Altered mucosa-associated microbiota in the ileum and colon of neonatal calves in response to delayed first colostrum feeding.

The present study investigated whether delaying the first feeding of colostrum affected ileum and colon mucosa-associated microbiota in calves. Twenty-seven male Holstein calves were randomly assigned to 1 of 3 groups, fed colostrum at 45 min, 6 h, and 12 h after birth, respectively. Ileum and colon mucosa were collected at 51 h after birth, and their associated microbial profiles were assessed using amplicon sequencing. Both ileum and colon mucosa-associated microbiota were predominated by genus Escherichia-Shigella. The negative correlation between the molar proportion of short-chain fatty acids (SCFA) and ileum mucosa-associated opportunistic pathogens, and the positive correlation between the molar proportion of SCFA and colon mucosa-associated beneficial bacteria, suggest that SCFA might play an important role in maintaining the gut health of 2-d-old calves. A higher relative abundance of ileum mucosa-associated Enterococcus and Streptococcus was detected when the first colostrum feeding was delayed for 12 h. The relative abundance of colon mucosa-associated Lactobacillus tended to be lower in calves fed colostrum 12 h than those under the other 2 treatments, whereas that of Faecalibacterium tended to be lower in calves fed colostrum immediately after birth than those fed colostrum 6 and 12 h after birth, respectively. Our findings suggest that delayed first colostrum feeding affects the establishment of ileum and colon mucosa-associated bacteria, which may have long-term effects on gut health of calves.

Selenium reduction by a defined co-culture of Shigella fergusonii strain TB42616 and Pantoea vagans strain EWB32213-2.

Selenium reduction was evaluated with pure batch cultures of Shigella fergusonii strain TB42616 (TB) and Pantoea vagans strain EWB32213-2 (EWB), respectively. A two-stage process, from Se(VI) to Se(IV) and then from Se(IV) to Se(0), was observed. The second stage of reduction, from Se(IV) to Se(0), was observed as the rate-limiting step resulting in accumulation of the more toxic Se(IV). In order to facilitate Se(VI) reduction and reduce Se(IV) accumulation, the Se(VI)-reducing strain TB was co-cultured with a Se(IV)-reducing strain EWB. Although Se(VI) reduction rate was not affected, Se(IV) reduction was significantly enhanced with low Se(IV) accumulation in the defined co-culture. Effects of culture composition as well as nitrate and arsenate on Se(VI) reduction were also investigated. A co-culture composition of 10:1 (EWB:TB) ratio was observed to achieve the best total selenium reduction. In addition, nitrate at 50 mg/L was observed to inhibit Se(IV) reduction but not Se(VI) reduction, while arsenate at 200 mg/L exhibited slight inhibition on both Se(VI) and Se(IV) reduction.

One-pot green synthesis and structural characterisation of silver nanoparticles using aqueous leaves extract of Carissa carandas: antioxidant, anticancer and antibacterial activities.

Facile green synthesis of silver nanoparticles (AgNPs) using an aqueous extract of Carissa carandas (C. carandas) leaves was studied. Fabrication of AgNPs was confirmed by the UV-visible spectroscopy which gives absorption maxima at 420 nm. C. carandas leaves are the rich source of the bioactive molecules, acts as a reducing and stabilising agent in AgNPs, confirmed by Fourier transforms infrared spectroscopy. The field emission scanning electron microscope revealed the spherical shape of biosynthesised AgNPs. A distinctive peak of silver at 3 keV was determined by energy dispersive X-ray spectroscopy. X-ray diffraction showed the facecentred cubic structure of biosynthesised AgNPs and thermal stability was confirmed by the thermogravimetric analysis. Total flavonoid and total phenolic contents were evaluated in biosynthesised AgNPs. Biosynthesised AgNPs showed free radical scavenging activities against 2, 2-diphenyl-1-picrylhydrazyl test and ferric reducing antioxidant power assay. In vitro cytotoxicity against hepatic cell lines (HUH-7) and renal cell lines (HEK-293) were also assessed. Finally, biosynthesised AgNPs were scrutinised for their antibacterial activity against methicillin-resistant Staphylococcus aureus, Shigella sonnei, Shigella boydii and Salmonella typhimurium. This study demonstrated the biofabrication of AgNPs by using C. carandas leaves extract and a potential in vitro biological application as antioxidant, anticancer and antibacterial agents.

FABRICATION AND EVALUATION OF SMART NANOCRYSTALS OF ARTEMISININ FOR ANTIMALARIAL AND ANTIBACTERIAL EFFICACY.

