Neisseria gonorrhoeae and its characteristics
One of the greatest health care concerns of the present day in both developing and developed nations is the variety of different communicable outbreaks. Communicable outbreaks have been increasing excessively and threat of the communicable outbreaks is fast becoming the greatest public health priorities. It has to be mentioned in this context that both global and national health authorities have attempted to reduce and manage the extent of the outbreaks, however despite the international strategies being planned and executed frequently, the rate of communicable diseases continue to escalate (Unemo and Shafer 2014).
Among the most common communicable outbreaks, the sexually transmitted infection by the Neisseria gonorrhoeae can be categorized as a global concern. According to the recent statistics, the one of the five most frequently reported communicable infections has been caused by this pathogen (www.who.int 2018). Along with that, the predominance of this particular pathogen is exceptionally high in the rest of the nations as well. The prevalence of Neisseria gonorrhoeae infection in the United States is considered to be the second highest, and in the developing countries the condition is far worse, for instance, UK is accountable for close to 60% of the total sexually transmitted diseases reported in England per annum (Gov.uk., 2018). One of the most crucial contributing factors behind the excessive prevalence of this communicable disease can be the unique characteristics features of the pathogen and its pathogenecity. This assignment will attempt to analyse the pathogen, its epidemiological demographics, host preference analysis and critical pathogenecity.
Neisseria gonorrhoeae and its characteristics:
Neisseria gonorrhoeae can be described as a gram negative diplococcal bacterial species also known as gonococcus is singular and gonococci in the plural sense (Liu, Feinen and Russell 2011). The pathogen causes the genitor- urinary infectious diseases called gonorrhoea which is one of the most common and frequently observed or reported sexually transmitted communicable diseases. However, apart from this particular disease, different strains of this infectious pathogenic entity are also known to cause other infectious diseases like the disseminated gonococcemia, septic arthritis, and gonococcal ophthalmia neonatorum (Johnson and Criss 2011).
(sources: Liu, Feinen and Russell 2011)
Considering the anatomical features of the pathogen, the pathogen can be characterized by the unique set of surface proteins it has. This pathogen has been reported to bear hair like Pili on the surface of its body that helps in the adherence, mobility and genetic material exchange for the bacterial pathogen. The surface lipooligosaccharides of the pathogen is a unique endotoxin that along with the Opa proteins, porins and the pili help in inhibiting the immune response of the host and facilitates the process of symptomatic infection. It has to be mentioned that these unique and considerably rare phenomenon of asymptomatic infection in the initial stages of infection is the main reason behind the increasing morbidity due to this disease (Unemo and Shafer 2011). Hence, these characteristics features have been pegged my many authors as the key contributors of the increased pathogenecity of the Neisseria gonorrhoeae.
Epidemiological demographics and prevalence of the pathogen
(figure source: Liu, Feinen and Russell 2011)
Epidemiological demographics and prevalence of the pathogen:
Neisseria gonorrhoeae is a highly infectious obligate human pathogen and can be very widely found in all parts of the world. According to the most of the authors, the global burden of this particular pathogen is due to the lack of diagnostic capability of the different developing parts of the nation. Along with that, it also has been argued by another school of thought is the initial phases of asymptomatic infection phase is the main reason behind the increased predominance of this pathogen. According to the recent report published by the world health organization, the global incidence rate of the successful infection of the pathogen Neisseria gonorrhoeae is 106 million individuals, and based on this research studies have pointed out that the incidence rate of this particular infection has increased by 21% in the past decade (World Health Organization., 2018). Along with that, the WHO report also indicated at the fact that the risk factor this infectious pathogen is the highest in the developing nations like Africa and the western pacific nations like the China and Australia. Now coming to the developed nations, the prevalence of this pathogen in the United States is frightening. According to the Unemo et al. (2011), the Neisseria gonorrhoeae infection is the second most frequently reported sexually transmitted communicable disease. Along with that, the past couple of years has seen close to 400 thousand cases of Neisseria gonorrhoeae infection reported in the united states. However, the research authors have stated that the actual incidence can refer more or less due to many unreported cases and cases to asymptomatic infections leading to morbidity. Considering the statistics of Neisseria gonorrhoeae infection in UK, close to 67000 cases were reported in all of Europe, where as UK contributed to 58% of the total percentage, which is significantly frightening. The male to female ratio for STD incidence rate in case of the Neisseria gonorrhoeae infection in UK is 2:7:1 (Gov.uk., 2018).
