Leonardo Ferreyra

An environmental survey was conducted in order to assess the frequency of detection of picobirnavirus (PBV), human adenovirus (HAdV) and infective enterovirus (iEV) as indicators of faecal contamination in freshwater, and to determine their potential as reporters of the presence of other enteric viruses, such as group A rotavirus (RVA). The study w...

MICROBIOLOGICAL DIAGNOSIS OF BACTERIAL AND VIRAL INFECTIONS

Aims The purpose of the present study was to elucidate the presence of human herpesvirus 6A (HHV-6A), HHV-6B and HHV-7 in samples of the uterine cervix through detection of viral DNA. We analysed normal tissues, samples with low-grade squamous intraepithelial lesions (LSILs) and high-grade squamous intraepithelial lesions (HSILs). We correlated the...

Surface waters are used by local populations for different purposes, such as recreational activities, water source for human and animal consumption, and irrigation among others, which lead to the need for management strategies on water health and associated risks. During this study, we investigated physicochemical parameters, fecal coliform bacteri...

Human herpesvirus 6A (HHV-6A), Human herpesvirus 6B (HHV-6B), and Human herpesvirus 7 (HHV-7) can persist by establishing a lifelong infection which could have implications on the immunocompetent host. The aim of this work is to contribute with some knowledge about the HHV-6 A/B and HHV-7 infection in healthy individuals. We have carried out a long...

The original publication of this article [1] was missing the below author that made contributions to the research and the published article:

Innovations in educational institutions are of great complexity, considering they impact their very constituent elements. This work analyzes institutional dynamics in situations of curricular innovation, embodied in intersubjectivities of different professor groups, through the grading of final exams of the students. In this sense, different types...

Data from the year-long monitoring campaign of the Suquía River (Córdoba, Argentina) were analyzed to characterize river water quality. The measured variables (11) reflected an important deterioration in the river water quality when passing through the city, which was observed by a continuous increase of chloride, chemical oxygen demand, biologi...

Las innovaciones en las instituciones educativas tienen una gran complejidad, al considerar que operan sobre los diferentes componentes constitutivos de las mismas. En este trabajo, las dinámicas institucionales en situaciones de innovación curricular, encarnadas en las intersubjetividades en diferentes grupos de docentes, son analizadas a través...

In recent years, several types of human adenovirus (HAdV) have arisen from the recombination between two or more previously known HAdV types, but their epidemiology is poorly understood. In this study, we investigated the circulation of HAdV-58, a recently described HAdV isolated from an HIV-positive patient in Córdoba city, Argentina. For this pur...

Innovations in educational institutions are of great complexity, considering they impact their very constituent elements. This work analyzes institutional dynamics in situations of curricular innovation, embodied in intersubjectivities of different professor groups, through the grading of final exams of the students. In this sense, different types...

Percent identities of the nucleotide coding sequences of loop1 (L1) and loop2 (L2) HAdV-D58 coding regions to homologous sequences from other viruses in species HAdV-D. (PDF)

Percent identities of the nucleotide coding sequences of selected E3 HAdV-D58 coding sequences and their homologs. (PDF)

In February of 1996 a human adenovirus (formerly known as Ad-Cor-96-487) was isolated from the stool of an AIDS patient who presented with severe chronic diarrhea. To characterize this apparently novel pathogen of potential public health significance, the complete genome of this adenovirus was sequenced to elucidate its origin. Bioinformatic and ph...

To date, human adenoviruses are classified into 53 types (types 1-51 and types 53 and 54), which have been grouped into six species named A through F, and the recently identified type 52 has been proposed as member of a new species, G. Type classification is based on type-specific epitopes within loop 1 (L1) and loop 2 (L2) of the hexon protein, wh...

A study aimed to further understand the biology of porcine picobirnaviruses (PBV) was conducted between November 2003 and January 2008, on a farm located in the outskirts of Córdoba City, Argentina. PBV prevalence was examined by polyacrylamide gel electrophoresis and silver staining (PAGE S/S) on a total of 265 samples collected from pigs divided...

Human herpesvirus 6 (HHV-6) and 7 (HHV-7) are common opportunistic agents in immunocompromised hosts, although infection with HHV-6 and HHV-7 can also be observed in immunocompetent hosts. Despite similar biology and epidemiology, this study evaluated differences in the IgG subclass distribution associated with HHV-6 and HHV-7 in seropositive, heal...

