Genetic Lineages Research Articles

Genetic diversity of the mantellid frog Blommersia blommersae, and description of a new anuran species from south-eastern Madagascar

ABSTRACT A range-wide assessment of genetic variation in one mitochondrial (16S rRNA) and one nuclear-encoded (Rag-1) gene fragment of the widespread Madagascar frog Blommersia blommersae revealed the presence of up to 12 deep genetic lineages. Many of these differed by genetic distances >3% in the 16S gene. In the Ranomafana area in the southern central east of Madagascar, two mitochondrial lineages differing by 1.2–1.8% in 16S occurred in close syntopy across multiple sites. A phylogeny of representative samples based on multiple mitochondrial genes supported three main mitochondrial clades within B. blommersae, with lineages from the (i) north, (ii) north and northern central east, and (iii) southern central east, respectively. In addition, one lineage from Sainte Luce in the south-east was sister to all other species of Blommersia, and thus clearly not belonging to B. blommersae, to which it has been tentatively assigned previously. Except for the Sainte Luce population, most of the mitochondrial lineages did not show a concordant and consistent differentiation in Rag-1 and no obvious morphological differences were detected among the lineages. We therefore refrain from taxonomic conclusions for them at this time, although indications exist that the populations from the northern central east and southern central east may show certain differences in relative note duration of advertisement calls, which require further study. However, the Sainte Luce individuals were highly divergent in 16S (>10%) and Rag-1, phylogenetically isolated, and characterised by differences in colour pattern. This lineage represents the most evolutionarily divergent species of Blommersia known to date and is herein formally named and described as Blommersia dupreezi sp. nov.

Identification of distinct subpopulations of Gli1-lineage cells in the mouse mandible.

The Hedgehog pathway gene Gli1 has been proposed to mark a subpopulation of skeletal stem cells (SSCs) in craniofacial bone. Skeletal stem cells (SSCs) are multi-potent cells crucial for the development and homeostasis of bone. Recent studies on long bones have suggested that skeletal stem cells in endochondral or intramembranous ossification sites have different differentiation capacities. However, this has not been well-defined in neural crest derived bones. Generally, the long bones are derived from mesoderm and follow an endochondral ossification model, while most of the cranial bones are neural crest (NC) in origin and follow an intramembranous ossification model. The mandible is unique: It is derived from the neural crest lineage but makes use of both modes of ossification. Early in fetal development, the mandibular body is generated by intramembranous ossification with subsequent endochondral ossification forming the condyle. The identities and properties for SSCs in these two sites remain unknown. Here, we use genetic lineage tracing in mouse to identify cells expressing the Hedgehog responsive gene Gli1, which is thought to mark the tissue resident SSCs. We track the Gli1+ cells, comparing cells within the perichondrium to those in the periosteum covering the mandibular body. In juvenile mice, these have distinct differentiation and proliferative potential. We also assess the presence of Sox10+ cells, thought to mark neural crest stem cells, but find no substantial population associated with the mandibular skeleton, suggesting that Sox10+ cells have limited contribution to maintaining postnatal mandibular bone. All together, our study indicates that the Gli1+ cells display distinct and limited differentiation capacity dependent on their regional associations.

Genomic and evolutionary relationships among wild and cultivated blueberry species

