Serotypes Of Salmonella Isolates From Chickens And Their Susceptability To Local Plant Extracts

Abstract

Chicken salmonellosis is considered as threatening factor to poultry industry. On the other hand, human food-borne infection due to Salmonella from poultry products is of significant value. No much data regarding the main serotypes encountered in chicken and human infection in Sudan is available, hence this study was designed to determine the main serotypes of Salmonella prevalent in some open system laying farms in Khartoum State and to evaluate drug sensitivity and effect of some natural plant extracts on isolated Salmonellae . One hundred and ten faecal, ٢٠ manure(dry faeces) and ٤٠ drinking water samples were collected for bacteriological examinations from four laying farms to detect the presence of Salmnonella , two of the farms from which the samples were taken are known to harbuor the infection, while birds in the other two farms were showing no clinical symptoms of salmonellosis. From the total isolates, eighty three non lactose fermenting isolates were recovered and thirty were proved to be Salmonlella . Identification of Salmonlella isolates to the genus level was based on morphological , cultural characteristic and biochemical reactions and confirmation was based on serological test . From the ٣٠ Salmonlella isolates, twelve have been serotyped. Five serotypes have been identified. They were Salmonella gombe, S. bonariensis, S. potsdam and two unclassified salmonella serotypes. Classification to the serotype level was based on serotyping method using specific antisera subgroup (O) and (H) . The five isolated serotypes were tested for in vitro antibiotic sensitivity using disk diffusion test. Four antibiotics namely, gentamycin , tetracycline , neomycin and colistin were used. Generally the serotypes showed different responses to different antibiotics. S. bonariesis and S .gombe were sensitive to gentamycin , the two unclassified seroytpes (NS) (N١٩) were found to be sensitive to neomycin while S .potsdam was less sensitive to all antibiotics . In vitro testing using natural plants extracts was carried out for the same serotypes. Acacia nilotica ( Cissus quandrugularis) locally named (Garad) and Solensomma largel (laryl) (Del) Hayne locally named (Hargel) were used. Garad extracts in different concentrations were found to be highly effect against all serotypes of salmonella . The methanol extract was found to be more effective compared with chloroform extract . Hargel extracts were found to be of low activity against salmonella serotypes in different concentrations . The epidemiological investigations showed that all farms with good hygiene management have low infection rate with Salmonella, on the other hand, in farms with poor hygiene, high rate of infection occurred. It could be concluded that salmonellosis was endemic in the examined farms and affect the productivity. New serotypes were isolated, gentamycin and extracts of Garad specially the methanol extracts are highly effective against Salmonella and could be used for the treatment of the disease.