1
|
Yang N, Ding N, Qi S, Shang Z, Ma P, Khan IM, Wang Z, Xia Y, Zhang Y, Zhang L. High-affinity truncated aptamers for detection of Cronobacter spp with magnetic separation-assisted DNAzyme-driven 3D DNA walker. Mikrochim Acta 2024; 191:130. [PMID: 38351361 DOI: 10.1007/s00604-024-06199-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/07/2024] [Indexed: 02/16/2024]
Abstract
After optimizing the original aptamer sequence by truncation strategy, a magnetic separation-assisted DNAzyme-driven 3D DNA walker fluorescent aptasensor was developed for detecting the food-borne pathogen Cronobacter species. Iron oxide magnetic nanoparticles (MNPs) modified with a hybrid of truncated aptamer probe and DNAzyme strand (AP-E1) denoted as MNPs@AP-E1, were employed as capture probes. Simultaneously, a DNAzyme-driven 3D-DNA walker was utilized as the signal amplification element. The substrate strand (Sub) was conjugated with the gold nanoparticles (AuNPs), resulting in the formation of AuNPs@Sub, which served as a 3D walking track. In the presence of the target bacteria and Mg2+, E1-DNAzyme was activated and moved along AuNPs@Sub, continuously releasing the signal probe. Under optimized conditions, a strong linear correlation was observed for Cronobacter sakazakii (C. sakazakii) in the concentration range 101 to 106 CFU mL-1, with a low detection limit of 2 CFU mL-1. The fluorescence signal responses for different Cronobacter species exhibited insignificant differences, with a relative standard deviation of 3.6%. Moreover, the aptasensor was successfully applied to determine C. sakazakii in real samples with recoveries of 92.86%-108.33%. Therefore, the novel method could be a good candidate for ultra-sensitive and selective detection of Cronobacter species without complex manipulation.
Collapse
Affiliation(s)
- Ningru Yang
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Ning Ding
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Shuo Qi
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Zixuan Shang
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Pengfei Ma
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Imran Mahmood Khan
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
- College of Ocean Food and Biological Engineering, Jimmie University, Jimei University, Jimei District, Xiamen City, 361021, Fujian Province, China
| | - Zhouping Wang
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China.
- Key Laboratory of Meat Processing of Sichuan, Chengdu University, Chengdu, 610106, China.
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122, China.
| | - Yu Xia
- State Key Laboratory of Food Science and Resources, School of Food Science and Technology, International Joint Laboratory On Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Yin Zhang
- Key Laboratory of Meat Processing of Sichuan, Chengdu University, Chengdu, 610106, China
| | - Lili Zhang
- Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| |
Collapse
|
2
|
Arslan S, Ertürk HG. Occurrence, Virulence and Antimicrobial Susceptibility Profiles of Cronobacter spp. from Ready-to-Eat Foods. Curr Microbiol 2021; 78:3403-3416. [PMID: 34241669 DOI: 10.1007/s00284-021-02585-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/17/2021] [Indexed: 10/20/2022]
Abstract
Cronobacter spp. can cause foodborne diseases in infants, but Cronobacter infections in healthy adults and vulnerable people have also been reported. These bacteria have ubiquitous nature and can contaminate various foods. Therefore, we assessed the presence of Cronobacter spp. in popularly consumed ready-to-eat (RTE) food products. In the present study, 51 (15%) of the 340 RTE food samples were contaminated with Cronobacter spp The highest contamination rates were found in spices (46.7%), meat-free cig koftes (44.4%), desserts (23.3%), cereals (23.1%), doners (12.2%), and ice cream (11.1%). Phenotypic and molecular methods, including 16S rRNA, gluA, rpoB, cgcA genes, and fusA allele sequencing were tested to identify Cronobacter species. Of the 51 contaminated samples, 54 isolates were identified as C. sakazakii (n = 43), C. malonaticus (n = 7), C. muytjensii (n = 3) and C. turicensis (n = 1) using fusA analysis. These isolates were assigned to 15 different fusA alleles, two of which (191 and 192) were new alleles. Putative virulence factors such as the ompA and zpx gene, biofilms, and siderophores were detected in most of the Cronobacter isolates (> 85%). Cronobacter isolates were resistant to cephalothin (85.2%), cefoxitin (33.3%), cefotaxime (14.8%), ampicillin (11.1%), cefepime (5.6%), aztreonam (5.6%), and piperacillin (1.9%). The multidrug resistance (against three or more classes of antimicrobial agents) was 7.4%. The results indicated presence of Cronobacter spp. in RTE foods, which may be a risk to human health. It is important to adopt rigorous hygiene and sanitization practices to ensure the microbiological safety of these foods consuming without any processing.
Collapse
Affiliation(s)
- Seza Arslan
- Department of Biology, Faculty of Arts and Sciences, Bolu Abant Izzet Baysal University, Gölköy, 14030, Bolu, Turkey.
| | - Hafize Gizem Ertürk
- Department of Biology, Faculty of Arts and Sciences, Bolu Abant Izzet Baysal University, Gölköy, 14030, Bolu, Turkey
| |
Collapse
|
3
|
Changes in physico-chemical characteristics and viable bacterial communities during fermentation of alfalfa silages inoculated with Lactobacillus plantarum. World J Microbiol Biotechnol 2021; 37:127. [PMID: 34181131 DOI: 10.1007/s11274-021-03095-2] [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: 07/11/2020] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
This study investigated the effect of inoculating Lactobacillus (L.) plantarum PS-8 in fermentation of alfalfa silages. We monitored the fermentation characteristics and bacterial population dynamics during the ensiling process. PacBio single molecule real time sequencing was combined with propidium monoazide (PMA) treatment to monitor the viable microbiota dynamics. We found that inoculating L. plantarum PS-8 may improve the silage quality by accelerating acidification, reducing the amounts of clostridia, coliform bacteria, molds and yeasts, elevating the protein and organic acid contents (except butyrate), and enhancing lactic acid bacteria (LAB) while suppressing harmful microorganisms. Some significant differential abundant taxa were found between the PMA-treated and non-treated microbiota. For example, the relative abundances of L. brevis, L. plantarum, and Pediococcus pentosaceus were significantly higher in the PMA-treated group than the non-PMA-treated group, suggesting obvious differences between the viable and non-viable microbiota. It would thus be necessary to distinguish between the viable and non-viable microbial communities to further understand their physiological contribution in silage fermentation. By tracking the dynamics of viable microbiota in relation with changes in the physico-chemical parameters, our study provided novel insights into the beneficial effects of inoculating L. plantarum PS-8 in silage fermentation and the physiological function of the viable bacterial communities.
