ABSTRACT
Objective:To analyse molecular detection of coliforms and shorten the time of PCR. Methods:Rapid detection of coliforms by amplification of lacZ and uidA genes in a multiplex PCR reaction was designed and performed in comparison with most probably number (MPN) method for 16 artificial and 101 field samples. The molecular method was also conducted on isolated coliforms from positive MPN samples; standard sample for verification of microbial method certificated reference material; isolated strains from certificated reference material and standard bacteria. The PCR and electrophoresis parameters were changed for reducing the operation time. Results:Results of PCR for lacZ and uidA genes were similar in all of standard, operational and artificial samples and showed the 876 bp and 147 bp bands of lacZ and uidA genes by multiplex PCR. PCR results were confirmed by MPN culture method by sensitivity 86%(95%CI:0.71-0.93). Also the total execution time, with a successful change of factors, was reduced to less than two and a half hour. Conclusions:Multiplex PCR method with shortened operation time was used for the simultaneous detection of total coliforms and Escherichia coli in distribution system of Arak city. It’s recommended to be used at least as an initial screening test, and then the positive samples could be randomly tested by MPN.
ABSTRACT
Brucellosis is a zoonotic disease of worldwide distribution and has great economic importance. Despite its control in many countries, it remains endemic in Iran. Brucellosis was investigated in many high risk occupational groups; however, few studies on the prevalence of brucellosis among blood donors are available. To determine the seroprevalence of brucellosis antibodies in blood donors, a serological study was carried out in central province of Iran. A total of 897 healthy blood donors with mean age 37.23 +/- 10.9 years were enrolled in the study. Laboratory tests including Standard Tube Agglutination Test [STA] and 2-mercaptoethanol [2ME] agglutination were checked in all samples. STA dilution >/= 1:80, and in the presence of 2-mercaptoethanol [2ME] agglutination >/= 20 was considered positive, Out of 897 cases, 11.9% were inhabitants of rural areas. 41.5% had history of consumption of unpasteurized dairy products and 9.3% had history of contact with domestic animals. A very low level of Brucella agglutinins was present in 3[0.33%] of the samples and only one sample [0.11%] was found to be truly positive for Brucella agglutinins. 2ME was negative in all samples. None of these 4 subjects showed signs and symptoms of brucellosis in 6 months follow-up. On the basis of our data, brucellosis has no epidemiological and clinical importance in our blood donors; therefore, it is not recommended to perform screening tests such as, STA and 2ME to identify brucellosis antibodies in the sera of blood donors