Comparison of DNA Microarray, Loop-Mediated Isothermal Amplification (LAMP) and Real-Time PCR with DNA Sequencing for Identification of Fusarium spp. Obtained from Patients with Hematologic Malignancies.

The performance of three molecular biology techniques, i.e., DNA microarray, loop-mediated isothermal amplification (LAMP), and real-time PCR were compared with DNA sequencing for properly identification of 20 isolates of Fusarium spp. obtained from blood stream as etiologic agent of invasive infections in patients with hematologic malignancies. DNA microarray, LAMP and real-time PCR identified 16 (80%) out of 20 samples as Fusarium solani species complex (FSSC) and four (20%) as Fusarium spp. The agreement among the techniques was 100%. LAMP exhibited 100% specificity, while DNA microarray, LAMP and real-time PCR showed 100% sensitivity. The three techniques had 100% agreement with DNA sequencing. Sixteen isolates were identified as FSSC by sequencing, being five Fusarium keratoplasticum, nine Fusarium petroliphilum and two Fusarium solani. On the other hand, sequencing identified four isolates as Fusarium non-solani species complex (FNSSC), being three isolates as Fusarium napiforme and one isolate as Fusarium oxysporum. Finally, LAMP proved to be faster and more accessible than DNA microarray and real-time PCR, since it does not require a thermocycler. Therefore, LAMP signalizes as emerging and promising methodology to be used in routine identification of Fusarium spp. among cases of invasive fungal infections.

MOLECULAR IDENTIFICATION AND ANTIMICROBIAL RESISTANCE PATTERN OF SEVEN CLINICAL ISOLATES OF Nocardia spp. IN BRAZIL / Identificação molecular e perfil de sensibilidade a antimicrobianos de sete isolados clínicos de Nocardia spp. no Brasil

Nocardia is a ubiquitous microorganism related to pyogranulomatous infection, which is difficult to treat in humans and animals. The occurrence of the disease is on the rise in many countries due to an increase in immunosuppressive diseases and treatments. This report of cases from Brazil presents the genotypic characterization and the antimicrobial susceptibility pattern using the disk-diffusion method and inhibitory minimal concentration with E-test® strips. In summary, this report focuses on infections in young adult men, of which three cases were cutaneous, two pulmonary, one neurological and one systemic. The pulmonary, neurological and systemic cases were attributed to immunosuppressive diseases or treatments. Sequencing analysis of the 16S rRNA segments (1491 bp) identified four isolates of Nocardia farcinica, two isolates of Nocardia nova and one isolate of Nocardia asiatica. N. farcinica was involved in two cutaneous, one systemic and other pulmonary cases; N. nova was involved in one neurological and one pulmonary case; and Nocardia asiatica in one cutaneous case. The disk-diffusion antimicrobial susceptibility test showed that the most effective antimicrobials were amikacin (100%), amoxicillin/clavulanate (100%), cephalexin (100%) and ceftiofur (100%), while isolates had presented most resistance to gentamicin (43%), sulfamethoxazole/trimethoprim (43%) and ampicillin (29%). However, on the inhibitory minimal concentration test (MIC test), only one of the four isolates of Nocardia farcinica was resistant to sulfamethoxazole/trimethoprim.

Nocardia é um microorganismo ubiquitário relacionado a infecções piogranulomatosas, com difícil resolução tecidual em humanos e animais. A doença é mundialmente emergente devido ao aumento de doenças e tratamentos imunossupressores. Este relato de casos ocorridos no Brasil visa apresentar a identificação molecular dos isolados e o padrão de sensibilidade a antimicrobianos por disco-difusão e concentração inibitória mínima (CIM) através de fitas E-test®. Os casos ocorreram em homens, em idade adulta. Três quadros foram cutâneos, dois pulmonares, um neurológico e um sistêmico. O quadro respiratório, o neurológico e um sistêmico estavam associados à doença ou terapia imunossupressoras. O sequenciamento do gene 16S rRNA (1491pb) possibilitou a identificação de quatro isolados de Nocardia farcinica, dois de Nocardia nova e um de Nocardia asiatica. N. farcinica foi observada em dois casos dermatológicos, um pulmonar e um quadro sistêmico, N. nova foi isolada de um caso neurológico e outro pulmonar; e N. asiatica em um caso dermatológico. O teste de disco-difusão mostrou que amicacina (100%), amoxicilina/clavulanato (100%), cefalexina (100%) e ceftiofur (100%) foram mais efetivos; enquanto gentamicina (43%), sulfametoxazol/trimetoprim (43%) e ampicilina (29%) foram menos efetivos. No entanto, no teste de concentração inibitória mínima (CIM), apenas um dos quatro isolados da espécie Nocardia farcinica mostrou-se resistente a sulfametoxazole-trimetropina.

