مجله دانشکده پزشکی اصفهان
پیاپی 729 (هفته اول مهر 1402)

Colistin, tigecycline and ampicillin/sulbactam (high dose) are the only antibiotics with high efficacy against Acinetobacter baumannii and their last line of treatment. So, investigation of new antimicrobial agents with potential activity against these pathogens seems essential. Antimicrobial peptides are natural agents that play an important role in innate immunity against various types of pathogens. In this project, the antimicrobial activity of TP4-LYC1, an antimicrobial peptide consisting of Tilapia Piscidin 4 (TP4) with lycosin-1, was investigated against resistant A. baumannii as well as the synergistic effects of this chimeric peptide with colistin and meropenem.

Optimization the cleavage of each peptides (TP4, LYC1, and TP4-LYC1) to earn the most amounts of peptides was performed based on the incubation temperature, time of incubation and the cleavage buffer pH. Finally, the antimicrobial effects of each peptide, alone or in combination with colistin or meropenem was analyzed by broth micro-dillusion and checker board methods, respectively.

The best condition for the cleavage of TP4, was pH 6.5 for 24 Hours incubation time. These conditions for LYC1 and the chimeric peptide was concluded as pH 4 for 24 and 48 Hours incubation time, respectively. The antibacterial activity of TP4 was less than TP4-LYC1 for each biological sample. Also, TP4-LYC1 has synergistic effects with Meropenem and Colistin in most cases.

TP4-LYC1 has the potential to be used as a candidate for the treatment of infections caused by A. baumanni in combination with routine effective antibiotics in order to reduce the dosage of these antibiotics.

The present study aimed to investigate the effect of delay in serum separation on the results of some biochemical tests, as one of the pre-analytical errors.

In this study, 50 healthy volunteers participated. 12 ml of blood was taken from each person and divided into 6 tubes assigned. In order to separate the serum, one of the samples of each person was centrifuged as a base sample at the standard time (1 hour after blood sampling), and the other samples of that person were centrifuged with a delay of 1,2,3,4 and 5 hours compared to the base sample. The serum from each sample was analyzed for 21 different analytes including blood sugar (BS), blood urea nitrogen (BUN), uric acid (U.A), calcium (Ca), magnesium (Mg), triglyceride (TG), cholesterol (Chol), high-density lipoprotein (HDL), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin (T.B), direct bilirubin (D.B), albumin (Alb), total protein (TP), amylase (Amy), lipase (Lip), lactate dehydrogenase (LDH) and creatine phosphokinase (CPK).

A significant difference was found between the means of blood sugar (BS) in the elapsed times from the time of blood sampling. The means of BS showed a decrease of 4.78 % on average for each hour of delay in serum separation. In the case of other analytes, no significant difference was observed between their means at each of the time points elapsed since the time of blood sampling.

Considering the significant effect of delay in serum separation on BS test, it is necessary to centrifuge the whole blood sample and separate its serum as soon as possible. In the case of the other investigated analytes, the delay in serum separation up to 6 hours does not have a significant effect on the results.

Increasing widespread resistance in all available antibiotics, as well as the risk of using other germicidal agents, leads research to search for additional and new antimicrobial methods. Recently cold plasma (CP) and nanoparticles are used for microbial disinfection, wound healing and cancer treatment. The purpose of this article is to review the antimicrobial properties, various methods of synthesis and stabilization of nanoparticles along with cold plasma technology. Atmospheric and how it affects the inactivation of pathogenic microorganisms in the food industry and clinical departments.

In the present review, articles published from 2011 to 2023 were used and scientific information databases such as Google Scholar, PubMed, ScienceDirect and Scopus have been used.

Bacteria can be deactivated by the effect of agents in cold plasma including reactive oxygen species (ROS) and nitrogen (RNS), UV radiation and charged particles. Among the effective species of ROS, ozone, superoxide, peroxide, etc., and among the species of RNS, atomic nitrogen, and excited nitrogen can be mentioned. Also, charged particles can be used directly and indirectly for antimicrobial purposes.

Cold plasma can be used to improve the health of food, destroy bacterial biofilms, destroy pathogenic microorganisms, inactivate spores, and also deactivate viruses. In spite of the mentioned effects of cold plasma and the low pollution after its processing, for its full acceptance, its environmental and human approaches should be considered along with its effectiveness.