[Optimization of gene expression and purification of Legionella pneumophila peptidoglycan associated lipoprotein recombinant protein]

There are many problems with most of the available diagnostic tests used to diagnose Legionella pneumonia, including inadequate sensitivity and specificity, and inability to provide a result in a clinically useful time period. Legionella pneumophila PAL protein has been considred as a target for detecting of Legionella infection from urine specimen, because it is conserved sequence and is secreted into the urine. The aim of this study was to optimize expression and purification of L. pneumophila PAL protein. In this experimental study, optimizing of 5 parameters [cell density, induction time, growth temperature, IPTG concentration and type of medium] was performed. After expression, periplasmic extract was prepared and recombinant PAL protein purified using Ni2+-charged resin column. Finally, recombinant PAL protein was verified by Western blotting. In terrific broth medium, the optimum condition of r-PAL protein induction was occurred at an OD600 of 0.6, 1mM IPTG concentration and 15 hours incubation at 25°C Recombinant periplasmic PAL protein was highly purified [>80%] using Ni-NTA column. Western blotting analysis showed that recombinant PAL protein was also specifically recognized by anti-His6-peroxidase antibody. By purification of recombinant PAL protein in purity greater than 80% it can be used to evaluate its capacity in diagnosis of Legionella infection and preparation of diagnostic kit

[Seroprevalence of legionella pneumophila in patients with, community acquired pneumonia]

Legionella pneumophila [LP] is a major cause of pneumonia worldwide. In spite of suitable epidemiological conditions and probability of LP existence in the region, the incidence of LP infection has not been determined in Ahvaz. Determination the seroprevalence of LP in patients with Community Acquired Pneumonia [CAP]. In this prospective descriptive study, during one year period [2007-2008], 80 admitted patients were selected in Razi Hospital of Jundi Shapoor University of Medical Science in Ahvaz with CAP and was studied the serprevalence of LP among them. Sera were tested for L. pneumophila IgG and IgM by using Elisa kit [Vircell, Spain]. Data were analyzed by using SPSS, version 16 statistical package. Among 80 serum samples, 12 cases [15%] were positive for LP- IgG+ IgM. Age, gender and area of residency did not significantly affect the seroprevalence of L P. [P>0.05]. The prevalence of L P seropositivity was not significantly affected by co-morbidities except diabetes mellitus [P>0.05]. Smoking and receiving antibiotic was observed in 100% seropositive patients. Legionella Pneumophila is a prevalent infectious agent in Ahvaz and should be considered in patients with CAP especially in diabetic and smoker patients

[Rapid detection of Clarithromycin-resistant Helicobacter pylori in dyspeptic patients by fluorescent in situ hybridization [FISH] compared with E-test]

Rapid detection of H. pylori is important for determining of resistant are susceptible strains to clarithromycin and recovery of patients will be acelerated, if clarithromycin is added to therapeutic protocol. Rapid detection of susceptible or resistant strains of Helicobacter pylori to clarithromycin in patients with dyspeptic ulcers by FISH technique and also comparison of FISH results with E-test technique. Frozen sections of gastric biopsies from 50 patients with dyspeptic ulcers were hybridized in situ with 5 fluorescent oligonucleotide probes [FISH]. Following staining with DAPI, the slides were examined using fluorescent microscopy. Also, susceptibility and resistance of isolated strains of H. pylori to clarithromycin was determined by E-test. The results obtained from both E-test and FISH techniques were compared. Twenty five out of 50 examined gastric biopsy samples were positive for H. pylori by FISH. Out of 25 H. pylori strains, 17 strains [68%] were susceptible, 6 strains [24%] resistant and 2 strains [8%] showed intermediate response to clarithromycin. This study showed that there was no significant difference between FISH and E-test results in terms of the number of susceptible or resistance strains. Regarding the results of this study, it seems that the FISH technique to be a suitable method to determine the susceptibility are H. pylori to clarithromycin, especially when a quickly decision is necessary for treating of dyspeptic patients