Molecular characterization of glycopeptide-resistant enterococci from hospitals of the picardy region (france)

Antibiogram Pattern and Virulence Trait Characterization of Enterococcus Species Clinical Isolates in Eastern India: A Recent Analysis

Objective We aimed to evaluate the current antimicrobial susceptibility pattern and characterize putative virulence traits among Enterococcus species isolates from various clinical specimens in view of their increased isolation rates in both community-related and serious nosocomial infections, as well as resistance to many antibiotics.

Methods Study (April 2017–March 2018) included consecutive, nonrepeated, discrete, and clinically significant isolates of enterococci. Susceptibility testing included detection of high-level aminoglycoside-resistant (HLAR) and glycopeptide-resistant enterococci (GRE). All screen-positive GRE isolates were investigated by polymerase chain reaction for species confirmation and presence of vanA/vanB genes. Virulence genes ace, asa1, cyt, efa, esp, gelE, and hyl were investigated by molecular methods. Hemolysin and biofilm production were studied using phenotypic methods.

Results Of 111 isolates, 89 (80.1%), 16 (14.4%), and 6 (5.4%) were from urine, pus, and blood, respectively, consisting predominantly of E. faecalis (67, 60.4%) and E. faecium (32, 28.8%). E. hirae (5, 4.5%) was the predominant non-E. faecalis non-E. faecium isolate. Other species were E. durans (4, 3.6%), E. avium (2, 1.8%), and E. mundtii (1, 0.9%). Seven (6.3%) out of the 111 isolates were GRE, all vanA genotype. HLAR was observed in 70 (63.1%) isolates, significantly higher in E. faecium than E. faecalis (81.2 vs. 58.2%; p < 0.05). All were susceptible to daptomycin. Hemolysin activity and biofilm production were observed in 38 (34.2%) and 36 (32.4%) isolates. Most frequent virulence genes were efa (77, 69.4%), ace (71, 63.9%), asa1 (67, 60.3%), and gelE (66, 59.4%). There was a predominant association of esp and hyl genes with E. faecium and that of the other genes with E. faecalis.

Conclusion The study will contribute to the existing limited data on virulence trait characterization of clinical E. spp. isolates in India. At the same time, it will help to serve as a guide in the choice of empirical therapy in enterococcal infections leading to favorable clinical outcomes by decreasing the clinical failure, microbiological persistence, and associated mortality, and will lead to future studies on controlling the spread of virulent and multiresistant isolates.

Isolation of Enterococcus faecalis pathogenic genes isolated from oral infection by the effect of ionic liquids based on amino acid and its expression by real-time PCR

Enterococcus faecalis is an important factor in nosocomial infections. The aim of this study was the isolation of the pathogenic genes of Enterococcus faecalis in mouth infection and the study of the expression of these genes by real-time PCR. In this study, 60 isolates of E. faecalis were isolated from oral infections. The presence and frequency of cyl, hyl, and esp genes and their expression by ionic liquid were evaluated using real-time PCR. MIC was determined by broth dilution method and biofilm production was measured, then biofilm inhibition ability and cytotoxicity test were performed by MTT method. The esp, cyl, and hyl genes were observed in 10, 11, and 2 isolates, respectively. cyl gene with the highest frequency of expression in the treated group was reduced by 1.14% under the influence of ionic liquid with methionine base. The results of MIC and Sub MIC concentrations were obtained with the effect of ionic liquid including 125 and 225 µg/mL, respectively. Amino-acid-based ionic liquids can also reduce biofilm production at sub-MIC concentrations (P < 0.05), and changes in cytotoxicity at different concentrations and over time are significant (P-value < 0.001). E. faecalis strains are genetically diverse and this indicates the polyclonal prevalence of strains in clinical specimens. Combination treatment of ionic liquid with common antimicrobial drugs has good antibacterial effects against Enterococcus species, and ionic liquid with a minimum dose can be a good alternative to single-drug treatment of Enterococcus infections.

