Molecular typing of Treponema pallidum isolates from Buenos Aires, Argentina: Frequent Nichols-like isolates and low levels of macrolide resistance

A total of 54 clinical samples, including genital lesion swabs, whole blood and cerebrospinal fluid from patients diagnosed with syphilis were collected in 2006 and in 2013 in Buenos Aires, Argentina. Treponemal DNA was detected in 43 of the analyzed samples (79.6%) and further analyzed using Sequencing-based molecular typing (SBMT) and Enhanced CDC-typing (ECDCT). By SBMT, 10 different Treponema pallidum subsp. pallidum (TPA) genotypes were found, of which six were related to the TPA SS14 strain, and four to the TPA Nichols strain. The 23S rRNA gene was amplified in samples isolated from 42 patients, and in six of them (14.3%), either the A2058G (four patients, 9.5%) or the A2059G (two patients, 4.8%) mutations were found. In addition to Taiwan, Madagascar and Peru, Argentina is another country where the prevalence of Nichols-like isolates (26.8%) is greater than 10%.Fil: Gallo Vaulet, Maria Lucia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Grillová, Linda. Masaryk University; República ChecaFil: Mikalová, Lenka. Masaryk University; República ChecaFil: Casco, Ricardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Pando, María de los Ángeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Smajs, David. Masaryk University; República Chec

Incorporation of the rapid HIV test in a sexually-transmitted disease clinic in Buenos Aires: Dramatic increase in the frequency of HIV diagnosis

Improving access to diagnosis constitutes a key step in the control of the Human immunodeficiency virus (HIV)/AIDS epidemic. Rapid testing is increasingly gaining interest as a powerful diagnostic tool to achieve this goal. The purpose of this study was to implement the rapid HIV test (RHT) in a clinical setting in order to evaluate its effectiveness in increasing HIV diagnosis and patient linkage to the healthcare system. The RHT was offered to all patients attending a sexually-transmitted disease clinic in the City of Buenos Aires between March and December 2015. A total of 593 RHT were performed. The implementation of the RHT yielded an increase in frequency of diagnosis from 6.9% to 31.4% (p < 0.001). The first steps of the care cascade showed high retention rates around 90%. RHT yielded an HIV prevalence of 6.3% (95% CI: 4.2–8.5) in this population. HIV prevalence tended to be higher in individuals with no previous HIV testing (p = 0.09). Linkage to the healthcare system was associated with a higher probability of having been tested for HIV (p = 0.008). The incorporation of the RHT resulted in a high retention of patients and an increase in both frequency of diagnosis and results reception when compared to the classic methodology. Resumen El mejoramiento del acceso al diagnóstico constituye un punto clave en el control de la epidemia del virus de la inmunodeficiencia humana (Human immunodeficiency virus: HIV)/sida. El testeo rápido se ha convertido en una poderosa herramienta diagnóstica de interés para alcanzar este objetivo. El propósito de este estudio fue la implementación del test rápido del HIV (TRH) en un contexto clínico con el fin de evaluar su efectividad para incrementar la tasa de diagnóstico de HIV y la vinculación de los pacientes al sistema de salud. Se ofreció el TRH a todos los pacientes que acudieron a una clínica de enfermedades de transmisión sexual en la Ciudad Autónoma de Buenos Aires entre marzo y diciembre del 2015. Se realizaron un total de 593 TRH. La implementación del TRH resultó en un aumento en la frecuencia de diagnóstico del 6,9 al 31,4% (p < 0,001). Los primeros pasos en la cascada de cuidados mostraron altas tasas de retención alrededor del 90%. La prevalencia del HIV según TRH en la población de estudio fue del 6,3% (IC 95%: 4,2-8,5), tendiendo a ser mayor en individuos sin testeo previo de HIV (p = 0,09). La vinculación al sistema de salud se asoció a una mayor probabilidad de haber sido testeado previamente para HIV (p = 0,008). La incorporación del TRH resultó en una mayor retención de los pacientes, así como en un aumento tanto en la frecuencia de diagnóstico como en la de retiro de resultados, en comparación con la metodología clásica.Fil: Morando, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Gallo Vaulet, Maria Lucia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Melgar, Asunta. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Casco, Ricardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Pando, María de los Ángeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Evaluation of the utility of a rapid test for syphilis at a sexually transmitted disease clinic in Buenos Aires, Argentina

