Rosa roxburghii Tratt Pomace Crude Extract Inactivates Cronobacter sakazakii Isolated from Powdered Infant Formula.

Cronobacter sakazakii is an important foodborne pathogen in powder infant formula (PIF). The objective of this study was to evaluate the inactivation effect of Rosa roxburghii Tratt pomace crude extract (RRPCE) on C. sakazakii isolated from PIF and to reveal the mechanism of action. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were used to evaluate the inhibitory activity of RRPCE against C. sakazakii. The inhibitory mechanism was revealed from the perspective of effects of RRPCE on intracellular adenosine 5'-triphosphate (ATP), reactive oxygen species (ROS), membrane potential, protein and nucleic acid leakage, and cell morphology of C. sakazakii. The inactivation effects of RRPCE on C. sakazakii in biofilms on stainless steel, tinplate, glass, silica gel, polyethylene terephthalate, and polystyrene to evaluate its potential as a natural disinfectant. The results showed that the MIC and MBC of RRPCE against C. sakazakii were 7.5 and 15 mg/mL, respectively. After treatments with RRPCE, intracellular ATP content decreased significantly while intracellular ROS level increased significantly (p < 0.05). The cell membrane depolarization, large leakage of proteins and nucleic acids, and severely damaged cell morphology also occurred in C. sakazakii treated with RRPCE. In addition, a 20-minute treatment with 2 MIC (15 mg/mL) of RRPCE could inactivate all C. sakazakii (from 6.10 to 6.40 CFU/mL) in biofilms on all six contact surfaces. Our findings suggest that RRPCE is ideal for the inactivation of C. sakazakii and has the potential to be used as a natural disinfectant for the inactivation of PIF packaging materials and containers.

Antibacterial Activity and Mechanism of Polygonatum sibiricum Extract Against Bacillus cereus and Its Application in Pasteurized Milk.

The purpose of this study was to reveal the antibacterial activity and mechanism of Polygonatum sibiricum extract (PSE) against Bacillus cereus and further analyze the application of PSE in pasteurized milk (PM). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values and growth curve analysis were used to evaluate the antibacterial activity of PSE against B. cereus. The changes in contents of intracellular adenosine 5'-triphosphate (ATP) and reactive oxygen species (ROS), activities of ß-galactosidase, adenosine triphosphatase (ATPase) and alkaline phosphatase (AKP), cell membrane potential, protein and nucleic acid leakage, and cell morphology were used to reveal the antibacterial mechanism. The effects of PSE on viable count and sensory evaluation of PM during storage were analyzed. The results showed that the MIC and MBC values of PSE against B. cereus were 2 and 4 mg/mL, respectively. Growth curve analysis showed that PSE with a concentration of 2 MIC could completely inhibit the growth of B. cereus. After treatments with PSE, the levels of intracellular ATP and ROS, and activities of ß-galactosidase, ATPase and AKP of B. cereus were significantly reduced (p < 0.05). Cell membrane was depolarized, amounts of protein and nucleic acid leakage were significantly increased (p < 0.05), and cell morphology was destroyed. Furthermore, PSE significantly reduced the viable count of B. cereus in PM and improved the sensory quality of PM during storage (p < 0.05). Together, our findings suggested that PSE had the desired effect as a natural preservative applied in PM.

Deep sequencing of circulating miRNAs and target mRNAs level in deep venous thrombosis patients.

Deep venous thrombosis is one of the most common peripheral vascular diseases that lead to major morbidity and mortality. The authors aimed to identify potential differentially expressed miRNAs and target mRNAs, which were helpful in understanding the potential molecule mechanism of deep venous thrombosis. The plasma samples of patients with deep venous thrombosis were obtained for the RNA sequencing. Differentially expressed miRNAs were identified, followed by miRNA-mRNA target analysis. Enrichment analysis was used to analyze the potential biological function of target mRNAs. GSE19151 and GSE173461 datasets were used for expression validation of mRNAs and miRNAs. 131 target mRNAs of 21 differentially expressed miRNAs were identified. Among which, 8 differentially expressed miRNAs including hsa-miR-150-5p, hsa-miR-326, hsa-miR-144-3p, hsa-miR-199a-5p, hsa-miR-199b-5p, hsa-miR-125a-5p, hsa-let-7e-5p and hsa-miR-381-3p and their target mRNAs (PRKCA, SP1, TP53, SLC27A4, PDE1B, EPHB3, IRS1, HIF1A, MTUS1 and ZNF652) were found associated with deep venous thrombosis for the first time. Interestingly, PDE1B and IRS1 had a potential diagnostic value for patients. Additionally, 3 important signaling pathways including p53, PI3K-Akt and MAPK were identified in the enrichment analysis of target mRNAs (TP53, PRKCA and IRS1). Identified circulating miRNAs and target mRNAs and related signaling pathways may be involved in the process of deep venous thrombosis.

