Emergence of multidrug resistant enterococci at a tertiary care centre

Dramatic increase in antimicrobial resistance in ESKAPE clinical isolates over the 2010-2020 decade in India

RATIONALE AND OBJECTIVES

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) constitute a threat to humans worldwide. India is now the most populous country. The goal was to investigate the evolution of the rates of antimicrobial resistance in ESKAPE pathogens across India over the 2010-20 decade.

METHODS

The data (89 studies) were retrieved from the Medline PubMed repository using specific keywords.

RESULTS

The study of 20 177 ESKAPE isolates showed that A. baumannii isolates were the most represented (35.9%, n = 7238), followed by P. aeruginosa (25.3%, n = 5113), K. pneumoniae (19.5%, n = 3934), S. aureus (16.3%, n = 3286), E. faecium (2.6%, n = 517) and Enterobacter spp. (0.4%, n = 89). A notable increase in the resistance rates to antimicrobial agents occurred over the 2010-20 decade. The most important levels of resistance were observed in 2016-20 for A. baumannii (90% of resistance to the amoxicillin-clavulanate combination) and K. pneumoniae (81.6% of resistance to gentamycin). The rise in β-lactamase activities was correlated with an increase in the positivity of Gram-negative isolates for β-lactamase genes.

CONCLUSIONS

This review highlighted that, in contrast to developed countries that kept resistance levels under control, a considerable increase in resistance to various classes of antibiotics occurred in ESKAPE pathogens in India over the 2010-2020 decade.

Prevalence of vancomycin-resistant Enterococci in India between 2000 and 2022: a systematic review and meta-analysis

BACKGROUND

Vancomycin-resistant Enterococci (VRE) infections are recurrently reported in different parts of India in the last two decades. However, an up-to-date, countrywide information concerning the prevalence and the rate of VRE in India is limited and hence this study aimed to estimate the pooled prevalence of VRE in India.

METHODS

A literature search was performed using various databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed throughout. Cross-sectional studies reporting the prevalence of VRE in India from human samples whereby at least two Enterococci were isolated between 1 January 2000 and 31 December 2022 were sought for inclusion. Data were extracted and analysed using Microsoft Excel and Comprehensive Meta-analysis version 4, respectively.

RESULTS

Nineteen studies were included in the analyses. A collective total of 3683 Enterococci isolates were examined, of which 368 were VRE strains. The pooled prevalence of VRE in India was calculated at 12.4% (95% CI: 8.6-17.5; Q = 189.69; I2 = 90.51%; p = < 0.001). E. faecalis was the most frequently isolated species (1450 [39.37%]) followed by E. faecium (724 [19.66%]). Amongst the VRE strains, E. faecium was the most prevalent (214 [58.15%]) followed by E. faecalis (134 [36.41%]). An upsurge in the rate of VRE infections was observed in India over time: VRE prevalence was estimated at 4.8% between 2000 and 2010 and 14.1% between 2011 and 2020.

CONCLUSION

This study presents the most up-to-date information on the rate of VRE infections in India. Though lower than the findings for some less developed countries, VRE prevalence in India is notable and on the rise.

Novel Starter Strain Enterococcus faecium DMEA09 from Traditional Korean Fermented Meju

The Enterococcus faecium strain DMEA09 was previously isolated from traditional Korean fermented meju. The objective of the current study was to investigate the traits of E. faecium strain DMEA09 as a starter candidate, focusing on its safety and technological properties. Regarding its safety, the DMEA09 strain was found to be sensitive to nine antibiotics (ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, tylosin, and vancomycin) by showing lower minimum inhibitory concentrations (MICs) than the cut-off values suggested by the European Union Food Safety Authority for these nine antibiotics. However, its MIC value for clindamycin was twice as high as the cut-off value. A genomic analysis revealed that strain DMEA09 did not encode the acquired antibiotic resistance genes, including those for clindamycin. The DMEA09 strain did not show hemolysis as a result of analyzing α- and β-hemolysis. It did not form biofilm either. A genomic analysis revealed that strain DMEA09 did not encode for any virulence factors including hemolysin. Most importantly, multilocus sequence typing revealed that the clonal group of strain DMEA09 was distinguished from clinical isolates. Regarding its technological properties, strain DMEA09 could grow in the presence of 6% salt. It showed protease activity when the salt concentration was 3%. It did not exhibit lipase activity. Its genome possessed 37 putative protease genes and salt-tolerance genes for survivability under salt conditions. Consequently, strain DMEA09 shows safe and technological properties as a new starter candidate. This was confirmed by genome analysis.

