ABSTRACT
BACKGROUND: Necrotizing enterocolitis is the most severe life-threatening acquired gastrointestinal disorder among preterm neonates. We describe here an outbreak of Clostridium butyricum-related necrotizing enterocolitis in preterm neonates that occurred in three different neonatal centres, in southeast France. METHODS: We defined a confirmed case of C. butyricum-related necrotizing enterocolitis in preterm neonates by the presence of clinical signs according to modified Bell criteria and C. butyricum identified from stools sample using real-time polymerase chain reaction or culture. A phylogenetic analysis of the isolated strains by whole genome sequencing was also performed. RESULTS: Between 5 and 27 January 2022, we identified ten confirmed cases of C. butyricum-related necrotizing enterocolitis, including five from neonatal centre 1, four from neonatal centre 2, and one from neonatal centre 3. The attack rate of necrotizing enterocolitis in neonatal centre 1 was 7.1% (5/70). The positivity rate of C. butyricum detected from stool samples was higher during the outbreak period (37/276; 13.4%) than outside this period (7/369; 1.9%), while systematic screening was maintained (P<0.001). Phylogenetic analysis showed a clonality between strains inside four clusters. Two clusters included neonates hospitalised in different neonatal centres, suggesting the transmission of C. butyricum strains during the transfer of neonates between neonatal centres. CONCLUSIONS: This outbreak of C. butyricum-related necrotizing enterocolitis confirms a cross-transmission between preterm neonates, including twin or triplet siblings, and involving necrotizing enterocolitis cases together with asymptomatic carriers. After three months of follow-up, no further cases were identified following the implementation of contact precautions with sporicidal agents.
ABSTRACT
Pregnant women represent a high-risk population for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. The presence of SARS-CoV-2 has been reported in placenta from infected pregnant women, but whether the virus influences placenta immune response remains unclear. We investigated the properties of maternal-fetal interface macrophages (MFMs) in a cohort of unvaccinated women who contracted coronavirus disease 2019 (COVID-19) during their pregnancy. We reported an infiltration of CD163+ macrophages in placenta from COVID-19 women 19 whereas lymphoid compartment was not affected. Isolated MFMs exhibited nonpolarized activated signature (NOS2, IDO1, IFNG, TNF, TGFB) mainly in women infected during the second trimester of pregnancy. COVID-19 during pregnancy primed MFM to produce type I and III interferon response to SARS-CoV-2 (Wuhan and δ strains), that were unable to elicit this in MFMs from healthy pregnant women. COVID-19 also primed SARS-CoV-2 internalization by MFM in an angiotensin-converting enzyme 2-dependent manner. Activation and recall responses of MFMs were influenced by fetal sex. Collectively, these findings support a role for MFMs in the local immune response to SARS-CoV-2 infection, provide a basis for protective placental immunity in COVID-19, and highlight the interest of vaccination in pregnant women.
Subject(s)
COVID-19 , Macrophages , Placenta , Pregnancy Complications, Infectious , SARS-CoV-2 , Humans , Female , Pregnancy , COVID-19/immunology , COVID-19/virology , Placenta/immunology , Placenta/virology , Macrophages/immunology , Macrophages/virology , Pregnancy Complications, Infectious/virology , Pregnancy Complications, Infectious/immunology , SARS-CoV-2/immunology , Adult , Antigens, CD/immunology , Antigens, Differentiation, Myelomonocytic , Receptors, Cell Surface/immunology , Receptors, Cell Surface/metabolism , Virus InternalizationABSTRACT
The diversity and evolution of the genomes of human bocavirus (HBoV), which causes respiratory diseases, have been scarcely studied. Here, we aimed to obtain and characterize HBoV genomes from patients's nasopharyngeal samples collected between 2017 and 2022 period (5 years and 7 months). Next-generation sequencing (NGS) used Illumina technology after having implemented using GEMI an in-house multiplex PCR amplification strategy. Genomes were assembled and analyzed with CLC Genomics, Mafft, BioEdit, MeV, Nextclade, MEGA, and iTol. A total of 213 genomes were obtained. Phylogeny classified them all as of Bocavirus 1 (HBoV1) species. Five HBoV1 genotypic clusters determined by hierarchical clustering analysis of 27 variable genome positions were scattered over the study period although with differences in yearly prevalence. A total of 167 amino acid substitutions were detected. Besides, coinfection was observed for 52% of the samples, rhinoviruses then adenoviruses (HAdVs) being the most common viruses. Principal component analysis showed that HBoV1 genotypic cluster α tended to be correlated with HAdV co-infection. Subsequent HAdV typing for HBoV1-positive samples and negative controls demonstrated that HAdVC species predominated but HAdVB was that significantly HBoV1-associated. Overall, we described here the first HBoV1 genomes sequenced for France. HBoV1 and HAdVB association deserves further investigation.
