فصلنامه دنیای میکروب ها
سال دوم شماره 2 (پیاپی 3، تابستان 1388)

Traditional methods for detection of foodborne pathogenic bacteria, which cause disease in human, are time consuming and laborious, so there is a necessity for developing a reliable and powerful method for the rapid detection of microbial pathogens in food. The aim of this study, is designing primers to amplify the DNA encoding the 23S rDNA genes from a wide range of bacterial species and tested the ability and efficiency of 23S rDNA sequence to detection of foodborne pathogenic bacteria. The 23S rDNA sequences of 9 foodborne pathogenic bacterial species based on the GenBank DNA sequence database were used to design oligonucleotide probes by Vector NTI software. Oligonucleotide probes for each bacterial species (total 28 probes) were designed and applied to nitrocellulose membranes. Digoxigeni (DIG) labeled 23S rDNAs were amplified by polymerase chain reaction (PCR) from bacteria using two universal primers, and were hybridized to the membrane array. Escherichia coli, Listeria monocytogenes, Enterococcus faecalis, Vibrio cholerae, Shigella dysantria, Staphylococcus aurues, Salmonella enterica, Proteus vulgaris, and Bacillus cereus were used as the most common foodborne pathogens and results showed that except Shigella dysantria, the others can be detected and identified by our microarrays. The sensitivity of the microarray assay was 103 CFU of bacteria. This study showed that 23S rDNA has sufficient sequence diversity for species identification and is useful for monitoring the populations of pathogenic bacteria. Thus, the oligonucleotide microarray is a powerful tool for the rapid detection and identification of pathogens.

Several days after infection with HIV and before serum changes in the stage that there is RNA HIV in the blood, the antigen P24 of the HIV is measurable in the blood. The studies done show that in the primary stages of the infection, antigen p24 appears sooner than antibody; therefore, the evaluation of antigen p24 can be an appropriate index for diagnosing the infection in the first stages of the disease. 300 negative samples from blood donor were tested with the third-generation kit for determining the antibody against HIV. 30 positive samples were collected from the AIDS Research Center and the patients confirmed with Immunoblot and NAT methods. All the samples were investigated with the designed kit for antigen p24 in Elisa method. From among the samples, the samples of serums the antibody test of which were positive, pretreatment with different solutions including 1.5 molars of Buffer Glycin with PH=2, hydrochloric acid 0.5 N, Trition X-100 with a concentration of 0.1%, alkaline buffer No.1 and 2 for removing the probable interventional effect of antibody against antigen p24. From among 30 positive samples, 21samples of antigen tests were positive in the kit designed by human monoclonal and 18 cases in the kit designed by mouse monoclonal antibody before pretreatment samples with Glycin (the diagnostic sensitivity is 70% and 60% respectively). After pretreatment, 28 samples in the kit designed by human monoclonal antibody and 27 samples in the kit designed by mouse monoclonal were positive.(the diagnostic sensitivity were 93% and 90% respectively). In the kit designed for detecting antigen p24, the cut off was determined on the basis of optical density of the negative samples 0.15(equal to 2 pg/ml of antigen P24). The difference between the average of optical density of the positive and negative samples in antigen test was significant statistically(p<0.005).(1.6 optical density against 0.08). By using human monoclonal antibody,1 unit in per milliliter of WHO antigen, and 2 picograms in per milliliter of recombinant antigen, the analytic sensitivity of measurement was obtained. If the mouse monoclonal antibody is used, these values are 4 and 8 respectively. According to results gained from the negative samples, the measurement specificity is 100%. In pretreatment the samples of serum positive and the samples of BBI panels for which the antigen, antibody, and PCR tests were positive; the glycin buffer of 1.5 molar and PH=2 increased the diagnostic sensitivity(70% against 93%). This test has high sensitivity and specificity in diagnosing HIV and is more simple, fast, accurate, and economical in comparison with other diagnostic methods. This test may be used for screening newborns from the mothers with positive HIV and the taking decision about the cases for whom the fourth-generation of Elisa Tests are positive but Western Blot Test has not confirmed it.

Introduction and Phenol and phenol compounds are extremely toxic which found abundantly in the compounds such as pesticides, herbicides, poisons and chemical fertilizer. Phenol are highly harmful for the creatures, particularly for human beings. It leaves irretrievable effects, so it deems advisable to eliminate these compounds from the nature in different ways. Physicochemical methods were used formerly to eliminate phenol. In addition to much expenditures, these methods also cause the production of the dangerous intermediary compounds. Now, the biological analysis of phenol being considered. Among the microorganisms, bacteria have particular importance in phenol analysis. This research has been done on the sediment and water samples of Parishan lake which is one of the international wetland of Iran. Many samples of bacteria were detached. The separation method for sediment samples is as follows in which 10gr of sample is mixed with 100ml of phenol broth culture medium. Then it is supplied with air in a 30-degree temperature on a shaker having 170rpm. In water sample, 10ml of water sample mixed with 100ml of phenol broth medium. Other stages are repeated again similarly. This process continues until the pure bacteria are separated. The technical medium which is the basis of this experiment including KH2PO4, K2HPO4, (NH4)2SO4, MgSO4, FeCl3, phenol, water and pH7. The obtained results presented that the bacteria analyzing phenol formed a wide range of bacteria. These bacteria are mainly gram negative and belongs to the Pseudomonas family. These bacteria has got various ability in phenol analysis (0.2-0.9 gr/lit phenol). According to the obtained results, the separation and purification of such bacteria can be used for phenol elimination and its toxic derivations in the environment. This is an important step for men's health protection.

