Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
Records 1-30 (of 33 Records) |
Query Trace: Chen CY[original query] |
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Molecular investigation of Treponema pallidum strains associated with ocular syphilis in the United States, 2016-2020
Pillay A , Vilfort K , Debra A , Katz SS , Thurlow CM , Joseph SJ , Lundy S , Ji A , Jaeyoung H , Workowski KA , Barrow RY , Danavall D , Pettus K , Chi KH , Kersh EN , Cao W , Chen CY . Microbiol Spectr 2024 e0058124 Ocular syphilis is a serious complication of Treponema pallidum infection that can occur at any stage of syphilis and affect any eye structure. It remains unknown if certain T. pallidum strains are associated with ocular infections; therefore, we performed genotyping and whole genome sequencing (WGS) to characterize strains from patients with ocular syphilis. Seventy-five ocular or non-ocular specimens from 55 ocular syphilis patients in 14 states within the United States were collected between February 2016 and November 2020. Sufficient T. pallidum DNA was available from nine patients for genotyping and three for WGS. Genotyping was done using the augmented Centers for Disease Control and Prevention typing scheme, and WGS was performed on Illumina platforms. Multilocus sequence typing allelic profiles were predicted from whole genome sequence data. T. pallidum DNA was detected in various specimens from 17 (30.9%) of the 55 patients, and typing was done on samples from 9 patients. Four complete strain types (14d10/g, 14b9/g, 14d9/g, and 14e9/f) and five partial types were identified. WGS was successful on samples from three patients and all three strains belonged to the SS14 clade of T. pallidum. Our data reveal that multiple strain types are associated with ocular manifestations of syphilis. While genotyping and WGS were challenging due to low amounts of T. pallidum DNA in specimens, we successfully performed WGS on cerebrospinal fluid, vitreous fluid, and whole blood.IMPORTANCESyphilis is caused by the spirochete Treponema pallidum. Total syphilis rates have increased significantly over the past two decades in the United States, and the disease remains a public health concern. In addition, ocular syphilis cases has also been on the rise, coinciding with the overall increase in syphilis rates. We conducted a molecular investigation utilizing traditional genotyping and whole genome sequencing over a 5-year period to ascertain if specific T. pallidum strains are associated with ocular syphilis. Genotyping and phylogenetic analysis show that multiple T. pallidum strain types are associated with ocular syphilis in the United States. |
Evaluation of a laboratory-developed multiplex real-time PCR assay for diagnosis of syphilis, herpes and chancroid genital ulcers in four public health laboratories in the USA.
Koralur M , Chen CY , Pillay A , White B , Pettus K , Chi KH , Stringer J , Aroh C , Dasu T , Bhattacharyya S , Perkins K , Chen J , Riner D , Soehnlen M , Cao W , Gaynor AM , Kersh EN . Sex Transm Infect 2021 98 (6) 448-450 OBJECTIVE: To evaluate the field performance of a multiplex PCR (M-PCR) assay for detection of herpes simplex virus (HSV)-1 and HSV-2, Treponema pallidum (T. pallidum) and Haemophilus ducreyi (H. ducreyi) in genital ulcer disease (GUD) specimens. METHODS: GUD M-PCR was performed on 186 remnant specimens, previously collected for HSV testing, by four public health laboratories (PHLs) and the Laboratory Reference and Research Branch (LRRB) at the Centers for Disease Control and Prevention. The results from the PHLs were compared with those of LRRB, which served as the reference testing method, and percentage agreement was calculated. RESULTS: HSV was detected in 31 of 52 (59.6%), 20 of 40 (50%), 43 of 44 (97.7%) and 19 of 50 (38.0%) specimens from PHL1, PHL2, PHL3 and PHL4, respectively. There were seven discrepant results for HSV, and the overall percent agreement between the PHLs and the LRRB was 94%-100%, with a kappa value of 0.922, which demonstrates high agreement. T. pallidum was identified in 7 of 51 (13.7%) specimens from PHL1 with 94.1% agreement and in 2 of 40 (5.0%) specimens from PHL2 with 100% agreement. The LRRB identified three additional T. pallidum-positive specimens from PHL1. The kappa value (0.849) for T. pallidum testing suggests good agreement. Consistent with the LRRB results, no T. pallidum was detected in specimens from PHL3 and PHL4, and H. ducreyi was not detected at any of the study sites. CONCLUSIONS: The GUD M-PCR assay performed well in four independent PHLs and 12 suspected syphilis cases were identified in this study. The M-PCR assay could provide improved diagnostic options for GUD infections in state and local PHLs. |
Antibody responses to two recombinant treponemal antigens (rp17 and TmpA) before and after azithromycin treatment for yaws in Ghana and Papua New Guinea
Parameswaran N , Mitjà O , Bottomley C , Kwakye C , Houinei W , Pillay A , Danavall D , Chi KH , Ballard RC , Solomon AW , Chen CY , Bieb SV , Adu-Sarkodie Y , Mabey DC , Asiedu K , Marks M , Martin D . J Clin Microbiol 2021 59 (5) WHO and its partners aim to interrupt yaws transmission in endemic countries and to certify others as being yaws-free. Transmission can be assessed using rapid plasma reagin (RPR) tests, reflecting current or recent infection, but RPR is operationally impractical.We evaluated changes in antibody levels against two recombinant treponemal antigens, rp17 (also known as Tp17) and TmpA, after antibiotic treatment given as part of a randomized controlled trial for yaws in Ghana and Papua New Guinea. Paired serum samples from children aged 6-15 years with confirmed yaws, collected before and after treatment, were tested for antibodies to rp17 and TmpA using a semi-quantitative bead-based immunoassay.Of 344 baseline samples, 342 tested positive for anti-rp17 antibodies and 337 tested positive for anti-TmpA antibodies. Six months after treatment, the median decrease in anti-rp17 signal was 3.2%, whereas the median decrease in anti-TmpA was 53.8%. The magnitude of change in the anti-TmpA response increased with increasing RPR titer fold-change. These data demonstrate that responses to TmpA decrease markedly within 6 months of treatment whereas (as expected) those to rp17 do not.Incorporating responses to TmpA as a marker of recent infection within an integrated sero-surveillance platform could provide a way to prioritize areas for yaws mapping. |
Successful isolation of Treponema pallidum strains from patients' cryopreserved ulcer exudate using the rabbit model.
