Cronobacter sakazakii is an enteropathogen that causes neonatal meningitis, septicemia, and necrotizing enterocolitis in preterm infants and newborns with a mortality rate of 15 to 80%. Powdered and dairy formulas (P-DF) have been implicated as major transmission vehicles and subsequently the presence of this pathogen in P-DF led to product recalls in Chile in 2017. The objective of this study was to use whole genome sequencing (WGS) and laboratory studies to characterize Cronobacter strains from the contaminated products. Seven strains were identified as C. sakazakii, and the remaining strain was Franconibacter helveticus. All C. sakazakii strains adhered to a neuroblastoma cell line, and 31 virulence genes were predicted by WGS. The antibiograms varied between strains. and included mcr-9.1 and bla CSA genes, conferring resistance to colistin and cephalothin, respectively. The C. sakazakii strains encoded I-E and I-F CRISPR-Cas systems, and carried IncFII(pECLA), Col440I, and Col(pHHAD28) plasmids. In summary, WGS enabled the identification of C. sakazakii strains and revealed multiple antibiotic resistance and virulence genes. These findings support the decision to recall the contaminated powdered and dairy formulas from the Chilean market in 2017.
- Klíčová slova
- CRISPR-cas, Cronobacter sakazakii, antibiotic resistance genes, powdered formula, virulence,
- Publikační typ
- časopisecké články MeSH
ABSTRACT: Cronobacter is a bacterial genus that includes seven species, and the species Cronobacter sakazakii is most related to meningitis and septicemia in infants associated with powdered infant formula (PIF). The objectives of this study were to evaluate the presence of C. sakazakii and to determine the microbiological quality of PIF for infant consumption. To do this, a total of 128 PIF samples were analyzed in four brands and countries (Chile, Mexico, Holland, and Brazil), considering three types of PIF: premature (PIF1), infant (PIF2), and follow-up (PIF3). Aerobic plate counts (APC) and Enterobacteriaceae (ENT) were assessed in accordance with Chilean official standards. The outer membrane protein A (ompA) gene was amplified to detect Cronobacter spp. and the fusA gene was amplified to identify C. sakazakii by using the PubMLST Web site and BLAST (NCBI). The antibiotic resistance profile was performed according to the Clinical and Laboratory Standards Institute standards. The pathogen was quantified by the most probable number (MPN). The results showed that APC median values for PIF1, PIF2, and PIF3 were 3.2, 4.9, and 4.8 log CFU g-1, respectively. The APC were higher in PIF2 (P < 0.01) from Holland (P < 0.01) in the commercial brand 4 (P < 0.01). The ENT median values in PIF1, PIF2, and PIF3 were 1.8, 1.5, and 1.7 log CFU g-1, respectively. Five strains of C. sakazakii and one strain of Cronobacter malonaticus were identified as having values between 0.023 and 2.3 MPN/g. All strains (100%) harbored the ompA, plasminogen activator (cpa), and hemolysin (hly) virulence genes. To conclude, C. sakazakii was found in four PIF samples from four Chilean products and one from Mexico, which is distributed throughout America. C. sakazakii strains exhibit virulence factors and resistance to ampicillin, thus posing a risk when PIFs are consumed by infants.
- Klíčová slova
- Cronobacter sakazakii, Antibiotic resistance, Microbiological quality, Powdered infant formula, Virulence,
- MeSH
- Cronobacter sakazakii * MeSH
- Cronobacter MeSH
- kojenec MeSH
- kontaminace potravin analýza MeSH
- lidé MeSH
- náhražky mateřského mléka * mikrobiologie normy MeSH
- potravinářská mikrobiologie MeSH
- prášky, zásypy, pudry MeSH
- spotřebitelská bezpečnost produktů MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Brazílie MeSH
- Chile MeSH
- Latinská Amerika MeSH
- Mexiko MeSH
- Nizozemsko MeSH
- Názvy látek
- prášky, zásypy, pudry MeSH