Various Helicobacter species causes contamination of birds, human and other mammals. H.hepaticus infection associated with intestinal, biliary and hepatic disorders such as liver, gall bladder and pancreas cancers. Mus musculus is the most common host of this bacteria that play an important role in transmission of zoonotic infection. The aim of this study was determination of the rate of H.hepaticus in Mus musculuses of Esfahan province by PCR. This was a cross-sectional study, which was done on 261 Mus musculuses isolated in Esfahan in 2009. Following the description of mice in steril condition hepatic samples isolated. Then for identification Helicobacter genus and H.hepaticus, general and specific primers were used respectively. Helicobacter genus identified in 72% of tatal samples. Out of all Helicobacter genus 42% was be H.hepaticus. According high rate of Helicobacter species infection, it sounds that the widespread surveillance of Mus musculuses in studied area was be necessary.

Brucella spp and Salmonella abortus ovis are important causes of ovine abortion around the world. Both Bacteria can be serologically diagnosed, but many factors may cause false positive and negative results. Direct methods based on bacteriological isolation are usual, but they are difficult, time consuming and dangerous. Polymerase chain reaction (PCR) have been successfully described for the detection of Brucella spp. and Salmonella abortus ovis.The detection of these agents in aborted ovine fetuses by multiplex PCR is described. The mPCR was applied to 38 fetal stomach contents. 5(13.1%) samples collected from ovine fetus were Brucella spp. 19 (50%) samples collected were salmonella abortus ovis. 10 (26.3%) samples collected were negative and 4 (10.6%) samples collected were Brucella spp. and Salmonella abortus ovis. in Bacteriological examination 5(13.1%)samples collected from ovine fetus were Brucella spp. 9(23.7%)samples collected were salmonella abortus ovis and 24 (63.2%) samples collected were negative.Simplicity and the possibility of detection of both bactera in a single tube reaction support the use of the mPCR in the routine diagnosis.

Introduction and Escherichia coli and Klebsiella pneumoniae are the most agent of urinary tract infection (UTI) and prevalence Extended-Spectrum Beta-lactamase (ESBLs) in these bacteria due to spread of antibiotic resistance and mortality and morbidity in patients. The best manner for control of ESBLs in bacteria, are inhibition of spread these bacteria and use of standard method for recognizes ESBLs producer strains.Subject of this study was comparison frequency of ESBLs in Escherichia coli and Klebsiella pneumonia strain in UTI acquired patients with phenotypic test. This cross-sectional search was performed in Azzahra and Shariaty hospitals during of 2008-2009 years in Esfahan, according to statistical formula randomly selected 91 samples from urinary infections. Bacterial identification was performed with microbiological methods, ESBLs production was performed with screening and confirmatory test and survey antibiotics resistant pattern was performed with Kirby method. Frequence of ESBLs in E.coli and K.pneumoniae strains was respectively 47.97% and 41.66%. According to antibiogram result respectively 59.2%, 54.9%, 30.3%, 27.8%, 19.5% and 16.7% of E.coli strains were resistant into Co-Trimoxazole, Nalidixic acid, Ciprofloxacin, Gentamicin, Ceftazidime and Nitrofurantoin and respectively 75%, 50%, 40%, 44.5%,37.5%, 37.5%, 22.3% and 0% of K.pneumoniae strains were resistant into Ampicillin, Co-Trimoxazole, Nitrofurantoin, Ceftazidime, Amikacin, Cephotaxime, Imipenem and Ciprofloxacin. The result showed high frequence of ESBLs, so antibiotic resistant in isolated bacteria from hospitalized into out patience's that represent high spread antibiotic resistant strains in hospitals.

Tuberculosis (TB) is the most common cause of death due to infectious disease, worldwide. In fact only 10% of people infected with Mycobacterium tuberculosis develop clinical disease which suggests, the role of host genetic factors in susceptibility against TB. For this reason, we aimed to determined IL-12 gene polymorphism among PTB cases. A case-control study was carried out in one hundred twenty TB patient and one hundred sixty seven healthy control individuals. The Single Nucleotide Polymorphism (SNP) in 5 regions of IL12 RB1 gene +705A/G +1158T/C, +1196G/C,+1664C/T and +1637 G/A were determinate by PCR-RFLP. No significance differences were detected at +1664 C/T and +1637 G/A allele frequencies. In this study, the IL-12 gene polymorphism at +1664 C/T and +1637G/A allele were associated with susceptibility against TB. Although, further studies suggested on more number of samples.

In this research, the effect of mix ratio and culture type on the bioleaching of a heap leaching 1 sulfide copper ore using Mesophile bacteria has been investigated. The different bacteria types have a special mechanism in sulfide ore dissolution. So increase recovery can reached with change of bacteria mix ratio. The microorganism, employed in bioleaching process, reach energy for existence from culture and the materials which has been rest under leaching. So the poor and strong culture can be effective for increase of recovery. The residual ore of Sarcheshmeh copper heap leaching 1 because of leaching is more than sulfide type. The copper grade at provided sample of heap was 0.23%. About 66% of copper minerals were sulfide which about 51% of them was chalcopyrite. The pyrite amount at the sample was 6%. These tests were down at the shake flask and by using of mixture of mesophile bacteria. Design of experiments was down based on perfect factorial with two levels. Bacteria with producing sulfuric acid at the medium cause more solution and less acid consumption. Norris culture medium in comparison to 9K culture medium causes more recovery for sulfide ore. The reason of this is increase of iron in the solid medium due to precipitation of iron ions and probably formation of Jarosite. The insemination ratio did not show a remarkable effect but amount of added iron ions had a remarkable effect. The maximum of copper recovery was 66.38% after 25 days. The optimum conditions were obtained for reaching to maximum recovery with Norris culture, pH equal 1.6, mix ratio equal 40,40,20 for Tf, Tt, Lf and adding Fe2+ ion (1.5 g/l).