RESUMEN
Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by internal transcribed spacer sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silvicola (n = 1) and Moesziomyces aphidis (n = 1), respectively. The six H. capsulatum sensu lato isolates were further characterised by multilocus sequence analysis. Four distinct gene loci (arf [462 bases], H-anti [410 bases], ole1 [338 bases] and tub1 [272 bases]) of these six isolates as well as those of two H. capsulatum sensu lato ('var. farciminosum') reference strains (ATCC 58332 and ATCC 28798) were polymerase chain reaction (PCR)-amplified and sequenced. Phylogenetic analyses of their concatenated nucleotide sequences showed that three of the isolates and the reference strain ATCC 58332 were identical and belonged to the Eurasia clade within Latin American (LAm) A (H. suramericanum), and those of the other three isolates and the reference strain ATCC 28798 were identical and belonged to the Africa clade. At least two distinct phylogenetic clades of H. capsulatum sensu lato were circulating in Ethiopian horses with EL. Advanced molecular technologies and bioinformatics tools are crucial for the accurate identification and typing of pathogens as well as the discovery of novel microorganisms in veterinary microbiology.
Using multilocus sequence analysis with four concatenated housekeeping gene loci, at least two distinct phylogenetic clades, namely Eurasia clade and Africa clade, of Histoplasma capsulatum sensu lato were confirmed to be circulating in Ethiopian horses with epizootic lymphangitis.
Asunto(s)
ADN de Hongos , Histoplasma , Histoplasmosis , Enfermedades de los Caballos , Tipificación de Secuencias Multilocus , Filogenia , Animales , Histoplasma/genética , Histoplasma/clasificación , Histoplasma/aislamiento & purificación , Etiopía , Histoplasmosis/microbiología , Histoplasmosis/veterinaria , Caballos/microbiología , Enfermedades de los Caballos/microbiología , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Análisis de Secuencia de ADN , Técnicas de Tipificación MicológicaRESUMEN
Electrochemical nitrate reduction (NO3RR) provides a new option to abate nitrate contamination with a low carbon footprint. Restricted by competitive hydrogen evolution, achieving satisfied nitrate reduction performance in neutral media is still a challenge, especially for the regulation of this multielectron multiproton reaction. Herein, facile element doping is adopted to tune the catalytic behavior of IrNi alloy nanobranches with an unconventional hexagonal close-packed (hcp) phase toward NO3RR. In particular, the obtained hcp IrNiCu nanobranches favor the ammonia production and suppress byproduct formation in a neutral electrolyte indicated by in situ differential electrochemical mass spectrometry, with a high Faradaic efficiency (FE) of 85.6% and a large yield rate of 1253 µg cm-2 h-1 at -0.4 and -0.6 V (vs reversible hydrogen electrode (RHE)), respectively. In contrast, the resultant hcp IrNiCo nanobranches promote the formation of nitrite, with a peak FE of 33.1% at -0.1 V (vs RHE). Furthermore, a hybrid electrolysis cell consisting of NO3RR and formaldehyde oxidation is constructed, which are both catalyzed by hcp IrNiCu nanobranches. This electrolyzer exhibits lower overpotential and holds the potential to treat polluted air and wastewater simultaneously, shedding light on green chemical production based on contaminate degradation.
