Isolation and Molecular Identification of Salmonella in Organic and Inorganic Eggs in District Abbottabad

Salmonella is a gram-negative bacterium responsible for salmonellosis. A disease transmitted by the consumption of contaminated poultry products such as eggs and raw chicken meat. Pakistan is presently producing around 18 billion table eggs per annum but unfortunately the country’s per capita consumption is just 65-70 eggs annually against the world average usage of around 160 eggs. The present study is aimed at the identification of bacterial contaminated eggs especially with salmonella infection.The salmonella serovars present on the surface of marketed eggs in district Abbottabad are currently unknown. The present study also aimed at the antibiotic resistance on salmonella isolates. A total of 300 eggs samples were collected at random from variety of chicken farms (Havelian, Salhad, Sultanpur, Mandian) and processed for isolation of salmonella. The identification was done in the lab by microscopic examination' biochemical tests (vp, Indole, simmon citrate, methyl red, sugar iron) and molecular method by PCR. All isolates were further confirmed on the basis of cultural and biochemical characteristics and by targeting 16s rRNA gene of salmonella. All salmonella isloates were also examined for their antimicrobial drug susceptibility pattern against commonly used antibiotics. Out of to be 300 samples, the prevalence of salmonella in in organic and inorganic eggs was found 65% and 35% respectively, with an overall prevalence of 13%. Polymerase chain reaction (PCR) targeting 16s rrna gene of salmonella showed positive result with 40 isolates. All 40 salmonella isolates were found to be highly sensitive to ampicillin while 70%, 55% and 40% were sensitive to tetracycline, amoxicillin and penicillin respectively. The isolates were 68% and 50% isolates were resistant to chloramphenicol and gentamycin, respectively. Out of 40, 14 isolates had multiple antibiotic resistance index equal to or more than 0.2. Salmonella in in organic and inorganic eggs samples is prevailing in the areas of sampling due to poor hygienic conditions and secondly antimicrobial resistance including several drug resistant phenotypes. Therefore, the present study emphasizes the need for continued surveillance of zoonotic foodborne pathogens including antimicrobial-resistant variants throughout the food production including eggs.