Status of Biofilm Production and Vancomycin Resistance in Enterococcus in the Rural Population of Mathura, India

Introduction Hospital-acquired or nosocomial infections caused by the rapidly emerging bacteria vancomycin-resistant enterococci can be dangerous and even fatal. Therefore, this study aimed to investigate the presence of enterococci in various clinical specimens along with their vancomycin resistance status and biofilm-producing capabilities. Methods A total of 164 Enterococcus species were isolated and further included in this study. Isolation and identification were done by the standard bacteriological procedure, antibiotic susceptibility testingwas done by clinical laboratory standard guidelines, and biofilm production test was done by microtiter plate methods. Results Among the total of 164 isolates, Enterococcus faecalis constituted 60.97% and Enterococcus faecium constituted 39.02%. Maximum isolates were from urine samples. The prevalence of vancomycin-resistant Enterococcus was 6.70%, and 18.29% of Enterococcus isolates were biofilm producers. The sensitivity among the biofilm producers was maximum for linezolid (87.33%), followed by teicoplanin (86.43%) and vancomycin (79.64%). Conclusion High prevalence of enterococci was found in urine samples and biofilm producers Enterococcus isolates were more antibiotic-resistant than non-biofilm producers.

Antibiotic Susceptibility Patterns and Virulence-Associated Factors of Vancomycin-Resistant Enterococcal Isolates from Tertiary Care Hospitals

This study explored the prevalence of multi-drug resistance and virulence factors of enterococcal isolates obtained from various clinical specimens (n = 1575) including urine, blood, pus, tissue, catheter, vaginal wash, semen, and endotracheal secretions. Out of 862 enterococcal isolates, 388 (45%), 246 (29%), 120 (14%), and 108 (13%) were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Enterococcus hirae, respectively, using standard morphological and biochemical methods. The antibiotic resistance profile of all these enterococcal isolates was checked using the disc diffusion technique. High-level resistance was observed for benzylpenicillin (70%) and vancomycin (43%) among E. faecalis and E. faecium isolates, respectively. This study also revealed the prevalence of 'multi-drug resistance (resistant to 3 antibiotic groups)' among the vancomycin-resistant enterococcal strains, and this was about 11% (n = 91). The virulence determinants associated with vancomycin resistance (VR) were determined phenotypically and genotypically. About 70 and 39% of E. faecalis and E. faecium isolates showed to be positive for all four virulence factors (gelatinase, protease, hemolysin, and biofilm). Among the several virulence genes, gelE was the most common virulence gene with a prevalence rate of 76 and 69% among E. faecalis and E. faecium isolates, respectively. More than 50% of VRE isolates harbored other virulence genes, such esp, asa, ace, and cylA. Similarly, the majority of the VR enterococcal isolates (n = 88/91) harbored vanA gene and none of them harbored vanB gene. These results disclose the importance of VR E. faecalis and E. faecium and the associated virulence factors involved in the persistence of infections in clinical settings.

Antimicrobial susceptibility pattern of enterococci isolated from various clinical samples in a tertiary care hospital in India

