TY - JOUR
T1 - Analysis of single nucleotide polymorphisms (SNPs) associated with antibiotic resistance genes in Chilean Piscirickettsia salmonis strains
AU - Figueroa, Jaime
AU - Castro, Diana
AU - Lagos, Fernando
AU - Cartes, Carlos
AU - Isla, Adolfo
AU - Yáñez, Alejandro J.
AU - Avendaño-Herrera, Rubén
AU - Haussmann, Denise
N1 - Funding Information:
The authors gratefully acknowledge the support given to this work through grants FIEV014 (No. 122929) and FONDAP 15110027, awarded to the Interdisciplinary Centre for Aquaculture Research (INCAR) at Universidad Austral de Chile.
Publisher Copyright:
© 2019 John Wiley & Sons Ltd
PY - 2019/12/1
Y1 - 2019/12/1
N2 - The aetiological agent of Piscirickettsiosis is Piscirickettsia salmonis, a Gram-negative intracellular pathogen, and high doses of antibiotics have regularly been employed to treat this infection. Seven florfenicol and/or oxytetracycline resistance genes (tet pump, tetE, Tclor/flor, Tbcr, TfloR, ompF and mdtN) were identified in strains by in silico genome analyses. Later, the number of single nucleotide polymorphisms (SNPs) and its relationship with the resistance to these antibiotics were identified and analysed, using the original LF-89 strain as reference. Trials to determine and compare the minimum inhibitory concentration (MIC) of oxytetracycline and florfenicol in each strain, as well as to quantify the gPCR transcripts levels in the selected genes, were performed. Therefore, variations in the resistance to both antibiotics were observed, where the strain with fewer SNPs showed the highest susceptibility. Consistently, the in silico 3D analyses of proteins encoded by the selected genes revealed structural changes, evident in the sequences with the highest number of SNPs. These results showed that the bacterial resistance to oxytetracycline was mainly linked to the presence of SNPs in relevant sites, antibiotic resistance genes and an OmpF porin, leading to important changes in the protein structure.
AB - The aetiological agent of Piscirickettsiosis is Piscirickettsia salmonis, a Gram-negative intracellular pathogen, and high doses of antibiotics have regularly been employed to treat this infection. Seven florfenicol and/or oxytetracycline resistance genes (tet pump, tetE, Tclor/flor, Tbcr, TfloR, ompF and mdtN) were identified in strains by in silico genome analyses. Later, the number of single nucleotide polymorphisms (SNPs) and its relationship with the resistance to these antibiotics were identified and analysed, using the original LF-89 strain as reference. Trials to determine and compare the minimum inhibitory concentration (MIC) of oxytetracycline and florfenicol in each strain, as well as to quantify the gPCR transcripts levels in the selected genes, were performed. Therefore, variations in the resistance to both antibiotics were observed, where the strain with fewer SNPs showed the highest susceptibility. Consistently, the in silico 3D analyses of proteins encoded by the selected genes revealed structural changes, evident in the sequences with the highest number of SNPs. These results showed that the bacterial resistance to oxytetracycline was mainly linked to the presence of SNPs in relevant sites, antibiotic resistance genes and an OmpF porin, leading to important changes in the protein structure.
KW - florfenicol
KW - oxytetracycline
KW - Piscirickettsiosis
KW - resistance genes
KW - SNPs
UR - http://www.scopus.com/inward/record.url?scp=85073958640&partnerID=8YFLogxK
U2 - 10.1111/jfd.13089
DO - 10.1111/jfd.13089
M3 - Article
C2 - 31591746
AN - SCOPUS:85073958640
VL - 42
SP - 1645
EP - 1655
JO - Journal of Fish Diseases
JF - Journal of Fish Diseases
SN - 0140-7775
IS - 12
ER -