Running Head: CHLAMYDIA TRACHOMATIS
1
Chlamydia Trachomatis Chlamydia trachomatis is a bacterium that appears in multiple ways. Some of the most common manifestations of the bacterium are in the form of trachoma, nongonococcal urethritis, lymphogranuloma, cervicitis, and pelvic inflammatory disease (Elwell, Mirrashidi, and Engel, 2016). Among sexually transmitted bacteria, Chlamydia is the leading cause of blindness. There are many types of Chlamydia trachomatis. The most common species are found in the genital tract (Malhotra et, al. 2013, Elwell, Mirrashidi, and Engel, 2016), while others are located in the eye and lymph nodes. This essay looks at Chlamydia, its morphology, adaptation, and the harm it does to the human body. The discussion herein focuses on genes of Chlamydia and breaks down unearthed myths concerning the bacteria and its infections. Morphological physiology Song et al. (2013) explain how Chlamydia is classified. C. trachomatis, like any other species, has distinct advancements and growth. The morphological distinction between C. trachomatis and other species is that it has two distinct morphological stages; elementary bodies (EB) and reticulate bodies (RB). Elementary bodies refer to a bacterium that is spore-like and infectious; in contrast, reticulate bodies refer to those that are of a replicative stage and only seen in the body of the host. C. trachomatis is a gram-negative bacterium that multiply only within the body of the host. In the course of its life cycle, C. trachomatis takes two different forms. Elementary bodies measure between 200 and 400 nanometers in length, and a firm cell wall surrounds them, allowing them to survive outside the host. Elementary bacteria can cause a new infection when in contact with a potential host. Reticulate bodies, on the other hand, are between 600 and 1500 nanometers across and only found within a host. Neither of the forms is motile (the ability of a cell to move spontaneously).
CHLAMYDIA TRACHOMATIS
2
Genetic nuance The C. trachomatis genome is generally smaller than that of other similar bacteria with an approximation of 1.04 megabases and encoding about 900 genes. Metabolic functions essential for any living organism are not encoded in the C. trachomatis genome but drawn from the host cell in, the chromosome carrying most of the genetic information for the bacteria in almost all C. trachomatis types carries a 7.5 kilobase plasmid with eight genes. The plasmid primary purpose is unknown. However, traits without the plasmid isolate suggesting and survive, indicating the plasmid is not necessary for the survival of the C. trachomatis bacteria. Pathophysiology Like every other Chlamydia species, this Chlamydia species has a life span with the two morphological stages. The C. trachomatis bacteria attaches itself to the host cell as a spore-like body and enters the host though a vacuole known as an inclusion. In the inclusion, the C. trachomatis metamorphosizes into a greater, more metabolic form known as a reticulated form. This body modifies the inclusion creating a more hospitable environment where it can rapidly multiply. This metabolic process happens withing 30 and 72 hours of the bacteria entering the body. The process creates millions of bacteria so fast that within the said hours, there are massive numbers of it in the host. The intracellular bacterium now transitions back to elementary forms but with more resistance. As they continue to multiple, the cell rapture releasing the bacteria into the environment of the cell. The bacteria are released during ejaculation in men or emitted from epithelial cells found in the female genitalia tract and cling to any host cells surrounding the cervix cells. Taxonomy
CHLAMYDIA TRACHOMATIS
3
C. trachomatis is in the genus class of Chlamydia, an intracellular parasite of eukaryotic cells. Chlamydia cells do not have any metabolic energy as they rely on their host. They also lack biosynthetic pathways. C. trachomatis has three main biovars depending on the type of disease caused. They then subdivide into multiple serovars based on surface antigens released by the immune system. Serovars A to C causes trachoma, the leading cause of blindness in the world. Serovars D through K affects genital tracts leading to pelvic inflammatory disease, infertility, and ectopic pregnancies. In addition, serovars L1 to L3 invade lymph nodes around the genitalia known as lymphogranuloma venereum. C. trachomatis came from various Chlamydia species from 6 million years ago. This gene is made up of nine species known as C. trachomatis. C. muridarum, C. suis, C. abortus, C pneumoniae, C. pectorum, C. caviae, C. felis, and C. psittaci. C. trachomatis is closely related to C. muridarum dominant in mice. C. trachomatis and C. pneumoniae are the species known to bring infections to humans to a broader extent with C. trachomatis, specifically affecting only humans. C. pneumoniae has been found in other species, such as frogs, horses, and marsupials. The larger scope of Chlamydia can potentially affect human health and are classified under zoonotic transmissions (Knittler, and Sachse, 2015). Epidemiology Nunes and Gomes (2014) state genital Chlamydia infections in the US are mainly reported as bacterial infections and is the most common infection that is sexually transmitted globally. Overall, the rate of urogenital infection among women in the US is twice that of men with the bacteria. Women between the age of 15 and 24 report more cases than men aged between 20 and 24 (CDC) Infectivity
