Characterization of hospital-associated lineages of ampicillin-resistant Enterococcus faecium from clinical cases in dogs and humans

Abstract

Ampicillin-resistant Enterococcus faecium (ARE) has rapidly emerged worldwide and is one of the most important nosocomial pathogens. However, very few reports are available on ARE isolates from canine clinical cases. The objective of this study was to characterize ARE strains of canine clinical origin from a veterinary teaching hospital in Canada and to compare them with human strains. Ten ARE strains from dogs and humans were characterized by multilocus sequence typing (MLST), pulsed field gel electrophoresis (PFGE), antibiotic susceptibility and biofilm activities, presence of rep-families, CRISPR-cas and putative virulence genes. All ARE strains (n = 10) were resistant to ciprofloxacin and lincomycin. Resistances to tetracycline (n = 6), macrolides (n = 6), and to high concentrations of gentamicin, kanamycin and streptomycin (n = 5) were also observed. Canine ARE isolates were found to be susceptible to vancomycin whereas resistance to this antibiotic was observed in human strains. Ampicillin resistance was linked to PBP5 showing mutations at 25 amino acid positions. Fluoroquinolone resistance was attributable to ParC, GyrA, and GyrB mutations. Data demonstrated that all canine ARE were acm (collagen binding protein)-positive and that most harbored the efaAfm gene, encoding for a cell wall adhesin. Biofilm formation was observed in two human strains but not in canine strains. Two to five rep-families were observed per strain but no CRISPR sequences were found. A total of six STs (1, 18, 65, 202, 205, and 803) were found with one belonging to a new ST (ST803). These STs were identical or closely related to human hospital-associated lineages. This report describes for the first time the characterization of canine ARE hospital-associated strains in Canada and also supports the importance of prudent antibiotic use in veterinary medicine to avoid zoonotic spread of canine ARE.

Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria

“…Similarly, Bacillus anthracis , E. coli and A. baumannii also have the analogous serine mutated to leucine 43 44 45 . In VRE the serine is mutated to multiple different residues (Ile, Arg and Tyr), while in Streptococcus pneumoniae , Klebsiella pneumonia and N. gonorrhoeae this Ser is often changed to either Phe or Tyr 22 23 24 25 26 46 47 48 . P. aeruginosa differs in that it naturally has a Thr instead of the Ser.…”

“…Nearly 100% of MRSA substitute Ser84 of GyrA with Leu 13 14 15 16 17 18 19 20 21 . Similarly, nearly all FQR VRE substitute Ser83 of GyrA with Ile, Arg or Tyr 22 23 24 25 26 .…”

The Role of CRISPR-Cas Systems in Virulence of Pathogenic Bacteria

“…Note that increased antibiotic resistance as well as the uptake of phages and pathogenicity islands by this bacterium was found to be associated with deletions of cas genes (48). Indeed, in a recent Canadian study, the emergence of ampicillin-resistant E. faecium isolates was associated with a total absence of CRISPR sequences (49). An anticorrelation between the presence/absence of a CRISPR-Cas system and the absence/presence of mobile elements providing antibiotic resistance was also observed in methicillin-resistant Staphylococcus aureus (MRSA) isolate ST779 (50).…”

Nosocomial Infections and their Surveillance in Veterinary Hospitals

“…The hospital associated ARE have been recovered from dogs suffering from urinary tract infections in US (Simjee et al, 2002), Denmark (Damborg et al, 2009), Korea (Kwon et al, 2012) and also from the faeces of dogs departing the intensive care unit of an American veterinary medicine teaching hospital (Ghosh et al, 2011). In a study conducted in veterinary teaching hospital of Canada with the objective of characterizing the ARE strains of dogs and human revealed the cross-transmission between humans and dogs and further supports the significance of antibiotic stewardship to avoid zoonotic spread of canine ARE (Tremblay et al, 2013).…”

“…In a study conducted in veterinary teaching hospital in Switzerland, two multiresistant E. faecium isolates with similar antibiotic resistant and PFGE profiles was recovered from two different cats with less than one month interval suggesting the persistence in hospital environment and nosocomial transmission (Boerlin et al, 2001). In the early 1980's the emergence of Hospital associated Ampicillin resistant Enterococci (ARE) in USA preceded rise of vancomycin resistance in enterococci, which happend in the 1990s, is the reason why virtually all VRE of nosocomial infections in humans are also ampicillin resistant (Grayson et al, 1991) but ARE associated with human infections remain vancomycin susceptible (Tremblay et al, 2013). The hospital associated ARE have been recovered from dogs suffering from urinary tract infections in US (Simjee et al, 2002), Denmark (Damborg et al, 2009), Korea (Kwon et al, 2012) and also from the faeces of dogs departing the intensive care unit of an American veterinary medicine teaching hospital (Ghosh et al, 2011).…”