Expression of the recombinant C-terminal of the S1 domain and N-terminal of the S2 domain of the spike protein of porcine epidemic diarrhea virus

Research (Published online: 12-11-2021)

10. Expression of the recombinant C-terminal of the S1 domain and N-terminal of the S2 domain of the spike protein of porcine epidemic diarrhea virus

Jiraporn Sritun, Natnaree Inthong, Siriluk Jala, Sakuna Phatthanakunanan, Khomson Satchasataporn, Kaitkanoke Sirinarumitr, Preeda Lertwatcharasarakul and Theerapol Sirinarumitr

Veterinary World, 14(11): 2913-2918

ABSTRACT

Background and Aim: Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea in suckling piglets, leading to severe economic losses in the swine industry. Commercial vaccines have limited effectiveness against different genogroups of PEDV and the shedding of virus. The C-terminal of the S1 domain and the N-terminal of the S2 domain (S1-2) protein of the spike (S) protein have four neutralizing epitopes. However, research on the expression of the S1-2 segment of the S gene has been limited. In this study, we expressed a recombinant S1-2 protein of the S protein of the PEDV Thai isolate and characterized the immunological properties of the recombinant S1-2 protein.

Materials and Methods: The S1-2 segment of the S gene of the PEDV Thai isolate (G2b) was amplified, cloned into the pBAD202/D-TOPO® vector (Invitrogen, Carlsbad, CA, USA), and expressed in Escherichia coli. The optimum concentration of arabinose and the optimum induction time for the expression of the recombinant S1-2 protein were determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The immunogenic reactivity of the recombinant S1-2 protein was determined using Western blot analysis with rabbit polyclonal antibodies against the SM98 strain of PEDV (G1a).

Results: The recombinant S1-2 segment of the S gene of the PEDV Thai isolate protein was cloned and the recombinant S1-2 protein was successfully expressed. The optimum concentration of arabinose and the optimum induction time for the induction of the recombinant S1-2 protein were 0.2% and 8 h, respectively. The recombinant S1-2 protein reacted specifically with both rabbit anti-histidine polyclonal antibodies and rabbit anti-PEDV polyclonal antibodies.

Conclusion: The recombinant S1-2 protein reacted with rabbit anti-PEDV polyclonal antibodies induced by the different PEDV genogroup. Therefore, the recombinant S1-2 protein may be a useful tool for the development of a diagnostic test for PEDV or for a vaccine against PEDV.

Keywords: diagnostics, genogroup, porcine epidemic diarrhea virus, recombinant protein, vaccine.

Phenytoin: A promising non-antibiotic drug for the topical treatment of digital dermatitis in dairy cows

Research (Published online: 12-11-2021)

9. Phenytoin: A promising non-antibiotic drug for the topical treatment of digital dermatitis in dairy cows

El-Sayed El-Shafaey, Mohamed A. Hamed, Eman Abo Elfadl, Naglaa A. Gomaa and Mohamed Abdo Rizk

Veterinary World, 14(11): 2907-2912

ABSTRACT

Background and Aim: Digital dermatitis (DD) is one of the most common causes of lameness in dairy cattle. It is seen in nearly all dairy herds across the world and has substantial welfare and economic implications. In this study, we aimed to investigate the efficacy of phenytoin sodium topical treatment on painful ulcerative stage of bovine digital dermatitis (BDD).

Materials and Methods: In total, 45 Holstein-Friesian dairy cows with DD were randomly assigned to one of the three topical treatment trials (15 each): Saline solution (first treatment, negative control), chlortetracycline spray (second treatment, positive control), or phenytoin sodium powder (third treatment, positive control) (third treatment). On day 0 (pre-treatment) and on days 7, 14, 21, and 28 post-treatment, the response of DD-affected cows to the medications used was evaluated by measuring lesion depth and size, as well as the total clinical score (lameness, pain, and discomfort).

Results: The cure rate in cows treated with phenytoin (86.66%) on day 28 was significantly improved compared to cows treated with either chlortetracycline (60%) or normal saline (6.66 %).

Conclusion: Our findings highlight the superiority of phenytoin over the commonly used antibacterial agent, chlortetracycline, in the topical treatment of BDD, and subsequently suggest that phenytoin should be considered a suitable alternative treatment option for the treatment of BDD.

