- Volume:4 Issue: 2, 2018
- تاریخ انتشار: 1397/04/05
- تعداد عناوین: 7
Background andPurposeAflatoxins are naturally produced by some species of Aspergillus, such as A. flavus and A. parasiticus. Aflatoxins reportedly have carcinogenic effects on human, poultry, and livestock, and therefore could be linked to severe human illnesses. Aflatoxin biosynthesis pathway involves different clustered genes, including structural, regular, and unassigned genes. The present study was conducted to detect aflR, aflP, and aflD as three important genes contributing to aflatoxin B1 production cycle in Aspergillus species isolated from the feedstuffs of animal husbandry.Materials and MethodsThis study was conducted on 25 isolates of A. flavus, A. parasiticus, A. nomius, and A. nidulans, isolated from animal feedstuff as a test group. The test group was compared with two standard strains (i.e., A. flavus and A. parasiticus) as aflatoxigenic reference organisms and negative controls (i.e., A. fumigatus, A. fusarium, and A. penicillium) in terms of the presence of aflR, aflP, and aflD genes using polymerase chain reaction (PCR). The determination of the toxigenicity and aflatoxin production of isolated Aspergillus species was accomplished using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC).ResultsThe results obtained by the amplification of the selected genes by PCR method for the detection of aflatoxigenic Asprgillus species were significantly correlated with TLC and HPLC results. Accordingly, all samples, having positive results for aflatoxin B1 production in TLC and HPLC, were able to show the amplification of three target genes. However, 4 cases out of 6 (66%) non-aflatoxigenic isolates were positive for three or two genes.ConclusionBased on the findings, the molecular detection of aflatoxin biosynthesis genes (i.e., aflP, aflD, and aflR) could be considered as a quick and reliable method for the detection of aflatoxigenic Aspergillus. Furthermore, this method could be useful in planning and implementing strategies targeted toward improving the safety of human or animal foodKeywords: Aflatoxigenic, Aspergillus, HPLC, PCR, TLC
Catheter-related candidemia and identification of causative Candida species in patients with cardiovascular disorderPages 7-13
Background andPurposeCatheter-related blood circulation infection is the most dangerous and serious side-effects of vascular catheters, which leads to the enhancement of the costs, mortality, and hospital stay duration, especially in the Intensive Care Unit. Regarding this, the aim of the current study was to identify the prevalence of catheter-induced candidemia in the Tehran Heart Center, a heart hospital in Tehran, Iran.Materials and MethodsThis study was conducted on patients admitted to Tehran Heart Center for a minimum of 7 days during 18 months. To detect the fungal elements, blood culture and catheter culture were performed in the patients receiving central or peripheral venous catheter. Then, the polymerase chain reaction (PCR) was applied to determine the possible diagnosis.ResultsThe investigation of 223 samples led to the identification of a total of 15 (6.7%) yeast isolates obtained from 9 (60%), 4 (26.6 %), and 2 (13.4%) catheter, blood, and skin (of the catheter insertion areas) cultures, respectively. Out of nine Candida isolates obtained from the catheter samples, 1 (11.1%), 1 (11.1%), 2 (22.2%), and 5 (55.6%) cases were identified as C. tropicalis, C. membranifaciens, C. glabrata, and C. albicans, respectively, using the internal transcribed spacer region sequencing. Furthermore, the four yeasts isolated from the blood culture included C. tropicalis, C. carpophila, C. membranifaciens, and Cryptococcus albidus. Additionally, one case of C. glabrata and one case of C. albicans were isolated from the skin culture of the catheter insertion areas in patients with positive catheter culture. We reported two cases of catheter-related candidemia caused by C. membranifaciens and C. tropicalis on the basis of the genetic similarity of the species isolated from the blood and catheter. These cases were treated successfully with intravenous fluconazole and catheter removal.ConclusionThere is some evidence indicating the growing prevalence of non-albicans Candida infections. Many risk factors, including prior antibiotic therapy, use of a central venous catheter, surgery, and parenteral nutrition, are considered to be associated with candidemia in hospitalized heart failure patients. The identification of the route of infection in candidemia is difficult. In the current study, the positive blood and catheter cultures for Candida isolates and the similarity of the ITS region of ribosomal DNA sequence of Candida isolated from two patients confirmed the diagnosis of intravenous catheter-related candidemiaKeywords: Candidiasis, Catheter-related candidemia, Nosocomial infection
Pages 14-20Background andPurposeCandidemia is one of the most important fungal infections caused by Candida species. Infections and mortality caused by Candida species have been on a growing trend during the past two decades. The resistance of yeasts to antifungal drugs and their epidemiological issues have highlighted the importance of accurately distinguishing the yeasts at the species level. The technique applied for yeast identification should be fast enough to facilitate the imminent initiation of the appropriate therapy. Candidemia has not been studied comprehensively in Iran yet. Regarding this, the current study aimed to assess the epidemiology of candidemia at Tehran hospitals and compare the results with the previous findings.Materials and MethodsThis study was conducted on 204 positive blood cultures obtained from 125 patients hospitalized in several hospitals located in Tehran, Iran, within a period of 13 months. The yeast isolation and species identification were accomplished using several phenotypic methods (i.e., production of germ tube in human serum, culture on CHROMagar Candida, and Corn meal agar containing Tween 80) and molecular methods, such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown cases were subjected to PCR sequencing. These methods were then compared in terms of accuracy, sensitivity, and speed of identification.ResultsAccording to the results, C. albicans (62.4%) was the most common isolate, followed by C. parapsilosis (n=36, 17.5%), C. glabrata (n=18, 8.8%), C. tropicalis (n=13, 6.3%), Trichosporon asahii (n=3, 1.5%), C. kefyr (n=2, 1.0%), C. lusitaniae (n=2, 1.0%), C. intermedia (n=1, 0.5%), C. guilliermondii (n=1, 0.5%), and C. krusei (n=1, 0.5%), respectively.ConclusionAs the findings indicated, the most common species causing candidemia were C. albicans, C. parapsilosis, and C. glabrata, respectively. Children less than one year old and people with cancer were at higher risk for candidemia, compared to other groups. Moreover, phenotypic and molecular methods resulted in the identification of 65.2% and 96.6% of the isolates, respectively. Consequently, PCR-RFLP could be concluded as a more favorable technique for species identificationKeywords: Candidemia, Blood Culture, Epidemiology, PCR-RFLP