On the basis of the published literature, it is still difficult to draw conclusions as to whether picobirnavirus (PBV) circulation is influenced by host species restriction. To provide data regarding the genetic relatedness between porcine and human PBV strains present in Argentina as a means of defining the host range and epidemiology of these vir...

Routine rotavirus A (RV-A) surveillance is based on clinical cases, so only symptomatic infections are reported. The objective of this study was to determine whether the RV-A genotypes and cold seasonal pattern described in patients with diarrhea is reflected by sewage surveillance, which could be representative of the RV-A genotypes circulating in...

Human herpesvirus 6 (HHV-6) is widespread in the human population by infecting most individuals in early childhood. After primary infection, HHV-6 establishes a latent infection by remaining in circulating mononuclear cells of healthy individuals. The HHV-6 antibody titer increases after primary infection with measles virus. The present study was u...

Picobirnavirus' (PBV) association with diarrhea in children is not reliably established and the potential role of pathogenic PBV needs further investigations. The aim of this study is to clarify the role of PBV in diarrhea illness in children. Between January 1977 and December 2002, 2224 stool specimens were collected from children <3 years old wit...

The persistence of poliovirus-neutralizing antibodies was investigated in 297 individuals residing in Argentina who had completed the vaccination cycle with four or five oral polio vaccine (OPV) doses 1 mo to 19 yr before this study. Seropositivity for the three polio types in individuals who had received four OPV doses remained high and stable, sh...

A picobirnavirus (PBV) analysis was carried out by polyacrylamide gel electrophoresis of 513 stool samples obtained from 150 animal species collected from the Córdoba city zoo. The purpose of the present study was to determine susceptible species for PBV infection, the viral excretion pattern in infected animals, and the potential association with...

Human herpes virus-7 (HHV-7) infection is widespread throughout the world. No data are available in Argentina about loss of maternally-derived HHV-7 immunity and natural infection. The objective of this study was to characterize the time when children lose maternal antibodies and become susceptible to natural infection. Sera from 39 pregnant women...

The incidence of human rotavirus G types was determined over a 25-year period (1979-2003) by using reverse transcription-PCR (RT-PCR) to examine 519 stool specimens found to be positive for rotavirus by enzyme linked immunosorbent assay (ELISA) or polyacrylamide gel electrophoresis (PAGE). These stool samples were obtained from children under 3 yea...

In previous research, we concluded that measles virus specific IgG4 antibody titer could be used to differentiate between natural [IgG4 GMT 80 (95% CI, 33 to 191)] and vaccinal source of measles infection [IgG4 GMT 13 (95% CI, 7 to 26)]. The aim of this paper is to show that this new serologic marker (IgG4 measles antibody titer) can be applied to...

A variable rate of false-positive results may be observed with commercial assays for the detection of rotavirus and adenovirus antigen in stool specimens, depending on the quality of the reagents and the presence of potentially interfering substances in stool samples. The present report analyse the discrepant results that could be obtained by the c...

We studied the occurrence of reovirus infection in children hospitalized with acute gastroenteritis in Argentina during a 20-year interval (1981 through 2001). Three of 2854 (0.10%) stools were positive for reovirus but negative for adenovirus, astrovirus and rotavirus. Children infected with reovirus were <1 year old; one had meningoencephalitis i...

Since 1993, ministers of health of countries of America established as a goal the eradication of measles by the year 2000. As a consequence of measles eradication vaccination strategy there has been a reduction in the incidence of reported cases. Despite that, measles has continued occurring in epidemic outbreaks in many Argentinian provinces. This...

Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in Córdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children...

The aim of this study was to report on the occurrence of conventional and emerging viral agents as well as their etiological link with diarrhea in kidney transplanted subjects from Cordoba, Argentina. A total of 42 stool samples were analysed. They were obtained from both ambulatory and hospitalized kidney transplanted patients with and without dia...

Diarrheic syndrome related to viral agents in kidney transplanted patients. The aim of this study was to report on the occurrence of conventional and emerging viral agents as well as their etiological link with diarrhea in kidney transplanted subjects from Cordoba, Argentina. A total of 42 stool samples were analysed. They were obtained from both a...

Las innovaciones en las instituciones educativas, tienen una gran complejidad, al considerar que operan sobre los diferentes componentes constitutivos de las mismas. En este trabajo las dinámicas institucionales en situaciones de innovación curricular, encarnadas en las intersubjetividades en diferentes grupos de docentes son analizadas a través de...