MONTES I; Interscience Conference on Antimicrobial Agents and Chemotherapy.

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 1999 Sep 26-29; 39: 191 (abstract no. 214).

Dept. of Microbiol. Hosp. Virgen del Puerto, Plasencia, SPAIN.

BACKGROUND: Brucella melitensis is a fastidious micro-organism than represents a challenge for the automatic blood culture detection systems. We have evaluated the performance of the Vital Aer system (Bio Merieux).METHODS: Out of 399 cases of acute brucellosis diagnosed by seroconversion and clinical profile in our hospital, in 280 cases two blood samples were taken by venopuncture in different anatomic sites in accordance with the recommendations of the comertial provider. All samples were incubated in the machine for up to 10 days. All positive samples, as well as all negative bottles at the end of the ten-day incubation period, were passed into a chocolate-agar plate to confirm brucella growth.RESULTS: In 242 patients out of the 280 suspected cases (86.4%) Brucella melitensis was isolated. The Vital Aer machine detected 211 cases (87.2% sensibility) according to the following time distribution: 1 case at the 3[rd] day, 7 at the 4[th], 15 at the 5[th], 50 at the 6[th], 68 at the 7[th], 49 at the 8[th], and 22 at the 9[th]. The average time for positive growth detection was 179.3 hours (7,4 days). In 31 patients Brucella melitensis was detected in the chocolate-agar plate once they were considered as negative after 10-day follow-up period in the machine (12.8% false negative cases).CONCLUSIONS: 1.Brucella melitensis growth detection by the Vital Aer system requires an average incubation period of 7.4 days. 2. The 12.8% false negative rate of the automatic system forced us to perform a rutine subculture of the samples once completed the 10-days incubation period in case of clinical possibility of brucellosis.

Publication Types:

• Meeting Abstracts

Keywords:

• Brucella
• Brucella melitensis
• Brucellosis
• Evaluation Studies
• Humans
• methods

Other ID:

• GWAIDS0007699

UI: 102245195

From Meeting Abstracts