Revisiting the genotypes of Theileria equi based on the V4 hypervariable region of the 18S rRNA gene.

Introduction: Equine theileriosis, an economically important disease that affects horses and other equids worldwide, is caused by a tick-borne intracellular apicomplexan protozoa Theileria equi. Genotyping of T. equi based on the 18S rRNA gene revealed the presence of two, three, four or five genotypes. In previous published reports, these genotypes have been labelled either alphabetically or numerically, and there is no uniformity in naming of these genotypes. The present study was aimed to revisit the phylogeny, genetic diversity and geographical distribution of T. equi based on the nucleotide sequences of the V4 hypervariable region of the 18S rRNA gene available in the nucleotide databases. Methods: Out of 14792 nucleotide sequences of T. equi available in the GenBank™, only 736 sequences of T. equi containing the complete V4 hypervariable region of the 18S rRNA gene (>207 bp) were used in multiple sequence alignment. Subsequently, a maximum likelihood phylogenetic tree was constructed based on the Kimura 2-parameter model (K2+I). Results: The phylogenetic tree placed all the sequences into four distinct clades with high bootstrap values which were designated as T. equi clades/ genotypes A, B, C and D. Our results indicated that the genotype B of Nagore et al. and genotype E of Qablan et al. together formed the clade B with a high bootstrap value (95%). Furthermore, all the genotypes probably originated from clade B, which was the most dominant genotype (52.85%) followed by clades A (27.58%), and C (9.78%) and D (9.78%). Genotype C manifested a comparatively higher genetic diversity (91.0-100% identity) followed by genotypes A (93.2-99.5%), and B and D (95.7-100%). The alignment report of the consensus nucleotide sequences of the V4 hypervariable region of the 18S rRNA gene of four T. equi genotypes (A-D) revealed significant variations in one region, between nucleotide positions 113-183, and 41 molecular signatures were recognized. As far as geographical distribution is concerned, genotypes A and C exhibited far-extending geographical distribution involving 31 and 13 countries of the Asian, African, European, North American and South American continents, respectively. On the contrary, the genotypes B and D exemplified limited distribution with confinement to 21 and 12 countries of Asian, African and European continents, respectively. Interestingly, genotypes A and C have been reported from only two continents, viz., North and South America. It was observed that genotypes A and C, and B and D exhibit similar geographical distribution. Discussion: The present study indicated the presence of only four previously described T. equi genotypes (A, B, C and D) after performing the molecular analyses of all available sequences of the complete V4 hypervariable region of the 18S rRNA gene of T. equi isolates in the GenBank™.

Phylogenomic and molecular markers based studies on clarifying the evolutionary relationships among Peptoniphilus species. Identification of several Genus-Level clades of Peptoniphilus species and transfer of some Peptoniphilus species to the genus Aedoeadaptatus.

To clarify the evolutionary relationships among Peptoniphilus species, whose members show association with increased risk for prostate cancer, detailed phylogenomic and comparative analyses were conducted on their genome sequences. In phylogenetic trees based on core genome proteins and 16S rRNA gene sequences, Peptoniphilus species formed eight distinct clades, with Aedoeadaptatus and Anaerosphaera species branching between them. The observed clades designated as Peptoniphilus sensu stricto (encompassing its type species), Harei, Lacrimalis, Duerdenii, Mikwangii, Stercorisuis, Catoniae and Aedoeadaptatus, show genus level divergence based on 16S rRNA similarity and average amino acid identity (AAI). The Genome Taxonomy Database also assigns most of these clades to distinct taxa. Several Peptoniphilus species (viz. P. coxii, P. ivorii, P. nemausensis and some non-validly published species) grouped reliably with the type species of Aedoeadaptatus (A. acetigenes) and are affiliated to this genus based on 16S rRNA similarity, AAI, and multiple uniquely shared molecular signatures. Hence, we are proposing the transfer of these species into the emended genus Aedoeadaptatus. Our analyses on protein sequences from Peptoniphilus genomes have also identified 54 novel molecular markers consisting of conserved signature indels (CSIs), which are specific for different Peptoniphilus species clades and provide reliable means for their demarcation in molecular terms. Lastly, we also show that based on the shared presence of these CSIs in the genomes of uncharacterized Peptoniphilus spp. (cultured and uncultured), their affiliations to the specific Peptoniphilus clades can be accurately predicted. These results should prove useful in understanding the potential involvement of Peptoniphilus-related species in diseases.

Molecular characterisation of Amblyomma integrum circulating in southern India.