Background and objectives: Enterococci are significant human pathogens that are capable of causing various nosocomial infections. This study determined the antibiotic susceptibility pattern of enterococcal species isolated from various clinical specimens with special reference to vancomycin-resistant enterococci. Material and methods: The study was carried out for 6 months on enterococci isolated from various clinical specimens at a tertiary care hospital. Organisms were identified by standard procedures, and subjected to antimicrobial testing as per the standard guidelines. Results: Total 116 enterococci were isolated from various clinical samples. Of the total isolates, 56.9%, 30.2% and 12.9% were isolated from indoor, intensive care unit and non-hosptalized (outdoor) patients respectively.The most common Enterococcus species from blood was E. faecium (72%) followed by E. faecalis (12%) and E. galinarrium (9.4%). Out of 116 enterococci isolates, 31 (26.7%) were resistant to vancomycin and only 1 (0.9%) was resistant to linezolid. Conclusion:The study demonstrated high prevalence of multidrug-resistant enterococci in our hospital setting, thus posing a serious therapeutic challenge. The result would be useful in monitoring the future trends of antimicrobial susceptibility of enterococci in this region. *Correspondence: Dr. Nikunja Kumar Das, Department of Microbiology, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, Maharashtra, India-411018. E-mail: nikunjdas3085@gmail.com IMC J Med Sci. 2023; 17(2):004. DOI: https://doi.org/10.55010/imcjms.17.014

Vancomycin and Linezolid-Resistant Enterococcus Isolates from a Tertiary Care Center in India

INTRODUCTION

There is increasing development of antibiotic resistance among the Enterococcus species.

OBJECTIVES

This study was performed to determine prevalence and characterize the vancomycin-resistant and linezolid-resistant enterococcus isolates from a tertiary care center. Moreover, the antimicrobial susceptibility pattern of these isolates was also determined.

MATERIALS AND METHODS

A prospective study was performed in Medical College, Kolkata, India, over a period of two years (from January 2018 to December 2019). After obtaining clearance from the Institutional Ethics Committee, Enterococcus isolates from various samples were included in the present investigation. In addition to the various conventional biochemical tests, the VITEK 2 Compact system was used to identify the Enterococcus species. The isolates were tested for antimicrobial susceptibility to different antibiotics using the Kirby-Bauer disk diffusion method and VITEK 2 Compact to determine the minimum inhibitory concentration (MIC). The Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines were used to interpret susceptibility. Multiplex PCR was performed for genetic characterization of the vancomycin-resistant Enterococcus isolates and sequencing was performed for characterization of the linezolid-resistant Enterococcus isolates.

RESULTS

During the period of two years, 371 isolates of Enterococcus spp. were obtained from 4934 clinical isolates showing a prevalence of 7.52%. Among these isolates, 239 (64.42%) were Enterococcus faecalis, 114 (30.72%) Enterococcus faecium, and others were Enterococcus durans, Enterococcus casseliflavus, Enterococcus gallinarum, and Enterococcus avium. Among these, 24 (6.47%) were VRE (Vancomycin-Resistant Enterococcus) of which 18 isolates were Van A type and six isolates of Enterococcus casseliflavus and Enterococcus gallinarum were resistant VanC type. There were two linezolid-resistant Enterococcus, and they were found to have the G2576T mutation. Among the 371 isolates, 252 (67.92%) were multi-drug resistant.

CONCLUSION

This study found an increasing prevalence of vancomycin-resistant Enterococcus isolates. There is also an alarming prevalence of multidrug resistance among these isolates.

Genetic Diversity, Antimicrobial Resistance, and Virulence Factors of Enterococcus Faecalis Isolates Obtained from Stool Samples of Hospitalized Patients

