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We used variant typing polymerase chain reaction to describe the evolution of severe acute respiratory syndrome coronavirus 2 Omicron sublineages between December 2021 and mid-March 2022. The selective advantage of the BA.2 variant over BA.1 is not due to greater nasopharyngeal viral loads.

Characterization of the respiratory tract bacterial microbiome is in its infancy when compared to the gut microbiota. To limit bias mandates a robust methodology. Specific amplification of the hypervariable (V) region of the 16SrRNA gene is a crucial step. Differences in accuracy exist for one V region to another depending on the sampled environment. We aimed to assess the impact of the primer sequences targeting the V4 region currently used for gut microbiota studies in respiratory samples.

Fast, accurate sequencing methods are needed to identify new variants and genetic mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome. Single-molecule real-time (SMRT) Pacific Biosciences (PacBio) provides long, highly accurate sequences by circular consensus reads. This study compares the performance of a target capture SMRT PacBio protocol for whole-genome sequencing (WGS) of SARS-CoV-2 to that of an amplicon PacBio SMRT sequencing protocol. The median genome coverage was higher (p 0.05) with the target capture protocol (99.3% [interquartile range, IQR: 96.3-99.5]) than with the amplicon protocol (99.3% [IQR: 69.9-99.3]). The clades of 65 samples determined with both protocols were 100% concordant. After adjusting for C

Objectives To evaluate the routine use of the Sentosa ultra-deep sequencing (UDS) system for HIV-1 polymerase resistance genotyping in treatment-naïve individuals and to analyse the virological response (VR) to first-line antiretroviral treatment. Methods HIV drug resistance was determined on 237 consecutive samples from treatment-naïve individuals using the Sentosa UDS platform with two mutation detection thresholds (3% and 20%). VR was defined as a plasma HIV-1 virus load Results Resistance to at least one antiretroviral drug with a mutation threshold of 3% was identified in 29% and 16% of samples according to ANRS and Stanford algorithms, respectively. The ANRS algorithm also revealed reduced susceptibility to at least one protease inhibitor (PI) in 14.3% of samples, to one reverse transcriptase inhibitor in 12.7%, and to one integrase inhibitor (INSTI) in 5.1%. For a mutation threshold of 20%, resistance was identified in 24% and 13% of samples according to ANRS and Stanford algorithms, respectively. The 6 months VR was 87% and was similar in the 58% of patients given INSTI-based treatment, in the 16% given PI-based treatment and in the 9% given NNRTI-based treatment. Multivariate analysis indicated that the VR was correlated with the baseline HIV virus load and resistance to at least one PI at both 3% and 20% mutation detection thresholds (ANRS algorithm). Conclusions The Vela UDS platform is appropriate for determining antiretroviral resistance in patients on a first-line antiretroviral treatment. Further studies are needed on the use of UDS for therapeutic management.

Human-animal pathogenic transmissions threaten both human and animal health, and the processes catalyzing zoonotic spillover and spillback are complex. Prior field studies offer partial insight into these processes but overlook animal ecologies and human perceptions and practices facilitating human-animal contact. Conducted in Cameroon and a European zoo, this holistic study elucidates these processes, integrating metagenomic, historical, anthropological and great ape ecological analyses, and real-time evaluation of human-great ape contact types and frequencies. Surprisingly, we find more enteric virome sharing between Cameroonian humans and great apes than in the zoo, a virome convergence between Cameroonian humans and gorillas, and adenovirus and enterovirus taxa as most frequently shared between Cameroonian humans and great apes. In addition to physical contact from hunting, meat handling and fecal exposure, overlapping human cultivation and gorilla pillaging in forest gardens explain these unexpected findings. Our multidisciplinary study identifies environmental co-use as a complementary mechanism for viral sharing.

International audience; The B.1.1.529 SARS-CoV-2 lineage, named Omicron, was recently divided into three lineages (BA.1, BA.2 and BA.3). BA.1 and BA.2 are much more dominant than BA.3. BA.1 could cause breakthrough infections in highly immune populations [1]. Preliminary studies indicate that BA.2 can readily overcome the immunity provided by vaccination and/or infection with an earlier variant. We used data for the French city of Toulouse to evaluate the impact of the proportions of the BA.1 and BA.2 variants in positive-testing samples and the impact of vaccination on SARS-CoV-2 proliferation.