Subject(s)
Coinfection , Genome, Viral , Genotype , High-Throughput Nucleotide Sequencing , Human bocavirus , Parvoviridae Infections , Phylogeny , Humans , Human bocavirus/genetics , Human bocavirus/classification , Human bocavirus/isolation & purification , Genome, Viral/genetics , France/epidemiology , Parvoviridae Infections/virology , Parvoviridae Infections/epidemiology , Female , Child, Preschool , Male , Child , Adult , Infant , Middle Aged , Coinfection/virology , Coinfection/epidemiology , Adolescent , Nasopharynx/virology , Young Adult , Aged , Sequence Analysis, DNA , Genetic Variation , DNA, Viral/geneticsABSTRACT
We report a large-scale outbreak of Mycoplasma pneumoniae respiratory infections encompassing 218 cases (0.8% of 26,449 patients tested) during 2023-2024 in Marseille, France. The bacterium is currently circulating and primarily affects children <15 years of age. High prevalence of co-infections warrants the use of a syndromic diagnostic strategy.
Subject(s)
Disease Outbreaks , Mycoplasma pneumoniae , Pneumonia, Mycoplasma , Humans , France/epidemiology , Pneumonia, Mycoplasma/epidemiology , Pneumonia, Mycoplasma/microbiology , Pneumonia, Mycoplasma/history , Adolescent , Child , Child, Preschool , Male , Female , Adult , Infant , Young Adult , Middle Aged , History, 21st Century , Aged , Prevalence , Coinfection/epidemiology , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiologyABSTRACT
Vertical transmission has been described following monkeypox virus (MPXV) infection in pregnant women. The presence of MPXV has been reported in the placenta from infected women, but whether pathogens colonize placenta remains unexplored. We identify trophoblasts as a target cell for MPXV replication. In a pan-microscopy approach, we decipher the specific infectious cycle of MPXV and inner cellular structures in trophoblasts. We identified the formation of a specialized region for viral morphogenesis and replication in placental cells. We also reported infection-induced cellular remodeling. We found that MPXV stimulates cytoskeleton reorganization with intercellular extensions for MPXV cell spreading specifically to trophoblastic cells. Altogether, the specific infectious cycle of MPXV in trophoblast cells and these protrusions that were structurally and morphologically similar to filopodia reveal new insights into the infection of MPXV.
Subject(s)
Monkeypox virus , Pseudopodia , Trophoblasts , Trophoblasts/virology , Humans , Pseudopodia/virology , Female , Pregnancy , Monkeypox virus/physiology , Virus Release , Virus Replication , Cytoskeleton/virology , Placenta/virology , Placenta/cytology , Virion/ultrastructure , Microscopy/methods , Cell LineABSTRACT
OBJECTIVES: The SARS-CoV-2 pandemic and large-scale genomic surveillance provided an exceptional opportunity to analyze mutations that appeared over three years in viral genomes. Here we studied mutations and their epidemic consequences for SARS-CoV-2 genomes from our center. METHODS: We analyzed 61,397 SARS-CoV-2 genomes we sequenced from respiratory samples for genomic surveillance. Mutations frequencies were calculated using Nextclade, Microsoft Excel, and an in-house Python script. RESULTS: A total of 22,225 nucleotide mutations were identified, 220 (1.0%) being each at the root of ≥836 genomes, classifying mutations as 'hyperfertile'. Two seeded the European pandemic: P323L in RNA polymerase, associated with an increased mutation rate, and D614G in spike that improved fitness. Most 'hyperfertile' mutations occurred in areas not predicted with increased virulence. Their mean number was 8±6 (0-22) per 1000 nucleotides per gene. They were 3.7-times more frequent in accessory than informational genes (13.8 versus 3.7/1000 nucleotides). Particularly, they were 4.1-times more frequent in ORF8 than in the RNA polymerase gene. Interestingly, stop codons were present in 97 positions, almost only in accessory genes, including ORF8 (21/100 codons). CONCLUSIONS: most 'hyperfertile' mutations did not predict emergence of a new epidemic, and some were stop codons indicating the existence of so-named 'non-virulence' genes.
