Publications by authors named "Lisa McTaggart"

Article Synopsis
  • - An emerging fungal pathogen is causing a rise in difficult-to-treat dermatophytosis cases, especially in India, with some infections spreading globally, raising public health concerns.
  • - In Ontario, Canada, there has been a notable increase in cases between 2014 and 2023, particularly affecting adults aged 20 to 64, and these cases are genetically similar to those found in other countries.
  • - The majority of isolates in Ontario show resistance to terbinafine, a common treatment, highlighting the urgent need for better detection methods and public health awareness to control future outbreaks and treat infections effectively.
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Article Synopsis
  • Blastomyces dermatitidis and Blastomyces gilchristii are closely related fungi that cause a serious disease called blastomycosis, which primarily affects the lungs but can spread throughout the body.
  • Genetic analysis reveals that while the species look alike, they differ significantly in their genome size, with B. gilchristii being larger and having more retrotransposons, particularly Gypsy elements.
  • These differences in genetic makeup and retrotransposon content may have contributed to their speciation through processes that lead to reproductive isolation.
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Using phylogenomic analysis, we provide genomic epidemiology analysis of a large blastomycosis outbreak in Ontario, Canada, caused by Blastomyces gilchristii. The outbreak occurred in a locale where blastomycosis is rarely diagnosed, signaling a possible shift in geographically associated incidence patterns. Results elucidated fungal population genetic structure, enhancing understanding of the outbreak.

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is a common cause of nonalbicans candidemia. It can be transmitted in healthcare settings resulting in serious healthcare-associated infections and can develop drug resistance to commonly used antifungal agents. Following a significant increase in the percentage of fluconazole (FLU)-nonsusceptible isolates from sterile site specimens of patients in two Ontario acute care hospital networks, we used whole genome sequence (WGS) analysis to retrospectively investigate the genetic relatedness of isolates and to assess potential in-hospital spread.

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There is an increasing body of literature on the utility of MALDI-TOF MS in the identification of filamentous fungi. However, the process still lacks standardization. In this study, we attempted to establish a practical workflow for the identification of three clinically important molds: Aspergillus, Fusarium, and Mucorales using MALDI-TOF MS.

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Article Synopsis
  • * Although widespread vaccination against serotype b (Hib) resulted in low incidence rates of Hib, nontypeable H. influenzae (NTHi) was responsible for the majority of infections (74.2%) during this period.
  • * The research highlighted varying antibiotic susceptibility among different H. influenzae serotypes, noting that while most serotypes were susceptible to tested antibiotics, a significant portion of NTHi isolates showed resistance to ampicillin, emphasizing the need for ongoing monitoring.
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We aimed to determine whether T cell-specific STAT3 deletion influences the immune response to in the immunosuppressed context in CD4 mice. Immunosuppressed and nonimmunosuppressed CD4 mice and littermate Stat3 (Stat3) mice were infected with in an aerosol chamber, and the weight, activity, appearance, and respiratory rate of the mice were monitored daily for 21 days to evaluate their survival. infection was confirmed by lung fungal culture counts, histology, and a galactomannan test.

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Unlabelled: Azole resistance in Aspergillus fumigatus is increasing worldwide and can affect prognosis. It is mostly mediated by cytochrome P51 (CYP51) mutations. In lung transplant recipients (LTR), little is known regarding the prevalence and clinical impact of CYP51 mutations.

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Blastomycosis due to and is a significant cause of respiratory mycoses in North America with occasional reported outbreaks. We developed a highly sensitive, specific, and reproducible TaqMan duplex real-time PCR assay for the differentiation of and The new assay permitted retrospective analysis of cultures (2005 to 2019) and primary clinical specimens from blastomycosis cases (2013 to 2019) from New York patients. We identified as the predominant pathogen in 38 cases of blastomycosis, while was a minor pathogen involved in five cases; these findings expand understanding of blastomycosis in New York.

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Background: Blastomycosis has been reported from countries in Africa and the Middle East, but a decades-long debate has persisted regarding whether this is the same disease known in North America and caused by Blastomyces dermatitidis and Blastomyces gilchristii.

Methods: We reviewed published cases of human and veterinary blastomycosis from Africa and the Middle East. We abstracted epidemiological and clinical features of cases, including sites of disease, diagnosis, management, outcomes, and, where available, genetic and antigenic typing of case isolates.