(figure source: Unemo et al. 2010) (figure source: Gov.uk., 2018)
Coming to the age specific demographic data, it has to be mentioned that, in case of UK, the highest level of increase in the incidence rate has been for the 45- year old age groups at 2.7 folds. However, two other age groups, 35 to 44 years old and 25-34 year olds have seen a considerable increase in the incidence rate as well (Hughes and Field 2015). However, in a more broader sense of the idea, many authors have commented that all the risk groups have encountered a considerable rise in the incidence rate overall, and the lack of health literacy, awareness and lifestyle patterns can be the most significant contributing factors (Allen et al. 2013).
Brief idea of the host
(figure source: CDC 2012)
Brief idea of the host:
The most important characteristics feature of this pathogen is the fact that the pathogen is essentially a human pathogen. It has to be mentioned in this context that the pathogen only affects the humans and does not affect the animals or experimental animals, and along with that it has to be mentioned that the host system is essential for the survival of the pathogen, Neisseria gonorrhoeae can into survive freely in the environment. According to the Allen et al. (2013), tis sexually transmitted disease caused by Neisseria gonorrhoeae can occur to all different age groups. However, it has to be mentioned that this pathogenic agent causes asymptomatic infection in the 80% of the cases for females and 10% of the cases of the males. According to the authors, it has to be mentioned that the males in case of this infection start to show the symptoms within 5 to 7 days of incubation, however, the signs and symptoms can vary between male of female hosts. In case of the males the signs and symptoms, include swelling of the urethra, painful and frequent urination, irregular penal discharge of pus. In case of the females, the signs and symptoms include chronic abdominal pain, inflamed cervix, and bleeding due to painful urination.
The main sites of infection for the pathogen are the urethra, cervix, rectum and the throat of the host. And the main reason behind is the fact that the pathogen can only survive in an environment with CO2. According to the authors, the urethral discharge contains the bacteria within the polymorphs. These bacteria do not contain and capsule and hence are sensitive to the dehydration and colder environments. Yet the pathogenecity of the bacteria is extremely high and there have been many treatment pathways developed to control the infection, however the resistance of the pathogen has only led to many failures; and the pathogenecity of the bacteria can be only clue to finding better treatment procedures (Unemo and Shafer 2011).
Critical analysis of the pathogenecity:
As stated by the Allen et al. (2013), Neisseria gonorrhoeae is the pathogen that has been categorized ti be pathogenic at all times and the pathogenic properties of the bacteria are considered to be deadly. It has to be mentioned in this context that this pathogen is never found in the normal human body flora and hence in order to understand the pathogenecity effectively, the mode of transmission needs to be discussed. This pathogen is mainly sexually transmitted, however the neonates can also acquire infection from the mother by the passage through the birth canal..
Critical analysis of the pathogenecity
However, many authors have commented on the fact that the extreme pathogenecity of the pathogen is due to the combination of the virulence factors expressed by it. The main point of entry for this pathogen is the mucous membranes and the type Iv Pili mediate the successful attachment of the bacteria to the mucosal cell surface. This idea is further supported by the research findings of many others, furthermore, many authors have argued that the pili of the pathogen are anti-phagocytic and are able to twitch and form bundles to exchange DNA, acting as a potent virulence factor and aiding in the process of successful infection. An argument by the Edwards and Butler (2011), indicate the fact that there are other more factors that play a profound role in the mucosal attachment of the bacteria, other than the antiphagocytic pili. On a more elaborative note, it has also been reported that the lipooligosacharides or the LOS in combination with the IgA protease secreted by the pathogen acts as the key mediator in the mucosal attachment of the pathogen. This protease has been reported to hydrolyse the secretory IgA by the host, and very easily overcome the resistance to mucosal membrane of the host.
