Shanta Barua

Objective: Staphylococcus aureus and Escherichia coli are the most common opportunistic patho¬gens frequently associated with respiratory tract infection (RTI) in different animals. This cross-sec¬tional study aimed to identify the occurrence of S. aureus and E. coli in goats with RTI, analyze the antimicrobial resistance patterns, and explore potential risk factors contributing to RTI. Materials and Methods: A total of 120 nasal swab samples were collected from goats, and stan¬dard classical bacteriological methods were performed to isolate and identify S. aureus and E. coli. Subsequently, the disc diffusion method was employed to evaluate the antimicrobial sensitivity test. A logistic regression model was used to analyze the factors associated with RTI. Results: About 13.3% (N = 16; N = 120) isolates were confirmed as S. aureus, and 6.67% (N = 8; N = 120) isolates were confirmed as E. coli. All S. aureus isolates were resistant to ampicillin, and all E. coli isolates were resistant to amoxicillin and penicillin. Among the isolated organisms, 43.7% (N = 7; N = 16) S. aureus and 62.5% (N = 5; N = 8) E. coli isolates were found to be multidrug-resistant (resistant to ≥3 classes of antimicrobials). Multivariable logistic regression analysis revealed that female goats [(odds ratio) OR: 4.2; 95% confidence intervals (CI): 0.8–20.8; p = 0.074] and goats in poor health condition (OR: 3.8; 95% CI: 0.7–19.3; p = 0.100) were more prone to RTI caused by S. aureus. Besides, goats that were not dewormed (OR: 4.8; 95% CI: 1–23.6; p = 0.051) and those reared in semi-intensive conditions (OR: 2.7; 95% CI: 0.8–8.7; p = 0.092) were found to be at higher risk of S. aureus-mediated RTI. Conclusion: The findings highlight the importance of implementing improved farm management practices and efficient antimicrobial resistance control approaches to minimize respiratory infections and reduce the burden of antibiotic resistance in goats.

Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are vector-borne orbiviruses that pose an emerging threat to livestock, including cattle and sheep. This review summarizes the global distribution, genetic diversity, and key factors driving their spread along with the existing knowledge gaps and recommendations to mitigate their impact. Both viruses cause hemorrhagic disease in susceptible ruminants and are commonly reported in tropical and subtropical regions including North America, Asia, Africa, Oceania, and some parts of Europe. The geographical distribution of these viruses, encompassing 27 BTV and 7 EHDV serotypes, has shifted, particularly with the recent invasion of BTV-3, 4, and 8 and EHDV-8 serotypes in Europe. Several factors contribute to the recent spread of these viruses such as the distribution of virulent strains by the movement of temperature-dependent Culicoides vectors into new areas due to rapid climate change, the reassortment of viral strains during mixed infections, and unrestricted global trade. These diseases cause significant economic impacts including morbidity, mortality, reduced production, high management costs, and the disruption of international trade. Effective prevention and control strategies are paramount and rely on vaccination, vector control using insecticides, and the destruction of breeding sites, husbandry practices including the isolation and quarantine of infected hosts, restriction of animal movement, prompt diagnosis and identification of circulating strains, and effective surveillance and monitoring plans such as the pre-export and post-import screening of semen used for artificial insemination. However, challenges remain with intercontinental virus spread, live vaccines, and the failure of inactivated vaccines to produce protective immunity against dissimilar strains. Significant knowledge gaps highlight the need for a better scientific understanding and a strategic plan to ensure healthy livestock and global food security.