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1.
J Infect Dis ; 225(4): 686-695, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-34417806

RESUMEN

BACKGROUND: Cryptosporidiosis is a parasitic disease associated with potentially fatal diarrhea. The most used method in Cryptosporidium subtyping is based on the glycoprotein gene gp60. Each infection can represent a parasite population, and it is important to investigate the influence on transmission and virulence, as well as any impact on public health investigations. However, an easy-to-use method for detection is lacking. METHODS: Here we report on the use of the bioinformatic program TIDE for deconvolution of gp60 chromatograms. A combination of single oocyst analysis and cloning successfully confirmed the within-sample parasite population diversity. Retrospective sample analysis was conducted on archived chromatograms. RESULTS: For Cryptosporidium parvum, 8.6% multistrain infections (13 of 152) obscured by currently used consensus base calling were detected. Importantly, we show that single oocysts can harbor a mixed population of sporozoites. We also identified a striking dominance of unappreciated polymerase stutter artefacts in all 218 chromatograms analyzed, challenging the uncritical use of gp60 typing. CONCLUSIONS: We demonstrate the value of a new, easy-to-use analytical procedure for critical characterization of C. parvum and Cryptosporidium hominis in epidemiological investigations, also applicable retrospectively. Our findings illuminate the hidden parasite diversity with important implications for tracing zoonotic and person-to-person transmissions.


Asunto(s)
Coinfección , Criptosporidiosis , Cryptosporidium parvum , Cryptosporidium , Animales , Criptosporidiosis/parasitología , Cryptosporidium/genética , Cryptosporidium parvum/genética , ADN Protozoario/genética , Heces/parasitología , Genotipo , Humanos , Oocistos , Estudios Retrospectivos
2.
Parasitol Res ; 121(5): 1295-1304, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35230547

RESUMEN

Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94-1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23-0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097-0.309) in Chilean hakes, 15% (CI: 0.07-0.26) in snoeks, and 1.7% (CI: 0-0.089) in sea breams. Meanwhile, prevalence of anisakid larvae in internal organs showed highest values for peritoneum (100% and 83.3%) for snoeks and Chilean hakes, respectively, for liver (96.7%) and gonads (86.6%) in Chilean hakes, and for intestine (98.3%) in snoeks. Molecular analysis of collected anisakid L3 unveiled presence of two potentially zoonotic nematode species, i.e., Pseudoterranova cattani and Anisakis pegreffii. P. cattani was found in Chilean hakes and snoeks being the first molecular host species report for Chilean snoeks. Besides, A. pegreffii was also identified in these species being the first molecular report on this regard. These findings are relevant for better understanding of epidemiology of anisakiasis in Chilean coasts and for public health issues considering potential risk of human population due to its culinary preferences in eating raw fish.


Asunto(s)
Anisakiasis , Anisakis , Ascaridoidea , Enfermedades de los Peces , Gadiformes , Perciformes , Animales , Anisakiasis/epidemiología , Anisakiasis/veterinaria , Anisakis/genética , Ascaridoidea/genética , Chile/epidemiología , Enfermedades de los Peces/epidemiología , Peces , Humanos , Larva/genética , Prevalencia
3.
Int J Mol Sci ; 23(19)2022 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-36232449

RESUMEN

Molecular diagnostic approaches are increasingly included in the diagnostic workup and even in the primary diagnosis of malaria in non-endemic settings, where it is difficult to maintain skillful microscopic malaria detection due to the rarity of the disease. Pathogen-specific nucleic acid amplification, however, bears the risk of overlooking other pathogens associated with febrile illness in returnees from the tropics. Here, we assessed the discriminatory potential of metagenomic sequencing for the identification of different Plasmodium species with various parasitemia in EDTA blood of malaria patients. Overall, the proportion of Plasmodium spp.-specific sequence reads in the assessed samples showed a robust positive correlation with parasitemia (Spearman r = 0.7307, p = 0.0001) and a robust negative correlation with cycle threshold (Ct) values of genus-specific real-time PCR (Spearman r = -0.8626, p ≤ 0.0001). Depending on the applied bioinformatic algorithm, discrimination on species level was successful in 50% (11/22) to 63.6% (14/22) instances. Limiting factors for the discrimination on species level were very low parasitemia, species-depending lacking availability of reliable reference genomes, and mixed infections with high variance of the proportion of the infecting species. In summary, metagenomic sequencing as performed in this study is suitable for the detection of malaria in human blood samples, but the diagnostic detection limit for a reliable discrimination on species level remains higher than for competing diagnostic approaches like microscopy and PCR.


