Gonorrhea researchers identify novel route to vaccine, new antibiotic

Researchers have identified a protein that powers the virulence of the bacteria that causes gonorrhea, opening the possibility of a new target for antibiotics and, even better, a vaccine.

The findings, published today in PLOS Pathogens, are especially important since the microbe, Neisseria gonorrhoeae, is considered a "superbug" because of its resistance to all classes of antibiotics available for treating infections.

Gonorrhea, a sexually transmitted disease that results in 78 million new cases worldwide each year, is highly damaging if untreated or improperly treated.

It can lead to endometritis, pelvic inflammatory disease, ectopic pregnancy, epididymitis and infertility. Babies born to infected mothers are at increased risk of blindness.

"The infections very often are silent," said Oregon State University researcher Aleksandra Sikora. "Up to 50 percent of infected women don't have symptoms, but those asymptomatic cases can still lead to some very severe consequences for the patient's reproductive health, miscarriage or premature delivery."

The need for better antibiotic therapy, and a vaccine, is pressing. N. gonorrhoeae strains resistant to the last effective treatment options have emerged, and failures in treatment are occurring.

Sikora and her research team at the OSU/OHSU College of Pharmacy and Ann Jerse's lab at the Uniformed Services University of the Health Sciences in Bethesda, Maryland, collaborated to discover a novel lipoprotein that N. gonorrhoeae uses to defeat the body's first line of innate immune defense.

The body relies on enzymes known as lysozymes that, as their name suggests, thwart bacteria by causing their cell wall to lyse, or break apart. Lysozymes are abundant both in epithelial cells, which make up the tissue on the outside of organs and the inside of body cavities, and in the phagocytic cells that protect the body by ingesting foreign particles and bacteria.

In turn, many gram-negative bacteria -- characterized by their cell envelope that includes a protective outer membrane -- have developed ways of defeating lysozymes. Prior to the work by Sikora's team, however, only one lysozyme-fighting protein had been discovered in the Neisseria genus.

Now that new targets have been identified, they can be explored as bullseye candidates for new antibiotics or a vaccine -- if the lysozyme inhibitor can itself be inhibited, then the bacteria's infection-causing ability is greatly reduced.

Sikora and her collaborators named the new protein SliC, short for surface-exposed lysozyme inhibitor of c-type lysozyme.

Studying SliC's function in culture as well as in a gonorrhea mouse model -- mice were infected with N. gonorrhoeae, then checked for SliC expression at one, three and five days -- researchers determined the protein was essential to bacterial colonization because of its anti-lysozyme role.

"This is the first time an animal model has been used to demonstrate a lysozyme inhibitor's role in gonorrhea infection," Sikora said. "Together, all of our experiments show how important the lysozyme inhibitor is. This is very exciting."

Source: https://www.sciencedaily.com/releases/2018/07/180705143834.htm

Abstract submission for the conference STD 2018 held at Toronto, Canada on August 20-21, 2018 is welcome!! Submit your abstract here: https:/std-hiv-aids.cmesociety.com/abstract-submission

Chlamydia: Sexually Transmitted Infection

Chlamydia is a common sexually transmitted disease (STD) caused by infection with Chlamydia trachomatis. It can cause cervicitis in women and urethritis and proctitis in both men and women. Chlamydial infections in women can lead to serious consequences including pelvic inflammatory disease (PID), tubal factor infertility, ectopic pregnancy, and chronic pelvic pain. Lymphogranuloma venereum (LGV), another type of STD caused by different serovars of the same bacterium, occurs commonly in the developing world, and has more recently emerged as a cause of outbreaks of proctitis among men who have sex with men (MSM) worldwide.

Chlamydia is the most frequently reported bacterial sexually transmitted infection in the United States. In 2010, 1.4 million cases of chlamydia were reported to the U.S.CDC from 50 states and the District of Columbia, but an estimated 2.86 million infections occur annually. Many cases are not reported because most people with chlamydia do not have symptoms and do not seek testing. Chlamydia is most common among young people. It is estimated that one in 15 sexually active females aged 14-19 years has chlamydia.

People at risk for chlamydia

Any sexually active person can be infected with chlamydia. Anyone with genital symptoms such as discharge, burning during urination, unusual sores, or rash should refrain from having sex until they are able to see a health care provider about their symptoms.

Also, anyone with an oral, anal or vaginal sex partner who has been recently diagnosed with an STD should see a health care provider for evaluation.

Because chlamydia is usually asymptomatic, screening is necessary to identify most infections. Screening programs have been demonstrated to reduce rates of adverse sequelae in women. CDC recommends yearly chlamydia screening of all sexually active women age 25 or younger and older women with risk factors for chlamydial infections (e.g., women who have a new or more than one sex partner). Pregnant women should be screened during their first prenatal care visit. Pregnant women younger than 25 or at increased risk for chlamydia (e.g., women who have a new or more than one sex partner) should be screened again in their third trimester. Any woman who is sexually active should discuss her risk factors with a health care provider who can then determine if more frequent screening is necessary.