Collapse
|
4
|
Jiang L, Wang D, Kim JS, Lee JH, Kim DH, Kim SW, Lee J. Reclassification of genus Izhakiella into the family Erwiniaceae based on phylogenetic and genomic analyses. Int J Syst Evol Microbiol 2020; 70:3541-3546. [PMID: 32369001 DOI: 10.1099/ijsem.0.004192] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The genus Izhakiella was established and designated as a member of the family Enterobacteriaceae in 2016. Although the taxonomical classification of most members in this family has been relatively resolved after two reclassifications in 2016 and 2017, the classification of the genus Izhakiella remains ambiguous. In this study, a polyphasic approach was used to provide evidence supporting the fact that the genus Izhakiella should no longer be considered a member of Enterobacteriaceae and proposes its reclassification into the family Erwiniaceae. The phylogenetic tree of type species in the families Enterobacteriaceae and Erwiniaceae based on the sequences of the 16S rRNA gene, rpoB housekeeping gene, and the whole-genome comprising the 92 core genes revealed that the genus Izhakiella forms a phylogenetic lineage within the family Erwiniaceae. The average nucleotide identity (ANI) value of the type species with genus Izhakiella was found to be higher for the family Erwiniaceae than that for the family Enterobacteriaceae. Notably, 12 conserved signature indels (CSIs) that are exclusively shared among the Erwiniaceae clade members were found in the type strains of the genus Izhakiella. Based on these analyses, this study suggests the reclassification of I. capsodis and I. australiensis into the family Erwiniaceae.
Collapse
Affiliation(s)
- Lingmin Jiang
- Department of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Republic of Korea.,Korean Collection for Type Cultures, Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea
| | - Dexin Wang
- Radiation Utilization and Facilities Management Division, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea.,Department of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Ji-Sun Kim
- Korean Collection for Type Cultures, Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea
| | - Ju Huck Lee
- Korean Collection for Type Cultures, Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea
| | - Dae-Hyuk Kim
- Department of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Suk Weon Kim
- Korean Collection for Type Cultures, Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea
| | - Jiyoung Lee
- Korean Collection for Type Cultures, Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea
| |
Collapse
|
5
|
Siccibacter turicensis from Kangaroo Scats: Possible Implication in Cellulose Digestion. Microorganisms 2020; 8:microorganisms8050635. [PMID: 32349400 PMCID: PMC7284360 DOI: 10.3390/microorganisms8050635] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 11/19/2022] Open
Abstract
Microbiota in the kangaroo gut degrade cellulose, contributing to the kangaroo’s energy and survival. In this preliminary study, to discover more about the gut microbes that contribute to the survival of kangaroos, cellulose-degrading bacteria were isolated from kangaroo scats by selection on solidified media containing carboxymethyl cellulose as the main carbon source. One frequently occurring aerobic bacterium was Siccibacter turicensis, a microbe previously isolated in fruit powder and from a patient with angular cheilitis. The whole genome sequence of the kangaroo isolate was obtained using the Illumina MiSeq platform. Its sequence shared 97.98% identity of the S. turicensis Type strain, and the ability of the Type strain to degrade cellulose was confirmed. Analysis of the genomic data focused on the cellulose operon. In addition to genes from the operon, we suggest that a gene following the operon may have an important role in regulating cellulose metabolism by signal transduction. This is the first report of S. turicensis found within microbiota of the animal gut. Because of its frequent presence in the kangaroo gut, we suggest that S. turicensis plays a role in cellulose digestion for kangaroos.
Collapse
|
6
|
Jiang L, Wang D, Lee JS, Kim DH, Jeong JC, Kim CY, Kim SW, Lee J. Jejubacter calystegiae gen. nov., sp. nov., moderately halophilic, a new member of the family Enterobacteriaceae, isolated from beach morning glory. J Microbiol 2020; 58:357-366. [DOI: 10.1007/s12275-020-9294-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/30/2019] [Accepted: 01/23/2020] [Indexed: 01/01/2023]
|
7
|
A sensitive electrochemical aptasensor based on MB-anchored GO for the rapid detection of Cronobacter sakazakii. J Solid State Electrochem 2019. [DOI: 10.1007/s10008-019-04426-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
8
|
Identification and Characterization of Cronobacter Strains Isolated from Environmental Samples. Curr Microbiol 2019; 76:1467-1476. [DOI: 10.1007/s00284-019-01776-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 09/17/2019] [Indexed: 10/25/2022]
|
9
|
Song X, Shukla S, Kim M. An immunoliposome-based immunochromatographic strip assay for the rapid detection of Cronobacter species. J Microbiol Methods 2019; 159:91-98. [DOI: 10.1016/j.mimet.2019.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/28/2019] [Accepted: 02/05/2019] [Indexed: 02/06/2023]
|
10
|
Wang Q, Forsythe SJ, Zhao XJ, Wang ZW, Li D, Ma D, Cao JY, Zeng J. Species identification and molecular characterization of Cronobacter spp. isolated from food imported over nine years into Beijing, China. Food Microbiol 2019; 82:11-19. [PMID: 31027763 DOI: 10.1016/j.fm.2019.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/18/2019] [Accepted: 01/18/2019] [Indexed: 01/07/2023]
Abstract
Cronobacter spp. are associated with serious infections in neonates with the clinical presentations of necrotizing enterocolitis, bacteraemia and meningitis. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to identify 203 Cronobacter isolates from imported food during 2006-2015 with an optimized in-house database. The isolates were predominantly C. sakazakii (88.18%), followed by C. malonaticus (8.37%), C. muytjensii (1.48%), C. turicensis (0.99%) and C. dublinensis (0.99%). The result was totally consistent with that of fusA allele sequencing. 12.32% (25/203) of isolates gave inconsistent spectra following separate protein extractions. Sixty C. sakazakii isolates and 24 isolates from the other four species were chosen for multi-locus sequence type analyses (MLST) and PCR-serotyping. Thirty-one sequence types were identified. The common sequence types were ST1 (19/60) and ST4 (13/60) for C. sakazakii and ST7 (12/17) for C. malonaticus. The primary serotypes were Csak O:1 (30/60), Csak O:2 (25/60) and Cmal O:2 (16/17) for C. sakazakii and C. malonaticus isolates, respectively. In conclusion, appropriate in-house database could make MALDI-TOF MS method identifying Cronobacter spp. isolates to the species level. But the spectra data were not sufficiently consistent for subtyping, unlike MLST. The Cronobacter spp. isolates have a high diversity including recognized pathovars.
