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BACKGROUND: The Centers for Disease Control and Prevention's Active Bacterial Core surveillance (ABCs) identified increased serotype 4 invasive pneumococcal disease (IPD), particularly among adults experiencing homelessness (AEH). METHODS: We quantified IPD cases during 2016-2022. Employing genomic-based characterization of IPD isolates, we identified serotype-switch variants. Recombinational analyses were used to identify the genetic donor and recipient strains that generated a serotype 4 progeny strain. We performed phylogenetic analyses of the serotype 4 progeny and serotype 12F genetic recipient to determine genetic distances. RESULTS: We identified 30 inter-related (0-21 nucleotide differences) IPD isolates recovered during 2022-2023, corresponding to a serotype 4 capsular-switch variant. This strain arose through a multi-fragment recombination event between serotype 4/ST10172 and serotype 12F/ST220 parental strains. Twenty-five of the 30 cases occurred within Oregon. Of 29 cases with known residence status, 16 occurred in AEH. Variant emergence coincided with a 2.6-fold increase (57 to 148) of cases caused by the serotype 4/ST10172 donor lineage in 2022 compared to 2019 and its first appearance in Oregon. Most serotypes showed sequential increases of AEH IPD/all IPD ratios during 2016-2022 (for all serotypes combined, 247/2198, 11.2% during 2022 compared to 405/5317, 7.6% for 2018-2019, p<0.001). Serotypes 4 and 12F each caused more IPD than any other serotypes in AEH during 2020-2022 (207 combined reported cases primarily in 4 western states accounting for 38% of IPD in AEH). CONCLUSION: Expansion and increased transmission of serotypes 4 and 12F among adults potentially led to recent genesis of an impactful hybrid "serotype-switch" variant.
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We report a single case of invasive pneumococcal disease (IPD) by serotype 4, multilocus sequence type 10172 (serotype 4/ST10172) isolate with vanG-type resistance genes and reduced vancomycin susceptibility. The isolate was recovered during 2022 from a 66-year-old resident with bacteremic pneumococcal pneumonia within a CDC Active Bacterial Core surveillance (ABCs) site hospital. The patient had received 23-valent pneumococcal polysaccharide vaccine and there was no evidence of concurrent or prior receipt of vancomycin in the previous year. Serotype 4/ST10172 IPD has shown increases within western ABCs sites and the recent acquisition of a vanG element warrants close monitoring of this lineage.
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PacBio and Illumina MiSeq platforms were used for genomic sequencing of a Leishmania (Leishmania) tropica strain isolated from a patient infected in Pakistan. PacBio assemblies were generated using Flye v2.4 and polished with MiSeq data. The results represent a considerable improvement of the currently available genome sequences in the GenBank database.
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In the United States, phlebotomine sand flies carrying Leishmania (Leishmania) mexicana are endemic along the southern border. However, relatively little is known about the enzootic and zoonotic transmission of L. (L.) mexicana within the United States, and autochthonous cases of the consequent disease are rarely reported. We investigated an atypical case of cutaneous leishmaniasis (CL) caused by L. (L.) mexicana in a patient from central Texas which did not respond to a typical antileishmanial chemotherapy. We also investigated sand fly vectors around the patient's residence. PCR followed by DNA sequencing was used for determination of Leishmania spp., sand fly species, and host blood meal source. The L. (L.) mexicana genotype from the patient was identical to one found in a positive sand fly. Moreover, this genotype presented the same single-nucleotide polymorphisms as other historical CL cases acquired in Texas over the last 10 years, but distinct from those originating in Mexico and Central America. Three sand fly species were identified among the samples analyzed (n = 194), the majority of which were Lutzomyia (Dampfomyia) anthophora (n = 190), of which four specimens tested positive for Leishmania and two blood-fed specimens showed the presence of a human blood meal. This study highlights the complexity of clinical management of CL in a setting where the disease is infrequently encountered. The detection of human blood in Lu. (D.) anthophora is the first documentation of anthropophagy in this species. This is the first report of wild-caught, naturally infected sand flies found in association with an autochthonous case of human leishmaniasis and the specific strain of Leishmania (Leishmania) mexicana in the United States.
