scholarly journals DjinniChip: Evaluation of a novel molecular rapid diagnostic device for the detection of Chlamydia trachomatis in trachoma-endemic areas

2020 ◽  
Author(s):  
Tamsyn R Derrick ◽  
Natalia Sandetskaya ◽  
Harry Pickering ◽  
Andreas Kölsch ◽  
Athumani Ramadhani ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Low Cost ◽  
Bacterial Species ◽  
Clinical Signs ◽  
Field Conditions ◽  
Clinical Samples ◽  
Chlamydia Trachomatis Infection ◽  
Low Concentrations ◽  
Control Programmes ◽  
The Right

Abstract Background The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection, particularly following mass drug administration. Treatment decisions following impact surveys and in post-control surveillance for communities are currently based on the prevalence of clinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and the increased spread of macrolide resistance alleles in ‘off-target’ bacterial species. We therefore developed a simple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use by trachoma control programmes. Methods The study was conducted in London, Germany and Tanzania. For clinical testing in Tanzania, specimens from a sample of 350 children between the ages of 7 to15 years, which were part of a longitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from the right eye. The second swab was collected dry, kept cool in the field and archived at -80 o C before sample lysis for DjinniChip detection and parallel nucleic acid purification and detection/quantification by qPCR assay. Results Djinnichip was able to reliably detect >10 copies of C. trachomatis per test and correctly identified 7/10 Quality Control for Molecular Diagnostics C. trachomatis panel samples, failing to detect 3 positive samples with genome equivalent amounts >10 copies. Djinnichip performed well across a range of typical trachoma field conditions and when used by lay personnel using a series of mock samples. In the laboratory in Tanzania, using clinical samples the sensitivity and specificity of DjinniChip for C. trachomatis was 66% (95% CI 51–78) and 94.8 (95% CI 91–97%) with an overall accuracy of 90.1 (95% CI 86.4 – 93). Conclusions DjinniChip performance is extremely promising, particularly its ability to detect low concentrations of C. trachomatis and its usability in field conditions. The DjinniChip requires further development to reduce inhibition and advance toward a closed system. DjinniChip results did not vary between local laboratory results and typical trachoma field settings, illustrating its potential for use in low-resource areas to prevent unnecessary rounds of MDA and to monitor for C. trachomatis recrudescence.

scholarly journals DjinniChip: Evaluation of a novel molecular rapid diagnostic device for the detection of Chlamydia trachomatis in trachoma-endemic areas

2020 ◽  
Author(s):  
Tamsyn R Derrick ◽  
Natalia Sandetskaya ◽  
Harry Pickering ◽  
Andreas Kölsch ◽  
Athumani Ramadhani ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Low Cost ◽  
Bacterial Species ◽  
Clinical Signs ◽  
Field Conditions ◽  
Clinical Samples ◽  
Chlamydia Trachomatis Infection ◽  
Low Concentrations ◽  
Control Programmes ◽  
The Right

Abstract Background The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection, particularly following mass drug administration. Treatment decisions following impact surveys and in post-control surveillance for communities are currently based on the prevalence of clinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and the increased spread of macrolide resistance alleles in ‘off-target’ bacterial species. We therefore developed a simple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use by trachoma control programmes. Methods The study was conducted in London, Germany and Tanzania. For clinical testing in Tanzania, specimens from a sample of 350 children between the ages of 7 to15 years, which were part of a longitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from the right eye. The second swab was collected dry, kept cool in the field and archived at -80 o C before sample lysis for DjinniChip detection and parallel nucleic acid purification and detection/quantification by qPCR assay. Results Djinnichip was able to reliably detect >10 copies of C. trachomatis per test and correctly identified 7/10 Quality Control for Molecular Diagnostics C. trachomatis panel samples, failing to detect 3 positive samples with genome equivalent amounts >10 copies. Djinnichip performed well across a range of typical trachoma field conditions and when used by lay personnel using a series of mock samples. In the laboratory in Tanzania, using clinical samples the sensitivity and specificity of DjinniChip for C. trachomatis was 66% (95% CI 51–78) and 94.8 (95% CI 91–97%) with an overall accuracy of 90.1 (95% CI 86.4 – 93). Conclusions DjinniChip performance is extremely promising, particularly its ability to detect low concentrations of C. trachomatis and its usability in field conditions. The DjinniChip requires further development to reduce inhibition and advance toward a closed system. DjinniChip results did not vary between local laboratory results and typical trachoma field settings, illustrating its potential for use in low-resource areas to prevent unnecessary rounds of MDA and to monitor for C. trachomatis recrudescence.

