Background: The emergence of antibiotic resistance, particularly resistance to methicillin in Staphylococcus aureus has made the treatment process more difficult. Therefore, producing of an effective vaccine seems to be necessary to prevent infections with methicillin-resistant Staphylococcus aureus (MRSA). In this study, a mixture of naloxone and alum has been used to improve the efficacy of a vaccine against MRSA.

Materials and Methods: MRSA 834 strain was grown on TSB medium and the grown cells were harvested and killed by sonication and were used as a vaccine model. Balb/c mice were divided into six groups and the vaccines were either injected alone, with naloxone, alum, or a mixture of naloxone - alum and control group received naloxone and PBS buffer. Total IgG antibody level was measured by ELISA method and finally, the challenge test of this bacterium was performed and the mice were examined regarding the degree of bacteria growth in their kidneys.

Results: The serum level of Total IgG antibody in the mixture of naloxone – alum with MRSA group was shown to be significantly increased (p<0.05). Furthermore, the lowest bacterial load was observed in this group.

Conclusion: It seems that a mixture of naloxone and alum as an adjuvant with the killed methicillin-resistant Staphylococcus aureus enhances the humoral immunity leading to a high level of protection against MRSA infections. Therefore, this seems to be a good option for improving the performance of this vaccine.

Abstract

Background: The aim of this study was to evaluate the effects of different concentrations of morphine and naloxone on epileptic activity in live brain slices taken from morphine-dependent and control infant mice.

Materials and Methods: Forty neonatal mice were randomly selected. To establish dependency, 2, 4, 8, 16 and 32 mg / kg morphine was injected subcutaneously once daily (0.1 cc) for 5 consecutive days from day 14-18 after birth. On postnatal days 19-20, brain slices were prepared and cerebrospinal fluid was perfused with low magnesium to induce experimental- epiletform activity. The effects of 10, 100 and 1000 µM concentrations of morphine and 10 µM naloxone were investigated on epileptic activity. Chenges in the number as well as onset and amplitude of activities were considered as an indicator to determine the quantity of their effect.  

Results: The results showed that morphine 100 µM increased the activity while 10 and 1000 µM concentrations of morphine and 10 µM naloxone attenuated epileptic activity in both groups. Naloxone reduced pro-seizure effect of morphine, but anti-seizure effect of morphine couldn't restored by naloxone.

Conclusion: Morphine has a two-phase concentration-dependent effect on epileptic activity in the infant mice; so that low and high concentrations of morphine inhibit epileptic activity, but its moderate concentration potentiates the epileptic activity. Naloxone has an anti-seizure effect.