Keywords: chlortetracycline, cows, digital dermatitis, phenytoin.

Review of herbal medicine works in the avian species

Review (Published online: 11-11-2021)

8. Review of herbal medicine works in the avian species

Tyagita Hartady, Mas Rizky A. A. Syamsunarno, Bambang Pontjo Priosoeryanto, S. Jasni and Roostita L. Balia

Veterinary World, 14(11): 2889-2906

Poultry meat consumption is increasing worldwide but the overuse of antimicrobials for prevention and treatment of diseases has increased antimicrobial resistance (AMR), triggering a major public health issue. To restrict AMR emergence, the government supports the optimization of natural products that are safe and easy to obtain with minimal side effects on poultry, humans, and the environment. Various studies have explored the potential of herbs in animal health for their antiviral, antibacterial, antifungal, antiparasitic, immunomodulatory, antioxidant, and body weight gain properties. Therefore, this study reviewed plants with potential application in avian species by summarizing and discussing the mechanisms and prophylactic/therapeutic potential of these compounds and their plant origin extracts.

Keywords: antimicrobial resistance, avian herbal therapy, avian medicinal plants, chicken disease, herbal medicine, poultry herbal medicine.

Prebiotic and synbiotic effect on rumen papilla length development and rumen pH in 12-week-old calves

Research (Published online: 11-11-2021)

7. Prebiotic and synbiotic effect on rumen papilla length development and rumen pH in 12-week-old calves

A. Arne and A. Ilgaza

Veterinary World, 14(11): 2883-2888

ABSTRACT

Background and Aim: Europe and the USA have banned antibiotics use as growth promoters. There is a need for alternative products that can ensure production and health protection. Prebiotics has been proposed as alternatives because these materials have wide-ranging physiological effects on gut function, activity of the large intestinal microflora, mineral absorption, and immunity. The aim of this study was to determine the effect of three different doses of inulin, a prebiotic, in combination with probiotic Enterococcus faecium (a new synbiotic) on postnatal rumen development by comparing rumen papilla length, width, muscle layer thickness, and content pH level.

Materials and Methods: Randomly selected 23 (±5)-days-old healthy male Holstein crossbreed calves, weighing 50 kg (±5 kg), were randomly allocated to seven groups, ten in each group. The calves were kept in a pen of 5, under the same conditions and were fed twice a day, ∼3.5 liters of whole milk per feeding. Control group (C n=10) was fed with whole milk only (no additives were added). The six other groups (three prebiotics and three synbiotics) received food additives with their morning milk feeding. The source of prebiotics, Jerusalem artichoke powder concentrate (JAPC) contained 50% of inulin. JAPC in doses of 6 g, 12 g, or 24 g were added to the milk. Formed prebiotic groups were denoted as PreG6, PreG12, and PreG24. To evaluate if the addition of the probiotic E. faecium 2×109 colony forming unit g–1 to manufacturer recommended dose of 0.25 g improves inulin effect on rumen, it was added to all their JAPC doses. The new content synbiotic groups were denoted as SynG6, SynG12, and SynG24. On day 57 of the study, when all calves were approximately 12 weeks old, they were slaughtered in a certified slaughterhouse. Tissue cultures for histological analysis were obtained from Saccus dorsalis and Saccus ventralis of the rumen. Tissue culture staining for histology was carried out using hematoxylin and eosin staining method. Rumen histological samples were used to measure papilla length, width, and muscle layer thickness. Each sample was used to make five measurements on the present rumen papilla.

Results: The results showed that by adding 12 g of inulin to whole milk when feeding calves improves rumen papilla development, which is seen by increased length and width of papilla, especially in the Saccus ventralis region. By combing this dose of inulin with 0.25 g of E. faecium, a significant increase of papilla is achieved. Saccus ventralis muscle layer in the rumen is thicker than it is in Saccus dorsalis regardless of addition of prebiotics or synbiotics.

Conclusion: The addition of inulin to whole milk can influence the pH of the rumen by making it more alkaline. The addition of prebiotic inulin and a novel synbiotic (inulin combined with E. faecium) can accelerate postnatal rumen development and improve its functionality.

Keywords: calf, pH, prebiotic, rumen, symbiotic.

