From phaeohyphomycosis to disseminated chromoblastomycosis: A retrospective study of infections caused by dematiaceous fungi.

OBJECTIVE: Infections caused by dematiaceous fungi are more common in tropical and subtropical areas. We aimed to describe the clinical, microbiological and therapeutic aspects of case patients diagnosed at a University Hospital located on an Indian Ocean island. PATIENTS AND METHODS: We performed an observational retrospective study of infections caused by dematiaceous fungi diagnosed at the University Hospital of Saint-Pierre, Reunion, from 2000 to 2015. Mycological identifications were performed at the National Reference Center for Invasive Mycosis and Antifungal Agents (Paris). RESULTS: The review of clinical and microbiological data of 11 patients identified revealed that five were infected by dematiaceous fungi. Two had cutaneous phaeohyphomycosis, two had cerebral phaeohyphomycosis and one had cutaneous chromoblastomycosis with brain and potentially medullary dissemination. Skin lesions and cerebral abscesses were quite varied. CONCLUSION: Infections caused by dematiaceous fungi are rare. Medullary and brain localizations are extremely rare, especially for chromoblastomycosis. Cutaneous manifestations of phaeohyphomycosis are varied; diagnosis is thus more difficult. It is therefore important, when confronted with a chronic tumor-like lesion in endemic areas, to perform a biopsy for pathology and fungal culture. While surgical excision is not always sufficient, medical treatment of these infections is not standardized, but relies on an azole, which can be associated with another antifungal agent.

[Fungal keratitis: A 5-year monocentric retrospective study on Reunion Island]. / Kératites fongiques : étude rétrospective monocentrique sur 5ans à l'île de la Réunion.

OBJECTIVES: Fungal keratitis is rare in France, but could be a severe sight-threatening condition. Here, we aimed to describe the epidemiology of fungal keratitis in Réunion Island. METHODS: In a retrospective study, we analyzed 13 culture-proven keratitis episodes, occurred between January 2013 and July 2017 in the ophthalmology ward of a University Hospital, Saint-Pierre. Twelve isolates were genotyped and antifungal susceptibility testing was performed. RESULTS: Corneal abrasion caused by vegetable matter was the main predisposing factor. Stromal infiltration was observed in 12 patients. Six patients did not response to medical treatment, requiring surgical care, including two enucleations surgery. Fusarium solani (n = 6) and Fusarium dimerum (n = 4) were the main fungal species involved in fungal keratitis. Clinical failures were more prevalent with F. solani infections. The lowest minimal inhibitory concentrations for Fusarium sp. were observed with voriconazole and amphotericin B. CONCLUSION: In Reunion Island, the epidemiology of fungal keratitis is characterized by the predominance of Fusarium species, potentially involved in visual loss. This pattern is consistent with the epidemiology usually observed in tropical areas.

Helicobacter pylori resistance to clarithromycin in Reunion Island.

OBJECTIVE: The increasing resistance of Helicobacter pylori to clarithromycin led to developing new eradication treatment regimens. The objective of our observational study was to determine the proportion of H. pylori strains resistant to clarithromycin in infected patients in Reunion Island and to suggest a first-line treatment in agreement with the local ecology. PATIENTS AND METHODS: We included 200 patients who underwent esophagogastroduodenoscopy at the University Hospital of Saint-Pierre from February to July 2014. H. pylori was isolated from 73 patients. RESULTS: A wild-type susceptibility profile to clarithromycin was observed in 64 isolates (87.7%) and nine isolates (12.3%) had a resistant mutation profile. CONCLUSION: With a proportion of resistant strains below the critical threshold of 15%, physicians in Reunion Island may continue to prescribe the usual treatment regimen as a first-line option (clarithromycin, amoxicillin, and proton pump inhibitor for 14 days).

Invasive aspergillosis: an important risk factor on the short- and long-term survival of acute myeloid leukemia (AML) patients.

