High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank
<i>Bacillus cereus</i> poses a persistent challenge for human milk banks (HMBs) due to its ability to survive Holder pasteurization (HoP; 62.5 °C for 30 min). To ensure neonatal safety, any milk found to be contaminated post-HoP must be discarded, which impacts milk supply and adds to th...
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| Language: | English |
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MDPI AG
2025-05-01
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| Online Access: | https://www.mdpi.com/2076-2607/13/5/1136 |
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| author | Mathew Gene Jennifer L. Guthrie Kevin Li Sarah Teatero Aimee Paterson Angel Li Alain Doyen Deborah Yamamura Sarah Khan Jocelyn A. Srigley Debbie Stone Deborah L. O’Connor Susan Poutanen Sharon Unger Allison McGeer Nahuel Fittipaldi |
| author_facet | Mathew Gene Jennifer L. Guthrie Kevin Li Sarah Teatero Aimee Paterson Angel Li Alain Doyen Deborah Yamamura Sarah Khan Jocelyn A. Srigley Debbie Stone Deborah L. O’Connor Susan Poutanen Sharon Unger Allison McGeer Nahuel Fittipaldi |
| author_sort | Mathew Gene |
| collection | DOAJ |
| description | <i>Bacillus cereus</i> poses a persistent challenge for human milk banks (HMBs) due to its ability to survive Holder pasteurization (HoP; 62.5 °C for 30 min). To ensure neonatal safety, any milk found to be contaminated post-HoP must be discarded, which impacts milk supply and adds to the operational demands of HMBs. In this study, we analyzed 688 <i>B. cereus</i> isolates from human milk (pre- and post-HoP), as well as from patient and environmental sources, to investigate human milk contamination by <i>B. cereus</i> at a Canadian HMB. Despite the limited temporal and geographic scope of the collection, the isolates exhibited remarkable genomic diversity, comparable to global <i>B. cereus</i> collections. Phylogenetic analysis at the core genome level revealed no clear clustering by isolate source, suggesting multifactorial pathways of <i>B. cereus</i> contamination. Isolates surviving HoP displayed gene variants linked to sporulation and cell wall integrity, suggesting a potential basis for HoP tolerance. Our findings emphasize that while genomic analyses offer major valuable insights, they alone are insufficient to address the complexities of <i>B. cereus</i> contamination in HMBs. Addressing this challenge will require combining genomic tools with robust monitoring systems, improved human milk-handling protocols, and pasteurization strategies better-suited to countering <i>B. cereus</i> resilience. |
| format | Article |
| id | doaj-art-bcddda7f685a48348e151ce978ec5f77 |
| institution | Kabale University |
| issn | 2076-2607 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj-art-bcddda7f685a48348e151ce978ec5f772025-08-20T03:47:54ZengMDPI AGMicroorganisms2076-26072025-05-01135113610.3390/microorganisms13051136High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk BankMathew Gene0Jennifer L. Guthrie1Kevin Li2Sarah Teatero3Aimee Paterson4Angel Li5Alain Doyen6Deborah Yamamura7Sarah Khan8Jocelyn A. Srigley9Debbie Stone10Deborah L. O’Connor11Susan Poutanen12Sharon Unger13Allison McGeer14Nahuel Fittipaldi15Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, CanadaPublic Health Ontario, Toronto, ON M5G 1M1, CanadaGREMIP and CRIPA, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC J2S 2M2, CanadaPublic Health Ontario, Toronto, ON M5G 1M1, CanadaSinai Health System, Toronto, ON M5G 1X5, CanadaSinai Health System, Toronto, ON M5G 1X5, CanadaDepartment of Food Sciences, Institute of Nutrition and Functional Foods (INAF) and Dairy Science and Technology Research Center (STELA), Laval University, Quebec City, QC G1V 0A6, CanadaMicrobiology Department, Hamilton General Hospital, Hamilton, ON L8L 2X2, CanadaDivision of Pediatric Infectious Diseases, McMaster Children’s Hospital, Hamilton Health Sciences, Hamilton, ON L8N 3Z5, CanadaDepartment of Pathology & Laboratory Medicine, BC Children’s Hospital & BC Women’s Hospital + Health Centre, Vancouver, BC V6H 3N1, CanadaSinai Health System, Toronto, ON M5G 1X5, CanadaDepartment of Nutritional Sciences, University of Toronto, Toronto, ON M5G 1A8, CanadaSinai Health System, Toronto, ON M5G 1X5, CanadaThe Rogers Hixon Ontario Human Milk Bank, Toronto, ON M5G 1X5, CanadaSinai Health System, Toronto, ON M5G 1X5, CanadaPublic Health Ontario, Toronto, ON M5G 1M1, Canada<i>Bacillus cereus</i> poses a persistent challenge for human milk banks (HMBs) due to its ability to survive Holder pasteurization (HoP; 62.5 °C for 30 min). To ensure neonatal safety, any milk found to be contaminated post-HoP must be discarded, which impacts milk supply and adds to the operational demands of HMBs. In this study, we analyzed 688 <i>B. cereus</i> isolates from human milk (pre- and post-HoP), as well as from patient and environmental sources, to investigate human milk contamination by <i>B. cereus</i> at a Canadian HMB. Despite the limited temporal and geographic scope of the collection, the isolates exhibited remarkable genomic diversity, comparable to global <i>B. cereus</i> collections. Phylogenetic analysis at the core genome level revealed no clear clustering by isolate source, suggesting multifactorial pathways of <i>B. cereus</i> contamination. Isolates surviving HoP displayed gene variants linked to sporulation and cell wall integrity, suggesting a potential basis for HoP tolerance. Our findings emphasize that while genomic analyses offer major valuable insights, they alone are insufficient to address the complexities of <i>B. cereus</i> contamination in HMBs. Addressing this challenge will require combining genomic tools with robust monitoring systems, improved human milk-handling protocols, and pasteurization strategies better-suited to countering <i>B. cereus</i> resilience.https://www.mdpi.com/2076-2607/13/5/1136<i>Bacillus cereus</i>human milk bank and hospitalhuman milkholder pasteurizationcontamination routesgenetic diversity |
| spellingShingle | Mathew Gene Jennifer L. Guthrie Kevin Li Sarah Teatero Aimee Paterson Angel Li Alain Doyen Deborah Yamamura Sarah Khan Jocelyn A. Srigley Debbie Stone Deborah L. O’Connor Susan Poutanen Sharon Unger Allison McGeer Nahuel Fittipaldi High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank Microorganisms <i>Bacillus cereus</i> human milk bank and hospital human milk holder pasteurization contamination routes genetic diversity |
| title | High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank |
| title_full | High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank |
| title_fullStr | High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank |
| title_full_unstemmed | High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank |
| title_short | High Genetic Diversity Among <i>Bacillus cereus</i> Isolates Contaminating Donated Milk at a Canadian Human Milk Bank |
| title_sort | high genetic diversity among i bacillus cereus i isolates contaminating donated milk at a canadian human milk bank |
| topic | <i>Bacillus cereus</i> human milk bank and hospital human milk holder pasteurization contamination routes genetic diversity |
| url | https://www.mdpi.com/2076-2607/13/5/1136 |
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