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Xue J, Lv J, Liu L, Duan F, Shi A, Ji X, Ding L. Maltodextrin-binding protein as a key factor in Cronobacter sakazakii survival under desiccation stress. Food Res Int 2024; 177:113871. [PMID: 38225116 DOI: 10.1016/j.foodres.2023.113871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/07/2023] [Accepted: 12/14/2023] [Indexed: 01/17/2024]
Abstract
Cronobacter sakazakii (C. sakazakii) is a notorious pathogen responsible for infections in infants and newborns, often transmitted through contaminated infant formula. Despite the use of traditional pasteurization methods, which can reduce microbial contamination, there remains a significant risk of pathogenic C. sakazakii surviving due to its exceptional stress tolerance. In our study, we employed a comparative proteomic approach by comparing wild-type strains with gene knockout strains to identify the essential genes crucial for the successful survival of C. sakazakii during desiccation. Our investigation revealed the significance of envZ-ompR, recA, and flhD gene cassettes in contributing to desiccation tolerance in C. sakazakii. Furthermore, through our comparative proteomic profiling, we identified the maltodextrin-binding protein encoded by ESA_03421 as a potential factor influencing dry tolerance. This protein is regulated by EnvZ-OmpR, RecA, and FlhD. Notably, the knockout of ESA_03421 resulted in a 150% greater reduction in Log CFU compared to the wild-type C. sakazakii. Overall, our findings offer valuable insights into the mechanisms underlying C. sakazakii desiccation tolerance and provide potential targets for the development of new antimicrobial strategies aimed at reducing the risk of infections in infants and newborns.
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Affiliation(s)
- Juan Xue
- Institute of Infection and Immunity, Department of Neurology, Department of Critical Care Medicine,Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Jun Lv
- Institute of Infection and Immunity, Department of Neurology, Department of Critical Care Medicine,Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Lanfang Liu
- Shiyan Center for Disease Control and Prevention, Shiyan, Hubei, China
| | - Fangfang Duan
- Institute of Infection and Immunity, Department of Neurology, Department of Critical Care Medicine,Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Aiying Shi
- School of Medicine, Nankai University, Tianjin, China
| | - Xuemeng Ji
- School of Medicine, Nankai University, Tianjin, China.
| | - Li Ding
- Institute of Infection and Immunity, Department of Neurology, Department of Critical Care Medicine,Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China.
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Chauhan R, Tall BD, Gopinath G, Azmi W, Goel G. Environmental risk factors associated with the survival, persistence, and thermal tolerance of Cronobacter sakazakii during the manufacture of powdered infant formula. Crit Rev Food Sci Nutr 2023; 63:12224-12239. [PMID: 35838158 DOI: 10.1080/10408398.2022.2099809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cronobacter sakazakii is an opportunistic foodborne pathogen of concern for foods having low water activity such as powdered infant formula (PIF). Its survival under desiccated stress can be attributed to its ability to adapt effectively to many different environmental stresses. Due to the high risk to neonates and its sporadic outbreaks in PIF, C. sakazakii received great attention among the scientific community, food industry and health care providers. There are many extrinsic and intrinsic factors that affect C. sakazakii survival in low-moisture foods. Moreover, short- or long-term pre-exposure to sub-lethal physiological stresses which are commonly encountered in food processing environments are reported to affect the thermal resistance of C. sakazakii. Additionally, acclimation to these stresses may render C. sakazakii resistance to antibiotics and other antimicrobial agents. This article reviews the factors and the strategies responsible for the survival and persistence of C. sakazakii in PIF. Particularly, studies focused on the influence of various factors on thermal resistance, antibiotic or antimicrobial resistance, virulence potential and stress-associated gene expression are reviewed.
