Extension of shelf life of Nile tilapia (Oreochromis niloticus) fillets using seaweed extracts during refrigerated storage.

The effects of seaweed (Padina tetrastromatica, Sargassum natans, and Sargassum fluitans) ethanolic extracts on the quality and shelf life extension of Nile tilapia (Oreochromis niloticus) fillets were investigated during refrigerated storage for 20 days. Each of the seaweed ethanolic extracts solution (2%, w/v) was used for dipping the fish fillets for 10 min at 4°C. The control and seaweed extract-treated fillets were stored at 4 ± 1°C in air-tight polyethylene bags, and chemical, bacteriological, and sensory evaluation were performed at every 4 days' intervals. During the storage period, P. tetrastromatica extract significantly (p < .05) reduced the increment of pH, peroxide value, thiobarbituric acid reactive substances, and total volatile basic nitrogen values in Nile tilapia fillets compared to other seaweed extracts-treated and untreated fillets. The maximal total viable count of control, P. tetrastromatica, S. natans, and S. fluitans extracts-treated fillets was 6.53, 7.11, 6.75, and 7.10 log CFU/g at the 8th, 20th, 12th, and 16th days of storage, respectively. The total psychrotrophic count of control and seaweed extracts-treated fillets was also significantly increased (p < .05) throughout the storage period. The P. tetrastromatica extracts-treated fillets showed better sensory characteristics than other seaweed extracts-treated and control fillets. Results of this study suggest that ethanolic extracts (2%, w/v) of P. tetrastromatica extend the shelf life for 12 days longer than the control fillets in refrigerated conditions.

The effect of increased inoculum on oral rotavirus vaccine take among infants in Dhaka, Bangladesh: A double-blind, parallel group, randomized, controlled trial.

BACKGROUND: Oral, live-attenuated rotavirus vaccines suffer from impaired immunogenicity and efficacy in low-income countries. Increasing the inoculum of vaccine might improve vaccine response, but this approach has been inadequately explored in low-income countries. METHODS: We performed a double-blind, parallel group, randomized controlled trial from June 2017 through June 2018 in the urban Mirpur slum of Dhaka, Bangladesh to compare vaccine take (primary outcome) among healthy infants randomized to receive either the standard dose or double the standard dose of oral Rotarix (GlaxoSmithKline) vaccine at 6 and 10 weeks of life. Infants with congenital malformations, birth or enrollment weight <2000 gm, known immunocompromising condition, enrollment in another vaccine trial, or other household member enrolled in the study were excluded. Infants were randomized using random permuted blocks. Vaccine take was defined as detection of post-vaccination fecal vaccine shedding by real-time reverse transcription polymerase chain reaction with sequence confirmation or plasma rotavirus-specific immunoglobulin A (RV-IgA) seroconversion 4 weeks following the second dose. RESULTS: 220 infants were enrolled and randomized (110 per group). 97 standard-dose and 92 high-dose infants completed the study per-protocol. For the primary outcome, no significant difference was observed between groups: vaccine take occurred in 62 (67%) high-dose infants versus 69 (71%) standard-dose infants (RR 0.92, 95% CI 0.67-1.24). However, in post-hoc analysis, children with confirmed vaccine replication had significantly increased RV-IgA responses, independent of the intervention. No significant adverse events related to study participation were detected. CONCLUSIONS: Administration of double the standard dose of an oral, live-attenuated rotavirus vaccine (Rotarix) did not improve vaccine take among infants in urban Dhaka, Bangladesh. However, improved immunogenicity in children with vaccine replication irrespective of initial inoculum provides further evidence for the need to promote in-host replication and improved gut health to improve oral vaccine response in low-income settings. ClinicalTrials.gov: NCT02992197.