Jundishapur Journal of Microbiology
Volume:6 Issue: 4, Jun 2013

Helicobacter 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.

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.. 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.. In this study, patients were selected who had suspicious clinical symptoms of brucellosis. Serological and Elisa tests were performed simultaneously.. 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.. 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..

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.. 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 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.. 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).. 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..

Leishmania tropica and Leishmania major are the main causes of cutaneous leishmaniasis in endemic regions of Iran..Patients and 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.. 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.. 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.. The aim of this study was the identification of cutaneous leishmaniasis agents in Khuzestan province located southwest of Iran..

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.. 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 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.. 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).. 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..

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.. 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.. 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.. 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%).. 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..

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.. Thus to overcome this problem, in this research outer membrane vesicle (OMV) containing PorA was extracted and evaluated by biological and immunological 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.. The results revealed that the content of protein extracted was 0.1mg/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.. 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..

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.. We evaluated patients with each respiratory complaints and apical fibrocalcification in chest CT scan to detect active TB..Patients and 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.. We gathered 40 patients out of which 15 patients were women. The average age was calculated at 64 ± 8. In total 6 patients had positive results.. According to our observations fibrocalcified lesions should be evaluated for detecting M. tuberculosis particularly in the endemic regions..

Adenylate cyclase toxin (CyaA) is an important virulence factor of Bordetella pertussis, the causative agent of whooping cough, and a potential component of acellular pertussis vaccine.. In the present study the impact of invasive CyaA on oxidative activities of phagocytes was compared with the other form of this molecule to investigate the activity of different parts of molecules on leukocytes.. The work involved the production of two purified forms of CyaA with different enzymic and invasive properties. They were: the native enzymatically-active, invasive toxin (CyaA), an invasive derivative lacking AC enzymic activity (CyaA*). Different concentrations of CyaA and CyaA* were used to investigate dose-dependent effects of the toxins on oxidative burst in U937 human monoblastic cells, J774.2 mouse macrophage-like cells and fresh human granulocyte cells by Burst Test assay.. Significant effects were observed with 0.2 µg protein/ml of CyaA. For instance, there was almost complete (80%) inhibition of phagocytosis by J774.2 cells and 70% inhibition of phagocotosis by human granulocyte cells. The results showed that production of the oxidative burst was significantly impaired by increasing concentrations of CyaA compared to cells treated with PBS. However, there was no significant effect with CyaA* on either cells.. The results of the study showed that both enzymatic and invasive functions were required for the oxidative burst effects of adenylate cyclase toxin in leukocytes..

Influenza A and B viruses are the major causative agents of human respiratory infections, and these viruses are responsible for considerable mortality and morbidity around the world.. The objective of this study was to determine the frequency of influenza among suspected patients with influenza-like syndrome by RT- PCR assay in Khuzestan province of Iran during 2009-2010..Patients and Nasopharyngeal swabs were collected from 655 suspected patients with influenza-like syndrome in Khuzestan province Iran from March 2009 to February 2010. Clinical samples were taken within the 48 hours of initial symptoms, and were stored at -70 ͦ C. The patients were between 1 month and 85 years old. Initially all samples were tested for Influenza A and B viruses. Subsequently, for those samples with positive results for influenza A virus, influenza A/H3N2, and A/H1N1 tests were performed. The total assays were performed using RT-PCR.. Of 655 samples, 69 (10.53%) had positive results for human influenza A virus, and 5 (0.7%) samples had positive results for influenza B. Of those 69 samples with positive results for influenza A viruses, 45 (6.8%) were H3N2, and 24 (3.6%) were H1N1 subtypes. In this study most cases with positive results were less than 20 years. The sample positive included 49% males and 51% females. The peak seasonal influenza was between October and December 2009.. This finding showed that the predominant subtype of influenza virus among patients is A/H3N2, followed by A/H1N1 and B in Khuzestan province during the 2009-2010..

