Cronobacter spp. isolated from aquatic products in China: Incidence, antibiotic resistance, molecular characteristic and CRISPR diversity

Relevance of genetic causes and environmental adaptation of Cronobacter spp. isolated from infant and follow-up formula production factories and retailed products in China: A 7-year period of continuous surveillance based on genome-wide analysis

The possible contamination routes, environmental adaptation, and genetic basis of Cronobacter spp. in infant and follow-up formula production factories and retailed products in mainland China have been determined by laboratory studies and whole-genome comparative analysis in a 7-year nationwide continuous surveillance spanning from 2012 to 2018. The 2-year continuous multicenter surveillance of the production process (conducted in 2013 and 2014) revealed that the source of Cronobacter spp. in the dry-blending process was the raw dry ingredients and manufacturing environment (particularly in the vibro sieve and vacuum cleaner), while in the combined process, the main contamination source was identified as the packing room. It is important to note that, according to the contamination control knowledge obtained from the production process surveillance, the contamination rate of retail powdered infant formula (PIF) and follow-up formula (FUF) products in China decreased significantly from 2016 onward, after improving the hygiene management practices in factories. The prevalence of Cronobacter spp. in retailed PIF and FUF in China in 2018 was dramatically reduced from 1.55 % (61/3925, in 2012) to an average as low as 0.17 % (13/7655 in 2018). Phenotype determination and genomic analysis were performed on a total of 90 Cronobacter spp. isolates obtained from the surveillance. Of the 90 isolates, only two showed resistance to either cefazolin or cefoxitin. The multilocus sequence typing results revealed that C. sakazakii sequence type 1 (ST1), ST37, and C. malonaticus ST7 were the dominant sequence types (STs) collected from the production factories, while C. sakazakii ST1, ST4, ST64, and ST8 were the main STs detected in the retailed PIF and FUF nationwide. One C. sakazakii ST4 isolate (1.1 %, 1/90) had strong biofilm-forming ability and 13 isolates (14.4 %, 13/90) had weak biofilm-forming ability. Genomic analysis revealed that Cronobacter spp. have a relatively stable core-genome and an increasing pan-genome size. Plasmid IncFIB (pCTU3) was prevalent in this genus and some contained 14 antibacterial biocide- and metal-resistance genes (BMRGs) including copper, silver, and arsenic resistant genes. Plasmid IncN_1 was predicted to contain 6 ARGs. This is the first time that a multi-drug resistance IncN_1 type plasmid has been reported in Cronobacter spp. Genomic variations with respect to BMRGs, virulence genes, antimicrobial resistance genes (ARGs), and genes involved in biofilm formation were observed among strains of this genus. There were apparent differences in copies of bcsG and flgJ between the biofilm-forming group and non-biofilm-forming group, indicating that these two genes play key roles in biofilm formation. The findings of this study have improved our understanding of the contamination characteristics and genetic basis of Cronobacter spp. in PIF and FUF and their production environment in China and provide important guidance to reduce contamination with this pathogen during the production of PIF and FUF.

Biofilm formation and associated gene expression changes in Cronobacter from cereal related samples in China

Cronobacter is an important foodborne pathogen that can cause severe neonatal meningitis, necrotizing enterocolitis, and bacteremia. Currently, there is limited knowledge of biofilm formation in Cronobacter. In the present study, biofilm formation ability and associated gene expression changes in Cronobacter from cereal related samples was carried out systematically. Our results from 307 Cronobacter isolates analyzed for 48 h showed strong biofilm-forming ability in 14 strains (4.6%), moderate in 47 strains (15.3%), weak in 142 strains (46.2%), and no such ability in the remaining 104 strains (33.9%). Further studies on five strains with strong biofilm-forming ability showed that maximum biofilm formation in Cronobacter occurred after 24 h of cultivation, reaching a peak around 48 h-72 h, reducing gradually thereafter. Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that differentially expressed genes (DEGs) involved in flagellar assembly, oxidative phosphorylation, ribosome, photosynthesis, O-Antigen nucleotide sugar biosynthesis, citrate cycle (tricarboxylic acid cycle, TCA) and bacterial chemotaxis were enriched in biofilm forming cells. The genes involved these enrichment pathways were mostly downregulated when compared to planktonic cells. Several transcriptional regulator genes such as csrA and bolA, and the cell surface composition regulator gene glgS were significantly upregulated. 12 of 13 (92.3%) selected genes was found to be in agreement with the RNA-Seq of planktonic and biofilm cells by Quantitative real-time PCR analysis, thus increasing confidence in our data. Our research lays a sound theoretical basis for further studies on mechanisms regulating biofilm formation and provides a foundation for development of new food safety measures, clinical disease prevention and control.

Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR-Associated Protein and Its Utility All at Sea: Status, Challenges, and Prospects

Initially discovered over 35 years ago in the bacterium Escherichia coli as a defense system against invasion of viral (or other exogenous) DNA into the genome, CRISPR/Cas has ushered in a new era of functional genetics and served as a versatile genetic tool in all branches of life science. CRISPR/Cas has revolutionized the methodology of gene knockout with simplicity and rapidity, but it is also powerful for gene knock-in and gene modification. In the field of marine biology and ecology, this tool has been instrumental in the functional characterization of 'dark' genes and the documentation of the functional differentiation of gene paralogs. Powerful as it is, challenges exist that have hindered the advances in functional genetics in some important lineages. This review examines the status of applications of CRISPR/Cas in marine research and assesses the prospect of quickly expanding the deployment of this powerful tool to address the myriad fundamental marine biology and biological oceanography questions.

Co-culture of Cronobacter sakazakii and Staphylococcus aureus: Explore the influence of mixed biofilm formation and regulation of Cronobacter sakazakii biofilm formation genes

Bacterial biofilm is a protective matrix composed of metabolites secreted by bacteria that envelop bacteria. By forming a biofilm, bacteria can considerably improve their environmental tolerance. In food-related processing environment, different types of microorganisms are often present in biofilms. The main contaminating strain in the powdered infant formula (PIF) processing environment, Cronobacter sakazakii and Staphylococcus aureus continues to pollute the PIF processing environment after biofilm production. This study selected Cronobacter sakazakii with a weak biofilm-forming ability as one of the test organisms. The coexistence of Cronobacter sakazakii and Staphylococcus aureus on the surface of production equipment was simulated to analyze the interaction. Biofilm formation in the co-culture group was significantly higher than the others. In-depth study of the effect of Staphylococcus aureus on the biofilm formation genes of Cronobacter sakazakii. Results show two bacteria can coexist on the surface of a metal device, forming a more compact hybrid biofilm structure. Under co-culture conditions, S. aureus increased bcsA and fliD expression in Cronobacter sakazakii, whereas decreased bcsC expression. Signaling molecules produced by Staphylococcus aureus (Autoinducer 2) significantly promoted the biofilm formation of Cronobacter sakazakii at the concentration of 0-500 ng/mL (0.099-0.177) and up-regulated the expression of bcsA, filD and flhD genes.

Environmental risk factors associated with the survival, persistence, and thermal tolerance of Cronobacter sakazakii during the manufacture of powdered infant formula

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.

The Genotyping Diversity and Hemolytic Activity of Cronobacter spp. Isolated from Plant-Based Food Products in Poland

The present study aimed to determine the genotyping diversity and hemolytic properties of 24 strains of Cronobacter spp. (15 Cronobacter sakazakii, 6 Cronobacter malonaticus, 2 Cronobacter turicensis, and 1 Cronobacter condimenti) isolated from commercial ready-to-eat leaf vegetables, sprouts, nuts, and dried fruits. The multilocus sequence typing (MLST) method was used to determine the sequence types (ST) and clonal complexes (CC) of these strains. The study demonstrated the high genotypic diversity of the Cronobacter genus bacteria isolated from plant-based foods. Five novel sequence types (804, 805, 806, 807, and 808) and the presence of novel alleles in the ppsA, gltB, gyrB, and infB loci were detected. In total, 16 of the 24 strains were assigned to the sequence types ST99, ST258, ST17, ST648, ST21, ST494, and ST98. One C. sakazakii strain (s12) isolated from alfalfa sprouts was assigned to the clonal complex CC4, which encompasses strains often associated with severe infections leading to meningitis in infants. In addition, 87.5% and 16.7% of the Cronobacter spp. strains showed β-hemolysis of equine and sheep red blood cells, respectively. The presence of the pathogenic species C. sakazakii, C. malonaticus, and C. turicensis in ready-to-eat plant-derived food products shows they are potential sources of infection, especially to those with compromised immunity, which substantiates their further multi-faceted characterization. The significance of this study may prove useful not only in epidemiological investigations, but also in assessing the risk of infections caused by the presence of Cronobacter.

