High β-Lactam and Quinolone Resistance of Enterobacteriaceae from the Respiratory Tract of Sheep and Goat with Respiratory Disease

Simple Summary beta-lactams and quinolones are major groups of antibiotics that are commonly used for the treatment of severe infection both in animals and humans. Little is known about their resistance mechanisms in animals. Our results revealed high resistance rates against both groups in Gram-negative bacteria recovered from small ruminants suffering from respiratory disease. Phenotypically, 9.2% of the isolates were multidrug-resistant, and 11.8% and 6.6% of the isolates were positive for AmpC and ESBL production, respectively. Genetic characterization identified different beta-lactamase-encoding genes such as bla(TEM), bla(SHV), and bla(CTX-M) which are responsible for beta-lactam resistance. Furthermore, the plasmid-mediated quinolone resistance gene, qnrS, was identified to be associated with quinolone resistance. Our results regenerate interest in the wise use of antimicrobials in animal fields as well as to apply a One Health approach to prevent and/or mitigate their dissemination to the human environment. During the last decade's increase of antimicrobial resistance (AMR) in animals, animal-human transmission has become a major threat. Therefore, the present study aimed to evaluate the genetic basis of AMR in Gram-negative bacteria recovered from sheep and goats with respiratory disease. Nasal and ocular swabs were collected from 69 diseased animals, and 76 Gram-negative bacterial isolates were identified from 59 animals. All isolates were checked phenotypically for resistance and genotypically for different resistance mechanisms, including beta-lactam, quinolone, and aminoglycoside resistance. Our results demonstrated that 9.2% (95% CI 4.5-17.8%) of the isolates were multidrug-resistant, with high resistance rates to beta-lactams and quinolones, and 11.8% (95% CI 6.4-21%) and 6.6% (95% CI 2.8-14.5%) of the isolates were phenotypically positive for AmpC and ESBL, respectively. Genotypically, bla(TEM) was the most identified beta-lactamase encoding gene in 29% (95% CI 20-40%) of the isolates, followed by bla(SHV) (14.5%, 95% CI 8.3-24.1%) and bla(CTX-M) (4%, 95% CI 1.4-11%). Furthermore, 7.9% (95% CI 3.7-16.2%) of the isolates harbored plasmid-mediated quinolone resistance gene qnrS. Our study revealed for the first time to our knowledge high beta-lactam and quinolone resistance associated with the bacteria recovered from sheep and one goat with respiratory disease. Furthermore, different antimicrobial resistant determinants were identified for the first time from animals in Africa, such as bla(LEN-13/55), bla(TEM-176) and bla(TEM-198/214). This study highlights the potential role of sheep and goats in disseminating AMR determinants and/or resistant bacteria to humans. The study regenerates interest for the development of a One Health approach to combat this formidable problem.