Study and Comparison of Diagnostic Methods (Culture- Molecular) for Brucella in the Samples Isolated from Patients Suspected to Brucellosis in Different Regions of Tehran

Aim and Brucellosis as zoonosis diseases is a public health concern in many countries, including Iran. New detection methods with high sensitivity are of importance and minimize the risk of infection in laboratory staffs. One of these methods is polymerase chain reaction (PCR). At the present study, culture and molecular methods for detection of Brucella obtained from patients with suspected brucellosis in various parts of Tehran were compared and evaluated.
100 blood samples were obtained from patients with suspected brucellosis who referred to the Massoud Laboratory, Baghiatallah and Hospitals affiliated to Iran University of Medical Sciences. Each sample was inoculated in Castaneda medium and incubated in a chamber with 5% CO2 at 370C for 7 to 30 days. DNA extraction from samples and PCR carried out using commercial kit and standard procedure, respectively.
Two samples were positive from culture of 100 blood samples, while after the PCR, fifteen samples were positive. The sensitivity and specificity of PCR determined to be %100 and 86.73%, respectively.
Culture of Brucella spp. is not always successful due to their growth difficulty; also the growth and culture require viable organisms. Many bacteria are lost during sample taking or using antibiotics. This may cause the sensitivity of culture to be low in comparison with PCR.
conclusoin:PCR compared with culture method appears to be more sensitive and so this method might be the reason for the replacement of this method as a detection method in the laboratory.