Comparison of the first time detected Oesophagostomum asperum with Oesophagostomum columbianum in sheep and goats in Bangladesh based on the trinity: Morphology, morphometry and genetic diversity.

Oesophagostomum spp. (Family: Chabertiidae) is keeping a low profile in terms of severity in Bangladesh while maintaining economic loss through disguise within sheep and goats. The study was performed to identify prevalence, confirmation of species through morphology and morphometry followed by phylogeny using ITS2 and COX1 genes. In total 384 slaughterhouse-sourced small and large intestines were pooled from Mymensingh, Kishoreganj, Netrokona, Sherpur and Tangail districts of Mymensingh division. Followed by isolation, O. columbianum and O. asperum were identified following their key morphological features. Notably, O. asperum was first time detected in Bangladesh. The overall prevalence of Oesophagostomum spp. was found 60.93%. The prevalence of O. columbianum (64.95%) was almost double than that of O. asperum (35.04%). Among several characters, only the distance between anus to tail tip showed a significant morphological disparity in female. The Neighbor-joining (NJ) phylogenic trees based on ITS2 and COX1 genes confirmed the study species. The first time identified O. asperum along with morphometry and phylogeny will add value to the fact that nematodes are invisibly present with high prevalence in this country. This study will help to draw specific attention to command a practical control strategy for intervening in economic loss.

Ascaridia galli infection in chicken: Pathobiology and immunological orchestra.

BACKGROUND: Ascaridia galli is the largest gut-dwelling helminth of chickens, which confers adverse effects on meat and egg production; thus, on the animal protein supply and the economy. Both adult and immature parasites affect gut health, but larval stages play a major role in pathology. AIMS: Here, we present immunology and pathology of A. galli in chickens. MATERIALS AND METHODS: Literatures were surveyed through online platforms such as PubMed, Google Scholar and Researchgate. RESULTS: The larvae cause excessive mucus production, damage to the intestinal gland, hemorrhage, anemia, diarrhea, and malnutrition. The adult worms can cause death by intestinal obstruction and intussusception. Although both cellular and humoral immunity are involved in fighting against ascariasis, the role of naturally acquired immunity is poorly defined. In cellular immunity, Th-2 cytokines (IL-4, IL-5, IL-9, and IL-13), goblet cells (mucin), gut-associated lymphoid tissues, CD8α+ intraepithelial cells, TCRγδ + T cells, and TGF-ß4 form a protective band. Type 2 immunity provides protection by forming a network of endogenous damage-associated molecular patterns, chitin, and parasitic antigens. Among antibodies, IgY is the most prominent in chickens and provides temporary humoral protection. During parasitic infection, infiltration of various immune cells is evident, especially in the intestinal epithelium, lamina propria, and crypts of the duodenum and jejunum. In chickens older than 12 weeks, gradual reduction of worm burden is more successful than the younger birds. Female chickens exert a short-lived but higher level of protection by passing IgY to chicks in the form of egg yolk antibodies. In laying conditions, immunity differs between breeds. This review provides an overview of the silent but inevitable pathological changes induced by A. galli and the interaction of host immunity with the parasite.

Ex-vivo efficacy of commercially available anthelmintics against blood feeding stomach worm Haemonchus contortus of ruminants.

Haemonchus contortus is the most prevalent and pathogenic gastrointestinal nematodes (GINs) in ruminants causing extensive economic losses. It is essential to estimate the efficacy of common commercially available anthelmintics against Haemonchus contortus parasite. Here, we standardized an ex-vivo culture platform for H. contortus and evaluated the efficacy of commonly used anthelmintics namely, albendazole (ABZ), levamisole (LVM), ivermectin (IVM), closantel (CLS) and rafoxanide (RFX). Adult worms were collected from abomasa of slaughtered animals, cultured in MEM, DMEM, M199 or RPMI with or without 20% FBS for up to 72 h. Cultured worms were incubated with ABZ, LVM, IVM, RFX or CLS in DMEM supplemented with 20% FBS at different concentrations (0.5-50 µg/ml) in triplicates and examined at 0, 3, 6, 12, 24, 36 and 48 h post treatment. Of the culture conditions, DMEM supplemented with 20% FBS supported the survival of H. contortus for (P < 0.001) longer period of time which was used in the evaluation of anthelmintics. The efficacy of CLS and RFX were significantly (P < 0.001) higher than other drugs and 100% mortality was observed at 2 µg/ml of CLS and RFX within 12 h post treatment. However, ABZ, LVM, and IVM showed significant effect at the concentration of 50 µg/ml with 48, 36, and 24 h, respectively. Morphological changes included severe cuticle disruption around the buccal cavity, posterior region and vulva as well as loss of cuticle structure integrity coupled with expulsion and fragmentation of digestive components of parasites when treated with 50 µg/ml of ABZ, LVM, and IVM and 2 µg/ml of RFX and CLS. Collectively, DMEM supplemented with 20% FBS can be used as ex-vivo culture platform for maintenance of H. contortus, and RFX and CLS can be used as the promising drugs for the prevention, control and treatment of H. contortus infections.