BackgroundBlueberries (Vaccinium section Cyanococcus) are an economically important fruit crop in the United States. Understanding genetic structure and relationships in blueberries is essential to advance the genetic improvement of horticulturally important traits. In the present study, we investigated the genomic and evolutionary relationships in 195 blueberry accessions from five species (comprising 33 V. corymbosum, 14 V. boreale, 81 V. darrowii, 29 V. myrsinites, and 38 V. tenellum) using single nucleotide polymorphisms (SNPs) mined from genotyping-by-sequencing (GBS) data.ResultsGBS generated ~ 751 million raw reads, of which 79.7% were mapped to the reference genome V. corymbosum cv. Draper v1.0. After filtering (read depth > 3, minor allele frequency > 0.05, and call rate > 0.9), 60,518 SNPs were identified and used in further analyses. The 195 blueberry accessions formed three major clusters on the principal component (PC) analysis plot, in which the first two PCs accounted for 29.2% of the total genetic variance. Nucleotide diversity (π) was highest for V. tenellum and V. boreale (0.023 each), and lowest for V. darrowii (0.012). Using TreeMix analysis, we identified four migration events and deciphered gene flow among the selected species. In addition, we detected a strong V. boreale lineage in cultivated blueberry species. Pairwise SweeD analysis identified a wide sweep (encompassing 32 genes) as a strong signature of domestication on the scaffold VaccDscaff 12. From this region, five genes encoded topoisomerases, six genes encoded CAP-gly domain linker (which regulates the dynamics of the microtubule cytoskeleton), and three genes coded for GSL8 (involved in the synthesis of the cell wall component callose). One of the genes, augustus_masked-VaccDscaff12-processed-gene-172.10, is a homolog of ArabidopsisAT2G25010 and encodes the protein MAINTENANCE OF MERISTEMS-like involved in root and shoot growth. Additional genomic stratification by admixture analysis identified genetic lineages and species boundaries in blueberry accessions. The results from this study indicate that V. boreale is a genetically distant outgroup, while V. darrowii, V. myrsinites, and V. tenellum are closely related.ConclusionOur study provides new insights into the evolution and genetic architecture of cultivated blueberries.

Evaluation of the diagnostic efficacy of a reagent kit for <i>in vitro</i> diagnosis of West Nile fever using reverse transcription polymerase chain reaction with fluorescent probe-based detection

West Nile fever is a vector-borne zoonotic arbovirus infection with natural foci. Its clinical course is similar to that of acute febrile syndrome, and severe cases may result in neuroinvasive disease. Several genetic lineages (1, 2, and 4) of the West Nile virus (WNV) with different pathogenicity for humans are circulating in the Russian Federation. Therefore, it is an urgent task to develop a diagnostic reagent kit for differentiating between WNV genetic lineages and to implement the kit in clinical laboratory practice.The aim of the study was to conduct technical and clinical tests and evaluate the quality, efficacy, and safety of the Ampligen-WNV-genotype-1/2/4 diagnostic reagent kit for detecting WNV RNA and differentiating between WNV genetic lineages 1, 2, and 4 by reverse transcription polymerase chain reaction (RT-PCR) with fluorescent probe-based detection.Materials and methods. The authors determined the diagnostic sensitivity and specificity of the Ampligen-WNV-genotype-1/2/4 reagent kit (Volgograd Research Institute for Plague Control, Russia) by real-time RT-PCR with 216 clinical samples and 204 biological samples. Sanger sequencing was used as a reference method. Statistical analysis of clinical test results was carried out in accordance with the Russian national standard for clinical laboratory tests (GOST R 53022.3-2008).Results. When tested with the Ampligen-WNV-genotype-1/2/4 reagent kit, real-time RT-PCR demonstrated the analytical sensitivity of 1×104 GEq/mL for the detection of WNV cDNA of genetic lineages 1, 2, and 4. The assessment of its analytical specificity showed no positive results for cDNA samples of heterologous viruses at a concentration of 1×106 GEq/mL. The diagnostic sensitivity with the reagent kit was at least 98.5%, and the diagnostic specificity was at least 99%, with 90% confidence levels for both parameters.Conclusions. The Ampligen-WNV-genotype-1/2/4 reagent kit can be recommended for use in clinical laboratory diagnostics to detect WNV RNA and differentiate between WNV genetic lineages 1, 2, and 4.

PHYLOGENY OF THE <i>DIPUS SAGITTA</i> SPECIES COMPLEX BASED ON THE SEQUENCING OF NUCLEAR GENES

The northern three-toed jerboa Dipus sagitta was long considered to be a single polytypic species. Earlier, a high genetic diversity of D. sagitta was revealed on the basis of several mitochondrial and nuclear genes, and the existence of several separate species within it was hypothesized. However, a small number of available nuclear genes prevented the establishment of relationships between identified phylogenetic lineages. Here, we significantly expand the set of utilized nuclear DNA loci, which resulted in a sufficiently higher resolution of the phylogenetic tree for 10 forms of D. sagitta. The identified species structure mainly confirms the topology and relationship of the mtDNA lineages. At the same time, the mitochondrial and nuclear phylogenies are not completely consistent. Hence, a part of the genetic lineages of D. sagitta is apparently a product of reticular evolutionary processes. This taxon is thus the diverse species complex D. sagitta sensu lato, in which long-diverged lineages are not always reproductively isolated.

