Efficacy of novel antiseptic product containing essential oil of Lippia origanoides to reduce intramammary infections in cows.

BACKGROUND AND AIM: The use of antimicrobials in the control of mastitis is of concern in public health due to their inefficiency in targeting microorganisms. Studies with medicinal plants have risen as an alternative to the use of conventional products. The objective of this study was to evaluate the efficacy of an experimental disinfectant based on the essential oil (EO) from Lippia origanoides in preventing the development of new intramammary infections (IMI) in Holstein cows. MATERIALS AND METHODS: The conventional protocol of pre- and post-milking was used and the control (Conventional treatment [CNV]) and experimental (Experimental treatment [PEX]) products containing EO at 120 µL/mL were applied by immersion. Individual milk samples were analyzed using sheep blood agar methodologies and biochemical tests. The efficiency of the treatment was defined by the presence or absence of Staphylococcus aureus, coagulase-negative Staphylococcus, and Streptococcus spp. RESULTS: There were no clinical and subclinical mastitis cases, no lesions in the mucosal of teats, nor dirt score between groups in this study. Both treatments did not influence the occurrence of IMI. CONCLUSION: The results revealed that PEX acts efficiently against microorganisms compared to the disinfection by the conventional product demonstrating the efficacy of the alternative product on the prevention of new IMIs in dairy cows.

Anti-botulism single-shot vaccine using chitosan for protein encapsulation by simple coacervation.

The aim of the present study was to compare the potency and safety of vaccines against Clostridium botulinum (C. botulinum) type C and D formulated with chitosan as controlled release matrix and vaccines formulated in conventional manner using aluminum hydroxide. Parameters were established for the development of chitosan microspheres, using simple coacervation to standardize the use of this polymer in protein encapsulation for vaccine formulation. To formulate a single shot vaccine inactivated antigens of C. botulinum type C and D were used with original toxin titles equal to 5.2 and 6.2 log LD50/ml, respectively. For each antigen a chitosan based solution of 50 mL was prepared. Control vaccines were formulated by mixing toxoid type C and D with aluminum hydroxide [25% Al(OH)3, pH 6.3]. The toxoid sterility, innocuity and potency of vaccines were evaluated as stipulated by MAPA-BRASIL according to ministerial directive no. 23. Encapsulation efficiency of BSA in chitosan was 32.5-40.37%, while that the encapsulation efficiency to toxoid type C was 41,03% (1.94 mg/mL) and of the toxoid type D was 32.30% (1.82 mg/mL). The single shot vaccine formulated using chitosan for protein encapsulation through simple coacervation showed potency and safety similar to conventional vaccine currently used in Brazilian livestock (10 and 2 IU/mL against C. botulinum type C and D, respectively). The present work suggests that our single shot vaccine would be a good option as a cattle vaccine against these C. botulinum type C and D.