Chancroid by Alia Nur Alissa https://padlet.com/alianuralissa/wpjj5vdkcf74 Knowledge of STD en-us 2018-10-10 10:45:44 UTC 2025-12-16 06:29:40 UTC hello@padlet.com Mode of Transmission, Symptoms and Treatments alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291257388 1) Mode of Transmission
Occurs through direct contact with the lesions. Sexual partners exposed by vaginal, oral or anal sex, without using a condom or dam, are at high risk of infection.

2) Symptoms
-Men may notice a small, red bump on their genitals that may change to an open sore within a day or two. The ulcer may form on any area of the genitals, including the penis and scrotum. The ulcers are frequently painful.
-Women may develop four or more red bumps on the labia, between the labia and anus, or on the thighs. The labia are the folds of skin that cover the female genitals. After the bumps become ulcerated, or open, women may experience a burning or painful sensation during urination or bowel movements.

3) Treatments
-Chancroid may be successfully treated with medication or surgery.
-Doctor will prescribe antibiotics to kill the bacteria that are causing ulcers. Antibiotics may also help decrease the chance of scarring as the ulcer heals.
-Doctor may drain a large and painful abscess in lymph nodes with a needle or through surgery. This reduces swelling and pain as the sore heals but might cause some light scarring at the site.





]]> 2018-10-10 14:13:31 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291257388 How pathogen invade and what immmune response involves? Firdauskun26 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291409710 1. How pathogen invade?
  • H. ducreyi infect  human skin.
  • The host responds with a robust infiltrate of polymorphonuclear leukocytes (PMNs) and macrophages.
  • This will leads to development of lesions which progress from papules to pustules to ulcers.
  • These bacteria are surrounded by PMNs and macrophages but remain extracellular.

2. What immmune response involves?
  • - A delayed-type (type IV) hypersensitivity reaction is response to H. ducreyi.Type IV hypersensitivity is a cell mediated immune response. This response will not effective against H. ducreyi infection. This is because cell mediated immune response only effective killing intracellular bacteria and viruses. H. ducreyi is extracellular in present to Chancroid lesions. Suggested that humoral immune response could be protective against infection. Protection does not 100% prevent from infection but reduced the viable H. ducreyi cells .
  • The bacteria induces rapid recruitment of innate and adaptive immune cells to infected sites. Then, dermal infiltrate of memory/effector CD4 and CD8 T cells, NK cells, myeloid DC, and macrophages. Only few B cells and no serum antibody induction during experimental infection. The cutaneous immune responses to H. ducreyi could promote phagocytosis and disease resolution.


Reference 

  1. Cole, L. E., Toffer, K. L., Fulcher, R. A., San Mateo, L. R., Orndorff, P. E., & Kawula, T. H. (2003). A Humoral Immune Response Confers Protection against Haemophilus ducreyi Infection. Infection and Immunity, 71(12), 6971–6977. http://doi.org/10.1128/IAI.71.12.6971-6977.2003.
  2.  Janowicz, D. M., Li, W., & Bauer, M. E. (2010). Host-pathogen Interplay of Haemophilus ducreyi. Current Opinion in Infectious Diseases, 23(1), 64–69. http://doi.org/10.1097/QCO.0b013e328334c0cb

]]> 2018-10-10 18:15:02 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291409710 A Humoral Immune Response Confers Protection against Haemophilus ducreyi Infection Firdauskun26 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291418079 2018-10-10 18:28:41 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291418079 Host–pathogen interplay of Haemophilus ducreyi Firdauskun26 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291418412 2018-10-10 18:29:17 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291418412 Pathogenicity pkavesha5 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291982158 *Pathophysiology*
-cytocidal toxin (HdCDT)
Haemophilus ducreyi penetrates into host through breaks in the mucosal barriers and microabrasionson the skin. It produces a cytocidal toxin (HdCDT) with swelling properties, which causes cell cycle arrest and apoptosis/necrosis of human cells and contributes to the aggravation of ulcers. Phagocytosis by macrophages is also impaired. Other virulence mechanisms:-
 *LspA proteins- have antiphagocytic functions,
*DsrA map-facilitates adherence, and an
 *influx transporter- protects pathogen from antimicrobial killing]]> 2018-10-11 22:54:54 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/291982158 alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041091 Penile ulcers associated with chancroid

Adapted from J. Miller, Public Health Image Library, CDC (1974)

