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Ultrastructural study on the morphological changes in indigenous bacteria of mucous layer and chyme throughout the rat intestine.

Mantani Y, Ito E, Nishida M, Yuasa H, Masuda N, Qi WM, Kawano J, Yokoyama T, Hoshi N, Kitagawa H - J. Vet. Med. Sci. (2015)

Bottom Line: The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine.Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine.In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.

ABSTRACT
Indigenous bacteria in the alimentary tract are exposed to various bactericidal peptides and digestive enzymes, but the viability status and morphological changes of indigenous bacteria are unclear. Therefore, the present study aimed to ultrastructurally clarify the degeneration and viability status of indigenous bacteria in the rat intestine. The majority of indigenous bacteria in the ileal mucous layer possessed intact cytoplasm, but the cytoplasm of a few bacteria contained vacuoles. The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine. In the dividing bacteria of the mucous layer and chyme throughout the intestine, the ratio of area occupied by vacuoles was almost always less than 10%. Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine. In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed. From these findings, indigenous bacteria in the mucous layer were ultrastructurally confirmed to be the source of indigenous bacteria in the chyme. Furthermore, the results suggested that indigenous bacteria were more severely degenerated toward the large intestine and were probably degraded in the intestine.

No MeSH data available.


Related in: MedlinePlus

a–d) Ultrastructure of indigenous bacteria in the mucous layer of the ileum (a, b),cecum (c) and ascending colon (d). a) Rod-shaped indigenous bacteria have intactcytoplasm with homogeneous electron density and nucleoid bodies in their cytoplasm inthe ileal mucous layer on the epithelial surface. b) Segmented filamentous bacteriaare visible in the ileal mucous layer. c, d) Coccal or rod-shaped indigenous bacteriahave vacuoles in their cytoplasm in the mucous layer of the cecum (c) and ascendingcolon (d). Extremely slim spiral-shaped bacteria in the cecum (c, arrow) and long andthick bacilli in the ascending colon (d, arrow) are visible in each intestinalsegment. e, f) In the intestinal crypts, spiral-shaped bacteria are numerously visiblein the cecum (e, arrowheads), while a sole indigenous bacterium is visible in theascending colon (f). The vacuolation of indigenous bacteria is lower degree in theintestinal crypt of the cecum (e, arrow) and ascending colon (f, arrow) than in themucous layers of the cecum (c) and ascending colon (d). Bar=1 µm.
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fig_001: a–d) Ultrastructure of indigenous bacteria in the mucous layer of the ileum (a, b),cecum (c) and ascending colon (d). a) Rod-shaped indigenous bacteria have intactcytoplasm with homogeneous electron density and nucleoid bodies in their cytoplasm inthe ileal mucous layer on the epithelial surface. b) Segmented filamentous bacteriaare visible in the ileal mucous layer. c, d) Coccal or rod-shaped indigenous bacteriahave vacuoles in their cytoplasm in the mucous layer of the cecum (c) and ascendingcolon (d). Extremely slim spiral-shaped bacteria in the cecum (c, arrow) and long andthick bacilli in the ascending colon (d, arrow) are visible in each intestinalsegment. e, f) In the intestinal crypts, spiral-shaped bacteria are numerously visiblein the cecum (e, arrowheads), while a sole indigenous bacterium is visible in theascending colon (f). The vacuolation of indigenous bacteria is lower degree in theintestinal crypt of the cecum (e, arrow) and ascending colon (f, arrow) than in themucous layers of the cecum (c) and ascending colon (d). Bar=1 µm.

Mentions: Indigenous bacteria in the mucous layer of rat intestine: Cocci andbacilli ordinarily existed in the mucous layer throughout the rat intestine. Additionally,segmented filamentous bacteria (SFB) were occasionally contained in the mucous layer of theileum, but not in those of the cecum and ascending colon. Spiral-shaped bacteria were foundin the mucous layer of the cecum and ascending colon, but not in that of the ileum.Indigenous bacteria in the mucous layer of the ascending colon contained numerous long andthick bacilli. These long and thick bacilli were also rarely found in the mucous layer ofthe cecum, but not in that of the ileum. The mucous layers of intestinal crypts of the ileumnever contained bacteria, whereas those of the cecum were often packed with numerousspiral-shaped bacteria and a few bacilli, while those of the ascending colon rarelycontained some kinds of bacteria, such as short bacilli and long and thick bacilli (Fig. 1a–1fFig. 1.


