scholarly journals Investigating the Epidemiology of Repeat Chlamydia trachomatis Detection after Treatment by Using C. trachomatis OmpA Genotyping

2014 ◽  
Vol 53 (2) ◽  
pp. 546-549 ◽  
Author(s):  
Richa Kapil ◽  
Christen G. Press ◽  
M. Lisa Hwang ◽  
LaDraka Brown ◽  
William M. Geisler
Keyword(s):  
Chlamydia Trachomatis ◽  
Sexual Partner ◽  
Protein A ◽  
Genotype Distribution ◽  
Gene Encoding ◽  
Content Type ◽  
Sexually Transmitted ◽  
Infection Treatment ◽  
Outer Membrane Protein A

RepeatChlamydia trachomatisdetection frequently occurs within months afterC. trachomatisinfection treatment. The origins of such infection (persistence versus reinfection from untreated or new partners) are varied and difficult to determine.C. trachomatisstrains can be differentiated by sequencing theompAgene encoding the outer membrane protein A (OmpA). We used OmpA genotyping to investigate the epidemiology of repeatC. trachomatisdetection after treatment inC. trachomatis-infected subjects seen at a sexually transmitted diseases clinic. Subjects were enrolled, tested forC. trachomatis, treated with azithromycin, and scheduled for a 6-month follow-up for repeatC. trachomatistesting. OmpA genotyping was performed onC. trachomatis-positive urogenital specimens obtained from patients at enrollment and follow-up. The enrollment visit OmpA genotypes forC. trachomatiswere determined for 162 subjects (92% female, 94% African American).C. trachomatiswas detected at follow-up in 39 subjects (24%). The OmpA genotype distribution at enrollment did not differ in those with versus those without repeatC. trachomatisdetection. Of the 35 subjects withC. trachomatisstrains genotyped at enrollment and follow-up, 7 (20%) had the sameompAsequence at both visits, while 28 (80%) had discordant sequences. A new sexual partner was reported more often in subjects with discordantC. trachomatisstrains than in those with concordant strains (13 [46%] versus 1 [14%];P= 0.195). Half of the subjects with discordantC. trachomatisstrains who reported sexual activity since treatment denied a new sexual partner; 62% of these subjects reported that their partner was treated. Our study demonstrates that most repeatC. trachomatisdetections after treatment were new infections with a differentC. trachomatisstrain rather than reinfection with the same strain. OmpA genotyping can be a useful tool in understanding the origins of repeatC. trachomatisdetection after treatment.

scholarly journals Anaplasma phagocytophilum Outer Membrane Protein A Interacts with Sialylated Glycoproteins To Promote Infection of Mammalian Host Cells

2012 ◽  
Vol 80 (11) ◽  
pp. 3748-3760 ◽  
Author(s):  
Nore Ojogun ◽  
Amandeep Kahlon ◽  
Stephanie A. Ragland ◽  
Matthew J. Troese ◽  
Juliana E. Mastronunzio ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Anaplasma Phagocytophilum ◽  
Protein A ◽  
Host Cells ◽  
Mammalian Host ◽  
Content Type ◽  
Outer Membrane Protein A ◽  
Sialylated Glycoproteins

ABSTRACTAnaplasma phagocytophilumis the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis (HGA).A. phagocytophilumbinding to sialyl Lewis x (sLex) and other sialylated glycans that decorate P selectin glycoprotein 1 (PSGL-1) and other glycoproteins is critical for infection of mammalian host cells. Here, we demonstrate the importance ofA. phagocytophilumouter membrane protein A (OmpA) APH_0338 in infection of mammalian host cells. OmpA is transcriptionally induced during transmission feeding ofA. phagocytophilum-infected ticks on mice and is upregulated during invasion of HL-60 cells. OmpA is presented on the pathogen's surface. Sera from HGA patients and experimentally infected mice recognize recombinant OmpA. Pretreatment ofA. phagocytophilumorganisms with OmpA antiserum reduces their abilities to infect HL-60 cells. The OmpA N-terminal region is predicted to contain the protein's extracellular domain. GlutathioneS-transferase (GST)-tagged versions of OmpA and OmpA amino acids 19 to 74 (OmpA19-74) but not OmpA75-205bind to, and competitively inhibitA. phagocytophiluminfection of, host cells. Pretreatment of host cells with sialidase or trypsin reduces or nearly eliminates, respectively, GST-OmpA adhesion. Therefore, OmpA interacts with sialylated glycoproteins. This study identifies the firstA. phagocytophilumadhesin-receptor pair and delineates the region of OmpA that is critical for infection.

