Detection of Colistin-Resistant MCR-1-Positive Escherichia coli by Use of Assays Based on Inhibition by EDTA and Zeta Potential.

The emergence and rapid dissemination of colistin-resistant carrying the plasmid-mediated gene have created an urgent need to develop specific screening methods. In this study, we evaluated four assays based on the inhibition of MCR-1 activity by EDTA: (i) a combined-disk test (CDT) comparing the inhibition zones of colistin and colistin (10 μg) plus EDTA (100 mM); (ii) reduction of colistin MIC (CMR) in the presence of EDTA (80 μg/ml); (iii) a modified rapid polymyxin Nordmann/Poirel test (MPNP); and (iv) alteration of zeta potential (R = ZP/ZP). We obtained encouraging results for the detection of MCR-1 in isolates recovered from human, food, and animal samples, using the following assay parameters: ≥3 mm difference in the inhibition zones between colistin disks without and with EDTA; ≥4-fold colistin MIC decrease in the presence of EDTA; R of ≥2.

High-virulence CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from commercial turkeys.

This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the bla Extended Spectrum Beta-Lactamase encoding gene.

Silent dissemination of colistin-resistant Escherichia coli in South America could contribute to the global spread of the mcr-1 gene.

During a Brazilian multicentric antimicrobial resistance surveillance study, colistin resistance was investigated in 4,620 Enterobacteriaceae isolated from human, animal, food and environmental samples collected from 2000 to 2016. We present evidence that mcr-1-positive Escherichia coli has been emerging in South America since at least 2012, supporting a previous report on the possible acquisition of mcr-1-harbouring E. coli by European travellers visiting Latin American countries.

Free-Ranging Frigates (Fregata magnificens) of the Southeast Coast of Brazil Harbor Extraintestinal Pathogenic Escherichia coli Resistant to Antimicrobials.

Seabirds may be responsible for the spread of pathogenic/resistant organisms over great distances, playing a relevant role within the context of the One World, One Health concept. Diarrheagenic E. coli strains, known as STEC (shiga toxin-producing E.

Suppurative peritonitis by Klebsiella pneumoniae in captive gold-handed tamarin (Saguinus midas midas).

This report describes an outbreak of suppurative peritonitis caused by Klebsiella pneumoniae in an adult female of captive golden-handed tamarin (Saguinus midas midas). Two virulent and multidrug-resistant strains were isolated and classified through MLST as ST60 and ST1263. The microbiological diagnosis works as a support tool for preventive measures.

Clostridium perfringens type A enteritis in blue and yellow macaw (Ara ararauna).

This study describes an outbreak of necrotic enteritis caused by Clostridium perfringens type A in captive macaws (Ara ararauna). Two psittacine birds presented a history of prostration and died 18 hr after manifestation of clinical signs. The necropsy findings and histopathologic lesions were indicative of necrotic enteritis.

Virulence profiles, phylogenetic background, and antibiotic resistance of Escherichia coli isolated from turkeys with airsacculitis.

Avian Pathogenic Escherichia coli (APEC) has been studied for decades because of its economic impact on the poultry industry. Recently, the zoonotic potential of APEC and multidrug-resistant strains have emerged. The aim of this study was to characterize 225 APEC isolated from turkeys presenting airsacculitis.