Identification Of Enterococcus Species Research Articles

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.

Isolation, identification and antibiotic susceptibility of various clinical Enterococcus species in Sabah, Malaysia

Background: Enterococcus spp. are Gram-positive facultatively anaerobic pathogens causing community-acquired and hospital-acquired infections. Common clinical manifestation are the bloodstream, urinary tract and surgical site infections. The increasing incidence of Enterococcus infections has gained immense public interest recently. The objectives of this study were to isolate, and identify, and antibiotic resistance profiling of Enterococcus spp. from patients in a tertiary hospital in Sabah, Malaysia. Methods and materials: Enterococcus isolates from various clinical specimens from body fluids (blood, urine, pus, high vaginal swab and peritoneal fluid) were collected from July to October 2019. The Enterococcus species, antibiotic susceptibility and resistance profiles were determined using Vitek2 (Biomerieux, Hazelwood, MO, USA) according to manufacturer's instruction. DNA were extracted using the DNeasy tissue kit (Qiagen, Valencia, CA). Identification of Enterococcus species was confirmed by polymerase chain reaction (PCR) using species specific primers. The E. gallinarum and E. raffinosus were also confirmed by 16S DNA sequencing. This research was approved by the Medical Research Ethics Committee (MREC), Ministry of Health, Malaysia (No. NMRR-19-1770-48622). Results: Among the 48 clinical specimens, four different Enterococcus species were identified of which 34 (70.8%) were E. faecalis 12 (25.0%), E. faecium and another 2 (4.2%) were E. gallinarum and E. raffinosus. Majority of the cases were diagnosed as urinary tract or blood stream infections with patient's age ranges from 1 to 87 years old. The antibiotic susceptibility pattern indicates that resistance to ampicillin was 31.3% and ciprofloxacin was 25.0%. One isolate, E. faecalis, showed resistance to both vancomycin and linezolid from a pus sample. Another strain, E. faecalis, from urine showed resistant to linezolid, ciprofloxacin and gentamicin. Conclusion: The occurrence of clinical vancomycin resistance Enterococcus spp. was very low with only one isolate out the total 48 samples examined. It was observed that E. faecium is more resistant to ampicillin (18.8%) than E. faecalis isolates (4.2%). Enhanced surveillance for multidrug resistant organisms (MDRO) and vancomycin resistant Enterococcus (VRE) pathogens could be helpful for effective infection control measures in healthcare facilities.

Excellent fosfomycin and linezolid susceptibility among multidrug resistant urinary Enterococcus isolates in Eastern India

Urinary tract infection (UTI) is one of the most common infectious diseases. Enterococcus spp. is an important causative agent of UTI. Emergence of resistance is high among enterococcus isolates. Fosfomycin has emerged as a novel oral therapeutic option for urinary isolates. A prospective study was done in Medical College, Kolkata for a period of 6 months (from January to June 2018). After obtaining ethical clearance from the Institutional Review Board (IRB) urine samples with significant growth of enterococcus were included in the study. Identification of Enterococcus species was preliminary 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 like ampicillin/ penicillin, tetracycline, ciprofloxacin, levofloxacin, vancomycin, teicoplanin, linzolid, fosfomycin and nitrofurantoin by Kirby Bauer disc diffusion method and minimum inhibitory concentration (MIC) by VITEK 2 Compact. MIC for fosfomycin was done by E-test method. Interpretation of susceptibility was done according to the Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines. During the period of 6 months (from January to June 2018) there were 194 isolates of Enterococcus spp. from 2732 urine samples showing a prevalence of 7.1%. Among these 194 isolates there were 148 Enterococcus faecalis, 40 Enterococcus faecium, 2 Enterococcus casseliflavus, 2 Enterococcus gallinarum and 2 Enterococcus avium. All isolates were highly susceptible to vancomycin, teicoplanin, linezolid and fosfomycin. There were total of 8 (4.12%) isolates of vancomycin resistant enterococcus. Resistance to ampicillin and high level gentamicin was significantly related in Enterococcus faecium. Fosfomycin is a highly susceptible for urinary enterococcus isolates. However, larger prospective in vivo studies are required to determine the efficacy.

