Diagnosis & treatment Of Chlamydia Infection

Ans. is a i.e. Azithromycin and contact tracing

 Management :

• Azithromycin + contact tracing is the treatment of choice.
• In pregnancy drug of choice is erythromycin and second drug of choice is amoxicillin.

Partner should also be treated in chlamydial infection.

Tetracycline

The most common organisms causing urethritis in men are Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium.

The syndromic management of urethral discharge includes treatment of Neisseria gonorrhoea and Chlamydia trachomatis.

The treatment given includes ceftriaxone and azithromycin which are directed against N.gonorrhoeae and C.trachomatis.

Most common bacterial cause of urethritis is Neisseria gonorrhoeae.

Most common cause of non-gonococcal uretheritis is Chlamydia trachomatis.

Ref: Sexually Transmitted Infections: Diagnosis, Management and Treatment By Jonathan M. Zenilman, Page 400; CURRENT Diagnosis and Treatment of Sexually Transmitted Diseases, Chapter 3.

Chlamydia species are obligate intracellular bacteria that require growth inside mammalian cells for propagation and survival.

As a result, Chlamydia cannot be grown on conventional bacteriological medium.

Yolk sac inoculation is used for diagnosing chlamydia from tissue specimen.

Macchiavello was the first to describe the isolation of C.

trachomatis in embryonated hens’ eggs, McCoy cells (mouse fibroblasts), HeLa 229 (derived from human cervical carcinoma cells) and BHK-21 cells (baby hamster kidney cells) are the cell types regularly used for the culture of C. trachomatis.

Ref: Quality Control of Veterinary Vaccines in Developing Countries, Page 141 ; Textbook of Ophthalmology By Sunita Agarwal, Athiya Agarwal, David J Apple, Volume 2, Page 858 ; Harrison’s Principles of Internal Medicine, 17th Edition, Page 1074

Ligase chain reaction (LCR) or polymerase chain reaction (PCR) are the most sensitive NAA methods.

  Isolation of C trachomatis has been the gold standard for diagnosis, but it is clear that it is less sensitive than specific nucleic acid amplification (NAA) assays. 

Culture is usually performed using idoxuridine or cycloheximide treated McCoy cells.

C trachomatis inclusions contain glycogen and are stainable with iodine

Serodiagnosis not helpful for most genital infections.

Detection of IgM antibodies against C trachomatis is helpful in cases of infant pneumonitis. 

Ref: Ray C.G., Ryan K.J. (2010). Chapter 39. Chlamydia. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.

If Chlamydia Trachomatis is suspected or diagnosed, both the patient and the partner should be treated. Recommended therapy includes azithromycin 1g orally in a single dose or doxycycline 100mg orally twice daily for 7 days.

Ref: Harrison’s Principles of Internal Medicine, 15th Edition, Page 1001 ; Current Obs and Gynae Diagnosis and Treatment, 9th Edition, Pages 652-3

Azithromycin 1gm as a single dose is the drug of choice in Chlamydia infection during pregnancy.

As a prophylaxis to ophthalmia neonatorum 1% erythromycin ointment is applied to the infants eye soon following birth.

Neonatal infection is treated with erythromycin  for 14-21days.

Ref:  Williams Obstetrics, 23rd Edition, Page 1241; Practical Gynaecology, 2nd Edition, 2009, Page 200; Textbook of Obstetrics By DC Dutta, 6th Edition, Pages 294-5.

From the options listed in the question erythromycin is the drug used in the treatment of chlamydial infections in pregnancy.

Erythromycin should be given for 7-10days.

According to the latest recommendation  Azithromycin 1gm as a single dose is the drug of choice in Chlamydia infection during pregnancy.

As a prophylaxis to ophthalmia neonatorum 1% erythromycin ointment is applied to the infant’s eye soon following birth.

Neonatal infection is treated with erythromycin  for 14-21days.

Ref: Williams Obstetrics, 23rd Edition, Page 1241 ; Practical Gynecology, 2nd Edition, Page 200 ; Textbook of Obstetrics By DC Dutta, 6th Edition, Page 294-5

Ans. is ‘d’ i.e., Community acquired pneumonia 

Ans. is ‘b’ i.e., Enzyme immunoassay 

Ans. is ‘b’ i.e., Yolk sac 

Isolation of chlammydia

. Chlamydiae are obligate intracellular parsite, therefore cannot be cultured on nonliving artificial media (cell free media).

. Isolation of chalamydia can be done by inoculation into :‑

1. Embryonated eggs particularly in yolk.
2. Experimental animals
3. Tissue culture (cell culture, e.g., McCoy cells, HeLa cells).

.  Amongst these, cell culture is the preferred method of isolation.

Ans. is ‘c’ i.e., Polymerase chain reaction 

.  Nucleic acid probes have also been developed for use in amplification assay such as LCR and PCR. These tests are now the most sensitive chlamydial diagnostic methods available.

Ans. is ‘a’ i.e., HeLa; ‘c’ i.e., McCoy 

.   Cell culture is the prefered mode of isolation for chalamydia. Many cell lines are susceptible but those commonly used are McCoy and HeLa cells.

.   Cell cultures used for isolation are pretreated by irradiation or chemicals such as 5-iodo-2-dexoyuridine or cycloheximide to enhance chlamydial replication and facilitate detection of inclusion antibodies.

. Cell culture is usually used for the cultivation of viruses.

However, some bacterial can also be cultivated in cell culture

Bacteria growing in cell culture

.     Chlamydia trachomatis                          . Trophyrema whippeli

.     Rickettsiae                                                 . F. tularensis

.     Ureoplasma                                               . B. henselae

.     L. pneumophilia                                       . B. Quintana

.    B. melitensis

Ans. is ‘a’ i.e., Chlamydia trachomatis

. STD in man presenting with urethritis is usually caused by following organisms :-

. Neisseria Gonorrhoeae             . Ureaplasma urealyticum                 . HSV

. Chlamydia trachomatis          . Trichomonas vaginalis

.  So, from the options given in the question our choice comes to Neisseria gonorrhoeae and Chlamydia trachomatis.

.  Two points favour the diagnosis of chlamydia i.e.

a) Presence of pus cells with absence of any microorganisms on gram stain.

Chlamydia can’t be stained by ordinary stains,it needs to be stained by specialised stains.

b.)Chlamydia does not grows on Ordinary Culture and medium but can only be cultivated by cell lines(Mc.Coy) or Embryonated egg.

Answer is A (Erythromycin):

Erythromycin is the answer of choice here as Doxycycline has been not provided in the options.