Subject(s)
COVID-19 , Genome, Viral , Mutation , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/virology , COVID-19/epidemiology , Evolution, Molecular , Mutation Rate , PandemicsABSTRACT
Vγ9Vδ2 T cells play a key role in the innate immune response to viral infections through butyrophilin 3A (BTN3A). Here, we report blood Vγ9Vδ2 T cells decreased in clinically mild COVID-19 compared to healthy volunteers, and this was maintained up to 28 days and in the recovery period. Terminally differentiated Vγ9Vδ2 T cells tended to be enriched on the day of diagnosis, 28 days after, and during the recovery period. These cells showed cytotoxic and inflammatory activities following anti-BTN3A activation. BTN3A upregulation and Vγ9Vδ2 T-cell infiltration were observed in a lung biopsy from a fatal SARS-CoV-2 infection. In vitro, SARS-CoV-2 infection increased BTN3A expression in macrophages and lung cells that enhanced the anti-SARS-CoV-2 Vγ9Vδ2 T-cell cytotoxicity and interferon-γ and tumor necrosis factor-α. Increasing concentrations of anti-BTN3A lead to viral replication inhibition. Altogether, we report Vγ9Vδ2 T cells are important in the immune response against SARS-CoV-2 infection and activation by anti-BTN3A antibody may enhance their response. Clinical Trials Registration. NCT04816760.
Subject(s)
Butyrophilins , COVID-19 , SARS-CoV-2 , Virus Replication , Humans , COVID-19/immunology , COVID-19/virology , Virus Replication/drug effects , SARS-CoV-2/immunology , Butyrophilins/metabolism , Male , Female , Middle Aged , Adult , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocytes/immunology , Lung/virology , Lung/immunology , Lung/pathology , Phenotype , Interferon-gamma/metabolism , Interferon-gamma/immunology , Macrophages/immunology , Macrophages/virology , Antigens, CDABSTRACT
OBJECTIVES: This study aimed to investigate the prevalence of mpox virus (MPXV) infections in the general population consulting for routine sexually transmitted infections (STIs) in our Marseille public hospital. In fact, the recent worldwide MPXV outbreak mainly impacted men who have sex with men and the prevalence of MPXV infections in the general population remains poorly defined. METHODS: All samples addressed routinely to our microbiological laboratory for STIs between July 1 and October 15, 2022 were screened with MPXV-specific quantitative polymerase chain reaction. RESULTS: A total of 2688 samples from 1896 patients suspected of having STIs were tested and eight (0.4%) patients were incidentally diagnosed with MPXV infection, including six men and two women. MPXV was detected in rectal swabs (n = 2), urine (n = 2), vaginal swabs (n = 2), a urethral swab (n = 1), and a skin swab (n = 1). CONCLUSIONS: This study suggests that some MPXV infections are likely to be underdiagnosed because of their non-specific clinical presentation and/or insufficient clinical knowledge of the disease. Our data showed that systematic screening was particularly useful for detecting MPXV in patients without classic lesions or cases of asymptomatic carriage in patients reporting recent high-risk exposure and in patients presenting no obvious risk factor.