Collapse
Affiliation(s)
- Qi Wang
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | | | - Xiao-Juan Zhao
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | - Zi-Wei Wang
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | - Dan Li
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | - Dan Ma
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | - Jia-Yue Cao
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| | - Jing Zeng
- Beijing Customs, Tianshuiyuan Street 6, Beijing, 100026, China.
| |
Collapse
|
11
|
Silva JN, Vasconcellos L, Forsythe SJ, de Filippis I, Luiz Lima Brandão M. Molecular and phenotypical characterization ofCronobacterspecies isolated with high occurrence from oats and linseeds. FEMS Microbiol Lett 2018; 366:5266300. [DOI: 10.1093/femsle/fny289] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/14/2018] [Indexed: 12/19/2022] Open
Affiliation(s)
- Júlia Nunes Silva
- Laboratory of Food and Sanitizes, INCQS/Fiocruz, Av. Brasil, 4365. Manguinhos, Rio de Janeiro-RJ, Brazil, CEP:21040-900
| | - Luiza Vasconcellos
- Laboratory of Food and Sanitizes, INCQS/Fiocruz, Av. Brasil, 4365. Manguinhos, Rio de Janeiro-RJ, Brazil, CEP:21040-900
| | | | - Ivano de Filippis
- Laboratory of Reference Microorganisms, INCQS/Fiocruz, Av. Brasil, 4365. Manguinhos, Rio de Janeiro-RJ, Brazil, CEP:21040-900
| | - Marcelo Luiz Lima Brandão
- Laboratory of Food and Sanitizes, INCQS/Fiocruz, Av. Brasil, 4365. Manguinhos, Rio de Janeiro-RJ, Brazil, CEP:21040-900
| |
Collapse
|
12
|
Mashoufi A, Ghazvini K, Hashemi M, Mobarhan MG, Vakili V, Afshari A. A novel primer targetedgyrBgene for the identification ofCronobacter sakazakiiin powdered infant formulas (PIF) and baby foods in Iran. J Food Saf 2018. [DOI: 10.1111/jfs.12609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Afsaneh Mashoufi
- Department of Nutrition, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Kiarash Ghazvini
- Department of Microbiology, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Mohammad Hashemi
- Department of Nutrition, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Majid Ghayour Mobarhan
- Department of Nutrition, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Vida Vakili
- Department of Social Medicine, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Asma Afshari
- Department of Nutrition, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| |
Collapse
|
13
|
Parra-Flores J, Cerda-Leal F, Contreras A, Valenzuela-Riffo N, Rodríguez A, Aguirre J. Cronobacter sakazakii and Microbiological Parameters in Dairy Formulas Associated With a Food Alert in Chile. Front Microbiol 2018; 9:1708. [PMID: 30108565 PMCID: PMC6079297 DOI: 10.3389/fmicb.2018.01708] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/09/2018] [Indexed: 11/18/2022] Open
Abstract
The objective of this study was to evaluate the presence of Cronobacter sakazakii and microbiological parameters in dairy products associated with a food alert. Ninety dairy product samples were analyzed, including seven commercial brands and two product types (liquid and powdered) from four countries. Aerobic plate count (APC) and Enterobacteriaceae count were performed according to Chilean standards. Cronobacter spp. and C. sakazakii were identified by polymerase chain reaction real time amplification of rpoB and cgcA genes and the genotype by multilocus sequence typing. Eighty-eight percent of dairy products showed APC higher than the detection limit. Fifty percent of liquid commercial brand samples contained APC: 2.6, 2.3, 1.1, and 2.9 CFU/mL in brands A, C, E, and G, respectively. Results for powdered commercial brands were 3.0, 3.6, and 5.7 CFU/g in brands B, D, and F, respectively. Maximum count (5.7 CFU/g) occurred in brand F dairy product manufactured in Chile. Enterobacteriaceae were found in 55% of the samples, 64% in liquid and 51% in powdered commercial brands. In 50% of brands B, D, and E, samples contained 2.9, 2.8, and 2.7 log CFU/g, respectively. Only liquid commercial brands from the United States had Enterobacteriaceae values between 0.1 and 4.5 CFU/mL. Seventeen suspicious strains were isolated and nine were identified as Enterobacter spp. Only eight suspicious strains from four powdered commercial brands (Chile and Singapore) were confirmed as C. sakazakii by rpoB and cgcA gene amplification and fusA sequencing. C. sakazakii prevalence in the analyzed samples was 8.8%. There were 11% of powdered milk brands that contained APC between 4.0 and 4.7 log CFU/g and 55% of the samples contained Enterobacteriaceae. C. sakazakii was found in dairy products manufactured in Chile and Singapore. On the basis of this information, the Chilean Ministry of Health (RSA) decreed a national and international food alert and recalled all the product batches that resulted positive in the present study from supermarkets and pharmacies.