Routine screening is not recommended for men. However, the screening of sexually active young men should be considered in clinical settings with a high prevalence of chlamydia (e.g., adolescent clinics, correctional facilities, and STD clinics) when resources permit and do not hinder screening efforts in women.

Men who have sex with men (MSM) who have receptive anal sex should be screened for chlamydia each year. MSM who have multiple and/or anonymous sex partners should be screened more frequently (e.g., at three to six-month intervals).

HIV-infected sexually active women who are age 25 or younger or have other risk factors, and all HIV-infected patients who report having receptive anal sex should be screened for chlamydia at their first HIV care visit and then at least annually. A patient’s health care provider might determine more frequent screening is necessary, based on the patient’s risk factors.

Symptoms

Chlamydia is known as a “silent” infection because most infected people have no symptoms. If symptoms do occur, they may not appear until several weeks after exposure. Even when it causes no symptoms, chlamydia can damage a woman’s reproductive organs.

In women, the bacteria first infect the cervix (structure that connects the vagina or birth canal to the uterus or womb) and/or the urethra (urine canal). Some infected women have an abnormal vaginal discharge or a burning sensation when urinating. Untreated infections can spread upward to the uterus and fallopian tubes (tubes that carry fertilized eggs from the ovaries to the uterus), causing pelvic inflammatory disease (PID). PID can be silent or can cause symptoms such as abdominal and pelvic pain. Even if PID causes no symptoms initially, it can lead to infertility (not being able to get pregnant) and other complications later on.

Some infected men have discharge from their penis or a burning sensation when urinating. Pain and swelling in one or both testicles (known as “epididymitis”) may occur but is less common.

Chlamydia can infect the rectum in men and women, either through receptive anal sex, or possibly via spread from the cervix and vagina. While these infections often cause no symptoms, they can cause rectal pain, discharge, and/or bleeding (known as “proctitis”).

Complications due to Chlamydia Infection

The initial damage that chlamydia causes often goes unnoticed. However, chlamydial infections can lead to serious health problems.

In women, Untreated infection can spread upward to the uterus and fallopian tubes (tubes that carry fertilized eggs from the ovaries to the uterus), causing pelvic inflammatory disease (PID). PID can be silent or can cause symptoms such as abdominal and pelvic pain. Both symptomatic and silent PID can cause permanent damage to a woman’s reproductive tract and lead to long-term pelvic pain, inability to get pregnant and potentially deadly ectopic pregnancy (pregnancy outside the uterus).

Complications are rare in men. Infection sometimes spreads to the tube that carries sperm from the testis, causing pain, fever, but, rarely, preventing a man from being able to father children.

Chlamydia in pregnant woman

In pregnant women, untreated chlamydia has been associated with pre-term delivery, and can spread to the new born, causing an eye infection or pneumonia. Screening and treatment of chlamydia during pregnancy is the best way to prevent these complications. All pregnant women should be screened for chlamydia at their first prenatal visit.

Diagnosis

There are laboratory tests to diagnose chlamydia. Specimens commonly used for testing include a cotton swab of the vagina (collected by the woman herself or her health care provider) or a urine sample.

Chlamydia Treatment

Penicillin is not effective against chlamydia.

Chlamydia can be easily treated and cured with antibiotics. HIV-positive persons with chlamydia should receive the same treatment as those who are HIV-negative.

Persons with chlamydia should abstain from having sex for seven days after single dose antibiotics, or until completion of a seven-day course of antibiotics, to prevent spreading the infection to partners.

Repeat infection with chlamydia is common. Persons whose sex partners have not been appropriately treated are at high risk for re-infection. Having multiple chlamydial infections increases a woman's risk of serious reproductive health complications, including pelvic inflammatory disease and ectopic pregnancy. Women and men with chlamydia should be retested about three months after treatment of an initial infection, regardless of whether they believe that their sex partners were successfully treated.

Infants infected with chlamydia may develop conjunctivitis (infection of the membrane lining the eyelids) and/or pneumonia. Chlamydial infection in infants can be treated with antibiotics.

Prevention Strategies

Not having sex is the best protection against chlamydia and other STDs. Having sex with only one uninfected partner who only has sex with you is also safe. Latex male condoms, when used consistently and correctly, can reduce the risk of getting or giving chlamydia. The surest way to avoid chlamydia is to abstain from vaginal, anal and oral sex or to be in a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected.

To submit your abstracts at the conference STD 2018: http://bit.ly/stdabst2018

Source: http://www.dph.illinois.gov/topics-services/diseases-and-conditions/diseases-a-z-list/chlamydia