Effects of passaging through scarabeid hosts on virulence and host specificity of two strains of the entomopathogenic hyphomycete Metarhizium anisopliae

1983 ◽  
Vol 29 (5) ◽  
pp. 576-583 ◽  
Author(s):  
Jacques F. Fargues ◽  
Pierre H. Robert
Keyword(s):  
Host Species ◽  
Metarhizium Anisopliae ◽  
Insect Host ◽  
Artificial Medium ◽  
Susceptible Host ◽  
Single Host ◽  
Entomopathogenic Hyphomycete ◽  
Enzymatic Mechanisms ◽  
Phenotypic Responses

The effects on pathogenicity of Metarhizium anisopliae (Metsch.) Sor. following one or more passages through the original and the heterologous insect host species were investigated by using two pathotypes specific for Cetonia aurata L. and Oryctes rhinoceros L., respectively. A significant increase in virulence occurred after a single host passage. Thus, the infection potential of host-passed inocula could be increased by a factor of 10 to 100, and its host-induced adaptation was almost complete after the first in vivo passage. Bacteria located on the integument of the host cadaver were not implicated in this phenomenon. When the fungus was again grown on artificial medium, the loss in virulence was also very fast. Consequently, changes in virulence of the two tested strains seemed to be phenotypic responses implicating inducible enzymatic mechanisms. Nevertheless, the parasitic behaviour of the two pathotypes toward the larvae of the nonsusceptible species was not modified by host passaging through their respective insect hosts. It is concluded that changes in entomopathogenic hyphomycete virulence, resulting from host passage, concern only the naturally susceptible host species.

scholarly journals Application of Pulsed-Field Gel Electrophoresis and Binary Typing as Tools in Veterinary Clinical Microbiology and Molecular Epidemiologic Analysis of Bovine and HumanStaphylococcus aureus Isolates

2000 ◽  
Vol 38 (5) ◽  
pp. 1931-1939 ◽  
Author(s):  
Ruth Zadoks ◽  
Willem van Leeuwen ◽  
Herman Barkema ◽  
Otlis Sampimon ◽  
Henri Verbrugh ◽  
...  
Keyword(s):  
Host Species ◽  
Gel Electrophoresis ◽  
Genetic Relatedness ◽  
Pulsed Field Gel Electrophoresis ◽  
Simple Method ◽  
Pulsed Field ◽  
Strain Characterization ◽  
Single Host

Thirty-eight bovine mammary Staphylococcus aureusisolates from diverse clinical, temporal, and geographical origins were genotyped by pulsed-field gel electrophoresis (PFGE) afterSmaI digestion of prokaryotic DNA and by means of binary typing using 15 strain-specific DNA probes. Seven pulsed-field types and four subtypes were identified, as were 16 binary types. Concordant delineation of genetic relatedness was documented by both techniques, yet based on practical and epidemiological considerations, binary typing was the preferable method. Genotypes of bovine isolates were compared to 55 previously characterized human S. aureusisolates through cluster analysis of binary types. Genetic clusters containing strains of both human and bovine origin were found, but bacterial genotypes were predominantly associated with a single host species. Binary typing proved an excellent tool for comparison ofS. aureus strains, including methicillin-resistant S. aureus, derived from different host species and from different databases. For 28 bovine S. aureus isolates, detailed clinical observations in vivo were compared to strain typing results in vitro. Associations were found between distinct genotypes and severity of disease, suggesting strain-specific bacterial virulence. Circumstantial evidence furthermore supports strain-specific routes of bacterial dissemination. We conclude that PFGE and binary typing can be successfully applied for genetic analysis of S. aureusisolates from bovine mammary secretions. Binary typing in particular is a robust and simple method and promises to become a powerful tool for strain characterization, for resolution of clonal relationships of bacteria within and between host species, and for identification of sources and transmission routes of bovine S. aureus.