Invasive aspergillosis (IA) during induction chemotherapy of acute myeloid leukemia (AML) could worsen the prognosis. Our objective was to study how the development of IA during AML interferes with the therapeutic strategy and to evaluate its impact on the short- and long-term survival. Newly diagnosed AML patients between the years 2004 and 2007 were retrospectively analyzed. The outcome was death of the patient. A Cox proportional hazards model with the diagnosis of IA and post-induction response evaluation as the main exposure was fitted. Overall, 262 patients were analyzed and 58 IA were observed. The 2-year survival of patients having had remission of AML was 54% and, for patients with failure of chemotherapy, it was 5% (p < 0.001). The 2-year survival of patients having had IA was 14%, and without IA, it was 32% (p = 0.01). Multivariate analysis showed that IA was associated with a higher risk of death in case of remission compared to no IA (hazard ratio [HR] = 1.66 [1.05-2.65], p = 0.031) and also in case of failure (HR = 6.43, p < 0.001). IA was associated with an increased risk of death for patients if they were either in remission or in failure after induction chemotherapy.

Maxillary sinus fungal infection by Acremonium.

OBJECTIVE: To illustrate by this case report that Acremonium must now be considered as a differential diagnosis in cases of maxillary fungus balls. CASE REPORT: Seventy-seven-year-old woman consulted for persistent pain of the right maxillary sinus, with rhinorrhea and nocturnal coughing. Computed tomography (CT) of the sinuses showed a heterogeneous opacification of the right maxillary sinus with well-defined hyperdense foci suggesting aspergillosis. She underwent a middle meatus antrectomy by an endonasal approach. Six months after the surgery, her symptoms were gone and had not recurred. Mycological examination found Acremonium. DISCUSSION/CONCLUSION: Acremonium is a genus of saprobic fungi that rarely cause disease in humans. Infection with Acremonium has recently been described in immunocompromised patients. We describe the first case of fungal maxillary sinusitis caused by Acremonium in an immunocompetent person. Clinically and radiologically, the initial diagnosis was aspergillosis. Acremonium must be considered together with aspergillosis in all situations of fungus ball chronic sinusitis.

Candida species distribution in bloodstream cultures in Lyon, France, 1998-2001.

In order to determine the types of Candida spp. isolated from bloodstream cultures in Lyon, France, a retrospective study of isolates collected at five different bacteriology laboratories from 1998 to 2001 was conducted. During this period Candida spp. were isolated from 190 patients hospitalized in the internal medicine (32%), hematology (23%) and surgery (23%) wards, and in intensive care units (22%). C. albicans was the leading cause of Candida infection (49.5%), followed by C. glabrata (12.6%) and C. parapsilosis (12.1%). Among the onco-hematology patients, the major cause of candidemia was C. krusei (34%), followed by C. albicans (19%), while these two species were identified in 4% and 59% of patients in the other wards, respectively. In the single onco-hematology ward that was specialized in treating acute myeloid leukemia, 14 C. krusei isolates were identified in this study, which contrasts with the single C. krusei isolate recorded between 1992 and 1996. Since C. krusei has inherent resistance to the antifungal agent fluconazole, prophylactic use of fluconazole in these patients was investigated, but no relationship between these two parameters was found.

Synergistic and antagonistic interactions between haemozoin and bacterial endotoxin on human and mouse macrophages.

Haemozoin (malaria pigment) is a birefringent crystalline material made of Fe (III) Protoporphyrin IX dimers that derives from the degradation of haemoglobin by intraerythrocytic Plasmodia. At schizont rupture, it accumulates indigested inside phagocytic cells altering their immunological properties. Both pro-inflammatory and immunosuppressive activities have been associated with pigment-fed monocyte-macrophages or dendritic cells. These conflicting results were attributed to the source of macrophages or the different preparations of pigment. However, the interactions of malaria pigment with other phagocytes stimuli, such as bacterial endotoxin (LPS) or interferon-gamma have not been fully analysed, yet. The purpose of this study was to compare the immunological properties of native haemozoin (HZ), freshly extracted from Plasmodium falciparum cultures, versus beta-haematin (BH), the synthetic crystals identical to native haemozoin, and to evaluate the relationship between haemozoin and endotoxin on the immune response of different macrophages populations. The results indicate that the iron-porphyrin moiety of both native and synthetic pigment can exert either a synergistic or antagonistic effect with LPS that is related to the length and sequence of treatment, the source of macrophages and is associated with the generation of oxidative stress. These data rise the question of whether and how in vivo concomitant gram(-) bacteremia may affect the pathogenesis and/or the immune response of malaria infections and vice versa.

