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PURPOSE: Rare yeasts species are increasingly reported as causative agents of invasive human infection. Proper identification and antifungal therapy are essential to manage these infections. Candida blankii is one of these emerging pathogens and is known for its reduced susceptibility to multiple antifungals. METHODS: To obtain more insight into the characteristics of this species, 26 isolates reported as C. blankii were investigated using genetic and phenotypical approaches. RESULTS: Among the 26 isolates, seven recovered either from blood, sputum, urine, or the oral cavity, displayed substantial genetic and some phenotypical differences compared to the other isolates, which were confirmed as C. blankii. We consider these seven strains to represent a novel species, Tardiomyces depauwii. Phylogenomics assigned C. blankii, C. digboiensis, and the novel species in a distinct branch within the order Dipodascales, for which the novel genus Tardiomyces is erected. The new combinations Tardiomyces blankii and Tardiomyces digboiensis are introduced. Differences with related, strictly environmental genera Sugiyamaella, Crinitomyces, and Diddensiella are enumerated. All three Tardiomyces species share the rare ability to grow up to 42 °C, display slower growth in nutrient-poor media, and show a reduced susceptibility to azoles and echinocandins. Characteristics of T. depauwii include high MIC values with voriconazole and a unique protein pattern. CONCLUSION: We propose the novel yeast species Tardiomyces depauwii and the transfer of C. blankii and C. digboiensis to the novel Tardiomyces genus.
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Zinc ions are one of the 2nd most abundant mineral after iron and it is important for immune system, enzymatic catalysis, DNA synthesis, and maintaining structural integrity in humans. But, monitoring the Zn levels in human body poses more challenges. This review paper investigates (paper from 2010 to 2023) the synthesis of pyrazoline derivatives by different methods, including conventional methods and green chemistry protocol. These Pyrazoline derivatives highlighted for their potential application as chemo-sensor for Zn2+ ions recognition. Pyrazoline compounds exhibit excellent sensitivity & selectivity and emitting blue-light with high quantum yields and electroluminescence, along with a superior limit of detection. These derivatives are stable bioactive molecule, with well-known diverse biological activities. This review not only gives valuable insights into the essential role of Zinc in human physiology but also provides a practical method for accurate Zinc detection in various samples. Which holds the potential for advancements in health diagnostics and environmental monitoring. Because of their significant biological application and selectivity as sensors, researchers have much more attention to prepare green environmentally-friendly pyrazoline derivatives.
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An Indane-1-one derivative 11-(1-benzyl-1H-indol-3-yl)-10,12-dihydrodiindeno[1,2-b:2',1'-e]-pyridine (BDP) has been synthesized by the reaction of Indan-1-one with 1-benzyl-1H-indole-3-carbaldehyde. FT-IR, 1H-NMR, 13N-NMR and Mass spectroscopic techniques has been used to confirmed the structure of BDP. The observed photophysical changes in BDP across various solvents were associated. The impact of various interactions on photophysical parameters, including Stokes shift, dipole moment, oscillator strength, and fluorescence quantum yields, has been assessed in relation to solvent polarity. Moreover, BDP demonstrates potential as a selective fluorescent chemosensor for detecting Fe3+ ion within a range of cations in an aqueous DMSO environment. A thorough investigation into the recognition mechanism of BDP towards Fe3+ ion has been conducted using Benesi-Hildebrand and Stern-Volmer, measurements. BDP forms a 2:1 complex with the Fe3+ ion, exhibiting fluorescent quenching behaviour.
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The chalcone compound DHPO was synthesized through a chemical reaction between 1-(2-hydroxyphenyl)-ethanone and 3,4-dimethoxy benzaldehyde under ultrasound irradiation. The interaction between the DHPO compound and several metal ions was studied using fluorescence behavior, revealing that the chalcone function as a "turn on and turn off" switch fluorescent sensor, for selectively and sensitively detecting Fe3+ ions. The process of fluorescence quenching and complexation of DHPO with Fe3+ ion was further studied using methods such as Benesi-Hildebrand, Stern-Volmer plot, and job plot.
