Contamination, persistence and dissemination of Chronobacter during the production of powdered infant formula in China in 2016

Main Article Content

Xin Gan
Baowei Yang
Xiaofei Wang
Yinping Dong
Yujie Hu
Jin Xu
Fengqin Li


Cronobacter, Powdered infant formula, biofilm, PFGE


A total of 620 samples collected from two factories in China producing powdered infant formula (PIF) between July and November 2016 were analyzed for Cronobacter. Antimicrobial susceptibility, pulsed-field gel electropho-resis (PFGE), and biofilm formation of Cronobacter were carried out. The results showed that 2.26% samples were positive for Cronobacter among the 33 isolates that were identified. All Cronobacter isolates were susceptible to 12 antimicrobial agents tested except one isolate which showed intermediate resistance to Chloramphenicol. PFGE analysis showed that nine clusters comprising the 33 isolates were identified, among which C8, C4, and C5 were the predominant types. All 33 isolates were capable of forming biofilm, and particularly, C. malonaticus isolates showed a good biofilm-forming ability at both 28°C and 37°C. The results illustrated that it is necessary for PIF manufactures to develop control measures for reducing Cronobacter contamination and its associated foodborne illness among infants.

Abstract 43 | PDF Downloads 11 XML Downloads 0 HTML Downloads 1


Chen, Z., L. Ren, and L. Ma. 2011. Analysis on the antimicrobial susceptibility testing of enterobacter sakazakii isolated from xinjiang. Mod. Prev. Med. 38:3539-3541.
Chenu, J. W., and J. M. Cox. 2009. Cronobacter (‘Enterbacter sakazakii’): current status and future prospects. Lett. Appl. Microbiol. 49:153–159. doi: 10.1111/j.1472-765X.2009.02651.x
Choi, Y., S. Kim, H. Hwang, K. P. Kim, and S. Ryu. 2014. Plasmid-encoded mcp is involved in virulence, motility, and biofilm formation of Cronobacter sakazakii ATCC 29544. Infect. Immun. 83:197-204. doi: 10.1128/iai.02633-14
Dancer, G. I., J. H. Mah, M. S. Rhee, I. G. Hwang, and D. H. Kang. 2009. Resistance of Enterbacter sakazakii (Cronobacter spp.) to environmental stresses. J. Appl. Microbiol. 107:1606-1614. doi: 10.1111/j.1365-2672.2009.04347.x
Fei, P., C. Man, B. Lou, S. J. Forsythe, Y. Chai, R. Li, J. Niu, and Y. Jiang. 2015. Genotyping and source tracking of cronobacter sakazakii and c. malonaticus isolates from powdered infant formula and an infant formula production factory in china. Appl. Environ. Microb. 81:5430-5439. doi: 10.1128/AEM.01390-15
Fei, P., Y. Jiang, Y. Jiang, X. Yuan, T. Yang, J. Chen, Z. Wang, H. Kang, and S. J. Forsythe. 2017. Prevalence, molecular characterization, and antibiotic susceptibility of cronobacter sakazakii isolates from powdered infant formula collected from chinese retail markets. Front Microbiol. 8:2026. doi: 10.3389/fmicb.2017.02026
Forsythe, S. J. 2018. Updates on the Cronobacter Genus. Annu. Rev. Food Sci. T. 9:23-44. doi: 10.1146/annurev-food-030117-012246
Friedemann, M. 2008. Enterobacter sakazakii in powdered infant formula. Bundesgesundheitsbla. 51:664-674. doi: 10.1007/s00103-008-0543-4
Gan, X., L. Bai, S. Yan, J. Wang, W. Wang, Z. Li, J. Zhang, F. Li, and J. Xu. 2015. Drug resistant analysis of Cronobacter isolated from infant foods in 2012-2014 in China. J. Food Saf. Qual. 6:3491-3496.
Gan, X., Y. Dong, S. Yan, Y. Hu, F. Séamus, J. Wang, and F. Li. 2018. Contamination and characterization of multiple pathogens in powdered formula at retail collected between 2014 and 2015 in China. Food Control. 87:40-45. doi: 10.1016/j.foodcont.2017.12.014
GB4789.40. 2016. Cronobacter. National food safety standard Food microbiological examination.
