1
|
Godoi APDS, Sobral GG, da Silva Vieira JC, Carneiro GF, Conceição FR, da Silva ER, Mendonça M. Phenotypical and molecular characterization of Rhodococcus equi isolated from foals in the Agreste region of Pernambuco - Brazil. Braz J Microbiol 2025; 56:1321-1331. [PMID: 40048142 PMCID: PMC12095708 DOI: 10.1007/s42770-025-01640-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2024] [Accepted: 02/13/2025] [Indexed: 05/22/2025] Open
Abstract
Equine rhodococcosis is caused by Rhodococcus equi, an intracellular coccobacillus whose main virulence factor is a plasmid that harbors genes encoding proteins from the Vap family, with the vapA gene being the most important in equine isolates. Furthermore, other factors observed in R. equi strains, such as antimicrobial resistance and biofilm production, may represent significant challenges in the treatment of affected animals. The objective of this study was to characterize four isolates of R. equi from foals in the state of Pernambuco, Brazil. All isolates were identified as R. equi through biochemical tests, amplification of the choE gene, and sequencing of 16 S rRNA. PCR analysis revealed that three isolates were positive for the plasmid virulence genes (vapA, -C, -D, -E, -F, -H and traA), although vapD was absent in one of the three isolates. One isolate did not present any virulence genes, possibly due to the loss of the plasmid after repeated passages at 37ºC. In the antimicrobial susceptibility test, all isolates were susceptible to erythromycin, clarithromycin, azithromycin, rifampicin, gentamicin, and doxycycline. However, all isolates were capable of forming biofilms, with moderate biofilm formation in isolates Rhodo1 and Rhodo2, and weak biofilm formation in isolates Rhodo3 and Rhodo4, which may be associated with increased antimicrobial tolerance. This molecular characterization demonstrated, for the first time, the presence of the virulence plasmid in R. equi isolates from foals in Northeast Brazil, as well as their capacity for biofilm formation.
Collapse
Affiliation(s)
- Alysson Paulo Dos Santos Godoi
- Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manuel de Medeiros, Recife, Pernambuco, 52171-900, Brazil
- Programa de Pós-Graduação em Sanidade e Reprodução de Animais de Produção, Universidade Federal do Agreste de Pernambuco, Avenida Bom Pastor, Boa Vista, Garanhuns, 55292-270, Pernambuco, Brazil
| | - Gilvannya Gonçalves Sobral
- Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manuel de Medeiros, Recife, Pernambuco, 52171-900, Brazil
| | - Júlio César da Silva Vieira
- Programa de Pós-Graduação em Sanidade e Reprodução de Animais de Produção, Universidade Federal do Agreste de Pernambuco, Avenida Bom Pastor, Boa Vista, Garanhuns, 55292-270, Pernambuco, Brazil
| | - Gustavo Ferrer Carneiro
- Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manuel de Medeiros, Recife, Pernambuco, 52171-900, Brazil
| | - Fabricio Rochedo Conceição
- Centro de Desenvolvimento Tecnológico, Núcleo de Biotecnologia, Universidade Federal de Pelotas, Campus Capão do Leão, Pelotas, 96010-610, Rio Grande do Sul, Brazil
| | - Elizabete Rodrigues da Silva
- Programa de Pós-Graduação em Sanidade e Reprodução de Animais de Produção, Universidade Federal do Agreste de Pernambuco, Avenida Bom Pastor, Boa Vista, Garanhuns, 55292-270, Pernambuco, Brazil
| | - Marcelo Mendonça
- Programa de Pós-Graduação em Sanidade e Reprodução de Animais de Produção, Universidade Federal do Agreste de Pernambuco, Avenida Bom Pastor, Boa Vista, Garanhuns, 55292-270, Pernambuco, Brazil.
| |
Collapse
|
2
|
Current taxonomy of Rhodococcus species and their role in infections. Eur J Clin Microbiol Infect Dis 2018; 37:2045-2062. [PMID: 30159693 DOI: 10.1007/s10096-018-3364-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
Abstract
Rhodococcus is a genus of obligate aerobic, Gram-positive, partially acid-fast, catalase-positive, non-motile, and none-endospore bacteria. The genus Rhodococcus was first introduced by Zopf. This bacterium can be isolated from various sources of the environment and can grow well in non-selective medium. A large number of phenotypic characterizations are used to compare different species of the genus Rhodococcus, and these tests are not suitable for accurate identification at the genus and species level. Among nucleic acid-based methods, the most powerful target gene for revealing reliable phylogenetic relationships is 16S ribosomal RNA gene (16S rRNA gene) sequence analysis, but this gene is unable to differentiation some of Rhodococcus species. To date, whole genome sequencing analysis has solved taxonomic complexities in this genus. Rhodococcus equi is the major cause of foal pneumonia, and its implication in human health is related to cases in immunocompromised patients. Macrolide family together with rifampicin is one of the most effective antibiotic agents for treatment rhodococcal infections.
Collapse
|