Targeting Listeria monocytogenes consensus sequence of internalin genes using an antisense molecule

As an intracellular pathogen, Listeria monocytogenes can enter host cells where it can replicate and escape detection and eradication by the host immune response making the clearance of infection very challenging. Furthermore, with the advent of antimicrobial resistance, the need for alternative targets is inevitable. Internalin proteins are crucial to this bacterium as they contribute to bacterial entry to the systemic circulation. In this study, we targeted a highly conserved region of these proteins by an antisense sequence that was covalently conjugated to the cell penetrating peptides (CPP) to overcome the challenging delivery barriers. Then, we evaluated the efficiency of this construct in vitro. We also assessed the antigenicity, cytotoxicity, and probability of apoptosis induction by this construct. The studied CPP-PNA inhibited bacterial growth and suppressed the mRNA expression of internalins in a dose-dependent manner. In addition, at all studied concentrations, CPP-PNA significantly reduced the invasion rate of L. monocytogenes in the examined cell lines. Moreover, different concentrations of CPP-PNA did not have a significant antigenic, cytotoxic, and apoptotic properties compared to the control. These results suggest the effectiveness of CPP-antisense in targeting the mRNAs of internalins for various research, therapeutic and preventive purposes. However, additional research is required to evaluate the potency, safety, and pharmacokinetics of this compound for the prevention and treatment of listeriosis

Dynamics of bacteriophages as a promising antibiofilm agents

Pseudomonas aeruginosa is an ubiquitous organism which has emerged as a major threat in the hospital environment. Overuse of antibiotics has also significantly increased the emergence of antimicrobial multiresistant bacteria. P. aeruginosa has an innate ability to adhere to surfaces and form virulent biofilms. Bacteriophage might represent one attractive solution to this problem. In this study, P.aeruginosa phage were utilized to Biofilm inhibition and remove.Sample collected from University sewage. Isolation was done according to Martha.R.J.Clokie protocol. Serial dilution prepared, then equally incubated with bacteria to investigate Biofilm inhibition potential. Biofilm formed base on Microplate Biofilm Assay. The effect of isolated phage investigated on biofilm remove of Pseudomonas putida, E.coli and Acinetobacter baumanii. P.aeruginosa biofilm had OD: 1.688 in 492n.m. Pure phage, 10-2 and 10-3 diluted phage decreased OD to 1.587, 1.341 and 1.461, respectively. Isolated phage dramatically decline OD of Biofilm of all strains.Phages have various affinity to attach to hosts, thereby it is supposed to phages compete for their receptors. Therefore it is supposed phages have most efficiency in optimum concentration to remove biofilm or growth inhibition

E-test antibiotic susceptibility of E.coli strains isolated from hospital acquired infections of Imam Khomeini hospital, Ilam, Iran

Introduction: Escherichia coli (E.coli) as a main cause of both nosocomial and community-acquired infections in humans have a relative potential to develop resistance. Nowadays, most infections caused by ESBL-producing E.coli (ESBLEC) had mostly been described as nosocomial acquired or nursing home related. In this study, we employed E-test assay to detect antibiotic resistance of E.coli strains and determine MIC of antibiotics. Materials and methods: Thirty E.coli strains gathered from Imam Khomeini hospital of Ilam, and cultured on TSB and bacterial suspension prepared by 0.5 µF concentration for E-test. Mueller Hinton agar and E-test strips of Amikacin, Cefepime, Ceftazidime, Ceftriaxone, Gentamicin, Meropenem, Nitrofurantoin, Piperacillin/Tazobactam, Tetracycline, Ticarcillin/ Clavulanic acid, Tobramycin, Trimethoprim were used Results: Resistance to Ceftriaxone, Tobramycin, Gentamicin, Ticarcillin/ Clavulanic, Amikacin were 19.8%, 26.4%, 23.3%, 62.7%, 70.3%, respectively. Conclusion: the results indicated, E.coli strains in this study were high sensitivity to Meropenem ,Nitrofuratoin, Ciprofloxacin , Ceftazidime, Cefepime