Enhancement of Thermal Inactivation of Foodborne Pathogenic Bacteria at Mild Heating Temperatures with Inclusion of Butyl Paraben and the Application on Foods

Thermal processing is widely used in food industry to ensure the microbial safety, however, there is increasing demand on reducing the processing temperature and duration. This study specifically focused on mild heating temperatures (<60 °C) with inclusion of low level (≤ 125 ppm) of the approved preservative butyl-parahydroxy-benzoate (BPB). In a BHI model matrix, four pathogens were studied with submerged coil apparatus: Cronobacter sakazakii 607, Salmonella enterica serotype Typhimurium, attenuated Escherichia coli O157:H7 and Listeria monocytogenes. The results indicated that low concentrations of BPB combined with temperatures < 60 °C achieved 5 – 6 log reductions in less than 15 minutes with tested gram-negative microorganisms, whereas reductions without BPB were only 1 – 2 logs. We further extended the study to food applications: powdered infant formula, non-fat dry milk, and apple juice. The results indicate BPB will be inhibited by proteins, but apple juice is a suitable application

High nitrate accumulation in the Vadose Zone after land-use change from croplands to orchards

Additional evidence indicates that the nitrate stored in the deep soil profile has an important role in regulating the global nitrogen (N) cycle. This study assessed the effects of land-use changes from croplands to intensive orchards (LUCO) on N surplus, nitrate accumulation in deep soil, and groundwater quality in the kiwifruit belt of the northern slope region of the Qinling Mountains, China. LUCO resulted in comparatively high N surplus in orchards (282 vs 1206 kg ha–1 yr–1, respectively). The average nitrate accumulation within the 0–10 m profiles of orchards was 7113 kg N ha–1, which was equal to approximately the total N surplus of 6 years of the orchards. The total nitrate stock within 0–10 m soil profiles of the kiwifruit belt was 266.5 Gg N, which was 3.5 times higher than the total annual N input. The nitrate concentrations of 97% of groundwater samples exceeded the WHO standard. The LUCO resulted in large nitrate storage in the vadose zone and caused serious contamination of groundwater. Our study highlights that nitrate accumulation in the vadose zone of an intensive land-use system is one of the main fates of surplus N and also a hotspot of nitrate accumulation

Land-use change from arable lands to orchards reduced soil erosion and increased nutrient loss in a small catchment

China has been undergoing dramatic land-use change since the1980s. More arable lands have been converted to orchards to produce high-value fruits. There is an urgent need to assess the effects of these land-use changes on soil erosion and nutrient loss in the country. In this study, the Revised Universal Soil Loss Equation model, geographical information systems, and, remote sensing data were used to evaluate the effects of land-use change on soil erosion and nutrient loss in the Yujiahe Catchment, where a significant portion of the arable land that grew wheat and maize between1957 and 1989 was converted to kiwifruit orchards between 1990 and 2013. The total soil erosion from the catchment during 1957–2013 was in line with the sediments in the reservoir at the catchment outlet. Arable land was the major source of soil erosion and its erosion intensity was approximately ten times that of the orchards. The land-use change from arable land to orchard land since 1990 has reduced soil erosion intensity from severe to moderate. The arable land covering 28% of the catchment contributed to 81.3% of total organic matter loss and 80.4% of total nitrogen loss. However, the loss of available phosphorus mainly occurred in the orchards, representing 66.7% of the available phosphorus loss in the catchment. The soil erosion intensity of the arable land was highly sensitive to the land slope. We concluded that land use change from arable land to orchard land reduced soil erosion and increased the risk of nutrient loss from the catchment

Genomic analysis of the Meningococcal ST-4821 complex – western clade, potential sexual transmission and predicted antibiotic susceptibility and vaccine coverage

Introduction: The ST-4821 complex (cc4821) is a leading cause of serogroup C and serogroup B invasive meningococcal disease in China where diverse strains in two phylogenetic groups (groups 1 and 2) have acquired fluoroquinolone resistance. cc4821 was recently prevalent among carriage isolates in men who have sex with men in New York City (USA). Genome-level population studies have thus far been limited to Chinese isolates. The aim of the present study was to build upon these with an extended panel of international cc4821 isolates. Methods: Genomes of isolates from Asia (1972 to 2017), Europe (2011 to 2018), North America (2007), and South America (2014) were sequenced or obtained from the PubMLST Neisseria database. Core genome comparisons were performed in PubMLST. Results: Four lineages were identified. Western isolates formed a distinct, mainly serogroup B sublineage with alleles associated with fluoroquinolone susceptibility (MIC &lt;0.03 mg/L) and reduced penicillin susceptibility (MIC 0.094 to 1 mg/L). A third of these were from anogenital sites in men who have sex with men and had unique denitrification gene alleles. Generally 4CMenB vaccine strain coverage was reliant on strain-specific NHBA peptides. Discussion: The previously identified cc4821 group 2 was resolved into three separate lineages. Clustering of western isolates was surprising given the overall diversity of cc4821. Possible association of this cluster with the anogenital niche is worthy of monitoring given concerns surrounding antibiotic resistance and potential subcapsular vaccine escape