The next phase of the pathogenesis is the bacteria targeting the epithelial cells that are columnar and non-ciliated. This infection procedure has many factors that facilitate it, according to one school of thought, the outer membrane proteins and Opa proteins play the crucial pat in mediating the invasion of the pathogen to the epithelial cells. However, as argued by the Ohnishi et al. (2011), the pilE virulence gene is the key mediator for the successful invasion and has been reported to guide the signalling of the porin A protein (Goytia, Dhulipala and Shafer 2013).
A contradictory school of thought has explained that the key role of the pile gene is not in the invasion procedure itself, instead the most crucial role by the pathogen is in the adherence of the pathogen to the epithelial cells. Many authors have supported this school of thought; moreover, a study has revealed that a mis-sense mutation in the pilE gene causes a altered fibre morphology, which then eventually leads to a defective filament assembly. Due to these two alterations that pathogen is unable to form as strong adherence to the epithelial cells, hence it can be stated that pilE gene plays a profound role in the mode of entry to the epithelial cells of the host.
The next and final step of the pathogenesis phase of the pathogen is the replication of the pathogens inside the epithelial cells that then leads to cellular death that is triggered by the lipopolysachharides, and which then triggers the destruction of the ciliary beat, which then affects the host response effectively. As per the authors, following the impairment of the ciliary cells, the pathogens cannot be cleared from the mucosal membrane by any means. Following that the pathogen undergoes parasite directed endocytosis and within these cells the pathogen replicate. This is another key factor by which the bacteria maintains its high virulence; according to the authors, the bacteria replicated within the non-ciliated cells that act like the phagocuytes and within the protective environment of the vacuoles they avoid the defence mechanism of the hot completely, be it the hosts or any antimicrobial agents.
As explained by the Ison et al. (2011), the pathogenecity of the Neisseria gonorrhoeae is further heightened by the fact that hosts are not able to build any immunity to second infection. A key contributing factor to this is the ability of the pathogen to undergo multiple antigenic variations that rearranges the surface proteins of the pathogen. The virulent Pilin genes have also been reported to undergo genetic rearrangement leading to new variants with better virulence. In support, the Whiley et al. (2012), state that the new serotypic expression of the bacteria after frequent antigenic rearrangements and altered genotypic expression is the main contributing factor behind the ability of the pathogen to evade any host immune response effectively and repeatedly.
Conclusion:
On a concluding note, it can be mentioned that there are various school of thoughts regarding the increased pathogenecity of the Neisseria gonorrhoeae. Whereas some research, studies recommend the pathogenecity to be due to the genetic mechanism of the pathogen. On the other hand, the serotypic rearrangements and asymptomatic infectious properties are regraded as the main contributing factor behind the increased pathogenecity and resistance to all possible treatment options. According to the recent studies, the pathogenic strain has developed resistance to even fluroquinolone. Although, the centre for disease control has now started recommendation of dual therapies for Neisseria gonorrhoeae infection, the pathogen is expected to grow immune to these therapies as well. Hence, there is need for further research studies investing in discovering the key factors of the process of pathogenesis and the virulence factors of the pathogen, so that better treatment options can be derived.
References:
Allen, V.G., Mitterni, L., Seah, C., Rebbapragada, A., Martin, I.E., Lee, C., Siebert, H., Towns, L., Melano, R.G. and Low, D.E., 2013. Neisseria gonorrhoeae treatment failure and susceptibility to cefixime in Toronto, Canada. Jama, 309(2), pp.163-170.
Cahoon, L.A. and Seifert, H.S., 2013. Transcription of a cis-acting, noncoding, small RNA is required for pilin antigenic variation in Neisseria gonorrhoeae. PLoS pathogens, 9(1), p.e1003074.
Centers for Disease Control and Prevention (CDC, 2011. Cephalosporin susceptibility among Neisseria gonorrhoeae isolates–United States, 2000-2010. MMWR. Morbidity and mortality weekly report, 60(26), p.873.
Centers for Disease Control and Prevention (CDC, 2012. Update to CDC’s Sexually transmitted diseases treatment guidelines, 2010: oral cephalosporins no longer a recommended treatment for gonococcal infections. MMWR. Morbidity and mortality weekly report, 61(31), p.590.
