Effects of colistin sulphate, tigecycline, and cefoperazone-sulbactam on the multi-drug resistant acinetobacter baumannii experimental mouse sepsis model

Abstract

Objective: Incidence of Acinetobacter infections is increasing both in Turkey and worldwide. Based on their ability to develop resistance, Acinetobacter species can cause morbidity and mortality, particularly in newborns, children, immunocompromised patients, and critically ill intensive care patients. There are limited treatment options, particularly in carbapenem resistant Acinetobacter strains. In this study, we aimed to compare in vivo activities of colistin sulphate, tigecycline, and cefoperazone-sulbactam in an experimental mouse sepsis model. Material and Methods: Each of the four study groups consisted of eight Wistar breed albino rats. In total, 107 colonies of the Acinetobacter baumannii/calcoaceticus complex were administered intraperitoneally to each rat after the presence of neutropenia with cyclophosphamide. Blood culture samples were taken from all rats after 24 h of treatment and colony count from lung, liver, and kidney specimens were taken after 72 h of treatment. Results: In the tigecycline-treated group, the presence of positive blood culture results at 24 h were found to be lower than the control group (p=0.01). Presence of positive cultures from lung samples in the tigecycline (p<0.05), colistin (p<0.05), and cefoperazone-sulbactam (p<0.05) groups were found to be lower than the control group. Positive culture of liver samples were found to be significantly lower in colistin (p<0.05) and cefoperazone-sulbactam (p<0.05) groups than the control. Positive culture of kidney samples were found to be significantly lower in colistin (p<0.05), cefoperazone-sulbactam (p<0.05), and tigecycline (p<0.05) groups than the control. However, antibiotic groups did not differ among themselves with respect to positive culture. A comparison of colony counts in lung samples revealed a statistically significant decrease in tigecycline and colistin groups than the control group (p<0.01 and p<0.05, respectively). Conclusion: In our study, tigecycline, colistin, and cefoperazone-sulbactam were found to be effective on culture positivity in lung, kidney, and liver specimens of rats and they may be a choice for treatment. Tigecycline was found to be more effective on colony counts in lungs and kidneys and is also more effective in reducing the 24 h bacteraemia than the control group. The results of the ongoing clinical trials about tigecycline use in children with severe infection due to resistant microorganisms will give us an idea about this situation.