VanA-Type Enterococci from Humans, Animals, and Food: Species Distribution, Population Structure, Tn 1546 Typing and Location, and Virulence Determinants

Abstract

VanA-type human (n ‫؍‬ 69), animal (n ‫؍‬ 49), and food (n ‫؍‬ 36) glycopeptide-resistant enterococci (GRE) from different geographic areas were investigated to study their possible reservoirs and transmission routes. Pulsed-field gel electrophoresis (PFGE) revealed two small genetically related clusters, M39 (n ‫؍‬ 4) and M49 (n ‫؍‬ 13), representing Enterococcus faecium isolates from animal and human feces and from clinical and fecal human samples. Multilocus sequence typing showed that both belonged to the epidemic lineage of CC17. purK allele analysis of 28 selected isolates revealed that type 1 was prevalent in human strains (8/11) and types 6 and 3 (14/15) were prevalent in poultry (animals and meat). One hundred and five of the 154 VanA GRE isolates, encompassing different species, origins, and PFGE types, were examined for Tn1546 type and location (plasmid or chromosome) and the incidence of virulence determinants. Hybridization of S1-and I-CeuI-digested total DNA revealed a plasmid location in 98% of the isolates. Human intestinal and animal E. faecium isolates bore large (>150 kb) vanA plasmids. Results of PCR-restriction fragment length polymorphism and sequencing showed the presence of prototype Tn1546 in 80% of strains and the G-to-T mutation at position 8234 in three human intestinal and two pork E. faecium isolates. There were no significant associations (P > 0.5) between Tn1546 type and GRE source or enterococcal species. Virulence determinants were detected in all reservoirs but were significantly more frequent (P < 0.02) among clinical strains. Multiple determinants were found in clinical and meat Enterococcus faecalis isolates. The presence of indistinguishable vanA elements (mostly plasmid borne) and virulence determinants in different species and PFGE-diverse populations in the presence of host-specific purK housekeeping genes suggested that all GRE might be potential reservoirs of resistance determinants and virulence traits transferable to human-adapted clusters.

Antimicrobial Resistance of Bacteria in Food

“…The presence of indistinguishable vanA elements,mostly plasmid-borne, and virulence determinants in different species and PFGE-diverse populations suggested that all GRE might be potential reservoirs of resistance determinants and virulence traits transferable to human-adapted clusters. [25].…”

The Antibacterial Effect of Aqueous Extract of Garlic against Resistant Enterococci

“…Enterococci are commensal gut bacteria and as opportunistic pathogens, are capable of causing urogenital tract infections, endocarditis, meningitis, intra-abdominal abscesses, bacteremia, neonatal sepsis and nosocomial infections (5). Almost 20 species are in the genus Enterococcus, two of which (E.faecalis and E.feacium) are responsible for almost 90% of all Enterococcal infections in humans (5). The pathogenicity of Enterococci is affected by resistance to various antibiotics, rather than its virulence factors.…”

“…The antibacterial effects of garlic on different bacteria types has been reported (3,6). Enterococci are commensal gut bacteria and as opportunistic pathogens, are capable of causing urogenital tract infections, endocarditis, meningitis, intra-abdominal abscesses, bacteremia, neonatal sepsis and nosocomial infections (5). Almost 20 species are in the genus Enterococcus, two of which (E.faecalis and E.feacium) are responsible for almost 90% of all Enterococcal infections in humans (5).…”

Epidemiologia molecular e genética da resistência à vancomicina em enterococos isolados de pacientes de dois hospitais de Ribeirão Preto

“…ORT Ortopedia (BIAVASCO et al, 2007;FISHER et al, 2009;HIDRON et al, 2008;TEIXEIRA et al, 2007;TREITMAN et al, 2005;TSAI et al, 2005).…”

“…As infecções enterocócicas ocorrem principalmente em pacientes imunodeprimidos ou debilitados, hospitalizados e incluem infecções intra-abdominais, do trato urinário, sepse hepatobiliares, bacteremia e endocardites, infecções de feridas cirúrgicas e sepse neonatal (FISHER et al, 2009;POH;TAN, 2006). Enterococos são a segunda causa mais comum de infecções nosocomiais da corrente sanguínea nos Estados Unidos e a resistência à vancomicina ocorre em aproximadamente um terço dos isolados (BIAVASCO et al, 2007;TSAI et al, 2005 A vancomicina atua inibindo a síntese da parede celular de bactérias sensíveis por meio da sua ligação de alta afinidade à extremidade terminal D-alanina-D-alanina de unidades precursoras da parede celular. Com isso, inibe a utilização dos substratos pela glicosiltransferase (uma enzima de síntese da parede celular) para produzir a cadeia de peptidoglicano nascente (CUI et al, 2006).…”