Primary cutaneous melanoma in hidden sites is associated with thicker tumours - a study of 829 patients.

The aim of this study was to determine if primary cutaneous melanomas in hidden anatomical sites were associated with thicker tumours. Retrospective medical data of 829 patients with melanomas diagnosed at our centre between January 1976 and July 1998 were recorded from our database. Three groups were defined according to the anatomical site of the primary melanoma: (1) visible areas (group 1: 493 patients); (2) visible areas only to the patients or to their partners in privacy (group 2: 281 patients); and (3) hidden areas (group 3: 55 patients). Univariate analysis indicated that patients with melanoma in hidden regions presented significantly thicker tumours (median for group 3: 2.25 versus 1.17 for group 1 and 1.42 for group 2). This group were also more commonly males (group 3: 58% men versus group 1: 38% and group 2: 51%), in a more advanced stage (metastatic disease at diagnosis in 16% of patients in group 3 versus 6% in groups 1 and 2) and at a more advanced age (median group 3: 66 years versus group 1: 59 years and group 2: 51 years), than patients in the other two groups. The association between tumour thickness and body site remained statistically significant after a multivariate analysis. As a delay in diagnosis may be responsible for the thicker size of melanoma in the hidden areas, preventive programmes should stress the importance of not forgetting these locations in self-examination and screening. Special attention should be given to educating elderly men.

Detection of Pneumocystis carinii DNA in blood specimens from human immunodeficiency virus-infected patients by nested PCR.

The detection of Pneumocystis carinii DNA in blood by PCR could be useful for studying the natural history of pneumocystosis and could also be a noninvasive diagnostic method. The results of previous studies are nevertheless conflicting. In our study, we compared three commercially available DNA extraction kits (GeneReleaser, QIAamp Tissue Kit, and ReadyAmp Genomic DNA Purification System) and proteinase K and proteinase K-phenol-chloroform treatments for the extraction of P. carinii DNA from dilutions of a P. carinii f. sp. hominis cyst suspension mixed with human whole blood. A rapid and simple nested PCR protocol which amplifies a portion of the mitochondrial large-subunit rRNA gene was applied to all the extraction products. The QIAmp Tissue Kit was the most effective kit for the isolation of amplification-ready P. carinii DNA and was used with nested PCR for the testing of whole-blood specimens from 35 immunocompetent control patients and 84 human immunodeficiency virus (HIV)-infected patients investigated for pulmonary disease and/or fever. In HIV-infected patients, P. carinii DNA was detected by nested PCR in blood samples from 3 of 14 patients with microscopically proven P. carinii pneumonia, 7 of 22 patients who were considered to be colonized with P. carinii, and 9 of 48 patients who were neither infected nor colonized with P. carinii. P. carinii DNA was not detected in blood specimens from the 35 immunocompetent patients. P. carinii DNA in blood might represent viable P. carinii organisms or DNA complexes released from pulmonary phagocytes. In conclusion, P. carinii DNA may be detected in whole blood from HIV-infected patients, but the nature and the meaning of the circulating form of P. carinii remain to be established.

Human platelet inhibition of Toxoplasma gondii growth.

