Biomarkers, immune responses and cellular changes in vaccinated and non-vaccinated goats during experimental infection of M. haemolytica A2 under tropical conditions.

BACKGROUND: We investigated the biomarkers, immune responses and cellular changes in vaccinated and non-vaccinated goats experimentally challenged with M. haemolytica serotype A2 under rainy and hot tropical conditions. A total of twenty-four clinically healthy, non-pregnant, female goats randomly allocated to 2 groups of 12 goats each were used for the study. The 12 goats in each season were subdivided into three groups (n = 4), which served as the control (G-NEG), non-vaccinated (G-POS), and vaccinated (G-VACC). In week-1, the G-VACC received 2 mL of alum-precipitated pasteurellosis vaccine while G-POS and G-NEG received 2 ml of sterile PBS. In week 2, the G-POS and G-VACC received 1 mL intranasal spray containing 105 CFU of M. haemolytica serotype A2. Inoculation was followed by daily monitoring and weekly bleeding for eight weeks to collect data and serum for biomarkers and immune responses using commercial ELISA test kits. The goats were humanely euthanised at the end of the experiments to collect lungs and the submandibular lymph nodes tissue samples for gross and histopathological examinations. RESULTS: Regardless of the season, we have observed a significant (p < 0.05) increase in serum concentrations of acute-phase proteins (haptoglobin, serum amyloid A), proinflammatory cytokines (interleukine-1ß, interleukin-6), antibodies (immunoglobulin M, immunoglobulin G), and stress markers (cortisol and heat shock protein 70) in the G-POS goats compared to G-VACC and G-NEG. With regards to seasons, there was a significantly (p < 0.05) higher serum concentration with 1.5, 2 and 1-folds increase in the serum interleukin (IL)-1ß, cortisol, and heat shock protein (HSP)-70 in the G-POS during rainy compared to the hot season. Histopathology of the lungs in G-POS goats revealed inflammatory cell infiltration, degeneration, haemorrhage/congestion, and pulmonary oedema in the alveoli spaces; thickening of the interstitium, and desquamation of bronchiolar epithelium. Cellular changes in the lymph node were characterized by a marked hypercellularity in G-POS goats. CONCLUSION: Host responses to pneumonic mannheimiosis based on increased serum levels of biomarkers (cortisol, HSP70, IL-1ß and IL-6) and severe cellular changes seen in the lungs and lymph nodes of G-POS goats compared to vaccinated goats and control group are influenced by the high environmental humidity recorded in the rainy season. Increased relative humidity in the rainy season is a significant stress factor for the higher susceptibility and severity of pneumonic mannheimiosis of goats in the tropics. Vaccination of goats using the alum precipitated Pasteurella multocida vaccine before the onset of the rainy season is recommended to minimise mortality due to potential outbreaks of pneumonia during the rainy season.

Further Insights Into Caprine Arthritis Encephalitis (CAE): The Current Status of Seroprevalence Among Small Ruminants in Two Selected States of Peninsular Malaysia.

Caprine arthritis-encephalitis virus (CAEV) is a member of the genus lentivirus causing caprine arthritis-encephalitis (CAE), a chronic inflammatory condition affecting the lungs, joints, udder and central nervous system of small ruminants such as sheep and goats. CAE is distributed worldwide and is recognised as a significant cause of morbidity and decreased milk production in dairy goats. Earlier studies highlighted the clinicopathological features and supplied preliminary serological evidence for the existence of CAE among selected goat herds in Malaysia. Therefore, this study aims to provide further insights into the seroprevalence and contributing factors of CAE among sheep and goat herds in two states of Peninsular Malaysia. The blood samples and biodata were randomly collected from a total of 262 individual sheep (40) and goat (222) in seven smallholder farms. Blood sera were tested for specific anti-CAEV antibodies using Qayee-Bio CAEV sandwich-ELISA test kits according to standard procedures. Our results of the study revealed 21.4% (95% CI: 15.8-28.6) apparent and 20.6% (95% CI: 14.5-27.8) true seroprevalence with significant differences (p < 0.05) in seroconversion rates between the states, farms, production systems and breeds of small ruminants. The prevalence of CAE in the Malaysian Peninsular is a potential threat to the small ruminant industry and developing agricultural economy. Further studies are required to determine the genetic characteristics, distribution and risk factors of CAEV for effective prevention and control in Malaysia.

