The Growing Threat to Human Health: Antibiotic-Resistant Bacteria
In February, the World Health Organization (WHO) published their first list of antibiotic-resistant “priority pathogens”. This is a list of the most concerning bacteria that pose the “greatest threat to human health”. This list is divided into three levels of antibiotic-resistant bacteria based on their significance and potential impact to global health. The priority levels are listed as Priority 1 ‘Critical’, Priority 2 ‘High’ and Priority 3 ‘Medium’. Priority 1 (or ‘Critical’) is the most worrisome. It includes antibiotic-resistant Acinetobacter, Pseudomonas and various Enterobacteriaceae (including Klebsiella, Escherichia coli, Serratia, and Proteus species). These antibiotic-resistant gram-negative bacteria can cause serious infections, such as pneumonia and bloodstream infections, leading to significant morbidity and mortality.¹
Priority One: A Deeper Dive into Enterobacteriaceae:
Enterobacteriaceae are a group of bacteria that usually reside in the human gut. They have been watched carefully in recent years due to their significant multidrug resistance. This includes the difficult to treat Carbapenem resistant Enterobacteriaceae (CRE), which is resistant to ß-lactam (beta-lactam) antibiotics, including the “last line” carbapenem antibiotics. And, most recently in the US with the emergence of colistin resistance, which comes from a gene called the MCR-1 gene. Colistin is a “last-resort” antibiotic used to treat patients with multidrug-resistant infections such as CRE. The Centers for Disease Control and Prevention (CDC) states that CRE can contribute to death in up to 50% of patients who become infected.² And with colistin resistance, the outlook is even more ominous.
Even more concerning is the increase of multidrug resistance in children. A recent study looked at children under 18 years of age that were diagnosed with an Enterobacteriaceae-associated infection between January 1, 2007 and March 31, 2015. They reviewed data from 48 hospitals and about 94,000 children. The report showed a significant increase in MDR-GNE (Multidrug-resistant Gram-negative enteric Enterobacteriaceae) diagnosis with an Enterobacteriaceae-associated infection (0.2% in 2007 to 1.5% by 2015). This is an increase of more than 700%, with 23% of these infections defined as nosocomial (hospital acquired).³
Prevention of antibiotic resistance:
Antibiotic-resistant organisms such as CRE are increasing globally across all patient types. Prevention of antibiotic resistance is key! The CDC suggests five steps to slow global antibiotic resistance:
- “Awareness and education:Raising public awareness about this threat is an important first step.”
- “Surveillance:Countries need systems to track antimicrobial resistance and share findings with international partners.”
- “Infection, prevention and control:Infection control and hygiene are critical to stopping spread of resistant germs in healthcare settings.” [Infection control practices such as good hand hygiene, isolation precautions, and environmental cleaning/disinfection are critical in stopping transmission of multi-drug resistant organisms (MDROs). Typically patients with MDROs such as CRE are placed on standard and contact isolation precautions (use gowns and gloves) to prevent the transmission of these resistant organisms.]
- “Optimize use:Ensuring that antibiotics are still effective in the future requires that they be used correctly today.” [This includes antibiotic use in food supplies.]
- “R&D and investment:Research and development of new drugs, diagnostic tools and vaccines are a global priority.”⁴
These five steps highlight the importance of antibiotic stewardship, surveillance, infection prevention and the development of new antibiotics to combat the growing pandemic of antibiotic-resistant organisms. With careful attention to these priorities, the forecast for antibiotic-resistant bacteria such as CRE, becomes more optimistic.
¹World Health Organization (WHO). Global priority list of antibiotic-resistant bacteria to guide research, discovery, and development of new antibiotics. Feb 2017. Available from: http://www.who.int/medicines/publications/global-priority-list-antibiotic-resistant-bacteria/en/
²The Centers for Disease Control and Prevention (CDC). Carbapenem-resistant Enterobacteriaceae in Healthcare Settings. Last updated March 2016. Available from https://www.cdc.gov/hai/organisms/cre/
³Sharon B. Meropol, Allison A. Haupt, Sara M. Debanne; Incidence and Outcomes of Infections Caused by Multidrug-Resistant Enterobacteriaceae in Children, 2007–2015. J Pediatric Infect Dis Soc 2017 piw093. doi: 10.1093/jpids/piw093
⁴The Centers for Disease Control and Prevention (CDC). International Activities to Combat AR. Last updated Jan 2017. Available from: https://www.cdc.gov/drugresistance/us-activities/national-strategy.html