ISOLATION IDENTIFICATION AND ANTIBIOTIC SENSITIVITY PATTERN OF PATHOGENIC ENTEROBACTERIA FROM TABLE EGG

Abstract

newline The present study aims to isolate, characterize and identify the pathogenic Enterobacteria responsible for egg contamination and to assess the antibiotic sensitivity pattern of the characterized isolates. Unfertilized eggs were seasonally collected from 15 different sites of Jaipur city from the roadside vendors, dairies and poultry farms. From each site, 10 eggs (both fresh and stored) were randomly collected in sterile plastic bags and directed to the laboratory within 6-8 hours for further processing. Samples were processed by using swab technique for the eggshells and serial dilution method for albumin and yolk contents. Gram-negative Enterobacteria were initially isolated on nutrient agar and then on selective-differential media by spread and streak-plate method and later, characterized by various biochemical tests. All the characterized isolates were subjected to antibiotic sensitivity test and different resistance pattern was observed (plt0.01) against different antibiotics. The highest resistance rate was detected against amoxycillin (90.34%) and cefixime (85.96%) whereas highest sensitivity rate was recorded against gentamicin (100%), levofloxacin (96.48%) and ciprofloxacin (90.78%). Moreover, most of the bacterial isolates (82.89%) were found to be multi-drug resistant (MDR) as they were resistant to three or more antibiotics tested. Multiple antibiotic resistance (MAR) index of isolated microbes from table egg ranged from 0.10 to 0.70. According to the results obtained, the table eggs should be consumed within 5 days if stored at normal room temperature and within 15 days if refrigerated. Isolates with higher MAR indexes, a total of twenty-nine isolates were subjected to molecular characterization. 16S rRNA gene analysis revealed that most of the isolates were of the family Enterobacteriaceae and were identified as Escherichia alberti, Escherichia coli, Escherichia hermannii, Escherichia vulneris, Enterobacter aerogenes, Enterobacter gergoviae, Salmonella enterica serovar Typhimurium, Shigella dysenteriae, Shigella boydii, Proteus mirabilis, Leclercia adecarboxylata, Pasteurella multocida, Staphylococcus epidermidis, Mannheimia haemolytica, Raoultella electrica and Providencia rettgeri, from which Mannheimia haemolytica and Raoultella electrica have been isolated very first time from the hen s egg. Thus, it can be concluded that marketed eggs may harbor multi-drug resistant bacterial pathogens and if consumed uncooked or undercooked may cause newlinesevere ailments in consumers. It is also recommended that strict hygienic systems should be implemented in the handling and transportation of eggs so as to prevent the occurrence of prevalence of microbial contamination in eggs and to assess the risk of antimicrobial resistance occurring in eggs and its potential transfer in humans, it is necessary to monitor antimicrobial resistance time to time.