Amblyomma integrum is a large gooseberry sized longirostrate tick (when fully repleted) found in India and Sri Lanka. In Kerala (India), this tick is commonly found in the forest and its fringe areas frequently infesting deer and hence it is locally known as "maan chellu / maanunny" (deer tick). In the present study, molecular characterisation and phylogenetic analysis of A. integrum collected from the area grazed by the sambar deer (Rusa unicolor) of Kerala, south India was performed using three molecular markers viz., the mitochondrial cytochrome c oxidase subunit 1 (COI), mitochondrial 16S ribosomal RNA, and nuclear 18S ribosomal RNA genes. Cytochrome c oxidase subunit 1 (COI) gene showed better resolving ability for elucidating the evolutionary relationship of A. integrum and identified two distinct clades, viz., A and B. The Tamil Nadu isolates of south India and Marayoor isolate 1 (from Idukki district of Kerala bordering with Tamil Nadu) belonged to clade A. Majority of Wayanad isolates from Kerala, occupied clade B. The intraspecific genetic distance among the A. integrum species ranged from 0.00 to 13.34%. Between clades A and B, the genetic distance observed was 11.49%. The clade B isolates were genetically close to A. geoemydae (GD: 1.22%). Morphological variations between the clades included darker exoskeletal coloration in clade A and distinct differences in the shape of basis capitulum. Further analysis using Assemble Species by Automatic Partitioning (ASAP) and Generalized Mixed Yule Coalescent (GMYC) provided additional insights. Assemble Species by Automatic Partitioning (ASAP) identified 26 Molecular Operational Taxonomic Units (MOTUs) at a threshold distance of 5.38%, supporting the species partition of A. integrum clade B. Generalized Mixed Yule Coalescent (GMYC) analysis retained the same species complex (A. integrum-geoemydae Complex) inferred from the ASAP analyses. It could be inferred from the present study that the A. integrum clades A and B could be two different putative pseudocryptic species.

Sphingolipid diversity in Candida auris: unraveling interclade and drug resistance fingerprints.

In this study, we explored the sphingolipid (SL) landscape in Candida auris, which plays pivotal roles in fungal biology and drug susceptibility. The composition of SLs exhibited substantial variations at both the SL class and molecular species levels among clade isolates. Utilizing principal component analysis, we successfully differentiated the five clades based on their SL class composition. While phytoceramide (PCer) was uniformly the most abundant SL class in all the isolates, other classes showed significant variations. These variations were not limited to SL class level only as the proportion of different molecular species containing variable number of carbons in fatty acid chains also differed between the isolates. Also a comparative analysis revealed abundance of ceramides and glucosylceramides in fluconazole susceptible isolates. Furthermore, by comparing drug-resistant and susceptible isolates within clade IV, we uncovered significant intraclade differences in key SL classes such as high PCer and low long chain base (LCB) content in resistant strains, underscoring the impact of SL heterogeneity on drug resistance development in C. auris. These findings shed light on the multifaceted interplay between genomic diversity, SLs, and drug resistance in this emerging fungal pathogen.

Isofagomine Inhibits Multiple TcdB Variants and Protects Mice from Clostridioides difficile-Induced Mortality.

Clostridioides difficile causes life-threatening diarrhea and is one of the leading causes of nosocomial infections. During infection, C. difficile releases two gut-damaging toxins, TcdA and TcdB, which are the primary determinants of disease pathogenesis and are important therapeutic targets. Once in the cytosol of mammalian cells, TcdA and TcdB use UDP-glucose to glucosylate host Rho GTPases, which leads to cytoskeletal changes that result in a loss of intestinal integrity. Isofagomine inhibits TcdA and TcdB as a mimic of the glucocation transition state of the glucosyltransferase reaction. However, sequence variants of TcdA and TcdB across the clades of infective C. difficile continue to be identified, and therefore, evaluation of isofagomine inhibition against multiple toxin variants is required. Here, we show that isofagomine inhibits the glucosyltransferase domain of multiple TcdB variants and protects TcdB-induced cell rounding of the most common full-length toxin variants. Furthermore, we demonstrate that isofagomine protects against C. difficile-induced mortality in two murine models of C. difficile infection. Isofagomine treatment of mouse C. difficile infection also permitted the recovery of the gastrointestinal microbiota, an important barrier to preventing recurring C. difficile infection. The broad specificity of isofagomine supports its potential as a prophylactic to protect against C. difficile-induced morbidity and mortality.