Asunto(s)
Malaria , Ácidos Nucleicos , Plasmodium , Ácido Edético , Humanos , Malaria/diagnóstico , Parasitemia/diagnóstico , Plasmodium/genética , Plasmodium falciparum/genética , Plasmodium vivax/genética , Reacción en Cadena en Tiempo Real de la Polimerasa
4.
Exp Appl Acarol ; 84(2): 459-471, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33909190

RESUMEN

Ticks will diminish productivity among farm animals and transmit zoonotic diseases. We conducted a study to identify tick species infesting slaughter bulls from Adama City and to screen them for tick-borne pathogens. In 2016, 291 ticks were collected from 37 bulls in Adama, which were ready for slaughter. Ticks were identified morphologically. Total genomic DNA was extracted from ticks and used to test for Rickettsia spp. with real-time PCR. Species identification was done by phylogenetic analysis using sequencing that targeted the 23S-5S intergenic spacer region and ompA genes. Four tick species from two genera, Amblyomma and Rhipicephalus, were identified. Amblyomma cohaerens was the dominant species (n = 241, 82.8%), followed by Amblyomma variegatum (n = 22, 7.5%), Rhipicephalus pulchellus (n = 19, 6.5%), and Rhipicephalus decoloratus (n = 9, 3.0%). Among all ticks, 32 (11%) were positive for Rickettsia spp. and 15 (5.2%) of these were identified as R. africae comprising at least two genetic clades, occurring in A. variegatum (n = 10) and A. cohaerens (n = 5). The remainder of Rickettsia-positive samples could not be amplified due to low DNA yield. Furthermore, another 15 (5.2%) samples carried other pathogenic bacteria: Ehrlichia ruminantium (n = 9; 3.1%) in A. cohaerens, Ehrlichia sp. (n = 3; 1%) in Rh. pulchellus and A. cohaerens, Anaplasma sp. (n = 1; 0.5%) in A. cohaerens, and Neoehrlichia mikurensis (n = 2; 0.7%) in A. cohaerens. All ticks were negative for Bartonella spp., Babesia spp., Theileria spp., and Hepatozoon spp. We reported for the first time E. ruminatium, N. mikurensis, Ehrlichia sp., and Anaplasma sp. in A. cohaerens. Medically and veterinarily important pathogens were mostly detected from A. variegatum and A. cohaerens. These data are relevant for a One-health approach for monitoring and prevention of tick-borne disease transmission.


Asunto(s)
Enfermedades de los Bovinos , Ixodidae , Rickettsia , Infestaciones por Garrapatas , Enfermedades por Picaduras de Garrapatas , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Etiopía/epidemiología , Masculino , Filogenia , Rickettsia/genética , Infestaciones por Garrapatas/epidemiología , Infestaciones por Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/veterinaria
5.
Eur J Pediatr ; 179(6): 979-984, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32020333

RESUMEN

Blastocystis is a parasite with a worldwide distribution and a varying prevalence in different countries. The pleomorphic nature of the protozoon and the lack of understanding a possible pathogenesis have led to confusion regarding its clinical significance. The aim of the study was to shed light on clinical characteristics of pediatric patients in Swiss children with a positive stool sample for Blastocystis, in order to provide recommendations for a practical approach for the clinician to know whom, when, and how to test. This is a retrospective study of pediatric patients, whose stool has been tested positive for Blastocystis in the last 10 years in northern Switzerland. A total of 4047 stool samples, belonging to 1887 different patients, were analyzed; 240 stool samples (of 160 patients) were tested positive for Blastocystis. On average, 2.2 (CI 1.98-2.35) stool samples per patient were analyzed, of which 1.48 (CI 1.36-1.61) were positive for Blastocystis. In 63% abdominal pain was the leading symptom, while in 17.5% it was an accidental finding without symptoms. There was a high significance in correlation of abdominal pain and chronicity (p < 0.0001) but none in diarrhea (p = 0.082) nor nausea/vomiting or other symptoms and chronicity. Followed by Entamoeba coli (8%), 26.3% of the patients with Blastocystis had a co-infection with another parasite, mostly Endolimax nana (13%).Conclusion: Carriage of Blastocystis is common; therefore, only children/teenagers at risk for a symptomatic Blastocystis infection should be tested. There is a good correlation between Blastocystis and chronic abdominal pain. Children with abdominal symptoms persisting over 4 weeks should have two different stool samples analyzed. No screening after travels/immigration is recommended.What is Known:• Blastocystis has a worldwide distribution.• The clinical significance is unclear.What is New:• Based on retrospective data, we recommend to only test children/teenagers with chronic abdominal pain for Blastocystis.• Two different stool samples should be examined by microscopy; serological investigations are not warranted.


