An Hcp100 gene fragment reveals Histoplasma capsulatum presence in lungs of Tadarida brasiliensis migratory bats

2011 ◽  
Vol 140 (11) ◽  
pp. 1955-1963 ◽  
Author(s):  
A. E. GONZÁLEZ-GONZÁLEZ ◽  
C. M. ALIOUAT-DENIS ◽  
L. E. CARRETO-BINAGHI ◽  
J. A. RAMÍREZ ◽  
G. RODRÍGUEZ-ARELLANES ◽  
...  
Keyword(s):  
Reference Strain ◽  
Histoplasma Capsulatum ◽  
Gene Fragment ◽  
Sequence Analyses ◽  
Tadarida Brasiliensis ◽  
Environmental Distribution ◽  
Fungal Isolation ◽  
Fungal Burden ◽  
High Level ◽  
New Evidence

SUMMARYHistoplasma capsulatum was sampled in lungs from 87 migratory Tadarida brasiliensis bats captured in Mexico (n=66) and Argentina (n=21). The fungus was screened by nested-PCR using a sensitive and specific Hcp100 gene fragment. This molecular marker was detected in 81·6% [95% confidence interval (CI) 73·4–89·7] of all bats, representing 71 amplified bat lung DNA samples. Data showed a T. brasiliensis infection rate of 78·8% (95% CI 68·9–88·7) in bats captured in Mexico and of 90·4% (95% CI 75·2–100) in those captured in Argentina. Similarity with the H. capsulatum sequence of a reference strain (G-217B) was observed in 71 Hcp100 sequences, which supports the fungal findings. Based on the neighbour-joining and maximum parsimony Hcp100 sequence analyses, a high level of similarity was found in most Mexican and all Argentinean bat lung samples. Despite the fact that 81·6% of the infections were molecularly evidenced, only three H. capsulatum isolates were cultured from all samples tested, suggesting a low fungal burden in lung tissues that did not favour fungal isolation. This study also highlighted the importance of using different tools for the understanding of histoplasmosis epidemiology, since it supports the presence of H. capsulatum in T. brasiliensis migratory bats from Mexico and Argentina, thus contributing new evidence to the knowledge of the environmental distribution of this fungus in the Americas.

scholarly journals Comparison of the Echinocandin Caspofungin with Amphotericin B for Treatment of Histoplasmosis following Pulmonary Challenge in a Murine Model

2000 ◽  
Vol 44 (7) ◽  
pp. 1850-1854 ◽  
Author(s):  
Steve Kohler ◽  
L. Joseph Wheat ◽  
Patricia Connolly ◽  
Carol Schnizlein-Bick ◽  
Michelle Durkin ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Histoplasma Capsulatum ◽  
Clinical Laboratory ◽  
Antigen Detection ◽  
National Committee ◽  
Slight Effect ◽  
Fungal Burden ◽  
Detection Techniques ◽  
The Mean

ABSTRACT Twenty clinical isolates of Histoplasma capsulatum were tested for their in vitro susceptibilities to caspofungin in comparison to those to amphotericin B by following National Committee for Clinical Laboratory Standards guidelines for yeasts. The mean MICs were 16.6 μg/ml (range, 8 to 32 μg/ml) for caspofungin and 0.56 μg/ml (range, 0.5 to 1.0 μg/ml) for amphotericin B. Survival experiments used a 105 dose in a pulmonary challenge model with B6C3F1 mice. All mice that received amphotericin B at 2 mg/kg of body weight every other day (q.o.d.), 30% of mice that received caspofungin at 8 mg/kg/day, and 20% of mice that received caspofungin at 4 mg/kg/day survived to day 15, while mice that received caspofungin at 2 mg/kg/day and all control mice that received the vehicle died by day 14. Amphotericin B at 2 mg/kg q.o.d. markedly reduced the fungal burden in the lungs and spleens, as measured byHistoplasma antigen detection techniques and quantitative cultures, for each comparison. Caspofungin at 10 mg/kg twice a day (b.i.d.) did not reduce the fungal burden, as measured by antigen detection techniques, but slightly reduced the levels of fungi in both the lungs and spleens, as determined by quantitative cultures. Caspofungin at 5 mg/kg b.i.d. did not affect fungal burden. Overall, caspofungin had only a slight effect on survival or fungal burden.

