Host specificity in the Giardia duodenalis species complex

2018 ◽  
Vol 66 ◽  
pp. 335-345 ◽  
Author(s):  
Simone M. Cacciò ◽  
Marco Lalle ◽  
Staffan G. Svärd
Keyword(s):  
Host Specificity ◽  
Species Complex ◽  
Giardia Duodenalis

scholarly journals Comparison of Colletotrichum orbiculare and Several Allied Colletotrichum spp. for mtDNA RFLPs, Intron RFLP and Sequence Variation, Vegetative Compatibility, and Host Specificity

2007 ◽  
Vol 97 (10) ◽  
pp. 1305-1314 ◽  
Author(s):  
B. Liu ◽  
L. A. Wasilwa ◽  
T. E. Morelock ◽  
N. R. O'Neill ◽  
J. C. Correll
Keyword(s):  
Host Specificity ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Species Complex ◽  
Sequence Variation ◽  
Distinct Species ◽  
Vegetative Compatibility ◽  
Haplotype A ◽  
Restriction Fragment Length ◽  
Mtdna Haplotype

Based on spore morphology, appressorium development, sequence similarities of the rDNA, and similarities in amplified restriction fragment length polymorphism (AFLP), it has been proposed that Colletotrichum orbiculare, C. trifolii, C. lindemuthianum, and C. malvarum represent a single phylogenetic species, C. orbiculare. In the current study, the phylogenetic relationship among isolates in the C. orbiculare species complex was reassessed. In all, 72 isolates of C. orbiculare from cultivated cucurbit or weed hosts, C. trifolii from alfalfa, C. lindemuthianum from green bean, and C. malvarum from prickly sida (Sida spinosa) were examined for mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs), RFLPs and sequence variation of a 900-bp intron of the glutamine synthetase gene and a 200-bp intron of the glyceraldehyde-3-phosphate dehydrogenase gene, and vegetative compatibility. In addition, host specificity was examined in foliar inoculations on cucurbit, bean, and alfalfa hosts. Inoculations also were conducted on cucumber fruit. Genetically distinct isolates, based on vegetative compatibility, within the species complex (C. orbiculare, C. trifolii, and C. malvarum) had an identical mtDNA haplotype (haplotype A) when examined with each of three different restriction enzymes. Isolates of C. lindemuthianum had a very similar mtDNA haplotype to haplotype A, with a single polymorphism detected with the enzyme HaeIII. The four species represent a phylogenetically closely related group based on a statistical analysis of the 900- and 200-bp intron sequences. However, distinct RFLPs in the 900-bp intron were consistently associated with each species and could be used to qualitatively and quantitatively distinguish each species. Furthermore, each of the species showed distinct host specificity, with isolates of C. orbiculare (from cucurbits), C. lindemuthianum, and C. trifolii being pathogenic only on cucurbits, green bean, and alfalfa, respectively. Consequently, distinct and fixed nucleotide, or genotypic (intron sequences and RFLPs) and phenotypic (host specificity) characteristics can be used to distinguish C. orbiculare, C. lindemuthianum, and C. trifolii from one another; therefore, they should be recognized as distinct species. This species delineation is consistent with the most current species concepts in fungi. More isolates and further characterization is needed to determine whether C. orbiculare from cocklebur and C. malvarum represent distinct species. RFLPs of the 900-bp intron may represent a relatively inexpensive, reliable, and useful diagnostic tool for general species differentiation in the genus Colletotrichum.

Host specificity in diatom–bacteria interactions alleviates antagonistic effects

2019 ◽  
Vol 95 (11) ◽  
Author(s):  
Willem Stock ◽  
Lander Blommaert ◽  
Marleen De Troch ◽  
Sven Mangelinckx ◽  
Anne Willems ◽  
...  
Keyword(s):  
Host Specificity ◽  
Species Complex ◽  
Antagonistic Effect ◽  
Diatom Species ◽  
Bacterial Isolates ◽  
Growth Responses ◽  
Associated Bacteria ◽  
Antagonistic Effects ◽  
Cylindrotheca Closterium ◽  
The Impact

ABSTRACT While different microalgae tend to be associated with different bacteria, it remains unclear whether such specific associations are beneficial for the microalgae. We assessed the impact of bacterial isolates, derived from various marine benthic diatoms, on the growth of several strains belonging to the Cylindrotheca closterium diatom species complex. We first tested the effect of 35 different bacterial isolates on the growth of a single C. closterium strain, and then evaluated the impact of 8 of these isolates on the growth of 6 C. closterium strains and 1 Cylindrotheca fusiformis strain. Surprisingly, most interactions were neutral to antagonistic. The interactions were highly specific, with diatom growth in the presence of specific bacteria differing between Cylindrotheca strains and species, and closely related bacteria eliciting contrasting diatom growth responses. These differences could be related to the origin of the bacterial isolates, as only isolates from foreign diatom hosts significantly reduced diatom growth, implying coadaptation between different Cylindrotheca strains and their associated bacteria. Interestingly, the antagonistic effect of a Marinobacter strain was alleviated by the presence of a microbial inoculum that was native to the diatom host, suggesting that coadapted bacteria might also benefit their host indirectly by preventing the establishment of harmful bacteria.