Asunto(s)
Nitratos , Oxidación-Reducción , Nitratos/química , Técnicas Electroquímicas , Catálisis , Metales/químicaRESUMEN
OBJECTIVES: To describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number of P. jirovecii sequence reads for the diagnosis of P. jirovecii pneumonia. METHODS: We examined the NGS results for P. jirovecii in respiratory samples collected from patients and analysed their clinical, radiological and microbiological characteristics. RESULTS: Among 285 respiratory samples collected over a 12-month period (January to December 2022), P. jirovecii sequences were detected in 56 samples from 53 patients. Fifty (94.3%) of the 53 patients were HIV-negative. Following our case definitions, 37 (69.8%) and 16 (30.2%) of the 53 patients had P. jirovecii infection and colonization respectively. P. jirovecii infection was associated with presence of underlying disease with immunosuppression (94.6% vs 18.8%, P < 0.05), positive serum 1,3-ß-D-glucan (41.2% vs 0%, P < 0.01) and higher number of P. jirovecii sequence reads (P < 0.005). In contrast, P. jirovecii colonization was associated with the male sex (93.8% vs 54.1%, P < 0.01), another definitive infectious disease diagnosis of the respiratory tract (43.8% vs 2.7%, P < 0.001) and higher survival (100% vs 67.6%, P < 0.01). Although P. jirovecii pneumonia was associated with higher number of P. jirovecii reads in respiratory samples, only a sensitivity of 82.14% and a specificity of 68.75% could be achieved. CONCLUSION: Detection of P. jirovecii sequences in respiratory samples has to be interpreted discreetly. A combination of clinical, radiological and laboratory findings is still the most crucial in determining whether a particular case is genuine P. jirovecii pneumonia.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Pneumocystis carinii , Neumonía por Pneumocystis , Humanos , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/microbiología , Masculino , Pneumocystis carinii/genética , Pneumocystis carinii/aislamiento & purificación , Femenino , Persona de Mediana Edad , Anciano , Adulto , Anciano de 80 o más Años , Sistema Respiratorio/microbiología , Adulto Joven , Técnicas de Diagnóstico Molecular/métodosRESUMEN
BACKGROUND: The number of patients infected with Aspergillus rose dramatically in recent years. However, studies on the clinical spectrum and antifungal susceptibilities of non-classical (non-fumigatus, non-flavus, non-niger and non-terreus) pathogenic Aspergillus species are very limited. OBJECTIVES: We examined the clinical spectrum and antifungal susceptibilities of 34 non-duplicated, non-classical Aspergillus isolates collected from Hong Kong, Shenzhen and Shanghai. METHODS: The Aspergillus isolates were identified by internal transcribed spacer, partial BenA and partial CaM sequencing and phylogenetic analyses. Susceptibility testing against eight antifungals was performed following the European Committee for Antimicrobial Susceptibility Testing's methodology. RESULTS: The 34 Aspergillus isolates were identified as 14 different rare/cryptic species of four sections (Flavi [n = 8], Nidulantes [n = 8], Nigri [n = 17] and Restricti [n = 1]). Except for one patient whose clinical history could not be retrieved, 72.7% of the remaining patients had underlying conditions predisposing them to Aspergillus infections. The most common diseases were pulmonary infections (n = 15), followed by skin/nail infections (n = 6), chronic otitis externa and/or media (n = 5), wound infections (n = 2) and mastoiditis/radionecrosis (n = 1), while three were colonisations. Five patients succumbed due to the infections during the admission, and another two died 5 years later because of chronic pulmonary aspergillosis. Antifungal susceptibility testing showed that they possessed different susceptibility profiles compared to the classical Aspergillus species. The majority of isolates characterised were sensitive or wild-type to amphotericin B. The minimum effective concentrations for all the three echinocandins were also low. CONCLUSION: Susceptibility testing should be performed for infections due to these rare/cryptic Aspergillus species to guide proper patient management.
Asunto(s)
Antifúngicos/farmacología , Aspergillus/clasificación , Aspergillus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/uso terapéutico , Aspergilosis/complicaciones , Aspergilosis/tratamiento farmacológico , Preescolar , China , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Análisis de Secuencia de ADNRESUMEN
To control the COVID-19 pandemic and prevent its resurgence in areas preparing for a return of economic activities, a method for a rapid, simple, and inexpensive point-of-care diagnosis and mass screening is urgently needed. We developed and evaluated a one-step colorimetric reverse-transcriptional loop-mediated isothermal amplification assay (COVID-19-LAMP) for detection of SARS-CoV-2, using SARS-CoV-2 isolate and respiratory samples from patients with COVID-19 (n = 223) and other respiratory virus infections (n = 143). The assay involves simple equipment and techniques and low cost, without the need for expensive qPCR machines, and the result, indicated by color change, is easily interpreted by naked eyes. COVID-19-LAMP can detect SARS-CoV-2 RNA with detection limit of 42 copies/reaction. Of 223 respiratory samples positive for SARS-CoV-2 by qRT-PCR, 212 and 219 were positive by COVID-19-LAMP at 60 and 90 min (sensitivities of 95.07% and 98.21%) respectively, with the highest sensitivities among nasopharyngeal swabs (96.88% and 98.96%), compared to sputum/deep throat saliva samples (94.03% and 97.02%), and throat swab samples (93.33% and 98.33%). None of the 143 samples with other respiratory viruses were positive by COVID-19-LAMP, showing 100% specificity. Samples with higher viral load showed shorter detection time, some as early as 30 min. This inexpensive, highly sensitive and specific COVID-19-LAMP assay can be useful for rapid deployment as mobile diagnostic units to resource-limiting areas for point-of-care diagnosis, and for unlimited high-throughput mass screening at borders to reduce cross-regional transmission.