scholarly journals ClearTrachoma: Evaluation of a Novel Molecular Rapid Diagnostic Device for the Detection of Chlamydia Trachomatis in Trachoma-Endemic Areas

2020 ◽  
Author(s):  
Tamsyn R Derrick ◽  
Natalia Sandetskaya ◽  
Harry Pickering ◽  
Andreas Kölsch ◽  
Athumani Ramadhani ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Low Cost ◽  
Bacterial Species ◽  
Clinical Signs ◽  
Field Conditions ◽  
Clinical Samples ◽  
Low Concentrations ◽  
Control Programmes ◽  
Nucleic Acid Purification ◽  
The Right

Abstract Background: The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection, particularly following mass drug administration. Treatment decisions following impact surveys and in post-control surveillance for communities are currently based on the prevalence of clinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and the increased spread of macrolide resistance alleles in ‘off-target’ bacterial species. We therefore developed a simple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use by trachoma control programmes.Methods: The study was conducted in London, Germany and Tanzania. For clinical testing in Tanzania, specimens from a sample of 350 children between the ages of 7 to15 years, which were part of a longitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from the right eye. The second swab was collected dry, kept cool in the field and archived at -80oC before sample lysis for DjinniChip detection and parallel nucleic acid purification and detection/quantification by qPCR assay. Results: Djinnichip was able to reliably detect >10 copies of C. trachomatis per test and correctly identified 7/10 Quality Control for Molecular Diagnostics C. trachomatis panel samples, failing to detect 3 positive samples with genome equivalent amounts £10 copies. Djinnichip performed well across a range of typical trachoma field conditions and when used by lay personnel using a series of mock samples. In the laboratory in Tanzania, using clinical samples the sensitivity and specificity of DjinniChip for C. trachomatis was 66% (95% CI 51–78) and 94.8 (95% CI 91–97%) with an overall accuracy of 90.1 (95% CI 86.4 – 93). Conclusions: DjinniChip performance is extremely promising, particularly its ability to detect low concentrations of C. trachomatis and its usability in field conditions. The DjinniChip requires further development to reduce inhibition and advance toward a closed system. DjinniChip results did not vary between local laboratory results and typical trachoma field settings, illustrating its potential for use in low-resource areas to prevent unnecessary rounds of MDA and to monitor for C. trachomatis recrudescence.

scholarly journals DjinniChip: evaluation of a novel molecular rapid diagnostic device for the detection of Chlamydia trachomatis in trachoma-endemic areas

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Tamsyn R. Derrick ◽  
Natalia Sandetskaya ◽  
Harry Pickering ◽  
Andreas Kölsch ◽  
Athumani Ramadhani ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Low Cost ◽  
Bacterial Species ◽  
Clinical Signs ◽  
Field Conditions ◽  
Clinical Samples ◽  
Low Concentrations ◽  
Control Programmes ◽  
The Uk ◽  
The Right