Mini Review on Clinical Aspects of Monkeypox.

Monkeypox is a disease caused by the monkeypox virus, which is a type of orthopox virus that comes from the virus family Poxviridae. Its first case reported in animals and humans was in 1958 and 1970, respectively. It is a viral zoonosis disease with two modes of transmission: animal to human (via direct contact or eating the meat of an infected animal) and human to human (via contact or contact with skin lesions, body fluids, and infected person's contaminated objects). The literature depicts that monkeypox is less contagious among individuals in contrast to smallpox; the infection chain of monkeypox is nearly five to six patients approximately. It has two clades, the West African and the Central African (the Congo basin). The Congo basin subgroup of monkeypox is highly transmissible and severe. The symptoms of monkeypox include fever, lethargy, headache, lymphadenopathy, myalgia, myodynia, fainting, shivers, backache, and rashes on the face and extremities. The most common symptom of monkeypox is lymphatic hyperplasia or, lymph adenopathy or swollen lymph nodes. It is proven to be very useful in the diagnosis of monkeypox. The antiviral drugs that are used for its treatment are tecovirimat, brincidofovir and cidofovir. Tecovirimat has fewer side effects and it shows better therapeutic action in comparison to brincidofovir and cidofovir. For the prevention of monkeypox, the Center for Disease Control and Prevention recommends the administration of the same vaccine used for smallpox named INVAMUNE, which is currently in its third generation. Its first and second generations have adverse side effects in patients having HIV or atopic dermatitis.

In Vitro Phagocytosis of Different Dinoflagellate Species by Coral Cells.

Coral-dinoflagellate symbiosis is a unique biological phenomenon, in which animal cells engulf single-celled photosynthetic algae and maintain them in their cytoplasm mutualistically. Studies are needed to reveal the complex mechanisms involved in symbiotic processes, but it is difficult to answer these questions using intact corals. To tackle these issues, our previous studies established an in vitro system of symbiosis between cells of the scleractinian coral Acropora tenuis and the dinoflagellate Breviolum minutum, and showed that corals direct phagocytosis, while algae are likely engulfed by coral cells passively. Several genera of the family Symbiodiniaceae can establish symbioses with corals, but the symbiotic ratio differs depending on the dinoflagellate clades involved. To understand possible causes of these differences, this study examined whether cultured coral cells show phagocytotic activity with various dinoflagellate strains similar to those shown by intact A. tenuis. We found that (a) A. tenuis larvae incorporate Symbiodinium and Breviolum, but not Cladocopium, and very few Effrenium, (b) cultured coral cells engulfed all four species but the ratio of engulfment was significantly higher with Symbiodinium and Breviolum than Cladocopium and Effrenium, (c) cultured coral cells also phagocytosed inorganic latex beads differently than they do dinoflagellates . It is likely that cultured coral cells preferentially phagocytose Symbiodinium and Breviolum, suggesting that specific molecular mechanisms involved in initiation of symbiosis should be investigated in the future.

Mutations in Coding and Non-Coding Regions in Varicella-Zoster Virus Causing Fatal Hemorrhagic Fever Without Rash in an Immunocompetent Patient: Case Report.

INTRODUCTION: We report the case of a fatal hemorrhagic varicella primary infection in an immunocompetent man and whole-genome characterization of the virus for the investigation of biomarkers of virulence. CASE: A 38-year-old patient born in Nigeria presented to the emergency department with abdominal pain and subsequently developed fatal hemorrhagic disease without skin rash. Extensive laboratory tests including serology and PCR for arenaviruses, bunyaviruses and ebolaviruses were negative. Varicella-zoster virus (VZV) PCR of sera, liver and spleen tissue samples from autopsy revealed the presence of VZV DNA. Primary infection by varicella-zoster virus with hemorrhagic manifestations was diagnosed after virological testing. The VZV genome was sequenced using a mWGS approach. Bioinformatic analysis showed 53 mutations across the genome, 33 of them producing non-synonymous variants affecting up to 14 genes. Some of them, such as ORF11 and ORF 62, encoded for essential functions related to skin or neurotropism. To our knowledge, the mutations reported here have never been described in a VZV causing such a devastating outcome. DISCUSSION: In immunocompetent patients, viral factors should be considered in patients with uncommon symptoms or severe diseases. Some relevant mutations revealed by using whole genome sequencing (WGS) directly from clinical samples may be involved in this case and deserves further investigation. CONCLUSION: Differential diagnosis of varicella-zoster virus in immunocompetent adults should be considered among patients with suspected VHF, even if the expected vesicular rash is not present at admission and does not arise thereafter. Whole genome sequencing of strains causing uncommon symptoms and/or mortality is needed for epidemiological surveillance and further characterization of putative markers of virulence. Additionally, this report highlights the recommendation for a VZV vaccination policy in non-immunized migrants from developing countries.

