Deciphering Unexpected Vascular Locations of Scedosporium spp. and Lomentospora prolificans Fungal Infections, France.

Scedosporium spp. and Lomentospora prolificans are emerging non-Aspergillus filamentous fungi. The Scedosporiosis/lomentosporiosis Observational Study we previously conducted reported frequent fungal vascular involvement, including aortitis and peripheral arteritis. For this article, we reviewed 7 cases of Scedosporium spp. and L. prolificans arteritis from the Scedosporiosis/lomentosporiosis Observational Study and 13 cases from published literature. Underlying immunosuppression was reported in 70% (14/20) of case-patients, mainly those who had solid organ transplants (10/14). Osteoarticular localization of infection was observed in 50% (10/20) of cases; infections were frequently (7/10) contiguous with vascular infection sites. Scedosporium spp./Lomentospora prolificans infections were diagnosed in 9 of 20 patients ≈3 months after completing treatment for nonvascular scedosporiosis/lomentosporiosis. Aneurysms were found in 8/11 aortitis and 6/10 peripheral arteritis cases. Invasive fungal disease--related deaths were high (12/18 [67%]). The vascular tropism of Scedosporium spp. and L. prolificans indicates vascular imaging, such as computed tomography angiography, is needed to manage infections, especially for osteoarticular locations.

Impact of EUCAST rapid antimicrobial susceptibility testing (RAST) on management of Gram-negative bloodstream infection.

OBJECTIVES: During bloodstream infections, reducing the time to antimicrobial susceptibility testing is crucial to initiation of early appropriate antibiotic therapy. For Gram-negative infections, a phenotypic approach remains necessary. Rapid antimicrobial testing (RAST) is a recently developed phenotypic EUCAST method. The goal of this study was to evaluate the accuracy and clinical impact of RAST. PATIENTS AND METHODS: From September 2020 to August 2021, Gram-negative episodes with positive blood culture detected in the morning were included in the RAST group. Categorical agreement of RAST with conventional antimicrobial testing on strains was determined. To assess antibiotic management and patient outcomes, the RAST group was compared with a control group (CG) with positive blood culture detected in the afternoon for which overnight antimicrobial testing was performed. RESULTS: The RAST group included 61 episodes from 61 patients, while the CG group included 49 episodes from 48 patients. While RAST performed on 41 E. coli, 11 K. pneumoniae and 9 P. aeruginosa strains highlighted 99.3 % of categorical agreement, 7.4 % of unreadable zones and 9.4 % of technical uncertainty area at 4 h incubation were also reported. For the RAST group, effective antibiotic therapy was prescribed in 100 % of patients on the day of positive blood culture (day 1) vs 88 % in CG (p = 0,007). As for beta-lactams on day 1, RAST led to 9 escalations and 6 de-escalations. Mortality and length of hospital stay did not significantly differ between the two groups. CONCLUSION: RAST improves management of antibiotic therapy in patients with Gram-negative sepsis.

[Optimization of incubation duration of culture media in microbiology]. / Optimisation des durées d'incubation des milieux de culture en microbiologie.

In order to perform biological analysis, clinical laboratories apply the instructions of reagent suppliers. For culture media these instructions are often incomplete and poorly adapted to the variety of clinical samples and micro-organisms. The REMIC can help to overcome these shortcomings. Required time of incubation for culture media are proposed based on the nature of the sample and the type of micro-organism suspected. Nevertheless, they are most often expressed in multiple of 24 hours and they are often considered as minimal by the laboratories. As the samples are inoculated "continuously", while the readings are most often done at a single definite time of the day, we propose a strategy to optimize incubation duration of cultures medium. A time of incubation in the day so-called "limit" is defined. From this, the incubations are stopped or prolonged according to the results of the culture and the direct examination. As the instructions of suppliers of culture media are not adapted, it appears necessary that these suppliers relies on the repositories of professional societies as this is the case for agars medias used for antibiotic susceptibility testing.

[Contribution and evolution of blood culture quality indicators]. / Apports et perspectives d'évolution des indicateurs qualité de l'hémoculture.

The monitoring of quality indicators, combined with a detailed risk analysis, validates the process of automated blood culture. Here we report the methodology of 5 years monitoring for 5 indicators at the Biology Department of Foch Hospital: volume sampled, proportion of contaminants, proportion of positive blood cultures in each instrument and drawer, epidemiological indicator and proportion of false-positive instrument signals. The results obtained were outside the expected target for the volume sampled and were acceptable for the other indicators. The analysis of these results leads us to discuss the evolution of quality indicators and more particularly the implementation of corrective measures, their periodicity, their relevance as well as the need to refine their results to carry out targeted actions.

Rapid identification of Escherichia coli colonies from clinical sample inoculated on CHROMagar Orientation media (Becton Dickinson).

CHROMmagar Orientation media (Becton Dickinson) was developed and validated for the culture of urinary samples. It allows a direct identification of E. coli colonies without additional tests. As CHROMmagar Orientation media is superior to non-chromogenic media for the distinction of enterobacterial colonies, it is used for the inoculation of a large variety of samples in clinical laboratories. Direct identification of E. coli colonies cultured from these samples is not validated by the manufacturer. The difference in microbial ecology and the nature of the sample may impact CHROMagar Orientation performances for this use. We evaluated these media for the direct identification of E. coli colonies from 410 samples (excluding urine). Its sensitivity of 99% allows a direct identification of E. coli colonies cultured from a wide variety of samples. On-site testing using a large number of representative samples, allows laboratories to assess agar media performance and adapt their uses. Suppliers who are aware of frequent and non-recommended use of their culture media should perform tests and if conclusive, adapt their technical instructions.