scholarly journals Candida Albicans ERG11 Gene Polymorphism: Impact on Its In Vivo Virulence and Susceptibility to Fluconazole According to the Galleria Mellonella Model

2021 ◽  
Author(s):  
Marcel Patindoilba Sawadogo ◽  
Adama Zida ◽  
Issiaka Soulama ◽  
Samuel S Sermé ◽  
Thierry Kiswendsida Guiguemdé ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Molecular Mechanisms ◽  
Reference Strain ◽  
Galleria Mellonella ◽  
Larval Mortality ◽  
Fungal Burden ◽  
Significant Difference ◽  
Strain Sc5314 ◽  
Resistant Strains

The aim of this study is to have an idea on the molecular mechanisms of C. albicans resistance to fluconazole in Burkina Faso, by studying the polymorphism of the ERG11 gene, and its implication in the C. albicans virulence and resistance in vivo according to the Galleria mellonella model; (2) Methods: Ten (10) clinical strains including, 5 resistant and 5 susceptible and 1 virulent and susceptible reference strain SC5314 are used. For the estimation of virulence, the larvae were inoculated with 10 μL of C. albicans cell suspension at variable concentrations: 2,5.105, 5.105, 1.106, and 5.106 CFU/larva of each strain. For the in vivo efficacy study, fluconazole was administered at 1, 4 and 16 mg/kg respectively to G. mellonella larvae, after infection by inoculum 5.106 CFU / larvae of each strain; (3) Results: Six (6) non-silent mutations in the ERG11 gene (K143R, F145L, G307S, S405F, G448E, V456I on ERG11p) were found in 4 resistant isolates. Larval mortality depended on fungal burden and strain. The inoculum 5.106 CFU caused 100% mortality in 2 days for the 2 CAAL-1 and CAAL-2 strains carrying the F145L mutation, in 3 days for the reference strain SC5314, in 4 days for the ensemble of resistant strains, and in 5 days for the ensemble of susceptible strains. The comparison of the mortality due to the reference strain SC5314 CFU / larva and the average mortality due to the two mutant F145L strains, shows a significant difference (P <0.05).Fluconazole significantly protected (P> 0.05) the larvae from infection by susceptible strains and the reference strain. However, 100% mortality in 6 days after injection of the resistant strains, was observed (4) Conclusions: Certain mutations in the ERG11 gene such as the F145L mutation are thought to be a source of increased virulence in Candida albicans. Fluconazole effectively protected larvae from infection by susceptible strains in vivo, unlike resistant strain

scholarly journals Genomic stability among O3:K6 V. parahaemolyticus pandemic strains isolated between 1996 to 2012 in American countries

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Abraham Guerrero ◽  
Bruno Gomez-Gil ◽  
Marcial Leonardo Lizarraga-Partida
Keyword(s):  
Reference Strain ◽  
Genomic Stability ◽  
Gastrointestinal Illness ◽  
Reference Sequence ◽  
Aquatic Habitats ◽  
Genetic Changes ◽  
Pandemic Strain ◽  
Toxigenic Strains ◽  
Pandemic Strains ◽  
High Level

Abstract Background The V. parahaemolyticus pandemic clone, results in the development of gastrointestinal illness in humans. Toxigenic strains of this species are frequently isolated from aquatic habitats and organisms such as mollusks and crustaceans. Reports on the isolation of the pandemic clone started in 1996, when a new O3:K6 clone was identified in Asia, that rapidly spread worldwide, becoming the predominant clone isolated from clinical cases. In this study whole genome sequencing was accomplished with an Illumina MiniSeq platform, upon six novel V. parahaemolyticus strains, that have been isolated in Mexico since 1998 and three representative genomes of strains that were isolated from reported outbreaks in other American countries, and were deposited in the GenBank. These nine genomes were compared against the reference sequence of the O3:K6 pandemic strain (RIMD 2210633), which was isolated in 1996, to determine sequence differences within American isolates and between years of isolation. Results The results indicated that strains that were isolated at different times and from different countries, were highly genetically similar, among them as well as to the reference strain RIMD 2210633, indicating a high level of genetic stability among the strains from American countries between 1996 to 2012, without significant genetic changes relative to the reference strain RIMD 2210633, which was isolated in 1996 and was considered to be representative of a novel O3:K6 pandemic strain. Conclusions The genomes of V. parahaemolyticus strains isolated from clinical and environmental sources in Mexico and other American countries, presented common characteristics that have been reported for RIMD 2210633 O3:K6 pandemic strain. The major variations that were registered in this study corresponded to genes non associated to virulence factors, which could be the result of adaptations to different environmental conditions. Nevertheless, results do not show a clear pattern with the year or locality where the strains were isolated, which is an indication of a genomic stability of the studied strains.