Pereira LE , Katz SS , Sun Y , Mills P , Taylor W , Atkins P , Thurlow CM , Chi KH , Danavall D , Cook N , Ahmed T , Debra A , Philip S , Cohen S , Workowski KA , Kersh E , Fakile Y , Chen CY , Pillay A . PLoS One 2020 15 (1) e0227769 Clinical isolates of Treponema pallidum subspecies pallidum (T. pallidum) would facilitate study of prevalent strains. We describe the first successful rabbit propagation of T. pallidum from cryopreserved ulcer specimens. Fresh ulcer exudates were collected and cryopreserved with consent from syphilis-diagnosed patients (N = 8). Each of eight age-matched adult male rabbits were later inoculated with a thawed specimen, with two rabbits receiving 1.3 ml intratesticularly (IT), and six receiving 0.6 ml intravenously (IV) and IT. Monitoring of serology, blood PCR and orchitis showed that T. pallidum grew in 2/8 rabbits that were inoculated IV and IT with either a penile primary lesion specimen (CDC-SF003) or a perianal secondary lesion specimen (CDC-SF007). Rabbit CDC-SF003 was seroreactive by T. pallidum Particle Agglutination (TP-PA) and Rapid Plasma Reagin (RPR) testing, PCR+, and showed orchitis by week 6. Euthanasia was performed in week 7, with treponemal growth in the testes confirmed and quantified by qPCR and darkfield microscopy (DF). Serial passage of the extract in a second age-matched rabbit also yielded treponemes. Similarly, rabbit CDC-SF007 showed negligible orchitis, but was seroreactive and PCR+ by week 4 and euthanized in week 6 to yield T. pallidum, which was further propagated by second passage. Using the 4-component molecular typing system for syphilis, 3 propagated strains (CDC-SF003, CDC-SF007, CDC-SF008) were typed as 14d9f, 14d9g, and 14d10c, respectively. All 3 isolates including strain CDC-SF011, which was not successfully propagated, had the A2058G mutation associated with azithromycin resistance. Our results show that immediate cryopreservation of syphilitic ulcer exudate can maintain T. pallidum viability for rabbit propagation. |
Increased discrimination of Treponema pallidum strains by subtyping with a four-component system incorporating a mononucleotide tandem repeat in rspA.
Pillay A , Lee MK , Slezak T , Katz SS , Sun Y , Chi KH , Morshed M , Philip S , Ballard RC , Chen CY . Sex Transm Dis 2019 46 (4) e42-e45 A guanine mononucleotide repeat in the rpsA (tp0279) gene was evaluated for improved strain discrimination using 72 Treponema pallidum-positive specimens. The tandem repeat combined with the enhanced Centers for Disease Control and Prevention typing system resulted in increased discrimination and should be useful for molecular epidemiologic studies on syphilis especially in outbreaks and among men who have sex with men. |
Chronic immune barrier dysregulation among women with a history of violence victimization
Swaims-Kohlmeier A , Haddad LB , Li ZT , Brookmeyer KA , Baker JM , Widom CS , Lamousin JC , Chi KH , Chen CY , Kersh EN , Johnson JA , Herbst-Kralovetz MM , Hogben M , Ofotokun I , Kohlmeier JE . JCI Insight 2019 4 (10) We explored the association between violence victimization and increased risk for acquiring sexually transmitted infections (STIs) in women by measuring cellular immune barrier properties from the female reproductive tract. STI-negative participants reporting repeated prior victimization occurrences through the lifetime trauma and victimization history (LTVH) instrument were more likely to exhibit alterations in barrier homeostasis and the composition of critical immune mediators irrespective of demographic parameters or presence of bacterial vaginosis. By combining cellular data with mixed-effect linear modeling, we uncovered differences in local T cells, MHCII+ antigen-presenting cells, and epithelial cells indicative of altered trafficking behavior, increased immunosuppressive function, and decreased barrier integrity at sites of STI exposure that correlate most strongly with LTVH score. These data evidence a biological link between a history of violence victimization and risk of STI acquisition through immune dysregulation in the female reproductive tract. |
A case of inguinal lymphogranuloma venereum imitating malignancy on CT imaging
Promer K , Pillay A , Chi KH , Vahdat N , Katz SS , Chen CY , Fierer J . Radiol Case Rep 2019 14 (5) 581-583 Lymphogranuloma venereum is a sexually transmitted infection caused by serovars L1, L2, and L3 of Chlamydia trachomatis. We here report a case of Lymphogranuloma venereum, confirmed by PCR testing, which mimicked malignancy on CT imaging. |
Molecular strain typing of the yaws pathogen, Treponema pallidum subspecies pertenue.
