Browsing by Author "Louni, Meriem"

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    Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria
    (Joseph M. Vinetz, University of California San Diego School of Medicine, UNITED STATES, 2018) Louni, Meriem; Mana, Nassima; Bitam, Idir; Dahmani, Mustapha; Parola, Philippe; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg
    Human lice, Pediculus humanus, are obligate blood-sucking parasites. Body lice, Pediculus h. humanus, occur in two divergent mitochondrial clades (A and D) each exhibiting a particular geographic distribution. Currently, the body louse is recognized as the only vector for louse-borne diseases. In this study, we aimed to study the genetic diversity of body lice collected from homeless populations in three localities of northern Algeria, and to investigate louse-borne pathogens in these lice
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    Detection of bacterial pathogens in clade E head lice collected from Niger’s refugees in Algeria
    (BMS, 2018) Louni, Meriem; Amanzougaghene, Nadia; Mana, Nassima; Fenollar, Florence; Raoult, Didier; Bitam, Idir
    Background: Head lice, Pediculus humanus capitis, are obligate blood-sucking parasites. Phylogenetically, they occur in five divergent mitochondrial clades (A, D, B, C and E), each having a particular geographical distribution. Recent studies have revealed that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Here, we aimed to study the genetic diversity of head lice collected from Niger’s refugees (migrant population) arriving in Algeria, northern Africa, and to look for louse-borne pathogens. Comparative head lice samples collected from indigenous population of schoolchildren (non-immigrant) were also analyzed to frame the study. Results: In this study, 37 head lice samples were collected from 31 Nigerien refugees, as well as 45 head lice from 27 schoolchildren. The collection was established in three localities of eastern Algiers, north Algeria. Quantitative real-time PCR screening of pathogens bacteria and the genetic characterisation of the head lice satut were performed. Through amplification and sequencing of the cytb gene, results showed that all head lice of Nigerien refugees 37/82 (45.12%) belonged to clade E with the presence of four new haplotypes, while, of the 45 head lice of schoolchildren, 34/82 lice (41.46%) belonged to clade A and 11/82 (13.41%) belonged to clade B. Our study is the first to report the existence of clade E haplogroup in Nigerien head lice. DNA of Coxiella burnetii was detected in 3/37 (8.10%) of the head lice collected from 3 of the 31 (9.67%) migrant population. We also revealed the presence of Acinetobacter DNA in 20/37 (54.05%) of head lice collected from 25/31 (80.64%) of the Nigerien refugees, and in 25/45 (55.55%) head lice collected from 15/27 (55.55%) schoolchildren. All positive Nigerien-head lice for Acinetobacter spp. were identified as A. baumannii, while positive schoolchildren-head lice were identified as A. johnsonii 15/25 (60%), A. variabilis 8/25 (32%) and A. baumannii 2/25 (8%). Conclusions: Based on these findings from head lice collected on migrant and non-migrant population, our results show, for the first time, that head lice from Niger belong to haplogroup E, and confirm that the clade E had a west African distribution. We also detected, for the first time, the presence of C. burnetii and A. baumannii in these Nigerien head lice. Nevertheless, further studies are needed to determine whether the head lice can transmit these pathogenic bacteria from one person to another
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    Gènes de résistance des poux humains et détection des agents pathogènes en Algérie
    (2018) Louni, Meriem
    Les poux humains (Phthiraptera : Anoplura) sont des ectoparasites hématophages obligatoires. Les poux parasitant l’Homme appartiennent à deux genres Pthirus et Pediculus. Ce dernier présente une préoccupation majeure de santé publique et comprend deux écotypes : le pou de tête (Pediculus humanus capitis) et le pou de corps (Pediculus humanus humanus). Dans le cadre de cette thèse de doctorat, nous avons pour objectifs d’apporter notre contribution dans le domaine de la recherche et l’enrichissement des connaissances scientifiques sur les poux humains par l’étude phylogénétique, la détection des agents pathogènes et l’étude des gènes de résistances des poux à la perméthrine en Algérie. Dans un premier volet de travail, nous avons effectué une collecte de poux de corps et de poux de tête chez la population des Sans Domicile Fixe, des réfugiés Nigériens