]]> 2018-10-12 06:48:28 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041091 alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041449 Chancroid pustule resembling syphilis

Adapted from Public Health Image Library, CDC (1971)

]]> 2018-10-12 06:50:02 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041449 alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041627 Buboes associated with Haemophilus ducreyi infection

Adapted from S. Lindsley, Public Health Image Library, CDC (1971)

]]> 2018-10-12 06:50:52 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041627 alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041837 Gram stain of Haemophilus ducreyi

Adapted from G. Hammond, Public Health Image Library, CDC (1978)

]]> 2018-10-12 06:51:44 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292041837 alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292043197 2018-10-12 06:58:33 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292043197 Introduction on Chancroid alianuralissa https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292043867 Primarily a sexually transmitted disease that is most common in resource-poor countries. Rare in North America and Europe.

Caused by the fastidious, gram-negative coccobacillus Haemophilus ducreyi . Classically presents with the acute onset of a painful genital ulcer, and often associated with fluctuant lymphadenitis (bubo formation).

An important co-factor in HIV transmission. HIV status must be assessed.

Most cases resolve with antibiotic therapy; recurrence is rare.

Sexual partners within 10 days prior to onset of symptoms must be traced and treated, even if asymptomatic.

Several reports now describe non-genital cutaneous limb ulcerations due to H ducreyi in yaws-endemic countries.

]]> 2018-10-12 07:02:20 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292043867 Detection of Pathogen Using Immunology Method lindajainsandau https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292046732 1) IMMUNOCHROMATOGRAPHIC LATERAL FLOW ASSAYS:
Requiring only the dilution of the test agent in a sample buffer and applying several drops (∼200 μl) to the test strip.

A capture antibody is applied in a line on the strip and dried. To perform the test, a specimen is suspended in buffer and added to the pad containing the colloidal gold-labeled antibody.  The antibody specifically binds to antigen present in the specimen, and the resulting complex wicks down the membrane where it binds to the capture antibody.

A positive reaction is visualized as a red line created by the bound colloidal gold.]]> 2018-10-12 07:16:40 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292046732 Detection of Pathogen Using Immunology Method lindajainsandau https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292049661 2) ELISA
combine the specificity of antibodies with the sensitivity of simple enzyme assays, by using antibodies or antigens coupled to an easily-assayed enzyme. ELISAs can provide a useful measurement of antigen or antibody concentration.

A capture antibody affixed to the solid phase is exposed to a test sample (as well as to positive- and negative-control samples) 
After washing, the complex is exposed further to diluted detector antibody specific to the same antigen.

