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Brazilian Oral Research 2024This study aimed to identify and characterize the antimicrobial susceptibility profile of bacteria found in primary endodontic infections in the teeth of patients...
This study aimed to identify and characterize the antimicrobial susceptibility profile of bacteria found in primary endodontic infections in the teeth of patients treated at the Dental Clinic of the University of Ribeirão Preto, São Paulo, Brazil. From September to December 2019, samples were obtained from 21 patients with primary endodontic infections. The collections were carried out in triplicate using paper cones placed close to the total length of the root canal. Bacterial isolation was performed in Brain Heart Infusion agar, Blood agar, and other selective culture media cultured at 37°C for up to 48 h under aerobiosis and microaerophilic conditions. The bacterial species were identified using the Vitek 2 automated system. The disk diffusion method on agar Müeller-Hinton was used to assess antimicrobial susceptibility with the recommended antimicrobials for each identified bacterial species. A total of 49 antibiotics were evaluated. Fifteen of the 21 samples collected showed bacterial growth, and 17 bacterial isolates were found. There were 10 different bacterial species identified: Enterococcus faecalis (four isolates), Streptococcus mitis/oralis (three isolates), Streptococcus anginosus (three isolates) being the most common, followed by Staphylococcus epidermidis, Enterococcus faecium, Streptococcus constellatus, Streptococcus alactolyticus, Enterobacter cloacae, Klebsiella variicola, and Providencia rettgeri (one isolate of each species). The analysis demonstrated significant susceptibility to most of the tested antibiotics. However, some Enterococcus isolates resisted the antibiotic's erythromycin, ciprofloxacin, and tetracycline. A Staphylococcus epidermidis isolate was characterized as multidrug-resistant. Five Streptococcus isolates were non-susceptible to all antibiotics tested.
Topics: Humans; Agar; Microbial Sensitivity Tests; Brazil; Anti-Bacterial Agents; Enterococcus faecium; Culture Media; Anti-Infective Agents
PubMed: 38597544
DOI: 10.1590/1807-3107bor-2024.vol38.0024 -
Canadian Journal of Veterinary Research... Apr 2024Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern...
Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern Quebec to: i) estimate the prevalence of 11 bee pathogens; ii) assess the agreement between beekeeper suspicion of a disease and laboratory detection of the causative pathogen; and iii) explore the association between observed clinical signs and pathogen detection in a colony. A total of 242 colonies in 31 apiaries owned by 15 beekeepers was sampled in August 2017. The prevalence of detection was estimated as 48% for colonies and 93% for apiaries. The apparent prevalence of colonies infected by spp. and was estimated as 40% and 21%, respectively. At least 180 colonies were tested by polymerase chain reaction (PCR) for deformed wing virus (DWV), acute-Kashmir-Israeli complex (AKI complex), and black queen cell virus (BQCV), which were detected in 33%, 9%, and 95% of colonies, respectively. , and were not detected. Varroasis was suspected by beekeepers in 14 of the 15 beekeeping operations in which the mite was detected. However, no correlation was found between suspected European foulbrood and detection of or between suspected nosemosis and detection of spp. Colony weakness was associated with spore counts of at least 0.5 × 10 per bee. was more frequently detected in colonies showing scattered brood.
Topics: Bees; Animals; Quebec; Cross-Sectional Studies; Prevalence; RNA Viruses; Enterococcaceae
PubMed: 38595951
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy May 2024Phage therapy has (re)emerged as a serious possibility for combating multidrug-resistant bacterial infections, including those caused by vancomycin-resistant strains....
Phage therapy has (re)emerged as a serious possibility for combating multidrug-resistant bacterial infections, including those caused by vancomycin-resistant strains. These opportunistic pathogens belong to a specific clonal complex 17, against which relatively few phages have been screened. We isolated a collection of 21 virulent phages growing on these vancomycin-resistant isolates. Each of these phages harbored a typical narrow plaquing host range, lysing at most 5 strains and covering together 10 strains of our panel of 14 clinical isolates. To enlarge the host spectrum of our phages, the Appelmans protocol was used. We mixed four out of our most complementary phages in a cocktail that we iteratively grew on eight naive strains from our panel, of which six were initially refractory to at least three of the combined phages. Fifteen successive passages permitted to significantly improve the lytic activity of the cocktail, from which phages with extended host ranges within the species could be isolated. A single evolved phage able to kill up to 10 of the 14 initial strains was obtained, and it barely infected nearby species. All evolved phages had acquired point mutations or a recombination event in the tail fiber genetic region, suggesting these genes might have driven phage evolution by contributing to their extended host spectra.
