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1.
J Med Virol ; 96(6): e29706, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38888111

ABSTRACT

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/genetics
2.
J Med Virol ; 95(6): e28799, 2023 06.
Article in English | MEDLINE | ID: mdl-37342884

ABSTRACT

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/genetics
3.
Travel Med Infect Dis ; 52: 102515, 2023.
Article in English | MEDLINE | ID: mdl-36470351

ABSTRACT

BACKGROUND: Respiratory and gastrointestinal symptoms and febrile illness are the most common complaints among ill pilgrims attending the Grand Magal of Touba (GMT) in Senegal. METHODS: Patients presenting with respiratory or gastrointestinal symptoms or febrile systemic illnesses were recruited between 2018 and 2021 at a healthcare centre close to Touba. Respiratory, gastrointestinal and blood samples were tested for potential pathogens using qPCR. RESULTS: 538 patients were included. 45.5% of these were female, with a median age of 17 years. Of the 326 samples collected from patients with a cough, 62.8% tested positive for at least one virus, including influenza viruses (33.1%). A high positivity rate of bacterial carriage was observed for Haemophilus influenzae (72.7%), Streptococcus pneumoniae (51.2%) and Moraxella catarrhalis (46.0%). Of the 95 samples collected from patients with diarrhoea, 71.3% were positive, with high rates of bacterial carriage, ranging from 4.2% for Tropheryma whipplei to 45.3% for Entero-pathogenic Escherichia coli. Of the 141 blood samples collected from patients with fever, 31.9% were positive including Plasmodium falciparum (21.3%), Borrelia sp. (5.7%) and dengue virus (5.0%). CONCLUSION: This study provides insight into the aetiology of most common infections at the GMT on which to base therapeutic options.


Subject(s)
Respiratory Tract Infections , Streptococcus pneumoniae , Humans , Female , Adolescent , Male , Streptococcus pneumoniae/genetics , Bacteria , Moraxella catarrhalis/genetics , Polymerase Chain Reaction , Delivery of Health Care , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology
4.
J Med Virol ; 95(1): e28102, 2023 01.
Article in English | MEDLINE | ID: mdl-36031728

ABSTRACT

The nature and dynamics of mutations associated with the emergence, spread, and vanishing of SARS-CoV-2 variants causing successive waves are complex. We determined the kinetics of the most common French variant ("Marseille-4") for 10 months since its onset in July 2020. Here, we analyzed and classified into subvariants and lineages 7453 genomes obtained by next-generation sequencing. We identified two subvariants, Marseille-4A, which contains 22 different lineages of at least 50 genomes, and Marseille-4B. Their average lifetime was 4.1 ± 1.4 months, during which 4.1 ± 2.6 mutations accumulated. Growth rate was 0.079 ± 0.045, varying from 0.010 to 0.173. Most of the lineages exhibited a bell-shaped distribution. Several beneficial mutations at unpredicted sites initiated a new outbreak, while the accumulation of other mutations resulted in more viral heterogenicity, increased diversity and vanishing of the lineages. Marseille-4B emerged when the other Marseille-4 lineages vanished. Its ORF8 gene was knocked out by a stop codon, as reported in SARS-CoV-2 of mink and in the Alpha variant. This subvariant was associated with increased hospitalization and death rates, suggesting that ORF8 is a nonvirulence gene. We speculate that the observed heterogenicity of a lineage may predict the end of the outbreak.


Subject(s)
COVID-19 , Epidemics , RNA Viruses , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , Phylogeny
5.
Viruses ; 14(6)2022 06 10.
Article in English | MEDLINE | ID: mdl-35746737