Asunto(s)
Infecciones por Blastocystis/diagnóstico , Infecciones por Blastocystis/epidemiología , Dolor Abdominal/parasitología , Adolescente , Blastocystis/aislamiento & purificación , Infecciones por Blastocystis/complicaciones , Infecciones por Blastocystis/terapia , Niño , Preescolar , Dolor Crónico/parasitología , Coinfección/epidemiología , Diarrea/parasitología , Heces/parasitología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Prevalencia , Estudios Retrospectivos , Suiza/epidemiología
6.
Parasitol Res ; 119(2): 385-394, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31901105

RESUMEN

Ticks are important parasites from economic and public health points of view because of their ability to reduce farm animals' productivity and transmit zoonotic diseases. We conducted this cross-sectional study between January and March 2016 and between March and April 2017 to identify tick species in West Darfur, Al-Jazeera, and the River Nile states in the Sudan and to investigate whether these ticks carry Rickettsia spp. and Crimean-Congo hemorrhagic fever (CCHF) virus. In total, 1593 ticks were collected from 207 animals and identified based on morphology or 16S rRNA gene and tested for Rickettsia spp. and CCHF virus either individually or as pools containing 2 to 10 pooled ticks using molecular methods. Overall, 14 tick species belonging to three genera, namely Amblyomma, Hyalomma, and Rhipicephalus, were identified. Hyalomma anatolicum and Rhipicephalus evertsi evertsi were the most frequent ticks. A total of 561 tests comprised of individual or pooled ticks were conducted and 13.7% (77/561) were positive for Rickettsia spp. which were mostly Rickettsia aeschlimannii and R. africae. The highest positivity was noticed among H. rufipes collected from cattle and camels in West Darfur. However, none of the screened Hyalomma ticks harbored CCHF viral RNA. These findings suggest that there might be a risk of zoonotic transmission of Rickettsia spp. by ticks but zoonotic transmission of CCHF virus is apparently doubtful. An in-depth and a country-wide epidemiological study is needed to better understand the dynamic of Rickettsia spp. and CCHF virus in the Sudan.


Asunto(s)
Virus de la Fiebre Hemorrágica de Crimea-Congo/aislamiento & purificación , Fiebre Hemorrágica de Crimea/transmisión , Ixodidae/microbiología , Infecciones por Rickettsia/transmisión , Rickettsia/aislamiento & purificación , Enfermedades por Picaduras de Garrapatas/microbiología , Animales , Camelus , Bovinos , Estudios Transversales , Virus de la Fiebre Hemorrágica de Crimea-Congo/genética , Parásitos/genética , ARN Ribosómico 16S/genética , Rickettsia/genética , Sudán , Zoonosis/transmisión
7.
Clin Infect Dis ; 69(Suppl 6): S449-S458, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31665776

RESUMEN

BACKGROUND: Antimicrobial resistance (AMR) is a major global health concern, yet, there are noticeable gaps in AMR surveillance data in regions such as sub-Saharan Africa. We aimed to measure the prevalence of extended-spectrum ß-lactamase (ESBL) producing Gram-negative bacteria in bloodstream infections from 12 sentinel sites in sub-Saharan Africa. METHODS: Data were generated during the Typhoid Fever Surveillance in Africa Program (TSAP), in which standardized blood cultures were performed on febrile patients attending 12 health facilities in 9 sub-Saharan African countries between 2010 and 2014. Pathogenic bloodstream isolates were identified at the sites and then subsequently confirmed at a central reference laboratory. Antimicrobial susceptibility testing, detection of ESBL production, and conventional multiplex polymerase chain reaction (PCR) testing for genes encoding for ß-lactamase were performed on all pathogens. RESULTS: Five hundred and five pathogenic Gram-negative bloodstream isolates were isolated during the study period and available for further characterization. This included 423 Enterobacteriaceae. Phenotypically, 61 (12.1%) isolates exhibited ESBL activity, and genotypically, 47 (9.3%) yielded a PCR amplicon for at least one of the screened ESBL genes. Among specific Gram-negative isolates, 40 (45.5%) of 88 Klebsiella spp., 7 (5.7%) of 122 Escherichia coli, 6 (16.2%) of 37 Acinetobacter spp., and 2 (1.3%) of 159 of nontyphoidal Salmonella (NTS) showed phenotypic ESBL activity. CONCLUSIONS: Our findings confirm the presence of ESBL production among pathogens causing bloodstream infections in sub-Saharan Africa. With few alternatives for managing ESBL-producing pathogens in the African setting, measures to control the development and proliferation of AMR organisms are urgently needed.


