Jundishapur Journal of Microbiology
Year:2011 | Volume:4 | Issue:4 (S.N. 14)|Papers Count:14

Introduction and objective: Legionella are the causative agents of pneumonia in human and it is reported that up to 90% cases of legionnaires disease are due to Legionella pneumophila. These organisms are ubiquitous distributed in natural and man made water sources. They are spread to human by inhalation or aspiration of contaminated aerosols of these sources. We studied some of man made water sources in view of the presence of Legionella, by two methods of culture and PCR.Materials and methods: One hundred and fifty water samples collected from different man made water sources were examined. After acidic treatment of samples, water pellet was inoculated onto buffered charcoal yeast extract agar (BCYE) and BMPA (BCYE supplemented with three antibiotics) media. Isolated colonies were identified by morphological and biochemical tests. DNA was extracted from the bacteria and was used for PCR technique. DNA pattern of Legionella were identified after electrophoresis of PCR products.Results: Survey of water samples collected from different sources resulted in isolation of Legionella pneumophila (7.3%) by culture, and identification of them (15.3%) by PCR. The highest isolates of L. pneumophila were from fish ponds in rates of 6.6% by culture and 13.3% by PCR method. Sensitivity and specificity of PCR in this survey were 100% and 95%, respectively.Conclusion: This study showed that legionnaires disease agents were widely spread in our examined water sources and compared with culture; PCR method has suitable sensitivity and specificity for rapid detection of these organisms in environmental water sources.Significance and impact of the study: The results of this study will increase physicians and microbiologists awareness about spreading of Legionella and this will be useful for control of legionellosis agents.

Introduction and objective: Toxoplasma gondii and Neospora caninum are two closely related cyst forming apicomplexean protozoa that infect a wide range of warm-blooded animals. N. caninum has similar morphologic and biologic characteristics to T. gondii and until 1988 was misdiagnosed as T. gondii. Tachyzoites and tissue cysts of both parasites are found intracellularly in the intermediate hosts. The aim of this study was to determine the seroprevalence rate of anti-Neospora caninum and anti-Toxoplasma gondii antibodies in feral cats (Felis catus) in Ahvaz, Iran.Materials and methods: Antibodies to N. caninum and T. gondii were determined in serum samples of 100 feral cats in Ahvaz, Khuzestan province, Iran. IgG antibodies were assayed by the modified agglutination test using whole tachyzoites of T. gondii and N. caninum, incorporating 2-mercaptoethanol, modified agglutination test and Neospora agglutination test, for T. gondii and N. caninum, respectively.Results: Anti-T. gondii antibodies were found in 54 (54%) of 100 cats but anti-N. caninum antibodies were detected in 19 (19%) of 100 cats. There was no difference between the presence of antibodies for both parasites in male and female cats (P>0.05), but occurrence of antibodies was significantly increased with age for both parasites (P<0.05).Conclusion: Because of high occurrence of anti-T. gondii antibodies in cats in this study, cats may play a serious role in human and other mammalian toxoplasmosis in Ahvaz.Significance and impact of the study: This study was the first considering survey T. gondii and N. caninum simultaneously in cats in Iran and revealed the importance of cats in prevalence of theses two parasites.

Introduction and objective: Aspergillus and Mucor are found to cause life threatening infections. Though cerebral aspergillosis and mucormycosis are rare, the disease mortality rate is found to be predominant in patients with immune system being compromised. Because of the high mortality rate of this infection, early diagnosis and prompt initiation of treatment are crucial as effective treatment improves the overall management of diseases. The objective of the present study was to screen for a method in diagnosing cerebral aspergillosis and cerebralmucor-mycosis.Materials and methods: In the present study the antigens were effectively extracted from Aspergillus and Mucor, and then they were characterized using native polyacrylamide gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and their diagnostic potential was evaluated by ELISA.Results: Among the bands visualized Aspergillus flavus showed four distinct bands, two bands in A. fumigatus but a diffused band was noticed with Mucor. Clinical analysis by ELISA conducted in 47 cerebro spinal fluid samples from patients suspected for chronic meningitis infection were found to be positive for antigens in 8.51%, 6.38% and 12.76% for A. flavus, A. fumigatus and Mucor, respectively.Conclusion: From the results, it was concluded that ELISA can be used as a sensitive and reproducible test for diagnosis of cerebral aspergillosis and mucormycosis.Significance and impact of the study: With regard to the study on the fungal antigen which infects the central nervous system and also understanding the importance of ELISA as a sensitive and reproducible diagnostic tool, early diagnosis of cerebral aspergillosis and mucormycosis is possible.

