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We performed an observational study to investigate intensive care unit incidence, risk factors, and outcomes of coronavirus disease-associated pulmonary aspergillosis (CAPA). We found 10%-15% CAPA incidence among 823 patients in 2 cohorts. Several factors were independently associated with CAPA in 1 cohort and mortality rates were 43%-52%.
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COVID-19 , Aspergilosis Pulmonar Invasiva , Aspergilosis Pulmonar , Estudios de Cohortes , Humanos , SARS-CoV-2RESUMEN
We determined the susceptibility of 182 Fusarium species isolates to five antifungal drugs (amphotericin B, voriconazole, posaconazole, isavuconazole, and terbinafine) by the EUCAST method. Based on the latest taxonomic insights, isolates collected from 20 European centers were distributed into seven complexes and 27 species. The susceptibility was variable, depending on the species. Comparison with the gradient concentration strip method, which was used for 77 isolates, showed essential agreement values for voriconazole, posaconazole, isavuconazole, and amphotericin B of 17%, 91%, 83%, and 70%, respectively.
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Antifúngicos , Fusarium , Anfotericina B/farmacología , Antifúngicos/farmacología , Pruebas de Sensibilidad Microbiana , Voriconazol/farmacologíaRESUMEN
Cryptosporidiosis is a gastrointestinal illness with profuse diarrhoea. Although there are no other Food and Drug Administration (FDA)-approved alternatives for the treatment of cryptosporidiosis, nitazoxanide (NTZ) can be qualified as partially effective. In immunosuppressed conditions, severe and/or disseminated cryptosporidiosis may occur and patients should be treated parenterally. To achieve the goal of developing parenteral treatment for cryptosporidiosis, the current study was undertaken to investigate the in vitro and in vivo anticryptosporidial activity of aminoxanide. This new l-tert-leucyl thiazolide is a soluble prodrug of tizoxanide (TIZ), the main metabolite of NTZ. Confirming the good efficacy of aminoxanide in Cryptosporidium parvum-infected HCT-8 cells with a 50% inhibitory concentration of 1.55 µm (±0.21), in immunosuppressed C. parvum-infected Mongolian gerbils (Meriones unguiculatus), a 5-day treatment with a daily intramuscular dose of 100 mg kg−1 aminoxanide resulted in a 72.5% oocyst excretion inhibition, statistically equivalent to 75.5% in gerbils treated with a 4-fold lower oral dose of NTZ. Cryptosporidium parvum-induced intestinal pathology and inflammation were improved. Aminoxanide provides an injectable form of TIZ that NTZ was unable to do and is a promising drug for which optimization of the formulation should be further explored. These results represent a first promising step towards the goal of developing a parenteral treatment for cryptosporidiosis.
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Criptosporidiosis/tratamiento farmacológico , Cryptosporidium parvum/efectos de los fármacos , Ésteres/uso terapéutico , Profármacos/uso terapéutico , Tiazoles/uso terapéutico , Animales , Bovinos , Línea Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ésteres/química , Ésteres/farmacología , Heces/parasitología , Femenino , Gerbillinae , Íleon/parasitología , Íleon/patología , Concentración 50 Inhibidora , Masculino , Estructura Molecular , Profármacos/química , Profármacos/farmacología , Tiazoles/química , Tiazoles/farmacologíaRESUMEN
OBJECTIVES: Aspergillus cryptic species are increasingly recognised causes of Aspergillus diseases, including life-threatening invasive aspergillosis (IA). However, as their accurate identification remains challenging in a routine practice, few is known from a clinical and epidemiological perspective. Recently, the MSI application has emerged as a powerful tool for the detection and identification of Aspergillus cryptic species. We aimed to use to the network of users of the MSI application to conduct a multicentre prospective screening of Aspergillus cryptic species-related IA and analyse their epidemiological, clinical and mycological characteristics. METHODS: Over a 27-month period, the clinical involvement of 369 Aspergillus cryptic isolates, from 13 French and Danish MSI application users, was prospectively analysed. Species identification was confirmed by DNA-sequencing and antifungal susceptibility testing was performed using EUCAST reference method. Fifty-one A fumigatus sensu stricto invasive cases were also analysed. RESULTS: Fifteen cryptic isolates were responsible of IA. Eight species were involved, including 5 cases related to the species A sublatus. These species showed high rate of in vitro low susceptibility to antifungal drugs. In comparison with A fumigatus sensu stricto invasive cases, pre-exposure to azole drugs was significantly associated with cryptic IA (P = .02). DISCUSSION: This study brings new insights in cryptic species related IA and underlines the importance to identify accurately at the species level these Aspergillus isolates. The increasing use of antifungal drugs might lead in the future to an epidemiologic shift with an emergence of resistant isolates involved in IA.