Diversity and prevalence of gastrointestinal parasites of Black Bengal goats in Natore, Bangladesh.

Objectives: The objective of this work was to estimate the diversity of gastrointestinal (GI) parasite species, their prevalence, and risk factors in Black Bengal goats (BBGs) of Natore, Bangladesh. Materials and Methods: Fecal samples from randomly selected 260 BBGs were processed through Stoll's ova counting method, floatation, and simple sedimentation method. Microscopy-based identification of parasitic eggs, cysts, or oocysts was made. A semi-structured questionnaire-based data on host and management practices were collected from the owner. Data analysis was done using Statistical Package for Social Sciences. Results: The overall prevalence of GI parasites in BBGs was 65.4%, with an individual prevalence of 8.5% for Fasciola gigantica, 21.5% for Paramphistomum spp., 20% for Haemonchus spp., 34.2% for Strongyloides spp., 8.5% for Trichuris spp., and 9.2% for Eimeria spp. No significant effect of host age, gender, body condition, animal rearing system, or housing floor type was observed on parasitism. Animals of young age, female, poorly body-conditioned, living in a free-range system, and housed on a muddy floor had a relatively higher susceptibility to infection. Deworming had a significant impact on reducing the frequency of caprine GI parasitism. Conclusions: Despite the significant effect of anthelmintic, the elevated prevalence of GI parasites in BBGs suggests a critical need for developing effective strategies to prevent caprine parasitoses.

Phylogenetic analysis of Eimeria tenella isolated from the litter of different chicken farms in Mymensingh, Bangladesh.

BACKGROUND: Eimeria tenella is the most pathogenic intracellular protozoan parasite of seven Eimeria species causing chicken coccidiosis around the world. This species is particularly responsible for caecal coccidiosis leading to serious morbidity-mortality and financial loss in poultry production. METHODS: The present study explored the genetic diversity of E. tenella. Litter slurry was collected from 18 broiler farms located in Mymensingh district, Bangladesh. Litter samples were processed for oocyst isolation-identification using parasitological techniques followed by genomic DNA extraction from sporulated oocysts. For molecular analysis, the internal transcribed spacer 1 gene of E. tenella was amplified using species-specific primers and sequenced. After editing and alignment, 263 bp sequences were used for analysis. RESULTS: Genetic analysis showed seven distinct genotypes and detected six single nucleotide polymorphisms among the 18 E. tenella isolates. The nucleotide and genotype diversity were 0.00507 and 0.8235, respectively. A phylogenetic tree was constructed with 66 sequences (seven studied genotypes and 59 reference sequences from GenBank database). The neighbour-joining tree represented that the studied E. tenella isolates were grouped with reference E. tenella isolates with strong nodal support (100%) and the nucleotide sequences of E. tenella, E. necatrix, E. acervulina, E. brunetti, E. maxima, E. mitis and E. praecox formed separate clusters without any geographical boundaries. CONCLUSIONS: This is the first study on the genetic analysis of E. tenella from Mymensingh district, Bangladesh. These findings will provide baseline data on the species conformation and genetic variations of E. tenella. Further extensive investigation will be needed to reveal the population genetic structure of this parasite and thus will facilitate the planning of effective control strategies.

Frequency of benzimidazole resistance in Haemonchus contortus populations isolated from sheep and goats in Bangladesh.

