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12. A Neglected Part of Bovine Genital Leptospirosis: Bulls.

Author

Pedrosa, Juliana, Ezepha, Camila, Carvalho‐Costa, Felipe Anibal, Di Azevedo, Maria Isabel Nogueira, and Lilenbaum, Walter

Subjects
LEPTOSPIRA interrogans, GENITALIA, POLYMERASE chain reaction, AGGLUTINATION tests, LEPTOSPIROSIS
Abstract

Bovine leptospirosis is a worldwide disease that causes reproductive issues, including early embryonic death, stillbirths and infertility, which result in significant economic losses. Although bovine leptospirosis is well‐documented in cows, the role of bulls in harbouring and potentially transmitting genital leptospirosis has been largely neglected. We examined genital and blood samples from 16 slaughtered bulls using microscopic agglutination testing (MAT), polymerase chain reaction (PCR) and sequencing of amplicons. Our results showed that 81.2% of bulls were seroreactive, and 75% were genitally infected. The amplicons displayed an identity greater than 99% with Leptospira interrogans strains from the Sejroe serogroup, specifically serovar Hardjoprajitno. This study demonstrates that bulls can harbour in their genital tract the same leptospires associated with reproductive syndromes in cows from the same geographic region, highlighting the importance of bulls in maintaining and transmitting Sejroe serogroup strains associated with reproductive disease. [ABSTRACT FROM AUTHOR]

Published
2024
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38. Production of bacteriocin-like inhibitory substance (BLIS) by Staphylococcusspp. isolates from dogs

Author

Santos, Ilana Nascimento de Sousa, Lilenbaum, Walter, Moreno, Daniela Sales Alviano, and Bastos, Maria do Carmo de Freire

Abstract

In the present study, 39 canine isolates of Staphylococcusspp. were tested for antimicrobial substance (AMS) production. Seven AMS producers were identified, whose products exhibited a non-acidic character and a proteinaceous nature, therefore being considered bacteriocin-like inhibitory substances (BLIS). The producer strains of BLIS P1, P16 and I3 showed a broad spectrum of antimicrobial activity. Human, veterinary and plant pathogens, such as Listeria monocytogenes, Klebsiella pneumoniae, Staphylococcusspp. and Clavibacter michiganensis, were among the inhibited micro-organisms, suggesting the potential biotechnological application of these peptides. MALDI-TOF mass spectrometry and 16 S rDNA sequencing identified the producer strains of BLIS P1, P16 and I3 as Staphylococcus pseudintermediusP1, Staphylococcus schleiferiP16 and Staphylococcus pseudintermediusI3. The plasmid profile of these strains suggests that the BLIS production is linked to biosynthetic genes located on plasmids. PCR analyses revealed that BLIS P1, P16 and I3 are different from 11 staphylococcins already described in the literature and that their genomic DNAs do not carry the most prevalent staphylococcal enterotoxin genes. The highest levels of BLIS production were achieved after 18–24 h of growth of the producer strains in TSB medium. Moreover, BLIS P1 and I3 exhibited high resistance to temperature and pH variations, and BLIS P16 maintained 100% of its activity in almost all conditions tested. The characteristics associated with BLIS P1, P16 and I3 described in this work encourage further investigation of these substances, in addition to this study being the first report of BLIS production by a strain of S. schleiferi.

Published
2024
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41. Molecular Detection of Pathogenic Leptospira sp. in Cetaceans from the Brazilian Coast

Author

Torres, Felipe D’Azeredo, Borges, Ana Luiza dos Santos Baptista, Castilho, Pedro Volkmer de, Kolesnikovas, Cristiane, Domit, Camila, dos Santos, Jonathas, Bonfim, Waltyane Alves Gomes, Carvalho, Vitor Luz, Barbosa, Carla Beatriz, Ribeiro, Vanessa Lanes, Carvalho-Costa, Filipe Anibal, Di Azevedo, Maria Isabel Nogueira, and Lilenbaum, Walter

