Post epizootic persistence of asymptomatic Mycoplasma conjunctivae infection in a wild mountain ungulate
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PROVIDER: PRJEB15465 | ENA |
REPOSITORIES: ENA
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Project description:The susceptibility of the Iberian ibex (Capra pyrenaica) to Mycoplasma conjunctivae ocular infection and the changes in their interaction over time were studied in terms of clinical outcome, molecular detection, and IgG immune response in a captive population that underwent a severe infectious keratoconjunctivitis (IKC) outbreak. Mycoplasma conjunctivae was detected in the Iberian ibex, coinciding with the IKC outbreak. Its prevalence had a decreasing trend in 2013 that was consistent with the clinical resolution (August, 35.4%; September, 8.7%; November, 4.3%). Infections without clinical outcome were, however, still detected in the last handling in November. Sequencing and cluster analyses of the M. conjunctivae strains found 1 year later in the ibex population confirmed the persistence of the same strain lineage that caused the IKC outbreak but with a high prevalence (75.3%) of mostly asymptomatic infections and with lower DNA load of M. conjunctivae in the eyes (mean quantitative PCR [qPCR] cycle threshold [CT ], 36.1 versus 20.3 in severe IKC). Significant age-related differences of M. conjunctivae prevalence were observed only under IKC epizootic conditions. No substantial effect of systemic IgG on M. conjunctivae DNA in the eye was evidenced with a linear mixed-models selection, which indicated that systemic IgG does not necessarily drive the resolution of M. conjunctivae infection and does not explain the epidemiological changes observed. The results show how both epidemiological scenarios, i.e., severe IKC outbreak and mostly asymptomatic infections, can consecutively occur by entailing mycoplasma persistence.IMPORTANCEMycoplasma infections are reported in a wide range of epidemiological scenarios that involve severe disease to asymptomatic infections. This study allows a better understanding of the transition between two different Mycoplasma conjunctivae epidemiological scenarios described in wild host populations and highlights the ability of M. conjunctivae to adapt, persist, and establish diverse interactions with its hosts. The proportion of asymptomatic and clinical M. conjunctivae infections in a host population may not be regarded only in response to intrinsic host species traits (i.e., susceptibility) but also to a specific host-pathogen interaction, which in turn influences the infection dynamics. Both epidemic infectious keratoconjunctivitis and a high prevalence of asymptomatic M. conjunctivae infections may occur in the same host population, depending on the circulation of M. conjunctivae, its maintenance, and the progression of the host-pathogen interactions.
| S-EPMC5514678 | biostudies-literature
Project description:BACKGROUND: The mollicute Mycoplasma conjunctivae is the etiological agent leading to infectious keratoconjunctivitis (IKC) in domestic sheep and wild caprinae. Although this pathogen is relatively benign for domestic animals treated by antibiotics, it can lead wild animals to blindness and death. This is a major cause of death in the protected species in the Alps (e.g., Capra ibex, Rupicapra rupicapra). METHODS: The genome was sequenced using a combined technique of GS-FLX (454) and Sanger sequencing, and annotated by an automatic pipeline that we designed using several tools interconnected via PERL scripts. The resulting annotations are stored in a MySQL database. RESULTS: The annotated sequence is deposited in the EMBL database (FM864216) and uploaded into the mollicutes database MolliGen http://cbi.labri.fr/outils/molligen/ allowing for comparative genomics. CONCLUSION: We show that our automatic pipeline allows for annotating a complete mycoplasma genome and present several examples of analysis in search for biological targets (e.g., pathogenic proteins).
| S-EPMC2697654 | biostudies-literature
Project description:Species of the Neisseria genus harbor close relationships with their mamallian hosts, including humans. The outcome of these interactions can result in commensalism, asymptomatic carriage, or acute inflammatory responses. Little is known of the mechanisms Neisseria use to maintain and shape their host niche in the context of asymptomatic infection or long term commensal colonization and persistence. To identify novel host interaction factors contributing to host persistence, a Tn5 transposon library was created in Neisseria musculi, and inoculated into a permissive strain of laboratory mice (CAST/EiJ). At various time points post inoculation, transposon mutants were recovered from fecal and oral samples, and analyzed to identifiy mutants incapable of maintaining a host niche at either site.
2022-04-12 | GSE188969 | GEO
Project description:Survey of relative gene expression profiles in larvae, pupae, and midguts and fatbodies of teneral, unfed, and fed adult mountain pine beetles from western Nevada, USA.
2009-08-29 | GSE17858 | GEO
Project description:During the dry season, in many African regions, persistent asymptomatic malaria cases have been linked to downregulated virulence gene expression encoded by the var gene family, resulting in low adhesion and increased circulation time of Plasmodium falciparum-infected erythrocytes 1. Several studies have investigated associations between parasite transcription and clinical severity, but the underlying process that results in lower virulence gene expression in asymptomatic malaria remains unknown. Here we report an RNA Polymerase III-dependent mechanism that in response to external stimuli, decreases var gene transcription and parasite multiplication rate. The singular expression of var gene members, while under tight epigenetic regulation by the parasite 2, is additionally controlled by a family of ncRNA, termed RUF6 3. We show that Pol III transcription of tRNAs and RUF6 is severely decreased in field isolates of asymptomatic individuals infected with P. falciparum during the dry season. We identified Maf1 as a negative effector of RUF6 ncRNA transcription and show that external stimuli depend on plasmodial Maf1 to trigger lower expression of RNA Pol III-transcribed genes. Our results uncover a TOR-independent unprecedented signaling pathway in a protozoan pathogen that is highly relevant for establishing asymptomatic subclinical parasite persistence in the dry season.
2024-06-25 | PXD040576 | Pride
Project description:Molecular epidemiology of infectious keratoconjunctivitis caused by Mycoplasma conjunctivae in European countries
| PRJEB14126 | ENA