scholarly journals Microbial Eukaryotes: a Missing Link in Gut Microbiome Studies

mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Isabelle Laforest-Lapointe ◽  
Marie-Claire Arrieta
Keyword(s):  
Microbial Communities ◽  
Microbial Ecology ◽  
High Throughput Sequencing ◽  
Sequencing Technology ◽  
Human Gut ◽  
Microbial Eukaryotes ◽  
Host Health ◽  
High Level ◽  
Eukaryotic Organisms ◽  
New Evidence

ABSTRACTHuman-associated microbial communities include prokaryotic and eukaryotic organisms across high-level clades of the tree of life. While advances in high-throughput sequencing technology allow for the study of diverse lineages, the vast majority of studies are limited to bacteria, and very little is known on how eukaryote microbes fit in the overall microbial ecology of the human gut. As recent studies consider eukaryotes in their surveys, it is becoming increasingly clear that eukaryotes play important ecological roles in the microbiome as well as in host health. In this perspective, we discuss new evidence on eukaryotes as fundamental species of the human gut and emphasize that future microbiome studies should characterize the multitrophic interactions between microeukaryotes, other microorganisms, and the host.

scholarly journals Efficacy of Nikkomycin Z in the Treatment of Murine Histoplasmosis

1998 ◽  
Vol 42 (9) ◽  
pp. 2371-2374 ◽  
Author(s):  
John R. Graybill ◽  
Laura K. Najvar ◽  
Rosie Bocanegra ◽  
Richard F. Hector ◽  
Michael F. Luther
Keyword(s):  
Body Weight ◽  
Nude Mice ◽  
Histoplasma Capsulatum ◽  
Combined Therapy ◽  
Additive Effect ◽  
Prolonged Survival ◽  
Fungal Burden ◽  
Athymic Nude Mice ◽  
Icr Mice ◽  
Nikkomycin Z

ABSTRACT Immune-competent ICR and BALB/c athymic (nude) mice were infected intravenously with Histoplasma capsulatum and treated with either fluconazole or nikkomycin Z or 5% dextrose (controls). In immune-competent ICR mice, fluconazole and nikkomycin Z both prolonged survival when given at 5 mg/kg of body weight twice daily. When administered in doses as low as 2.5 mg/kg twice daily, nikkomycin Z reduced fungal counts in both the spleen and liver. When both drugs were combined, there was no antagonism, and in combined therapy spleen and liver counts were reduced more than for either drug alone. However, nikkomycin Z had no effect on brain fungal burden. In nude mice fluconazole and nikkomycin Z had an additive effect in prolongation of survival and reduction of liver and spleen burden. Nikkomycin Z is well tolerated, is at least as effective as fluconazole, and may interact beneficially with fluconazole for treatment of murine histoplasmosis.

scholarly journals A Histoplasma capsulatum-Specific IgG1 Isotype Monoclonal Antibody, H1C, to a 70-Kilodalton Cell Surface Protein Is Not Protective in Murine Histoplasmosis

2010 ◽  
Vol 17 (7) ◽  
pp. 1155-1158 ◽  
Author(s):  
Livia Cristina Liporagi Lopes ◽  
Allan J. Guimarães ◽  
Mariana Duarte de Cerqueira ◽  
Beatriz L. Gómez ◽  
Joshua D. Nosanchuk
Keyword(s):  
Nitric Oxide ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Histoplasma Capsulatum ◽  
Fungal Growth ◽  
Surface Protein ◽  
Cell Surface Protein ◽  
Fungal Burden ◽  
Nitric Oxide Release ◽  
Igg1 Isotype

