Relationship between virulence and antibiotic resistant genes in some Gram negative bacteria causing diarrhea in calves

Abstract

Diarrhea in calves is a multifactorial disease. It is the main cause of high morbidity and mortality in calves during the first three weeks of life, resulting in negative economic effects on the livestock industry worldwide. In the current study a total of 80 fecal samples from diarrheic calves were collected and bacteriologically examined. The results revealed that 72 out of 80 samples were positive for variety of Gram negative bacteria in percentage of 90%. Enterobacteriaceae were predominant, with the isolation of E. coli (37.5%) which serotyped to (O164:K, O125:K70 ,O86:K61, O111:K58 , O119:K69, O78:K80 and O44:K70) and Klebsiella oxytoca (33.3%), while Salmonella were in percentage of 9.7% and serotyped to  ( S. Typhimurium, S. Montevideo, S. Mississippi and S. Infantis)other isolates included : protues sp., pseudomonas aeruginosa, Citrobacter freundiiin percentage of 9.9%, 5.6% and 4.2%, respectively .There was a high level of antimicrobial resistance among   isolates. All tested isolates salmonella and E. coli were multiple antimicrobial resistance. Virulence genes (invA, stn, bcfc) were detected in all tested isolates of Salmonella while (ompT (100%), papC (71.42%), astA (42.85%) were detected in tested E. coli isolates. Resistance genes (blaTEM (100%) and, TetA(A), Sul1) were detected in most tested isolates. This study highlights the significant level of multiple resistance to antimicrobials and its high relation with virulence in these pathogens, emphasizing the importance of surveillance and targeted treatment and stressing the dangers associated with the use of antibiotics on a random basis.