Comparison of polymerase chain reaction and microscopy for the detection of Fasciola spp. in the fecal matter of domestic bovines in Kalasin Province, Thailand

Research (Published online: 10-11-2021)

6. Comparison of polymerase chain reaction and microscopy for the detection of Fasciola spp. in the fecal matter of domestic bovines in Kalasin Province, Thailand

Sirikanda Thanasuwan and Anupong Tankrathok

Veterinary World, 14(11): 2878-2882

ABSTRACT

Background and Aim: Fasciola spp. are important foodborne trematodes and waterborne zoonotic parasites that cause health problems and economic losses worldwide, including in Thailand. Fasciola spp. are usually detected by sedimentation or the formalin-ethyl acetate concentration technique (FECT) under microscopy, which is less specific and sensitive. Accurate detection is important to detect real incidence for protection against and elimination of fasciolosis in the area. This study aimed to determine the distribution of Fasciola spp. and compare the specificity and sensitivity of FECT under microscopy to that of polymerase chain reaction (PCR) in cattle feces.

Materials and Methods: The study was conducted in Kalasin Province, Thailand. Feces of 46 cattle were investigated for infection with Fasciola spp. To detect infection, FECT under microscopy and PCR amplification of the 28S rRNA gene of Fasciola spp. were used to identify egg parasites.

Results: Feces of 16 of 46 (34.78%) cattle were positive for Fasciola spp. using FECT under microscopy, whereas PCR showed that 67.39% (31 of 46) were positive for Fasciola spp. False-negative results were as high as 32.61% when diagnosed under microscopy.

Conclusion: This study confirmed the infection of cattle with Fasciola spp. in Kalasin Province, indicating that PCR demonstrated higher sensitivity and specificity when diagnosing infection. FECT under microscopy can still be used as a primary and traditional method for diagnosis. However, relapse cases of Fasciola spp. and Paramphistomum spp. should be diagnosed by microscopy combined with PCR. This is the first report on the molecular distribution of fecal samples in cattle in Kalasin Province.

Keywords: 28s rRNA, bovine, Fasciola gigantica, Kalasin province, Lampao dam, polymerase chain reaction.

Multidrug resistance, biofilm formation, and virulence genes of Escherichia coli from backyard poultry farms

Research (Published online: 10-11-2021)

5. Multidrug resistance, biofilm formation, and virulence genes of Escherichia coli from backyard poultry farms

Theeb Al-Marri, Abdulla Al-Marri, Reham Al-Zanbaqi, Ahmad Al Ajmi and Mahmoud Fayez

Veterinary World, 14(11): 2869-2877

ABSTRACT

Background and Aim: Backyard chicken flocks have traditionally been regarded as an essential food source in developed countries; however, they may act as reservoirs and spread various zoonotic bacterial pathogens. This study was designed to investigate the prevalence, phenotypic resistance, biofilm formation (BF), and pathotypes of Escherichia coli isolates from backyard poultry farms.

Materials and Methods: Cloacal swabs (n=150) and internal organs (n=150) were collected from 30 backyard chicken flocks; 20 of them were experiencing systemic infection, and the other ten were apparently healthy. Samples were bacteriologically examined for E. coli isolation. Isolates were identified biochemically by the VITEK® 2 COMPACT system (BioMérieux, France). For molecular identification, 16S rRNA was amplified and sequenced. Ten antimicrobials were selected for E. coli antimicrobial susceptibility testing. The minimum inhibitory concentration for each antimicrobial was determined. The extended-spectrum β-lactamase activity in isolates was investigated using cephalosporin/clavulanate combination disks. The ability of isolates for BF was determined by the microtiter plate method. Thirteen virulence genes linked to different E. coli pathotypes and two serotype-related genes were investigated by real-time polymerase chain reaction.