Abstract Background The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection, particularly following mass drug administration. Treatment decisions following impact surveys and in post-control surveillance for communities are currently based on the prevalence of clinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and the increased spread of macrolide resistance alleles in ‘off-target’ bacterial species. We therefore developed a simple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use by trachoma control programmes. Methods The study was conducted in the UK, Germany and Tanzania. For clinical testing in Tanzania, specimens from a sample of 350 children between the ages of 7 to 15 years, which were part of a longitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from the right eye. The second swab was collected dry, kept cool in the field and archived at – 80 °C before sample lysis for DjinniChip detection and parallel nucleic acid purification and detection/quantification by qPCR assay. Results DjinniChip was able to reliably detect > 10 copies of C. trachomatis per test and correctly identified 7/10 Quality Control for Molecular Diagnostics C. trachomatis panel samples, failing to detect 3 positive samples with genome equivalent amounts ≤ 10 copies. DjinniChip performed well across a range of typical trachoma field conditions and when used by lay personnel using a series of mock samples. In the laboratory in Tanzania, using clinical samples the sensitivity and specificity of DjinniChip for C. trachomatis was 66% (95% CI 51–78) and 94.8 (95% CI 91–97%) with an overall accuracy of 90.1 (95% CI 86.4–93). Conclusions DjinniChip performance is extremely promising, particularly its ability to detect low concentrations of C. trachomatis and its usability in field conditions. The DjinniChip requires further development to reduce inhibition and advance toward a closed system. DjinniChip results did not vary between local laboratory results and typical trachoma field settings, illustrating its potential for use in low-resource areas to prevent unnecessary rounds of MDA and to monitor for C. trachomatis recrudescence.

scholarly journals Trachoma, Anti-Pgp3 Serology, and Ocular Chlamydia trachomatis Infection in Papua New Guinea

2020 ◽  
Author(s):  
Colin K Macleod ◽  
Robert Butcher ◽  
Sarah Javati ◽  
Sarah Gwyn ◽  
Marinjho Jonduo ◽  
...  
Keyword(s):  
Public Health ◽  
Chlamydia Trachomatis ◽  
Papua New Guinea ◽  
Clinical Signs ◽  
Public Health Problem ◽  
New Guinea ◽  
Dried Blood Spots ◽  
Causative Organism ◽  
Ocular Infection ◽  
Chlamydia Trachomatis Infection

Abstract Background In Melanesia, the prevalence of trachomatous inflammation–follicular (TF) suggests that public health–level interventions against active trachoma are needed. However, the prevalence of trachomatous trichiasis is below the threshold for elimination as a public health problem and evidence of conjunctival infection with trachoma’s causative organism (Chlamydia trachomatis [CT]) is rare. Here, we examine the prevalence of ocular infection with CT and previous exposure to CT in three evaluation units (EUs) of Papua New Guinea. Methods All individuals aged 1–9 years who were examined for clinical signs of trachoma in 3 Global Trachoma Mapping Project EUs were eligible to take part in this study (N = 3181). Conjunctival swabs were collected from 349 children with TF and tested by polymerase chain reaction to assess for ocular CT infection. Dried blood spots were collected from 2572 children and tested for anti-Pgp3 antibodies using a multiplex assay. Results The proportion of children with TF who had CT infection was low across all 3 EUs (overall 2%). Anti-Pgp3 seroprevalence was 5.2% overall and there was no association between anti-Pgp3 antibody level and presence of TF. In 2 EUs, age-specific seroprevalence did not increase significantly with increasing age in the 1- to 9-year-old population. In the third EU, there was a statistically significant change with age but the overall seroprevalence and peak age-specific seroprevalence was very low. Conclusions Based on these results, together with similar findings from the Solomon Islands and Vanuatu, the use of TF to guide antibiotic mass drug administration decisions in Melanesia should be reviewed.

scholarly journals High-resolution multilocus sequence typing for Chlamydia trachomatis: improved results for clinical samples with low amounts of C. trachomatis DNA

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shlomo Pilo ◽  
Gal Zizelski Valenci ◽  
Mor Rubinstein ◽  
Lea Pichadze ◽  
Yael Scharf ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Multilocus Sequence Typing ◽  
Phylogenetic Trees ◽  
Melting Curve ◽  
Pcr Amplification ◽  
Clinical Samples ◽  
Melting Curve Analysis ◽  
Whole Genome ◽  
Mlst Scheme ◽  
Low Concentrations