Introduction and objective: Oxalis corniculata is well known because of its anti-dysentery and antidiarrheal effects and also its application in skin diseases. The aim of this study was to evaluate the antibacterial activity of aqueous extract of O. corniculata on Staphylococcus aureus and Escherichia coli species and to formulate a herbal antibacterial cream.Materials and methods: Disk diffusion method was used to assess antibacterial activity of O. corniculata extract. Antibacterial activity of this plant was compared with doxycycline, streptomycin, chloramphenicol, carbeincillin and nalidixic acid. In order to prepare cream, different amount of ingredients were incorporated together, then the required amount of the herbal extract was added. The cream formulations were compared according to their physical and chemical stability. Finally, the best formulation was selected by altering the type and quantity of formulation factors.Results: Results showed that aqueous extract of O. corniculata was effective on S. aureus and E. coli and the antibacteria were more effective when the extract concentration increased. Control experiments and stability determination showed a stable homogenous appearance during three months storage period and no phase of separation was occurred.Conclusion: The aqueous extract of O. corniculata exhibited strong antibacterial activity especially with increase of the extract concentration. The results of different chemical and physical tests of cream showed that the formation could be used topically in order to protect skin against damage caused by this S. aureus and E. coli.Significance and impact of the study: The results of the present investigation suggest that this plant is a suitable candidate for further pharmacological evaluation.

Introduction and objective: Intracellular polyhydroxyal-kanoate granules (PHA) are biodegradable polyesters and produce by different kind of prokaryotic microorganisms. Polyhydroxybutyrate (PHB) is one of the PHA polyesters and consists of hydroxybutyrate unit. PHB has a wide range of applications in pharmacy and drug delivery systems. The aims of this study were PHB production and determination of granules distribution in different subpopulations of single genus by Nile red staining method and flow cytometry.Materials and methods: Bacterial PHB producers were screened by viable colony staining method. Kinetic study or secondary screening of strains was performed by fluorometric and photometric methods. Also distribution of PHB granules in different subpopulations of single genus of Ralstonia and Sinorhizobium had been determined by flow cytometry.Results: Different genera of bacteria were isolated and selected for PHB production. Among all studied strains, Ralstonia (L1) and Sinorhizobium (AR2) have the highest ability for granule formation. Flow cytometry distinguished four subpopulations (QA1, QA2, QA3 and QA4) with different PHB content and side scatter parameter in both strains at Mid-log phase.Conclusion: These heterogeneous subpopulations have diverse characteristics related to granule formation and multiplication activity. Flow cytometry showed each individual subpopulation has specific cell size, complexity and granularity related to cell biochemical and physiological states.Significance and impact of the study: These strains are not pathogen and have been isolated from plant roots and soil. They are appropriate to get high PHB for drug delivery applications.