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Aspergillus/clasificación , Aspergilosis Pulmonar Invasiva/microbiología , Adulto , Anciano , Antifúngicos/farmacología , Aspergillus/efectos de los fármacos , Farmacorresistencia Fúngica , Femenino , Francia/epidemiología , Humanos , Aspergilosis Pulmonar Invasiva/epidemiología , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Candida albicans can form biofilm on tissues and medical devices, becoming, in that case, less susceptible to antifungal agents. Treatment of candidiasis associated with the formation of C. albicans biofilms is restricted to echinocandins and lipid forms of amphotericin B. This study investigated the activity of micafungin and resveratrol modified molecule (EB487) against C. albicans biofilms. The anti-biofilm growth (Bgrowth) and anti-preformed biofilm (Bpreformed) activities of micafungin (0 to 3.94 µM) and EB487 (0 to 20.32 mM) were comparatively studied separately and combined, using XTT, flow cytometry and cell counts approaches. Concentrations causing 50% inhibition of the studied steps (IC50) were evaluated. When tested separately, IC50 Bgrowth was obtained for 4.8 mM and 0.13 µM of EB487 and micafungin respectively, and IC50 Bpreformed for 3.6 mM and 0.06 µM of EB487 and micafungin respectively. Micafungin used alone was not able to totally eradicate fungi. Micafungin combined with EB487 displayed synergistic activity (both anti-growth- and anti-preformed biofilm-activities). Optimal combination concentrations were EB487 (≤9.12 mM -strain ATCC 28367™ or ≤8.12 mM -strain CAI4-p), micafungin (≤0.05 µM for both) and caused a total eradication of fungi. Dose reduction indexes obtained using these concentrations were at least 9 (micafungin) and 3.2 (EB487) for both anti-biofilm growth- and anti-preformed biofilm-activities. Combinations indexes were consistently below one, demonstrating a synergistic relationship between micafungin and EB487 in these conditions. This study demonstrated the strong anti-biofilm activity of EB487 and highlighted its synergistic potential when combined with micafungin. EB487 is a promising semi-synthetic molecule with prophylactic and curative interests in fighting C. albicans biofilms.
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Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Resveratrol/farmacología , Antifúngicos/síntesis química , Biopelículas/crecimiento & desarrollo , Candida albicans/clasificación , Sinergismo Farmacológico , Concentración 50 Inhibidora , Micafungina/farmacología , Pruebas de Sensibilidad Microbiana , Prueba de Estudio Conceptual , Resveratrol/síntesis químicaRESUMEN
The taxonomy of Aspergillus species has recently been revolutionized with the introduction of cryptic species and section concepts. However, their species-level identification in routine laboratories remains a challenge. The aim of this study was to prospectively assess the identification accuracy of cryptic species of Aspergillus in various laboratories using the mass spectrometry identification (MSI) platform, an independent and freely accessible online mass spectrometry database. Over a 12-month period, when a select set of MSI users identified cryptic species, they were contacted and requested to send the isolates to our laboratory for sequence-based identification. Sequence and MSI identification results were then compared. During the study period, 5108 Aspergillus isolates were identified using MSI including 1477 (28.9%) cryptic species. A total of 245 isolates that corresponded to 56 cryptic species and 13 sections were randomly selected for DNA sequencing confirmation. Agreement between the two methods was 99.6% at the section level and 66.1% at the species level. However, almost all discrepancies (72/83, 86.7%) were misidentifications between closely related cryptic species belonging to the same section. Fifty-one isolates from noncryptic species were also identified, thus yielding 100% and 92.2% agreement at the section and species level, respectively. Although the MSI fungus database is a reliable tool to identify Aspergillus at the section level, the database still requires adjustment to correctly identify rare or cryptic species at the species level. Nevertheless, the application properly differentiated between cryptic and sensu stricto species in the same section, thus alerting on possible specific isolate characteristics.
