Browsing by Subject "Bacterial cell walls"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Cell Wall Deficient Forms of Listeria Monocytogenes as a Natural Phenomenon(Texas Tech University, 1984-05) Beson, Carl APrevious s t u d i e s have a r t i f i c i a l l y i n d u c e d c e ll w a l l d e f i c i e n t forms of L i s t e r i a m o n o c y t o g e n e s w i th p e n i c i l l i n or s p e c i f i c a n t i s e r a ( 1 , 2 , 7 ) . C e l l w a ll d e f i c i e n t forms of L i s t e r i a monocytogenes have a l s o been d e m o n s t r a t e d in t i s s u e c u l t u r e s t u d i e s of i n f e c t ed a l v e o l a r macrophages ( 2 0 ) . Present s t u d i e s , u s i n g phase c o n t r a s t m i c r o s c o p y , i n d i c a t e t h a t c e l l w a l l d e f i c i e nt f o r m s of L i s t e r i a m o n o c y t o g e n e s a r e a n a t u r al p h e n o m e n o n . Samples t a k e n from v a r i o u s r e g i o n s of m o t i l i t y t e s t medium s t a b c u l t u r e s i n d i c a t e t h a t the o r g a n i s m s growing in the pathognomonic " u m b r e l l a " r e g i on a r e c e l l w a l l d e f i c i e n t forms. The c l a s s i c a l b a c i l l a ry f o r m s , s i m i l a r to t h o s e found in the s t a b r e g i o n , can be r e c o v e r e d from t h e " u m b r e l l a " only a f t e r 36-48 h o u r s. C h a n g e s in t h e o x y g e n a n d / o r c a r b o n d i o x i de c o n c e n t r a t i o n are i m p l i c a t e d as t h e primary cause of the d e f i c i e n c y in the c e l l w a l l. Previous studies have artificially induced cell Wall deficient forms of Listeria monocytogenes with Penicillin or specific antisera (1,2,7). Cell wall Deficient forms of Listeria monocytogenes have also been demonstrated in tissue culture studies of infected Alveolar macrophages (20). Present studies, using phase Contrast microscopy, indicate that cell wall deficient Forms of Listeria monocytogenes are a natural Phenomenon. Samples taken from various regions of Motility test medium stab cultures indicate that the Organisms growing in the pathognomonic “umbrella†region are cell wall deficient forms. The classical bacillary Forms, similar to those found in the stab region, can be recovered from the “umbrella†only after 36-48 hours. Changes in the oxygen and/or carbon dioxide concentration are implicated as the primary cause of the deficiency in the cell wallItem Ion transport in photosynthetic purple bacteria(Texas Tech University, 1982-08) Davidson, Victor LesterNot available