MicrobiologyBytes

During the 1960s a ‘sexual revolution’ occurred in many Western human societies. In a similar fashion, mycologists now find themselves caught up in a fungal sexual revolution as previously accepted norms for fungal sex are being overturned. In particular need of reappraisal is the view that a significant number of fungal species are restricted solely to asexual reproduction. Fungi are unusual amongst eukaryotic organisms in that at least 20% of all species lack a known sexual state and instead appear to rely solely on asexual methods of reproduction. This is very surprising because a sexual phase in the life cycle, even if only intermittent, has several evolutionary advantages over purely asexual reproduction. In the specific case of fungi, sexual reproduction also confers the ability to produce dormant survival structures and a transient ‘capacitor’ diploid state that might allow selection of evolutionarily favourable sets of genes in a fitness ‘selection arena’.

However, recent experimental and genomic discoveries are now challenging the supposed asexual status of mitosporic fungi. Instead it is becoming apparent that many species have a previously unidentified ‘cryptic’ or ‘covert’ sexual state and are ‘holding back the truth’ about their sexuality. This review focuses on lessons being learnt from investigations involving Aspergillus and Penicillium species that are helping pave the way to fungal sexual realisation.

A fungal sexual revolution: Aspergillus and Penicillium show the way. Curr Opin Microbiol. Oct 25 2011
Fungi have some of the most diverse sex lives in nature, ranging from self-fertility to obligate outcrossing systems with several thousand different sexes, although at least 20% of fungal species have no known sexual stage. However, recent evidence suggests that many supposed ‘asexual’ species do indeed have the potential to undergo sexual reproduction. Using experimental and genomic findings from Aspergillus and Penicillium species as examples, it is argued that evidence such as the presence and expression of apparently functional sex-related genes, the distribution of mating-type genes, detection of recombination from population genetic analyses, and the discovery of extant sexual cycles reveal an on-going revolution in the understanding of fungal asexuality.

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The delightful NCBI ROFL carried this item recently. Certainly something to think about over the “festive” season.

Scent Recognition of Infected Status in Humans. J Sex Med. Dec 6 2011. doi: 10.1111/j.1743-6109.2011.02562.x
There is a body of experimental evidence that mice and rats use chemical signals to avoid sexual contact with infected conspecifics. In contrast to animals, body scent of sick humans is employed only in medical diagnostics. A modification of human body odor, due to an infection, has not been studied as a potential signal for choice of a sexual partner. It might, however, be especially important for sexually transmitted infections (STI) because many such infections have no obvious external manifestations.
Aim: In this study, we have investigated odor pleasantness of young men infected with gonorrhea, Neisseria gonorrhoeae.
Methods:We collected armpit sweat and saliva from young men (17-25 years old) belonging to three groups: healthy persons (N=16), young men infected with gonorrhea, Neisseria gonorrhoeae (N=13), and persons recovered due to specific therapy (N=5). The sweat samples odor was then assessed by healthy young women (17-20 years old). Concentrations of cortisol, testosterone, immunoglobulin A (IgA), and immunoglobulin G (IgG) were measured in saliva by means of enzyme-linked immunosorbent assay.
Main Outcome Measures: Subjective rates of odor pleasantness, association of scent of armpit sweat with odor descriptors, stepwise regression of odor pleasantness and salivary cortisol, testosterone, IgA, and IgG. Results: The odor from infected individuals was reported as less pleasant in comparison with the odor of healthy and recovered young men. The scent of infected men was more frequently associated by raters with the descriptor “putrid.” Odor pleasantness of the male sweat correlated negatively with concentration of the nonspecific salivary IgA and IgG, which was measured as an indicator of current immunoenhancement.
Conclusion: Perhaps, the immune-dependent reduction of the scent pleasantness in the acute phase of STI is part of an evolutionary mechanism ensuring, unconsciously, avoidance of a risky romantic partner.

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Partner notification is accepted as a vital component in the control of chlamydia. However, in reality, many sexual partners of individuals diagnosed with chlamydia are never informed of their risk. The newer technologies of email and SMS have been used as a means of improving partner notification rates. This study explored the use and acceptability of different partner notification methods to help inform the development of strategies and resources to increase the number of partners notified. Semi-structured telephone interviews were conducted with 40 people who were recently diagnosed with chlamydia from three sexual health centres and two general practices across three Australian jurisdictions. Most participants chose to contact their partners either in person (56%) or by phone (44%). Only 17% chose email or SMS. Participants viewed face-to-face as the “gold standard” in partner notification because it demonstrated caring, respect and courage. Telephone contact, while considered insensitive by some, was often valued because it was quick, convenient and less confronting. Email was often seen as less personal while SMS was generally considered the least acceptable method for telling partners. There was also concern that emails and SMS could be misunderstood, not taken seriously or shown to others. Despite these, email and SMS were seen to be appropriate and useful in some circumstances. Letters, both from the patients or from their doctor, were viewed more favourably but were seldom used. These findings suggest that many people diagnosed with chlamydia are reluctant to use the new technologies for partner notification, except in specific circumstances, and our efforts in developing partner notification resources may best be focused on giving patients the skills and confidence for personal interaction.