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Aspergillus/química , Aspergillus/clasificación , Bases de Datos Factuales , Internet , Técnicas Microbiológicas/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , HumanosRESUMEN
Cryptosporidiosis is a common disease in children and immunodeficient individuals. In 2006, a national network was set up on the surveillance of human cryptosporidiosis in France. Since January 2015, the 41 tertiary care hospitals and the 3 private laboratories of the French National Network on the surveillance of human cryptosporidiosis have been able to declare confirmed cases of cryptosporidiosis online. Between 2015 and 2017, 210 cases of cryptosporidiosis were declared in immunodeficient patients in France; Cryptosporidium parvum and Cryptosporidium hominis represented 66% and 22% of cases, respectively. A peak was observed in autumn. Cryptosporidiosis occurred mainly in a context of solid organ transplantation (SOT) (49%) and of HIV infection (30%). In SOT recipients, cryptosporidiosis appeared more frequently in the first 6 months post transplantation. Regarding cases declared in SOT recipients, mycophenolate mofetil was used in 68%. A mortality rate of 6% was observed. Present results underline the importance of screening for cryptosporidiosis in immunocompromised patients suffering from diarrhea, especially in the course of major cell mediated immunodeficiency or even systematic screening before SOT. Exclusive Cryptosporidium free water feeding could be suggested during major cell mediated immunodeficiency.
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Criptosporidiosis/epidemiología , Huésped Inmunocomprometido , Inmunoterapia/efectos adversos , Adolescente , Adulto , Anciano , Niño , Preescolar , Criptosporidiosis/inmunología , Ciclosporina/efectos adversos , Ciclosporina/uso terapéutico , Femenino , Francia/epidemiología , Humanos , Terapia de Inmunosupresión/efectos adversos , Terapia de Inmunosupresión/métodos , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Inmunoterapia/métodos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Ácido Micofenólico/efectos adversos , Ácido Micofenólico/uso terapéutico , Factores de Riesgo , Tacrolimus/efectos adversos , Tacrolimus/uso terapéutico , Adulto JovenRESUMEN
BACKGROUND: Since several malaria parasite species are usually present in a particular area, co-infections with more than one species of Plasmodium are more likely to occur in humans infected in these areas. In many mixed infections, parasite densities of the cryptic species may be low and often not recognized in clinical practice. CASE PRESENTATION: Two children (3 and 6 years old) adopted recently from Central African Republic were admitted to hospital because of intermittent fever. Thin blood smears stained with Giemsa showed Plasmodium falciparum and Plasmodium malariae co-infection for both children at admission. They were both treated with atovaquone-proguanil combination for 3 days. At day 7, both thin blood smears examination remained negative but at day 28, thin blood smear was positive for P. malariae trophozoites and for Plasmodium ovale for the girl and her brother, respectively. Samples collected at day 1 and day 28 were submitted to real-time PCR showing the presence of the three parasite species (P. falciparum, P malariae and P. ovale) in admission blood samples from the two children and only P. ovale at day 28. CONCLUSIONS: Twenty-eight days follow-up after treatment led to detection of a third parasite species in the blood of these two patients suggesting covert co-infection and a delayed appearance of one cryptic species following treatment. Concurrently infecting malaria species could be mutually suppressive, with P. falciparum tending to dominate other species. These observations provide more evidence that recommendations for treatment of imported malaria should take into account the risk of concurrent or cryptic infection with Plasmodium species. Clinicians and biologists should be aware of the underestimated frequency of mixed infections with cryptic species and of the importance of patient follow-up at day 28. Future guidelines should shed more light on the treatment of mixed infection and on the interest of using artemisinin-based combinations for falciparum and non-falciparum species.