Topics: Enterococcus faecium; Bacteriophages; Vancomycin-Resistant Enterococci; Host Specificity; Phage Therapy; Gram-Positive Bacterial Infections; Vancomycin Resistance; Vancomycin; Humans; Anti-Bacterial Agents
PubMed: 38591854
DOI: 10.1128/aac.01439-23 -
JPMA. the Journal of the Pakistan... Mar 2024To investigate the isolation rates, antimicrobial resistance rates, minimum inhibitory concentration values of antimicrobial agents, and clonal relationships of...
OBJECTIVES
To investigate the isolation rates, antimicrobial resistance rates, minimum inhibitory concentration values of antimicrobial agents, and clonal relationships of Enterococcus faecalis and Enterococcus faeciumdue to the relocation of a hospital to a newly constructed building.
METHODS
The comparative, prospective study was conducted at adult general intensive care units of the Mus State Hospital, Mus, Turkey, in two phases; before the relocation from January 25 to December 1, 2014, and after the relocation from February 10 to May 24, 2015. Rectal swab samples were collected 72 hours post-hospitalisation. Identification of Enterococcus faecalis and Enterococcus faeciumisolates was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and antimicrobial resistance with minimum inhibitory concentration values was detected with Vitek 2 system. The clonal relatedness among the strains was investigated by pulsed-field gel electrophoresis. Data was analysed using SPSS 23.
RESULTS
Of the 69 patients, 37(53.62%) were related to pre-relocation phase; 20(54.1%) females and 17(45.9%) males with mean age 62.81±21.71 years. There were 32(46.37%) patients in the post-relocation phase; 13(40.6%) females and 19(59.4%) males with mean age 62.69±21.35 years (p>0.05). Of the 84 enterococci strains isolated, 51(60.7%) were Enterococcus faecium; 28(55%) before relocation and 23(45%) after relocation (p=0.77). The remaining 33(39.3%) isolates were Enterococcus faecalis; 16(48.5%) before relocation and 17(51.5%) after relocation (p=0.73). Multiple strains were located in 7(18.9%) patients before relocation and in 7(21.9%) after relocation. In 1(3.1%) patient after relocation, 2(8.7%) Enterococcus faecium isolates with different resistance and pulsed-field gel electrophoresis patterns were detected. There were no significant differences between the isolation and antibiotic resistance rates before and after relocation (p>0.05), and a clonal relation between the isolates was not detected (p>0.05). Decreased minimum inhibitory concentration values were noted for some antibiotics.
CONCLUSIONS
Clonal relationship between the isolates and change in the rates of isolation and antimicrobial resistance of Enterococcus faecalis and Enterococcus faecium was not detected due to relocation. Minimum inhibitory concentration values could be used to reveal relocation-related changes in isolates obtained from patients hospitalised in intensive care units.
Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Male; Middle Aged; Anti-Bacterial Agents; Drug Resistance, Bacterial; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Hospitals; Microbial Sensitivity Tests; Prospective Studies
PubMed: 38591280
DOI: 10.47391/JPMA.8688 -
MBio May 2024Fungal resistance to commonly used medicines is a growing public health threat, and there is a dire need to develop new classes of antifungals. We previously described a...
UNLABELLED
Fungal resistance to commonly used medicines is a growing public health threat, and there is a dire need to develop new classes of antifungals. We previously described a peptide produced by , EntV, that restricts to a benign form rather than having direct fungicidal activity. Moreover, we showed that one 12-amino acid (aa) alpha helix of this peptide retained full activity, with partial activity down to the 10aa alpha helix. Using these peptides as a starting point, the current investigation sought to identify the critical features necessary for antifungal activity and to screen for new variants with enhanced activity using both biofilm and infection assays. First, the short peptides were screened for residues with critical activity by generating alanine substitutions. Based on this information, we used synthetic molecular evolution (SME) to rationally vary the specific residues of the 10aa variant in combination to generate a library that was screened to identify variants with more potent antifungal activity than the parent template. Five gain-of-function peptides were identified. Additionally, chemical modifications to the peptides to increase stability, including substitutions of D-amino acids and hydrocarbon stapling, were investigated. The most promising peptides were additionally tested in mouse models of oropharyngeal and systemic candidiasis where their efficacy in preventing infection was demonstrated. The expectation is that these discoveries will contribute to the development of new therapeutics in the fight against antimicrobial resistant fungi.
IMPORTANCE
Since the early 1980s, the incidence of disseminated life-threatening fungal infections has been on the rise. Worldwide, and species are among the most common agents causing these infections. Simultaneously, with this rise of clinical incidence, there has also been an increased prevalence of antifungal resistance, making treatment of these infections very difficult. For example, there are now strains of auris that are resistant to all three classes of currently used antifungal drugs. In this study, we report on a strategy that allows for the development of novel antifungal agents by using synthetic molecular evolution. These discoveries demonstrate that the enhancement of antifungal activity from naturally occurring peptides is possible and can result in clinically relevant agents that have efficacy in multiple models as well as the potential for broad-spectrum activity.
