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Background & Objective: Brucellosis is one of the most common zoonotic diseases in Iran and is endemic in all parts of the country. Patients recorded in 1988 were 71,051(132. 4 per 100,000). Brucella species are facultative intracellular bacteria, and therefore a limited number of antibiotics are effective against these organisms. The aim of this study was the
evaluation of in vitro sensitivity of various antimicrobial agents against 47 brucella melitensis strains isolated from blood culture.
Methods: The susceptibility of 47 Brucella melitensis isolates derived from clinical samples were tested in vitro. The minimum inhibitory concentrations (MICs) of the tested antimicrobials were measured by the agar dilution method.MIC90 and MIC50 values were defined as the lowest concentration of the antibiotic at which 90 and 50 percent of the isolates
were inhibited, respectively. The NCCLS criteria for slow growing bacteria were considered to interpret the results.
Results: Tetracycline (MIC50: 0.13μg/ml, MIC90: 0.25 μg/ml) and streptomycin (MIC50:0.003 μg/ml, MIC90:0.25 μg/ml) had the lowest MICs in vitro against the B. melitensis strains. Norfloxacin had the highest (8 μg/ml) MIC90 value. More than half
isolates presented reduced susceptibility to rifampin (MIC value: 2μg/ml).
Conclusion: Brucella isolates remain susceptible in vitro to most antibiotics used for treatment of brucellosis. There is no significantly important resistance problem for antibiotics targeted against Brucella species in Iran. However, since rifampin is commonly used for prevalent diseases such as tuberculosis, the regional susceptibility pattern of rifampin should be assessed periodically.

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Background & Objectives: Salmonellosis is the most common food-borne disease in the world. The purpose of this study was to determine the prevalence of salmonella serogroups and their antimicrobial susceptibility patterns in chicken meat and viscera in Ardabil, Iran.

Methods: In this cross-sectional study done in spring and summer of 2014,260 samples) 160 chicken meat, 50 gizzard and liver) were collected for isolation and identification of salmonella. The technique used in this study was recommended by Iran standard organization andKirby-bauer method was also used for detection of antibiotic resistance.

Results: Amongallthe samples,the range of detected salmonella was 10%I n which the 42.3% of them detected in spring and 57.7% in the summer.92.3% of samples belong to C serogroup and 3.8% of them were serogroup B and 3.8% serogroup D. All isolates show resistance to at least two antibiotics. Concurrent resistance to 2-6 antibiotics was detected in 70% of the isolates. The highest resistance was to Nalidixicacid�and Streptomycin (100%)and toTetracyclin (92.3%), Penicillin (88.5%), Neomycin, Kanamycin and Furazolidon (84.6%), cloramfenicol (73.1%), Ofloxacin (15.4%), Co-Amoxi clave and Ampicillin (11.5%) and Siprophloxacin 7.7%. The lowest levels of resistance were for Gentamycin and Amikacin (3.8%). No salmonella isolates were resistant to ceftazidime, Azitromicin, Meropenem, Imipenem and cefixime.

Conclusion: According to 10% pollution to salmonella and prevalence of serogroup C and salmonella importance in the human&rsquos health, as well as high rate of antibiotic resistance of isolates, applying a health strategy for reduction of contamination level is necessary.