Strain diversity of Treponema pallidum subsp. pertenue suggests rare interspecies 4 transmission in African nonhuman primates

In our most recent study, we found that in Tanzania infection with Treponema pallidum (TP) subsp. pertenue (TPE) is present in four different monkey species. In order to gain information on the diversity and epidemiological spread of the infection in Tanzanian nonhuman primates (NHP), we identified two suitable candidate genes for multi-locus sequence typing (MLST). We demonstrate the functionality of the MLST system in invasively and non-invasively collected samples. While we were not able to demonstrate frequent interspecies transmission of TPE in Tanzanian monkeys, our results show a clustering of TPE strains according to geography and not host species, which is suggestive for rare transmission events between different NHP species. In addition to the geographic stability, we describe the relative temporal stability of the strains infecting NHPs and identified multi-strain infection. Differences between TPE strains of NHP and human origin are highlighted. Our results show that antibiotic resistance does not occur in Tanzanian TPE strains of nHp origin

Widespread Treponema pallidum Infection in Nonhuman Primates, Tanzania

We investigated Treponema pallidum infection in 8 nonhuman primate species (289 animals) in Tanzania during 2015–2017. We used a serologic treponemal test to detect antibodies against the bacterium. Infection was further confirmed from tissue samples of skin-ulcerated animals by 3 independent PCRs (polA, tp47, and TP_0619). Our findings indicate that T. pallidum infection is geographically widespread in Tanzania and occurs in several species (olive baboons, yellow baboons, vervet monkeys, and blue monkeys). We found the bacterium at 11 of 14 investigated geographic locations. Anogenital ulceration was the most common clinical manifestation; orofacial lesions also were observed. Molecular data show that nonhuman primates in Tanzania are most likely infected with T. pallidum subsp. pertenue–like strains, which could have implications for human yaws eradication

LAMP4yaws: Treponema pallidum, Haemophilus ducreyi loop mediated isothermal amplification - protocol for a cross-sectional, observational, diagnostic accuracy study.

INTRODUCTION: Yaws, caused by the bacterium Treponema pallidum subsp. pertenue, is a neglected tropical disease targeted for eradication by 2030. Improved diagnostics will be essential to meet this goal. Diagnosis of yaws has relied heavily on clinical and serological tools. However, the presence of coendemic cutaneous skin ulcer diseases, such as lesions caused by Haemophilus ducreyi (HD), means these techniques do not provide a reliable diagnosis. Thus, new diagnostic tools are needed. Molecular tools such as PCR are ideal, but often expensive as they require trained technicians and laboratory facilities, which are often not available to national yaws programmes. METHODS AND ANALYSIS: The LAMP4yaws project is a cross-sectional, observational, diagnostic accuracy study of a combined Treponema pallidum (TP) and HD loop mediated isothermal amplification (TPHD-LAMP) test performed under real world conditions in three endemic countries in West Africa. Individuals with serologically confirmed yaws will be recruited in Cameroon, Côte d'Ivoire and Ghana. Each participant will provide paired swabs, one of which will be sent to the respective national reference laboratory for yaws quantitative PCR and the other will be tested for both TP and HD using the TPHD-LAMP test at local district laboratories. Sensitivity and specificity of the TPHD-LAMP test will be calculated against the reference standard qPCR. We will also assess the acceptability, feasibility and cost-effectiveness of the test. We anticipate that results from this study will support the adoption of the TPHD-LAMP test for use in global yaws eradication efforts. ETHICS AND DISSEMINATION: We have received ethical approval from all relevant institutional and national ethical committees. All participants, or their parents or guardians, must provide written informed consent prior to study enrolment. Study results will be published in an open access journal and disseminated with partners and the World Health Organization. TRIAL REGISTRATION NUMBER: NCT04753788

Corrigendum: A metataxonomic tool to investigate the diversity of Treponema

A Corrigendum on A Metataxonomic Tool to Investigate the Diversity of Treponema by Hallmaier-Wacker, L. K., Lüert, S., Gronow, S., Spröer, C., Overmann, J., Buller, N., et al. (2019). Front. Microbiol. 10:2094. doi: 10.3389/fmicb.2019.02094 In the original article, there was a mistake in Figure 1 as published. The figure contains an error in the number of cycles for the "add indices and adapters" step. The step should read 8 cycles instead of 20 cycles. The corrected Figure 1 appears below

Gene target selection for loop-mediated isothermal amplification for rapid discrimination of <i>Treponema pallidum</i> subspecies