Topics: Antifungal Agents; Animals; Mice; Candida albicans; Biofilms; Candidiasis; Enterococcus faecalis; Microbial Sensitivity Tests; Caenorhabditis elegans; Bacterial Proteins; Disease Models, Animal; Peptides
PubMed: 38587425
DOI: 10.1128/mbio.00570-24 -
Zoological Research May 2024The gut microbiota significantly influences host physiology and provides essential ecosystem services. While diet can affect the composition of the gut microbiota, the...
The gut microbiota significantly influences host physiology and provides essential ecosystem services. While diet can affect the composition of the gut microbiota, the gut microbiota can also help the host adapt to specific dietary habits. The carrion crow ( ), an urban facultative scavenger bird, hosts an abundance of pathogens due to its scavenging behavior. Despite this, carrion crows infrequently exhibit illness, a phenomenon related to their unique physiological adaptability. At present, however, the role of the gut microbiota remains incompletely understood. In this study, we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing, China. Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria (75.51%) and Firmicutes (22.37%). Significant differences were observed in the relative abundance of among groups, highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows. Subsequently, isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against infection. Results showed that down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin 6 (IL-6), prevented colonization, and regulated the composition of gut microbiota in mice, thereby modulating the host's immune regulatory capacity. Therefore, exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior, offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.
Topics: Animals; Mice; Crows; Enterococcus faecalis; Ecosystem; RNA, Ribosomal, 16S; Feeding Behavior; Birds
PubMed: 38583936
DOI: 10.24272/j.issn.2095-8137.2023.320 -
Nature Communications Apr 2024Bacteriophage therapy is a promising approach to address antimicrobial infections though questions remain regarding the impact of the immune response on clinical...
Bacteriophage therapy is a promising approach to address antimicrobial infections though questions remain regarding the impact of the immune response on clinical effectiveness. Here, we develop a mouse model to assess phage treatment using a cocktail of five phages from the Myoviridae and Siphoviridae families that target Vancomycin-Resistant Enterococcus gut colonization. Phage treatment significantly reduces fecal bacterial loads of Vancomycin-Resistant Enterococcus. We also characterize immune responses elicited following administration of the phage cocktail. While minimal innate responses are observed after phage administration, two rounds of treatment induces phage-specific neutralizing antibodies and accelerate phage clearance from tissues. Interestingly, the myophages in our cocktail induce a more robust neutralizing antibody response than the siphophages. This anti-phage immunity reduces the effectiveness of the phage cocktail in our murine model. Collectively, this study shows phage-specific immune responses may be an important consideration in the development of phage cocktails for therapeutic use.
Topics: Humans; Animals; Mice; Bacteriophages; Vancomycin; Disease Models, Animal; Myoviridae; Vancomycin-Resistant Enterococci; Anti-Bacterial Agents
PubMed: 38582763
DOI: 10.1038/s41467-024-47192-w -
The Science of the Total Environment Jun 2024Identification of methods for the standardized assessment of bacterial pathogens and antimicrobial resistance (AMR) in environmental water can improve the quality of... (Review)
Review
An analysis of culture-based methods used for the detection and isolation of Salmonella spp., Escherichia coli, and Enterococcus spp. from surface water: A systematic review.
Identification of methods for the standardized assessment of bacterial pathogens and antimicrobial resistance (AMR) in environmental water can improve the quality of monitoring and data collected, support global surveillance efforts, and enhance the understanding of environmental water sources. We conducted a systematic review to assemble and synthesize available literature that identified methods for assessment of prevalence and abundance of bacterial fecal indicators and pathogens in water for the purposes of monitoring bacterial pathogens and AMR. After screening for quality, 175 unique publications were identified from 15 databases, and data were extracted for analysis. This review identifies the most common and robust methods, and media used to isolate target organisms from surface water sources, summarizes methodological trends, and recognizes knowledge gaps. The information presented in this review will be useful when establishing standardized methods for monitoring bacterial pathogens and AMR in water in the United States and globally.
Topics: Water Microbiology; Enterococcus; Salmonella; Environmental Monitoring; Escherichia coli
PubMed: 38575025
DOI: 10.1016/j.scitotenv.2024.172190 -
BMC Microbiology Apr 2024All gastrointestinal pathogens, including Enterococcus faecalis and Enterococcus faecium, undergo adaptation processes during colonization and infection. In this study,...