Edwards, J.L. and Butler, E.K., 2011. The pathobiology of Neisseria gonorrhoeae lower female genital tract infection. Frontiers in microbiology, 2, p.102.
Gov.uk. (2018). Public Health England – GOV.UK. [online] Available at: https://www.gov.uk/government/organisations/public-health-england [Accessed 5 Feb. 2018].
Gov.uk. (2018). Sexually transmitted infections (STIs): annual data tables – GOV.UK. [online] Available at: https://www.gov.uk/government/statistics/sexually-transmitted-infections-stis-annual-data-tables [Accessed 5 Feb. 2018].
Goytia, M., Dhulipala, V.L. and Shafer, W.M., 2013. Spermine impairs biofilm formation by Neisseria gonorrhoeae. FEMS microbiology letters, 343(1), pp.64-69.
Hughes, G. and Field, N., 2015. The epidemiology of sexually transmitted infections in the UK: impact of behavior, services and interventions. Future microbiology, 10(1), pp.35-51.
Ison, C.A., Hussey, J., Sankar, K.N., Evans, J. and Alexander, S., 2011. Gonorrhoea treatment failures to cefixime and azithromycin in England, 2010. Eurosurveillance, 16(14), p.19833.
Jennings, M.P., Jen, F.E.C., Roddam, L.F., Apicella, M.A. and Edwards, J.L., 2011. Neisseria gonorrhoeae pilin glycan contributes to CR3 activation during challenge of primary cervical epithelial cells. Cellular microbiology, 13(6), pp.885-896.
Johnson, M. and Criss, A.K., 2011. Resistance of Neisseria gonorrhoeae to neutrophils. Frontiers in microbiology, 2, p.77.
Liu, Y., Feinen, B. and Russell, M.W., 2011. New concepts in immunity to Neisseria gonorrhoeae: innate responses and suppression of adaptive immunity favor the pathogen, not the host. Frontiers in microbiology, 2, p.52.
Ohnishi, M., Golparian, D., Shimuta, K., Saika, T., Hoshina, S., Iwasaku, K., Nakayama, S.I., Kitawaki, J. and Unemo, M., 2011. Is Neisseria gonorrhoeae initiating a future era of untreatable gonorrhea?: detailed characterization of the first strain with high-level resistance to ceftriaxone. Antimicrobial agents and chemotherapy, 55(7), pp.3538-3545.
Unemo, Á., Golparian, D., Stary, A. and Eigentler, A., 2011. First Neisseria gonorrhoeae strain with resistance to cefixime causing gonorrhoea treatment failure in Austria, 2011. Eurosurveillance, 16(43), p.19998.
Unemo, M. and Shafer, W.M., 2011. Antibiotic resistance in Neisseria gonorrhoeae: origin, evolution, and lessons learned for the future. Annals of the New York Academy of Sciences, 1230(1).
Unemo, M. and Shafer, W.M., 2014. Antimicrobial resistance in Neisseria gonorrhoeae in the 21st century: past, evolution, and future. Clinical microbiology reviews, 27(3), pp.587-613.
Unemo, M., Golparian, D., Syversen, G., Vestrheim, D.F. and Moi, H., 2010. Two cases of verified clinical failures using internationally recommended first-line cefixime for gonorrhoea treatment, Norway, 2010. Eurosurveillance, 15(47), p.19721.
Whiley, D.M., Goire, N., Lahra, M.M., Donovan, B., Limnios, A.E., Nissen, M.D. and Sloots, T.P., 2012. The ticking time bomb: escalating antibiotic resistance in Neisseria gonorrhoeae is a public health disaster in waiting. Journal of Antimicrobial Chemotherapy, 67(9), pp.2059-2061.
World Health Organization. (2018). United Kingdom. [online] Available at: https://www.who.int/countries/gbr/en/ [Accessed 5 Feb. 2018].
www.who.int (2018). Who.int. Available at: https://www.who.int/mediacentre/factsheets [Accessed 5 Feb. 2018]
Order an Essay Now & Get These Features For Free:
Turnitin Report
Formatting
Title Page
Citation
Outline