Collapse
Affiliation(s)
- Julio Parra-Flores
- Molecular Microbiology Laboratory, Faculty of Health and Food Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Fabiola Cerda-Leal
- Molecular Microbiology Laboratory, Faculty of Health and Food Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Alejandra Contreras
- Molecular Microbiology Laboratory, Faculty of Health and Food Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Nicole Valenzuela-Riffo
- Molecular Microbiology Laboratory, Faculty of Health and Food Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Alejandra Rodríguez
- Molecular Microbiology Laboratory, Faculty of Health and Food Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Juan Aguirre
- Department of Agricultural Industry and Enology, Universidad de Chile, Santiago, Chile
| |
Collapse
|
14
|
Song X, Shukla S, Kim M. Detection of Cronobacter species in powdered infant formula using immunoliposome-based immunomagnetic concentration and separation assay. Food Microbiol 2018; 72:23-30. [DOI: 10.1016/j.fm.2017.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 09/24/2017] [Accepted: 11/06/2017] [Indexed: 12/23/2022]
|
15
|
Vasconcellos L, Carvalho CT, Tavares RO, de Mello Medeiros V, de Oliveira Rosas C, Silva JN, dos Reis Lopes SM, Forsythe SJ, Brandão MLL. Isolation, molecular and phenotypic characterization of Cronobacter spp. in ready-to-eat salads and foods from Japanese cuisine commercialized in Brazil. Food Res Int 2018; 107:353-359. [DOI: 10.1016/j.foodres.2018.02.048] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 02/14/2018] [Accepted: 02/18/2018] [Indexed: 11/15/2022]
|
16
|
Abstract
Being able to track bacterial pathogens is essential for epidemiological purposes as well as monitoring in-house production facilities. Common bacterial pathogens, such as Salmonella serovars, are already been well defined, and their detection methods are very advanced. However, this will not be the case for emergent bacterial pathogens, as was the case for Cronobacter. The clinical significance of the organism is due to its association with rare sporadic infections in adults, and severe life-threatening outbreaks of necrotizing enterocolitis and meningitis in newborn babies. The main recognized route of infection being through the consumption of contaminated reconstituted powdered infant formula. Key to the advances in being able to track this organism during formula production and outbreaks in neonatal intensive care units has been the use of DNA sequence-based methods, and most recently those which profile whole-genome sequences. This chapter considers how the latest DNA sequence-based methods in genotyping Cronobacter serve as a model for analyzing emergent bacterial pathogens in the future. The methods considered will initially highlight the limitations of phenotyping, then advance from the DNA probe-based methods for serotyping through to DNA sequence-based methods, especially multilocus sequence typing which is supported by an open access database. Finally the development of typing methods based on whole-genomes sequences, CRISPR-cas array profiling and SNP analysis, will be covered. The overall perspective is that emergent pathogens need to be investigated with the most advanced methods in order for robust and reliable control measures to be adopted.
Collapse
|
17
|
Abstract
There has been considerable concern related to Cronobacter spp. in foods, especially due to their highlighted association with neonatal infections through the ingestion of reconstituted powdered infant formula (PIF). This concern resulted in improved microbiological criteria recommendations by the Codex Alimentarius Commission and revised WHO advice on the preparation of infant feeds. In recent years, the diversity of the genus has been well described, and various detection and typing methods have been developed. This review considers our current knowledge of the genus and how DNA-sequence-based methods have contributed considerably to research into improved detection methods and more reliable identification procedures, genotyping schemes, and genomic analysis. The broader occurrence of Cronobacter in food ingredients, finished products, and food manufacturing environments is covered. This review also highlights the significance of clonal lineages in microbial source tracking and the use of CRISPR-cas array profiling.
Collapse
Affiliation(s)
- Stephen J Forsythe
- foodmicrobe.com, Adams Hill, Keyworth, Nottinghamshire, NG12 5GY, United Kingdom;
| |
Collapse
|
18
|
Akineden Ö, Heinrich V, Gross M, Usleber E. Reassessment of Cronobacter spp. originally isolated as Enterobacter sakazakii from infant food. Food Microbiol 2017; 65:44-50. [DOI: 10.1016/j.fm.2017.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 01/17/2017] [Accepted: 01/31/2017] [Indexed: 11/15/2022]
|
19
|
Novel Method for Reliable Identification of Siccibacter and Franconibacter Strains: from "Pseudo-Cronobacter" to New Enterobacteriaceae Genera. Appl Environ Microbiol 2017; 83:AEM.00234-17. [PMID: 28455327 DOI: 10.1128/aem.00234-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/12/2017] [Indexed: 11/20/2022] Open
Abstract
In the last decade, strains of the genera Franconibacter and Siccibacter have been misclassified as first Enterobacter and later Cronobacter Because Cronobacter is a serious foodborne pathogen that affects premature neonates and elderly individuals, such misidentification may not only falsify epidemiological statistics but also lead to tests of powdered infant formula or other foods giving false results. Currently, the main ways of identifying Franconibacter and Siccibacter strains are by biochemical testing or by sequencing of the fusA gene as part of Cronobacter multilocus sequence typing (MLST), but in relation to these strains the former is generally highly difficult and unreliable while the latter remains expensive. To address this, we developed a fast, simple, and most importantly, reliable method for Franconibacter and Siccibacter identification based on intact-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Our method integrates the following steps: data preprocessing using mMass software; principal-component analysis (PCA) for the selection of mass spectrum fingerprints of Franconibacter and Siccibacter strains; optimization of the Biotyper database settings for the creation of main spectrum projections (MSPs). This methodology enabled us to create an in-house MALDI MS database that extends the current MALDI Biotyper database by including Franconibacter and Siccibacter strains. Finally, we verified our approach using seven previously unclassified strains, all of which were correctly identified, thereby validating our method.IMPORTANCE We show that the majority of methods currently used for the identification of Franconibacter and Siccibacter bacteria are not able to properly distinguish these strains from those of Cronobacter While sequencing of the fusA gene as part of Cronobacter MLST remains the most reliable such method, it is highly expensive and time-consuming. Here, we demonstrate a cost-effective and reliable alternative that correctly distinguishes between Franconibacter, Siccibacter, and Cronobacter bacteria and identifies Franconibacter and Siccibacter at the species level. Using intact-cell MALDI-TOF MS, we extend the current MALDI Biotyper database with 11 Franconibacter and Siccibacter MSPs. In addition, the use of our approach is likely to lead to a more reliable identification scheme for Franconibacter and Siccibacter strains and, consequently, a more trustworthy epidemiological picture of their involvement in disease.