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To understand the epidemiology and susceptibility patterns of yeast infections in Ontario, Canada, we examined 4,715 clinical yeast isolates submitted to our laboratory for antifungal susceptibility testing from 2014 to 2018. was the most frequently submitted species (43.0%), followed by (21.

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Article Synopsis
  • Bioinformatic analysis of whole genome sequencing (WGS) is becoming essential for understanding clinical microbiology, particularly for investigating bacterial outbreaks.
  • A study focused on clinical isolates in Ontario aimed to determine if a single-strain outbreak of a specific bacterial pathogen existed but found that the isolates were genetically different, indicating no outbreak was present.
  • The increase in reported cases was attributed to better lab identification methods rather than an actual rise in infections, showcasing WGS's value in public health for quickly assessing outbreaks.
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Invasive fungal infections are an increasingly important cause of human morbidity and mortality. We generated a next-generation sequencing (NGS)-based method designed to detect a wide range of fungi and applied it to analysis of the fungal microbiome (mycobiome) of the lung during fungal infection. Internal transcribed spacer 1 (ITS1) amplicon sequencing and a custom analysis pipeline detected 96% of species from three mock communities comprised of potential fungal lung pathogens with good recapitulation of the expected species distributions (Pearson correlation coefficients = 0.

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Identification of Nocardia can be challenging, even by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS). We examined the impact of incubation duration, culture media and bead-beading on identification success. When isolates were grown for 3 days on SAB (Saboround dextrose agar), then extracted using a bead-beating, ethanol/formic acid (EtOH/FA) procedure, MALDI-ToF MS correctly identified 36.

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Endemic mycoses represent a growing public health challenge in North America. We describe the epidemiology of 1,392 microbiology laboratory-confirmed cases of blastomycosis, histoplasmosis, and coccidioidomycosis in Ontario during 1990-2015. Blastomycosis was the most common infection (1,092 cases; incidence of 0.

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spp. cause serious invasive lung infections, and is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating infections; however, rising resistance rates have been reported.

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Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date.

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Antimicrobial susceptibility patterns of 112 clinical isolates, 28 type strains, and 9 reference strains of Nocardia were determined using the Sensititre Rapmyco microdilution panel (Thermo Fisher, Inc.). Isolates were identified by highly discriminatory multilocus sequence analysis and were chosen to represent the diversity of species recovered from clinical specimens in Ontario, Canada.

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Manipulation of Blastomyces dermatitidis requires the use of containment level 3 (CL3) practices. However, access to CL3 laboratories is limited and working conditions are restrictive. We describe the validation of a "heat-killing" method to inactivate B.

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Background: Analysis of the population genetic structure of microbial species is of fundamental importance to many scientific disciplines because it can identify cryptic species, reveal reproductive mode, and elucidate processes that contribute to pathogen evolution. Here, we examined the population genetic structure and geographic differentiation of the sexual, dimorphic fungus Blastomyces dermatitidis, the causative agent of blastomycosis.

Methodology/principal Findings: Criteria for Genealogical Concordance Phylogenetic Species Recognition (GCPSR) applied to seven nuclear loci (arf6, chs2, drk1, fads, pyrF, tub1, and its-2) from 78 clinical and environmental isolates identified two previously unrecognized phylogenetic species.

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Pneumocystis jirovecii pneumonia is a significant cause of morbidity and mortality in AIDS patients as well as those with non-HIV immunosuppressive diseases. To aid diagnosis, the commercial MycAssay Pneumocystis real-time PCR assay (Myconostica, Ltd., Manchester, United Kingdom) targeting the mitochondrial ribosomal large subunit (mtLSU) has been developed to detect P.

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We compared the FXG™: RESP (Asp +) real-time PCR assay (Myconostica Ltd) with two microscopic staining methods (direct immunofluorescence [IFA] and calcofluor white) for the detection of Pneumocystis jirovecii in 411 respiratory specimens submitted for P. jirovecii examination. We considered the specimen to be microscopically positive if the organism could be visualized through the use of either IFA or calcofluor white.

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Compared to DNA sequence analysis, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) correctly identified 100% of Cryptococcus species, distinguishing the notable pathogens Cryptococcus neoformans and C. gattii. Identification was greatly enhanced by supplementing a commercial spectral library with additional entries to account for subspecies variability.

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