Genomic Characterization of Cronobacter spp. and Salmonella spp. Strains Isolated From Powdered Infant Formula in Chile

Frontiers in Microbiology

Ariane Pietzka¹  Sarah Lepuschitz¹  Stephen Forsythe¹  Sergio Acuña²  Alejandro Castillo³  Julio Parra-Flores⁴  Pamela Chavarría-Sepulveda⁴  Jetsi Mancilla-Rojano⁵  Alejandra Contreras-Fernández⁶  Ariadnna Cruz-Córdova⁷  Juan Xicohtencatl-Cortes⁷  Werner Ruppitsch⁸  Ondřej Holý⁹ 

[1] Austrian Agency for Health and Food Safety, Institute for Medical Microbiology and Hygiene, Vienna, Austria;Department of Food Engineering, Universidad del Bío-Bío, Chillán, Chile;;Department of Nutrition and Food Science, Texas A&Department of Nutrition and Public Health, Universidad del Bío-Bío, Chillán, Chile;Faculty of Medicine, Biological Sciences Graduate Program, Universidad Nacional Autónoma de México, Mexico City, Mexico;Food Quality Testing and Certification Laboratory, Universidad del Bío-Bío, Chillán, Chile;Intestinal Bacteriology Research Laboratory, Hospital Infantil de México Federico Gómez, Mexico City, Mexico;M University, College Station, TX, United States;Science and Research Centre, Faculty of Health Sciences, Palacký University Olomouc, Olomouc, Czechia;

关键词: Cronobacter sakazakii;    Cronobacter malonaticus;    Salmonella Typhimurium;    powdered infant formula;    virulence;    resistance genes;   

DOI  :  10.3389/fmicb.2022.884721

来源: DOAJ

【 摘 要 】

This study characterized five Cronobacter spp. and six Salmonella spp. strains that had been isolated from 155 samples of powdered infant formula (PIF) sold in Chile and manufactured in Chile and Mexico in 2018–2020. Two strains of Cronobacter sakazakii sequence type (ST) ST1 and ST31 (serotypes O:1 and O:2) and one strain of Cronobacter malonaticus ST60 (O:1) were identified. All Salmonella strains were identified as Salmonella Typhimurium ST19 (serotype O:4) by average nucleotide identity, ribosomal multilocus sequence typing (rMLST), and core genome MLST (cgMLST). The C. sakazakii and C. malonaticus isolates were resistant to cephalothin, whereas the Salmonella isolates were resistant to oxacillin and ampicillin. Nineteen antibiotic resistance genes were detected in the C. sakazakii and C. malonaticus isolates; the most prevalent were mcr-9.1, blaCSA, and blaCMA. In Salmonella, 30 genes encoding for aminoglycoside and cephalosporin resistance were identified, including aac(6′)-Iaa, β-lactamases ampH, ampC1, and marA. In the Cronobacter isolates, 32 virulence-associated genes were detected by WGS and clustered as flagellar proteins, outer membrane proteins, chemotaxis, hemolysins, invasion, plasminogen activator, colonization, transcriptional regulator, survival in macrophages, use of sialic acid, and toxin-antitoxin genes. In the Salmonella strains, 120 virulence associated genes were detected, adherence, magnesium uptake, resistance to antimicrobial peptides, secretion system, stress protein, toxin, resistance to complement killing, and eight pathogenicity islands. The C. sakazakii and C. malonaticus strains harbored I-E and I-F CRISPR-Cas systems and carried Col(pHHAD28) and IncFIB(pCTU1) plasmids, respectively. The Salmonella strains harbored type I-E CRISPR-Cas systems and carried IncFII(S) plasmids. The presence of C. sakazakii and Salmonella in PIF is a health risk for infants aged less than 6 months. For this reason, sanitary practices should be reinforced for its production and retail surveillance.

【 授权许可】

Unknown