International audience; Objectives: To evaluate the impact of neutralizing monoclonal antibody (mAb) treatment and to determine whether the selective pressure of mAbs could facilitate the proliferation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with spike protein mutations that might attenuate mAb effectiveness.Patients and methods: We evaluated the impact of mAbs on the nasopharyngeal (NP) viral load and virus quasispecies of mAb-treated patients using single-molecule real-time sequencing. The mAbs used were: Bamlanivimab alone (four patients), Bamlanivimab/Etesevimab (23 patients) and Casirivimab/Imdevimab (five patients).Results: The NP SARS-CoV-2 viral load of mAb-treated patients decreased from 8.2 log10 copies/mL before administration to 4.3 log10 copies/mL 7 days after administration. Five immunocompromised patients given Bamlanivimab/Etesevimab were found to have mAb activity-reducing spike mutations. Two patients harboured SARS-CoV-2 variants with a Q493R spike mutation 7 days after administration, as did a third patient 14 days after administration. The fourth patient harboured a variant with a Q493K spike mutation 7 days post-treatment, and the fifth patient had a variant with a E484K spike mutation on day 21. The emergence of the spike mutation was accompanied by stabilization or rebound of the NP viral load in three of five patients.Conclusion: Two-mAb therapy can drive the selection of resistant SARS-CoV-2 variants in immunocompromised patients. Patients given mAbs should be closely monitored and measures to limit virus spread should be reinforced.

International audience; The SARS-CoV-2 B.1.1.529 (Omicron) variant, divided in five lineages (BA.1/BA.2/BA.3/BA.4/BA.5), harbors numerous spike protein mutations particularly in the receptor-binding domain (RBD). Recent studies showed that the Omicron variant resists the majority of RBD-targeting monoclonal antibodies (mAb). Sotrovimab, a pan-sarbecovirus neutralizing mAb recently authorized, seems to remain efficient to neutralize the omicron variant. However, as it targets a single epitope, the risk of developing resistance mutations is not negligible. We determined the evolution of the virus load, the development of spike mutations, and the evolution of the virus complexity in nasopharyngeal (NP) swabs from sotrovimab-treated ambulatory Omicron-infected patients.

International audience; The spread of SARS-CoV-2 and the resulting disease COVID-19 has killed over 2.6 million people as of 18 March 2021. We have used a modified susceptible, infected, recovered (SIR) epidemiological model to predict how the spread of the virus in regions of France will vary depending on the proportions of variants and on the public health strategies adopted, including anti-COVID-19 vaccination. The proportion of SARS-CoV-2 variant B.1.1.7, which was not detected in early January, increased to become 60% of the forms of SARS-CoV-2 circulating in the Toulouse urban area at the beginning of February 2021, but there was no increase in positive nucleic acid tests. Our prediction model indicates that maintaining public health measures and accelerating vaccination are efficient strategies for the sustained control of SARS-CoV-2.

Human adenovirus (HAdV) represents a major cause of mortality and morbidity in pediatric recipients of allogeneic hematopoietic stem cell transplants (HSCT). HAdV species F type 41 (HAdV-F41) infections in HSCT patients are scarce, whereas HAdV-F41 circulates commonly in healthy individuals. Between March and July 2018, HAdV-F41 infections were identified in four children (A, B, C, and E) who received allogeneic HSCT and one child before HSCT (D) at Robert Debré Hospital, Paris, France. We report here the clinical course of HAdV-F41 infection and the phylogenetic investigation to identify interpatient transmission. HAdV DNA was quantified in stool and plasma samples by real-time PCR. HAdV type was determined by sequencing of the fiber and hexon genes. Phylogenetic investigation was done with whole-genome sequences obtained by next-generation sequencing. HAdV loads in stool samples ranged from 6.60 to 10.10 log(10) copies/ml. HAdV-F41 detection in plasma was observed in four patients, but no disseminated disease was reported. Two patients died, but neither death was attributed to HAdV. While sequencing limited to the fiber gene suggested a cluster with four patients, phylogenetic analysis with whole-genome sequencing (WGS) and HVR7 revealed a cluster that included three patients (C, D, and E), suggesting an interpatient transmission in that cluster and two other independent infections. HAdV-F41 levels in stool specimens of pediatric HSCT patients are high and represent a risk of interpatient transmission. WGS helped to identify related cases. Prompt detection of HAdV in stool and control measures are warranted to limit any risk of nosocomial transmission.

