Novel Mycobacterium tuberculosis Complex Pathogen, M. mungi

Seven outbreaks involving increasing numbers of banded mongoose troops and high death rates have been documented. We identified a Mycobacterium tuberculosis complex pathogen, M. mungi sp. nov., as the causative agent among banded mongooses that live near humans in Chobe District, Botswana. Host spectrum and transmission dynamics remain unknown

Effect of food limitation and reproductive activity on fecal glucocorticoid metabolite levels in banded mongooses

Abstract Background Glucocorticoids mediate responses to perceived stressors, thereby restoring homeostasis. However, prolonged glucocorticoid elevation may cause homeostatic overload. Using extensive field investigations of banded mongoose (Mungos mungo) groups in northern Botswana, we assessed the influence of reproduction, predation risk, and food limitation on apparent homeostatic overload (n=13 groups, 1542 samples from 268 animals). We experimentally manipulated reproduction and regulated food supply in captive mongooses, and compared their glucocorticoid responses to those obtained from free-living groups. Results At the population level, variation in glucocorticoid levels in free-living mongooses was explained by food limitation: fecal organic matter, recent rainfall, and access to concentrated anthropogenic food resources. Soil macrofauna density and reproductive events explained less and predation risk very little variation in glucocorticoid levels. Reproduction and its associated challenges alone (under regulated feeding conditions) increased glucocorticoid levels 19-fold in a captive group. Among free-living groups, glucocorticoid elevation was seasonal (occurring in late dry season or early wet season when natural food resources were less available), but the timing of peak glucocorticoid production was moderated by access to anthropogenic resources (groups with fewer anthropogenic food sources had peaks earlier in dry seasons). Peak months represented 12- and 16-fold increases in glucocorticoids relative to nadir months with some animals exhibiting 100-fold increases. Relative to the captive group nadir, some free-living groups exhibited 60-fold increases in peak glucocorticoid levels with some animals exhibiting up to 800-fold increases. Most of these animals exhibited 1- to 10-fold increases relative to the captive animal peak. Conclusions Banded mongooses exhibit seasonal chronic glucocorticoid elevation, associated primarily with food limitation and secondarily with reproduction. Magnitude and duration of this elevation suggests that this may be maladaptive for some animals, with possible fitness consequences. In late dry season, this population may face a convergence of stressors (food limitation, agonistic encounters at concentrated food resources, evictions, estrus, mate competition, parturition, and predation pressure on pups), which may induce homeostatic overload

Effects of an anti-gonadoliberin releasing hormone vaccine on testicular, epididymal and spermatogenic development in the horse

The effects of the GnRH vaccine Improvac® on testicular and epididymal morphometrics, histology and spermatogenesis were measured in 19 young (15–20 months) colts randomly assigned to one control (saline, castration at 57 days, n = 6) or either of two GnRH vaccine-treatment groups, T-57 (castration at 57 days, n = 7) or T-100 (castration at 100 days, n = 6), respectively. All were immunized on Day 0 with a single booster on Day 28. Excised testes and epididymides were weighed and processed for histology to measure tubule, epithelial and muscle dimensions, the ratio of interstitial tissue to seminiferous tubules and determine the stage of spermatogenesis. Testis volume, unchanged within controls, decreased in T-57 and T-100 groups by 50% and 70%, respectively. Treated colts' testes were significantly lighter than controls (64% relative difference); however, epididymal mass showed no significant differences between groups. Proportionally less seminiferous tubule relative to interstitial tissue was observed in both treatment groups (5%) versus controls (22%) with a mean tubule size 28% smaller than controls. Controls exhibited a high proportion of seminiferous tubules with advanced stages of spermatogenesis, whereas treated colts showed a high proportion of tubules in the early stages of spermatogenesis. In conclusion, immunization against GnRH in prepubertal colts was effective at reducing the development of their intra-scrotal reproductive organs and preventing normal spermatogenesis. GnRH vaccination of young colts effectively and consistently reduced testis mass, tubule size and relative proportion of seminiferous tubule tissue while retarding spermatogenesis. The epididymis showed changes with a smaller tubule diameter, lower epithelial height and thicker muscle layer recorded in treated compared to control colts.http://www.wileyonlinelibrary.com/journal/rdahj2022Anatomy and PhysiologyProduction Animal Studie