Whole-genome sequencing reveals a complex African population demographic history and signatures of local adaptation.

We conduct high coverage (>30×) whole-genome sequencing of 180 individuals from 12 indigenous African populations. We identify millions of unreported variants, many predicted to be functionally important. We observe that the ancestors of southern African San and central African rainforest hunter-gatherers (RHG) diverged from other populations >200 kya and maintained a large effective population size. We observe evidence for ancient population structure in Africa and for multiple introgression events from "ghost" populations with highly diverged genetic lineages. Although currently geographically isolated, we observe evidence for gene flow between eastern and southern Khoesan-speaking hunter-gatherer populations lasting until ∼12kya. We identify signatures of local adaptation for traits related to skin color, immune response, height, and metabolic processes. We identify a positively selected variant in the lightly pigmented San that influences pigmentation invitro by regulating the enhancer activity and gene expression of PDPK1.

Variability of the Gene Cytochrome <i>b</i> mtDNA of the Tundra Vole (<i>Alexandromys oeconomus</i> Pallas, 1776) in North-Eastern Asia and Alaska

The nucleotide sequence polymorphism and haplotype diversity of the cytochrome b gene in samples of the tundra vole (Alexandromys oeconomus) from North-Eastern Asia and Alaska were studied. 63 haplotypes of cytb gene (51 variants of Central Asian and 12 of Beringian genetic lineages), differing among themselves by 94 mutations, were found. The Upper Kolyma River is inhabited by voles of the Central Asian clade. Mixed population of this species in the basin of the Omolon River (right tributary of the Kolyma River) was found. In Chukotka and Alaska, only specimens of the Beringian phylogroup were found. Genetic differences between all samples are statistically significant. Genetic data of A. oeconomus populations of the Kolyma River basin, Alaska, and Northern Okhotomorye were compared. A total of 231 substitutions in 226 sites were found in the nucleotide sequence of cytochrome b mtDNA gene in voles from both clades. The values of molecular diversity indices testify to the stability of populations with a high value of effective abundance over a long period of time. An analysis of population gene pool formation was performed and a proposed reconstruction of the complex dispersal history of this species across North-Eastern Asia was proposed.

Genetic Diversity and Demographic Evolution Using <I>SRY </I>Gene Polymorphism in Four Lineages of Ladoum Sheep in Senegal

Knowledge of spatial and temporal distribution of genetic diversity within and between populations is a crucial step for establishing strategies management of Animal genetic resources. This study aims to contribute to a better understanding of the genetic structure of local sheep breeds. Specifically, it will characterize the genetic diversity, differentiation and evolution of the <I>SRY </I>gene in four main lineages of Ladoum sheep in Senegal. After alignments and corrections, a total of 42 sequences were used for analysis of <I>SRY</I> genetic diversity and demographic evolution. The standard indices of genetic diversity, genetic differenciation, analyses of hierarchical molecular variance (AMOVA) and demographic tests were compute. Analysis of genetic variability parameters in the overall population revealed a low level of polymorphism in the <I>SRY </I>gene. Haplotypic diversity is much higher than the average nucleotide divergence between all pairs of haplotypes. The genetic distances, as well as the values of the genetic differentiation factor beetween lineages, reveal two genetic groups; one made up of the individuals of “Birahim” and the other, grouping the three lineages individuals. Differences in frequencies of essential proteins for a multitude of functions in the body are observed between the "Birahim" lineage and the others. The comparative trends in genetic diversity indices, the shape of the mismatch distribution curves, demographic indices and demogenetic tests show a rapid and recent expansion population from an ancestral small size. The Z-test analysis of selection revealed that <I>SRY </I>gene is under selection. Unlike “Batling” who is under negative selection, "Birahim" and "Gorgui" are under positive selection. This study has made a significant contribution to understanding the genetic structure of the Ladoum raised in Senegal.