Katz SS , Chi KH , Nachamkin E , Danavall D , Taleo F , Kool JL , Addo KK , Ampofo W , Simpson SV , Ye T , Asiedu KB , Ballard RC , Chen CY , Pillay A . PLoS One 2018 13 (9) e0203632 Yaws is a neglected tropical disease caused by the bacterium Treponema pallidum subspecies pertenue. The disease primarily affects children under 15 years of age living in low socioeconomic conditions in tropical areas. As a result of a renewed focus on the disease owing to a recent eradication effort initiated by the World Health Organization, we have evaluated a typing method, adapted from and based on the enhanced Centers for Disease Control and Prevention typing method for T. pallidum subsp. pallidum, for possible use in epidemiological studies. Thirty DNA samples from yaws cases in Vanuatu and Ghana, 11 DNA samples extracted from laboratory strains, and 3 published genomic sequences were fully typed by PCR/RFLP analysis of the tpr E, G, and J genes and by determining the number of 60-bp repeats within the arp gene. Subtyping was performed by sequencing a homonucleotide "G" tandem repeat immediately upstream of the rpsA gene and an 84-bp region of tp0548. A total of 22 complete strain types were identified; two strain types in clinical samples from Vanuatu (5q11/ak and 5q12/ak), nine strain types in clinical samples from Ghana (3q12/ah, 4r12/ah, 4q10/j, 4q11/ah, 4q12/ah, 4q12/v, 4q13/ah, 6q10/aj, and 9q10/ai), and twelve strain types in laboratory strains and published genomes (2q11/ae, 3r12/ad, 4q11/ad, 4q12/ad, 4q12/ag, 4q12/v, 5r12/ad, 6r12/x, 6q11/af, 10q9/r, 10q12/r, and 12r12/w). The tpr RFLP patterns and arp repeat sizes were subsequently verified by sequencing analysis of the respective PCR amplicons. This study demonstrates that the typing method for subsp. pallidum can be applied to subsp. pertenue strains and should prove useful for molecular epidemiological studies on yaws. |
Community-based mass treatment with azithromycin for the elimination of yaws in Ghana - Results of a pilot study
Abdulai AA , Agana-Nsiire P , Biney F , Kwakye-Maclean C , Kyei-Faried S , Amponsa-Achiano K , Simpson SV , Bonsu G , Ohene SA , Ampofo WK , Adu-Sarkodie Y , Addo KK , Chi KH , Danavall D , Chen CY , Pillay A , Sanz S , Tun Y , Mitja O , Asiedu KB , Ballard RC . PLoS Negl Trop Dis 2018 12 (3) e0006303 INTRODUCTION: The WHO yaws eradication strategy consists of one round of total community treatment (TCT) of single-dose azithromycin with coverage of > 90%.The efficacy of the strategy to reduce the levels on infection has been demonstrated previously in isolated island communities in the Pacific region. We aimed to determine the efficacy of a single round of TCT with azithromycin to achieve a decrease in yaws prevalence in communities that are endemic for yaws and surrounded by other yaws-endemic areas. METHODS: Surveys for yaws seroprevalence and prevalence of skin lesions were conducted among schoolchildren aged 5-15 years before and one year after the TCT intervention in the Abamkrom sub-district of Ghana. We used a cluster design with the schools as the primary sampling unit. Among 20 eligible primary schools in the sub district, 10 were assigned to the baseline survey and 10 to the post-TCT survey. The field teams conducted a physical examination for skin lesions and a dual point-of-care immunoassay for non-treponemal and treponemal antibodies of all children present at the time of the visit. We also undertook surveys with non-probabilistic sampling to collect lesion swabs for etiology and macrolide resistance assessment. RESULTS: At baseline 14,548 (89%) of 16,287 population in the sub-district received treatment during TCT. Following one round of TCT, the prevalence of dual seropositivity among all children decreased from 10.9% (103/943) pre-TCT to 2.2% (27/1211) post-TCT (OR 0.19; 95%CI 0.09-0.37). The prevalence of serologically confirmed skin lesions consistent with active yaws was reduced from 5.7% (54/943) pre-TCT to 0.6% (7/1211) post-TCT (OR 0.10; 95% CI 0.25-0.35). No evidence of resistance to macrolides against Treponema pallidum subsp. pertenue was seen. DISCUSSION: A single round of high coverage TCT with azithromycin in a yaws affected sub-district adjoining other endemic areas is effective in reducing the prevalence of seropositive children and the prevalence of early skin lesions consistent with yaws one year following the intervention. These results suggest that national yaws eradication programmes may plan the gradual expansion of mass treatment interventions without high short-term risk of reintroduction of infection from contiguous untreated endemic areas. |
Comparative efficacy of low-dose versus standard-dose azithromycin for patients with yaws: a randomised non-inferiority trial in Ghana and Papua New Guinea
Mitja O , Bottomley C , Kwakye C , Houinei W , Bauri M , Adwere P , Abdulai AA , Dua F , Boateng L , Wangi J , Ohene SA , Wangnapi R , Simpson SV , Miag H , Addo KK , Basing LA , Danavall D , Chi KH , Pillay A , Ballard R , Solomon AW , Chen CY , Bieb SV , Adu-Sarkodie Y , Mabey DCW , Asiedu K . Lancet Glob Health 2018 6 (4) e401-e410 BACKGROUND: A dose of 30 mg/kg of azithromycin is recommended for treatment of yaws, a disease targeted for global eradication. Treatment with 20 mg/kg of azithromycin is recommended for the elimination of trachoma as a public health problem. In some settings, these diseases are co-endemic. We aimed to determine the efficacy of 20 mg/kg of azithromycin compared with 30 mg/kg azithromycin for the treatment of active and latent yaws. METHODS: We did a non-inferiority, open-label, randomised controlled trial in children aged 6-15 years who were recruited from schools in Ghana and schools and the community in Papua New Guinea. Participants were enrolled based on the presence of a clinical lesion that was consistent with infectious primary or secondary yaws and a positive rapid diagnostic test for treponemal and non-treponemal antibodies. Participants were randomly assigned (1:1) to receive either standard-dose (30 mg/kg) or low-dose (20 mg/kg) azithromycin by a computer-generated random number sequence. Health-care workers assessing clinical outcomes in the field were not blinded to the patient's treatment, but investigators involved in statistical or laboratory analyses and the participants were blinded to treatment group. We followed up participants at 4 weeks and 6 months. The primary outcome was cure at 6 months, defined as lesion healing at 4 weeks in patients with active yaws and at least a four-fold decrease in rapid plasma reagin titre from baseline to 6 months in patients with active and latent yaws. Active yaws was defined as a skin lesion that was positive for Treponema pallidum ssp pertenue in PCR testing. We used a non-inferiority margin of 10%. This trial was registered with ClinicalTrials.gov, number NCT02344628. FINDINGS: Between June 12, 2015, and July 2, 2016, 583 (65.1%) of 895 children screened were enrolled; 292 patients were assigned a low dose of azithromycin and 291 patients were assigned a standard dose of azithromycin. 