Ultrastructural study on the morphological changes in indigenous bacteria of mucous layer and chyme throughout the rat intestine.

Mantani Y, Ito E, Nishida M, Yuasa H, Masuda N, Qi WM, Kawano J, Yokoyama T, Hoshi N, Kitagawa H - J. Vet. Med. Sci. (2015)

a–d) Ultrastructure of indigenous bacteria in the mucous layer of the ileum (a, b),cecum (c) and ascending colon (d). a) Rod-shaped indigenous bacteria have intactcytoplasm with homogeneous electron density and nucleoid bodies in their cytoplasm inthe ileal mucous layer on the epithelial surface. b) Segmented filamentous bacteriaare visible in the ileal mucous layer. c, d) Coccal or rod-shaped indigenous bacteriahave vacuoles in their cytoplasm in the mucous layer of the cecum (c) and ascendingcolon (d). Extremely slim spiral-shaped bacteria in the cecum (c, arrow) and long andthick bacilli in the ascending colon (d, arrow) are visible in each intestinalsegment. e, f) In the intestinal crypts, spiral-shaped bacteria are numerously visiblein the cecum (e, arrowheads), while a sole indigenous bacterium is visible in theascending colon (f). The vacuolation of indigenous bacteria is lower degree in theintestinal crypt of the cecum (e, arrow) and ascending colon (f, arrow) than in themucous layers of the cecum (c) and ascending colon (d). Bar=1 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591154&req=5

fig_001: a–d) Ultrastructure of indigenous bacteria in the mucous layer of the ileum (a, b),cecum (c) and ascending colon (d). a) Rod-shaped indigenous bacteria have intactcytoplasm with homogeneous electron density and nucleoid bodies in their cytoplasm inthe ileal mucous layer on the epithelial surface. b) Segmented filamentous bacteriaare visible in the ileal mucous layer. c, d) Coccal or rod-shaped indigenous bacteriahave vacuoles in their cytoplasm in the mucous layer of the cecum (c) and ascendingcolon (d). Extremely slim spiral-shaped bacteria in the cecum (c, arrow) and long andthick bacilli in the ascending colon (d, arrow) are visible in each intestinalsegment. e, f) In the intestinal crypts, spiral-shaped bacteria are numerously visiblein the cecum (e, arrowheads), while a sole indigenous bacterium is visible in theascending colon (f). The vacuolation of indigenous bacteria is lower degree in theintestinal crypt of the cecum (e, arrow) and ascending colon (f, arrow) than in themucous layers of the cecum (c) and ascending colon (d). Bar=1 µm.
Mentions: Indigenous bacteria in the mucous layer of rat intestine: Cocci andbacilli ordinarily existed in the mucous layer throughout the rat intestine. Additionally,segmented filamentous bacteria (SFB) were occasionally contained in the mucous layer of theileum, but not in those of the cecum and ascending colon. Spiral-shaped bacteria were foundin the mucous layer of the cecum and ascending colon, but not in that of the ileum.Indigenous bacteria in the mucous layer of the ascending colon contained numerous long andthick bacilli. These long and thick bacilli were also rarely found in the mucous layer ofthe cecum, but not in that of the ileum. The mucous layers of intestinal crypts of the ileumnever contained bacteria, whereas those of the cecum were often packed with numerousspiral-shaped bacteria and a few bacilli, while those of the ascending colon rarelycontained some kinds of bacteria, such as short bacilli and long and thick bacilli (Fig. 1a–1fFig. 1.

Bottom Line: The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine.Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine.In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.

ABSTRACT
Indigenous bacteria in the alimentary tract are exposed to various bactericidal peptides and digestive enzymes, but the viability status and morphological changes of indigenous bacteria are unclear. Therefore, the present study aimed to ultrastructurally clarify the degeneration and viability status of indigenous bacteria in the rat intestine. The majority of indigenous bacteria in the ileal mucous layer possessed intact cytoplasm, but the cytoplasm of a few bacteria contained vacuoles. The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine. In the dividing bacteria of the mucous layer and chyme throughout the intestine, the ratio of area occupied by vacuoles was almost always less than 10%. Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine. In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed. From these findings, indigenous bacteria in the mucous layer were ultrastructurally confirmed to be the source of indigenous bacteria in the chyme. Furthermore, the results suggested that indigenous bacteria were more severely degenerated toward the large intestine and were probably degraded in the intestine.

No MeSH data available.


Related in: MedlinePlus