Tag: Staphyloccous areus

Antibiotic Resistance Among Key Bacterial Species Plateaus Over Time


Use of antibiotics was weakly associated with resistance, indicating additional factors may be at play

Photo by CDC on Unsplash

Antibiotic resistance tends to stabilise over time, according to a study published April 3, 2025 in the open-access journal PLOS Pathogens by Sonja Lehtinen from the University of Lausanne, Switzerland, and colleagues. 

Antibiotic resistance is a major public health concern, contributing to an estimated 5 million deaths per year. Understanding long-term resistance patterns could help public health researchers to monitor and characterise drug resistance as well as inform the impact of interventions on resistance.

In this study, researchers analysed drug resistance in more than 3 million bacterial samples collected across 30 countries in Europe from 1998 to 2019. Samples encompassed eight bacteria species important to public health, including Streptococcus pneumoniae, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. 

They found that while antibiotic resistance initially rises in response to antibiotic use, it does not rise indefinitely. Instead, resistance rates reached an equilibrium over the 20-year period in most species. Antibiotic use contributed to how quickly resistance levels stabilised as well as variability in resistance rates across different countries. But the association between changes in drug resistance and antibiotic use was weak, suggesting that additional, yet unknown, factors are at play.

The study highlights that continued increase in antibiotic resistance is not inevitable and provides new insights to help researchers monitor drug resistance.

Senior author Francois Blanquart notes: “When we looked into the dynamics of antibiotic resistance in many important bacterial pathogens all over Europe and in the last few decades, we often found that resistance frequency initially increases and then stabilises to an intermediate level. The consumption of the antibiotic in the country explained both the speed of initial increase and the level of stabilisation.”

Senior author Sonja Lehtinen summarises: “In this study, we were interested in whether antibiotic resistance frequencies in Europe were systematically increasing over the long-term. Instead, we find a pattern where, after an initial increase, resistance frequencies tend to reach a stable plateau.”

Provided by PLOS

Topical Mupirocin Reduces Cutaneous Lupus Inflammation

A woman with Systemic Lupus Erythematosus. Source: Wikimedia CC0

Researchers have found that topical mupirocin is effective in reducing rashes caused by systemic lupus erythematosus. Instead of directly lowering inflammation, the treatment kills bacteria that promote it. The findings are published in Arthritis & Rheumatology.

Cutaneous lupus erythematosus is a common manifestation of systemic lupus erythematosus, caused by the autoimmune conditions. The condition is characterised by rashes on various parts of the body including the face and scalp, hair loss and scarring of the skin.

The standard treatment for cutaneous lupus erythematosus is using immunosuppressants and biologic drugs to reduce inflammation. While the medications can be helpful, many patients with systemic lupus erythematosus already take several drugs and are looking for alternatives to pills.

J. Michelle Kahlenberg, MD, PhD, a professor of internal medicine in the Division of Rheumatology at University of Michigan Health led a team of researchers investigating topical mupirocin which is one such alternatives.

This trial was based on Kahlenberg’s previous discovery that cutaneous lupus rashes are often colonised with a common skin bacteria, Staphyloccous areus, also known as staphand contributes to inflammation in the rashes. Mupirocin kills this type of bacteria.

The study randomly selected systemic lupus erythematosus patients currently experiencing cutaneous lupus erythematosus flares to treat their skin lesions with mupirocin or with an inactive control, petrolatum jelly.

Samples from the nose and lesional skin were used to determine baseline and post treatment Staphylococcus abundance and microbial community profiles. Paired samples collected prior to treatment with the topical solution and seven days after treatment showed decreases in lesional staphylococcus aureus in the mupirocin treated samples.

Importantly, the reduction in staph also was accompanied by a reduction in inflammatory signals, including interferon-driven gene expression, in the lesions.

“In addition to decreasing the inflammation by decreasing lesional staphylococcus aureus, the mupirocin treatment also lowered skin monocyte levels, which are important in driving cutaneous lupus,” said Kahlenberg.

Mupirocin is a prescription treatment, and while this early study showed signs of decreasing inflammation, the study wasn’t designed to see if it can decrease the rash of cutaneous lupus erythematosus.

“Additional larger studies are needed to determine whether topical antibiotics will be helpful to make rashes go away,” Kahlenberg said.

“However, this is an exciting first step to show that there may be additional treatments that can improve inflammation beyond our usual immunosuppressant and biologic drugs.”

Source: Michigan Medicine – University of Michigan