Analysis of Resistance to Florfenicol and the Related Mechanism of Dissemination in Different Animal-Derived Bacteria

Abstract

Bacterial resistance to antibiotics has become an important concern for public health. This study was aimed to investigate the characteristics and the distribution of the florfenicol-related resistance genes in bacteria isolated from four farms. A total of 106 florfenicol-resistant Gram-negative bacilli were examined for florfenicol-related resistance genes, and the positive isolates were further characterized. The antimicrobial sensitivity results showed that most of them (100, 94.33%) belonged to multidrug resistance Enterobacteriaceae. About 91.51% of the strains carried floR gene, while 4.72% carried cfr gene. According to the pulsed-field gel electrophoresis results, 34 Escherichia coli were subdivided into 22 profiles, the genetic similarity coefficient of which ranged from 80.3 to 98.0%. The multilocus sequence typing (MLST) results revealed 17 sequence types (STs), with ST10 being the most prevalent. The genome sequencing result showed that the Proteus vulgaris G32 genome consists of a 4.06-Mb chromosome, a 177,911-bp plasmid (pG32-177), and a 51,686-bp plasmid (pG32-51). A floR located in a drug-resistant region on the chromosome of P. vulgaris G32 was with IS91 family transposase, and the other floR gene on the plasmid pG32-177 was with an ISCR2 insertion sequence. The cfr gene was located on the pG32-51 flanked by IS26 element and TnpA26. This study suggested that the mobile genetic elements played an important role in the replication of resistance genes and the horizontal resistance gene transfer.

Antimicrobial resistance genes and genetic characteristics of multidrug-resistant Escherichia coli in a veterinary hospital in Taiwan

“…The high incidence of florfenicol resistance in the E. coli isolates analysed in this study is consistent with a recent study that reported dissemination of floR among different animalderived bacteria [28]. The study showed a similar tendency for tetracycline and chloramphenicol resistance.…”

Characterization of florfenicol resistance genes in the coagulase-negative Staphylococcus (CoNS) isolates and genomic features of a multidrug-resistant Staphylococcus lentus strain H29

“…CoNS infection can lead to arthritis, cow mastitis, and even systemic infections [ 2 ]. Florfenicol is an antimicrobial widely used in veterinary medicine that acts by binding to the 50S ribosomal subunit, leading to inhibition of protein synthesis [ 3 ]. Because of its broad antibacterial activity and few adverse effects, florfenicol has been licensed exclusively for use in veterinary medicine to treat infections caused by, for example, Pasteurella multocida , Staphylococcus sp .…”

Re-Emergence of Salmonellosis in Hog Farms: Outbreak and Bacteriological Characterization

“…This fact can explain the contradictory ciprofloxacin phenotypic results in isolates that harbor the gyrA resistance gene that were classified as susceptible. For florfenicol, only one isolate showed phenotypic resistance to this drug without finding the floR or other florfenicol resistance genes, like clm [ 61 ]. Most of the florfenicol resistance genes are located in the mobile plasmids and the transposons.…”