Contamination and antibiotic resistance profile of Cronobacter sakazakii isolated from raw milk and infant formula
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Abstract
Background and Objectives: Cronobacter sakazakii is an opportunistic pathogen associated with severe fatal infections. This study aimed to investigate the contamination of raw milk delivered to a powdered milk factory and the produced powdered milk, with C. sakazakii, and also the antibiotic resistance patterns of the isolates.
Materials and Methods: During 2024, 120 raw milk and 60 powdered milk samples were collected from one of the milk powder processing plants in Shahrekord city. A peptone water medium supplemented with nutrients, followed by Cronobacter Selective Broth, was used as the enrichment medium. Chromogenic Cronobacter Isolation (CCI) agar was used to isolate the suspicious colonies. Biochemical tests were performed on the isolates. The PCR test was performed to confirm the molecular identity of the isolates. The antibiogram test was performed using the disk diffusion method on Mueller-Hinton agar.
Results: A total of 14 suspected C. sakazakii colonies were isolated from the raw milk. However, the PCR test confirmed that only 2 isolates (1.67%) were C. sakazakii. Also, the results revealed that none of the powdered milk samples were contaminated with C. sakazakii. The antibiogram test showed that the isolated C. sakazakii were resistant to erythromycin, ampicillin, amoxicillin, cephalexin, and tetracycline antibiotics.
Conclusion: According to the results, some raw milk is contaminated with C. sakazakii, which is resistant to certain common antibiotics. However, contamination with this bacterium was not observed in the powdered milk samples. Given the importance of C. sakazakii in infant health, further studies should be conducted on other powdered milk and infant food supplements produced in Iran to ensure their safety.
2. Bonyadian M, Isvand Haidari F, Sami M. Virulence genes and pulsed-field gel electrophoresis profiles of Shiga toxin-producing Escherichia coli isolated from different food samples and patients with acute diarrhea. Iran J Microbiol 2024; 16: 329-336.
3. M. Farber J, J. Forsythe S. Enterobacter sakazakii. American Soc Microb, ASM Press, 2008; 10-13.
4. Iranian National Standard No. 9430. Food Chain Microbiology - Comprehensive Method for Searching and Identifying Cronobacter Species. Iranian Institute of Standards and Industrial Research. First Revision. 2018.
5. Norberg S, Stanton C, Hill C, F.Fitzgerald G, Ross R.P, Beresford T, et al. Cronobacter spp. in Powdered Infant Formula. J Food Protec 2012; 75: 607-620.
6. Wang X, Ge W, Li K, Xie X, Li ZH, Kim H.R, et al. Prevalence and Characterization of Cronobacter sakazakii in Retail Milk-Based Infant and Baby Foods in Shaanxi, China. Foodborne Pathogen Dis 2016; 13: 222-223.
7. Abbasi Bafitrot S, Goli M, Mumtaz H. Study of the antibiotic resistance pattern of Cronobacter sakazakii isolated from various types of powdered milk and baby food. J Food Microbiol 2016; 4: 41-39.
8. Bar-Oz B, Preminger A, Peleg O. Enterobacter sakazakii infection in the newborn. Acta Paedia 2007; 90: 356-358.
9. Holý O, Parra-Flores J, Lepuschitz S, Paula Alarcón-Lavín M, Cruz-Córdova A, Forsythe S, et al. Molecular Characterization of Cronobacter sakazakii Strains Isolated from Powdered Milk. Foods 2021; 10: 23-31.
10. Pakbin B, Brück W.M, Allahyari S, W. A. Rossen J, Mahmoudi R. Antibiotic Resistance and Molecular Characterization of Cronobacter sakazakii Strains Isolated from Powdered Infant Formula Milk. Foods 2022; 11: 16-24.
11. Van Acker J, Desmet F, Bougatef A, Muyldermans G, Naessens A, et al. Outbreak of Necrotizing Enterocolitis Associated with Enterobacter sakazakii in Powdered Milk Formula. J Clin Microbiol 2001; 39: 293-294.
12. Centers for Disease Control (CDC). Coronobacter Infection. May 2024. https://www.cdc.gov/cronobacter/about/index.html
13. Mardaneh J, Ahmadi K, Farajzadeh Sheikh A, Modarresi F, Shoja S. Detection of Enterobacter sakazakii in newborns with sepsis using PCR on the 16S ribosomal RNA gene. Iran South Med J 2014; 3: 279-272.
