Prevalence and antimicrobial resistance of Listeria monocytogenes, Salmonella enterica and Escherichia coli O157:H7 in imported beef cattle in Jordan.

This study characterized Listeria monocytogenes, Salmonella enterica, and E. coli O157:H7 by collecting rectoanal mucosal swabs and fecal samples from 518 imported beef cattle at Jordan's major abattoir. A unique 53 L. monocytogenes, 287 S. enterica, and 17 E. coli O157:H7 were isolated from 37, 120 and 9 different animals; respectively. The prevalence of S. enterica, L. monocytogenes and E. coli O157:H7 were 23.2 % (95 % CI, 19.7-27.0 %), 7.1 % (95 % CI, 5.2-9.7 %) and 1.7 % (95 % CI, 0.9-3.3 %); respectively. All L. monocytogenes, all E. coli O157:H7 and 93.0 % of S. enterica isolates resisted at least one antimicrobial class. All L. monocytogenes, 94.1 % of E. coli O157:H7 and 69.7 % of S. enterica isolates exhibited multidrug resistance (resistant to ≥3 antimicrobials classes). Moreover, high percentages of L. monocytogenes (98.1 %), E. coli O157:H7 (64.7 %) and S. enterica (45.3 %) isolates resisted ≥5 antimicrobial classes. More than 90 % of the L. monocytogenes isolates resisted ampicillin, penicillin and erythromycin and more than 75 % resisted vancomycin. S. enterica isolates resisted several treatment-of-choice antimicrobials such as nalidixic acid (85.4 %), ciprofloxacin (26.8 %) and ceftriaxone (19.5 %). Furthermore, greater than 50 % of the E. coli O157:H7 isolates resisted streptomycin, nalidixic acid, tetracycline, ampicillin, sulfamethoxazole-trimethoprim, kanamycin, chloramphenicol and ciprofloxacin. The high prevalence and the high resistance percentages of the studied pathogens toward clinically important antimicrobials is alarming. Thus, applying strict sanitation procedures at the abattoirs in Jordan is crucial to lower the risk of carcasses contamination.