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OBJECTIVE: Increasing reports of resistance to newer anti-tuberculosis drugs have prompted the search for other alternative drugs. Streptomycin could be used for the treatment of drug-resistant tuberculosis if susceptibility of Mycobacterium tuberculosis isolate to streptomycin could be accurately detected. We performed phenotypic and genotypic drug susceptibility testing (DST) of 118 M. tuberculosis isolates for streptomycin. MATERIALS AND METHODS: Fifty pansusceptible and 68 multidrug-resistant M. tuberculosis (MDR-TB) isolates were used. Phenotypic DST for streptomycin, rifampicin, isoniazid and ethambutol was performed by mycobacteria growth indicator tube (MGIT) 960 System. Genotypic DST was done by GenoTypeMTBDRplus assay for rifampicin and isoniazid and by PCR-sequencing of rpsL, rrs and gidB genes for streptomycin. MDR-TB isolates were genotyped by spoligotyping. RESULTS: Phenotypic DST identified 50 isolates susceptible to all four drugs (pansusceptible). Sixty-one of 68 MDR-TB isolates were resistant to streptomycin. Genotypic testing for rifampicin and isoniazid yielded expected results. Fifty pansusceptible and 7 streptomycin-susceptible MDR-TB isolates contained no mutation in rpsL or rrs, while 47, 2 and 1 STR-resistant isolate contained rpsL, rrs and rpsL + rrs mutations, respectively. Of the remaining 11 STR-resistant MDR-TB, 9 isolates contained deletion frame-shift/nonsynonymous mutations in gidB. Surprisingly, 13 pansusceptible isolates also contained deletion frame-shift/nonsense/nonsynonymous mutations in gidB. Also, 30 of 68 MDR-TB but only 2 of 50 pansusceptible isolates belonged to the Beijing genotype. CONCLUSIONS: Our data show that, like ifampicin, ethambutol and pyrazinamide, streptomycin also exhibits discordant phenotypic and genotypic DST results for some M. tuberculosis isolates. Hence, streptomycin should be included in therapy regimens only if both phenotypic and genotypic resistance testing indicate susceptibility to avoid amplification of resistance and drug toxicity.
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Invasive fungal infections caused by non-albicans Candida species are increasingly reported. Recent advances in diagnostic and molecular tools enabled better identification and detection of emerging pathogenic yeasts. The Candida haemulonii species complex accommodates several rare and recently described pathogenic species, C. duobushaemulonii, C. pseudohaemulonii, C. vulturna, and the most notorious example is the outbreak-causing multi-drug resistant member C. auris. Here, we describe a new clinically relevant yeast isolated from geographically distinct regions, representing the proposed novel species C. khanbhai, a member of the C. haemulonii species complex. Moreover, several members of the C. haemulonii species complex were observed to be invalidly described, including the clinically relevant species C. auris and C. vulturna. Hence, the opportunity was taken to correct this here, formally validating the names of C. auris, C. chanthaburiensis, C. konsanensis, C. metrosideri, C. ohialehuae, and C. vulturna.
Although C. albicans remains the major pathogenic yeast, other previously rare or even novel species are on the rise in the clinic. The most notorious example is the rapid global emergence of multidrug-resistant C. auris. Here we describe its novel sibling species C. khanbhai.
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Candidiasis , Infecciones Fúngicas Invasoras , Animales , Candidiasis/microbiología , Candidiasis/veterinaria , Saccharomyces cerevisiae , Candida/genética , Infecciones Fúngicas Invasoras/veterinaria , AntifúngicosRESUMEN
Candida auris is an emerging, multidrug-resistant yeast, causing outbreaks in healthcare facilities. Echinocandins are the antifungal drugs of choice to treat candidiasis, as they cause few side effects and resistance is rarely found. Previously, immunocompromised patients from Kuwait with C. auris colonisation or infection were treated with echinocandins, and within days to months, resistance was reported in urine isolates. To determine whether the development of echinocandin resistance was due to independent introductions of resistant strains or resulted from intra-patient resistance development, whole genome sequencing (WGS) single-nucleotide polymorphism (SNP) analysis was performed on susceptible (n = 26) and echinocandin-resistant (n = 6) isolates from seven patients. WGS SNP analysis identified three distinct clusters differing 17-127 SNPs from two patients, and the remaining isolates from five patients, respectively. Sequential isolates within patients had a maximum of 11 SNP differences over a time period of 1-10 months. The majority of isolates with reduced susceptibility displayed unique FKS1 substitutions including a novel FKS1M690V substitution, and nearly all were genetically related, ranging from only three to six SNP differences compared to susceptible isolates from the same patient. Resistant isolates from three patients shared the common FKS1S639F substitution; however, WGS analysis did not suggest a common source. These findings strongly indicate that echinocandin resistance is induced during antifungal treatment. Future studies should determine whether such echinocandin-resistant strains are capable of long-term colonisation, cause subsequent breakthrough candidiasis, have a propensity to cross-infect other patients, or remain viable for longer time periods in the hospital environment.
