Molecular epidemiology of methicillin-resistant Staphylococcus aureus in slaughterhouse pigs and of extended-spectrum β-lactamase- producing Escherichia coli in hens on farms of western and central Cuba

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase-producing Escherichia coli are two of the most clinically important resistant microorganisms studied worldwide, In Cuba, infections in humans at the hospital level are reported, but it is unknown whether production and animal processing facilities are reservoirs of multi-resistant clones of these bacteria. The objective of the present work was to demonstrate MRSA and ESBL-producing E. coli colonization, epidemiological traits, and resistance mechanisms in slaughterhouse pigs and farm hens. For MRSA isolation, 285 nasal exudates were taken from pigs in slaughterhouses in Matanzas, Mayabeque, and Cienfuegos before slaughter in 2015, and for E. coli, a total of 434 cloacal swabs were taken from poultry in Mayabeque in the period 2013-2015. MRSA was detected in 7.7 % (22/285) of the samples with a predominance of the type 8 sequence (ST8), 18/22 associated with the pandemic clone USA300 lineage and 4/22 with the ST5. β-lactamases were confirmed in the 32 selected isolates of E. coli: blaCTX-M-1 (n = 27), blaCTX-M-15 (n = 4), and blaLAP-2 (n = 1). ESBL-producing E. coli showed high genetic diversity and multi-resistance; among the isolates, the high-risk ST410/CTX-M-15 clone was detected. The presence of multidrug-resistant clones with zoonotic potential that colonize pigs and poultry for human consumption are a danger for the workers in contact with the animals and the food production chain, which requires measures of hygiene and biosafety and an adequate use of antibiotics.