Finally, a conjugate antibody is added and the reaction is visualized. In this system, the antigen must have multiple epitope for antibody binding or a repeating, spatially distant, single epitope  ]]> 2018-10-12 07:29:42 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292049661 How ELISA works. lindajainsandau https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292051613 2018-10-12 07:38:00 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292051613 How Immunochromatographic Lateral Flow Assays work. lindajainsandau https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292058116 2018-10-12 08:02:57 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292058116 Genetic manipulation for vaccines development. izatianuar96 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292158145 The Haemophilus ducreyi trimeric autotransporter adhesin DsrA is an effective vaccine immunogen in the experimental swine model of chancroid.The passenger domain of DsrA (rNT-DsrA) was tested as a vaccine against chancroid.rNT-DsrA protected against a homologous challenge.High titered DsrA antisera bound the surface of viable Haemophilus ducreyi.Anti-DsrA IgG partially blocked fibrinogen binding by viable bacteria. Protection by the rNT-DsrA vaccine may involve a novel mechanism.
Adherence of pathogens to cellular targets is required to initiate most infections. Defining strategies that interfere with adhesion is therefore important for the development of preventative measures against infectious diseases. As an adhesin to host extracellular matrix proteins and human keratinocytes, the trimeric autotransporter adhesin DsrA, a proven virulence factor of the Gram-negative bacterium Haemophilus ducreyi, is a potential target for vaccine development. A recombinant form of the N-terminal passenger domain of DsrA from H. ducreyi class I strain 35000HP, termed rNT-DsrAI, was tested as a vaccine immunogen in the experimental swine model of H. ducreyi infection. Viable homologous H. ducreyi was not recovered from any animal receiving four doses of rNT-DsrAI administered with Freund's adjuvant at two-week intervals. Control pigs receiving adjuvant only were all infected. All animals receiving the rNT-DsrAI vaccine developed antibody endpoint titers between 3.5 and 5 logs. All rNT-DsrAI antisera bound the surface of the two H. ducreyi strains used to challenge immunized pigs. Purified anti-rNT-DsrAI IgG partially blocked binding of fibrinogen at the surface of viable H. ducreyi. Overall, immunization with the passenger domain of the trimeric autotransporter adhesin DsrA accelerated clearance of H. ducreyi in experimental lesions, possibly by interfering with fibrinogen binding.
Reference:
https://www.sciencedirect.com/science/article/pii/S0264410X14006987]]> 2018-10-12 13:40:48 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292158145 The genome of an H. ducreyi strain that is virulent in humans izatianuar96 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292165578 The genome is composed of a single 1.7-Mb chromosome.Although there is substantial homology observed for many genes, there is little long-range conservation of the order of genes or operons in the chromosome when H. ducreyi is compared to these related species.
*Additional info
Chancroid vaccine may help reduce the transmission of HIV ]]> 2018-10-12 13:53:31 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292165578 Molecular methods for detection izatianuar96 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292168619 Simplified PCR for detection of Haemophilus ducreyi and diagnosis of chancroid.
Straightforward chloroform extraction sample preparation method.
A one-tube nested PCR to minimize contamination risks, and a colorimetric method for detection of products.
Primers were designed from published nucleotide sequences of the 16S rRNA gene of H. ducreyi. A pair of primers was selected from sequences of an anonymous fragment of DNA cloned from H. ducreyi.The primers were tested in amplification reactions with both purified DNA and lysed organisms for their ability to detect H. ducreyi, and with DNA from a variety of different bacteria for their specificity.
With longer outer primers for annealing at a higher temperature and shorter inner primers labelled with biotin and digoxigenin for binding with avidin and colorimetric detection. 
The adaptations of this simplified PCR strategy, at the sensitivity and specificity levels obtained, mean it will be useful for detection of H. ducreyi in areas where the organism is endemic, particularly where testing by culture is difficult or impossible.
Additional studies demonstrated that the failure of PCR to detect H. ducreyi in all of the culture-positive specimens probably resulted from inhibitors of the Taq DNA polymerase that were present in the nucleic acids extracted from the clinical specimen.]]> 2018-10-12 13:58:26 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292168619 Macrolides (antibiotic) for treatment of H ducreyi infection in sexually active adults izatianuar96 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292173663
There was no difference between the types of antibiotics in sexually active adults with genital ulcers compatible with chancroid. Erythromycin is usually the first choice for treatment but low quality evidence suggested that azithromycin (as a single dose, oral (by mouth) administration) had similar safety and effectiveness.

Because of sparse evidence about the safety and effectiveness of macrolides to treat Haemophilus ducreyi infection in people with HIV, these results should be taken with caution.

Macrolides are antibiotics that could be effective and safe for treating H ducreyi infection.
]]> 2018-10-12 14:07:06 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292173663 EPIDEMIOLOGY pkavesha5 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292224281
Generally, the global epidemiology of chancroid is poorly documented, and it is not included in World Health Organization estimates of the global incidence of curable sexually transmitted infections (STIs). 

Key challenges in interpreting data on the epidemiology of H. ducreyi as a causative agent of genital ulcer diseases (GUD):

 *genital herpes cases are easily misdiagnosed as chancroid on clinical examination (reports based only on clinical diagnosis can be invalid) 

* laboratory culture is technically difficult, and the highly sensitive and specific nucleic acid amplification tests, such as PCR, are rarely available outside national reference laboratories or specialized STI research settings (makes it difficult to confirm clinical diagnoses)

Determining the true global incidence of chancroid is made more difficult due to widespread adoption of syndromic management for bacterial GUD without microbiological confirmation in many countries.
*Example; treatment with antimicrobial drugs effective against syphilis and chancroid. 
Hence, countries often report only the total number of GUD cases.

Also, identification of GUD etiology is rarely conducted in resource-poor countries to validate syndromic management for which chancroid could also be common.

]]> 2018-10-12 15:35:22 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292224281 Statistics pkavesha5 https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292230203 2009- 2015, 0 number of reported cases in Malaysia (repersented by flat green line in the graph)]]> 2018-10-12 15:47:23 UTC https://padlet.com/alianuralissa/wpjj5vdkcf74/wish/292230203