Virus Kaprin Artritis Ensefalitis (CAEV) merupakan ahli kumpulan dalam genus virus lentivirus dimana akan menyebabkan penyakit kaprin artritis ensefalitis (CAE) di mana penyakit ini akan menyebabkan keradangan kronik pada paru-paru, sendi, kelenjar mamari dan sistem saraf pusat bagi haiwan ruminan kecil seperti bebiri dan kambing. CAE telah merebak ke seluruh dunia dan penyakit ini akan menyebabkan penularan wabak pada kadar morbiditi yang tinggi dan mengurangkan kuantiti penghasilan susu bagi kambing tenusu. Kajian terdahulu memberi penekanan kepada dapatan klinikal patologi dan data bukti serologi kewujudan penyakit CAE dalam kalangan gerompok kambing di Malaysia. Maka, kajian kini bertujuan memberikan pendedahan awal berkaitan kadar kelaziman serologi dan faktor yang menyumbang penyakit CAE dalam kalangan bebiri dan kambing bagi dua negeri di Semanjung Malaysia. Sampel darah dan data biologi telah dikumpulkan secara rawak dengan jumlah sampel 262 ekor (40 ekor bebiri dan 222 ekor kambing) daripada tujuh buah ladang peternak kecil. Serum yang telah dikumpul diuji dengan antibodi spesifik anti-CAEV dengan menggunakan prosedur piawai kit elisa daripada Qayee-Bio CAEV. Keputusan kajian ini menunjukkan kadar kelaziman serologi 21.4% (95% CI: 15.8­28.6) jelas dan 20.6% (95% CI: 14.5­27.8) kadar kelaziman benar dengan perbezaan ketara (p < 0.05) dalam kadar perubahan kelaziman serologi antara negeri, ladang, sistem produksi dan baka haiwan ruminan kecil. Dengan wujudnya kelaziman penyakit CAE di Semenanjung Malaysia ini akan menyumbang kepada kemungkinan ancaman negatif terhadap industri ruminan kecil dan sektor ekonomi dalam bidang penternakan. Lebih banyak kajian diperlukan untuk menentukan ciri genetik virus penyebab penyakit ini, taburan penyakit dan faktor penyumbang bagi CAEV supaya dapat mengadakan kawalan dan pencegahan efektif bagi penyakit ini di Malaysia.

Association between Mannheimia haemolytica infection with reproductive physiology and performance in small ruminants: A review.

Mannheimiosis or pneumonic pasteurellosis commonly occurs in small ruminants. Mannheimiosis is caused by Mannheimia haemolytica (M. haemolytica) a Gram-negative coccobacillus producing acute febrile and infectious condition resulting in death of animal if not diagnosed and treated promptly. M. haemolytica serotype A2 is a commensal of the nasopharynx, gaining access to the lungs when host defenses are compromised by stress or infection in small ruminants. Till date, there is a vast literature and research that has been conducted on the pathogenesis of M. haemolytica invariably on respiratory system and its related immune system and mechanisms. From the clinical point of view, infection or diseases involving vital organs will systemically affect the production and performance of the infected animal. Therefore, there is a huge gap of knowledge and research to answer the question whether there is any association between M. haemolytica infection with reproductive physiology and performance in small ruminants and how it affects the productivity level. This review will explore the possibilities of involvement and new potential research to be carried out to determine the involvement of male and female reproductive system with M. haemolytica infection among small ruminants.