Emerging Threat: Colistin-Resistant Bacteria Found in Wastewater
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Understanding the Colistin Resistance Crisis
Recent findings have uncovered a troubling reality regarding antibiotic resistance. Researchers at the University of Georgia have identified the MCR-9 gene, which confers resistance to colistin, in municipal wastewater across the United States. This discovery is alarming because colistin, known as the “antibiotic of last resort,” is administered when other antibiotics fail. The World Health Organization (WHO) classifies this drug as critically important for treating serious infections.
In their examination of wastewater, the researchers were surprised to find the resistance gene in the very first sample collected, suggesting its prevalence in the US, as noted by Prof. Ismar Kassem, an expert in the global distribution of this gene.
The specific bacterium harboring this colistin resistance gene was identified as Morganella morganii, which raises further concerns. This is the first recorded instance of such a resistance gene in this species, which is typically found in the intestines of various mammals, including humans.
Impact of Agriculture and Antibiotic Use
Prof. Kassem emphasizes that the widespread nature of colistin-resistant bacteria is likely greater than previously understood, primarily because M. morganii has not been commonly tested for this resistance. Historically, the overuse of colistin, particularly in agriculture, has been blamed for the rise of resistant strains. Its use in veterinary medicine was only prohibited in China in 2016 and in India in 2019, where it was often added to animal feed as a precautionary measure.
Bacteria such as E. coli and Salmonella in livestock can develop the ability to resist colistin. The global food trade facilitates the movement of these resistant strains across borders, and bacteria can transfer genes among themselves through a process known as horizontal gene transfer. This means that microbes from animals can pass on resistance capabilities to pathogens affecting humans.
Consequences of Resistance and the Future of Antibiotics
Colistin, discovered in 1949, was infrequently used due to its side effects. It became a treatment of last resort for infections resistant to carbapenems, another class of critical antibiotics. However, the emergence of colistin-resistant strains poses significant risks for both human and veterinary medicine.
Prof. Kassem warns that if colistin loses its effectiveness, routine surgical procedures could become as perilous as they were before the advent of antibiotics. The WHO has cautioned that the 21st century may see a rise in deaths from minor infections, such as pharyngitis or skin infections, due to antibiotic-resistant bacteria.
Preventing Further Resistance: Strategies and Recommendations
To combat antibiotic resistance, it is crucial to use antibiotics judiciously, only when necessary. Many infections, such as the flu or common cold, are viral and do not benefit from antibiotic treatment. Antibiotics should only be taken when prescribed by a healthcare professional, and patients must complete the full course of treatment, even if symptoms improve.
In ideal scenarios, doctors should conduct tests to determine which antibiotic will effectively target the bacteria involved, rather than resorting to broad-spectrum treatments that could encourage resistance.
Additionally, adherence to proper hand hygiene protocols, as promoted by the WHO since 2009, is essential in healthcare settings. These practices help prevent the transmission of antibiotic-resistant bacteria, which often spread via contaminated hands.
The challenge of developing new antibiotics remains significant. Despite the ambition to discover 20 new antibiotics by 2020, only eight were identified, none of which effectively combat strains producing metallo-beta-lactamases, known for degrading many antibiotics, including carbapenems.
Awareness of this ongoing crisis is vital. Researchers and health professionals must work collaboratively to ensure that antibiotics remain effective tools in combating infections.
The first video titled "USC scientists find antibiotic-resistant bacteria growing in LA's wastewater" discusses the discovery of resistant bacteria in urban wastewater systems, highlighting the implications for public health.
The second video titled "Antimicrobial resistance is increased at wastewater treatment plants" explores how wastewater treatment facilities can contribute to the spread of antimicrobial resistance, emphasizing the need for better monitoring and management.