Prevalence of virulence factors and antibiotic resistance in vancomycin-resistant Enterococcus faecium isolated from sewage and clinical samples in Iran

Abstract In addition to an overall rise in vancomycin-resistant Enterococcus faecium (VREfm), an increase in certain other strain types has been reported in Germany over the past few years. Outbreak analyses at Charité - Universitätsmedizin Berlin revealed the frequent occurrence of VREfm ST117 CT71 isolates in 2017 and 2018. To investigate whether ST117 CT71 have emerged in recent years or whether these strains have been circulating for a longer time, we retrospectively analyzed non-outbreak strains that occurred between 2008 and 2018 to identify frequent sequence types (STs) and cluster types (CTs). Methods In total, 120 VREfm isolates obtained from clinical and surveillance cultures from the years 2008, 2013, 2015, and 2018 were analyzed. Thirty isolates per year comprising the first 7 to 8 non-outbreak isolates of each quarter of the respective year were sequenced using whole genome sequencing. MLST and cgMLST were determined as well as resistance genes and virulence factors. Risk factors for VREfm ST117 were analyzed in a multivariable analysis with patient characteristics as possible confounders. Results The percentage of VREfm of type ST117 increased from 17% in 2008 to 57% in 2018 (p=0.012). In 2008, vanA genotype accounted for 80% of all ST117 isolates compared to 6% in 2018. VanB CT71 first appeared in 2018 and predominated over all other ST117 at 43% (p<0.0001). The set of resistance genes and virulence factors in CT71 (msrC, efmA, ermB, dfrG, and aac(6')-Ii) and virulence factors (acm, esp, hyl, ecbA and sgrA) was also found in other ST117 non-CT71 strains, mainly in CT36. The study population did not differ among the different calendar years analyzed in terms of age, gender, length of stay, or ward type (each p>0.2). Conclusion This study revealed an increase in ST117 strains from 2008 to 2018, accompanied by a shift toward CT71 strains with the vanB genotype in 2018. We did not detect resistance or virulence traits in CT71 that could confer survival advantage compared to other CTs among ST117 strains. To date, it is not clear why ST117 and in particular strain type ST117 CT71 predominates over other strains.

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Comparative Analysis of Prevalence and Antibiotic Resistance in Vancomycin-Resistant Enterococcus from Clinical Samples – Demographics and Phenotypes

Avicenna Journal of Clinical Microbiology and Infection ◽

10.34172/ajcmi.2021.11 ◽

2021 ◽

Vol 8 (2) ◽

pp. 57-65

Author(s):

Folasade Muibat Adeyemi ◽

Nana-Aishat Yusuf ◽

Rashidat Ronke Adeboye ◽

Odunola Oluwaseun Oluwajide ◽

Ajibade Kwashie Ako-Nai

Keyword(s):

Antibiotic Resistance ◽

Skin Lesions ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Phenotypic Characterization ◽

Clinical Samples ◽

Vancomycin Resistant Enterococcus ◽

Southwest Nigeria ◽

Vancomycin Resistant

Background: Of all enterococci species, the most renowned clinically as multidrug-resistant pathogens are Enterococcus faecium and Enterococcus faecalis. Vancomycin-resistant Enterococcus (VRE) species are the principal cause of opportunistic hospital-acquired infections, due to numerous resistance mechanisms. Methods: In this study, the prevalence and antibiotic resistance profiles of VRE according to clinical sources from three selected hospitals in Southwest-Nigeria were investigated. Altogether, 431 samples (urine, rectal, and wound swabs - caesarian section (CS), automobile accidents, and other skin lesions and abrasions) were collected from three selected hospitals in Osun State, Nigeria. Established techniques were employed for the recovery of enterococci and screening for VRE while antibiotic susceptibility tests were carried out by disc diffusion technique. Results: Altogether, 208 (48.3%) enterococci strains were recovered from which 85 (40.9%) were VRE. E. faecium predominated at 71.8% (61/85) and E. faecalis at 28.2% (24/85) as determined by phenotypic characterization. VRE isolates exhibited 100%, 97.6%, and 92.9% resistance to ampicillin, clindamycin, and quinupristin-dalfopristin (Q/D) respectively. The least resistance in-vitro was to tigecycline (27.1%). None of the antibiotics exhibited 100% activity against all the isolates. vanA resistant phenotype was prevalent at 65.9%. E. faecium from all study locations displayed higher levels of resistance than E. faecalis. Multiple antibiotic resistance (MAR) indices in all VRE isolates were ≥0.2, all being multidrug-resistant. Conclusions: The high prevalence rate along with the high level of multidrug resistance observed in the present study is worrisome and poses a continuous threat in the therapy of illnesses triggered by VRE as vancomycin was perceived as a drug of choice to curb enterococcal infections.

