Deadly drug-resistant bacteria that killed more than 2,000 people in 2015 rapidly spreading through hospitals, experts warn
Reseachers say hospitals in Europe are speeding up the spread of bacteria Klebsiella pneumoniae, which are difficult to treat as they are resistant to carbapenems
Hospitals in Europe have become the primary breeding ground of a life-threatening and highly drug-resistant bacteria, according to a new study.
Researchers say the findings are extremely concerning as the number of deaths caused by this antibiotic-resistant bacteria - called Klebsiella pneumoniae - has increased six-fold in Europe - from 341 in 2007 to 2,094 in 2015.
Infants, the elderly and those with a weak immune are at very high risk, the experts say.
The study - which is the largest of its kind - examined the genomes of almost 2,000 K. pneumoniae samples taken from patients in 244 hospitals in 32 countries, and concluded that antibiotic-resistant strains of the bacteria are spreading through hospitals in Europe. A majority of the Klebsiella pneumoniae infections are being transmitted as a result of person-to-person contact within these hospitals, the study said.
The findings, published in the journal Nature Microbiology, are meant at informing and boosting public health efforts to control the spread of these infections in hospitals across Europe, say the researchers.
“The bacterium Klebsiella pneumoniae, a major cause of both hospital- and community-acquired infections, is listed by the World Health Organization (WHO) as a critical priority antibiotic-resistant bacterial pathogen for which new antibiotics are urgently needed. Indeed, a recent study showed that carbapenem-resistant K. pneumoniae represents the fastest growing antibiotic resistance threat in Europe, in terms of human morbidity and mortality. It is, therefore, critical to identify priority areas on which to intensify public health intervention strategies,” says the research team from the Centre for Genomic Pathogen Surveillance, Wellcome Genome Campus, (UK); University of Freiburg, (Germany); and Pathogen Genomics, Wellcome Sanger Institute (UK), among others.
What is Klebsiella pneumoniae?
The WHO publishes a list of bacteria for which new antibiotics are required urgently. Klebsiella belongs to the category of ‘critical’ priority, that pose a particular threat in hospitals, nursing homes, and among patients whose care requires devices such as ventilators and blood catheters.
According to the Centers for Disease Control and Prevention (CDC), Klebsiella pneumoniae is a type of bacteria can cause different types of infections, including pneumonia, bloodstream infections, wound or surgical site infections, and meningitis.
The CDC explains that to get Klebsiella infection, a person must be exposed to the bacteria. “For example, Klebsiella must enter the respiratory (breathing) tract to cause pneumoniae, or the blood to cause a bloodstream infection. In healthcare settings, Klebsiella bacteria can be spread through person-to-person contact. Patients in healthcare settings also may be exposed to Klebsiella when they are on ventilators (breathing machines), or have intravenous (vein) catheters or wounds (caused by injury or surgery),” says CDC.
Carbapenems are a class of highly effective antibiotics that are used for the treatment of severe or high-risk bacterial infections. However, says the research team, certain strains of K. pneumoniae are resistant to the carbapenem antibiotics that represent the last line of defense in treating infections and are, therefore, regarded as extremely drug-resistant (XDR).
“Increasingly, Klebsiella bacteria have developed antimicrobial resistance, most recently to the class of antibiotics known as carbapenems,” says the CDC.
Healthcare systems play a critical role in the bacteria's spread
For the study, more than 2,000 samples of K. pneumoniae were collected from patients across the hospitals surveyed and sent to the Wellcome Sanger Institute, where the genomes of 1,700 of them were sequenced.
The researchers identified a small number of genes that can cause resistance to carbapenem antibiotics. These genes, explains the team, produce enzymes called carbapenemases, which “chew up” the antibiotics, and make them useless. The analysis shows that hospitals are the principal facilitator of transmission - over half of the samples carrying a carbapenemase gene were closely related to others collected from the same hospital, suggesting that the bacteria are spreading from person-to-person primarily within hospitals.
Further, says the research team, antibiotic-resistant bacteria samples were also much more likely to be closely related to samples from a different hospital in the same country rather than across countries. This, according to the researchers, shows that national healthcare systems as a whole play an essential role in the spread of these antibiotic-resistant bacteria.
“Of concern to public health is the recent emergence of a small number of ‘high-risk’ clones carrying one or more carbapenemase genes, which have spread rapidly. It is thought that the heavy use of antibiotics in hospitals favors the spread of these highly-resistant bacteria, which outcompete other strains that are more easily treatable with antibiotics,” says the study.
According to the researchers, effective infection control in hospitals and good hospital hygiene - including early identification and isolation of patients carrying these bacteria - could help delay the spread of these pathogens, and even control them.
They say genomic surveillance will be key to tackling new breeds of antibiotic-resistant pathogen strains that this study has identified.
“Currently, new strains are evolving almost as fast as we can sequence them. This research emphasizes the importance of infection control and ongoing genomic surveillance of antibiotic-resistant bacteria to ensure we detect new resistant strains early and act to combat the spread of antibiotic resistance,” says the study.