Antimicrobial Resistance of Enterococcus sp. Isolated from Sheep and Goat Cheeses

This study aimed to calculate the proportion of antibiotic resistance profiles of Enterococcus faecium, E. faecalis, and E. durans isolated from traditional sheep and goat cheeses obtained from a selected border area of Slovakia with Hungary (region Slanské vrchy). A total of 110 Enterococcus sp. were isolated from cheese samples, of which 52 strains (E. faecium (12), E. faecalis (28), E. durans (12)) were represented. After isolation and identification by polymerase chain reaction and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry, the enterococci (E. faecium, E. faecalis, and E. durans) were submitted to susceptibility tests against nine antimicrobial agents. In general, strains of E. faecalis were more resistant than E. durans and E. faecium. A high percentage of resistance was noted in E. faecalis to rifampicin (100%), vancomycin (85.7%), teicoplanin (71.4%), erythromycin (71.4%), minocycline (57.1%), nitrofurantoin (57.1%), ciprofloxacin (14.3%), and levofloxacin (14.3%). E. durans showed resistance to rifampicin (100%), teicoplanin (100%), vancomycin (66.7%), erythromycin (66.7%), nitrofurantoin (66.7%), and minocycline (33.3%), and E. faecium showed resistance to vancomycin, teicoplanin, and erythromycin (100%). Multidrug-resistant strains were confirmed in 80% of the 52 strains in this study. Continuous identification of Enterococcus sp. and monitoring of their incidence and emerging antibiotic resistance is important in order to prevent a potential risk to public health caused by the contamination of milk and other dairy products, such as cheeses, made on farm level.

Clonal distribution of vancomycin-resistant Enterococcus faecium in Turkey and the new singleton ST733

Background

The aim of this study was to provide information about the spread and characteristics of the vancomycin‐resistant Enterococcus faecium isolates (VREfm) in Turkey.

Methods

Seventy‐one nonduplicate consecutive isolates of VREfm were obtained from various clinical specimens of inpatients treated at university or training hospitals in seven regions of Turkey. Further characteristics included antibiotic susceptibility testing, pulsed‐field gel electrophoresis (PFGE) of SmaI‐digested genomic DNA, and multilocus sequence typing (MLST) of selected isolates. The presence of vancomycin resistance and virulence genes (esp and hyl) was investigated by polymerase chain reaction (PCR).

Results

All VREfm isolates had MICs to vancomycin of ≥32 mg/L and contained the vanA gene. The presence of esp gene was identified in 64 and hyl in eight VREfm isolates. All VREfm showed the multiresistance phenotype, including ampicillin (99%), penicillin (99%), imipenem (99%), ciprofloxacin (87%), moxifloxacin (87%), erythromycin (97%), streptomycin (86%), gentamicin (82%), tetracycline (70%), and teicoplanin (99%). All were susceptible to tigecycline while quinupristin‐dalfopristin (97%) and linezolid (93%) were the most active other agents. Analysis of the PFGE profiles showed that 53 (74.6%) VREfm isolates shared a similar electrophoretic profile, designed as type 1, and were closely related (>85%). The sequence type was identified by MLST in 44 VRE isolates with unrelated or closely related PFGE patterns. MLST revealed that nosocomial spread of VREfm resulted from dissemination of lineage C1 E faecium clones. Sequence types ST78, ST203, and ST117 were the most frequently isolated. This is the first report of ST733 around the world.

Conclusions

Lineage C1 clones are disseminated among clinical VREfm isolates in seven different regions in Turkey. Regarding VREfm isolates, the worldwide epidemic strains are in circulation in Turkey.

High prevalence of vancomycin and high-level gentamicin resistance in Enterococcus faecalis isolates