Influence of Oral Anaerobic Bacteria on Hematopoietic Stem Cell Transplantation Patients: Oral Mucositis and General Condition

ObjectiveOral mucositis (OM) caused by infection facilitated by myelosuppression and immunosuppression can be controlled through oral care. We investigated changes in oral anaerobic bacterial flora during the onset of OM with hematopoietic stem cell transplantation (HSCT). MethodsThis study included 19 patients who underwent HSCT. All received professional oral care before initiating the preparative regimen. We assessed OM, oral health and obtained microbial samples from the oral cavity during 5 assessment points: before initiating the preparative regimen; the day before HSCT (day 1); and at 7, 14, and 30 days after HSCT. Microbial species were identified by using a mass spectrometer. ResultsThe number of patients with serious OM increased initially after HSCT and decreased thereafter. Many Streptococcus species were identified before HSCT, but these gradually decreased and were replaced by coagulase-negative staphylococci. An increase in Candida species after HSCT and the identification of Enterococcus species were significantly associated with OM. Nutritional status recovery and prognosis were significantly worse in patients who developed OM. ConclusionsTo the best of our knowledge, this study is the first which shows that anaerobic bacteria were identified in patients' oral flora before and after HSCT by using a mass spectrometer. These results indicate that Enterococcus species and Candida species may have been associated with OM. OM affected the patients' improvement in nutritional status and their prognosis. We concluded that it is important to provide more complete oral care instructions and interventions to prevent these bacterial infections.

Pitfalls in the identification of Enterococcus species and the detection of vanA and vanB genes.

The aims were to assess the performance of Vitek 2 in identifying enterococcal species and the implementation of GeneXpert(®) vanA/vanB PCR for the detection of vancomycin-resistant enterococci (VRE). Gram-positive cocci from clinical and environmental specimens (n=431) suspicious of being enterococci by conventional methods were evaluated by Vitek 2. This system identified 296 Enterococcus faecium, 87 Enterococcus faecalis, 10 Enterococcus villorum, 9 Enterococcus gallinarum, 9 Enterococcus durans, 5 Enterococcus casseliflavus, 1 Enterococcus spp. and 14 isolates as Non-Enterococcus. All strains were submitted to pulsed field gel electrophoresis (PFGE) analysis showing 64 banding patterns. Representative strains from each banding pattern were further characterized to species level by 16S rDNA sequencing. The misidentification rate by Vitek 2 to species level among 429 molecularly identified enterococci was 6% (26 isolates). Additionally, 372 rectal swabs were obtained from critically ill patients. They were evaluated for the presence of VRE by ChromID VRE combined with in-house PCR vs GeneXpert(®) . GeneXpert(®) showed high (>92%) sensitivity, specificity, accuracy for vanA-positive Enterococcus detection, as well as, sensitivity and specificity for vanB-positive strains. Positive predictive value for detection of vanB-positive enterococci by GeneXpert(®) vanA/vanB was low (30%). GeneXpert(®) showed the same efficacy as ChromID VRE in detecting vanA-positive enterococci, but lower for vanB-gene detection. The study shows that even though the performance of Vitek 2 Advanced Expert System was good in identifying enterococci to species level, it is important to verify results by a molecular method when phenotypic findings are discordant with epidemiologic patterns. Furthermore, GeneXpert(®) vanA/vanB PCR and ChromID VRE combined with in-house PCR were applied in rectal samples for the detection of VRE colonization among critically ill patients. GeneXpert(®) showed an excellent performance in detecting vanA-positive enterococci, but false-positive results for vanB-gene detection render its application problematic in departments with high incidence of vanB-positive enterococci.

