Comparative study ofvanAgene transfer fromEnterococcus faeciumtoEnterococcus faecalisand toEnterococcus faeciumin the intestine of mice

Bourgeois-Nicolaos, Nadège; Moubareck, Carole Ayoub; Mangeney, Nicole; Butel, Marie-JosÃ©; Doucet‐Populaire, Florence

doi:10.1111/j.1574-6968.2005.00004.x

Cited by 44 publications

(23 citation statements)

References 41 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We focused on the analysis of these bacteria because they are Nasal ( (20). Similar findings were previously reported, however, for healthy volunteers and only for intestinal enterococci (10).…”

Section: Discussionsupporting

confidence: 56%

The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics

Bourgeois-Nicolaos

Nguyễn

Defrance

et al. 2014

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. We assessed the impact of linezolid on the microbiota and the emergence of resistance and investigated its relationship with plasma pharmacokinetics of the antibiotic. Twenty-eight patients were treated for the first time with linezolid administered orally (n ‫؍‬ 17) or parenterally (n ‫؍‬ 11) at 600 mg twice a day. Linezolid plasma pharmacokinetic analysis was performed on day 7. Colonization by fecal enterococci, pharyngeal streptococci, and nasal staphylococci were assessed using selective media with or without supplemental linezolid. The resistance to linezolid was characterized. The treatment led to a decrease of enterococci, staphylococci, and streptococci in the fecal (P ‫؍‬ 0.03), nasal, and pharyngeal (P < 0.01) microbiotas. The appearance of resistant strains was observed only in enterococci from the fecal microbiota between the 7th and 21st days of treatment in four patients (14.3%). The resistance was mainly due for the first time to the mutation G2447T in the 23S rRNA gene. No pharmacokinetic parameters were significantly different between the patients, regardless of the appearance of resistance. The emergence of linezolid resistance during treatment was observed only in the intestinal microbiota and unrelated to pharmacokinetic parameters. However, colonization by Grampositive bacteria was reduced as a result of treatment in all microbiotas. L inezolid, the only oxazolidinone antibiotic on the market, is an antibiotic for the treatment of multiresistant Gram-positive infections which inhibits the earliest initiation step of protein synthesis (1), while other antibiotics interfere later in the process. Linezolid resistance in Staphylococcus aureus, coagulase-negative staphylococci (CoNS), and enterococci is lower than 1% and appears stable (2, 3); however, the appearance of resistant strains could affect long-term efficacy. All resistance mechanisms described to date involve the 50S ribosomal subunit. Early reports described only nontransferable resistance (23S rRNA and ribosomal protein L3 and L4 mutations) appearing after prolonged exposure. However, the mobile cfr gene encoding a methyltransferase catalyzing the methylation of A2503 (Escherichia coli numbering) in the 23S rRNA can also confer resistance to linezolid and other antibiotics (4-8).As a rule, antibiotic use alters the endogenous microbiota and facilitates colonization by exogenous, potentially pathogenic, and/or resistant strains or selects resistant microorganisms that are already present (9). Nonetheless, the extent to which resistance occurs with linezolid treatment remains unknown. After 7 days, linezolid suppressed enterococci in the volunteers' intestinal microbiotas. Simultaneously, linezolid decreased the concentration of bifidobacteria, lactobacilli, clostridia, and Bacteroides (10). In mice, linezolid promoted the colonization of Klebsiella pneumoniae with extended-spectrum ␤-lactamase (11). We demonstrated that in gnotobiotic m...

show abstract

Section: Discussionsupporting

confidence: 56%

The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics

Bourgeois-Nicolaos

Nguyễn

Defrance

et al. 2014

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…10 2 CFU/g of feces over 30 days and stabilized at this level (data not shown). This observation suggests an ecological disadvantage of transconjugant cells as previously described in transfer experiments between enterococci or other species [Andremont et al, 1985;Bourgeois-Nicolaos et al, 2006;Doucet-Populaire et al, 1991;Duval-Iflah et al, 1980, 1981Johnsen et al, 2002].…”

Section: In Vivo Transfermentioning

confidence: 56%

“…The potential contribution of probiotics needs further attention since preparations usually contain high titers of live bacteria and are generally consumed repeatedly. The human microbiota may, however, play a role as a potential barrier against emerging van R transconjugants [Bourgeois-Nicolaos et al, 2006;Lester et al, 2006;Mater et al, 2005]. Otherwise, probiotics should be used prudently in case of immunocompromised patients and also in antibiotherapy, since antibiotic pressure might favor the emergence of resistances.…”

Section: Resultsmentioning

confidence: 99%

A Probiotic Lactobacillus Strain Can Acquire Vancomycin Resistance during Digestive Transit in Mice