BackgroundCharacterization of the respiratory tract bacterial microbiota is in its infancy when compared to the gut microbiota knowledge. As key methodological steps can directly affect the accuracy of the results, it is crucial to determine a robust methodology in order to limit bias.Two different pairs of primers 515F-806R targeting the V4 hypervariable region of the 16SrRNA gene, “S-V4” for “Stringent V4” primer pair and “R-V4” for “Relaxed V4” primer pair, are respectively used in two ongoing international projects “the Human microbiome project” and “the Earth microbiome project”. We compared two methods of sample processing using these two different primer pairs for bacterial microbiota analyses of respiratory samples from critically-ill ventilated patients. For the later, Illumina 250 paired-end sequencing was done on a MiSeq platform after DNA extraction using mechanical lysis (bead-beating) and NucliSENS easyMAG. The concordance with conventional microbiology is the criterion of choice to determine the optimal method.ResultsTwenty samples from seven patients and four controls were sequenced. The two primer pair provided highly different results. Only 54% of the samples had a similar microbial composition with both pairs of primers. “S-V4” gave the best agreement with the conventional microbiology for ETA: 89% as compared to 44% for the “R-V4” primer pair. The main difference related to Enterobacteriaceae, which were concordant between conventional cultures and microbiota analyses using “S-V4”. Enterobacteriaceae detection was poor for “R-V4”. Among patients with VAP, a decrease in alpha diversity in ETA was observed. The mean of pairwise Unifrac distance was higher inside this group of patients at the time of VAP diagnosis as compared to control patients.ConclusionAccuracy of the bacterial lung microbiota composition was highly correlated to the pair of primers used for amplification of the 16s rRNA hypervariable sequence. Comparison of microbiota results obtained by sequencing and conventional microbiology allowed us to select the best option for further studies. This work validates our methodology based on 16SrRNA gene amplification with 515F-806R “S-V4” primer pair associated to Illumina® MiSeq 250 paired-end sequencing.

We are grateful to the inhabitants and authorities in southeastern Cameroon for their warm welcome and their support of this study. We also acknowledge the invaluable assistance of the European zoo and its employees where we conducted the investigation. We also greatly appreciate the contributions of Olivia Cheny of the Center for Translational Science at the Institut Pasteur.; International audience; Comparisons of mammalian gut microbiota across different environmental conditions shed light on the diversity and composition of gut bacteriome and suggest consequences for human and animal health. Gut bacteriome comparisons across different environments diverge in their results, showing no generalizable patterns linking habitat and dietary degradation with bacterial diversity. The challenge in drawing general conclusions from such studies lies in the broad terms describing diverse habitats ("wild", "captive", "pristine"). We conducted 16S ribosomal RNA gene sequencing to characterize intestinal microbiota of free-ranging sympatric chimpanzees and gorillas in southeastern Cameroon and sympatric chimpanzees and gorillas in a European zoo. We conducted participant-observation and semi-structured interviews among people living near these great apes to understand better their feeding habits and habitats. Unexpectedly, bacterial diversity (ASV, Faith PD and Shannon) was higher among zoo gorillas than among those in the Cameroonian forest, but zoo and Cameroonian chimpanzees showed no difference. Phylogeny was a strong driver of species-specific microbial composition. Surprisingly, zoo gorilla microbiota more closely resembled that of zoo chimpanzees than of Cameroonian gorillas. Zoo living conditions and dietary similarities may explain these results. We encourage multidisciplinary approach integrating environmental sampling and anthropological evaluation to characterize better diverse environmental conditions of such investigations. Over the last decade, numerous studies have demonstrated the importance of environmental changes on the mammalian gut microbiome, which is strongly associated with host metabolic, immune, and neurological functions 1. Broad-ranging influences, including host genetics, living conditions, diet, stress, and antibiotic use can affect gut microbial diversity 2-5. Among these influences, diet and living conditions have been evaluated for human and animal populations, entailing significant effects on gut microbiota and consequences for human and animal health. Adverse microbial profile shifts, for instance, have been associated with dysbiosis and wide-ranging diseases among human beings, from obesity to pediatric environmental enteropathy, and from autism to asthma 2,6,7. Outside of laboratory conditions, disentangling the effects of living and dietary conditions on gut microbial composition from other influences remains a complex question. In humans, such questions have catalyzed multiple studies comparing environmental and gut microbiota between "westernized" and "rural" peoples 8-10. Among other mammalian populations, degradation in habitat quality affects the diversity of available flora and fauna for consumption, and in some cases, is associated with declines in microbial gut composition 11-14. Microbiome OPEN