Background: Enterococcus faecalis rapidly develops resistance to different antibiotics, thereby resulting in serious nosocomial infections associated with high mortality rates and different problems in the healthcare systems. Objectives: This study aimed to analyze the genetic diversity, antimicrobial resistance, and virulence factors of E. faecalis isolates obtained from the stool samples of patients in a hospital in the center of Iran. Methods: In this cross-sectional descriptive-analytical study, 108 stool samples were collected from September 2019 to February 2020 from 108 patients hospitalized in a hospital in the center of Iran. Enterococcus faecalis isolates were detected using the ddlE gene detection technique, and antimicrobial resistance testing was performed using the disc agar diffusion method. Moreover, polymerase chain reaction (PCR) was used to detect antimicrobial resistance genes and virulence factors. Genetic diversity was also analyzed by enterobacterial repetitive intergenic consensus using PCR (ERIC-PCR). The BioNumerics software was used to construct a dendrogram. Results: Of 108 isolates, 50 samples were E. faecalis (46.2%). The prevalence of multidrug resistance among E. faecalis isolates was 62%, and most isolates were resistant to antibiotics tetracycline (70%), erythromycin (68%), and rifampin (60%). Among the E. faecalis isolates, the most prevalent antimicrobial resistance genes were ermB (96%), aph (2′′) Ia (66%), aac(6′)-Ie (40%), and ermC (30%), and the most prevalent virulence genes were gelE (78%), asa1 (74%), and esp (74%). The genetic diversity analysis showed 25 ERIC types in two major clusters (ie, clusters H and J) and eight minor clusters (ie, clusters A-G and I). There was no significant difference between clusters H and J in terms of antimicrobial resistance and resistance genes (P > 0.05). In contrast, the prevalence of the asa1 gene was significantly higher in cluster J than in cluster H (P < 0.05). Conclusions: This study showed the high prevalence of multidrug resistance, and high heterogeneity among the E. faecalis isolates obtained from the stool samples of hospitalized patients.

Prevalence and Antimicrobial Resistance of Enterococcus Species: A Retrospective Cohort Study in Italy

Antimicrobial resistance represents one of the main threats to healthy ecosystems. In recent years, among the multidrug-resistant microorganisms responsible for nosocomial infections, the Enterococcus species have received much attention. Indeed, Enterococcus have peculiar skills in their ability to acquire resistance genes and to cause severe diseases, such as endocarditis. This study showed the prevalence and antimicrobial resistance rate of Enterococcus spp. isolated from clinical samples, from January 2015 to December 2019 at the University Hospital "San Giovanni di Dio e Ruggi d'Aragona" in Salerno, Italy. A total of 3236 isolates of Enterococcus&nbsp;faecalis (82.2%) and Enterococcus&nbsp;faecium (17.8%) were collected from urine cultures, blood cultures, catheters, respiratory tract, and other samples. Bacterial identification and antibiotic susceptibility were performed with VITEK 2. E. faecium showed a high resistance rate against ampicillin (84.5%), ampicillin/sulbactam (82.7%), and imipenem (86.7%), while E. faecalis showed the highest resistance rate against gentamicin and streptomycin high level, but both were highly sensitive to such antibiotics as tigecycline and vancomycin. Studies of surveillance are an important tool to detect changes in the resistance profiles of the main pathogens. These antimicrobial susceptibility patterns are necessary to improve the empirical treatment guideline of infections.

Biofilm Producing Enterococcus Isolates from Vaginal Microbiota

BACKGROUND

Enterococcus is an important cause of infection in the hospital as well as in the community.

METHODS

A prospective study was done in Medical College, Kolkata for a period of 2 years (from January 2018 to December 2019). After obtaining clearance from the Institutional Ethics Committee, Enterococcus isolates from cases of vaginitis were included in the study. Identification of Enterococcus species was done by Gram stain and conventional biochemical tests along with automated identification by VITEK 2 Compact. These isolates were tested for antimicrobial susceptibility to different antibiotics by Kirby Bauer disc diffusion method and minimum inhibitory concentration (MIC) by VITEK 2 Compact. Interpretation of susceptibility was done according to the Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines. Biofilm detection for Enterococcus species was done.

RESULTS

During the period of 2 years, 39 isolates of Enterococcus spp. were obtained from vaginitis cases. Among these, 27 were Enterococcus faecalis and 12 Enterococcus faecium. All isolates were highly susceptible to vancomycin, teicoplanin, and linezolid. Biofilm was detected in eight isolates of which five were strong biofilm producer and three moderate biofilm producers.

CONCLUSION

Biofilm production is an important virulence factor in Enterococcus isolates from vaginitis.