Antibacterial Pattern of Rosa roxburghii Tratt Pomace Crude Extract Against Staphylococcus aureus and Its Application in Preservation of Cooked Beef.

Staphylococcus aureus is a common foodborne pathogen and spoilage bacterium in meat products. To develop a natural preservative for meat products, this study revealed the antibacterial activity and mechanism of Rosa roxburghii Tratt pomace crude extract (RRPCE) against S. aureus, and applied RRPCE to the preservation of cooked beef. The diameter of inhibition zone, minimum inhibitory concentration (MIC), and minimum bactericide concentration of RRPCE against S. aureus were 15.85 ± 0.35 to 16.21 ± 0.29 mm, 1.5 mg/mL, and 3 mg/mL, respectively. The growth curve of S. aureus was completely stalled by treatment with RRPCE at 2 MIC. RRPCE results in the decrease of intracellular adenosine 5'-triphosphate (ATP) content, depolarization of cell membrane, leakage of cell fluid including nucleic acid and protein, and destruction of cell membrane integrity and cell morphology. During storage, RRPCE significantly reduced S. aureus viable counts, pH, and total volatile basic nitrogen of cooked beef compared with untreated samples (p < 0.05). In addition, RRPCE could significantly increase the redness (a*) value, decrease lightness (L*) and yellowness (b*) values, and slow down the color change of cooked beef (p < 0.05). These findings suggest that RRPCE can effectively inhibit S. aureus, and has the potential as a natural preservative for the preservation of cooked beef.

Antibacterial Activity of Thymoquinone Against Shigella flexneri and Its Effect on Biofilm Formation.

Thymoquinone (TQ) has been demonstrated to have anti-cancer, anti-inflammatory, antioxidant, and anti-diabetic activities. Shigella flexneri is the main pathogen causing shigellosis in developing countries. In this study, the antibacterial activity of TQ against S. flexneri and its possible antibacterial mechanism were studied. In addition, the inhibitory effect of TQ on the formation of S. flexneri biofilm was also investigated. The results showed that both the minimum inhibitory concentration and the minimum bactericidal concentration of TQ against S. flexneri ATCC 12022 were 0.2 mg/mL. After treatment with TQ at 0.4 mg/mL in Luria-Bertani broth for 3 h, or treatment with 0.2 mg/mL TQ in phosphate-buffered saline for 60 min, the number of S. flexneri (initial number is 6.5 log colony-forming units/mL) dropped below the detection limit. TQ also displayed good antibacterial activity in contaminated lettuce juice. TQ caused an increase in intracellular reactive oxygen species level, a decrease in intracellular adenosine triphosphate (ATP) concentration, a change in the intracellular protein, damage to cell membrane integrity and changes in cell morphology. In addition, TQ showed the ability to inhibit the formation of S. flexneri biofilm; treatment resulted in a decrease in the amount of biofilm and extracellular polysaccharides, and the destruction of biofilm structure. These findings indicated that TQ had strong antimicrobial and antibiofilm activities and a potential to be applied in the fruit and vegetable processing industry or other food industries to control S. flexneri.

Antibacterial Mechanism of Eugenol Against Shigella sonnei and Its Antibacterial Application in Lettuce Juice.

Shigella sonnei is a species of Shigella, and the infection rate of S. sonnei is increasing year by year. Eugenol is an active ingredient in clove essential oil and is a generally recognized as safe (GRAS)-certified food ingredient. The mechanism of inhibition of S. sonnei by eugenol has been investigated in this study. The minimum inhibitory concentration of eugenol against both S. sonnei ATCC 25931 and S. sonnei CMCC 51592 was 0.5 mg/mL and minimum bactericidal concentration (MBC) for both strains was 0.8 mg/mL. The inhibition effect of eugenol against S. sonnei was due to increased levels of reactive oxygen species in cells, changed cell membrane permeability, and induced cell membrane dysfunction, for instance, cell membrane hyperpolarization and intracellular ATP concentration drops. The results of confocal laser scanning microscope and field emission scanning electron microscopy showed that eugenol leads to decreased cell membrane integrity, resulting in changed cell morphology. Moreover, eugenol inactivated S. sonnei in Luria-Bertani (LB) broth and lettuce juice. These results indicated that eugenol could inactivate S. sonnei and has the potential to control S. sonnei in the food industry.