Isolation and drug susceptibility of Candida parapsilosis sensu lato and other species of C. parapsilosis complex from patients with blood stream infections and proposal of a novel LAMP identification method for the species.

Candida parapsilosis complex (CPC) is the third Candida species isolated in blood cultures of patients from our Hospital, following C. albicans and C. tropicalis. From 2006 to 2010, the median annual distribution of CPC was 8 cases/year. Records of 36 patients were reviewed. CPC were 31 (86.1%) C. parapsilosis; 4 (11.1%) C. orthopsilosis; and 1 (2.8%) C. metapsilosis. Clinical characteristics were central venous catheter, 34 (94.4%); parental nutrition, 25 (70%); surgery, 27 (57.9%); prior bacteremia, 20 (51.3%); malignancy, 18 (50%). General mortality was 47.2%. Death was higher in immunosuppressed patients (17 vs. 11; p = 0.003). Three out four (75%) patients with C. orthopsilosis and 14 out 31 (45.2%) with C. parapsilosis died (p = 0.558). Thirty-nine individual isolates were tested for susceptibility to seven antifungal drugs, with MICs values showing susceptibility to all of them. Two isolates, one C. orthopsilosis and one C. parapsilosis, had fluconazole MIC = 4 µg/mL. Differentiation among CPC has implication in caring for patients with invasive candidiasis since there are differences in virulence, pathogenicity and drug susceptibility. A method targeting the topoisomerase II gene based on loop-mediated isothermal amplification (LAMP) was developed. LAMP emerges as a promising tool for the identification of fungal species due to the high sensitivity and specificity. LAMP can be performed at the point-of-care, being no necessary the use of expensive equipment. In our study, the method was successful comparing to the DNA sequencing and proved to be a reliable and fast assay to distinguish the three species of CPC.

Fusarium napiforme systemic infection: case report with molecular characterization and antifungal susceptibility tests.

INTRODUCTION: During the last decades, Fusarium spp. has been reported as a significant cause of disease in humans, especially in immunocompromised patients, who have high risk of invasive life-threatening disease. Fusarium species usually reported as cause of human disease are F. solani, F. oxysporum and F. verticillioides. CASE DESCRIPTION: We describe the second case in the literature of disseminated fusariosis caused by Fusarium napiforme, that occurred in a 60-year-old woman with multiple myeloma after subsequent cycles of chemotherapy. DISCUSSION AND EVALUATION: We identified the F. napiforme not only by standard morphologic criteria by macroscopic and microscopic characteristics, but also confirmed by molecular biology methods, including sequencing. The antifungal susceptibility of the F. napiforme isolates were tested to seven antifungal drugs; the azoles were the most active drug against all the isolates tested. CONCLUSIONS: Fusarium spp. are of relevance in medical mycology, and their profiles of low susceptibility to antifungal drugs highlight the importance for faster and more accurate diagnostic tests, what can contribute to an earlier and precise diagnosis and treatment.

Testicular nocardiosis accompanied by cutaneous lesions in an immunocompetent man.

We herein report the case of a 77-year-old man admitted for an acute cutaneous infection and persistent fever. A physical examination revealed systemic small blisters and scrotal swelling. He was suspected of having complications from chickenpox or bullous impetigo as the initial diagnosis. Nocardia was detected on an aspiration biopsy of the small blisters and the surgically removed testis at a later date. Testicular nocardiosis is a rare condition; however, we should consider nocardiosis in the differential diagnosis because delay in providing treatment may worsen a patient's general condition.