The human platelet contribution against the intracellular growth of the parasite in vitro in human pulmonary fibroblasts was explored. It was observed that tachyzoites of Toxoplasma gondii induced activation of human platelets and additionally that platelets mediated inhibition of intracellular growth in a virulent T. gondii strain. A prominent role for platelet-derived growth factor (PDGF) was demonstrated in this phenomenon, by testing human recombinant PDGF-AA, -AB and -BB and antibodies to human PDGF-AB that partially reversed its effects. Moreover, the effect of PDGF was significantly higher if the host cells were treated 2 h before parasite infection. PDGF was not directly 'toxic' to free tachyzoites, but only affected parasites within host cells. PDGF-mediated inhibition may involve the cyclooxygenase cycle of the fibroblasts being partially reversed by the cyclooxygenase inhibitors, acetylsalicylic acid and indomethacin. However, a thromboxane synthetase pathway was not implicated. PDGF action against intracellular tachyzoites may also include increased IL-6 production in fibroblasts. Finally, transforming growth factor-beta 1 (TGF-beta1), another component of alpha-granules released at the same time as PDGF, may not be antagonistic to the PDGF parasite inhibitory effect in confluent host cells.

Chloroquine self-treatment and clinical outcome of cerebral malaria in children.

Chloroquine is widely used as self-medication for presumptive treatment of malaria despite the existence of parasite resistance to the drug. Recent studies suggest that tumour necrosis factor-alpha (TNF-alpha) overproduction probably has a causal association with poor outcome in cerebral malaria. In addition, chloroquine has been shown to have inhibitory action on TNF-alpha synthesis. The present study aimed at evaluating chloroquine/TNF-alpha interaction in 90 children hospitalized for severe malaria in a malaria-endemic zone. TNF-alpha and chloroquine varied in the same range on admission, but there was an inverse correlation between the two: the higher the chloroquine level, the lower the TNF-alpha level. Parasite resistance to chloroquine in vitro was high. The clinical course in the patients was uneventful, save for two fatal cases and one survivor with neurological sequela. The above data suggest beneficial effects of chloroquine self-medication with respect to anti-TNF-alpha action. Rational use of this tool should be encouraged.

Apoptosis related to chloroquine sensitivity of the human malaria parasite Plasmodium falciparum.

As chemoresistance of Plasmodium falciparum to chloroquine has arisen, new ways of combating the infection are needed. Similarities exist between the multidrug resistance of mammalian cells and chloroquine resistance of P. falciparum, based on the occurrence of internucleosomal deoxyribonucleic acid (DNA) breakdown and the ability of some anticancer drugs and chloroquine to induce apoptosis. Using chloroquine, oligonucleosomal DNA fragmentation was observed with a sensitive strain of P. falciparum, but not with a resistant one. This suggests that apoptosis may be involved in the action of chloroquine on the parasite.

Signal transduction pathways involved in tumour necrosis factor secretion by Plasmodium falciparum-stimulated human monocytes.

Tumour necrosis factor (TNF) plays a pivotal role in the induction of cerebral complications during Plasmodium falciparum malaria. TNF secretion by macrophages can be induced by lipopolysaccharide (LPS) and by P. falciparum antigens, but it is unclear whether similar mechanisms control the monokine expression in both cases. The signal transduction pathway by which parasite antigens induce TNF secretion remains to be established. The results reported here, using various inhibitors of second messenger pathways, clearly demonstrate that the signal transduction leading to TNF secretion is mediated partly through protein kinase C and calmodulin-dependent protein kinase activation. Furthermore, this signal seems to be differentially regulated after LPS or parasite stimulation, since cyclo-oxygenase inhibition by indomethacin resulted in twofold more TNF production enhancement with LPS stimulation than with parasite stimulation. The nature of the receptor involved in the parasite induced-macrophage stimulation remains obscure. However, the results discussed here indicate that parasite antigens stimulate multiple signal transduction pathways via G protein. Identification of the different pathways involved in these receptor-mediated events may be invaluable in the development of specific inhibitors against TNF over-production during cerebral malaria.

The multifactorial and multistage character of protective immunity to Plasmodium falciparum, naturally acquired by an indigenous population in Burkina Faso.