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Coinfección/diagnóstico , Coinfección/parasitología , Malaria Falciparum/complicaciones , Malaria/complicaciones , Malaria/parasitología , Plasmodium falciparum/aislamiento & purificación , Plasmodium malariae/aislamiento & purificación , Plasmodium ovale/aislamiento & purificación , Infecciones Asintomáticas , República Centroafricana , Niño , Niño Adoptado , Preescolar , Coinfección/tratamiento farmacológico , Femenino , Francia , Humanos , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria Falciparum/diagnóstico , Malaria Falciparum/tratamiento farmacológico , MasculinoRESUMEN
Even though it has been studied for many years, water-related infectious risk still exists in both care and community environments due to the possible presence of numerous microorganisms such as bacteria, fungi and protists. People can be exposed directly to these microorganisms either through aerosols and water, after ingestion, inhalation, skin contact and entry through mucosal membranes, or indirectly usually due to pre-treatment of some medical devices. Species belonging to genera such as Aspergillus, Penicillium, Pseudallesheria, Fusarium, Cuninghamella, Mucor and in some particular cases Candida have been isolated in water from health facilities and their presence is particularly related to the unavoidable formation of a polymicrobial biofilm in waterlines. Fungi isolation methods are based on water filtration combined with conventional microbiology cultures and/or molecular approaches; unfortunately, these are still poorly standardized. Moreover, due to inappropriate culture media and inadequate sampling volumes, the current standardized methods used for bacterial research are not suitable for fungal search. In order to prevent water-related fungal risk, health facilities have implemented measures such as ultraviolet radiation to treat the input network, continuous chemical treatment, chemical or thermal shock treatments, or microfiltration at points of use. This article aims to provide an overview of fungal colonization of water (especially in hospitals), involvement of biofilms that develop in waterlines and application of preventive strategies.
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Biopelículas , Agua Dulce/microbiología , Hongos/fisiología , Abastecimiento de Agua/normas , Hongos/genética , Hongos/aislamiento & purificación , Humanos , Micosis/microbiología , Contaminación del AguaRESUMEN
Malaria remains a global health problem, with 247 million cases and 619,000 deaths in 2021. Diagnosis of Plasmodium species is important for administering the appropriate treatment. The gold-standard diagnosis for accurate species identification remains the thin blood smear. Nevertheless, this method is time-consuming and requires highly skilled and trained microscopists. To overcome these issues, new diagnostic tools based on deep learning are emerging. This study aimed to evaluate the performances of a real-time detection transformer (RT-DETR) object detection algorithm to discriminate Plasmodium species on thin blood smear images. The algorithm was trained and validated on a data set consisting in 24,720 images from 475 thin blood smears corresponding to 2,002,597 labels. Performances were calculated with a test data set of 4,508 images from 170 smears corresponding to 358,825 labels coming from six French university hospitals. At the patient level, the RT-DETR algorithm exhibited an overall accuracy of 79.4% (135/170) with a recall of 74% (40/54) and 81.9% (95/116) for negative and positive smears, respectively. Among Plasmodium-positive smears, the global accuracy was 82.7% (91/110) with a recall of 90% (38/42), 81.8% (18/22), and 76.1% (35/46) for P. falciparum, P. malariae, and P. ovale/vivax, respectively. The RT-DETR model achieved a World Health Organization (WHO) competence level 2 for species identification. Besides, the RT-DETR algorithm may be run in real-time on low-cost devices such as a smartphone and could be suitable for deployment in low-resource setting areas lacking microscopy experts.IMPORTANCEMalaria remains a global health problem, with 247 million cases and 619,000 deaths in 2021. Diagnosis of Plasmodium species is important for administering the appropriate treatment. The gold-standard diagnosis for accurate species identification remains the thin blood smear. Nevertheless, this method is time-consuming and requires highly skilled and trained microscopists. To overcome these issues, new diagnostic tools based on deep learning are emerging. This study aimed to evaluate the performances of a real-time detection transformer (RT-DETR) object detection algorithm to discriminate Plasmodium species on thin blood smear images. Performances were calculated with a test data set of 4,508 images from 170 smears coming from six French university hospitals. The RT-DETR model achieved a World Health Organization (WHO) competence level 2 for species identification. Besides, the RT-DETR algorithm may be run in real-time on low-cost devices and could be suitable for deployment in low-resource setting areas.
