02140nas a2200265   4500008004100000020001400041245009600055210006900151260000900220300001400229490000700243520136800250653001201618653001101630653001901641653003501660653001401695653003701709653001101746100001701757700002101774700001501795700002401810856004001834       2003                        eng d  a0932-011300aPotential role of head lice, Pediculus humanus capitis, as vectors of Rickettsia prowazekii0 aPotential role of head lice Pediculus humanus capitis as vectors  c2003  a209 - 2110 v903 aSince the pioneering work of Charles Nicolle in 1909 [see Gross (1996) Proc Natl Acad Sci USA 93:10539-10540] most medical officers and scientists have assumed that body lice are the sole vectors of Rickettsia prowazekii, the aetiological agent of louse-borne epidemic typhus (LBET). Here we review the evidence for the axiom that head lice are not involved in epidemics of LBET. Laboratory experiments demonstrate the ability of head lice to transmit R. prowazekii, but evidence for this in the field has not been reported. However, the assumption that head lice do not transmit R. prowazekii has meant that head lice have not been examined for R. prowazekii during epidemics of LBET. The strong association between obvious (high) infestations of body lice and LBET has contributed to this perception, but this association does not preclude head lice as vectors of R. prowazekii. Indeed, where the prevalence and intensity of body louse infections may be high (e.g. during epidemics of LBET), the prevalence and intensity of head louse infestations is generally high as well. This review of the epidemiology of head louse and body louse infestations, and of LBET, indicates that head lice are potential vectors of R. prowazekii in the field. Simple observations in the field would reveal whether or not head lice are natural vectors of this major human pathogen.10aanimals10ahumans10aInsect vectors10aLice Infestations/epidemiology10aPediculus10aRickettsia prowazekii/physiology10atyphus1 aRobinson, D.1 aLeo, Natalie, P.1 aProciv, P.1 aBarker, Stephen, C.  uhttps://cats.myspecies.info/node/7700462nas a2200133   4500008004100000245009000041210006900131260000900200300001400209490000700223100001900230700002400249856005500273       2003                        eng d00aSusceptibility of head lice (Pediculus humanus capitis) to pediculicides in Australia0 aSusceptibility of head lice Pediculus humanus capitis to pedicul  c2003  a476 - 4780 v901 aHunter, J., A.1 aBarker, Stephen, C.  uhttp://www.phthiraptera.info/Publications/6651.pdf02044nas a2200361   4500008004100000245015200041210006900193260000900262300001400271490000700285520099900292653001201291653001401303653001801317653001001335653000801345653001401353653001101367653001201378653001001390653003501400653002801435653001401463653001401477653001501491653003701506653001301543653001101556653001401567100002101581700002401602856005601626       2002                        eng d00aIntragenomic variation in ITS2 rDNA in the louse of humans, Pediculus humanus: ITS2 is not a suitable marker for population studies in this species0 aIntragenomic variation in ITS2 rDNA in the louse of humans Pedic  c2002  a651 - 6570 v113 aThe two internal transcribed spacers (ITS) of ribosomal DNA are often used as markers of populations of insects. We studied the ITS2 of the head lice and body lice of humans, to determine whether this gene is a suitable marker of populations of these insects. ITS2 sequences were amplified by PCR from lice from four different countries: Australia, China, Japan and the USA. Direct cycle-sequencing of some of these PCR products gave equivocal nucleotide chromatograms. This indicated that some lice had more than one ITS2 sequence, so we cloned PCR products from these lice. Temperature gradient gel electrophoresis (TGGE) revealed that 50 of the 67 clones we screened had different nucleotide sequences. All lice had several ITS2 types, including those with unequivocal chromatograms. A phylogenetic tree of 15 different ITS2 sequences showed that the sequences from individual lice were not monophyletic. We conclude that the ITS2 is not a useful marker of populations for Pediculus humanus.10aanimals10aAustralia10aBase Sequence10aChina10adna10ageography10ahumans10aIntrons10aJapan10aLice Infestations/parasitology10aMolecular Sequence Data10aPediculus10aphylogeny10apolymerase10aResearch Support, Non-U.S. Gov't10asequence10aU.S.A.10avariation1 aLeo, Natalie, P.1 aBarker, Stephen, C.  uhttp://www.phthiraptera.info/Publications/44841.pdf01760nas a2200157   4500008004100000245013800041210006900179260000900248300001400257490000700271520122100278100001601499700002301515700002401538856004001562       2009                        eng d00aThe single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus0 asingle mitochondrial chromosome typical of animals has evolved i  c2009  a904 - 9120 v193 aThe mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is ∼16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3–4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes.1 aShao, Renfu1 aKirkness, Ewen, F.1 aBarker, Stephen, C.  uhttps://cats.myspecies.info/node/1701751nas a2200157   4500008004100000245011900041210006900160260000900229300001400238490000800252520123200260100001901492700001801511700002401529856004001553       2008                        eng d00aMetalloproteases and egg-hatching in Pediculus humanus, the body (clothes) louse of humans (Phthiraptera: Insecta)0 aMetalloproteases and egghatching in Pediculus humanus the body c  c2008  a125 - 1300 v1353 aTo investigate the biochemical components of egg-hatch in the body louse, Pediculus humanus, egg-shell-washings (ESW) were collected during the first 2 h post-hatching and analysed by gelatin SDS-PAGE. These ESW contained proteases with molecular mass in the range of 25–100 kDa; the most abundant proteases were ~25 kDa. The 3 main regions of protease activity in the one-dimensional gelatin SDS-PAGE gels resolved to at least 23 distinct regions of protease activity when analysed by two-dimensional gelatin SDS-PAGE, with iso-electric points spread over the entire 3 to 10 pH range. Mechanistic characterization indicated that the ESW contained proteases of the metallo-class, inhibited by both 1,10-phenanthroline and EDTA. Several protease inhibitors were tested for their ability to inhibit louse egg-hatch in vitro. The metalloprotease inhibitor 1,10-phenanthroline and the aminopeptidase inhibitor bestatin significantly inhibited (P<·05) louse egg-hatch (100% and 58%, respectively). The presence of metalloproteases at the time of egg-hatch and the inhibition of egg-hatch in P. humanus by metalloprotease inhibitors suggests a crucial role for these proteases in the hatching of this medically important parasite.1 aBowles, V., M.1 aYoung, A., R.1 aBarker, Stephen, C.  uhttps://cats.myspecies.info/node/1801361nas a2200157   4500008004100000020001400041245010100055210006900156260000900225300001200234490000700246520084800253100002201101700002401123856005601147       2006                        eng d  a0018-067X00aTransmission ratio distortion in the human body louse, Pediculus humanus (Insecta: Phthiraptera)0 aTransmission ratio distortion in the human body louse Pediculus   c2006  a63 - 680 v963 aWe studied inheritance at three microsatellite loci in eight F(1) and two F(2) families of the body (clothes) louse of humans, Pediculus humanus. The alleles of heterozygous female-parents were always inherited in a Mendelian fashion in these families. Alleles from heterozygous male-parents, however, were inherited in two different ways: (i) in a Mendelian fashion and (ii) in a non-Mendelian fashion, where males passed to their offspring only one of their two alleles, that is, 100% nonrandom transmission. In male body lice, where there was non-Mendelian inheritance, the paternally inherited set of alleles was eliminated. We interpret this pattern of inheritance as evidence for extreme transmission ratio distortion of paternal alleles in this species.Heredity advance online publication, 21 September 2005; doi:10.1038/sj.hdy.6800760.1 aMcMeniman, C., J.1 aBarker, Stephen, C.  uhttp://www.phthiraptera.info/Publications/44614.pdf