A Phylogeographic Description of Histoplasma capsulatum in the United States.

Histoplasmosis is one of the most under-diagnosed and under-reported endemic mycoses in the United States. Histoplasma capsulatum is the causative agent of this disease. To date, molecular epidemiologic studies detailing the phylogeographic structure of H. capsulatum in the United States have been limited. We conducted genomic sequencing using isolates from histoplasmosis cases reported in the United States. We identified North American Clade 2 (NAm2) as the most prevalent clade in the country. Despite high intra-clade diversity, isolates from Minnesota and Michigan cases were predominately clustered by state. Future work incorporating environmental sampling and veterinary surveillance may further elucidate the molecular epidemiology of H. capsulatum in the United States and how genomic sequencing can be applied to the surveillance and outbreak investigation of histoplasmosis.

One size does not fit all - Trehalose metabolism by Clostridioides difficile is variable across the five phylogenetic lineages.

Clostridioides difficile, the leading cause of antibiotic-associated diarrhoea worldwide, is a genetically diverse species which can metabolise a number of nutrient sources upon colonising a dysbiotic gut environment. Trehalose, a disaccharide sugar consisting of two glucose molecules bonded by an α 1,1-glycosidic bond, has been hypothesised to be involved in the emergence of C. difficile hypervirulence due to its increased utilisation by the RT027 and RT078 strains. Here, growth in trehalose as the sole carbon source was shown to be non-uniform across representative C. difficile strains, even though the genes for its metabolism were induced. Growth in trehalose reduced the expression of genes associated with toxin production and sporulation in the C. difficile R20291 (RT027) and M120 (RT078) strains in vitro, suggesting an inhibitory effect on virulence factors. Interestingly, the R20291 TreR transcriptional regulatory protein appeared to possess an activator function as its DNA-binding ability was increased in the presence of its effector, trehalose-6-phosphate. Using RNA-sequencing analysis, we report the identification of a putative trehalose metabolism pathway which is induced during growth in trehalose: this has not been previously described within the C. difficile species. These data demonstrate the metabolic diversity exhibited by C. difficile which warrants further investigation to elucidate the molecular basis of trehalose metabolism within this important gut pathogen.

The phylogenetic analysis of the new emerging ALV-K revealing the co-prevailing of multiple clades in chickens and a proposal for the classification of ALV-K.

Subgroup K avian leukosis virus (ALV-K) is a new subgroup of avian leukosis virus (ALV) that was first defined in 2012 and has been become prevalent in Chinese native chickens in recent years. An in-depth analysis of the genetic diversity of ALV-K was performed in the study. By Blast analysis, the env gene and the sequences of the 25 ALV-K isolates we isolated were found to be closely related to the isolates from Guangdong, Hebei, Jiangsu, and Hubei provinces, China. Further eighty-nine sequences of the gp85 gene of ALV-K strains available were used in the phylogenetic and genetic distance analyses for the classification. ALV-K was divided into two second-order clades (Clades 1.1 and 1.2) and three third-order clades (Clades 1.2.1, 1.2.2, and 1.2.3), indicating that not only 1.1 and 1.2.3, the two old clades which are prevalent in Japan, but also two new clades (1.2.1, 1.2.2), are co-prevalent in China. The representative strains of each clade were defined for the first time. Notably, Clade 1.2.2 was found to have a deletion of an amino acid residue in the gp85 gene, which was obviously different from Clades 1.1, 1.2.1, and 1.2.3. The proposed classification method will facilitate future studies of ALV-K epidemiology and the comparison of sequences obtained across the world. The first global comprehensive molecular epidemiological analysis was accomplished on the emerging ALV-K.

Mutation Analysis of SARS-CoV-2 Variants Isolated from Symptomatic Cases from Andhra Pradesh, India.