Inhibitory effect of protocatechualdehyde on Yersinia enterocolitica and its critical virulence factors.

Yersinia enterocolitica (Y. enterocolitica) is a gastrointestinal pathogen that is distributed worldwide, involved in systemic, extraintestinal and invasive infections in immunocompromised patients. Establishment of antibiotic resistance in the pathogen has produced a need for new antibacterial agents. The purpose of this study was to elucidate antibacterial mechanism of protocatechualdehyde (PCA) extracted from the roots of Salvia miltiorrhiza towards Y. enterocolitica, and to investigate effects of PCA on key virulence factors associated with human infection. Present results indicated that PCA exerted its antibacterial activity against Y. enterocolitica mainly by the rapid rise of intracellular reactive oxygen species, leading to change in permeability and integrity of cell membrane, and ultimately decline of membrane potential and intracellular ATP. Furthermore, scanning electron microscopic analysis revealed that Y. enterocolitica presented gradually shrinkage in length and partial wrinkles upon PCA treatment. PCA also effectively decreased motility, biofilm formation, quorum sensing in a dose-dependent manner without affecting bacterial growth. Further, at SICs, PCA substantially suppressed the adhesion and invasion of Y. enterocolitica to HT-29 cells and the downregulation of essential virulence factor-encoding genes unveiled impaired virulence. Overall, the findings revealed the potential of PCA as an alternative antibacterial agent to combat Y. enterocolitica contamination and infections.

Effects of cinnamaldehyde against planktonic bacteria and biofilm formation of Shigella flexneri.

Cinnamaldehyde (CA) has demonstrated anti-inflammatory, anti-tumor and anti-cancer activities; Its antimicrobial and antibiofilm actions against Shigella flexneri, on the other hand, have not been investigated. Sh. flexneri is a gram-negative foodborne pathogen that can be widely found in nature and some industrial production environments. In this current research, our aim was to examine the influences of CA on planktonic bacteria and biofilm formation. The minimum inhibitory concentration (MIC) of CA against Sh. flexneri strain was 100 µg/mL, while bacteria treated with CA showed a longer lag phase compared with the untreated control. CA effectively inactivated the Sh. flexneri in LB broth and fresh lettuce juice. CA treatment resulted in cell membrane permeability changes and dysfunction, as proven by cell membrane depolarization, decreased intracellular ATP concentration. In addition, CA was also discovered to increase the level of reactive oxygen species (ROS) in cells, and induce morphological changes in cells. Crystal violet staining showed that the biomass of biofilm was decreased significantly with CA in 24 h. Light microscopy and field emission scanning electron microscopy (FESEM) observations demonstrated decreased biofilm adhesion and destruction of biofilm architecture after treatment with CA. These findings indicated that CA acts as a natural bacteriostatic agent to control Sh. flexneri in food processing and production.

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.

The prevalence and characterization of Bacillus cereus isolated from raw and pasteurized buffalo milk in southwestern China.

Bacillus cereus is an important food-borne pathogenic bacteria and a putrid microorganism in the dairy industry. Raw and pasteurized buffalo milk play important roles in the dairy market in southwestern China. However, the reports on the prevalence and characterization of B. cereus strains isolated from the above sources are lacking. In this study, 150 raw buffalo milk samples and 300 pasteurized buffalo milk samples were collected from 3 provinces in southwestern China. The genotype, virulence gene distribution, antibiotic resistance, and biofilm-forming ability of isolates were analyzed. Ninety-six B. cereus strains were isolated and identified: 50 isolates (33.3%) from buffalo raw milk and 46 isolates (15.3%) from pasteurized buffalo milk. These strains were classified into 41 sequence types (ST) and 5 groups, of which ST857 was the predominant ST. The detection rates of virulence genes nheABC cluster, hblACD cluster, cytK, bceT, entFM, hlyII, and cesB were 89.6%, 13.5%, 64.6%, 71.9%, 84.4%, 62.5%, and 6.25%, respectively. The antimicrobial susceptibility testing showed that more than 90% of the isolates were susceptible to gentamicin, chloramphenicol, ciprofloxacin, erythromycin, vancomycin, and tetracycline, as well as resistant to ampicillin, cefepime, oxacillin, and rifampin. The results of biomass biofilm evaluation of the isolates on the stainless-steel tube showed that the optical density values at a wavelength of 595 nm of all strains in group I were greater than 1, with the strongest overall biofilm-forming ability among 5 groups, and the overall biofilm-forming ability of group III was the weakest. There was a relationship between the biofilm-forming ability and phylogenetic relationship of B. cereus strains. Taken together, our findings are the first to report the contamination situation and characterization of B. cereus isolated from raw and pasteurized buffalo milk in southwestern China as well as indicate the potential risk posed by this pathogen to dairy industry and public health.

