Ege Bölgesindeki Deney Hayvanı Tesislerindeki Ratlarda Clostridium piliforme Varlığı

Abstract

Laboratuvar hayvanlarının sağlık durumu, araştırmaların güvenilirliği ve hayvan refahı açısından büyük önem taşır. Tyzzer hastalığının etkeni Clostridium piliforme, zorunlu hücre içi yaşayan ve spor oluşturan bir bakteridir. İmmün sistemi baskılanmış hayvanlarda yüksek mortaliteye yol açabilmesine rağmen, enfeksiyon genellikle subklinik seyredip kolonilerde uzun süre persiste olabilir. Bu tür latent enfeksiyonlar deneysel sonuçları olumsuz etkileyebileceğinden, düzenli sağlık izlemi büyük önem taşır. Bu çalışma, Türkiye’nin Ege Bölgesi’ndeki ruhsatlı laboratuvar hayvanı tesislerinde C. piliforme’nin varlığını ve yaygınlığını araştırmıştır. Sekiz tesisten her birinden 10’ar adet olmak üzere toplam 80 dışkı örneği toplanmış, DNA ticari bir kit kullanılarak ekstrakte edilmiş ve tür-spesifik primerlerle konvansiyonel PCR yöntemiyle analiz edilmiştir. Seksen örnekten dördü (%5,0) pozitif bulunmuş olup tamamı tek bir tesise aittir (%40,0; 4/10). Wilson skor yöntemiyle %95 güven aralığı 1,6–12,3 olarak hesaplanmış, Fisher’ın Kesin Testi ise tesisler arasında istatistiksel olarak anlamlı fark bulunduğunu göstermiştir (p<0,001). Bu bulgular, C. piliforme’nin Ege Bölgesi sıçanlarında ilk, Türkiye genelinde ise ikinci kez rapor edildiğini göstermekte; daha düşük prevalansın yöntemsel farklar ve tesis koşullarından kaynaklandığı düşünülmektedir. Çalışma, subklinik C. piliforme enfeksiyonlarının araştırma geçerliliği açısından oluşturduğu riski vurgulamakta ve bu patojenin FELASA tarafından önerilen rutin sağlık izleme programlarına dâhil edilmesinin gerekliliğini ortaya koymaktadır.

Keywords

• Clostridium piliforme
• conventional PCR
• laboratory animals
• rat
• Tyzzer’s disease

Presence of Clostridium piliforme in Rats from Laboratory Animal Facilities in the Aegean Region of Türkiye

Abstract

The health status of laboratory animals is essential for both research reliability and animal welfare. Clostridium piliforme, the causative agent of Tyzzer’s disease, is an obligate intracellular and spore-forming bacterium. While it may cause high mortality in immunocompromised animals, the infection often remains subclinical and can persist in colonies for long periods. Such latent infections may compromise experimental outcomes, making regular health monitoring highly important. This study aimed to investigate the presence and prevalence of C. piliforme in rats from licensed laboratory animal facilities in the Aegean Region of Türkiye. A total of 80 fecal samples, 10 from each of eight facilities, were collected. DNA was extracted using a commercial kit and analyzed by conventional PCR with species-specific primers. Of the 80 samples, four (5.0%) were positive, all originating from a single facility (40.0%, 4/10). The Wilson score method estimated a 95% confidence interval of 1.6–12.3, and Fisher’s Exact Test indicated a statistically significant difference among facilities (p<0.001).These findings represent the first report of C. piliforme in rats from the Aegean Region and the second in Türkiye. The prevalence was lower compared to national and international reports, likely due to methodological differences and facility conditions. The study emphasizes the potential risk of subclinical C. piliforme infections for research validity and highlights the necessity of including this pathogen in FELASA recommended routine health monitoring programs.

Keywords

• Clostridium piliforme
• conventional PCR
• laboratory animals
• rat
• Tyzzer’s disease