Phenotypic and Molecular Characterization of Plasmid-Mediated Virulence and Antimicrobial Resistance Traits among Multidrug Resistant Enterococcus spp. in Egypt

Enterococcus spp. are remarkable multidrug resistant (MDR) bacteria that are causing serious healthcare-associated infections. The current study investigated the frequency of Enterococcus spp., antimicrobial susceptibility, biofilm formation and the presence of some plasmid-mediated virulence characters and antimicrobial resistance determinants in enterococcal isolates from Egyptian hospitals in Cairo. Enterococcus bacterial isolates were recovered from different clinical specimens and identified using biochemical testing and KB005A HiStrep™ identification kit. Kirby-Bauer disc diffusion method and/or broth microdilution method were used to determine the antimicrobial susceptibility patterns. Phenotypic assays were performed to study biofilm formation and cytolysin and gelatinase production. PCR assays targeting the plasmid-carried genes aac(6’)-aph(2’), aph(3)-IIIa, vanA, agg and cylA were performed. In this study, 50 isolates of diverse Enterococcus spp. were identified with E. faecium was the most frequently isolated one. High resistance profiles were determined against tested antimicrobials and all isolates were MDR. Moderate biofilm formation was detected in 20% of isolates, 18% showed complete blood hemolysis and 12% produced gelatinase. All isolates carried the tested aminoglycosides resistance genes, while vanA was found only in 4 isolates (8%). The virulence genes agg and cylA were detected in 4% and 32% of isolates, respectively. In conclusion, E. faecium was the most prevalent species. The entire isolates set were MDR and the plasmid-carried aminoglycoside resistance genes were extensively disseminated among MDR isolates. Thus, regular surveillance studies, from the area of study or other geographical regions in Egypt, and strict infection control measures are required to monitor the emerging MDR enterococci.

Biofilm synthesis and other virulence factors in multidrug-resistant uropathogenic enterococci isolated in Northern India

Purpose

Enterococci express high degree of resistance towards wide range of antibiotics. Production of biofilm and many virulence factors along with drug resistance makes it difficult to eradicate the infection from urinary tract. The present study detected the expression of such factors including biofilm production by multidrug-resistant (MDR) enterococci.

Materials and Methods

Drug susceptibility of 103 uropathogenic enterococci was performed followed by estimation of minimum inhibitory concentration of high-level gentamicin and vancomycin by microbroth dilution method. Vancomycin-resistant genes were detected by multiplex polymerase chain reaction. Production of virulence factors such as haemagglutination, caseinase, lipase, gelatinase, haemolysin and β-lactamase was detected by phenotypic methods in MDR strains. Biofilm production was detected by calcofluor-white fluorescence staining and semi-quantitative adherence assay.

Results

45% and 18.4% of the isolates were high-level gentamicin-resistant and vancomycin-resistant enterococci (VRE), respectively. vanA gene was detected in 14 and vanB gene in 5 strains. Biofilm, caseinase and gelatinase were the most expressed virulence factor. Expression of caseinase, gelatinase and lipase was significantly higher in Enterococcus faecalis (P < 0.05). Expression of haemagglutination, gelatinase and haemolysin among the vancomycin-resistant isolates was significantly higher (P < 0.05).

Conclusion

VanA and vanB are the prevalent genotypes responsible for vancomycin resistance. The high prevalence of MDR enterococcal strains producing biofilm and virulence determinants raises concern. asa1, hyl, esp, gelE, cyl and other genes are known to express these factors and contribute to biofilm formation. Most uropathogenic enterococci expressed biofilm at moderate level and can be detected effectively by calcofluor-white staining. No correlation was noted between vancomycin resistance and biofilm production.

Effect of the lantibiotic nisin on inhibitory and bactericidal activities of antibiotics used against vancomycin-resistant enterococci

OBJECTIVES

Antibiotic resistance is a serious issue facing clinicians all over the world. Vancomycin-resistant enterococci (VRE) are amongst the most common resistant pathogens that are isolated from patients suffering from infections in our locality. New antimicrobial agents such as the lantibiotic nisin have been previously examined against resistant bacteria as it has strong antibacterial action with no chance of resistance development. This study aimed to explore the effect of nisin in combination with the conventional antibiotics against VRE, with a view to using it as an auxiliary therapy with such antibiotics for combating resistant isolates.