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Candidiasis , Equinocandinas , Humanos , Equinocandinas/farmacología , Equinocandinas/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Candida auris , Candida , Candidiasis/microbiología , Secuenciación Completa del Genoma , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Fúngica/genéticaRESUMEN
BACKGROUND: Candida auris is an emerging, potentially multidrug-resistant pathogen that exhibits clade-specific resistance to fluconazole and also develops resistance to echinocandins and amphotericin B easily. This study analysed 49 C auris isolates for alterations in hotspot-1 and hotspot-2 of FKS1 for the detection of mutations conferring reduced susceptibility to echinocandins. METHODS: C auris isolates (n = 49) obtained from 18 immunocompromised patients during June 2016-December 2018 were analysed. Antifungal susceptibility testing was performed by Etest and broth microdilution-based MICRONAUT-AM assay. Mutations in hotspot-1 and hotspot-2 regions of FKS1 were detected by PCR sequencing and fingerprinting of the isolates was done by short tandem repeat typing. RESULTS: The patients had multiple comorbidities/risk factors for Candida spp. infection including cancer/leukaemia/lymphoma/myeloma (n = 16), arterial/central line (n = 17), urinary catheter (n = 17), mechanical ventilation (n = 14) and major surgery (n = 9) and received antifungal drugs as prophylaxis and/or empiric treatment. Seven patients developed C auris candidemia/breakthrough candidemia, nine patients had candiduria with/without candidemia and four patients developed surgical site/respiratory infection. Resistance to fluconazole and amphotericin B was detected in 44 and four isolates, respectively. Twelve C auris isolates from eight patients showed reduced susceptibility to echinocandins. Seven isolates contained hostspot-1 mutations and three isolates from a candidemia patient contained R1354H mutation in hotspot-2 of FKS1. Ten patients died, five were cured, two were lost to follow-up and treatment details for one patient were not available. CONCLUSIONS: Our findings describe development of a novel mutation in FKS1 conferring reduced susceptibility to echinocandins in one patient during treatment and unfavourable clinical outcome for many C auris-infected patients.
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Antifúngicos/farmacología , Candida auris/genética , Candidemia , Farmacorresistencia Fúngica , Equinocandinas , Candidemia/microbiología , Farmacorresistencia Fúngica/genética , Equinocandinas/farmacología , Humanos , Huésped Inmunocomprometido , Kuwait/epidemiología , Pruebas de Sensibilidad Microbiana , Mutación , Centros de Atención TerciariaRESUMEN
Peritoneal dialysis (PD) was introduced in China more than 60 years ago and has grown continuously since then. Now China leads the first of the world in number of patients on PD. In this manuscript a brief review of the history of peritoneal dialysis in China is presented; this includes a description of pioneers and their important contributions, discussion of peritoneal dialysate, the technique of the use of Tenckhoff catheter, the use of continuous ambulatory peritoneal dialysis (CAPD) and dialysis registration. Current ongoing PD research activities among Chinese PD academicians are also discussed. Finally, we present four areas of future focus: 1) the promotion of PD in rural areas where PD use is still very limited due to the lack of PD awareness and education; 2) PD quality management and continuous quality improvement (CQI) program particularly focusing on PD adequacy and patient rehabilitation; 3) development and enforcement of national standards on PD management; 4) multi-center studies to compare the benefits of PD and hemodialysis (HD) that should include survival, rehabilitation and cost-effectiveness.
