In response to outbreaks of multidrug-resistant (MDR) Shigella across multiple regions worldwide, conventional antibiotic treatments are increasingly losing effectiveness. UV-C LED disinfection technology, characterized by its “physical inactivation with no resistance risk,” provides a frontline barrier in interrupting transmission pathways. It complements pharmacological treatment by forming an integrated “prevention–treatment” framework. The following analysis, supported by authoritative research, compares the two approaches and highlights the scientific value of UV-C LEDs in Shigella control.
1. Challenges of Multidrug-Resistant Shigella: Limitations of Antibiotic Therapy
According to the latest CDC surveillance report (2025), the proportion of extensively drug-resistant (XDR) Shigella in the United States has risen from nearly zero in 2011 to 8.5% in 2023 , indicating a worsening trend in resistance spread.
Shigella, an enteric pathogen transmitted primarily via the fecal–oral route, spreads rapidly through contaminated water, food, and close contact. Infection can cause severe diarrhea and abdominal pain, with serious cases progressing to renal failure or septicemia .
The effectiveness of commonly used antibiotics such as amoxicillin, ceftriaxone, and ciprofloxacin continues to decline. Currently, no approved oral first-line treatment is fully effective against MDR strains. Moreover, antibiotics only treat infected individuals and do not eliminate environmental reservoirs of pathogens, leaving public health transmission pathways unaddressed. Widespread antibiotic use further accelerates resistance selection, intensifying the “post-antibiotic” crisis.
2. Mechanism of UV-C LED Disinfection and Its Efficacy Against Shigella
UV-C LEDs emit deep ultraviolet light (200–280 nm), with peak microbial absorption around 260–265 nm. This radiation is absorbed by nucleic acids (DNA/RNA), particularly pyrimidine bases such as thymine, inducing the formation of pyrimidine dimers (primarily thymine dimers, as well as cytosine dimers and cytosine–thymine dimers).
These dimers disrupt the DNA double-helix structure, blocking replication and transcription, thereby rendering microorganisms—including bacteria, viruses, and fungi—unable to reproduce and infect . As a purely physical mechanism independent of metabolic pathways, UV-C disinfection is effective regardless of antibiotic resistance and does not induce resistance development.
Chourabi et al. demonstrated that multiple Shigella strains are highly sensitive to UV-C radiation. The study confirmed that UV-C is effective across all tested strains, with inactivation efficiency dependent on dose. Transmission electron microscopy revealed structural damage in surviving cells, including cytoplasmic disorganization and membrane disruption, along with alterations in outer membrane proteins, secreted proteins, and lipopolysaccharides .
3. Core Differences: Complementary Roles of UV-C LED Disinfection and Drug Therapy
These two approaches are not substitutes but complementary components of a comprehensive Shigella control strategy, differing in several key aspects:
1. Stage of Action: Upstream Prevention vs Downstream Treatment
UV-C LED disinfection: A preventive measure acting at the upstream stage of transmission. By disinfecting water, food, surfaces, and wastewater before human exposure, it reduces environmental pathogen loads and prevents infection at the source .
Drug therapy: A reactive intervention targeting infected individuals. Antibiotics help control symptoms and disease progression but do not address environmental contamination or protect uninfected populations.
2. Target Scope: Broad-Spectrum vs Specific Action
UV-C LED disinfection: Broad-spectrum and non-selective, effective against all bacteria including resistant strains. It can simultaneously inactivate Shigella, E. coli, Salmonella, and other enteric pathogens, making it suitable for public health applications .
Drug therapy: Strain-specific, with reduced efficacy against MDR organisms. Long-term use may disrupt gut microbiota and increase the risk of secondary infections.
3. Resistance Risk: None vs Escalating
UV-C LED disinfection: Physical inactivation does not induce microbial resistance. Repeated application maintains consistent efficacy without contributing to resistance evolution.
Drug therapy: Antibiotic use applies selective pressure, promoting the emergence of stronger resistant strains and reinforcing the cycle of resistance development.
4. Integrated Strategy: UV-C LED Pre-Disinfection + Drug Therapy
In the face of MDR Shigella, relying solely on antibiotics is insufficient. A combined strategy of “UV-C LED pre-disinfection + drug therapy” establishes a comprehensive control system:
UV-C LED pre-disinfection: Reduces pathogen transmission via water, food, and environmental surfaces, lowering infection rates and alleviating healthcare burden. For example, deploying UV-C LED systems in community drinking water treatment can effectively block waterborne transmission.
Drug therapy as clinical support: Provides targeted treatment for infected patients, preventing severe outcomes. Coupled with antimicrobial susceptibility testing, it enables more precise and responsible antibiotic use.
This integrated model balances population-level prevention with individual-level treatment, enhancing both public health control and clinical outcomes.
5. Conclusion and Outlook
The rise of multidrug-resistant Shigella underscores the limitations of traditional antibiotic-based strategies in public health. UV-C LEDs, operating in the 260–280 nm range where nucleic acid absorption is maximized, offer highly effective microbial inactivation without chemicals or disinfection by-products.
Crucially, UV-C targets DNA directly—an essential structure independent of metabolic pathways—making resistance development unlikely, unlike antibiotics that act on specific biochemical targets.
As UV-C LED technology continues to advance—achieving higher efficiency, lower cost, and smarter system integration—its applications in drinking water safety, food processing, healthcare environments, and community sanitation will expand. It is poised to become a key tool in combating antimicrobial resistance and enabling sustainable infectious disease control.
References
1. Logan N, B.M.M.S., et al., DR Shigella Working Group. Emergence of Extensively Drug-Resistant Shigellosis - United States. MMWR Morb Mortal Wkly Rep., 2026. 13(75): p. 173-178.
2. Scott TA, B.K., et al., Shigella Sonnei Epidemiology, Evolution Pathogenesis Resistance And. Nat Rev Microbiol, 2025. 5(23): p. 303-317.
3. Song K, T.F.M.M., Microorganisms inactivation by wavelength combinations of ultraviolet light-emitting diodes (UV-LEDs). Sci Total Environ, 2019: p. 665:1103-1110.
4. Song K, M.M.T.F., Application of ultraviolet light-emitting diodes (UV-LEDs) for water disinfection: A review. Water Res, 2016(94:341-349).
5. Chourabi K, C.S., K.S. Rodriguez JA and C.A. Landoulsi A, UV-C Adaptation of Shigella: Morphological, Outer Membrane Proteins, Secreted Proteins, and Lipopolysaccharides Effects. Curr Microbiol., 2017. 11(74): p. 1261-1269.
6. Shin JY, K.S. and K.D. Kim DK, Fundamental Characteristics of Deep-UV Light-Emitting Diodes and Their Application To Control Foodborne Pathogens. Appl Environ Microbiol, 2015. 1(82): p. 2-10.