Isolation and species identification of enterococci from clinical specimen with their antimicrobial susceptibility pattern in a tertiary care hospital, Bangladesh

Isolation and species identification of enterococci from clinical specimen with their antimicrobial susceptibility pattern in a tertiary care hospital, Bangladesh

Antibiotic Resistance and Prevalence of Enterococcus Spp. and Escherichia Coli Isolated from Bryndza Cheese

The study aimed at determining the prevalence antibiotic resistance of species – identified enterococci and Escherichia (E.) coli isolated from typical fresh Slovak cheese, bryndza. Antibiotic resistance of enterococci was determined by disk diffusion method. Of isolated enterococci, 240 were obtained from bryndza cheese. The first two decimal dilutions from 24 bryndza cheese samples purchased at supermarkets in Košice (0.1 mL) were spread on the surface of Slanetz and Bartley agar and incubated for 48±2 h at 37±1°C. Species identification of enterococci and E. coli was detected by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) based on bacterial protein profiling. The following species of enterococci were identified by MALDI-TOF MS: Enterococcus (Ent.) faecalis (22 strains), Ent. faecium (18 strains), Ent. sacharolyticus (6 strains), Ent. gilvus (4 strains), Ent. durans (9 strains), and Ent. casseliflavus (6 strains). All of the 45 E. coli strains and 74 strains of enterococci identified by MALDI-TOF MS were determined for occurrence of blaTEM, blaSHV and blaCTX-M genes. The results of our study suggest that the highest resistance of enterococci was on tetracycline (29.73%) and any resistance was recorded on vancomycin (0%). The highest multidrug-resistance was recorded on two antibiotics (32.43%). Neither one isolate of enterococci was resistant to all 6 antibiotics used in the experiment. In total, 19 (42.22%) E. coli were found to be producers of extended-spectrum β-lactamase.

Neonatal Piglet Diarrhoea Associated with Enteroadherent Enterococcus hirae

Neonatal porcine diarrhoea of uncertain aetiology is an increasing problem in several countries. The aim of the present study was to investigate the unexpected finding of enteroadherent cocci in the small intestine of piglets selected for necropsy examination from six herds (18 diarrhoeic piglets and 11 healthy controls). Gross and microscopical lesions were characterized and selected intestinal sections were further examined by immunohistochemistry for expression of active caspase-3. The enteroadherent bacterium was characterized in situ by Gram staining, ultrastructural imaging, fluorescence in-situ hybridization (FISH) and 16S rRNA gene analysis. Species identification of enterococci from intestinal cultures was performed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for one diarrhoeic and one control animal per herd. Gross changes were mild. Microscopically, small intestinal colonization by gram-positive cocci was observed in diarrhoeic animals only and was accompanied by villus atrophy (4/18) and mild epithelial lesions (10/18), including increased apoptosis of enterocytes. Transmission electron microscopy revealed coccoid bacteria adjacent to the epithelium, but without effacement of microvilli. 16S rRNA gene analysis yielded a sequence identical to Enterococcus hirae and FISH identified the enteroadherent bacteria as Enterococcus spp. in all colonized animals. The proportion of bacterial isolates identified as E. hirae by MALDI-TOF MS analysis was significantly higher (P = 0.0138) in diarrhoeic pigs. Species identification was confirmed by species-specific polymerase chain reaction for one E. hirae isolate per herd. These isolates were further tested for antimicrobial susceptibility, which indicated decreased susceptibility to ciprofloxacin for one isolate (minimum inhibitory concentration >4 mg/l). These findings suggested that neonatal porcine diarrhoea was associated with small intestinal colonization by E. hirae accompanied by mucosal lesions.