Control biológico de garrapata (Boophilus spp.) con diferentes cepas de Metarhizium anisopliae (Metchnikoff) Sorokin en bovinos

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
López Osorio
Keyword(s):  
Metarhizium Anisopliae

Con el objetivo de evaluar cuatro cepas del hongo Metarhizium anisopliae (Metschincoff) Sorokin para el control garrapatas del genero Boophilus spp., se seleccionaron dos cepas de garrapatas para su evaluación en su fase adulta sobre terneros parasitados. Se utilizó un diseño completamente al azar, con seis tratamientos y diez repeticiones.En esta fase las cepas PLH y CH 93-3 fueron las que mostraron la mayor efectividad, por lo que fueron evaluadas en garrapatas adultas sobre terneros previamente parasitados; en la prueba in vivo se utilizó un diseño de bloques completamente al azar, cuatro tratamientos (Las dos cepas seleccionadas, un compuesto químico y un placebo a base de agua) y ocho repeticiones. Los resultados mostraron que las dos cepas evaluadas presentaron una efectividad del 50% con respecto al producto químico.

scholarly journals Exposure of ichnovirus particles to digitonin leads to enhanced infectivity and induces fusion from without in an in vitro model system

2007 ◽  
Vol 88 (11) ◽  
pp. 2977-2984 ◽  
Author(s):  
Don Stoltz ◽  
Renée Lapointe ◽  
Andrea Makkay ◽  
Michel Cusson
Keyword(s):  
Outer Membrane ◽  
In Vitro Model ◽  
Model System ◽  
Host Cells ◽  
Fusion Event ◽  
Susceptible Host ◽  
In Vitro Model System ◽  
Vitro Model

Unlike most viruses, the mature ichnovirus particle possesses two unit membrane envelopes. Following loss of the outer membrane in vivo, nucleocapsids are believed to gain entry into the cytosol via a membrane fusion event involving the inner membrane and the plasma membrane of susceptible host cells; accordingly, experimentally induced damage to the outer membrane might be expected to increase infectivity. Here, in an attempt to develop an in vitro model system for studying ichnovirus infection, we show that digitonin-induced disruption of the virion outer membrane not only increases infectivity, but also uncovers an activity not previously associated with any polydnavirus: fusion from without.

Effects of UVB Irradiance on Conidia and Germinants of the Entomopathogenic Hyphomycete Metarhizium anisopliae: A Study of Reciprocity and Recovery¶

2007 ◽  
Vol 73 (2) ◽  
pp. 140-146
Author(s):  
Gilberto U. L. Braga ◽  
Stephan D. Flint ◽  
Claudio L. Messias ◽  
Anne J. Anderson ◽  
Donald W. Roberts
Keyword(s):  
Metarhizium Anisopliae ◽  
Entomopathogenic Hyphomycete

scholarly journals Quantifying relative virulence: when μ max fails and AUC alone just is not enough

2020 ◽  
Author(s):  
Ruben Michael Ceballos ◽  
Carson Len Stacy
Keyword(s):  
Specific Growth ◽  
Area Under The Curve ◽  
Maximum Specific Growth Rate ◽  
Curve Analysis ◽  
Growth Curve Analysis ◽  
Virus Infections ◽  
Susceptible Host ◽  
Host Interactions ◽  
Biological Phenomena ◽  
Single Host

A challenge in virology is quantifying relative virulence (V R) between two (or more) viruses that exhibit different replication dynamics in a given susceptible host. Host growth curve analysis is often used to mathematically characterize virus–host interactions and to quantify the magnitude of detriment to host due to viral infection. Quantifying V R using canonical parameters, like maximum specific growth rate (μ max), can fail to provide reliable information regarding virulence. Although area-under-the-curve (AUC) calculations are more robust, they are sensitive to limit selection. Using empirical data from Sulfolobus Spindle-shaped Virus (SSV) infections, we introduce a novel, simple metric that has proven to be more robust than existing methods for assessing V R. This metric (I SC) accurately aligns biological phenomena with quantified metrics to determine V R. It also addresses a gap in virology by permitting comparisons between different non-lytic virus infections or non-lytic versus lytic virus infections on a given host in single-virus/single-host infections.

Genetic variation in the mitochondrial cytochrome c oxidase subunit 1 within Progamotaenia festiva (Cestoda: Anoplocephalidae) from macropodid marsupials

Parasitology ◽  
2007 ◽  
Vol 134 (10) ◽  
pp. 1465-1476 ◽  
Author(s):  
I. BEVERIDGE ◽  
S. SHAMSI ◽  
M. HU ◽  
N. B. CHILTON ◽  
R. B. GASSER
Keyword(s):  
Genetic Variation ◽  
Host Species ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Enzyme Electrophoresis ◽  
Single Strand Conformational Polymorphism ◽  
Oxidase Subunit ◽  
Single Host ◽  
Distinct Sequence ◽  
Sequence Types

