scholarly journals Enterococci populations of a metropolitan river after an extreme flood event: prevalence, persistence and virulence determinants

2017 ◽  
Vol 15 (5) ◽  
pp. 684-694
Author(s):  
Nicole M. Masters ◽  
Aaron Wiegand ◽  
Jasmin M. Thompson ◽  
Tara L. Vollmerhausen ◽  
Eva Hatje ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Virulence Genes ◽  
Species Level ◽  
Flood Event ◽  
Recreational Water ◽  
Virulence Determinants ◽  
Extreme Flood ◽  
High Prevalence ◽  
Biochemical Fingerprinting ◽  
Multiple Antibiotics

We investigated the prevalence, persistence and virulence determinants of enterococci populations in water samples collected over three rounds following an extreme flood event in a metropolitan river. Enterococci (n = 482) were typed using the high resolution biochemical fingerprinting method (PhP typing) and grouped into common (C) or single (S) biochemical phenotypes (BPTs). In all, 23 C-BPTs (72.6% of isolates) were found across the sites. A representative isolate of each C-BPT was identified to the species level and tested for the presence of seven virulence genes (VGs), biofilm formation and resistance to 14 antibiotics. The enterococci concentrations in samples collected during the first two rounds were above national recreational water guidelines. By round three, enterococci concentrations decreased significantly (P < 0.05). However, 11 C-BPTs (55.5% of isolates) persisted across all sampling rounds. E. casseliflavus and E. mundtii were the most common enterococci populations comprising of >57% of all isolates. Ten of the 11 most dominant C-BPTs were resistant to multiple antibiotics and harboured one or more VGs. The high prevalence of antibiotic resistance and VGs among enterococci isolates in this catchment not only provides them with niche advantages but also poses a risk to public health.

scholarly journals Assessing the population dynamics of Escherichia coli in a metropolitan river after an extreme flood event

2016 ◽  
Vol 15 (2) ◽  
pp. 196-208 ◽  
Author(s):  
Nicole M. Masters ◽  
Aaron Wiegand ◽  
Jasmin M. Thompson ◽  
Tara L. Vollmerhausen ◽  
Eva Hatje ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Population Dynamics ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Wastewater Treatment Plants ◽  
Vero Cells ◽  
Flood Event ◽  
Typing Method ◽  
E Coli ◽  
Extreme Flood

We investigated Escherichia coli populations in a metropolitan river after an extreme flood event. Between nine and 15 of the 23 selected sites along the river were sampled fortnightly over three rounds. In all, 307 E. coli were typed using the PhP typing method and were grouped into common (C) or single (S) biochemical phenotypes (BPTs). A representative from each of the 31 identified C-BPTs was tested for 58 virulence genes (VGs) associated with intestinal and extra-intestinal E. coli, resistance to 22 antibiotics, production of biofilm and cytotoxicity to Vero cells. The number of E. coli in the first sampling round was significantly (P < 0.01) higher than subsequent rounds, whereas the number of VGs was significantly (P < 0.05) higher in isolates from the last sampling round when compared to previous rounds. Comparison of the C-BPTs with an existing database from wastewater treatment plants (WWTPs) in the same catchment showed that 40.6% of the river isolates were identical to the WWTP isolates. The relatively high number of VGs and antibiotic resistance among the C-BPTs suggests possessing and retaining these genes may provide niche advantages for those naturalised and/or persistent E. coli populations which may pose a health risk to the community.

scholarly journals Antimicrobial resistance, virulence genes and biofilm formation in Enterococcus species isolated from milk of sheep and goat with subclinical mastitis

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259584
Author(s):  
Mona A. El-Zamkan ◽  
Hams M. A. Mohamed
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Subclinical Mastitis ◽  
Virulence Determinants ◽  
Antimicrobial Susceptibility Test ◽  
Rdna Sequencing ◽  
Dairy Animals ◽  
Mastitic Milk