Multiple drug-resistant enterococci are major cause of healthcare-associated infections due to their antibiotic resistance traits. Among them, Enterococcus faecalis is an important opportunistic pathogen causing various hospital-acquired infections. A total of 53 E. faecalis isolates were obtained from various infections. They were identified by phenotypic and genotypic methods. Determination of antimicrobial resistance patterns was done according to CLSI guidelines. The isolates that were non-susceptible to at least one agent in ≥3 antimicrobial categories were defined as multidrug-resistant (MDR). Detection of antimicrobial resistance genes was performed using standard procedures. According to MDR definition, all of the isolates were MDR (100%). High-level gentamicin resistance was observed among 50.9% of them (MIC ≥ 500 μg/ml). The distributions of aac(6')-Ie-aph(2'')-Ia and aph(3')-IIIa genes were 47.2% and 69.8%, respectively. The aph(2'')-Ib, aph(2'')-Ic, aph(2'')-Id, and ant(4')-Ia genes were not detected. Vancomycin resistance was found in 45.3% of strains. The vanA gene was detected in 37.7% of isolates, whereas vanB and vanC₁ genes were not observed in any strain. Erythromycin resistance rate was 79.2% and the frequencies of ermB and ermC genes were 88.6% and 69.8%, respectively. The ermA and msrA genes were not present in any of the isolates. Our data indicate a high rate of MDR E. faecalis strains. All of high-level gentamicin-resistant isolates carried at least one of aac(6')-Ie-aph(2'')-Ia or aph(3')-IIIa genes. Distribution of vanA was notable among the isolates. In addition, ermB and ermC were accountable for resistance to erythromycin.

Correlation between Infective Factors and Antibiotic Resistance in Enterococci Clinical Isolates in West of Iran

The present study was done to scrutinize the possible relation between infective genes and antimicrobial resistance in Enterococcus faecalis and Enterococcus faecium. Considering the fact that the presence of recognized infective determinants among clinical isolates may promote the emergence of infections and persistence of Enterococci in hospital settings, which can lead to an increase in antimicrobial resistance. 175 E. faecalis and 67 E. faecium isolated from clinical specimens were used. The isolates were identified, and then antibiotic susceptibility testing was performed. The MIC of vancomycin and teicoplanin were determined by broth microdilution method. The presence of infective genes esp, hyl and asa₁ was scrutinized using PCR. Of the 280 enterococcal isolates, 175 (62.5%) isolates were identified as E. faecalis, 67 (24%) as E. faecium and 38 (13.5%) as Enterococcus spp. The results of the antibiotic susceptibility testing showed resistance rates of 5% and 73% to vancomycin and teicoplanin in E. faecalis and E. faecium isolates, respectively. The statistical analysis showed that the esp infective gene has significant associations with ciprofloxacin, erythromycin and tetracycline in E. faecium and with chloramphenicol in E. faecalis strains; the hyl with teicoplanin and vancomycin in E. faecium strains; and also asa₁ with vancomycin in E. faecium and with ampicillin and chloramphenicol in E. faecalis strains. Regarding the relationships between virulence genes and antibiotic resistance in strains of E. faecalis and E. faecium, detection of infective factors associated with invasive diseases has become a major issue of concern.

Virulence Genes among Enterococcus faecalis and Enterococcus faecium Isolated from Coastal Beaches and Human and Nonhuman Sources in Southern California and Puerto Rico

Most Enterococcus faecalis and E. faecium are harmless to humans; however, strains harboring virulence genes, including esp, gelE, cylA, asa1, and hyl, have been associated with human infections. E. faecalis and E. faecium are present in beach waters worldwide, yet little is known about their virulence potential. Here, multiplex PCR was used to compare the distribution of virulence genes among E. faecalis and E. faecium isolated from beaches in Southern California and Puerto Rico to isolates from potential sources including humans, animals, birds, and plants. All five virulence genes were found in E. faecalis and E. faecium from beach water, mostly among E. faecalis. gelE was the most common among isolates from all source types. There was a lower incidence of asa1, esp, cylA, and hyl genes among isolates from beach water, sewage, septage, urban runoff, sea wrack, and eelgrass as compared to human isolates, indicating that virulent strains of E. faecalis and E. faecium may not be widely disseminated at beaches. A higher frequency of asa1 and esp among E. faecalis from dogs and of asa1 among birds (mostly seagull) suggests that further studies on the distribution and virulence potential of strains carrying these genes may be warranted.

Rapid Detection of Bloodstream Pathogens in Liver Transplantation Patients With FilmArray Multiplex Polymerase Chain Reaction Assays: Comparison With Conventional Methods

BACKGROUND

Bloodstream infection (BSI) is an important concern in transplant patients. Early intervention with appropriate antimicrobial therapy is critical to better clinical outcome; however, there is significant delay when conventional identification methods are used.