Asunto(s)
Bacterias Gramnegativas/patogenicidad , Infecciones por Bacterias Gramnegativas/sangre , Infecciones por Bacterias Gramnegativas/epidemiología , Adolescente , Adulto , África del Sur del Sahara/epidemiología , Antibacterianos/farmacología , Niño , Preescolar , Farmacorresistencia Bacteriana Múltiple/genética , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/enzimología , Humanos , Lactante , Recién Nacido , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Prevalencia , Vigilancia de Guardia , Adulto Joven , beta-Lactamasas
8.
BMC Microbiol ; 19(1): 75, 2019 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-30961537

RESUMEN

BACKGROUND: The potential of next-generation sequencing (NGS) for hypothesis-free pathogen diagnosis from (poly-)microbially contaminated, formalin-fixed, paraffin embedded tissue samples from patients with invasive fungal infections and amebiasis was investigated. Samples from patients with chromoblastomycosis (n = 3), coccidioidomycosis (n = 2), histoplasmosis (n = 4), histoplasmosis or cryptococcosis with poor histological discriminability (n = 1), mucormycosis (n = 2), mycetoma (n = 3), rhinosporidiosis (n = 2), and invasive Entamoeba histolytica infections (n = 6) were analyzed by NGS (each one Illumina v3 run per sample). To discriminate contamination from putative infections in NGS analysis, mean and standard deviation of the number of specific sequence fragments (paired reads) were determined and compared in all samples examined for the pathogens in question. RESULTS: For matches between NGS results and histological diagnoses, a percentage of species-specific reads greater than the 4th standard deviation above the mean value of all 23 assessed sample materials was required. Potentially etiologically relevant pathogens could be identified by NGS in 5 out of 17 samples of patients with invasive mycoses and in 1 out of 6 samples of patients with amebiasis. CONCLUSIONS: The use of NGS for hypothesis-free pathogen diagnosis from contamination-prone formalin-fixed, paraffin-embedded tissue requires further standardization.


Asunto(s)
Amebiasis/diagnóstico , Coinfección/microbiología , Secuenciación de Nucleótidos de Alto Rendimiento , Infecciones Fúngicas Invasoras/diagnóstico , Coinfección/diagnóstico , Entamoeba histolytica/genética , Entamoeba histolytica/patogenicidad , Formaldehído , Hongos/genética , Hongos/patogenicidad , Genómica , Humanos , Infecciones Fúngicas Invasoras/microbiología , Adhesión en Parafina , Prueba de Estudio Conceptual , Análisis de Secuencia de ADN , Fijación del Tejido
9.
Artículo en Inglés | MEDLINE | ID: mdl-29358295

RESUMEN

Scrub typhus is a potentially lethal infection caused by the obligate intracellular bacterium Orientia tsutsugamushi Reports on the emergence of doxycycline-resistant strains highlight the urgent need to develop novel antiinfectives against scrub typhus. Corallopyronin A (CorA) is a novel α-pyrone compound synthesized by the myxobacterium Corallococcus coralloides that was characterized as a noncompetitive inhibitor of the switch region of the bacterial RNA polymerase (RNAP). We investigated the antimicrobial action of CorA against the human-pathogenic Karp strain of O. tsutsugamushiin vitro and in vivo The MIC of CorA against O. tsutsugamushi was remarkably low (0.0078 µg/ml), 16-fold lower than that against Rickettsia typhi In the lethal intraperitoneal O. tsutsugamushi mouse infection model, a minimum daily dose of 100 µg CorA protected 100% of infected mice. Two days of treatment were sufficient to confer protection. In contrast to BALB/c mice, SCID mice succumbed to the infection despite treatment with CorA or tetracycline, suggesting that antimicrobial treatment required synergistic action of the adaptive immune response. Similar to tetracycline, CorA did not prevent latent infection of O. tsutsugamushiin vivo However, latency was not caused by acquisition of antimicrobial resistance, since O. tsutsugamushi reisolated from latently infected BALB/c mice remained fully susceptible to CorA. No mutations were found in the CorA-binding regions of the ß and ß' RNAP subunit genes rpoB and rpoC Inhibition of the RNAP switch region of O. tsutsugamushi by CorA is therefore a novel and highly potent target for antimicrobial therapy for scrub typhus.


