Methods for evaluating some antibiotics activity against some virulence factors of bacterial septicemia in Karbala province

Abstract

This study aimed to isolate the most common cause of bacterial sepsis at Al-Hussein Hospital in the holy Karbala province from November 2014 to May 2015 and also studied the effect of some antibiotics on the virulence factors of the bacterial isolates. Out of the 60 samples of blood culture, 20 samples (33.33%) was positive and 40 samples (66.67%) gave negative growth . Gram positive to gram negative bacteria ratio was (70%) to (30%), respectively . It was found the most of isolates was Staphylococcus aureus (S.aureus) (35%) , Coagulase negative staphylococcus (CoNS) (35%) , Acinetobacter buamanii (A.buamanii) (20%) and the Escherichia coli (E.coli) (10%). The antibiogram has been showed that (85.71%) of the Staphylococcus aureus was resistant to Ampicillin and Ceftriaxone as well as (CoNS) also had resistance to both antibiotics as (71.42%).The strains of S.aureus was resistant to Erythromycin and Gentamicin as (71.42%) and (42.8%), respectively . On the other hand these strains was quite sensitive to antibiotics Amikacin, Ciprofloxacin, Carbapenem, Vancomycin and Oxacillin.In gram negative bacteria , the results showed that E.coli was 100% resistant to Ampicillin and Ceftriaxone but sensitive to Amikacin , Ciprofloxacin , Carbapenem and Oxacillin. Acinetobacter buamanii was multidrugs resistance. The production of virulence factors of S.aureus has been monitored such as hemolysin, protease and coagulase. The hemolytic activity of hemolysin was (640) unit / ml and the enzymatic activity of protease was (44) units / ml and the diameter of zone formed by coagulase was 3.8 millimeters. The concentration of ½ MIC and ¼ MIC of Amikacin , Ciprofloxacin and Oxacillin was used to demonstrate the effect on certain virulence factors. It was found that hemolysin production decreased at a Sub-MIC concentrations of Amikacin and Ciprofoxacin while increased to double when they using with Oxacillin antibiotic. Protease production was dropped at the presence of Sub-MIC of all antibiotics as well as in the case of coagulase production .