Jundishapur Journal of Microbiology
Year:2013 | Volume:6 | Issue:4 (S.N. 22)|Papers Count:10

Background: Since tuberculosis (TB) is a major public health problem that is a leading cause of mortality and morbidity among infectious diseases worldwide, early diagnosis and treatment are important to control an effective tuberculosis (TB) and also the increasing number of patients with atypical manifestations of active TB. It suggests more evaluation for active TB in fibrotic lesion in CT scan.Objectives: We evaluated patients with each respiratory complaints and apical fibrocalcification in chest CT scan to detect active TB. Patients and Methods: This study was an observational cross sectional study and was carried out from July 2010 to September 2011 in our teaching hospital. Patients with apical fibrocalcification or fibrocystic lesion in lung CT scan (regardless of the size), without history of TB or other diseases which can cause these lesions were enrolled, then sputum analysis was performed, and in case the result was negative, we did bronchoalveolar lavage for them. Results: We gathered 40 patients out of which 15 patients were women. The average age was calculated at 64±8 years old. In total 6 patients had positive results. Conclusions: According to our observations fibrocalcified lesions should be evaluated for detecting M. tuberculosis particularly in the endemic regions.

Background: Fungi are ubiquitous in our environment and they are one of the important causes of allergic diseases. Identification of the most common aeroallergens to which patients are sensitized in a specific area is important in the diagnosis and treatment of allergic rhinitis. Objectives: The purpose of this study was to determine the prevalence of skin reactivity to common fungal allergens and total IgE in patients with allergic rhinitis in Ahvaz city. Patients and Methods: In this cross sectional study, 295 volunteers with the signs and symptoms of allergic diseases who referred to the Khuzestan Jahad Daneshgahi Medical Center in Ahvaz during 2010 were investigated. All patients were subjected to skin prick test (SPT) with common allergenic extracts. Data were analyzed by SPSS-18 software using Chi square test. Results: Seventy subjects, comprising 23.7% of the study group had positive skin test to at least one of the fungal allergens. The prevalence rate of sensitivity to fungal allergens was as follow: Cephalosporin 11.5%, mold mix 9.8%, Penicillium mix 9.5%, Alternaria mix 8.1%, and Aspergillus 5.1%. Mean total IgE in patients with SPT was significantly higher than in patients without any positive skin prick test (251 vs. 125 IU/mL, P=0.001). There was no statistical difference in the prevalence of sensitization to these allergens between two sexes, whereas, 15-35 age groups had significantly higher rates of allergy to fungal allergens (P=0.047). Conclusions: Fungal sensitization is a relatively common finding among patients with allergic rhinitis. Elimination or reduction of mold exposure in allergic patients is of special consideration and measures to reduce environmental factors which facilitate mold growth and proliferation are very important

Background: Brucellosis is a disease carried by animals that can be transmitted to humans. The signs and symptoms of brucellosis are nonspecific, blood tests and blood/tissue cultures are necessary for making the diagnosis of brucellosis. Testing for antibodies against the bacteria and isolating the organism from blood cultures and biopsy of body tissue (from the bone marrow or the liver) are various methods of diagnosis of brucellosis. In the absence of bacteriologic confirmation, a presumptive diagnosis can be made on the basis of high or rising titers of specific antibodies. Objectives: It is observed practically, that the sensitivity of serological tests is less than the amounts mentioned in the reference books. Elisa is a new method for diagnosis of the disease and in this study, application and its assimilation rate are compared with traditional serological tests. Materials and Methods: In this study, patients were selected who had suspicious clinical symptoms of brucellosis. Serological and Elisa tests were performed simultaneously. Results: In this setting, detection rate of the disease is 34.86%, if the high normal titer for the Wrights test titer assumed 1.80 and is 44.95% if the titer assumed 1.40, while Elisa test had detection rate of 58.72% for those suspicious cases. Furthermore, the detection rate for diagnosis of active brucellosis with 2ME tests was 17.54% with high normal titer of 1.80 and was 59.64% with a high normal titer of 1.40. Conclusions: The use of the Elisa tests is preferable for the diagnosis, and if the serological tests are used it is better that the high normal titer assumed to be 1.40.

