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Scientific Reports Jun 2024Nasally colonized staphylococci carry antibiotic resistance genes and may lead to serious opportunistic infections. We are investigating nasal carriage of Staphylococcus...
Nasally colonized staphylococci carry antibiotic resistance genes and may lead to serious opportunistic infections. We are investigating nasal carriage of Staphylococcus aureus and Staphylococci other than S. aureus (SOSA) among young volunteers in Egypt to determine their risk potential. Nasal swabs collected over 1 week in June 2019 from 196 volunteers were cultured for staphylococcus isolation. The participants were interviewed to assess sex, age, general health, hospitalization and personal hygiene habits. Identification was carried out using biochemical tests and VITEK 2 automated system. Disc diffusion and minimum inhibitory concentration tests were performed to determine antibiotic susceptibility. Screening for macrolide resistance genes (ermA, ermB, ermC, ermT and msrA) was performed using polymerase chain reaction. Thirty four S. aureus and 69 SOSA were obtained. Multi-drug resistance (MDR) was detected among most staphylococcal species, ranging from 30.77% among S. hominis to 50% among S. epidermidis. Phenotypic resistance to all tested antibiotics, except for linezolid, was observed. Susceptibility to rifampicin, vancomycin and teicoplanin was highest. ermB showed the highest prevalence among all species (79.41% and 94.2% among S. aureus and SOSA, respectively), and constitutive macrolide-lincosamide-streptogramin B (MLS) resistance was equally observed in S. aureus and SOSA (11.11% and 16.22%, respectively), whereas inducible MLS resistance was more often found in S. aureus (77.78% and 43.24%, respectively). The species or resistance level of the carried isolates were not significantly associated with previous hospitalization or underlying diseases. Although over all colonization and carriage of resistance genes are within normal ranges, the increased carriage of MDR S. aureus is alarming. Also, the fact that many macrolide resitance genes were detected should be a warning sign, particularly in case of MLS inducible phenotype. More in depth analysis using whole genome sequencing would give a better insight into the MDR staphylococci in the community in Egypt.
Topics: Humans; Egypt; Female; Male; Staphylococcus; Microbial Sensitivity Tests; Staphylococcal Infections; Anti-Bacterial Agents; Adult; Phenotype; Young Adult; Genotype; Staphylococcus aureus; Drug Resistance, Multiple, Bacterial; Adolescent
PubMed: 38937465
DOI: 10.1038/s41598-024-60924-8 -
International Microbiology : the... Jun 2024This study aimed to isolate and characterize biological and genomic features of a phage infecting Enterococcus faecalis. The phage was isolated from environmental water...
This study aimed to isolate and characterize biological and genomic features of a phage infecting Enterococcus faecalis. The phage was isolated from environmental water and temperature and pH stability, one-step growth curve, and multiplicity of infection (MOI) were determined. Whole genome sequencing (WGS) and structural and functional annotations were performed. Its antibiofilm activity was also evaluated. The optimal MOI was 0.01, the latency period was 5 min, and the burst size was 202 plaque forming unit (PFU). High phage survival rates were observed at between pH 4-10 and temperatures between 4-50 °C. WGS and Transmission electron microscopy (TEM) showed that it was an Efquatrovirus representing siphovirus morphotype respectively. It was named as Enterococcus phage Ef212 and has a linear 40,690 bp double-stranded DNA with 45.3% G + C content (GenBank accession number: OR052631). BACPHLIP tool demonstrated that Enterococcus phage Ef212 is a lytic phage (88%). A total of 80 open reading frames (ORFs) were found and there were no antibiotic resistance genes, pathogenicity, virulence genes, or tRNAs in the phage genome. It was diverged from the most similar phages (identity, 88.35%; coverage, 89%) by phylogenetic analysis. Phage Ef212 shared a large part of its genome (60/80) with several other phages, yet some unique parts were found in their genomes. Host range analysis showed that phage Ef212 showed lytic activity against vancomycin-resistant and vancomycin-susceptible E. faecalis clinical isolates. This novel phage Ef212 showed the ability to inhibit and reduce the biofilm formation by around 42% and 38%, respectively. The biological and genomic features indicate that having an effective antibacterial activity, phage Ef212 seemed a promising therapeutic and biocontrol agent.