Introduction and objective: Nowadays the microbial resistance to antibiotics and other physicochemical agents has caused various problems in the process of disinfecting devices and surfaces of the hospitals and in treatment of the patients. Thus, the aim of this study has been to examine resistance patterns of some penicillin resistant bacteria to physiochemical agents (UV and gamma radiation, cetrimide, and some of heavy metals).Materials and methods: In the present study, strains of penicillin resistant bacteria isolated from Alzahra hospital of Esfahan, including 39 strains of Escherichia coli and 23 strains of Pseudomonas aeruginosa were studied. To screen for cetrimide and cadmium, mercury and arsenate resistance was measured using micro titer plates, steer’s replicator and serial dilution for determining minimal inhibitory concentration (MIC).Results: The most MIC determined in E. coli and P. aeruginosa strains respectively were 50 and 400 mg/ml (Cd and Hg). MIC of metals was determined in adaptation condition for some of resistant bacteria. Results showed that in the most cases bacteria were selected and radiated with intensity of 0.25J/m2s. Mean of cfu/0.1 ml after 240s radiation in E. coli and P. aeruginosa were, respectively 4.7 and 3.6. Gamma radiation was performed with intensity of 20 Gray/min (GY/min) in different times in these resistance bacteria. Mean of cfu/ml for E. coli and P. aeruginosa strains in 1000 Gray dose were, respectively 2.4×102 and 8.2×102.Conclusion: Pseudomonas aeruginosa strains showed higher resistance than E. coli. But there was no significant difference in MIC of arsenate between these bacteria.Significance and impact of the study: The impact of this study is to find E. coli and P. aeruginosa strains that are multi resistant to physicochemical agents; and to suggest a solution for destroying these specific strains.

Introduction and objective: Contaminated egg and its products are increasing the risks of illness in humans. The significance of these diseases in humans can vary from mild symptoms to life threatening conditions. This study was conducted to determine the contamination of egg to food borne pathogens; Salmonella spp., Listeria monocytogens, Campylobacter jejuni and Escherichia coli in Shahrekord.Materials and methods: One hundred normal eggs randomly purchased in the spring and summer of 2008 from small and big supermarkets of Shahrekord, and delivered to the food microbiology lab to be tested. The contents of eggs cultured for those bacteria on selective agar and standard microbiological tests performed to identify the isolated organism.Results: The result showed that there was no contamination by Salmonella spp., L. monocytogens and C. jejuni in all 100 eggs. However, 19 samples were contaminated by E. coli, four samples by Proteus spp. and one sample by Klebsiella spp. Average colony count of coli form bacteria was 20 cfu/g and E. coli was 12/6 cfu/g.Conclusion: We concluded that Salmonella spp., L. monocytogens and C. jejuni contamination of eggs does not make up a serious health hazard in this area. E. coli are known to contaminate the surface of egg while mechanical process can spread the bacteria through eggs.Significance and impact of the study: It is important to remember that control is required at all levels in the food chain and by separating cooked and raw.

Introduction and objective: Presence of fungi in exhibition and storage spaces of museums may be dangerous to museum professionals and users. The aim of the present study was to assess the level of allergenic fungi in deteriorating historic objects of the Shahrekord Museum collection.Materials and methods: In this investigation, samples of 115 deteriorating historic objects aged from 50 to 200 years were inoculated on Sabouraud dextrose agar and incubated up to two weeks at 28oC in order to isolate fungal contaminants.Results: Samples of 105 items (91.3%) were positive for the presence of fungi. The most common isolated fungi were Aspergillus spp. (32.9%), Penicillium spp. (19.1%), and Madurella spp. (5.2%). The number for Zygomycota was 17.3%. Differences in contamination rates between fabrics, leather made and wooden objects for Aspergillus spp. and Penicillium spp. were statistically significant (P<0.05).Conclusion: In fabrics Aspergillus spp. and Zygomycota, in leather made objects Aspergillus spp. and Penicillium spp. and in wooden objects Zygomycota, Aspergillus spp. were dominant moulds. Majority of isolated species were common allergens.Significance and impact of the study: Most of the isolated fungi are allergenic and can cause adverse human health effects in both museum workers and users.

