Screening Fecal Enterococci from Greek Healthy Infants for Susceptibility to Antimicrobial Agents

Kirtzalidou, Ekaterini; Mitsou, Evdokia K.; Pramateftaki, Paraskevi; Kyriacou, Adamantini

doi:10.1089/mdr.2012.0028

Cited by 20 publications

(13 citation statements)

References 45 publications

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“…These equilibrated constant rates of colonization indicate a major resiliency of the genus Enterococcus under heterogeneous conditions imposed by age, changing environments, and highly variable host niches. Previous studies (6,(58)(59)(60) have described changes in the rates of recovery of the genus Enterococcus in fecal microbiota with aging, which was not confirmed in our work, and a consistent predominance of the species E. faecalis in the fecal flora of young and elderly individuals, which is essentially consistent with our findings, with the important exception of the growing predominance of E. faecium in elderly individuals, particularly hospitalized elderly patients. Other studies yielded contradictory information about the frequency and diversity of E. faecium and other enterococcal species in the fecal microbiota (1,15).…”

Section: Discussionsupporting

confidence: 76%

Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

Tedim

Ruíz-Garbajosa

Corander

et al. 2015

Appl Environ Microbiol

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fThe diversity of enterococcal populations from fecal samples from hospitalized (n ‫؍‬ 133) and nonhospitalized individuals (n ‫؍‬ 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages >60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium populations from hospitalized patients and from community-based individuals differ, with a predominance of certain clonal lineages, often in association with elderly individuals, occurring in the hospital setting. Enterococci are relatively minor constituents of the human gastrointestinal microbiota (less than 1%) but are able to cause a wide diversity of infections, mostly in patients with underlying diseases (1, 2). High-density colonization by antibiotic-resistant enterococci increases the risk of bacteremia and transmission; however, the population structure and ecological and evolutionary forces influencing the population dynamics of gut colonizers largely remain unknown (3-5). Next-generation sequencing has provided a wealth of data about the influence of characteristics of the host (age, diet, health status, and antibiotic treatment) on the diversity and population frequency of different bacterial groups, including enterococci (6-10). However, the information provided by current metagenomic analysis, based on 16S rRNA (11, 12), or by the traditi...

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Section: Discussionsupporting

confidence: 76%

Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

Tedim

Ruíz-Garbajosa

Corander

et al. 2015

Appl Environ Microbiol

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“…PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates. A study from Greece demonstrated high incidence of antibiotic resistance in enterococci isolated from neonates' gut microbiota [20]. The study showed the prevalence of fecal enterococci in Greek healthy infants and their susceptibility to antimicrobial agents as well as the presence of genetic determinants encoding for certain antibiotic resistance traits.…”

Section: Epidemiology Of Enterococci Resistance In Infantsmentioning

confidence: 94%

The emergence of antimicrobial resistance in enterococci isolates from infants: A review study

Shehabi

Badran²,

Alnasra³

2015

iajaa

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The emergence of antibiotic resistance in potential bacterial pathogens is considered as an important consequence of antibiotic misuse and overuse in humans and animals. In addition, lacks of adequate knowledge about proper using of antimicrobial drugs as well as infectioncontrol practice in hospital and medical care settings have led to the continuing development of extensive antimicrobial resistance problems worldwide. Certain multidrug-resistant commensal and potential pathogens are now widely spread in community and hospital patients. Examples are meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistance enterococcci (VRE), extended-spectrum β-lactamase and carbapenemase-producing coliforms, floroquinolone-resistant and toxin-hyperproducing Clostridium difficile. During the last decade, Enterococcus faecalis and Enterococcus faecium were the most prevalent species cultured from human infections. Incidence of resistant to multiple antibiotics in these two species has become increasingly common in the hospitalized patients all over the world, particularly E. faecium is reported to be responsible for most vancomycin-resistant enterococci (VRE) infections. This short review is focusing on the recent emergence of antimicrobial resistance among enterococci isolates from infants and the available option of their infection treatment.

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“…Therefore, verifying the safety of enterococci from infants is of utmost importance. Kirtzalidou et al (2012) focused on enterococci from Greek healthy infants to enlighten the spread of resistant enterococci in the infant gut microbiota. Hufnagel et al (2007) found that colonization of newborn infants with enterococci and drug-resistant enterococci increased in preterm infants.…”

Section: Introductionmentioning

confidence: 99%

Screening probiotic strains for safety: Evaluation of virulence and antimicrobial susceptibility of enterococci from healthy Chinese infants

Zhang

Jiang

Wan

et al. 2016

Journal of Dairy Science

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The aim of this study was to evaluate the safety of enterococci isolated from Chinese infants and screen out potential probiotic candidates. One hundred eight strains were isolated from feces of 34 healthy infants, and 38 strains of Enterococcus spp. were categorized as follows: E. faecalis (22), E. faecium (10), E. hirae (3), E. durans (2), and E. casseliflavus (1). Of these, 72.7% of E. faecalis came from infants delivered by cesarean and 62.5% of E. faecium from infants delivered vaginally. For safety evaluation of strains, we determined presence of virulence genes; production of hemolysin, gelatinase, and biofilm; and antimicrobial susceptibility of enterococci. Six out of 14 virulence genes were detected with a distribution of gelE (26.3%), cylA (39.4%), esp (15.8%), efaA (63.2%), asa1 (50.0%), and ace (50.0%). In phenotype analysis, 36.8% of the strains exhibited positive hemolytic activity and 17.5% were positive for production of gelatinase. Results of antimicrobial susceptibility showed that different percentages of the strains were resistant to ciprofloxacin (5.2%), vancomycin (7.8%), rifampicin (10.5%), erythromycin (52.6%), and gentamycin (52.6%); remarkably, none of the strains were resistant to ampicillin or chloramphenicol. In total, 10 strains, including 6 E. faecium, which are free of virulence determinants and sensitive to common antimicrobial agents (e.g., ampicillin and vancomycin), were further assessed for their probiotic properties. All strains survived well in simulated gastric fluid and intestinal tract, with maximum reductions of 0.600 and 0.887 log cfu/mL, respectively. Six strains of E. faecium could resist 0.3 to 1.0% bile salt, of which E. faecium WEFA23 presented the highest growth (75.06%) at 1.0% bile salt. All strains showed bile salt hydrolase activity on glycodeoxycholic acid, but only 3 of E. faecium showed activity on taurodeoxycholic acid. These results deliver useful information on the safety of enterococci in infants in China, and provide a protocol to screen probiotics for absence of virulence and antimicrobial susceptibility of enterococci.

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Screening Fecal Enterococci from Greek Healthy Infants for Susceptibility to Antimicrobial Agents

Cited by 20 publications

References 45 publications

Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

The emergence of antimicrobial resistance in enterococci isolates from infants: A review study

Screening probiotic strains for safety: Evaluation of virulence and antimicrobial susceptibility of enterococci from healthy Chinese infants

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