Abstract

Sulfonamides, once widely effective antibiotics, now face escalating resistance due to decades of overuse in clinical and agricultural settings. This narrative review synthesizes evidence (2000-2024) on the evolutionary drivers of resistance, highlighting key mechanisms such as folP gene mutations, the acquisition of sul1, sul2, and sul3 resistance genes via mobile genetic elements, and efflux pump activation. Resistance proliferation is exacerbated by environmental contamination—particularly in hospital effluents and manure- treated soils—where antibiotic residues select for resistant strains and facilitate gene transfer to human pathogens. Clinical misuse (e.g., subtherapeutic dosing) further accelerates resistance, complicating infections like UTIs and respiratory diseases. Emerging data underscore the need for integrated strategies: antimicrobial stewardship to curb unnecessary prescriptions, surveillance of resistance hotspots (e.g., wastewater, livestock), and policy reforms to limit agricultural overuse. Combination therapies (e.g., trimethoprim-sulfamethoxazole) may delay resistance, but long-term solutions require a One Health approach. This review equips clinicians with insights to navigate sulfonamide resistance while advocating for systemic interventions to preserve antibiotic efficacy.

Keywords: Sulfonamides, infection, resistance, gene, sul, folP.

INTRODUCTION

One of the earliest synthetic antimicrobial agents in the 1930s was the sulfonamide, also referred to as sulfa drug. Sulfa drugs function by inhibiting the bacterial enzyme dihydropteroate synthase (DHPS); which is involved in the synthesis of folate [1]. Bacteria require folate to produce DNA and other vital biomolecules. Sulfonamides have played an enormous role in the treatment of many infections, such as urinary tract infections, pneumonia, and wound infections [2]. However, in the last few decades, the emergence and proliferation of resistance have derailed their effectiveness [3]. The evolution of sulfonamide resistance is associated with a variety of adaptive mechanisms, which include the accumulation of point mutations in the gene encoding DHPS, such as the folP gene and horizontally transferred resistance genes such as sul1, sul2, and sul3 [4]. These pathways allow pathogens to circumvent or surpass the inhibition of folate synthesis, making treatment with sulfonamide less effective [5]. Resistance has also been noted in several different bacterial species including Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus; the concern is that sulfonamides have low effectiveness in contemporary clinical settings [6].

However, in the last few years research efforts have been focused on innovative therapeutic strategies to overcome sulfonamide resistance. Some of the approaches included novel inhibitors of folate pathways, combination therapies with synergistic antibiotics and bacteriophage therapy, which demonstrate promise in preclinical models [7, 8]. Furthermore, genomic surveillance and molecular diagnostics are more frequently used for the surveillance of resistance patterns and for the facilitation of personalized treatment strategies and for optimizing the use of sulfonamides [9]. In an environmental study, research was done on multiple water samples and the result showed that the presence of sul1, sul2, and sul3 is associated with resistance [10]. Research reports the rising threat of infections caused by multi-drug resistant (MDR) bacteria anti-microbial resistance (AMR), which is a significant challenge [11]. Research also described sulfonamide resistance mechanisms from the literature and claims that enzyme production, efflux systems, target site modification and genetic factors are frequently involved in drug resistance [12].

Therefore, the purpose of this narrative review article was to conduct a complete analysis of the evolutionary aspects of sulfonamide resistance in bacterial pathogens. This also entailed a comprehensive search for the mutant genes and sites, including the DHPS gene, which helps gain insight into how bacteria acquire new genetic information to evade the effects of sulfonamides. At the same time, the review will account for the individual ecological and environmental factors that contribute to the selection of resistant strains and further release them into different environments where such release may favor the proliferation of resistance.

METHODOLOGY

The methodology of our current narrative review comprises the following sub-elements: an article search, eligibility criteria, information resources, search strategy, study selection, extraction of data, synthesis of the data, risk of bias assessment, statistical analysis, and results reporting after qualifying the eligibility criteria. Studies considered were based on the inclusion criteria of reporting mechanisms of resistance to sulfonamide, the prevalence of resistance genes and new therapeutic approaches published between 2000 and 2024. In qualifying studies, exclusion criteria included those written in a language other than English, reviews, case reports, and research lacking original information regarding mechanisms of resistance and treatment strategies. A thorough search was conducted from the databases of PubMed, web of science, google scholar, sciencedirect, springer and directory of open access journals. The keywords "sulfonamide resistance", "DHPS mutations", "antibiotic resistance" and "therapeutic strategies" were employed for carrying out this work.

