ompA Sequencing and Multilocus Sequence Typing of Lymphogranuloma Venereum Cases in Buenos Aires Reveal New Chlamydia trachomatis Genotypes.

Since the Lymphogranuloma venereum (LGV) outbreak was first described in Buenos Aires in 2017, the detected strains presented peculiar characteristics. Our goal was to increase the understanding of the strains involved in the LGV outbreak in Argentina. We characterized the ompA gene sequences, using Sanger sequencing, of 88 LGV strains from 239 symptomatic patients in Buenos Aires enrolled between 2017 and 2019, and selected 20 C. trachomatis strains for further characterization using Multilocus Sequence Typing (MLST). Following the ompA gene analysis of the 88 LGV strains, we detected 43% L2b, 31% L1-like, and 26% L2. Among the 38 L2b samples analyzed, there were 7 distinct sequences, 3 of them not previously reported (L2bv12, L2bv13, and L2bv14). Additionally, we detected a strain with a new mutation (AM884176.1:g.59122A>T) found in the position defining L2 or L2b, proposed as L2i. Using MLST, five different sequence types (STs) were detected, including the ST2 (corresponding to the L1-like strains) and a new one (ST60). ST58 was associated with the concomitant presence of another STI and HIV. A high genetic diversity in C. trachomatis LGV strains in Argentina was observed in a short period of time, with a relatively low number of samples from a limited geographical area.

Analysis of the value of copper erythrocyte concentration measurement in the diagnosis of copper deficiency in bovines.

BACKGROUND: A reliable and practical method for assessing Cu status in live animals is not available. Blood Cu levels may not accurately reflect the true Cu status of the herd, and can over-predict Cu status during stress and inflammation. On the other hand, assessment of liver Cu is the most reliable indicator of Cu stores, but it is an invasive procedure that requires specialized training. The aim of this study was to evaluate the usefulness of Cu levels in red blood cells to determine the Cu status, with special emphasis in their correlation with erythrocyte Cu, Zn superoxide dismutase enzyme activity (ESOD), in bovines with Cu deficiency induced by high molybdenum and sulfur levels in the diet. METHODS: Three similar assays were performed, with a total of twenty eight calves. The Cu-deficient group (n = 15) received a basal diet supplemented with 11 mg of Mo/kg DM as sodium molybdate, and S as sodium sulfate. The control group (n = 13) received a basal diet supplemented with 9 mg of Cu/kg DM as copper sulfate. Samples of blood and liver were taken every 28-35 days. Cu levels were measured in liver (expressed as µg/g DM), plasma (expressed as µg/dl), and erythrocytes (expressed as µg/g Hb) by flame atomic absorption spectroscopy. Superoxide dismutase (SOD1) activity was determined in red blood cells and was expressed as IU/mg hemoglobin. InfoStat Statistical Software 2020 was used for the statistical analysis. Cu levels in plasma, red blood cells and liver, and ESOD activity were analyzed by ANOVA. The correlation between erythrocyte Cu levels and the rest of the parameters were analyzed by Pearson Correlation test. Unweighted Least Squares Linear Regression of SOD1 was developed. The autocorrelation between the monthly measurements was also determined by Durbin-Watson test and autocorrelation function. RESULTS: The assays lasted 314-341 days, approximately. Levels indicative of Cu deficiency for bovines were detected at 224 days (23 ± 11.6 µg/g DM) for liver Cu concentration; and at 198 days (55 ± 10.4 µg/dl) for plasma Cu concentration, in Cu-deficient animals. Liver and plasma Cu values indicative of Cu deficiency were not observed in the control group. Pearson Correlation test indicated that all indices of Cu status used in this study were significantly correlated. The highest value was obtained between ESOD and red blood Cu (0.74). There was a significant correlation between red blood Cu and plasma Cu (0.65), and with hepatic Cu (0.57). ESOD activity showed a similar significant positive correlation with liver Cu concentrations and with plasma Cu (0.59 and 0.58, respectively). CONCLUSION: The extremely low levels of liver and plasma Cu, the ESOD activity, erythrocyte Cu levels, and the periocular achromotrichia observed in the Cu-deficient animals showed that the clinic phase of Cu deficiency was reached in this group. The ESOD activity and erythrocyte Cu levels showed a strong association, indicating that the values of erythrocyte Cu may serve as an effective tool in assessing Cu status and diagnose a long-term Cu deficiency in cattle.