Genotyping, Antimicrobial Susceptibility and Biofilm Formation of Bacillus cereus Isolated from Powdered Food Products in China.

This study was conducted to reveal the genotyping, antimicrobial susceptibility, and biofilm formation of Bacillus cereus isolated from powdered food products in China. Five hundred powdered food samples were collected from five provinces in China: 100 samples each of powdered infant formula (PIF), soy milk powder (SMP), lotus root powder (LRP), walnut powder (WP), and rice flour (RF). The genotyping of isolates was analyzed using multilocus sequence typing; meanwhile, antimicrobial susceptibility, and ability of biofilms formation on stainless steel tube of isolates were evaluated. Forty-two B. cereus strains were detected with an overall contamination rate of 8.4%, as well as, the highest B. cereus contamination rate was found in SMP (10%), followed by LRP (9%), WP (9%), RF (8%), and PIF (6%). These isolates were divided into 22 sequence types (STs); among them, ST32 (4/42, 9.5%) was the predominant ST. Phylogenetic relationships showed that the 42 strains of B. cereus were divided into three groups (group I, group II, and group III). Antimicrobial susceptibility testing indicated that all isolates were susceptible to tetracycline, gentamicin, erythromycin, and chloramphenicol, while resistant to ampicillin, cefepime, oxacillin, and rifampin. The analysis of ability of biofilm formation on stainless steel tube showed optical density (OD)595 value of 66.7% of B. cereus isolates was greater than 1. The OD595 level of isolates belonging to group III was higher compared with the other two groups, and OD595 values of B. cereus HB1 and HN5 were greater than 2. These findings improved the understanding of the characteristics of B. cereus isolated from powdered food products in China, and provided a theoretical basis for the prevention and control of B. cereus in food industry.

Amaranthus tricolor crude extract inhibits Cronobacter sakazakii isolated from powdered infant formula.

The purpose of this study was to elucidate the antibacterial activity and possible mechanism of action of Amaranthus tricolor crude extract (ATCE) against Cronobacter sakazakii isolated from powdered infant formula (PIF). The antibacterial activity of ATCE was assessed by measuring the diameter of inhibition zone (DIZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The possible mechanism of action of ATCE was revealed by analyzing the effects of ATCE on growth curves and changes in cell membrane potential, intracellular pH, content of bacterial protein and genomic DNA, and cell morphology. Finally, ATCE was applied to the disinfection of C. sakazakii in biofilm on stainless steel tube. The results showed that the DIZ, MIC, and MBC of ATCE against C. sakazakii strains were from 14.35 ± 0.67 to 14.84 ± 0.67 mm, 20 mg/mL, and 40 mg/mL, respectively. Treatment with ATCE ended the logarithmic growth phase of C. sakazakii, and led to depolarization of the cell membranes, reducing intracellular pH and bacterial protein and genomic DNA contents, and resulting in cytoplasmic leakage and deformation. In addition, ATCE effectively inactivated C. sakazakii in biofilm, reducing viable bacteria by approximately 6.5 log cfu/mL bacterial count after treatment with 1 MIC (1 MIC = 20 mg/mL) of ATCE for 20 min at 25°C. Our findings showed that ATCE inactivated C. sakazakii strains isolated from PIF and has potential as a natural disinfectant to reduce the contamination of PIF by C. sakazakii.

Antibacterial Activity of Chrysanthemum buds Crude Extract Against Cronobacter sakazakii and Its Application as a Natural Disinfectant.