Abstract Background Several Multilocus Sequence Typing (MLST) schemes have been developed for Chlamydia trachomatis. Bom’s MLST scheme for MLST is based on nested PCR amplification and sequencing of five hypervariable genes and ompA. In contrast to other Chlamydia MLST schemes, Bom’s MLST scheme gives higher resolution and phylogenetic trees that are comparable to those from whole genome sequencing. However, poor results have been obtained with Bom’s MLST scheme in clinical samples with low concentrations of Chlamydia DNA. Results In this work, we present an improved version of the scheme that is based on the same genes and MLST database as Bom’s MLST scheme, but with newly designed primers for nested-1 and nested-2 steps under stringent conditions. Furthermore, we introduce a third primer set for the sequencing step, which considerably improves the performance of the assay. The improved primers were tested in-silico using a dataset of 141 Whole Genome Sequences (WGS) and in a comparative analysis of 32 clinical samples. Based on cycle threshold and melting curve analysis values obtained during Real-Time PCR of nested-1 & 2 steps, we developed a simple scoring scheme and flow chart that allow identification of reaction inhibitors as well as to predict with high accuracy amplification success. The improved MLST version was used to obtain a genovars distribution in patients attending an STI clinic in Tel Aviv. Conclusions The newly developed MLST version showed great improvement of assay results for samples with very low concentrations of Chlamydia DNA. A similar concept could be applicable to other MLST schemes.

scholarly journals Development of a novel rationally designed antibiotic to inhibit a nontraditional bacterial target

2017 ◽  
Vol 95 (5) ◽  
pp. 595-603 ◽  
Author(s):  
Pavel Dibrov ◽  
Elena Dibrov ◽  
Thane G. Maddaford ◽  
Melissa Kenneth ◽  
Jordan Nelson ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Mammalian Cells ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Membrane Vesicles ◽  
Microbial Pathogens ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Bacterial Membrane ◽  
Infectious Process ◽  
Chlamydia Trachomatis Infection

The search for new nontraditional targets is a high priority in antibiotic design today. Bacterial membrane energetics based on sodium ion circulation offers potential alternative targets. The present work identifies the Na+-translocating NADH:ubiquinone oxidoreductase (Na+-NQR), a key respiratory enzyme in many microbial pathogens, as indispensible for the Chlamydia trachomatis infectious process. Infection by Chlamydia trachomatis significantly increased first H+ and then Na+ levels within the host mammalian cell. A newly designed furanone Na+-NQR inhibitor, PEG-2S, blocked the changes in both H+ and Na+ levels induced by Chlamydia trachomatis infection. It also inhibited intracellular proliferation of Chlamydia trachomatis with a half-minimal inhibitory concentration in the submicromolar range but did not affect the viability of mammalian cells or bacterial species representing benign intestinal microflora. At low nanomolar concentrations (IC50 value = 1.76 nmol/L), PEG-2S inhibited the Na+-NQR activity in sub-bacterial membrane vesicles isolated from Vibrio cholerae. Taken together, these results show, for the first time, that Na+-NQR is critical for the bacterial infectious process and is susceptible to a precisely targeted bactericidal compound in situ. The obtained data have immediate relevance for many different diseases caused by pathogenic bacteria that rely on Na+-NQR activity for growth, including sexually transmitted, pulmonary, oral, gum, and ocular infections.

scholarly journals Discovery of Spilanthol Endoperoxide as a Redox Natural Compound Active against Mammalian Prx3 and Chlamydia trachomatis Infection

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1220
Author(s):  
Rosine Dushime ◽  
Yunhuang Zhu ◽  
Hanzhi Wu ◽  
Daniel Saez ◽  
Kirtikar Shukla ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Natural Compound ◽  
Inflammatory Diseases ◽  
Low Cost ◽  
Mitochondrial Protein ◽  
Underlying Mechanism ◽  
Chlamydia Trachomatis Infection ◽  
Development Of Resistance ◽  
Peroxidation Product ◽  
Mitochondrial Oxidation