BACKGROUND
All gastrointestinal pathogens, including Enterococcus faecalis and Enterococcus faecium, undergo adaptation processes during colonization and infection. In this study, we investigated by data-independent acquisition mass spectrometry (DIA-MS) two crucial adaptations of these two Enterococcus species at the proteome level. Firstly, we examined the adjustments to cope with bile acid concentrations at 0.05% that the pathogens encounter during a potential gallbladder infection. Therefore, we chose the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) as well as the secondary bile acid deoxycholic acid (DCA), as these are the most prominent bile acids. Secondly, we investigated the adaptations from an aerobic to a microaerophilic environment, as encountered after oral-fecal infection, in the absence and presence of deoxycholic acid (DCA).
RESULTS
Our findings showed similarities, but also species-specific variations in the response to the different bile acids. Both Enterococcus species showed an IC in the range of 0.01- 0.023% for DCA and CDCA in growth experiments and both species were resistant towards 0.05% CA. DCA and CDCA had a strong effect on down-expression of proteins involved in translation, transcription and replication in E. faecalis (424 down-expressed proteins with DCA, 376 down-expressed proteins with CDCA) and in E. faecium (362 down-expressed proteins with DCA, 391 down-expressed proteins with CDCA). Proteins commonly significantly altered in their expression in all bile acid treated samples were identified for both species and represent a "general bile acid response". Among these, various subunits of a V-type ATPase, different ABC-transporters, multi-drug transporters and proteins related to cell wall biogenesis were up-expressed in both species and thus seem to play an essential role in bile acid resistance. Most of the differentially expressed proteins were also identified when E. faecalis was incubated with low levels of DCA at microaerophilic conditions instead of aerobic conditions, indicating that adaptations to bile acids and to a microaerophilic atmosphere can occur simultaneously.
CONCLUSIONS
Overall, these findings provide a detailed insight into the proteomic stress response of two Enterococcus species and help to understand the resistance potential and the stress-coping mechanisms of these important gastrointestinal bacteria.
Topics: Bile Acids and Salts; Enterococcus faecalis; Enterococcus faecium; Deoxycholic Acid; Proteomics; Cholic Acid; Chenodeoxycholic Acid; Enterococcus
PubMed: 38570789
DOI: 10.1186/s12866-024-03253-0 -
MBio May 2024Penicillin-binding protein 5 (PBP5) of () is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in clade B strains...
UNLABELLED
Penicillin-binding protein 5 (PBP5) of () is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in clade B strains [ampicillin susceptible (AMP-S)], PBP5-S/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here, deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.01-0.09 µg/mL for clade B and 0.12-0.19 µg/mL for clade A strains; complementation restored parental AMP MICs. Using D344SRF (lacking ), constructs with (from a clade A1 strain) cloned upstream of and alleles resulted in modest increases in MICs to 3-8 µg/mL, while high MICs (64 µg/mL) were seen using from A1 strains. Next, using from clade B and clade A/B and B/A hybrid constructs, the presence of , even alone or in , resulted in much lower AMP MICs (3-8 µg/mL) than when was present (MICs 64 µg/mL). qRT PCR showed relatively greater expression ( = 0.007) with cloned downstream of clade A1 (MIC 128 µg/mL) vs when cloned downstream of clade B (MIC 4-16 µg/mL), consistent with results in western blots. In conclusion, we report the effect of clade A vs B on AMP MICs as well as the impact of alleles from different clades. While previously, Psr was not thought to contribute to AMP MICs in our results showed that the presence of resulted in a major decrease in AMP MICs.
IMPORTANCE
The findings of this study shed light on ampicillin resistance in clade A strains. They underscore the significance of alterations in the amino acid sequence of penicillin-binding protein 5 (PBP5) and the pivotal role of the psr region in PBP5 expression and ampicillin resistance. Notably, the presence of a full-length psrB leads to reduced PBP5 expression and lower minimum inhibitory concentrations (MICs) of ampicillin compared to the presence of a shorter psrA, regardless of the pbp5 allele involved. Additionally, clade B strains exhibit lower AMP MICs when both alleles from clades A and B are present, although it is important to consider other distinctions between clade A and B strains that may contribute to this effect. It is intriguing to note that the divergence between clade A and clade B and the subsequent evolution of heightened AMP MICs in hospital-associated strains appear to coincide with changes in and . These changes in may have resulted in an inactive Psr, facilitating increased PBP5 expression and greater ampicillin resistance. These results raise the possibility that a mimicker of PsrB, if one could be designed, might be able to lower MICs of ampicillin-resistant , thus potentially resorting ampicillin to our therapeutic armamentarium for this species.
Topics: Enterococcus faecium; Penicillin-Binding Proteins; Microbial Sensitivity Tests; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactam Resistance; Ampicillin; Genome, Bacterial
PubMed: 38564699
DOI: 10.1128/mbio.00170-24