Cronobacter spp. Isolated from Quick-Frozen Foods in China: Incidence, Genetic Characteristics, and Antibiotic Resistance

Cronobacter spp. are emerging foodborne pathogens that cause severe diseases. However, information on Cronobacter contamination in quick-frozen foods in China is limited. Therefore, we studied the prevalence, molecular characterization, and antimicrobial susceptibility of Cronobacter in 576 quick-frozen food samples collected from 39 cities in China. Cronobacter spp. were found in 18.75% (108/576) of the samples, and the contamination degree of the total positive samples was 5.82 MPN/g. The contamination level of frozen flour product samples was high (44.34%). Among 154 isolates, 109 were C. sakazakii, and the main serotype was C. sakazakii O1 (44/154). Additionally, 11 serotypes existed among four species. Eighty-five sequence types (STs), including 22 novel ones, were assigned, indicating a relatively high genetic diversity of the Cronobacter in this food type. Pathogenic ST148, ST7, and ST1 were the main STs in this study. ST4, epidemiologically related to neonatal meningitis, was also identified. All strains were sensitive to cefepime, tobramycin, ciprofloxacin, and imipenem, in which the resistance to cephalothin was the highest (64.94%).Two isolates exhibited multidrug resistance to five and seven antimicrobial agents, respectively. In conclusion, these findings suggest that the comparatively high contamination level of Cronobacter spp. in quick-frozen foods is a potential risk warranting public attention.

Occurrence, molecular characterization and antibiotic resistance of Cronobacter spp. isolated from wet rice and flour products in Guangdong, China

This study explored the prevalence of Cronobacter spp. in wet rice and flour products from Guangdong province, China, the molecular characteristics and antimicrobial susceptibility profiles of the isolates were identified. Among 249 samples, 100 (40.16%) were positive for Cronobacter spp., including 77 wet rice and 23 wet flour products. Eleven serotypes were characterized among 136 isolates with C. sakazakii O2 (n = 32) predominating. Forty-nine MLST patterns were assigned, 15 of which were new. C. sakazakii ST4 (n = 17) was the dominant ST, which is previously reported to have caused three deaths; followed by C. malonaticus ST7 (n = 15), which is connected to adult infections. All strains presented susceptibility to ampicillin/sulbactam, imipenem, aztreonam and trimethoprim/sulfamethoxazole. The isolates showed maximum resistance to cephalothin, and the resistance and intermediate rates were 91.91% and 3.68%, each. Two strains, croM234A1 and croM283-1, displayed resistance to three antibiotics. High contamination level and predominant number of pathogenic STs of Cronobacter in wet rice and flour products implied a potential risk to public healthiness. This survey could provide comprehensive information for establishing more targeted control methods for Cronobacter spp.

Identification and antibiotic resistance of Cronobacter spp. isolated from dried edible mushrooms