Chlamydia trachomatis (Ct) is a bacterial intracellular pathogen responsible for a plethora of diseases ranging from blindness to pelvic inflammatory diseases and cervical cancer. Although this disease is effectively treated with antibiotics, concerns for development of resistance prompt the need for new low-cost treatments. Here we report the activity of spilanthol (SPL), a natural compound with demonstrated anti-inflammatory properties, against Ct infections. Using chemical probes selective for imaging mitochondrial protein sulfenylation and complementary assays, we identify an increase in mitochondrial oxidative state by SPL as the underlying mechanism leading to disruption of host cell F-actin cytoskeletal organization and inhibition of chlamydial infection. The peroxidation product of SPL (SPL endoperoxide, SPLE), envisioned to be the active compound in the cellular milieu, was chemically synthesized and showed more potent anti-chlamydial activity. Comparison of SPL and SPLE reactivity with mammalian peroxiredoxins, demonstrated preferred reactivity of SPLE with Prx3, and virtual lack of SPL reaction with any of the reduced Prx isoforms investigated. Cumulatively, these findings support the function of SPL as a pro-drug, which is converted to SPLE in the cellular milieu leading to inhibition of Prx3, increased mitochondrial oxidation and disruption of F-actin network, and inhibition of Ct infection.

scholarly journals Classical and molecular methods for diagnosis of Chlamydia trachomatis infections

2011 ◽  
Vol 64 (9-10) ◽  
pp. 477-480 ◽  
Author(s):  
Snezana Tomanovic ◽  
Slobodanka Djukic
Keyword(s):  
Nucleic Acid ◽  
Chlamydia Trachomatis ◽  
Deoxyribonucleic Acid ◽  
Nucleic Acid Amplification ◽  
Clinical Samples ◽  
Direct Immunofluorescence ◽  
Nucleic Acid Amplification Tests ◽  
Chlamydia Trachomatis Infection ◽  
Culture Cells ◽  
Chlamydial Infections

Introduction. Genital Chlamydia trachomatis infection is the leading cause of bacterial sexually transmitted diseases in industrial countries, particularly among young people. The consequences of chlamydial infections may involve pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility. Methods. Available tests for detection of chlamydia in men and women include culture in tissue culture cells, direct immunofluorescence test, enzyme immune assay, nucelic acid probe hibridization and polymerase chain reaction. Nucleic acid amplification tests use different ribonucleic and deoxyribonucleic acid regions as target molecules for amplifying Chlamydia trachomatis ribonucleic/deoxyribonucleic acid in clinical samples. Nucleic acid amplification tests are more sensitive than non-nucleic acid amplification tests. Conclusion. Although screening programmes exist in a number of countries, the continuously increasing prevalence of chlamydial infections demonstrates the necessity for defining the best method for the diagnosis and the population for screening.

Acute abdomen in pregnancy: a retrospective study of pregnant patients hospitalised for abdominal pain

2020 ◽  
Vol 99 (3) ◽  
pp. 131-135
Keyword(s):  
Abdominal Pain ◽  
Clinical Signs ◽  
University Hospital ◽  
Diagnostic Process ◽  
Abdominal Emergency ◽  
Lower Abdominal Quadrant ◽  
Abdominal Emergencies ◽  
The Right ◽  
Abdominal Quadrant ◽  
In Pregnancy

Introduction: Abdominal emergencies occur in pregnant women with the rate of 1:500−635 pregnancies. Such conditions usually develop from full health and worsen rapidly. Symptoms are often similar to those in physiological pregnancy (abdominal pain, vomiting, constipation). The diagnostic process is thus difficult and both the mother and her child are at risk. Our aim was to evaluate the frequency of abdominal emergencies in the Department of Surgery, University Hospital in Pilsen and to consider their impact on pregnancy and on the newborn. Methods: We acquired a set of patients by retrograde collection of data. We searched for pregnant patients suspected of developing an abdominal emergency admitted to the Department of Surgery, Faculty of Medicine, Pilsen between 2004 and 2015. We evaluated a number of clinical signs to statistically describe the set. Results: The set included 121 patients; 42 of the patients underwent a surgical procedure and 79 received conservative treatment. 38 patients underwent appendectomy; 6 appendixes were with no pathologies. McBurney’s incision was an approach of choice in most cases. The most frequent symptom was pain in the right lower abdominal quadrant. The foetus has been lost in none of the cases. Conclusion: Acute appendicitis was the most frequent abdominal emergency in our set and also the most frequent reason for surgical intervention. The most specific sign was pain in the right lower abdominal quadrant. No impact of appendicitis or appendectomy on the health of the newborn has been observed. Even though abdominal emergencies in pregnancy are relatively rare, the results of the department are very good.

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