et des enfants scolarisés en Algérie. Nous avons mis en évidence en utilisant les outils moléculaires le statut phylogénétique des poux ainsi que nous rapportons pour la première fois en Algérie et au nord d’Afrique, à notre connaissance, l’existence de l’ADN de multiples agents pathogènes bactériens, à savoir : Bartonella quintana, Borrelia recurrentis, Coxiella burnetii, Anaplasma phagocytophilum et différentes espèces d’Acinetobacter chez les poux humains appartenant à différents clades et haplotypes mitochondriaux. Dans un deuxième volet, nous rapportons pour la première fois la détection et la détermination des mutations génétiques conférant aux gènes la résistance des poux à la perméthrine en Algérie en utilisant le séquençage automatique par la méthode de Sanger. Nous avons testé un échantillonnage sélectionnés parmi notre collection de poux de tête et de poux de corps et nos résultats ont montré que la résistance des poux humains à la perméthrine s’avère bien installer en Algérie. A travers les résultats obtenus au cours de cette thèse, nous avons pu, pour la première fois en Algérie et au Nord d’Afrique, approfondir et enrichir des connaissances préalables sur les poux humains. Nous avons mené de larges enquêtes épidémiologiques sur terrain où nous avons pu collecter un nombre de spécimens de poux humains chez différentes population et dans différentes wilayas en Algérie. Nous avons pu révéler la présence d’ADN de plusieurs agents bactériens ainsi que le statut génétique des poux humains. Nous avons pu également détecter et déterminer les mutations conférant aux gènes la résistance des poux à la perméthrine où nos résultats montrent une grande prévalence de cette dernière
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    Human head lice and pubic lice reveal the presence of several Acinetobacter species in Algiers, Algeria
    (Elsevier, 2017) Manaa, Nassima; Louni, Meriem; Parola, Philippe; Bitam, Idir
    There are two majorspecies of medically important lice that parasitize humans: Phthirus pubis, found in pubic hair, and Pediculus humanus. Pediculus humanus consists of two eco types that live in specific niches on the human host: body lice (Pediculus humanus humanus), found on the human body and clothing, and head lice (Pediculus humanus capitis), found on the scalp. To date, only body lice are known to be vectors of human disease; however, it has recently been reported that the DNA of several bacterial agents has been detected in head lice, raising questions about their role in the transmission of pathogens. This issue caught our attention, in addition to the fact that the pathogenic bacteria associated with P. pubis and P. humanus capitis have never been investigated in Algeria. To investigate this,molecular techniques (real-time PCR) were used to screen for the presence of Acinetobacter spp., Bartonella spp., Borrelia spp. and Rickettsia prowazekii DNA from P. humanus capitis (64 lice) collected from schoolchildren,and P. pubis (4 lice),collected from one adultman living in Algiers. Positive samples for Acinetobacter spp.were identified by sequencing therpoBgene. Conventional PCR targeting the partial Cytb gene was used to determine the phylogenetic clade of the collected lice. Of the 64 samples collected, Acinetobacter spp. DNA was detected in 17/64 (27%) of head lice, identified as: A. baumannii (14%), A. johnsonii (11%) and A. variabilis (2%). Of the four P. pubissamples, 2(50%) were positive for A. johnsonii. The phylogenetic tree based on the Cytb gene revealed that P. humanus capitis were grouped into clades A and B. In this study, we report andidentify for the first time Acinetobacter spp.in Algerian P. pubis and P. humanus capitis. The detection of the genus Acinetobacter in lice should not be underestimated, especially in P. humanus capitis, which is distributed worldwide. However, additional epidemiological data are required to determine if human lice may act as an environmental reservoir and are actively involved in the propagation of these bacteria to humans
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    Molecular survey of head and body lice, pediculus humanus, in France
    (PubMed, 2018) Candy, Kerdalidec; Amanzougaghene, Nadia; Izri, Arezki; Brun, Sophie; Durand, Rémy; Louni, Meriem; Raoult, Didier
