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Stephen J Forsythe

Stephen J Forsythe
foodmicrobe.com · Email: sforsythe4j@gmail.com

BSc PhD
I am currently visiting Professor at universities of Hong Kong, Kuopio, Guangzhou and Stellenbosch.

About

286
Publications
42,159
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Introduction
I have a strong research interest in foodborne bacteria, with a focus on Cronobacter primary isolation, phenotyping , genotyping, tissue culture, genomic and bioinformatic analysis. I have published the genomes of all the species in the Cronobacter genus, and established the open access MLST scheme for 7-loci, rMLST & core genome MLST (www.pubMLST.org/cronobacter). Our group identified the Cronobacter pathovars (CC4), as well as capsule (K-antigen-colanic acid) and CRISPR-cas profiles.
Additional affiliations
January 2009 - present
The University of Warwick
January 2008 - December 2010
Jordan University of Science and Technology
January 2007 - present
University of Southern California

Publications

Publications (286)
Article
Full-text available
A 7-loci (3,036 nt) multilocus sequence typing scheme was applied to 41 clinical isolates of Cronobacter sakazakii. Half (20/41) of the C. sakazakii strains were sequence type (ST) 4, and 9/12 meningitis isolates were ST4. C. sakazakii ST4 appears to be a highly stable clone with a high propensity for neonatal meningitis.
Thesis
Full-text available
The genus Cronobacter includes food-borne pathogens causing neonatal infections such as meningitis, and necrotizing enterocolitis as well as bacteraemia in immunocompromised adults. Understanding the molecular characterisation, clonality and phenotypic diversity of Cronobacter species is essential to reduce the source of microbial contamination o...
Presentation
Full-text available
Cronobacter is a bacterium of primary concern due to the potential severity of infection in infants and especially neonates. Nevertheless, the majority of infections occur in the adult population. This video reviews how the identification of the organism has changed over the years, and the confusion that has occurred with related organisms. The vi...
Presentation
Full-text available
This is the first of two videos on the analysis of Cronobacter sakazakii strains from an outbreak with four fatalities at a neonatal intensive care unit. The first video covers the initial analysis using PFGE, shows an example of mis-identification, and that a baby can be infected with more than one strain. It was also the first time that the varia...
Presentation
Full-text available
This is the second of two videos on the analysis of Cronobacter sakazakii strains from an outbreak with four fatalities at a neonatal intensive care unit. It will show how progress in DNA sequencing techniques led to the recognition of Cronobacter pathovars such as CC4. It will then show how the application of MLST, CRISPR-cas array and SNP analysi...
Article
Full-text available
This study characterized five Cronobacter spp. and six Salmonella spp. strains that had been isolated from 155 samples of powdered infant formula (PIF) sold in Chile and manufactured in Chile and Mexico in 2018–2020. Two strains of Cronobacter sakazakii sequence type (ST) ST1 and ST31 (serotypes O:1 and O:2) and one strain of Cronobacter malonaticu...
Article
Full-text available
The Curtobacterium genus is a member of the family Microbacteriaceae, and Curtobacterium species are recognized as plant pathogens. The aim of this study was to investigate a dubious result of species identification for an infection located on a catheter tip of a patient with Covid‐19. A strain isolated from a catheter tip sample, identified by VIT...
Article
Full-text available
This study characterized five Cronobacter spp. and six Salmonella spp. strains that had been isolated from 155 samples of powdered infant formula (PIF) sold in Chile and manufactured in Chile and Mexico in 2018-2020. Two strains of C. sakazakii sequence type (ST) ST1 and ST31 (serotypes O:1 and O:2) and one strain of C. malonaticus ST60 (O:1) were...
Presentation
Full-text available
Cronobacter is well known for severe infant infections. This video shows you how to use the COG-MLST function (1865 loci) in the Cronobacter PubMLST database to analyse whole genomes. The analysis reveals strains from clinical, formula and environmental sources (ie. breast pump) which are indistinquishable.
