Drosophila Me31B is a conserved protein of germ granules, ribonucleoprotein complexes essential for germ cell development. Me31B post-transcriptionally regulates mRNAs by interacting with other germ granule proteins. However, a Me31B interactome is lacking. Here, we use an in vivo proteomics approach to show that the Me31B interactome contains polypeptides from four functional groups: RNA regulatory proteins, glycolytic enzymes, cytoskeleton/motor proteins, and germ plasm components. We further show that Me31B likely colocalizes with the germ plasm components Tudor (Tud), Vasa, and Aubergine in the nuage and germ plasm and provide evidence that Me31B may directly bind to Tud in a symmetrically dimethylated arginine-dependent manner. Our study supports the role of Me31B in RNA regulation and suggests its novel roles in germ granule assembly and function.

In March 2017, a patient became febrile within 4 days after visiting a rustic conference center in Austin, Texas, USA, where Austin Public Health suspected an outbreak of tickborne relapsing fever a month earlier. Evaluation of a patient blood smear and molecular diagnostic assays identified Borrelia turicatae as the causative agent. We could not gain access to the property to collect ticks. Thus, we focused efforts at a nearby public park, <1 mile from the suspected exposure site. We trapped Ornithodoros turicata ticks from 2 locations in the park, and laboratory evaluation resulted in cultivation of 3 B. turicatae isolates. Multilocus sequencing of 3 chromosomal loci (flaB, rrs, and gyrB) indicated that the isolates were identical to those of B. turicatae 91E135 (a tick isolate) and BTE5EL (a human isolate). We identified the endemicity of O. turicata ticks and likely emergence of B. turicatae in this city.

Vector competence refers to the ability of an arthropod to acquire, maintain, and successfully transmit a microbial pathogen. Tick-borne relapsing fever (TBRF) spirochetes are globally distributed pathogens, and most species are transmitted by argasid ticks in the genus A defining characteristic in vector competence is an apparent specificity of a species of TBRF spirochete to a given tick species. In arid regions of the southern United States, is the primary cause of TBRF. Interestingly, there are two populations of the tick vector distributed throughout this region. is a western population that ranges from California to Texas. There is a gap through Louisiana, Mississippi, and Alabama where the tick has not been identified. An isolated eastern population exists in Florida and was designated a subspecies, A knowledge gap that exists is the poor understanding of vector competence between western and eastern populations of tick for In this study, we generated uninfected colonies of that originated in Texas and Kansas and acquisition, maintenance through the molt, and subsequent transmission was evaluated. Our findings revealed significant differences in murine infection after feeding infected and on the animals. Interestingly, the salivary glands of both tick populations were colonized with to similar densities. Our results suggest that the salivary glands of the tick colonies assessed in this study impact vector competence of the evaluated isolates.Several knowledge gaps exist in vector competence of various geographical populations of that transmit A western population of tick is distributed from California to Texas, and an eastern population exists in Florida. Utilizing western and eastern populations of the vector, we studied acquisition and transmission of two isolates. Regardless of the isolate used, infection frequencies were poor in mice after feeding the eastern population. Since salivary gland colonization is essential for transmission, these tissues were further evaluated. Interestingly, the salivary glands from both populations were similarly colonized with These findings suggest the role of tick saliva in the establishment of infection and that the salivary glands may be a bottle neck for successful transmission.

Tick-borne relapsing fever (TBRF) is caused by several Borrelia spp. (including Borrelia turicatae), which are primarily transmitted by Ornithodoros ticks. Relapsing fever group species are found worldwide, except for Antarctica. Approximately 500 human cases were reported between 1990 and 2011 in the United States (likely an underestimate), while cases in domestic and wild dogs were reported from Florida, Texas, and Washington. TBRF spirochetes are related to Borrelia burgdorferi, the agent of Lyme borreliosis. Dogs are routinely screened for B. burgdorferi, but it is unknown if infection with TBRF agents produces antibodies cross-reactive with B. burgdorferi assays. These data are critical for accurate surveillance of TBRF and Lyme borreliosis in dogs. In this study, B. burgdorferi-negative dogs were inoculated with B. turicatae, and seroconversion was confirmed by the rBipA (recombinant Borrelia immunogenic protein A) Western blot. Seropositive samples were tested with commercial and veterinary diagnostic laboratory B. burgdorferi-based tests. Borrelia turicatae-seroreactive samples cross-reacted with a whole-cell indirect fluorescent antibody (IFA) test and two multiantigen tests, but not with single-antigen tests using C6. Cross-reactivity with TBRF can confound epidemiology and surveillance efforts and confuse recommendations made by veterinarians for prevention and control. These findings demonstrate the need to critically evaluate results from B. burgdorferi diagnostic tests in the context of the assay type and the animal’s geographical location and history of travel, as well as highlighting the need for commercially available specific diagnostic tests for TBRF spirochetes.