Data extraction was carried out using a standardized form to record the following: study type, design, publication year, resistance mechanisms, objectives of the study and main findings. Qualitative synthesis was carried out on the incorporated studies; findings related to resistance mechanisms and the appropriate therapeutic approaches for them were thematically consolidated.

RESULTS AND DISCUSSION

After the careful review of the literature, the results were summarized in Table 1 pertaining to the resistance of sulfonamides. This review tries to detail the evolutionary dynamics of sulfonamide resistance and discuss modern therapeutic strategies by efficiently combating resistant infections [13]. Among the general goals, one of the most important is the explanation of the reasons why resistance genes have stable conditions, such as an absence of the effects of antibiotics [14]. It is also imperative to discuss how sulfonamide resistance is maintained by the conjugational transfer in bacteria; processes of adaptations in bacteria and sustainability of sulfonamide resistance [15]. Further research indicated that sulfonamide resistance is due to sul2 gene and the resistance rate is 5.2%-100% (avg. 57.4%) [16]. In Biochemical and microbiological analysis, the mechanism for resistance is primary mutations (F17L, S18L, and T51M) and secondary mutations (E208K, KE257 dup) that result in resistant structural transformation as observed in 56 S. aureus reference strains and 80 non-redundant S. aureus [17]. One of the studies where two soil-type samples were treated with manure shows that sul1 and sul2 genes are resistant to sulfadiazine [18].

Several studies make an excellent contribution to understanding the mechanisms of sulfonamide resistance development across various settings, especially from a clinical and laboratory perspective. [19]. One important aspect that recurs in these works is the various mutations, gene additions, or even drug efflux that lead to the development of resistance [19]. The various studies, for example, observe that mutations within the DHPS and folP genes are implicated in resistance by changing the enzyme's ability to bind to the drug target [20]. Several studies have detected sul1, sul2, and sul4 genes in soils and aquatic environments, especially those that have been subject to farming activities [21]. The results showed that farming activities could act as a source of development of antimicrobial- resistant genes and pose a higher risks to the public health systems [12, 22]. Studies on the presence of wastewater contaminants have also shown that almost all sul genes are predominantly detected in cities, which is alarming as it indicates that such resistance genes located in water systems for the communities may be hard to eradicate [23].

From a clinical point of view, various publications advocate for the monitoring of genetic alterations and sul gene distribution in various environments since such changes pose difficulties in treatment. For instance, Pseudomonas isolates from clinical samples have shown that in the presence of gene mutations, efflux pumps may work together in enhancing resistance, which presents challenges for the treatment of patients [25]. In the same way, it has been documented through enzyme kinetics studies that some mutations in dihydropteroate synthase (DHPS) interfere with the binding of sulfa drugs [32]. The recent evidence corroborated that the generation of sulfonamide-resistant strains is caused by selective genetic mutations, sheep-like horizontal gene transfer, and environmental factors [35]. Several pieces of evidences indicated that amino acid substitutions in genes known as folP and DHPS are present in multiple bacteria (e.g. E. coli and S. aureus), where such mutations diminish the drug binding affinity and eventually efficacy of sulfonamide drugs. [35]. Moreover, the environmental research further indicated that certain farming practices, such as the application of manure, enhanced the dissemination of antibiotic resistance genes into the soil and water, since sul genes can disseminated through mobile genetic elements to wide bacterial populations [35]. Also, genomic surveying of the effluent discharged from hospitals, other public health facilities, fecal and febrile wastes has shown that sul1 and sul2 genes exist in high frequencies, suggesting a worrying expansion of resistance in natural and clinical environments [36]. On top of this, the studies showed the role of efflux pumps, which are commonly performed alongside sulfonamide- specific gene mutations as additional mechanisms of resistance [37]. These observations establish the necessity for effective management of containments from health care and agricultural systems by active surveillance and other environmental interventions [38].