Presentation
Full-text available
The Powerpoint shows how to use the Cronobacter PubMLST database to analyse genomes of C. sakazakii, by using strains recently isolated by the FDA in Michigan
Article
This is the first report of acute deaths in five European brown hares (Lepus europaeus) attributed to mucoid and necrotizing typhlocolitis caused by genetically different Cronobacter (C.) turicensis strains in northeastern Austria. As this opportunistic pathogen is mainly known for causing disease in immunocompromised humans and neonates, this prev...
Article
Full-text available
Cronobacter spp. are opportunistic foodborne pathogens that most often infect neonates and infants through contaminated powdered infant formula. No reports have been published in Serbia on the prevalence of Cronobacter spp. in powdered milk production environments. Consequently, this study aimed to determine the prevalence, molecular characterizati...
Presentation
Full-text available
Multilocus sequence typing has primarily been a genotyping tool using 7 housekeeping loci of about 500 nt in length. This was due to the historic laboratory limitations of PCR and DNA sequencing giving reliable lengths of ~500 nts. However these days because of whole genome sequencing, the MLST approach can be expanded to core genome loci. I am the...
Article
Members of the Cronobacter genus include food-borne pathogens that can cause infections in infants, with a mortality rate as high as 40 to 80%. The high fatality rate of Cronobacter and its isolation from numerous types of food, especially from powdered infant formula, demonstrate the serious nature of this organism. The source tracking of Cronobac...
Article
Full-text available
Cronobacter sakazakii is a pathogen that causes severe diseases such as meningitis and necrotizing enterocolitis in infants under 12 months, associated with the consumption of contaminated rehydrated powdered infant formula (PIF). We present seven C. sakazakii genome sequences isolated from PIF and dairy products in Chile in 2017.
Article
Stress resistance of Cronobacter spp. affecting its control during food production.
Article
Cronobacter sakazakii is an enteropathogen that causes neonatal meningitis, septicemia, and necrotizing enteritis in preterm infants and newborns with a mortality rate of 40% to 80%. Powdered and dairy formulas (P-DF) have been implicated as transmission vehicles and the presence of this pathogen in P-DF led to product recalls in Chile in 2017. The...
Article
Cronobacter sakazakii is a pathogen that causes severe diseases such as meningitis and necrotizing enteritis in infants under 12 months associated with the consumption of rehydrated powdered infant formula (PIF) contaminated with the pathogen. We present seven C. sakazakii genomes isolated from PIF and dairy products in Chile in 2017.
Article
The genus Cronobacter is an opportunistic food-borne pathogen which is able to adapt to diverse environments and shows considerable genetic diversity. Genomic analysis can be used to reveal the variation across the genus with respect to virulence, drug resistance and factors involved in horizontal gene transfer mechanisms, such as integrons, conjug...
Article
Cronobacter species are a group of Gram-negative opportunistic pathogens, which cause meningitis, septicemia, and necrotizing enterocolitis in neonates and infants, with neurological sequelae in severe cases. Interest in Cronobacter has increased significantly in recent years due to its high virulence in children. In this review, we summarize the c...
Article
Cronobacter spp. cause serious diseases, such as necrotizing enterocolitis, bacteremia, and meningitis in neonates and infants. Most Cronobacter-associated meningitis is reportedly due to C. sakazakii and the majority of infections caused by C. malonaticus occur in adults and are less severe. We report the case of meningitis and brain abscess cause...
Article
The emergence of Cronobacter as an important potential pathogen for newborn children and its occurrence in powdered infant formulae has generated a need to develop new management practices for this food group. This includes reduction of the prevalence of Cronobacter in manufacturing environments which can be a source of Cronobacter. This study was...
Article
This study aimed to evaluate the Cronobacter spp. strains isolated on the American continent and characterized using multi-locus sequence typing (MLST) available in the PubMLST database and current literature. From 465 Cronobacter spp. strains, the majority (n = 267, 57.4%) was from North America, mainly from USA (n = 234), and 198 (42.6%) were fro...