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Nefrología/historia , Diálisis Peritoneal/historia , China , Historia del Siglo XX , Historia del Siglo XXI , HumanosRESUMEN
OBJECTIVE: C. nivariensis is a rare Candida species which is phenotypically closely related to Candida glabrata and Candida bracarensis. The 3 species form the C. glabrata sensu lato complex. Here, we describe the first isolation and characterization of a C. nivariensis isolate cultured from the tracheal aspirate obtained from a young man in Kuwait. MATERIALS AND METHODS: The yeast isolate was initially tested by VITEK 2 followed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and multiplex PCR. The identification was confirmed by sequencing of internal transcribed spacer (ITS) region of rDNA. Antifungal susceptibility testing was performed by Etest, and phylogenetic comparison with other international strains was carried out by using MEGA version 7 software. RESULTS: The C. nivariensis isolate was misidentified by VITEK 2, but correctly identified by MALDI-TOF MS with updated software and multiplex PCR. The identity was confirmed by sequence comparisons of ITS region of rDNA. Antifungal susceptibility testing revealed high minimum inhibitory concentration (MIC) against fluconazole, but low MICs against amphotericin B and echinocandins. Phylogenetically, our isolate was closely related to Indian isolates. CONCLUSIONS: This report extends the geographic distribution of C. nivariensis to the Arabian Peninsula. MALDI-TOF MS with updated software and molecular tests are needed to correctly identify C. nivariensis. Since C. nivariensis may exhibit reduced susceptibility to antifungal agents, accurate identification and antifungal susceptibility testing are essential, particularly for isolates from sterile sites, for optimal patient management.
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Antifúngicos/farmacología , Saccharomycetales/efectos de los fármacos , Saccharomycetales/aislamiento & purificación , Adulto , Humanos , Kuwait , Masculino , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa MultiplexRESUMEN
OBJECTIVE: Kuwait is considered a non-endemic country for most parasitic infections. However, â¼70% of 4.7 million residents in Kuwait are expatriates from Asian and African countries, which are endemic for parasitic infections. Results of microbiological investigations for schistosomiasis and cystic echinococcosis (CE) performed in a reference national laboratory were retrospectively collected and analyzed to provide an insight on the epidemiology of these 2 neglected tropical diseases in Kuwait. SUBJECTS AND METHODS: Schistosoma infection in fecal and urine specimens from suspected patients was detected by microscopy. Schistosoma and CE infections were also detected by indirect hemagglutination assays (IHAs) using blood specimens. Patients' epidemiological data were extracted from the laboratory records. RESULTS: The overall prevalence rates of schistosomiasis and CE were 19.0 and 5.8%, respectively. Almost all schistosomiasis cases were seen among Egyptians, especially among males, and a significantly higher prevalence (p < 0.05) was seen for CE cases among the Syrian residents. A decreasing annual trend was observed for both the parasitic infections over time in Kuwait. CONCLUSIONS: This study confirmed that schistosomiasis is not autochthonous in Kuwait, as all cases were detected among expatriates from Schistosoma-endemic countries. Our data also showed that CE remains endemic among humans and livestock in Kuwait as is also seen in other Middle Eastern countries.