Factores ecoambientales relacionados con potenciales reservorios de Leptospira spp. en la Reserva Ecológica Costanera Sur, Buenos Aires, Argentina / Eco-environmental Factors Related to Potential Reservoirs of Leptospira spp. in the Costanera Sur Ecological Reserve, Buenos Aires, Argentina

Resumen Las modificaciones ambientales generan entornos de interfaz en los que la transmisión de Leptospira spp. puede verse afectada. Con el objetivo de identificar y analizar variables ecoambientales asociadas a potenciales reservorios de Leptospira spp. en la Reserva Ecológica Costanera Sur (RECS) (Buenos Aires, Argentina) y áreas urbanizadas contiguas, se realizó un muestreo por conveniencia en líneas transectas, estratificado y proporcionado. Fueron capturados 170 mamíferos de 11 especies y se analizó la presencia de Leptospira spp. por serología, cultivo y PCR. En áreas conservadas, se registraron mayormente Didelphis albiventris y Deltamys kempi, mientras que Oligoryzomys flavescens también fue hallado en áreas degradadas, y Rattus norvegicus solo fue encontrada en áreas degradadas. No se detectó Leptospira spp. en los mamíferos silvestres. Un perro sin tenedor responsable resultó positivo por serología. Las condiciones ambientales de la RECS sugieren un ecosistema poco propicio para Rattus, evidenciando la importancia de la conservación de áreas naturales en entornos urbanos.

Abstract Environmental modifications generate interface environments in which Leptospira spp. transmission may be affected. In order to identify and analyze eco-environmental variables associated with potential reservoirs of Leptospira spp. in the Reserva Ecológica Costanera Sur (RECS) (Buenos Aires, Argentina) and adjacent urbanized areas, a stratified and proportionate transect line convenience sampling was carried out. A total of 170 mammals of 11 species were captured and analyzed for the presence of Leptospira spp. by serology, culture and PCR. In conserved areas, Didelphis albiventris and Deltamys kempi were mostly recorded, while Oligoryzomys flavescens was also found in degraded areas, and Rattus norvegicus was only found in degraded areas. Leptospira spp. were not detected in wild mammals. One dog without a responsible keeper tested positive by serology. The environmental conditions of the RECS suggest a poor ecosystem for Rattus, demonstrating the importance of the conservation of natural areas in urban environments.

Detection and Characterization of Enteropathogenic and Shiga Toxin-Producing Escherichia coli Strains in Rattus spp. from Buenos Aires.

Enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) are pathovars of E. coli that impact human health by causing childhood diseases. In this work, 118 synanthropic rodents of the genus Rattus from Buenos Aires, Argentina were evaluated as EPEC and STEC carriers. Rectal swab samples from captured animals were evaluated by conventional PCR to detect the presence of the eae, stx1, stx2, and rfbO157 genes. Twenty-one isolates were obtained (17 EPEC isolates from seven animals and four STEC isolates from the same animal). All EPEC isolates tested negative for the presence of the bfpA gene. One EPEC isolate carried the iha gene, and five EPEC isolates carried the toxB gene. STEC isolates exhibited two different virulence profiles: stx1a/stx2a/stx2c/stx2d/saa/ehxA/subA (3/4) and stx1a/stx2a/saa/ehxA/subA (1/4). EPEC isolate serotypes included O109:H46 (7), O71:H40 (4), O71:NM (2), O138:H40 (1), O108:H21 (1), O88:H25 (1), and O76:NM (1), and STEC isolates belonged to the O108:H11 (4) serotype. Antimicrobial susceptibility testing was carried out, and resistance to tetracycline was observed in one EPEC strain. Our results demonstrate that Rattus spp. may act as carriers of EPEC and STEC strains and may be involved in the epidemiology of diarrheal disease in infancy.

