[ antimicrobial activity of thyme, sweet marjoram, savory and eucalyptus oils on escherichia coli, salmonella typhimurium, aspergillus niger and aspergillus flavus]

The presence of pathogenic microorganisms in aviculture threatens the health of fowl and humans. Thyme [Zataria multiflora Boiss], sweet marjoram [Origanum majorana], savory [Satureja hortensis] and eucalyptus [Eucalyptus globules] are Iranian herbal medicines that are used in folk medicines. The aims of this study were to evaluate the antimicrobial activity of these oils separately and in combination against Escherichia coli, Salmonella typhimurium, Aspergillus niger and Aspergillus flavus in vitro condition. The antimicrobial activity of essential oils against different isolates of microorganisms was evaluated by disc diffusion and macro broth dilution assays. The results showed that the antimicrobial activity of thyme, sweet marjoram and savory oils against different bacteria and fungi were more than the eucalyptus oil. When ethanol was used as a solvent in comparison with dimethyl sulfoxide, the antimicrobial activity of oils was increased. The type of solvent creates meaningful discrepancy on effectiveness of oils [p<0.001]. In disc diffusion method, the fungi were sensitive than bacteria and A. niger was more sensitive than A. flavus. The sensitivity of bacteria was dependent to the type of bacteria and essential oil and the oils showed inhibitory effect against fungi and the fungicidal effect of oils were weaker than bactericidal effect. The antimicrobial activities of effective oils were related to thymol and carvacrol components in respect. Due to limitations in usage of chemical compounds in poultry and food industries, the essential oils look to be appropriate alternatives for some disinfectants to control the human and animal diseases in the future

Isolation, identification and drug susceptibility patterns of campylobacter strains cultured from children with diarrhea at two pediatric hospitals in Tehran, 2003-2004

Campylobacter spp. that have been frequently isolated from livestocks, meat and chicken cause acute diarrhea in developed countries. This study was conducted to screen the cases of diarrhea at two children hospitals in Tehran to detect the bactriologically confirmed cases of campylobacteriosis and to determine the rate of causative agents to different antimicrobial drugs. Five-hundred fecal samples of patients with acute diarrhea were received from two children hospitals, Children Medical Center and Mofid Hospitals during October 2003 and October 2004. Samples were received in Cary Blair transport medium to the Food Borne Disease Laboratory. They were then plated either directly on Brucella agar containing supplement or enriched in Preston broth for subsequent plating. The inoculated plates were incubated in microaerophilic condition for 48 hours. Drug susceptibility testing was performed using disk diffusion agar. During the study period, 39 campylobacter strains were isolated [7.8%]. Campylobacter jejuni was the dominant species isolated from the clinical specimen [75.7%]. The rates of susceptibilities to different antibiotics were as follows: gentamicin, imipenem and colistin [100%], streptomycin and chloramphenicol [97%], neomycin [94.1%], ampicillin [88.2%], erythromycin [85.2%], tetracycline [70.5%], cefotaxime [58.8%], ciprofloxacin [20.5], carbenicillin [50%] ceftazidime [32.2%]. All isolates were resistant to cephalexin.The frequency of recovery [7.8%] from children with diarrhea shows that the organism could be one of the major etiologic factors of diarrhea among children in Tehran. The high rate of resistance to quinolone warrants further for the possible reasons