The aim of this study is to evaluate opportunistic pathogenic bacteria of the genus Pseudomonas in anthropogenically impacted bathing waters, primarily focusing on bathing ponds. The findings include the detection of these bacteria, their susceptibility to selected antibiotics, and the determination of the Exotoxin A (exoA) gene using PCR method. P. aeruginosa was present in most samples, albeit in low concentrations (1-14 CFU/100 mL). The presence of P. otitidis, which is associated with ear infection, in this type of bathing water, was not rare (up to 90 CFU/100 mL). This species would not be detected by the standard methods, including tests on acetamid medium, used for P. aeruginosa in water. The isolated strains of P. otitidis lack the exoA gene and exhibited higher resistance to meropenem compared to P. aeruginosa.
- MeSH
- ADP Ribose Transferases genetics MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Drug Resistance, Bacterial MeSH
- Bacterial Proteins genetics MeSH
- Bacterial Toxins genetics MeSH
- Pseudomonas aeruginosa Exotoxin A MeSH
- Exotoxins genetics MeSH
- Virulence Factors genetics MeSH
- Microbial Sensitivity Tests * MeSH
- Water Microbiology * MeSH
- Polymerase Chain Reaction MeSH
- Pseudomonas * genetics isolation & purification classification drug effects MeSH
- Ponds * microbiology MeSH
- Publication type
- Journal Article MeSH
Background: Stenotrophomonas infections are becoming more widespread around the world and can be counted as a "newly emerging pathogen of concern". The present study aimed to detect a variety of Stenotrophomonas species (S. maltophilia) using specific 23S rRNA gene primers and investigate their multi-drug resistance potential.Methods: This study includes 375 clinical samples from different clinical sources 175 from males and 200 from females collected from Mosul City Hospital. Identification of Stenotrophomonas was conducted through multiple steps including culturing methods, molecular methods in addition to some biochemical tests 11(3%) of isolates belonged to Stenotrophomonas maltophilia. The isolates understudy were tested for their ability to resist 10 different antibiotics using the Kirby-Bauer disk diffusion method.Results: The resistance rate to amoxicillin, gentamicin, and amikacin (100%), cefixime (91%), imipenem (64%), meropenem(55%), Azithromycin (36%), nalidixic acid and trimethoprim (18%), ciprofloxacin(0%). The virulence factors of S. maltophilia siderophores were found in all (11) isolates belonging to S. maltophilia at a percentage (100%). The result of PCR assay using specific primers designed for detecting 23S rRNA genes of S. maltophilia gives amplification for 11 isolates from 14 suspected isolates. Nucleic acid sequencing for the 23S rRNA gene shows that all isolates belong to S. maltophilia with a similarity rate (91-99) in NCBI.Because the 23S rRNA gene sequence in Stenotrophomonas species shows more variety in this location this study used specific 23S rRNA gene primers to identify S. maltophilia.Conclusion: The study used phenotypic and molecular diagnostic techniques to isolate the bacteria, including the S rRNA23 gene. The results emphasize the need for increased vigilance in hospitals to prevent the spread of antibiotic-resistant bacteria and the development of new treatment strategies.
- MeSH
- Drug Resistance, Microbial genetics MeSH
- Drug Resistance, Bacterial genetics MeSH
- Cross Infection genetics microbiology MeSH
- Clinical Studies as Topic methods MeSH
- Humans MeSH
- Microbiological Techniques methods MeSH
- Polymerase Chain Reaction methods MeSH
- RNA, Ribosomal, 23S * analysis genetics MeSH
- Siderophores analysis genetics MeSH
- Stenotrophomonas maltophilia * genetics pathogenicity MeSH
- Check Tag
- Humans MeSH
INTRODUCTION: Despite being implicated in a wide spectrum of community- and healthcare-acquired infections, anaerobes have not yet been incorporated into systematic surveillance programs in Europe. METHODS: We conducted a multicentre retrospective observational study analysing all anaerobic strains isolated from blood cultures in 44 European Hospital Centres over a 4-y period (2020-2023). Diagnostic approach, epidemiology, and antimicrobial susceptibility according to EUCAST v. 15.0 were investigated. RESULTS: Our study included 14,527 anaerobes, most of which were Gram-positive (45%) or Gram-negative (40%) bacilli. MALDI-TOF coupled to mass spectrometry was the most widely used tool for species identification (98%). Antimicrobial susceptibility testing was performed in the vast majority of centres, using mostly gradient diffusion strip (77%) and disk diffusion (45%) methods according to EUCAST guidelines. The most prevalent species were Cutibacterium acnes (18.7%), Bacteroides fragilis (16.3%), Clostridium perfringens (5.3%), Bacteroides thetaiotaomicron (4.2%), Fusobacterium nucleatum (3.5%), and Parvimonas micra (3.4%). C. acnes showed high resistance to benzylpenicillin (18%), clindamycin (39%), and imipenem (19% and 13% by MIC methods and disk diffusion, respectively). B. fragilis showed high resistance to amoxicillin/clavulanate (24%), piperacillin/tazobactam (22% and 14% by MIC methods and disk diffusion, respectively), clindamycin (22% by both MIC methods and disk diffusion), meropenem (13%), and metronidazole (10%, only by disk diffusion). A similar resistance pattern was observed in B. thetaiotaomicron, Bacteroides ovatus, and Parabacteroides distasonis. C. perfringens showed high resistance to clindamycin (69% and 45% by MIC methods and disk diffusion, respectively), while benzylpenicillin and metronidazole maintained over 90% activity. F. nucleatum showed high resistance to benzylpenicillin (11%), while Fusobacterium necrophorum showed alarming rates of resistance to clindamycin (12%), meropenem (16%) and metronidazole (11%). CONCLUSIONS: This study presented an up-to-date analysis of the diagnostics and epidemiology of anaerobic bacteria in Europe, providing insights for future comparative analyses and the development of antimicrobial diagnostic and management strategies, as well as the optimization of current antibiotic treatments.