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Affiliation(s)
- Rajni Chauhan
- Department of Biotechnology, Himachal Pradesh University, Shimla, India
| | | | - Gopal Gopinath
- Center for Food Safety and Applied Nutrition, U. S. Food and Drug Administration, Laurel, MD, USA
| | - Wamik Azmi
- Department of Biotechnology, Himachal Pradesh University, Shimla, India
| | - Gunjan Goel
- Department of Microbiology, School of Interdisciplinary and Applied Sciences, Central University of Haryana, Mahindra, India
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Cechin CDF, Carvalho GG, Bastos CP, Kabuki DY. Cronobacter spp. in foods of plant origin: occurrence, contamination routes, and pathogenic potential. Crit Rev Food Sci Nutr 2023; 63:12398-12412. [PMID: 35866516 DOI: 10.1080/10408398.2022.2101426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cronobacter is an emerging bacterial pathogen associated with infections such as necrotizing enterocolitis, sepsis, and meningitis in neonates and infants, related to the consumption of powdered infant formula. In addition, this bacterium can also cause infections in adults by the ingestion of other foods. Thus, this review article aims to report the occurrence and prevalence of Cronobacter spp. in foods of plant origin, as well as the possible sources and routes of contamination in these products, and the presence of pathogenic strains in these foods. Cronobacter was present in a wide variety of cereal-based foods, vegetables, herbs, spices, ready-to-eat foods, and foods from other categories. This pathogen was also found in cultivation environments, such as soils, compost, animal feces, rice and vegetable crops, as well as food processing industries, and domestic environments, thus demonstrating possible contamination routes. Furthermore, sequence types (ST) involved in clinical cases and isolates resistant to antibiotics were found in Cronobacter strains isolated from food of plant origin. The identification of Cronobacter spp. in plant-based foods is of great importance to better elucidate the vehicles and routes of contamination in the primary production chain and processing facility, until the final consumption of the food, to prevent infections.
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Affiliation(s)
- Carine da Fonseca Cechin
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Gabriela Guimarães Carvalho
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Caroline Peixoto Bastos
- Center of Chemical, Pharmaceutical and Food Sciences, Federal University of Pelotas (UFPel), Pelotas, Rio Grande do Sul, Brazil
| | - Dirce Yorika Kabuki
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Mousavi ZE, Hunt K, Koolman L, Butler F, Fanning S. Cronobacter Species in the Built Food Production Environment: A Review on Persistence, Pathogenicity, Regulation and Detection Methods. Microorganisms 2023; 11:1379. [PMID: 37374881 DOI: 10.3390/microorganisms11061379] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
The powdered formula market is large and growing, with sales and manufacturing increasing by 120% between 2012 and 2021. With this growing market, there must come an increasing emphasis on maintaining a high standard of hygiene to ensure a safe product. In particular, Cronobacter species pose a risk to public health through their potential to cause severe illness in susceptible infants who consume contaminated powdered infant formula (PIF). Assessment of this risk is dependent on determining prevalence in PIF-producing factories, which can be challenging to measure with the heterogeneity observed in the design of built process facilities. There is also a potential risk of bacterial growth occurring during rehydration, given the observed persistence of Cronobacter in desiccated conditions. In addition, novel detection methods are emerging to effectively track and monitor Cronobacter species across the food chain. This review will explore the different vehicles that lead to Cronobacter species' environmental persistence in the food production environment, as well as their pathogenicity, detection methods and the regulatory framework surrounding PIF manufacturing that ensures a safe product for the global consumer.