Species identification of enterococci by biochemical test and molecular-genetic methods

The aim of this study was comparison different methods of species identification of enterococci. One hundred and fifty three suspected colonies were isolated from milk and dairy products (cheeses from cow´s, ewe´s and goat´s milk). On the bases of their growth on BEA agar, microscopic characteristic, results of Gram staining, catalase test and PYRAtest was thirty four isolates assigned to the genus Enterococcus. These isolates were identified by commercial biochemical test EN-COCCUS. 52.9% of them were included in species E. faecalis, 29.4% in E. faecium, 14.7% in E. durans and 2.9% in E. group III. This group includes 3 species: E. durans, E. hirae, E. faecalis asaccharolytic var. Then 16S rRNA sequencing nucleotide of all isolates was realized. Results of sequencing were compared with NCBI database. Only 14.7% of isolates were in 100% accordance. One from them was species E. durans and others were designated as E. faecium. For 20.6% of detected isolates was in accordance with more reference strains. Other isolates were identical with reference strain on 99%. For verification of all results species-specific PCR was used and 52.9% isolates were identified as species E. faecalis, 32.4% as E. faecium and 14.7% as E. durans. Strains belonging to the species E. faecalis were identified the most reliable by all used methods.

Faecal enterococci from camels in Tunisia: species, antibiotic resistance and virulent genes

Enterococci species are commensal microorganisms found in the gastrointestinal tract of animals and humans, being commonly isolated from faeces, water, plants, soil and food products, among others (Aarestrup and others 2000, Mannu and others 2003, Abriouel and others 2008). Enterococci are also important human pathogens being frequently implicated in human infections. These microorganisms present a high capacity of acquisition of antibiotic resistance mechanisms through horizontal gene transfer (Hammerum and others 2010). Of special relevance is the acquisition by enterococci of vancomycin-resistant genes, and the emergence of these resistant isolates in animals is being associated to the use of avoparcin in the past as an animal growth-promoter in some countries (Hammerum and others 2010). It is important to characterise the resistance and virulence trait characteristics of enterococci borne in different animals that could come in contact with human beings, and also to identify the species and clones circulating within animal ecosystems. Toward these aims, this study has been focused in order to study antibiotic resistance and presence of virulent genes in enterococci recovered from faecal samples of camels in Tunisia, and to determine the genetic diversity among the predominant species detected by pulsed-field gel electrophoresis (PFGE). To our knowledge, this is the first study that analyses the diversity and the characteristics of faecal enterococci in camels. Faecal samples of 100 camels (one sample per animal) from different regions of Tunisia (north, centre and south) were collected in this study. Samples were diluted and seeded in Slanetz-Bartley agar plates and they were incubated for 48 hours at 37°C. Phenotypic identification at the genus level of recovered isolates was based on Gram stain, bile-aesculin and hypersalin tests. Identification of Enterococcus species …

Prevalence of hospital acquired enterococci infections in two primary-care hospitals in Osogbo, Southwestern Nigeria

Enterococci are opportunistic bacteria that become pathogenic when they colonize niches where they are not normally found. Of recent, they have become major cause of nosocomial infections, especially of the bloodstream, urinary tract and surgical sites. The aim of this study is to determine the point-prevalence rate of human enterococci infections among hospitalized patients in Osogbo, Nigeria. The study was conducted between January and June 2009 in two primary-care hospitals in Osogbo and involved a total of 118 patients who developed clinical evidence of infection at least 48 hours after hospital admission. Appropriate clinical samples were collected from the patients after an informed consent and cultured for isolation/biochemical identification of Enterococcus species at the Bacteriology Laboratory of Ladoke Akintola University of Technology, Osogbo using standard microbiological methods. There were 525 hospital admissions within the time frame of the study of which 118 (22.5%) developed hospital acquired infection (HAI); 58 (49.2%) of which cultured positive for bacterial pathogens. Enterococci were isolated from infective focus in 7 patients, giving a prevalence rate of hospital-acquired enterococci infection of 5.9%. Two species of Enterococcus were identified; Enterococcus faecalis from urinary tract infection (UTI) and surgical site infection (SSI) of 6 (85.7%) patients and Enterococcus faecium from UTI in 1 (14.3%) patient. Other bacteria recovered from other infective foci were Klebsiella spp 31.0%, Pseudomonas spp 20.7%, Staphylococcus aureus 17.2%, Escherichia coli 12.1%, Staphylococcus epidermidis 3.4%, Streptococcus pneumoniae 1.7% and Serratia spp 1.7%. All the enterococci isolates were multiply antibiotic resistant, and 42.9% were vancomycin-resistant enterococci (VRE) with the VRE strains showing resistance to wider range of antibiotics than the vancomycin-sensitive strains. Other Gram-positive and Gram negative bacterial isolates also demonstrated multiple resistance to all commonly available antibiotics in this community except E. coli and Pseudomonas spp which were relatively sensitive to ciprofloxacin and ceftazidime. This limited study demonstrated a high prevalence rate of multiple antibiotic resistant enterococci infections among hospitalized patients in this environment. There is need for systematic surveillance of hospitals for enterococci infections; prudent use and rational prescription of antibiotics and stringent measures to reduce the prevalence rate by health education on infection control measures such as isolation, cleaning, disinfection and sterilization.