Asunto(s)
Betacoronavirus/genética , Colorimetría/métodos , Infecciones por Coronavirus/diagnóstico , Tamizaje Masivo/economía , Neumonía Viral/diagnóstico , ARN Viral/análisis , Betacoronavirus/aislamiento & purificación , COVID-19 , Colorimetría/economía , Infecciones por Coronavirus/virología , Humanos , Límite de Detección , Nasofaringe/virología , Técnicas de Amplificación de Ácido Nucleico/métodos , Pandemias , Neumonía Viral/virología , Sistemas de Atención de Punto , ARN Viral/metabolismo , SARS-CoV-2 , Carga ViralRESUMEN
The emergence of Middle East respiratory syndrome showed once again that coronaviruses (CoVs) in animals are potential source for epidemics in humans. To explore the diversity of deltacoronaviruses in animals in the Middle East, we tested fecal samples from 1,356 mammals and birds in Dubai, The United Arab Emirates. Four novel deltacoronaviruses were detected from eight birds of four species by reverse transcription-PCR (RT-PCR): FalCoV UAE-HKU27 from a falcon, HouCoV UAE-HKU28 from a houbara bustard, PiCoV UAE-HKU29 from a pigeon, and QuaCoV UAE-HKU30 from five quails. Complete genome sequencing showed that FalCoV UAE-HKU27, HouCoV UAE-HKU28, and PiCoV UAE-HKU29 belong to the same CoV species, suggesting recent interspecies transmission between falcons and their prey, houbara bustards and pigeons, possibly along the food chain. Western blotting detected specific anti-FalCoV UAE-HKU27 antibodies in 33 (75%) of 44 falcon serum samples, supporting genuine infection in falcons after virus acquisition. QuaCoV UAE-HKU30 belongs to the same CoV species as porcine coronavirus HKU15 (PorCoV HKU15) and sparrow coronavirus HKU17 (SpCoV HKU17), discovered previously from swine and tree sparrows, respectively, supporting avian-to-swine transmission. Recombination involving the spike protein is common among deltacoronaviruses, which may facilitate cross-species transmission. FalCoV UAE-HKU27, HouCoV UAE-HKU28, and PiCoV UAE-HKU29 originated from recombination between white-eye coronavirus HKU16 (WECoV HKU16) and magpie robin coronavirus HKU18 (MRCoV HKU18), QuaCoV UAE-HKU30 from recombination between PorCoV HKU15/SpCoV HKU17 and munia coronavirus HKU13 (MunCoV HKU13), and PorCoV HKU15 from recombination between SpCoV HKU17 and bulbul coronavirus HKU11 (BuCoV HKU11). Birds in the Middle East are hosts for diverse deltacoronaviruses with potential for interspecies transmission.IMPORTANCE During an attempt to explore the diversity of deltacoronaviruses among mammals and birds in Dubai, four novel deltacoronaviruses were detected in fecal samples from eight birds of four different species: FalCoV UAE-HKU27 from a falcon, HouCoV UAE-HKU28 from a houbara bustard, PiCoV UAE-HKU29 from a pigeon, and QuaCoV UAE-HKU30 from five quails. Genome analysis revealed evidence of recent interspecies transmission between falcons and their prey, houbara bustards and pigeons, possibly along the food chain, as well as avian-to-swine transmission. Recombination, which is known to occur frequently in some coronaviruses, was also common among these deltacoronaviruses and occurred predominantly at the spike region. Such recombination, involving the receptor binding protein, may contribute to the emergence of new viruses capable of infecting new hosts. Birds in the Middle East are hosts for diverse deltacoronaviruses with potential for interspecies transmission.
Asunto(s)
Enfermedades de las Aves , Aves/virología , Infecciones por Coronaviridae , Coronavirus , Secuenciación de Nucleótidos de Alto Rendimiento , Porcinos/virología , Animales , Enfermedades de las Aves/genética , Enfermedades de las Aves/transmisión , Infecciones por Coronaviridae/genética , Infecciones por Coronaviridae/transmisión , Infecciones por Coronaviridae/veterinaria , Coronavirus/clasificación , Coronavirus/genética , Coronavirus/aislamiento & purificación , Coronavirus/patogenicidad , Arabia SauditaRESUMEN
With new or emerging fungal infections, human and animal fungal pathogens are a growing threat worldwide. Current diagnostic tools are slow, non-specific at the species and subspecies levels, and require specific morphological expertise to accurately identify pathogens from pure cultures. DNA barcodes are easily amplified, universal, short species-specific DNA sequences, which enable rapid identification by comparison with a well-curated reference sequence collection. The primary fungal DNA barcode, ITS region, was introduced in 2012 and is now routinely used in diagnostic laboratories. However, the ITS region only accurately identifies around 75% of all medically relevant fungal species, which has prompted the development of a secondary barcode to increase the resolution power and suitability of DNA barcoding for fungal disease diagnostics. The translational elongation factor 1α (TEF1α) was selected in 2015 as a secondary fungal DNA barcode, but it has not been implemented into practice, due to the absence of a reference database. Here, we have established a quality-controlled reference database for the secondary barcode that together with the ISHAM-ITS database, forms the ISHAM barcode database, available online at http://its.mycologylab.org/ . We encourage the mycology community for active contributions.