ABSTRACT

Genetic recombination is a major evolutionary mechanism among RNA viruses, and it is common in coronaviruses, including those infecting humans. A few SARS-CoV-2 recombinants have been reported to date whose genome harbored combinations of mutations from different mutants or variants, but only a single patient's sample was analyzed, and the virus was not isolated. Here, we report the gradual emergence of a hybrid genome of B.1.160 and Alpha variants in a lymphoma patient chronically infected for 14 months, and we isolated the recombinant virus. The hybrid genome was obtained by next-generation sequencing, and the recombination sites were confirmed by PCR. This consisted of a parental B.1.160 backbone interspersed with two fragments, including the spike gene, from an Alpha variant. An analysis of seven sequential samples from the patient decoded the recombination steps, including the initial infection with a B.1.160 variant, then a concurrent infection with this variant and an Alpha variant, the generation of hybrid genomes, and eventually the emergence of a predominant recombinant virus isolated at the end of the patient's follow-up. This case exemplifies the recombination process of SARS-CoV-2 in real life, and it calls for intensifying the genomic surveillance in patients coinfected with different SARS-CoV-2 variants, and more generally with several RNA viruses, as this may lead to the appearance of new viruses.


Subject(s)
COVID-19 , SARS-CoV-2 , Genome, Viral , Humans , Immunocompromised Host , Mutation , SARS-CoV-2/genetics
6.
J Med Virol ; 94(8): 3739-3749, 2022 08.
Article in English | MEDLINE | ID: mdl-35467028

ABSTRACT

Multiple SARS-CoV-2 variants have successively, or concomitantly spread worldwide since the summer of 2020. A few co-infections with different variants were reported and genetic recombinations, common among coronaviruses, were reported or suspected based on co-detection of signature mutations of different variants in a given genome. Here we report three infections in southern France with a Delta 21J_AY.4-Omicron 21K/BA.1 "Deltamicron" recombinant. The hybrid genome harbors signature mutations of the two lineages, supported by a mean sequencing depth of 1163-1421 reads and a mean nucleotide diversity of 0.1%-0.6%. It is composed of the near full-length spike gene (from codons 156-179) of an Omicron 21K/BA.1 variant in a Delta 21J/AY.4 lineage backbone. Importantly, we cultured an isolate of this recombinant and sequenced its genome. It was observed by scanning electron microscopy. As it is misidentified with current variant screening quantitative polymerase chain reaction (qPCR), we designed and implemented for routine diagnosis a specific duplex qPCR. Finally, structural analysis of the recombinant spike suggested its hybrid content could optimize viral binding to the host cell membrane. These findings prompt further studies of the virological, epidemiological, and clinical features of this recombinant.


Subject(s)
COVID-19 , SARS-CoV-2 , Base Sequence , COVID-19/diagnosis , Humans , Phylogeny , SARS-CoV-2/genetics
7.
Travel Med Infect Dis ; 46: 102277, 2022.
Article in English | MEDLINE | ID: mdl-35158042

ABSTRACT

BACKGROUND: We describe the epidemiology of the first cases diagnosed in our institute of infections with the SARS-CoV-2 Beta variant and how this variant was imported to Marseille. METHODS: The Beta variant was identified based on analyses of sequences of viral genomes or of a spike gene fragment obtained by next-generation sequencing using Illumina technology, or by a real-time reverse-transcription-PCR (qPCR) specific of the Beta variant. RESULTS: The first patient diagnosed as infected with the SARS-CoV-2 Beta variant was sampled on January 15, 2021. Twenty-nine patients were diagnosed in January 2021 (two weeks). Fifteen (52%) patients were of Comorian nationality. Eight (28%) had travelled abroad, including six who had returned from Comoros. Phylogeny based on SARS-CoV-2 genomes from 11 of these patients and their best BLAST hits from the GISAID database showed that seven patients, including the four returning from Comoros, were clustered with 27 other genomes from GISAID that included the six first Beta variant genomes described in Comoros in January 2021. CONCLUSIONS: Our analyses highlight that, as for the case of other SARS-CoV-2 variants that have been diagnosed in Marseille, the Beta variant was imported to Marseille through travel from abroad. It had limited spread in our geographical area.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , Comoros/epidemiology , Genome, Viral , Humans , Mutation , Phylogeny , SARS-CoV-2/genetics
8.
Front Med (Lausanne) ; 8: 737602, 2021.
Article in English | MEDLINE | ID: mdl-34540874

ABSTRACT

Since the start of COVID-19 pandemic the Republic of Djibouti, in the horn of Africa, has experienced two epidemic waves of the virus between April and August 2020 and between February and May 2021. By May 2021, COVID-19 had affected 1.18% of the Djiboutian population and caused 152 deaths. Djibouti hosts several foreign military bases which makes it a potential hot-spot for the introduction of different SARS-CoV-2 strains. We genotyped fifty three viruses that have spread during the two epidemic waves. Next, using spike sequencing of twenty-eight strains and whole genome sequencing of thirteen strains, we found that Nexstrain clades 20A and 20B with a typically European D614G substitution in the spike and a frequent P2633L substitution in nsp16 were the dominant viruses during the first epidemic wave, while the clade 20H South African variants spread during the second wave characterized by an increase in the number of severe forms of COVID-19.

