The relevance of in vitro anthelmintic screening tests employing the free-living stages of trichostrongylid nematodes

1984 ◽  
Vol 58 (2) ◽  
pp. 107-112 ◽  
Author(s):  
O.F. Ibarra ◽  
D.C. Jenkings
Keyword(s):  
Broad Spectrum ◽  
Haemonchus Contortus ◽  
Screening Tests ◽  
Nippostrongylus Brasiliensis ◽  
Good Activity ◽  
Free Living ◽  
Ostertagia Ostertagi ◽  
Nematospiroides Dubius ◽  
Antiparasitic Agents

AbstractThe response of the free-living stages of Nippostrongylus brasiliensis, Nematospiroides dubius, Haemonchus contortus, Trichostrongylus colubriformis and Ostertagia ostertagi to a wide variety of antiparasitic agents in vitro was investigated.All the major broad spectrum veterinary anthelmintics showed good activity against each of these worms with EC30 values varying from about 00002mg/1 for certain benzimidazoles and ivermectin to about 6–5 mg/1 for febantel. Of 22 known narrow spectrum anthelmintics useful only against H. contortus and/or helminths other than trichostrongyles, only 10% showed good activity at concentrations equal to or less than 100mg/1. Further, only one of 15 antiprotozoal agents showed good activity in these tests at the 100mg/1 level.

Nippostrongylus brasiliensis: the effect of mitochondnal inhibitors on life-cycle stages

Parasitology ◽  
1984 ◽  
Vol 88 (1) ◽  
pp. 163-177 ◽  
Author(s):  
M. Fry ◽  
D. C. Jenkins
Keyword(s):  
Life Cycle ◽  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Adult Worm ◽  
Nippostrongylus Brasiliensis ◽  
Free Living ◽  
Mitochondrial Inhibitors ◽  
Life Cycle Stages ◽  
Transport Inhibitors

SUMMARYThe effects of mitochondrial inhibitors on the in vitro development of Nippostrongylus brasiliensis have been studied in free-living and parasitic life-cycle stages. Mitochondrial inhibitors were chosen as being representative of established electron transport inhibitors and oxidative phosphorylation inhibitors and uncouplers of the classical mammalian respiratory chain. All mitochondrial inhibitors tested were highly effective in killing or retarding development of free-living stages of N. brasiliensis. Free-living stages were particularly susceptible to such inhibitors upon hatching of embryonated eggs to 1st-stage larvae. Concentrations of inhibitors effective against free-living stages were consistent with their level of inhibition against isolated mitochondria from embryonated eggs and 3rd-stage infective larvae. Results suggest an absolute requirement in the development of free-living stages for the mammalian-like respiratory chain and associated oxidative phosphorylation. Electron transport inhibitors were effective in retarding at least the initial development of 4th-stage larvae to adults, but only antimycin A and azide produced a lasting effect leading to worm death. Oxidative phosphorylation inhibitors and uncouplers were ineffective against developing parasitic stages of N. brasiliensis. Experiments on whole-worm respiration indicated that most electron transport inhibitors were able to penetrate the adult worm, but oxidative phosphorylation inhibitors were without effect on whole-worm respiration. Results suggest that the mammalian-like electron transport chain is a necessary requirement to adult N. brasiliensis, but oxidative phosphorylation in the adult worm may not be required for development and survival in vitro although it could be necessary to support the parasite in vivo.

scholarly journals In Vitro Activity of Ceftaroline against 623 Diverse Strains of Anaerobic Bacteria

2010 ◽  
Vol 54 (4) ◽  
pp. 1627-1632 ◽  
Author(s):  
D. M. Citron ◽  
K. L. Tyrrell ◽  
C. V. Merriam ◽  
E. J. C. Goldstein
Keyword(s):  
Soft Tissue ◽  
Broad Spectrum ◽  
Anaerobic Bacteria ◽  
Soft Tissue Infections ◽  
Good Activity ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Amoxicillin Clavulanate ◽  
Gram Negative Organisms

ABSTRACT The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and four comparator antimicrobials were determined against anaerobic bacteria. Against Gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin-clavulanate and four to eight times greater than that of ceftriaxone. Against Gram-negative organisms, ceftaroline showed good activity against β-lactamase-negative strains but not against the members of the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft tissue infections.

scholarly journals Activity of Ceftolozane-Tazobactam against a Broad Spectrum of Recent Clinical Anaerobic Isolates

2013 ◽  
Vol 58 (2) ◽  
pp. 1218-1223 ◽  
Author(s):  
David R. Snydman ◽  
Laura A. McDermott ◽  
Nilda V. Jacobus
Keyword(s):  
Broad Spectrum ◽  
Bacteroides Fragilis ◽  
Good Activity ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Cocci

ABSTRACTWe evaluatedin vitroactivity of ceftolozane-tazobactam (TOL-TAZ), formerly CXA-201, against recent clinical anaerobic isolates with emphasis on theBacteroides fragilisgroup. Ceftolozane-tazobactam showed good activity againstB. fragilisspecies and intermediate to limited activity against other species ofBacteroides. Ceftolozane-tazobactam showed very good activity againstPrevotellaspp.,Fusobacteriumspp., andPropionibacteriumspp., varying activities against Gram-positive cocci, and limited activity againstClostridiumspp.

Comparative efficacy of standard antihookworm drugs against various test nematodes

1981 ◽  
Vol 55 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Anuradha Misra ◽  
P. K. S. Visen ◽  
J. C. Katiyar
Keyword(s):  
Broad Spectrum ◽  
Lethal Effect ◽  
Economic Importance ◽  
Nippostrongylus Brasiliensis ◽  
Comparative Efficacy ◽  
Ancylostoma Ceylanicum ◽  
Primary Screening ◽  
Host Parasite ◽  
Hookworm Infections

ABSTRACTThe chemotherapeutic responses of three test nematodes, Nippostrongylus brasilietxsis, Nematospiroidesdubius and Ancylostoma ceylanicum to standard antihookworm drugs were assessed in order to select asuitable host-parasite system for the primary screening of potential antihookworm compounds. N. dubiusbehaved inconsistently and, with some infections, required more drug to achieve 100% clearance. Nippostrongylus brasiliensis was found to be sensitive to thiabendazole, tetramisole and levamisole but the broad spectrum anthclmintic mebendazole was ineffective. A. ceylanicum was very sensitive to mebendazole, sensitive to tetramisole and levamisole and refractory to thiabendazole. In vitro, none of the compounds had any lethal effect against any of the nematodes, except mebendazole against A. ceylanicum.A. ceylanicum does occur in man and its chemotherapeutic reactions are similar to those of target hookworm infections of economic importance. As such, although not equally sensitive to standard anthelmintics, it is recommended for routine primary screening.

Sign in / Sign up

Export Citation Format

Share Document