ABSTRACT Monoclonal antibodies to Histoplasma capsulatum can modify pathogenesis. We now show that monoclonal antibody H1C to a 70-kDa antigen increases intracellular fungal growth and reduces macrophage nitric oxide release but has no effect on fungal burden or survival in murine infection. This further demonstrates the complexities of host-pathogen interactions.

scholarly journals The Critical Role of Biliary Candidiasis in Development of Surgical Site Infections after Pancreatoduodenectomy: Results of Prospective Study Using a Selective Culture Medium for Candida Species

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hiroyuki Kato ◽  
Yusuke Iizawa ◽  
Kei Nakamura ◽  
Kazuyuki Gyoten ◽  
Aoi Hayasaki ◽  
...  
Keyword(s):  
Risk Factor ◽  
Candida Species ◽  
Critical Role ◽  
Significant Risk ◽  
Surgical Site Infections ◽  
Preoperative Assessment ◽  
Significant Risk Factor ◽  
High Level ◽  
New Evidence

In accordance with previous reports, the incidence of biliary candidiasis (BC) after pancreaticoduodenectomy (PD) was reported to be 0 to 5%, and the clinical significance of BC still has been elusive. In this study, we prospectively evaluated the precise incidence of BC after PD using the CHROMagar Candida plate in an attempt to elucidate whether BC has a significant impact on the clinical outcomes after PD.Patients and Method. From November 2014 to March 2016, the consecutive 51 patients who underwent PD were enrolled for this study. The bile juice was prospectively collected through the biliary stent tube on postoperative days (POD) 3, 7, and 14 and directly incubated onto the CHROMagar Candida plate for the cultivation of various Candida species. In the presence or absence of BC, we compared the incidence of SSIs.Results. The incidence of postoperative BC was 15% on POD 3, 24% on POD 7, and 39% on POD 14, respectively. Taken together, 22 patients out of 51 (43.1%) developed BC after PD. Moreover, the incidence of SSIs was significantly higher in patients with BC than in those without it (71% versus 7%, p=0.005). BC was selected as the only significant risk factor of SSIs after PD among the various risk factors. Even though a cause of BC is unknown, high level of alkaline phosphatase (cut-off line >300 IU/L) was selected as the only preoperative risk factor of the development of BC.Conclusion. We elucidated new evidence in which BC could be the independent cause of SSIs after PD and should not be recognized as just contamination artifacts. Preoperative assessment for identifying carriers of Candida species might be essential for reducing the incidence of SSIs after PD.

scholarly journals Cellular and Molecular Regulation of Vaccination with Heat Shock Protein 60 from Histoplasma capsulatum

2002 ◽  
Vol 70 (7) ◽  
pp. 3759-3767 ◽  
Author(s):  
George S. Deepe ◽  
Reta S. Gibbons
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Histoplasma Capsulatum ◽  
Regulatory Elements ◽  
Interleukin 10 ◽  
Gamma Interferon ◽  
Yeast Cells ◽  
Heat Shock Protein 60 ◽  
Fungal Burden ◽  
Inductive Phase

ABSTRACT Vaccination with heat shock protein 60 (Hsp60) from Histoplasma capsulatum induces a protective immune response in mice. We explored the cellular and molecular requirements for the efficacy of recombinant Hsp60 in mice. Depletion of CD4+, but not CD8+, cells during the inductive phase of vaccination abolished protection, as assessed by survival and by the fungal burden in lungs and spleens. In the expressive phase, the elimination of CD4+ or CD8+ cells after immunization did not significantly alter fungal recovery or survival from a lethal challenge. Depletion of both subpopulations after Hsp60 vaccination resulted in a failure to control a lethal infection and a higher fungal burden in lungs and spleens. Cytokine release by spleen cells from mice vaccinated with Hsp60 produced substantially more gamma interferon and interleukin-10 and -12 than that of cells from mice immunized with either H. capsulatum recombinant Hsp70 or bovine serum albumin. The generation of gamma interferon, but not of interleukin-10, was dependent on T cells, in particular CD4+ cells. Treatment of Hsp60-immunized mice with monoclonal antibody to gamma interferon or interleukin-10 or -12 in the inductive phase of vaccination was accompanied by increased recovery of yeast cells from lungs and spleens and 100% mortality. Likewise, the neutralization of gamma interferon or interleukin-12 abolished the protective effect of Hsp60 in the expressive phase. These results delineate the complexity of the regulatory elements necessary for vaccination against this fungus.