METHODS

Twenty-three VRE had been examined for the combined effect of nisin with the routine sets of antibiotics using the microplate dilution technique for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) testing. Checkerboard microbroth assay was conducted for inspection of synergism between nisin and either ampicillin or chloramphenicol.

RESULTS

An obvious improvement of inhibitory and bactericidal activities of the tested antibiotics after addition of lantibiotic nisin was observed, with a remarkable reduction in the MIC values of vancomycin against all of the isolates. Nisin recorded a synergistic outcome when combined with either ampicillin or chloramphenicol using the checkerboard assay.

CONCLUSION

Nisin could be effectively considered as a supplementary agent to traditional antibiotics in the management of VRE-associated infections, as it had a synergistic outcome with commonly prescribed antibiotics such as ampicillin and chloramphenicol.

Detection of high level aminoglycoside resistance genes among clinical isolates of Enterococcus species

Background

Enterococci are intrinsically resistant to clinically achievable concentrations of aminoglycosides. However, high-level resistance to aminoglycosides (HLAR) is primarily due to the acquisition of genes encoding aminoglycoside-modifying enzymes (AMEs). Aminoglycosides along with cell wall inhibitors are given clinically for treating enterococcal infections. The current study was conducted to investigate the rate of HLAR and to determine aminoglycoside resistance encoding genes profile in enterococcal isolates from different clinical specimens.

Results

From 120 Enterococcus species, 50 (41.7%) enterococcal isolates were proven to have HLAR, 78% (39/50) have high-level gentamicin resistance (HLGR), and 74% (37/50) were high-level streptomycin-resistant (HLSR). HLGR isolates carried aminoglycoside modifying gene aac (6′)-Ie-aph (2′)-Ia in 26/39 (66.7%) of isolates, whereas 32/37 (86.5%) of HLSR carried aph (3′)-IIIa gene and were observed in E. faecalis, E. faecium, E. gallinarum, and E. casseliflavus. The aph (2′)-Ib, aph (2′)-Ic, and aph (2′)-Id that encode HLGR could not be detected.

Conclusions

The high detection rate of HLAR among the studied Enterococcus species and the coexistence of HLGR and HLSR strains provide crucial insights to the necessity of routine testing for HLAR in the microbiology lab. The main AME genes among HLGR and HLSR enterococci were aac (6′)-Ie-aph (2″)-Ia and aph (3′)-IIIa, respectively.

Prevalence of Multidrug-Resistant Enterococcus faecalis in Hospital-Acquired Surgical Wound Infections and Bacteremia: Concomitant Analysis of Antimicrobial Resistance Genes

Background:

The study aimed to assess the prevalence of Enterococcus faecalis infections among patients with hospital-acquired surgical wound sepsis and bacteremia in surgical wards and identify the antimicrobial susceptibility in these pathogens. Genetic role of erythromycin, vancomycin, and cephalosporin resistance in these pathogens was also examined.

Methods:

Two hundred samples were collected from surgical wound infections and 100 blood cultures from patients with suggested bacteremia to identify E faecalis by phenotypic and genotypic methods. Antimicrobial susceptibility to 12 antimicrobial agents was tested. The presence of resistance genes was examined by polymerase chain reaction (PCR) assay.

Results:

E faecalis was isolated with a frequency of 24/200 (12%) from surgical wound samples and 2/100 (2%) from blood cultures. All isolates were completely resistant to cefepime, ampicillin, and tetracycline, 96% of isolates were resistant to erythromycin, 53.8% to vancomycin, and 23.1% to linezolid. Multidrug resistance (MDR) was found in 100% of isolates. ere(B) and erm(B) genes were present in 20/25 (80%) and 17/25 (68%) of erythromycin-resistant isolates, respectively, 15 (60%) isolates carry both ere(B) and erm(B) genes. Van A gene was detected in 71.4% of vancomycin-resistant isolates. All isolates were negative for mef(A/E), blaSHV, and blaTEM genes.

Conclusion:

MDR in all isolates (100%) and high-level resistance to gentamicin, erythromycin, and vancomycin were reported in E Faecalis isolates. In the studied isolates, erythromycin resistance mainly related to the presence of ere(B) and erm(B) genes and vancomycin resistance was mainly related to the presence of vanA gene.