Introduction and objective: Hepatitis B is a disease of public health importance in Iran. The aim of this study was to evaluate some possible risk factors for the spread of hepatitis B infection from the hepatitis B virus (HBV) carriers.Materials and methods: A cross-sectional study was conducted among chronic HBV individuals who referred to gastrointestinal department, Imam Khomeini hospital, Ahvaz Jundishapur University of medical sciences from October 2009 to June 2010. All subjects were evaluated using a face-to-face questionnaire about demographic aspects. The analysis included data on past medical history, physical examination and periodic evaluation clinically and serologically. The control group consisted of the patients referred to the gastrointestinal clinics with negative HBV serologic markers of HBV infection. The risk factors among infected subjects (HBV-positive) were compared to those of subjects never exposed (HBV-negative) to HBV.Results: A total of 560 subjects were studied for HBV, of which 272 were HBV-positive and 288 HBV negative cases comprised the control group. Mean age of the patients was 35±9 years. HBV-positive subjects were more likely to be of female gender (61.39% versus 41.31%, P<0.0001). Endoscopy 54.77%, major surgery 44.48%, and tattooing history 8.45% were found to be independent risk factors of being chronically infected with hepatitis B virus.Conclusion: Our data indicate that a history of endoscopy, major surgery and tattooing are important risk factors for spreading of HBV infection.Significance and impact of the study: Improvements in certain lifestyle patterns and customs in this area may be essential to prevent transmission of the infection.

Introduction and objective: Phytic acid, which is the main constituent of animal diet, is not digested by monogastric animals and hence, create problem in the availability of phosphorus in their diet. It also causes environmental pollution by extra supplemented phosphorus in animal’s diet. Hence, acido-thermophilic phytase producer bacterial strain has been isolated in this study for its potential use in poultry feedings.Material and methods: Samples for the screening of phytase producers were collected from different habitats. 1g of soil was inoculated in culture broth containing 2% (w/w) phytate organic substrate. The qualitative screening for phytase production was performed by agar plate containing sodium phytate followed by quantitative screening using shaking flask method. Phytase activity was determined and the selected isolate was biochemically characterized using the standard biochemical techniques.Results: AR58 bacterial isolate, isolated from poultry field soil, showing significant extracellular phytase production was selected. After qualitative and quantitative screening, AR58 showed a hydrolytic zone of 42 mm diameter and 395 IU/ml phytase activity. AR58 was identified as Klebsiella sp. The enzyme had maximum activity at 55oC and pH range from 3.5 to 5.5.Conclusion: Our finding suggests that acido-thermophilic phytase from Klebsiella sp. could have great potential for feed industries.Significance and impact of the study: In the present study, phytase accumulation by the strain of Klebsiella sp. has significant values. Hence, this enzyme could find application in the animal feed industry for improving the nutritional status of feed as well as combating environmental pollution.

Introduction and objective: One of the most likely factors influencing on the clinical manifestations of cutaneous leishmaniasis, is genetic variability of Leishmania parasites that is currently controversial. The aim of this study was to identify the possible correlation between clinical cutaneous lesions and genetic of the causative Leishmania agents in Khuzestan, south west of Iran.Materials and methods: Fourteen samples from patients with different size of cutaneous leishmaniasis (CL) lesions referred to health centers and medical diagnosis laboratories of Ahvaz, Dashteazadegan, Shush, Hendijan and Ramhormoz were collected and studied by mini-exonePCR-RFLP and sequencing methods. The diameter of lesions was measured by a blinded caliper and flexible ruler.Results: Enzyme electrophoretic analysis of different isolates of L. major and L. tropica separated from lesions with different sizes have revealed no heterogeneity in this species, whereas alignment of the mini-exonesequencing isolates revealed 97-99% identity and 2-8 nucleotide substitution. Identity was 99% in isolates obtained from Lesions with near Sizes.Conclusion: This study revealed nucleotides substitutions among sequences of causative agents for different size of lesions. In order to find any correlation between genetic and clinical manifestation in CL, a comprehensive study with more samples from more geographical area is needed.Significance and impact of the study. Information about relationship between the parasite's genetic variability and the clinical form of CL may help us to understand the pathway and a molecular target for devising effective treatment.