CHLAMYDIA TRACHOMATIS
4
Intracytoplasmic inclusions and free Chlamydiae are similar in Giemsa-stained cell makeups scraping from the eye. Those strained conjunctival scrapings usually turn up positive in 90% of children born with congenital conjunctivitis and half of the adults with inclusion conjunctivitis. There are techniques to identify endocervical scrapings such as cytology. Sensitivity and specificity are, however, low (Boiko et, al 2014). Signs, symptoms and treatment Symptoms and signs of a C. trachomatis infection in genitals appear distinguishable from other sexually transmitted diseases. The infection usually is confused with symptoms of gonorrhea as they both cause other conditions such as pelvic inflammatory disease and urethritis (LeFevre, 2014). C. trachomatis is the primary leading agent linked with blindness (trachoma) and is responsible for 19% of inclusion conjunctivitis in adults. When a patient has C. trachomatis infection, lungs show signs of Chlamydia pneumoniae, a respiratory infection for all ages. Presentation Most patients with C. trachomatis are asymptomatic, but the bacteria occur in any of these ways; lungs, genitals, and eyes, as stated earlier. Symptoms of genital infections include genital discharge, itchiness, vaginal bleeding, painful urination, among others. These symptoms reflect more often as a urinary tract infection (Cossé, Hayward, and Subtil, 2016). When C. trachomatis affects the eyes, it forms trachoma and begins to gradually thicken the eyelids, eventually pulling the lashes into the eyelid. In inclusion conjunctivitis, the bacteria present it with redness, swelling, discharge from the eye (mucopurulent). When in the lungs, C. trachomatis presents itself in the form of a lung infection and shows infections such as low-grade fever, stuffy nose,
CHLAMYDIA TRACHOMATIS
5
shivers, and hoarseness of voice, similar to those of pneumonia. C. trachomatis infects villi tissues in expectant women and impact pregnancy outcomes such as ectopic pregnancy (Kuo et al. 2015) Prevalence Women are diagnosed three times as much with C. trachomatis, especially genitourinary Chlamydia than men. Women in their teen years, 15-19 have the highest rate of infection, followed by those between 20 and 24 years (Torrone, Papp, and Weinstock, 2014). Such differences happen due to a lack of diagnosis in men as men are carriers of the bacteria. Risk factors for Chlamydia include but not limits to unprotected sex with multiple partners, not using a condom, lack of education and knowledge of proper and safe sexual practices, and low-income strata for people living in town centers. Pulmonary infections in infants occur as the bacteria can be transmitted through pregnancy. Women with active Chlamydia infections infect less than 10% of infants. Ocular infections occur as inclusion conjunctivitis or trachoma in both adults and children (Boiko et al. 2014). More than eighty -four million people suffer from Chlamydia eye infections resulting in the blinding of about 8 million of that population. In rural parts of Africa and Asia, trachoma is the leading cause of blindness, yet little is done in tropical zones. The world health organization targets to eliminate Chlamydia by 2020 (CDC).
Treatment and measurement.
CHLAMYDIA TRACHOMATIS
6
The treatment of C. trachomatis depends on a variety of factors such as the age of the patient, infection site, and prevalence of a similar infection. It is possible to have C. trachomatis and other sexually transmitted diseases as a different factor that causes each disease. Treatment occurs to both partners to completely kill the bacteria and avoid re-occurrence. Antibiotics such as azithromycin, erythromycin, ofloxacin, and tetracycline are used to treat it. Tetracycline is the best antibiotic against Chlamydia as it has a high success rate when compared against other antibiotics. Azithromycin dose is a 1-gram tablet taken orally as a single dose. Erythromycin is not a choice for treatment due to its side effects that lead to no-adherence. When medication is unavoidable during pregnancy, levofloxacin ofloxacin is avoided. Tetracycline is also not administered as most adults and children do not withstand it, and it has severe side effects for the unborn baby (Geisler et al. 2015). A pregnant woman needs to retest after three weeks to identify whether the bacteria are all out. Virulence When left unchecked, Chlamydia progresses into the reproduction system and develops into pelvic inflammatory. Upon developing further, it damages the fallopian tube, which is irreversible if highly affected. Treatment usually is done on an outpatient basis. Unchecked Chlamydia in pregnancy leads to premature tearing of uterine membranes, neonatal infection, preterm labor, and postpartum endometritis.