Background: Neisseria meningitidis Serogroup A, is a major cause of bacterial meningitidis outbreaks in Africa and the Middle East. While polysaccharide vaccines have been available for many years, these vaccines have many disadvantages including the induction of T-cell independent responses which do not induce memory responses. Objectives: Thus to overcome this problem, in this research outer membrane vesicle (OMV) containing PorA was extracted and evaluated by biological and immunological methods. Materials and Methods: OMVs were extracted with deoxycholate and EDTA, and purification was performed by sequential ultracentrifugation. Physicochemical properties of extracted OMVs were analyzed by electron microscopy and SDS-PAGE. The toxicity of LPS content in its was assayed by LAL test. The Presence of PorA as a major component of OMV was confirmed by western blot. To study antibodies synthesis after immunization with OMV, ELISA method was used. Also serum bactericidal assay (SBA) was performed to determine the serum bactericidal activity against N. meningitidis serogroup A. Results: The results revealed that the content of protein extracted was 0.1 mg/mL. The electron microscopy showed that intactness of the vesicle in these preparation ranged more than 70%. The SDS-PAGE showed that PorA as a major immunological part of outer membrane vesicle was located in 35-40kDa. LAL test showed that the endotoxin activity was around 126EU/mL which is safe for using. The ELISA test revealed that the IgG total titer was elevated after the first injection. SBA indicates that bactericidal antibodies rise after the second dose of booster. Conclusions: The results showed that the extracted OMVs were conformationally stable, and there were no pyrogenic determinants in OMV. Also the results showed that the OMV elicited high level of specific antibodies against N. meningitidis serogroup A. These results indicate that the OMV obtained here, can be used as a meningococcal vaccine after further investigation.

Background: Helicobacter pylori virulence factors are important in development of the clinical outcomes. The initial stage of colonization is binding of H. pylori to gastric epithelial cells through the babA protein. Heterogeneity among H. pylori strains in presence and expressing the babA gene may be a factor in the variation of clinical outcomes. Likewise, another recently H. pylori described virulence factor, iceA has been shown to be a marker for ulcerative diseases. Objectives: We investigated the presence of babA2, iceA1 and iceA2 H. pylori virulence factors in patients with clinical outcomes in the southeast of Iran.Patients and Methods: In this study, 63 positive culture samples out of 191 biopsies examined to determine of babA2, iceA1 and iceA2 genes by PCR. DNA extracted from 63 Helicobacter positive specimens including 46 chronic active gastritis, 6 ulcerative diseases and non-ulcer dyspepsia 11. Results: The frequency of the babA2, iceA1 and iceA2 genes in the total isolates were 34 (54%), 14 (22.2%) and 34 (54%), respectively. The association of these virulence factors based on sex and age groups were not statistically significant (P>0.05). There was a borderline significant association between iceA1 and the clinical outcomes (P=0.094). Conclusions: Our study showed that the prevalence of babA2, iceA1 and iceA2 virulence factors were lower than the other studies that highlighted the role of the geographic factor.

Background: Leishmania tropica and Leishmania major are the main causes of cutaneous leishmaniasis in endemic regions of Iran. Objectives: The aim of this study was the identification of cutaneous leishmaniasis agents in Khuzestan province located southwest of Iran. Patients and Methods: 146 samples were collected from the lesions of 146 individuals including 67 (59.59%) male and 59 (40.41%) female with cutaneous leishmaniasis. The samples were then delivered to Iran-Zamin diagnostic laboratory and smeared on slides, stained with Wright’s eosin methylene blue stain and examined microscopically and graded from 1+to 4+.DNA was extracted from the slides and the identification of cutaneous leishmaniasis agents was performed using Nested PCR with the primers of CSB1XR, CSB2XF, LIR and 13Z. Results: 138 (94.5%) out of 146 cases of four regions were L. major and 8 (5.5%) were L. tropica. 57.97% of L. major cases were male and 42.03% were female. 87.5% of L. tropica were male and 12.5% were female. The maximum number of L. tropica cases was found in the northern region (8.16%) and the minimum was found in the western region (3.22%). 96.78% of L. major cases belonged to the western region of Khuzestan. Conclusions: L. major is the main species responsible for cutaneous leishmsniasis in four geographical regions of Khuzestan province southwestern of Iran and Nested PCR can be used for diagnosis and Leishmania species identification.

Background: Silver has been used from ancient times by humans, and recently nanoparticles of silver have been used in many aspects of human life including as a potent antibacterial agent. Objectives: In the current study a completely green method to prepare silver nanoparticles is reported. Two types of starches (potato and corn starches) were used to produce and stabilize silver nanoparticles. Antimicrobial activities of prepared nanofoods were investigated. Materials and Methods: Nanosilver particles have been produced using high temperature water containing bulk silver nitrate and starch sources. Presence of nanosilver containing particles and formation of the nanoparticles were confirmed using transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy, respectively. The anti-bacterial activity of emulsions made from nanoparticles containing starches was evaluated by assessing minimum inhibitory concentrations (MIC) against the studied standard, and pathogenic bacteria. Results: Findings of the current study indicated that the size and shape of silver nanoparticles depended on the type of starch. For example for a special type of potato starch the cubic silver nanoparticles were obtained whereas for other types of potato starch and corn starch spherical silver nanoparticles were produced. Nanoparticle sizes were mainly about 20 nm, but ranging from 2-30 nm in different situations. Due to the biocompatibility of starch synthesized silver nanoparticles, this method can be used for medicinal purposes. Both kinds of nanosilver containing starch sources have excellent antibacterial activity.Conclusions: The current study indicated that silver nanoparticles produced using different starches had strong antibacterial activities on the studied standard and pathogenic bacteria including gram positive and gram negative.