Background andPurposeHerbal toothpastes are more secure and efficacious and less poisonous due to containing natural chemicals as compared with the synthetic toothpastes. The present study aimed to formulate a polyherbal toothpaste using accessible medicinal plants in Iran and evaluate its efficiency in the protection of oral hygiene and prevention of dental caries.Materials and MethodsThe developed toothpaste was made of the leaf extracts of Artemisia dracunculus, Satureja khuzestanica (Jamzad), and Myrtus communis (Linn), combined at four different dilutions, namely 1:4 (25%), 1:1 (50%), 3:4 (75%), and (100%), with sterile distilled water. The product was tested against five microorganisms, including Streptococcus mutans, Lactobaccilus caseie, S. sanguis, S. salivarius, and Candida albicans, using agar well diffusion method.ResultsAfter 24 h of incubation, the maximum mean diameters of inhibition zone against L. caseie and C. albicans were obtained as 17-30 and 10-25 mm, respectively. Furthermore, the minimum mean diameter of inhibition zone against S. salivarious was estimated as 15-20 mm.ConclusionThe formulated toothpaste showed potent inhibitory activities against Gram-positive bacteria and C. albicans. Therefore, more studies are required to accurately investigate the efficacy of the formulated toothpasteKeywords: Antibacterial, Antifungal, Oral pathogens, Polyherbal toothpaste, Yeast
Pages 27-31Background andPurposeCandida-associated denture stomatitis is one of the most common forms of oral candidiasis among denture wearers. Regarding this, the aim of the present study was to evaluate the antifungal effects of home-generated ozonated water on the adhesion of the C. albicans attached to the surface of the denture base acrylic resins.Materials and MethodsFor the purpose of the study, different concentrations of C. albicans were added to the tubes containing acrylic resin blocks, and then incubated for 2 h at 35°C. The samples were assigned into three groups, each of which contained 42 samples, including normal saline (NS) solution as the negative control, nystatin (N) solution as the positive control, and ozonated water as the test group. The samples were washed and placed in an ultrasonic bath. Subsequently, the saline solution was cultured on Sabouraud dextrose agar. The concentrations of Candida were evaluated during the contact times.ResultsThe test group (i.e., ozonated water) with 114 colony-forming units (CFU) showed a significant reduction of Candida colonies, compared to the NS group with 2,172 CFU. The 120- and 1-minute incubation with ozonated water showed the highest and lowest effects on the viability of Candida adhered to the acrylic resin, respectively.ConclusionBased on the findings, home-generated ozonated water can be applied to remove the Candida attached to the surface of the denture platesKeywords: Antifungal, Candida, Denture, Ozonated water, Stomatitis
Complicated bilateral fungal emphysematous pyelonephritis in a 55-year-old diabetic female: A case report and review of literaturePages 32-35Background andPurposeEmphysematous pyelonephritis (EPN) is a rare and serious disease causing acute renal failure. Diabetes is a major risk factor for this infection.
Case report: Herein, we present the case of a 55-year-old female patient with diabetes and EPN caused by Candida albicans. The infection was complicated with endophthalmitis and endocarditis. The results of antifungal susceptibility analysis showed that C. albicans was resistant to fluconazole and susceptible to amphotericin-B and itraconazole. Infection could be controlled by amphotericin-B followed by itraconazole therapy, and the patient was discharged in good condition while receiving antifungal therapy.ConclusionComplicated pyelonephritis with unusual microorganisms should be considered in patients with diabetes and urinary symptomsKeywords: Candida albicans, Emphysematous pyelonephritis
An unusual case of hyalohyphomycosis due to Purpureocillium lilacinum in a patient with myasthenia gravisPages 36-39Background andPurposePurpureocillium lilacinum (previously known as Paecilomyces lilacinus) and Paecilomyces variotii cause hyalohyphomycosis.
Case report: In this study, we present a case of multiple subcutaneous abscesses of the lower limbs due to Purpureocillium lilacinum in a patient with myasthenia gravis and uncontrolled diabetes. Subcutaneous involvement of the lower limbs with this fungus is an unusual presentation. Pus aspirate collected on multiple occasions revealed hyaline septate hyphae under microscopic examination and Purpureocillium lilacinum grew on Sabouraud Dextrose Agar. The patient was initially treated by surgical excision and itraconazole therapy. Swelling regressed but discharge was noticed from the excision site after three months of itraconazole therapy. Culture from the discharge material yielded the same fungal growth. Treatment was changed to ketoconazole and he responded.ConclusionThis case report emphasizes the importance of identifying Purpureocillium lilacinum at an unusual site like the lower limbs in an immunocompromised patient. Ketoconazole may be used as an alternative treatment option for hyalohyphomycosis caused by Purpureocillium lilacinumKeywords: Hyalohyphomycosis, Immunocompromised patient, Myasthenia gravis, Paecilomyces lilacinus, Purpureocillium lilacinum