SUMMARYGenetic variation was examined in the anoplocephalid cestode Progamotaenia festiva, from Australian marsupials, in order to test the hypothesis that P. festiva, is a complex of sibling species and to assess the extent of host switching reported previously based on multilocus enzyme electrophoresis (MEE). Polymerase chain reaction (PCR)-based single-strand conformational polymorphism (SSCP) was used for the analysis of sequence variation in the cytochrome c oxidase subunit 1 (cox1) gene among 179 specimens of P. festiva (identified based on morphology and predilection site in the host) from 13 different host species, followed by selective DNA sequencing. Fifty-three distinct sequence types (haplotypes) representing all specimens were defined. Phylogenetic analyses of these sequence data (utilizing maximum parsimony and neighbour-joining methods) revealed 12 distinct clades. Other heterologous species, P. ewersi and P. macropodis, were used as outgroups and the remaining bile-duct inhabiting species, P. diaphana and P. effigia, were included in the analysis for comparative purposes. The latter 2 species were nested within the clades representing P. festiva. Most clades of P. festiva identified were restricted to a single host species; one clade primarily in Macropus robustus was also found in the related host species M. antilopinus in an area of host sympatry; another clade occurring primarily in M. robustus occurred also in additional kangaroo species, M. rufus and M. dorsalis. High levels of genetic divergence, the existence of distinct clades and their occurrence in sympatry provide support for the hypothesis that P. festiva represents a complex of numerous species, most of which, but not all, are host specific. Three distinct clades of cestodes were found within a single host, M. robustus, but there was no evidence of within-host speciation.

Epidemiology and optimal foraging: modelling the ideal free distribution of insect vectors

Parasitology ◽  
2000 ◽  
Vol 120 (3) ◽  
pp. 319-327 ◽  
Author(s):  
D. W. KELLY ◽  
C. E. THOMPSON
Keyword(s):  
Host Species ◽  
Disease Transmission ◽  
Ideal Free Distribution ◽  
Host Population ◽  
Control Effort ◽  
Susceptible Host ◽  
Vector Density ◽  
Free Distribution ◽  
Blood Sucking ◽  
Ideal Free

Existing models of the basic case reproduction number (R0) for vector-borne diseases assume (i) that the distribution of vectors over the susceptible host species is homogenous and (ii) that the biting preference for the susceptible host species rather than other potential hosts is a constant. Empirical evidence contradicts both assumptions, with important consequences for disease transmission. In this paper we develop an Ideal Free Distribution (IFD) model of host choice by blood-sucking insects, predicated on the argument that vectors must have evolved to choose the least defensive hosts in order to maximize their feeding success. From a re-analysis of existing data, we demonstrate that the interference constant, m, of the IFD can vary between host species. As a result, the predicted distribution of insects over hosts has 2 desirable and intuitively plausible behaviours: that it is heterogeneous both within and between host species; and that the intensity of heterogeneity varies with host and vector density. When the IFD model is incorporated into R0, the relationship with the vector: host ratio becomes non-linear. If correct, the IFD could add considerable realism to models which seek to predict the effect of these ecological parameters on disease transmission as they vary naturally (e.g. through seasonality in vector density or host population movement) or as a consequence of artificial manipulation (e.g. zooprophylaxis, vector control). It raises the possibility of targeting transmission hot spots with greater accuracy and concomitant reduction in control effort. The robustness of the model to simplifying assumptions is discussed.

The occurrence of species flocks in the nematode genus Cloacina (Strongyloidea : Cloacininae), parasitic in the stomachs of kangaroos and wallabies

2002 ◽  
Vol 50 (6) ◽  
pp. 597 ◽  
Author(s):  
I. Beveridge ◽  
N. B. Chilton ◽  
D. M. Spratt
Keyword(s):  
Host Specificity ◽  
Host Species ◽  
Nematode Species ◽  
Morphological Data ◽  
Species Flock ◽  
Sampling Effort ◽  
Nematode Genus ◽  
Single Host ◽  
Species Flocks ◽  
Occurrence Of Species

The occurrence of species flocks within the nematode genus Cloacina was examined using the criteria of host specificity, co-occurrence and monophyly. Species of Cloacina generally exhibited a high degree of host specificity, with most species occurring either in a single host species or in two closely related host species. The frequency distribution of numbers of component species of Cloacina per host species indicated that most host species harboured 2–4 species of nematodes, with an approximately exponential decline in the number of species of parasites to a maximum of 20 species of nematode per host species. Host species harbouring eight or more species of Cloacina were found within a single recent macropodid clade, but there was no correlation between evolutionary age of the host and the number of parasite species harboured. Sampling effort was significantly correlated with the number of nematode species found and, in partial regression analysis, subsumed the effects of host body size and geographic range, which were found to be significant correlates with the number of nematode species present in preliminary analyses. Analysis of co-occurrences of nematode species indicated significant variation between host species, with some hosts (e.g. Macropus agilis) most commonly harbouring a single species of Cloacina, while closely related host species (e.g. M. dorsalis) most commonly harboured numerous species. Parsimony analysis of species of Cloacina based on morphological data suggested that while small series of related nematode species could be identified within a single host species, the species flock in each host species is polyphyletic in origin. Species flocks contributed significantly to community richness in some host species.

