Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0012872 (
DNA marker
)
929
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
13 species and several genotypes have been described so far within the genus Cryptosporidium. All of them have very small stages which makes morphological differentiation difficult. The most common species is C. parvum, an enteric pathogen with a broad host spectrum including man and domestic mammals. Molecular biological studies on isolates of C. parvum and other species have shown that the species is likely not to be monophyletic but consists of several species with different host spectra. Based on
DNA marker
sequences one human and various animal genotypes can be differentiated.
Infections
of immunocompetent patients with C. parvum are usually associated with the human genotype, while infections of immunodeficient (HIV-positive) patients can also be correlated with various animal genotypes or even primarily animal pathogenic species of Cryptosporidium (e.g., C. felis). According to our current knowledge cryptosporidia are zoonotic agents; however, an animal source of human infections cannot automatically be assumed. Parasites from human patients with low infectivity for cattle and laboratory rodents could be isolated which are not considered as zoonotic.
...
PMID:[Is Cryptosporidium a zoonotic agent?]. 1568 36
The effectiveness of a new first-in-class antibiotic, tigecycline (glycylcycline), was evaluated during the early dissemination (1 week), early immune (3 weeks), or late persistent (4 months) phases of Borrelia burgdorferi infection in C3H mice. Mice were treated with high or low doses of tigecycline, saline (negative-effect controls), or a previously published regimen of ceftriaxone (positive-effect controls).
Infection
status was assessed at 3 months after treatment by culture, quantitative ospA real-time PCR, and subcutaneous transplantation of joint and heart tissue into SCID mice. Tissues from all saline-treated mice were culture and ospA PCR positive, tissues from all antibiotic-treated mice were culture negative, and some of the tissues from most of the mice treated with antibiotics were ospA PCR positive, although the
DNA marker
load was markedly decreased compared to that in saline-treated mice. Antibiotic treatment during the early stage of infection appeared to be more effective than treatment that began during later stages of infection. The viability of noncultivable spirochetes in antibiotic-treated mice (demonstrable by PCR) was confirmed by transplantation of tissue allografts from treated mice into SCID mice, with dissemination of spirochetal DNA to multiple recipient tissues, and by xenodiagnosis, including acquisition by ticks, transmission by ticks to SCID mice, and survival through molting into nymphs and then into adults. Furthermore, PCR-positive heart base tissue from antibiotic-treated mice revealed RNA transcription of several B. burgdorferi genes. These results extended previous studies with ceftriaxone, indicating that antibiotic treatment is unable to clear persisting spirochetes, which remain viable and infectious, but are nondividing or slowly dividing.
...
PMID:Ineffectiveness of tigecycline against persistent Borrelia burgdorferi. 1999 19
The Atlantic salmon, Salmo salar L., in the Tornio River in the Northern Baltic Sea basin accommodates a monogenean ectoparasite, Gyrodactylus salaris. The aim of the study was to understand the population structure of apparently co-adapted host-parasite system: no parasite-associated mortality has been reported. The parasite burden among salmon juveniles (parr) was monitored along 460km of the river in 2000-2009. Among the parr, 33.0% were infected (n
fish
=1913). The genetic structure of the parasite population was studied by sequencing an anonymous nuclear
DNA marker
(ADNAM1, three main genotypes) and mitochondrial CO1 (three clades, six haplotypes). During the ten years, the parasite population was strongly and stably genetically differentiated among up- and downstream nurseries (n
ADNAM1
=411, F
ST
=0.579; n
CO1
=443, F
ST
=0.534).
Infection
prevalence among the smolts migrating to sea was higher than in the sedentary parr populations (82.2%, n
fish
=129). The spatial differentiation observed among the sedentary juveniles was reflected temporally in the smolt run: parasite genotypes dominating the upper part of the river arrived later than downstream dwellers (medians June 4 and June 2) to the trap 7km from the river mouth. The nuclear and mitochondrial markers were in stable disequilibrium which was not relaxed in the contact zone or among the smolts where the parasite clones often met on individual fish. Only five parasite specimens on smolts (n
worms
=217) were putative recent sexual recombinants. The contribution of extant salmon hatcheries into the infection was negligible. The host salmon population in Tornio River is known to show significant spatial differentiation (F
ST
=0.022). The stable spatial genetic structure of the parasite against the high physical mobility suggested a possibility of local co-adaptation of the host-parasite subpopulations.
...
PMID:Genetic gradient of a host-parasite pair along a river persisted ten years against physical mobility: Baltic Salmo salar vs. Gyrodactylus salaris. 2750 27
