Comparison of the Bactec and lysis concentration methods for recovery ofBrucella species from clinical specimens

Abstract

In a comparison of the Bactec system and the lysis concentration procedure in the isolation of Brucella species in 54 patients the recovery rate was similar (60% and 55%, respectively). However, the recovery time was significantly shorter with the lysis concentration method than with the Bactec system (3.5 days versus 14 days). The lysis concentration procedure for the culture of Brucella is simple, inexpensive and reliable, and produces results for the clinician relatively quickly.

Recent advances in brucellosis

“…Diagnosis should always be supported by laboratory tests. Blood culture is often effective during the acute phase, but allowance should be made for the relatively slow growth of the organism; the lysis concentration method gives the best results [23]. Presumptive identification is made on the basis of morphological, cultural and serological properties.…”

Blood Cultures for the Diagnosis of Human Brucellosis

“…A new and original method was subsequently developed in which blood cells were osmotically lysed, and this step was followed by centrifugation and spread of the lysate on the surface of solid culture media [26,27]. In 1984, Etemadi et al evaluated this lysis centrifugation procedure -also known as lysis concentration-and compared its performance with that of the Castañeda flask for the detection of B. melitensis from blood and other normally sterile body fluids [26].…”

“…However, the detection times differed significantly and were 3.8±0.8 days for the lysis centrifugation and 13.6±6.5 days for the Castañeda method (P<0.001). In a prospective study, Kolman et al obtained blood cultures from Israeli patients with serologically proven brucellosis [27]. Blood sample aliquots were subjected to an in-house lysis centrifugation procedure and inoculated into an aerobic radiometric BACTEC system (Becton Dickinson Diagnostic Instrument Systems, Towson, Md., USA) vial [27].…”

“…In a prospective study, Kolman et al obtained blood cultures from Israeli patients with serologically proven brucellosis [27]. Blood sample aliquots were subjected to an in-house lysis centrifugation procedure and inoculated into an aerobic radiometric BACTEC system (Becton Dickinson Diagnostic Instrument Systems, Towson, Md., USA) vial [27]. The lysis centrifugation detected B. melitensis in only 15 (27.8%) out of 54 patients, whereas the comparator succeeded in 19 (35.2%) patients.…”

“…Published experience with the use of this method for the recovery of brucellae from blood is limited and obtained results were suboptimal [27,[36][37][38]. In 1984, Arnow et al investigated a cluster of foodborne B. melitensis infections among travelers to endemic Spain [36].…”