9.
J Clin Med ; 10(12)2021 Jun 18.
Article in English | MEDLINE | ID: mdl-34207314

ABSTRACT

(1) Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) excretion in stools is well documented by RT-PCR, but evidences that stools contain infectious particles are scarce. (2) Methods: After observing a Corona Virus 2019 Disease (COVID-19) epidemic cluster associated with a ruptured sewage pipe, we search for such a viable SARS-CoV-2 particle in stool by inoculating 106 samples from 46 patients. (3) Results: We successfully obtained two isolates from a unique patient with kidney transplantation under immunosuppressive therapy who was admitted for severe diarrhea. (4) Conclusions: This report emphasizes that SARS-CoV-2 is an enteric virus, and infectious virus particles can be isolated from the stool of immune-compromised patients like, in our case, kidney transplant recipient. Immune-compromised patients are likely to have massive multiplication of the virus in the gastrointestinal tract and this report suggests possible fecal transmission of SARS-CoV-2.

11.
J Clin Virol ; 139: 104814, 2021 06.
Article in English | MEDLINE | ID: mdl-33836314

ABSTRACT

INTRODUCTION: The SARS-CoV-2 pandemic has been associated with the occurrence since summer 2020 of several viral variants that overlapped or succeeded each other in time. Those of current concern harbor mutations within the spike receptor binding domain (RBD) that may be associated with viral escape to immune responses. In our geographical area a viral variant we named Marseille-4 harbors a S477 N substitution in this RBD. MATERIALS AND METHODS: We aimed to implement an in-house one-step real-time reverse transcription-PCR (qPCR) assay with a hydrolysis probe that specifically detects the SARS-CoV-2 Marseille-4 variant. RESULTS: All 6 cDNA samples from Marseille-4 variant strains identified in our institute by genome next-generation sequencing (NGS) tested positive using our Marseille-4 specific qPCR, whereas all 32 cDNA samples from other variants tested negative. In addition, 39/42 (93 %) respiratory samples identified by NGS as containing a Marseille-4 variant strain and 0/26 samples identified as containing non-Marseille-4 variant strains were positive. Finally, 2018/3960 (51%) patients SARS-CoV-2-diagnosed in our institute, 10/277 (3.6 %) respiratory samples collected in Algeria, and none of 207 respiratory samples collected in Senegal, Morocco, or Lebanon tested positive using our Marseille-4 specific qPCR. DISCUSSION: Our in-house qPCR system was found reliable to detect specifically the Marseille-4 variant and allowed estimating it is involved in about half of our SARS-CoV-2 diagnoses since December 2020. Such approach allows the real-time surveillance of SARS-CoV-2 variants, which is warranted to monitor and assess their epidemiological and clinical characterics based on comprehensive sets of data.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2/genetics , COVID-19/virology , Humans , SARS-CoV-2/isolation & purification
12.
Int J Infect Dis ; 106: 228-236, 2021 May.
Article in English | MEDLINE | ID: mdl-33785459