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Insetos Vetores/parasitologia , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Phlebotomus/parasitologia , Idoso , Animais , Humanos , Leishmania mexicana/genética , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , TexasRESUMO
We present here the draft genome sequences of Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) mexicana, and Leishmania (Leishmania) aethiopica, potential etiological agents of diffuse cutaneous leishmaniasis (DCL). Sequence data were obtained using PacBio and MiSeq platforms. The PacBio assemblies generated using Canu v1.6 are more contiguous than are those in the available data.
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We present here the first draft genome sequence of Leishmania (Viannia) lainsoni strain 216-34, sequenced using PacBio and MiSeq platforms. PacBio contigs were generated from de novo assemblies using CANU version 1.6 and polished using Illumina reads.
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The early light-induced proteins (ELIPs) are nuclear-encoded, light stress-induced proteins located in thylakoid membranes and related to light-harvesting Chl a/b-binding proteins. Recent evidence from physiological and genetic (mutant) studies supports a photoprotective function for ELIPs, particularly when green tissues are exposed to high light intensities at suboptimal temperatures. Broad-leaved evergreens belonging to genus Rhododendron are often exposed to a combination of low temperatures and high light in their natural habitat as the understory plants in deciduous forests and, therefore, are expected to employ photoprotective strategies during overwintering phase. Here we report analysis and characterization of previously identified ELIP expressed sequence tags (ESTs) from winter-collected Rhododendron catawbiense leaves. 5' or 3' rapid amplification of complementary DNA ends (RACEs) coupled with bioinformatic analyses were used to identify seven unique ELIPs from the 40 ESTs and were designated as RcELIP1-RcELIP7. Phylogenetic analysis revealed separate clustering of ELIP homologs from lower plants, monocots and eudicots (including RcELIPs) and further indicated an evolutionary divergence of ELIPs among angiosperms and gymnosperms. To gain insights into the cold acclimation (CA) physiology of rhododendrons, relative and absolute quantitative expression of RcELIPs was examined during seasonal CA of R. catawbiense leaves using real time reverse transcriptase-polymerase chain reaction. All seven RcELIPs were distinctly upregulated during the CA. It is postulated that RcELIPs expression constitutes an adaptive response to cold and high light in winter-adapted rhododendron leaves and perhaps plays a key role in the protection of photosynthetic apparatus from these stresses.
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Aclimatação , Regulação da Expressão Gênica de Plantas , Luz , Proteínas de Plantas/genética , Proteínas de Plantas/efeitos da radiação , Rhododendron/fisiologia , DNA de Plantas/genética , Etiquetas de Sequências Expressas , Amplificação de Genes , Filogenia , Reação em Cadeia da Polimerase , Rhododendron/classificação , Rhododendron/genética , Estações do AnoRESUMO
We present here the draft genome sequence for Leishmania (Viannia) guyanensis. The isolate was obtained from a clinical case of cutaneous leishmaniasis in French Guiana. Genomic DNA was sequenced using PacBio and MiSeq platforms.
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To investigate the mechanisms whereby treatment with chitosan (CHN) is observed to increase the capacity of plants to resist pathogens, CHNs of different molecular weights (MWs) prepared by enzyme hydrolysis were used to treat rice cells in suspension culture and also rice seedlings. The results obtained with cultured cells showed that in this material CHN treatment could trigger a set of defence responses, including the production of hydrogen peroxide (H2O2), increases in the activities of phenylalanine ammonialyase (PAL; EC 4.3.1.5) and chitinase (CHI; EC 3.2.1.14), increases in transcription of defence-related genes beta-1,3-glucanase (glu) and chitinase (chi) and accumulation of pathogen-related protein (PR1). Furthermore, CHNs of different MWs were observed to have different capacities to induce defence responses. CHNs of low MWs were more effective at inducing the described defence responses than those of higher MWs. Enhanced defence against rice blast pathogen Magnaporthe grisea 97-23-2D1 was observed in rice seedlings treated with low MW CHNs compared to seedlings treated with higher MW CHNs. In all cases, suppressing the production of H2O2 by adding scavengers dimethylthiourea (DMTU), 2,5-dihydroxycinnamic acid methyl ester (DHC), catalase (Cat) or ascorbate (As) blocked the defence responses. These results indicate that CHNs of low MWs have a greater capacity to induce the production of H2O2, thus resulting in stronger defence responses, than those with higher MWs.
