Marina S. Monetti

Molecular evidence of Chlamydophila pneumoniae infection in reptiles in Argentina

In the central area of Argentina, the epidemiological and molecular characteristics of Chlamydophila pneumoniae infections in reptiles are still unknown. A nested polymerase chain reaction of the rpoB gene was used to detect C. pneumoniae in cloacal swab samples from 19 reptiles at a recreational area. Eleven (57.89%) reptiles were positive; the sequencing and phylogenetic analysis confirmed the presence of this bacterium. Neither C. pneumoniae DNA in the caregivers pharynges nor IgM antibodies anti-C. pneumoniae in their serum samples were detected; however, caregivers presented very high titers of IgG anti-C. pneumoniae. The detection of C. pneumoniae DNA in reptiles demonstrated the circulation of this agent in the recreational area and could be responsible for the exacerbated immune response of the personnel handling the reptiles, which suggests a potential zoonotic cycle. This is the first report of the detection of C. pneumoniae in reptiles in Argentina.

Mutation Detection of E6 and LCR Genes from HPV 16 Associated with Carcinogenesis

Human papillomavirus (HPV) is responsible for one of the most frequent sexually transmitted infections. The first phylogenetic analysis was based on a LCR region fragment. Nowadays, 4 variants are known: African (Af-1, Af-2), Asian-American (AA) and European (E). However the existence of sub-lineages of the European variant havs been proposed, specific mutations in the E6 and LCR sequences being possibly related to persistent viral infections. The aim of this study was a phylogenetic study of HPV16 sequences of endocervical samples from Cordoba, in order to detect the circulating lineages and analyze the presence of mutations that could be correlated with malignant disease. The phylogenetic analysis determined that 86% of the samples belonged to the E variant, 7% to AF-1 and the remaining 7% to AF-2. The most frequent mutation in LCR sequences was G7521A, in 80% of the analyzed samples; it affects the binding site of a transcription factor that could contribute to carcinogenesis. In the E6 sequences, the most common mutation was T350G (L83V), detected in 67% of the samples, associated with increased risk of persistent infection. The high detection rate of the European lineage correlated with patterns of human migration. This study emphasizes the importance of recognizing circulating lineages, as well as the detection of mutations associated with high-grade neoplastic lesions that could be correlated to the development of carcinogenic lesions.

Genetic diversity of Chlamydia among captive birds from central Argentina

To study the occurrence of Chlamydia spp. and their genetic diversity, we analysed 793 cloacal swabs from 12 avian orders, including 76 genera, obtained from 80 species of asymptomatic wild and captive birds that were examined with conventional nested polymerase chain reaction and quantitative polymerase chain reaction. Chlamydia spp. were not detected in wild birds; however, four species (Chlamydia psittaci, Chlamydia pecorum, Chlamydia pneumoniae and Chlamydia gallinacea) were identified among captive birds (Passeriformes, n = 20; Psittaciformes, n = 15; Rheiformes, n = 8; Falconiformes n = 2; Piciformes n = 2; Anseriformes n = 1; Galliformes n = 1; Strigiformes n = 1). Two pathogens (C. pneumoniae and C. pecorum) were identified simultaneously in samples obtained from captive birds. Based on nucleotide-sequence variations of the ompA gene, three C. psittaci-positive samples detected were grouped into a cluster with the genotype WC derived from mammalian hosts. A single positive sample was phylogenetically related to a new strain of C. gallinacea. This report contributes to our increasing understanding of the abundance of Chlamydia in the animal kingdom.

Genotyping of C. psittaci in central area of Argentina

In central area of Argentina, the epidemiologic and molecular characteristics of Chlamydophila psittaci infections are still unknown. Nested polymerase chain reaction of domains II, III, and IV of the omp A gene was used to detect Chlamydophila in 43 pharyngeal swab samples from patients with suspected human psittacosis (2010-2011); 9 (21%) of them yielded positive results. Molecular typing was performed by direct sequencing demonstrating the presence of C. psittaci genotypes A, E/B, and WC.

Pixuna virus modifies host cell cytoskeleton to secure infection

Pixuna virus (PIXV) is an enzootic member of the Venezuelan Equine Encephalitis Virus complex and belongs to the New World cluster of alphaviruses. Herein we explore the role of the cellular cytoskeleton during PIXV replication. We first identified that PIXV undergoes an eclipse phase consisting of 4 h followed by 20 h of an exponential phase in Vero cells. The infected cells showed morphological changes due to structural modifications in actin microfilaments (MFs) and microtubules (MTs). Cytoskeleton-binding agents, that alter the architecture and dynamics of MFs and MTs, were used to study the role of cytoskeleton on PIXV replication. The virus production was significantly affected (p < 0.05) after treatment with paclitaxel or nocodazole due to changes in the MTs network. Interestingly, disassembly of MFs with cytochalasin D, at early stage of PIXV replication cycle, significantly increased the virus yields in the extracellular medium (p < 0.005). Furthermore, the stabilization of actin network with jasplakinolide had no effect on virus yields. Our results demonstrate that PIXV relies not only on intact MTs for the efficient production of virus, but also on a dynamic actin network during the early steps of viral replication.

Molecular characterization of Chlamydia pneumoniae in animals and humans from Argentina: Genetic characterization of Chlamydia pneumoniae.

In this study, genetic diversity of Chlamydia pneumoniae was investigated and the relationships between sequences amplified of different sources, clinical conditions and geographical regions of central Argentina were established. Samples amplified were similar to human C. pneumoniae patterns and show the high clonality of the population.