scholarly journals Protective Efficacy of H Antigen fromHistoplasma capsulatum in a Murine Model of Pulmonary Histoplasmosis

2001 ◽  
Vol 69 (5) ◽  
pp. 3128-3134 ◽  
Author(s):  
George S. Deepe ◽  
Reta Gibbons
Keyword(s):  
Histoplasma Capsulatum ◽  
Protective Efficacy ◽  
Interleukin 10 ◽  
Interleukin 4 ◽  
Fungal Burden ◽  
Pulmonary Exposure ◽  
Pulmonary Histoplasmosis ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

ABSTRACT We previously reported that immunization with H antigen fromHistoplasma capsulatum did not protect mice against an intravenous challenge with yeasts. Here, we investigated the utility of H antigen to protect mice in a model of pulmonary histoplasmosis. Mice immunized with H antigen and challenged intranasally 4 weeks postvaccination were protected against sublethal and lethal challenges with H. capsulatum yeasts. If the challenge was performed 3 months after vaccination, there was a reduction in fungal burden following sublethal challenge and a modest delay in mortality in mice given a lethal inoculum. Vaccination was associated with production of gamma interferon, granulocyte-macrophage colony-stimulating factor, interleukin-4, and interleukin-10 by splenocytes. Vaccination with H antigen was not accompanied by a major expansion of CD4+ or CD8+ cells in spleens of mice. These results demonstrate that H antigen may be useful as a protective immunogen against pulmonary exposure to H. capsulatum.

scholarly journals Low Utility of Pediatric Isolator Blood Culture System for Detection of Fungemia in Children: a 10-Year Review

2016 ◽  
Vol 54 (9) ◽  
pp. 2284-2287 ◽  
Author(s):  
Aaron Campigotto ◽  
Susan E. Richardson ◽  
Michael Sebert ◽  
Erin McElvania TeKippe ◽  
Aparna Chakravarty ◽  
...  
Keyword(s):  
Blood Culture ◽  
Histoplasma Capsulatum ◽  
Medical Center ◽  
Clinical Information ◽  
Automated System ◽  
Coccidioides Immitis ◽  
Dimorphic Fungi ◽  
Fungal Isolation ◽  
Content Type ◽  
Clinically Significant

The use of the Wampole Isolator 1.5-ml pediatric blood culture tube for the detection of fungemia in children was assessed by a 10-year retrospective review at two pediatric hospitals, The Hospital for Sick Children in Toronto, Canada, and the Children's Medical Center of Dallas, Texas. Over this period, a total of 9,442 pediatric Isolator specimens were processed, with yeast or yeast-like organisms recovered in 297 (3.1%) of the specimens (151 [1.6%] unique clinical episodes) and filamentous or dimorphic fungi recovered in 31 (0.3%) of the specimens (25 unique clinical episodes). Only 18 of the 151 clinical episodes of fungemia attributable to yeast were not detected by automated blood culture systems. The majority of isolated yeast wereCandidaspp., which were usually detected by automated systems, whereas the most common non-Candidayeast wasMalassezia furfur, which the automated system failed to detect. Filamentous or dimorphic fungi were detected in 25 episodes, of which only 9 (36%) episodes were deemed clinically significant after chart review, indicating that in the majority of cases (16/25, 64%) fungal isolation represented contamination. In five of the nine clinically significant episodes, the isolated fungus (Histoplasma capsulatum,Coccidioides immitis/posadasii,Fusarium oxysporum,Aspergillusspp., andBipolarisspp.) was also identified in other clinical specimens. Over the 10-year study period, the use of the pediatric Isolator system, at the discretion of the treating physician, only rarely provided useful clinical information for the diagnosis of fungemia in children, with the exception ofM. furfurand possibly endemic mycoses.

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