Collapse
|
20
|
Brandão MLL, Umeda NS, Jackson E, Forsythe SJ, de Filippis I. Isolation, molecular and phenotypic characterization, and antibiotic susceptibility of Cronobacter spp. from Brazilian retail foods. Food Microbiol 2017; 63:129-138. [DOI: 10.1016/j.fm.2016.11.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 11/07/2016] [Accepted: 11/17/2016] [Indexed: 10/20/2022]
|
21
|
Vlach J, Javůrková B, Karamonová L, Blažková M, Fukal L. Novel PCR-RFLP system based on rpoB gene for differentiation of Cronobacter species. Food Microbiol 2016; 62:1-8. [PMID: 27889135 DOI: 10.1016/j.fm.2016.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/24/2016] [Accepted: 08/17/2016] [Indexed: 01/28/2023]
Abstract
Bacteria from the genus Cronobacter are opportunistic foodborne pathogens that can cause severe infections. More rapid, cost-effective and reliable methods are still required for the species identification of Cronobacter spp. In this study, we present a novel PCR-RFLP-based method that uses a newly designed pair of primers for the PCR-amplification of a partial rpoB gene sequence (1635 bp). The amplified products of DNA from 80 Cronobacter strains were separately digested with three restriction endonucleases (Csp6I, HinP1I, MboI). Using the obtained restriction patterns, a PCR-RFLP identification system was created to enable differentiation between all seven currently-known Cronobacter species. The functionality of our method was successfully verified on real food samples. Moreover, the relationships between the Cronobacter species were determined via a phylogenetic tree created from the RFLP patterns.
Collapse
Affiliation(s)
- Jiří Vlach
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, Czech Republic
| | - Barbora Javůrková
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, Czech Republic
| | - Ludmila Karamonová
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, Czech Republic
| | - Martina Blažková
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, Czech Republic.
| | - Ladislav Fukal
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, Czech Republic
| |
Collapse
|
22
|
Structural characterization of the O-polysaccharide isolated from Franconibacter helveticus LMG23732(T). Carbohydr Res 2016; 431:39-41. [PMID: 27288973 DOI: 10.1016/j.carres.2016.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 05/09/2016] [Accepted: 05/16/2016] [Indexed: 12/28/2022]
Abstract
The bacterial strain Franconibacter helveticus LMG 23732(T) was previously misidentified as the neonatal pathogen Cronobacter zurichensis. O-polysaccharide (OPS) is a part of lipopolysaccharide (LPS), which is an important cell envelope compound of Gram-negative bacteria. OPS isolated from the bacterium Franconibacter helveticus LMG23732(T) was characterized by chemical analyses as well as 1D and 2D NMR experiments. Compositional analyses indicated the presence of glucose and unusual 6-deoxy sugar - 6-deoxy-talose (6-dTal). The studied strain produced OPS, which consists of 6-l-dTalp in main chain and terminal d-Glcp as a branch: This is the first structural determination of the OPS isolated from genus Franconibacter.
Collapse
|
23
|
Jackson EE, Forsythe SJ. Comparative study of Cronobacter identification according to phenotyping methods. BMC Microbiol 2016; 16:146. [PMID: 27401027 PMCID: PMC4940867 DOI: 10.1186/s12866-016-0768-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/08/2016] [Indexed: 12/14/2022] Open
Abstract
Background Microbiological criteria applied to powdered infant formula (PIF) require the absence of all Cronobacter spp. Consequently, misidentification of isolates from finished products can lead to significant financial losses for manufacturers and could increase the risk of neonatal infection. Biochemical identification of suspect isolates using commercially available test panels is recommended for use by PIF manufacturers by both the US FDA and ISO standard methods for Cronobacter species; however, phenotyping can be unreliable, particularly for a genus such as Cronobacter where the taxonomy has been subject to frequent changes. This study compared the predicted identification by commonly used phenotyping kits (API20E and ID32E) for over 240 strains of Cronobacter from diverse sources, which had been identified using DNA sequence analysis. In 2015, the databases associated with the API20E and ID32E biochemical test panels were updated, including the recognition of the Cronobacter genus. Thus, the identifications from multiple versions the databases were compared to each other and to identifications based on DNA sequencing methods. Results Using previous versions of the API20E database, 90.0 % of strains (216/240) resulted in a match for the species identification; however, version 5.0 produced matches for only 82.3 % of strains (237/288). Similarly, the update to version 4.0 in the ID32E database caused the percentage of matches to drop from 88.9 % (240/270) to 43.2 % (139/322). A smaller study showed that the Vitek GN system identified all 14 strains, belonging all seven Cronobacter species, as members of the ‘C. sakazakii group,’ but also attributed three strains of Franconibacter helveticus and F. pulveris to this group. In silco analysis of a PCR-based method targeting ompA predicted that amplification would only occur with Cronobacter species and this method may be a feasible alternative to biochemical phenotyping. Conclusions These results indicate that commercially available biochemical test panels are not sufficiently reliable for speciation of Cronobacter isolates. Although DNA-sequence based methods would be the more reliable approach; however, this is not currently feasible for many food microbiology laboratories. Instead, a previously published PCR-based method targeting ompA is suggested as an alternative for identification of Cronobacter species based on in silico analysis. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0768-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Emily E Jackson
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK
| | - Stephen J Forsythe
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK.