METHODS

We aimed to determine the diagnostic performance of the FilmArray Blood Culture Identification Panel, a recently approved multiplex polymerase chain reaction assay detecting 24 BSI pathogens and 3 resistance genes, in comparison with the performances of conventional identification methods in liver transplant (LT) patients. A total of 52 defined sepsis episodes (signal-positive by blood culture systems) from 45 LT patients were prospectively studied.

RESULTS

The FilmArray successfully identified 37 of 39 (94.8%) bacterial and 3 of 3 (100%) yeast pathogens in a total of 42 samples with microbial growth, failing to detect only 2 of 39 (5.1%) bacterial pathogens that were not covered by the test panel. The FilmArray could also detect additional pathogens in 3 samples that had been reported as having monomicrobial growth, and it could detect Acinetobacter baumannii in 2 samples suspected of skin flora contamination. The remaining 8 blood cultures showing a positive signal but yielding no growth were also negative by this assay. Results of MecA, KPC, and VanA/B gene detection were in high accordance. The FilmArray produced results with significantly shorter turnaround times (1.33 versus 36.2, 23.6, and 19.5 h; P < .05) than standard identification methods, Vitek II, and Vitek MS, respectively.

CONCLUSIONS

This study showed that the FilmArray appeared as a reliable alternative diagnostic method with the potential to mitigate problems with protracted diagnosis of the BSI pathogens in LT patients.

Spread of an Enterococcus faecalis sequence type 6 (CC2) clone in patients undergoing selective decontamination of the digestive tract

Enterococcus faecalis (E. faecalis) is a common cause of nosocomial infection in immunocompromised patients. The presence and dissemination of high-risk clonal complexes, such as CC2, is an ongoing problem in hospitals. The aim of this work was to characterize 24 E. faecalis isolates from ICU patients undergoing selective decontamination of the digestive tract (SDD) by phenotypical (antimicrobial susceptibility) and genotypical (presence of virulence genes, RAPD-PCR and MLST) methods. Our results showed high prevalence of the ST6 E. faecalis clone (91.6%), especially adapted to the hospital environment, with a multidrug resistance pattern and a multitude of putative virulence genes. In addition, ST179 (4.2%) and ST191 (4.2%) were detected. By RAPD-PCR analysis, the 22 isolates identified as ST6 showed six different DNA patterns, while the two remaining isolates, ST179 and ST191, showed two additional profiles. CC2 is a known clonal complex with high adaptability to hospital environment and worldwide distribution. The high prevalence of the ST6 clone in the studied population could be related to the presence of gentamicin in the SDD mixture since most strains were gentamicin resistant. Consequently, strict surveillance should be applied for rapid detection and control of this clone to prevent future spread outside the ICU.

Molecular analysis and distribution of multidrug-resistant Enterococcus faecium isolates belonging to clonal complex 17 in a tertiary care center in Mexico City

Background

Enterococcus faecium has recently emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. A high rate of resistance to different antibiotics has been associated with virulent clonal complex 17 isolates carrying the esp and hyl genes and the purK1 allele.

Results

Twelve clinical vancomycin-resistant Enterococcus faecium (VREF) isolates were obtained from pediatric patients at the Hospital Infantil de México Federico Gómez (HIMFG). Among these VREF isolates, 58.3% (7/12) were recovered from urine, while 41.7% (5/12) were recovered from the bloodstream. The VREF isolates showed a 100% rate of resistance to ampicillin, amoxicillin-clavulanate, ciprofloxacin, clindamycin, chloramphenicol, streptomycin, gentamicin, rifampicin, erythromycin and teicoplanin. In addition, 16.7% (2/12) of the isolates were resistant to linezolid, and 66.7% (8/12) were resistant to tetracycline and doxycycline. PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates, esp in 83.3% (10/12) of the isolates and hyl in 50% (6/12) of the isolates. Phylogenetic analysis via molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and demonstrated 44% similarity among the VREF isolates. MLST analysis identified four different sequence types (ST412, ST757, ST203 and ST612).

