Motile Aeromonas septicemia in tambaqui Colossoma macropomum: Pathogenicity, lethality and new insights for control and disinfection in aquaculture

Sílvia Umeda Gallani; Gustavo Moraes Ramos Valladão; Inácio Mateus Assane; Lindomar de Oliveira Alves; Suzana Kotzent; Diogo Teruo Hashimoto; Fabiana Pilarski

doi:10.1016/j.micpath.2020.104512

Motile Aeromonas septicemia in tambaqui Colossoma macropomum: Pathogenicity, lethality and new insights for control and disinfection in aquaculture

Microb Pathog. 2020 Dec:149:104512. doi: 10.1016/j.micpath.2020.104512. Epub 2020 Sep 20.

Authors

Sílvia Umeda Gallani¹, Gustavo Moraes Ramos Valladão², Inácio Mateus Assane³, Lindomar de Oliveira Alves⁴, Suzana Kotzent⁵, Diogo Teruo Hashimoto⁶, Fabiana Pilarski⁷

Affiliations

¹ Laboratory of Microbiology Applied to Aquatic Organisms, Nilton Lins University (UNL), Amazonas, 69058-030, Brazil. Electronic address: silviaugallani@gmail.com.
² Laboratory of Parasitology and Pathology of Aquatic Organisms, Nilton Lins University (UNL), Amazonas, 69058-030, Brazil. Electronic address: gmrvalladao@gmail.com.
³ Zambeze University (UniZambeze), Faculty of Agricultural Sciences, Ulónguè, 2306, Mozambique; Laboratory of Microbiology and Parasitology of Aquatic Organisms, São Paulo State University (Unesp), Aquaculture Center of Unesp, São Paulo, 14884-900, Brazil. Electronic address: inaciomateusassane@gmail.com.
⁴ Laboratory of Microbiology and Parasitology of Aquatic Organisms, São Paulo State University (Unesp), Aquaculture Center of Unesp, São Paulo, 14884-900, Brazil. Electronic address: lindomar.alves@unesp.br.
⁵ Laboratory of Microbiology and Parasitology of Aquatic Organisms, São Paulo State University (Unesp), Aquaculture Center of Unesp, São Paulo, 14884-900, Brazil. Electronic address: su_kotzent@hotmail.com.
⁶ São Paulo State University (Unesp), Aquaculture Center of Unesp, Laboratory of Aquaculture Genetics and Conservation, São Paulo, 14884-900, Brazil. Electronic address: diogo.hashimoto@unesp.br.
⁷ Laboratory of Microbiology and Parasitology of Aquatic Organisms, São Paulo State University (Unesp), Aquaculture Center of Unesp, São Paulo, 14884-900, Brazil. Electronic address: fabiana.pilarski@unesp.br.

PMID: 32966864
DOI: 10.1016/j.micpath.2020.104512

Abstract

Tambaqui Colossoma macropomum is the most produced native fish in South America. Besides the lack of knowledge regarding bacteria-stricken diseases, the unappropriated using of off-label therapies are common. In this study, Aeromonas hydrophila pathogenicity for tambaqui was first established by Koch's Postulate. Lethal doses (LD) were settled for investigation of clinical signs and mortality. The antimicrobial activities were investigated by disk-diffusion test against 11 antibiotics and by broth microdilution methods against 3 antibiotics, 7 disinfectants and 11 herbal medicines. LD experiment showed up to 80% of fish mortality, skin darkness, ulcers, hemorrhage, lethargy and hypo/anorexia in all groups, with exception of control. The LD₁₀,₅₀,₉₀ and ₉₉ were established in 4.1 × 10⁷, 8.8 × 10⁷, 1.9 × 10⁸ e 3.6 × 10⁸ CFU/mL, respectively. Ceftriaxone, florfenicol, oxytetracycline and thiamphenicol were considered promising against A. hydrophila. All herbal medicines were classified as bactericides, but clove Eugenia caryophyllata and cinnamon Cinnamomum zeylanicum displayed strongest activities. Among disinfectants, malachite green was the only that did not present acceptable values, discouraging its use. In conclusion, Koch's postulate was fulfilled and tambaqui entered to the vast list of A. hydrophila hosts and promising results of chemical substances were provided, contributing to motile Aeromonas septicemia (MAS) control.

Keywords: Aeromonas hydrophila; Antibiotic; Black pacu; Disease; Disinfectant; Essential oil.

MeSH terms

Aeromonas*
Animals
Aquaculture
Disinfection
Fish Diseases*
Sepsis*
South America
Virulence