PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Cigarette smoke makes superbugs more aggressive

In lab and mouse experiments, cigarette smoke helps drug-resistant bacteria fight off the immune system

2015-04-02
(Press-News.org) Methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant superbug, can cause life-threatening skin, bloodstream and surgical site infections or pneumonia. Researchers at the University of California, San Diego School of Medicine now report that cigarette smoke may make matters worse. The study, published March 30 by Infection and Immunity, shows that MRSA bacteria exposed to cigarette smoke become even more resistant to killing by the immune system.

"We already know that smoking cigarettes harms human respiratory and immune cells, and now we've shown that, on the flipside, smoke can also stress out invasive bacteria and make them more aggressive," said senior author Laura E. Crotty Alexander, MD, assistant clinical professor of medicine at UC San Diego and staff physician at the Veterans Affairs San Diego Healthcare System.

Crotty Alexander is a pulmonologist who sees many patients who smoke cigarettes. She also sees many MRSA infections, and that got her wondering if one might influence the other. To test the hypothesis, Crotty Alexander and her team infected macrophages, immune cells that engulf pathogens, with MRSA. Some of the bacteria were grown normally and some were grown with cigarette smoke extract. They found that while the macrophages were equally able to take up the two bacterial populations, they had a harder time killing the MRSA that had been exposed to cigarette smoke extract.

To better understand why, the Crotty Alexander team tested the bacteria's susceptibility to individual mechanisms macrophages typically employ to kill bacteria. Once inside macrophages, smoke-exposed MRSA were more resistant to killing by reactive oxygen species, the chemical burst that macrophages use to destroy their microbial meals. The team also discovered that smoke-exposed MRSA were more resistant to killing by antimicrobial peptides, small protein pieces the immune system uses to poke holes in bacterial cells and trigger inflammation. The effect was dose-dependent, meaning that the more smoke extract they used, the more resistant the MRSA became.

MRSA treated with cigarette smoke extract were also better at sticking to and invading human cells grown in the lab. In a mouse model, MRSA exposed to cigarette smoke survived better and caused pneumonia with a higher mortality rate.

The data suggest that cigarette smoke strengthens MRSA bacteria by altering their cell walls in such a way that they are better able to repel antimicrobial peptides and other charged particles.

"Cigarette smokers are known to be more susceptible to infectious diseases. Now we have evidence that cigarette smoke-induced resistance in MRSA may be an additional contributing factor," Crotty Alexander said.

INFORMATION:

Study co-authors include Elisa K. McEachern, John H. Hwang, Katherine M. Sladewski, UC San Diego and Veterans Affairs San Diego Healthcare System; Shari Nicatia, UC San Diego, Veterans Affairs San Diego Healthcare System and Utrecht University; Carola Dewitz, UC San Diego, Veterans Affairs San Diego Healthcare System and University of Veterinary Medicine, Hannover, Germany; Denzil P. Mathew, Veterans Affairs San Diego Healthcare System; and Victor Nizet, UC San Diego.

This research was funded, in part, by the U.S. Department of Veterans Affairs.



ELSE PRESS RELEASES FROM THIS DATE:

Small RNA plays big role suppressing cancer

2015-04-02
(SACRAMENTO, Calif.) -- The micro RNA miR-22 has long been known for its ability to suppress cancer. However, questions remain about how it achieves this feat. For example, which molecules are regulating miR-22, and which are miR22 targets? Researchers at UC Davis have unraveled some of these relationships, identifying several interactions that directly impact liver and colon cancer. The work provides new insights into how miR-22 operates and could potentially lead to new cancer therapies. The study was published in the Journal of Biological Chemistry. "There are quite ...

The science of stress (video)

The science of stress (video)
2015-04-02
WASHINGTON, April 2, 2015 -- It's supposed to help keep our bodies healthy in stressful situations. But the constant stress of our everyday lives means we're getting overexposed to cortisol. Raychelle Burks, Ph.D., explains why too much cortisol is bad for you in the latest episode of the Reactions series Get To Know A Molecule. Check it out here: https://youtu.be/fPnDaRYXHs4. INFORMATION: Subscribe to the series at http://bit.ly/ACSReactions, and follow us on Twitter @ACSreactions to be the first to see our latest videos. The American Chemical Society is a nonprofit ...

Virginia Tech, Ecuadoran scientists study rare 'Pinocchio Lizard' in effort to save it

Virginia Tech, Ecuadoran scientists study rare Pinocchio Lizard in effort to save it
2015-04-02
For more than 50 years, scientists thought that the horned anole lizard -- sometimes called the "Pinocchio Lizard" for its long, protruding nose -- was extinct. But it turns out this is a tall tale. Scientists re-discovered the lizard in 2005, living elusively at the tops of tall trees in the cloud forests of Ecuador -- the only place in the world that it is known to exist. A team led by a Virginia Tech scientist recently uncovered new information about the role that the lizard's long nose plays. Only the males have long noses, and they appear to be used in social ...

Placenta reflects arsenic exposure in pregnant women and fetuses, Dartmouth study shows

2015-04-02
HANOVER, N.H. - The placenta can be used to reliably measure arsenic exposure in pregnant women and how much of the toxic metal is transferred to their fetuses, a Dartmouth College study shows. The study, the largest ever analysis of household drinking water arsenic and the mother-to-fetus connection, appears in the Journal of Exposure Science and Environmental Epidemiology. A PDF is available on request. Recent studies have used the placenta to identify early effects of exposure to lead, mercury, cadmium and other metals. Previous studies also have shown that arsenic ...

