Comparative Genotypic and Phenotypic Analysis of Cronobacter Species Cultured from Four Powdered Infant Formula Production Facilities: Indication of Pathoadaptation along the Food Chain.
Cronobacter species are opportunistic pathogens commonly found in the environment. Among the seven Cronobacter species, Cronobacter sakazakii sequence type 4 (ST-4) is predominantly associated with recorded cases of infantile meningitis. This study reports on a 26-month powdered infant formula (PIF) surveillance program in four production facilities located in distinct geographic regions. The objective was to identify the ST(s) in PIF production environments and to investigate the phenotypic features that support their survival. Of all 168 Cronobacter isolates, 133 were recovered from a PIF production environment, 31 were of clinical origin, and 4 were laboratory type strains. Sequence type 1 (n = 84 isolates; 63.9%) was the dominant type in PIF production environments. The majority of these isolates clustered with an indistinguishable pulsotype and persisted for at least an 18-month period. Moreover, DNA microarray results identified two phylogenetic lineages among ST-4 strains tested. Thereafter, the ST-1 and -4 isolates were phenotypically compared. Differences were noted based on the phenotypes expressed by these isolates. The ST-1 PIF isolates produced stronger biofilms at both 28°C and 37°C, while the ST-4 clinical isolates exhibited greater swimming activity and increased binding to Congo red dye. Given the fact that PIF is a low-moisture environment and that the clinical environment provides for an interaction between the pathogen and its host, these differences may be consistent with a form of pathoadaptation. These findings help to extend our current understanding of the epidemiology and ecology of Cronobacter species in PIF production environments.
UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference & Training on Cronobacter, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland.
Qiongqiong
Q
Yan
UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference & Training on Cronobacter, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland.
Juan
J
Wang
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Silver Spring, Maryland, USA.
Jayanthi
J
Gangiredla
UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference & Training on Cronobacter, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland.
Yu
Y
Cao
UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference & Training on Cronobacter, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland.
Marta
M
Martins
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Silver Spring, Maryland, USA.
Gopal R
GR
Gopinath
Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Roger
R
Stephan
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Silver Spring, Maryland, USA.
Keith
K
Lampel
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Silver Spring, Maryland, USA.
Ben D
BD
Tall
UCD Centre for Food Safety, WHO Collaborating Centre for Research, Reference & Training on Cronobacter, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland sfanning@ucd.ie.
Séamus
S
Fanning
D018441:Biofilms / Q000254:growth & development; D059126:Cronobacter / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D004783:Environmental Microbiology; D020387:Food Chain; D005838:Genotype; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D041943:Infant Formula / Q000382:microbiology*; D008124:Locomotion; D046228:Microarray Analysis; D058889:Molecular Typing; D013696:Temperature