Even though syphilis can be easily diagnosed by simple and low-cost laboratory methods, it continues to be an important health problem. Rapid tests (RT) for the detection of treponemal antibodies can facilitate earlier diagnosis, access to treatment and linkage to care. The aim of this study was to analyse the usefulness of the incorporation of a RT in the detection of patients infected with T. pallidum in a sexually-transmitted disease (STD) clinic. Between March and December 2015, a syphilis RT was offered to patients who spontaneously attended the clinic. Conventional serology testing was additionally indicated to every participant. The RT for syphilis was offered to 1887 patients, of whom 31.1% agreed to get tested. VDRL test was performed in 84.0% of patients that were also tested with syphilis RT, with a significantly higher frequency observed among participants with reactive RT (94.3% vs. 79.8%, p < 0.001). These results showed that 33.7% of the participants were reactive for the RT and 27.0% were reactive for the VDRL test. Both tests were reactive in 24.9% and non-reactive in 64.3%. A high prevalence of active syphilis was detected in patients attending the clinic. The use of a syphilis RT had a positive impact, which in combination with the VDRL test increased the number of patients that were effectively diagnosed.Fil: Gallo Vaulet, Maria Lucia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Morando, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Casco, Ricardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Melgar, Asunta. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Nacher, Silvia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Pando, María de los Ángeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Incidence of Chlamydia trachomatis and other potential pathogens in neonatal conjunctivitis.

Abstract Objective: Ocular infection in neonatology is a permanent and important health problem. To improve primary attention, prevention, and control, the study of the potential bacterial etiology of all consecutive cases of conjunctivitis was incorporated as a regular procedure in primary care from July 1995 to December 1998. Materials and Methods: Prof. A. Posadas Hospital (Great Buenos Aires) has an average of 4294 births per year. This report analyzes the results obtained in 332 infants (age range, 0–30 d) with conjunctivitis. Clinical conjunctivitis was diagnosed in inpatients and outpatients by the same specialized staff. Isolation and characterization of bacteria were done by conventional microbiologic methods, including specific search for Neisseria gonorrhoeae and Chlamydia trachomatis . Chlamydia trachomatis was studied by antigen immunodetection and polymerase chain reaction, and genotyped by restriction fragment length polymorphism. Results: Conjunctivitis had an incidence (cases per 1000 live births) of 39.6 in 1995, 25.3 in 1996, 15.4 in 1997, and 15.2 in 1998. Microbial growth was detected in 167 (50.3%) of 332 cases. Ocular C. trachomatis infection was detected in 26 cases (7.83%). Five of seven isolates in tissue cultures belonged to type E and two to type G. Bacteria from respiratory ecology were the main isolates: Haemophilus influenzae (16.9%), Streptococcus pneumoniae (12.3%), and Staphylococcus aureus (8.7%). Haemophilus influenzae isolates were not serotyped and 17.2% of them were β-lactamase producers. In 15 cases both H. influenzae and S. pneumoniae were isolated together. Of S. pneumoniae , 4,9% were oxacillin resistant. Conclusions: There has been a decline in the total number of cases of neonatal conjunctivitis, but the disease is still an important health problem. Chlamydia trachomatis also shows a decreasing profile with an incidence of (cases per 1000 live births) 4.39 in 1995, 1.85 in 1996, 1.01 in 1997, and 0.78 in 1998, and a tendency to show more incidence in spring-summer and significant accumulation of cases in babies between 7 and 9 days of age. Haemophilus influenzae alone (12.3%) or associated with S. pneumoniae (4.5%) appears as a prevalent potential bacterial pathogen. A significant accumulation of H. influenzae and S. pneumoniae cases occurs in winter. In 47.6% of cases, there was no bacterial growth. No significant seasonal differences in percentage of negative cultures or among the three-day age groups were detected. Neisseria gonorrhoeae was not found associated with ophthalmia neonatorum in this series

Importancia en el sistema de salud de la infección por Treponema pallidum, la enfermedad de Chagas y el virus de la inmunodeficiencia humana 1 en amerindios de Argentina: un estudio observacional