Characterization of Clinical Isolates of Enterococci with Special Reference to Glycopeptide Susceptibility at a Tertiary Care Center of Eastern Nepal

Background

Enterococci, once considered as a harmless commensal of intestine, have now emerged as medically important pathogens and are associated with both community-acquired and nosocomial infections. They bear the potential to exhibit resistance against all commonly used antibiotics either by inherent or acquired mechanism, posing a therapeutic challenge.

Objectives

This study aimed to characterize enterococci up to the species level and study their antibiogram with special regard to vancomycin.

Methods

A descriptive cross-sectional study was conducted in the Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal, from February to May 2017. A total of 91 enterococcal isolates recovered from clinical specimens were investigated in this study. Their identification and speciation were done according to standard microbiological guidelines. Kirby–Bauer disc diffusion technique was used to study antimicrobial susceptibility pattern, whereas minimum inhibitory concentration of vancomycin was determined by the agar dilution method, with reference to Clinical and Laboratory Standards Institute guidelines.

Results

Seven different species of enterococci were isolated, E. faecalis and E. faecium accounting about 45% each. The other species encountered were E. avium, E. cecorum, E. dispar, E. durans, and E.

Conclusions

Enterococcus faecalis and E. faecium were the predominant species in causing enterococcal infections. The alarming rise in prevalence of vancomycin and multidrug resistance strains warrants immediate, adequate, and efficient surveillance program to prevent and control its spread.

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.

Incidence of Virulence Determinants Among Enterococcal Clinical Isolates in Egypt and Its Association with Biofilm Formation

Background: Although Enterococci compromise an essential part of normal gut microbiota of both animals and humans, they have emerged as a leading opportunistic pathogen causing infections. The pathogenesis of enterococci is attributed to an array of virulence determinants. Objectives: This study aims to explore the prevalence and characteristics of enterococcal clinical isolates collected from Mansoura University Hospitals, Egypt, assess their ability to form biofilm, and the correlation with virulence determinants and antimicrobial resistance. Materials and Methods: A total of 70 Enterococcal clinical isolates were collected from different clinical sources between June and December 2016. Biofilm formation capacity was assessed, and characterization of virulence factors and antibiotic susceptibility was performed. Clonal relatedness between isolates was assessed using enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) approach. Results and Conclusion: The molecular analysis demonstrated high genetic diversity among enterococcal clinical isolates. The gelE was the most frequently detected gene (91.4%), followed by asa1 (70%), esp (65.7%), and cylA (17.1%), while hyl was not detected in any isolate. Gelatinase activity was detected in 35.7%, while hemolysin and lipase activity was detected in 12.9% and 78.5%, respectively. Most of the enterococcal isolates were biofilm producers, of which 67.1% were strong/moderate biofilm producers. All linezolid-resistant isolates exhibited strong/moderate biofilm formation capacity. Strong/moderate biofilm formation was more frequently observed among esp-positive (esp+) and gelatinase nonproducing (gelatinase-) enterococcal isolates. Multiple regression analysis denoted that esp (odds ratio [OR] 5.371, p = 0.003) and gelatinase production (OR 0.264, p = 0.015) were associated with strong/moderate biofilm formation capacity. These findings suggest that esp gene positivity and gelatinase production may affect biofilm formation capacity among enterococcal clinical isolates.

High level aminoglycoside resistant enterococci in hospital-acquired urinary tract infections in Mansoura, Egypt

Introduction

Resistance to different antimicrobial agents is increasing in enterococci and effective treatment represents a major health concern. The aim of this study was to determine the antimicrobial resistance patterns and the frequency of high level aminoglycoside resistance (HLAR) among enterococci.

Methods

A total of 80 enterococcal isolates, (73 Enterococcus faecalis, 7 Enterococcus faecium) were collected from patients with hospital acquired urinary tract infections (UTI) at Mansoura University hospitals in Egypt. Antimicrobial susceptibility testing was performed via the disc diffusion method. PCR was used for identification of species and detection of aminoglycoside-modifying enzymes genes (AME).

