Lassa fever: History, causes, effects, and reduction strategies

Review (Published online: 25-08-2020)

1. Lassa fever: History, causes, effects, and reduction strategies

Promise Tewogbola and Norah Aung

International Journal of One Health, 6(2): 95-98

ABSTRACT

Lassa fever is a disease that is not well-known worldwide, particularly due to the inability of the multimammate rat, the primary vector of the Lassa virus, to breed in temperate regions. The aim of this review is to provide an overview of the disease and its modus operandi while also providing information about trends in the past decade, as well as proven strategies that have been used to manage its spread.

Keywords: Arenavirus, epidemic, epidemiology, Lassa fever, Lassa virus, virus.

Investigation of Trypanosoma evansi infection in bullfighting cattle in Southern Thailand

Research (Published online: 22-08-2020)

27. Investigation of Trypanosoma evansi infection in bullfighting cattle in Southern Thailand

Ketsarin Kamyingkird, Piangjai Chalermwong, Vannarat Saechan, Domechai Kaewnoi, Marc Desquesnes and Ruttayaporn Ngasaman

Veterinary World, 13(8): 1674-1678

ABSTRACT

Background and Aim: Trypanosoma evansi infection has been reported in Thai livestock such as beef and dairy cattle. However, there is little information on T. evansi infection in bullfighting cattle in Southern Thailand. The aim of this study was to investigate the infection of T. evansi in bullfighting cattle presented for health checks at the Animal Hospital, Faculty of Veterinary Science, Prince of Songkla University, Thailand.

Materials and Methods: Blood and serum samples were collected from 177 bullfighting cattle from April 2016 to February 2017 after bullfighting matches. Animal inspected showed signs of fever, weight loss, or exercise intolerance. Investigation of T. evansi infection was tested using polymerase chain reaction (PCR) with TBR primers and using indirect enzyme-linked immunosorbent assay with T. evansi crude antigen.

Results: The seroprevalence of T. evansi in bullfighting cattle was 22.60% (40/177). The PCR results detected no parasite DNA in this study. However, bullfighting cattle may serve as T. evansi reservoirs.

Conclusion: Health checking procedures for T. evansi should be promoted for bullfighting events so that infected animals can be quarantined in the preparatory stages of such events.

Keywords: bullfighting cattle, seroprevalence, Thailand, Trypanosoma evansi.

Expressions of miR-155 and miR-181 and predictions of their structures and targets in pigs (Sus scrofa)

Research (Published online: 21-08-2020)

26. Expressions of miR-155 and miR-181 and predictions of their structures and targets in pigs (Sus scrofa)

Jirapat Ninsuwon, Pitchaporn Waiyamitra, Atthaporn Roongsitthichai and Win Surachetpong

Veterinary World, 13(8): 1667-1673

ABSTRACT

Background and Aim: MicroRNAs (miRNAs) are responsible for gene expression control at the post-transcription level in many species. Several miRNAs are required in the regulation of immune responses, such as B-cell differentiation, T-cell receptor signaling pathway, CD4+ T cell selection, and so on. Studies on miRNAs have been extensively conducted in humans and mice; however, reports relevant to miRNAs, especially miR-155 and miR-181, in pigs are limited. Consequently, the present study aimed to investigate the structures, target genes, and expressions of miR-155 and miR-181 in various porcine cells and tissues.

Materials and Methods: Five healthy male pigs from a porcine reproductive and respiratory syndrome virus-negative farm were studied. Before slaughter, blood samples were collected for peripheral blood mononuclear cell isolation. After slaughter, samples of spleen, lymph nodes, and forelimb muscles were collected. Both miR-155 and miR-181 were investigated for their structures with RNAfold web server, for their target genes from three online web servers, and for their expressions using polymerase chain reaction (PCR).

Results: The structures of miR-155 and miR-181 contained hairpins with free energies of –35.27 and –35.29 kcal/mole, respectively. Target gene prediction revealed that miR-155 had perfect complementarity with Socs1 and Mapk3k14, while miR-181 had perfect complementarity with Ddx3x, Nfat5, Foxp1, and Mpp5. PCR showed that both miRNAs were detectable from all investigated cells and tissues. Moreover, the highest expression of both miRNAs was found from the lymph node of the pigs.

Conclusion: Both miR-155 and miR-181 might be involved with the regulation of porcine immune functions as both miRNAs were detected in several cells and tissues of the pigs. In addition, they had very high complementarities with the seed regions of several immune-related genes.

Keywords: immune system, microRNA, miR-155, miR-181, porcine.