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Increase of vancomycin-resistant Enterococcus faecium strain type ST117 CT71 at Charité - Universitätsmedizin Berlin, 2008 to 2018

10.21203/rs.2.17129/v2 ◽

2020 ◽

Author(s):

Anna Weber ◽

Friederike Maechler ◽

Frank Schwab ◽

Petra Gastmeier ◽

Axel Kola

Keyword(s):

Virulence Factors ◽

Resistance Genes ◽

Enterococcus Faecium ◽

Multivariable Analysis ◽

Patient Characteristics ◽

Vancomycin Resistant Enterococcus ◽

The Past ◽

Study Population ◽

Strain Type ◽

Vancomycin Resistant

Abstract Background: In addition to an overall rise in vancomycin-resistant Enterococcus faecium (VREfm), an increase in certain strain types marked by sequence type (ST) and cluster type (CT) has been reported in Germany over the past few years. Outbreak analyses at Charité - Universitätsmedizin Berlin revealed the frequent occurrence of VREfm ST117 CT71 isolates in 2017 and 2018. To investigate whether ST117 CT71 have emerged in recent years or whether these strains have been circulating for a longer time, we retrospectively analyzed non-outbreak strains that occurred between 2008 and 2018 to identify frequent STs and CTs.Methods: In total, 120 VREfm isolates obtained from clinical and surveillance cultures from the years 2008, 2013, 2015, and 2018 were analyzed. Thirty isolates per year comprising the first 7 - 8 non-outbreak isolates of each quarter of the respective year were sequenced using whole genome sequencing. MLST and cgMLST were determined as well as resistance genes and virulence factors. Risk factors for VREfm ST117 were analyzed in a multivariable analysis with patient characteristics as possible confounders. Results: The percentage of VREfm of type ST117 increased from 17% in 2008 to 57% in 2018 (p=0.012). In 2008, vanA genotype accounted for 80% of all ST117 isolates compared to 6% in 2018. VanB CT71 first appeared in 2018 and predominated over all other ST117 at 43% (p<0.0001). The set of resistance genes (msrC, efmA, ermB, dfrG, aac(6')-Ii, gyrA, parC and pbp5) and virulence factors (acm, esp, hylEfm, ecbA and sgrA) in CT71 was also found in other ST117 non-CT71 strains, mainly in CT36. The study population did not differ among the different calendar years analyzed in terms of age, gender, length of stay, or ward type (each p>0.2).Conclusion: This study revealed an increase in ST117 strains from 2008 to 2018, accompanied by a shift toward CT71 strains with the vanB genotype in 2018. We did not detect resistance or virulence traits in CT71 that could confer survival advantage compared to other CTs among ST117 strains. To date, it is not clear why ST117 and in particular strain type ST117 CT71 predominates over other strains.

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Increase of vancomycin-resistant Enterococcus faecium strain type ST117 CT71 at Charité - Universitätsmedizin Berlin, 2008 to 2018

10.21203/rs.2.17129/v3 ◽

2020 ◽

Author(s):

Anna Weber ◽

Friederike Maechler ◽

Frank Schwab ◽

Petra Gastmeier ◽

Axel Kola

Keyword(s):

Virulence Factors ◽

Resistance Genes ◽

Enterococcus Faecium ◽

Multivariable Analysis ◽

Patient Characteristics ◽

Vancomycin Resistant Enterococcus ◽

The Past ◽

Study Population ◽

Strain Type ◽

Vancomycin Resistant

Abstract Background: In addition to an overall rise in vancomycin-resistant Enterococcus faecium (VREfm), an increase in certain strain types marked by sequence type (ST) and cluster type (CT) has been reported in Germany over the past few years. Outbreak analyses at Charité - Universitätsmedizin Berlin revealed the frequent occurrence of VREfm ST117 CT71 isolates in 2017 and 2018. To investigate whether ST117 CT71 have emerged in recent years or whether these strains have been circulating for a longer time, we retrospectively analyzed non-outbreak strains that occurred between 2008 and 2018 to identify frequent STs and CTs.Methods: In total, 120 VREfm isolates obtained from clinical and surveillance cultures from the years 2008, 2013, 2015, and 2018 were analyzed. Thirty isolates per year comprising the first 7 - 8 non-outbreak isolates of each quarter of the respective year were sequenced using whole genome sequencing. MLST and cgMLST were determined as well as resistance genes and virulence factors. Risk factors for VREfm ST117 were analyzed in a multivariable analysis with patient characteristics as possible confounders. Results: The percentage of VREfm of type ST117 increased from 17% in 2008 to 57% in 2018 (p=0.012). In 2008, vanA genotype accounted for 80% of all ST117 isolates compared to 6% in 2018. VanB CT71 first appeared in 2018 and predominated over all other ST117 at 43% (p<0.0001). The set of resistance genes (msrC, efmA, erm(B), dfrG, aac(6')-Ii, gyrA, parC and pbp5) and virulence factors (acm, esp, hylEfm, ecbA and sgrA) in CT71 was also found in other ST117 non-CT71 strains, mainly in CT36. The study population did not differ among the different calendar years analyzed in terms of age, gender, length of stay, or ward type (each p>0.2).Conclusion: This study revealed an increase in ST117 strains from 2008 to 2018, accompanied by a shift toward CT71 strains with the vanB genotype in 2018. We did not detect resistance or virulence traits in CT71 that could confer survival advantage compared to other CTs among ST117 strains. To date, it is not clear why ST117 and in particular strain type ST117 CT71 predominates over other strains.

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