scholarly journals Analysis and modeling of Blastomyces dermatitidis environmental prevalence in Minnesota using soil collected to compare basal and outbreak levels

2020 ◽  
pp. AEM.01922-20
Author(s):  
Katrina M. Jackson ◽  
Keith C. Pelletier ◽  
Joni Scheftel ◽  
Joshua D. Kerkaert ◽  
Serina L. Robinson ◽  
...  
Keyword(s):  
United States ◽  
Environmental Samples ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Environmental Parameters ◽  
The United States ◽  
Blastomyces Dermatitidis ◽  
Site Classification ◽  
Environmental Niche ◽  
Culture Independent

Outbreaks of blastomycosis, caused by the fungus Blastomyces dermatitidis, occur in endemic areas of the United States and Canada but the geographic range of blastomycosis is expanding. Previous studies inferred the location of B. dermatitidis through epidemiologic data associated with outbreaks because culture of B. dermatitidis from the environment is often unsuccessful. In this study, we used a culture-independent, PCR-based method to identify B. dermatitidis DNA in environmental samples using the BAD1 promoter region. We tested 250 environmental samples collected in Minnesota, either associated with blastomycosis outbreaks or environmental samples collected from high- and low-endemic regions to determine basal prevalence of B. dermatitidis in the environment. We identified a fifth BAD1 promoter haplotype of B. dermatitidis prevalent in Minnesota. Ecological niche analysis identified latitude, longitude, elevation, and site classification as environmental parameters associated with the presence of B. dermatitidis. Using this analysis, a Random Forest model predicted B. dermatitidis presence in basal environmental samples with 75% accuracy. These data support use of culture-independent, PCR-based environmental sampling to track spread into new regions and to characterize the unknown B. dermatitidis environmental niche.Importance Upon inhalation of spores from the fungus Blastomyces dermatitidis from the environment, humans and animals can develop the disease blastomycosis. Based on disease epidemiology, B. dermatitidis is known to be endemic in the United States and Canada around the Great Lakes and in the Ohio and Mississippi River Valleys but is starting to emerge in other areas. B. dermatitidis is extremely difficult to culture from the environment so little is known about the environmental reservoirs for this pathogen. We used a culture-independent PCR-based assay to identify the presence of B. dermatitidis DNA in soil samples from Minnesota. By combining molecular data with ecological niche modeling, we were able to predict the presence of B. dermatitidis in environmental samples with 75% accuracy and to define characteristics of the B. dermatitidis environmental niche. Importantly, we showed the effectiveness of using a PCR-based assay to identify B. dermatitidis in environmental samples.

The Biology of Invasive Alien Plants in Canada. 11. Tamarix ramosissima Ledeb., T. chinensis Lour. and hybrids

2010 ◽  
Vol 90 (1) ◽  
pp. 111-124 ◽  
Author(s):  
C. Lindgren ◽  
C. Pearce ◽  
K. Allison
Keyword(s):  
United States ◽  
Ecological Niche ◽  
Flood Control ◽  
Ecological Niche Modeling ◽  
Invasion Biology ◽  
The United States ◽  
Tamarix Ramosissima ◽  
Niche Modelling ◽  
Alien Plant ◽  
Invasive Alien Plant

These Tamarix species and their hybrids, known collectively as saltcedar, are perennial small trees or shrubs native to Eurasia, and were among the Tamarix species introduced to the United States in 1800s as ornamentals, for plantings in windbreaks, and to stabilize eroding stream banks. They have since escaped and become damaging invasive plants in large areas of the western and Great Plains regions of the United States. They are able to reproduce vigorously by both seed and vegetative propagation, and are persistent and long-lived once established. Ecological problems include hydrologic impacts, displacement of native flora and fauna including endangered species, and excretion of salt, which increases soil salinity. Economic impacts include costs associated with control as well as losses of irrigation and municipal water, flood control costs, and loss of recreational opportunities. Invaded habitats include floodplains, salt flats, marshes, reservoirs, stock watering ponds, and irrigation ditches. Saltcedar is difficult to control and almost impossible to eradicate once established. In 2007, naturalized saltcedar was found near Penticton and at Osoyoos Lake in British Columbia, Canada. It is also currently sold in several Canadian provinces as an ornamental. Ecological niche modelling indicates that large areas of the Canadian Prairies are susceptible to invasion. Hybridization, multiple intentional introductions through garden plantings, natural dispersal from populations in the northern United States, and climate warming will increase the risk and promote the spread of saltcedar in Canada. Key words: Saltcedar, Tamarix ramosissima, Tamarix chinensis, invasive alien plant, weed biology, invasion biology, ecological niche modeling

scholarly journals Ecological Niche Modeling of Francisella tularensis Subspecies and Clades in the United States