Abstract

Leptospirosis is a zoonosis with ubiquitous distribution caused by spirochetes belonging to the genus Leptospira sp., endemic mainly in tropical and subtropical regions of the world and capable of infecting domestic animals, free-living animals, and humans. Although well documented in terrestrial animals and humans, little information is available on its distribution and impact on marine animals. There are few studies assessing cetaceans’ health status, and even scarcer are those focused on leptospirosis research. In this context, considering the One Health approach, the present study aimed to investigate the occurrence of pathogenic Leptospira sp. in cetaceans on the Brazilian coast. Kidneys of 142 cetaceans belonging to 19 species were collected. DNA was extracted, and the diagnosis was performed by LipL32-polymerase chain reaction. Genetic characterization was conducted based on secY gene sequencing. Pathogenic Leptospira sp. DNA was detected in 14.8% (21/142) of the tested cetaceans, with coastal species presenting a significantly higher frequency (p-value = 0.03) of infected individuals (25%, 17/68) than oceanic species (7.5%, 4/53). It was possible to amplify and sequence three strains (one for Sotalia guianensis, one for Stenella clymene, and one for Pontoporia blainvillei), all of them identified as Leptospira interrogans, with high similarity with sequences from Icterohaemorrhagiae serogroup. Phylogenetic analysis revealed sequences from the present study grouped in species-specific unique clusters but very close to pinnipeds in the same area, evidencing the presence of two distinct haplotypes circulating on marine mammals in the region. We could demonstrate that cetaceans can act as carriers of pathogenic leptospires. Moreover, the proximity with anthropogenic areas could play an important role in leptospirosis’ dynamics of transmission in a One Health context.

Published
2023
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47. Genetic Evidence for a Potentially New Pathogenic Leptospira sp. Circulating in Bats from Brazilian Amazon.

Author

Di Azevedo, Maria Isabel Nogueira, Verde, Rair de Souza, Ezepha, Camila, Carvalho-Costa, Filipe Anibal, D'Andrea, Paulo Sérgio, Medeiros, Luciana dos Santos, and Lilenbaum, Walter

Subjects
LEPTOSPIRA interrogans, LEPTOSPIRA, BIOLOGICAL evolution, BATS, POLYMERASE chain reaction, HAPLOTYPES
Abstract

Leptospirosis is a neglected zoonosis frequently reported worldwide, caused by a spirochete of the genus Leptospira. It is capable of infecting domestic animals, free-living animals, and humans. Among wild animals, the role of bats in the epidemiology of leptospirosis has been investigated but is far from being elucidated. The Amazonian biome has the ideal conditions for maintaining and disseminating leptospires and, despite efforts that have been made to better understand leptospires' occurrence in wild animals in the region, few studies aimed to explore and genetically characterize leptospires in bats. Based on this, the aim of the present study is to deeper investigate and genetically characterize leptospires detected in bats from the southwest Amazon. Animals were trapped by mist netting at five sites in the state of Acre, Brazil. Kidney samples were obtained and stored for molecular analysis. Polymerase chain reaction (PCR) was conducted first based on the LipL32 gene, and positive samples were submitted to rrs and secY-PCR and sequencing. Sequences were then submitted to phylogenetic analyses through multiple bioinformatic tools. The rrs sequences from the present study formed one single haplotype, different from any other previously deposited, grouped in a highly supported cluster with sequences from bats from Madagascar and China. The initial secY screening revealed no identity with previously deposited sequences. The phylogenetic trees revealed the sequences from the present study in an isolated branch, clearly separated from all previously known pathogenic Leptospira spp., suggesting the existence of a potentially undescribed species. The haplotype network including only leptospires from the Amazon region confirmed two new haplotypes from the same taxon unity, isolated from the others, with a probable origin of the species from L. noguchii. The characterization of this potentially new species in bats reinforces the complexity of the transmission dynamics of leptospires, including wild, periurban, and urban environments, emphasizing the need for an integrative look at leptospirosis vigilance within the context of One Health. [ABSTRACT FROM AUTHOR]

Published
2023
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