scholarly journals Comparative Analysis of Chlamydia psittaci Genomes Reveals the Recent Emergence of a Pathogenic Lineage with a Broad Host Range

mBio ◽  
2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Timothy D. Read ◽  
Sandeep J. Joseph ◽  
Xavier Didelot ◽  
Brooke Liang ◽  
Lisa Patel ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
New World ◽  
Evolutionary Dynamics ◽  
Chlamydia Psittaci ◽  
South American ◽  
Content Type ◽  
Sexually Transmitted ◽  
Genome Wide ◽  
Life Threatening ◽  
History Of

ABSTRACT Chlamydia psittaci is an obligate intracellular bacterium. Interest in Chlamydia stems from its high degree of virulence as an intestinal and pulmonary pathogen across a broad range of animals, including humans. C. psittaci human pulmonary infections, referred to as psittacosis, can be life-threatening, which is why the organism was developed as a bioweapon in the 20th century and is listed as a CDC biothreat agent. One remarkable recent result from comparative genomics is the finding of frequent homologous recombination across the genome of the sexually transmitted and trachoma pathogen Chlamydia trachomatis. We sought to determine if similar evolutionary dynamics occurred in C. psittaci. We analyzed 20 C. psittaci genomes from diverse strains representing the nine known serotypes of the organism as well as infections in a range of birds and mammals, including humans. Genome annotation revealed a core genome in all strains of 911 genes. Our analyses showed that C. psittaci has a history of frequently switching hosts and undergoing recombination more often than C. trachomatis. Evolutionary history reconstructions showed genome-wide homologous recombination and evidence of whole-plasmid exchange. Tracking the origins of recombinant segments revealed that some strains have imported DNA from as-yet-unsampled or -unsequenced C. psittaci lineages or other Chlamydiaceae species. Three ancestral populations of C. psittaci were predicted, explaining the current population structure. Molecular clock analysis found that certain strains are part of a clonal epidemic expansion likely introduced into North America by South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. IMPORTANCE Chlamydia psittaci is classified as a CDC biothreat agent based on its association with life-threatening lung disease, termed psittacosis, in humans. Because of the recent remarkable findings of frequent recombination across the genome of the human sexually transmitted and ocular trachoma pathogen Chlamydia trachomatis, we sought to determine if similar evolutionary dynamics occur in C. psittaci. Twenty C. psittaci genomes were analyzed from diverse strains that may play a pathogenic role in human disease. Evolution of the strains revealed genome-wide recombination occurring at a higher rate than for C. trachomatis. Certain strains were discovered to be part of a recent epidemic clonal expansion originating in South America. These strains may have been introduced into the United States from South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. Our analyses indicate that C. psittaci strains have a history of frequently switching hosts and undergoing recombination.

scholarly journals In Vitro Activity of Lefamulin against Sexually Transmitted Bacterial Pathogens

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Susanne Paukner ◽  
Astrid Gruss ◽  
Jørgen Skov Jensen
Keyword(s):  
Chlamydia Trachomatis ◽  
Bacterial Pathogens ◽  
Mycoplasma Genitalium ◽  
Standard Of Care ◽  
Multidrug Resistant ◽  
In Vitro Activity ◽  
First Line ◽  
Content Type ◽  
Sexually Transmitted

ABSTRACT The pleuromutilin antibiotic lefamulin demonstrated in vitro activity against the most relevant bacterial pathogens causing sexually transmitted infections (STI), including Chlamydia trachomatis (MIC 50/90 , 0.02/0.04 mg/liter; n = 15), susceptible and multidrug-resistant Mycoplasma genitalium (MIC range, 0.002 to 0.063 mg/liter; n = 6), and susceptible and resistant Neisseria gonorrhoeae (MIC 50/90 , 0.12/0.5 mg/liter; n = 25). The results suggest that lefamulin could be a promising first-line antibiotic for the treatment of STI, particularly in populations with high rates of resistance to standard-of-care antibiotics.

