scholarly journals Effects of artificially introduced Enterococcus faecalis strains in experimental necrotizing enterocolitis

2019 ◽  
Author(s):  
Patrick T. Delaplain ◽  
Brandon A. Bell ◽  
Jin Wang ◽  
Mubina Isani ◽  
Emily Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Necrotizing Enterocolitis ◽  
Biofilm Formation ◽  
Opportunistic Pathogens ◽  
First Feeding ◽  
Naturally Occurring ◽  
Old Rats ◽  
Artificial Introduction

AbstractEnterococcus faecalis is a ubiquitous intestinal symbiont and common early colonizer of the neonatal gut. Although colonization with E. faecalis has been previously associated with decreased NEC pathology, these bacteria have been also implicated as opportunistic pathogens. Here we characterized 21 strains of E. faecalis, naturally occurring in 4-day-old rats, for potentially pathogenic properties and ability to colonize the neonatal gut. The strains differed in hemolysis, gelatin liquefaction, antibiotic resistance, biofilm formation, and ability to activate the pro-inflammatory transcription factor NF-κB in cultured enterocytes. Only 3 strains appreciably colonized the neonatal intestine on day 4 after artificial introduction with the first feeding. The best colonizer, strain BB70, effectively displaced maternal E. faecalis and significantly increased NEC pathology. Our results show that colonization with E. faecalis may predispose neonates to NEC.

scholarly journals The Role of Biofilm Formation in Antibiotic Resistance of Bacteria Isolated from Saliva of Patients with Dental Caries

2021 ◽  
pp. 40-49
Author(s):  
Merriam Ghadhanfar Alwan ◽  
Hadeel Adil Al Rubaye ◽  
Noor Adil Abood ◽  
Hind Tahseen Ibrahem ◽  
Hamiza Bt Hamidon ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Dental Caries ◽  
Antimicrobial Resistance ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Rrna Gene ◽  
Tissue Culture Plate

Objectives: This study aim to determine the bacterial diversity, biofilm forming ability and the antimicrobial resistance of bacteria isolated from saliva of patients with dental caries conditions with the using of 16S rRNA gene sequencing technique for identification of the most virulent isolates. Methods: Isolation and identification of microorganisms were done employing standard bacteriologic techniques, followed by biofilm detection using tissue culture plate method. The strong biofilm forming isolates were selected for antibiotic susceptibility test against selected antibiotics using disk diffusion technique. In order to identify the selected isolates. The genomic DNA obtained following the extraction process were used for the amplification of the bacterial 16S rRNA gene. Results: A total of 137 bacterial isolates were obtained and identified as belonging to 21 genera. Tissue culture plate (TCP) method were employed for screening the isolates according to its biofilm forming ability, its showed that 55 (40.1%) of the total isolates were strong, 57 (41.6%) were moderate and 25 (18.3%) were weak biofilm producers. The antimicrobial susceptibility test showed the multi antibiotics resistance of the strong biofilm former isolates to the conventional antibiotics. Enterococcus faecalis isolates showed the highest biofilm formation and antibiotic resistance. The 16S rRNA gene for two of these isolates have been amplified using PCR and the product sequenced, analyzed and registered in the National Center for Biotechnology Information (NCBI) as UKMS1 and UKMS2 and the accession numbers KX960104.1 and KX960105.1 respectively. Conclusion: The study has revealed that antimicrobial resistance of bacteria isolates from saliva of patients with dental caries conditions is associated with biofilm formation. Other uncommon pathogenic bacteria were also isolated in this study as a result of the use of non-selective enrichment medium for culturing. Enterococcus faecalis isolates indicated the highest biofilm formation and antibiotic resistance.

scholarly journals Antibiotic Resistance and Biofilm Formation of Enterococcus faecalis in Patient and Environmental Samples

2015 ◽  
Vol 8 (10) ◽  
Author(s):  
Malihe Talebi ◽  
Nastaran Asghari Moghadam ◽  
Zeynab Mamooii ◽  
Mohsen Enayati ◽  
Mahnaz Saifi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Environmental Samples

scholarly journals Biofilm Formation in Acinetobacter Baumannii: Genotype-Phenotype Correlation

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1849 ◽  
Author(s):  
Cheng-Hong Yang ◽  
Pai-Wei Su ◽  
Sin-Hua Moi ◽  
Li-Yeh Chuang
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Diffusion Method ◽  
Multiple Drug ◽  
Opportunistic Pathogens ◽  
Antibiotic Resistant ◽  
Multiple Drug Resistant ◽  
Polymerase Chain ◽  
And Control