191 participants had active yaws and 392 had presumed latent yaws. Complete follow-up to 6 months was available for 157 (82.2%) of 191 patients with active yaws. In cases of active yaws, cure was achieved in 61 (80.3%) of 76 patients in the low-dose group and in 68 (84.0%) of 81 patients in the standard-dose group (difference 3.7%; 95% CI -8.4 to 15.7%; this result did not meet the non-inferiority criterion). There were no serious adverse events reported in response to treatment in either group. The most commonly reported adverse event at 4 weeks was gastrointestinal upset, with eight (2.7%) participants in each group reporting this symptom. INTERPRETATION: In this study, low-dose azithromycin did not meet the prespecified non-inferiority margin compared with standard-dose azithromycin in achieving clinical and serological cure in PCR-confirmed active yaws. Only a single participant (with presumed latent yaws) had definitive serological failure. This work suggests that 20 mg/kg of azithromycin is probably effective against yaws, but further data are needed. FUNDING: Coalition for Operational Research on Neglected Tropical Diseases. |
A macaque model for rectal lymphogranuloma venereum and non-lymphogranuloma venereum Chlamydia trachomatis: Impact on rectal simian/human immunodeficiency virus acquisition
Vishwanathan SA , Aubert RD , Morris MR , Zhao C , Philips C , Khalil GM , Deyounks F , Kelley K , Ritter JM , Chen CY , Kersh EN , McNicholl JM . Sex Transm Dis 2017 44 (9) 551-556 BACKGROUND: Sustained genital tract inflammation caused by sexually transmitted infections (STIs) is known to increase risk of vaginal human immunodeficiency virus (HIV) infections but, to our knowledge, there are no nonhuman primate studies that have evaluated its link to rectal HIV acquisition. METHODS: Rhesus macaques inoculated with Chlamydia trachomatis (CT) (serovars LGV-L2 and CT-E; n = 7) or saline (n = 7) received up to 20 rectal challenges twice a week of simian/HIV immunodeficiency virus (SHIVSF162p3). SHIV viremia was determined by real-time PCR and Chlamydia infection by APTIMA Combo 2 testing. The rectal cytokine-chemokine levels were evaluated by multiplex bead assays. RESULTS: Rectal Chlamydia infection was maintained throughout the study. We did not observe significant differences (P = 1.0) in frequency of SHIV acquisition between the STI and control arms. It took fewer SHIV challenges to infect the STI animals although the difference was not significant (P = 0.59). There were no significant differences in peak plasma viremia between STI and control arms (P = 0.63). The association of plasma viremia with rectal shedding was significantly different by arm (P = 0.038). CONCLUSIONS: In the first such study in a macaque model, we did not observe an increased risk of SHIV acquisition due to rectal Chlamydia coinfection. This macaque model can be further developed and expanded to better investigate the impact of different rectal STIs on HIV acquisition. |
Development of a rectal sexually transmitted infection (STI) model in Rhesus macaques using Chlamydia trachomatis serovars E and L2
Henning TR , Morris M , Ellis S , Kelley K , Phillips C , Ritter J , Jones T , Nachamkin E , Chen CY , Hong J , Kang J , Patton D , McNicholl J , Papp J , Kersh EN . J Med Primatol 2017 46 (5) 218-227 BACKGROUND: Rectal STI coinfection models enhance the understanding of rectal HIV transmission risk factors. MATERIALS AND METHODS: Rhesus macaques (n=9) were exposed to one of three rectal Chlamydia trachomatis (CT) challenges: C. trachomatis L2 (CT-L2 ); C. trachomatis serovar E (CT-E), followed by CT-L2 ; or CT-E, treatment/clearance, then CT-L2 . Infections were monitored by PCR. Weekly blood and rectal secretion/lavage samples were collected for cytokine analyzes and/or epithelial sloughing, occult, and overt blood determinations. RESULTS: Chlamydial infections were successfully established in each animal, with varying degrees of persistence. Mucosal IL-1beta was upregulated in animals consecutively infected with CT-E then CT-L2 (P=.05). Epithelial sloughing was also significantly increased post-infection in this group (P=.0003). CONCLUSIONS: This study demonstrates successful rectal infection of rhesus macaques with CT-E and CT-L2 and describes measures of assessing rectal inflammation and pathology. Different infection strategies yield varying inflammatory and pathologic outcomes, providing well-described models for future SIV/SHIV susceptibility studies. |
Pathogenic events in a nonhuman primate model of oral poliovirus infection leading to paralytic poliomyelitis
Shen L , Chen CY , Huang D , Wang R , Zhang M , Qian L , Zhu Y , Zhang AZ , Yang E , Qaqish A , Chumakov K , Kouiavskaia D , Vignuzzi M , Nathanson N , Macadam AJ , Andino R , Kew O , Xu J , Chen ZW . J Virol 2017 91 (14) Despite a great deal of prior research, the early pathogenic events in natural oral poliovirus infection remain poorly defined. To establish a model for study, we infected 39 macaques by feeding single high doses of the virulent Mahoney strain of wild type 1 poliovirus. Doses ranging from107-109 TCID50 consistently infected all animals, and most monkeys receiving 108 or 109 TCID50 developed paralysis. There was no apparent difference in the susceptibility of the three macaque species (rhesus, cynomolgus, and bonnet) used. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia, and virus was isolated from tonsils, gut mucosa, and draining lymph nodes. Viral replication proteins were detected in both epithelial and lymphoid cell populations expressing CD155 in the tonsil and intestine, as well as in spinal cord neurons. Necrosis was observed in these three cell types, and viral replication in tonsil/gut was associated with histopathologic destruction and inflammation. The sustained response of neutralizing antibody correlated temporally with resolution of viremia and termination of virus shedding in oropharynges and feces. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), consistent with previous studies of poliovirus pathogenesis in humans. Because this model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis, and to assess efficacy of candidate antiviral drugs and new vaccines. IMPORTANCE Early pathogenic events of poliovirus infection remain largely undefined, and there is a lack of animal models mimicking natural oral human infection leading to paralytic poliomyelitis. All of 39 macaques fed with single high doses ranging from 107-109 TCID50 Mahoney type 1 virus were infected, and most monkeys developed paralysis. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia; tonsil, mesentery lymph nodes and intestinal mucosa served as major target sites of viral replication. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), thereby supplementing historical reconstructions of poliovirus pathogenesis. Because this model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis, candidate antiviral drugs, and the efficacy of new vaccines. |
Complete Genome Sequences of 11 Haemophilus ducreyi Isolates from Children with Cutaneous Lesions in Vanuatu and Ghana.