Anthelmintic resistance against gastrointestinal nematodes especially H. contortus of sheep and goat is a global issue. To address the gravity and extension of AR in Bangladesh, genotyping of 160 adult H. contortus parasitesw ere performed to confirm benzimidazole resistance allele from different geographic zones of Bangladesh based on allele specific PCR (AS-PCR). The genotype frequencies were 9.4% for homozygous resistant (rr), 61.2% for heterozygous (rS) and 29.4% for homozygous susceptible (SS) among the selected areas. The allelic frequency of the mutation conferring resistance (r) ranged from 27.5% to 52.5% indicating substantial existence of benzimidazole resistance in H. contortus in small ruminant nematodes. Therefore, it can be concluded that genotyping the F200Y polymorphism can be used to monitor the resistance and thereby to enhance the control on the development of anthelmintic resistance against H. contortus in small ruminant nematodes.

ITS1-PCR based identification of chicken Eimeria species in poultry litter from Mymensingh district, Bangladesh.

OBJECTIVES: The purpose of this study was to determine the species composition of Eimeria circulating in Mymensingh district, Bangladesh, using Internal Transcribed Spacer 1 (ITS1) sequences in polymerase chain reaction (PCR) assay. MATERIALS AND METHODS: Coccidian oocysts were isolated and sporulated in a solution containing 2% potassium dichromate from litter slurry collected from 13 commercially active broiler farms in the research region. Genomic DNA was isolated from sporulated oocysts and used to amplify the Eimeria species-specific ITS1 gene by PCR amplification. Electrophoresis of 1.5% agarose gel was used to visualize the amplified PCR products. RESULTS: In the study samples from Mymensingh district, Bangladesh, the presence of Eimeria brunetti, Eimeria acervulina, Eimeria necatrix, Eimeria mitis, and Eimeria tenella was identified. CONCLUSIONS: The findings of this study may shed light on the zonal approach to chicken coccidiosis control. Additionally, it suggests that ITS1-based PCR might be used in the field to accurately identify Eimeria species.

Small-scale farmers' perception and practice on coccidiosis management in broiler farm at Gazipur, Bangladesh.

Farmers' knowledge and farm management practices can potentially help to mitigate the prevalence and severity of chicken coccidiosis, a devastating protozoan disease. Here, we assessed the farmers' perception and on-farm practices of coccidiosis management in small-scale broiler farms at Gazipur district, Bangladesh. A semi-structured questionnaire was used to obtain data from the randomly selected 119 small-scale broiler producers followed by detection of coccidiosis cases through gross and microscopic examination of 58 broilers. Overall bird-level prevalence of coccidiosis was 34.48% in this study. Survey data revealed that most of the farmers maintained all-in-all-out strategy (68.91%), good quality chicks (73.11%) and floor system rearing (96.63%) in their farms, and a mixture of old and new litter was used as bedding in all the study farms. Interval between flocks in 57.99% of farms was 8 to 14 days. Prevalence of coccidiosis was recorded in all surveyed farms, even though routine anticoccidial treatment. At the age of 15 to 18 days of broiler, 68.07% of farmers used chemoprophylaxis. Usage of amprolium was the highest (74.78%) followed by toltrazuril (55.46%), sulphaquinoxaline (23.52%), sulphaclozine (28.57%), sulphadimidine (24.36%) and sulphadimethoxine (24.36%). Traditional herbal medicines like extracts of bollygum (Litsea glutinosa), sal (Shorea robusta) and arjuna (Terminalia arjuna) bark and leaves were also in-use by 4.20% farmers during coccidiosis outbreak. In conclusions, this study explored the field scenario of coccidiosis, relevant farmers' knowledge and practices, and recommends the judicious use of drugs for safe broiler production.

Improvement of Disease Resistance in Livestock: Application of Immunogenomics and CRISPR/Cas9 Technology.

Disease occurrence adversely affects livestock production and animal welfare, and have an impact on both human health and public perception of food-animals production. Combined efforts from farmers, animal scientists, and veterinarians have been continuing to explore the effective disease control approaches for the production of safe animal-originated food. Implementing the immunogenomics, along with genome editing technology, has been considering as the key approach for safe food-animal production through the improvement of the host genetic resistance. Next-generation sequencing, as a cutting-edge technique, enables the production of high throughput transcriptomic and genomic profiles resulted from host-pathogen interactions. Immunogenomics combine the transcriptomic and genomic data that links to host resistance to disease, and predict the potential candidate genes and their genomic locations. Genome editing, which involves insertion, deletion, or modification of one or more genes in the DNA sequence, is advancing rapidly and may be poised to become a commercial reality faster than it has thought. The clustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) [CRISPR/Cas9] system has recently emerged as a powerful tool for genome editing in agricultural food production including livestock disease management. CRISPR/Cas9 mediated insertion of NRAMP1 gene for producing tuberculosis resistant cattle, and deletion of CD163 gene for producing porcine reproductive and respiratory syndrome (PRRS) resistant pigs are two groundbreaking applications of genome editing in livestock. In this review, we have highlighted the technological advances of livestock immunogenomics and the principles and scopes of application of CRISPR/Cas9-mediated targeted genome editing in animal breeding for disease resistance.

