Background and Aim:Recently, bacterial surveys for mastitis-causing pathogens in bulk tank milk (BTM) have been conducted in several countries worldwide. However, no such surveys have been reported from Bolivia. Therefore, the present study aimed to estimate the prevalence of mastitis pathogens in BTM from dairy farms in Montero, Santa Cruz, Bolivia.Materials and Methods:Between July 2016 and August 2017, a total of 43 BTM samples were collected from 3264 cows to determine bulk tank somatic cell counts (BTSCC) and identify mastitis-causing bacteria. BTSCC was classified as follows: <100×103, 100-500×103, 500-1000×103, and >1000×103 cells/mL.Results:Mastitis-causing pathogens identified by agar medium cultures included Bacillus spp., coagulase-negative staphylococci (CNS), coliforms, Staphylococcus aureus (SA), streptococci, and other species. The proportions of BTSCC of <100×103, 200-500×103, 500-1000×103, and >1000×103 cells/ml were 0%, 37%, 51%, and 12%, respectively. The proportions of coliforms, streptococci, CNS, Bacillus spp., SA, and others detected in BTM were 33%, 30%, 16%, 7%, 2%, and 16%, respectively.Conclusion:Although the herd prevalence of contagious mastitis-causing pathogens, such as SA, in BTM was low, increased BTSCC were identified in Montero, Santa Cruz, Bolivia.

Chagas disease can lead to life-threatening cardiac manifestations that occur more frequently in geographic areas more prevalent with the TcI/II circulating genetic strains. To elucidate the differential transcriptomic signatures of the cardiomyocyte resulting from infection with TcI/II or TcVIT. cruzistrains and explore their relationships with pathogenesis, HL-1 rodent cardiomyocytes were infected with TcI/II or TcVIT. cruzitrypomastigotes. RNA was isolated serially post-infection for microarray analysis. Enrichment analyses of differentially expressed genes (fold-change ≥2 or ≤ 0.5) highlighted the over-represented biological pathways. We found that Oxidative stress-related GO terms, ‘Hypertrophy model’, ‘Apoptosis’, and ‘MAPK signaling’ pathways (all with p<0.01) were upregulated. ‘Glutathione and one-carbon metabolism’ pathway, and ‘Cellular nitrogen compound metabolic process’ GO term (all with p <0.001) were upregulated exclusively in the cardiomyocytes infected with the TcI/II strains. Upregulation in the oxidative stress-related and hypertrophic responses are shared hallmarks with viral myocarditis, another inflammatory cardiac pathology. Nitrogen metabolism upregulation and Glutathione metabolism imbalance may implicate the relation of nitrosative stress and poor oxygen radicals scavenging in the unique pathophysiology of chagasic cardiomyopathy development.ImportanceChagas disease affects more than 6 million people worldwide. One-third of those chronically infected will develop the life-threatening condition Chagas Cardiomyopathy (CCM).Trypanosoma cruzi (T. cruzi), grouped based on their genetic variability into six discrete typing units (DTU), are associated with DTU-specific clinical phenotypes. The diverse genetic make-up of parasite virulence factors shall evoke unique host defense responses of variable magnitude, collectively affecting the phenotypic expression of CCM. To address this, we performed a transcriptome analysis of cardiomyocytes infected with three differentT. cruzistrains each belonging to a different DTU. As a result, we were able to point out dysregulation in nitrogen metabolic processes, Glutathione, and one-carbon metabolism pathways as main features in the host response against cardiomyopathy-proneT. cruzistrains. Further research on these pathways could serve not only in the lookout for progression biomarkers but also in the lead toward the discovery of new therapeutic targets.