Telling partners about chlamydia: how acceptable are the new technologies? BMC Infectious Diseases 2010, 10:58 doi:10.1186/1471-2334-10-58

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• Chlamydia Infection
• UK chlamydia cases up in under-16s
• Low uptake of Chlamydia screening in the UK

The first publications exploring the interface between sexually transmitted infections (STIs) and the Internet appeared in the 26 July 2000 issue of the Journal of the American Medical Association. In one article, Klausner et al. described a cluster of early syphilis cases among men having sex with men (MSM) who had met each other online. In the second article in the same issue, McFarlane et al. reported on a survey among clients of the Denver HIV counseling and testing program, showing that among MSM visiting the site, 25% had sex with at least one partner first met on the Internet. Together, these articles suggested that the Internet was emerging as a new risk environment for STIs and HIV. Since the publication of these articles, numerous studies have been conducted and published that have further investigated the role of the Internet, both as an STI/HIV risk “venue” as well as a potential place for the delivery of STI/HIV prevention services.

In recent years, the Internet and its users have undergone a fundamental transformation. Originally, the Internet was designed to allow access of information provided by the publisher of a given website. Although websites have become very sophisticated in how this information is presented and while the information given can be tailored to the individual user, the information stream is predominantly unidirectional from the website to the user, and the content of the site is determined by its owner. Examples include sites that aim to convey general information about businesses or organizations, for example, the website of the Centers for Disease Control and Prevention, or allow for minimal manipulation of personalized information, such as online banking or bill payment. In Internet terms, this use of the Internet is referred to as Web 1.0. By contrast, Web 2.0 comprises Internet applications in which the information stream is more or less reversed. Here, the content of a website is mostly driven by the users of the site. This information can take multiple forms, including a variety of uploaded file formats (text, graphics, audio, video), blogs (web-logs), vlogs (video logs), chats, etc. Social networking sites, including YouTube, MySpace, and FaceBook are among the prime examples of the Web 2.0 applications that have revolutionized Internet use in the last decade.

In this article, the authors discuss the implications of the shift from Web 1.0 to Web 2.0 technology on sexual health from three perspectives: the Internet as an STI risk environment, the Internet as a venue for STI prevention, and, finally, the Internet as a tool for STI service and prevention providers. The growth of the Internet as a communication medium has had far-reaching consequences for STI/HIV prevention ranging from a venue for partner recruitment with potential risk as well as prevention benefits, to the use of the Internet as a place to deliver STI/HIV prevention services in a variety of more or less interactive formats, and finally as a tool for the development of a prevention work force. However, while the Internet has great potential as an important STI/HIV prevention medium, it appears that the greatest potential is yet untapped and that the providers of these services are considerably lagging behind their target audience in the creative and innovative uses of the new medium.

Web 2.0 and beyond: risks for sexually transmitted infections and opportunities for prevention. Curr Opin Infect Dis. 2009 22(1): 67-71
The continued growth of the Internet as a communication medium has had major implications for the transmission and prevention of sexually transmitted infections (STIs). The purpose of this review is to describe recent developments in this rapidly changing environment. The interface between the Internet and STIs is described from three perspectives: the Internet as a risk environment, that is, a place where prospective, potentially STI-infected, sex partners can be recruited; the Internet as a venue where public health prevention interventions aimed at STIs and HIV prevention can be placed; and the Internet as an increasingly important work environment for all STI prevention disciplines. The review highlights recent developments and identifies potential avenues for future research and program development. The increasing interactivity of the Internet, known as ‘Web 2.0′, especially the user-driven social networking sites that allow users to share near limitless amounts of personal information with their peers in the network, is compounding the potential of the Internet as an environment for both STI risk and prevention.

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• Health Risk Behaviors on MySpace
• You’ve Got Mail

A study conducted by Johns Hopkins University in the USA suggests that Human Papillomavirus (HPV) poses a greater risk in contracting cancer than smoking or alcohol. The study of 300 people also found that that those with more than six partners were almost nine times at greater risk of contracting the disease. And those who had already experienced a previous oral HPV infection were 32 times more likely to develop cancer. HPV is the cause of roughly 70 per cent of cervical cancers. Researchers believed oral sex was the main mode of transmission of HPV but could not rule out that it could also be passed through kissing. During the study, men and women who had been recently diagnosed with oropharyngeal cancer had blood and saliva samples taken and were also asked about their sexual practices and family history. They found HPV16 – one of the most common cancer-causing strains of the virus – was present in the tumours of 72 per cent of cancer patients. Scientists said the majority of HPV infections had no symptoms and often did not require treatment, but a small percentage of those who contracted high-risk strains may go on to develop cancer.

Oral Sexual Behaviors Associated with Prevalent Oral Human Papillomavirus Infection. J Infect Dis. Mar 25 2009
Oral human papillomavirus (HPV) infection is a cause of oropharyngeal cancer. We investigated whether sexual behaviors that elevated the odds of oropharyngeal cancer developing in a case-control study similarly elevated the odds of oral HPV infection developing among control patients. HPV infection was detected in 4.8% of 332 control patients from an outpatient clinic and in 2.9% of 210 college-aged men (age range, 18-23 years). Among control patients, the odds of infection developing independently increased with increases in the lifetime number of oral or vaginal sex partners. Among college-aged men, the odds of oral HPV infection developing increased with increases in the number of recent oral sex partners or open-mouthed kissing partners but not vaginal sex partners. Oral sex and open-mouthed kissing are associated with the development of oral HPV infection.

Related:

• Should we cure cancer?
• HPV vaccines: prospects for eliminating ano-genital cancer
• Dumb and Dumber