Asunto(s)
Antibacterianos/uso terapéutico , ARN Polimerasas Dirigidas por ADN/antagonistas & inhibidores , Lactonas/uso terapéutico , Orientia tsutsugamushi/patogenicidad , Tifus por Ácaros/tratamiento farmacológico , Animales , Femenino , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Myxococcales/efectos de los fármacos , Myxococcales/patogenicidad , Orientia tsutsugamushi/efectos de los fármacos , Rickettsia typhi/efectos de los fármacos , Rickettsia typhi/patogenicidad , Tifus por Ácaros/microbiología
10.
BMC Infect Dis ; 18(1): 47, 2018 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-29351771

RESUMEN

BACKGROUND: Non-typhoidal Salmonella (NTS) cause the majority of bloodstream infections in Ghana, however the mode of transmission and source of invasive NTS in Africa are poorly understood. This study compares NTS from water sources and invasive bloodstream infections in rural Ghana. METHODS: Blood from hospitalised, febrile children and samples from drinking water sources were analysed for Salmonella spp. Strains were serotyped to trace possible epidemiological links between human and water-derived isolates.. Antibiotic susceptibility testing was performed, RESULTS: In 2720 blood culture samples, 165 (6%) NTS were isolated. S. Typhimurium (70%) was the most common serovar followed by S. Enteritidis (8%) and S. Dublin (8%). Multidrug resistance (MDR) was found in 95 (58%) NTS isolates, including five S. Enteritidis. One S. Typhimurium showed reduced fluroquinolone susceptibility. In 511 water samples, 19 (4%) tested positive for S. enterica with two isolates being resistant to ampicillin and one isolate being resistant to cotrimoxazole. Serovars from water samples were not encountered in any of the clinical specimens. CONCLUSION: Water analyses demonstrated that common drinking water sources were contaminated with S. enterica posing a potential risk for transmission. However, a link between S. enterica from water sources and patients could not be established, questioning the ability of water-derived serovars to cause invasive bloodstream infections.


Asunto(s)
Agua Potable/microbiología , Infecciones por Salmonella/microbiología , Salmonella enterica/efectos de los fármacos , Salmonella enterica/aislamiento & purificación , Ampicilina/farmacología , Antibacterianos/farmacología , Bacteriemia/microbiología , Niño , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Ghana , Humanos , Pruebas de Sensibilidad Microbiana , Salud Rural , Población Rural , Combinación Trimetoprim y Sulfametoxazol/farmacología , Microbiología del Agua
11.
Emerg Infect Dis ; 23(8): 1428-1431, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28726623

RESUMEN

We report a human case of ocular Dirofilaria infection in a traveler returning to Austria from India. Analysis of mitochondrial sequences identified the worm as Candidatus Dirofilaria hongkongensis, a close relative of Dirofilaria repens, which was only recently described in Hong Kong and proposed as a new species.


Asunto(s)
Dirofilaria , Dirofilariasis/epidemiología , Dirofilariasis/parasitología , Infecciones del Ojo/epidemiología , Infecciones del Ojo/parasitología , Enfermedad Relacionada con los Viajes , Adulto , Animales , Austria , Dirofilaria/clasificación , Dirofilaria/genética , Dirofilaria/aislamiento & purificación , Dirofilariasis/diagnóstico , Infecciones del Ojo/diagnóstico , Femenino , Genes Bacterianos , Humanos , India , Filogenia
12.
Emerg Infect Dis ; 23(2): 343-344, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28098549

RESUMEN

Diffuse unilateral subacute neuroretinitis is an ocular infectious disease caused by several distinct nematodes. Definite identification of the involved nematodes is rarely achieved. We report on the molecular-based genetic identification of an Ancylostoma ceylanicum hookworm implicated in a case of diffuse unilateral subacute neuroretinitis in a child.


Asunto(s)
Ancylostoma , Anquilostomiasis/diagnóstico , Anquilostomiasis/parasitología , Retinitis/diagnóstico , Retinitis/parasitología , Ancylostoma/genética , Ancylostoma/inmunología , Anquilostomiasis/inmunología , Animales , Anticuerpos Antihelmínticos/inmunología , Niño , ADN de Helmintos , Ensayo de Inmunoadsorción Enzimática , Genes de Helminto , Humanos , Masculino , Oftalmoscopios , Reacción en Cadena de la Polimerasa , Retinitis/inmunología
13.
Crit Rev Microbiol ; 43(3): 263-293, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28129707

RESUMEN

Early identification of microbial pathogens is essential for rational and conservative antibiotic use especially in the case of known regional resistance patterns. Here, we describe fluorescence in situ hybridization (FISH) as one of the rapid methods for easy identification of microbial pathogens, and its advantages and disadvantages for the diagnosis of pathogens in human infections in the laboratory diagnostic routine. Binding of short fluorescence-labeled DNA or nucleic acid-mimicking PNA probes to ribosomes of infectious agents with consecutive analysis by fluorescence microscopy allows identification of bacterial and eukaryotic pathogens at genus or species level. FISH analysis leads to immediate differentiation of infectious agents without delay due to the need for microbial culture. As a microscopic technique, FISH has the unique potential to provide information about spatial resolution, morphology and identification of key pathogens in mixed species samples. On-going automation and commercialization of the FISH procedure has led to significant shortening of the time-to-result and increased test reliability. FISH is a useful tool for the rapid initial identification of microbial pathogens, even from primary materials. Among the rapidly developing alternative techniques, FISH serves as a bridging technology between microscopy, microbial culture, biochemical identification and molecular diagnostic procedures.


