Natural approach of using nisin and its nanoform as food bio-preservatives against methicillin resistant Staphylococcus aureus and E.coli O157:H7 in yoghurt.

BACKGROUND: Natural antimicrobial agents such as nisin were used to control the growth of foodborne pathogens in dairy products. The current study aimed to examine the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against methicillin resistant Staphylococcus aureus (MRSA) and E.coli O157:H7 during the manufacturing and storage of yoghurt. Nisin NPs were prepared using new, natural, and safe nano-precipitation method by acetic acid. The prepared NPs were characterized using zeta-sizer and transmission electron microscopy (TEM). In addition, the cytotoxicity of nisin NPs on vero cells was assessed using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined using agar well-diffusion method. Further, fresh buffalo's milk was inoculated with MRSA or E.coli O157:H7 (1 × 106 CFU/ml) with the addition of either nisin or nisin NPs, and then the inoculated milk was used for yoghurt making. The organoleptic properties, pH and bacterial load of the obtained yoghurt were evaluated during storage in comparison to control group. RESULTS: The obtained results showed a strong antibacterial activity of nisin NPs (0.125 mg/mL) against MRSA and E.coli O157:H7 in comparison with control and pure nisin groups. Notably, complete eradication of MRSA and E.coli O157:H7 was observed in yoghurt formulated with nisin NPs after 24 h and 5th day of storage, respectively. The shelf life of yoghurt inoculated with nisin nanoparticles was extended than those manufactured without addition of such nanoparticles. CONCLUSIONS: Overall, the present study indicated that the addition of nisin NPs during processing of yoghurt could be a useful tool for food preservation against MRSA and E.coli O157:H7 in dairy industry.

Combination of valproate and paroxetine in mice exposed to picrotoxin.

The frequent coexistence of depression in epileptic patients raises the issue of simultaneous use of antidepressants along with antiepileptic drugs in the management of such cases. However, it is necessary to evaluate the safety of these antiepileptic/antidepressant drug combinations. The present study investigates the effect of the antidepressant paroxetine (a selective serotonin reuptake inhibitor) administered alone or in combination with the antiepileptic drug sodium valproate on chemoconvulsions induced by picrotoxin (PTX). Seizure score was recorded in vivo, and the levels of thiobarbituric acid-reactive substances and gamma aminobutyric acid (GABA) were measured in the nucleus accumbens of the tested groups of mice. The results show enhancement of seizure severity with significant reduction in GABA levels upon PTX treatment that were reversed by its combination with sodium valproate. On the other hand, paroxetine administered in combination with sodium valproate provided significant protection against PTX-induced convulsions as well as a significant increase in GABA levels in selected brain areas. These results favor their application in management of epilepsy-depression comorbidities.

Comparison between betamethasone gel applied over endotracheal tube and ketamine gargle for attenuating postoperative sore throat, cough and hoarseness of voice.

BACKGROUND: Tracheal intubation for general anesthesia often leads to trauma of the airway mucosa resulting in postoperative sore throat, hoarseness of voice and cough. The aim of this study was to evaluate two different methods as regard their efficacy for controlling the postoperative pharyngo-laryngo-tracheal sequelae (sore throat, cough, hoarseness of voice) after general anesthesia with laryngoscopy and tracheal intubation. We compared between the effects of betamethasone gel applied over the endotracheal tube and gargling with ketamine solution in reducing these complications during the first 24 postoperative hours after elective surgical procedures in a prospective randomized controlled single blind clinical trial. METHODS: Seventy five patients ASA physical status I and II, undergoing elective surgery under general anesthesia using endotracheal intubation were enrolled in this prospective, randomized, single-blind study. Patients were randomly divided into 3 groups of 25 patients each: Group (K): (n: 25) Patients in this group were asked to gargle with ketamine 40 mg in 30 ml saline for 60 seconds as repeated smaller attempts, 5 minutes before induction of anesthesia. Group (B) (n: 25): Endotracheal tubes were lubricated with 0.05% betamethasone gel. Group (C) (n: 25): CONTROL GROUP: patients did not receive ketamine gargle nor betamethasone gel. The incidence and the severity of Postoperative sore throat, cough, and hoarseness of voice were graded at 0, 2, 4, and 24 h after operation by a blinded investigator. RESULTS: The incidence and severity of sore throat were significantly lower in group (K) and group (B) than group (C) (p < 0.05) at all time intervals. While there was no significant difference between group (K) and group (B) (p > 0.05). The incidence and severity of cough and hoarseness of voice were significantly lower in group (B) than group (C) and group (k) (p < 0.05) at all time intervals. CONCLUSION: Gargling with ketamine before induction of anesthesia is comparable with application of 0.05% betamethasone gel over the Endotracheal tubes in decreasing postoperative sore throat. In addition, Betmethasone application decreased the incidence and severity of postoperative cough and hoarsness of voice.