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Equinococosis/etnología , Esquistosomiasis/etnología , Migrantes/estadística & datos numéricos , Adulto , Equinococosis/diagnóstico , Femenino , Humanos , Kuwait/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Esquistosomiasis/diagnóstico , Distribución por SexoRESUMEN
OBJECTIVE: This study evaluated the performance of GeneXpert MTB/RIF (Xpert) and ProbeTec ET (PTec-ET) assays in diagnosing extrapulmonary tuberculosis (EPTB) in Kuwait. MATERIALS AND METHODS: We tested nonrespiratory clinical specimens (n = 3,995) collected from 3,995 patients suspected to have EPTB. These included cavitary fluids (n = 2,054), fine-needle aspirate (FNA)/pus/tissue biopsy (n = 1,461), urine (n = 302), cerebrospinal fluid (CSF, n = 118), and others (n = 60). All specimens were processed for acid-fast bacilli (AFB), culture in mycobacteria growth indicator tube 960 system, and nucleic acid detection by Xpert and PTec-ET according to manufacturer's instructions. RESULTS: Of 3,995 specimens, 95 were AFB-positive, 403 were culture-positive, and an additional 86 samples had histopathology suggestive of TB. Using culture as reference, the sensitivity and specificity values were 88.33 and 97.3% for Xpert and 72.95 and 97.80% for PTec-ET, respectively. Although performance of both tests was comparable in AFB-positive samples, Xpert detected significantly more cases in culture-positive samples. Among culture-negative samples, Xpert detected 18 more cases including 16 with histopathological evidence of TB. Lowest positivity was detected for both tests in cavitary fluids. Xpert performed better than PTec-ET in culture-positive FNA/pus/tissue biopsy and CSF samples. CONCLUSIONS: Although performance of both tests was suboptimal for AFB-negative/culture-positive samples, Xpert performed better than PTec-ET and also detected more cases of AFB-negative/culture-negative/histopathology-positive samples. PTec-ET was positive in 3, while Xpert was positive in all 6 culture-positive CSF specimens for rapid diagnosis of TB meningitis. Xpert was thus superior to PTec-ET or smear microscopy in rapid diagnosis of EPTB.
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Tipificación Molecular/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Tuberculosis Meníngea/diagnóstico , Tuberculosis/diagnóstico , Humanos , Kuwait , Mycobacterium tuberculosis/clasificación , Mycobacterium tuberculosis/genética , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Zika virus (ZIKV) belongs to the Flavivirus genus of the Flaviviridae family. It is an arbovirus that can cause congenital abnormalities and is sexually transmissible. A series of outbreaks accompanied by unexpected severe clinical complications have captured medical attention to further characterize the clinical features of congenital ZIKV syndrome and its underlying pathophysiological mechanisms. Endoplasmic reticulum (ER) and ER-related proteins are essential in ZIKV genome replication. This review highlights the subcellular localization of ZIKV to the ER and ZIKV modulation on the architecture of the ER. This review also discusses ZIKV interaction with ER proteins such as signal peptidase complex subunit 1 (SPCS1), ER membrane complex (EMC) subunits, and ER translocon for viral replication. Furthermore, the review covers several important resulting effects of ZIKV infection to the ER and cellular processes including ER stress, reticulophagy, and paraptosis-like death. Pharmacological targeting of ZIKV-affected ER-resident proteins and ER-associated components demonstrate promising signs of combating ZIKV infection and rescuing host organisms from severe neurologic sequelae.
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Estrés del Retículo Endoplásmico/fisiología , Retículo Endoplásmico/virología , Replicación Viral/fisiología , Infección por el Virus Zika/virología , Humanos , Proteínas de la Membrana/metabolismoRESUMEN
BACKGROUND: Candida auris, a multidrug-resistant species, has the propensity of nosocomial transmission despite normal decontamination procedures. Here, we describe the isolation of C auris from patients in various hospitals in Kuwait during 2014-2018. Susceptibility to antifungal drugs and molecular basis of resistance to fluconazole, voriconazole and micafungin were also studied. METHODS: Candida auris (n = 314) obtained from 126 patients in eight hospitals were studied. All isolates were identified by PCR amplification and/or PCR-sequencing of ribosomal DNA (rDNA). Antifungal susceptibility was determined by Etest. Molecular basis of resistance to fluconazole and micafungin was studied by PCR-sequencing of ERG11 and FKS1 genes, respectively. FINDINGS: Bloodstream (n = 58), urine (n = 124), respiratory (n = 98) and other (n = 34) specimens yielded 314 C auris isolates. The proportion of bloodstream C auris among all yeast isolates was higher (42 of 307, 13.7%) in 2018 as compared to 2014-2017 (16 of 964, 1.7%) (P = .001). More bloodstream isolates (42 of 139) were cultured in 2018 than during 2014-2017 (16 of 175) (P = .001). Resistance to amphotericin B, fluconazole, voriconazole and micafungin was detected in 27.1%, 100%, 41.1% and 1.7% isolates, respectively. Fluconazole-resistant isolates contained either Y132F or K143R mutation in ERG11. Isolates with K143R mutation were additionally resistant to voriconazole. Micafungin-resistant isolates contained S639F mutation in hot spot 1 of FKS1. CONCLUSIONS: Our study highlights spreading of C auris in major hospitals across Kuwait and its increasing role as a bloodstream pathogen in 2018. Cross-resistance to voriconazole was also seen in isolates with K143R mutation in ERG11, while micafungin-resistant isolates harboured S639F mutation in hot spot 1 of FKS1.