Subject(s)
Incidental Findings , Humans , Male , Female , Adult , France/epidemiology , Middle Aged , Prevalence , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/virology , Young Adult , Mass Screening/methodsABSTRACT
Mutations associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resistance to antiprotease nirmatrelvir were reported. We aimed to detect them in SARS-CoV-2 genomes and quasispecies retrieved in our institute before drug availability in January 2022 and to analyze the impact of mutations on protease (3CLpro) structure. We sought for 38 3CLpro nirmatrelvir resistance mutations in a set of 62 673 SARS-CoV-2 genomes obtained in our institute from respiratory samples collected between 2020 and 2023 and for these mutations in SARS-CoV-2 quasispecies for 90 samples collected in 2020, using Python. SARS-CoV-2 protease with major mutation E166V was generated with Swiss Pdb Viewer and Molegro Molecular Viewer. We detected 22 (58%) of the resistance-associated mutations in 417 (0.67%) of the genomes analyzed; 325 (78%) of these genomes had been obtained from samples collected in 2020-2021. APOBEC signatures were found for 12/22 mutations. We also detected among viral quasispecies from 90 samples some minority reads harboring any of 15 nirmatrelvir resistance mutations, including E166V. Also, we predicted that E166V has a very limited effect on 3CLpro structure but may prevent drug attachment. Thus, we evidenced that mutations associated with nirmatrelvir resistance pre-existed in SARS-CoV-2 before drug availability. These findings further warrant SARS-CoV-2 genomic surveillance and SARS-CoV-2 quasispecies characterization.
Subject(s)
COVID-19 , Humans , SARS-CoV-2/genetics , Endopeptidases , Peptide Hydrolases , Lactams , Leucine , Mutation , Nitriles , Antiviral Agents/pharmacologyABSTRACT
The on-going emergence of the Omicron BA.2.86 variant is one of the major events in SARS-CoV-2 genetic evolution that remain enigmatic regarding the overall virus mutation rate, together with the emergence of the initial Omicron variant, BA.1. Indeed, the genomes of the Omicron BA.2.86 lineage, an offspring of the second major Omicron subvariant, BA.2, harbor 39 additional mutations in the spike compared to this ancestor. Here we comment on the phylogeny of BA.2.86, on the positions, and frequencies in other SARS-CoV-2, of mutations in its spike, and on the structural model of this protein that concentrates most of BA.2.86 additional mutations.
Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , SARS-CoV-2/genetics , Family , Evolution, Molecular , Spike Glycoprotein, Coronavirus/geneticsABSTRACT
Extending our knowledge on human skin microbiota is a challenge to better decipher its role in health and disease. Using the culturomics method, we isolated strain Marseille-Q4368 from the healthy forehead of a 59-year-old woman. We describe here the main characteristics of this bacterium using a taxonogenomic approach. This new bacterial species is Gram-positive, non-motile, and non-spore-forming. Its 16S rRNA sequence exhibited a similarity of 99.59% with Leucobacter chromiiresistens, the most closely related species in terms of nomenclature. However, a digital DNA-DNA hybridization analysis between these two species revealed a maximum identity similarity of only 27.5%. We found phenotypical and genomic differences between strain Marseille-Q4368 and its closely related species. These findings underscore the classification of this bacterium as a distinct species. Hence, we propose the name Leucobacter manosquensis sp. nov. strain Marseille-Q4368 (=CSUR Q4368 = DSM 112403) for this newly identified bacterial species.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 XBB.1.5 is the first recombinant lineage to predominate at the country and global scales. Very interestingly, like the Marseille-4B subvariant (or B.1.160) and the pandemic variant B.1.1.7 (or Alpha) previously, it has its ORF8 gene inactivated by a stop codon. We aimed here to study the distribution of stop codons in ORF8 of XBB.1.5 and non-XBB.1.5 genomes. We identified that a stop codon was present at 89 (74%) ORF8 codons in ≥1 of 15 222 404 genomes available in GISAID. The mean proportion of genomes with a stop codon per codon was 0.11% (range, 0%-7.8%). In addition, a stop codon was detected at 15 (12%) codons in at least 1000 genomes. These 15 codons are notably located on seven stem-loop hairpin regions and in the signal peptide region for the case of the XBB.1.5 lineage (codon 8). Thus, it is very likely that stop codons in ORF8 gene contributed on at least three occasions and independently during the pandemic to the evolutionary success of a lineage that became transiently predominant. Such association of gene loss with evolutionary success, which suits the recently described Mistigri rule, is an important biological phenomenon very unknown in virology while largely described in cellular organisms.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Codon, Terminator , COVID-19/epidemiology , PhylogenyABSTRACT
