Isolation of Tetracycline-Resistant Chlamydia suis from a Pig Herd Affected by Reproductive Disorders and Conjunctivitis

Antibiotics

Lukas Schwarz¹  Christine Unterweger¹  Martina Jelocnik²  René Brunthaler³  Aleksandra Inic-Kanada⁴  Hanna Marti⁵  Nicole Borel⁵ 

[1] Department for Farm Animals and Veterinary Public Health, University Clinic for Swine, University of Veterinary Medicine, 1210 Vienna, Austria;Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia;Institute of Pathology, Department of Pathobiology, University of Veterinary Medicine, 1210 Vienna, Austria;Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, 1090 Vienna, Austria;Institute of Veterinary Pathology, Vetsuisse Faculty University Zurich, 8057 Zurich, Switzerland;

关键词: Chlamydia suis;    fertility problems;    conjunctivitis;    minimal inhibition concentration;    multilocus sequence typing;    recovery testing;   

DOI  :  10.3390/antibiotics9040187

来源: DOAJ

【 摘 要 】

Due to various challenges in diagnosing chlamydiosis in pigs, antibiotic treatment is usually performed before any molecular or antibiotic susceptibility testing. This could increase the occurrence of tetracycline-resistant Chlamydia (C.) suis isolates in the affected pig population and potentiate the reoccurrence of clinical signs. Here, we present a case of an Austrian pig farm, where tetracycline resistant and sensitive C. suis isolates were isolated from four finishers with conjunctivitis. On herd-level, 10% of the finishers suffered from severe conjunctivitis and sows showed a high percentage of irregular return to estrus. Subsequent treatment of whole-herd using oxytetracycline led to a significant reduction of clinical signs. Retrospective antibiotic susceptibility testing revealed tetracycline resistance and decreased susceptibility to doxycycline in half of the ocular C. suis isolates, and all isolates were able to partially recover following a single-dose tetracycline treatment in vitro. These findings were later confirmed in vivo, when all former clinical signs recurred three months later. This case report raises awareness of tetracycline resistance in C. suis and emphasizes the importance of preventative selection of tetracycline resistant C. suis isolates.

【 授权许可】

Unknown