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Biodiversidad , Código de Barras del ADN Taxonómico/métodos , ADN de Hongos/genética , Bases de Datos Factuales , Hongos/clasificación , Hongos/genética , Factor 1 de Elongación Peptídica/genética , ADN de Hongos/análisis , ADN Espaciador Ribosómico/genéticaRESUMEN
Although case series of talaromycosis have been reported in China, their detailed clinical and microbiological characteristics have never been systematically profiled. In this study, we report the clinical characteristics, molecular epidemiology, rapid identification and antifungal susceptibilities of talaromycosis in The University of Hong Kong-Shenzhen Hospital in Shenzhen. Seven cases of talaromycosis were observed since commencement of hospital service in 2012. Three patients were local Shenzhen residents, whereas the other four were immigrants from other parts of China. Two patients were HIV-negative, but with underlying diseases requiring immunosuppressive therapy. Two of the seven patients succumbed. All the seven isolates were successfully identified as T. marneffei by MALDI-TOF MS using Bruker database expanded with in-house generated T. marneffei mass spectra. MLST showed that the seven strains belonged to six different, novel sequences types. Phylogenetic analyses of the concatenated five-locus sequence revealed that the seven strains were scattered amongst other T. marneffei strains. The MICs of itraconazole, isavuconazole, posaconazole and voriconazole against the seven clinical isolates were low but MICs of anidulafungin were high. Underlying diseases other than HIV infection are increasingly important risk factors of talaromycosis. MALDI-TOF MS is useful for rapid identification. Highly diverse T. marneffei sequence types were observed.
Asunto(s)
Antifúngicos/farmacología , Técnicas Microbiológicas/métodos , Micosis/epidemiología , Micosis/patología , Talaromyces/aislamiento & purificación , Adulto , Anciano , Femenino , Genotipo , Hong Kong , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica , Micosis/diagnóstico , Micosis/microbiología , Estudios Retrospectivos , Factores de Riesgo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Análisis de Supervivencia , Talaromyces/clasificación , Talaromyces/efectos de los fármacos , Talaromyces/genéticaRESUMEN
The fungus Talaromyces marneffei was described by Professor Gabriel Segretain in 1959, originally as a member of the genus Penicillium. As early as 60 years ago, its peculiarity in exhibiting temperature-dependent morphological dimorphism, its characteristic ability to secrete diffusing red pigment during the mycelial phase and its pathogenicity have already been recognised. Six decades have passed, and our understanding on this intriguing fungus has improved. Apart from the clinical aspect, we have gained a glimpse on its taxonomy, animal or environmental source(s), mechanism of thermal dimorphism, molecular genetics, virulence as well as pathogenesis. However, we are still on our way to get out of the talaromycosis mist. A lot more collective endeavour on T. marneffei research is needed to solve the jigsaw puzzle.
Asunto(s)
Talaromyces , Animales , Humanos , Estadios del Ciclo de Vida , Talaromyces/clasificación , Talaromyces/citología , Talaromyces/metabolismo , Talaromyces/patogenicidadRESUMEN
Five bacterial strains, UAE-HKU57T, UAE-HKU58, UAE-HKU59, UAE-HKU60 and UAE-HKU61, were isolated in Dubai, UAE, from necrotic foot tissue samples of four dromedaries (Camelus dromedarius) and associated maggots (Wohrlfartia species). They were non-sporulating, Gram-negative, non-motile bacilli. They grew well under aerobic conditions at 37 °C, but not anaerobically. The pH range for growth was pH 7.0-9.0 (optimum, pH 7.5-8.0) and the strains could tolerate NaCl concentrations (w/v) up to 2â% (optimum, 0.5â%). They were catalase- and cytochrome oxidase-positive, but caseinase-, gelatinase- and urease-negative. Their phenotypic characters were distinguishable from other closely related species. Phylogenetic analyses of the almost-complete 16S rRNA gene and partial 23S rRNA gene, gyrB, groEL and recA sequences revealed that the five isolates were most closely related to undescribed Ignatzschineria strain F8392 and Ignatzschineria indica, but in most phylogenies clustered separately from these close relatives. Average nucleotide identity analysis showed that genomes of the five isolates (2.47-2.52 Mb, G+C content 41.71-41.86 mol%) were 98.00-99.97% similar to each other, but ≤87.18â% similar to other Ignatzschineriaspecies/strains. Low DNA relatedness between the five isolates to other Ignatzschineriaspecies/strains was also supported by Genome-to-Genome Distance Calculator analysis. The chemotaxonomic traits of the five strains were highly similar. They were non-susceptible (intermediate or resistant) to tetracycline and resistant to trimethoprim/sulphamethoxazole. The name Ignatzschineria cameli sp. nov. is proposed to accommodate these five strains, with strain UAE-HKU57T (=CCOS1165T=NBRC 113042T) as the type strain.