Home country supportiveness/unfavorableness and outward foreign direct investment from China

What drives the outward foreign direct investments (OFDIs) by emerging market firms (EMFs)? Drawing on a strategy tripod framework, this article proposes a theoretical model to predict OFDI by EMFs from China. Specifically, we use institution- and industry-based views to examine two facets of home country environment, namely the supportiveness from home government and unfavorableness from home industry, as important determinants of OFDI, and compare the relative strength of these effects. Further, we use resource-based view to argue that the effect of the home country environment is contingent on the international experience portfolios of EMFs

Investigation into the Impact of Food Matrix on Bacterial Survival during Gastric Digestion

Over the years, food safety research often focused on the bacterial survival during food processing and storage, whereas physiological studies extensively explored the host-pathogen interaction in gastrointestinal tract. There is a need to understand the intermediate step on pathogen survival during gastric digestion and the potential impact from its food carrier. This study utilized water-in-oil (W-O) and oil-in-water (O-W) emulsion as well as deionized water (DI) as the fundamental model food matrices to study the potential protection by food matrix during simulated gastric digestion. Using Salmonella enterica subsp. enterica serovar Typhimurium as a sample foodborne pathogen, this study investigated the survival kinetics of bacteria using various models of simulated gastric digestion. In a simplified static pH simulated gastric digestion model, inoculated W-O and O-W emulsion matrices were challenged with simulated gastric fluid (SGF) containing HCl and pepsin with mixing using a stomacher for two hours. W-O emulsion showed significant protection of Salmonella survival compared to O-W emulsion and DI water. This protective effect appeared to be matrix dependent regardless of the inoculation location of Salmonella (in dispersed phase vs. in continuous phase). Within the same emulsion type, inoculating Salmonella in water phase or oil phase did not show significant difference in its survivability during simulated gastric digestion. The study was then extended to an improved gastric digestion model where the chyme pH dropped from 4.0 to 1.5 over three hours, and the chyme mixing was achieved by an orbital shaker. In addition, the new SGF was modified to be HCl solution with pepsin, amano lipase A, mucin and NaCl. Under this digestion condition, there was no significant difference in Salmonella survival between W-O emulsion, O-W emulsion, and DI water. Moreover, the dispersed-continuous phase ratio of emulsion composition also showed no impact on Salmonella survival. The simulated gastric digestion model setup was also further analyzed including the role of individual digestive enzyme, the pH impact, and the mechanical mixing approach. In the dynamic pH simulated gastric digestion model, partial activity from lipase accelerated the disruption of emulsion structure for both W-O and O-W emulsion matrices. Mild mixing using an orbital shaker also showed difference in Salmonella survival compared to vigorous mixing using a stomacher. Lastly, this study expanded from using Salmonella as the single bacteria strain into a tailored natural microbiome community. Natural microbiome communities from Golden Delicious (GD) and Empire (EP) apples were manually enriched using bacteria culturing broth at pH 5 and pH 7, respectively. The enriched apple microbiome was then collected and analyzed using 16S rRNA sequencing to study the microbial composition. With a significant decrease in Alpha diversity, the culturable apple microbiome was successfully enriched from less than 3 log CFU/ml to more than 8 log CFU/ml. There was no known foodborne human pathogens detected in the enrichment, and the most abundant genera appeared to be potential plant growth promoting bacteria. The collected apple microbiome was then inoculated in various food matrices to study its survivability during dynamic pH simulated gastric digestion including DI water, apple sauce (AS), chicken puree (CK), sweet potato puree (SP), and W-O emulsion. The enriched apple microbiome showed remarkably high survivability in W-O emulsion throughout the full three-hour digestion treatment. CK also exhibited moderate protective effect compared to SP at the same condition. There was no significant difference between DI and AS on bacterial survivability. In addition, the apple microbiome enriched at two pH levels (5 & 7) showed similar bacteria inactivation kinetics. In conclusion, this study revealed the potential impact from food matrix on bacterial survival during simulated gastric digestion. W-O emulsion offered significant protection of certain bacteria strains or communities in specific simulated gastric digestion models. The parameters in gastric digestion models also affected bacterial survival. Future work should focus on exploring the potential impact from other types of food matrices, expanding the microbial survival study into other bacterial strains as well as a more complex microbiome community, and further comparing the various gastric digestion models

Experimental data for Development and evaluation of a modified most probable number (MPN) method for enumerating rifampicin-resistant Escherichia coli in agricultural, food, and environmental samples

This is the dataset for manuscript titled Development and evaluation of a modified most probable number (MPN) method for enumerating rifampicin-resistant Escherichia coli in agricultural, food, and environmental samples that has a DOI of https://doi.org/10.1111/jfs.13127USDA-NIFAhttps://doi.org/10.1111/jfs.1312