Apomictic Mountain Whitebeam (Sorbus austriaca, Rosaceae) Comprises Several Genetically and Morphologically Divergent Lineages

The interplay of polyploidisation, hybridization, and apomixis contributed to the exceptional diversity of Sorbus (Rosaceae), giving rise to a mosaic of genetic and morphological entities. The Sorbus austriaca species complex from the mountains of Central and South-eastern Europe represents an allopolyploid apomictic system of populations that originated following hybridisation between S. aria and S. aucuparia. However, the mode and frequency of such allopolyploidisations and the relationships among different, morphologically more or less similar populations that have often been described as different taxa remain largely unexplored. We used amplified fragment length polymorphism (AFLP) fingerprinting, plastid DNA sequencing, and analyses of nuclear microsatellites, along with multivariate morphometrics and ploidy data, to disentangle the relationships among populations within this intricate complex. Our results revealed a mosaic of genetic lineages-many of which have not been taxonomically recognised-that originated via multiple allopolyploidisations. The clonal structure within and among populations was then maintained via apomixis. Our results thus support previous findings that hybridisation, polyploidization, and apomixis are the main drivers of Sorbus diversification in Europe.

Cre-loxP-mediated genetic lineage tracing: Unraveling cell fate and origin in the developing heart.

The Cre-loxP-mediated genetic lineage tracing system is essential for constructing the fate mapping of single-cell progeny or cell populations. Understanding the structural hierarchy of cardiac progenitor cells facilitates unraveling cell fate and origin issues in cardiac development. Several prospective Cre-loxP-based lineage-tracing systems have been used to analyze precisely the fate determination and developmental characteristics of endocardial cells (ECs), epicardial cells, and cardiomyocytes. Therefore, emerging lineage-tracing techniques advance the study of cardiovascular-related cellular plasticity. In this review, we illustrate the principles and methods of the emerging Cre-loxP-based genetic lineage tracing technology for trajectory monitoring of distinct cell lineages in the heart. The comprehensive demonstration of the differentiation process of single-cell progeny using genetic lineage tracing technology has made outstanding contributions to cardiac development and homeostasis, providing new therapeutic strategies for tissue regeneration in congenital and cardiovascular diseases (CVDs).

Disease phenotypic and geospatial features vary across genetic lineages for Tuberculosis within Arkansas, 2010-2020.

Tuberculosis (TB) elimination in the United States remains elusive, and community-specific, localized intervention strategies may be necessary to meet elimination goals. A better understanding of the genotypic diversity of Mtb, the population subgroups affected by different TB strains, and differences in disease presentation associated with these strains can aid in identifying risk groups and designing tailored interventions. We analyze TB incidence and genotype data from all Arkansas counties over an 11-year time span from 2010 through 2020. We use statistical methods and geographic information systems (GIS) to identify demographic and disease phenotypic characteristics that are associated with different Mtb genetic lineages in the study area. We found the following variables to be significantly associated with genetic lineage (p<0.05): patient county, patient birth country, patient ethnicity, race, IGRA result, disease site, chest X-ray result, whether or not a case was identified as part of a cluster, patient age, occupation risk, and date arrived in the US. Different Mtb lineages affect different subpopulations in Arkansas. Lineage 4 (EuroAmerican) and Lineage 2 (East Asian) are most prevalent, although the spatial distributions differ substantially, and lineage 2 (East Asian) is more frequently associated with case clusters. The Marshallese remain a particularly high-risk group for TB in Arkansas.

Genetic diversity of Plasmodium falciparum erythrocyte membrane protein 1 in field isolates from central Myanmar.

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), encoded by the polymorphic var multigene family, is a highly polymorphic antigen that plays a crucial role in the pathology of malaria. The contribution of the genetic diversity of var toward the immune escape of P. falciparum has not yet been fully elucidated. This study aimed to characterize the diversity of var repertoires by screening P. falciparum Duffy-binding-like α domain (PfDBLα) among field isolates from central Myanmar. Genetic analysis revealed that the D-H segments of var in Myanmar populations have an extensive polymorphic repertoire, with high numbers of unique sequence types in each individual. However, var genes from the global population, including Myanmar, shared close genetic lineages regardless of their geographic origins, indicating that they have not undergone rapid evolutionary changes.