scholarly journals Whole genome sequencing of dog specific assemblages C and D of Giardia duodenalis from single and pooled cysts indicates host associated genes

2019 ◽  
Author(s):  
F.N.J. Kooyman ◽  
J.A. Wagenaar ◽  
A. Zomer
Keyword(s):  
Whole Genome Sequencing ◽  
Host Specificity ◽  
Genome Sequencing ◽  
Cathepsin B ◽  
Multiple Displacement Amplification ◽  
Giardia Duodenalis ◽  
Marker Genes ◽  
Giardia Cyst ◽  
Whole Genome ◽  
Allelic Sequence

AbstractGiardia duodenalis (Syn. G. intestinalis or G. lamblia) infects over 280 million people each year and numerous animals. G. duodenalis can be subdivided into 8 assemblages with different host specificity. Unculturable assemblages have so far resisted genome sequencing efforts. In this study we isolated single and pooled cysts of assemblage C and D from dog faeces by FACS and sequenced them using multiple displacement amplification and Illumina paired end sequencing. The genomes of assemblages C and D were compared with genomes of assemblages A and B from humans and assemblage E from ruminants and pigs. The genomes obtained from the pooled cysts and from the single cysts were considered complete (>99% marker genes observed) and the allelic sequence heterozygosity (ASH) of assemblage C and D was 0.89% and 0.74%, respectively. Higher than for assemblage B (> 0.43%) and much higher than for assemblages A and E (<0.01%). The flavohemoglobin and 4Fe-4S binding domain family gene involved in O2 and NO detoxification were only present in assemblages A, B and E. Cathepsin-B orthologs were found in all genomes. Six clades of cathepsin-B orthologs contained one gene of each genome, while in three clades not all assemblages were represented. We conclude that whole genome sequencing from a single Giardia cyst results in complete draft genomes making the genomes of unculturable Giardia assemblages accessible. Observed differences between the genomes of assemblage C and D on one hand and the assemblages A, B and E on the other hand are possibly associated with host specificity.

Three new species of Fergusonina Malloch gall-flies (Diptera: Fergusoninidae) from terminal leaf bud galls on Eucalyptus (Myrtaceae) in south-eastern Australia

Zootaxa ◽  
2011 ◽  
Vol 3112 (1) ◽  
pp. 36 ◽  
Author(s):  
LEIGH A. NELSON ◽  
SONJA J. SCHEFFER ◽  
DAVID K. YEATES
Keyword(s):  
New Species ◽  
Host Specificity ◽  
Species Complex ◽  
The Other ◽  
Adult Size ◽  
Dorsal Shield ◽  
South Eastern ◽  
Eastern Australia ◽  
Three New Species ◽  
South Eastern Australia

Three new species of Fergusonina (Diptera: Fergusoninidae) flies are described from terminal leaf bud galls on Eucalyptus L'Hér. from south eastern Australia. Fergusonina omlandi Nelson and Yeates sp. nov. is the first species of fly from the genus Fergusonina to be described from the Eucalyptus pauciflora Sieb. ex Spreng. (Snow Gum) species complex; although another two species occur in sympatry on this host at higher elevations. Fergusonina omlandi sp. nov. can be distinguished from the latter by differences in adult size and markings on the mesonotum and morphology of the dorsal shield of the larva. The other new species, Fergusonina williamensis Nelson and Yeates sp. nov. and Fergusonina thornhilli Nelson and Yeates sp. nov. are the first flies to be described from Eucalyptus baxteri (Benth.) Maiden & Blakely and Eucalyptus dalrympleana Maiden, respectively. These two species can be distinguished from all other described Fergusonina by host specificity, adult colour and setation and morphology of the dorsal shield.

scholarly journals Phytopathogen Genome Announcement: Draft Genome Sequences of 62 Pseudomonas syringae Type and Pathotype Strains

2016 ◽  
Vol 29 (4) ◽  
pp. 243-246 ◽  
Author(s):  
Shalabh Thakur ◽  
Bevan S. Weir ◽  
David S. Guttman
Keyword(s):  
Host Specificity ◽  
Pseudomonas Syringae ◽  
Species Complex ◽  
Draft Genome ◽  
Genome Sequences ◽  
Diverse Species ◽  
Important Crop ◽  
Genomic Basis

Pseudomonas syringae is a diverse species-complex that includes many important crop pathogens. Here, we report the draft genomes of 62 type and pathotype strains, which provide a genomic reference for the diversity of this species complex and will contribute to the elucidation of the genomic basis of pathogenicity and host specificity.

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