Conclusion
CHLAMYDIA TRACHOMATIS
7
The consequences of C. trachomatis infection differ from person to person. Despite all efforts done to prevent the occurrence of the bacteria in women, the rate continues to soar with more cases reported annually. There have been efforts to develop a vaccine for Chlamydia (Brunham, and Rappuoli, 2013). With over 220 vaccines tested on the infection. The main barrier to attaining an effective vaccine stems from the individualization of the bacteria as it takes the molecular structure of the host. Its mutation changes with every new host making it increasingly difficult to find a baseline for developing a vaccine. A more profound comprehension of differences between women concerning factors influencing the consequences of Chlamydia in genitourinary infection and utilizing this knowledge is the call needed to develop more personalized and focused treatment thereby reducing any occurrence
CHLAMYDIA TRACHOMATIS
8
References Boiko, E. V., Pozniak, A. L., Maltsev, D. S., Suetov, A. A., & Nuralova, I. V. (2014). Chronic ocular Chlamydia trachomatis infection in rabbits: clinical the posterior segment. Investigative
and histopathological findings in
ophthalmology & visual science, 55(2), 1176-1183.
Brunham, R. C., & Rappuoli, R. (2013). Chlamydia trachomatis control requires a vaccine. Vaccine, 31(15), 1892-1897. Centers for Disease Control and Prevention. (2014). Recommendations for the
laboratory-
based detection of Chlamydia trachomatis and Neisseria gonorrhoeae--2014. MMWR. Recommendations and reports: Morbidity and mortality weekly report. Recommendations and reports, 63(RR-02), 1. Cossé, M. M., Hayward, R. D., & Subtil, A. (2016). One face of Chlamydia infectious elementary body. In Biology of Chlamydia (pp.
trachomatis: the
35-58). Springer, Cham.
Elwell, C., Mirrashidi, K., & Engel, J. (2016). Chlamydia cell biology and pathogenesis. Nature Reviews Microbiology, 14(6), 385. Geisler, W. M., Uniyal, A., Lee, J. Y., Lensing, S. Y., Johnson, S., Perry, R. C., ... & Kerndt, P. R. (2015). Azithromycin versus doxycycline for urogenital infection. New England Journal of Medicine, 373(26),
Chlamydia trachomatis
2512-2521.
CHLAMYDIA TRACHOMATIS
9
Knittler, M. R., & Sachse, K. (2015). Chlamydia psittaci: update on an
underestimated
zoonotic agent. Pathogens and disease, 73(1), 1-15. Kuo, C. C., Stephens, R. S., Bavoil, P. M., & Kaltenboeck, B. (2015).
Chlamydia. Bergey's
Manual of Systematics of Archaea and Bacteria, 1-28. LeFevre, M. L. (2014). Screening for chlamydia and gonorrhea: US Preventive Force recommendation statement. Annals of internal
Services Task
medicine, 161(12), 902-910.
Malhotra, M., Sood, S., Mukherjee, A., Muralidhar, S., & Bala, M. (2013). Genital Chlamydia trachomatis: an update. The Indian journal of medical
research, 138(3), 303.
Nunes, A., & Gomes, J. P. (2014). Evolution, phylogeny, and molecular epidemiology of Chlamydia. Infection, Genetics and Evolution, 23, 49-64. Song, L., Carlson, J. H., Whitmire, W. M., Kari, L., Virtaneva, K., Sturdevant, D. E., ... & McClarty, G. (2013). Chlamydia trachomatis plasmid-encoded Pgp4 is regulator of virulence-associated genes. Infection and
a transcriptional
immunity, 81(3), 636-644.
Torrone, E., Papp, J., & Weinstock, H. (2014). Prevalence of Chlamydia trachomatis genital infection among persons aged 14–39 years—United Morbidity and mortality weekly report, 63(38), 834.
States, 2007–2012. MMWR.