muscle samples, which were examined using the digestion technique. Furthermore, 90 serum samples from high-risk individuals in Qena and Sohag Governorates, Upper Egypt, were analyzed using an enzyme-linked immunosorbent assay.

Results: The investigation revealed that the overall prevalence was 1.06% in pigs by trichinoscope. Of the examined 170 samples, 2.35% and 3.35% were found to harbor Trichinella by trichinoscope and artificial digestion, respectively. Trichinella was identified as T. spiralis using a polymerase chain reaction (PCR) technique. A significant relationship was affirmed between the prevalence of trichinellosis and the sex and age of the examined pigs. Likewise, for the first time, there was a considerable seasonal trend in the prevalence of Trichinella with the maximum infection, which was observed during Autumn (1.18%). The prevalence of trichinellosis in humans was 10%, with a significant association with age.

Conclusion: Our findings are intended to serve as a starting point for developing effective preventive and control measures for trichinellosis (as application of Hazard Analysis Critical Control Points (HACCP) in pig farms, stop feeding pigs on garbage as well as, preventing illegal slaughter of pigs outside the slaughterhouses). It also fortifies the establishment of the digestion technique because of its high specificity and sensitivity, although it is difficult to apply to a large number of samples.

Keywords: Egypt, enzyme-linked immunosorbent assay, humans, pigs, polymerase chain reaction, Trichinella spiralis.

Pathological, molecular, and serological study of small ruminant lentiviruses in Jordan

Research (Published online: 09-06-2022)

4. Pathological, molecular, and serological study of small ruminant lentiviruses in Jordan

Nabil Q. Hailat, Tameem B. Algharaibeh and Laith N. Al-Eitan

Veterinary World, 15(6): 1423-1429

ABSTRACT

Background and Aim: Maedi-visna is a chronic viral disease of sheep with worldwide distribution causing substantial economic losses to the small ruminant industry. Pneumonia and mastitis are the main manifestations of the disease. This study aimed to investigate the occurrence of maedi-visna virus (MVV) in sheep using histopathology and nested polymerase chain reaction (PCR) techniques and also to estimate the seroprevalence of small ruminant lentiviruses (SRLVs) in sheep and goats using commercially available enzyme-linked immunosorbent assay (ELISA).

Materials and Methods: Lung tissue samples from 380 sheep were collected and fixed in 10% formalin for histopathology and molecular diagnosis of MVV. Separately, 806 serum samples were randomly collected from 633 sheep and 173 goats to detect the seroprevalence of SRLVs using ELISA.

Results: The results showed that 4.7% of lung samples (n=190) were positive by both histopathology and nested PCR, 5.8% (n = 380) were positive by histopathology only (have lymphoid follicular hyperplasia), and 7.4% (n = 190) were positive by nested PCR only. Statistical analysis revealed a moderate agreement between the two tests (Kappa=0.451, n = 190). Serology results revealed that sheep and/or goats herd prevalence was 59.8% (n = 87), while individual seroprevalence in sheep (40.1%, n = 633) was significantly higher than that in the other six countries and also significantly higher than that in goats (18.5%, n = 173) (at p < 0.05).

Conclusion: The moderate statistical agreement between nested PCR and histopathological diagnosis of MVV in formalin-fixed paraffin-embedded sheep lung tissue samples (Kappa=0.451, n = 190) suggests combining both tests for more sensitive MVV detection in sheep lung samples. SRLVs seropositivity in sheep was significantly higher than in goats, thus, it is of high concern and urges the inquiry into the economic impact of the disease and the financial benefit of adopting eradication measures.

Keywords: caprine arthritis encephalitis virus, enzyme-linked immunosorbent assay, histopathology, maedi-visna virus, polymerase chain reaction, small ruminant lentiviruses.