| |
Collapse
|
24
|
Parra-Flores J, Juneja V, Garcia de Fernando G, Aguirre J. Variability in Cell Response of Cronobacter sakazakii after Mild-Heat Treatments and Its Impact on Food Safety. Front Microbiol 2016; 7:535. [PMID: 27148223 PMCID: PMC4836016 DOI: 10.3389/fmicb.2016.00535] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/01/2016] [Indexed: 12/05/2022] Open
Abstract
Cronobacter spp. have been responsible for severe infections in infants associated with consumption of powdered infant formula and follow-up formulae. Despite several risk assessments described in published studies, few approaches have considered the tremendous variability in cell response that small micropopulations or single cells can have in infant formula during storage, preparation or post process/preparation before the feeding of infants. Stochastic approaches can better describe microbial single cell response than deterministic models as we prove in this study. A large variability of lag phase was observed in single cell and micropopulations of ≤50 cells. This variability increased as the heat shock increased and growth temperature decreased. Obviously, variability of growth of individual Cronobacter sakazakii cell is affected by inoculum size, growth temperature and the probability of cells able to grow at the conditions imposed by the experimental conditions should be taken into account, especially when errors in bottle-preparation practices, such as improper holding temperatures, or manipulation, may lead to growth of the pathogen to a critical cell level. The mean probability of illness from initial inoculum size of 1 cell was below 0.2 in all the cases and for inoculum size of 50 cells the mean probability of illness, in most of the cases, was above 0.7.
Collapse
Affiliation(s)
- Julio Parra-Flores
- Departamento de Nutrición y Salud Pública, Universidad del Bío-BíoChillán, Chile
| | - Vijay Juneja
- Residue Chemistry and Predictive Microbiology Research Unit, Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, WyndmoorPA, USA
| | - Gonzalo Garcia de Fernando
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de ChileSantiago, Chile
| | - Juan Aguirre
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de ChileSantiago, Chile
- Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad ComplutenseMadrid, Spain
| |
Collapse
|
25
|
Qiming C, Tingting T, Xiaomei B, Yingjian L, Fengxia L, Ligong Z, Zhaoxin L. Mining for sensitive and reliable species-specific primers for PCR for detection of Cronobacter sakazakii by a bioinformatics approach. J Dairy Sci 2016; 98:5091-101. [PMID: 26074237 DOI: 10.3168/jds.2015-9304] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 04/24/2015] [Indexed: 11/19/2022]
Abstract
Although several studies have reported PCR assays for distinguishing Cronobacter sakazakii from other species in the genus, reports regarding assay sensitivity and specificity, as well as applications for food testing, are lacking. Hence, the objective of this study was to develop a sensitive and reliable PCR-based method for detection of C. sakazakii by screening for specific target genes. The genome sequence of C. sakazakii in the GenBank database was compared with that of other organisms using BLAST. Thirty-eight DNA fragments unique to C. sakazakii were identified, and primers targeting these sequences were designed. Finally, 3 primer sets (CS14, CS21, and CS38) were found to be specific for C. sakazakii by PCR verification. The detection limit of PCR assays using the 3 pairs of primers was 1.35 pg/μL, 135 fg/μL, and 135 fg/μL, respectively, for genomic DNA, and 5.5×10(5), 5.5×10(3), 5.5×10(3) cfu/mL, respectively, using pure cultures of the bacteria, compared with 13.5 pg/μLand 5.5×10(5) cfu/mLfor primer set SpeCronsaka, which has been previously described. Cronobacter sakazakii were detected in artificially contaminated powdered infant formula (PIF) by PCR using primer sets CS21 and CS38 after 8h of enrichment. The detection limit was 5.5×10(-1) cfu/10g of PIF. Thus, the PCR assay can be used for rapid and sensitive detection of C. sakazakii in PIF.
Collapse
Affiliation(s)
- Chen Qiming
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China
| | - Tao Tingting
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China
| | - Bie Xiaomei
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China
| | - Lu Yingjian
- Department of Nutrition and Food Sciences, University of Maryland, College Park 20742
| | - Lu Fengxia
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China
| | - Zhai Ligong
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China
| | - Lu Zhaoxin
- College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, People's Republic of China.