There has been a continuous evolution in the SARS-CoV-2 genome; therefore, it is necessary to monitor the shifts in the SARS-CoV-2 variants. This study aimed to detect various SARS-CoV-2 variants circulating in the state of Andhra Pradesh, India. The study attempted to sequence the complete S-gene of SARS-CoV-2 of 104 clinical samples using Sanger's method to analyze and compare the mutations with the global prevalence. The method standardized in this study was able to amplify the complete length of the S-gene (3822 bp). The resulting nucleotide and amino acid mutations were analyzed and compared with the local and global SARS-CoV-2 databases using Nextclade and GISAID tools. The Delta variant was the most common variant reported in the present study, followed by the Omicron variant. A variant name was not assigned to thirteen samples using the Nextclade tool. There were sixty-nine types of amino acid substitutions reported (excluding private mutations) throughout the spike gene. The T95I mutation was observed predominantly in Delta variants (15/38), followed by Kappa (3/8) and Omicron (1/31). Nearly all Alpha and Omicron lineages had the N501Y substitution; Q493R was observed only in the Omicron lineage; and other mutations (L445, F486, and S494) were not observed in the present study. Most of these mutations found in the Omicron variant are located near the furin cleavage site, which may play a role in the virulence, pathogenicity, and transmission of the virus. Phylogenetic analysis showed that the 104 complete CDS of SARS-CoV-2 belonged to different phylogenetic clades like 20A, 20B, 20I (Alpha), 21A (Delta), 21B (Kappa), 21I (Delta), 21J (Delta), and 21L (Omicron).

A contemporary review of clade-specific virological differences in monkeypox viruses.

BACKGROUND: Monkeypox virus (MPXV) is an emerging zoonotic virus that has had on-going public health impacts in endemic regions of Central and West Africa for over a half-century. Historically, the MPXV clade endemic in regions of Central Africa is associated with higher morbidity and mortality as compared with the clade endemic in West Africa. OBJECTIVES: Here, we review the virological characteristics of MPXV and discuss potential relationships between virulence factors and clade- (and subclade-) specific differences in virulence and transmission patterns. SOURCES: Targeted search was conducted in PubMed using ((monkeypox virus) OR (Orthopoxvirus)) AND (zoonosis)) OR ((monkeypox) OR (human mpox). CONTENT: Forty-seven references were considered that included three publicly available data reports and/or press releases, one book chapter, and 44 published manuscripts. IMPLICATIONS: Although zoonosis has been historically linked to emergence events in humans, epidemiological analyses of more recent outbreaks have identified increasing frequencies of human-to-human transmission. Furthermore, viral transmission during the 2022 global human mpox outbreak, caused by a recently identified MPXV subclade, has relied exclusively on human-to-human contact with no known zoonotic link.

Insights into the challenging multi-country outbreak of Mpox: a comprehensive review.

Human monkeypox virus (hMpoxV) is of zoonotic origin and is closely related to the once-dreaded smallpox virus. It is largely endemic to the African continent but has moved out of the endemic regions as sporadic clusters in the past 20 years, raising concerns worldwide. Human Mpox is characterized by a mild to severe, self-limiting infection, with mortality ranging from less than 1% to up to 10% during different outbreaks caused by different clades of MpoxV. Bushmeat hunting is one of the primary reasons for its transmission from animals to humans. Various international and national health regulatory bodies are closely monitoring the disease and have laid down guidelines to manage and prevent hMpox cases. Emergency Use Status has been granted to Tecovirimat and Brincidofovir to treat severe cases and vaccination with the smallpox vaccine is recommended for high-risk group individuals. Strategies to repurpose and discover novel therapeutics and vaccines to control the outbreak are being researched. The current Mpox outbreak that has mainly affected men as approximately 96% of all cases are reported in men, is probably the result of a complex intersection of various factors. This necessitates a strong One Health response coordination involving human, animal and environmental health institutions. This review is an attempt to provide an all-inclusive overview of the biology, history, epidemiology, pathophysiology, diagnosis and management of hMpox in context to the recent 2022-2023 multi-country outbreak which is termed by WHO a 'Public Health Emergency of International Concern (PHEIC)'.

Selective events at individual sites underlie the evolution of monkeypox virus clades.