Las carcasas ovinas como fuente de infección de Escherichia coli shigatoxigénico en Tierra del Fuego / Sheep carcasses as a source of infection of shigatoxigenic Escherichia coli in Tierra del Fuego

La provincia de Tierra del Fuego, Antártida e Islas del Atlántico Sur en Argentina, se caracteriza por altas tasas de diarreas y síndrome urémico hemolítico. El principal agente asociado a dichas patologías es Escherichia coli shigatoxigénico (STEC). En la isla de Tierra del Fuego (TDF) el 90% de la producción ovina es destinada al consumo local alcanzando un consumo de 25-30 kg/h/año. El objetivo del presente trabajo fue determinar el grado de contaminación con STEC de las carcasas ovinas, identificar el perfil de virulencia de las cepas y la relación témporo espacial con las aisladas de casos clínicos. Se realizó un estudio observacional en los tres frigoríficos ovinos de la isla con muestreos proporcionales a la faena histórica por sitio, y en cada sitio un muestreo aleatorio simple sin reposición. Se recolectaron 382 esponjados de carcasas ovinas entre el 5 y 20 de diciembre de 2018. La prevalencia de carcasas contaminadas por STEC fue del 4,7%, no se detectaron los serogrupos O26, O45, O121, O145, O103, O104, O111 ni O174. En seis muestras se identificó la presencia del antígeno O157 por inmunocromatografía. Por PCR en 2/6 de las muestras O157 positivas se detectaron los amplicones stx1/stx2. Las dos muestras sospechosas a STEC O157 procedían de la misma estancia, y se faenaron en el frigorífico privado de Rio Grande, las otras 4/6 muestras O157 no-STEC procedían de 3 estancias diferentes e ingresaron a faena en Rio Grande. Se aislaron 6 cepas no-O157 que presentaron el perfil stx1c (1), stx2b (2), stx2NT (2) y stx1c/stx2b/ehxA (1). Los aislamientos fueron saa y eae negativos. Los cinco casos de SUH registrados en el año de estudio no se relacionaron temporalmente con los aislamientos ovinos obtenidos. Pese a no existir relación epidemiológica entre los casos y la contaminación en carne ovina, este es el primer registro de sospecha de STEC O157 en una fuente de infección en TDF y señala la importancia de considerar la carne ovina como un factor de riesgo en la región

Synanthropic rodents as possible reservoirs of shigatoxigenic Escherichia coli strains.

Shigatoxigenic Escherichia coli (STEC) strains are worldwide zoonotic pathogen responsible for different cases of human disease including hemolytic uremic syndrome (HUS). Transmission of STEC to humans occurs through the consumption of food and water contaminated by faeces of carriers and by person-to-person contact. The objective of this study was two-fold: (1) to investigate whether synanthropic rodents are possible reservoirs of STEC in the urban area and (2) whether a particular genus out of synanthropic rodent is the principal carrier of STEC. One hundred and forty-five rodents were captured in Buenos Aires City. Screening for stx1/stx2 and rfbO157 was done by PCR from the confluence zone. STEC isolates were further characterized with biochemical tests by standard methods. Additional virulence factors (eae, ehxA, and saa) were also determined by PCR. Forty-one of the rodents were necropsied and sample of kidney and small and large intestine were taken for histopathological diagnosis. The samples sections were stained with hematoxylin-eosin, and observed by light microscopy to evaluate the systemic involvement of these species in natural infections. STEC was isolated from seven out of 27 suspect animals at screening. The following genotypes were found in the STEC strains: stx1/stx2/ehxA (1), stx2 (4), stx2/ehxA (1), stx2/ehxA/eae (1). Neither gross nor microscopic lesions compatible with those produced by Shiga toxin were observed in the studied organs of necropsied rodents. The bivariate analysis including the 145 rodent's data showed that the isolation of STEC is associated positively to Rattus genus. This synanthropic species may play a role in the transmissibility of the agent thus being a risk to the susceptible population. Their control should be included specifically in actions to dismiss the contamination of food and water by STEC in the urban area, as additional strategies for epidemiological control.