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Camelus/microbiología , Gammaproteobacteria/clasificación , Larva/microbiología , Necrosis/microbiología , Filogenia , Sarcofágidos/microbiología , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Pie/microbiología , Gammaproteobacteria/genética , Gammaproteobacteria/aislamiento & purificación , Genes Bacterianos , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ubiquinona/química , Emiratos Árabes UnidosRESUMEN
No study has comprehensively evaluated the performance of 28S nrDNA and ITS sequencing, commercial biochemical test kits, MALDI-TOF MS platforms, and the emerging rep-PCR DNA fingerprinting technology using a cohort of yeast strains collected from a clinical microbiology laboratory. In this study, using 71 clinically important yeast isolates (excluding Candida albicans) collected from a single centre, we determined the concordance of 28S nrDNA and ITS sequencing and evaluated the performance of two commercial test kits, two MALDI-TOF MS platforms, and rep-PCR DNA fingerprinting. 28S nrDNA and ITS sequencing showed complete agreement on the identities of the 71 isolates. Using sequencing results as the standard, 78.9% and 71.8% isolates were correctly identified using the API 20C AUX and Vitek 2 YST ID Card systems, respectively; and 90.1% and 80.3% isolates were correctly identified using the Bruker and Vitek MALDI-TOF MS platforms, respectively. Of the 18 strains belonging to the Candida parapsilosis species complex tested by DiversiLab automated rep-PCR DNA fingerprinting, all were identified only as Candida parapsilosis with similarities ≥93.2%, indicating the misidentification of Candida metapsilosis and Candida orthopsilosis. However, hierarchical cluster analysis of the rep-PCR DNA fingerprints of these three species within this species complex formed three different discrete clusters, indicating that this technology can potentially differentiate the three species. To achieve higher accuracies of identification, the databases of commercial biochemical test kits, MALDI-TOF MS platforms, and DiversiLab automated rep-PCR DNA fingerprinting needs further enrichment, particularly for uncommonly encountered yeast species.
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Candida parapsilosis/aislamiento & purificación , Candidiasis/diagnóstico , Dermatoglifia del ADN/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Tipificación Micológica/métodos , Análisis de Secuencia de ADN/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Candida parapsilosis/química , Candida parapsilosis/clasificación , Candida parapsilosis/genética , Candidiasis/microbiología , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Humanos , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 28S/genéticaRESUMEN
Aspergillosis in falcons may be associated with high mortality and difficulties in clinical and laboratory diagnosis. We previously cloned an immunogenic protein, Afmp1p, in Aspergillus fumigatus and showed that anti-Afmp1p antibodies were present in human patients with A. fumigatus infections. In this study, we hypothesise that a similar Afmp1p-based enzyme-linked immunosorbent assay (ELISA) could be applied to serodiagnose falcon aspergillosis. A specific polyclonal antibody was first generated to detect falcon serum IgY. Horseradish peroxidase-conjugate of this antibody was then used to measure anti-Afmp1p antibodies in sera collected from falcons experimentally infected with A. fumigatus, and the performance of the Afmp1p-based ELISA was evaluated using sera from healthy falcons and falcons with documented A. fumigatus infections. All four experimentally infected falcons developed culture- and histology-proven invasive aspergillosis. Anti-Afmp1p antibodies were detected in their sera. For the Afmp1p-based ELISA, the mean ± SD OD450 nm using sera from 129 healthy falcons was 0.186 ± 0.073. Receiver operating characteristics curve analysis showed an absorbance cut-off value of 0.407. One negative serum gave an absorbance outside the normal range, giving a specificity of 99.2%. For the 12 sera from falcons with confirmed aspergillosis, nine gave absorbance values ≥ cut-off, giving a sensitivity of 75%. The Afmp1p-based ELISA is useful for serodiagnosis of falcons with aspergillosis.