In endemic regions (West Africa and the Congo Basin), the genetic diversity of monkeypox virus (MPXV) is geographically structured into two major clades (Clades I and II) that differ in virulence and host associations. Clade IIb is closely related to the B.1 lineage, which is dominating a worldwide outbreak initiated in 2022. Lineage B.1 has however accumulated mutations of unknown significance that most likely result from apolipoprotein B mRNA editing catalytic polypeptide-like 3 (APOBEC3) editing. We applied a population genetics-phylogenetics approach to investigate the evolution of MPXV during historical viral spread in Africa and to infer the distribution of fitness effects. We observed a high preponderance of codons evolving under strong purifying selection, particularly in viral genes involved in morphogenesis and replication or transcription. However, signals of positive selection were also detected and were enriched in genes involved in immunomodulation and/or virulence. In particular, several genes showing evidence of positive selection were found to hijack different steps of the cellular pathway that senses cytosolic DNA. Also, a few selected sites in genes that are not directly involved in immunomodulation are suggestive of antibody escape or other immune-mediated pressures. Because orthopoxvirus host range is primarily determined by the interaction with the host immune system, we suggest that the positive selection signals represent signatures of host adaptation and contribute to the different virulence of Clade I and II MPXVs. We also used the calculated selection coefficients to infer the effects of mutations that define the predominant human MPXV1 (hMPXV1) lineage B.1, as well as the changes that have been accumulating during the worldwide outbreak. Results indicated that a proportion of deleterious mutations were purged from the predominant outbreak lineage, whose spread was not driven by the presence of beneficial changes. Polymorphic mutations with a predicted beneficial effect on fitness are few and have a low frequency. It remains to be determined whether they have any significance for ongoing virus evolution.

Genetic Analysis of Dengue Virus in Severe and Non-Severe Cases in Dhaka, Bangladesh, in 2018-2022.

Dengue virus (DENV) infections have unpredictable clinical outcomes, ranging from asymptomatic or minor febrile illness to severe and fatal disease. The severity of dengue infection is at least partly related to the replacement of circulating DENV serotypes and/or genotypes. To describe clinical profiles of patients and the viral sequence diversity corresponding to non-severe and severe cases, we collected patient samples from 2018 to 2022 at Evercare Hospital Dhaka, Bangladesh. Serotyping of 495 cases and sequencing of 179 cases showed that the dominant serotype of DENV shifted from DENV2 in 2017 and 2018 to DENV3 in 2019. DENV3 persisted as the only representative serotype until 2022. Co-circulation of clades B and C of the DENV2 cosmopolitan genotype in 2017 was replaced by circulation of clade C alone in 2018 with all clones disappearing thereafter. DENV3 genotype I was first detected in 2017 and was the only genotype in circulation until 2022. We observed a high incidence of severe cases in 2019 when the DENV3 genotype I became the only virus in circulation. Phylogenetic analysis revealed clusters of severe cases in several different subclades of DENV3 genotype I. Thus, these serotype and genotype changes in DENV may explain the large dengue outbreaks and increased severity of the disease in 2019.

Experimental Crosses Between Two Dung Beetle Lineages Show Transgressive Segregation in Physiological Traits.

Physiological traits in insects are intrinsically related to their behavior, fitness, and survival and can reflect adaptations to ecological stressors in different environments, leading to population differentiation that may cause hybrid failure. In this study, we characterized five physiological traits related to body condition (body size, body mass, amount of fat, total hemolymph protein, and phenoloxidase activity) in two geographically separated and recently differentiated lineages of Canthon cyanellus LeConte, 1859 within their natural distribution in Mexico. We also performed experimental hybrid crosses between these lineages to better understand the differentiation process and explore the presence of transgressive segregation over physiological traits in them. We found differences between lineages in all traits except body mass, suggesting selective pressures related to different ecological pressures. These differences were also apparent in the transgressive segregation of all traits in F1 and F2 hybrids, except for phenoloxidase activity. Protein content was sexually dimorphic in both parental lineages but was reversed in hybrids, suggesting a genetic basis for the differences between sexes. The negative sign of transgressive segregation for most traits indicates that hybrids would be smaller, thinner, and generally unfit. Our results suggest that these two lineages may undergo postzygotic reproductive isolation, confirming the cryptic diversity of this species complex.

Characterization of Gardnerella vaginalis isolates: correlations among clades, biofilm formation and cytokine stimulation.

We characterized 61 Gardnerella vaginalis (GV) strains isolated from women with bacterial vaginosis. GV clade 1 was the most commonly found (52.5%), followed by clade 4 (36.1%). All the strains were susceptible to ampicillin and clindamycin, whereas 96.7% and 6.6% of strains showed metronidazole and tetracycline resistance, respectively. Isolates within clade 4 tended to possess the highest ability to form biofilm. Strains resistant to metronidazole and tetracycline were all intermediate or high biofilm producers. All GV clades significantly upregulated the production of pro-inflammatory cytokines by HeLa cells, especially IL-8 and IL-6. Clade 4 induced a significantly higher production of IL-1ß compared to other clades.