The Hemagglutinin of Bat-Associated Influenza Viruses Is Activated by TMPRSS2 for pH-Dependent Entry into Bat but Not Human Cells

New World bats have recently been discovered to harbor influenza A virus (FLUAV)-related viruses, termed bat-associated influenza A-like viruses (batFLUAV). The internal proteins of batFLUAV are functional in mammalian cells. In contrast, no biological functionality could be demonstrated for the surface proteins, hemagglutinin (HA)-like (HAL) and neuraminidase (NA)-like (NAL), and these proteins need to be replaced by their human counterparts to allow spread of batFLUAV in human cells. Here, we employed rhabdoviral vectors to study the role of HAL and NAL in viral entry. Vectors pseudotyped with batFLUAV-HAL and -NAL were able to enter bat cells but not cells from other mammalian species. Host cell entry was mediated by HAL and was dependent on prior proteolytic activation of HAL and endosomal low pH. In contrast, sialic acids were dispensable for HAL-driven entry. Finally, the type II transmembrane serine protease TMPRSS2 was able to activate HAL for cell entry indicating that batFLUAV can utilize human proteases for HAL activation. Collectively, these results identify viral and cellular factors governing host cell entry driven by batFLUAV surface proteins. They suggest that the absence of a functional receptor precludes entry of batFLUAV into human cells while other prerequisites for entry, HAL activation and protonation, are met in target cells of human origin.     

Validation of a Novel Collection Device for Non-Invasive Urine Sampling from Free-Ranging Animals

Recent advances in non-invasively collected samples have opened up new and exciting opportunities for wildlife research. Different types of samples, however, involve different limitations and certain physiological markers (e.g., C-peptide, oxytocin) can only be reliably measured from urine. Common collection methods for urine to date work best for arboreal animals and large volumes of urine. Sufficient recovery of urine is thus still difficult for wildlife biologists, particularly for terrestrial and small bodied animals. We tested three collection devices (two commercially available saliva swabs, Salivette synthetic and cotton, and cotton First aid swabs) against a control to permit the collection of small volumes of urine from the ground. We collected urine samples from captive and wild macaques, and humans, measured volume recovery, and analyzed concentrates of selected physiological markers (creatinine, C-peptide, and neopterin). The Salivette synthetic device was superior to the two alternative devices. Concentrations of creatinine, absolute C-peptide, C-peptide per creatinine, absolute neopterin, and neopterin per creatinine measured in samples collected with this device did not differ significantly from the control and were also strongly correlated to it. Fluid recovery was also best for this device. The least suitable device is the First aid collection device; we found that while absolute C-peptide and C-peptide per creatinine concentrations did not differ significantly from the control, creatinine concentrations were significantly lower than the control. In addition, these concentrations were either not or weakly correlated to the control. The Salivette cotton device provided intermediate results, although these concentrations were strongly correlated to the control. Salivette synthetic swabs seem to be useful devices for the collection of small amounts of urine from the ground destined for the assessment of physiological parameters. They thus provide new opportunities for field studies to incorporate physiological markers, particularly on smaller bodied and terrestrial animals and where urine collection is difficult.     

Frequent non-reciprocal exchange in microsatellite-containing-DNA-regions of vertebrates

Microsatellites are DNA-fragments containing short repetitive motifs with 2–10 bp. They are highly variable in most species and distributed throughout the whole genome. It is broadly accepted that their high degree of variability is closely associated with mispairing of DNA-strands during the replication phase, termed slippage, although recombination is also observed. The aim of this study is to demonstrate evidence that non-reciprocal recombination processes changing the total genomic structure are common in microsatellites and flanking regions. We sequenced DNA fragments from birds in which microsatellites are located, and analyzed the structure of the microsatellites and their flanking regions. Additionally, other data and those from literature of three microsatellite regions of primates coding for the Ataxin-2, the Huntingtin and the TATA-box binding protein were analyzed. The structures of seven avian and three primate microsatellites support the hypothesis that non-reciprocal recombination is a common process that may also contribute considerably to the variation at microsatellite loci. We conclude that results of population genetic studies that are analyzed statistically with methods based on stepwise mutation models should be interpreted with caution if no detailed information on the allelic variation of microsatellites is available.     

Patterns of Infection with Cryptosporidium sp. and Giardia sp. in Three Species of Free-Ranging Primates in the Peruvian Amazon

Recent evidence of pathogen transmission to humans from wild primates and a greater recognition of the risk of human pathogen transmission to free-ranging primates have raised awareness of the potential impact of zoonotic pathogen transmission on primate conservation and nonhuman primate and human health. Cryptosporidium and Giardia are zoonotic protozoan parasites transmitted via fecal–oral contamination or water that can cause gastritis or enteritis in human and nonhuman primates. From June 2002 to September 2003, we collected fecal samples noninvasively from two species of tamarins (Saguinus mystax and S. nigrifrons) and one species of titi monkeys (Callicebus cupreus) at the Estación Biológica Quebrada Blanco in the Peruvian Amazon to determine the distribution and prevalence of these potential pathogens. We screened 140 fecal samples representing known individuals of each species for Cryptosporidium and Giardia using the Merifluor immunoflourescence assay to determine the prevalence and intensity of infection with these organisms. With the exception of two samples we collected during the same week from a juvenile male Saguinus mystax, all samples were negative for Cryptosporidium. None of the fecal samples were positive for Giardia. The low prevalence of infection we observed limited our ability to examine the effects of demographic and environmental variables on patterns of infection; however, the exceptionally low prevalence of Cryptosporidium suggests that it is not a current health threat to these primate populations. Although the origin of infection with Cryptosporidium in the juvenile male Saguinus mystax cannot be determined, its presence alerts us to the potential for cross-species transmission and highlights the need for more detailed research to improve our understanding of the distribution and diversity of potentially pathogenic protozoa in Neotropical primate populations.