Gu, M., W. Han, and J. Yang. 2008. Study on antibiotic resistance of Enterobacter sakazakii isolated from imported dairy product. J. Inspe. Quar. 21:14-16. doi: 10.3969/j.issn.1674-5354.2008.01.005
Gurtler, J. B., and L. R. Beuchat. 2007. Survival of enterobacter sakazakii in powdered infant formula as affected by composition, water activity, and temperature. J. Food Protect. 70:1579. doi: 10.1016/j.jfoodeng.2006.05.001
Iversen, C., M. Lane, and S. J. Forsythe. 2004. The growth profile, thermotolerance and biofilm formation of Enterbacter sakazakii grown in infant formula milk. Lett. Appl. Microbiol. 38:378-382. doi: 10.1111/j.1472-765X.2004.01507.x
Jaradat, Z. W., M. W. Al, A. Elbetieha, N. A. Al, and B. D. Tall. 2014. Cronobacter spp.- opportunistic foodborne pathogens. A review of their virulence and environmental-adaptive traits. J. Med. Microbiol. 63: 1023-1037. doi: 10.1099/jmm.0.073742-0
Jason, J. 2015. The roles of epidemiologists, laboratorians, and public health agencies in preventing invasive Cronobacter infection. Front Pediatr. 3:110. doi: 10.3389/fped.2015.00110
Kalyantanda, G., L. Shumyak, and L. K. Archibald. 2015. Cronobacter Species Contamination of Powdered Infant Formula and the Implications for Neonatal Health. Front Pediatr. 3:56. doi: 10.3389/fped.2015.00056
Lee, Y. D., J. H. Park, and H. I. Chang. 2012. Detection, antibiotic susceptibility and biofilm formation of cronobacter spp. from various foods in Korea. Food Control. 24:225-230. doi: 10.1016/j.foodcont.2011.09.023
Lehner, A., C. Fricker-Feer, and R. Stephan. 2012. Identification of the recently described Cronobacter condiment by an rpoB-gene-based PCR system. J. Med. Microbiol. 61:1034-1035. doi: 10.1099/jmm.0.042903-0
Ling, N., C. Li, J. Zhang, Q. Wu, H. Zeng, W. He, Y. Ye, J. Wang, Y. Ding, M. Chen, L. Xue, Q. Ye, and W. Guo. 2018. Prevalence and Molecular and Antimicrobial Characteristics of Cronobacter spp. Isolated From Raw Vegetables in China. Front Microbiol. 9:1149. doi: 10.3389/fmicb.2018.01149
Liu, Y., Q. Gao, X. Zhang, Y. Hou, J. Yang, and X. Huang. 2006. PCR and oligonucleotide array for detection of Enterobacter sakazakii in infant formula. Mol. Cell Probe. 20:11-17. doi: 10.1016/j.mcp.2005.08.004
Martins, M., M. P. Mccusker, E. M. Mccabe, D. O'Leary, G. Duffy, and F. Séamus. 2013. Evidence of metabolic switching and implications for food safety from the phenome(s) of salmonella enterica serovar typhimurium dt104 cultured at selected points across the pork production food chain. Appl. Environ. Microb. 79:5437-5449. doi: 10.1128/AEM.01041-13
Pei, X., Y. Guo, J. Xu, and X. Liu. 2007. Antibiotic susceptibility of enterobacter sakazakii isolated from powdered formula for infant and young children. J. Hygiene Res. 36:63-65. doi: 10.1016/S1672-6529(07)60007-9
Römling, U., and C. Balsalobre. 2012. Biofilm infections, their resilience to therapy and innovative treatment strategies. J. Intern. Med. 272:541-561. doi: 10.1111/joim.12004
Stoop, B., A. Lehner, C. Iversen, S. Fanning, and R. Stephan. 2009. Development and evaluation of rpob based pcr systems to differentiate the six proposed species within the genus Cronobacter. Int. J. Food Microbiol. 136:165-168. doi: 10.1016/j.ijfoodmicro.2009.04.023
Ueda, S. 2017. The Effects of Temperature on the Growth and Heat Resistance of Cronobacter spp.. Biocontrol Sci. 22:125-129. doi: 10.4265/bio.22.125
Yan, Q., J. Wang, J. Gangiredla, Y. Cao, M. Martins, G. R. Gopinath, R. Stephan, K. Lampel, B. D. Tall, and S. Fanning. 2015. Comparative genotypic and phenotypic analysis of cronobacter species cultured from four powdered infant formula production facilities: indication of pathoadaptation along the food chain. Appl. Environ. Microb. 81:4388-402. doi: 10.1128/AEM.00359-15