Unique mutation, accelerated mTOR signaling and angiogenesis in the pulmonary cysts of Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant disorder characterized by fibrofolliculomas, renal tumors and pulmonary cysts with repeated pneumothorax. This disorder is caused by mutations in the gene that encodes folliculin (FLCN). FLCN is known to be involved in the signaling of mammalian target of rapamycin (mTOR). We investigated the lung of a BHD patient who presented with a unique mutation. A 33-year-old woman visited our hospital due to repeated pneumothorax. Histopathologic study of the resected lung demonstrated multiple epithelial cysts. An increase of blood vessels was observed in the vicinity of subpleural cysts. Genomic DNA analysis revealed heterozygous mutation at the 3' end of intron 5 of the FLCN gene. Total mRNA and protein were extracted from the resected lung tissue. RT-PCR and sequence analysis demonstrated the production of exon 6-skipped FLCN mRNA. In Western blotting, the band intensities of phospho-mTOR, phospho-S6, phospho-Akt, hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) were increased in the BHD lung compared with normal lungs. Histopathologic analysis demonstrated strong immunostainings of mTOR signaling molecules in cyst-lining cells. Collective data indicates that dysregulation of mTOR signaling facilitates S6-mediated protein synthesis and HIF-1α-mediated angiogenesis, which may contribute to the development of pulmonary cysts in this disorder.

Development of rapid and specific molecular discrimination methods for pathogenic emericella species.

Aspergillosis is an important mycosis caused primarily by Aspergillus fumigatus and its relatives. The genus Emericella is a teleomorph related to the Aspergillus section Nidulantes. The typical anamorphic stage species in this genus is Aspergillus nidulans, which is sometimes a significant agent in chronic granulomatous disease (CGD) patients. The mortality rate of osteomyelitis in CGD patients due to A. nidulans ( E. nidulans ) is very high compared to that due to A. fumigatus. Moreover, two Emericella species ( E. nidulans and E. quadrilineata ) from clinical specimens exhibit different sensitivities against several antifungal drugs. In aspergillosis, correct species identification is important for antifungal therapy. We attempted to develop rapid and specific molecular discrimination by polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) methods in the principal pathogenic Emericella species, and succeeded in establishing species-specific primers corresponding to the hydrophobin gene. These primers discriminate E. nidulans and E. quadrilineata rapidly and specifically. These methods and primers make it possible to diagnose etiological agents in aspergillosis quickly and easily.

C-type lectin Mincle is an activating receptor for pathogenic fungus, Malassezia.

Mincle (also called as Clec4e and Clecsf9) is a C-type lectin receptor expressed in activated phagocytes. Recently, we have demonstrated that Mincle is an FcRgamma-associated activating receptor that senses damaged cells. To search an exogenous ligand(s), we screened pathogenic fungi using cell line expressing Mincle, FcRgamma, and NFAT-GFP reporter. We found that Mincle specifically recognizes the Malassezia species among 50 different fungal species tested. Malassezia is a pathogenic fungus that causes skin diseases, such as tinea versicolor and atopic dermatitis, and fatal sepsis. However, the specific receptor on host cells has not been identified. Mutation of the putative mannose-binding motif within C-type lectin domain of Mincle abrogated Malassezia recognition. Analyses of glycoconjugate microarray revealed that Mincle selectively binds to alpha-mannose but not mannan. Thus, Mincle may recognize specific geometry of alpha-mannosyl residues on Malassezia species and use this to distinguish them from other fungi. Malassezia activated macrophages to produce inflammatory cytokines/chemokines. To elucidate the physiological function of Mincle, Mincle-deficient mice were established. Malassezia-induced cytokine/chemokine production by macrophages from Mincle(-/-) mice was significantly impaired. In vivo inflammatory responses against Malassezia was also impaired in Mincle(-/-) mice. These results indicate that Mincle is the first specific receptor for Malassezia species to be reported and plays a crucial role in immune responses to this fungus.