Abstract
There are numerous studies on Neisseria gonorrhoeae due to the many diseases this bacterium is known to cause. Neisseria gonorrhoeae is an agent of gonorrhea which is transmitted through sexual intercourse and which is possible to treat at present, even though this infection constantly develops resistance towards the antibiotics which are commonly used for its treatment. As a rule, this infection affects the urogenital tract with symptoms for men and women being quite similar. The complications, however, are different for males and females; the consequences for the latter, especially in the neonatal period, are rather severe. This paper is going to present the taxonomy of this bacterium in detail, as well as discuss the issues related to Neisseria gonorrhoeae and the diseases which it causes.
Introduction
Neisseria gonorrhoeae is a species of Gram-negative agents of gonorrhea, a disease which became quite widespread these days. Albert Neisser was the first to discover this bacterium in 1879. Concerning its structure, it should be mentioned that Neisseria gonorrhoeae is protected by the multilayer capsule which covers the membrane responsible for preserving the internal structure of the gonococcus. Gonococcus may be active both in the intercellular space and beyond the cell surface. The taxonomy of Neisseria gonorrhoeae reveals the complexity of this species; apart from this taxonomy, the paper will also present the pathogenesis of Neisseria gonorrhoeae infection and the methods of treating the diseases which it may cause.
Taxonomy
Neisseria gonorrhoeae as a bacterium can be discussed concerning its Genus, Family, Order, Class, Phylum, and Domain. The Genus of Neisseria gonorrhoeae is Neisseria which presents a vast family of commensal bacteria with one of the species, N. gonorrhea, being able to cause gonococcal infections, often asymptomatic. Neisseria is gram-negative cocci which occur singly “but more often in pairs with adjacent sides flattened; one species (N. elongate) is an exception and consists of short rods 0.5 µm wide, often arrange as diplobacilli or in short chains” (1). The whole family is often referred to as Neisseriaceae with many organisms which this family comprises being a part of normal flora. However, Neisseria gonorrhoeae which belongs to this family is a human symbiotic pathogen this is why its presence in normal flora causes infection. The Order of Neisseria gonorrhoeae is the Neisseriales, while its class is Beta Proteobacteria which, apart from this pathogen, also contains phototrophs and some facultative bacteria (1). The Phylum to which Neisseria gonorrhoeae belongs is Protobacteria which is one of the major groups of bacteria consisting of pathogens and other types of bacteria. Finally, the Domain of Neisseria gonorrhoeae is Bacteria which comprise a vast variety of unicellular microorganisms of different shapes and species (1). Therefore, Neisseria gonorrhoeae Genus, Family, Order, Class, Phylum, and Domain give a better idea of this infection and contribute to identifying the diseases which it may cause.
Diseases Caused by Neisseria gonorrhoeae
Neisseria gonorrhoeae is the second common bacterial infection that is transmitted in the United States (2). It may cause a wide variety of diseases “including asymptomatic infection, urethritis, cervicitis, pelvic inflammatory disease, and disseminated gonococcal infection” (3). Gonorrhea is the main disease caused by the bacterium under consideration, though it is also an agent of a range of other illnesses. Gonorrhea as such is transmitted sexually; its symptoms differ with males and females through the ways to catch the infection are mostly the same. With men, the most common symptoms of gonorrhea are penile discharge which in some instances may be accompanied by scrotal pain and the presence of blood in the urine (often referred to as hematuria). Painful urination and vaginal discharge are common for women who have gonorrhea. The symptoms which can take place quite seldom are pain during sexual intercourse, fever, as well as vomiting, and abdominal pain. The symptoms of gonorrhea are not always evident, especially among women; they may be either absent at all or so insignificant that they are often ignored. For some people, the disease is asymptomatic. At this, men are less susceptible to this disease or, to be exact, they are more resistant to it.
Apart from these, Neisseria gonorrhoeae bacterium may also cause such diseases as orchitis, epididymitis, and urethritis in men, as well as endometritis, perihepatitis, cervicitis, and pelvic inflammatory disease in women; in both genders, the bacterium may cause pharyngitis, conjunctivitis, proctitis, etc (4). Thus, Neisseria gonorrhoeae bacterium may cause not only sexually transmitted diseases but the ones which have no relation to sexual intercourse. Therefore, sometimes Neisseria gonorrhoeae can cause the inflammation of the conjunctiva, which results in conjunctivitis. The main symptoms of this disease are redness and irritation of the eyes; in the case of viral conjunctivitis, the infection may spread to another eye or originate in the sore throat which should be treated first. Sometimes a conjunctival infection may occur through perinatal transmission or due to poor hygiene in adults (4). The throat inflammation due to Neisseria gonorrhoeae bacterium often results in pharyngitis; this disease is spread through direct contact, for instance, through inhaling air (and even vapor) where the microorganism is present.
In general, the number and complexity of diseases which N. gonorrhea may cause varies. This depends on the gender of the carrier and on how long the disease has not been treated. For instance,
… uncomplicated N. gonorrhoeae infection is usually confined to the mucosa of the cervix, urethra, rectum, and throat; N. gonorrhea infection is often asymptomatic among females; and, if untreated, N. gonorrhea infection can lead to PID, tubal infertility, ectopic pregnancy, and chronic pelvic pain. (5)
As far as the males are concerned, N. gonorrhoeae can also cause the inflammation of the urethra and epididymitis (rarely). Complications are also possible; if the infection is not treated in time, it may cause dermatitis tenosynovitis syndrome further complicated by arthritis or meningitis (5).
