Çanakkale Rekreasyonel Kıyı Sularında Antibiyotik Dirençli Bakterilerin İncelenmesi

Öz

Bu çalışma, artan kentleşme, denizcilik faaliyetleri ve mevsimsel turizm nedeniyle insan kaynaklı baskı altındaki Türkiye’nin Çanakkale Boğazı kıyılarındaki rekreasyonel sularda antibiyotik dirençli bakterilerin yaygınlığını araştırmaktadır. 2024 yaz döneminde, 14 farklı rekreasyonel kıyı noktasından alınan yüzey deniz suyu örneklerinden toplam 211 bakteri izolatı elde edilmiştir. Bu izolatlar, VITEK® 2 Compact sistemi kullanılarak tanımlanmış ve CLSI (2018) standartlarına uygun şekilde Kirby-Bauer disk difüzyon yöntemi ile 15 farklı antibiyotiğe karşı test edilmiştir.Sonuçlar, en yüksek direnç oranlarının sırasıyla vankomisin (%92,89), kanamisin (%81,04) ve sülfonamidler grubu (%64,45) antibiyotiklere karşı geliştiğini göstermiştir. Multiple Antibiotic Resistance (MAR) indeks değerleri 0.14 ile 0.71 arasında değişmiş; izolatların %95’inden fazlası ≥ 0.2 değerinde bulunarak yüksek riskli çevresel maruziyeti işaret etmiştir. En sık izole edilen çoklu dirençli bakteri türleri arasında Escherichia coli, Enterococcus faecalis, Staphylococcus intermedius ve Bacillus cereus yer almıştır.Türkiye’de yapılan diğer denizel çalışmalarla karşılaştırmalı analizler, Çanakkale kıyı sularının antibiyotik kontaminasyonundan önemli ölçüde etkilendiğini doğrulamaktadır. Elde edilen bulgular, direnç genlerinin kıyı ekosistemlerinde yayılımını önlemek amacıyla düzenli çevresel izleme ve atık su arıtma stratejilerinin güçlendirilmesi gerekliliğini vurgulamaktadır. Bu çalışma, denizel antibiyotik dirençliliği konusunda ulusal veri tabanı için temel veri sağlamakta ve rekreasyonel su yoluyla dirençli bakterilere maruz kalmanın halk sağlığı açısından oluşturduğu risklerin altını çizmektedir.

Anahtar Kelimeler

• antibiyotik dirençliliği
• heteretrofik bakteri
• deniz suyu
• Çanakkele Boğazı

Assessment of Antibiotic-Resistant Bacteria in Recreational Coastal Waters of Çanakkale, Türkiye

Öz

This study investigates the prevalence of antibiotic-resistant bacteria in recreational coastal waters along the Çanakkale Strait (Türkiye), a region experiencing increasing anthropogenic pressure from urbanization, maritime activity, and seasonal tourism. A total of 211 bacterial isolates were obtained from surface seawater samples collected at 14 different recreational coastal sites during the summer season of 2024. These isolates were identified using the VITEK® 2 Compact system and tested against 15 antibiotics via the Kirby-Bauer disk diffusion method, following CLSI (2018) guidelines. The results revealed alarmingly high resistance rates, with vancomycin (92.89%), kanamycin (81.04%), and sulphonamides (64.45%) being the most affected. The Multiple Antibiotic Resistance (MAR) index ranged from 0.14 to 0.71, with over 95% of isolates scoring ≥ 0.2, indicating exposure to high-risk environments. Escherichia coli, Enterococcus faecalis, Staphylococcus intermedius and Bacillus cereus were among the most frequently isolated multidrug-resistant species. Comparative analysis with other marine studies from Türkiye confirms that Çanakkale’s coastal waters are significantly impacted by antibiotic contamination. The findings highlight the urgent need for regular surveillance and enhanced wastewater treatment strategies to mitigate the spread of resistance genes in coastal ecosystems. This study contributes essential baseline data to the national inventory on marine antibiotic resistance and underscores the public health risks posed by recreational waterborne exposure to resistant bacteria.

Anahtar Kelimeler

• antibiotic resistance
• Heterotrophic
• bacteria
• marine water
• Çanakkale Strait

