Occurrence of Mycoplasma hyopneumoniae in slaughter pigs from Southern Brazil / Ocorrência de Mycoplasma hyopneumoniae em amostras de pulmão de suínos obtidas de frigorífico do sul do Brasil

Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia (EP), a disease that is highly prevalent and globally distributed, causing significant economic losses to the swine industry. Disease progression is characterized by reduced feed conversion and the development of lung lesions. Considering the limited information about the epidemiology of EP in Southern Brazil, the main objective of this study was to determine the occurrence of M. hyopneumoniae in swine lung samples and to evaluate the scores of lung lesions caused by local strains. A total of 120 samples was randomly collected and processed. DNA was extracted from lung tissue to perform nested-PCR and lungs were inspected to evaluate the presence of the pneumonia-like gross lesions of M. hyopneumoniae. The results showed 95.8% positive samples, while the lung lesion score analysis showed suggestive lesions in 60% of samples. The detection of positive samples in nested-PCR was associated with the presence of pneumonia-like gross lesions (P < 0.01). The results demonstrate a high occurrence of EP in slaughter pigs from southern Brazil.(AU)

O Mycoplasma hyopneumoniae é o agente causador da Pneumonia Enzoótica Suína (PES), doença altamente prevalente e mundialmente distribuída, causando grandes perdas econômicas para a indústria suinícola. A progressão da doença é caracterizada pela redução das taxas de conversão alimentar e o desenvolvimento de lesões pulmonares. Visto que há informação limitada sobre a epidemiologia da PES no sul do Brasil, o objetivo do presente trabalho foi determinar a prevalência de M. hyopneumoniae em amostras de pulmão suíno e avaliar o score de lesões pulmonares causadas pelas cepas locais. Um total de 120 amostras foram coletadas aleatoriamente, processadas e analisadas. O DNA foi extraído do tecido pulmonar para realização de Nested-PCR e os pulmões foram inspecionados para presença de lesões macroscópicas sugestivas de M. hyopneumoniae. Os resultados demonstraram 95,8% das amostras positivas para o patógeno. A análise do score pulmonar mostrou lesões sugestivas da PES em 60% das amostras. A detecção de amostras positivas no Nested-PCR foi associada com a presença de lesões sugestivas (P < 0.01). Os dados obtidos neste trabalho demonstram a alta prevalência da PES em granjas do RS.(AU)

Whole-genome sequencing of Leptospira interrogans from southern Brazil: genetic features of a highly virulent strain

BACKGROUND Leptospirosis is the most widespread zoonotic disease. It is caused by infection with pathogenic Leptospira species, of which over 300 serovars have been described. The accurate identification of the causative Leptospira spp. is required to ascertain the pathogenic status of the local isolates. OBJECTIVES This study aimed to obtain the complete genome sequence of a virulent Leptospira interrogans strain isolated from southern Brazil and to describe its genetic features. METHODS The whole genome was sequenced by next-generation sequencing (Ion Torrent). The genome was assembled, scaffolded, annotated, and manually reviewed. Mutations were identified based on a variant calling analysis using the genome of L. interrogans strain Fiocruz L1-130 as a reference. FINDINGS The entire genome had an average GC content of 35%. The variant calling analysis identified 119 single nucleotide polymorphisms (SNPs), from which 30 led to a missense mutation. The structural analyses identified potential evidence of genomic inversions, translocations, and deletions in both the chromosomes. MAIN CONCLUSIONS The genome properties provide comprehensive information about the local isolates of Leptospira spp., and thereby, could facilitate the identification of new targets for the development of diagnostic kits and vaccines.