BACKGROUND: Nanocrystals have the potential to substantially increase dissolution rate, solubility with subsequent enhanced bioavailability via the oral route of a range of poor water soluble drugs. Regardless of other issues, scale up of the batch size is the main issue associated with bottom up approach. MATERIAL AND METHODS: Smart nanocrystals of artemisinin (ARM) was produced relatively at large batch sizes (100, 200, 300 and 400ml) compared to our previously reported study by (Shah, et al., 2016). ARM nanosuspensions/nanocrystals were characterised using zeta sizer, SEM, TEM, DSC, PXRD and RP-HPLC. The nanosuspensions were finally subjected to in vitro antimalarial and antimicrobial activity. RESULTS: The average particle size (PS) for 400 ml batches was 126.5 ±1.02 nm, and the polydispersity index (PI) was 0.194 ± 0.04. The saturation solubility of the ARM nanocrystals was substantially increased to (725.4± 2.0 µg/ml) compared to the raw ARM in water 177.4± 1.3 µg/ml and stabilizer solution (385.3± 2.0 µg/ml). The IC50 value of ARM nanosuspension against P. vivax was 65 and 21 folds lower than micronized 19.5 ng/mL and unprocessed drug (6.4 ng/mL) respectively. The ARM nanosuspension was found highly effective compared to unprocessed drug against all the tested microorganism except E. coli, Shigella and C. albican. CONCLUSION: The simple precipitation-ultrasonication approach was efficiently employed for fabrication of ARM nanosuspension to scale up the batch size. Similarly, the solubility, antimalarial potential and antimicrobial efficacy of ARM in the form of nanosuspension were significantly enhanced. Findings from this study can persuade research interest for further comprehensive studies using animals model.

Etiology of Diarrhea, Nutritional Outcomes, and Novel Intestinal Biomarkers in Tanzanian Infants.

OBJECTIVE: Diarrheal diseases are a leading cause of morbidity and mortality worldwide, but the etiology of diarrhea and its relation to nutritional outcomes in resource-limited settings is poorly defined. We sought to determine the etiology of community-acquired diarrhea in Tanzanian infants and to assess the association with anthropometrics and novel intestinal biomarkers. METHODS: A convenience sample of infants in a trial of zinc and/or multivitamin supplementation in Tanzania was selected. Subjects were enrolled at age 6 weeks and studied for 18 months. Stool samples were obtained from children with acute diarrhea. A novel, polymerase chain reaction-based TaqMan array was used to screen stool for 15 enteropathogens. A subset of subjects had serum gastrointestinal biomarkers measured. RESULTS: One hundred twenty-three subjects with diarrhea were enrolled. The mean ± SD age at stool sample collection was 12.4 ±â€Š3.9 months. Thirty-five enteropathogens were identified in 34 (27.6%) subjects: 11 rotavirus, 9 Cryptosporidium spp, 7 Shigella spp, 3 Campylobacter jejuni/coli, 3 heat stable-enterotoxigenic Escherichia coli, and 2 enteropathogenic E coli. Subjects with any identified enteropathogen had significantly lower weight-for-length z scores (-0.55 ±â€Š1.10 vs 0.03 ±â€Š1.30, P = 0.03) at the final clinic visit than those without an identified pathogen. Fifty of the 123 subjects (40.7%) had serum analyzed for antibodies to lipopolysaccharide (LPS) and flagellin. Subjects with any identified enteropathogen had lower immunoglobulin (IgA) antibodies to LPS (0.75 ±â€Š0.27 vs 1.13 ±â€Š0.77, P = 0.01) and flagellin (0.52 ±â€Š0.16 vs 0.73 ±â€Š0.47, P = 0.02) than those without an identified pathogen. CONCLUSIONS: This quantitative polymerase chain reaction method may allow identification of enteropathogens that place children at higher risk for suboptimal growth. IgA anti-LPS and flagellin antibodies hold promise as emerging intestinal biomarkers.

Decontamination of Salmonella, Shigella, and Escherichia coli O157:H7 from leafy green vegetables using edible plant extracts.