Article
Full-text available
This review considers how research in China has progressed our understanding and subsequent improved control of Cronobacter. This emergent bacterial pathogen is associated with neonatal infections through the ingestion of contaminated prepared feed. The review includes large‐scale surveys of various sources of the organism, including infant formula...
Article
Full-text available
Cronobacter spp. are opportunistic pathogens of the Enterobacteriaceae family. The organism causes infections in all age groups, but the most serious cases occur in outbreaks related to neonates with meningitis and necrotizing enterocolitis. The objective was to determine the in silico and in vitro putative virulence factors of six Cronobacter saka...
Article
Aims: The objective of this study was to evaluate the cytotoxic activity of Cronobacter strains isolated from foods (n = 50) and clinical samples (n = 6) in Brazil and genotype selected strains (n = 18) using multi-locus sequence typing (MLST) METHODS AND RESULTS: The cytotoxic activity of C. sakazakii (n = 29), C. dublinensis (n = 13), C. malonat...
Article
Full-text available
Background: Kitchen sponges are a major source of cross-contamination as they can transfer foodborne pathogens, infectious agents and spoilage causing microorganisms to food contact surfaces. Several studies have revealed that university students adopt poor practices regarding food safety, hygiene, and the handling of kitchen cleaning equipment....
Book
Full-text available
This third edition has been thoroughly revised to cater to the food scientists and manufacturers of today, addressing such new areas as: Advances in genomic analysis techniques for key organisms, including E. coli, Salmonella, and L. monocytogenes Emerging information on high-throughput sequencing and genomic epidemiology based on genomic analysi...
Article
Full-text available
Cronobacter sakazakii (C. sakazakii) is a foodborne opportunistic pathogen that can cause life-threatening invasive diseases, such as necrotizing enterocolitis, meningitis, and sepsis in infants. The potential risk of C. sakazakii contamination of powdered infant formula (PIF) is an issue that has attracted considerable attention from manufacturers...
Conference Paper
Full-text available
Cronobacter species are opportunistic food-borne pathogens that may cause life-threatening infections in neonates and infants. This study was conducted to investigate the phenotypic and genotypic diversity of Cronobacter spp. from food isolates. Fifty four strains have been used in this study. Most strains were motile except two C. sakazakii strain...
Conference Paper
Full-text available
The genus Cronobacter are opportunistic pathogens. This genus is associated with neonatal and immunocompromised adults infections causing meningitis, necrotizing enterocolitis (NEC) and bacteraemia in neonates. Cronobacter strains were studied phenotypically to investigate their ability to produce indole, malonate metabolism and utilize sialic acid...
Article
The aim of this study was to evaluate the microbiological quality of 45 samples of corn-based farinaceous foods commercialized in Brazil. The bacteriological analysis performed were: detection of Salmonella and Cronobacter, and enumeration of faecal coliforms and Bacillus cereus. The Cronobacter isolates were phenotypically characterized by Vitek 2...
Article
Cronobacter infections of infants are commonly regarded as due to the ingestion of contaminated feed. The aim of this study was to determine the occurrence of Cronobacter, total coliforms and Escherichia coli in different brands of natural mineral waters as sold in 20L returnable bottles in Rio de Janeiro, Brazil. The quantification of total colifo...
Article
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...
Article
Full-text available
Cronobacter malonaticus is a member of the genus Cronobacter which is considered an opportunistic pathogen. The significance of C. malonaticus has recently increased since it was documented to be involved in several serious neonatal infections. However, the virulence factors of C. malonaticus including their ability to adhere, invade and overcome h...
Article
Full-text available
Cronobacter sakazakii has been documented as a cause of life-threating infections, predominantly in neonates. We conducted a multicenter study to assess the occurrence of C. sakazakii across Europe and the extent of clonality for outbreak detection. National coordinators representing 24 countries in Europe were requested to submit all human C. saka...
Article
Full-text available
This article presents the UK Ministry of Supply survey of agar property for various seaweeds collected the UK coast during WWII, and also the various seaweeds in applied countries.
Article
Full-text available
Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of t...