NYU researchers dramatically improve ART adherence for minority PHLA

2015-04-02
Up to 60% of persons living with HIV (PLHA) in the U.S. are neither taking antiretroviral therapy (ART) nor well engaged in HIV primary care, with racial/ethnic minorities more likely to experience barriers to engagement along this HIV continuum of care than their White counterparts. In fact, only 30% of persons living with HIV/AIDS (PLHA) in the United States have achieved "viral suppression," the ultimate goal of HIV treatment. Indeed, PLHA poorly engaged in HIV primary care and/or who are not on ART are at elevated risk for a host of poor outcomes, including more frequent ...

Raising retirement age would widen benefit disparities for disadvantaged

2015-04-02
The age to receive full Social Security benefits should be closer to 70, according to a report published in the journal Daedalus. "We're living longer and healthier than ever before, but the statutory age of retirement for receiving Social Security benefits doesn't reflect that," says lead author S. Jay Olshansky, professor of epidemiology in the University of Illinois at Chicago School of Public Health. When Social Security was enacted in 1935, the age of full retirement was set at 65. Back then, a 25-year-old had a 62.4 percent chance of living to retirement age, and ...

Older people at higher risk of emergency cancer diagnosis

2015-04-02
People over 60 are at higher risk of being diagnosed with lung or bowel cancer as an emergency in hospital than younger people, according to a Cancer Research UK-supported report *, published today by BMJ Open (Thursday). The researchers also found that women and less affluent people are at higher risk of an emergency lung cancer diagnosis. While being unmarried, divorced or widowed was associated with having bowel cancer diagnosed as an emergency. The Cancer Research UK review looked at over 20 studies featuring more than 687,000 lung or bowel cancer cases, of which ...

MA health reform did not lower preventable hospitalizations or reduce racial disparities

2015-04-02
CAMBRIDGE, Mass. - In the first three years after Massachusetts implemented its 2006 health care reform, which reduced the number of uninsured people in the state by roughly half, the rate of preventable hospitalizations did not decline compared with states with similar populations that did not expand health insurance coverage. Nor did the reform reduce racial and ethnic disparities in the rate of such hospitalizations. Those are some of the chief findings of a new study by researchers at Harvard Medical School and the Boston University School of Medicine, published today ...

Low T not just in males: Testosterone, atherosclerosis and obesity may be linked in females

2015-04-02
While testosterone replacement therapies may be controversial in males, new research in The FASEB Journal may extend this controversy to females too. That's because research involving mice, appearing in the April 2015 issue, suggests that there is an association between low levels of androgens (which includes testosterone), and atherosclerosis and obesity in females. "We hope that our study will contribute to intensified research efforts on the definition of androgen deficiency in women (e.g. which levels of androgens in the blood should be considered too low?), the ...

Pathway known to suppress tumors may also reduce burden of neurodegenerative diseases

2015-04-02
A molecular pathway known to suppress tumors appears to also be a major player in clearing cells of damaged proteins implicated in neurodegenerative diseases such as ALS and certain types of dementia, new research in roundworms and human cells suggests. Johns Hopkins Bloomberg School of Public Health researchers, publishing April 2 in the journal PLOS Biology, say their findings shed new light on how a cell's protein quality control mechanism works - and how this system could be harnessed one day to combat diseases caused by a buildup of proteins in cells. To function ...

LAST 30 PRESS RELEASES:

Research spotlight: regional disparities in opioid overdose mortality persist despite national decline

Fighting myeloma with fiber: Plant-based diet offers promise

What makes someone leave a Medicare Advantage plan?

ASCO: New antibody-drug conjugate shows promising safety and response rates for patients with rare blood cancer

Advancing personalized medicine through pharmacogenomics: Insights from Ochsner Health

Researchers tested an asthma drug for treating alcoholism. It failed except with this group

Set it and forget it: Autonomous structures can be programmed to jump days in advance

Iron from coal, steel industries alters North Pacific ecosystem

Canadian researcher receives funding from ARIA to unlock potential of plants

Visionary support from Veale Foundation will establish university hospitals Veale Healthcare Transformation Institute

Investigating cocaine addiction using fruit flies

Fruit flies on cocaine could reveal better therapies for addiction

New data shows MMR vaccination rate decline across US

Clinical validation of a circulating tumor DNA–based blood test to screen for colorectal cancer

Screening colonoscopy yields among adults ages 45 to 49 after lowering the colon cancer screening age

Trends in county-level MMR vaccination coverage in children in the United States

Brewed for longevity: drinking coffee linked with healthy aging in women

Researchers find early driver of prostate cancer aggressiveness

Insect protein blocks bacterial infection

New study casts doubt on the likelihood of a Milky Way – Andromeda collision

Prevalence of artificial sweetener neotame in U.S.-marketed disposable e-cigarettes

E-cigarette warnings lower vaping interest and raise quit intentions

Record high: Study finds growing cannabis use among older adults

Trends in past-month cannabis use among older adults

How to create aqueous 100 nm-sized materials with polycavities

Epilepsy is more common in patients with frontotemporal dementia than expected

Pre-operative THP leads to a pCR in two-thirds of early-stage HER2+ ER- breast cancer patients

Immune system discovery reveals potential solution to Alzheimer’s

Salamanders suffering from rising temperatures

It’s not too late to start eating better for your brain

[Press-News.org] Cigarette smoke makes superbugs more aggressive
In lab and mouse experiments, cigarette smoke helps drug-resistant bacteria fight off the immune system