Hospital disinfectants struggling to kill C. diff bacteria colonies

November 06, 2019

The deadly and notoriously stubborn superbug, Clostridioides difficile (C. diff), is putting up a winning fight against hospital-grade disinfectants meant to kill it, according to results of a new study published in the Antimicrobial Agents and Chemotherapy journal of the American Society for Microbiology. The C. diff bacterium causes inflammation of the colon with symptoms ranging from diarrhea to life-threatening sepsis and is most common among the elderly in hospitals or other health care facilities.

"We found no disinfectant was able to completely eliminate C. difficile embedded within biofilms, although we did note differences among disinfectants," reports Kevin Garey, professor of pharmacy practice at the University of Houston and chair of the College of Pharmacy Department of Pharmacy Practice and Translational Research. Garey was the project's principal investigator. The paper was the doctoral thesis of first author, Tasnuva Rashid, of the University of Texas School of Public Health.

Overall, Clorox, Cidex OPA, and Virex were most effective at killing C. diff spores. Clorox and OPA were also effective at killing total vegetative cell growth, the cellular stage responsible for causing infections. Virex was found to be ineffective against vegetative cell growth in biofilms. Clorox and Virex were most effective in reducing biomass followed by Nixall, Cidex OPA and Vital oxide.

No previous studies have investigated chemical disinfection of C. diff spores embedded in biofilms. For the project, five unique C. diff strains, embedded in three different biofilm types grown for 72 or 120 hours, were exposed to seven different hospital disinfectants.

Bacteria can grow on almost any surface and forms a complex biofilm, like a "suit of armor," as Garey described it, where it can survive and thrive - think of slime inside an old garden hose or plaque on your teeth - biofilms both. More devastating biofilms form on medical devices like catheters or injection ports, giving bacteria direct access to a patient.

In the center of a biofilm, a spot exists without oxygen, an attractive locale for the anaerobic C. diff spore, which dies when it touches oxygen. Rashid was able to get a spore to germinate and replicate itself within a biofilm while exposed to an oxygen-rich environment.

"This study helps explain why C. diff is so hard to eradicate from the environment and demonstrates the ability of these spores to be so omnipresent and self-propagate in the environment," said Garey.

The survival of C. diff in hospitals and nursing homes is especially hazardous. The Centers for Disease Control and Prevention report that within a month of diagnosis, one in 11 people over age 65 died of a health care-associated C. diff infection. Garey reports that approximately 1% of all people over age 80, whether sick or not, will die of a C. diff infection.

Garey said future research could include improving existing cleansers. "Clorox is the best we have but is still quite caustic to the environment. There is likely a future where we could improve upon it to make an even more superior disinfectant to fight deadly superbugs."

University of Houston

Related Health Care Articles from Brightsurf:

Study evaluates new World Health Organization Labor Care Guide for maternity care providers
The World Health Organization developed the new Labor Care Guide to support clinicians in providing good quality, women-centered care during labor and childbirth.

Six ways primary care "medical homes" are lowering health care spending
New analysis of 394 U.S. primary care practices identifies the aspects of care delivery that are associated with lower health care spending and lower utilization of emergency care and hospital admissions.

Modifiable health risks linked to more than $730 billion in US health care costs
Modifiable health risks, such as obesity, high blood pressure, and smoking, were linked to over $730 billion in health care spending in the US in 2016, according to a study published in The Lancet Public Health.

Spending on primary care vs. other US health care expenditures
National health care survey data were used to assess the amount of money spent on primary care relative to other areas of health care spending in the US from 2002 to 2016.

MU Health Care neurologist publishes guidance related to COVID-19 and stroke care
A University of Missouri Health Care neurologist has published more than 40 new recommendations for evaluating and treating stroke patients based on international research examining the link between stroke and novel coronavirus (COVID-19).

Large federal program aimed at providing better health care underfunds primary care
Despite a mandate to help patients make better-informed health care decisions, a ten-year research program established under the Affordable Care Act has funded a relatively small number of studies that examine primary care, the setting where the majority of patients in the US receive treatment.

International medical graduates care for Medicare patients with greater health care needs
A study by a Massachusetts General Hospital research team indicates that internal medicine physicians who are graduates of medical schools outside the US care for Medicare patients with more complex medical needs than those cared for by graduates of American medical schools.

The Lancet Global Health: Improved access to care not sufficient to improve health, as epidemic of poor quality care revealed
Of the 8.6 million deaths from conditions treatable by health care, poor-quality care is responsible for an estimated 5 million deaths per year -- more than deaths due to insufficient access to care (3.6 million) .

Under Affordable Care Act, Americans have had more preventive care for heart health
By reducing out-of-pocket costs for preventive treatment, the Affordable Care Act appears to have encouraged more people to have health screenings related to their cardiovascular health.

High-deductible health care plans curb both cost and usage, including preventive care
A team of researchers based at IUPUI has conducted the first systematic review of studies examining the relationship between high-deductible health care plans and the use of health care services.

Read More: Health Care News and Health Care Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to