Strains of Acinetobacter baumannii are commensal and opportunistic pathogens that have emerged as problematic hospital pathogens due to its biofilm formation ability and multiple antibiotic resistances. The biofilm-associated pathogens usually exhibit dramatically decreased susceptibility to antibiotics. This study was aimed to investigate the correlation of biofilm-forming ability, antibiotic resistance and biofilm-related genes of 154 A. baumannii isolates which were collected from a teaching hospital in Taiwan. Biofilm-forming ability of the isolates was evaluated by crystal violet staining and observed by scanning electron microscopy. Antibiotic susceptibility was determined by disc diffusion method and minimum inhibitory concentration; the biofilm-related genes were screened by polymerase chain reaction. Results showed that among the 154 tested isolates, 15.6% of the clinical isolates were weak biofilm producers, while 32.5% and 45.4% of them possessed moderate and strong biofilm formation ability, respectively. The experimental results revealed that the multiple drug resistant isolates usually provided a higher biofilm formation. The prevalence of biofilm related genes including bap, blaPER-1, csuE and ompA among the isolated strains was 79.2%, 38.3%, 91.6%, and 68.8%, respectively. The results indicated that the antibiotic resistance, the formation of biofilm and the related genes were significantly correlated. The results of this study can effectively help to understand the antibiotic resistant mechanism and provides the valuable information to the screening, identification, diagnosis, treatment and control of clinical antibiotic-resistant pathogens.

scholarly journals Genomic Based Characterization of Enterococcus Spp-An Emerging Pathogen Isolated from Human Gut

2021 ◽  
Author(s):  
Zumara younus ◽  
Sagar M. Goyal ◽  
Vikash Singh ◽  
Aamer Ikram ◽  
Muhammad Imran
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Ecological Niches ◽  
Opportunistic Pathogens ◽  
Human Gut ◽  
Enterococcus Spp ◽  
Enterococcus Casseliflavus ◽  
Enterococcus Gallinarum

Abstract Background Enterococci are ubiquitous microorganisms having diverse ecological niches but mostly prominently in gastrointestinal tract of humans and animals. Production of enterocins make them used as probiotics, but in last few years their role as probiotic become ambiguous. This ambiguity in their probiotic role is related to presence of virulence factors and antibiotic resistance genes. Moreover, these virulence traits are also known to be transfer genetically which make them opportunistic pathogens in gastrointestinal track. These reports suggest serious concerns related to enterococcus before using them as probiotics. In present study Whole-genome sequencing (WGS) of Enterococcus spp was done for checking presence of resistance and virulence genes, isolated from human gut.Methods and resultsFour human origin Enterococcus spp including Enterococcus faecalis, Enterococcus casseliflavus, and two Enterococcus gallinarum were isolated from human fecal samples, further cultured on blood and MacConkey agar. Sanger sequencing was done using Applied Biosystems 3730xl DNA Analyzer. These strains were further subjected to WGS using oxford nano pore technology MinION. Raw data was analyzed using free online tool epi2me. The Comprehensive Antibiotic Resistance Database (CARD) and RAST software’s were used to look for presence of antibiotic resistance genes in these strains. Resistance determinants for clinically important antibiotics (vancomycin) and functional virulence factor genes were detected. G-view server was used for comparative genomics of all strains.Conclusion:The draft genomic sequencing of enterococcus suggested that Enterococcus faecalis, Enterococcus casseliflavus and Enterococcus gallinarum strains are opportunistic pathogens, having antibiotic resistance genes. All isolates have vancomycin resistance genes which they also expressed phenotypically. Some genes related to bacteriocin resistance were also present in E. casseliflavus and E. gallinarum.

scholarly journals Genomic and phenotypic diversity of Enterococcus faecalis isolated from endophthalmitis

2020 ◽  
Author(s):  
Gayatri Shankar Chilambi ◽  
Hayley R. Nordstrom ◽  
Daniel R. Evans ◽  
Regis P. Kowalski ◽  
Deepinder K. Dhaliwal ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Phenotypic Diversity ◽  
Medical Center ◽  
Phenotypic Variability ◽  
Comparative Genomic ◽  
Mismatch Repair Gene ◽  
Ocular Infection ◽  
First Case