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Anticuerpos Antifúngicos/sangre , Antígenos Fúngicos/inmunología , Aspergilosis/veterinaria , Enfermedades de las Aves/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Falconiformes , Glicoproteínas de Membrana/inmunología , Pruebas Serológicas/métodos , Animales , Aspergilosis/diagnóstico , Curva ROC , Sensibilidad y EspecificidadRESUMEN
Two bacterial strains, HKU50T and HKU46, were isolated in Hong Kong from the blood culture and the peritoneal dialysis effluent of two patients. The strains are Gram-stain-positive, acid-fast, non-motile, non-sporulating bacilli. They grow on Columbia agar with 5 % defibrinated sheep blood and brain-heart infusion agar under aerobic conditions with 5 % CO2 at 37 °C as pink-to-orange, non-haemolytic colonies. The strains are catalase-positive and oxidase-negative, and have a unique biochemical profile distinguishable from other closely related species. DNA sequencing revealed that both isolates possessed multiple intra-genomic 16S rRNA gene copies (99.8-100 % sequence identities to Gordonia lacunae NRRL B-24551T and Gordonia terrae NRRL B-16283T). Phylogenetic analysis of the 16S rRNA gene, secA1 and gyrB showed that the two isolates formed a distinct branch within the genus Gordonia and were most closely related to G. lacunae and G. terrae. DNA-DNA hybridization demonstrated ≤53.7 % and ≤49.4 % DNA relatedness between the two isolates and G. lacunae, and between the two isolates and G. terrae, respectively. Hierarchical cluster analysis of MALDI-TOF MS main spectrum profiles showed that strains HKU50T and HKU46 were closely related to each other, but were distinct from G. lacunae, G. terrae, or any other species of the genus Gordonia in the Bruker database. The chemotaxonomic traits of the two strains were highly similar, and the major fatty acids were summed feature 4 (iso-C15 : 0 2-OH/C16 : 1trans-9), C16 : 0, C18 : 1cis-9, and tuberculostearic acid. A novel species named Gordonia hongkongensis sp. nov. is proposed to accommodate strains HKU50T and HKU46, with strain HKU50T (=CCOS 955T=CIP 111027T=NBRC 111234T=NCCP 16210T) as the type strain.
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Cultivo de Sangre , Bacteria Gordonia/clasificación , Diálisis Peritoneal , Filogenia , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , ADN Bacteriano/genética , Ácidos Grasos/química , Genes Bacterianos , Bacteria Gordonia/genética , Bacteria Gordonia/aislamiento & purificación , Hong Kong , Humanos , Lactante , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Three bacterial strains, HKU51T, HKU52T and HKU53, were isolated from a conjunctival swab, corneal scraping and blood culture of three patients in Hong Kong with conjunctivitis, keratitis and catheter-related bacteraemia, respectively. Cells were Gram-stain-positive, aerobic, catalase-positive, non-sporulating and non-motile bacilli. The three strains had unique biochemical profiles that were distinguishable from those of closely related species of the genus Tsukamurella. Fatty acids, mycolic acids, cell-wall sugars and peptidoglycan analyses showed that they were typical of members of Tsukamurella. 16S rRNA gene sequence analysis revealed 100 % sequence identity between HKU52T and HKU53, and the two strains shared 99.5 % sequence identity with Tsukamurella sunchonensis JCM 15929T and Tsukamurella pseudospumae JCM 13375T; HKU51T shared 99.6 % sequence identity with Tsukamurella pulmonis CCUG 35732T. The DNA G+C contents of strains HKU51T, HKU52T and HKU53 were 70.9 ± 2.2, 71.3 ± 2.1 and 71.2 ± 2.3âmol% (mean ± sd; n = 3), respectively. DNA-DNA hybridization confirmed that the novel strains were distinct from other known species of the genus Tsukamurella ( ≤ 50.1 ± 3.7 % DNA-DNA relatedness); two of the isolates, HKU52T and HKU53, represented the same species ( ≥ 94.6 ± 5.6 % DNA-DNA relatedness), while the third isolate, HKU51T, represented another species. The novel species Tsukamurella hongkongensis sp. nov. is proposed to accommodate strains HKU52T and HKU53, with HKU52T ( = JCM 30715T = DSM 100208T) as the type strain; whilst another novel species, Tsukamurella sinensis sp. nov., is proposed to accommodate the third isolate, HKU51T ( = JCM 30714T = DSM 100207T), which is designated the type strain.