scholarly journals Structure and Metal Binding Properties of Chlamydia trachomatis YtgA

2019 ◽  
Vol 202 (1) ◽  
Author(s):  
Zhenyao Luo ◽  
Stephanie L. Neville ◽  
Rebecca Campbell ◽  
Jacqueline R. Morey ◽  
Shruti Menon ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Transition Metal ◽  
Metal Binding ◽  
Developed Countries ◽  
Biochemical Properties ◽  
Host Cells ◽  
Transmitted Infection ◽  
Content Type ◽  
Sexually Transmitted ◽  
Serious Disease

Chlamydia trachomatis is the most common bacterial sexually transmitted infection in developed countries, with an estimated global prevalence of 4.2% in the 15- to 49-year age group. Although infection is asymptomatic in more than 80% of infected women, about 10% of cases result in serious disease. Infection by C. trachomatis is dependent on the ability to acquire essential nutrients, such as the transition metal iron, from host cells. In this study, we show that iron is the most abundant transition metal in C. trachomatis and report the structural and biochemical properties of the iron-recruiting protein YtgA. Knowledge of the high-resolution structure of YtgA will provide a platform for future structure-based antimicrobial design approaches.

scholarly journals Role for GrgA in Regulation of σ28-Dependent Transcription in the Obligate Intracellular Bacterial PathogenChlamydia trachomatis

2018 ◽  
Vol 200 (20) ◽  
Author(s):  
Malhar Desai ◽  
Wurihan Wurihan ◽  
Rong Di ◽  
Joseph D. Fondell ◽  
Bryce E. Nickels ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Chlamydia Trachomatis ◽  
Sigma Factor ◽  
Bacterial Pathogen ◽  
Direct Interaction ◽  
Developmental Cycle ◽  
Content Type ◽  
Sexually Transmitted ◽  
Obligate Intracellular ◽  
Specific Transcription Factor

ABSTRACTThe obligate intracellular bacterial pathogenChlamydia trachomatishas a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primaryChlamydiasigma factor, σ66, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, σ28. In prior work, we identified GrgA as aChlamydia-specific transcription factor that activates σ66-dependent transcription by binding DNA and interacting with a nonconserved region (NCR) of σ66. Here, we extend these findings by showing GrgA can also activate σ28-dependent transcription through direct interaction with σ28. We measure the binding affinity of GrgA for both σ66and σ28, and we identify regions of GrgA important for σ28-dependent transcription. Similar to results obtained with σ66, we find that GrgA's interaction with σ28involves an NCR located upstream of conserved region 2 of σ28. Our findings suggest that GrgA is an important regulator of both σ66- and σ28-dependent transcription inC. trachomatisand further highlight NCRs of bacterial RNA polymerase as targets for regulatory factors unique to particular organisms.IMPORTANCEChlamydia trachomatisis the number one sexually transmitted bacterial pathogen worldwide. A substantial proportion ofC. trachomatis-infected women develop infertility, pelvic inflammatory syndrome, and other serious complications.C. trachomatisis also a leading infectious cause of blindness in underdeveloped countries. The pathogen has a unique developmental cycle that is transcriptionally regulated. The discovery of an expanded role for theChlamydia-specific transcription factor GrgA helps us understand the progression of the chlamydial developmental cycle.

scholarly journals Asymptomatic Lymphogranuloma Venereum among Nigerian Men who have Sex with Men

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S69-S70
Author(s):  
Trevor Crowell ◽  
Justin Hardick ◽  
Kara Lombardi ◽  
Senate Amusu ◽  
Sunday Odeyemi ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Rectal Swab ◽  
Lymphogranuloma Venereum ◽  
Rectal Pain ◽  
Sexually Transmitted ◽  
Oropharyngeal Swab ◽  
Rapid Tests ◽  
Sex With Men ◽  
Incident Cases

