Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

Borrelia miyamotoi a neglected tick-borne relapsing fever spirochete in Thailand.

Borrelia miyamotoi is a relapsing fever spirochete that shares the same vector as Lyme disease causing Borrelia. This epidemiological study of B. miyamotoi was conducted in rodent reservoirs, tick vectors and human populations simultaneously. A total of 640 rodents and 43 ticks were collected from Phop Phra district, Tak province, Thailand. The prevalence rate for all Borrelia species was 2.3% and for B. miyamotoi was 1.1% in the rodent population, while the prevalence rate was quite high in ticks collected from rodents with an infection rate of 14.5% (95% CI: 6.3-27.6%). Borrelia miyamotoi was detected in Ixodes granulatus collected from Mus caroli and Berylmys bowersi, and was also detected in several rodent species (Bandicota indica, Mus spp., and Leopoldamys sabanus) that live in a cultivated land, increasing the risk of human exposure. Phylogenetic analysis revealed that the B. miyamotoi isolates detected in rodents and I. granulatus ticks in this study were similar to isolates detected in European countries. Further investigation was conducted to determine the serological reactivity to B. miyamotoi in human samples received from Phop Phra hospital, Tak province and in rodents captured from Phop Phra district using an in-house, direct enzyme-linked immunosorbent assay (ELISA) assay with B. miyamotoi recombinant glycerophosphodiester-phosphodiesterase (rGlpQ) protein as coated antigen. The results showed that 17.9% (15/84) of human patients and 9.0% (41/456) of captured rodents had serological reactivity to B. miyamotoi rGlpQ protein in the study area. While a low level of IgG antibody titers (100-200) was observed in the majority of seroreactive samples, higher titers (400-1,600) were also detected in both humans and rodents. This study provides the first evidence of B. miyamotoi exposure in human and rodent populations in Thailand and the possible roles of local rodent species and Ixodes granulatus tick in its enzootic transmission cycle in nature

Applying next generation sequencing to detect tick-pathogens in Dermacentor nuttalli, Ixodes persulcatus, and Hyalomma asiaticum collected from Mongolia

Ticks and tick-borne diseases represent major threats to the public health of the Mongolian population, of which an estimated 26% live a traditional nomadic pastoralist lifestyle that puts them at increased risk for exposure. Ticks were collected by dragging and removal from livestock in Khentii, Selenge, Tuv, and Umnugovi aimags (provinces) during March-May 2020. Using next-generation sequencing (NGS) with confirmatory PCR and DNA sequencing, we sought to characterize the microbial species present in Dermacentor nuttalli (n = 98), Hyalomma asiaticum (n = 38), and Ixodes persulcatus (n = 72) tick pools. Rickettsia spp. were detected in 90.4% of tick pools, with Khentii, Selenge, and Tuv tick pools all having 100% pool positivity. Coxiella spp. were detected at an overall pool positivity rate of 60%, while Francisella spp. were detected in 20% of pools and Borrelia spp. detected in 13% of pools. Additional confirmatory testing for Rickettsia-positive pools demonstrated Rickettsia raoultii (n = 105), Candidatus Rickettsia tarasevichiae (n = 65) and R. slovaca/R. sibirica (n = 2), as well as the first report of Candidatus Rickettsia jingxinensis (n = 1) in Mongolia. For Coxiella spp. reads, most samples were identified as a Coxiella endosymbiont (n = 117), although Coxiella burnetii was detected in eight pools collected in Umnugovi. Borrelia species that were identified include Borrelia burgdorferi sensu lato (n = 3), B. garinii (n = 2), B. miyamotoi (n = 16), and B. afzelii (n = 3). All Francisella spp. reads were identified as Francisella endosymbiont species. Our findings emphasize the utility of NGS to provide baseline data across multiple tick-borne pathogen groups, which in turn can be used to inform health policy, determine regions for expanded surveillance, and guide risk mitigation strategies