Article
The aim of this study was to determine the prevalence Cronobacter from 30 samples of oats and 30 of linseeds commercially available in Brazil. The detection of Cronobacter was as according to the ISO 22964:2017. The isolates were characterized according to their phenotypically using Vitek 2.0 and antibiotic susceptibility profile. Molecular charact...
Article
Full-text available
Analysis of Cronobacter genomes using Genbank accession numbers and the PubMLST database. This will be applicable to other whole genome sequenced organisms with PubMLST sites.
Presentation
Full-text available
Presentation on searching Cronobacter genomes using Genbank accession numbers through the PubMLST database. This will be applicable to other organisms with similar MLST databases.
Article
Full-text available
Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of t...
Article
Molecular and phenotypical characterization of Cronobacter spp. isolated with high occurrence from oats and linseeds One-sentence Summary: This study shows that oats and linseeds offered in markets, presenting products contaminated by Cronobacter, can be a potential threat to human health, particularly for elderly, immunosuppressed and neonates. Ab...
Presentation
Full-text available
This is a Powerpoint description of how to do core genome MLST analysis of Cronobacter, for which there are >500 genomes in the PubMLST database. The method will be applicable to other organisms with genome sequences in the PubMLST database.
Article
Full-text available
This is the first time a neonatal intensive care unit outbreak of Cronobacter sakazakii has been studied and published over a 10 year period, starting with PFGE, followed by 7-loci MLST and then whole genome sequencing enabling CRISPR-cas array profiling, and SNP analysis.
Article
Full-text available
Cronobacter malonaticus is a member of the genus Cronobacter which is considered an opportunistic pathogen. The significance of C. malonaticus has recently increased since it was documented to be involved in several serious neonatal infections. However, the virulence factors of C. malonaticus including their ability to adhere, invade and overcome h...
Article
Full-text available
Cronobacter spp. are bacterial pathogens that cause neonatal meningitis, septicemia, and necrotizing enterocolitis in infants with a lethality rate of 40-80%. Powdered infant formulas (PIF) have been implicated as the main vehicles of transmission. This pathogen can also cause infection through contaminated expressed breast milk, and it has been re...
Data
Milk kitchen floor plan: (A) PIF bottles preparation area (sterile), and (B) Washing and disinfection area.
Article
Full-text available
We describe a case of infection with Cronobacter sakazakii sequence type 494 causing bacteremia and meningitis in a hospitalized late premature infant in Brazil. We conducted microbiological analyses on samples of powdered infant formula from the same batch as formula ingested by the infant but could not identify the source of contamination.
Article
Full-text available
We describe a case of infection with Cronobacter sakazakii sequence type 494 causing bacteremia and meningitis in a hospitalized late premature infant in Brazil. We conducted microbiological analyses on samples of powdered infant formula from the same batch as formula ingested by the infant but could not identify the source of contamination.
Article
Full-text available
Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many years...
Article
Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections ; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many year...
Article
Full-text available
Bacteria belonging to the genus Cronobacter are opportunistic pathogens known for causing rare but serious infections in neonates, including meningitis, necrotising enterocolitis and sepsis. Cronobacter infections occur also in adult populations, however, they generally have milder manifestations and their prevalence is uncertain. In this study, th...
Article
Full-text available
Background: Cronobacter species are associated with severe foodborne infections in neonates and infants, with particular pathovars associated with specific clinical presentations. However, before 2008 the genus was regarded as a single species named Enterobacter sakazakii which was subdivided into 8 phenotypes. This study re-analyzed, using multi-l...
Conference Paper
Full-text available
The webinar reviews issues concerning Salmonella and Cronobacter in powdered infant formula
Article
Full-text available
The nonpathogenic species Siccibacter turicensis is closely related to members of the food-associated pathogenic genus Cronobacter and has been detected in fruit powders, formula, spices, and herbs. Here, we report on the first clinical isolate of S. turicensis, recovered from the labial angle of a patient with angular cheilitis.