Asunto(s)
Bacterias/genética , Infecciones Bacterianas/microbiología , Hibridación Fluorescente in Situ/métodos , Técnicas Microbiológicas/métodos , Bacterias/patogenicidad , Biopelículas , Colorantes Fluorescentes , Humanos , Enfermedades de la Boca/microbiología , Mycobacterium/genética , Mycobacterium/patogenicidad , Permeabilidad , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/microbiología , Fijación del Tejido , Virosis/virología , Infección de Heridas/microbiología
14.
J Clin Microbiol ; 54(1): 172-4, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26491175

RESUMEN

Rarely, zoonotic Taenia species other than Taenia solium cause human cysticercosis. The larval stages are morphologically often indistinguishable. We therefore investigated 12 samples of suspected human cysticercosis cases at the molecular level and surprisingly identified one Taenia crassiceps and one Taenia serialis (coenurosis) infection, which were caused by tapeworm larvae normally infecting rodents and sheep via eggs released from foxes and dogs.


Asunto(s)
Cisticercosis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Parasitología/métodos , Taenia/aislamiento & purificación , Zoonosis/diagnóstico , Adolescente , Adulto , Animales , Cisticercosis/parasitología , Femenino , Humanos , Larva , Masculino , Persona de Mediana Edad , Taenia/clasificación , Adulto Joven , Zoonosis/parasitología
15.
BMC Infect Dis ; 16(1): 420, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27526771

RESUMEN

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) clones pose a significant threat to hospitalised patients because the bacteria can be transmitted by asymptomatic carriers within healthcare facilities. To date, nothing is known about the prevalence of S. aureus and MRSA among healthcare workers in Madagascar. The objective of our study was to examine the prevalence and clonal epidemiology of nasal S. aureus and MRSA among healthcare workers and non-medical University students in Antananarivo, Madagascar. METHODS: This cross sectional study screened nasal swabs taken from students and healthcare workers for S. aureus. Multiplex PCR was performed to identify S. aureus-specific (nuc), MRSA-specific mecA and mecC genes, Panton-Valentine leukocidin (PVL) (lukF-PV), and toxic shock syndrome toxin-1 (TSST-1) specific genes in methicillin-sensitive S. aureus (MSSA) and MRSA isolates. Staphylococcus protein A gene (spa) typing was performed for all confirmed MRSA isolates. The frequency distribution of nasal S. aureus and MRSA of healthcare workers and non-medical students was compared using Pearson's χ(2) test. RESULTS: Of 1548 nasal swabs tested, 171 (11 %) were positive for S. aureus; 20 (1.3 %) of these isolates were identified as MRSA. S. aureus was detected in 91 of 863 healthcare workers (10.4 %) and in 80 (11.8 %) of 685 students; however, 14 (1.5 %) healthcare workers carried MRSA compared with six (0.9 %) students. Nasal carriage of S. aureus and MRSA was more prevalent in women than in men, and 21 (11.7 %) S. aureus isolates were PVL-positive and 36 (21 %) were TSST-1 positive. The mecC gene was not detected in any isolates. Five different spa types were identified, with spa type t186 being the predominant MRSA clone (16/20). CONCLUSION: The results of the present study reveal a low frequency of S. aureus and MRSA nasal carriage in both students and healthcare workers from Antananarivo, Madagascar. The predominant MRSA clone (t186) was previously described in hospitalised patients in Madagascar.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina/genética , Infecciones Estafilocócicas/diagnóstico , Staphylococcus aureus/genética , Adulto , Toxinas Bacterianas/genética , Estudios Transversales , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/metabolismo , Enterotoxinas/genética , Exotoxinas/genética , Femenino , Personal de Salud , Humanos , Leucocidinas/genética , Madagascar/epidemiología , Masculino , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Reacción en Cadena de la Polimerasa Multiplex , Cavidad Nasal/microbiología , Prevalencia , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificación , Estudiantes , Superantígenos/genética
16.
Malar J ; 14: 188, 2015 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-25935753