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Affiliation(s)
- Zeinab Ebrahimzadeh Mousavi
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
- Department of Food Science and Engineering, Faculties of Agriculture and Natural Resources, University of Tehran, Karaj 6719418314, Iran
| | - Kevin Hunt
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
| | - Leonard Koolman
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Francis Butler
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
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Li H, Zhao Y, Zhang J, Li W, You Q, Zeng X, Xu H. Silver nanoparticles reduce the tolerance of Cronobacter sakazakii to environmental stress by inhibiting expression of related genes. J Dairy Sci 2022; 105:6469-6482. [PMID: 35840406 DOI: 10.3168/jds.2022-21833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/25/2022] [Indexed: 11/19/2022]
Abstract
Cronobacter sakazakii is a food-borne pathogen that is resistant to a variety of environmental stress conditions. It can survive in harsh environments. We studied the effects of silver nanoparticles (AgNP) on the environmental tolerance and biofilm formation of C. sakazakii. First, we determined the minimum inhibitory concentration (MIC) of AgNP to C. sakazakii and determined the growth curve of C. sakazakii treated with different concentrations of AgNP by using the plate counting method. After determining the sub-inhibition concentrations (SIC) of AgNP on C. sakazakii, we studied the effects of AgNP on the resistance of C. sakazakii to heat, desiccation, osmotic pressure, and acid. The antibiofilm activity of AgNP was also studied. Finally, real-time quantitative PCR was used to analyze the transcription levels of 16 genes related to the environmental tolerance of C. sakazakii. The SIC of AgNP significantly reduced the survival rate of C. sakazakii under various environmental stress conditions. The results showed that AgNP at 0.625 and 1.25 μg/mL significantly inhibited the formation of C. sakazakii biofilms. The expression levels of most genes were significantly downregulated in C. sakazakii cells treated with 0.625 and 1.25 μg/mL AgNP. Therefore, AgNP may reduce the environmental tolerance of C. sakazakii by inhibiting the expression of genes related to stress tolerance. Moreover, AgNP inhibited the production of ATP in C. sakazakii cells and the formation of C. sakazakii biofilms. Our research provides a theoretical basis for the application of AgNP in food packaging, bactericidal coatings, and other fields.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Yi Zhao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Jingjing Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Wen Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Qixiu You
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Xianxiang Zeng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Hengyi Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China.
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Michael M, Acuff JC, Vega D, Sekhon AS, Channaiah LH, Phebus RK. Survivability and thermal resistance of Salmonella and Escherichia coli O121 in wheat flour during extended storage of 360 days. Int J Food Microbiol 2022; 362:109495. [PMID: 34872756 DOI: 10.1016/j.ijfoodmicro.2021.109495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/15/2022]
Abstract
Foodborne pathogens like Salmonella and Escherichia coli O121 can endure the harsh low water activity (aw) environment of wheat flour for elongated periods of time and can proliferate when hydrated for baking or other purposes. This study determined the survivability and thermal tolerance (D- and z-values) of Salmonella and Escherichia coli O121 in wheat flour and muffin batter (prepared from inoculated flour on the days of analyses) during the storage period of 360 days. The Salmonella and E. coli O121 studies were conducted as two independent experiments. Both studies were designed as randomized complete block with three replications as blocks. All experimental data were analyzed using one-way ANOVA and Tukey's test in Minitab® software, and P ≤ 0.05 was considered significant. The wheat flour was spray inoculated individually with 7-isolate Salmonella or 3-isolate E. coli O121 cocktail and then dried back to the original aw levels. On each analysis day, inoculated wheat flour (~5 g) or muffin batter (~2.5 g) was placed inside the TDT disks, heat treated at set temperatures in hot water baths, and sampled at predetermined time intervals for determining the survival microbial population. The population of E. coli O121 and Salmonella cocktails in wheat flour at day 1 were 7.6 ± 0.18 and 7.8 ± 0.07 log CFU/g, respectively, which decreased to 2.0 ± 0.40 and 2.8 ± 0.59 log CFU/g on day 360, respectively. The D-values of Salmonella and E. coli O121 cocktails in inoculated flour and muffin batter prepared from inoculated flour (on the day of analysis) were determined on days 1, 30, 90, 180, 270, and 360 [given enough surviving bacterial population (~3 to 4 log CFU/g) was present in the flour]. The population of Salmonella and E. coli O121 in wheat flour decreased by 5.0 and 5.6 log CFU/g, respectively, during the storage period of 360 days. The D70°C, D75°C, and D80°C values of Salmonella in wheat flour remained similar during the storage period. Whereas, for E. coli O157:H7 in wheat flour, the D70°C value decreased from 20.3 ± 2.82 to 7.1 ± 2.82 min, and D75°C decreased from 10.2 ± 2.14 to 2.7 ± 0.27 min, during the storage period of 180 days. The z-values of Salmonella or E. coli O157:H7 remained similar during the storage period. The D- and z-values from this research can be employed for validation of thermal process to ensure safety of wheat flour.