Article
Full-text available
The air in a powdered infant formula (PIF) factory is a potential transfer medium for microorganisms. In this study, air samples from 6 main processing areas, almost covering the whole PIF processing line and 1 outdoor location, were collected from a PIF manufacturing plant during the winter and summer periods. A cultivation-based and an Illumina (...
Article
Full-text available
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 advic...
Article
Cronobacter is a ubiquitous Gram‐negative pathogen bacterium capable of surviving in low water activity environments, in particular powdered infant formula (PIF). Seven Cronobacter strains representing four different species (C. sakazakii, n=4; C. malonaticus, n=1; C. muytjensii, n=1; C. turicensis, n=1) were subjected to dry stress and stored in P...
Article
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...
Article
Full-text available
The bacterial flora of nasogastric feeding tubes and faecal samples were analysed for a low-birth weight (725 g) neonate EGA 25 weeks in intensive care. Samples were collected at age 6 and 8 weeks of life. Optical coherence tomography (OCT) was used to visualise bacterial biofilms inside the nasogastric feeding tubes. The biofilm was heterogeneousl...
Article
Full-text available
Cronobacter are an important group of foodborne pathogens that has been linked to life-threatening infections in both infants and adults. The major infections associated with Cronobacter species are neonatal meningitis, necrotizing enterocolitis, and septicaemia. There are seven species in the Cronobacter genus, of which only three are of clinical...
Article
Full-text available
Cronobacter sakazakii is an opportunistic pathogen that causes severe infections in neonates and infants through contaminated powdered infant formula (PIF). Therefore, the aim of this study was a large-scale study on determine the prevalence, molecular characterization and antibiotic susceptibility of C. sakazakii isolates from PIF purchased from C...
Article
Full-text available
The Cronobacter genus is composed of seven species, within which a number of pathovars have been described. The most notable infections by Cronobacter spp. are of infants through the consumption of contaminated infant formula. The description of the genus has greatly improved in recent years through DNA sequencing techniques, and this has led to a...
Article
Several Cronobacter species are opportunistic pathogens that cause infections in humans. This study evaluated the phenotypic characteristics of 57 Cronobacter strains (C. sakazakii n = 41, C. malonaticus n = 10, C. dublinensis n = 4, and C. muytjensii n = 2) isolated from food (n = 54) and clinical specimens (n = 3) in Brazil. These strains include...
Article
Developments in our understanding of the Cronobacter genus generated from studying an outbreak at a neonatal intensive care unit for 10 years Stephen J. Forsythe ABSTRACT In 1994 an outbreak attributed to Enterobacter sakazakii occurred in a French neonatal intensive care unit. Four babies died due to meningitis and necrotizing enterocolitis. Since...
Chapter
Members of the Cronobacter genus are opportunistic pathogens within the bacterial family Enterobacteriaceae. They are associated with rare and sporadic infections in adults and associated with severe life threatening outbreaks of necrotizing enterocolitis, as well as causing meningitis and sepsis in neonates and infants. The organism is most common...
Chapter
MLST is a molecular typing technique that involves the identification and clustering of bacterial isolates based on the partial sequence analysis of multiple housekeeping genes (generally seven) which are distributed across the length of the genome of the organism. The Cronobacter whole genus MLST scheme can be successfully used for an accurate spe...
Article
Several Cronobacter species are opportunistic pathogens that cause infections in humans. The aim of this study was to detect Cronobacter spp. from 90 samples of retail foods in Brazil, and characterize the strains by phenotypic tests, molecular assays and antibiotic susceptibility. Three isolation methodologies were evaluated using different select...
Article
Full-text available
This study evaluated the antimicrobial and desiccation resistance of Cronobacter sakazakii and Cronobacter malonaticus isolates from powdered infant formula and processing environments. The antimicrobial susceptibility tests showed that the 70 Cronobacter strains, representing 19 sequence types, were susceptible to the most of the antibiotics excep...
Article
This article considers a range of emergent or recently recognized enteric pathogens, which may be foodborne. It will be seen that the amount of information known on these organisms depends upon both their severity and also relevance to international policies for microbiological safety. Some like Cronobacter are currently associated with one particu...