RESUMEN

BACKGROUND: Malaria epidemiology in Madagascar is classified into four different areas, ranging from unstable seasonal transmission in the highlands to hyperendemic perennial transmission areas in the costal level. Most malaria studies in Madagascar are focused on symptomatic children. However, because of the low transmission in some areas with correspondingly low level of semi-immunity, adults are also at risk, in particular pregnant women. The objective of this study was to gain information on the genetic epidemiology of malarial infections in pregnant women in order to provide information for malaria control and elimination programmes in Madagascar. METHODS: Between May and August 2010, we carried out cross-sectional surveys targeting healthy pregnant women in six locations, three in the coastal area and three in the highlands at 850-1300 m. 1244 blood samples were screened for anti-Plasmodium falciparum antibodies by immunofluorescence test and for malarial infection by realtime-PCR. The prevalence of chloroquine and sulphadoxine-pyrimethamine resistance markers was also determined in all Plasmodium falciparum samples by PCR-RFLP as well as the multiplicity of infection through genotyping six neutral microsatellites. RESULTS: In the highlands, 67.4% of the women presented antibodies against Plasmodium falciparum and 9.2% were carrying parasites, at the coast 95.6% and 14.8%, respectively. In the mean, 1.2 clones were detected in infected pregnant woman in the highlands and 1.5 at the coast. A higher level of monoclonal infections was found in the highlands (85.4%) compared to the coast (61.8%). Resistance markers for sulphadoxine-pyrimethamine were present only in two sites. CONCLUSION: Immunity is triggered in Malagasy highland populations when they are infected with malaria parasites, but these populations could also serve as a reservoir for epidemics.


Asunto(s)
Antimaláricos/farmacología , Infecciones Asintomáticas/epidemiología , Resistencia a Medicamentos , Malaria/epidemiología , Malaria/parasitología , Plasmodium/efectos de los fármacos , Plasmodium/genética , Adolescente , Adulto , Anticuerpos Antiprotozoarios , Cloroquina/farmacología , Combinación de Medicamentos , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Madagascar/epidemiología , Persona de Mediana Edad , Epidemiología Molecular , Embarazo , Prevalencia , Proteínas Protozoarias/genética , Pirimetamina/farmacología , Reacción en Cadena en Tiempo Real de la Polimerasa , Estudios Seroepidemiológicos , Sulfadoxina/farmacología , Adulto Joven
17.
Med Mycol ; 53(2): 160-4, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25537280

RESUMEN

Fluorescence in situ hybridization (FISH) has been shown to be useful for the detection of Candida and Cryptococcus species in blood culture materials. FISH procedures for the detection of Histoplasma capsulatum var. capsulatum have not been reported so far. This study describes the development and evaluation of fluorescently labeled rRNA-targeting FISH probes to detect and identify H. capsulatum in blood cultures. All three analyzed H. capsulatum reference strains and clinical isolates showed positive signals with the newly designed specific oligonucleotide probes for H. capsulatum, whereas negative reactions were observed for all three nontarget yeast species and the two nontarget bacteria. The assay was also successfully applied for detections of H. capsulatum cells in pre-incubated blood culture samples of patients with clinical suspicion of histoplasmosis (n = 33). The described FISH-based assay was shown to be easy to apply, sensitive, and specific (compared to polymerase chain reaction) for the detection and identification of H. capsulatum in this proof-of-principle analysis. Larger multicentric assessments are recommended for a thorough diagnostic evaluation of the procedure.


Asunto(s)
Sangre/microbiología , Histoplasma/aislamiento & purificación , Histoplasmosis/diagnóstico , Hibridación Fluorescente in Situ/métodos , Técnicas de Diagnóstico Molecular/métodos , Histoplasma/genética , Histoplasmosis/microbiología , Humanos , Sondas de Oligonucleótidos/genética , ARN de Hongos/genética , ARN Ribosómico/genética , Sensibilidad y Especificidad , Factores de Tiempo
18.
BMC Infect Dis ; 15: 88, 2015 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-25879490