El objetivo de este trabajo fue estimar la prevalencia de Treponema pallidum, Trypanosoma cruzi y virus de la inmunodeficiencia humana (HIV-1) en 5 comunidades originarias de Argentina. Para ello, se realizó un estudio retrospectivo en 857 individuos (112 kollas, 298 mbyá-guaraníes, 79 sagua huarpes, 368 wichis) desde el 2007 hasta el 2010. Se realizó el diagnóstico completo para T. pallidum, T. cruzi y HIV-1. En todas las comunidades se confirmaron infecciones por T. pallidum y T. cruzi con una prevalencia total del 4,2 y del 16,8%, respectivamente. Aunque no se detectó HIV-1, sífilis y Chagas, representan un desafío para el sistema de salud, teniendo que reforzarse las estrategias de salud pública teniendo en cuenta el aislamiento socio-económico que sufren estas poblaciones.The objective of this study was to estimate the prevalence of Treponema pallidum, Trypanosoma cruzi and Human immunodeficiency virus 1 (HIV-1) in five Amerindian populations of Argentina. A retrospective study was conducted among 857 Amerindian populations (112 Kollas, 298 Mbyá-guaraníes, 79 Sagua Huarpes, 368 Wichis) from 2007 to 2010. Screening and confirmation of T. pallidum, T. cruzi and HIV-1 were performed. T. pallidum and T. cruzi infections were detected in all communities with an overall prevalence rate of 4.2% and 16.8%, respectively. Although HIV was not detected, syphilis and Chagas’ disease represent a challenge for the health care system and the reinforcement of public health strategies is necessary considering the socioeconomic isolation of these populations.Fil: Eirin, Maria Emilia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Delfino, Cecilia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Pedrozo, Williams René. Provincia de Misiones. Banco de Sangre Central; ArgentinaFil: Malan, Richard. Provincia de Misiones. Banco de Sangre Central; ArgentinaFil: Puca, Alberto. Laboratorio de Bioquímica "A. A. Puca"; ArgentinaFil: de Rissio, Ana María. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Espejo, Rogelio. Provincia de San Juan. Ministerio de Salud. Hospital Público "Dr. Guillermo Rawson". Laboratorio Central; ArgentinaFil: Gallo Vaulet, Maria Lucia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Biglione, Mirna Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Berini, Carolina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Renal dopaminergic system: pathophysiological implications and clinical perspectives

Fluid homeostasis, blood pressure and redox balance in the kidney are regulated by an intricate interaction between local and systemic anti-natriuretic and natriuretic systems. Intrarenal dopamine plays a central role on this interactive network. By activating specific receptors, dopamine promotes sodium excretion and stimulates anti-oxidant and anti-inflammatory pathways. Different pathological scenarios where renal sodium excretion is dysregulated, as in nephrotic syndrome, hypertension and renal inflammation, can be associated with impaired action of renal dopamine including alteration in biosynthesis, dopamine receptor expression and signal transduction. Given its properties on the regulation of renal blood flow and sodium excretion, exogenous dopamine has been postulated as a potential therapeutic strategy to prevent renal failure in critically ill patients. The aim of this review is to update and discuss on the most recent findings about renal dopaminergic system and its role in several diseases involving the kidneys and the potential use of dopamine as a nephroprotective agent.Fil: Choi, Marcelo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Kouyoumdzian, Nicolás Martín. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Fisiopatología; ArgentinaFil: Rukavina Mikusic, Natalia Lucía. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Fisiopatología; ArgentinaFil: Kravetz, Maria Cecilia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Roson, Maria Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Fisiopatología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Rodríguez Fermepin, Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Fisiopatología; ArgentinaFil: Fernandez, Belisario Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Case report: viral shedding for 120 days in an allergic child with Covid 19

