The efficacy of commercially available antimicrobials for fresh produce—electrolyzed water(EW;around 60 mg/L of free chlorine),a combination of lactic acid and phosphoric acid-based(LPA)and citric acid-based(CA)—was...The efficacy of commercially available antimicrobials for fresh produce—electrolyzed water(EW;around 60 mg/L of free chlorine),a combination of lactic acid and phosphoric acid-based(LPA)and citric acid-based(CA)—was compared with tap water(TW)in preventing cross-contamination during the soaking step of crisping at a retail setting.A bunch of cilantro((103.7±14.9)g/bunch)was inoculated with a three-strain cocktail of nalidixic acid-resistant Salmonella enterica(S.enterica)and Escherichia coli(E.coli)O157:H7,S.enterica and Listeria monocytogenes(L.monocytogenes),or E.coli O157:H7 and L.monocytogenes(around 5.0 log CFU/g).One inoculated and seven non-inoculated cilantro bunches were soaked in 76 L of TW,EW,LPA,and CA for 5 min.Two additional soakings,each with eight bunches of non-inoculated cilantro,were performed in the same soaking water.To determine the cross-contamination of inoculated foodborne pathogens via soaking water,the cilantro samples and soaking water following each soaking step were subjected to microbiological analyses using selective media supplemented with nalidixic acid(100μg/mL).During the first soaking,significantly greater reductions in Salmonella((2.9±0.5)log CFU/g),E.coli O157:H7((3.0±0.1)log CFU/g),and L.monocytogenes((2.7±0.3)log CFU/g)on cilantro were achieved with EW compared to soaking with TW,LPA,and CA(P<0.05).Cross-contamination of foodborne pathogens from inoculated cilantro to non-inoculated cilantro was completely mitigated by EW during three subsequent soaking events.With the exception of TW soaking water,no inoculated foodborne pathogens were detected in the 100 mL soaking water of EW,CA,and LPA collected.Including an appropriate concentration of chemical antimicrobial in water during the soaking step of crisping aids in mitigating cross-contamination of foodborne pathogen(s)in cilantro bunches.展开更多
The effect of different constant air temperatures (18°C, 21°C, 24°C and 27°C) and variable temperatures (24°C/18°C and 27°C/15°C in 12 h/12 h periods) on basil, sage, thyme, lem...The effect of different constant air temperatures (18°C, 21°C, 24°C and 27°C) and variable temperatures (24°C/18°C and 27°C/15°C in 12 h/12 h periods) on basil, sage, thyme, lemon balm, cilantro, rosemary, oregano and rocket was studied. Supplementary lighting was given 16 h·day-1 at a photon flux density (PFD) of 150 μmol·m-2·s-1 (corresponding to 8.6 mol·m-2·day-1 photosynthetic active radiation [PAR]). Including daylight the PAR was 29.6 ± 6.9 mol·m-2·day-1 as a mean during the experimental period. Increasing the temperature from 18°C to 27°C increased the fresh weight in basil (106%), sage (95%), rosemary (126%) and rocket (62%), while an increase from 18°C to 24°C increased the weight in lemon balm (78%), cilantro (41%), oregano (40%) and thyme (58%). For the last four species the fresh weight was unaffected by a further increase to 27°C. No significant difference was found between the 24°C/18°C and 27°C/15°C treatments. These treatments gave a mean temperature of about 21°C, and no significant differences were found between these treatments and the constant 21°C treatment. The plant height generally increased in the same proportion as the fresh weight increased in the different species. No differences were visually observed between the treatments after two weeks under indoor conditions. All species remained green except cilantro and rocket, for which some leaf yellowing took place. A simple test indicated that the flavour increased with increasing temperature (from 18°C to 27°C) in all species except cilantro.展开更多
The global increased antibiotic resistance level in pathogenic microbes has posed a significant threat to human health.Fresh vegetables have been recognized to be an important vehicle of antibiotic resistance genes(AR...The global increased antibiotic resistance level in pathogenic microbes has posed a significant threat to human health.Fresh vegetables have been recognized to be an important vehicle of antibiotic resistance genes(ARGs)from environments to human beings.Phyllosphere ARGs have been indicated to be changed with plant species,yet the influence of plant cultivar on the phyllospheric resistome is still unclear.Here,we detected the ARGs and bacterial communities in the phyllosphere of two cultivars of cilantros and their corresponding soils using high-throughput quantitative PCR technique and bacterial 16S rRNA gene-based high-throughput sequencing,respectively.We further identified the potential bacterial pathogens and analyzed the effects of plant cultivar on ARGs,mobile genetic elements(MGEs),microbiome and potential bacterial pathogens.The results showed that the cultivars did not affect the ARG abundance and composition,but significantly shaped the abundance of MGEs and the composition structure of bacteria in the phyllosphere.The relative abundance of potential bacterial pathogenswas significantly higher in the phyllosphere than that in soils.Mantel test showed that the ARG patterns were significantly correlated to the patterns of potential bacterial pathogens.Our results suggested that the horizontal gene transfer of ARGs in the phyllosphere might be different between the two cultivars of cilantro and highlighted the higher risk of phyllospheric microorganisms compared with those in soils.These findings extend our knowledge on the vegetable microbiomes,ARGs,and potential pathogens,suggesting more agricultural and hygiene protocols are needed to control the risk of foodborne ARGs.展开更多
基金funded by the HATCH Project(NJ10170)of the USDA National Institute for Food and Agriculture,USA.