| |
Collapse
|
26
|
Characterization of Cronobacter spp. isolated from food of plant origin and environmental samples collected from farms and from supermarkets in the Czech Republic. Int J Food Microbiol 2016; 217:130-6. [DOI: 10.1016/j.ijfoodmicro.2015.10.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/29/2015] [Accepted: 10/16/2015] [Indexed: 01/09/2023]
|
27
|
Almajed FS, Forsythe SJ. Cronobacter sakazakii clinical isolates overcome host barriers and evade the immune response. Microb Pathog 2015; 90:55-63. [PMID: 26616163 DOI: 10.1016/j.micpath.2015.11.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/17/2015] [Accepted: 11/19/2015] [Indexed: 01/19/2023]
Abstract
Cronobacter sakazakii is the most frequently clinically isolated species of the Cronobacter genus. However the virulence factors of C. sakazakii including their ability to overcome host barriers remains poorly studied. In this study, ten clinical isolates of C. sakazakii were assessed for their ability to invade and translocate through human colonic carcinoma epithelial cells (Caco-2) and human brain microvascular endothelial cells (HBMEC). Their ability to avoid phagocytosis in human macrophages U937 and human brain microglial cells was investigated. Additionally, they were tested for serum sensitivity and the presence of the Cronobacter plasminogen activation gene (cpa) gene, which is reported to confer serum resistance. Our data showed that the clinical C. sakazakii strains invaded and translocated through Caco-2 and HBMEC cell lines and some strains showed significantly higher levels of invasion and translocation. Moreover, C. sakazakii was able to persist and even multiply in phagocytic macrophage and microglial cells. All strains, except one, were able to withstand human serum exposure, the single serum sensitive strain was also the only one which did not encode for the cpa gene. These results demonstrate that C. sakazakii clinical isolates are able to overcome host barriers and evade the host immune response indicating their capacity to cause diseases such as necrotizing enterocolitis (NEC) and meningitis. Our data showed for the first time the ability of C. sakazakii clinical isolates to survive and multiply within human microglial cells. Additionally, it was shown that C. sakazakii clinical strains have the capacity to translocate through the Caco-2 and HBMEC cell lines paracellularly.
Collapse
Affiliation(s)
- Faisal S Almajed
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG 11 8NS, UK; College of Applied Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia
| | - Stephen J Forsythe
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG 11 8NS, UK.
| |
Collapse
|
28
|
Ogrodzki P, Forsythe S. Capsular profiling of the Cronobacter genus and the association of specific Cronobacter sakazakii and C. malonaticus capsule types with neonatal meningitis and necrotizing enterocolitis. BMC Genomics 2015; 16:758. [PMID: 26449318 PMCID: PMC4599207 DOI: 10.1186/s12864-015-1960-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/29/2015] [Indexed: 12/21/2022] Open
Abstract
Background Cronobacter sakazakii and C. malonaticus can cause serious diseases especially in infants where they are associated with rare but fatal neonatal infections such as meningitis and necrotising enterocolitis. Methods This study used 104 whole genome sequenced strains, covering all seven species in the genus, to analyse capsule associated clusters of genes involved in the biosynthesis of the O-antigen, colanic acid, bacterial cellulose, enterobacterial common antigen (ECA), and a previously uncharacterised K-antigen. Results Phylogeny of the gnd and galF genes flanking the O-antigen region enabled the defining of 38 subgroups which are potential serotypes. Two variants of the colanic acid synthesis gene cluster (CA1 and CA2) were found which differed with the absence of galE in CA2. Cellulose (bcs genes) were present in all species, but were absent in C. sakazakii sequence type (ST) 13 and clonal complex (CC) 100 strains. The ECA locus was found in all strains. The K-antigen capsular polysaccharide Region 1 (kpsEDCS) and Region 3 (kpsMT) genes were found in all Cronobacter strains. The highly variable Region 2 genes were assigned to 2 homology groups (K1 and K2). C. sakazakii and C. malonaticus isolates with capsular type [K2:CA2:Cell+] were associated with neonatal meningitis and necrotizing enterocolitis. Other capsular types were less associated with clinical infections. Conclusion This study proposes a new capsular typing scheme which identifies a possible important virulence trait associated with severe neonatal infections. The various capsular polysaccharide structures warrant further investigation as they could be relevant to macrophage survival, desiccation resistance, environmental survival, and biofilm formation in the hospital environment, including neonatal enteral feeding tubes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1960-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- P Ogrodzki
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK
| | - S Forsythe
- Pathogen Research Group, School of Science and Technology, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK.
| |
Collapse
|
29
|
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 Microbiol 2015; 81:5430-9. [PMID: 26048942 DOI: 10.1128/aem.01390-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 05/26/2015] [Indexed: 11/20/2022] Open
Abstract
Cronobacter spp. (formerly defined as Enterobacter sakazakii) are opportunistic bacterial pathogens of both infants and adults. In this study, we analyzed 70 Cronobacter isolates from powdered infant formula (PIF) and an infant formula production facility in China to determine possible contamination routes. The strains were profiled by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), PCR-based O-antigen serotyping, and ompA and rpoB sequence analyses. The isolates were primarily Cronobacter sakazakii (66/70) or Cronobacter malonaticus (4/70). The strains were divided into 38 pulsotypes (PTs) using PFGE and 19 sequence types (STs) by MLST. In contrast, rpoB and ompA sequence analyses divided the strains into 10 overlapping clusters each. PCR serotyping of the 66 C. sakazakii and 4 C. malonaticus strains resulted in the identification of four C. sakazakii serotypes (O1, O2, O4, and O7) and a single C. malonaticus serotype, O2. The dominant C. sakazakii sequence types from PIF and an infant formula production factory in China were C. sakazakii clonal complex 4 (CC4) (n = 19), ST1 (n = 14), and ST64 (n = 11). C. sakazakii CC4 is a clonal lineage strongly associated with neonatal meningitis. In the process of manufacturing PIF, the spray-drying, fluidized-bed-drying, and packing areas were the main areas with Cronobacter contamination. C. sakazakii strains with the same pulsotypes (PT3 and PT2) and sequence types (ST1 and ST64) were isolated both from processing equipment and from the PIF finished product.
