Identification and Characterization of Cronobacter Strains Isolated from Environmental Samples

Area of Science:

• Environmental microbiology
• Food safety
• Bacteriology

Background:

• Cronobacter species are emerging foodborne pathogens found globally in food and environmental settings.
• Understanding the environmental prevalence and characteristics of Cronobacter is crucial for food safety and public health.

Purpose of the Study:

• To investigate the molecular typing and antibiotic resistance profiles of Cronobacter species isolated from environmental soil and water samples.
• To assess the potential role of the environment as a reservoir for Cronobacter.

Main Methods:

• Collection and analysis of 141 soil and water samples from Beijing.
• Identification of Cronobacter isolates using real-time PCR, 16s rRNA sequencing, and whole-genome sequencing.
• Molecular subtyping via pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST); antibiotic susceptibility testing.

Main Results:

• Cronobacter species were detected in 15.60% of samples, with four species identified: C. dubliniensis, C. sakazakii, C. turicensis, and C. malonaticus.
• Twelve novel MLST types were identified, indicating significant genetic diversity among environmental isolates.
• A high prevalence of resistance to cefazolin (68.18%) was observed, suggesting natural resistance.

Conclusions:

• The environment, including soil and water, serves as a reservoir for diverse Cronobacter species.
• Environmental Cronobacter isolates exhibit significant genetic diversity and notable resistance to cefazolin.
• The findings highlight the environment as a potential source of Cronobacter contamination and infection, necessitating integrated control strategies.