2010 ◽  
Vol 82 (5) ◽  
pp. 912-918 ◽  
Author(s):  
Yoshinori Nakazawa ◽  
Kiersten J. Kugeler ◽  
Richard A. J. Williams ◽  
Paul S. Mead ◽  
A. Townsend Peterson ◽  
...  
Keyword(s):  
United States ◽  
Francisella Tularensis ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
The United States ◽  
Niche Modeling

Using ecological niche modeling for quantitative biogeographic analysis: a case study of Miocene and Pliocene Equinae in the Great Plains

Paleobiology ◽  
2009 ◽  
Vol 35 (4) ◽  
pp. 587-611 ◽  
Author(s):  
Kaitlin Clare Maguire ◽  
Alycia L. Stigall
Keyword(s):  
Great Plains ◽  
Late Miocene ◽  
Ecological Niche ◽  
Middle Miocene ◽  
Ecological Niche Modeling ◽  
Environmental Parameters ◽  
Geographic Range ◽  
Individual Species ◽  
Geographic Ranges ◽  
Speciation Rates

The subfamily Equinae in the Great Plains region of North America underwent a dramatic radiation and subsequent decline as climate changed from warm and humid in the middle Miocene to cooler and more arid conditions during the late Miocene. Here we use ecological niche modeling (ENM), specifically the GARP (Genetic Algorithm using Rule-set Prediction) modeling system, to reconstruct the geographic distribution of individual species during two time slices from the middle Miocene through early Pliocene. This method combines known species occurrence points with environmental parameters inferred from sedimentological variables to model each species' fundamental niche. The geographic range of each species is then predicted to occupy the geographic area within the study region wherever the set of environmental parameters that constrain the fundamental niche occurs. We analyze changes in the predicted distributions of individual species between time slices in relation to Miocene/Pliocene climate change. Specifically, we examine and compare distribution patterns for two time slices that span the period from the mid-Miocene (Barstovian) Climatic Optimum into the early Pliocene (Blancan) to determine whether habitat fragmentation led to speciation within the clade and whether species survival was related to geographic range size. Patchy geographic distributions were more common in the middle Miocene when speciation rates were high. During the late Miocene, when speciation rates were lower, continuous geographic ranges were more common. Equid species tracked their preferred habitat within the Great Plains region as well as regionally throughout North America. Species with larger predicted ranges preferentially survived the initial cooling event better than species with small geographic ranges. As climate continued to deteriorate in the late Miocene, however, range size became irrelevant to survival, and extinction rates increased for species of all range sizes. This is the first use of ENM and GARP in the continental fossil record. This powerful quantitative biogeographic method offers great promise for studies of other taxa and geologic intervals.

Salmonella Contamination during Production of Cantaloupe: A Binational Study

2004 ◽  
Vol 67 (4) ◽  
pp. 713-720 ◽  
Author(s):  
A. CASTILLO ◽  
I. MERCADO ◽  
L. M. LUCIA ◽  
Y. MARTÍNEZ-RUIZ ◽  
J. PONCE de LEÓN ◽  
...  
Keyword(s):  
United States ◽  
Water Samples ◽  
Environmental Samples ◽  
Rio Grande Valley ◽  
The United States ◽  
South Texas ◽  
Pcr Analysis ◽  
E Coli ◽  
Binational Study ◽  
Valley Area

