Research on Antibiotic-Resistant Infections in Australian Hospitals

Background of the Study

Researchers from the University of Melbourne have explored the rising rates of infections caused by antibiotic-resistant bacteria in Australian hospitals, despite the common use of hand sanitizers. Nosocomial infections, which are acquired in hospital settings, are predominantly bacterial. The increasing use of antibiotics in these environments raises the risk of antibiotic resistance, complicating the treatment of these infections.

Risk Factors for Nosocomial Infections

While any patient can develop a nosocomial infection, certain groups are at a higher risk, including those who are:
– Infants or elderly individuals
– Patients with indwelling catheters
– Individuals on ventilators
– Patients receiving antibiotics or histamine receptor blockers
– Those with medical conditions or treatments that weaken the immune system

Preventing Hospital Infections

Effective Preventative Measures

Implementing simple preventative strategies can greatly reduce the spread of hospital infections. Promoting annual flu vaccinations for both the public and hospital staff is an effective method to decrease nosocomial infection transmission.

Hand hygiene practices, particularly compliance with handwashing protocols, are crucial in minimizing the spread of infections. Given that some bacteria can survive on surfaces for extended periods, hospitals have established protocols to ensure thorough cleaning and disinfection of medical surfaces.

Use of Hand Sanitizers in Hospitals

Most hospitals have introduced stations for ethyl alcohol- and isopropyl alcohol-based hand sanitizers in high-traffic locations, such as entrances and elevators. The adoption of alcohol-based disinfectants began in 2002, and by 2015, the monthly usage of alcohol hand sanitizers surged to 1,000 liters.

Findings on Enterococcus faecium Resistance

Study Overview

Despite the implementation of these preventive measures, researchers observed a concerning trend: while the rates of hospital-acquired Staphylococcus aureus infections decreased, infections caused by Enterococcus faecium have risen. This prompted inquiries into whether E. faecium exhibits greater resistance to disinfectants.

The findings of this study were published in *Translational Medicine*, where researchers analyzed 139 samples of E. faecium bacteria collected from two Melbourne hospitals between 1997 and 2015. The samples were cultivated and tested for alcohol tolerance by exposing them to diluted isopropyl alcohol, commonly found in hand sanitizers.

Research Results

In a subsequent phase of the study, the bacteria were introduced into the floor of mice cages and cleaned with alcohol-based disinfectants, with control experiments conducted using water. Researchers recorded and analyzed data on infection rates and severity.

The results indicated that E. faecium bacteria isolated from 2009 onward exhibited greater resistance to disinfectants compared to those collected before 2004. Additionally, the alcohol-resistant strains were more aggressive in causing infections.

Conclusion

This research highlights the potential for antibiotic-resistant bacteria to also develop resistance to disinfectants. The research team emphasized that “global efforts to mitigate bacterial resistance should consider how microbes can adapt not only to drugs, but also to alcohols and other ingredients used in disinfectants.”

Reference

Pidot, S. J., Gao, W., Buultjens, A. H., Monk, I. R., Guerillot, R., Carter, G. P., … & Mahony, A. A. (2018). Increasing tolerance of hospital Enterococcus faecium to handwash alcohols. *Science Translational Medicine*, 10(452), eaar6115. DOI: 10.1126/scitranslmed.aar6115