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Pereira FL, Tavares GC, de Carvalho AF, Rosa JCC, Rezende CP, Leal CAG, Figueiredo HCP. Effects of temperature changes in the transcriptional profile of the emerging fish pathogen Francisella noatunensis subsp. orientalis. Microb Pathog 2019; 133:103548. [PMID: 31112771 DOI: 10.1016/j.micpath.2019.103548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 01/05/2023]
Abstract
One of the major challenges in Nile tilapia (Oreochromis niloticus L.) farming is the occurrence of bacterial infections, and the Francisella noatunensis subsp. orientalis (FNO) is an important pathogen that has emerged in last decades. Francisellosis outbreaks have been reported in the literature as occurring seasonally when water temperature is below 24 °C. The aim of this study was to quantify the median lethal doses (LD50) of FNO in experimental challenges at 28 °C and 22 °C, and to investigate the impact of temperature changes in whole genome expression using microarray technology. The LD50 for Nile tilapia at 28 °C was ∼105.7, whereas at 22 °C, the LD50 was ∼102.2, showing that the decrease in temperature enhanced disease outcome. Out of 1917 genes screened, a total of 31 and 19 genes were down- and up-regulated at 22 °C, respectively. These genes were grouped by orthology into functional categories of: amino acid, inorganic ion, and carbohydrate transport and metabolism; transcription; and posttranslational modification, protein turnover, and chaperones. Expression of genes related to metabolism, oxidative stress, and thermal shock were regulated by temperature changes, reflecting an ability of FNO to adapt to the environment. Expression of virulence genes usually required for the Francisella genus was not changed between tested temperatures, including that of genes located on the Francisella Pathogenicity Island.
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Affiliation(s)
- Felipe Luiz Pereira
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Guilherme Campos Tavares
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Alex Fiorini de Carvalho
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Júlio César Camara Rosa
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Cristiana Perdigão Rezende
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Carlos Augusto Gomes Leal
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil.
| | - Henrique César Pereira Figueiredo
- AQUACEN, National Reference Laboratory for Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Federal University of Minas Gerais, Brazil. http://www.vet.ufmg.br/
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Pulpipat T, Lin KH, Chen YH, Wang PC, Chen SC. Molecular characterization and pathogenicity of Francisella noatunensis subsp. orientalis isolated from cultured tilapia (Oreochromis sp.) in Taiwan. JOURNAL OF FISH DISEASES 2019; 42:643-655. [PMID: 30715744 DOI: 10.1111/jfd.12964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/28/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Francisella noatunensis subsp. orientalis is a causative agent of systemic granulomatous disease in tilapia. The present study was designed to understand the genetic and phenotypic diversities among Taiwanese Fno isolates obtained from tilapia (n = 17) and green Texas cichlid (Herichthys cyanoguttatus) (n = 1). The enzymatic profiles of the isolates were studied using the API ZYM system. Phylogenetic tree analysis of the 16S rRNA and housekeeping gene and pulsed-field gel electrophoresis (PFGE) were carried out to determine the genotypic characters of all isolates. The phylogenetic tree showed similarity of 99%-100% nucleotide sequences of 16S rRNA and housekeeping genes compared to the Fno references genes from GenBank database. Comparatively, the results revealed an identical profile of enzymatic and PFGE pattern which was distincted from that of F. philomiragia. To understand the pathogenicity, the isolates were intraperitoneal injected to tilapia the gross lesions were observed concomitant with natural outbreak. Median lethal dose upon Nile tilapia and red tilapia were 9.06 × 103 CFU/fish and 2.08 × 102 CFU/fish, respectively. Thus, our data provide understanding the epidemiology of Taiwanese Fno isolates, and help in development of future control and prevention.
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Affiliation(s)
- Theeraporn Pulpipat
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Kuo-Hua Lin
- Animal Protection Office, Taoyuan City, Taiwan
| | | | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shih-Chu Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Southern Taiwan Fish Diseases Research Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung, Taiwan
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung, Taiwan
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