Study detects increase in new generation of superbugs – 07/16/2023 – Health

A Brazilian study demonstrated, for the first time, the increase of an enzyme linked to a new generation of multiresistant bacteria in hospitals in the country, triggering the alert of hospital infection control commissions.

Called New Delhi metallobetalactamase (NDM-1), the enzyme was first isolated in 2009 in India and has since caused outbreaks in that country, Pakistan and England. Japan, Australia, Canada and the United States also recorded an increase in cases.

In Brazil, NDM had already been detected, but never quantified. According to the publication, the detection rate of this enzyme in a group of bacteria (enterobacteria) almost sixfold in seven years, from 4.2% to 23.8%, between 2015 and 2022, with a peak in the Covid-19 pandemic. .

NDM is part of a larger group of enzymes produced by bacteria, the carbapenemases, which today represent a global threat to public health due to the high levels of resistance to current antibiotics. Another old acquaintance is KPC, Klebsiella pneumoniaeresponsible for several outbreaks in hospitals in Brazil and around the world.

One hypothesis is that the scenario of overcrowded hospitals, unprepared professionals and the indiscriminate use of antibiotics have contributed to the increase. The study shows that, between 2020 and 2022, there was a 65.2% increase in the detection of enterobacteria and 61.3% in the Pseudomonas aeruginosa in the total of isolated samples.

Other research had already detected that up to 94% of patients infected with Covid-19 received antimicrobials in hospitals during the pandemic. However, many of these indications may have been unnecessary because they were viral and not bacterial conditions.

But the problem of bacteria resistant to even more modern antibiotics, such as carbapenems, predates the pandemic and is still the subject of many studies. In Europe, for example, even with the reduction in the use of antibiotics, bacterial resistance also increased between 2019 and 2020.

One strategy has been to go back to using older antibiotics, such as polymyxin, which, although more toxic, have proven effective in combating some of these resistant bacteria. It turns out that even they are losing the race.

Published in the journal Clinical Infectious Diseases, the Brazilian study was funded by the CDC (Center for Disease Control and Prevention), in the United States, and is part of an international project to improve detection and knowledge about bacterial resistance.

In Brazil, more than 80,000 bacteria from the database of the public laboratory information system were tested. The KPC enzyme remains the most frequent, with a detection rate of 68.6% among enterobacteria, while NDM had 14.4%.

What stands out, however, is the NDM’s growth rate. It had an annual percentage increase of 41.1% among enterobacteria and 71.6% among P. aeruginosa. KPC, on the other hand, showed a drop of 4% in the first group of bacteria and a rise of 22% in the second.

“We knew we were detecting more NDM, but we hadn’t quantified it”, says Carlos Kiffer, the main author of the study and associate professor of infectology at Unifesp (Federal University of São Paulo).

He says that, until then, the main concern revolved around KPC. “We always thought that NDM was less important. Although it has been found in smaller proportions in the total number of isolates, its growth rate is frightening over the last few years.”

Kiffer says that if NDM maintains this high growth rate, it could take over hospital environments in the next three to four years. Unlike KPC, which can be combated with new, more effective antibiotics, NDM does not yet have this alternative.

“Here in Brazil there is no [antibiótico] proven effective for NDM. What we do is use old antibiotics, some may or may not have an effect on this resistance, but we cannot guarantee that it will work.”

According to him, among the prevention strategies to contain the spread of bacterial resistance are proper hand hygiene, more controlled use of antibiotics in hospitals, in the community and in veterinary environments, in addition to early diagnosis.

“Laboratory diagnosis is problematic in many places outside the major centers in the South and Southeast, which greatly increases the chances of mortality”, he says.

An improvement of the hospital infrastructure is another recommendation. “Many Brazilian hospitals are in a process of scrapping and with a reduction in personnel available to control nosocomial infection.”

Kiffer explains that the level of knowledge of public health managers about bacterial resistance is very uneven in the country. “There are people who know the subject well, but others are not convinced that it is a priority issue.”

He recalls that the lack of control of hospital infections generates preventable deaths and an impact on the hospitalization rate, with an increase in length of stay and costs.

“It’s a silent epidemic of this century. If we don’t do something now, we will suffer in the very near future with the restriction of therapeutic options, at a very high cost, and, in many cases, dealing with intractable infections, which is already a reality in many hospitals.”

The project also has other action fronts in the areas of education, training and qualification of centers to improve testing in public microbiology laboratories.