This study is designed to discuss the antimicrobial resistance, virulence determinants and biofilm formation capacity of Enterococcus spp. isolated from milk of sheep and goat with subclinical mastitis in Qena, Egypt. The obtained isolates were identified by the VITEK2 system and 16S rDNA sequencing as E. faecalis, E. faecium, E. casseliflavus and E. hirae. Overall, E. faecalis and E. faecium were the dominant species recovered from mastitic milk samples. The antimicrobial susceptibility test evidenced multidrug resistance of the isolates against the following antimicrobials: oxacillin (89.2.%), followed by vancomycin (75.7%) and linezolid (70.3%). Also, most of these isolates (73%) could form biofilms. For example, 18.9% of Enterococcus strains formed strong biofilm, whereas 32.4% of isolates formed moderate biofilm and 21.6% of isolates formed weak biofilm. The most prevalent resistance genes found in our isolates were blaZ (54%), vanA (40%), ermB (51.4%), tetM (13.5%) and optrA (10.8%). Moreover, asa1 (37.8%), cylA (42.3%), gelE (78.4%), esp (32.4%), EF3314(48.6%) and ace (75.5%) were the most common virulence genes. A significant correlation was found between biofilm formation, multidrug resistance and virulence genes of the isolates. This study highlights several aspects of virulence and harmfulness of Enterococcus strains isolated from subclinical mastitic milk, which necessitates continuous inspection and monitoring of dairy animals.

scholarly journals CRISPR-cas system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of Enterococcus faecalis

2019 ◽  
Author(s):  
Pourya Gholizadeh ◽  
Mohammad Aghazadeh ◽  
Reza Ghotaslou ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Tahereh Pirzadeh ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Virulence Determinants ◽  
Root Canals ◽  
Causative Agents ◽  
Life Threatening ◽  
Selective Forces ◽  
Hospital Acquired

Abstract Introduction Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- cas is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of E. faecalis .Methods and materials Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as efaA , esp , cylA , hyl , gelE , ace , ebpR , and asa1 .Results Biofilm formation, and gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was ace , which was followed by efaA , whereas cylA was the least identified. The presence of CRISPR1- cas , orphan CRISPR2 and CRISPR3- cas was determined in 13%, 55.3% and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canals isolates. An inverse significant correlation was found between CRISPR- cas loci, esp and gelE , while direct correlations were observed in the case of cylA , hyl , gelE (among CRISPR-loci 1 and 3), asa1 , ace , biofilm formation, and hemolysis activity.Conclusion Findings, therefore, indicate that CRISPR- cas might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits.

scholarly journals CRISPR-cas system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of Enterococcus faecalis

2019 ◽  
Author(s):  
Pourya Gholizadeh ◽  
Mohammad Aghazadeh ◽  
Reza Ghotaslou ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Tahereh Pirzadeh ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Virulence Determinants ◽  
Root Canals ◽  
Causative Agents ◽  
Life Threatening ◽  
Selective Forces ◽  
Hospital Acquired

Abstract Introduction Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- cas is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of E. faecalis .Methods and materials Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as efaA , esp , cylA , hyl , gelE , ace , ebpR , and asa1 .Results Biofilm formation, and gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was ace , which was followed by efaA , whereas cylA was the least identified. The presence of CRISPR1- cas , orphan CRISPR2 and CRISPR3- cas was determined in 13%, 55.3% and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canals isolates. An inverse significant correlation was found between CRISPR- cas loci, esp and gelE , while direct correlations were observed in the case of cylA , hyl , gelE (among CRISPR-loci 1 and 3), asa1 , ace , biofilm formation, and hemolysis activity.Conclusion Findings, therefore, indicate that CRISPR- cas might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits.

scholarly journals Study of Antifungal Susceptibility, Virulence Genes and Biofilm Formation in Candida albicans

2019 ◽  
Vol 13 (1) ◽  
pp. 241-248
Author(s):  
Raghdaa Shrief ◽  
Maysaa El Sayed Zaki ◽  
Eman Mousa El-Sehsah ◽  
Sara Ghaleb ◽  
Mohamed Mofreh
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Antifungal Susceptibility ◽  
Molecular Study ◽  
Antifungal Resistance ◽  
Antifungal Drugs ◽  
Molecular Technique ◽  
Microdilution Method ◽  
High Prevalence