Abstract Background Among men who have sex with men (MSM), lymphogranuloma venereum (LGV) has been associated with proctocolitis that can lead to chronic complications and requires a longer course of antibiotic therapy than is recommended for infections due to other serovars of Chlamydia trachomatis (CT). We describe the prevalence and clinical features of LGV among Nigerian MSM diagnosed with anorectal CT. Methods MSM were recruited into the ongoing RV368 cohort in Lagos, Nigeria, using respondent-driven sampling. Participants were screened for HIV and bacterial sexually transmitted infections (STIs) every three months for up to 18 months. HIV was diagnosed using a parallel algorithm of rapid tests on fingerstick blood samples. PCR testing for Neisseria gonorrheae and CTwas performed on voided urine, oropharyngeal swab, and rectal swab specimens. For this analysis, prevalent and incident cases of rectal CT infection underwent additional testing to identify LGV serovars utilizing novel real-time PCR assays specific for the L serovars of CT Chlamydia trachomatis. Results From 28 April 2014–19 July 2016, 420 men underwent screening for rectal STIs, including 66 (15.7%) who had prevalent rectal infection with CT. An additional 68 participants developed incident infections during 208 person-years of follow-up. Of 134 eligible rectal swab specimens, 128 underwent further testing for LGV serovars. Seven (5.5%) of the tested samples were identified as LGV serovars of CT. None of the seven participants with LGV reported any symptoms such as fever or rectal pain. Two of the participants with LGV were simultaneously co-infected with rectal gonorrhea. HIV co-infection was common among participants with both LGV and non-LGV serovars of CT (71% and 77%, respectively, P = 0.74). Conclusion LGV was uncommon but present among Nigerian MSM in this study. LGV needs to be considered even in asymptomatic cases, particularly if anorectal CT infection fails to respond to the usual course of therapy. Consistent screening for L serovars of CT, or empiric treatment for LGV in cases with a high suspicion for this diagnosis, could potentially improve patient outcomes and decrease transmission. Disclosures All authors: No reported disclosures.

scholarly journals HtrA Is Important for Stress Resistance and Virulence in Haemophilus parasuis

2016 ◽  
Vol 84 (8) ◽  
pp. 2209-2219 ◽  
Author(s):  
Luhua Zhang ◽  
Ying Li ◽  
Yiping Wen ◽  
Gee W. Lau ◽  
Xiaobo Huang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Protein Quality ◽  
Protein A ◽  
Opportunistic Pathogen ◽  
Dependent Manner ◽  
Haemophilus Parasuis ◽  
Content Type ◽  
Outer Membrane Protein A ◽  
Dipeptide Transport ◽  
Atp Binding Protein

Haemophilus parasuisis an opportunistic pathogen that causes Glässer's disease in swine, with polyserositis, meningitis, and arthritis. The high-temperature requirement A (HtrA)-like protease, which is involved in protein quality control, has been reported to be a virulence factor in many pathogens. In this study, we showed that HtrA ofH. parasuis(HpHtrA) exhibited both chaperone and protease activities. Finally, nickel import ATP-binding protein (NikE), periplasmic dipeptide transport protein (DppA), and outer membrane protein A (OmpA) were identified as proteolytic substrates for HpHtrA. The protease activity reached its maximum at 40°C in a time-dependent manner. Disruption of thehtrAgene from strain SC1401 affected tolerance to temperature stress and resistance to complement-mediated killing. Furthermore, increased autoagglutination and biofilm formation were detected in thehtrAmutant. In addition, thehtrAmutant was significantly attenuated in virulence in the murine model of infection. Together, these data demonstrate that HpHtrA plays an important role in the virulence ofH. parasuis.

scholarly journals Assessment of Coinfection of Sexually Transmitted Pathogen Microbes by Use of the Anyplex II STI-7 Molecular Kit

2014 ◽  
Vol 53 (3) ◽  
pp. 991-993 ◽  
Author(s):  
B. Berçot ◽  
R. Amarsy ◽  
A. Goubard ◽  
C. Aparicio ◽  
H. U. Loeung ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Young Women ◽  
Genital Infection ◽  
Content Type ◽  
Sexually Transmitted ◽  
Ureaplasma Parvum ◽  
Reference Methods

Anyplex STI-7 is a new molecular kit that detects seven sexually transmitted pathogens. Among 202 subjects screened for genital infection, 143 (70.4%) were diagnosed with at least one pathogen, in concordance with reference methods. In addition, the Anyplex STI-7 demonstrated coinfections, such as that withUreaplasma parvumandChlamydia trachomatis, in young women.

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