References

1. Aboellail, T.A., Naikare, H.K., & Mahapatra, D. (2013). A naturally occurring enterotyphlocolitis associated with dual infection by Clostridium piliforme and enteropathogenic attaching and effacing Escherichia coli in Syrian hamsters. Journal of Veterinary Science and Medicine, 1(1), 1–7. https://doi.org/10.13188/2325-4645.1000003
2. Baker, D.G. (1998). Natural pathogens of laboratory mice, rats, and rabbits and their effects on research. Clinical Microbiology Reviews, 11(2), 231–266. https://doi.org/10.1128/cmr.11.2.231
3. Besselsen, D.G. (2017). Infectious diseases of rats. In J.G. Fox, M.T. Davisson, F.W. Quimby, S.W. Barthold, C.E. Newcomer, & A.L. Smith (Eds.), Laboratory animal medicine (3rd ed., pp. 261–294). Academic Press.
4. Bracken, T.C., Cooper, C.A., Ali, Z., Truong, H., & Moore, J.M. (2017). Helicobacter infection significantly alters pregnancy success in laboratory mice. Journal of the American Association for Laboratory Animal Science, 56(3), 322–329.
5. Brown, L.D., Cai, T.T., & DasGupta, A. (2001). Interval estimation for a binomial proportion. Statistical Science, 16(2), 101–133. https://doi.org/10.1214/ss/1009213286
6. Clifford, C.B. (2008). Clostridium piliforme. In M.A. Suckow, S.H. Weisbroth, & C.L. Franklin (Eds.), The laboratory rat (pp. 411–424). Elsevier.
7. Fallahi, R., & Mansouri, M.A. (2017). Health monitoring of Razi Institute laboratory mice (NIH strain) to Clostridium piliforme in 1395. Veterinary Research on Biological Products, 30(4), 78–84.
8. Fisher, R.A. (1922). On the interpretation of χ² from contingency tables, and the calculation of P. Journal of the Royal Statistical Society, 85(1), 87–94. https://doi.org/10.2307/2340521

9. Ganaway, J.R., Allen, A.M., & Moore, T.D. (1971). Tyzzer’s disease. American Journal of Pathology, 64(3), 717–730.
10. Ganaway, J.R. (1980). Tyzzer’s disease: A review. Journal of the American Veterinary Medical Association, 177(9), 841–845.
11. İçil, N. İ ., & Erbaş, G. (2024). The prevalence of Helicobacter spp. in licensed experimental animal facilities in Aegean Region, Turkey. Laboratuvar Hayvan Bilimi Uygulamaları Dergisi, 4(1), 33–43. https://doi.org/10.5281/zenodo.10894467
12. İpek, E., Epikmen, E.T., Nuhay, Ç., & Tunca, R. (2023). Intense exercise stress may trigger Corynebacterium kutscheri infection in Sprague-Dawley rats. Veterinary Journal of Mehmet Akif Ersoy University, 8(2), 136–144. https://doi.org/10.24880/maeuvfd.1249794
13. Jacoby, R.O., & Lindsey, J.R. (1998). Health care and control of disease. In G.J. Krinke (Ed.), The laboratory rat (pp. 385–400). Academic Press.
14. Livingston, R.S., Riley, L.K., Steffen, E.K., Besch-Williford, C., Hook, R.R., & Franklin, C.L. (1997).Cytokine responses in rats infected with Clostridium piliforme. Laboratory Animal Science, 47(1), 48–52.
15. Mähler, M., Berard, M., Feinstein, R., Gallagher, A., Illgen-Wilcke, B., Pritchett-Corning, K., & Raspa, M. (2014). FELASA recommendations for the health monitoring of mouse, rat, hamster, guinea pig and rabbit colonies in breeding and experimental units. Laboratory Animals, 48(3), 178–192. https://doi.org/10.1177/0023677213516312
16. Matos-Rodrigues, G.E., Masseron, C.C., Silva, F.J., Frajblat, M., Moreira, L.O., & Martins, R.A. (2020). PCR-based detection of Helicobacter spp. in animal facilities of a university in Rio de Janeiro, Brazil. Anais da Academia Brasileira de Ciências, 92(4), e20200020. https://doi.org/10.1590/0001-3765202020200020
17. Merck Veterinary Manual. (2023). Tyzzer disease in animals. Merck & Co., Inc. https://www.merckvetmanual.com/digestive-system/tyzzer-disease/tyzzer-disease-in-animals
18. Newcombe, R.G. (1998). Two-sided confidence intervals for the single proportion: Comparison of seven methods. Statistics in Medicine, 17(8), 857–872.
19. Nicklas, W., Baneux, P., Boot, R., Decelle, T., Deeny, A.A., Fumanelli, M., & Illgen-Wilcke, B. (2002). Recommendations for the health monitoring of rodent and rabbit colonies in breeding and experimental units. Laboratory Animals, 36(1), 20–42. https://doi.org/10.1258/0023677021911740
20. Percy, D.H., & Barthold, S.W. (2007). Pathology of laboratory rodents and rabbits. Blackwell Publishing.
21. Sorzano, C.O. S., Sánchez, I., & Naranjo, A. (2024). Statistical design for health monitoring in laboratory animal facilities using sentinel animals. Laboratory Animals, 58(4), 345–353. https://doi.org/10.1177/00236772231219292
22. Ülker, U., Kızıl, S., Çeçen, E.M., & Aydın, E. (2024). Molecular diagnosis of Clostridium piliforme, the causative agent of Tyzzer’s disease in mice and rats. Laboratuvar Hayvan Bilimi Uygulamaları Dergisi, 4(2), 78–82. https://doi.org/10.62425/jlasp.1426993