O105 Evaluation of a rapid test panel, the API Strep 20, the BD Phoenix and VITEK 2 automated instruments, and Raman spectroscopy for species identification of Enterococci

O105 Evaluation of a rapid test panel, the API Strep 20, the BD Phoenix and VITEK 2 automated instruments, and Raman spectroscopy for species identification of Enterococci

Anomalies in species identification of enterococci from veterinary sources using a commercial biochemical identification system.

A commercial biochemical panel ID kit was used to identify presumptive enterococci isolates of veterinary or agricultural origin obtained during different steps of culture. Fifty isolates identified as enterococci using a genus PCR assay were tested for genus and species identification using the BBL Crystal Identification Gram-Positive ID kit (Becton Dickinson, Sparks, MD, USA). Following sub-culture of the isolates three times, 59% agreement with the original panel ID was obtained. After four and six sub-cultures, percentage agreement increased to 61 and 64%, respectively. Nineteen of the 50 cultures were identified as both Enterococcus faecalis and E. faecium. As a result of the variability between speciation of isolates following re-culture, additional methods for speciation are warranted. This study suggests that the identification of the genus and species of non-human enterococcal isolates can vary greatly during successive passages when using this kit.

Metodología clásica y molecular en la identificación de especies de Enterococcus spp

Enterococcus is a bacterial genus with low virulence. However, in the last years, the importance of some enterococcus species as nosocomial pathogens has increased, specially due to their resistance to some antimicrobial. To identify enterococcus strains using classical biochemical techniques and genomic amplification with Polymerase Chain Reaction (PCR). Three hundred and five enterococcus strains, isolated between 1996 and 1999, from different clinical specimens in hospitals and other centers of the VIIIth Region of Chile, were studied. The isolates were identified, to the species level, according to the scheme proposed by Carvalho et al. Identification of some strains was confirmed by PCR. Eighty nine percent of isolates were identified as E foecalis, 10.2% as E foecium and 3.3% as other species. PCR is a fast and promising technique, useful in the identification of Enterococcus species.

Rapid group and species identification of enterococci by means of tests with pooled phages.

SUMMARY Preliminary observations are reported on the use of phage pools for the group and species diagnosis of enterococci together in one test. Three principal pools were used, namely: (1) pool of 20 phages for group diagnosis, (2) pool of 17 phages for Streptococcus faecalis species diagnosis and (3) pool of 3 phages for S. faecium diagnosis. By this method, 171 of 175 strains of enterococci isolated in the clinical laboratory (97.7%) were identified. A collection of standard group D strains showed different sensitivities according to species. The separate pools of phages for S. faecalis and for S. faecium can be used to distinguish between members of these two species, but this test is at present rather less sensitive than the test with the 20-phage pool.