During the current global outbreak of mpox (formerly monkeypox), atypical features were frequently described outside endemic areas, raising concerns around differential diagnosis. In this study, we included 372 adult patients who had clinical signs consistent with mpox and who were screened using non-variola orthopoxvirus specific quantitative polymerase chain reaction (PCR) between 15 May and 15 November 2022 at the University Hospital Institute Méditerranée Infection, Marseille, France. At least one clinical sample was positive for 143 (38.4%) of these patients and 229 (61.6%) were negative. Clinically, patients who had mpox presented more frequently with systemic signs (69.9% vs. 31.0%, p < 10-6 ) including fever (51.0% vs. 30.1%, p < 10-3 ), myalgia (33.5% vs. 17.9%, p = 0.002), and lymphadenopathy (38.5% vs. 13.1%, p < 10-6 ). Among the patients who were negative for the non-variola orthopoxvirus, an alternative diagnosis was identified in 58 of them (25.3%), including chickenpox (n = 30, 13.1%), syphilis (n = 9, 4%), bacterial skin infection (n = 8, 3.5%), gonococcus (n = 5, 2.2%), HSV infection (n = 5, 2.2%), and histoplasmosis (n = 1, 0.4%). Overall, in the current outbreak, we show that mpox has a poorly specific clinical presentation. This reinforces the importance of microbiological confirmation. In symptomatic patients who are negative for the monkeypox virus by PCR, a broad differential diagnosis should be maintained.
Subject(s)
Chickenpox , Cross Infection , Mpox (monkeypox) , Orthopoxvirus , Adult , Humans , Retrospective Studies , Diagnosis, DifferentialABSTRACT
Respiratory syncytial virus is among the most common causes of respiratory infections. Typically, this viral infection has a seasonality during the cold months but with the SARS-CoV-2 pandemic this has been considerably modified. Here, we studied the epidemiology of this virus in university hospitals of Marseille, South of France, over the period 2020 to 2023. We tested in our laboratory from July 2020 to October 2021 16,516 nasopharyngeal swabs from 16,468 patients for RSV infection using different qPCR assays. We then analyzed data from previous and subsequent winters (from 2018 to 2023) and previous summers (from 2015 to 2021). A total of 676 patients were RSV-positive; their mean age was 3 years and 91 were under 5 years of age. We observed a delay of 4 months of the RSV epidemic's onset compared to other years with an epidemic that peaked in March 2021. We had significantly more RSV-positive cases during summer 2021 compared to previous summers, whereas the incidence of RSV infections was not significantly higher during winter 2022 versus previous winters. Moreover, 494 patients were diagnosed as RSV-positive in the emergency unit and 181 were subsequently hospitalized, and 34 patients were diagnosed RSV-positive while already in the intensive care unit. Over all the study periods, 38 patients diagnosed as RSV-positive died, the majority of whom (23/28) were over 65 years of age. These data show an atypical evolution of the incidence of RSV infections in our city and is another example of the unpredictability of infectious disease epidemiology.
Subject(s)
COVID-19 , Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus, Human , Humans , Child, Preschool , COVID-19/epidemiology , SARS-CoV-2 , Respiratory Syncytial Virus Infections/epidemiology , Pandemics , France/epidemiologyABSTRACT
To investigate the existence of any association between new putative periodontal pathogens and periodontitis. Two independent reviewers conducted electronic literature searches in the MEDLINE (PubMed), EMBASE, DOSS and Google Scholar databases as well as a manual search to identify eligible clinical studies prior to November 2022. Studies comparing the prevalence of microorganisms other than the already-known periodontal pathogens in subgingival plaque and/or saliva samples between subjects with periodontitis and subject with periodontal health were included. Meta-analyses were performed on data provided by the included studies. Fifty studies including a total of 2739 periodontitis subjects and 1747 subjects with periodontal health were included. The Archaea domain and 25 bacterial species (Anaeroglobus geminatus, Bacteroidales [G-2] bacterium HMT 274, Desulfobulbus sp. HMT 041, Dialister invisus, Dialister pneumosintes, Eubacterium brachy, Enterococcus faecalis, Eubacterium nodatum, Eubacterium saphenum, Filifactor alocis, Fretibacterium sp. HMT 360, Fretibacterium sp. HMT 362, Mogibacterium timidum, Peptoniphilaceae sp. HMT 113, Peptostreptococcus stomatis, Porphyromonas endodontalis, Slackia exigua, Streptococcus gordonii, Selenomonas sputigena, Treponema amylovorum, Treponema lecithinolyticum, Treponema maltophilum, Treponema medium, Treponema parvum and Treponema socranskii) were found to be statistically significantly associated with periodontitis. Network studies should be conducted to investigate the role of these newly identified periodontitis-associated microorganisms through interspecies interaction and host-microbe crosstalk analyses.