<div><p>We show proof of concept for gene targets (<i>polA</i>, <i>tprL</i>, and TP_0619) that can be used in loop-mediated isothermal amplification (LAMP) assays to rapidly differentiate infection with any of the three <i>Treponema pallidum</i> subspecies (<i>pallidum</i> (<i>TPA</i>), <i>pertenue</i> (<i>TPE</i>), and <i>endemicum</i> (<i>TEN</i>)) and which are known to infect humans and nonhuman primates (NHPs). Four <i>TPA</i>, six human, and two NHP <i>TPE</i> strains, as well as two human <i>TEN</i> strains were used to establish and validate the LAMP assays. All three LAMP assays were highly specific for the target DNA. Amplification was rapid (5–15 min) and within a range of 10E+6 to 10E+2 of target DNA molecules. Performance in NHP clinical samples was similar to the one seen in human <i>TPE</i> strains. The newly designed LAMP assays provide proof of concept for a diagnostic tool that enhances yaws clinical diagnosis. It is highly specific for the target DNA and does not require expensive laboratory equipment. Test results can potentially be interpreted with the naked eye, which makes it suitable for the use in remote clinical settings.</p></div

Detection limits of LAMP assays.

<p>(A-C) <i>TP</i> LAMP assay involving (A) <i>TPA</i> strain Nichols with copy numbers 10E+5 to 10E+0, (B) <i>TPE</i> strain Gauthier tested in a range of 10E+6 to 10E+0 copies, and (C) <i>TEN</i> strain Bosnia A in 10E+6 to 10E+0 copy numbers. (D-E) <i>TPA</i> LAMP assay run with <i>TPA</i> strain Nichols from 10E+5 to 10E+0 copy numbers, and the same LAMP assay run with (E) <i>TEN</i> strain Bosnia A in copy numbers ranging from 10E+6 to 10E+0. (F-G) <i>TPE</i>/<i>TEN</i> LAMP assay involving (E) <i>TPE</i> strain Gauthier tested in 10E+6 to 10E+0 copy numbers, and (F) <i>TEN</i> strain Bosnia A tested in 10E+6 to 10E+0 copies. Red cross = Negative control, <i>TPA</i> strain Nichols (blue), <i>TPE</i> strain Gauthier (green), <i>TEN</i> strain Bosnia A (black); symbols represent copy numbers: circle with cross = 10E+6, hexagon = 10E+5, square turned = 10E+4, square = 10E+3, circle = 10E+2, down-pointing triangle = 10E+1, up-pointing triangle = 10E+0.</p

Detection limits for the three LAMP assays.

<p>Corresponding graphs can be found in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0006396#pntd.0006396.g002" target="_blank">Fig 2</a>. + = exponential amplification, (+) = no exponential amplification,— = no amplification.</p

LAMP assays will simplify the existing test algorithm for human treponematoses.

<p>The test algorithm proposed by Ratnam 2005 [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0006396#pntd.0006396.ref042" target="_blank">42</a>] is shown in thin lines. The new LAMP assays for diagnosis of yaws is shown in bold lines and will simplify and accelerate yaws diagnosis. Furthermore, it enables the clinician to rapidly discriminate <i>TPE</i> infection from infection with other <i>TP</i> subspecies or pathogens.</p

Oligonucleotide primers used in this study.

<p>Oligonucleotide primers used in this study.</p

Performance characteristics of the three LAMP assays.

<p>(A) LAMP targeting the <i>polA</i> gene. All <i>TP</i> strains become positive. (B) LAMP assay targeting the <i>tprL</i> locus, which results in amplification of <i>TPA</i> and <i>TEN</i> strains. (C) Only <i>TPE</i> and <i>TEN</i> strains generate positive results in the LAMP assay targeting the TP_0619 locus. Note that the strain material in the three assays had different <i>TP</i> copy numbers as indicated in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0006396#pntd.0006396.s004" target="_blank">S1 Table</a>. Data points are presented as mean±SEM values. Red cross = Negative control; <i>TPA</i> strains (blue) up-pointing triangle = Mexico A, down-pointing triangle = SS14, circle = Nichols, square = Seattle 81–4; <i>TPE</i> strains (green) square = Gauthier, square turned = Sei Geringing K403, hexagon = Kampung Dalan K363, circle = Samoa D, circle with cross = CDC-1, square with cross CDC-2; <i>TPE</i> simian strains (purple) cross = Fribourg-Blanc, star = RNP; <i>TEN</i> strains (black) square = Bosnia A, circle with cross = Iraq B.</p