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Simple Summary: Joint infection, or septic arthritis, is an important disease in horses and requires aggressive treatment to eradicate the infection. Using current diagnostic methods, it is difficult to determine when the infection has been eliminated following treatment, leading to often prolonged antimicrobial therapy, which may be unnecessary and is associated with side effects and antimicrobial resistance. Thus, better markers of eradication of joint infection are needed. In this study, a class of molecules called messenger ribonucleic acid (mRNA) in synovial fluid was investigated for potential biomarkers of the eradication of infection in an experimental model of equine septic arthritis using transcriptomics methods. Transcriptomics data were also compared to our previously published data on putative protein biomarkers of the eradication of joint infection and to an mRNA biomarker panel used to differentiate septic from non-septic shock in humans. Eight mRNAs were identified that were at least three times increased in horses with active septic arthritis compared to horses post-eradication of infection after treatment and horses with non-septic synovitis. The presence of mRNAs corresponding to our previously reported protein markers of eradication of joint infection and to the validated mRNA biomarker panel detecting sepsis in humans was also confirmed. Further investigation of mRNAs as a source of potential markers of the eradication of joint infection in horses is needed. Septic arthritis (SA) in horses has long-term health implications. The success of its resolution hinges on the implementation of early, aggressive treatment, which is often sustained over a prolonged period. Common diagnostic methods do not allow for the reliable detection of the eradication of joint infection. A potential alternative is the discovery and characterization of mRNA biomarkers. The purpose of this study was to identify potential mRNA biomarkers for the eradication of joint infection in equine SA and to compare their expression with our previously published proteomics data. In addition, the transcriptomics data were compared to the mRNA biomarker panel, SeptiCyte Lab, used to distinguish sepsis from non-septic shock in humans. A comparative transcriptomics analysis of synovial fluid from the SA joints of five horses with active infection and subsequent post-treatment eradicated infection in the same joints and five horses with non-septic synovitis was performed. Eight novel mRNA transcripts were identified that were significantly upregulated (>3-fold) in horses with active SA compared to horses post-eradication of infection after treatment and horses with non-septic synovitis. Two proteins in our proteomics data corresponded to these mRNA transcripts, but were not statistically different. The transcripts used in the SeptiCyte test were not differentially expressed in our study. Our results suggest that mRNA may be a useful source of biomarkers for the eradication of joint infection in horses and warrants further investigation. [ABSTRACT FROM AUTHOR]

The accelerating decline of pollinator populations has become increasingly concerning in the last two decades. Honey bees are economically important pollinators and a model species to evaluate pollinator health. The decline in queen quality is one of the frequently reported causes associated with honey bee losses worldwide. Histopathology is an essential tool used for diagnostics and research in mammalian species and may provide insight into the histomorphological basis of a decline in queen quality. Thus, the purpose of this study was to summarize the previously described normal morphology of the entire reproductive tract of mated honey bee queens and to illustrate it by high quality photomicrographs. Accordingly, reproductive tracts of one-year old mated honey bee queens were processed for histology, serially sectioned, stained with hematoxylin and eosin, and used for the capture of high quality histological photomicrographs of the entire reproductive tract. This study illustrates the microscopic morphology of the queen reproductive tract which may facilitate further investigations of the cause and pathogenesis of the recent decline in reproductive fitness of honey bees using histopathology. [ABSTRACT FROM AUTHOR]

The normal developmental anatomy and histology of the reproductive tract of the honey bee drone, Apis mellifera (Linnaeus, 1758), has been well documented. The post-emergence maturation changes of the accessory glands are likewise well understood, but the normal histological changes of the testicle undergoing physiologic atrophy are not well characterized. To address this knowledge gap, herein we describe the anatomy and sequential histological stages of normal testicular atrophy of drones sampled daily from emergence to sexual maturity in the spring (June) and early summer (July). Testicular histological changes during maturation are characterized by the following stages: I) conclusion of spermiogenesis; II) evacuation of spermatodesms from tubular lumens; III) progressive follicular cell atrophy, and IV) complete atrophy and collapse of testicular parenchyma. Tubular changes occur in a basilar to apical direction where segments closer to the vas deferens are histologically more mature than corresponding apical segments. In addition, the rate of testicular maturation was found to change with seasonal progression. This description of physiologic testicular atrophy should be useful for future studies investigating potential pathological effects of stressors on drone testes during sexual maturation. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Veterinary Research / Revue Canadienne de Recherche Vétérinaire is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Veterinary Research / Revue Canadienne de Recherche Vétérinaire is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thiamethoxam, clothianidin, and imidacloprid are the most commonly used neonicotinoid insecticides on the Canadian prairies. There is widespread contamination of nectar and pollen with neonicotinoids, at concentrations which are sublethal for honey bees (Apis mellifera Linnaeus). We compared the effects of chronic, sublethal exposure to the three most commonly used neonicotinoids on honey bee colonies established from New Zealand packaged bees using colony weight gain, brood area, and population size as measures of colony performance. From May 7 to July 29, 2016 (12 weeks), sixty-eight colonies received weekly feedings of sugar syrup and pollen patties containing 0, 20 (median environmental dose), or 80 (high environmental dose) nM of one of three neonicotinoids (thiamethoxam, clothianidin, and imidacloprid). Colonies were weighed at three week intervals. There was a significant negative effect (P<0.01) on colony weight gain (honey production) after 9 and 12 weeks of exposure to 80 nM neonicotinoids and on cluster size (P<0.05) after 12 weeks. A significant effect of neonicotinoid exposure was not observed for brood area or number of adult bees, but these analyses lacked adequate (>80%) statistical power due to marked variation within treatment groups. Thus, continued reliance on colony-level parameters such as brood area and population size for pesticide risk assessment may not be the most sensitive method to detect sublethal effects of neonicotinoids on honey bees. [ABSTRACT FROM AUTHOR]