Six cantaloupe farms and packing plants in South Texas (950 cantaloupe, 140 water, and 45 environmental samples), including the Rio Grande Valley area, and three farms in Colima State, Mexico (300 cantaloupe, 45 water, and 15 environmental samples), were sampled to evaluate cantaloupe contamination with Salmonella and Escherichia coli during production and processing. Samples collected from external surfaces of cantaloupes, water, and the environments of packing sheds on cantaloupe farms were examined for the presence of Salmonella and E. coli. Of a total of 1,735 samples collected, 31 (1.8%) tested positive for Salmonella. Fifteen Salmonella serotypes were isolated from samples collected in Texas, and nine from samples collected in Colima. Two serotypes (Poona and Oranienburg) that have been associated with three large Salmonella outbreaks in the United States and Canada linked to the consumption of contaminated cantaloupe were found in water samples collected at four farms (three from the United States). Susceptibility of Salmonella isolates to 10 antimicrobials was evaluated by disk diffusion. Eighty-eight percent of the isolates from the United States and Mexico were pansusceptible to the antimicrobials tested; eight isolates from the United States demonstrated an intermediate susceptibility to streptomycin and only two isolates were resistant to the same antimicrobial. From Mexico, four isolates showed an intermediate susceptibility to streptomycin and one isolate was resistant to nalidixic acid and streptomycin. Repetitive sequence-based PCR analysis of Salmonella isolates helped to trace potential sources of Salmonella contamination in source water and in subsequent water samples obtained after the filtration systems of U.S. and Mexican cantaloupe farms. No differences could be seen between the levels of Salmonella contamination in melons from both countries.

scholarly journals Blastomycosis in a Young African Man Presenting with a Pleural Effusion

2006 ◽  
Vol 13 (8) ◽  
pp. 441-444 ◽  
Author(s):  
GG Alvarez ◽  
BF Burns ◽  
M Desjardins ◽  
SR Salahudeen ◽  
F AlRashidi ◽  
...  
Keyword(s):  
United States ◽  
Weight Loss ◽  
Pleural Effusion ◽  
The United States ◽  
Skin Lesions ◽  
Blastomyces Dermatitidis ◽  
Dimorphic Fungus ◽  
Northwestern Ontario ◽  
Unusual Occurrence ◽  
Chronic Pneumonia

Blastomyces dermatitidisis a dimorphic fungus endemic to northwestern Ontario, Manitoba and some parts of the United States. The fungus is also endemic to parts of Africa. Pulmonary and extrapulmonary findings of a 24-year-old African man who presented with weight loss, dry cough and chronic pneumonia not resolving with antibiotic treatment are presented. The unusual occurrence of pulmonary blastomycosis associated with skin lesions and a moderate pleural effusion is reported.

scholarly journals Genomic Characterization of Strains From a Cluster of Infant Botulism Type A in a Small Town in Colorado, United States

2021 ◽  
Vol 12 ◽  
Author(s):  
Lori Gladney ◽  
Jessica L. Halpin ◽  
Carolina Lúquez
Keyword(s):  
United States ◽  
Environmental Samples ◽  
Type A ◽  
The United States ◽  
Toxin Gene ◽  
Nucleotide Polymorphisms ◽  
Monophyletic Cluster ◽  
Infant Botulism ◽  
Genomic Characterization

Three cases of infant botulism were reported in a small Colorado town between 1981 and 1984. The first two cases occurred in 1981, 6 months apart, and the third case occurred in 1984. Clostridium botulinum type A was isolated from stool of all three case patients and from environmental samples of the patient’s homes. An epidemiological investigation and follow-up study were conducted from 1981 to 1986 and concluded the cases were likely related. In this study, we sought to determine whether the C. botulinum type A clinical isolates were related to each other and to isolates obtained from environmental samples. We performed whole genome sequencing (WGS) for 17 isolates associated with this potential cluster of infant botulism. Fifteen isolates were confirmed to be C. botulinum type A(B) and contained botulinum toxin gene subtypes A1 and B5 by WGS; these strains formed a monophyletic cluster in a phylogeny and were considered closely related to each other (0–18 high-quality single-nucleotide polymorphisms), but distinct from other C. botulinum type A(B) in Colorado and elsewhere in the United States. Results of our study suggest that the three infant botulism cases could have represented a cluster due to a C. botulinum type A(B) strain present in the environment.

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