Genomic sequence analysis of the multidrug-resistance region of avian Salmonella enterica serovar Indiana strain MHYL

Authors: LU, YAN - Beijing University Of Agriculture; WEN, YANJIA - Beijing University Of Agriculture; HU, GE - Beijing University Of Agriculture; LIU, YUQI - Beijing University Of Agriculture; Beier, Ross; HOU, XIAOLIN - Beijing University Of Agriculture

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2019
Publication Date: 8/9/2019
Publication URL: https://handle.nal.usda.gov/10113/6605058
Citation: Lu, Y., Wen, Y., Hu, G., Liu, Y., Beier, R.C., Hou, X. 2019. Genomic sequence analysis of the multidrug-resistance region of avian Salmonella enterica serovar Indiana strain MHYL. Microorganisms. 7(8):1-10. https://doi.org/10.3390/microorganisms7080248.
DOI: https://doi.org/10.3390/microorganisms7080248

Interpretive Summary: Human and animal diseases are caused by Salmonella infections, which pose a serious threat to human health and bring huge economic losses to the livestock industry. We found resistance genes in the MHYL genome from 133 strains of Salmonella Indiana from a poultry production site in Shandong Province, China. Resistance genes are segments of the bacterial genome that encode for proteins that allow the bacteria to be resistant to some antibiotics. Salmonella Indiana has become an important foodborne pathogen since it was first reported in 1984 and is often found in both poultry and poultry production. The emergence of multiple drug resistant pathogens is a worldwide problem. The genomic DNA of Salmonella Indiana has an area labelled MHYL, and this area of the genome was shown to contain two different sections possessing several resistance genes that encode for proteins that will provide Salmonella Indiana resistance to a number of antibiotics. But what makes these areas of the Salmonella Indiana MHYL genome so interesting is these regions also contain class 1 integrons and transposons. These types of DNA segments will allow Salmonella Indiana to move the antibiotic resistance genes to other places within the Salmonella Indiana genome, as well as provide the vehicle to move the antibiotic resistance genes to other bacteria, thereby, helping it spread antibiotic resistance genes. Subsequently, Salmonella Indiana can increase drug resistance within itself and distribute the resistance to other organisms, which may increase the numbers of multiple drug resistant pathogens.

Technical Abstract: A series of human and animal diseases are caused by Salmonella infections, which poses a serious threat to human health and brings huge economic losses to the livestock industry. We found antibiotic resistance genes in the MHYL genome from 133 strains of S. Indiana from a poultry production site in Shandong Province, China. Southern blot analysis was used to position the genomic DNA. High-throughput sequencing technology was used to determine the gene sequence of the MHYL genome. Areas containing multidrug resistance genes were mapped based on the results of gene annotation. The antibiotic resistance genes blaTEM, strA, tetA, aac(6')-Ib-cr were found on the MHYL genome. The resistance genes were located in two multidrug resistance regions containing type I integrons, Tn7 transposons, and multiple IS26 complex transposons with transposable functions. Portions of the multidrug resistance regions were determined highly homologous to the structure of plasmid pAKU_1 in S. enterica serovar Paratyphi A (accession number: AM412236), SGI11 in S. enterica serovar Typhimurium (accession number: KM023773), and plasmid pS414 in S. Indiana (accession number: KC237285). In conclusion, the MHYL genome carries resistance genes against ß-lactams, amide alcohols, tetracyclines, aminoglycosides, and sulfonamides. Most resistance genes were located within the two multidrug resistance regions containing class 1 integrons and transposons.