Since it was first detected in Dec 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread through the planet causing the novel coronavirus disease, Covid-19. Here, we report the case of a 9-year-old girl with persistent viral shedding based on RT-PCR detection. Her first positive (Ct=36) dated from March 4 2021, came in a preoperative physical examination (scheduled tonsillectomy), with no apparent symptoms. Her father fell ill and tested positive soon after that casual finding. Surgery was postponed. The patient came positive again on July 1 2021 (Ct=33) and on July 29 2021 (Ct=29). She had a persistent cough, which was also compatible with her allergic condition. Her surgery could not be postponed any longer and was operated on July 30 2021. Excised adenoids and tonsils were extensively rubbed with a swab to test whether the material detected resulted infectious or not, on Vero E6 cell cultures. Based on the absence of any cytopathic effect, we found it was not infective, even upon an intended amplification by a second passage. RT-PCR was negative when performed on the last supernatant. The histological pattern of her tonsillar and adenoid tissue was analyzed through H&E staining and immune cell populations were examined by FACS. Both aspects were compatible with her hyperplastic condition and also with a viral infection. We tested the anti-Spike specific response by ELISA on serum samples taken on Aug 6 2021 (IgM=1.34, cut off=0.584 and IgG=3.27, cut off=0.364). Finally, we determined the neutralizing antibodies titer on the same serum, using the wild type SARS-CoV-2 (titre=32, the mean of infected adults is 64). We concluded that, albeit the long period the genetic material of the virus was detected on her swabs, the patient does not seem to have a major immunological deficiency and could mount an appropriate immune response against the virus. Importantly, we demonstrated she was not able to transmit virus at the time of the surgery.Fil: Paletta, Ana Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Puyssegur, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Husain, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Gallo Vaulet, Lucía. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cabral, Cecilia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Paoli, Bibiana Patricia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Arana, Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaAnnual Meeting of Bioscience Societies 2021: LXVI Annual Meeting of Sociedad Argentina de Investigación Clínica (SAIC), LXIX Annual Meeting of Sociedad Argentina de Inmunología(SAI), LIII Annual Meeting of Asociación Argentina de Farmacología Experimental (AAFE), XI Annual Meeting of Asociación Argentina de Nanomedicinas (NANOMED-Ar)ArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaAsociación Argentina de Farmacología ExperimentalAsociación Argentina de Nanomedicin

Violence as a Barrier for HIV Prevention among Female Sex Workers in Argentina

Violence against female sex workers (FSWs) has been increasingly reported as an important determinant of HIV infection risk. This study explores the frequency of different violent experiences (sexual abuse, rejection, beating and imprisonment) among FSWs in Argentina and its association with condom use and HIV and T. pallidum prevalence.Fil: Pando, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomedicas en Retrovirus y Sida; Argentina; Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiologia. Centro Nacional de Referencia del Sida; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Coloccini, Romina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomedicas en Retrovirus y Sida; Argentina; Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiologia. Centro Nacional de Referencia del Sida; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Reynaga, Elena. Asociación de Mujeres Meretrices de Argentina; Argentina;Fil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina;Fil: Gallo Vaulet, Maria Lucia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina;Fil: Kochel, Tadeusz J.. United States Naval Medical Research Unit nº 6; Perú;Fil: Montano, Silvia M.. United States Naval Medical Research Unit nº 6; Perú;Fil: Avila, Maria Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomedicas En Retrovirus y Sida; Argentina; Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Cátedra de Microbiología Parasitología e Inmunología; Argentina

Chlamydiaceae-Like Bacterium in Wild Magellanic Penguins (Spheniscus magellanicus)

The family Chlamydiaceae is comprised of obligate intracellular bacteria, some of which are significant pathogens of humans and domestic animals. Magellanic penguins (Spheniscus magellanicus) are susceptible to Chlamydia psittaci outbreaks in captivity, and serological surveys detected antibodies against C. psittaci (or antigenically similar organisms) in wild populations of this species. To investigate the occurrence of Chlamydiaceae in wild Magellanic penguins, 167 cloacal swabs were collected from apparently healthy individuals at four breeding colonies along the coast of Chubut, Argentina. Real-time PCR revealed the presence of DNA from Chlamydiaceae-like bacteria in 61 cloacal swabs (36.5%). Detection did not correlate to nutritional status or to meaningful hematological abnormalities. Isolation in monkey kidney cells was unsuccessful, but DNA sequences for the 16S–23S rRNA region were obtained from one sample. Phylogenetic analysis showed a close relationship to unidentified Chlamydiaceae-like bacteria found in chinstrap penguins (Pygoscelis antarcticus) in Antarctica and seagulls in France and the Bering Sea, and to Chlamydiifrater spp. isolated from flamingos in France. Further studies are necessary to clarify the taxonomy and investigate the epidemiology, pathogenicity, and zoonotic potential of this group of Chlamydiaceae-like bacteria.Fil: Gallo Vaulet, Lucía. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Vanstreels, Ralph Eric Thijl. University of California at Davis; Estados UnidosFil: Gallo, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Entrocassi, Andrea Carolina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Peker, Laura Alejandra. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Blanco, Gabriela Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Rago, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Uhart, Marcela María. University of California at Davis; Estados Unido