Eight New Species of Sucking Lice (Psocodea: Phthiraptera) From Endemic Murine Rodents in Australia and an Updated Identification Key

2020 ◽  
Author(s):  
Wei Wang ◽  
Lance A Durden ◽  
Haylee Weaver ◽  
Renfu Shao
Keyword(s):  
New Species ◽  
Host Species ◽  
Identification Key ◽  
Museum Specimens ◽  
Dichotomous Key ◽  
Sucking Lice ◽  
Single Host ◽  
Murine Rodents ◽  
Louse Species ◽  
Comprehensive Study

Abstract Based on a comprehensive study of museum specimens, eight new species of sucking lice of the genus Hoplopleura Enderlein, 1904 (Psocodea: Phthiraptera: Hoplopleuridae), are described from six genera of Australian Old Endemic rodents: Conilurus Ogilby, 1838 (Rodentia: Muridae), Leggadina Thomas, 1910 (Rodentia: Muridae), Leporillus Thomas, 1906 (Rodentia: Muridae), Mesembriomys Palmer, 1906 (Rodentia: Muridae), Pogonomys Milne-Edwards, 1877 (Rodentia: Muridae), and Xeromys Thomas, 1889 (Rodentia: Muridae). The description of these new species increases the number of sucking louse species from endemic Australian rodents from 13 to 21 and extends the records of sucking lice to all of the 14 genera of endemic rodents in Australia. Our results show that sucking lice are much more diverse among rodents in Australia than previously known. Furthermore, the Australian Hoplopleura species are host specific—each Hoplopleura species, including the eight new species described in the present study, parasitizes only a single host species, except Hoplopleura irritans Kuhn and Ludwig, 1967 (Psocodea: Phthiraptera: Hoplopleuridae) and Hoplopleura melomydis Weaver, 2017 (Psocodea: Phthiraptera: Hoplopleuridae), each of which is found on two host species. An updated dichotomous key for identifying Australian Hoplopleura species is included.

scholarly journals Methods for Detecting Mycobacterial Mixed Strain Infections–A Systematic Review

2020 ◽  
Vol 11 ◽  
Author(s):  
Alexander Stephen Byrne ◽  
Alex Goudreau ◽  
Nathalie Bissonnette ◽  
Isdore Chola Shamputa ◽  
Kapil Tahlan
Keyword(s):  
Systematic Review ◽  
Host Species ◽  
Search Strategy ◽  
Concurrent Infection ◽  
Accurate Identification ◽  
Susceptible Host ◽  
Mycobacterial Diseases ◽  
Typing Methods ◽  
Multiple Strains ◽  
Work Done

Mixed strain infection (MSI) refers to the concurrent infection of a susceptible host with multiple strains of a single pathogenic species. Known to occur in humans and animals, MSIs deserve special consideration when studying transmission dynamics, evolution, and treatment of mycobacterial diseases, notably tuberculosis in humans and paratuberculosis (or Johne's disease) in ruminants. Therefore, a systematic review was conducted to examine how MSIs are defined in the literature, how widespread the phenomenon is across the host species spectrum, and to document common methods used to detect such infections. Our search strategy identified 121 articles reporting MSIs in both humans and animals, the majority (78.5%) of which involved members of the Mycobacterium tuberculosis complex, while only a few (21.5%) examined non-tuberculous mycobacteria (NTM). In addition, MSIs exist across various host species, but most reports focused on humans due to the extensive amount of work done on tuberculosis. We reviewed the strain typing methods that allowed for MSI detection and found a few that were commonly employed but were associated with specific challenges. Our review notes the need for standardization, as some highly discriminatory methods are not adapted to distinguish between microevolution of one strain and concurrent infection with multiple strains. Further research is also warranted to examine the prevalence of NTM MSIs in both humans and animals. In addition, it is envisioned that the accurate identification and a better understanding of the distribution of MSIs in the future will lead to important information on the epidemiology and pathophysiology of mycobacterial diseases.

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