Antibiotics can increase Risk of Resistance to that Antibiotic for up to 2 years

[Guest guest]

Society for General Microbiology

Antibiotics have long-term impacts on gut flora

Short courses of antibiotics can leave normal gut bacteria harboring antibiotic

resistance genes for up to two years after treatment, say scientists writing in

the latest issue of Microbiology, published on 3 November.

The researchers believe that this reservoir increases the chances of resistance

genes being surrendered to pathogenic bacteria, aiding their survival and

suggesting that the long-term effects of antibiotic therapy are more significant

than previously thought.

Antibiotics that are prescribed to treat pathogenic bacteria also have an impact

on the normal microbial flora of the human gut. Antibiotics can alter the

composition of microbial populations (potentially leading to other illnesses)

and allow micro-organisms that are naturally resistant to the antibiotic to

flourish.

The impact of antibiotics on the normal gut flora has previously been thought to

be short-term, with any disturbances being restored several weeks after

treatment. However, the review into the long-term impacts of antibiotic therapy

reveals that this is not always the case. Studies have shown that high levels of

resistance genes can be detected in gut microbes after just 7 days of antibiotic

treatment and that these genes remain present for up to two years even if the

individual has taken no further antibiotics.

The consequences of this could be potentially life-threatening explained Dr

Cecilia Jernberg from the Swedish Institute for Infectious Disease Control who

conducted the review. " The long-term presence of resistance genes in human gut

bacteria dramatically increases the probability of them being transferred to and

exploited by harmful bacteria that pass through the gut. This could reduce the

success of future antibiotic treatments and potentially lead to new strains of

antibiotic-resistant bacteria. "

The review highlights the necessity of using antibiotics prudently. " Antibiotic

resistance is not a new problem and there is a growing battle with multi-drug

resistant strains of pathogenic bacteria. The development of new antibiotics is

slow and so we must use the effective drugs we have left with care, " said Dr

Jernberg. " This new information about the long-term impacts of antibiotics is of

great importance to allow rational antibiotic administration guidelines to be

put in place, " she said.

###