Bayesian latent class evaluation of three tests for the screening of subclinical caprine mastitis in Bangladesh.

Routine monitoring for subclinical infection is one of the key mastitis control approaches. However, the accuracy of the most commonly used screening tests has not yet been established. The aim of the present study was therefore to evaluate the accuracy of three screening tests, namely California mastitis test (CMT), white side test (WST), and surf field mastitis test (SFMT) for the screening of subclinical caprine mastitis. A cross-sectional study based on 484 randomly collected milk (242 goats) samples from three districts of Bangladesh was conducted for the screening of subclinical mastitis by the aforementioned tests. The Bayesian latent class model was implemented in WinBUGS to estimate the tests' characteristics and true prevalence of subclinical mastitis. The Bayesian posterior estimates of sensitivities with a 95% credible intervals (CrIs) were 98.60% (95.18-99.95%), 98.28% (94.56-99.92%), and 89.98% (83.39-95.03%), and specificities with 95% CrIs were 99.19% (98.11-99.96%), 99.27% (97.34-99.98%), and 99.28% (97.35-99.98%), respectively for CMT, WST, and SFMT. The true prevalence of subclinical caprine mastitis was estimated to be 43.49% (95% CrI 37.46-48.98%). The positive predictive values (PPV) of the three tests were similar. The serial and parallel interpretation of any test pairs increased the PPV and negative predictive value respectively close to 100%. Based on the simplicity, cost and performance as well WST and SFMT simultaneously could be recommended for the screening of caprine subclinical mastitis in Bangladesh.

Deciphering transcriptome profiles of peripheral blood mononuclear cells in response to PRRSV vaccination in pigs.

BACKGROUND: Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important viral diseases affecting swine industry worldwide. Despite routine farm vaccination, effective control strategies for PRRS remained elusive which underscores the need for in-depth studies to gain insight into the host immune response to vaccines. The current study aimed to investigate transcriptional responses to PRRS Virus (PRRSV) vaccine in the peripheral blood mononuclear cells (PBMCs) within 3 days following vaccination in German Landrace pigs. RESULTS: Transcriptome profiling of PBMCs from PRRSV vaccinated and age-matched unvaccinated pigs at right before (0 h), and at 6, 24 and 72 h after PRRSV vaccination was performed using the Affymetrix gene chip porcine gene 1.0 st array. Comparison of PBMCs transcriptome profiles between vaccinated and unvaccinated pigs revealed a distinct host innate immune transcriptional response to PRRSV vaccine. There was a significant temporal variation in transcriptional responses of PRRSV vaccine in PBMCs accounting 542, 2,263 and 357 differentially expressed genes (DEGs) at 6, 24 and 72 h post vaccination, respectively compared to the time point before vaccination (controls). Gene ontology analysis revealed the involvement of these DEGs in various biological process including innate immune response, signal transduction, positive regulation of MAP kinase activity, TRIF-dependent toll-like receptor signaling pathway, T cell differentiation and apoptosis. Immune response specific pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, signal transduction, JAK-STAT pathway and regulation, TRAF6 mediated induction of NF-kB and MAPK, the NLRP3 inflammasome, endocytosis and interferon signaling were under regulation during the early stage of PRRSV vaccination. Network enrichment analysis revealed APP, TRAF6, PIN1, FOS, CTNNB1, TNFAIP3, TIP1, CDKN1, SIRT1, ESR1 and HDAC5 as the highly interconnected hubs of the functional network of PRRSV vaccine induced transcriptome changes in PBMCs. CONCLUSIONS: This study showed that a massive gene expression change occurred in PBMCs following PRRSV vaccination in German Landrace pigs. Within first 3 days of vaccine exposure, the highest transcript abundance was observed at 24 h after vaccination compared to that of control. Results of this study suggest that APP, TRAF6, PIN1, FOS, CDKN1A and TNFAIP3 could be considered as potential candidate genes for PRRSV vaccine responsiveness.