L-tryptophan (L-Trp) is a nutritionally essential amino acid that the body uses to synthesize proteins, niacin (vitamin B3) and serotonin (neurotransmitters). Human and animals depend on plants and microorganisms for its supply. Remarkable increasing demand has caused the development of a wide variety of biotechnological methods for its production which work as well for other amino acids.. The present work reports on the use of Iranian sugar beet molasses as an inexpensive source of L-serine (precursor) and PLP (cofactor) for the production of L-Trp by Escherichia coli (ATCC 11303). Carbon source and buffered condition are also optimized for L-Trp production by E. coli.. E. coli (ATCC 11303) was used as the microbial source of tryptophan. Batch fermentation was performed with 8L sugar beet molasses medium. The fermentation was carried out at 37 °C with an agitation speed at 250 rpm. The pH was controlled at 7 with 10 N NaOH. The cells were recovered by centrifugation. A 1g mass of E. coli cells (wet mass) was used as the biocatalyst in the reaction medium (100 cc) containing (in grams/100cc): Molasses/glucose=3.5; Indole=0.2; L-Serine=0.35; PLP=0.005; (NH4)2SO4 =0.5 The reaction medium was incubated on rotatory shaker (180 rpm) for 8 h at 37 °C. The reaction was carried out in KH2PO4-K2HPO4 buffering system (pH = 8, 0.1 M). The detection of produced L-Trp was carried out by the use of chromatography methods (HPLC and TLC), and fluorescence analysis.. Consequently, the potassium phosphate buffer system was considered as the suitably buffered reaction medium. The concentration of L-Trp produced in reaction medium was 0.3 mM and 0.12 mM for glucose and molasses (a combination of sugar beet and cane molasses), respectively.. In conclusion, our present study shows that sugar beet molasses is a source of PLP and L-Ser; and hence, suggests the general application of the approach to produce L-Trp more economically..

The immune system provides protection against infectious diseases that are caused by various microorganisms, in particular pathogenic fungi. Utilization of herbal immunostimulants is one solution to improve the immunity of humans and to decrease their susceptibility to infectious diseases.. The current study aimed to investigate the immunostimulatory effects of the aqueous extract of Heracleum persicum on mouse peritoneal macrophages.. The present in vitro study investigated the effect of the aqueous extract of H. perscium on the viability of macrophages and nitric oxide (NO) production using microculture tetrazolium (MTT) assay and Griess method, respectively. The effects on fungicidal activity and reactive oxygen species (ROS) production of stimulated peritoneal macrophages were also studied using killing method and nitroblue tetrazolium (NBT) assay, respectively.. The aqueous extract of H. persicum (Hp-W) at concentration of 10 mg/ mL resulted in a significant increase in NO production (8.17 nmol) by macrophages (P < 0.05). Moreover, H. persicum had a stimulatory effect on the level of ROS (P < 0.05) and a strong candidacidal activity in macrophages treated with 20 mg/ mL of the extract (P < 0.05).. The aqueous extract of H. persicum showed a significant immunostimulatory activity on macrophages. To clarify the exact mechanisms of this activity, more studies should be done with purified immunostimulatory components of H. persicum in future..

Staphylococcus aureus is one of the important human pathogens which are mainly isolated from wound, skin and contaminated respiratory excretions. Because many of hospital staff and patients carry this pathogen in their nose or skin, close contacts and touching have special role in spreading the infection in hospitals. Also, antibiotic resistant S. aureus, especially Methicillin Resistant S. Aureus (MRSA) have been seen among subjects. Thus, there should be an investigation for Bacteria colonization in nose of hospital staff and patients. Furthermore, investigation of antibiotic resistance pattern and examination of genotyping properties of resistant strains have a high efficacy in control and recognition of infection origin.. The current study aimed to determine the characteristics of S. aureus isolated from patients and staff in hospitals and compare them based on coa and spa typing methods.. In the current study, 157 clinical specimens were collected from patients who were treated at the Ahvaz medical university hospitals including 79 specimens (50.3%) from Sina hospital, 34 specimens (21.7%) from Imam Khomeini hospital, and 44 specimens (28%) from Golestan hospital and 157 nose swab specimens from the staff of these hospitals were collected during 2010. coa, spa genes of isolated Bacteria were amplified using PCR.. PCR results showed seven different patterns for staff and five different patterns for patients based on spa gene, and for coa gene five and six different patterns respectively. In addition, the prevalence of MRSA was 52.5 in staff and 83.7 in patient's specimens. Comparison of genetic diversity of spa, and coa genes in Ahvaz university hospitals doesn’t show significant difference (Chi-square and fisher's exact test).. The outcome of this study show that spa and coa typing are suitable meth­ods for MRSA isolates typing because it is easy to use and interpret them, and that these methods can be useful in infection source detection and its control especially in epidemic situations

Infectious diarrhoeal diseases cause major problems throughout the world and are responsible for considerable morbidity and mortality. Enteropathogenic Escherichia coli (EPEC) may cause infantile diarrhoea among children in developing countries.. The aim of this study was to define the prevalence of EPEC strains in raw milk samples.. Raw milk samples collected from various cow farms in Kermanshah, Iran, during the period of 22nd June to 22nd September 2009 and were examined for EPEC presence using PCR reactions targeting eaeA, and then stx1 and stx2.. Of the 206 samples, 17 (8.25%) were contaminated with E. coli eaeA positive and stx1 and stx2 negative (EPEC).. Our results confirm that raw milk recovered in Kermanshah may be a source for gastrointestinal infections by EPEC and strict preventive measures should be adopted to decrease contamination of milk with EPEC and other bacteria originated from animals..