Cronobacter spp. is an important foodborne pathogen that can cause life-threatening diseases in infants and immunocompromised adults. The present study was carried out to understand the prevalence and characterization of Cronobacter spp. in dried edible mushrooms in Jiangsu province, China. Cronobacter isolates were identified and genotyped by multilocus sequence typing (MLST); the antimicrobial susceptibility of Cronobacter strains was determined by the disk diffusion method; the biofilm formation ability of Cronobacter spp. was assessed using the microtiter plate method. The overall prevalence of Cronobacter spp. in dried edible mushrooms was 14.8%, with the highest contamination rate of after 37.2% found in Auricularia auricular. The Cronobacter isolates were identified as C. sakazakii (n = 26), C. malonaticus (n = 2), C. dublinensis (n = 2) and C. turicensis (n = 1). The MLST scheme produced 20 sequence types (STs), two of which were newly identified. ST148 was the most prevalent ST (n = 5), followed by ST4 (n = 3), ST17 (n = 3), ST64 (n = 3), and ST540 (n = 2). One (3.2%) and 15 (48.4%) Cronobacter isolates were resistant to tetracycline and meropenem, respectively. In contrast, all of the tested isolates were susceptible to the remaining 14 antibiotics. Moreover, 20 (64.5%) Cronobacter isolates showed weak ability to produce biofilm, but no isolates showed strong or moderate biofilm-forming ability. PRACTICAL APPLICATION: Our findings revealed a high genetic diversity of Cronobacter spp. in dried edible mushrooms and provided new epidemiological evidence for the widespread existence of Cronobacter spp. in such products. The presence of Cronobacter spp. in dried edible mushrooms may pose potential risks to human health and enhancing the hygiene of such products are necessary to ensure food safety.

Insights into the mechanisms of Cronobacter sakazakii virulence

Cronobacter species have adapted to survive harsh conditions, particularly in the food manufacture environment, and can cause life-threatening infections in susceptible hosts. These opportunistic pathogens employ a multitude of mechanisms to aid their virulence throughout three key stages: environmental persistence, infection strategy, and systemic persistence in the human host. Environmental persistence is aided by the formation of biofilms, development of subpopulations, and high tolerance to environmental stressors. Successful infection in the human host involves several mechanisms such as protein secretion, motility, quorum sensing, colonisation, and translocation. Survival inside the host is achieved via competitive acquisition and utilization of minerals and metabolites respectively, coupled with host immune system evasion and antimicrobial resistance (AMR) mechanisms. Across the globe, Cronobacter sakazakii is associated with often fatal systemic infections in populations including neonates, infants, the elderly and the immunocompromised. By providing insight into the mechanisms of virulence utilised by this pathogen across these three stages, this review identifies current gaps in the literature. Further research into these virulence mechanisms is required to inform novel mitigation measures to improve global food safety with regards to this food-borne pathogen.

Cronobacter spp. in Commercial Powdered Infant Formula Collected From Nine Provinces in China: Prevalence, Genotype, Biofilm Formation, and Antibiotic Susceptibility

The purpose of this study was to investigate the prevalence of Cronobacter spp. in commercial powdered infant formula (PIF) from nine provinces in China from March 2018 to September 2020, and to reveal the genotype, biofilm-forming ability, and antibiotic susceptibility of these isolates. A total of 27 Cronobacter strains, consisting of 22 Cronobacter sakazakii strains, 3 Cronobacter malonaticus strains, 1 Cronobacter turicensis strain, and 1 Cronobacter dublinensis strain, were isolated from 3,600 commercial PIF samples with a prevalence rate of 0.75%. Compared with the other 8 provinces, PIF from Shaanxi province had a higher prevalence rate (1.25%) of Cronobacter spp. These isolates were divided into 14 sequence types (STs), and 6 Cronobacter serotypes. The main Cronobacter STs were ST4, ST1, and ST64, and the dominant Cronobacter serotype was C. sakazakii serotype O2. Approximately 88.89% of Cronobacter isolates had a strong ability (OD595 > 1) to form biofilms on tinplate, among which the strains with ST4 were more dominant. All isolates were susceptible to ampicillin-sulbactam, ceftriaxone, cefotaxime, sulfadiazine, sulfadoxine, trimethoprim-sulfamethoxazole, gentamicin, tetracycline, ciprofloxacin, and colistin, while 55.56 and 96.30% isolates were resistant to cephalothin and vancomycin, respectively. Taken together, our findings highlighted the contamination status and characterization of Cronobacter spp. in commercial PIF from nine provinces of China, and provided guidance for the effective prevention and control of this pathogen in the production of PIF.