ABSTRACT

BACKGROUND: In Marseille, France, following a first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in March-May 2020, a second epidemic phase occurred from June, involving 10 new variants. The Marseille-4 variant caused an epidemic that started in August and is still ongoing. METHODS: The 1038 SARS-CoV-2 whole genome sequences obtained in our laboratory by next-generation sequencing with Illumina technology were analysed using Nextclade and nextstrain/ncov pipelines and IQ-TREE. A Marseille-4-specific qPCR assay was implemented. Demographic and clinical features were compared between patients with the Marseille-4 variant and those with earlier strains. RESULTS: Marseille-4 harbours 13 hallmark mutations. One leads to an S477N substitution in the receptor binding domain of the spike protein targeted by current vaccines. Using a specific qPCR, it was observed that Marseille-4 caused 12-100% of SARS-CoV-2 infections in Marseille from September 2020, being involved in 2106 diagnoses. This variant was more frequently associated with hypoxemia than were clade 20A strains before May 2020. It caused a re-infection in 11 patients diagnosed with different SARS-CoV-2 strains before June 2020, suggesting either short-term protective immunity or a lack of cross-immunity. CONCLUSIONS: Marseille-4 should be considered as a major SARS-CoV-2 variant. Its sudden appearance points towards an animal reservoir, possibly mink. The protective role of past exposure and current vaccines against this variant should be evaluated.


Subject(s)
COVID-19/genetics , Genome, Viral , Mutation , SARS-CoV-2/genetics , Whole Genome Sequencing , Animals , COVID-19/virology , Epidemics , France/epidemiology , Humans , Mink/virology , Molecular Epidemiology , Phylogeny , Reinfection/virology
14.
Travel Med Infect Dis ; 40: 101980, 2021.
Article in English | MEDLINE | ID: mdl-33535105

ABSTRACT

BACKGROUND: In Marseille, France, the COVID-19 incidence evolved unusually with several successive epidemic phases. The second outbreak started in July, was associated with North Africa, and involved travelers and an outbreak on passenger ships. This suggested the involvement of a new viral variant. METHODS: We sequenced the genomes from 916 SARS-CoV-2 strains from COVID-19 patients in our institute. The patients' demographic and clinical features were compared according to the infecting viral variant. RESULTS: From June 26th to August 14th, we identified a new viral variant (Marseille-1). Based on genome sequences (n = 89) or specific qPCR (n = 53), 142 patients infected with this variant were detected. It is characterized by a combination of 10 mutations located in the nsp2, nsp3, nsp12, S, ORF3a, ORF8 and N/ORF14 genes. We identified Senegal and Gambia, where the virus had been transferred from China and Europe in February-April as the sources of the Marseille-1 variant, which then most likely reached Marseille through Maghreb when French borders reopened. In France, this variant apparently remained almost limited to Marseille. In addition, it was significantly associated with a milder disease compared to clade 20A ancestor strains, in univariate analysis. CONCLUSION: Our results demonstrate that SARS-CoV-2 can genetically diversify rapidly, its variants can diffuse internationally and cause successive outbreaks.


Subject(s)
COVID-19/virology , SARS-CoV-2/classification , SARS-CoV-2/genetics , Adult , Africa South of the Sahara/epidemiology , Aged , Amino Acid Substitution , COVID-19/epidemiology , China/epidemiology , Coronavirus Papain-Like Proteases/genetics , Coronavirus RNA-Dependent RNA Polymerase/genetics , Female , France/epidemiology , Genome, Viral , Humans , Male , Middle Aged , Mutation , Phylogeny , Travel , Viral Nonstructural Proteins/genetics , Viral Proteins/genetics , Viroporin Proteins/genetics
15.
Front Microbiol ; 12: 786233, 2021.
Article in English | MEDLINE | ID: mdl-35197938

ABSTRACT

After the end of the first epidemic episode of SARS-CoV-2 infections, as cases began to rise again during the summer of 2020, we at IHU Méditerranée Infection in Marseille, France, intensified the genomic surveillance of SARS-CoV-2, and described the first viral variants. In this study, we compared the incidence curves of SARS-CoV-2-associated deaths in different countries and reported the classification of SARS-CoV-2 variants detected in our institute, as well as the kinetics and sources of the infections. We used mortality collected from a COVID-19 data repository for 221 countries. Viral variants were defined based on ≥5 hallmark mutations along the whole genome shared by ≥30 genomes. SARS-CoV-2 genotype was determined for 24,181 patients using next-generation genome and gene sequencing (in 47 and 11% of cases, respectively) or variant-specific qPCR (in 42% of cases). Sixteen variants were identified by analyzing viral genomes from 9,788 SARS-CoV-2-diagnosed patients. Our data show that since the first SARS-CoV-2 epidemic episode in Marseille, importation through travel from abroad was documented for seven of the new variants. In addition, for the B.1.160 variant of Pangolin classification (a.k.a. Marseille-4), we suspect transmission from farm minks. In conclusion, we observed that the successive epidemic peaks of SARS-CoV-2 infections are not linked to rebounds of viral genotypes that are already present but to newly introduced variants. We thus suggest that border control is the best mean of combating this type of introduction, and that intensive control of mink farms is also necessary to prevent the emergence of new variants generated in this animal reservoir.