Results: Eighty-six E. coli strains were isolated from 30 backyard chicken flocks. The isolates were biochemically identified to the species level. Genetically, sequences of the 16S rRNA gene showed >98% identity with E. coli in the National Center for Biological Information database. The frequency of isolation from diseased flocks was significantly higher (p<0.05) than apparently healthy flocks; 63.9% of the isolates were recovered from cloacal swabs and 36.04% were recovered from internal organs. E. coli isolates showed high resistance to ampicillin (AMP; 75.6%), gentamicin (39.5%), and tetracycline (29.1%). However, none of the isolates were resistant to imipenem. A variable drug resistance profile for E. coli isolates was reported. Twenty-one (24.4%) isolates were sensitive to all ten antimicrobials. Seven (8.1%) isolates were resistant only to AMP, and 28 (32.6%) were resistant to two antimicrobials, whereas the remaining 30 (34.9%) isolates showed multidrug resistance (MDR). Of the 86 isolates, 8 (9.3%) were confirmed as extended-spectrum β-lactamase (ESBL)-producing E. coli by the combination disk diffusion method. All ESBL isolates were MDR with an MDR index of 0.5-0.6. Fifty-seven (66.3%) isolates were capable of forming biofilms; 22 (25.6%) of them were strong biofilm producers, 24 (27.9%) moderate producers, and 11 (12.8%) weak producers. A statistically significant pairwise correlation was obtained for MDR versus BF (r=0.512) and MDR index versus BF (r=0.556). Based on virulence gene profiles, five pathotypes were identified, including enteropathogenic E. coli (39.5%), avian pathogenic E. coli (32.53%), enterohemorrhagic E. coli (EHEC; 9.3%), enterotoxigenic E. coli (ETEC; 5.8%), and enteroaggregative E. coli (EAEC; 1.2%). The lower frequency of EAEC and ETEC was statistically significant than other pathotypes. Three isolates were identified as O157 based on the detection of the rbfO157 gene.

Conclusion: This study reported a high prevalence of MDR, suggesting the misuse of antimicrobials in backyard chicken farms. The emergence of ESBL and EHEC isolates in backyard chickens is a public health concern. Furthermore, the backyard flocks environment may harbor different pathogenic bacteria that may enhance the persistence of infection and the transmission to in-contact humans. Regular monitoring for the occurrence of MDR and the zoonotic pathotypes among E. coli in backyard chicken flocks is recommended, as these bacteria can transmit to humans through food products or contaminated environments.

Keywords: backyard broilers, Escherichia coli, multidrug resistance, virulence genes.

Comparative study utilizing different post-breeding treatment regimens in cyclic Arabian mares

Research (Published online: 10-11-2021)

4. Comparative study utilizing different post-breeding treatment regimens in cyclic Arabian mares

Khalid Mohammed Karam, Ahmed Saed Alebady, Haitham O. Alhilfi and Dhia Hussain Al-Delemi

Veterinary World, 14(11): 2863-2868

ABSTRACT

Background and Aim: Post-breeding treatment is the most common practice in the reproductive management of mares. Oxytocin, uterine lavage, and intrauterine (I/U) antibiotic are usually used as prophylactic therapy. This study aimed to determine the most efficient prophylactic treatment regimen among six treatment protocols applied during natural breeding of cyclic Arabian mares.

Materials and Methods: The current study was conducted on cyclic Arabian mares that were subdivided into three age categories (n=968): Category I (5-10 years, n=380), Category II (11-15 years, n=361), and Category III (≥16 years, n=227). Six prophylactic treatments were applied after 4 h of breeding. According to the treatment regimen, treated mares (n=483) were divided into six treatment groups: A (n=80), treated with I/U antibiotic (1 g gentamicin); B (n=81), I/U lavage (normal saline 500 mL); C (n=83), intramuscular (I/M) oxytocin (10 IU); D (n=82), I/U antibiotic and I/M oxytocin; E (n=78), I/U lavage and I/M oxytocin; and F (n=79), I/U lavage with I/U antibiotic and I/M oxytocin. Non-treated mares were classified as controls (n=485). Ultrasonography was performed to monitor pregnant mares 30 and 60 days after mating, and mares were followed until foaling.

Results: Pregnancy and foaling results reveals that in age Category I, treatment with oxytocin alone or oxytocin with I/U lavage showed the highest pregnancy and foaling rates (p<0.01). In age Category II, the highest pregnancy and foaling rates were observed in lavage treatment (p<0.01), whereas, in age Category III, the good pregnancy and foaling rates were monitored in treatment with oxytocin and I/U lavage (p<0.01).

Conclusion: Treatment with systemic I/M oxytocin is ideal in early age group mares (5-10 years of age). However, irrespective of the age categories, all mares exhibited high pregnancy and foaling rates after treatment with systemic I/M oxytocin and I/U lavage with normal saline (0.9%) 4 h post-breeding.

Keywords: endometritis, lavage, mare, oxytocin, persistent breeding-induced endometritis, post-breeding.