Efficacy of common disinfection processes against infective spores (arthroconidia) and mycelia of Microsporum gallinae causing avian dermatophytosis

Research (Published online: 08-06-2022)

3. Efficacy of common disinfection processes against infective spores (arthroconidia) and mycelia of Microsporum gallinae causing avian dermatophytosis

Eakachai Thongkham, Sucheeva Junnu, Glenn Neville Borlace, Suwit Uopasai and Jareerat Aiemsaard

Veterinary World, 15(6): 1413-1422

ABSTRACT

Background and Aim: Microsporum gallinae is the major dermatophyte species that causes avian dermatophytosis. Disinfection plays an important role in controlling and preventing dermatophytosis; however, information about the effect of common disinfection processes on M. gallinae is limited. This study aimed to investigate the disinfection efficacy of ultraviolet (UV) irradiation, heat treatment, detergents, and germicides against infective spores (arthroconidia) and vegetative mycelia of M. gallinae.

Materials and Methods: The minimum inhibitory and minimum fungicidal concentrations of benzalkonium chloride, chlorhexidine, ethanol, formaldehyde, glutaraldehyde, hydrogen peroxide, phenol, povidone-iodine, and sodium hypochlorite germicides against arthroconidia and mycelia of M. gallinae American type culture collection (ATCC) 90749 were determined by broth microdilution. Time-kill assays were used to determine the fungicidal efficacy of moist heat treatment, UV irradiation, commercially available detergents, and germicides.

Results: There were no significant differences between the arthroconidia and mycelia growth stages of M. gallinae ATCC 90749 in the magnitude of the log10 cell reductions in the number of viable fungal cells induced by the disinfection treatments (all p > 0.05). Moist heat treatment at 40°C did not reduce the number of viable fungal cells at any time (1–60 min); however, treatment at 50°C for 25 min and either 60°C or 80°C for 5 min eliminated > 99.999% of viable fungal cells. Irradiation of fungal cultures with UVC and UVB at doses higher than or equal to 0.4 and 0.8 J/cm2, respectively, resulted in a 5-log10 reduction in the number of viable fungal cells, whereas UVA only reduced the number of viable fungal cells by < 2-log10 up to a dose of 1.6 J/cm2. All the tested detergents demonstrated minimal fungicidal effects with < 1-log10 reductions in the number of viable fungal cells at concentrations up to 8% w/v. All of the tested germicides eradicated the fungus after treatment for 1 min at 1–1000× minimum inhibitory concentration (MIC), except for hydrogen peroxide, which was not fungicidal after treatment for 20 min at 100× MIC.

Conclusion: Moist heat treatment at temperatures greater than or equal to 50°C, UVC and UVB irradiation at doses higher than or equal to 0.4 and 0.8 J/cm2, respectively, and treatment with all tested germicides except hydrogen peroxide can be considered effective processes for disinfecting the fungus M. gallinae from the equipment employed in poultry farming. In contrast, commercially available detergents are not suitable for use as M. gallinae disinfectants.

Keywords: arthroconidia, avian dermatophytosis, disinfection processes, Microsporum gallinae.

Analysis of insulin resistance using the non-linear homeostatic model assessment index in overweight canines

Research (Published online: 08-06-2022)

2. Analysis of insulin resistance using the non-linear homeostatic model assessment index in overweight canines

Franco Gonzlez-Villar and Francisco Pérez-Bravo

Veterinary World, 15(6): 1408-1412

ABSTRACT

Background and Aim: Diabetes mellitus is a carbohydrate metabolism disorder produced mainly by a deficit in insulin production or insulin resistance. The homeostatic model assessment (HOMA) is a broad method for estimating insulin resistance and β-cell function. This study aimed to evaluate the stages of insulin resistance using non-linear HOMA index analysis in normoglycemic normal weight and obese canines.

Materials and Methods: Insulin resistance was evaluated using the mathematical HOMA non-linear model in canines with different body and glycemic conditions. Forty canines were studied, including 20 normoglycemic normal weight canines and 20 normoglycemic obese canines. Chi-square statistical test was applied, in which the body condition and HOMA non-linear index were evaluated. The Spearman correlation test was conducted to evaluate the glycemic and insulin variables in both types of canines.