In malaria-endemic areas, protective immunity is acquired gradually. Some authors have proposed that different stages can be distinguished during development. To test this hypothesis, several in vitro assays of the host immune response to P. falciparum were performed in three groups of individuals: 'unprotected' children with clinical attacks, 'semi-immune' children, without clinical attacks but with transient high parasitaemias during the transmission period, and 'protected' adults with low residual parasitaemias. By comparison of immune responses in these groups and multifactorial analyses, discriminant factors and potential protective mechanisms were identified. Anti-RESA antibody levels were lower in 'unprotected' than in 'semi-immune' children, while specific cellular responses, TNF levels and percentage of activated T lymphocytes were higher. Low humoral immunity and high cellular activation in children were followed by high humoral immunity and low cellular activation in adults. Therefore, protective immunity seems to pass through different stages and to result from the association of different immune mechanisms according to the level and duration of the individual experience of malaria.

Intra-erythrocytic Plasmodium falciparum induces up-regulation of inter-cellular adhesion molecule-1 on human endothelial cells in vitro.

The stimulation of human vascular endothelial cells with P. falciparum-infected erythrocytes resulted in the non-transient up-regulation of ICAM-1 expression on human endothelial cells. The induction was independent from TNF as assured in various controls including the application of a TNF-neutralizing antibody. The possibility that TNF is produced by endothelial cells was investigated in a purified culture of human endothelial cells by TNF-ELISA and TNF-bio-assay both with negative results. This result may be evidence of the existence of TNF-independent mechanisms in the pathogenesis of human cerebral malaria.

Chloroquine-induced inhibition of the production of TNF, but not of IL-6, is affected by disruption of iron metabolism.

There is now considerable evidence that cerebral malaria may be related to the over-production of tumour necrosis factor (TNF). Nevertheless, our knowledge is very poor concerning the biological events which lead up to this TNF over-production. Furthermore, interleukin-6 (IL-6) is produced in large amounts during malaria infection and seems to have inhibitory action on TNF production. Anti-malarial drugs were investigated for their ability to interfere with TNF and IL-6 secretion by human non-immune macrophages stimulated by lipopolysaccharides (LPS) or Plasmodium falciparum culture supernatant. Macrophages were pretreated with chloroquine, quinine, proguanil, mefloquine or halofantrine before stimulation. TNF and IL-6 production were suppressed in a dose-dependent manner when macrophages were treated with chloroquine, but not with other anti-malarial drugs. Considering that chloroquine probably acts via lysosomotropic mechanisms, and that iron metabolism may interfere with the non-specific immune response, we focused our attention on these biochemical events in order to investigate the mechanisms by which chloroquine inhibits cytokine production. Our results demonstrated that chloroquine-induced inhibition of TNF and IL-6 production is not mediated through a lysosomotropic mechanism, and that chloroquine probably acts on TNF secretion by disrupting iron homeostasis. Inhibition of IL-6 production seems not to be mediated through these pathways. These observations suggest that chloroquine may help to prevent cerebral malaria whatever the drug sensitivity of the parasite strain, and may provide new tools for an anti-disease therapy regardless of the emergence of parasite multi-drug resistance.

Ring-infected erythrocyte surface antigen (Pf/155RESA) induces tumour necrosis factor-alpha production.

Cerebral malaria is probably related to an overstimulation of the immune system and the cytokine network. We have previously demonstrated that tumour necrosis factor (TNF) secretion by human macrophages can be induced by soluble and heat-stable malarial antigens. Indirect evidence from epidemiological and in vitro studies suggests that Pf155/RESA can be considered as a candidate for triggering TNF secretion. Thus we conducted experiments to investigate the relationship between Pf155/RESA and TNF production. The SGE1 strain of Plasmodium falciparum was compared with the P. falciparum FCR3 strain, which does not express Pf155/RESA protein, for ability to induce TNF secretion by normal human macrophages in vitro. Synthetic peptides from the Pf155/RESA antigen ((EENV)4, (EENVEHDA)4, (DDEHVEEPTVA)3), were used in some experiments. TNF levels were measured by an immunoradiometric assay. We observed that the RESA-defective strain induces lower levels of TNF after schizont rupture than the SGE1 strain. Moreover, substantial TNF secretion was detected when macrophages were incubated with all three peptides, maximum levels being obtained with the (EENV)4 peptide. Although previous reports have described TNF-inducing activity of phospholipid from P. falciparum, these findings strengthen the evidence for Pf155/RESA antigens also being involved in TNF production during malaria.