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Malaria Falciparum , Malaria , Piperazinas , Plasmodium , Humanos , Algoritmos , Plasmodium falciparumRESUMEN
Nowadays, the use of qPCR for the diagnosis of intestinal microsporidiosis is increasing. There are several studies on the evaluation of qPCR performance but very few focus on the stool pretreatment step before DNA extraction, which is nevertheless a crucial step. This study focuses on the mechanical pretreatment of stools for Enterocytozoon bieneusi spores DNA extraction. Firstly, a multicenter comparative study was conducted evaluating seven extraction methods (manual or automated) including various mechanical pretreatment. Secondly, several durations and grinding speeds and types of beads were tested in order to optimize mechanical pretreatment. Extraction methods of the various centers had widely-varying performances especially for samples with low microsporidia loads. Nuclisens® easyMAG (BioMérieux) and Quick DNA Fecal/Soil Microbe Microprep kit (ZymoResearch) presented the best performances (highest frequencies of detection of low spore concentrations and lowest Ct values). Optimal performances of mechanical pretreatment were obtained by applying a speed of 30 Hz during 60 s with the TissueLyser II (Qiagen) using commercial beads of various materials and sizes (from ZymoResearch or MP Biomedicals). Overall, the optimal DNA extraction method for E. bieneusi spores contained in stool samples was obtained with a strong but short bead beating using small-sized beads from various materials.
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ADN de Hongos , Enterocytozoon , Heces , Microsporidiosis , Heces/microbiología , Enterocytozoon/aislamiento & purificación , Enterocytozoon/genética , Humanos , Microsporidiosis/diagnóstico , Microsporidiosis/microbiología , ADN de Hongos/aislamiento & purificación , ADN de Hongos/genética , ADN de Hongos/análisis , Manejo de Especímenes/métodos , Esporas Fúngicas/aislamiento & purificación , Esporas Fúngicas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodosRESUMEN
Cryptosporidium is the causative agent of cryptosporidiosis, which results, among others, in profuse diarrhoea. Transmission to humans occurs via the faecal-oral route directly by contact with infected hosts or indirectly by waterborne or foodborne routes. For the latter, parasite transmission is closely linked to the oocyst's ability to persist and survive in food matrices. In this study, we evaluated the persistence and survival of Cryptosporidium oocysts in lamb's lettuce: i) during plant growth and ii) in conditions mimicking the industrial washing process applied in minimally-processed vegetables (MPV). Results show that oocysts persisted during the growth of lamb's lettuce, i.e. two months from the 2-leaf stage until the 8-leaf harvest time (-0.89 Log10 of oocysts). However, their survival decreased from as early as one week (-0.61 Log10), and only 6 % of oocysts remained infective at the time of harvest. The washing process had a limited effect on parasite load (<0.5 Log10) and no effect on survival; chlorination of washing water did not improve the efficiency (removal and inactivation) of the process. The ability of C. parvum to persist and survive throughout the food chain may drive its transmission to humans through MPV products. Appropriate management measures should be implemented at each operational level to limit contamination and ensure food safety of fresh produce.
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Criptosporidiosis , Cryptosporidium parvum , Cryptosporidium , Ensaladas , Valerianella , Humanos , Animales , Criptosporidiosis/prevención & control , Oocistos , Hojas de la PlantaRESUMEN
PURPOSE: To describe the management of bilateral chorioretinitis with Saprochaete clavata in a post-chemotherapy immunocompromised young patient. METHOD: A retrospective case report. RESULT: A 9-year-old boy treated with chemotherapy for type 2 acute myeloid leukaemia was diagnosed with Saprochaete clavata (formerly called Geotrichum clavatum) fungaemia. Systematic ocular examination revealed chorioretinitis of the left eye becoming bilateral within the next 3 days. Therapy was based on systemic administration of voriconazole, amphotericin B and flucytosine associated with granulocytic stimulation without stabilizing the ophthalmological situation. Bilateral intravitreal injections of amphotericin B were administered. Voriconazole residual blood concentration was monitored to adjust daily dose. Final best corrected visual acuity in the right eye was 20/50 and 20/20 in the left eye. CONCLUSION: This is the first report of chorioretinitis with Saprochaete clavata. Because of its unpredictable pharmacokinetics, especially in pediatric population, therapeutic drug monitoring of voriconazole is essential to control fungal infection.