Field serological investigation for peste des petits ruminants, foot-and-mouth disease, and bluetongue diseases in illegally introduced animals in Egypt

Research (Published online: 21-08-2020)

25. Field serological investigation for peste des petits ruminants, foot-and-mouth disease, and bluetongue diseases in illegally introduced animals in Egypt

Wafaa Abd El Wahab Hosny, Eman Mohamed Baheeg, Hala Abd El Raheem Aly, Samia Said Abd El Nabi and Nadia Maher Hanna

Veterinary World, 13(8): 1661-1666

ABSTRACT

Aim: In this study, laboratory scoping on the viruses that cause peste des petits ruminants (PPR), bluetongue (BT), and foot-and-mouth disease (FMD) was performed to evaluate the current status of animals illegally introduced into Egypt. This study aims to help control these infectious illnesses and tries to prevent the introduction of other strains of these three viruses to Egypt, as these illnesses spread quickly if not controlled.

Materials and Methods: In the year 2018, 62 serum samples were collected and serologically tested through competitive enzyme-linked immunosorbent assays (ELISA) kits to detect antibodies against PPR, BT, and FMD, which are three important transboundary infectious illnesses.

Results: The results indicated that 60 out of 62 serum samples were positive for PPR antibodies (96.7%), 31 out of 62 were positive for FMD antibodies (50%), and 59 out of 62 serum samples were positive for BT antibodies (95%).

Conclusion: This study revealed that PPR, FMD, and BT can be introduced into Egypt through the illegal introduction of sheep and goat from neighboring countries. Laboratory diagnostic abilities should be improved for the early detection and control of these illnesses.

Keywords: bluetongue and foot-and-mouth disease sheep-goats, competitive enzyme-linked immunosorbent assays, peste des petits ruminants.

The effect of the sex, age, and breed of farmed rabbits and the choice of management system on the extensity and intensity of Eimeria infection

Research (Published online: 20-08-2020)

24. The effect of the sex, age, and breed of farmed rabbits and the choice of management system on the extensity and intensity of Eimeria infection

B. Pilarczyk, A. Tomza-Marciniak, R. Pilarczyk, E. Januś, P. Stanek, B. Seremak and P. Sablik

Veterinary World, 13(8): 1654-1660

ABSTRACT

Background and Aim: The most common causes of loss and diarrhea in rabbit farming are nutritional errors and coccidiosis. The infection can spread rapidly throughout a breeding area, reducing the rabbit population, and causing heavy losses. The aim of the study was to determine the influence of the system of animal management on the extensity and intensity of infection by Eimeria of farmed rabbits, together with the effect of the sex, age, and breed of the rabbits themselves.

Materials and Methods: The study included 91 rabbits (Flemish Giant, New Zealand White, French Lope, Vienna Blue, California White, and mixed breed) from eight domestic (small-scale) farms from Poland. The prevalence and intensity of coccidial infection were determined by the Willis-Schlaf and McMaster coprological methods. The species were determined based on oocyst morphology: Their shape, color, form index, the presence or absence of micropyle and cap, and the presence or absence of residual, polar, and Stiedé bodies.

Results: Seven species of Eimeria were isolated from the tested rabbits: Eimeria magna, Eimeria media, Eimeria perforans, Eimeria stiedae, Eimeria coecicola, Eimeria exigua, and Eimeria irresidua. Most infections were found to be of relatively low intensity. No significant differences in the extensity of Eimeria protozoan infection were observed with regard to sex. However, rabbit age had a significant influence on the extensity of infection by E. magna and of Eimerian protozoans combined. The greatest extensity was observed in rabbits aged below 6 months. For all species of Eimeria, greater extensity was observed among rabbits kept in groups than individually. The system of rabbit management also had a significant influence on the intensity of infection. Those kept in groups demonstrated a significantly higher mean intensity of infection of E. magna and all Eimeria species combined than those kept individually.

Conclusion: Our findings indicate that Eimeria protozoa are a common occurrence on small-scale rabbit farms. As coccidiosis treatment does not always give good results, prevention is very important in the fight against this disease. It is necessary to develop a new preventive paradigm that pays special attention to the factors that promote the spread and development of infection in domestic (small-scale) farms from Poland. For example, it would be recommended to use large, dry, bright rooms with access to the sun, as these are conducive to preventing the occurrence of coccidia infections.

Keywords: Eimeria, rabbits, small-scale rabbit farms.