Subject(s)
Dental Plaque , Periodontitis , Humans , Bacteria , Periodontitis/microbiology , Dental Plaque/microbiology , Bacteroides , EubacteriumABSTRACT
A large outbreak of Monkeypox virus (MPXV) infections has arisen in May 2022 in nonendemic countries. Here, we performed DNA metagenomics using next-generation sequencing with Illumina or Nanopore technologies for clinical samples from MPXV-infected patients diagnosed between June and July 2022. Classification of the MPXV genomes and determination of their mutational patterns were performed using Nextclade. Twenty-five samples from 25 patients were studied. A MPXV genome was obtained for 18 patients, essentially from skin lesions and rectal swabbing. All 18 genomes were classified in clade IIb, lineage B.1, and we identified four B.1 sublineages (B.1.1, B.1.10, B.1.12, B.1.14). We detected a high number of mutations (range, 64-73) relatively to a 2018 Nigerian genome (genome GenBank Accession no. NC_063383.1), which were harbored by a large part of a set of 3184 MPXV genomes of lineage B.1 recovered from GenBank and Nextstrain; and we detected 35 mutations relatively to genome ON563414.3 (a B.1 lineage reference genome). Nonsynonymous mutations occurred in genes encoding central proteins, among which transcription factors and core and envelope proteins, and included two mutations that would truncate a RNA polymerase subunit and a phospholipase d-like protein, suggesting an alternative start codon and gene inactivation, respectively. A large majority (94%) of nucleotide substitutions were G > A or C > U, suggesting the action of human APOBEC3 enzymes. Finally, >1000 reads were identified as from Staphylococcus aureus and Streptococcus pyogenes for 3 and 6 samples, respectively. These findings warrant a close genomic monitoring of MPXV to get a better picture of the genetic micro-evolution and mutational patterns of this virus, and a close clinical monitoring of skin bacterial superinfection in monkeypox patients.
Subject(s)
Mpox (monkeypox) , Superinfection , Humans , Monkeypox virus/genetics , Genome, Viral , Gene Silencing , APOBEC Deaminases/geneticsABSTRACT
Acanthamoeba polyphaga mimivirus, so called because of its "mimicking microbe", was discovered in 2003 and was the founding member of the first family of giant viruses isolated from amoeba. These giant viruses, present in various environments, have opened up a previously unexplored field of virology. Since 2003, many other giant viruses have been isolated, founding new families and taxonomical groups. These include a new giant virus which was isolated in 2015, the result of the first co-culture on Vermamoeba vermiformis. This new giant virus was named "Faustovirus". Its closest known relative at that time was African Swine Fever Virus. Pacmanvirus and Kaumoebavirus were subsequently discovered, exhibiting phylogenetic clustering with the two previous viruses and forming a new group with a putative common ancestor. In this study, we aimed to summarise the main features of the members of this group of giant viruses, including Abalone Asfarvirus, African Swine Fever Virus, Faustovirus, Pacmanvirus, and Kaumoebavirus.