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Candida , Candidiasis , Farmacorresistencia Fúngica/genética , Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/genética , Candida/aislamiento & purificación , Candidemia/sangre , Candidiasis/diagnóstico , Candidiasis/epidemiología , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Fluconazol/farmacología , Genes Fúngicos , Humanos , Kuwait/epidemiología , Micafungina/farmacología , Pruebas de Sensibilidad Microbiana , Patología Molecular , Voriconazol/farmacologíaRESUMEN
OBJECTIVE: Taenia solium infection is not endemic to Kuwait, butseveral casesof cysticercosis have been detected in Kuwaiti nationals with no history of travelling to endemic countries. Infected domestic helpers/food handlers from endemic countries who may have escaped detection of infection by microscopy at the time of their arrival in Kuwait have been suspected as the possible source of infection. This study determined the seroprevalence of T. solium among domestic helpers/food handlers by screening their blood using a sensitive taeniasis-specific anti-rES33 antibody assay. SUBJECTS AND METHODS: Newly arrived domestic helpers (n = 500) and food handlers (n = 500) from endemic countries were enrolled in the period 2015-2017. T. solium-specific rES33 antigen was expressed and purified from human embryonic kidney (HEK)293-6E cells using the pTT5 mammalian expression vector. Stool samples were processed for microscopy, and blood samples were screened to detect anti-T. soliumtaeniasis-specific IgG antibodies by ELISA. RESULTS: All stool samples were negative for T. soliumparasiteeggs by microscopy. However, 42 individuals (4.2%) tested positive for T. soliumtaeniasis-specific IgG antibodies. Though statistically not significant, the IgG seropositivity was higher in individuals with a lower education level, a low-income background, and a lower frequency of hand-washing. CONCLUSIONS: This is the first report from Kuwait and the Middle East on the detection of anti-T. soliumtaeniasis-specific serum IgG antibodies among the high-risk expatriate population. The results emphasize the importance of efficient and sensitive screening of T. solium carriers and thus the prevention of infection transmission and development of cysticercosis in the local population.
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Cisticercosis/diagnóstico , Cisticercosis/epidemiología , Inmunoglobulina G/sangre , Taenia solium/inmunología , Adulto , Anciano , Animales , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Femenino , Humanos , Kuwait/epidemiología , Masculino , Persona de Mediana Edad , Taenia solium/aislamiento & purificación , Teniasis , Viaje , Adulto JovenRESUMEN
Candida glabrata is intrinsically less susceptible to azoles, and resistance to echinocandins and reduced susceptibility (RS) to amphotericin B (AMB) have also been detected. The molecular mechanisms of RS to AMB were investigated in C. glabrata strains in Kuwait by sequence analyses of genes involved in ergosterol biosynthesis. A total of 1,646 C. glabrata isolates were tested by Etest, and results for 12 selected isolates were confirmed by reference broth microdilution. PCR sequencing of three genes (ERG2, ERG6, and ERG11) was performed for all isolates with RS to AMB (RS-AMB isolates) and 5 selected wild-type C. glabrata isolates by using gene-specific primers. The total cell sterol content was analyzed by gas chromatography-mass spectrometry. The phylogenetic relationship among the isolates was investigated by multilocus sequence typing. Wild-type isolates contained only synonymous mutations in ERG2, ERG6, or ERG11, and the total sterol content was similar to that of the reference strains. A nonsynonymous ERG6 mutation (AGA48AAA, R48K) was found in both RS-AMB and wild-type isolates. Four RS-AMB isolates contained novel nonsense mutations at Trp286, Tyr192, and Leu341, and 2 isolates contained a nonsynonymous mutation in ERG6 (V126F or C198F); and the sterol content of these isolates was consistent with ERG6 deficiency. Two other RS-AMB isolates contained a novel nonsynonymous ERG2 mutation (G119S or G122S), and their sterol content was consistent with ERG2 deficiency. Of 8 RS-AMB isolates, 1 fluconazole-resistant isolate also contained nonsynonymous Y141H plus L381M mutations, while 7 isolates contained only synonymous mutations in ERG11 All isolates with ERG6, ERG2, and ERG11 mutations were genotypically distinct strains. Our data show that ERG6 and ERG2 are major targets conferring RS-AMB in clinical C. glabrata isolates.
