Coronavirus disease-2019 (COVID-19) pandemic has become a global threat and death tolls are increasing worldwide. The SARS-CoV-2 though shares similarities with SARS-CoV and MERS-CoV, immunopathology of the novel virus is not understood properly. Previous reports from SARS and MERS-CoV documents that preexisting, non-neutralizing or poorly neutralizing antibodies developed as a result of vaccine or infection enhance subsequent infection, a phenomenon called as antibody-dependent enhancement (ADE). Since immunotherapy has been implicated for COVID-19 treatment and vaccine is under development, due consideration has to be provided on ADE to prevent untoward reactions. ADE mitigation strategies like the development of vaccine or immunotherapeutics targeting receptor binding motif can be designed to minimize ADE of SARS-CoV-2 since full-length protein-based approach can lead to ADE as reported in MERS-CoV. The present mini-review aims to address the phenomenon of ADE of SARS-CoV-2 through the lessons learned from SARS-CoV and MERS-CoV and ways to mitigate them so as to develop better vaccines and immunotherapeutics against SARS-CoV-2.

Aim : To find out the organisms causing endometritis in cattle and to determine their in vitro sensitivity to various antibiotics Materials and methods: Thirty uterine secretion samples, 9 from Holstein Friesian and 21 from Jersey cows were collected in and around Namakkal district of Tamil Nadu from clinical cases of endometritis. The bacteria isolated both aerobically and anaerobically from endometritis showed the characteristic colony, were gram stained and confirmed by standard biochemical tests. The invitro antibiotic sensitivity test with different antibiotic discs were carried out. Results and Discussion: Out of 30 samples, 25 contained different strains of bacteria and 5 were found bacteriologically sterile. Different species of bacteria isolated from these samples were, Escherichia coli (36.66%), Klebsiella spp (30%), Proteus spp (13.33%), Pseudomonas aeruginosa (6.66%), Clostridium spp (3.33%). The in vitro antibiotic sensitivity test indicated that the highest number of isolates (64%) were sensitive to Ceftriaxone, followed by Gentamicin, Enrofloxacin and Chlortetracycline (32%). Chloramphenicol showed sensitivity in minimum number (8%) of isolates. Conclusion : This study revealed that the bacteria E.coli and Klebisella spp are more commonly isolated in endometritis in cows and the drug Ceftriaxone is highly effective. [Vet World 2013; 6(2.000): 100-102

This work has been undertaken to study the occurrence of Clostridium perfringens contamination in the poultry feed ingredients and find out its in-vitro antibiotic sensitivity pattern to various antimicrobial drugs. Two hundred and ninety-eight poultry feed ingredient samples received at Poultry Disease Diagnosis and Surveillance Laboratory, Namakkal, Tamil Nadu in South India were screened for the presence of C. perfringens. The organisms were isolated in Perfringens agar under anaerobic condition and subjected to standard biochemical tests for confirmation. In vitro antibiogram assay has been carried out to determine the sensitivity pattern of the isolates to various antimicrobial drugs. One hundred and one isolates of C. perfringens were obtained from a total of 298 poultry feed ingredient samples. Overall positivity of 33.89% could be made from the poultry feed ingredients. Highest level of C. perfringens contamination was detected in fish meal followed by bone meal, meat and bone meal and dry fish. Antibiogram assay indicated that the organisms are highly sensitive to gentamicin (100%), chlortetracycline (96.67%), gatifloxacin (93.33%), ciprofloxacin (86.67%), ofloxacin (86.67%) and lincomycin (86.67%). All the isolates were resistant to penicillin-G. Feed ingredients rich in animal proteins are the major source of C. perfringens contamination.

| Chronic Respiratory disease in Poultry is mainly caused by Mycoplasma gallisepticum (MG). It causes huge economic loss to the poultry industry. The present research work has been undertaken to know the sero-prevalence of MG in commercial layers in Namakkal region of Tamil Nadu, India. A total of 103 commercial layer sera samples from 6 commercial layer farms were subjected to indirect ELISA. From 103 sera samples, overall prevalence found 53.40% for commercial layer chickens. The highest (100%) sero-prevalence of MG was recorded at 32 weeks and the lowest (0%) was recorded at 68 weeks of commercial layer chicken. This study demonstrated high sero-prevalence of MG in Commercial Layers. Therefore, routine monitoring of the commercial layer farms for MG infection should be recommended and mycoplasma control programmes must be strictly adhered.

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