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Affiliation(s)
- Minto Michael
- School of Food Science, Food Science and Human Nutrition Building, Washington State University, Pullman, WA 99164, USA.
| | - Jennifer C Acuff
- Food Science Department, University of Arkansas, Fayetteville, AR 72704, USA
| | - Daniel Vega
- Food Science Institute, Call Hall, Kansas State University, Manhattan, KS 66506, USA
| | - Amninder S Sekhon
- School of Food Science, Food Science and Human Nutrition Building, Washington State University, Pullman, WA 99164, USA
| | | | - Randall K Phebus
- Food Science Institute, Call Hall, Kansas State University, Manhattan, KS 66506, USA
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Espinosa MF, Sancho AN, Mendoza LM, Mota CR, Verbyla ME. Systematic review and meta-analysis of time-temperature pathogen inactivation. Int J Hyg Environ Health 2020; 230:113595. [DOI: 10.1016/j.ijheh.2020.113595] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/04/2020] [Accepted: 07/06/2020] [Indexed: 11/16/2022]
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Zhang Y, Xie Y, Tang J, Wang S, Wang L, Zhu G, Li X, Liu Y. Thermal inactivation of Cronobacter sakazakii ATCC 29544 in powdered infant formula milk using thermostatic radio frequency. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107270] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Awadallah MA, Ahmed HA, Merwad AM, Abou Elez RM, Saleh KM. Molecular Characterization ofCronobacter sakazakiiin Egypt, Survival and Thermoresistance at Different Temperatures: A Potential Public Health Risk. Vector Borne Zoonotic Dis 2018; 18:101-107. [DOI: 10.1089/vbz.2017.2169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Maysa A.I. Awadallah
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Heba A. Ahmed
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Abdallah M.A. Merwad
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Rasha M.M. Abou Elez
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Karem M.A. Saleh
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
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Lambertini E, Buchanan RL, Narrod C, Pradhan AK. Transmission of Bacterial Zoonotic Pathogens between Pets and Humans: The Role of Pet Food. Crit Rev Food Sci Nutr 2015; 56:364-418. [DOI: 10.1080/10408398.2014.902356] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Huertas JP, Álvarez-Ordóñez A, Morrissey R, Ros-Chumillas M, Esteban MD, Maté J, Palop A, Hill C. Heat resistance of Cronobacter sakazakii DPC 6529 and its behavior in reconstituted powdered infant formula. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.01.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Michael M, Phebus R, Thippareddi H, Subbiah J, Birla S, Schmidt K. Validation of radio-frequency dielectric heating system for destruction of Cronobacter sakazakii and Salmonella species in nonfat dry milk. J Dairy Sci 2014; 97:7316-24. [DOI: 10.3168/jds.2013-7862] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 08/19/2014] [Indexed: 11/19/2022]
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Fakruddin M, Rahaman M, Ahmed MM, Hoque MM. Stress tolerant virulent strains of Cronobacter sakazakii from food. Biol Res 2014; 47:63. [PMID: 25723712 PMCID: PMC4335510 DOI: 10.1186/0717-6287-47-63] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 11/10/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cronobacter sakazakii is considered as an emerging foodborne pathogen. The aim of this study was to isolate and characterize virulent strains of Cronobacter sakazakii from food samples of Bangladesh. RESULT Six (6) Cronobacter sakazakii was isolated and identified from 54 food samples on the basis of biochemical characteristics, sugar fermentation, SDS-PAGE of whole cell protein, plasmid profile and PCR of Cronobacter spp. specific genes (esak, gluA, zpx, ompA, ERIC, BOX-AIR) and sequencing. These strains were found to have moderately high antibiotic resistance against common antibiotics and some are ESBL producer. Most of the C. sakazakii isolates were capable of producing biofilm (strong biofilm producer), extracellular protease and siderophores, curli expression, haemolysin, haemagglutinin, mannose resistant haemagglutinin, had high cell surface hydrophobicity, significant resistance to human serum, can tolerate high concentration of salt, bile and DNase production. Most of them produced enterotoxins of different molecular weight. The isolates pose significant serological cross-reactivity with other gram negative pathogens such as serotypes of Salmonella spp., Shigella boydii, Shigella sonnei, Shigella flexneri and Vibrio cholerae. They had significant tolerance to high temperature, low pH, dryness and osmotic stress. CONCLUSION Special attention should be given in ensuring hygiene in production and post-processing to prevent contamination of food with such stress-tolerant virulent Cronobacter sakazakii.
