Osmotically stable L forms of Haemophilus influenzae and their significance in testing sensitivity to penicillins.
J Clin Pathol
; 27(7): 560-4, 1974 Jul.
Article
en En
| MEDLINE
| ID: mdl-4547629
ABSTRACT
The sensitivity of Haemophilus influenzae to penicillins in vitro, determined either by serial antibiotic dilution in broth or by the disc method on agar, is apparently profoundly influenced by inoculum size if the results are read by macroscopic inspection. Microscopic inspection of the growth, however, reveals that the turbidity in heavily inoculated broth containing concentrations higher than the minimal inhibitory concentration is the product of L forms which have failed to succumb to osmotic lysis. Similarly, minute colonies appearing in the ;inhibition zone' of disc tests are composed of L forms. In both broth and agar tests reduction of the osmolality of the medium from 340 to 144 mOsm per kg failed to bring about lysis of organisms exposed either to ampicillin or amoxycillin. The significance of this remarkable osmotic stability of haemophilus L forms is discussed in relation both to testing of sensitivity of this organism to penicillins and to persistence of chronic haemophilus infections of the lower respiratory tract.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Penicilinas
/
Haemophilus influenzae
/
Formas L
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Año:
1974
Tipo del documento:
Article