Sulfonamide resistance is a major threat to antimicrobial therapy and its solution will require a multidisciplinary approach to understanding its evolution and management. Recently, the discovery of the fourth mobile sulfonamide resistance gene was identified and it gives alarm that how dynamic resistance evolution is occurring [17]. Due to the new identifcation of resistance gene, it was also further studied and new genomic features of antimicrobial resistance in Escherichia coli was noted [18]. Scientists also worked on wastewater in their studies and monitored sulfonamide resistance in different geographical regions [20]. The work was also done on enzymatic engineering and whole- genome sequencing; the methodologies employed revealed cutting-edge tools for studying the sulfonamide resistance pathways and therapeutic targets [39]. These studies strongly indicate that the resistance to sulfonamide could be perceived as undergoing changes in nature and could be seen as a momentum towards precision in surveillance, genomic analyses, and therapy. The surveillance of resistance and combination therapy may lead to heightened success of the treatment. New treatment options including the new generation of folate antagonists, combinations of antibiotics, and bacteriophages are promising but still have to be further researched to be clinically useful.

CONCLUSION

The sulfonamide resistance presents a serious challenge to the healthcare systems; these resistances of organisms are due to mechanisms such as folP mutations, acquisition of sul genes, and efflux pump activities. Genomic understanding, environmental management, and new therapies may provide strategic management of resistance.

RECOMMENDATIONS

The agricultural phenomenon of manure spreader chains of resistance; therefore, better regulatory policies are warranted. Combination therapy may lead to the success of the treatment and a reduction in resistance. New treatment options are required by future research that interact with folate metabolism. This multifaceted strategy will be critical in the fight against sulfonamide resistance and for the protection of public health services.

FUNDING

None.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

ACKNOWLEDGEMENTS

Declared none.

AUTHORS' CONTRIBUTION

SAK supervised the whole review and finalized the manuscript; WM conceived the idea, collected and evaluated the data; MS validated the data and wrote the initial draft of manuscript.

REFERENCES

1. Sánchez-Osuna M, Cortés P, Barbé J, Erill I. Origin of the mobile di- hydro-pteroate synthase gene determining sulfonamide resistance in clinical isolates. Front Microbiol 2019; 9(1): 3332. DOI: https://doi.org/10.3389/fmicb.2018.03332

2. Rohilla S, Sharma D. Sulfonamides, quinolones, antiseptics, and disinfectants. In: Acharya PC, Kurosu M, Eds. Medicinal Chemistry of Chemotherapeutic Agents. 1st ed. Tripura, India: Elsevier; 2023. pp. 21-63

3. Ovung A, Bhattacharyya J. Sulfonamide drugs: Structure, antibacterial property, toxicity, and biophysical interactions. Biophys Rev 2021; 13(2): 259-72. DOI: https://doi.org/10.1007/s12551-021-00795-9

4. Santos-Lopez A, Marshall CW, Haas AL, Turner C, Rasero J, Cooper VS. The roles of history, chance, and natural selection in the evolution of antibiotic resistance. Elife 2021; 10(1): e70676. DOI: https://doi.org/10.7554/eLife.70676

5. Ebmeyer S, Kristiansson E, Larsson DJ. A framework for identifying the recent origins of mobile antibiotic resistance genes. Commun Biol 2021; 4(1) : 8. DOI: https://doi.org/10.1038/s42003-020-01545-5

6. Ravishankar U, Sathyamurthy P, Thayanidhi P. Antimicrobial resistance among uropathogens: Surveillance report from South India. Cureus 2021; 13(1): e12913. DOI: https://doi.org/10.7759/cureus.12913

7. Bouhrour N, Nibbering PH, Bendali F. Medical device-associated biofilm infections and multidrug-resistant pathogens. Pathogens 2024; 13(5): 393. DOI: https://doi.org/10.3390/pathogens13050393

8. Laxminarayan R, Duse A, Wattal C, Zaidi AK, Wertheim HF, Sumpradit N, et al. Antibiotic resistance—the need for global solutions. Lancet Infect Dis 2013; 13(12): 1057-98. DOI: https://doi.org/10.1016/S1473-3099(13)70318-9.

9. Arshad MJ, Khan MI, Ali MH, Farooq Q, Hussain MI, Seleiman MF, et al. Enhanced wheat productivity in saline soil through the combined application of poultry manure and beneficial microbes. BMC Plant Biol 2024; 24(1): 423. DOI: https://doi.org/10.1186/s12870-024-05137-x

10. Wang N, Yang X, Jiao S, Zhang J, Ye B, Gao S. Sulfonamide- resistant bacteria and their resistance genes in soils fertilized with manures from Jiangsu Province, Southeastern China. PLoS one 2014; 9(11): e112626. DOI: https://doi.org/10.1371/journal.pone.0112626

