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Quorum sensing, as a unique communication sensing system among microorganisms, regulates the entire bacterial colony behavior by synthesizing and secreting signal molecules. Quorum sensing directly participates in the formation of bacterial biofilm, and thus affects the spread of bacterial drug resistance. This paper reviews the effects of quorum sensing on biofilm formation and the spread of bacterial drug resistance, as well as the role of quorum sensing inhibitors in biofilm formation and the spread of antibiotic resistance. Combined with the research status quo at home and abroad, the future research focus on bacterial drug resistance is prospected. [ABSTRACT FROM AUTHOR]

Elaphurus davidianus is one of the rare species originally come from China. And study on intestine histology observation of Elaphurus davidianus has not been reported widely. In the test, microscopic morphology on intestinal tissue of Elaphurus davidianus was observed by the method of paraffin sectioning. Test results showed that jejunum epithelium villi structure of Elaphurus davidianus was obvious, a large number of intestinal glands distributed in lamina propria of jejunal epithelium. There was lymphoid tissue distributing in the base of the mucosa. The muscularis mucosa was composed of smooth muscle, thickness of muscularis mucosae was about 53 µm. There was no villous structure in the cecal mucosa of Elaphurus davidianus, capillaries in mucosal lamina propria were rich, the mucosal thickness was (236 ± 55) µm. There were large amounts of intestinal glands in inherent layer, thickness of mucosal muscle was about 27 µm. The blood vessels located in submucosal loose connective tissue were rich. The structure of small intestine was similar with that of large intestine. There was no villus structure in rectal mucosal epithelium, the maximum thickness of mucosal layer was 833 µm, and the minimum thickness of mucosal layer was 313 µm. Mucosal muscular layer was developed, which was composed of several smooth muscle bands, different bundles scattered, the thickness was about 200-600 µm. [ABSTRACT FROM AUTHOR]

Elk (Elaphurus davidianus) is a rare species native to China, and much less efforts have been dedicated to gonadal histology of male elk.The microscopic morphology of gonadal tissue of elk was observed by paraffin method. The results showed that the tunica albuginea testis was com-posed of collagenous fibers and elastic fibers, with the thickness of about 1 054 μm, and a large number of blood vessels were distributed in tunica albuginea; the seminiferous tubule was about 203 μm in diameter, with uneven thickness of tubule wall, which was consisted of sustentacular cells and spermatogenic cells; there were interstitial cells and blood vessels between seminiferous tubules. The epididymis contained more than 20 effer-ent ducts and a long curly epididymal duct; the capsule thickness at epididymis head was about 53 μm, and that at epididymis body and tail was400-1 000 μm; the epithelium of efferent duct was pseudostratified columnar epithelial cells; the wall epithelium of epididymal duct was composed of tall columnar cells at proximal lumina and stroma cells at distal lumina; the epithelial basement membrane of efferent duct and epididymal duct contained circular smooth muscle. The wall of spermatic duct was divided into mucosae, tunica muscularis and tunica adventitia. The tunica muscu-laris was well developed, which was smooth muscle fiber. [ABSTRACT FROM AUTHOR]