Kaynakça

1. Al-Bahry S, Mahmoud IY, Al-Belushi KIA, Elshafie AE, Al-Harthy A, Bakheit CK (2009). Coastal sewage discharge and its impact on fish with reference to antibiotic-resistant enteric bacteria and enteric pathogens as bio-indicators of pollution. Chemosphere, 77, 1534– 1539. https://doi.org/10.1016/j.chemosphere.2009.09.052
2. Altuğ, G., Çardak, M., Türetken, P. S. Ç., Kalkan, S., & Gürün, S. (2020). Antibiotic and heavy metal resistant bacteria isolated from Aegean Sea water and sediment in Güllük Bay, Turkiye. Johnson Matthey Technology Review. https://doi.org/10.1595/205651320x15953337767424
3. Baquero, F., Martínez, J. L., & Cantón, R. (2008). Antibiotics and antibiotic resistance in water environments. Current Opinion in Biotechnology, 19(3), 260–265. https://doi.org/10.1016/j.copbio.2008.05.006
4. Baş, S. D. K., Altuğ, G., & Türetken, P. S. Ç. (2024). Frequency of Antibiotic-Resistant Bacteria isolated from the Kınalıada Coastal Areas of the Sea of Marmara, Türkiye. Aquatic Sciences and Engineering, 39(4), 216-221.
5. CLSI. (2018). Performance Standards for Antimicrobial Disk Susceptibility Tests (13th ed.). Clinical and Laboratory Standards Institute. CLSI Standard M02.
6. Çardak, M., Altug, G., Ay, M., & Erol, Ö. (2016). Distribution of antibiotic resistance and the presence of vancomycin-resistance genes (vanA and vanB) in Enterobacteriaceae isolated from the Sea of Marmara, the Canakkale Strait and the Istanbul Strait, Turkiye. Oceanological and Hydrobiological Studies, 45(2), 182–190. https://doi.org/10.1515/ohs-2016-0017
7. Çiftçi Türetken, P. S., Kalkan, S., & Altuğ, G. (2025). Investigation of multiple resistance frequencies (antibiotic and heavy metal) of bacteria isolated from Gökçeada Island coastal marine sediment. Aquatic Research, 8(1), 1–11. https://doi.org/10.3153/AR25001
8. Das S, Lyla PS, Khan SA.(2006). Marine microbial diversity and ecology: importance and future perspectives. Current Science. 90(10):1325–1335.

9. Delgado-Baquerizo, M., Maestre, F. T., Reich, P. B., Jeffries, T. C., Gaitan, J. J., Encinar, D., ... & Singh, B. K. (2016). Microbial diversity drives multifunctionality in terrestrial ecosystems. Nature communications,7(1), 10541.
10. Dewi, D. A. R., Thomas, T., Ahmad Mokhtar, A. M., Mat Nanyan, N. S., Zulfigar, S. B., & Salikin, N. H. (2021). Carbapenem Resistance among Marine Bacteria—An Emerging Threat to the Global Health Sector. Microorganisms, 9(10), 2147.
11. Di Cesare, A., Vignaroli, C., Luna, G. M., Pasquaroli, S., Biavasco, F. (2012) Antibiotic resistant enterococci in seawater and sediments from a coastal fish farm. Microbial Drug Resistance 18(5):502-9 DOI: 10.1089/ mdr.2011.0204
12. Kaçar, A., Koçyiğit, A., & Uluturhan, E. (2013). Heavy Metal Tolerance of Sediment Bacteria Isolated from Coastal City (Izmir, Turkiye). Rapports et procès-ver-baux des réunions Commission internationale pour l'exploration scientifique de la Mer Méditerranée, 40(410), Marseille France.
13. Krumperman, P. H. (1983). Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of fecal contamination of foods. Applied and Environmental Microbiology, 46(1), 165–170. https://doi.org/10.1128/aem.46.1.165-170.1983
14. Kümmerer, K. (2009). Antibiotics in the aquatic environment–a review–part II. Chemosphere, 75(4), 435–441. https://doi.org/10.1016/j.Chemosphere.2008.11.086
15. Larsson, D. G. J. (2014). Antibiotics in the environment. Upsala Journal of Medical Sciences, 119(2), 108–112. https://doi.org/10.3109/03009734.2014.896438
16. Marti, E., Variatza, E., & Balcazar, J. L. (2014). The role of aquatic ecosystems as reservoirs of antibiotic resistance. Trends in Microbiology, 22(1), 36–41. https://doi.org/10.1016/j.tim.2013.11.001
17. Matyar, F., Kaya, A., & Dinçer, S. (2008). Antibacterial agents and heavy metal resistance in Gram-negative bacteria isolated from seawater, shrimp and sediment in Iskenderun Bay, Turkiye. Science of the Total Environment, 407(1), 279–285. https://doi.org/10.1016/j.scitotenv.2008.08.014
18. Sabatino, R., Sbaffi, T., Sivalingam, P., Corno, G., Fontaneto, D., & Di Cesare, A. (2023). Bacteriophages limitedly contribute to the antimicrobial resistome of microbial communities in wastewater treatment plants. Microbiology Spectrum, 11(5), e01101-23.
19. Toraskar, A. D., Manohar, C. S., Fernandes, C. L., Ray, D., Gomes, A. D., & Antony, A. (2022). Seasonal variations in the water quality and antibiotic resistance of microbial pollution indicators in the Mandovi and Zuari estuaries, Goa, India. Environmental Monitoring and Assessment, 194(2), 71.
20. Twala SN.(2023). Antibiotic resistance profiling of marine bacterial communities in South African coastal waters [master’s thesis]. Potchefstroom, South Africa: North-West University; 2023.
21. Van Assche A.(2019). Marine pollution and emerging antibiotic resistance: the role of Sphingomonadaceae. [master’s thesis]. Leuven, Belgium: KU Leuven; 2019.
22. Zeglin, L. H. (2015). Stream microbial diversity in response to environmental changes: review and synthesis of existing research. Frontiers in microbiology, 6, 454.
23. Zhang, G., Lu, S., Wang, Y., Liu, X., Liu, Y., Xu, J., ... & Yang, Y. (2020). Occurrence of antibiotics and antibiotic resistance genes and their correlations in lower Yangtze River, China. Environmental Pollution, 257, 113365.