Mitra Ashayeripanah; fereshteh eftekhar; Bahram Kazemi; Mohammad Mehdi Feizabadi
Abstract
Due to the large population latently infected with Mycobacterium tuberculosis worldwide, vaccines against latent tuberculosis can make a dramatic impact on the global tuberculosis problem. In this study, bioinformatics analysis of a latency antigen from M. tuberculosis, Rv1733c, predicted that Rv1733c ...
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Due to the large population latently infected with Mycobacterium tuberculosis worldwide, vaccines against latent tuberculosis can make a dramatic impact on the global tuberculosis problem. In this study, bioinformatics analysis of a latency antigen from M. tuberculosis, Rv1733c, predicted that Rv1733c is an integral-membrane protein with a large number of B-cell and T-cell epitopes, making it a potential vaccine candidate. Therefore, rv1733c gene from M. tuberculosis strain H37Rv was chemically synthesized, inserted into pTG19-T plasmid and the recombinant plasmid was transformed into E. coli Top10. After confirming the presence of the DNA fragment by digestion with restriction endonucleases and sequencing, it was subcloned into pET-23a (+) and expressed in E. coli strain BL21 (DE3). The recombinant protein was observed as a band of ~ 24 kDa on SDS-PAGE gel and western blot analysis using an antibody against the hexa-histidine-tag of the protein revealed a band with the same size. Finally, the protein was successfully purified using a histidine-tag purification kit.
Fereshteh Raee; Fereshteh Eftekhar; Mohamad Mady Fazabady
Abstract
Klebsiella pneumoniae is an opportunistic pathogen that causes a significant proportion of community and hospital acquired infections. Among the antibiotic classes, β -lactams are often used for treatment of these infections. However, bacterial resistance has developed mostly due to the production ...
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Klebsiella pneumoniae is an opportunistic pathogen that causes a significant proportion of community and hospital acquired infections. Among the antibiotic classes, β -lactams are often used for treatment of these infections. However, bacterial resistance has developed mostly due to the production of a variety of β-lactamases, especially the extended-spectrum β-lactamases (ESBL). In this research, one hundred and ninety six K. pneumoniae isolates were collected from Imam Hussein Hospital in Tehran during 2008-2012. Antibiotic susceptibility was determined by disc diffusion and extended-spectrum β-lactamase production was shown by the phenotypic confirmatory test. Carriage of blaSHV, blaTEM and blaCTX-M genes was detected by PCR and specific primers. ESBL production was examined in relation to the presence of blaSHV, blaTEM and blaCTX-M genes. Overall, 160 isolates (81.6 %) carried blaCTX-M, 104 (53.06 %) had blaTEM and 82 (41.8%) harbored the blaSHV genes. ESBL production was observed in 92 isolates (46.9%) of which, 77 (83.6 %) harbored blaCTX-M, 57 (61.9 %) had blaTEM and 43 (46.7%) carried blaSHV. Finally, 7 (7.6 %) did not harbour any of the 3 genes and 24 (26.08%) carried all three. Our results show that gene carriage does not necessarily account for its expression and ESBL phenotype. In addition, the presence of blaCTX -M was dominant in our urinary Klebsiella pneumoniae isolates followed by blaTEM and blaSHV .