文摘The efficacy of commercially available antimicrobials for fresh produce—electrolyzed water(EW;around 60 mg/L of free chlorine),a combination of lactic acid and phosphoric acid-based(LPA)and citric acid-based(CA)—was compared with tap water(TW)in preventing cross-contamination during the soaking step of crisping at a retail setting.A bunch of cilantro((103.7±14.9)g/bunch)was inoculated with a three-strain cocktail of nalidixic acid-resistant Salmonella enterica(S.enterica)and Escherichia coli(E.coli)O157:H7,S.enterica and Listeria monocytogenes(L.monocytogenes),or E.coli O157:H7 and L.monocytogenes(around 5.0 log CFU/g).One inoculated and seven non-inoculated cilantro bunches were soaked in 76 L of TW,EW,LPA,and CA for 5 min.Two additional soakings,each with eight bunches of non-inoculated cilantro,were performed in the same soaking water.To determine the cross-contamination of inoculated foodborne pathogens via soaking water,the cilantro samples and soaking water following each soaking step were subjected to microbiological analyses using selective media supplemented with nalidixic acid(100μg/mL).During the first soaking,significantly greater reductions in Salmonella((2.9±0.5)log CFU/g),E.coli O157:H7((3.0±0.1)log CFU/g),and L.monocytogenes((2.7±0.3)log CFU/g)on cilantro were achieved with EW compared to soaking with TW,LPA,and CA(P<0.05).Cross-contamination of foodborne pathogens from inoculated cilantro to non-inoculated cilantro was completely mitigated by EW during three subsequent soaking events.With the exception of TW soaking water,no inoculated foodborne pathogens were detected in the 100 mL soaking water of EW,CA,and LPA collected.Including an appropriate concentration of chemical antimicrobial in water during the soaking step of crisping aids in mitigating cross-contamination of foodborne pathogen(s)in cilantro bunches.
基金This study was supported by Gjennestad Gardener School and the Norwegian Research Council.
文摘The effect of different constant air temperatures (18°C, 21°C, 24°C and 27°C) and variable temperatures (24°C/18°C and 27°C/15°C in 12 h/12 h periods) on basil, sage, thyme, lemon balm, cilantro, rosemary, oregano and rocket was studied. Supplementary lighting was given 16 h·day-1 at a photon flux density (PFD) of 150 μmol·m-2·s-1 (corresponding to 8.6 mol·m-2·day-1 photosynthetic active radiation [PAR]). Including daylight the PAR was 29.6 ± 6.9 mol·m-2·day-1 as a mean during the experimental period. Increasing the temperature from 18°C to 27°C increased the fresh weight in basil (106%), sage (95%), rosemary (126%) and rocket (62%), while an increase from 18°C to 24°C increased the weight in lemon balm (78%), cilantro (41%), oregano (40%) and thyme (58%). For the last four species the fresh weight was unaffected by a further increase to 27°C. No significant difference was found between the 24°C/18°C and 27°C/15°C treatments. These treatments gave a mean temperature of about 21°C, and no significant differences were found between these treatments and the constant 21°C treatment. The plant height generally increased in the same proportion as the fresh weight increased in the different species. No differences were visually observed between the treatments after two weeks under indoor conditions. All species remained green except cilantro and rocket, for which some leaf yellowing took place. A simple test indicated that the flavour increased with increasing temperature (from 18°C to 27°C) in all species except cilantro.
基金supported by the National Key Research and Development Plan from Ministry of Science and Technology of the People’s Republic of China(No.2020YFC1806902)the Alliance of International Science Organizations(No.ANSO-PA-2020-18).
文摘The global increased antibiotic resistance level in pathogenic microbes has posed a significant threat to human health.Fresh vegetables have been recognized to be an important vehicle of antibiotic resistance genes(ARGs)from environments to human beings.Phyllosphere ARGs have been indicated to be changed with plant species,yet the influence of plant cultivar on the phyllospheric resistome is still unclear.Here,we detected the ARGs and bacterial communities in the phyllosphere of two cultivars of cilantros and their corresponding soils using high-throughput quantitative PCR technique and bacterial 16S rRNA gene-based high-throughput sequencing,respectively.We further identified the potential bacterial pathogens and analyzed the effects of plant cultivar on ARGs,mobile genetic elements(MGEs),microbiome and potential bacterial pathogens.The results showed that the cultivars did not affect the ARG abundance and composition,but significantly shaped the abundance of MGEs and the composition structure of bacteria in the phyllosphere.The relative abundance of potential bacterial pathogenswas significantly higher in the phyllosphere than that in soils.Mantel test showed that the ARG patterns were significantly correlated to the patterns of potential bacterial pathogens.Our results suggested that the horizontal gene transfer of ARGs in the phyllosphere might be different between the two cultivars of cilantro and highlighted the higher risk of phyllospheric microorganisms compared with those in soils.These findings extend our knowledge on the vegetable microbiomes,ARGs,and potential pathogens,suggesting more agricultural and hygiene protocols are needed to control the risk of foodborne ARGs.