PubMed: 38935199
DOI: 10.1007/s10123-024-00547-1 -
Stereotactic and Functional Neurosurgery Jun 2024Infections related to deep brain stimulation (DBS) can lead to discontinuation of the treatment and increased morbidity. Various measures of reducing infection rates...
INTRODUCTION
Infections related to deep brain stimulation (DBS) can lead to discontinuation of the treatment and increased morbidity. Various measures of reducing infection rates have been proposed in the literature, but scientific consensus is lacking. The aim of this study was to report a 26-year single center experience of DBS infections and provide recommendations for the prevention and management of them.
METHODS
The retrospective analysis consisted of 978 DBS surgeries performed at Oulu University Hospital (OUH) from 1997 to 2022. This included 342 primary or reimplantations of DBS electrodes and 559 primary or reimplantations of implantable pulse generator (IPG). Infections within approximately 1 year after the surgery without secondary cause were considered surgical-site infections (SSIs). χ2 test was used to compare infection rates before and after 2013, when the systematic implementation of infection prevention measures was started.
RESULTS
A total of 35 DBS implants were found to be infected. The number of SSIs was 30, of which 29 were originally operated in OUH leading to a center-specific infection rate of 3.1%. Of the SSIs, 17.2% occurred after IPG replacement. Staphylococcus aureus was found in 75.0% of cultures and 32.1% were mixed infections. The treatment of SSIs included aggressive surgical revision combined with cefuroxime and vancomycin antibiotics, as most patients in the initial conservative treatment group eventually required surgical revision. A statistically significant difference in infection rates before and after the implementation of preventative measures was not observed (risk ratio 2.20, 95% confidence interval 0.94-5.75, p = 0.051), despite over two-fold difference in the incidence of SSIs.
CONCLUSION
Our findings show that the rates of surgical infections are low in modern DBS, but due to their serious consequences, preventative measures should be implemented. We highlight that mixed infections should be accounted for in the antibiotic selection. Furthermore, our treatment recommendation includes aggressive surgical revision combined with antibiotic treatment.
PubMed: 38934170
DOI: 10.1159/000539188 -
Infection and Drug Resistance 2024To analyze the antibiotic resistance profile, virulence genes, and molecular typing of () strains isolated in skin and soft tissue infections at the First Affiliated...
OBJECTIVE
To analyze the antibiotic resistance profile, virulence genes, and molecular typing of () strains isolated in skin and soft tissue infections at the First Affiliated Hospital, Gannan Medical University, to better understand the molecular epidemiological characteristics of .
METHODS
In 2023, 65 strains were isolated from patients with skin and soft tissue infections. Strain identification and susceptibility tests were performed using VITEK 2 and gram-positive bacteria identification cards. DNA was extracted using a DNA extraction kit, and all genes were amplified using polymerase chain reaction. Multilocus sequence typing (MLST) was used for molecular typing.
RESULTS
In this study, of the 65 strains were tested for their susceptibility to 16 antibiotics, the highest resistance rate to penicillin G was 95.4%. None of the staphylococcal isolates showed resistance to ceftaroline, daptomycin, linezolid, tigecycline, teicoplanin, or vancomycin. was the most prevalent virulence gene (100%) in strains isolated in skin and soft tissue infections, followed by (98.5%). Statistical analyses showed that the resistance rates of methicillin-resistant isolates to various antibiotics were significantly higher than those of methicillin-susceptible isolates. Fifty sequence types (STs), including 44 new ones, were identified by MLST.
CONCLUSION
In this study, the high resistance rate to penicillin G and the high carrying rate of virulence gene and of S.aureus were determine, and 44 new STs were identified, which may be associated with the geographical location of southern Jiangxi and local trends in antibiotic use. The study of the clonal lineage and evolutionary relationships of in these regions may help in understanding the molecular epidemiology and provide the experimental basis for pathogenic bacteria prevention and treatment.
PubMed: 38933775
DOI: 10.2147/IDR.S465951 -
Pharmaceutics May 2024Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen...
Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product's appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process.
PubMed: 38931852
DOI: 10.3390/pharmaceutics16060730 -
Molecules (Basel, Switzerland) Jun 2024The discovery and investigation of new natural compounds with antimicrobial activity are new potential strategies to reduce the spread of antimicrobial resistance. The...
