Molecular characterization of fungi causing colonization and infection in organ transplant recipients: A one-year prospective study.

BACKGROUND AND PURPOSE: Organ transplant recipients are vulnerable to fungal infections. The aim of this study was to determine the prevalence of fungal colonization and infections among patients who underwent various transplantations and molecularly characterize the etiological agents. MATERIALS AND METHODS: This study was conducted on candidates for transplantation in Imam Khomeini Hospital, Tehran, Iran, from April 2017 to April 2018. All patients were monitored for fungal colonization or infections before and after transplantation. Isolated fungi were identified using molecular methods. RESULTS: A total of 125 patients, including 86 males and 39 females, with the mean age of 52.2 years participated in the study (age range: 15-75 years). Out of 125 patients, 84 (67.2%) cases had fungal colonization that appeared pre- and post-transplantation in 21 and 63 cases, respectively (alone or concurrent with another infection in 55 and 29 cases, respectively). In addition, a total of 39 episodes of fungal infections were diagnosed in 36 (28.8%) recipients (alone or concurrent with colonization in 7 and 29 cases, respectively). Out of the 39 fungal infections, 9 cases appeared pre-transplantation, while the other 30 cases occurred post-transplantation. However, no fungal colonization or infection was observed in 34 (27.2%) patients. Oral candidiasis (n=20) was the most common type of infection, followed by funguria (n=7), onychomycosis (n=5), candidemia (n=3), rhinocerebral mucormycosis (n=1), cutaneous mucormycosis (n=1), cutaneous aspergillosis (n=1), and peritonitis (n=1). Six yeast species were recovered from colonization cases with the dominance of Candida albicans both before and after transplantation. The observed fungal infections were caused by 11 distinct species, including the members of Candida (i.e., C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei), Aspergillus (i.e., A. oryzae and A. candidus), Rhizopus (i.e., R. oryzae and R. microsporus), Trichosporon asahii, and Trichophyton interdigitale. The results also indicated that the development of a fungal infection post-transplantation was associated with fungal colonization (r=0.0184; P=0.043). CONCLUSION: Based on the results, fungal colonization was a common finding in transplant recipients at Imam Khomeini Hospital. However, the incidence of fungal infections was comparable with those of other centers. As the oral cavity was the most common site of colonization and infection, it might be beneficial to take further care about the oral health of patients using effective mouthwash.

Investigation of Intertriginous Mycotic and Pseudomycotic (Erythrasma) Infections and Their Causative Agents with Emphasize on Clinical Presentations.

BACKGROUND: Intertrigo is an erythematous inflammatory condition with multiple etiologies including fungi and bacteria. Intertrigo manifests in different clinical forms with various complaints. This study was conducted to evaluate the causative agents of intertriginous infections with emphasize on clinical presentations. METHODS: This descriptive cross-sectional study was carried out in 2015-2016, on 188 patients with clinical suspicion of superficial and cutaneous intertriginous infections in Tehran, Iran. Demographic and additional related data were obtained by questionnaire from all participants. Specimens were collected by gentle scraping of the affected areas. Direct examination and culture were performed for all specimens and grown colonies were identified based on the macroscopic and microscopic features. Supplementary tests were done whenever needed. Data were analyzed in SPSS. RESULTS: Overall, 80 (42.5%) cases with the mean age of 43.5 yr were confirmed for intertrigo. Dermatophytosis was the predominant cause in this study with 36 (45%) cases followed by erythrasma (28 cases, 35%), tinea versicolor (10 cases, 12.5%) and candidiasis (6 cases, 7.5%). Intertrigo lesions with dermatophytic agents significantly were observed in groin in comparison to different infections among body sites (P<0.05). Itching was the most common clinical presentation (57 cases, 71.3%) and also significant association between different infections and clinical manifestations were observed (P<0.05). CONCLUSION: Different clinical manifestations may be observed in infectious intertrigo. Regarding the significant association observed in this study, some clinical features can be used for presumptive diagnosis of diseases but further studies are required to make it clear.

Adherence of Streptococcus Mutans to Microhybrid and Nanohybrid Resin Composites and Dental Amalgam: An In Vitro Study.

OBJECTIVES: Streptococcus mutans (S. mutans) is a cariogenic microorganism. The restorative materials which harbor a biofilm with high levels of S. mutans can accelerate the occurrence of dental caries. The purpose of this study was to evaluate the influence of different restorative materials on S. mutans colonization in a simple in-vitro biofilm formation model. MATERIALS AND METHODS: Thirteen discs of each material (nanohybrid resin composite, microhybrid resin composite, and amalgam) were prepared, polished, and sterilized in a gamma radiation chamber. The saliva-free specimens were exposed to the S. mutans bacterial suspension (0.5 McFarland) and were incubated for 4 hours. Afterwards, the specimens were rinsed and sonicated in normal saline. 10µl of the obtained suspension was cultured in a sterile blood agar medium. After 24 hours, the number of colony forming units (CFU) of S. mutans was counted. A sterility test control was considered for each group of materials. The data were analyzed by one-way ANOVA at 5% significance level. RESULTS: The means and standard deviations of the logarithmic values of the colonies on the surfaces of amalgam, microhybrid, and nanohybrid resin composites were equal to 3.76±0.64, 3.91±0.52 and 3.34±0.74, respectively. CONCLUSIONS: There were no significant differences between the restorative materials in terms of S. mutans adhesion rate. The evaluated resin composites showed comparable numbers of CFUs, which could imply the importance of the polishing procedures.

Antifungal Activity and Aflatoxin Degradation of Bifidobacterium Bifidum and Lactobacillus Fermentum Against Toxigenic Aspergillus Parasiticus.

Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B1, B2, G1 and G2 fractions by more than 99%. Moreover, LAB metabolites reduced the level of standard AFB1, B2, G1 and G2 from 88.8% to 99.8% (p≤0.05). Based on these findings, B. bifidum and L. fermentum are recommended as suitable biocontrol agents against the growth and aflatoxin production by aflatoxigenic Aspergillus species.

A Case of Fungus Ball-Type Pansinusitis Due to Fusarium proliferatum.

Incidence of fungal sinusitis due to the genus Fusarium has increased during the last two decades. We report a case of fungus ball sinusitis with multiple sinuses involvement in an Iranian 21-year-old woman. The patient was diagnosed as having a fungus ball-type sinusitis in computed tomography scan. The sinus biopsy revealed fungal structures on histopathological and direct microscopic examinations and a Fusarium species arose in culture. Partial sequencing of the translation elongation factor 1-alpha identified the isolate as F. proliferatum. Removal of all lesions by endoscopic surgery resulted in a favorable outcome. To the best of our knowledge, this is the first case of F. proliferatum-associated fungus ball which involved multi-sinus and highlights the efficiency of molecular methods for discrimination of fungal agents involved.

Effects of low-level laser irradiation on the pathogenicity of Candida albicans: in vitro and in vivo study.

OBJECTIVE: The purpose of this study was to evaluate the effects of low-level laser irradiation (LLLI) on the in vitro growth characteristics and in vivo pathogenicity of Candida albicans in a murine model in the absence of a photosensitizer. BACKGROUND DATA: C. albicans is an opportunistic commensal organism that causes a wide variety of diseases in human beings, ranging from superficial infections to life-threatening invasive candidiasis. The incidence of C. albicans infection is increasing, because of the greater frequency of acquired immunodeficiency conditions. A high recurrence rate has been reported for vulvovaginal and oral candidiasis, despite the best available treatments. Therefore, the search for new treatment modalities seems quite rational. METHODS: Candida culture plates were exposed to common clinical energies of LLLI: 3, 5, 10, and 20 J at 685 nm (BTL Laser 5000, Medicinos Projektai, Czech Republic, Prague, max power output 50 mW) and 3, 5, 10, 30, and 50 J at 830 nm (BTL Laser 5000, Medicinos Projektai, Czech Republic, Prague, max power output 400 mW). RESULTS: Following LLLI with energies >10 J at both 685 and 830 nm wavelengths, statistically significant effects were observed in vitro on the turbidimetric growth kinetics of C. albicans and in vivo on the survival rate of infected mice (p value ≤ 0.05). Therefore, this energy could be considered a threshold for clinical investigation. CONCLUSIONS: Translating our data into the clinical setting, it can be proposed that a direct laser-based approach without using a photosensitizing dye can significantly reduce the pathogenicity of Candida albicans. It can also be concluded that laser light at specific wavelengths could be a possible promising novel treatment for superficial and mucocutaneous C. albicans infections.

Pulmonary nocardiosis associated with cerebral abscess successfully treated by co-trimoxazole: a case report.

Nocardiosis is an acute or chronic infectious disease caused by the soil-borne filamentous bacteria belonging to the genus Nocardia. The organisms opportunistically infect both immunocompromised and immunocompetent individuals. The lungs are the primary site of infection and brain abscess is, by far, the most common complication following nocardial metastasis from pulmonary lesions. Although surgical intervention must always be considered in the treatment of nocardial brain abscess, it can obviously be cured by antibiotic therapy alone. This report describes a case infected by Nocardia cyriacigeorgica. Identification of the infectious agent was achieved by conventional and semi-nested PCR techniques. A 55-year-old woman with fever was referred to the infect disclinic of Imam Khomeini hospital in Tehran and was hospitalized after clinical assessment. She was a kidney transplant recipient for 4 years and was taking immunosuppressive treatment including azathioprine and methylprednisolone. Follow-up of the patient by CT scan revealed pulmonary infection and cerebral lesions. Specimens of the brain lesions contained filamentous bacteria. The patient received a combination of co-trimoxazole and ceftriaxone and brain abscesses as well as lung inflammation disappeared gradually during the course of antibiotic therapy within 3 months. The patient was discharged from the hospital after 2 months of therapy.

Actinomycosis in Iran: Short Narrative Review Article.

Actinomycosis is an indolent, slowly progressive infection caused by anaerobic or microaerophilic bacteria, primarily of genus Actinomyces, which colonize the mouth, colon and vagina. Mucosal disruption may lead to infection virtually at any sites in the body. The aim of this study was to underline different features of actinomycosis and to represent total data about etiologic agents, clinical, diagnostic and therapeutic approaches these infections. From a total of 38 case reports or series, ninety one cases were obtained by using of relevant articles reported as recorded cases in Iran (1972 to 2012). Analyzed data represented 21 cases of oral-servicofacial (23.1%), 7 cases of thoracic (7.7%), 17 cases of abdominal (18.7%), 21 cases of disseminated forms (23.1%) and 25 cases of others (27.5%). Findings indicated more common of these infections in men (61.5%). Actinomyces naeslundii (21 cases) was found as the most common causative agents in comparison with A. Israeli (15 cases), A. viscosus (3 cases) and A. bovis (1 case). The most patients had been successfully treated with penicillin although some cases needed surgery along with antibiotic therapy. Since some clinical features of actinomycosis are similar to malignancies, so the differential diagnosis of invasive forms must be considered. This report emphasizes on the importance of differential diagnosis of actinomycosis from similar diseases by clinicians.