Occurrence of some pathogenic microorganisms in kareish cheese and their public health significance

Document Type : Original Article

Authors

1 Department of Food Hygiene, Faculty of Veterinary Medicine, Bani-Suef University, Egypt

2 Department of Microbiology, Animal health research Institute, Bani-Suef, Egypt.

Abstract

A number of 50 Ardeola ibis ibis birds were found harboring six nematodes species; Tetrameres species, Microtteramere species, Synhimantus invaginatus, Synhimantus equispeculatus, Ascaridia species, Paracamallanus species,and five species of trematodes; Euclinostomum heterostomum, Nephrostomum ramosum, Apharyngostrigea ibis, Apatemon gracilis and Centrocestus armatus. The most common infection by nematodes was (46%) in which highest infection rate Synhimantus invaginatus recorded (30 %) while the trematode infection was (24 %) and Apatemon gracilis was the most prevalent (16 %). Experimental infection of buff backed heron by encysted metacercaria (EMC) and exysted metacercaria (ExMC) of Clinostomum complanatum from freshwater fish Tilapia nilotica, resulted in adult worms formed after 6 days. Where the infection by EMC recorded higher worm burden (14-18 worm) and hatching percent (78%) while the infection by ExMC gave lower worm burden (7-10 worm / bird ) and hatching (48 %). In the present study, it is worthy to mention that buff backed heron act as final host model for Clinostomum complanatum and this will be helpful in further biological and immunological studies for this trematode to decrease its economic losses in fish intermediate host.Fifty random samples of Kareish cheese were collected from different localities in Bani-suef Governorate. All samples were examined chemically for acidity, salt and moisture percent and bacteriologicaly for the presence of Escherichia coli, Staphylococcus aureus, Enterococci, Bacillus cereus, Clostridium perfringens, Yersinia enterocolitica, Salmonella and Shigella species. The obtained results revealed that the mean values of acidity, salt and moisture % were 1.63 ± 0.095,3.55 ± 0.299 and 58.54 ± 0.599 in the examined kareish cheese samples, respectively.Escherichia coli, Staphylococcus aureus, Enterococci, Bacillus cereus, Clostridium perfringens were recovered from 16 (32%), 12(24%), 46 (92%), 25 (50 %) and 3 (6%) with a mean value of 4.86x102 ±4.21x10 2, 4.84x 10 5 ± 2.91x10 5, 3.74x10 6±1.55x10 6, 7.08x10 4±2.61x10 4 and 9.5x10 1 ± 7.37x10 1 of the examined samples , respectively. Yersinia enterocolitica could be isolated from 12% of the examined samples. Salmonella and Shigella species could not be detected in any of the examined samples. The isolated Escherichia coli were examined for serological identification, Enterotoxigenicity and the susceptibility of the isolated serovars to various chemotherapeutic agents. The public health significance and economical importance of the isolated organisms and the recommendations to be followed in the processing, handling and storage of such dairy product were discussed

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