Results: The Spearman correlation presented a correlation between increased blood glucose levels and insulin in obese canines, with a correlation of 0.79, while no significant changes in insulin were found in normal weight canines with different blood glucose levels, with a correlation of –0.11. The analysis of the non-linear HOMA index showed significant differences between non-linear HOMA insulin resistance in normal weight and obese canines, with a Chi-square statistic of 16.9424 and p = 0.000039. Canine with increased HOMA 2 showed higher levels of insulin with increasing blood glucose compared to those with normal HOMA 2.

Conclusion: The HOMA 2 is a marker for evaluating increased insulin resistance in obese dogs and can be used to determine patients at risk for glycemic alterations.

Keywords: diabetes, glycemia, insulin resistance, overweight.

Comparison of the oxidative respiratory burst and mitogen-induced leukocyte responses of camels, goats, sheep, and cows

Research (Published online: 07-06-2022)

1. Comparison of the oxidative respiratory burst and mitogen-induced leukocyte responses of camels, goats, sheep, and cows

Abeer Al-Hamrashdi, Khalid Al-Habsi, Elshafie I. Elshafie and Eugene H. Johnson

Veterinary World, 15(6): 1398-1407

ABSTRACT

Background and Aim: The reports from the Ministry of Agriculture and Fisheries suggest that camels suffer less compared to goats, sheep, and cows from a number of common infectious diseases in Oman. However, there is no immunological evidence to substantiate this claim. This present study is, therefore, an attempt to study the immunological responses of camels, goats, sheep, and cows by comparing their oxidative respiratory burst of peripheral blood leukocytes (PBLs) as a marker of innate immunity occurring during phagocytosis and the mitogenic responses of their peripheral blood mononuclear leukocytes (PBMLs) as a marker of their adaptive immune response.

Materials and Methods: Ten female adult animals (n = 10) were selected from each species (goats, sheep, and cows). The goats, sheep, and cows were maintained at the Agricultural Experiment Station, while camels were kept at the Royal Camel Corps (RCC). Blood samples were collected from the jugular vein in 7 mL of heparin and ethylenediaminetetraacetic acid vacutainer tubes. The oxidative respiratory burst of PBLs was measured using a chemiluminescence (CL) assay. Reactants consisted of 75 μL of whole blood diluted (1:50), 75 μL of luminol/isoluminol, and 75 μL of zymosan opsonized with non-heat inactivated serum/heat-inactivated serum or non-opsonized zymosan. CL responses were measured as relative light units and expressed as the mean count per minute and peak CL values. The mitogenic response of PBMLs to concanavalin A (Con-A), phytohemagglutinin (PHA), and pokeweed mitogen (PWM) was tested using a WST-8 assay and read spectrophotometrically at 450 nm.

Results: The present findings showed that camel PBLs generate significantly higher CL responses, both intracellularly as well as extracellularly, with zymosan opsonized with autologous serum. Camel PBLs demonstrated a significantly higher (p = 0.001) response when stimulated with zymosan opsonized with heat-inactivated serum compared to those of goat, sheep, and cow lymphocytes from camels exhibited significantly higher (p = 0.001) stimulation indices (SI) with Con-A, PHA, and PWM.

Conclusion: The present study suggests that camels are capable of mounting both superior innate as well as adaptive immune responses and provide immunological evidence supporting the belief of some authors, who have proposed that camels are less susceptible to a number of common infectious diseases than other domesticated ruminants.

Keywords: adaptive immune system, chemiluminescence, concanavalin A, innate immune system, phytohemagglutinin, pokeweed mitogen.

Comparative diagnosis of bovine tuberculosis using single intradermal cervical tuberculin technique, conventional methods, enzyme-linked immunosorbent assay, and the gamma-interferon assay

Research (Published online: 31-05-2022)

30. Comparative diagnosis of bovine tuberculosis using single intradermal cervical tuberculin technique, conventional methods, enzyme-linked immunosorbent assay, and the gamma-interferon assay

Sahar Hussein Abdalla Hekal, Amany N. Dapgh, Mai Badr-Eldien Abd-Elhafeez, Hassan Mohamed Sobhy and Fatma Ahmed Khalifa

Veterinary World, 15(5): 1391-1397

ABSTRACT

Background and Aim: Bovine tuberculosis (TB) is a zoonotic disease that causes huge economic losses. This study aimed to compare the result obtained from the single intradermal test, conventional methods (culture and microscopy), gamma-interferon (IFN-γ) assay, and indirect enzyme-linked immunosorbent assay (ELISA) to diagnose bovine TB.

