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.
Molecular and epidemiological studies of transmission routes and risk factors for infection by HTLV-1 are extremely important in order to implement control measures, especially because of the high prevalence of HTLV-1 in several regions of the world. San Salvador de Jujuy, Northwest Argentina, is a highly endemic area for HTLV-1 and foci of tropical spastic paraparesis/HTLV-1-associated myelopathy. To gain further insight into the role of intrafamilial transmission of HTLV-1 in a highly endemic region in Argentina. Cross-sectional study in Northwest Argentina. Epidemiological data and blood samples were collected from 28 HTLV-1 infected subjects (index cases) and 92 close relatives/cohabitants. HTLV-1 infection was diagnosed by detection of antibodies and proviral DNA. The LTR region was sequenced and analyzed for genetic distances (VESPA software), in addition to determination and identification of polymorphisms to define HTLV-1 family signatures. Fifty seven of the 120 subjects enrolled had antibodies against HTLV-1 and were typified as HTLV-1 by PCR. The prevalence rate of HTLV-1 infection in family members of infected index cases was 31.52% (29/92). The infection was significantly associated with gender, age and prolonged lactation. Identity of LTR sequences and presence of polymorphisms revealed high prevalence of mother-to-child and interspousal transmission of HTLV-1 among these families. There is an ongoing and silent transmission of HTLV-1 through vertical and sexual routes within family clusters in Northwest Argentina. This evidence highlights that HTLV-1 infection should be considered as a matter of public health in Argentina, in order to introduce preventive measures as prenatal screening and breastfeeding control.
1 January 2014 in Revista Argentina de Microbiologia
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
1 November 2012 in Diagnostic Microbiology and Infectious Disease
In some areas of Argentina endemic for human T-lymphotropic virus type 1 (HTLV-1), tropical spastic paraparesis is frequent in subjects who lack antibodies against the virus; however, the relevance of this seronegative status in the country has not been investigated. In neighboring countries, HTLV-1 seronegative status has been described in patients with different diseases; however, data regarding features of seronegative HTLV-1 carriers are scarce. We investigated the seronegative status in 124 relatives of 28 HTLV-1 infected subjects from an endemic area in Northwest Argentina. Blood samples and clinical/epidemiological data were collected. Human T-lymphotropic virus type 1 infection was diagnosed by serology and long terminal repeat (LTR) sequence, env and tax gene detection. IgG anti-Tax HTLV-1 antibody, tax gene sequence, and DNA proviral load were also evaluated. Seventy-five percent of the 124 relatives were negative for HTLV-1/2 antibodies; 35.5% were also negative by molecular assays and 64.5% were negative for HTLV-1 LTR and env sequences, but positive for two sequences of HTLV-1 tax gene. Also, 35.7% of these subjects had IgG anti-Tax antibodies. The seronegative HTLV-1 status was significantly associated with male gender, youth, and sensory symptoms/autonomic nervous system dysfunction. High rates of seronegative symptomatic and asymptomatic HTLV-1 carriers in Argentina are described. The evidence highlights that HTLV-1 prevalence may be underestimated worldwide. Larger cohort studies are required to assess disease outcome in these seronegative subjects. Also, the findings emphasize the limitations of ongoing screening assays for diagnosis and blood safety. Therefore, algorithms for HTLV-1 diagnosis should include not only serological but also molecular assays.
30 October 2018 in Transfusion Medicine and Hemotherapy
Introduction: Since anti-D immunoprophylaxis given to D-negative pregnant women is a blood product, blood donations have an impact on the availability of prophylactic doses. The Pan American Health Organization reported, in June 2017, that less than half of blood donors are volunteers in Latin America and the Caribbean. In these countries, guidelines for use of anti-D prophylaxis are still controversial. The aim of this study was to demonstrate the convenience of a simple and cost-effectivene non-invasive prenatal diagnostic assay for anti-D prophylaxis optimization in multiethnic populations. Methods: Cell-free fetal DNA from plasma samples of D-negative pregnant women were analyzed by real-time PCR for simultaneous amplification of sequences of exons 5 and 10 of the RHD gene. Fetal RHD genotype was determined in 111 pregnant women. Neonates' phenotype was determined 72 h after birth. Results: Genotyping predicted fetal phenotype with 100% accuracy. Prenatal diagnosis showed 78% RHD-positive and 22% RHD-negative neonates. Conclusion: We demonstrated that, beyond the large genetic variation of the Rh system and the numerous D variants present in multiethnic groups, non-invasive fetal RHD genotyping using two sequences of the gene can be enough for clinical application in an admixed population. This robust technique of simple implementation allows to determine fetal RHD in maternal blood with high sensitivity, specificity, and accuracy. The introduction of fetal RhD genotyping as part of an antenatal screening program constitutes a reliable manner to optimize anti-D prophylaxis; however, it has not been implemented so far in most American countries.