Investigation of the effect of chitosan and silver nanoparticles on the antibiotic resistance of Escherichia coli O157:H7 isolated from some milk products and diarrheal patients in Sohag city, Egypt

Research (Published online: 20-08-2020)

23. Investigation of the effect of chitosan and silver nanoparticles on the antibiotic resistance of Escherichia coli O157:H7 isolated from some milk products and diarrheal patients in Sohag city, Egypt

Alshimaa A. Hassanien and Eman M. Shaker

Veterinary World, 13(8): 1647-1653

ABSTRACT

Background and Aim: Antimicrobial-resistant Escherichia coli O157:H7 causes serious diseases in humans, especially when circulated in their food. This study was designed to detect the presence of E. coli O157:H7 using the fliC H7 gene in some milk products as kareish cheese, labena, and yoghurt sold in Sohag city, Egypt, and among diarrheal patients admitted to governmental hospitals in Sohag and also to highlight the risk factors associated with their infection. In addition, the antimicrobial resistance and the effect of chitosan nanoparticles (CNP) and silver nanoparticles (SNP) on E. coli O157:H7 isolates obtained from both milk products and patients were investigated.

Materials and Methods: Microbiological culture methods and polymerase chain reaction were used for detecting E. coli O157:H7 in 150 milk products and 150 stool samples. Resistance against some antimicrobials that were used in the treatment of animals and humans was investigated using the disk diffusion technique. CNP and SNP at two concentrations (30 and 60 μg/mL) and average sizes of 25.1 and 26.5 nm, respectively, were identified by transmission electron microscopy. Their effect on E. coli O157:H7 isolates was examined using the well diffusion method. Risk factors for infection were investigated using statistical analysis.

Results: There were 11.3% and 14.7% of milk products and stool samples positive for E. coli O157:H7, respectively. These isolates exhibited high antimicrobial resistance to ampicillin, tetracycline, and gentamycin. CNP and SNP demonstrated inhibitory effects on E. coli O157:H7 growth, which significantly increased at high concentrations (60 μg/mL), with mean inhibition zones of 31.941±3.749 and 30.681±3.871 mm for CNP in milk products and patient isolates, respectively. The respective values for SNP were 33.588±3.675 mm and 32.500±2.444 mm, indicating a higher bactericidal effect than that of CNP. Regarding risk factors for infection, both young and elderly subjects and those in contact with infected persons and/or having chronic diseases were infected.

Conclusion: CNP and SNP are suitable for both medical and agricultural applications for disease control and enhancement of food quality.

Keywords: chitosan nanoparticles, diarrheal patients, Escherichia coli O157:H7, kariesh cheese, labena, silver nanoparticles.

Improvements to the live-attenuated Newcastle disease virus vaccine using Carbopol® 940 as a stabilizer

Research (Published online: 19-08-2020)

22. Improvements to the live-attenuated Newcastle disease virus vaccine using Carbopol® 940 as a stabilizer

Mahmoud Mohamed Abd El-Moneam, Nada Adel Fathy, Naglaa I. Ali and Heba Mohamed El Naggar

Veterinary World, 13(8): 1641-1646

ABSTRACT

Background and Aim: One strategy that can be used to stabilize vaccines is to convert them into a dry powder. This can protect the integrity of the active ingredients as well as vaccine antigenicity during manufacture, storage, and transport. This study highlights the potent adjuvant activity of Carbopol® when used alone to stabilize live-attenuated Newcastle disease virus (NDV) vaccines or when used in a formulation together with skimmed milk. Tolerability and potency of these formulations were compared with those obtained from other local live NDV vaccines produced locally by the Veterinary Serum and Vaccine Research Institute.

Materials and Methods: We evaluated the cellular and humoral immune responses to a locally prepared, live-attenuated LaSota virus vaccine. Vaccine formulations were stabilized with Carbopol® 940 alone or in combination with skimmed milk.

Results: Our results indicate that the use of Carbopol® 940 alone to stabilize a live-attenuated LaSota vaccine resulted in enhanced cellular and humoral immunity. The antibody titer was prolonged through the 6th week post-vaccination (5.0 log2). Full (100%) protection was observed in response to challenge with very virulent NDV at day 21 after vaccination; there were no clinical signs or lesions on examination. Addition of Carbopol® 940 to the live-attenuated vaccine formulation resulted in a more compact, stable, and high-quality lyophilized cake after freeze-dried lyophilization compared with that produced by stabilization with skimmed milk alone.

Conclusion: Our data suggest that Carbopol® 940 may improve clinical responses to live-attenuated vaccines.

Keywords: Carbopol® 940, LaSota, lyophilization, Newcastle disease virus, stabilizers, vaccine.