Materials and Methods: This study evaluated 2913 animals from milk farms in Cairo, El-Sharkia, and El-Qalyubia Governorates by single intradermal cervical tuberculin technique (SICTT), ELISA, and IFN-γ assay.

Results: Of the 2913 dairy cows surveyed, 3.7% yielded positive results. Culture prepared samples on Lowenstein-Jensen and Middlebrook 7H10 agar media yielded 52 (1.85%) isolates of Mycobacterium spp. from 2805 milk samples that yielded negative tuberculin reactions and 56 (51.85%) isolates of Mycobacterium spp. were recovered from 108 lymph node samples from positive cases. ELISA analysis of the sera of 108 positive SICTT reactors revealed that 94 (87.03%) and 97 (89.81%) animals were positive for bovine purified protein derivative (PPD-B) antigen and commercial polypeptide antigen, respectively. IFN-γ assays were performed on whole blood samples collected from positive SICTT reactors and showed that 103 (95.37%) animals were positive.

Conclusion: M. tuberculosis complex may be isolated from raw milk and not all infected animals shed mycobacterial bacilli in their milk. The use of polypeptide antigen in ELISA provides better diagnostic efficacy than PPD-B antigen. The IFN-γ assay is more sensitive than both SICTT and ELISA. It should be used in parallel with SICTT to allow the detection of more positive animals before they become a source of infection to other animals and humans.

Keywords: bovine tuberculosis, enzyme-linked immunosorbent assay, Gamma-interferon assay, Mycobacterium tuberculosis, single intradermal cervical tuberculin skin test.

Preparation and the assessed efficacy of oral baits for the vaccination of free-roaming dogs against rabies

Research (Published online: 31-05-2022)

29. Preparation and the assessed efficacy of oral baits for the vaccination of free-roaming dogs against rabies

Naglaa I. Aly, Yasser F. Elnaker, Zeinab T. S. Salama, Mohamed S. Diab, Eman A. Saber, Sotohy A. Sotohy, Wael K. Elfeil and Mohamed H. Khodeir

Veterinary World, 15(5): 1383-1390

ABSTRACT

Background and Aim: Rabies is considered a highly fatal zoonotic disease and many deaths in humans have been associated with dog bites. This study was designed to prepare an oral anti-rabies vaccine in the form of baits to eliminate the disease in free-roaming dogs and subsequently protect humans from dog bites.

Materials and Methods: The Evelyn Rokintniki Abelseth (ERA) rabies virus strain was propagated in baby hamster kidney cell cultures and adjusted to the recommended dose for application. Four forms of oral baits were employed with the rabies vaccine, which was evaluated for safety, acceptability, and potency in different dog groups. Enzyme-Linked Immunosorbent Assay (ELISA) and the serum neutralization test (SNT) were used to determine the protective rabies antibody titer in the sera of vaccinated dogs.

Results: According to the results, a dose of 3 mL of the ERA strain, containing a viral titer of 107.6 TCID50/mL, induced a mean antibody titer of 25.6 by SNT, and the PI% was 75.7 by Block ELISA, providing a protective level of the rabies antibody in 100% of vaccinated dogs. All used baits were found to be safe, inducing no abnormal general post-vaccination signs (the signs are limited to mild fever, mild loss of appetite, and mild-to-moderate loss of energy for 24-36 h after vaccination).

Conclusion: It was found that most of the accepted and highly potent bait types consisted of a mixture of wheat flour, vegetable oil, sodium alginate, corn starch, meat meal, cellulose gum, and water. This dog meal was covered with bran and edible wax to seal the bait cavity after inserting the vaccine sachet. This bait was able to induce a protective level of rabies antibodies in 100% of vaccinated dogs after receiving one bait/dog. Hence, such a bait could be recommended for use in the protection of free-roaming dogs and the elimination of the disease.

Keywords: enzyme-linked immunosorbent assay, oral baits, potency, rabies, serum neutralization test.