Screening for canine coronavirus, canine influenza virus, and severe acute respiratory syndrome coronavirus 2 in dogs during the coronavirus disease-2019 pandemic.

Background and Aim: Although most cases of coronavirus disease-2019 (COVID-19) are in humans, there is scientific evidence to suggest that the virus can also infect dogs and cats. This study investigated the circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), canine coronavirus (CCV), and canine influenza virus (CIV) in domiciled and/or stray dogs from different locations in the State of Minas Gerais, Brazil, during the COVID-19 pandemic. Materials and Methods: In total, 86 dogs living in homes, on the streets, or in shelters in the cities of Taiobeiras, Salinas, Araçuaí, and Almenara were randomly selected for this study. The COVID Ag Detect® Self-Test was used to detect SARS-CoV-2. The ACCUVET CCV AG TEST - CANINE CORONAVIROSIS® was used to detect CCV, whereas canine influenza was detected using the ACCUVET CIV AG TEST - INFLUENZA CANINA®. All collected data were mapped using QGIS 3.28.1 for spatial data analysis and the identification of disease distribution patterns. Descriptive analysis of the collected data, prevalence calculations, odds ratios (ORs), and 95% confidence intervals, when possible, was performed. Results: Of the 86 animals tested, only one dog tested positive for SARS-CoV-2 using the rapid test for viral antigen detection. No animals tested positive for CIV. Canine coronavirus was detected in almost half of the animals tested in Almenara. Severe acute respiratory syndrome-CoV-2 had a low prevalence (1.16%), versus 15.62% for CCV. Although the results were not significant, the age and breed of animals appeared to be associated with the occurrence of CCV. The results indicated that younger animals were 2.375-fold more likely to be infected. Likewise, purebred animals were more likely to contract the disease (OR = 1.944). Conclusion: The results indicate the need to maintain preventive measures against CCV, canine influenza, and SARS-CoV-2 in dogs. More studies are needed to better elucidate the panorama of these diseases in dogs, mainly in underdeveloped and developing countries.

Antioxidant activity and chemical composition of meat from broilers fed diets containing different essential oils.

BACKGROUND AND AIM: Broiler meat is susceptible to lipid oxidation due to its high content of unsaturated fatty acids, especially when stored for a long time. Concerning with that problem, we can add natural compounds to the animal feed, as the plant essential oils, which have antioxidant, antimicrobial, and antifungal activities. The objective of this study was to evaluate the antioxidant activity, fatty acid profile, and chemical composition of the meat of broilers fed with diets containing different essential oil, including lemongrass (Cymbopogon flexuosus) and pedestrian tea (Lippia aff. rotundifolia). MATERIALS AND METHODS: The experimental design used was a 4×4 factorial scheme (storage time×diets), and each treatment was repeated thrice. The treatments were applied as negative control (without antimicrobial); positive control (ration supplemented with 10 ppm of enramycin and 42 ppm of salinomycin), lemongrass (ration with 120 mg of essential oil of lemongrass for each kilogram of live weight of the animals), and pedestrian tea (ration with 120 mg of essential oil of pedestrian tea for each kilogram of live weight of the animals). Storage was performed after slaughter and evaluated monthly for 4 months. RESULTS: The inclusion of lemongrass oil and pedestrian tea in the broiler diet did not change the ether extract content of the meat sample obtained from thigh and drumstick. The storage time promotes an increase in the moisture loss of the meat from the 2nd month in all treatments. There was an interaction between the additive and storage time for moisture loss. In the 2nd month of storage, the meat from broilers fed the antibiotic-containing feed had a lower moisture loss than those from broilers in the other treatment groups. The fatty acid profile did not differ statistically between the different treatment groups. The inclusion of additives in the food dropped the lipid oxidation at the 2nd month of storage. From the 3rd month, however, only the essential oils showed antioxidant effect. CONCLUSION: Antioxidant activity was positive for treatments that included essential oils. The lemongrass oil and pedestrian tea can be used as antioxidant additives in broiler diets to improve the oxidative stability of thigh-drumstick meat during storage. The results of the study suggest a good prospective for further research with profitability of usage essentials oils examined, for their economical application as feed components in broiler nutrition.

Characterization and molecular epidemiology of Staphylococcus aureus strains resistant to beta-lactams isolated from the milk of cows diagnosed with subclinical mastitis.

BACKGROUND AND AIM: The term ESKAPE, recognized by the WHO, is an acronym, which refers to the pathogens Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., which is extremely virulent and multidrug-resistant. Although the term is used to designate nosocomial pathogens, in a milking environment, strains of Methicillin-resistant S. aureus have been isolated from cattle diagnosed with clinical and subclinical mastitis. Resistant strains may be involved in the transfer of genes conferring resistance to beta-lactam antimicrobials among the species of microorganisms related to mastitis etiology. This study aimed to trace the phenotypic and genotypic profiles of susceptibility to beta-lactams in S. aureus isolated from milk of cattle diagnosed with subclinical mastitis obtained from different rural properties located in the North of Minas Gerais State, Brazil. MATERIALS AND METHODS: Sixteen microorganisms previously identified as S. aureus isolated from milk of cattle diagnosed with subclinical mastitis were submitted to matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF), mass spectrometry, and polymerase chain reaction (PCR) analysis for microbial species confirmation. The S. aureus beta-lactams antimicrobial phenotypic resistance profile was investigated by disk diffusion method. PCR methods were also performed to investigate the S. aureus genotypic beta-lactams resistance profile. For this purpose, bla Z, mec A, mec ALGA251, bla Oxa23, and bla KPC genes were screened among S. aureus isolates. The genetic diversity of S. aureus by fingerprint random amplified polymorphic DNA (RAPD)-PCR was also performed in this study. RESULTS: All isolates showed phenotypic resistance to at least three beta-lactams, among which was meropenem. None of the isolates tested positive for the genes mec ALGA251, bla Oxa23, and bla KPC; however, the presence of the genes bla Z and mecA was detected among the isolates. The fingerprint analysis divided isolates into two distinct groups and 15 different subgroups. Despite the presence of clonality among the isolates, the PCR-RAPD analysis unveiled a heterogeneous profile with genetic diversity among the S. aureus isolates. CONCLUSION: In this study, we identified beta-lactams resistant S. aureus strains isolated from the milk of cows diagnosed with subclinical mastitis. The S. aureus beta-lactams resistance was investigated using a phenotypic and genotypic approach. We believe that molecular epidemiology, improved knowledge, and genetic basis of resistance to beta-lactams might assist in asserting guidelines for better management practices of dealing with subclinical mastitis and mapping of origin of resistant pathogens in the studied Brazilian area.

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.