Cronobacter sakazakii is an opportunistic food-borne pathogen that endangers the health of neonates and infants. This study aims to elucidate the antibacterial activity and mechanism of Chrysanthemum buds crude extract (CBCE) against C. sakazakii and its application as a natural disinfectant. The antibacterial activity was evaluated by the determination of the diameter of inhibition zone (DIZ), minimum inhibitory concentration (MIC), and minimum bactericide concentration (MBC). The antibacterial mechanism was explored based on the changes of growth curve assay, intracellular ATP concentration, membrane potential, intracellular pH (pHin), content of soluble protein and nucleic acid, and cell morphology. Finally, the inactivation effects of CBCE against C. sakazakii in biofilm on stainless steel tube, tinplate, glass, and polystyrene were evaluated. The results showed that the DIZ, MIC, and MBC of CBCE against C. sakazakii were 14.55 ± 0.44-14.84 ± 0.38 mm, 10 mg/mL, and 20 mg/mL, respectively. In the process of CBCE acting on C. sakazakii, the logarithmic growth phase of the tested bacteria disappeared, and the concentrations of intracellular ATP, pHin, bacterial protein, and nucleic acid were reduced. Meanwhile, CBCE caused the cell membrane depolarization and leakage of cytoplasm of C. sakazakii. In addition, about 6.5 log CFU/mL of viable C. sakazakii in biofilm on stainless steel tube, tinplate, glass, and polystyrene could be inactivated after treatment with 1 MIC of CBCE for 30 min at 25°C. These findings reveal the antibacterial activity and mechanism of CBCE against C. sakazakii and provide a possibility of using a natural disinfectant to kill C. sakazakii in the production environment, packaging materials, and utensils.

[Application of multidisciplinary doctor-nurse collaboration team on the perioperation management of geriatric hip fractures].

OBJECTIVE: To investigate the effectiveness of multidisciplinary doctor-nurse collaboration team on the perioperation management of geriatric patients with hip fractures. METHODS: The clinical data of 489 geriatric patients with hip fractures (femoral neck fracture and intertrochanteric fracture) between January 1st 2016 and January 1st 2018 was retrospectively analyzed. Among them, 279 patients were treated with the multidisciplinary doctor-nurse collaboration care (observation group) and 210 patients were treated with the conventional therapeutics and nursing care (control group). There was no significant difference in gender, age, cause of injury, type and classification of fracture, the interval between injury and admission, and Charlson index between the two groups ( P>0.05). The surgery rates, time from hospitalization to operation, length of stay, and the incidences of perioperative complications were compared between the two groups. RESULTS: The surgery rate was 90.32% (252/279) in observation group and 80.48% (169/210) in control group, showing significant difference between the two groups ( χ 2=9.703, P=0.002). The time from hospitalization to operation and length of stay in observation group [(5.39±2.47), (10.56±3.76) days] were significant shorter than those in control group [(6.13±2.79), (12.27±3.11) days] ( t=-3.075, P=0.002; t=-5.330, P=0.000). The incidence of respiratory complications was 46.15% in control group and 30.56% in observation group; the incidence of cardiovascular system complications was 69.23% in control group and 51.19% in observation group; the incidence of cerebrovascular system complications was 20.12% in control group and 11.11% in observation group; the incidence of deep venous thrombosis was 40.24% in control group and 25.40% in observation group. The incidences of perioperative complications were significantly lower in observation group than in control group ( P<0.05). CONCLUSION: Multidisciplinary doctor-nurse collaboration team is conducive not only to improve the surgery rates, but also to reduce perioperative complications as well as shorten the length of stay and preoperative waiting time.

Effect of extruding full-fat soy flakes on trans fat content.

To evaluate the effects of extrusion process on the trans fatty acids (TFAs) formation in soybean crude oils, three different extrusion parameters, namely, extrusion temperature (80-160 °C), feed moisture (10-26%), and screw speed (100-500 rpm), were carried out. It was found that only five different types of TFAs were detected out using gas chromatography-mass spectrometry. Before the extrusion started, the initial amount of total TFAs was 3.04 g/100 g. However, after extruding under every level of any variable, the total amounts of TFAs were significantly higher than those in the control sample (P < 0.05). For example, taking the effect of extrusion temperature into account, we can find that the highest amount of total of trans fatty acid (TTFA) was 1.62 times the amount of that in the control sample, whereas the lowest amount of TTFA was 1.54 times the amount of that in the control sample. Importantly, it was observed that the amounts of every type of trans fatty acid were not continuously increasing with the increase of the level of any extrusion variable. This phenomenon demonstrated that the formation and diversification were intricate during extruding process and need to be further studied.