Mater

Langella²,

Corthier³

et al. 2007

Microb Physiol

View full text Add to dashboard Cite

The present study demonstrates for the first time the transfer of vancomycin resistance (vanA cluster) from enterococci to a Lactobacillusacidophilus commercial strain. Transfers were observed in vitro, but also in vivo in the gut of mice (in the absence of antibiotic pressure) where transconjugants arose at relatively high frequencies and could persist in the digestive environment. Since transfer of vancomycin resistance genes might also take place in the human digestive tract, lactobacilli probiotics should be carefully considered especially in either immunocompromised patients or during antibiotherapy. Acquisition and retransfer of resistance genes should be addressed in the safety evaluation of probiotics.

show abstract

“…The lack of gene transfer from an exogenous strain to the indigenous flora can be related to the results of BourgeoisNicolaos et al (8), who found no transfer of the vanA gene from E. faecium to E. faecalis in a similar HFA model. Colonization resistance of the indigenous flora toward exogenous Salmonella has rapidly decreased the number of donor strain bacteria, whereas for transfer to occur, large numbers of both the donor and recipient strains must be present simultaneously (27).…”

Section: Discussionmentioning

confidence: 72%

Transfer of Plasmid-Mediated CTX-M-9 from Salmonella enterica Serotype Virchow to Enterobacteriaceae in Human Flora-Associated Rats Treated with Cefixime

Faure

Perrin-Guyomard

Delmas

et al. 2010

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Food animals are a potential source of CTX-M resistance genes for humans. We evaluated the transfer of the bla CTX-M-9 gene from an animal strain of Salmonella enterica serotype Virchow to Enterobacteriaceae of the human intestinal flora by using human flora-associated (HFA) rats with and without cefixime treatment. In the absence of antibiotic, no transconjugant enterobacteria were found in the feces of HFA rats. However, the transfer rate was high if Escherichia coli J5 recipient strains were coinoculated orally with Salmonella. S. enterica serotype Virchow persisted in the rat fecal flora both during and after treatment with therapeutic doses of cefixime. The drug did not increase the transfer rate, and E. coli J5 transconjugants were eliminated from the flora before the end of cefixime treatment. No cefixime was recovered in the rat feces. In the presence of recipient strains, the bla CTX-M-9 resistance gene was transferred from a strain of animal origin to the human intestinal flora, although transconjugant colonization was transient. Antibiotic use enhanced the persistence of donor strains, increasing the resistance gene pool and the risk of its spread.CTX-M-type extended-spectrum ␤-lactamases (ESBLs) are enzymes responsible for catalyzing the hydrolysis of monobactam and extended-spectrum cephalosporins. Over the last 10 years, these ␤-lactamases have been identified around the world, and they now have the highest prevalence of any type of ESBL (9,10,14,15,28,32). This dramatic increase in their frequency may be attributed to the rapid dissemination of resistant bacterial clones and to their genetic structure, with the resistance genes carried on plasmids and transposons (14,43). The consumption of contaminated food is thought to be the principal mode of spread of ESBL-producing resistant strains to the general population (31, 38). Several epidemiological analyses have investigated possible clonal relationships between resistant animal and human strains (4,22,25,30,45). Experimental studies have generated conflicting findings concerning the transfer of resistance genes in the human intestinal tract. Bonner et al. (6) suggested that bacteria from livestock cannot persist in humans and therefore do not constitute a threat. Prescott et al. (37) agreed that conditions in the human gut do not favor the transfer of resistance genes but pointed out that continuous exposure to an antibiotic would lead to the selection of organisms best able to colonize the gut (i.e., resistant strains). However, plasmid-mediated antibiotic resistance transfer may occur in the ileum (5), and Schjørring et al. (40) recently highlighted the effect of antimicrobial treatment on horizontal gene transfer from exogenous bacteria to a susceptible strain present in the mouse intestinal flora.From 2002 to 2003, the dual emergence in France of CTX-M-9-producing multiresistant strains of Salmonella enterica serotype Virchow from poultry sources, and to a lesser extent from humans, was reported (45). Salmonella are mostly described as food-...

show abstract

Comparative study ofvanAgene transfer fromEnterococcus faeciumtoEnterococcus faecalisand toEnterococcus faeciumin the intestine of mice

Cited by 44 publications

References 41 publications

The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics

The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics

A Probiotic <i>Lactobacillus</i> Strain Can Acquire Vancomycin Resistance during Digestive Transit in Mice

Transfer of Plasmid-Mediated CTX-M-9 from Salmonella enterica Serotype Virchow to Enterobacteriaceae in Human Flora-Associated Rats Treated with Cefixime

Contact Info

Product

Resources

About