16.
Clin Infect Dis ; 73(9): e2571-e2579, 2021 11 02.
Article in English | MEDLINE | ID: mdl-32668457

ABSTRACT

BACKGROUND: The spectrum of infections caused by methanogens remains to be described. We searched for methanogens in the blood of febrile patients using specific tools. METHODS: Blood culture samples routinely collected in patients with fever were prospectively screened by specific PCR assays for methanogens. Positive samples were observed by autofluorescence and electron microscopy, analyzed by metagenomics and cultured using previously developed methods. Blood culture bottles experimentally inoculated were used as controls. The presence of methanogens in vascular and cardiac tissues was assessed by indirect immunofluorescence, fluorescent in situ hybridization and PCR-based investigations. RESULTS: PCR detection attempted in 7,716 blood samples, was negative in all 1,312 aerobic bottles and 810 bacterial culture-negative anaerobic bottles. PCRs were positive in 27/5,594 (0.5%) bacterial culture-positive anaerobic bottles collected from 26 patients. Sequencing confirmed Methanobrevibacter smithii associated with staphylococci in 14 patients, Enterobacteriaceae in nine patients and streptococci in three patients. Metagenomics confirmed M. smithii in five samples, and M. smithii was isolated in broth from two samples; the genomes of these two isolates were sequenced. Blood cultures experimentally inoculated with Enterobacteriaceae, Staphylococcus epidermidis or Staphylococcus hominis yielded hydrogen, but no methane, authentifying observational data. Three patients diagnosed with infectious mitral endocarditis, were indisputably diagnosed by microscopy, PCR-based detections and culture: we showed M. smithii microscopically and by a specific PCR followed by sequencing method in two of three cardiovascular tissues. CONCLUSIONS: Using appropriate laboratory methods, M. smithii is demonstrated as causing archaemia and endocarditis in febrile patients who are coinfected by bacteria.


Subject(s)
Bacteremia , Endocarditis , Bacteremia/diagnosis , Humans , In Situ Hybridization, Fluorescence , Metagenomics , Methanobrevibacter/genetics
17.
Microorganisms ; 8(10)2020 Oct 07.
Article in English | MEDLINE | ID: mdl-33036349

ABSTRACT

Mycobacterium tuberculosis causes pulmonary tuberculosis, a deadly infection of which the clinical expression and prognosis are not fully understood at the individual level, apart from genetic susceptibility traits. We investigated whether individual gut microbiota may correlate with pulmonary tuberculosis status. Culturomics investigations of gut microbiota in two pulmonary tuberculosis patients and two controls in Burkina Faso found 60 different bacterial species in patients and 97 in controls, including 45 in common. Further analysis of the results at the individual level indicated seven bacteria, including Enterococcus mundtii and Enterococcus casseliflavus, which were exclusively cultured in controls. Blind quantitative PCR-based exploration of faeces samples in two cohorts in Burkina Faso and in France confirmed a nonsignificant association of E. mundtii and E. casseliflavus with controls. Further in vitro explorations found four E. mundtii and E. casseliflavus strains inhibiting the growth of M. tuberculosis strains representative of four different lineages as well as Mycobacterium africanum, Mycobacterium canettii, and Mycobacterium bovis, in an inoculum-dependent manner. Heat-killed E. mundtii or E. casseliflavus were ineffective. These unprecedented observations of direct interactions between gut E. mundtii and E. casseliflavus with M. tuberculosis complex mycobacteria suggest that gut microbiota may modulate the expression of pulmonary tuberculosis.