Subject(s)
African Swine Fever Virus , Giant Viruses , Mimiviridae , Viruses , Swine , Animals , Phylogeny , African Swine Fever Virus/genetics , Viruses/genetics , Mimiviridae/genetics , DNA Viruses/genetics , Genome, ViralABSTRACT
Introduction: Kidney transplant recipients (KTRs) are at high risk of severe COVID-19, even when they are fully vaccinated. Additional booster vaccinations or passive immunization with prophylactic monoclonal antibodies are recommended to increase their protection against severe COVID-19. Methods: Here, we describe the neutralization of SARS-CoV-2 Delta, Omicron BA.1, BA.2, BA.4, and BA.5 variants, firstly by 39 serum samples from vaccinated KTRs exhibiting anti-spike antibody concentrations ≥264 binding antibody units (BAU)/mL and, secondly, by tixagevimab/cilgavimab. Results: No neutralization was observed for 18% of the KTRs, while serum from only 46% of patients could neutralize the five variants. Cross-neutralization of the Delta and Omicron variants occurred for 65-87% of sera samples. The anti-spike antibody concentration correlated with neutralization activity for all the variants. The neutralization titers against the Delta variant were higher in vaccinated KTRs who had previously presented with COVID-19, compared to those KTRs who had only been vaccinated. Breakthrough infections occurred in 39% of the KTRs after the study. Tixagevimab/cilgavimab poorly neutralizes Omicron variants, particularly BA.5, and does not neutralize BQ.1, which is currently the most prevalent strain. Discussion: As a result, sera from seropositive vaccinated KTRs had poor neutralization of the successive Omicron variants. Several Omicron variants are able to escape tixagevimab/cilgavimab.
ABSTRACT
The virome of the human oral cavity and the relationships between viruses and diseases such as periodontitis are scarcely deciphered. Redondoviruses were reported in the human oral cavity in 2019, including in periodontitis patients. Here, we aimed at detecting redondoviruses and at searching for a potential viral host in human saliva. Non-stimulated saliva was collected between December 2020 and June 2021. These samples were tested using real-time PCR regarding the presence of redondovirus and Entamoeba gingivalis DNA. Similarity searches were performed using BLAST against eukaryotic and prokaryotic sequences from GenBank. The redondovirus DNA was detected in 46% of the 28 human saliva samples. In addition, short fragments of redondovirus genomes were detected in silico within Entamoeba sequences. Finally, Entamoeba gingivalis DNA was detected in 46% of the 28 saliva samples, with a strong correlation between redondovirus DNA and E. gingivalis DNA detections, in 93% of the cases. Regarded together, these findings and previous ones strongly support the presence of redondoviruses in the human oral cavity and their association to E. gingivalis as their likely host.
Subject(s)
Amoeba , Entamoeba , Periodontitis , Humans , Entamoeba/genetics , Saliva , Porphyromonas gingivalis/geneticsABSTRACT
Antibiotic resistance is a worldwide public health concern and has been associated with reports of elevated mortality. According to the One Health concept, antibiotic resistance genes are transferrable to organisms, and organisms are shared among humans, animals, and the environment. Consequently, aquatic environments are a possible reservoir of bacteria harboring antibiotic resistance genes. In our study, we screened water and wastewater samples for antibiotic resistance genes by culturing samples on different types of agar media. Then, we performed real-time PCR to detect the presence of genes conferring resistance to beta lactams and colistin, followed by standard PCR and gene sequencing for verification. We mainly isolated Enterobacteriaceae from all samples. In water samples, 36 Gram-negative bacterial strains were isolated and identified. We found three extended-spectrum ß-lactamase (ESBL)-producing bacteria-Escherichia coli and Enterobacter cloacae strains-harboring the CTX-M and TEM groups. In wastewater samples, we isolated 114 Gram-negative bacterial strains, mainly E. coli, Klebsiella pneumoniae, Citrobacter freundii and Proteus mirabilis strains. Forty-two bacterial strains were ESBL-producing bacteria, and they harbored at least one gene belonging to the CTX-M, SHV, and TEM groups. We also detected carbapenem-resistant genes, including NDM, KPC, and OXA-48, in four isolates of E. coli. This short epidemiological study allowed us to identify new antibiotic resistance genes present in bacterial strains isolated from water in Marseille. This type of surveillance shows the importance of tracking bacterial resistance in aquatic environments. IMPORTANCE Antibiotic-resistant bacteria are involved in serious infections in humans. The dissemination of these bacteria in water, which is in close contact with human activities, is a serious problem, especially under the concept of One Health. This study was done to survey and localize the circulation of bacterial strains, along with their antibiotic resistance genes, in the aquatic environment in Marseille, France. The importance of this study is to monitor the frequency of these circulating bacteria by creating and surveying water treatments.