Pillay A , Katz SS , Abrams AJ , Ballard RC , Simpson SV , Taleo F , Lahra MM , Batra D , Rowe L , Trees DL , Asiedu K , Chen CY . Genome Announc 2016 4 (4) Haemophilus ducreyi causes chancroid and has recently been shown to be a significant cause of cutaneous lesions in tropical or subtropical regions where yaws is endemic. Here, we report the draft genome assemblies for 11 cutaneous strains of Haemophilus ducreyi, isolated from children in Vanuatu and Ghana. |
Progesterone levels associate with a novel population of CCR5+CD38+ CD4 T cells resident in the genital mucosa with lymphoid trafficking potential
Swaims-Kohlmeier A , Haaland RE , Haddad LB , Sheth AN , Evans-Strickfaden T , Lupo LD , Cordes S , Aguirre AJ , Lupoli KA , Chen CY , Ofotukun I , Hart CE , Kohlmeier JE . J Immunol 2016 197 (1) 368-76 The female genital tract (FGT) provides a means of entry to pathogens, including HIV, yet immune cell populations at this barrier between host and environment are not well defined. We initiated a study of healthy women to characterize resident T cell populations in the lower FGT from lavage and patient-matched peripheral blood to investigate potential mechanisms of HIV sexual transmission. Surprisingly, we observed FGT CD4 T cell populations were primarily CCR7hi, consistent with a central memory or recirculating memory T cell phenotype. In addition, roughly half of these CCR7hi CD4 T cells expressed CD69, consistent with resident memory T cells, whereas the remaining CCR7hi CD4 T cells lacked CD69 expression, consistent with recirculating memory CD4 T cells that traffic between peripheral tissues and lymphoid sites. HIV susceptibility markers CCR5 and CD38 were increased on FGT CCR7hi CD4 T cells compared with blood, yet migration to the lymphoid homing chemokines CCL19 and CCL21 was maintained. Infection with GFP-HIV showed that FGT CCR7hi memory CD4 T cells are susceptible HIV targets, and productive infection of CCR7hi memory T cells did not alter chemotaxis to CCL19 and CCL21. Variations of resident CCR7hi FGT CD4 T cell populations were detected during the luteal phase of the menstrual cycle, and longitudinal analysis showed the frequency of this population positively correlated to progesterone levels. These data provide evidence women may acquire HIV through local infection of migratory CCR7hi CD4 T cells, and progesterone levels predict opportunities for HIV to access these novel target cells. |
Epidemiology of Haemophilus ducreyi infections
Gonzalez-Beiras C , Marks M , Chen CY , Roberts S , Mitja O . Emerg Infect Dis 2016 22 (1) 1-8 The global epidemiology of Haemophilus ducreyi infections is poorly documented because of difficulties in confirming microbiological diagnoses. We evaluated published data on the proportion of genital and nongenital skin ulcers caused by H. ducreyi before and after introduction of syndromic management for genital ulcer disease (GUD). Before 2000, the proportion of GUD caused by H. ducreyi ranged from 0.0% to 69.0% (35 studies in 25 countries). After 2000, the proportion ranged from 0.0% to 15.0% (14 studies in 13 countries). In contrast, H. ducreyi has been recently identified as a causative agent of skin ulcers in children in the tropical regions; proportions ranged from 9.0% to 60.0% (6 studies in 4 countries). We conclude that, although there has been a sustained reduction in the proportion of GUD caused by H. ducreyi, this bacterium is increasingly recognized as a major cause of nongenital cutaneous ulcers. |
Challenges and key research questions for yaws eradication
Marks M , Mitja O , Vestergaard LS , Pillay A , Knauf S , Chen CY , Bassat Q , Martin DL , Fegan D , Taleo F , Kool J , Lukehart S , Emerson PM , Solomon AW , Ye T , Ballard RC , Mabey DC , Asiedu KB . Lancet Infect Dis 2015 15 (10) 1220-1225 Yaws is endemic in west Africa, southeast Asia, and the Pacific region. To eradicate yaws by 2020, WHO has launched a campaign of mass treatment with azithromycin. Progress has been made towards achievement of this ambitious goal, including the validation of point-of-care and molecular diagnostic tests and piloting of the strategy in several countries, including Ghana, Vanuatu, and Papua New Guinea. Gaps in knowledge need to be addressed to allow refinement of the eradication strategy. Studies exploring determinants of the spatial distribution of yaws are needed to help with the completion of baseline mapping. The finding that Haemophilus ducreyi causes lesions similar to yaws is particularly important and further work is needed to assess the effect of azithromycin on these lesions. The integration of diagnostic tests into different stages of the eradication campaign needs investigation. Finally, studies must be done to inform the optimum mass-treatment strategy for sustainable interruption of transmission. |
Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.
Gangaiah D , Webb KM , Humphreys TL , Fortney KR , Toh E , Tai A , Katz SS , Pillay A , Chen CY , Roberts SA , Munson RS Jr , Spinola SM . PLoS Negl Trop Dis 2015 9 (7) e0003918 BACKGROUND: Although cutaneous ulcers (CU) in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU) and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin? METHODOLOGY/PRINCIPAL FINDINGS: To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya) and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin. CONCLUSIONS/SIGNIFICANCE: These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions. |
Failure of PCR to detect Treponema pallidum ssp. pertenue DNA in blood in latent yaws