19.
J Clin Microbiol ; 56(10)2018 10.
Article in English | MEDLINE | ID: mdl-30068538

ABSTRACT

Routine staining of sputum specimens does not identify acid-fast bacilli as Mycobacterium tuberculosis with utmost precision, limiting its usability as a confirmatory test for pulmonary tuberculosis. We have combined Ziehl-Neelsen staining and fluorescence in situ hybridization (FISH) to detect M. tuberculosis in sputum specimens. We have developed a new fluorescent oligonucleotide rpoBMTC probe (5'-Alexa-555-AGCGGGGTGATGTCAACCCAG-3') targeting the M. tuberculosis complex rpoB gene. In silico alignment yielded 100% match for M. tuberculosis complex mycobacteria, 66.6% to 47.6% for other bacteria, and no significant hits for viruses and eukaryotes. Negative binding of rpoBMTC probe to the top six respiratory tract bacterial pathogens and to Mycobacterium abscessus and Mycobacterium avium experimentally confirmed its specificity. As for sensitivity, rpoBMTC-FISH detected 103 CFU/ml M. tuberculosis as confirmed by successful detection of M. tuberculosis in artificially seeded sputum samples. The application of rpoBMTC-FISH to 116 routine sputum specimens yielded a detection of M. tuberculosis in all of the 31 Ziehl-Neelsen-positive and culture-positive specimens, and no detection of M. tuberculosis in the 85 M. tuberculosis-negative specimens. These data established the proof of concept that rpoBMTC-FISH alone or combined with Ziehl-Neelsen staining can specifically "FISH out" M. tuberculosis complex mycobacteria in sputum samples collected from patients suspected of pulmonary mycobacteriosis. We are implementing this probe for the routine and specific detection of M. tuberculosis complex bacteria in sputum exhibiting acid-fast mycobacteria.


Subject(s)
Bacterial Proteins/genetics , Bacteriological Techniques/methods , DNA-Directed RNA Polymerases/genetics , In Situ Hybridization, Fluorescence , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Pulmonary/diagnosis , Fluorescent Dyes , Humans , Microscopy, Fluorescence , Mycobacterium tuberculosis/genetics , Sensitivity and Specificity , Sputum
20.
Front Microbiol ; 9: 463, 2018.
Article in English | MEDLINE | ID: mdl-29619012

ABSTRACT

The presence of the giant virus of amoeba Marseillevirus has been identified at many different sites on the human body, including in the bloodstream of asymptomatic subjects, in the lymph nodes of a child with adenitis, in one adult with Hodgkin's disease, and in the pharynx of an adult. A high seroprevalence of the Marseillevirus has been recorded in the general population. Whether Marseillevirus can disseminate and persist within a mammal after entry remains unproven. We aimed to assess the ability of the virus to disseminate and persist into healthy organisms, especially in the lymphoid organs. Parenteral inoculations were performed by intraperitoneal injection (in rats and mice) or intravenous injection (in rats). Airway inoculation was performed by aerosolization (in mice). Dissemination and persistence were assessed by using PCR and amebal co-culture. Serologies were performed by immunofluorescent assay. Pathological examination was conducted after standard and immunohistochemistry staining. After intraperitoneal inoculation in mice and rats, Marseillevirus was detected in the bloodstream during the first 24 h. Persistence was noted until the end of the experiment, i.e., at 14 days in rats. After intravenous inoculation in rats, the virus was first detected in the blood until 48 h and then in deep organs with infectious virus detected until 14 and 21 days in the liver and the spleen, respectively. Its DNA was detected for up to 30 days in the liver and the spleen. After aerosolization in mice, infectious Marseillevirus was present in the lungs and nasal associated lymphoid tissue until 30 days post inoculation but less frequently and at a lower viral load in the lung than in the nasal associated lymphoid tissue. No other site of dissemination was found after aerosol exposure. Despite no evidence of disease being observed, the 30-day long persistence of Marseillevirus in rats and mice, regardless of the route of inoculation, supports the hypothesis of an infective potential of the virus in certain conditions. Its constant and long-term detection in nasal associated lymphoid tissue in mice after an aerosol exposure suggests the involvement of naso-pharyngeal associated lymphoid tissues in protecting the host against environmental Marseillevirus.

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