Escherichia coli shigatoxigénica en animales relacionados con casos de diarreas sanguinolentas o síndrome urémico hemolítico y prevalencia en roedores de la Ciudad de Buenos Aires / Shiga toxin-producing escherichia coli in animals related to cases of bloody diarrhea

Escherichia coli shigatoxigénica (STEC) es un patógeno endémico en Argentina, responsable de diarrea aguda sanguinolenta (DAS) y/o síndrome urémico hemolítico (SUH). La correlación entre SUH y alimentos contaminados ha sido documentada, aunque no siempre se estableció la fuente de infección. La ruta de contagio persona-persona es relevante. Dados los registros previos de prevalencia de STEC en animales de compañía y los hábitos de convivencia humano-animal en centros urbanos, es necesario evaluar la ruta mascota-persona. A su vez, los roedores podrían tener un papel epidemiológico en la endemia. OBJETIVO: Estudiar posibles reservorios animales relacionados con casos de SUH/DAS en la Ciudad Autónoma de Buenos Aires y estimar la prevalencia de STEC en roedores. MÉ-TODOS: Se intervino en 28 casos de SUH y 49 de DAS. Se realizó rastrillaje de cepas STEC por PCR a partir de hisopados rectales de los animales vinculados a cada caso. La prevalencia en roedores se estimó por PCR de sus hisopados rectales. RESULTADOS: Se aislaron cepas STEC en 1/10 caninos y 1/3 felinos con vivientes con casos de SUH, y 1/9 felinos contacto con casos de DAS. Rattus rattus fue hospedero de cepas STEC en 33% de los animales capturados en focos de SUH. En roedores, la prevalencia fue de 3,1%. CONCLUSIONES: Las cepas STEC circulan en los animales que conviven o tienen al menos un hábitat compartido con la población en riesgo, quienes podrían participar en la transmisión del agente. Es necesario reevaluar las intervenciones sanitarias en focos y en programas de control de SUH/DAS

Shigatoxigenic Escherichia coli(STEC) is an endemic pathogen in Argentina, which causes bloody diarrhea (BD) and/or hemolytic uremic syndrome (HUS).The co-relation between HUS and contaminated food has been documented, although the source of infection was not always established. Person-to-person route of infection is relevant. Taking into account previous STEC prevalence data in companion animals and the habits of human-animal coexistence in urban centers, it is necessary to evaluate pet-to-person transmission. On the other hand, rodents may also play an epidemiologic role in the endemic transmission. OBJECTIVE: To study potential animal reservoirs related to HUS and BD cases in the City of Buenos Aires and to estimate the prevalence of STEC in rodents. METHODS: An intervention was conducted in 28 cases of HUS and 49 of BD. Screening for STEC was performed by PCR from rectal swabs of linked animals to each case. The prevalence in rodents was estimated by PCR from rectal swabs. RESULTS: STEC strains were isolated in 1/10 dogs and 1/3 cats cohabiting with HUS cases, and in 1/9 cats in contact with DAS cases. Rattus rattus was host of STEC strains in 33% of the animals captured in HUS areas. In rodents, the prevalence was 3.1%. CONCLUSIONS: STEC strains circulate in animals that live withor share at least the same habitat with the population at risk, and could participate in the transmission of the agent. It is necessary to re-evaluate health interventions both in outbreaks and in control programs of HUS/BD

Escherichia coli shigatoxigénica en animales relacionados con casos de diarreas sanguinolentas o síndrome urémico hemolítico y prevalencia en roedores de la Ciudad de Buenos Aires / Shiga toxin-producing escherichia coli in animals related to cases of bloody diarrhea