Marks M , Katz S , Chi KH , Vahi V , Sun Y , Mabey DC , Solomon AW , Chen CY , Pillay A . PLoS Negl Trop Dis 2015 9 (6) e0003905 Yaws, caused by Treponema pallidum ssp. pertenue, is a neglected tropical disease closely related to venereal syphilis and is targeted for eradication by 2020. Latent yaws represents a diagnostic challenge, and current tools cannot adequately distinguish between individuals with true latent infection and individuals who are serofast following successful treatment. PCR on blood has previously been shown to detect T. pallidum DNA in patients with syphilis, suggesting that this approach may be of value in yaws. We performed real-time PCR for Treponema pallidum ssp. pertenue on blood samples from 140 children with positive T. pallidum Particle Agglutination (TPPA) and Rapid Plasma Reagin (RPR) tests and 7 controls (negative serology), all collected as part of a prospective study of yaws in the Solomon Islands. All samples were also tested by a nested PCR for T. pallidum. 12 patients had clinical evidence of active yaws whilst 128 were considered to have latent yaws. 43 children had high titre rapid plasma reagins (RPRs) of ≥1:32. PCR testing with both assays gave negative results in all cases. It is possible that the failure to detect T. pallidum ssp. pertenue in blood reflects lower loads of organism in latent yaws compared to those in latent infection with T. pallidum ssp. pertenue, and/or a lower propensity for haematogenous dissemination in yaws than in syphilis. As the goal of the yaws control programme is eradication, a tool that can differentiate true latent infection from individuals who are serofast would be of value; however, PCR of blood is not that tool. |
Field evaluation of personal sampling methods for multiple bioaerosols
Wang CH , Chen BT , Han BC , Liu AC , Hung PC , Chen CY , Chao HJ . PLoS One 2015 10 (3) e0120308 Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols. |
A cross-sectional study of 'yaws' in districts of Ghana which have previously undertaken azithromycin mass drug administration for trachoma control
Ghinai R , El-Duah P , Chi KH , Pillay A , Solomon AW , Bailey RL , Agana N , Mabey DC , Chen CY , Adu-Sarkodie Y , Marks M . PLoS Negl Trop Dis 2015 9 (1) e0003496 Yaws, caused by Treponema pallidum ssp. pertenue, is reportedly endemic in Ghana. Mass distribution of azithromycin is now the cornerstone of the WHO yaws eradication campaign. Mass distribution of azithromycin at a lower target dose was previously undertaken in two regions of Ghana for the control of trachoma. Ongoing reporting of yaws raises the possibility that resistance may have emerged in T. pallidum pertenue, or that alternative infections may be responsible for some of the reported cases. We conducted a cross-sectional survey in thirty communities in two districts of Ghana where MDA for trachoma had previously been conducted. Children aged 5-17 years with ulcerative lesions compatible with yaws were enrolled. Samples for treponemal serology and lesion PCR were collected from all children. 90 children with 98 lesions were enrolled. Syphilis serology was negative in all of them. PCR for T. pallidum ssp pertenue was negative in all children, but Haemophilus ducreyi DNA was detected in 9 lesions. In these communities, previously treated for trachoma, we found no evidence of ongoing transmission of yaws. H. ducreyi was associated with a proportion of skin lesions, but the majority of lesions remain unexplained. Integration of diagnostic testing into both pre and post-MDA surveillance systems is required to better inform yaws control programmes. |
Molecular differentiation of Treponema pallidum subspecies in skin ulceration clinically suspected as yaws in Vanuatu using real-time multiplex PCR and serological methods.
Chi KH , Danavall D , Taleo F , Pillay A , Ye T , Nachamkin E , Kool JL , Fegan D , Asiedu K , Vestergaard LS , Ballard RC , Chen CY . Am J Trop Med Hyg 2014 92 (1) 134-8 We developed a TaqMan-based real-time quadriplex polymerase chain reaction (PCR) to simultaneously detect Treponema pallidum subspecies pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum, the causative agents of venereal syphilis, yaws, and bejel, respectively. The PCR assay was applied to samples from skin ulcerations of clinically presumptive yaws cases among children on Tanna Island, Vanuatu. Another real-time triplex PCR was used to screen for the point mutations in the 23S rRNA genes that have previously been associated with azithromycin resistance in T. pallidum subsp. pallidum strains. Seropositivity by the classical syphilis serological tests was 35.5% among children with skin ulcerations clinically suspected with yaws, whereas the presence of T. pallidum subsp. pertenue DNA was only found in lesions from 15.5% of children. No evidence of T. pallidum subsp. pertenue infection, by either PCR or serology was found in approximately 59% of cases indicating alternative causes of yaws-like lesions in this endemic area. |
Haemophilus ducreyi associated with skin ulcers among children, Solomon Islands
Marks M , Chi KH , Vahi V , Pillay A , Sokana O , Pavluck A , Mabey DC , Chen CY , Solomon AW . Emerg Infect Dis 2014 20 (10) 1705-7 During a survey of yaws prevalence in the Solomon Islands, we collected samples from skin ulcers of 41 children. Using PCR, we identified Haemophilus ducreyi infection in 13 (32%) children. PCR-positive and PCR-negative ulcers were phenotypically indistinguishable. Emergence of H. ducreyi as a cause of nongenital ulcers may affect the World Health Organization's yaws eradication program. |
Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33.
Wang Z , Zhu B , Zhang M , Parikh H , Jia J , Chung CC , Sampson JN , Hoskins JW , Hutchinson A , Burdette L , Ibrahim A , Hautman C , Raj PS , Abnet CC , Adjei AA , Ahlbom A , Albanes D , Allen NE , Ambrosone CB , Aldrich M , Amiano P , Amos C , Andersson U , Andriole G Jr , Andrulis IL , Arici C , Arslan AA , Austin MA , Baris D , Barkauskas DA , Bassig BA , Beane Freeman LE , Berg CD , Berndt SI , Bertazzi PA , Biritwum RB , Black A , Blot W , Boeing H , Boffetta P , Bolton K , Boutron-Ruault MC , Bracci PM , Brennan P , Brinton LA , Brotzman M , Bueno-de-Mesquita HB , Buring JE , Butler MA , Cai Q , Cancel-Tassin G , Canzian F , Cao G , Caporaso NE , Carrato A , Carreon T , Carta A , Chang GC , Chang IS , Chang-Claude J , Che X , Chen CJ , Chen CY , Chen CH , Chen C , Chen KY , Chen YM , Chokkalingam AP , Chu LW , Clavel-Chapelon F , Colditz GA , Colt JS , Conti D , Cook MB , Cortessis VK , Crawford ED , Cussenot O , Davis FG , De Vivo I , Deng X , Ding T , Dinney CP , Di Stefano AL , Diver WR , Duell EJ , Elena JW , Fan JH , Feigelson HS , Feychting M , Figueroa JD , Flanagan AM , Fraumeni JF Jr , Freedman ND , Fridley BL , Fuchs CS , Gago-Dominguez M , Gallinger S , Gao YT , Gapstur SM , Garcia-Closas M , Garcia-Closas R , Gastier-Foster JM , Gaziano JM , Gerhard DS , Giffen CA , Giles GG , Gillanders EM , Giovannucci EL , Goggins M , Gokgoz N , Goldstein AM , Gonzalez C , Gorlick R , Greene