Background: Air contamination with fungal spores and the presence of these spores on respiratory tract, especially in industrialized cities with contaminated air, can play an important role on the occurrence of respiratory and coetaneous mycoses, asthma and allergic reactions. This survey was carried out to determine the prevalence of different fungal spores in the atmosphere of Tabriz district. Objectives: The present study aimed to detect fungal air spores in Tabriz environments, and to compare the environmental samples of Aspergillus fumigatus with the clinical isolated samples of this fungus, due to the importance of the dangers of A.fumigatus for public health, particularly for the immunocompromised patients. Materials and Methods: During this survey, the presence of air fungal spores was analyzed using settle plate and prepared culture in Sabouraud's dextrose agar. Prior identifications were performed using macroscopic characters, and direct microscopy. 262 samples were collected from different areas of the atmosphere of Tabriz district within all four seasons of the year. Fungal colonies were isolated from all air samples and identified using macroscopic and microscopic characters, and slid culture. Results: The main isolated fungal spores from the atmosphere of Tabriz district were Penicillium Sp. (36.6%), Cladosporidium Sp. (26.8%) and Aspergillus Sp. (23.6%). Conclusions: The presence of fungal spores in the atmosphere as a part of air pollution can cause significant problems for human health, particularly in the respiratory tracts.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and affects more than half of the global human population. This microorganism shows variations in its geographical distribution and causes chronic gastritis, peptic ulcer, gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. The development of these clinical entities depends on the bacterial strain and its virulence, the host genetic predisposition, immunological response, concurrent infections and infestations. In the immune response for the eradication of H. pylori different types of cells and mediators are involved. Studies reveal that the bacterial infection predominate the cytokines of Th1 phenotype with secretion of abundant levels of IFN-gamma and IL-2 by mucosal T cells. The inability of patients to clear H. pylori infections is a consequence of active immunosuppression and evasive mechanisms of bacteria. Many immune factors are involved: chronic exposure of the DCs to H. pylori leading to DC exhaustion, influence of regulatory T (Treg) cells through immunosuppressive cytokines, and the mast cells that change the gastric mucosal environments among others. In the current review, the focus is restricted to Tregs and their participation in the anti-bacterial response. These cells are a heterogeneous T-cell subpopulation with biological actions determinants in the pathogenesis of H. pylori infection. Studies have demonstrated that the activation of Treg cells cause down-regulation of adaptive immunity facilitating the persistence of infection by H. pylori. Even, the regulations of the Th17/ Treg and Th1/Treg balances are important in the immune response against the pathogen, in the persistent colonization of the bacterium and in the affectation of the gastrointestinal system.

Background: Urinary tract infections are always treated empirically before the results of bacteriological cultures are obtained. The choice of antibiotics depends upon the causative organism and its expected local antibiotic susceptibility pattern. Objectives: We analyzed the spectrum and resistance patterns of uropathogens against common antimicrobial agents in Ahvaz Abuzar Children's Hospital, a tertiary care pediatric unit in southwest of Iran. Patients and Methods: In this retrospective study, all urine samples of children hospitalized with urinary tract infection (288 patients, aged 1mon -14.5 years) during October 2008 to May 2011 were included in the study. After bacteria were identified by standard methods, antimicrobial susceptibility testing was performed using a panel of antimicrobial agents. Results: The most of patients were girls (n=226, 78.5%), and the median age was 13 months. The most common pathogens were Escherichia coli (84%), Klebsiella spp. (10.1%), Enterococcus spp. (2.4%), Proteus spp. (1.7%), and Pseudomonas spp. (1.7%). Overall bacterial resistance spectrum was the highest for co-trimoxazole (64.8%), followed by gentamicin (44.6%), amikacin (40.5%), nalidixic acid (37.3%), cefotaxime (28.9%), cefixime (27.5%), ceftriaxone (27.4%), and nitrofurantoin (10.2%). The female:male ratio was 2:1 (67.1% versus 32.9%) in infants aged<1 year and 8:1 in those aged>1 year (89.4% vs. 10.6%). Vesicoureteral reflux and abnormal sonography findings were associated with high resistance to cefotaxime (P=0.017), ceftriaxone (P=0.004), nitrofurantoin (P=0.014), and nalidixic acid (P<0.001). Conclusions: Increasing resistance to third-generation cephalosporins changed our opinion for using them as a single empiric intravenous therapy in hospitalized and very ill patients with acute pyelonephritis, the success will be achieved by concomitant use of an aminoglycoside or using other potent antibiotics.