Global Veterinaria 3 (6): 489-494, 2009 ISSN 1992-6197 © IDOSI Publications, 2009 Corresponding Author: Hanan A. El-Sadawy, Department of Parasitology and Animal Diseases, National Research Center, Giza, Egypt 489 A Preliminary In Vitro Trial on the Efficacy of Products of Xenorhabdus and Photorhabdus Spp. on Eimeria Oocyst Hanan A. El-Sadawy, Rabab M. El-Khateeb and Mohamed A. Kutkat 1 1 2 Department of Parasitology and Animal Diseases, National Research Center, Giza, Egypt 1 Department of Poultry Diseases, National Research Center, Giza, Egypt 2 Abstract: The increased resistance of avian coccidia to anticoccidial drugs currently used by in poultry industry has stimulated the search for new methods of its control. In the last decades plant extracts were widely used for the controlling of avian coccidiosis and improving poultry performance worldwide. Anticoccidial efficacy of symbiotic bacterial proteins of Xenorhabdus and Photorhabdus spp. has been investigated against sporulated oocysts of mixed Eimeria species under laboratory conditions. Xenorhabdus spp. revealed higher effecacy than photorhabdus sp. on Eimeria oocysts as monitored by mortality percentage. In the treated group, most oocysts exhibited some deformities such as shrinking and fracture of oocystic cell wall as well as disappear of the embryo if compared with non treated group. It could be concluded that both Xenprhabdus and Photorhabdus bacteria produced protein toxin or Lecithinases secretion from phase I of Xenorhabdus spp. may have an important role in the induced of pathogenicity of coccedial oocyst, however further investigations are still recommended. Key words: Entomopathogenic bacteria Xenorhabdus Photorhabdus Eimeria Control INTRODUCTION anticoccidials less effective and this has threatened the Avian coccidiosis is an intestinal disease which is a developing countries where the problem has become a common health problem in poultry production in deep major concern to resource-poor farmers. Consequently, litter system around the world. It is considered to be one many different types of substances have been of the most economically devastating parasitic diseases investigated in the search as alternative methods for that currently plague the industry as it is responsible for controlling coccidiosis. high mortality and morbidity rates as well as poor feed A number of natural products have been tested as conversion in infected birds [1]. Poultry industry all anticoccidal dietary additives [3]. Sources of fats over the world is under threat of the disease and its continuing of n-3 fatty acids (n-3 FA) such as fish oils, prevalence results in the loss of millions of birds, flaxseed oil and whole flaxseed, when added to starter accounting for more than 800 million US dollars in rations from one day of age, effectively reduced lesions lost revenue annually all over the World [2]. A central resulting from challenge with E. tenella but not E. feature of avian coccidiosisis that it is caused by maxima. Curcumin (0.05%), appear to be effective in protozoan parasites, most notably Eimeria species. reducing upper-and mid small intestinal infections caused Chemoprophylactic use of anticoccidial such as by E. acervulvna and E. maxima [3], but not beneficial for Amprolium® or chemotherapy has been the primary E. tenella infections. Other traditional medical plants were means of controlling the disease in most poultry farms all applied by Allen et al.[4,5], Massoud et al. [6] and over the world. Predictably though expensive and Abu El-Ezz, [7] for controlling Coceidiosis in chickens. cumbersome, drug regimens have played a significant role Xenorhabdus and Photorhabdus are motile in the growth of the poultry industry [1]. Gram-negative bacteria that are highly pathogenic to Unfortunately, the emergence of drug-resistant insects [8]. The bacteria live in symbiosis with rhabditoid strains of coccidia has made the currently available nematodes belonging to the genera Steinernema and economic stability of the industry, especially in