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Affiliation(s)
- Md Fakruddin
- Industrial Microbiology Laboratory, Institute of Food Science and Technology (IFST), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh.
| | - Mizanur Rahaman
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
| | - Monzur Morshed Ahmed
- Industrial Microbiology Laboratory, Institute of Food Science and Technology (IFST), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh.
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Pina-Pérez MC, Benlloch-Tinoco M, Rodrigo D, Martinez A. Cronobacter sakazakii Inactivation by Microwave Processing. FOOD BIOPROCESS TECH 2013. [DOI: 10.1007/s11947-013-1063-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Selection for loss of RpoS in Cronobacter sakazakii by growth in the presence of acetate as a carbon source. Appl Environ Microbiol 2013; 79:2099-102. [PMID: 23335773 DOI: 10.1128/aem.03302-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We demonstrate that growth of Cronobacter sakazakii in the presence of acetate as a carbon source promotes loss of RpoS, with a consequent reduction in stress tolerance. This suggests that C. sakazakii is capable of regulating cell fitness through mutation of the rpoS gene.
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Polymorphisms in rpoS and stress tolerance heterogeneity in natural isolates of Cronobacter sakazakii. Appl Environ Microbiol 2012; 78:3975-84. [PMID: 22447602 DOI: 10.1128/aem.07835-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Significant phenotypic diversity was observed when we examined the abilities of a number of Cronobacter sakazakii natural isolates to cope with various sublethal stress conditions (acid, alkaline, osmotic, oxidative, or heat stress). Levels of catalase activity and use of acetate as a carbon source, phenotypes commonly used as indirect assays to predict RpoS function, revealed a high correlation between predicted RpoS activity and tolerance to acid, alkaline, osmotic, and oxidative treatments. The rpoS genes were sequenced and analyzed for polymorphisms. Loss-of-function mutations were found in two strains; C. sakazakii DPC 6523 and the genome-sequenced strain C. sakazakii ATCC BAA-894. The complementation of these strains with a functional rpoS gene resulted in an increase in bacterial tolerance to acid, osmotic, and oxidative stresses. The pigmentation status of strains was also assessed, and a high variability in carotenoid content was observed, with a functional rpoS gene being essential for the production of the characteristic yellow pigment. In conclusion, the evidence presented in this study demonstrates that rpoS is a highly polymorphic gene in C. sakazakii, and it supports the importance of RpoS for the tolerance under stress conditions that C. sakazakii may encounter in the food chain and in the host during infection.