ABSTRACTEnterococcus faecalis are hospital-associated opportunistic pathogens and also causative agents of post-operative endophthalmitis. Patients with enterococcal endophthalmitis often have poor visual outcomes, despite appropriate antibiotic therapy. Here we investigated the genomic and phenotypic characteristics of E. faecalis isolates collected from 13 patients treated at the University of Pittsburgh Medical Center Eye Center over 19 years. Comparative genomic analysis indicated that patients were infected with E. faecalis of diverse multi-locus sequence types (STs) previously associated with clinical, commensal, and environmental sources. We identified known E. faecalis virulence factors and antibiotic resistance genes in each genome, including genes conferring resistance to aminoglycosides, erythromycin, and tetracyclines. We assessed all isolates for their cytolysin production, biofilm formation, and antibiotic susceptibility, and observed phenotypic differences between isolates. Fluoroquinolone and cephalosporin susceptibilities were particularly variable, as were biofilm formation and cytolysin production. In addition, we found evidence of E. faecalis adaptation during recurrent endophthalmitis by identifying genetic variants that arose in sequential isolates sampled over eight-months from the same patient. We identified a mutation in the DNA mismatch repair gene mutS that was associated with a hypermutator phenotype in the final isolate from the patient, which was also more resistant to ceftazidime. Overall this study documents the genomic and phenotypic variability among E. faecalis causing endophthalmitis, as well as possible adaptive mechanisms underlying bacterial persistence during recurrent ocular infection.IMPORTANCEBacterial endophthalmitis is a sight-threatening infection of the inside of the eye. Enterococcus faecalis cause endophthalmitis occasionally, but when they do the infections are often severe. Here we investigated the genomes, antibiotic susceptibilities, and virulence-associated traits among E. faecalis collected from 13 patients with post-operative endophthalmitis. We wondered whether there were common bacterial factors that might explain why enterococcal endophthalmitis is so destructive to ocular tissues. Instead we found that E. feacalis isolated from endophthalmitis were genetically and phenotypically diverse; isolates belonged to a variety of genetic lineages and showed varying levels of antibiotic resistance and biofilm formation. We also undertook further characterization of three closely related E. faecalis isolates from a patient with recurrent endophthalmitis, and found that a hypermutator strain emerged during persistent infection. Hypermutators have been found in a variety of other infection contexts; here we describe what we believe is the first case of a hypermutator arising during ocular infection.

scholarly journals Novel Insights into Selection for Antibiotic Resistance in Complex Microbial Communities

2018 ◽  
Author(s):  
Aimee K. Murray ◽  
Lihong Zhang ◽  
Xiaole Yin ◽  
Tong Zhang ◽  
Angus Buckling ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Communities ◽  
Single Species ◽  
Dependent Manner ◽  
Opportunistic Pathogens ◽  
Antibiotic Resistant ◽  
Naturally Occurring ◽  
Selection For ◽  
Antibiotic Degradation ◽  
Dose Dependent

ABSTRACTRecent research has demonstrated selection for antibiotic resistance occurs at very low antibiotic concentrations in single species experiments, but the relevance of these findings when species are embedded in complex microbial communities is unclear. We show the strength of selection for naturally occurring resistance alleles in a complex community remains constant from low sub-inhibitory to above clinically relevant concentrations. Selection increases with antibiotic concentration before reaching a plateau where selection remains constant over a two order magnitude concentration range. This is likely to be due to cross-protection of the susceptible bacteria in the community following rapid extracellular antibiotic degradation by the resistant population, shown experimentally through a combination of chemical quantification and bacterial growth experiments. Metagenome and 16S rRNA analyses on sewage-derived bacterial communities evolved under cefotaxime exposure show preferential enrichment forblaCTX-Mgenes over all other beta-lactamase genes, as well as positive selection and co-selection for antibiotic resistant, opportunistic pathogens. These findings have far reaching implications for our understanding of the evolution of antibiotic resistance, by challenging the long-standing assumption that selection occurs in a dose-dependent manner.

Enterococcus faecalis Cell-Free Supernatant Inhibits Hyphal Morphogenesis and Biofilm Formation in Candida albicans

2018 ◽  
Vol 46 (2) ◽  
pp. 128-135
Author(s):  
Mohamed Hassan ◽  
Yasmine Tartor ◽  
Ashour Ashour ◽  
Elmowalid Elmowalid
Keyword(s):  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Cell Free Supernatant ◽  
Hyphal Morphogenesis

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

Sign in / Sign up

Export Citation Format

Share Document