Occurrence, Molecular Characterization, and Antibiotic Resistance of Cronobacter sakazakii in Goat Milk-Based Infant Formula from Shaanxi Province, China

This study aimed to investigate the prevalence of Cronobacter sakazakii in goat milk-based infant formula (GIF) collected from Shaanxi Province, China, and reveal the molecular characterization and antibiotic resistance profile of these isolates. A total of 750 GIF samples were collected from the retail markets in 5 cities in Shaanxi Province from February 2019 to February 2021. Molecular characterization was investigated using multilocus sequence typing and O-antigen serotyping. Antibiotic resistance of C. sakazakii isolates was assessed using antimicrobial susceptibility testing. Thirty-two strains of C. sakazakii were isolated from GIF samples with a prevalence rate of 4.27% and were divided into 16 sequence types (STs); among them, ST4 (6/32, 18.75%) and ST21 (5/32, 15.63%) were dominant. Five C. sakazakii serotypes (O2, O1, O7, O4, and O3) were detected, and C. sakazakii serotype O2 (15/32, 46.88%) was the main. Of the 21 antimicrobials, isolates showed higher resistance against cephalothin (87.5%), amoxicillin (25%), azithromycin (18.75%), oxytetracycline (18.75%), ampicillin (12.5%), and streptomycin (12.5%). In addition, three isolates were found to be resistant to three antimicrobials. These findings revealed the potential epidemiological risk and characterization of C. sakazakii in GIF from Shaanxi Province, China, and provided reference data for the effective prevention and control of C. sakazakii in powdered infant formula.

Prevalence, detection of virulence genes and antimicrobial susceptibility of pathogen Vibrio species isolated from different types of seafood samples at "La Nueva Viga" market in Mexico City

Some Vibrio species are important human pathogens owing to they cause infectious diseases such as gastroenteritis, wound infections, septicemia or even death. Many of these illnesses are associated with consumption of contaminated seafood. In the present study, we evaluated the presence of pathogenic Vibrio species, their virulence and antimicrobial susceptibility from 285 different kind of seafood samples from "La Nueva Viga" market in Mexico City. The PCR assay was used for amplification the vppC (collagenase), vmh (hemolysin), tlh (thermolabile hemolysin), and vvhA (hemolytic cytolysin) genes that are specific to Vibrio alginolyticus (detected in 27%), Vibrio mimicus (23.2%), Vibrio parahaemolyticus (28.8%) and Vibrio vulnificus (21.1%), respectively. Several genes encoding virulence factors were amplified. These included V. alginolyticus: pvuA (17.9%), pvsA (50%), wza and lafA (100%); V. mimicus: iut A (60%), toxR (100%); V. parahaemolyticus: pvuA (58.7%), pvsA (26.1%), wza (2.2%), and lafA (100%); and V. vulnificus: wcrA (77.5%), gmhD (57.5%), lafA (100%) and motA (30%). The antibiotic susceptibility of the Vibrio species isolates revealed that most of them were resistant to ampicillin, cephalothin and carbenicillin but susceptible to pefloxacin and trimethoprim-sulfamethoxazole. Our results indicated a high prevalence of pathogenic Vibrio species in seafood, a high presence of virulence genes and that Vibrio species continuously exposed to antibiotics, therefore, consumption of these kind of seafood carries a potential risk for foodborne illness.

Novel phage vB_CtuP_B1 for controlling Cronobacter malonaticus and Cronobacter turicensis in ready-to-eat lettuce and powered infant formula