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Anfotericina B/farmacología , Candida glabrata/efectos de los fármacos , Candida glabrata/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Proteínas Fúngicas/metabolismo , Metiltransferasas/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Proteínas Fúngicas/genética , Humanos , Metiltransferasas/genética , Mutación/genéticaRESUMEN
BACKGROUND: Accurate drug susceptibility testing (DST) of Mycobacterium tuberculosis in clinical specimens and culture isolates to first-line drugs is crucial for diagnosis and management of multidrug-resistant tuberculosis (MDR-TB). Resistance of M. tuberculosis to rifampicin is mainly due to mutations in hot-spot region of rpoB gene (HSR-rpoB). The prevalence of disputed (generally missed by rapid phenotypic DST methods) rpoB mutations, which mainly include L511P, D516Y, H526N, H526L, H526S, and L533P in HSR-rpoB and I572F in cluster II region of rpoB gene, is largely unknown. This study determined the occurrence of all disputed mutations in HSR-rpoB and at rpoB codon 572 in M. tuberculosis strains phenotypically susceptible to rifampicin in Kuwait. METHODS: A total of 242 M. tuberculosis isolates phenotypically susceptible to rifampicin were used. The DST against first-line drugs was performed by Mycobacteria growth indicator tube (MGIT) 960 system. Mutations in HSR-rpoB (and katG codon 315 and inhA-regulatory region for isoniazid resistance) were detected by GenoType MDBDRplus assay. The I572F mutation in cluster II region of rpoB was detected by developing a multiplex allele-specific (MAS)-PCR assay. Results were confirmed by PCR-sequencing of respective loci. Molecular detection of resistance for ethambutol and pyrazinamide and fingerprinting by spoligotyping were also performed for isolates with an rpoB mutation. RESULTS: Among 242 rifampicin-susceptible isolates, 0 of 130 pansusceptible/monodrug-resistant isolates but 4 of 112 polydrug-resistant isolates contained a disputed rpoB mutation. All 4 isolates were also resistant to isoniazid and molecular screening identified additional resistance to pyrazinamide and ethambutol in one isolate each. In final analysis, 2 of 4 isolates were resistant to all 4 first-line drugs. Spoligotyping showed that the isolates belonged to different M. tuberculosis lineages. CONCLUSIONS: Four of 242 (1.7%) rifampicin-susceptible M. tuberculosis isolates contained a disputed rpoB mutation including 2 isolates resistant to all four first-line drugs. The occurrence of a disputed rpoB mutation in polydrug-resistant M. tuberculosis isolates resistant at least to isoniazid (MDR-TB) suggests that polydrug-resistant strains should be checked for genotypic rifampicin resistance for optimal patient management since the failure/relapse rates are nearly same in isolates with a canonical or disputed rpoB mutation.