Conclusion

This study provides the first report of multidrug-resistant VREF isolates belonging to clonal complex 17 from a tertiary care center in Mexico City. Multidrug resistance and genetic determinants of virulence confer advantages among VREF in the colonization of their host. Therefore, the prevention and control of the spread of nosocomial infections caused by VREF is crucial for identifying new emergent subclones that could be challenging to treat in subsequent years.

Clonal spread of vancomycin resistance Enterococcus faecalis in an Iranian referral pediatrics center

Vancomycin-resistant enterococci (VRE) represent as an immediate threat to public health. Since few active compounds are available for VRE infections, rapid identification of these isolates are essential. In the absence of any report on the genetic relatedness of Enterococcus faecalis especially Vancomycin-resistant E. faecalis (VREF) isolates in Iran, we undertook this study to characterize these isolates using random amplification of polymorphic DNA (RAPD-PCR) genotyping method. In this study, E. faecalis strains isolated from various samples collected from different wards of Children Medical Hospital (Tehran, Iran). These isolates were identified by standard laboratory procedures and tested for antimicrobial resistance to vancomycin and teicoplanin. The genetic similarity of the strains was investigated by amplification of the RAPD-PCR. In our study among 91 E. faecalis isolates, 15 (16%) were identified as VREF. The similarity pattern built for E. faecalis isolates by RAPD-PCR, demonstrated the presence of four distinct clusters (A, B, C, D). It is of interest to note that 100% of VREF isolates belonged to Clusters A, indicating that there may have occurred horizontal transmission of the same strain between patients. In conclusion, rapid spread of VREF from a clonal origin calls for implementation of careful isolation and infection control measures. Therefore, environmental control by routine disinfection of patient area as well as screening of high risk patients and isolation of colonized patients should be imposed in order to diminish risk of acquiring nosocomial VRE.

Diversity of clones and genotypes among vancomycin-resistant clinical Enterococcus isolates recovered in a Spanish hospital

Forty-three vancomycin-resistant enterococci (VRE) from different patients were recovered in a Spanish Hospital (2003-2010), representing 0.4% of the total of enterococci recovered. Mechanisms detected were vanA (five Enterococcus faecium, two E. faecalis), vanB2 (seven E. faecium, five E. faecalis), vanB1 (one E. faecalis), and vanC1/2 (22 E. gallinarum, 1 E. casseliflavus). Four different Tn1546 structures were found among the seven vanA strains, three of them with insertions (ISEf1 or IS1542) or deletions. Most of the VRE presented a multiresistance phenotype and harbored different resistance genes [erm(B), tet(M), tet(L), ant(6)-Ia, aac(6')-aph(2''), aph(3')-IIIa, and catA]. Sixteen unrelated pulsotypes were detected among the 20 vanA/vanB E. faecalis and E. faecium isolates by pulsed-field-gel-electrophoresis and 11 unrelated pulsotypes among the 22 E. gallinarum isolates. Six different sequence types (ST) were demonstrated among the 12 vancomycin-resistant E. faecium strains (one of them new), and 5 were included into the clonal-complex (CC) CC17. Five different ST were detected among the eight E. faecalis strains. The esp gene was detected in 58% and 25% of E. faecium and E. faecalis strains, respectively, and the hyl gene in 78% and 89%, respectively. A high diversity of clones and genotypes of VRE were detected in this hospital.

Enterococci and their ability to form a biofilm

Number of enterococci determined in raw milk cistern samples was in range of 2.95 to 4.18 log CFU.ml-1 and raw milk samples obtained from storage tanks contained enterococci count in the range of 3.04 to 4.51 log CFU.ml-1. Results of microbiological quality evaluation showed, that count of enterococci increased during cold storage of raw milk. Portion of enterococci from the total microflora of raw milk taken from cistern samples was 0.44 %, otherwise in raw milk samples taken from storage tanks portion of enterococci decreased to 0.38 %. Among enterococci isolates  E. faecalis was the predominat species in tested samples of raw milk from both cistern – 58.1 % and storage tank – 71.7 %. The following species were identified E. faecium, E. group III., E. mundtii, E. casseliflavus. It was found that 38 % E. faecalis isolates were able to form a biofilm.