Collapse
|
30
|
Jackson EE, Flores JP, Fernández-Escartín E, Forsythe SJ. Reevaluation of a Suspected Cronobacter sakazakii Outbreak in Mexico. J Food Prot 2015; 78:1191-6. [PMID: 26038912 DOI: 10.4315/0362-028x.jfp-14-563] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In 2010, two infants became ill at a hospital in Mexico. Subsequently, a range of clinical, environmental, and powdered and rehydrated infant formula isolates were identified by using a combination of phenotyping and PCR probes. The strains were clustered according to pulsed-field gel electrophoresis. The causative agent was reported as Cronobacter sakazakii, with powdered infant formula (PIF) identified as the likely source of the infections. This new study further characterized the isolates from this outbreak by using multilocus sequence typing and whole genome sequencing of selected strains. Though four PIF isolates and one hospital environmental isolate were identified as C. sakazakii sequence type 297 by multilocus sequence typing, they were isolated 6 months prior to the outbreak. Genotypic analyses of patient isolates identified them as Enterobacter hormaechei and Enterobacter spp. The pulsed-field gel electrophoresis profile of the Enterobacter spp. isolates matched those of isolates from previously unopened tins of PIF. E. hormaechei was only isolated from the two infants and not PIF. The reevaluation of this outbreak highlights the need for accurate detection and identification assays, particularly during outbreak investigations in which incorrect identifications may mislead the investigation and attribution of the source. Though the species responsible for the symptoms could not be determined, this outbreak demonstrated the possible transmission of Enterobacter spp. from PIF to infants. These are possibly the first reported cases of Enterobacter spp. infection of infants from bacterial-contaminated PIF.
Collapse
Affiliation(s)
- Emily E Jackson
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK
| | - Julio Parra Flores
- Departamento de Nutrición y Salud Pública, Universidad del Bío-Bío, Chillán, Ñuble, 3780000, Chillán, Chile
| | - Eduardo Fernández-Escartín
- Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, 76010, México
| | - Stephen J Forsythe
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK.
| |
Collapse
|
31
|
Jackson EE, Masood N, Ibrahim K, Urvoy N, Hariri S, Forsythe SJ. Description of Siccibacter colletis sp. nov., a novel species isolated from plant material, and emended description of Siccibacter turicensis. Int J Syst Evol Microbiol 2015; 65:1335-1341. [PMID: 25667396 DOI: 10.1099/ijs.0.000108] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A re-evaluation of the taxonomic position of two strains, 1383(T) and 2249, isolated from poppy seeds and tea leaves, which had been identified as Siccibacter turicensis (formerly Cronobacter zurichensis ), was carried out. The analysis included phenotypic characterization, 16S rRNA gene sequencing, multilocus sequence analysis (MLSA) of five housekeeping genes (atpD, fusA, glnS, gyrB and infB; 2034 bp) and ribosomal MLSA (53 loci; 22 511 bp). 16S rRNA gene sequence analysis and MLSA showed that the strains formed an independent phylogenetic lineage, with Siccibacter turicensis LMG 23730(T) as the closest neighbour. Average nucleotide identity analysis and phenotypic analysis confirmed that these strains represent a novel species, for which the name Siccibacter colletis sp. nov. is proposed. The type strain is 1383(T) ( = NCTC 14934(T) = CECT 8567(T) = LMG 28204(T)). An emended description of Siccibacter turicensis is also provided.
Collapse
Affiliation(s)
- Emily E Jackson
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Naqash Masood
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Khaled Ibrahim
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Noémie Urvoy
- Université Paris Est Créteil, Département Génie Biologique, 61 Avenue du Général de Gaulle, 94000 Creteil, France
| | - Sumyya Hariri
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Stephen J Forsythe
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| |
Collapse
|
32
|
|
33
|
Forsythe SJ, Dickins B, Jolley KA. Cronobacter, the emergent bacterial pathogen Enterobacter sakazakii comes of age; MLST and whole genome sequence analysis. BMC Genomics 2014; 15:1121. [PMID: 25515150 PMCID: PMC4377842 DOI: 10.1186/1471-2164-15-1121] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 12/11/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Following the association of Cronobacter spp. to several publicized fatal outbreaks in neonatal intensive care units of meningitis and necrotising enterocolitis, the World Health Organization (WHO) in 2004 requested the establishment of a molecular typing scheme to enable the international control of the organism. This paper presents the application of Next Generation Sequencing (NGS) to Cronobacter which has led to the establishment of the Cronobacter PubMLST genome and sequence definition database (http://pubmlst.org/cronobacter/) containing over 1000 isolates with metadata along with the recognition of specific clonal lineages linked to neonatal meningitis and adult infections RESULTS Whole genome sequencing and multilocus sequence typing (MLST) has supports the formal recognition of the genus Cronobacter composed of seven species to replace the former single species Enterobacter sakazakii. Applying the 7-loci MLST scheme to 1007 strains revealed 298 definable sequence types, yet only C. sakazakii clonal complex 4 (CC4) was principally associated with neonatal meningitis. This clonal lineage has been confirmed using ribosomal-MLST (51-loci) and whole genome-MLST (1865 loci) to analyse 107 whole genomes via the Cronobacter PubMLST database. This database has enabled the retrospective analysis of historic cases and outbreaks following re-identification of those strains. CONCLUSIONS The Cronobacter PubMLST database offers a central, open access, reliable sequence-based repository for researchers. It has the capacity to create new analysis schemes 'on the fly', and to integrate metadata (source, geographic distribution, clinical presentation). It is also expandable and adaptable to changes in taxonomy, and able to support the development of reliable detection methods of use to industry and regulatory authorities. Therefore it meets the WHO (2004) request for the establishment of a typing scheme for this emergent bacterial pathogen. Whole genome sequencing has additionally shown a range of potential virulence and environmental fitness traits which may account for the association of C. sakazakii CC4 pathogenicity, and propensity for neonatal CNS.
Collapse
Affiliation(s)
- Stephen J Forsythe
- />School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS UK
| | - Benjamin Dickins
- />School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS UK
| | - Keith A Jolley
- />Department of Zoology, University of Oxford, Oxford, OX1 3PS UK
| |
Collapse
|
34
|
Lindsay D, Hill B, Venter P. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry as a confirmation procedure in internationally recognised standard test methods for Cronobacter sakazakii. Int Dairy J 2014. [DOI: 10.1016/j.idairyj.2014.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|