UNLABELLED: Fresh cilantro, parsley, and spinach are products that are regularly consumed fresh, but are difficult to decontaminate, as a result, they are common vehicles of transmission of enteropathogenic bacteria. In this study, the efficacy of plant extracts as alternatives for disinfection of cilantro, parsley, and spinach that were artificially contaminated with Salmonella, Escherichia coli O157:H7, and Shigella sonnei was determined. Edible plant extracts obtained using ethanol as the extraction solvent were tested to determine the minimum bactericidal concentration (MBC) and those that exhibited the lowest MBC were selected for further studies. Leaves of fresh greens were washed with sterile water and dried. For seeding, leaves were submerged in suspensions of 2 different concentrations of bacteria (1.5 × 10(8) and 1 × 10(5) ), dried, and then stored at 4 °C until use. To determine the effects of the extracts, inoculated leafy greens were submerged in a container and subjected to treatments with chlorine, Citrol®, or selected plant extracts. Each treatment type was stored at 4 °C for 0, 1, 5, and 7 d, and the bacterial counts were determined. From the 41 plant extracts tested, the extracts from oregano leaves and from the peel and pulp of limes were found to be as effective as chlorine or Citrol® in reducing by > 2 logs, the population of pathogenic bacteria on leafy greens and therefore, may be a natural and edible alternative to chemicals to reduce the risk of Salmonella, E. coli O157:H7 and S. sonnei contamination on leafy vegetables. PRACTICAL APPLICATION: The antimicrobial efficacy of the extracts of Mexican lime and oregano was clearly demonstrated on cilantro, parsley, and spinach. The extracts of Mexican lime and oregano provide alternatives to chlorine to significantly reduce bacterial pathogens that have been associated with outbreaks from contaminated leafy green vegetables. A simple, low cost, and labor-saving extraction system for production of the extracts was used.

The effects of a vegetable-derived probiotic lactic acid bacterium on the immune response.

The objective of this study was to investigate the probiotic properties of the fermented vegetable derived lactic acid bacterium, L. plantarum. L. plantarum 10hk2 showed antibacterial activity against pathogenic bacteria and immunomodulating effects on murine macrophage cell lines. RAW 264.7 cells stimulated with viable cells of this probiotic strain increased the amounts of pro-inflammatory mediators such as IL-1beta, IL-6 and TNF-alpha, as well as the anti-inflammatory mediator, IL-10. ICR mice fed with viable cells of L. plantarum 10hk2 had reduced numbers of enteric Salmonella and Shigella species in comparison to controls from 2 weeks after supplementation, and this effect was observed for up to 4 weeks. The findings of this study suggest that this specific lactic acid bacterial strain, which is derived from vegetable fermentation, holds great promise for use in probiotics and as a food additive since it can reduce the number of some pathogenic bacteria through production of lactic acids.

Enhanced anti-Shigella activity of erythromycin supplemented with sulfadiazine.

Sulfadiazine enhanced the anti-Shigella activity of erythromycin. Erythromycin passes through the type III secretion apparatus and suppresses the growth of invasive Shigella organisms. Sulfadiazine enhanced this effect at the concentration under minimum inhibitory concentration and it came from not only the folate-inhibiting activity but also from a new function. It has proved that sulfadiazine stimulated type III secretion in Shigella as determined from the secretion of the pathogenic protein IpaB. As Congo red induced secretion of Ipa proteins and uptake of erythromycin through the type III secretion gate, sulfadiazine which is similar to Congo red in chemical structure may induce the uptake in the same way.

Method for the detection of Shigella in foods.

A method for the detection of Shigella in foods was evaluated. The method consisted of selective enrichment at 37 degrees C in GN-broth supplemented with novobiocin (10 micrograms/ml) followed by subculture after 6 and 24 h incubation of 0.1 ml volumes to SS-agar with and without streptomycin (7.5 micrograms/ml). Test samples were contaminated by adding shigellae to 1:10 suspensions of foods (minced meat, fresh cut vegetables and cooked peeled shrimp) in the GN-broth with novobiocin. Shigella could be detected at a contamination level of 1 per 25 g in the presence of shrimp (in all 20 samples) and at 25 per 25 g in the presence of nearly all samples of fresh cut vegetables (in 13 out of 18 samples). Using this procedure Shigella could not be detected when the organism was present at a relatively high contamination level of 10(2) per 25 g in the presence of minced meat (with all 10 samples). However, the procedure described is an improvement on methods currently available for the detection of Shigella in foods.

Nutritional requirements of shigellae for growth in a minimal medium.

Most (about 81%) of the clinical isolates of shigellae that were tested failed to grow in a minimal medium. Of the auxotrophic isolates belonging to the four Shigella species, 98% grew in a minimal medium containing methionine, nicotinic acid, and tryptophan. The combination of methionine and tryptophan appears to be an obligatory requirement for Shigella dysenteriae serotype 1 strains, while the combination of nicotinic acid and tryptophan appears to be obligatory for serotype 2. Requirements which varied in other isolates were, however, genetically stable, indicating that the auxotypes may be useful as epidemiological markers. Cultures of shigellae in liquid minimal medium containing the above three supplements showed rapid growth and gave reasonably high cell yields.