Prevalence, Distribution, and Comparative Genomics of a Hemolysin III Gene (COG1272) and Related Hemolysin Genes among <i>Cronobacter</i> spp.

Lee, ChaeYoon; Lee, ChaeYoon

Tuesday, July 11, 2017

Exhibit Hall (Tampa Convention Center)

ChaeYoon Lee , U.S. Food and Drug Administration , Laurel , MD

HyeJin Jeong , U.S. Food and Drug Administration , Laurel , MD

HaNa Kwon , U.S. Food and Drug Administration , Laurel , MD

Kyuyoung Han , U.S. Food and Drug Administration , Laurel , MD

SeonJu Choi , U.S. Food and Drug Administration , Laurel , MD

SoHyun Kim , U.S. Food and Drug Administration , Laurel , MD

Jeong Woo Lee , U.S. Food and Drug Administration , Laurel , MD

Jung Youn Do , U.S. Food and Drug Administration , Laurel , MD

Samantha Finkelstein , U.S. Food and Drug Administration , Laurel , MD

Flavia Negrete , U.S. Food and Drug Administration , Laurel , MD

Hannah Chase , U.S. Food and Drug Administration , Laurel , MD

Isha Patel , U.S. Food and Drug Administration , Laurel , MD

Jayanthi Gangiredla , U.S. Food and Drug Administration , Laurel , MD

Gopal Gopinath , U.S. Food and Drug Administration , Laurel , MD

Ben Tall , U.S. Food and Drug Administration , Laurel , MD

Introduction: The Cronobacter genus is comprised of C. sakazakii (Csak), C. malonaticus (Cmal), C. turicensis (Ctur), C. universalis (Cuni), C. condimenti (Ccon), C. muytjensii (Cmuy) and C. dublinensis (Cdub); all of these except for Ccon, can cause foodborne infections. Several studies predict that Cronobacter spp. possess a hemolysin III homolog (COG1272) which is thought to play a role in pathogenesis. However, its prevalence and phylogenetic relatedness among Cronobacter species are not well studied.

Purpose: In an effort to better understand the prevalence and phylogenetic relatedness of COG1272, 388 Cronobacter strains were analyzed by PCR, DNA microarray (MA), and whole genome sequencing (WGS) analyses.

Methods: Strains were identified using species-specific PCR assays targeting rpoB and cgcA genes. PCR and MA analyses were performed using previously published primers and a pan-genomic DNA microarray. WGS was conducted using a MiSeq platform with Nextera chemistry.

Results: PCR analysis showed that COG1272 was present in 285/298 (95.6%) Csak strains; 3/7 (42.9%) Cmuy strains; 13/33 (39.4%) Cmal strains; 3/12 (25%) Ctur strains; 4/37 (10.8%) Cdub; and 1/1 Cuni strains, respectively. Ccon was PCR-negative for COG1272. However, MA and WGS showed that Ccon possessed a COG1272 orthologue, but Cuni did not. MA also showed the presence of 27 other hemolysin-related alleles which suggest that the PCR result for Cuni identified a related hemolysin, not COG1272.

Significance: Previously, prevalence of COG1272 was unknown due to the use of less specific identification techniques (i.e., amplification of 16s rDNA). In the current study, we show that COG1272 is present in all Cronobacter species except for Cuni. Through the use of MA and WGS, in addition to COG1272, 27 other hemolysin-related genes were found. The current study establishes a powerful platform for further genomics research of this genus, a prerequisite towards development of future countermeasures for this important foodborne pathogen.

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P2-157 Prevalence, Distribution, and Comparative Genomics of a Hemolysin III Gene (COG1272) and Related Hemolysin Genes among Cronobacter spp.