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Complete genome sequence and phenotype microarray analysis of Cronobacter sakazakii SP291: a persistent isolate
Qiongqiong Yan1, Karen A Power, Shane Cooney
1UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference and Training on Cronobacter, School of Public Health, Physiotherapy and Population Science, University College Dublin Dublin, Ireland.
Abstract:
Outbreaks of human infection linked to the powdered infant formula (PIF) food chain and associated with the bacterium Cronobacter, are of concern to public health. These bacteria are regarded as opportunistic pathogens linked to life-threatening infections predominantly in neonates, with an under developed immune system. Monitoring the microbiological ecology of PIF production sites is an important step in attempting to limit the risk of contamination in the finished food product. Cronobacter species, like other microorganisms can adapt to the production environment. These organisms are known for their desiccation tolerance, a phenotype that can aid their survival in the production site and PIF itself. In evaluating the genome data currently available for Cronobacter species, no sequence information has been published describing a Cronobacter sakazakii isolate found to persist in a PIF production facility. Here we report on the complete genome sequence of one such isolate, Cronobacter sakazakii SP291 along with its phenotypic characteristics. The genome of C. sakazakii SP291 consists of a 4.3-Mb chromosome (56.9% GC) and three plasmids, denoted as pSP291-1, [118.1-kb (57.2% GC)], pSP291-2, [52.1-kb (49.2% GC)], and pSP291-3, [4.4-kb (54.0% GC)]. When C. sakazakii SP291 was compared to the reference C. sakazakii ATCC BAA-894, which is also of PIF origin, the annotated genome data identified two interesting functional categories, comprising of genes related to the bacterial stress response and resistance to antimicrobial and toxic compounds. Using a phenotypic microarray (PM), we provided a full metabolic profile comparing C. sakazakii SP291 and the previously sequenced C. sakazakii ATCC BAA-894. These data extend our understanding of the genome of this important neonatal pathogen and provides further insights into the genotypes associated with features that can contribute to its persistence in the PIF environment.
Insights
Cronobacter sakazakii persists in powdered infant formula (PIF) production sites. Researchers sequenced the genome of a PIF-associated Cronobacter sakazakii isolate, revealing genes for stress response and toxic compound resistance, aiding its survival.
Area of Science:
- Microbiology
- Genomics
- Food Safety
Background:
- Cronobacter species are opportunistic pathogens causing severe infections in neonates, particularly through powdered infant formula (PIF).
- Understanding Cronobacter's adaptation to PIF production environments is crucial for preventing contamination.
- Cronobacter's desiccation tolerance aids survival in PIF and production facilities.
Purpose of the Study:
- To report the complete genome sequence of a Cronobacter sakazakii isolate (SP291) that persists in a PIF production facility.
- To analyze the genomic and phenotypic characteristics of this isolate and compare it to a reference strain.
- To identify genetic factors contributing to Cronobacter sakazakii's persistence in the PIF environment.
Main Methods:
- Whole-genome sequencing of Cronobacter sakazakii SP291.
- Bioinformatic analysis of the genome, including chromosome and plasmid composition.
- Phenotypic microarray analysis to compare metabolic profiles with a reference strain (C. sakazakii ATCC BAA-894).
Main Results:
- The complete genome sequence of Cronobacter sakazakii SP291 (4.3-Mb chromosome and three plasmids) was determined.
- Annotated genome data revealed genes associated with bacterial stress response and resistance to antimicrobial/toxic compounds.
- Phenotypic microarray analysis provided a comprehensive metabolic profile, highlighting differences between SP291 and the reference strain.
Conclusions:
- The genome data provides insights into the genetic makeup of a Cronobacter sakazakii isolate persistent in PIF production.
- Genes related to stress response and resistance likely contribute to the bacterium's survival in the PIF environment.
- This study enhances understanding of this neonatal pathogen and its adaptation strategies in food production settings.