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Ziemba C, Peccia J. Fecal coliform population dynamics associated with the thermophilic stabilization of treated sewage sludge. ACTA ACUST UNITED AC 2012; 14:2755-61. [DOI: 10.1039/c2em30373f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Liu Q, Lu X, Swanson BG, Rasco BA, Kang DH. Monitoring Ultraviolet (UV) Radiation Inactivation of Cronobacter sakazakii in Dry Infant Formula Using Fourier Transform Infrared Spectroscopy. J Food Sci 2011; 77:M86-93. [DOI: 10.1111/j.1750-3841.2011.02503.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yemiş GP, Pagotto F, Bach S, Delaquis P. Effect of vanillin, ethyl vanillin, and vanillic acid on the growth and heat resistance of Cronobacter species. J Food Prot 2011; 74:2062-9. [PMID: 22186046 DOI: 10.4315/0362-028x.jfp-11-230] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Preservatives could be part of an effective intervention strategy for the control of Cronobacter species in foods, but few compounds with the desired antimicrobial properties have been identified to date. We examined the antibacterial activity of vanillin, ethyl vanillin, and vanillic acid against seven Cronobacter spp. in quarter-strength tryptic soy broth with 5 g/liter yeast extract (TSBYE) adjusted to pH 5.0, 6.0, and 7.0 at 10, 21, and 37°C. All compounds exhibited pH- and temperature-dependant bacteriostatic and bactericidal activity. MICs of vanillin and ethyl vanillin consistently increased with decreasing pH and temperature, but vanillic acid had little activity at pH values of 6.0 and 7.0. The MICs for all temperatures, pH values, and bacterial strains tested were 2 mg/ml ethyl vanillin, 3 mg/ml vanillin, and >8 mg/ml vanillic acid. MBCs also were influenced by pH, although significantly higher concentrations were needed to inactivate the bacteria at 21°C than at 10 or 37°C. Survivor curves for Cronobacter sakazakii strains at the MBCs of each compound revealed that all treatments resulted in immediate loss of cell viability at 37°C. Measurements of propidium iodide uptake indicated that the cell membranes were damaged by exposure to all three compounds. The thermal resistance of C. sakazakii was examined at 58°C in TSBYE supplemented with MBCs of each compound at pH 5.0 and 6.0. D-values at pH 5.0 were reduced from 14.56 ± 0.60 min to 0.93 ± 0.01, 0.63 ± 0.01, and 0.98 ± 0.02 min for vanillin, ethyl vanillin, and vanillic acid, respectively. These results suggest that vanillin, ethyl vanillin, and vanillic acid may be useful for the control of Cronobacter spp. in food during preparation and storage.
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Affiliation(s)
- Gökçe Polat Yemiş
- Department of Food Engineering, Ankara University, Diskapi Campus, Ankara, Turkey 06110
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Al-Holy MA, Castro LF, Al-Qadiri HM. Inactivation of Cronobacter spp. (Enterobacter sakazakii) in infant formula using lactic acid, copper sulfate and monolaurin. Lett Appl Microbiol 2009; 50:246-51. [PMID: 20025649 DOI: 10.1111/j.1472-765x.2009.02782.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS To investigate the effect of lactic acid (LA), copper (II), and monolaurin as natural antimicrobials against Cronobacter in infant formula. METHODS AND RESULTS The effect of LA (0.1, 0.2 and 0.3% v/v), copper (II) (10, 50 and 100 microg ml(-1)) and monolaurin (1000, 2000, and 3000 microg ml(-1)) suspended into tween-80 or dissolved in ethanol against Cronobacter in infant formula was investigated. Reconstituted infant formula and powdered infant formula were inoculated with five strains of Cronobacter spp. at the levels of c. 1 x 10(6) CFU ml(-1) and 1 x 10(3) CFU g(-1), respectively. LA at 0.2% v/v had a bacteriostatic effect on Cronobacter growth, whereas 0.3% v/v LA resulted in c. 3 log(10) reduction. Copper (II) at the levels of 50 microg ml(-1) and 100 microg ml(-1) elicited c. 1 and 2 log(10) reductions, respectively. The combination of 0.2% LA and 50 microg ml(-1) copper (II) resulted in a complete elimination of the organism. Monolaurin exhibited a slight inhibitory activity against Cronobacter (c. 1.5 log(10) difference) compared to the control when ethanol was used to deliver monolaurin. CONCLUSIONS A complete elimination of Cronobacter was obtained when a combination of sublethal concentrations of LA (0.2%) and copper (II) (50 microg ml(-1)) was used. SIGNIFICANCE AND IMPACT OF THE STUDY The use of the synergistic interactive combination of LA and copper (II) could be beneficial to control Cronobacter in the infant formula industry.
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Affiliation(s)
- M A Al-Holy
- Department of Clinical Nutrition and Dietetics, Faculty of Allied Health Sciences, Hashemite University, Zarqa, Jordan.
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Arroyo C, Condón S, Pagán R. Thermobacteriological characterization of Enterobacter sakazakii. Int J Food Microbiol 2009; 136:110-8. [DOI: 10.1016/j.ijfoodmicro.2009.09.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 09/08/2009] [Accepted: 09/13/2009] [Indexed: 10/20/2022]
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