MH , Gross M , Grossman HB , Grubb R 3rd , Gu J , Guan P , Haiman CA , Hallmans G , Hankinson SE , Harris CC , Hartge P , Hattinger C , Hayes RB , He Q , Helman L , Henderson BE , Henriksson R , Hoffman-Bolton J , Hohensee C , Holly EA , Hong YC , Hoover RN , Hosgood HD 3rd , Hsiao CF , Hsing AW , Hsiung CA , Hu N , Hu W , Hu Z , Huang MS , Hunter DJ , Inskip PD , Ito H , Jacobs EJ , Jacobs KB , Jenab M , Ji BT , Johansen C , Johansson M , Johnson A , Kaaks R , Kamat AM , Kamineni A , Karagas M , Khanna C , Khaw KT , Kim C , Kim IS , Kim YH , Kim YC , Kim YT , Kang CH , Jung YJ , Kitahara CM , Klein AP , Klein R , Kogevinas M , Koh WP , Kohno T , Kolonel LN , Kooperberg C , Kratz CP , Krogh V , Kunitoh H , Kurtz RC , Kurucu N , Lan Q , Lathrop M , Lau CC , Lecanda F , Lee KM , Lee MP , Le Marchand L , Lerner SP , Li D , Liao LM , Lim WY , Lin D , Lin J , Lindstrom S , Linet MS , Lissowska J , Liu J , Ljungberg B , Lloreta J , Lu D , Ma J , Malats N , Mannisto S , Marina N , Mastrangelo G , Matsuo K , McGlynn KA , McKean-Cowdin R , McNeill LH , McWilliams RR , Melin BS , Meltzer PS , Mensah JE , Miao X , Michaud DS , Mondul AM , Moore LE , Muir K , Niwa S , Olson SH , Orr N , Panico S , Park JY , Patel AV , Patino-Garcia A , Pavanello S , Peeters PH , Peplonska B , Peters U , Petersen GM , Picci P , Pike MC , Porru S , Prescott J , Pu X , Purdue MP , Qiao YL , Rajaraman P , Riboli E , Risch HA , Rodabough RJ , Rothman N , Ruder AM , Ryu JS , Sanson M , Schned A , Schumacher FR , Schwartz AG , Schwartz KL , Schwenn M , Scotlandi K , Seow A , Serra C , Serra M , Sesso HD , Severi G , Shen H , Shen M , Shete S , Shiraishi K , Shu XO , Siddiq A , Sierrasesumaga L , Sierri S , Sihoe AD , Silverman DT , Simon M , Southey MC , Spector L , Spitz M , Stampfer M , Stattin P , Stern MC , Stevens VL , Stolzenberg-Solomon RZ , Stram DO , Strom SS , Su WC , Sund M , Sung SW , Swerdlow A , Tan W , Tanaka H , Tang W , Tang ZZ , Tardon A , Tay E , Taylor PR , Tettey Y , Thomas DM , Tirabosco R , Tjonneland A , Tobias GS , Toro JR , Travis RC , Trichopoulos D , Troisi R , Truelove A , Tsai YH , Tucker MA , Tumino R , Van Den Berg D , Van Den Eeden SK , Vermeulen R , Vineis P , Visvanathan K , Vogel U , Wang C , Wang C , Wang J , Wang SS , Weiderpass E , Weinstein SJ , Wentzensen N , Wheeler W , White E , Wiencke JK , Wolk A , Wolpin BM , Wong MP , Wrensch M , Wu C , Wu T , Wu X , Wu YL , Wunder JS , Xiang YB , Xu J , Yang HP , Yang PC , Yatabe Y , Ye Y , Yeboah ED , Yin Z , Ying C , Yu CJ , Yu K , Yuan JM , Zanetti KA , Zeleniuch-Jacquotte A , Zheng W , Zhou B , Mirabello L , Savage SA , Kraft P , Chanock SJ , Yeager M , Landi MT , Shi J , Chatterjee N , Amundadottir LT . Hum Mol Genet 2014 23 (24) 6616-33 Genome-wide association studies (GWAS) have mapped risk alleles for at least ten distinct cancers to a small region of 63,000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (ASSET) across six distinct cancers in 34,248 cases and 45,036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single nucleotide polymorphisms (SNPs): five in the TERT gene (region 1: rs7726159, P=2.10x10-39; region 3: rs2853677, P=3.30x10-36 and PConditional=2.36x10-8; region 4: rs2736098, P=3.87x10-12 and PConditional=5.19x10-6, region 5: rs13172201, P=0.041 and PConditional=2.04x10-6; and region 6: rs10069690, P=7.49x10-15 and PConditional=5.35x10-7) and one in the neighboring CLPTM1L gene (region 2: rs451360; P=1.90x10-18 and PConditional=7.06x10-16). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele specific effects on DNA methylation were seen for a subset of risk loci indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci. |
Acquired macrolide-resistant Treponema pallidum after a human bite
Fanfair RN , Wallingford M , Long LL , Chi KH , Pillay A , Chen CY , Workowski KA . Sex Transm Dis 2014 41 (8) 493-5 Syphilis is a systemic disease caused by the spirochete Treponema pallidum that is usually acquired through sexual exposure. |
Etiology of genital ulcer disease and association with HIV infection in Malawi
Phiri S , Zadrozny S , Weiss HA , Martinson F , Nyirenda N , Chen CY , Miller WC , Cohen MS , Mayaud P , Hoffman IF . Sex Transm Dis 2013 40 (12) 923-8 BACKGROUND: The World Health Organization recommends the use of syndromic management for patients presenting with genital ulcer disease (GUD) in developing countries. However, effective treatment guidelines depend on a current country-specific GUD etiological profile, which may change over time. METHODS: From 2004 to 2006, we conducted a cross-sectional analysis of baseline data from patients presenting with GUD at a reference STI clinic in Lilongwe, Malawi. Participants were enrolled in a randomized clinical trial of acyclovir added to syndromic management and followed up for up to 28 days. Serologies for HIV (using parallel rapid tests), herpes simplex virus type 2 (HSV-2; using Focus HerpeSelect IgG2 ELISA [Focus Technologies, Cypress Hill, CA]), and syphilis (rapid plasma reagin confirmed by Treponema pallidum hemagglutination) were determined, with plasma HIV-1 RNA and CD4 count in HIV-positive patients. Genital ulcer disease etiology was determined by real-time multiplex polymerase chain reaction from lesional swabs. RESULTS: A total of 422 patients with GUD (313 men; 74%) were enrolled. Overall seroprevalence of HIV-1, HSV-2, and syphilis were 61%, 72%, and 5%, respectively. Ulcer etiology was available for 398 patients and showed the following: HSV-2, 67%; Haemophilus ducreyi, 15%; T. pallidum, 6%; lymphogranuloma venereum, 6%; mixed infections, 14%, and no etiology, 20%. Most HSV-2 ulcers were recurrent (75%). Among all patients with HSV-2, HIV prevalence was high (67%) and HIV seroprevalence was higher among patients with recurrent HSV-2 compared with patients with first-episode HSV-2 (78% vs. 39%, P < 0.001). CONCLUSIONS: Herpes simplex virus type 2 ulcers are highly prevalent in this symptomatic population and strongly associated with HIV. Unlike most locations in sub-Saharan Africa, H. ducreyi remains prevalent in this population and requires periodic monitoring and an appropriate treatment regimen. |
Detection of the A2058G and A2059G 23S rRNA gene point mutations associated with azithromycin resistance in Treponema pallidum by use of a TaqMan real-time multiplex PCR assay.