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Antifúngicos , Coriorretinitis , Niño , Masculino , Humanos , Voriconazol/uso terapéutico , Antifúngicos/uso terapéutico , Anfotericina B/uso terapéutico , Estudios Retrospectivos , Coriorretinitis/diagnóstico , Coriorretinitis/tratamiento farmacológico , Coriorretinitis/microbiologíaRESUMEN
Nicardipine hydrochloride is an anti-hypertensive drug that is used off-label to treat hypertension in children. A previous oral formulation of nicardipine hydrochloride was developed using a commercial vehicle as an excipient. However, ready-to-use vehicles are prone to supply shortages, and their composition may undergo substantial modifications. The aim of this study was to propose a new oral formulation of nicardipine hydrochloride 2 mg/mL using simple excipients. The formulation included hydroxypropylmethylcellulose, simple syrup, polysorbate 80, sodium saccharin, citrate buffer, strawberry flavor and 0.2% potassium sorbate. The uniformity of content was maintained before and after agitation. Nicardipine hydrochloride concentration assessed by HPLC-MS/MS remained above 90% for 365 days before opening and for 28 days after opening. pH and osmolality were maintained throughout the study, and no microbial contamination was observed. The uniformity of mass of the delivered doses was evaluated using four different devices. A new oral formulation of nicardipine hydrochloride 2 mg/mL was developed using simple and safe excipients. Pharmacological and clinical parameters remain to be assessed and compared with those of the previous formulation.
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The protozoan parasites Cryptosporidium parvum, Cyclospora cayetanensis, and Toxoplasma gondii are major causes of waterborne and foodborne diseases worldwide. The assessment of their removal or inactivation during water treatment and food processing remains challenging, partly because research on these parasites is hindered by various economical, ethical, methodological, and biological constraints. To address public health concerns and gain new knowledge, researchers are increasingly seeking alternatives to the use of such pathogenic parasites. Over the past few decades, several non-pathogenic microorganisms and manufactured microparticles have been evaluated as potential surrogates of waterborne and foodborne protozoan parasites. Here, we review the surrogates that have been reported for C. parvum, C. cayetanensis, and T. gondii oocysts, and discuss their use and relevance to assess the transport, removal, and inactivation of these parasites in food and water matrices. Biological surrogates including non-human pathogenic Eimeria parasites, microorganisms found in water sources (anaerobic and aerobic spore-forming bacteria, algae), and non-biological surrogates (i.e. manufactured microparticles) have been identified. We emphasize that such surrogates have to be carefully selected and implemented depending on the parasite and the targeted application. Eimeria oocysts appear as promising surrogates to investigate in the future the pathogenic coccidian parasites C. cayetanensis and T. gondii that are the most challenging to work with.
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The estimated prevalence rate of adults living with HIV infection in MENA is one of the lowest in the world. To date, no data on the genetic characteristics of Cryptosporidium isolates from HIV/AIDS patients in Algeria were available. This study aimed to identify Cryptosporidium species and subtype families prevalent in Algerian HIV-infected patients and contribute to the molecular epidemiology mapping of Cryptosporidium in the MENA region. A total of 350 faecal specimens from HIV/AIDS patients were analysed using microscopy, and a Cryptosporidium infection was identified from 33 samples, with 22 isolates successfully sequencing and confirming species and subtypes. Based on sequence analysis, 15 isolates were identified as C. parvum with family subtypes IIa (n = 7) and IId (n = 8), while five were identified as C. hominis (family subtypes Ia (n = 2) and Ib (n = 3)) and two as C. felis. The C. parvum subtype families IIa and IId predominated, suggesting potential zoonotic transmission. More extensive sampling of both humans and farm animals, especially sheep, goats and calves, as well as a collection of epidemiological data are needed for a better understanding of the sources of human C. parvum infections in Algeria.