Asunto(s)
Actinomycetales/clasificación , Bacteriemia/microbiología , Conjuntivitis/microbiología , Queratitis/microbiología , Filogenia , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Adulto , Técnicas de Tipificación Bacteriana , Composición de Base , Catéteres de Permanencia/microbiología , Conjuntiva/microbiología , Córnea/microbiología , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Ácidos Micólicos/química , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
"Engyodontium album" is an environmental saprobic mould and an emerging opportunistic pathogen able to cause both superficial and systemic infections. In this study, we isolated a mould from the skin lesion biopsy specimen of the right shin in a patient who received renal transplantation for end-stage renal failure with prednisolone, tacrolimus, and azathioprine immunosuppressant therapy. Histology of the skin biopsy showed mild squamous hyperplasia and neutrophilic infiltrate in the epidermis, active chronic inflammation in the dermis, and fat necrosis in the subcutis, with numerous fungal elements within the serum crusts. On Sabouraud glucose agar, the fungus grew as white, cobweb-like, floccose colonies. Microscopically, conidiogenous cells were arranged in whorls of one to seven at wide angles, with zigzag-shaped terminal fertile regions and smooth, hyaline, oval, apiculate conidia. DNA sequencing showed the mould isolate belonged to "E. album" but matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) failed to identify the isolate. Phylogenetic analyses based on the internal transcribed spacer region, 28S nuclear ribosomal DNA, and ß-tubulin gene and MALDI-TOF MS coupled with hierarchical cluster analysis showed that "E. album" is distantly related to other Engyodontium species and should be transferred to a novel genus within the family Cordycipitaceae, for which the name Parengyodontium album gen. et comb. nov. is proposed. Three potential cryptic species within this species complex were also revealed. Antifungal susceptibility testing showed posaconazole and voriconazole had high activities against all clinical P. album isolates and may be better drug options for treating P. album infections.
Asunto(s)
Hialohifomicosis/diagnóstico , Hialohifomicosis/microbiología , Hypocreales/clasificación , Hypocreales/aislamiento & purificación , Animales , Biopsia , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Histocitoquímica , Humanos , Hypocreales/citología , Hypocreales/genética , Huésped Inmunocomprometido , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Masculino , Técnicas Microbiológicas , Microscopía , Persona de Mediana Edad , Filogenia , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Piel/microbiología , Piel/patología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Tubulina (Proteína)/genéticaRESUMEN
Recently, we reported the discovery of a dromedary camel coronavirus UAE-HKU23 (DcCoV UAE-HKU23) from dromedaries in the Middle East. In this study, DcCoV UAE-HKU23 was successfully isolated in two of the 14 dromedary fecal samples using HRT-18G cells, with cytopathic effects observed five days after inoculation. Northern blot analysis revealed at least seven distinct RNA species, corresponding to predicted subgenomic mRNAs and confirming the core sequence of transcription regulatory sequence motifs as 5'-UCUAAAC-3' as we predicted previously. Antibodies against DcCoV UAE-HKU23 were detected in 58 (98.3%) and 59 (100%) of the 59 dromedary sera by immunofluorescence and neutralization antibody tests, respectively. There was significant correlation between the antibody titers determined by immunofluorescence and neutralization assays (Pearson coefficient = 0.525, p < 0.0001). Immunization of mice using recombinant N proteins of DcCoV UAE-HKU23 and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively, and heat-inactivated DcCoV UAE-HKU23 showed minimal cross-antigenicity between DcCoV UAE-HKU23 and MERS-CoV by Western blot and neutralization antibody assays. Codon usage and genetic distance analysis of RdRp, S and N genes showed that the 14 strains of DcCoV UAE-HKU23 formed a distinct cluster, separated from those of other closely related members of Betacoronavirus 1, including alpaca CoV, confirming that DcCoV UAE-HKU23 is a novel member of Betacoronavirus 1.
Asunto(s)
Camelus/virología , Reacciones Cruzadas , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Animales , Línea Celular Tumoral , Genes Virales , Humanos , Ratones , Coronavirus del Síndrome Respiratorio de Oriente Medio/clasificación , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , FilogeniaRESUMEN
We report here four cases of continuous ambulatory peritoneal dialysis-related peritonitis caused by three different species of Gordonia. The portal of entry was likely through Tenckhoff catheters. 16S rRNA and secA1 gene sequencing are so far the most reliable methods for the accurate identification of Gordonia species.