Results

All enterococcal isolates were sensitive to vancomycin and linezolid. Fifty-three isolates exhibited HLAR. Our results show that HLAR was mediated by the presence of multiple AMEs genes. The aac(6')-Ie-aph(2')-Ia gene was associated with aph(3')-IIIa and ant(6)-Ia gene in 69% of HLAR isolates.

Conclusion

This study showed that enterococci isolated from hospital acquired UTI were resistant to multiple antibiotics. Furthermore, the frequency of high level gentamicin resistance (HLGR) was higher than high level of streptomycin resistance (HLSR). The most common AME genes were aph(3')-IIIa and ant(6)-Ia followed by aac(6')-Ie-aph(2')-Ia.

Prevalence and antimicrobial susceptibility pattern of Enterococcus species isolated from different clinical samples at Black Lion Specialized Teaching Hospital, Addis Ababa, Ethiopia

OBJECTIVE

Enterococci which are parts of the normal intestinal flora are opportunistic human pathogens. Their increasing importance is largely due to their resistance to antimicrobials. So the aim this study was to determine the prevalence and antimicrobial pattern of Enterococcus spp.

RESULT

From the total of 422 samples processed, 15 Enterococcus species were isolated. In this study, linezolid were the drug of choice for Enterococcus species, which showed 100% sensitive followed by vancomycin 93.3% sensitive. In contrast, highly resistance (80%) was observed for ampicillin followed by doxycycline (73.3%). All of isolated Enterococci were sensitive to linezolid, however, resistance was observed to common antibiotics. The presence of multidrug resistant Enterococci in our study should be considered as an alarm for Enterococcal infections.

Antimicrobial resistance of Enterococcus isolates in Turkey: A meta-analysis of current studies

OBJECTIVES

In this study, a meta-analysis of Enterococcus isolates collected in 2000-2015 in Turkey and their susceptibility/resistance to antibiotics, clinical indications for initial drug treatment, and identification of alternative treatments was conducted.

METHODS

The meta-analysis examined antibiotic susceptibility/resistance in Enterococcus spp. isolates. The study was planned and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Statements on antimicrobial resistance were grouped according to the antimicrobial stewardship programme (ASP).

RESULTS

The mean resistance rates of Enterococcus faecalis to vancomycin (VAN) and linezolid (LNZ) were 1.0±2.2% and 1.9±2.6%, respectively, whereas the mean resistance rates of Enterococcus faecium to VAN and LNZ were 10.3±11.3% and 2.4±0%, respectively.

CONCLUSIONS

This study is the first meta-analysis of the resistance of clinical Enterococcus isolates in Turkey to antimicrobial agents, which is a major problem stemming from the excessive usage of antibiotics. The development of antibiotic resistance in Turkey has changed over time. To support the practice of evidence-based medicine, more notifications about Enterococcus resistance status are needed, especially notifications following ASP rules.

Identification of Genes Coding Aminoglycoside Modifying Enzymes in E. coli of UTI Patients in India

This study is to probe the pattern of antibiotic resistance against aminoglycosides and its mechanism in E. coli obtained from patients from Chennai, India. Isolation and identification of pathogens were done on MacConkey agar. Antimicrobial sensitivity testing was done by disc diffusion test. The identification of genes encoding aminoglycoside modifying enzymes was done by Polymerase Chain Reaction (PCR). Out of 98 isolates, 71 (72.45%) isolates were identified as E. coli and the remaining 27 (27.55%) as other bacteria. Disc diffusion method results showed a resistance level of 72.15% for streptomycin, 73.4% for gentamicin, 63.26% for neomycin, 57.14% for tobramycin, 47.9% for netilmicin, and 8.16% for amikacin in E. coli. PCR screening showed the presence of four genes, namely, rrs, aacC2, aacA-aphD, and aphA3, in their plasmid DNA. The results point towards the novel mechanism of drug resistance in E. coli from UTI patients in India as they confirm the presence of genes encoding enzymes that cause resistance to aminoglycoside drugs. This could be an alarm for drug prescription to UTI patients.