14. Fatemizadeh S, Habibi Najafi MM, Sandris Nielsen D. Effect of Lactobacillus plantarum from Mutal cheese on the adhesion of Cronobacter sakazakii to intestinal cells. Iran J Food Sci Technol Res 2023; 19: 557-575.
15. Imm S, Chang Y. Evaluation of the biocontrol potential of a collagen peptide/trehalose-based Cronobacter sakazakii phage powder in rehydrated powdered infant formula. Food Res Int 2023; 1: 12-20.
16. Kim H.R., Kim B.C. Development of multi-reactive aptamers for Cronobacter spp. Using the sequential partitioning method to detect them in powdered infant formula. Analytica Chim Acta 2023; 1223: 340935.
17. Kashef S, Pishvan N. Investigation of necrotizing enterocolitis cases in neonates hospitalized in neonatal intensive care units affiliated with Shiraz University of Medical Sciences. J Med Res 2002; 1: 27-32.
18. Shakeir AJ, Albadry B, Naeem Abid I, Hafedh Hussein M. Diagnosis of Enterobacter sakazakii from Samples of Infant Milk, Stool, and Haboubi Hospital Environment in DHI QAR Province and Study the Sensitivity for some Antibiotics. Trop J Pharma Res 2015; 4: 2524-2531.
19. Jamshidi A, Vakili R, Seifi H, Hajizadeh J. Study of changes in microbial load of raw milk and its related factors from the milking place to the milk collection station in Esfarayen region. Food Heal 2012; 2: 81-87.
20. Ezzat Panah H. Evaluation of microbial load of raw milk produced by several semi-industrial livestock farms in Hamedan province. J Food Sci 2006; 3: 57-62.
21. Karim G. Milk Health and Technology. First edition. Tehran University Press, 2007.
22. Male J. Cronobacter sakazakii: A foodborne pathogenic bacterium in immunocompromised and hospitalized patients. Ofogh 2021; 27: 279-275.
23. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. CLSI Approved Standard 2018, M100-S15.
24. Quigley L, O’Sullivan O, Stanton C, P. Beresford T, Ross R.P, F. Fitzgerald G, et al. The complex microbiota of raw milk. FEMS Microbiol Rev 2013; 37: 664-698.
25. Yu S, Yan L, Wu X, Li F, Wang D, Xu H. Multiplex PCR coupled with propidium monoazide for the detection of viable Cronobacter sakazakii, Bacillus cereus, and Salmonella spp. in milk and milk products. J Dairy Sci 2017; 100: 7874-7882.
26. Tutar E, Sueda Akinci K, Akyol I. Development and application of a new multiplex real-time PCR assay for simultaneous identification of Brucella melitensis, Cronobacter sakazakii, and Listeria monocytogenes in raw milk and cheese. Int J Dairy Tech 2018; 71: 1-4.
27. Stevens M, Cernela N, Stephan R, Lehner A. Comparative genomics of Cronobacter sakazakii strains from a powdered infant formula plant reveals evolving populations. LWT 2023; 184: 115034.
28. El.Gamal M.S., El Dairouty R.K., Okda A.Y., H. Salah S, El-Shamy S.M. Incidence and Interrelation of Cronobacter sakazakii and Other Foodborne Bacteria in Some Milk Products and Infant Formula Milks in Cairo and Giza Area. World Appl Sci J 2013; 26: 1129-1141.
29. Lucey JA. Raw Milk Consumption: Risks and Benefits. Nutr Food Sci 2015; 50: 189-193.
30. Zink D, Bowen A, Cook P, Campbell D, Cordier J.L, Fein S, et al. Enterobacter sakazakii (Cronobacter spp.) in powdered follow-up formula: Meeting Report. Department of Food Safety, Zoon Foodborne Dis, 2008; 16-90. http://www.who.int/foodsafety
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| Issue | Vol 18 No 2 (2026) | |
| Section | Original Article(s) | |
| Keywords | ||
| Raw milk Antibiotic resistance Cronobacter sakazakii Infant formula | ||
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