Chen CY , Chi KH , Pillay A , Nachamkin E , Su JR , Ballard RC . J Clin Microbiol 2013 51 (3) 908-13 Macrolide treatment failure in syphilis patients is associated with a single point mutation (either A2058G or A2059G) in both copies of the 23S rRNA gene in Treponema pallidum strains. The conventional method for the detection of both point mutations uses nested PCR combined with restriction enzyme digestions, which is laborious and time-consuming. We initially developed a TaqMan-based real-time duplex PCR assay for detection of the A2058G mutation, and upon discovery of the A2059G mutation, we modified the assay into a triplex format to simultaneously detect both mutations. The point mutations detected by the real-time triplex PCR were confirmed by pyrosequencing. A total of 129 specimens PCR positive for T. pallidum that were obtained from an azithromycin resistance surveillance study conducted in the United States were analyzed. Sixty-six (51.2%) of the 129 samples with the A2058G mutation were identified by both real-time PCR assays. Of the remaining 63 samples that were identified as having a macrolide-susceptible genotype by the duplex PCR assay, 17 (27%) were found to contain the A2059G mutation by the triplex PCR. The proportions of macrolide-susceptible versus -resistant genotypes harboring either the A2058G or the A2059G mutation among the T. pallidum strains were 35.6, 51.2, and 13.2%, respectively. None of the T. pallidum strains examined had both point mutations. The TaqMan-based real-time triplex PCR assay offers an alternative to conventional nested PCR and restriction fragment length polymorphism analyses for the rapid detection of both point mutations associated with macrolide resistance in T. pallidum. |
Prevalence of the 23S rRNA A2058G point mutation and molecular subtypes in Treponema pallidum in the United States, 2007 to 2009.
Su JR , Pillay A , Hook EW , Ghanem KG , Wong W , Jackson D , Smith LD , Pierce E , Philip SS , Wilson S , Golden MR , Workowski KA , Chi KH , Parrish DD , Chen CY , Weinstock HS . Sex Transm Dis 2012 39 (10) 794-798 BACKGROUND: The 23S rRNA A2058G point mutation in Treponema pallidum is associated with macrolide antibiotic treatment failure. Its prevalence and potential association with a molecular subtype within the United States are unknown. METHODS: During 2007 to 2009, 11 clinics across the United States sent samples from genital ulcers to the Centers for Disease Control and Prevention. Molecular techniques were used to identify T. pallidum DNA sequences, the A2058G mutation, and subtype of T. pallidum. Accompanying epidemiologic information was abstracted from medical records. RESULTS: A total of 141 samples with T. pallidum were collected from individuals whose median age was 33 years (range, 13-68 years): 118 were male (69% reported as men having sex with men [MSM]). The A2058G mutation was carried in 75 samples (53%) with T. pallidum, with samples from MSM (versus women and other men) more likely carrying the A2058G mutation (65/82 samples versus 8/57 samples; prevalence ratio, 5.7; 95% confidence interval, 2.9-10.8). Of 98 strain-typed samples, 61 (62%) were the 14d9 subtype of T. pallidum, which was also associated with samples with T. pallidum from MSM (prevalence ratio, 3.5; 95% confidence interval, 1.9-6.5). However, among T. pallidum from MSM, the A2058G mutation was not associated with the 14d9 subtype. CONCLUSIONS: The A2058G mutation and 14d9 subtype of T. pallidum were present throughout the United States. Both were more commonly found in T. pallidum from MSM compared with women or other men but were not associated with each other. Treating syphilis with azithromycin should be done cautiously and only when treatment with penicillin or doxycycline is not feasible. (Copyright 2012 American Sexually Transmitted Diseases Association All rights reserved.) |
Protocol for the detection of Treponema pallidum in paraffin-embedded specimens.
Chen CY , Pillay A . Methods Mol Biol 2012 903 295-306 Formalin-fixed paraffin-embedded (FFPE) tissue blocks are routinely used for histopathological examination and are also useful for specific pathogen detection by polymerase chain reaction (PCR). FFPE tissue is stable at ambient temperature for an extended period of time and relatively easy to transport compared to fresh tissue, which has to be processed or frozen immediately. In addition, archival material is an invaluable source for retrospective molecular and clinical investigation. This chapter describes detailed procedures for nucleic acid extraction and PCR detection of Treponema pallidum using FFPE tissue. |
The molecular diagnosis of sexually transmitted genital ulcer disease.
Chen CY , Ballard RC . Methods Mol Biol 2012 903 103-12 Highly sensitive and specific nucleic acid amplification tests (NAATs) have emerged as the gold standard diagnostic tests for many infectious diseases. Real-time PCR has further refined the technology of nucleic acid amplification with detection in a closed system and enabled multiplexing to simultaneously detect multiple pathogens. It is a versatile, fast, and high-throughput system for pathogen detection that has reduced the risk of PCR contamination, eliminated post-PCR manipulations, and improved the cost-effectiveness of testing. In addition, real-time PCR can be applied to self-collected noninvasive specimens. Here, we describe an in-house developed TaqMan-based real-time multiplex PCR (M-PCR) assay for the diagnosis of sexually transmitted genital ulcer disease (GUD) and discuss briefly on issues associated with validation of assay performance. |
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