Prevalence of Gastrointestinal Parasitic Infestation and Virulence Patterns of Enteric Bacterial Pathogens in Some Wild Birds in North Egypt

Wild birds are considered significant carriers for a variety of harmful bacteria and parasite infestations, and they are crucial in these pathogens spreading to other birds and their surroundings. The study purpose was to identify gastrointestinal parasitic infestation molecularly and detect the prevalence, virulence patterns, and diversity of enteric bacterial pathogens in fifty-one apparently healthy free-living wild birds [doves (n = 24), cattle egrets (n = 12), crows (n = 12), and kites (n = 3)], which act as a reservoir for some zoonotic pathogens. In addition, parasitic infestation and phylogenetic tree clustering of Cryptosporidium sp. of infested wild birds were detected. Oppositely, 255 samples from wild bird species under investigation were examined for enteric bacterial infections that included examinations of the mouth, liver, spleen, heart, and feces. Hemolytic activity and the Congo red binding assay were used to assess the pathogenicity of 159 E. coli isolated strains. As a result, gastrointestinal tract (GIT) parasitic infestation in wild birds involved the highest percentage of Synhimantus invaginatus (50.0%), Desportesius invaginatus (33.33%), Raillietina tetragona (29.16%), and Porrocecum wui (25.0%) compared to Spirura sp. (16.66%), Cryptosporidium parvum (8.33%), Tetrameres sp. (8.33%) and Ascaridia columbaea (4.16%) which are concerning host-specific factors. Molecular characterization of Cryptosporidium sp. using the GP60 gene and gene sequencing (Gen Bank; Acc. no: PP661815.C) revealed Cryptosporidium parvum. Furthermore, the prevalence of enteric bacteria revealed that E. coli was the predominant, followed by Pseudomonas aeruginosa and Enterobacter spp. (62.35%, 22.35%, and 21.18%, respectively) as gram-negative bacteria. Meanwhile, Staphylococcus aureus (S. aureus) and Streptococcus spp. were isolated at 38.82% and 5.88%, respectively, as gram-positive bacteria. Serotyping of the most pathogenic E. coli isolates revealed the existence of O78:K80, O55:K59, O119:K69, O158:K-, O145:-, O125:K-,O44:K74, and O142:K86 serogroups. In conclusion, the parasite infestations and bacterial isolates of the wild birds under investigation exhibit a wide range of variability. In addition, various parasite infestations, including Cryptosporidium sp., pathogenic E. coli isolates containing pathogenic virulent pathotypes may cause zoonotic disease transmission between farm animals and wild birds. Therefore, to keep wild birds out of farms during their migration, biosecurity precaution measures must be established in place.