نشریه میکروبیولوژی دامپزشکی
سال نهم شماره 2 (پیاپی 27، پاییز و زمستان 1392)

Within the course of this 18-month long work spanning 2010 and 2011, a total of eight human Mycobacterium bovis isolates collected from 1,320 tuberculosis-suspected patients, along with 68 bovine isolates were subjected to PCR-RFLP of pncA gene to assess their resistance to Pyrazynamide. All the isolates were subsequently spoligotyped to better understand their potential epidemiological links. As results showed, only 0.6% of the patients were infected with M. bovis, i.e. a considerably smaller rate compared to previous reports from Iran. Besides, all the isolates proved to be resistant to pyrazynamide. Consulting the SPOLDB4 spoligotyping databank, two patterns, namely ST595 and ST694, were detected among human isolates. Moreover, 12 patterns were found among the bovine isolates. ST595 was the single spoligotype shared between human and bovine hosts. For health officials, these observations indicate that in the Iranian environment M. bovis continues to produce a health risk to human.

Bacteriophage treatment offers a possible alternative to conventional antibiotic therapy against multidrug-resistant bacteria. Phage therapy has already been proven to be advantageous since it is more specific, accurate and potent than antibiotics. The aim of this study was the isolation of E. coli O157:H7 specific phages. To isolate the phage from the samples of soil, agricultural soil enrichment with animal manure, and waste were investigated. Spot assay and soft agar overlay technique were used for the isolation of phage. Electron Microscope was used for observation of phage structure. Specificity of the phage isolated was investigated. E. coli O157 phage was isolated from agricultural soil enrichment with animal manure. This phage produced clear plaques (0.2 to 0.3 mm diameter) on E. coli O157 but not on the other tested bacteria. The number of phage was calculated 3×104 PFU/ml. Phage virions were observed and confirmed by TEM. The virulent phage isolated in this study may be used for biocontrol of E. coli O157 in animals and fresh foods without compromising the viability of other normal flora or food quality.

Argas persicus is of considerable veterinary importance as a parasite of poultry and wild birds causing weakness، anemia، reduction in egg production and growth، as well as death of poultry. Such a tick is the vector of many important diseases. In this study 150 adult ticks in 15 groups including control and experimental groups were studied، three replicates were made for the control and experimental groups. The virulence of each fungal strain was tested by immersing engorged A. persicus in conidial suspensions (2. 4×107 conidia/ml) for 3–5 seconds and in negative control group in sterilized distilled water contains Tween 80%، then ticks were studied for 20 days and the results were finally reported. Experimental fungal strains had different virulence. In day 20 mortality rate of DEMI 002 was 96. 6% and mortality rate of other three strains were 100%. There were significant differences between different groups. Metarhizium anisopliae IRAN 437 C was found to be the most virulent to adult stage of A. persicus and M. anisopliae DEMI 002 had least effect on adult form of soft ticks (A. persicus). The results obtained from this study showed the promising effect of entomopathogenic fungi as an alternative biocontrol agent against A. persicus as an important fowl tick. More studies need to confirm these results in field condition.

Canine visceral leishmaniasis is a zoonosis protozoan disease that is potentially fatal to humans and dogs. In Iran، this disease is common and it is caused by Leishmania infantum Iranian standard strain (MCAN/IR/07/Moheb-gh). Several proteins are used for vaccination، one of them is LACK (Leishmania homologue for receptors for activated C kinase)، a 36 KD protein. Because of the wide spread of canine visceral leishmaniasis in Iran، in this study molecular cloning of the LACK protective antigen of Leishmania infantum Iran strain was considered to produce an effective recombinant protein. Therefore، Genomic DNA of Leishmania infantum was extracted and used as a template for PCR test، Then، PCR product of the LACK was cloned into pTZ57R/T vector. Recombinant plasmid was extracted and analyzed by sequencing، restriction enzyme digestion and PCR test. The results showed that LACK gene was correctly cloned into pTZ57R/T vector and as expected it was 939bp. This study was the first step for designing a DNA vaccine based on LACK Leishmania infantum Iran stain for expression recombinant protein for subsequent studies.

Theileriosis and Babesiosis are the important tick-borne diseases. They are characterized by fever، anemia، and death and fall in animal production and caused a lot of economic loss in livestock industry. The aim of this study was microscopical and molecular examination of Theileria spp and Babesia spp infection in apparently healthy cattle in the desert (Yazd)، semi- mountainous (Torbat Jam) and Caspian climates (Tonkabon) of Iran. In this study، 270 blood smears and blood samples with anticoagulant material were collected from healthy dairy cattle during spring and summer seasons in Yazd، Torbate Jam and Tonekabon areas. The collected samples were transferred to the laboratory، and then the blood smears were prepared and stained with Giemsa method. DNA of blood samples were extracted using a commercial kit then examined to detect Theileria and Babesia infection in healthy cattle in two stages. Theileria spp was observed in four blood smears from cattle in Yazd area، the results of PCR showed that 12 blood samples of cattle in Yazd، 1 blood sample in Torbat Jam and 3 blood samples in Tonkabon area were infected with T. annulata. Any Babesia spp infection was not detected in blood samples by microscopical and molecular examination. The obtained results indicated that the Theileria annulata infection is more important in dairy cattle in different areas of Iran.

Candidiasis is a kind of fungal disease that the most common causative agent in both human beings and livestock is Candida albicans. With respect to the increasing resistance of fungi to anti-fungal medicine and also medical restrictions in treating fungal diseases such as high expenses and the side-effects of these medicines، it is vital to study combinations like medical herbs which can replace them. The aim of the present study was to investigate the effects of two herbal essences of eucalyptus and lavanda on the growth of clinical strains of Candida albicans taken from livestock with mucosal and cutaneous infections، and to compare them with Candida albicans resistant and sensitive to Itraconazole. The study was conducted over 20 Candida albicans taken from livestock (cow and dog) infected cutaneous and mucosal candidiasis. The degree of samples’ sensitivity to Eucalyptus and Lavanda were determined through applying broth microdilution method. In this method، essences were first dissolved in DMSO and were then diluted on the ratio of 1 to 100 with the RPMI culture medium. Serial dilutions were then prepared from them in microplates، and their MICs were finally determined after the inoculation of yeast samples and within the incubation period and by comparing them with the control wells. In the present study، the MIC of eucalyptus against Candida albicans was determined at 4-1024μl/ml، in which the most growth fluctuations it had were seen in the densities of 64 and 32 μl/ml. Also، the MIC of Lavanda was determined at 1-256 μl/ml، and the most fluctuations it had in its growth were in the densities of 16 and 8 μl/ml. The results of the study proved that eucalyptus and Lavanda essences have a very good anti-fungal effect on Candida albicans. In this study، the essences of both Lavanla and eucalyptus showed good anti-candidiasis effects، and no significant difference was observed in the MICs of strains sensitive and resistant to Itraconazole.