The discovery and investigation of new natural compounds with antimicrobial activity are new potential strategies to reduce the spread of antimicrobial resistance. The presented study reveals, for the first time, the promising antibacterial potential of two fractions from mucus with an MW < 20 kDa and an MW > 20 kDa against five bacterial pathogens- 1085, 1897, 8691, 3915, and 8754. Using de novo sequencing, 16 novel peptides with potential antibacterial activity were identified in a fraction with an MW < 20 kDa. Some bioactive compounds in a mucus fraction with an MW > 20 kDa were determined via a proteomic analysis on 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and bioinformatics. High homology with proteins and glycoproteins was found, with potential antibacterial activity in mucus proteins named aspernin, hemocyanins, H-lectins, and L-amino acid oxidase-like protein, as well as mucins (mucin-5AC, mucin-5B, mucin-2, and mucin-17). We hypothesize that the synergy between the bioactive components determined in the composition of the fraction > 20 kDa are responsible for the high antibacterial activity against the tested pathogens in concentrations between 32 and 128 µg/mL, which is comparable to vancomycin, but without cytotoxic effects on model eukaryotic cells of . Additionally, a positive effect, by reducing the levels of intracellular oxidative damage and increasing antioxidant capacity, on cells was found for both mucus extract fractions of . These findings may serve as a basis for further studies to develop a new antibacterial agent preventing the development of antibiotic resistance.
Topics: Anti-Bacterial Agents; Mucus; Microbial Sensitivity Tests; Peptides; Enterococcus faecalis; Enterococcus faecium; Bacillus cereus; Animals; Propionibacterium acnes; Salmonella enterica
PubMed: 38930951
DOI: 10.3390/molecules29122886 -
Medicina (Kaunas, Lithuania) May 2024: Enterococci are typically found in a healthy human gastrointestinal tract but can cause severe infections in immunocompromised patients. Such infections are treated...
: Enterococci are typically found in a healthy human gastrointestinal tract but can cause severe infections in immunocompromised patients. Such infections are treated with antibiotics. This study addresses the rising concern of antimicrobial resistance (AMR) in Enterococci, focusing on the prevalence of vancomycin-resistant enterococcus (VRE) strains. : The pilot study involved 140 Enterococci isolates collected between 2021 and 2022 from two multidisciplinary hospitals (with and without local therapeutic drug monitoring protocol of vancomycin) in Latvia. Microbiological assays and whole genome sequencing were used. AMR gene prevalence with resistance profiles were determined and the genetic relationship and outbreak evaluation were made by applying core genome multi-locus sequence typing (cgMLST). : The acquired genes and mutations were responsible for resistance against 10 antimicrobial classes, including 25.0% of isolates expressing resistance to vancomycin, predominantly of the B type. Genetic diversity among and isolates was observed and seven potential outbreak clusters were identified, three of them containing sequence types ST6, ST78 and ST80. The prevalence of vancomycin resistance was highest in the hospital without a therapeutic drug-monitoring protocol and in . Notably, a case of linezolid resistance due to a mutation was documented. : The study illustrates the concerning prevalence of multidrug-resistant Enterococci in Latvian hospitals, showcasing the rather widespread occurrence of vancomycin-resistant strains. This highlights the urgency of implementing efficient infection control mechanisms and the need for continuous VRE surveillance in Latvia to define the scope and pattern of the problem, influencing clinical decision making and planning further preventative measures.
Topics: Humans; Latvia; Anti-Bacterial Agents; Pilot Projects; Enterococcus; Microbial Sensitivity Tests; Gram-Positive Bacterial Infections; Vancomycin-Resistant Enterococci; Drug Resistance, Bacterial; Multilocus Sequence Typing; Whole Genome Sequencing
PubMed: 38929467
DOI: 10.3390/medicina60060850 -
Bioengineering (Basel, Switzerland) May 2024Although the incidence of infections in orthopedic surgeries, including periprosthetic surgeries, remains low at approximately 1-2%, the number of surgeries and the...
