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.saka...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,regulators,and consumers.C.sakazakii biofilms on the surfaces of equipment and in diverse food-production environments constitute a mode of cell growth that protects the pathogen from hostile environments,and are an important source of persistent contamination of food products.Bacterial biofilms are difficult to remove due to their resistant properties.Conventional cleaning and sterilizing procedures may be insufficient for biofilm control,and may lead to further biofilm development and dispersal.Consequently,novel control strategies are being developed,such as nanotechnology-based delivery systems,interspecies interactions,antimicrobial molecules of microbial origin,natural extracts,and phages.This review focuses on describing the mechanisms underlying the biofilm formation and behavior of C.sakazakii and discussing potential control strategies.展开更多
Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,and necrotizing enterocolitis in neonates and infants,with neurological sequelae in severe cases.Interest in ...Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,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 current understanding of the prevalence of Cronobacter species in several important food types.We discuss the response mechanisms enabling persistence in adverse growth con-ditions,as well as its pathogenicity.We emphasize the food safety concerns caused by Cronobacter and subsequent control methods and clinical treatments.展开更多
Cronobacter sakazakii is an emerging pathogen that can cause diseases for several infant groups. These bacteria were contaminated in foods, clinical utensils, and environments. In Indonesia, C. sakazakii has been isol...Cronobacter sakazakii is an emerging pathogen that can cause diseases for several infant groups. These bacteria were contaminated in foods, clinical utensils, and environments. In Indonesia, C. sakazakii has been isolated from powdered infant formulas, weaning foods, and other dried foods such as cornstarch. The objective of this research is to trace survival of C. sakazakii during cornstarch production step using its mutant. Mutant was constructed by inserting Green Fluorescent Protein plasmid inside to the bacterial cell that appeared green fluorescent colonies under UV observation. The presence of C. sakazakii during processing was conducted by artificial contamination. This research consists of three steps, i.e. determination of the suitable enumeration method of C. sakazakii’s mutant, cornstarch production from yellow corn, and survival analysis of C. sakazakii during endosperm soaking and cornstarch drying. The suitable enumeration method was surface plating method on TSA-ampicillin medium combining with UV light application because of ineffectiveness of ampicillin inhibition for growth of yeasts and molds. The cornstarch produced in laboratory has the same properties with commercial cornstarch in parameters of moisture content, density, and starch granule structure. The yield of cornstarch final product was 48.90% (dry whole kernel-based). C. sakazakii cannot survive in 48 hours soaking process at 52?C and 24 hours drying process at 50?C that is applied during cornstarch production.展开更多
Cronobacter spp.(formerly Enterobacter sakazakii) are special foodborne pathogens. Cronobacter infection can cause necrotizing enterocolitis, sepsis and meningitis in all age groups, especially neonates and infants, w...Cronobacter spp.(formerly Enterobacter sakazakii) are special foodborne pathogens. Cronobacter infection can cause necrotizing enterocolitis, sepsis and meningitis in all age groups, especially neonates and infants, with a high fatality of up to 80%, although the infection is rare. Outbreaks of Cronobacter infection are epidemiologically proven to be associated with contaminated powdered infant formula(PIF). Cronobacter spp.can resist dry environments and survive for a long period in food with low water activity. Therefore, Cronobacter spp.have become serious pathogens of neonates and infants, as well as in the dairy industry. In this review, we present the taxonomy, pathogenesis, resistance, detection and control of Cronobacter spp.展开更多
AIM To investigate whether patients with refractory epilepsy and healthy infants differ in gut microbiota(GM),and how ketogenic diet(KD) alters GM.METHODS A total of 14 epileptic and 30 healthy infants were recruited ...AIM To investigate whether patients with refractory epilepsy and healthy infants differ in gut microbiota(GM),and how ketogenic diet(KD) alters GM.METHODS A total of 14 epileptic and 30 healthy infants were recruited and seizure frequencies were recorded. Stool samples were collected for 16 S r DNA sequencing using the Illumina Miseq platform. The composition of GM in each sample was analyzed with MOTHUR,and intergroup comparison was conducted by R software.RESULTS After being on KD treatment for a week,64% of epileptic infants showed an obvious improvement,with a 50% decrease in seizure frequency. GM structure in epileptic infants(P1 group) differed dramatically from that in healthy infants(Health group). Proteobacteria,which had accumulated significantly in the P1 group,decreased dramatically after KD treatment(P2 group). Cronobacter predominated in the P1 group and remained at a low level both in the Health and P2 groups. Bacteroides increased significantly in the P2 group,in which Prevotella and Bifidobacterium also grew in numbers and kept increasing.CONCLUSION GM pattern in healthy infants differed dramatically from that of the epileptic group. KD could significantly modify symptoms of epilepsy and reshape the GM of epileptic infants.展开更多
Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical in...Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical industry and can be used for bioconversion of waste. From the municipal solid waste we have isolated an amylase producing bacteria that can grow in the irritant municipal waste and help in their bio conversation. The bacteria were identified as Cronobacter sakazakii Jor52 (C2). The optimized media for maximum amylase production after 24 h of incubation, contains 2% starch, 0.6% peptone, 0.01% CaCl2, 0.05% KCl, 0.05% MgSO4 and 0.05% K2HPO4. The crude enzyme activity and stability study revealed that the amylase is stable within the pH 6 - 8 and temperature 30°C - 40°C and give maximum activity at 37°C at pH-8.展开更多
Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this fa...Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this family are discovered continuously, compounding their threat to global health care. MBLs are divided into three subgroups, i.e. B1, B2 and B3. The recent discovery of an unusual MBL from Serratia proteamaculans (SPR-1) suggests the presence of an additional subgroup, i.e. B4. A database search reveals that SPR-1 has only one homologue from Cronobacter sakazakii, CSA-1.These two MBLs have a unique active site and may employ a mechanism distinct from other MBLs, but reminiscent of some organophosphate-degrading hydrolases.展开更多
基金financial support of National Key Research and Development Program of China(2017YFC1601200)the Science and Technology Planning Project of Guangdong Province(2017A070702018)+1 种基金the Science and Technology Planning Project of Guangzhou(201604020003)Guangdong Academy of Sciences Special Project of Science and Technology Development(2017GDASCX-0201).
文摘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,regulators,and consumers.C.sakazakii biofilms on the surfaces of equipment and in diverse food-production environments constitute a mode of cell growth that protects the pathogen from hostile environments,and are an important source of persistent contamination of food products.Bacterial biofilms are difficult to remove due to their resistant properties.Conventional cleaning and sterilizing procedures may be insufficient for biofilm control,and may lead to further biofilm development and dispersal.Consequently,novel control strategies are being developed,such as nanotechnology-based delivery systems,interspecies interactions,antimicrobial molecules of microbial origin,natural extracts,and phages.This review focuses on describing the mechanisms underlying the biofilm formation and behavior of C.sakazakii and discussing potential control strategies.
基金the financial support of National Key Research and Development program, China (2017YFC1601202 and 2017YFC1601200)China Postdoctoral Science Foundation (2021M690854)+2 种基金National Natural Science Foundation of China (31671951 and 31972175)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01S174)Fundamental Research Funds for the Central Universities, China (JZ2020HGQA0151)
文摘Cronobacter species are a group of Gram-negative opportunistic pathogens,which cause meningitis,sep-ticemia,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 current understanding of the prevalence of Cronobacter species in several important food types.We discuss the response mechanisms enabling persistence in adverse growth con-ditions,as well as its pathogenicity.We emphasize the food safety concerns caused by Cronobacter and subsequent control methods and clinical treatments.
文摘Cronobacter sakazakii is an emerging pathogen that can cause diseases for several infant groups. These bacteria were contaminated in foods, clinical utensils, and environments. In Indonesia, C. sakazakii has been isolated from powdered infant formulas, weaning foods, and other dried foods such as cornstarch. The objective of this research is to trace survival of C. sakazakii during cornstarch production step using its mutant. Mutant was constructed by inserting Green Fluorescent Protein plasmid inside to the bacterial cell that appeared green fluorescent colonies under UV observation. The presence of C. sakazakii during processing was conducted by artificial contamination. This research consists of three steps, i.e. determination of the suitable enumeration method of C. sakazakii’s mutant, cornstarch production from yellow corn, and survival analysis of C. sakazakii during endosperm soaking and cornstarch drying. The suitable enumeration method was surface plating method on TSA-ampicillin medium combining with UV light application because of ineffectiveness of ampicillin inhibition for growth of yeasts and molds. The cornstarch produced in laboratory has the same properties with commercial cornstarch in parameters of moisture content, density, and starch granule structure. The yield of cornstarch final product was 48.90% (dry whole kernel-based). C. sakazakii cannot survive in 48 hours soaking process at 52?C and 24 hours drying process at 50?C that is applied during cornstarch production.
