Detection and molecular characterization of staphylococci from eggs of domesticated chickens

Authors: SYED, MUHAMMAD - University Of Haripur; Jackson, Charlene; BANO, SHEHR - University Of Haripur; BIBI, SUMERA - University Of Haripur; FATIMA, BUSHRA - University Of Haripur; AFRIDI, RIAZUDDIN - Hazara University; TABASSUM, SADIA - Hazara University; JAMIL, BUSHRA - National University Of Medical Sciences; Barrett, John; Woodley, Tiffanie

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Background: Eggs of domesticated hens are considered as more nutritious and healthier than eggs of farmed chickens. Previously, many studies have reported the presence of pathogenic bacteria inside eggs. Nonetheless, these studies were conducted on eggs of farmed chickens. No study has been carried out on isolation and characterization of bacteria from eggs of domesticated chickens, that are free living in the natural habitat, fed on diverse types of foods and have longer life as compared to farmed chickens. The aim of the present study was to isolate and characterize strains of staphylococci from eggs of domesticated chickens. Methods: Eggs (n=275) of domesticated hens were collected from different villages of Khyber Pakhtunkhwa province, Pakistan, from November 2016 to March 2017. Presence of staphylococci was determined by inoculating the egg content on a selective medium i.e. mannitol salt agar. Initial identification of staphylococci was made on the basis of microbiological assays such as microscopy, biochemical tests, and growth characteristics. Genus specific primers for staphylococci, species specific primers for Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were used for PCR. Further identification to species level was made using Vitek 2 system. Antibiotic susceptibility was performed using disc diffusion agar assay. Genetic fingerprinting of Staphylococcus xylosus strains was carried out using Pulsed field gel electrophoresis (PFGE). Results: Sixty two eggs were positive for staphylococci identified as S. xylosus, S. lentus, S. sciuri, S. haemolyticus, S. gallinarium and S. aureus. The predominant isolated species was S. xylosus, which was isolated from 26 eggs. PFGE patterns show heterogeneity. S. aureus were isolated from two eggs and only one was identified as MRSA. Conclusions: To the best of our knowledge, this was the first study on the detection and characterization of bacteria from eggs of domesticated hens. In contrast to our previous study in which a high number S. aureus strains were isolated that showed high level of antibiotic resistance, most of the strains isolated from the brown eggs were non-pathogenic species. Further comparative studies are suggested.