11. Shindoh S, Kadoya A, Kanechi R, Watanabe K, Suzuki S. Marine bacteria harbor the sulfonamide resistance gene sul4 without mobile genetic elements. Front Microbiol 2023; 14(1): 1230548. DOI: https://doi.org/10.3389/fmicb.2023.1230548

12. Gan Y, Qi G, Hao L, Xin T, Lou Q, Xu W, et al. Analysis of whole- genome as a novel strategy for animal species identification. Int J Mol Sci 2024; 25(5): 2955. DOI: https://doi.org/10.3390/ijms25052955

13. Laborda P, Sanz-García F, Ochoa-Sánchez LE, Gil-Gil T, Hernando- Amado S, Martínez JL. Wildlife and antibiotic resistance. Front Cell Infect Microbiol 2022; 12(1): 873989. DOI: https://doi.org/10.3389/fcimb.2022.873989

14. Moher D, Liberati A, Tetzlaff J, Altman DG, Group P. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. Int J Surg 2010; 8(5): 336-41. DOI: https://doi.org/10.1016/j.ijsu.2010.02.007

15. Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ 2021; 372(1): n71. DOI: https://doi.org/10.1136/bmj.n71

16. Cassir N, Million M, Noudel R, Drancourt M, Brouqui P. Sulfonamide resistance in a disseminated infection caused by Nocardia wallacei: A case report. J Med Case Rep 2013; 7(1): 103. DOI: https://doi.org/10.1186/1752-1947-7-103

17. Razavi M, Marathe NP, Gillings MR, Flach C-F, Kristiansson E, Joakim Larsson D. Discovery of the fourth mobile sulfonamide resistance gene. Microbiome 2017; 5(1): 160. DOI: https://doi.org/10.1186/s40168-017-0379-y

18. Saini P, Bandsode V, Singh A, Mendem SK, Semmler T, Alam M, et al. Genomic insights into virulence, antimicrobial resistance, and adaptation acumen of Escherichia coli isolated from an urban environment. Mbio 2024; 15(3): e03545-23. DOI: https://doi.org/10.1128/mbio.03545-23

19. Bouiller K, David MZ. Staphylococcus aureus genomic analysis and outcomes in patients with bone and joint Infections: A systematic review. Int J Mol Sci 2023; 24(4): 3234. DOI: https://doi.org/10.3390/ijms24043234

20. Tierney BT, Foox J, Ryon KA, Butler D, Damle N, Young BG, et al. Towards geospatially-resolved public-health surveillance via wastewater sequencing. Nat Commun 2024; 15(1): 8386. DOI: https://doi.org/10.1038/s41467-024-52427-x

21. Demissie S, Mekonen S, Awoke T, Mengistie B. Dynamics of spatiotemporal variation of groundwater arsenic in central Rift Vally of Ethiopia: A serial cross-sectional study. Environ Health Insights 2024; 18(1): 1-11. DOI: https://doi.org/10.1177/11786302241285391

22. Watanabe S, Nsofor CA, Thitiananpakorn K, Tan X-E, Aiba Y, Takenouchi R, et al. Metabolic remodeling by RNA polymerase gene mutations is associated with reduced β-lactam susceptibility in oxacillin-susceptible MRSA. Mbio 2024; 15(6): e00339-24. DOI: https://doi.org/10.1128/mbio.00339-24

23. Valzano F, La Bella G, Lopizzo T, Curci A, Lupo L, Morelli E, et al. Resistance to ceftazidime–avibactam and other new β-lactams in Pseudomonas aeruginosa clinical isolates: A multi-center surveillance study. Microbiol Spectr 2024; 12(8): e04266-23. DOI: https://doi.org/10.1128/spectrum.04266-23

24. Jiang H, Dong Y, Jiao X, Tang B, Feng T, Li P, et al. In vivo fitness of sul gene-dependent sulfonamide-resistant Escherichia coli in the mammalian gut. Msystems 2024; 9(9): e00836-24. DOI: https://doi.org/10.1128/msystems.00836-24

25. García-González N, Cancino-Muñoz I, Sánchez-Busó L, González-Candelas F. Genomic Epidemiology and Surveillance of Antimicrobial Resistance. In: Tibayrenc M, editor. Infect Genet Evol. 1. 3rd ed. Montpellier, France: Elsevier; 2024. pp. 291-316.