BackgroundIn low elevation arid regions throughout the southern United States, Borrelia turicatae is the principal agent of tick-borne relapsing fever. However, endemic foci and the vertebrate hosts involved in the ecology of B. turicatae remain undefined. Experimental infection studies suggest that small and medium sized mammals likely maintain B. turicatae in nature, while the tick vector is a long-lived reservoir.Methodology/principal findingsSerum samples from wild caught rodents, raccoons, and wild and domestic canids from 23 counties in Texas were screened for prior exposure to B. turicatae. Serological assays were performed using B. turicatae protein lysates and recombinant Borrelia immunogenic protein A (rBipA), a diagnostic protein that is unique to RF spirochetes and may be a species-specific antigen.Conclusions/significanceSerological responses to B. turicatae were detected from 24 coyotes, one gray fox, two raccoons, and one rodent from six counties in Texas. These studies indicate that wild canids and raccoons were exposed to B. turicatae and are likely involved in the pathogen’s ecology. Additionally, more work should focus on evaluating rodent exposure to B. turicatae and the role of these small mammals in the pathogen’s maintenance in nature.

ARMSTRONG, B. A. (The University of Kansas, Lawrence), AND C. P. SWORD. Electron microscopy of Listeria monocytogenes-infected mouse spleen. J. Bacteriol. 91:1346-1355. 1966.-Mouse spleen infected with Listeria monocytogenes was observed during the acute phase of infection; 72 hr after infection, organisms were usually found within phagocytic vacuoles in the cytoplasm of macrophages. These vacuoles, which resembled phagosomes, often contained several organisms as well as varying amounts of amorphous electron-dense material, ferritin-like particles, membrane fragments, and vesicles of varying density. Breakdown of vacuolar membranes appeared to be accompanied by damage to the host cell cytoplasm. Nuclear membrane damage was occasionally observed when phagocytic vacuoles were close to the nucleus.

Tick-borne relapsing fever (TBRF) spirochetes are likely an overlooked cause of disease in Latin America. In Panama, the pathogens were first reported to cause human disease in the early 1900s. Recent collections of Ornithodoros puertoricensis from human dwellings in Panama prompted our interest to determine whether spirochetes still circulate in the country. Ornithodoros puertoricensis ticks were collected at field sites around the City of Panama. In the laboratory, the ticks were determined to be infected with TBRF spirochetes by transmission to mice, and we report the laboratory isolation and genetic characterization of a species of TBRF spirochete from Panama. Since this was the first isolation of a species of TBRF spirochete from Central America, we propose to designate the bacteria as Borrelia puertoricensis sp. nov. This is consistent with TBRF spirochete species nomenclature from North America that are designated after their tick vector. These findings warrant further investigations to assess the threat B. puertoricensis sp. nov. may impose on human health.

Aspergillus fumigatus is an important cause of pulmonary and systemic infections in immune compromised individuals, and of corneal ulcers and blindness in immune competent patients. To examine the role of chitin synthases inAspergillus corneal infection, we analyzed Aspergillus mutants of chitin synthase family 1 and family 2, and found that compared with the parent strain, the quadruple mutants from both families were more readily killed by neutrophils in vitro, and that both also exhibited impaired hyphal growth in the cornea. Further, inhibition of chitin synthases using Nikkomycin Z enhanced neutrophil killing in vitro and in vivo in a murine model of A. fumigatus corneal infection. Acidic mammalian chitinase (AMCase) is mostly produced by macrophages in asthmatic lungs; however, we now demonstrate that neutrophils are a major source of AMCase, which inhibits hyphal growth. In A. fumigatus corneal infection, neutrophils are the major source of AMCase, and addition of AMCase inhibitors or adoptive transfer of neutrophils from AMCase −/− mice resulted in impaired hyphal killing. Together, these findings identify chitin synthases as important fungal virulence factors and neutrophilderived AMCase as an essential mediator of host defense.Keywords: Acidic mammalian chitinase r Aspergillus fumigatus r Corneal infection r Chitin synthase r Keratitis r Neutrophil Additional supporting information may be found online in the Supporting Information section at the end of the article.