Escherichia coli shigatoxigénica (STEC) es un patógeno endémico en Argentina, responsable de diarrea aguda sanguinolenta (DAS) y/o síndrome urémico hemolítico (SUH). La correlación entre SUH y alimentos contaminados ha sido documentada, aunque no siempre se estableció la fuente de infección. La ruta de contagio persona-persona es relevante. Dados los registros previos de prevalencia de STEC en animales de compañía y los hábitos de convivencia humano-animal en centros urbanos, es necesario evaluar la ruta mascota-persona. A su vez, los roedores podrían tener un papel epidemiológico en la endemia. OBJETIVO: Estudiar posibles reservorios animales relacionados con casos de SUH/DAS en la Ciudad Autónoma de Buenos Aires y estimar la prevalencia de STEC en roedores. ME-TODOS: Se intervino en 28 casos de SUH y 49 de DAS. Se realizó rastrillaje de cepas STEC por PCR a partir de hisopados rectales de los animales vinculados a cada caso. La prevalencia en roedores se estimó por PCR de sus hisopados rectales. RESULTADOS: Se aislaron cepas STEC en 1/10 caninos y 1/3 felinos con vivientes con casos de SUH, y 1/9 felinos contacto con casos de DAS. Rattus rattus fue hospedero de cepas STEC en 33% de los animales capturados en focos de SUH. En roedores, la prevalencia fue de 3,1%. CONCLUSIONES: Las cepas STEC circulan en los animales que conviven o tienen al menos un hábitat compartido con la población en riesgo, quienes podrían participar en la transmisión del agente. Es necesario reevaluar las intervenciones sanitarias en focos y en programas de control de SUH/DAS (AU)

Shigatoxigenic Escherichia coli(STEC) is an endemic pathogen in Argentina, which causes bloody diarrhea (BD) and/or hemolytic uremic syndrome (HUS).The co-relation between HUS and contaminated food has been documented, although the source of infection was not always established. Person-to-person route of infection is relevant. Taking into account previous STEC prevalence data in companion animals and the habits of human-animal coexistence in urban centers, it is necessary to evaluate pet-to-person transmission. On the other hand, rodents may also play an epidemiologic role in the endemic transmission. OBJECTIVE: To study potential animal reservoirs related to HUS and BD cases in the City of Buenos Aires and to estimate the prevalence of STEC in rodents. METHODS: An intervention was conducted in 28 cases of HUS and 49 of BD. Screening for STEC was performed by PCR from rectal swabs of linked animals to each case. The prevalence in rodents was estimated by PCR from rectal swabs. RESULTS: STEC strains were isolated in 1/10 dogs and 1/3 cats cohabiting with HUS cases, and in 1/9 cats in contact with DAS cases. Rattus rattus was host of STEC strains in 33% of the animals captured in HUS areas. In rodents, the prevalence was 3.1%. CONCLUSIONS: STEC strains circulate in animals that live withor share at least the same habitat with the population at risk, and could participate in the transmission of the agent. It is necessary to re-evaluate health interventions both in outbreaks and in control programs of HUS/BD (AU)

Risk factors for Shiga toxin-producing Escherichia coli infections in preadolescent schoolchildren in Buenos Aires, Argentina.

INTRODUCTION: Shiga toxin-producing Escherichia coli (STEC) infections are the leading cause of hemolytic uremic syndrome (HUS). STEC is the most common cause of acute kidney disease, responsible for 20% of renal transplants in Argentina. METHODOLOGY: In 2007, an epidemiological survey was conducted among 883 students from the fifth and sixth years of elementary education in the public schools of San Martin City, Buenos Aires, Argentina. Degree of exposure to the known risk factors previously detected in the region as primary causes of STEC infections was evaluated. Risk factors assessed included consumption of hamburgers, poor personal hygiene, and exposure to various types of drinking and recreational water. The study was designed to evaluate exposure to risk factors for STEC infections among different socioeconomic groups. RESULTS: Ninety-five percent of children surveyed reported consumption of hamburgers. Most of these hamburgers were precooked. Children of high and medium strata attended private swimming-pools, while children from the low stratum attended public pools. Only 30.2% of students washed their hands after going to the toilet and only 43.5% reported hand-washing before eating. CONCLUSIONS: Students demonstrated high levels of exposure to identified risk factors for STEC infections. Reduction of these risks will require cultural changes aimed at decreasing morbidity caused by food-borne infections. Institutional framework must provide the necessary resources to implement these changes and emphasize the importance of good personal hygiene. Health education must be implemented to increase food safety awareness of the consumers.