Treatment of Neisseria gonorrhoeae
Antibiotics are the most common means of treating the infection in question. Penicillin and tetracycline are the most widely used antibiotics. In 1963 one more antibiotic, nalidixic acid, was also used in treating gonorrhea, but it proved to be less efficient due to bacteria rapidly developing resistance to it. However, this medicine served as a basis for further research on gonorrhea treatment:
Modifications to nalidixic acid were made based on structure-activity relationships in the 1980s and these revisions, through adding fluorine to the 6 carbon, were responsible for improving activity of this newly formed fluoroquinolone to include Gram-positive organisms and more Gram-negative species, such as Pseudomonas aeruginosa and Neisseria gonorrhoeae. (6)
At present, uncomplicated gonorrhea is treated using an antibiotic regime of ciprofloxacin and ofloxacin, though the resistance of the bacteria to these preparations becomes disturbing every year (6).
Antimicrobial Resistance
In the case of Neisseria gonorrhoeae, antimicrobial resistance “occurs as chromosomally mediated resistance to a variety of antimicrobial agents, including penicillin, tetracycline, spectinomycin, and fluoroquinolones, and high-level, plasmid-mediated resistance to penicillin and tetracycline” (7). Generally, the treatment of the patients infected with the bacterium is successful, though the cases of resistance to such antibiotics as ofloxacin and ciprofloxacin have also been registered. Currently, the Centers for Disease Control and Prevention is sponsoring the Gonococcal Isolate Surveillance Project the aim of which is to research the resistance of Neisseria gonorrhoeae bacteria to the antibiotics it is treated with at present and to find the ways to fight this infection (7). So far, cephalosporin is mostly used in those cases when Neisseria gonorrhoeae is resistant to commonly used antibiotics.
Conclusion
Neisseria gonorrhoeae is a bacterium of the Neisseriaceae family and, though some members of this family are typical for normal flora, this bacterium is a pathogen that affects the human health and health of those who surround its carrier. It is not always that this infection has symptoms, which makes it even more dangerous because treating the advanced cases of such diseases like gonorrhea, for instance, is extremely complicated. This bacterium may cause not only gonorrhea which is mostly associated with it, but such diseases as proctitis, conjunctivitis, and pharyngitis as well. As a rule, this infection is treated with antibiotics. In the last decades, however, Neisseria gonorrhoeae became resistant even to the newest antibiotics, which is why the Centers for Disease Control and Prevention has initiated a program aimed at developing medicine to which this infection will not be resistant.
Reference List
Bergey, D.H. & Holt, J.G. (1994). Bergey’s manual of determinative bacteriology, 9th edition. London: Lippincott Williams & Wilkins: 91: 91-149.
Pol, B.V.D., Ferrero, D.V., Buck-Barrington, L., Hook, E., Lenderman, C. Quinn, T. (2000). Multicenter Evaluation of the BDProbeTec ET System for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in UrineSpecimens, Female Endocervical Swabs, and Male Urethral Swabs. Journal for Clinical Microbiology, 39(3): 1008-1016. Web.
Ram, S., Sharma, A.K., Simpson, S.D., Gulati,S., McQuillen, D.P., Pangburn, M.K. (1998). A Novel Sialic Acid Binding Site on Factor H Mediates Serum Resistance of Sialylated Neisseria gonorrhoeae. The Journal of Experimental Medicine, 187(5): 743. Web.
Global strategy for the prevention and control of sexually transmitted infections, 2006-2015. (2006). Web.
Johnson, R.E., Newhall, W.J., Papp, J.R., Knapp, J.S., Black, C.M., Gift, T.L. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections. 2002.
Stancik, D.M. (2001). Emerging quinolone and antibiotic resistance to Neisseria gonorrhoeae. Web.
Neisseria gonorrhoeae reference strains for antimicrobial susceptibility testing. (2005).
Footnotes
- Bergey, D.H. & Holt, J.G. (1994). Bergey’s manual of determinative bacteriology, 9th edition. London: Lippincott Williams & Wilkins: 91: 91-149.
- Pol, B.V.D., Ferrero, D.V., Buck-Barrington, L., Hook, E., Lenderman, C. Quinn, T. (2000). Multicenter Evaluation of the BDProbeTec ET System for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in UrineSpecimens, Female Endocervical Swabs, and Male Urethral Swabs. Journal for Clinical Microbiology, 39(3): 1008-1016. Web.
- Ram, S., Sharma, A.K., Simpson, S.D., Gulati,S., McQuillen, D.P., Pangburn, M.K. (1998). A Novel Sialic Acid Binding Site on Factor H Mediates Serum Resistance of Sialylated Neisseria gonorrhoeae. The Journal of Experimental Medicine, 187(5): 743. Web.
- Global strategy for the prevention and control of sexually transmitted infections, 2006-2015. (2006). Web.
- Johnson, R.E., Newhall, W.J., Papp, J.R., Knapp, J.S., Black, C.M., Gift, T.L. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections. 2002.
- Stancik, D.M. (2001). Emerging quinolone and antibiotic resistance to Neisseria gonorrhoeae. Web.
- Neisseria gonorrhoeae reference strains for antimicrobial susceptibility testing. (2005).