Two Cases of Cronobacter Sakazakii Meningitis in Infants: The Importance Of Early Advanced Brain Imaging and Public Health Reporting

Fatal Necrotizing Enterocolitis in Neonate Caused by Cronobacter sakazakii Sequence Type 64 Strain of CRISPR Sublineage b

We report fatal neonatal necrotizing enterocolitis in China caused by Cronobacter sakazakii capsular profile K1:CA1, sequence type 64, and CRISPR type 197. Phylodynamic analyses indicated that the strain originated from the ancient, widespread, and antimicrobial drug-sensitive CRISPR sublineage b. Enhanced surveillance and pathogenesis research on this organism are required.

Cronobacter sakazakii Pyridoxal Kinase PdxY Mediated by TreR and pESA3 Is Essential for Vitamin B6 (PLP) Maintenance and Virulence

Cronobacter sakazakii is an opportunistic pathogen capable of causing severe infections, particularly in neonates. Despite the bacterium's strong pathogenicity, the pathogenicity of C. sakazakii is not yet well understood. Using a comparative proteomic profiling approach, we successfully identified pdxY, encoding a pyridoxal kinase involved in the recycling of pyridoxal 5'-phosphate (PLP), as a gene essential for the successful pathogenesis of C. sakazakii. Knocking out the pdxY gene resulted in slower growth and reduced virulence. Our study sheds light on the fundamental importance of pyridoxal kinase for the survival and virulence of C. sakazakii. The identification of pdxY as gene essential for successful pathogenesis provides a potential target for the development of new antibiotic treatments. IMPORTANCE The opportunistic pathogen Cronobacter sakazakii is known to cause severe infections, particularly in neonates, and can result in high mortality rates. In this study, we used a comparative proteomic profiling approach to identify genes essential for the successful pathogenesis of C. sakazakii. We successfully identified pdxY, encoding a pyridoxal kinase involved in the salvage pathway of pyridoxal 5'-phosphate (PLP), as a gene essential for the successful pathogenesis of C. sakazakii. Knocking out the pdxY gene resulted in impaired growth and reduced virulence. This study sheds light on the fundamental importance of pyridoxal kinase for the survival and virulence of C. sakazakii, which can be a potential target for the development of new antibiotic treatments. This study highlights the importance of comparative proteomic profiling in identifying virulence factors that can be targeted for the development of new antibiotics.

[The pathogenicity of Cronobacter in the light of bacterial genomics]

Cronobacter spp. is a genus of Gram-negative bacteria belonging to the family Enterobacteriaceae. Species of the genus Cronobacter, particularly C. sakazakii, are implicated in the development of severe disease in newborns, which occurs with necrotizing enterocolitis, sepsis and meningitis. The disease has been frequently associated with powdered infant formula (PIF) and can therefore occur in the form of outbreaks. The genus Cronobacter has undergone extensive diversification in the course of its evolution, with some species being clearly pathogenic to humans while the impact of other species on human health is uncertain or unknown. Whole genome sequencing is used both in population genetic studies to identify the limited number of genotypes associated with the disease and to detect genes associated with antibiotic resistance or virulence, ultimately allowing more precise epidemiological links to be established between pediatric disease and infant foods.

Comparison of Origanum Essential Oil Chemical Compounds and Their Antibacterial Activity against Cronobacter sakazakii

Origanum vulgare L. (oregano) is an aromatic plant with wide applications in the food and pharmaceutical industries. Cronobacter sakazakii, which has a high detection rate in powdered infant formula, adversely impacts susceptible individuals. Oregano essential oil (OEO) is a natural antibacterial agent that can be used to fight bacterial contamination. Here, OEO chemical compounds from eight oregano varieties were analyzed by gas chromatography–mass spectrometry and their antibacterial properties were assessed. The eight OEOs were clustered into two groups and were more diverse in group 2 than in group 1. Six compounds, including p-cymene, 3-thujene, γ-terpinene, thymol, carvacrol, and caryophyllene, were shared by eight OEOs. Among the eight oregano varieties, OEOs from O. vulgare sc2 had the strongest antibacterial activity against C. sakazaki, with the inhibition zone of 18.22mm. OEOs from O. vulgare jx, O. ‘Nvying’, O. vulgare ‘Ehuang’, and O. vulgare ssp. virens were also potent. Moreover, the antibacterial activity of OEOs was positively correlated with the relative content of thymol. As the main OEO antibacterial compound, thymol affected the normal growth and metabolism of C. sakazakii cells by destroying the bacterial membrane and decreasing the intracellular ATP concentration. Thus, in light of the antibacterial activity detected in the OEOs from the eight oregano varieties, this study provides a theoretical foundation for oregano cultivar management and development.