Javier Anibal Origlia¹ | Gustavo Daneri² | Marco Tizzano³ | Hernan Sguazza³ | Ana Harrington² | Esperanza Varela² | Maria Estela Cadario⁴

1. Catedra de Patología de Aves y Pilíferos, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Buenos Aires, Argentina; 2. Museo Argentino Ciencias Naturales “Bernardino Rivadavia” (MACN-CONICET), CABA, Argentina; 3. Laboratorio de Virología, Facultad Ciencias Veterinarias Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina; 4. Departamento Bacteriología. INEI-ANLIS “Dr. Carlos G. Malbrán”. Ciudad Autónoma de Buenos Aires. Argentina.

Ponente: Javier Anibal Origlia, javieroriglia@yahoo.com

Chlamydial agents have been described in a wide range of vertebrates. Despite this, few information is available on these bacteria in marine mammals. The aim of this study was the detection and molecular characterization of Chlamydiaceae in pinnipeds that inhabit the marine littoral zone of Río Negro province (Argentina). Between December 2017 and March 2022, respiratory samples were obtained from 12 pinniped specimens (5 alive and 7 dead) from Punta Bermeja and Promontorio Belen rookeries located on the north coast of the San Matías Gulf. Two Mirounga leonina (SES) and three Otaria byronia (SASL) individuals were anesthetized and nasal swabs were subsequently obtained. Additionally, nasal and/or tracheal swabs were taken from seven SASL specimens found dead with a grade 2 carcass conservation status. All samples were stored in transport medium and refrigerated. After DNA extraction with a commercial kit, a Chlamydiaceae-specific qPCR (23S rRNA) was performed and positive samples were rechecked with a Chlamydia psittaci-specific qPCR (ompA). An endpoint PCR (ompA) was used to obtain products to be sequenced. From 16 samples examined (12 nasal swabs and 4 tracheal swabs) Chlamydiaceae was identified in 3 nasal swabs (1 SES and 2 SASL) and in 1 tracheal swab with traces. All samples were negative for detection of Chlamydia psittaci. It was possible to sequence one of the nasal samples which showed 92.8% identity with Chlamydia felis when analyzed with BLAST. This is the first report of Chlamydiaceae-DNA being found in SES and SASL. Taking into account this finding, we consider of great importance to enhance this type of studies on the different populations of pinnipeds in Argentina and elsewhere. This will permit to determine whether or not these microorganisms are pathogenic and if they are typical of pinnipeds or they derive from anthropogenic impacts. Funds were partially provided by Zebra foundation.