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Síndrome de Inmunodeficiencia Adquirida , Criptosporidiosis , Cryptosporidium , Infecciones por VIH , Adulto , Humanos , Animales , Ovinos , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Criptosporidiosis/epidemiología , Argelia/epidemiología , Cryptosporidium/genética , CabrasRESUMEN
Free-Living Amebae (FLA) and Cryptosporidium oocysts occasionally share the same environment. From 2004 to 2016, Cryptosporidium was responsible for 60% of 905 worldwide waterborne outbreaks caused by protozoan parasites. The aim of this study was to evaluate interactions between C. parvum oocysts and two common FLAs (Acanthamoeba castellanii and Vermamoeba vermiformis) in a water environment. Encystment and survival of FLAs were evaluated by microscopy using trypan blue vital coloration. Oocysts were numerated on microscopy. Interactions were studied over time in conditions both unfavorable and favorable to phagocytosis. Potential phagocytosis was directly evaluated by several microscopic approaches and indirectly by numeration of microorganisms and oocyst infectivity evaluation. Occasional phagocytosis of C. parvum by FLAs was documented. However, oocyst concentrations did not decrease significantly, suggesting resistance of oocysts to phagocytosis. A temporary decrease of oocyst infectivity was observed in the presence of A. castellanii. The effect of these interactions on C. parvum infectivity is particularly interesting. The biofilm condition could favor the persistence or even the proliferation of oocysts over time. This study demonstrated interactions between C. parvum and FLAs. Further knowledge of the mechanisms involved in the decrease of oocyst infectivity in the presence of A. castellanii could facilitate the development of new therapeutic approaches.
Title: Interactions entre amibes libres et Cryptosporidium parvum : étude expérimentale. Abstract: Les amibes libres et les oocystes de Cryptosporidium partagent parfois le même environnement. Entre 2004 et 2016, Cryptosporidium a été responsable de 60 % des 905 épidémies d'origine hydrique dans le monde causées par des parasites protozoaires. Le but de cette étude était d'évaluer les interactions entre les oocystes de C. parvum et deux espèces d'amibes libres communes (Acanthamoeba castellanii et Vermamoeba vermiformis) en environnement aquatique. L'enkystement et la survie des amibes libres ont été évalués par microscopie en utilisant une coloration vitale au bleu trypan. Les oocystes ont été comptés au microscope. Les interactions ont été étudiées au cours du temps dans des conditions à la fois défavorables et favorables à la phagocytose. La phagocytose potentielle a été évaluée directement par plusieurs approches microscopiques et indirectement par la numération des micro-organismes et l'évaluation de l'infectiosité des oocystes. Une phagocytose occasionnelle de C. parvum par amibes libre a été documentée. Cependant, les concentrations d'oocystes n'ont pas diminué de manière significative, ce qui suggère une résistance des oocystes à la phagocytose. Une diminution temporaire de l'infectivité des oocystes a été observée en présence d'A. castellanii. L'effet de ces interactions sur l'infectiosité de C. parvum est particulièrement intéressant. La condition biofilm pourrait favoriser la persistance ou même la prolifération des oocystes de C. parvum au fil du temps. Cette étude a démontré des interactions entre C. parvum et amibes libres. Une meilleure connaissance des mécanismes impliqués dans la diminution de l'infectiosité des oocystes en présence d'A. castellanii pourrait faciliter le développement de nouvelles approches thérapeutiques.
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Amoeba , Criptosporidiosis , Cryptosporidium parvum , Cryptosporidium , Animales , Brotes de Enfermedades , OocistosRESUMEN
During the COVID-19 outbreak in 2020, public health measures (PHM) were implemented to prevent the spread of SARS-CoV-2. At university, we wondered whether health students would be more likely to comply with these safety measures against infectious disease transmission compared to other students. Thus, we collected 1 426 university students' responses to an online anonymous survey to describe their knowledge, attitudes and practices (KAP) of COVID-19 prevention measures and to compare the opinions and practices of health students and science students at the same university of Rouen Normandy (France). A higher proportion of science students (84.6%) compared to health students (73.9%) reported knowledge of the university's COVID-19 protocol, p<0.001. However, the health students compared to science students reported a higher compliance with PHM at home (91.4% vs 88.0%) and at university (94.1% vs 91.1%). In a multiple regression analysis, after adjustment for age, sex and university department, factors associated with higher compliance with PHM were knowledge of the university's COVID-19 protocol and a high perceived efficacy of PHM. A SARS-CoV-2 PCR result was not predictive of compliance with PHM. The results of this online survey in French students show a high level of knowledge and practices of COVID-19 prevention Although their performances could still be improved by training, the good results of health students regarding knowledge, attitudes and practices are encouraging as these students could be an added backup force to fight against viral pandemics.