基金supported by the China Postdoctoral Science Foundation(2017M611478)Fundamental Research Funds for the Central Universities
文摘Cronobacter spp.(formerly Enterobacter sakazakii) are special foodborne pathogens. Cronobacter infection can cause necrotizing enterocolitis, sepsis and meningitis in all age groups, especially neonates and infants, with a high fatality of up to 80%, although the infection is rare. Outbreaks of Cronobacter infection are epidemiologically proven to be associated with contaminated powdered infant formula(PIF). Cronobacter spp.can resist dry environments and survive for a long period in food with low water activity. Therefore, Cronobacter spp.have become serious pathogens of neonates and infants, as well as in the dairy industry. In this review, we present the taxonomy, pathogenesis, resistance, detection and control of Cronobacter spp.
基金Supported by the Innovation Fund of Science and Technology Commission of Shenzhen Municipality,China,No.JCYJ-2015-0403100317071
文摘AIM To investigate whether patients with refractory epilepsy and healthy infants differ in gut microbiota(GM),and how ketogenic diet(KD) alters GM.METHODS A total of 14 epileptic and 30 healthy infants were recruited and seizure frequencies were recorded. Stool samples were collected for 16 S r DNA sequencing using the Illumina Miseq platform. The composition of GM in each sample was analyzed with MOTHUR,and intergroup comparison was conducted by R software.RESULTS After being on KD treatment for a week,64% of epileptic infants showed an obvious improvement,with a 50% decrease in seizure frequency. GM structure in epileptic infants(P1 group) differed dramatically from that in healthy infants(Health group). Proteobacteria,which had accumulated significantly in the P1 group,decreased dramatically after KD treatment(P2 group). Cronobacter predominated in the P1 group and remained at a low level both in the Health and P2 groups. Bacteroides increased significantly in the P2 group,in which Prevotella and Bifidobacterium also grew in numbers and kept increasing.CONCLUSION GM pattern in healthy infants differed dramatically from that of the epileptic group. KD could significantly modify symptoms of epilepsy and reshape the GM of epileptic infants.
文摘Municipal waste is one of the most hazardous components of developing countries. However, enzymes do provide an eco-friendly solution in this case. Amylase is an important enzyme in food, textile and pharmaceutical industry and can be used for bioconversion of waste. From the municipal solid waste we have isolated an amylase producing bacteria that can grow in the irritant municipal waste and help in their bio conversation. The bacteria were identified as Cronobacter sakazakii Jor52 (C2). The optimized media for maximum amylase production after 24 h of incubation, contains 2% starch, 0.6% peptone, 0.01% CaCl2, 0.05% KCl, 0.05% MgSO4 and 0.05% K2HPO4. The crude enzyme activity and stability study revealed that the amylase is stable within the pH 6 - 8 and temperature 30°C - 40°C and give maximum activity at 37°C at pH-8.
基金N.M.thanks the Science Foundation Ireland(SFI)for financial support in the form of a President of Ireland Young Researcher Award(PIYRA)G.S.acknowledges the award of a Future Fellowship from the Australian Research Council(FT120100694)D.O.and G.S.are grateful to the National Health and Medical Research Council of Aus-tralia for funding.
文摘Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this family are discovered continuously, compounding their threat to global health care. MBLs are divided into three subgroups, i.e. B1, B2 and B3. The recent discovery of an unusual MBL from Serratia proteamaculans (SPR-1) suggests the presence of an additional subgroup, i.e. B4. A database search reveals that SPR-1 has only one homologue from Cronobacter sakazakii, CSA-1.These two MBLs have a unique active site and may employ a mechanism distinct from other MBLs, but reminiscent of some organophosphate-degrading hydrolases.