Salmonella enterica in raw and boiled eggs: call for comprehensive preventive measures throughout the production and processing chain.

Abstract

Eggs are good source of proteins to human. However, consumption of contaminated eggs may lead to ill-health. Salmonella enterica typifies one of such pathogens causing food poisoning in humans. The present study aimed at assessing the bacteriological quality of eggs from chicken in respect to Salmonella enterica. A total of 570 chicken eggs were collected and examined from November 2015 to May 2016 in Morogoro municipality.  Salmonella was isolated from egg content and eggshell samples by conventional culture and biochemical methods. Salmonella enterica were confirmed to genus level by PCR targeting invA gene. Salmonella enterica were tested for resistance against common antimicrobial agents.  Salmonella enterica was recovered from 11 out 30 sample pools, of which 6 (20.0%) from egg contents and 5 (16.7%) from eggshell surfaces. Eggs from local chicken breeds were highly contaminated (20.0%) than eggs from exotic chicken breeds (16.7%) whereas raw eggs were highly  contaminated (26.7%) than boiled eggs (10%). Clean eggs were highly contaminated (20.0%) than faecal socked (13.3%) and cracked eggs (3.4%). Salmonella enterica were susceptible to Ciprofloxacin, Chloramphenicol, Gentamicin, Tetracycline, Sulfamethaxole-Trimethoprim, Imepenem,  Cefotaxime, Ceftriaxone and Caftazidime, and resistant to Kanamycin. Presence of pathogenic Salmonellae in different forms of chicken eggs indicates that eggs are unwholesome for human consumption and control measures should be implemented throughout egg production chain to  prevent human and animal salmonellosis.

Keywords: Public health, food safety, Salmonella, egg, chicken, Morogoro