    Human lice, Pediculus humanus, are obligate blood-sucking parasites. Phylogenetically, they belong to several mitochondrial clades exhibiting some geographic differences. Currently, the body louse is the only recognized disease vector, with the head louse being proposed as an additional vector. In this article, we study the genetic diversity of head and body lice collected from Bobigny, a town located close to Paris (France), and look for louse-borne pathogens. By amplifying and sequencing the cytb gene, we confirmed the presence of clades A and B in France. Besides, by amplifying and sequencing both cytb and cox1 gene, we reported, for the first time, the presence of clade E, which has thus far only been found in lice from West Africa. DNA from Bartonella quintana was detected in 16.7% of body lice from homeless individuals, but in none of the head lice collected from 47 families. Acinetobacter DNA was detected in 11.5% of head lice belonging to all three clades and 29.1% of body lice. Six species of Acinetobacter were identified, including two potential new ones. Acinetobacter baumannii was the most prevalent, followed by Candidatus Acinetobacter Bobigny-1, Acinetobacter calcoaceticus, Acinetobacter nosocomialis, Acinetobacter junii, and Candidatus Acinetobacter Bobigny-2. Body lice were found to be infected only with A. baumannii. These findings show for the first time, the presence of clade E head lice in France. This study is also the first to report the presence of DNAs of several species of Acinetobacter in human head lice in France
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    Phylogenetic relationship between the endosymbiont “Candidatus Riesia pediculicola” and its human louse host
    (BioMed Central, 2022) Hammoud, Alissa; Louni, Meriem; Missé, Dorothée; Cortaredona, Sébastien; Fenollar, Florence; Mediannikov, Oleg
    Background: The human louse (Pediculus humanus) is a haematophagous ectoparasite that is intimately related to its host. It has been of great public health concern throughout human history. This louse has been classified into six divergent mitochondrial clades (A, D, B, F, C and E). As with all haematophagous lice, P. humanus directly depends on the presence of a bacterial symbiont, known as “Candidatus Riesia pediculicola”, to complement their unbalanced diet. In this study, we evaluated the codivergence of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus Riesia pediculicola housekeeping genes. Methods: The mitochondrial cytochrome b gene (cytb) of lice was selected for molecular analysis, with the aim to identify louse clade. In parallel, we developed four PCR primer pairs targeting three housekeeping genes of Candida- tus Riesia pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2). Results: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny using the ftsZ and rpoB-2 genes, in addition to showing a significant co-phylogenetic congruence, suggesting a strict vertical transmission and a host– symbiont co-speciation following the evolutionary course of the human louse. Conclusion: Our results unequivocally indicate that louse endosymbionts have experienced a similar co-evolution- ary history and that the human louse clade can be determined by their endosymbiotic bacteria
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    Phylogenetic relationship between the endosymbiont “Candidatus Riesia pediculicola” and its human louse host
    (BioMed Central, 2022) Hammoud, Alissa; Louni, Meriem; Missé, Dorothée; Cortaredona, Sébastien; Fenollar, Florence; Mediannikov, Oleg
    Background: The human louse (Pediculus humanus) is a haematophagous ectoparasite that is intimately related to its host. It has been of great public health concern throughout human history. This louse has been classified into six divergent mitochondrial clades (A, D, B, F, C and E). As with all haematophagous lice, P. humanus directly depends on the presence of a bacterial symbiont, known as “Candidatus Riesia pediculicola”, to complement their unbalanced diet. In this study, we evaluated the codivergence of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus Riesia pediculicola housekeeping genes. Methods: The mitochondrial cytochrome b gene (cytb) of lice was selected for molecular analysis, with the aim to identify louse clade. In parallel, we developed four PCR primer pairs targeting three housekeeping genes of Candidatus Riesia pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2). Results: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny using the ftsZ and rpoB-2 genes, in addition to showing a significant co-phylogenetic congruence, suggesting a strict vertical transmission and a host– symbiont co-speciation following the evolutionary course of the human louse. Conclusion: Our results unequivocally indicate that louse endosymbionts have experienced a similar co-evolutionary history and that the human louse clade can be determined by their endosymbiotic bacteria