Cronobacter spp. are important foodborne pathogens that are a threat to people of all ages, but especially neonates and infants. Bacteriophages are biological agents that are potentially useful for the control of foodborne pathogens. However, there has been little research on the control of C. malonaticus and C. turicensis using bacteriophages. In the present study, a novel lytic phage vB_CtuP_B1 (hereafter referred to as B1)-which can simultaneously lyse C. malonaticus and C. turicensis- was isolated from river water in Guangzhou, China, and was used in the control of Cronobacter contaminated food. The phage has a short tail, and has been identified as a new species of Kayfunavirus based on genomic and phylogenetic analyses. One-step growth and stability assays revealed that phage B1 has a very short latent period (<5 min) and a large burst size (4006 pfu/cell), and is highly stable between 25 and 60 °C and between pH 5 and 11. Its genome encodes two lytic proteins, but does not contain any genes responsible for antibiotic resistance and virulence factors. In broth, the phage B1 completely inhibited the growth of C. malonaticus cro2475W and C. turicensis cro1541A1-1 for up to 6 h. On lettuce, phage B1 reduced the viable count of C. turicensis cro1541A1-1 to below the detection limit for bacteria on lettuce (<10 cfu/mL) after 6 h at 4 °C and 2 h at 25 °C, and also significantly reduced the viable count of C. malonaticus cro2475W at those temperatures. In powdered infant formula, the viable counts of both the phage-treated bacterial hosts were significantly reduced after 2 h of storage at 4 °C or 37 °C. Furthermore, phage B1 reduced the viable count of C. turicensis cro1541A1-1 to below the detection limit (<10 cfu/mL) from 4 h to 24 h at 37 °C. It significantly inhibited the growth of C. turicensis cro1541A1-1 than that of C. malonaticus cro2475W (P < 0.05). In conclusion, phage B1 with high stability and strong lytic ability is potentially useful for controlling C. malonaticus and C. turicensis.

Applications of Non-invasive and Novel Methods of Low-Field Nuclear Magnetic Resonance and Magnetic Resonance Imaging in Aquatic Products

Aquatic products, such as fish, are popular throughout the world due to their satisfying flavor characteristics as well as rich animal nutrition, and they provide high-value food therapy, but they are easily oxidized and spoiled. It is necessary to detect aquatic products through rapid and accurate technology. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) have been widely used in the aquatic product industry due to their sensitivity, fast analysis, non-destructive nature and low cost. The applications of LF-NMR in the measurement of aquatic product quality and nutrients (water, fat, and protein) are summarized in this paper. Applications in aquatic products have been shown to depend on deep processing, storage and authentication. This review discusses the application of MRI technology in the quality control of aquatic products. Therefore, this review will guide the application of the aquatic products industry and aims to supply the reader with both the theory of the method and practical applications of the method for use as a rapid and non-destructive technology in scientific research and the industrial industry.

Isolation and characterization of new phage vB_CtuP_A24 and application to control Cronobacter spp. in infant milk formula and lettuce

Cronobacter spp. are opportunistic pathogenic bacteria that cause severe diseases in neonates and infants. Bacteriophages are novel antibacterial agents with a potential to control this pathogen. In the current study, a novel lytic Cronobacter phage, vB_CtuP_A24, was isolated from a river in Guangzhou, China. The phage was characterized by a short, non-contractile tail and a long head and identified as a new member of the family Podoviridae. Complete genome sequence analysis of this phage indicated that its genome contained 75,106 bp of DNA, an average GC content of 44.05%, and 108 predicted open reading frames (ORFs). The annotated ORFs were associated with phage structure, packaging, host lysis, DNA manipulation, transcription, and additional functions. Genes responsible for antibiotic resistance, virulence, and toxic effects were not present. Cronobacter phage vB_CtuP_A24 is a novel lytic phage that can lyse five Cronobacter spp. It was stable over a wide range of temperatures (25-60 °C) and pH values (pH 4-11) and displayed a short latent period (approximately 10 min) and a large burst size (500 plaque-forming units (PFUs)/cell). In Luria-Bertani (LB) broth, phage A24 effectively inhibited the growth of C. dublinensis cro280B, C. sakazakii 465G, and C. malonaticus cro695W up to 9, 10, and 12 h, respectively, while in infant milk formulas, it inhibited two strains, C. sakazakii 465G and C. malonaticus cro695W, up to 24 h at 37 °C, with maximum reduction levels of approximately 5.12 ± 3.95 and 7.38 ± 3.03 log10 colony-forming unit (CFU)/mL, respectively. In lettuce, the reduction of all three strains was highly significant at 25 °C. However, the growth of C. dublinensis cro280B and C. sakazakii 465G were not significantly inhibited at 4 °C. In conclusion, Cronobacter spp. phage vB_CtuP_A24, which has lytic ability against five Cronobacter species, stability under different environments, and shows potential as a promising biocontrol agent against Cronobacter spp. in food production.