Characterization of Blast Resistance in a Diverse Rice Panel from Sub-Saharan Africa.

There is a recent unparalleled increase in demand for rice in sub-Saharan Africa, yet its production is affected by blast disease. Characterization of blast resistance in adapted African rice cultivars can provide important information to guide growers and rice breeders. We used molecular markers for known blast resistance genes (Pi genes; n = 21) to group African rice genotypes (n = 240) into similarity clusters. We then used greenhouse-based assays to challenge representative rice genotypes (n = 56) with African isolates (n = 8) of Magnaporthe oryzae which varied in virulence and genetic lineage. The markers grouped rice cultivars into five blast resistance clusters (BRC) which differed in foliar disease severity. Using stepwise regression, we found that the Pi genes associated with reduced blast severity were Pi50 and Pi65, whereas Pik-p, Piz-t, and Pik were associated with increased susceptibility. All rice genotypes in the most resistant cluster, BRC 4, possessed Pi50 and Pi65, the only genes that were significantly associated with reduced foliar blast severity. Cultivar IRAT109, which contains Piz-t, was resistant against seven African M. oryzae isolates, whereas ARICA 17 was susceptible to eight isolates. The popular Basmati 217 and Basmati 370 were among the most susceptible genotypes. These findings indicate that most tested genes were not effective against African blast pathogen collections. Pyramiding genes in the Pi2/9 multifamily blast resistance cluster on chromosome 6 and Pi65 on chromosome 11 could confer broad-spectrum resistance capabilities. To gain further insights into genomic regions associated with blast resistance, gene mapping could be conducted with resident blast pathogen collections. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Single cell and lineage tracing studies reveal the impact of CD34+ cells on myocardial fibrosis during heart failure

BackgroundCD34+ cells have been used to treat the patients with heart failure, but the outcome is variable. It is of great significance to scrutinize the fate and the mechanism of CD34+ cell differentiation in vivo during heart failure and explore its intervention strategy.MethodsWe performed single-cell RNA sequencing (scRNA-seq) of the total non-cardiomyocytes and enriched Cd34-tdTomato+ lineage cells in the murine (male Cd34-CreERT2; Rosa26-tdTomato mice) pressure overload model (transverse aortic constriction, TAC), and total non-cardiomyocytes from human adult hearts. Then, in order to determine the origin of CD34+ cell that plays a role in myocardial fibrosis, bone marrow transplantation model was performed. Furthermore, to further clarify the role of CD34 + cells in myocardial remodeling in response to TAC injury, we generated Cd34-CreERT2; Rosa26-eGFP-DTA (Cre/DTA) mice.ResultsBy analyzing the transcriptomes of 59,505 single cells from the mouse heart and 22,537 single cells from the human heart, we illustrated the dynamics of cell landscape during the progression of heart hypertrophy, including CD34+ cells, fibroblasts, endothelial and immune cells. By combining genetic lineage tracing and bone marrow transplantation models, we demonstrated that non-bone-marrow-derived CD34+ cells give rise to fibroblasts and endothelial cells, while bone-marrow-derived CD34+ cell turned into immune cells only in response to pressure overload. Interestingly, partial depletion of CD34+ cells alleviated the severity of myocardial fibrosis with a significant improvement of cardiac function in Cd34-CreERT2; Rosa26-eGFP-DTA model. Similar changes of non-cardiomyocyte composition and cellular heterogeneity of heart failure were also observed in human patient with heart failure. Furthermore, immunostaining showed a double labeling of CD34 and fibroblast markers in human heart tissue. Mechanistically, our single-cell pseudotime analysis of scRNA-seq data and in vitro cell culture study revealed that Wnt-β-catenin and TGFβ1/Smad pathways are critical in regulating CD34+ cell differentiation toward fibroblasts.ConclusionsOur study provides a cellular landscape of CD34+ cell-derived cells in the hypertrophy heart of human and animal models, indicating that non-bone-marrow-derived CD34+ cells differentiating into fibroblasts largely account for cardiac fibrosis. These findings may provide novel insights for the pathogenesis of cardiac fibrosis and have further potential therapeutic implications for the heart failure.

