hasan kosha

Brucellosis is a zoonosis infectious disease and endemic in Iran. The certain diagnosis of disease is established on isolation of brucella from blood and other clinical samples. So, because of fastidious nature of this organism and problems in its isolation by conventional methods, and attending to the high prevalence of brucellosis in Kashan, Iran, the BACTEC9050 blood culture system was used in this survey for diagnosis of brucella bacteremia; advantages of this method has been discussed, too.

In this descriptive research, the blood samples of 206 patients suspected to brucellosis were studied in Brain-Heart Infusion (BHI) broth and BACTEC9050 blood culture system simultaneously.

In a period of 5 days, from 206 samples, totally 50 cases were positive; 32 cases were positive in both methods and 18 cases were positive only in BACTEC method. Continuing the incubation, 14 cases became positive but 4 cases were negative, even after 30 days of incubation. The average incubation period for specimens to become positive was 4 days.

The BACTEC automatic system reduced the examination process, and economized the time and the material. In cases that this system is not available for diagnosis of brucella, it is recommended to keep the final subcultures in 37°C for 1 month to get better diagnostic results.

Antimicrobial resistance in Pseudomonas aeruginosa has been increasing in recent years. The aim of this study was to investigate the relationship between antimicrobial resistance and class I integron in P. aeruginosa isolated from clinical specimens in Yazd city. This cross-sectional study was carried out on 144 P. aeruginosa strains from April 2012 to April 2013. All clinical samples were initially identified by the biochemical method and the antibiotic resistance test was performed using the disc diffusion method according to CLSI recommendations. PCR was carried out for the detection of class I integron. Seventy-nine (54.9%) out of 144 patients were male with mean age of 34.9+22.7 years. Resistance rates to various antibiotics were as follows: gentamicin (63.2%), imipenem (62.5%), amikacin (58.3%), ceftazidime (56.9%), ticarcillin (55.6%), tobramycin (55.6%), piperacillin (54.9%) and ciprofloxacin (48.6%) and 75.3% of the isolates were detected as multi-drug resistant. PCR results showed that 119 (82.6%) P. aeruginosa isolates carried class I integron. Class I integrons are commonly found in P. aeruginosa isolated from the clinical samples. Therefore, the transfer of antibiotic resistance genes is often related to these integrons and the contribution of integrons in antibiotic resistance should be evaluated.