Background: Candida albicans has emerged as an important nosocomial pathogen. The morbidity and mortality associated with this pathogen are related to the presence of virulence genes and antifungal resistance. The objective of the present study was to investigate the prevalence of antifungal resistance, biofilm formation and some virulence genes such as ALS1, PLB1, INT1, SAP1 and HWP1, among clinical isolates of Candida albicans recovered from immunocompromised patients. Methods: The study included one hundred C. albicans isolates identified phenotypically and by a molecular technique using Polymerase Chain Reaction (PCR). The identified C. albicans was further subjected to antifungal study by the microdilution method, biofilm study and molecular study for virulence genes by PCR. Results: The resistance to antifungal drugs, fluconazole, caspofungin and itraconazole was 8% for each of them and for amphotericin B, it was 9%. The prevalence of the studied virulence genes was HWP1 77%, INT1 72%, ALS1 65%, SAP1 65% and PLB1 52%. The biofilm capacity was identified by the microplate method in 58% of C. albicans. The OD was intense in 20 isolates, moderate in 21 isolates and mild in 17 isolates. There was a statistically significant increase in the prevalence of the studied virulence genes INT1, ALS1, HWP1, SAP1 and PLB1 among biofilm forming C. albicans as compared to non-biofilm forming isolates (P=0.0001). Additionally, the resistance to fluconazole, itraconazole and caspofungin was statistically, significantly higher in C. albicans with the capacity to form biofilm as compared to non-biofilm forming C. albicans. Conclusion: The present study highlights the prevalence of resistance to antifungal drugs among C. albicans which are not uncommon. Moreover, there was a high prevalence of INT1, ALS1, HWP1, SAP1 and PLB1 genes in C. albicans. The resistance to antifungal drugs was common among isolates with the capacity to form the biofilm. There was an association between the biofilm formation and virulence genes.

scholarly journals CRISPR-cas system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of Enterococcus faecalis

2020 ◽  
Author(s):  
Pourya Gholizadeh ◽  
Mohammad Aghazadeh ◽  
Reza Ghotaslou ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Tahereh Pirzadeh ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Virulence Determinants ◽  
Root Canals ◽  
Causative Agents ◽  
Life Threatening ◽  
Selective Forces ◽  
Hospital Acquired

Abstract Introduction Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- cas is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of E. faecalis . Methods and materials Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as efaA , esp , cylA , hyl , gelE , ace , ebpR , and asa1 . Results Biofilm formation, and gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was ace , which was followed by efaA , whereas cylA was the least identified. The presence of CRISPR1- cas , orphan CRISPR2 and CRISPR3- cas was determined in 13%, 55.3% and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canals isolates. An inverse significant correlation was found between CRISPR- cas loci, esp and gelE , while direct correlations were observed in the case of cylA , hyl , gelE (among CRISPR-loci 1 and 3), asa1 , ace , biofilm formation, and hemolysis activity. Conclusion Findings, therefore, indicate that CRISPR- cas might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits.

Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

2020 ◽  
Vol 26 (24) ◽  
pp. 2807-2816 ◽  
Author(s):  
Yun Su Jang ◽  
Tímea Mosolygó
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Biofilm ◽  
Experimental Investigations ◽  
Resistant Bacteria ◽  
Salmonella Spp ◽  
Food Borne ◽  
High Prevalence ◽  
Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

scholarly journals Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

2021 ◽  
Vol 22 (11) ◽  
pp. 5905
Author(s):  
Olivia M. Grünzweil ◽  
Lauren Palmer ◽  
Adriana Cabal ◽  
Michael P. Szostak ◽  
Werner Ruppitsch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Marine Mammals ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Healthcare Sector ◽  
Whole Genome ◽  
E Coli ◽  
High Prevalence ◽  
Lactamase Gene ◽  
Sequence Types

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

Assessing invertebrate response to an extreme flood event at a regional scale utilizing past survey data

Limnology ◽  
2021 ◽  
Vol 22 (2) ◽  
pp. 169-177
Author(s):  
Yo Miyake ◽  
Hiroto Makino ◽  
Kenta Fukusaki
Keyword(s):  
Survey Data ◽  
Regional Scale ◽  
Flood Event ◽  
Extreme Flood
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