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Quitosana/análogos & derivados , Peróxido de Hidrogênio/metabolismo , Oryza/fisiologia , Plântula/fisiologia , Células Cultivadas , Quitosana/farmacologia , Regulação da Expressão Gênica de Plantas/imunologia , Magnaporthe/imunologia , Peso Molecular , Oryza/imunologia , Fenilalanina Amônia-Liase/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/biossínteseRESUMO
Water movement across cellular membranes is regulated largely by a family of water channel proteins called aquaporins (AQPs). Since several abiotic stresses such as, drought, salinity and freezing, manifest themselves via altering water status of plant cells and are linked by the fact that they all result in cellular dehydration, we overexpressed an AQP (tonoplast intrinsic protein) from Panax ginseng, PgTIP1, in transgenic Arabidopsis thaliana plants to test its role in plant's response to drought, salinity and cold acclimation (induced freezing tolerance). Under favorable conditions, PgTIP1 overexpression significantly increased plant growth as determined by the biomass production, and leaf and root morphology. PgTIP1 overexpression had beneficial effect on salt-stress tolerance as indicated by superior growth status and seed germination of transgenic plants under salt stress; shoots of salt-stressed transgenic plants also accumulated greater amounts of Na(+) compared to wild-type plants. Whereas PgTIP1 overexpression diminished the water-deficit tolerance of plants grown in shallow (10 cm deep) pots, the transgenic plants were significantly more tolerant to water stress when grown in 45 cm deep pots. The rationale for this contrasting response, apparently, comes from the differences in the root morphology and leaf water channel activity (speed of dehydration/rehydration) between the transgenic and wild-type plants. Plants overexpressed with PgTIP1 exhibited lower (relative to wild-type control) cold acclimation ability; however, this response was independent of cold-regulated gene expression. Our results demonstrate a significant function of PgTIP1 in growth and development of plant cells, and suggest that the water movement across tonoplast (via AQP) represents a rate-limiting factor for plant vigor under favorable growth conditions and also significantly affect responses of plant to drought, salt and cold stresses.
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Aclimatação/efeitos dos fármacos , Aquaporinas/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Temperatura Baixa , Panax/metabolismo , Cloreto de Sódio/farmacologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Desastres , Expressão Gênica/efeitos dos fármacos , Plantas Geneticamente ModificadasRESUMO
The suppression subtractive hybridization technique was used to identify differentially expressed genes between hormone-autotrophic and hormone-dependent Panax ginseng callus lines. A tonoplast intrinsic protein cDNA (PgTIP1) was found to be highly and specifically expressed in hormone-autotrophic ginseng cells, which was slightly up-regulated by cytokinin while significantly down-regulated when treated with auxin. PgTIP1 encodes a polypeptide of 250 amino acids which shows sequence and structure similarity with tonoplast aquaporins in plants. The water channel activity of PgTIP1 was demonstrated by its expression in Xenopus laevis oocytes. When over-expressed in Arabidopsis thaliana, PgTIP1 substantially altered the plant's vegetative and reproductive growth and development. Arabidopsis plants over-expressing PgTIP1 showed significantly enhanced seed size and seed mass plus greatly increased growth rate compared with those of the wild type. Moreover, the seeds from PgTIP1 over-expressing Arabidopsis had 1.85-fold higher fatty acid content than the wild-type control. These results demonstrate a significant function of PgTIP1 in the growth and development of plant cells.