Introduction and objective: Klebsiella is an opportunistic pathogen that is an important cause of nosocomial infections. The prevalence of extended spectrum beta-lactamases (ESBLs)-producing strains and their resistance to betalactam antibiotics has had a daily increase. Because of the importance of these enzymes in Klebsiella pneumonia, this study was carried out to investigate it’s prevalence in Shahid Beheshti hospital of Kashan.Materials and methods: This descriptive study was done on clinical samples collected from different wards of Shahid Beheshti hospital of Kashan. K. pneumonia was isolated on the basis of standard procedures and ESBLs producing strains were confirmed by double disk diffusion method. Extracted DNAs were investigated using specific primers for SHV-1 and TEM-1 genes by PCR method.Results: Thirty two percent of all 100 isolated K. pneumonia had ESBL phenotype. Seven (21.8%) of isolates contained both SHV-1 and TEM-1 genes. Twelve (37.5%) had just TEM1 gene and 16 (50%) had SHV1 gene.Conclusion: Type and amount of antibiotic consumption and length of hospital stay has direct correlation with ESBL production. Because of more morbidity and mortality caused by ESBL isolates compared with infections caused by non-ESBL-producing organisms for treatment of a serious infection caused by an isolate confirmed for ESBL production, a carbapenem agent is indicated despite reports of treatment success with extended-spectrum cephalosporins.Significance and impact of the study: The results of our study help to well define of ESBL producers prevalence in hospitalized and other patients.

Introduction and objective: Sarcocystis is an obligatory intercellular protozoan parasite which can induce infection and clinical signs in carnivorous and herbivorous host. Humans acquire infection by ingestion of cyst or eating raw and undercooked infected meat or meat-production. The main goal of this study is to detect prevalence of the parasites in meat-production such as hamburger, sausage and hot dogs and determine its important role in human health.Materials and methods: Seventy five samples of hamburger, sausage and hot dogs (each 25 samples) were collected from retail stores in Ahvaz southwest of Iran. The samples were examined by digestion method using pepsin and HCl for detecting Sarcocystis parasite by light microscope.Results: Sarcocystis species were seen in 56% for hamburger, 20% for hot dogs and 8% for sausage.Conclusion: The results of this study indicated that the rate of the Sarcocystis sp. infection in meat-production is considerable and would be important for human. Many Sarcocystis sp. can infect meat many species from canine and feline definitive host. A molecular test such as PCR is needed to identify the parasite species. Digestion method is a sensitive, rapid and simple test for diagnosing Sarcocystis infection in meat. To prevent human infection, consumption of raw or under-cooked meat and meat-produced hyper endemic area should be avoided.Significance and impact of the study: Regarding to meat-born disease transmitted to human, to detect protozoa parasites in meat and their products can be important to prevent transmission of parasites which have cyst stage and promote hygienic level in human community.

Introduction and objective: Sodium benzoate (SB) and potassium sorbate (PS) have long been used as preservatives in foods and other products. The aims of this study were to compare the inhibitory effect of different concentrations of two preservatives SB and PS on Aspergillus niger and Penicillium notatum, and to study the probability of existing and synergistic effect in combining these two preservative together.Materials and methods: Preservative effects of separate concentrations (0.02, 0.04, 0.06, 0.08 and 0.1%) and different combinations of SB and PS (0.08 SB + 0.02 PS, 0.06 SB + 0.04 PS, 0.04 SB + 0.06 PS, 0.02 SB + 0.08 PS) on A. niger and P. notatum in yeast extract sucrose broth at preschedule days i.e. 0, 4, 10, 14, 18, 21, 24, 28 and 40 were investigated.Results: Sodium benzoate at 0.02% and 0.04% concentrations had no effect on the growth of A. niger but the 0.1% concentration had the highest effect. Sodium benzoate at 0.02% had a better effect than the same level of PS on P. notatum. Potassium sorbate with all the concentrations had a better effect on A. niger: like benzoate, increasing concentrations of sorbate resulted in a higher preservative effect; PS at 0.1% had the highest effect. Combination 0.02 SB + 0.08 PS and 0.08 SB + 0.02 PS had the greatest and the least effects respectively.Conclusion: Regarding the combinations, no synergistic effect has been observed, and no combination in the prevention of growth was better than the 0.1% concentrations of the two preservatives.Significance and impact of the study: The better use of preservatives includes increase of antimicrobial spectrum, extension of pH range, reduction of toxicity, and prevention of microbial resistance.