Although the incidence of infections in orthopedic surgeries, including periprosthetic surgeries, remains low at approximately 1-2%, the number of surgeries and the incidence of drug-resistant bacteria is increasing. The cost and morbidity associated with revision surgeries are huge. More effective drug combinations and delivery methods are urgently needed. In this paper, three anti-infective drugs (vancomycin, rifampicin, and silver sulfadiazine) have been jointly and effectively electrospun in thin (0.1 mm) flexible nanofiber mats of either poly (methyl methacrylate) (PMMA) or poly (lactic-co-glycolic acid) (PLGA). The inclusion of poly (ethylene glycol) (PEG) enabled optimal drug release with a reduced water contact angle for wetting. The controlled release of these three agents from 20% PEG (/ to polymer)-blended PMMA or PLGA nanofiber mats may allow for the prophylactical prevention of implant-related infections or provide methods to treat orthopedic infections at the time of revision surgeries. These combinations of drugs provide excellent additive or synergistic antibiotic action against a broader spectrum of bacteria than each drug alone.
PubMed: 38927765
DOI: 10.3390/bioengineering11060529 -
Antibiotics (Basel, Switzerland) Jun 2024species (formerly known as ) are Gram-positive filamentous bacteria in the family Promicromonosporaceae and are more commonly found in sewage and soil. The present... (Review)
Review
species (formerly known as ) are Gram-positive filamentous bacteria in the family Promicromonosporaceae and are more commonly found in sewage and soil. The present study aimed to identify all the published cases of species infections in the literature, describe the epidemiological, clinical, and microbiological characteristics, and provide data regarding its antimicrobial resistance, treatment, and outcomes. A narrative review was performed based on a PubMed and Scopus database search. In total, 38 studies provided data on 40 patients with infections by these species. The median age of patients was 52.5 years, and 55% were male. The most common infection types were bacteremia, infective endocarditis (IE), osteoarticular infections, peritoneal dialysis-associated peritonitis, and endophthalmitis. Antimicrobial resistance to vancomycin and the combination of trimethoprim and sulfamethoxazole was minimal, and vancomycin was the most commonly used antimicrobial for treating these infections. Overall mortality was minimal for all infections, except for bacteremia and IE, which carried high mortality rates.
PubMed: 38927228
DOI: 10.3390/antibiotics13060562 -
Antibiotics (Basel, Switzerland) Jun 2024Antimicrobial peptides (AMPs) are being explored as a potential strategy to combat antibiotic resistance due to their ability to reduce susceptibility to antibiotics....
Antimicrobial peptides (AMPs) are being explored as a potential strategy to combat antibiotic resistance due to their ability to reduce susceptibility to antibiotics. This study explored whether the [RW] peptide mode of action is bacteriostatic or bactericidal using modified two-fold serial dilution and evaluating the synergism between gentamicin and [RW] against () and methicillin-resistant (MRSA) by a checkered board assay. [RW] exhibited bactericidal activity against bacterial isolates (MBC/MIC ≤ 4), with a synergistic effect with gentamicin against (FICI = 0.3) but not against MRSA (FICI = 0.75). Moreover, we investigated the mechanism of action of [RW] against MRSA by applying biophysical assays to evaluate zeta potential, cytoplasmic membrane depolarization, and lipoteichoic acid (LTA) binding affinity. [RW] at a 16 mg/mL concentration stabilized the zeta potential of MRSA -31 ± 0.88 mV to -8.37 mV. Also, [RW] at 2 × MIC and 16 × MIC revealed a membrane perturbation process associated with concentration-dependent effects. Lastly, in the presence of BODIPY-TR-cadaverine (BC) fluorescence dyes, [RW] exhibited binding affinity to LTA comparable with melittin, the positive control. In addition, the antibacterial activity of [RW] against MRSA remained unchanged in the absence and presence of LTA, with an MIC of 8 µg/mL. Therefore, the [RW] mechanism of action is deemed bactericidal, involving interaction with bacterial cell membranes, causing concentration-dependent membrane perturbation. Additionally, after 30 serial passages, there was a modest increment of MRSA strains resistant to [RW] and a change in antibacterial effectiveness MIC [RW] and vancomycin by 8 and 4 folds with a slight change in Levofloxacin MIC 1 to 2 µg/mL. These data suggest that [RW] warrants further consideration as a potential AMP.
PubMed: 38927221
DOI: 10.3390/antibiotics13060555