No abstract

No abstract

SUMMARYA total of 316 samples of nasopharyngeal aspirate from infants up to two years of age with acute respiratory-tract illnesses were processed for detection of respiratory syncytial virus (RSV) using three different techniques: viral isolation, direct immunofluorescence, and PCR. Of the samples, 36 (11.4%) were positive for RSV, considering the three techniques. PCR was the most sensitive technique, providing positive findings in 35/316 (11.1%) of the samples, followed by direct immunofluorescence (25/316, 7.9%) and viral isolation (20/315, 6.3%) (p < 0.001). A sample was positive by immunofluorescence and negative by PCR, and 11 (31.4%) were positive only by RT-PCR. We conclude that RT-PCR is more sensitive than IF and viral isolation to detect RSV in nasopharyngeal aspirate specimens in newborn and infants.

The objective of this study was to evaluate the prevalence, genotypic characterization, and determination of the patterns of shedding of human polyomavirus JC (JCPyV) and BK (BKPyV) in consecutive urine samples collected from healthy adults. Urine samples collected monthly over a 6 month period were screened by polymerase chain reaction (PCR) with two sets of primers complementary to the VP1 protein region specific for the JCPyV or BKPyV genome. The viral load of JCPyV and BKPyV in positive samples was determined by quantitative real time PCR. Seventy-one healthy individuals (ages between 18 and 65) were included in the study. Polyomavirus DNA urinary shedding was identified in 44 (62%) of the 71 individuals evaluated: BKPyV only in 16 (22.5%); JCPyV only in 19 (26.7%); and both in 9 (12.7%). Among the 28 individuals shedding JCPyV, the shedding was nearly continuous in 13 (46.4%) and sporadic in 15 (53.6%), whereas all BKPyV shedding was sporadic. A total of 45 (19 BKPyV and 26 JCPyV) strains were identified. Of the BKPyV strains, individuals were observed that excreted all genotypes except genotype 3 and the JCPyV strains, excretion of 5 different genotypes. Evaluating the age of individuals who excrete JCPyV and BKPyV, mostly are young adults, with a slight increase with increasing age and observing the viral load can not draw any parallel between the increase or decrease of age or excreted genotype as there was a wide variation both in the excretion of BKPyV and JCPyV. The high occurrence of isolated or simultaneous urinary shedding of JCPyV and BKPyV in healthy individuals merits further study.

BK virus-(BKV) associated nephropathy (BKVN) is a major cause of allograft injury in kidney transplant recipients. In such patients, subclinical reactivation of latent BKV infection can occur in the pre-transplant period. The purpose of this study was to determine whether urinary BKV shedding in the immediate pre-transplant period is associated with a higher incidence of viruria and viremia during the first year after kidney transplantation. We examined urine samples from 34 kidney transplant recipients, using real-time quantitative polymerase chain reaction to detect BKV. Urine samples were obtained in the immediate pre-transplant period and during the first year after transplant on a monthly basis. If BKV viruria was detected, blood samples were collected and screened for BKV viremia. In the immediate pre-transplant period, we detected BKV viruria in 11 (32.3%) of the 34 recipients. During the first year after transplantation, we detected BKV viruria in all 34 patients and viremia in eight (23.5%). We found no correlation between pre-transplant viruria and post-transplant viruria or viremia (p = 0.2). Although reactivation of latent BKV infection in the pre-transplant period is fairly common among kidney transplant recipients, it is not a risk factor for post-transplant BKV viruria or viremia.

Septins are evolutionarily conserved proteins that contain a GTPase domain and are capable of forming filaments at the cell periphery. Septins are involved in many essential cellular processes, such as cytokinesis and cell polarization, and are used as markers of morphogenesis in several fungi. Dimorphism in fungi enables cells to switch between morphologies (yeast or filament forms), due to changes in the temperature of the environment. We analysed the localization of septin proteins in yeast and filamentous cells of the dimorphic fungus Paracoccidioides brasiliensis, a common cause of granulomatous mycosis. In order to determine septin localization, we first cloned Cdc12p, a septin homolog from P. brasiliensis, and expressed it in Escherichia coli. Following PbCdc12p purification, specific serum against PbCdc12p were raised for use in immunofluorescence assays. We observed the hourglass and ring forms of septin filaments during cell division in yeast. Septin filaments were also simultaneously localized in the necks of multiple budding cells. A distinctive pattern of punctuate and/or diffuse localization was also seen in the periphery of multinucleate yeast cells and at the tips and septa of filamentous cells. A more diffuse and punctuate pattern of localization observed in P. brasiliensis cells seems to be unique to filamentous and dimorphic fungi and may be related to their specialization in cell wall deposition, morphogenesis and cell cycle control.