RESUMEN

BACKGROUND: During weeks 32-33, 2013, 24 cases of cryptosporidiosis were notified in the city of Halle (annual mean 2008-2012: 9 cases). We investigated the outbreak to identify the source and recommend control measures, considering that between weeks 23-25 the river Saale which flows through the city centre overflowed the floodplain, parts of the city centre and damaged sewage systems. METHODS: We defined a case as a resident of Halle with gastroenteritis, Cryptosporidium-positive stool and disease onset weeks 27 through 47. In a case-control study among kindergarten children, we compared cases and controls regarding environmental exposure, use of swimming pools, zoo visits and tap water consumption 14 days pre-onset or a corresponding 14-days-period (controls) and adjusted for residence. Stool specimens were tested by microscopy and PCR, and Cryptosporidium DNA was sequenced. Samples from public water system, swimming pools and river Saale were examined for Cryptosporidium oocysts (microscopy and PCR). RESULTS: Overall, 167 cases were detected, 40/167 (24%) were classified as secondary cases. First disease onsets occurred during week 29, numbers peaked in week 34 and started to decrease in week 36. Median age was 8 years (range: 0-77). Compared to controls (n = 61), cases (n = 20) were more likely to report visits to previously flooded areas (OR: 4.9; 95%-CI: 1.4-18) and the zoo (OR: 2.6; 95%-CI: 0.9-7.6). In multivariable analysis visits to the floodplain remained the sole risk factor (OR: 5.5; 95%-CI: 1.4-22). Only C.hominis of a single genotype (IbA9G2) was detected in stools. Oocysts were detected in samples from the river, two local lakes and three public swimming pools by microscopy, but not in the public water supply. CONCLUSIONS: Evidence suggests that activities in the dried out floodplain led to infection among children. Secondary transmissions may be involved. Consequently, authorities recommended to avoid playing, swimming and having picnics in the flood-affected area. Health authorities should consider the potential health risks of long-term surviving parasites persisting on flooded grounds and in open waters even several weeks after the flooding and of bathing places close to sewage spill-overs. Preventive measures comprise water sampling (involving parasites), information of the public and prolonged closures of potentially contaminated sites.


Asunto(s)
Criptosporidiosis/epidemiología , Inundaciones , Ríos , Adolescente , Adulto , Anciano , Animales , Estudios de Casos y Controles , Niño , Preescolar , Criptosporidiosis/parasitología , Cryptosporidium/aislamiento & purificación , Brotes de Enfermedades , Femenino , Inundaciones/estadística & datos numéricos , Gastroenteritis/epidemiología , Gastroenteritis/parasitología , Alemania/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Ríos/parasitología , Piscinas , Abastecimiento de Agua , Adulto Joven
19.
Ann Clin Microbiol Antimicrob ; 14: 6, 2015 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-25637361

RESUMEN

The aim of this study was to evaluate the diagnostic performance of in-house FISH (fluorescence in situ hybridisation) procedures for the direct identification of invasive fungal infections in blood cultures and cerebrospinal fluid (CSF) samples and to compare these FISH results with those obtained using traditional microbiological techniques and PCR targeting of the ITS1 region of the rRNA gene. In total, 112 CSF samples and 30 positive blood cultures were investigated by microscopic examination, culture, PCR-RFLP and FISH. The sensitivity of FISH for fungal infections in CSF proved to be slightly better than that of conventional microscopy (India ink) under the experimental conditions, detecting 48 (instead of 46) infections in 112 samples. The discriminatory powers of traditional microbiology, PCR-RFLP and FISH for fungal bloodstream infections were equivalent, with the detection of 14 fungal infections in 30 samples. However, the mean times to diagnosis after the detection of microbial growth by automated blood culture systems were 5 hours, 20 hours and 6 days for FISH, PCR-RFLP and traditional microbiology, respectively. The results demonstrate that FISH is a valuable tool for the identification of invasive mycoses that can be implemented in the diagnostic routine of hospital laboratories.


Asunto(s)
Sangre/microbiología , Hongos/aislamiento & purificación , Hibridación Fluorescente in Situ/métodos , Micosis/microbiología , Adulto , ADN de Hongos/genética , Femenino , Hongos/clasificación , Hongos/genética , Humanos , Masculino , Micosis/diagnóstico , Reacción en Cadena de la Polimerasa
20.
Trop Med Int Health ; 19(4): 427-30, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24720755

RESUMEN

We describe a proof-of-principle evaluation of a fluorescence in situ hybridisation (FISH) procedure to identify Chlamydia trachomatis serovars L1-L3, the causative agents of lymphogranuloma venereum, in cell cultures based on newly designed DNA probes. Rapid and easy-to-perform FISH could facilitate the diagnosis of lymphogranuloma venereum without nucleic acid amplification or serotyping, but requires broader evaluation studies, for example, in tropical high-endemicity regions.


Asunto(s)
Infecciones por Chlamydia/diagnóstico , Chlamydia trachomatis/aislamiento & purificación , Hibridación Fluorescente in Situ/métodos , Linfogranuloma Venéreo/microbiología , Técnicas de Amplificación de Ácido Nucleico/métodos , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/genética , Humanos , Linfogranuloma Venéreo/diagnóstico , Serotipificación/métodos
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