Antimicrobial resistance – when bacteria and other microbes that can cause infections gain the ability to resist treatment by antibiotics or other antimicrobial medicines – is a growing, global concern.
Pneumonia, urinary tract infections and sepsis are just some of the infections that are usually treated with antibiotics, write Oxford University’s Maria Nieto-Rosado, Katy Thomson, Kirsty Sands and Timothy Walsh in The Conversation, with newborn infants being particularly susceptible because of their immature immune systems.
Their risk is greatest in low- and middle-income countries, where infections among newborns are three to 20 times higher than in developed countries.
In 2020, 2.4m newborn babies died of sepsis in the first month of their lives, most of them in sub-Saharan Africa. Sepsis is an immune system overreaction to an infection somewhere in the body.
As researchers at the Ineos Oxford Institute for Antimicrobial Research, we carried out a study to investigate antimicrobial resistance-carrying bacteria recovered from surfaces in 10 hospitals from six low- and middle-income countries.
The hospitals were in South Africa, Bangladesh, Ethiopia, Nigeria, Pakistan and Rwanda.
In total, 6 290 hospital surface swabs were processed from intensive care units for newborns and maternity wards.
The swabs were taken from:
• surfaces near the sink drain (including sink/basin, taps, tap handles, and surrounding countertop)
• emergency neonatal care
• ward furniture and surfaces
• mobile medical equipment
• medical equipment.
Many of the surfaces were found to be colonised with bacteria carrying antibiotic resistance genes. The largest growth was detected near sink drains.
These genes can confer resistance to carbapenem antibiotics, which are last-resort therapies for treating newborn sepsis.
The findings are alarming. They indicate that newborn babies could be at risk of infection by bacteria that are resistant to antibiotics, possibly leading to sepsis.
Bacteria colonisation
In the study, whole genome sequencing was used to identify bacterial species carrying resistance to carbapenems – used when other medicines no longer work to treat an infection.
A total of 18 different bacterial species carrying carbapenem antibiotic resistant genes were recovered from hospital surfaces. These included bacteria that can cause pneumonia, urinary tract infections and blood infections.
In one of the hospitals, a bacterial clone present on surfaces was, at the same time, found causing sepsis among newborn babies.
This could mean that bacteria from the surfaces could potentially be transmitted to the infants. Future research will need to confirm this.
Antibiotic resistance genes are often found on mobile parts of DNA that can be passed from one bacterium to another – a process called horizontal gene transfer.
These mobile elements move between nearby bacteria, helping resistance genes to spread. This means that antibiotic resistance can quickly pass to different bacteria on the same surface or across various surfaces. It makes infections harder to treat and increases risks for patients.
Our findings highlighted the possible antimicrobial resistance spread between different types of bacteria on the same hospital surface or across different surfaces. This was due to the presence of similar mobile genetic elements in different bacterial species.
This puts patients at greater risk of infection, and could limit their treatment options because the bacteria infecting them are resistant to antibiotics.
Looking ahead
Antibiotic resistance is a substantial economic burden to the whole world.
In 2006 in the US alone, deaths associated with pneumonia and sepsis, mostly, cost the US economy $8bn.
Our work points to the need for an urgent review of infection prevention and control guidelines, especially in low- and middle-income countries.
A number of steps could reduce the risk of hospital-acquired infections.
For example, ensuring:
• safe drinking water
• vaccinations to reduce infection and the need for antibiotics
• hospital infrastructure for waste management and recycling
• tailored infection prevention and control programmes in health facilities, including cleaning and disinfecting hospital surfaces.
A major challenge is that hospitals in low-resourced countries may not have funds and resources needed to implement or maintain these measures.
Financial institutions and governments therefore ought to invest in these preventive programmes. Accessible, effective and sustainable infection prevention and control measures could prevent the deaths of thousands of newborn deaths.
Maria Nieto-Rosado, PhD student, University of Oxford; Katy Thomson, Postdoctoral researcher, University of Oxford; Kirsty Sands, Scientific Lead, Global Surveillance of Antimicrobial Resistance Research, University of Oxford; Timothy Walsh, Professor of Medical Microbiology, University of Oxford.
Study details
Colonisation of hospital surfaces from low- and middle-income countries by extended spectrum β-lactamase- and carbapenemase-producing bacteria
Maria Nieto-Rosado, Katy Thomson, Kirsty Sands, Timothy Walsh.
Published in Nature in March 2024
Abstract and Figures
Hospital surfaces can harbour bacterial pathogens, which may disseminate and cause nosocomial infections, contributing towards mortality in low- and middle-income countries (LMICs). During the BARNARDS study, hospital surfaces from neonatal wards were sampled to assess the degree of environmental surface and patient care equipment colonisation by Gram-negative bacteria (GNB) carrying antibiotic resistance genes (ARGs). Here, we perform PCR screening for extended-spectrum β-lactamases (blaCTX-M-15) and carbapenemases (blaNDM, blaOXA-48-like and blaKPC), MALDI-TOF MS identification of GNB carrying ARGs, and further analysis by whole genome sequencing of bacterial isolates. We determine presence of consistently dominant clones and their relatedness to strains causing neonatal sepsis. Higher prevalence of carbapenemases is observed in Pakistan, Bangladesh, and Ethiopia, compared to other countries, and are mostly found in surfaces near the sink drain. Klebsiella pneumoniae, Enterobacter hormaechei, Acinetobacter baumannii, Serratia marcescens and Leclercia adecarboxylata are dominant; ST15 K. pneumoniae is identified from the same ward on multiple occasions suggesting clonal persistence within the same environment, and is found to be identical to isolates causing neonatal sepsis in Pakistan over similar time periods. Our data suggests persistence of dominant clones across multiple time points, highlighting the need for assessment of Infection Prevention and Control guidelines.
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