Tracking and Surveillance of Antibiotic Resistance
Better monitoring and tracking will help reduce risk
Monitoring and tracking antibiotic resistance are essential tools in reducing the public health threat of antibiotic resistance. This surveillance data of both human and animal antibiotic use and resistance is critical for improved understanding of ever-evolving bacterial pathogens and the identification of effective, prudent treatment options in humans and animals. Surveillance of emerging drug resistant genes is happening in 50 hospital microbiology labs across the United States.
Additionally, the U.S. government closely tracks antibiotic resistance through the National Antimicrobial Resistance Monitoring System (NARMS), a cooperative program among:
FDA, which coordinates the program and monitors resistant bacterial pathogens in retail meats;
CDC, which collects samples from public health laboratories to monitor the emergence of antibiotic-resistant foodborne pathogens in humans;
USDA’s Agricultural Research Service, which collects samples to monitor for antibiotic resistance trends in foodborne bacteria from animals at slaughter.
This graph shows the percentage of resistance from human infections over the last 15 years for four drugs that could be used to treat Salmonella infections. For virtually all drugs, resistances have shown a significant decrease or no change from 2000-2015,and even at their highest were not strongly resistant.
The antibiotics of choice for Campylobacter jejuni are macrolides, represented in this graph by azithromycin and erythromycin and fluoroquinolones, represented in this graph by ciprofloxacin. Resistance to the fluoroquinolones has been relatively high for C. jejuni before and after the removal of that class of antibiotics in poultry, and it has continued to slightly increase in humans after withdrawal. It is important to note that fluoroquinolones were never approved for use in feed or for growth promotion. Two other drugs that are mentioned as possible treatments are included in this graph (clindamycin and gentamicin).
To understand more about how antibiotic residues are monitored and controlled, see this link.
Trends in foodborne bacteria
NARMS tests pathogen isolates for susceptibility to 17 different antimicrobial compounds. More than 50,000 Salmonella and Campylobacter samples have been tested in all three arms of the NARMS program. Some important trends that FDA has noted in recent years portrays an encouraging picture — the resistance in foodborne bacteria is low and on the decline:
· Approximately 80% of human Salmonella isolates are not resistant to any of the tested antibiotics. This has remained relatively stable over the past ten years. Resistance for three important drugs (ceftriaxone, azithromycin and ciprofloxacin) in human non-typhoidal Salmonella isolates remained below 3%.
· Over the past ten years, multidrug resistance (MDR) has remained unchanged in human Salmonella isolates (~10%) and in cattle and chicken isolates collected the USDA Pathogen Reduction/Hazard Analysis and Critical Control Point program (PR/HACCP; ~20%). There was a decline in the proportion of retail chicken Salmonella that were multidrug resistant compared to the 2008-2012 average.
· Campylobacter jejuni and Campylobacter coli cause about 90% and 10% of human campylobacter infections, respectively. In retail chicken samples, C. jejuni resistance to ciprofloxacin was at its lowest level to date (11%), while ciprofloxacin resistance in C. jejuni isolated from chicken slaughter samples has not declined (22% in 2013). The prevalence of Campylobacter in retail chicken samples has gradually declined over the past 9 years.