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Proteínas Bacterianas/genética , ARN Polimerasas Dirigidas por ADN/genética , Mutación , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Etambutol/farmacología , Genotipo , Humanos , Incidencia , Isoniazida/farmacología , Kuwait/epidemiología , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Pirazinamida/farmacología , Rifampin/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/epidemiologíaRESUMEN
Dengue virus (DENV) and Zika virus (ZIKV) are flaviviruses transmitted to humans by their common vector, Aedes mosquitoes. DENV infection represents one of the most widely spread mosquito-borne diseases whereas ZIKV infection occasionally re-emerged in the past causing outbreaks. Although there have been considerable advances in understanding the pathophysiology of these viruses, no effective vaccines or antiviral drugs are currently available. In this study, we evaluated the antiviral activity of carnosine, an endogenous dipeptide (ß-alanyl-l-histidine), against DENV serotype 2 (DENV2) and ZIKV infection in human liver cells (Huh7). Computational studies were performed to predict the potential interactions between carnosine and viral proteins. Biochemical and cell-based assays were performed to validate the computational results. Mode-of-inhibition, plaque reduction, and immunostaining assays were performed to determine the antiviral activity of carnosine. Exogenous carnosine showed minimal cytotoxicity in Huh7 cells and rescued the viability of infected cells with EC50 values of 52.3 and 59.5 µM for DENV2 and ZIKV infection, respectively. Based on the mode-of-inhibition assays, carnosine inhibited DENV2 mainly by inhibiting viral genome replication and interfering with virus entry. Carnosine antiviral activity was verified with immunostaining assay where carnosine treatment diminished viral fluorescence signal. In conclusion, carnosine exhibited significant inhibitory effects against DENV2 and ZIKV replication in human liver cells and could be utilized as a lead peptide for the development of effective and safe antiviral agents against DENV and ZIKV.
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Antivirales/farmacología , Virus del Dengue/efectos de los fármacos , Virus Zika/efectos de los fármacos , Animales , Carnosina/farmacología , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Dengue/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Células Vero , Infección por el Virus Zika/tratamiento farmacológicoRESUMEN
BACKGROUND: Cyberlindnera fabianii has rarely been reported as a human pathogen. Here, we describe an outbreak of C. fabianii fungaemia involving 10 preterm neonates during a seven-month period in Kuwait and review the published reports. METHODS: Blood cultures were processed, and yeast isolates were initially identified by ID 32 C and/or VITEK 2. Molecular identification was done by PCR sequencing of internally transcribed spacer (ITS) region and D1/D2 domains of rDNA. Fingerprinting was performed with microsatellite-based and minisatellite-based primers to examine genetic relatedness among the isolates. Antifungal susceptibility testing of the isolates was done by Etest. FINDINGS: All infected neonates were preterm, received prior antibiotics and had an intravascular catheter in place. All bloodstream isolates were initially identified as Candida utilis by ID 32 C and/or VITEK 2 and showed reduced susceptibility to triazoles. PCR sequencing of rDNA identified all isolates as Cyberlindnera fabianii. Fingerprinting studies yielded identical patterns indicating clonality. One neonate died before treatment, one died during treatment, and eight neonates survived treatment with amphotericin B with/without fluconazole or caspofungin. Source of infection remained unknown despite surveillance cultures. CONCLUSION: The outbreak highlights emergence of C. fabianii as a neonatal pathogen and reinforces importance of molecular methods in its accurate identification.
Asunto(s)
Brotes de Enfermedades , Fungemia/epidemiología , Fungemia/microbiología , Recien Nacido Prematuro , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Antifúngicos/farmacología , Sangre/microbiología , Infecciones Relacionadas con Catéteres/epidemiología , Infecciones Relacionadas con Catéteres/microbiología , Análisis por Conglomerados , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , ADN de Hongos/química , ADN de Hongos/genética , ADN Intergénico/química , ADN Intergénico/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Pruebas Antimicrobianas de Difusión por Disco , Femenino , Humanos , Recién Nacido , Kuwait/epidemiología , Masculino , Repeticiones de Minisatélite , Epidemiología Molecular , Tipificación Molecular , Técnicas de Tipificación Micológica , Filogenia , ARN Ribosómico/genética , Saccharomycetales/efectos de los fármacos , Saccharomycetales/genética , Análisis de Secuencia de ADNRESUMEN
Fusarium petroliphilum is a recently described species within the Fusarium solani species complex. Some strains of Fusarium species are capable of forming yeast-like structures in tissue as well as in culture through a process known as "adventitious sporulation." Here, we describe the formation of these yeast-like reproductive structures in infected nail tissue obtained from a case of onychomycosis. These structures were also observed in culture grown on RPMI 1640 agar supplemented with 2% glucose. The isolate was resistant to azoles and echinocandins. To the best of our knowledge, this is the first report describing adventitious sporulation in F. petroliphilum and its etiologic role in onychomycosis.