Integrative taxonomy reveals a new species of the water mite genus Monatractides K. Viets, 1926 from Corsica (Acari, Hydrachnidia: Torrenticolidae)

ABSTRACT In the present study, we use morphological data and DNA barcodes to describe a new species, i.e. Monatractides corsicus sp. nov. from Corsica, France. The new species belongs to the M. stadleri-complex which includes at least four distinct genetic lineages in the Western Palaearctic. Morphologically, the new species can be identified on the basis of a comparatively large palp, thick chelicera and the colour pattern of the dorsal shield. Moreover, we present the first DNA barcoding data for M. latissimus (K. Viets, 1936) and M. lusitanicus (Lundblad, 1941). http://www.zoobank.org/urn:lsid:zoobank.org:pub:461D9E10-3897-4CF0-9384-CC4A582E125A

High Sox2 expression predicts taste lineage competency of lingual progenitors in vitro.

Taste buds on the tongue contain taste receptor cells (TRCs) that detect sweet, sour, salty, umami and bitter stimuli. Like non-taste lingual epithelium, TRCs are renewed from basal keratinocytes, many of which express the transcription factor SOX2. Genetic lineage tracing has shown that SOX2+ lingual progenitors give rise to both taste and non-taste lingual epithelium in the posterior circumvallate taste papilla (CVP) of mice. However, SOX2 is variably expressed among CVP epithelial cells, suggesting that their progenitor potential may vary. Using transcriptome analysis and organoid technology, we show that cells expressing SOX2 at higher levels are taste-competent progenitors that give rise to organoids comprising both TRCs and lingual epithelium. Conversely, organoids derived from progenitors that express SOX2 at lower levels are composed entirely of non-taste cells. Hedgehog and WNT/β-catenin are required for taste homeostasis in adult mice. However, manipulation of hedgehog signaling in organoids has no impact on TRC differentiation or progenitor proliferation. By contrast, WNT/β-catenin promotes TRC differentiation in vitro in organoids derived from higher but not low SOX2+ expressing progenitors.

Wolbachia and Spiroplasma endosymbionts in the Anurida maritima (Collembola) species group

Abstract A large proportion of arthropods carry maternally-inherited endosymbiotic bacteria with which they have developed close relationships. Some of these endosymbionts are selfish genetic elements and manipulate their hosts’ reproduction to their own advantage, for example via cytoplasmic incompatibility (CI) or male killing. Here we report that the sexually reproducing collembolan Anurida maritima carries two endosymbionts (Wolbachia and Spiroplasma) and provide genome sequences for both bacteria. Phylogenomic analyses indicate that the Wolbachia belong to the A supergroup and that the Spiroplasma are sister to the Citri-Chrysopicola-Mirum lineage. A. maritima is considered a species group and consists of at least two distinct genetic lineages. We show that both lineages carry both endosymbionts. No homologs of the Spiroplasma male-killing gene SpAID were observed within our datasets. Homologs of the male-killing associated wmk and the CI inducing cifA and cifB prophage genes were detected in the Wolbachia genome. Phylogenetic analyses placed the cif genes in the poorly characterised Type V clade. The cifA and cifB gene sequences of the two Anurida lineages are identical. It therefore seems unlikely that the genetic divergence within the species group stems from cifA and cifB induced CI. Laboratory controlled genetic crosses and sex ratio studies will be needed to reveal any potential effect of the two endosymbionts on A. maritima’s reproduction.