Suppression of basophil histamine release and other IgE-dependent responses in childhood Schistosoma mansoni/hookworm coinfection.

BACKGROUND: The poor correlation between allergen-specific immunoglobulin E (asIgE) and clinical signs of allergy in helminth infected populations suggests that helminth infections could protect against allergy by uncoupling asIgE from its effector mechanisms. We investigated this hypothesis in Ugandan schoolchildren coinfected with Schistosoma mansoni and hookworm. METHODS: Skin prick test (SPT) sensitivity to house dust mite allergen (HDM) and current wheeze were assessed pre-anthelmintic treatment. Nonspecific (anti-IgE), helminth-specific, and HDM-allergen-specific basophil histamine release (HR), plus helminth- and HDM-specific IgE and IgG4 responses were measured pre- and post-treatment. RESULTS: Nonspecific- and helminth-specific-HR, and associations between helminth-specific IgE and helminth-specific HR increased post-treatment. Hookworm infection appeared to modify the relationship between circulating levels of HDM-IgE and HR: a significant positive association was observed among children without detectable hookworm infection, but no association was observed among infected children. In addition, hookworm infection was associated with a significantly reduced risk of wheeze, and IgG4 to somatic adult hookworm antigen with a reduced risk of HDM-SPT sensitivity. There was no evidence for S. mansoni infection having a similar suppressive effect on HDM-HR or symptoms of allergy. CONCLUSIONS: Basophil responsiveness appears suppressed during chronic helminth infection; at least in hookworm infection, this suppression may protect against allergy.

Mycobacterium genavense as a cause of subacute pneumonia in patients with severe cellular immunodeficiency.

BACKGROUND: Mycobacterium genavense is a rare nontuberculous mycobacteria (NTM). Human infections are mostly disseminated in the setting of the AIDS epidemic or the use of aggressive immunosuppressive treatments. M. genavense culture is fastidious, requiring supplemented media. Pulmonary involvement rarely occurs as a primary localization. CASES PRESENTATION: We report here two patients with pneumonia as the predominant manifestation of M. genavense infection: one kidney transplanted patient and one HIV-infected patient. Both patients were initially treated with anti-tuberculous drugs before the identification of M. genavense on sputum or broncho-alveolar lavage fluid culture. A four-drug regimen including clarithromycin and rifabutin was started. Gamma interferon has been helpful in addition to antimycobacterial treatment for one patient. CONCLUSION: Clinicians should be aware that M. genavense could be the etiologic agent of sub-acute pneumonia mimicking tuberculosis in patients with cellular immunodeficiency status.

Applied and basic research on the epidemiology, morbidity, and immunology of schistosomiasis in fishing communities on Lake Albert, Uganda.

We report multidisciplinary studies on schistosomiasis which have been ongoing in the fishing communities of Piida, Booma, Bugoigo and Walakuba, on Lake Albert, Uganda, since 1996. Schistosomiasis is the major health problem in this area, with high infection intensities and prevalence. In addition to generating basic data on the epidemiology, morbidity and immunology of human schistosomiasis, this research programme is providing important descriptive and methodological information, and has contributed to the increase in operational capacity within Uganda in recent years. Such information and operational capacity are needed to facilitate much needed schistosomiasis control programmes, such as the Schistosomiasis Control Initiative that was launched in Uganda in 2003.

Changes in IgE- and antigen-dependent histamine-release in peripheral blood of Schistosoma mansoni-infected Ugandan fishermen after treatment with praziquantel.

BACKGROUND: Parasite-specific IgE levels correlate with human resistance to reinfection with Schistosoma spp. after chemotherapy. Although the role of eosinophils in schistosomiasis has been the focus of a great deal of important research, the involvement of other Fcepsilon receptor-bearing cells, such as mast cells and basophils, has not been investigated in relation to human immunity to schistosomes. Chemotherapy with praziquantel (PZQ) kills schistosomes living in an in vivo blood environment rich in IgE, eosinophils and basophils. This releases parasite Ags that have the potential to cross-link cell-bound IgE. However, systemic hypersensitivity reactions are not induced by treatment. Here, we describe the effects of schistosomiasis, and its treatment, on human basophil function by following changes in total cellular histamine and in vitro histamine-release induced by schistosome Ags or anti-IgE, in blood samples from infected Ugandan fishermen, who are continuously exposed to S. mansoni infection, before and 1-day and 21-days after PZQ treatment. RESULTS: There was a significant increase in the total cellular histamine in blood samples at 1-day post-treatment, followed by a very significant further increase by 21-days post-treatment. In vitro histamine-release induced by S. mansoni egg (SEA) or worm (SWA) Ags or anti-IgE antibody, was significantly reduced 1-day post-treatment. The degree of this reduction correlated with pre-treatment infection intensity. Twenty-1-days post-treatment, SEA-induced histamine-release was still significantly lower than at pretreatment. Histamine-release was not correlated to plasma concentrations of total or parasite-specific IgE, nor to specific IgG4 plasma concentrations. CONCLUSION: The biology of human blood basophils is modulated by S. mansoni infection and praziquantel treatment. Infection intensity-dependent suppression of basophil histamine-release, histamine-dependent resistance to infection, and similarities with allergen desensitisation are discussed as possible explanations of these observations.