Asunto(s)
Infecciones por Actinomycetales/diagnóstico , Adenosina Trifosfatasas/genética , Proteínas Bacterianas/genética , Bacteria Gordonia/aislamiento & purificación , Proteínas de Transporte de Membrana/genética , Técnicas de Diagnóstico Molecular/métodos , Peritonitis/diagnóstico , ARN Ribosómico 16S/genética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones por Actinomycetales/microbiología , Anciano , Análisis por Conglomerados , Femenino , Bacteria Gordonia/química , Bacteria Gordonia/genética , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Diálisis Peritoneal/efectos adversos , Peritonitis/microbiología , Filogenia , Canales de Translocación SEC , Proteína SecA , Análisis de Secuencia de ADN , Homología de SecuenciaRESUMEN
Our case series showed that uncomplicated Yarrowia lipolytica fungemia might be treated with catheter removal alone. The Vitek 2 YST identification (ID) card system, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and internal transcribed spacer and 25S nuclear ribosomal DNA (nrDNA) gene sequencing provided reliable identification. All isolates had low MICs to voriconazole, echinocandins, and amphotericin B.
Asunto(s)
Antifúngicos/uso terapéutico , Infecciones Relacionadas con Catéteres/diagnóstico , ADN Espaciador Ribosómico/genética , Fungemia/diagnóstico , Fungemia/tratamiento farmacológico , Yarrowia/genética , Adulto , Anciano , Anciano de 80 o más Años , Anfotericina B/farmacología , Secuencia de Bases , Infecciones Relacionadas con Catéteres/tratamiento farmacológico , Infecciones Relacionadas con Catéteres/microbiología , Cateterismo Venoso Central/efectos adversos , Cateterismo Periférico/efectos adversos , Preescolar , Equinocandinas/farmacología , Femenino , Fungemia/microbiología , Hospitalización , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Datos de Secuencia Molecular , Estudios Prospectivos , Análisis de Secuencia de ADN , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Voriconazol/farmacología , Yarrowia/efectos de los fármacosRESUMEN
Fusarium species are environmental saprophytic fungi. Among the many Fusarium species, members of the Fusarium solani species complex (FSSC) are the most prevalent and virulent in causing human and animal infections. In this study, we describe the first case of fatal FSSC infection in a black spotted stingray and three concomitant infections in scalloped hammerhead sharks. In the stingray, cutaneous lesions were characterised by ulcers and haemorrhage of the ventral pectoral fin, or 'ray', especially around the head; while cutaneous lesions in the sharks were characterised by ulcers, haemorrhage, as well as white and purulent exudates at the cephalic canals of the cephalofoil and lateral line. Histological sections of the cutaneous lesions revealed slender (1-4 µm in diameter), branching, septate fungal hyphae. Internal transcribed spacer region and 28S nrDNA sequencing of the fungal isolates from the fish showed two isolates were F. keratoplasticum (FSSC 2) and the other two were FSSC 12. Environmental investigation revealed the FSSC strains isolated from water and biofilms in tanks that housed the elasmobranchs were also F. keratoplasticum and FSSC 12. Fusarium is associated with major infections in elasmobranchs and FSSC 12 is an emerging cause of infections in marine animals. DNA sequencing is so far the most reliable method for accurate identification of Fusarium species.
Asunto(s)
Elasmobranquios/microbiología , Enfermedades de los Peces/microbiología , Fusariosis/veterinaria , Fusarium/aislamiento & purificación , Tiburones/microbiología , Piel/microbiología , Animales , Resultado Fatal , Fusariosis/microbiología , Fusarium/clasificación , Fusarium/genética , Humanos , Datos de Secuencia Molecular , Tipificación de Secuencias Multilocus , Filogenia , Análisis de Secuencia de ADN , Piel/ultraestructuraRESUMEN
Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR products difficult, has rarely been reported in pathogenic fungi. During the process of performing ITS sequencing on 71 yeast strains isolated from various clinical specimens, direct sequencing of the PCR products showed ambiguous sequences in six of them. After cloning the PCR products into plasmids for sequencing, interpretable sequencing electropherograms could be obtained. For each of the six isolates, 10-49 clones were selected for sequencing and two to seven intra-genomic ITS copies were detected. The identities of these six isolates were confirmed to be Candida glabrata (n=2), Pichia (Candida) norvegensis (n=2), Candida tropicalis (n=1) and Saccharomyces cerevisiae (n=1). Multiple sequence alignment revealed that one to four intra-genomic ITS polymorphic sites were present in the six isolates, and all these polymorphic sites were located in the ITS1 and/or ITS2 regions. We report and describe the first evidence of intra-genomic ITS sequence heterogeneity in four different pathogenic yeasts, which occurred exclusively in the ITS1 and ITS2 spacer regions for the six isolates in this study.