Survey of haemosporidian parasite infections in an endangered high alpine bird

The Brown-capped Rosy-Finch is an endangered high alpine specialist that breeds on cliffs in the Rocky Mountains of North America. We know little about the parasites that infect these birds but filling this knowledge gap is important for understanding their population decline. The aim of this study was to survey haemosporidian parasite infections in Brown-capped Rosy-Finches. We sampled 104 Brown-capped Rosy-Finches during their breeding season at six sampling sites spanning the Colorado Rocky Mountains where they are nearly endemic. We used nested PCR methods to screen birds for parasite infections, and Sanger sequencing data were used to identify parasite lineages. Four of the sampling sites had birds with infections. Females were more often infected than males (prevalence = 15.6% and 9.7%, respectively). We observed twice as many infected birds sampled in July compared to birds sampled in June (prevalence = 12.5% and 6.25%, respectively). The percent of infected birds by sampling site ranged from 0 to over 20%. In total we identified eight different genetic lineages of haemosporidian parasites infecting Brown-capped Rosy-Finches—seven were in the genus Leucocytozoon, and one was in the genus Haemoproteus. Network analysis clearly separates Haemoproteus from Leucocytozoon, with Leucocytozoon lineages comprising two major clusters. Based on reports made to the MalAvi database, all lineages in Cluster 1 have the same reported insect vector, Simulium silvestre. We report that Brown-capped Rosy-Finches experience infections with haemosporidian parasites and that the percentage of infected birds differed markedly between sampling sites. We hypothesize that vector ecology and associated variation in climate at sampling sites explain our observations.

Seroprevalence of Brucella Infection in Wild Boars (Sus scrofa) of Bavaria, Germany, 2019 to 2021 and Associated Genome Analysis of Five B. suis Biovar 2 Isolates

Brucella species are highly pathogenic zoonotic agents and are found in vertebrates all over the world. To date, Germany is officially declared free from brucellosis and continuous surveillance is currently limited to farm ruminants. However, porcine brucellosis, mostly caused by B. suis biovar 2, is still found in wild boars and hares. In the present study, a three-year monitoring program was conducted focusing on the wild boar population in the state of Bavaria. Serologic screening of 11,956 animals and a direct pathogen detection approach, including a subset of 681 tissue samples, was carried out. The serologic incidence was 17.9%, which is in approximate accordance with previously published results from various European countries. Applying comparative whole genome analysis, five isolated B. suis biovar 2 strains from Bavaria could be assigned to three known European genetic lineages. One isolate was closely related to another strain recovered in Germany in 2006. Concluding, porcine brucellosis is endemic in Bavaria and the wild boar population represents a reservoir for genetically distinct B. suis biovar 2 strains. However, the transmission risk of swine brucellosis to humans and farm animals is still regarded as minor due to low zoonotic potential, awareness, and biosafety measures.

Risk Factors of Clonally Related, Multi, and Extensively Drug-Resistant Acinetobacter baumannii in Severely Ill COVID-19 Patients.

The secondary infection of multi and extensively drug-resistant "Acinetobacter baumannii" in severely ill COVID-19 individuals is usually associated with extended hospitalisation and a high mortality rate. The current study aimed to assess the exact incidence rate of A. baumannii coinfection in severely ill COVID-19 patients admitted to intensive care unit (ICUs), to identify the possible mechanism of A. baumannii transfer to COVID-19 patients and to find out their resistance rate against different antibiotics. Fifty severely ill "COVID-19" individuals on respiratory support were selected with samples being collected from the pharynx. In addition, another 60 samples were collected from the surrounding environment. Bacterial isolates were diagnosed by microbiological cultures and confirmed by "Vitek 2 system" and real-time PCR. The "Vitek 2 Compact system" was used to evaluate these isolates for antimicrobial susceptibility. The recovered isolates' DNA fingerprints and genetic similarities were performed using ERIC-PCR. Twenty-six samples were tested positive for A. baumannii (20 out of 50 samples taken from patients, 40%; 6 out of 60 swabs from a nosocomial setting, 10%). All A. baumannii strains isolated from the nosocomial sites were clonally related (have the same genetic lineage) to some strains isolated from patients. However, the majority of the patients' strains were categorised as belonging to the same genetic lineage. Furthermore, "the multi and extensively drug" resistance patterns were seen in all isolates. In addition, total isolates showed resistance to the most commonly tested antibiotics, while none of them was found to be resistant to tigecycline. Secondary "A. baumannii" infection in severely ill "COVID-19" patients is a serious matter, especially when it has one spot of transmission in the ICU as well as when it is extensively drug-resistant, necessitating an immediate and tactical response to secure the issue.