26. Tettey R, Egyir B, Tettey P, Arko-Mensah J, Addo SO, Owusu- Nyantakyi C, et al. Genomic analysis of multidrug-resistant Escherichia coli from Urban Environmental water sources in Accra, Ghana, Provides Insights into public health implications. PLoS One 2024; 19(5): e0301531. DOI: https://doi.org/10.1371/journal.pone.0301531

27. Mushunje PK, Dube FS, Olwagen C, Madhi S, Odland JØ, Ferrand RA, et al. Characterization of bacterial and viral pathogens in the respiratory tract of children with HIV-associated chronic lung disease: A case-control study. BMC Infect Dis 2024; 24(1): 1-17. DOI: https://doi.org/10.1186/s12879-024-09540-5

28. Noreen S, Sumrra SH, Chohan ZH, Mustafa G, Imran M. Synthesis, characterization, molecular docking and network pharmacology of bioactive metallic sulfonamide-isatin ligands against promising drug targets. J Mol Struct 2023; 1277(1): 134780. DOI: https://doi.org/10.1016/j.molstruc.2022.134780

29. Venkatesan M, Fruci M, Verellen LA, Skarina T, Mesa N, Flick R, et al. Molecular mechanism of plasmid-borne resistance to sulfonamide antibiotics. Nat Commun 2023; 14(1): 4031. DOI: https://doi.org/10.1038/s41467-023-39778-7

30. Langella E, Esposito D, Monti SM, Supuran CT, De Simone G, Alterio V. A combined in silico and structural study opens new perspectives on aliphatic sulfonamides, a still poorly investigated class of Ca inhibitors. Biology 2023; 12(2): 281. DOI: https://doi.org/10.3390/biology12020281

31. Uddin TM, Chakraborty AJ, Khusro A, Zidan BRM, Mitra S, Emran TB, et al. Antibiotic resistance in microbes: History, mechanisms, therapeutic strategies and future prospects. J Infect Public Health 2021; 14(12): 1750-66. DOI: https://doi.org/10.1016/j.jiph.2021.10.020

32. Van Duijkeren E, Schink AK, Roberts MC, Wang Y, Schwarz S. Mechanisms of bacterial resistance to antimicrobial agents. AMR 2018; 54(12): 1420-33. DOI: https://doi.org/10.1093/ajhp/54.12.1420

33. Buwembo W, Aery S, Rwenyonyi C, Swedberg G, Kironde F. Point mutations in the folP gene partly explain sulfonamide resistance of Streptococcus mutans. Nt J Microbiol 2013; 2013(1): 1-6. DOI: https://doi.org/10.1155/2013/367021

34. Heuer H, Solehati Q, Zimmerling U, Kleineidam K, Schloter M, Müller T, et al. Accumulation of sulfonamide resistance genes in arable soils due to repeated application of manure containing sulfadiazine. AEM 2011; 77(7): 2527-30. DOI: https://doi.org/10.1128/AEM.02577-10

35. Woods RJ, Barbosa C, Koepping L, Raygoza JA, Mwangi M, Read AF. The evolution of antibiotic resistance in an incurable and ultimately fatal infection: A retrospective case study. Evol Med Public Health 2023; 11(1): 163-73. DOI: https://doi.org/10.1093/emph/eoad012

36. Ndagi U, Falaki AA, Abdullahi M, Lawal MM, Soliman ME. Antibiotic resistance: bioinformatics-based understanding as a functional strategy for drug design. RSC Adv 2020; 10(31): 18451-68. DOI: https://doi.org/10.1039/D0RA01484B

37. Baquero F, Martinez JL, F. Lanza V, Rodríguez-Beltrán J, Galán JC, San Millán A, et al. Evolutionary pathways and trajectories in antibiotic resistance. Clin Microbiol Rev 2021; 34(4): e00050-19. DOI: https://doi.org/10.1128/CMR.00050-19

38. Hossain AZ, Chowdhury AMA. Understanding the evolution and transmission dynamics of antibiotic resistance genes: A comprehensive review. J Basic Microbiol 2024; 64(10): e2400259. DOI: https://doi.org/10.1002/jobm.202400259

39. Gu J, Li L, Wang J, Su X, Zou M, Xu Y, et al. Integrated engineering at distal site and active center regulates stereoselectivity and activity of carbonyl reductase towards N-Boc-pyrrolidone. Mol Catal 2024; 558(1): 114057. DOI: https://doi.org/10.1016/j.mcat.2024.114057