Photoperiod modulates the gut microbiome and aggressive behavior in Siberian hamsters.

Seasonally breeding animals undergo shifts in physiology and behavior in response to changes in photoperiod (day length). Interestingly, some species, such as Siberian hamsters (Phodopus sungorus), are more aggressive during the short-day photoperiods of the non-breeding season, despite gonadal regression. While our previous data suggest that Siberian hamsters employ a 'seasonal switch' from gonadal to adrenal regulation of aggression during short-day photoperiods, there is emerging evidence that the gut microbiome, an environment of symbiotic bacteria within the gastrointestinal tract, may also change seasonally and modulate social behaviors. The goal of this study was to compare seasonal shifts in the gut microbiome, circulating levels of adrenal dehydroepiandrosterone (DHEA) and aggression in male and female Siberian hamsters. Hamsters were housed in either long-day (LD) or short-day (SD) photoperiods for 9 weeks. Fecal samples were collected and behaviors were recorded following 3, 6 and 9 weeks of housing, and circulating DHEA was measured at week 9. SD females that were responsive to changes in photoperiod (SD-R), but not SD-R males, displayed increased aggression following 9 weeks of treatment. SD-R males and females also exhibited distinct changes in the relative abundance of gut bacterial phyla and families, yet showed no change in circulating DHEA. The relative abundance of some bacterial families (e.g. Anaeroplasmataceae in females) was associated with aggression in SD-R but not LD or SD non-responder (SD-NR) hamsters after 9 weeks of treatment. Collectively, this study provides insight into the complex role of the microbiome in regulating social behavior in seasonally breeding species.

First detection and genotyping of Enterocytozoon bieneusi in pet golden hamsters (Mesocricetus auratus) and Siberian hamsters (Phodopus sungorus) in China.

Enterocytozoon bieneusi, a common opportunistic pathogen, has been detected in humans and a wide range of animals worldwide. However, no information on the prevalence and molecular characterization of E. bieneusi in hamsters is available worldwide. In this study, fecal specimens were collected from 175 golden hamsters and 175 Siberian hamsters purchased from pet shops in three provinces of China. The average infection rate of E. bieneusi was 12.0% (42/350), with 14.9% (26/175) in pet golden hamsters and 9.1% (16/175) in pet Siberian hamsters. Four genotypes were identified in pet golden hamsters, including three known genotypes (D, Henan-II, and SHW5) and one novel genotype (named Ebph1). Five genotypes were found in pet Siberian hamsters, including one known genotype (D) and four novel genotypes (named Ebph2 to Ebph5). Genotypes D and Ebph2 were the dominant genotype in pet golden hamsters (23/26, 88.5%) and Siberian hamsters (9/16, 56.3%), respectively. Phylogenetic analysis showed that the E. bieneusi isolates clustered into two groups: Group 1 (D, Henan-II, SHW5, and Ebph1) and Group 3 (Ebph2 to Ebph5). To the best of our knowledge, this is the first report of E. bieneusi infection in golden hamsters and Siberian hamsters worldwide. The identification of four genotypes belonging to Group 1 of high zoonotic potential suggests that pet hamsters especially golden hamsters can be potential sources of human microsporidiosis.

Title: Première détection et génotypage d'Enterocytozoon bieneusi chez des hamsters dorés de compagnie (Mesocricetus auratus) et des hamsters sibériens (Phodopus sungorus) en Chine. Abstract: Enterocytozoon bieneusi, un agent pathogène opportuniste commun, a été détecté chez les humains et un large éventail d'animaux dans le monde. Cependant, aucune information sur la prévalence et la caractérisation moléculaire d'E. bieneusi chez les hamsters n'est disponible. Dans cette étude, des échantillons fécaux ont été prélevés sur 175 hamsters dorés et 175 hamsters sibériens achetés dans des animaleries de trois provinces de Chine. Le taux d'infection moyen d'E. bieneusi était de 12,0 % (42/350), avec 14,9 % (26/175) chez les hamsters dorés et 9,1 % (16/175) chez les hamsters sibériens. Quatre génotypes ont été identifiés chez les hamsters dorés, dont trois génotypes connus (D, Henan-II et SHW5) et un nouveau génotype (nommé Ebph1). Cinq génotypes ont été trouvés chez des hamsters sibériens, dont un génotype connu (D) et quatre nouveaux génotypes (nommés Ebph2 à Ebph5). Les génotypes D et Ebph2 étaient les génotypes dominants, respectivement chez les hamsters dorés (23/26, 88,5 %) et les hamsters sibériens (9/16, 56,3 %). L'analyse phylogénétique a montré que les isolats d'E. bieneusi se regroupaient en deux groupes : le groupe 1 (D, Henan-II, SHW5 et Ebph1) et le groupe 3 (Ebph2 à Ebph5). À notre connaissance, il s'agit du premier signalement d'infection par E. bieneusi chez des hamsters dorés et des hamsters de Sibérie dans le monde. L'identification de quatre génotypes appartenant au groupe 1, à fort potentiel zoonotique, suggère que les hamsters de compagnie, en particulier les hamsters dorés, peuvent être des sources potentielles de microsporidiose humaine.

Detection of pathogenic Yersinia enterocolitica in pet Djungarian hamsters in Japan.

The prevalence of Yersinia enterocolitica (Y. enterocolitica) and Yersinia pseudotuberculosis was examined in 151 pet animals including 108 rodents, 39 rabbits and four sugar gliders from 13 pet stores in the Yamaguchi Prefecture, Japan. Y. enterocolitica serogroup O:3 biotype 3 negative for the Voges-Proskauer reaction (O:3/3 variant VP-) was isolated from five Djungarian hamsters (Phodopus sungorus) raised at the same pet store. These pathogenic Y. enterocolitica isolates carried the virulence genes, yadA, ail and virF, and were shown to be clonal by pulsed-field gel electrophoresis with NotI digestion. This is a first report of pathogenic Y. enterocolitica O:3/3 variant VP- in pet Djungarian hamsters in Japan.

[The participation of vaginal bacteria in Phodopus campbelli in the chemical communication between male and female]. / Uchastie vaginal'nykh bakterii khomiachka Kémbella v khimicheskoi kommunikatsii mezhdu samtsom i samkoi.

Phodopus campbelli commonly occurs in dry steppe and semidesert zone of south Siberia, Mongolia and China. Using radiotelemetry we found that a male has to cover about 2 km from his burrow to encounter a receptive female. Female in estrus marks a small area around its burrow by vaginal smear. Experiments were carried out in laboratory to discover the nature of this strong signal. In a "open field" area four boxes within stimuli we recorded the time complemented spent by males near boxes to study the attractive effect of intact receptive female, germ culture of vaginal smear and artificial mixed culture of bacteria which were found in the vaginal smear of Ph. campbelli receptive female. Males (n = 15) spent significantly more time near the boxes with female in estrus or day before estrus as compared with two other days of cycle. Germ culture from vaginal smear sampled on the estrus day was more attractive to males on 6th day than on the 2, -3, -5, -7, -8--or 9th days of cultivation, pure culture or germ culture sampled on anestrus. Mixed culture, which simulated the proportion of predominant bacteria in the estrus vaginal smear, was significantly more attractive for males on the 3rd day of cultivation. Thus sexual attractant of Ph. campbelli could be produced by some bacteria located in the vagina in estrus and it takes a couple of days of cultivation for maximum attractive effect.