- MeSH
- Bacteria, Anaerobic * drug effects isolation & purification classification MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Bacterial Infections * epidemiology diagnosis microbiology MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Retrospective Studies MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Observational Study MeSH
- Geographicals
- Europe MeSH
BACKGROUND: Multidrug-resistant (MDR) bacteria pose a significant challenge to the treatment of infectious diseases. Of particular concern are members of the Klebsiella pneumoniae species complex (KpSC), which are frequently associated with hospital-acquired infections and have the potential to spread outside hospitals via wastewaters. In this study, we aimed to investigate the occurrence and phylogenetic relatedness of MDR KpSC from patients with urinary tract infections (UTIs), hospital sewage, municipal wastewater treatment plants (mWWTPs) and surface waters and to evaluate the clinical relevance of the KpSC subspecies. METHODS: A total of 372 KpSC isolates resistant to third-generation cephalosporins and/or meropenem were collected from patients (n = 130), hospital sewage (n = 95), inflow (n = 54) and outflow from the mWWTPs (n = 63), river upstream (n = 13) and downstream mWWTPs (n = 17) from three cities in the Czech Republic. The isolates were characterized by antimicrobial susceptibility testing and whole-genome sequencing (Illumina). The presence of antibiotic resistance genes, plasmid replicons and virulence-associated factors was determined. A phylogenetic tree and single nucleotide polymorphism matrix were created to reveal the relatedness between isolates. RESULTS: The presence of MDR KpSC isolates (95%) was identified in all water sources and locations. Most isolates (99.7%) produced extended-spectrum beta-lactamases encoded by blaCTX-M-15. Resistance to carbapenems (5%) was observed mostly in wastewaters, but carbapenemase genes, such as blaGES-51 (n = 10), blaOXA-48 (n = 4), blaNDM-1 (n = 4) and blaKPC-3 (n = 1), were found in isolates from all tested locations and different sources except rivers. Among the 73 different sequence types (STs), phylogenetically related isolates were observed only among the ST307 lineage. Phylogenetic analysis revealed the transmission of this lineage from patients to the mWWTP and from the mWWTP to the adjacent river and the presence of the ST307 clone in the mWWTP over eight months. We confirmed the frequent abundance of K. pneumoniae (K. pneumoniae sensu stricto and K. pneumoniae subsp. ozaenae) in patients suffering from UTIs. K. variicola isolates formed only a minor proportion of UTIs, and K. quasipneumoniae was not found among UTIs isolates; however, these subspecies were frequently observed in hospital sewage communities during the first sampling period. CONCLUSION: This study provides evidence of the transmission and persistence of the ST307 lineage from UTIs isolates via mWWTPs to surface waters. Isolates from UTIs consisted mostly of K. pneumoniae. Other isolates of KpSC were observed in hospital wastewaters, which implies the impact of sources other than UTIs. This study highlights the influence of urban wastewaters on the spread of MDR KpSC to receiving environments.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Bacterial Proteins genetics MeSH
- beta-Lactamases * genetics MeSH
- Phylogeny * MeSH
- Klebsiella Infections * microbiology epidemiology MeSH
- Urinary Tract Infections microbiology epidemiology MeSH
- Cross Infection microbiology epidemiology MeSH
- Klebsiella pneumoniae * drug effects genetics isolation & purification classification MeSH
- Humans MeSH
- Microbial Sensitivity Tests * MeSH
- Drug Resistance, Multiple, Bacterial * MeSH
- Hospitals * MeSH
- Wastewater * microbiology MeSH
- Sewage microbiology MeSH
- Whole Genome Sequencing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are major causes of hospital-acquired infections and sepsis. Due to increasing antibiotic resistance, new treatments are needed. Mesenchymal stem cells (MSCs) have antimicrobial effects, which can be enhanced by preconditioning with antibiotics. This study investigated using antibiotics to strengthen MSCs against MRSA and P. aeruginosa. MSCs were preconditioned with linezolid, vancomycin, meropenem, or cephalosporin. Optimal antibiotic concentrations were determined by assessing MSC survival. Antimicrobial effects were measured by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antimicrobial peptide (AMP) gene expression. Optimal antibiotic concentrations for preconditioning MSCs without reducing viability were 1 μg/mL for linezolid, meropenem, and cephalosporin and 2 μg/mL for vancomycin. In MIC assays, MSCs preconditioned with linezolid, vancomycin, meropenem, or cephalosporin inhibited MRSA or P. aeruginosa growth at lower concentrations than non-preconditioned MSCs (p ≤ 0.001). In MBC assays, preconditioned MSCs showed enhanced bacterial clearance compared to non-preconditioned MSCs, especially when linezolid and vancomycin were used against MRSA (p ≤ 0.05). Preconditioned MSCs showed increased expression of genes encoding the antimicrobial peptide genes hepcidin and LL-37 compared to non-preconditioned MSCs. The highest hepcidin expression was seen with linezolid and vancomycin preconditioning (p ≤ 0.001). The highest LL-37 expression was with linezolid preconditioning (p ≤ 0.001). MSCs' preconditioning with linezolid, vancomycin, meropenem, or cephalosporin at optimal concentrations enhances their antimicrobial effects against MRSA and P. aeruginosa without compromising viability. This suggests preconditioned MSCs could be an effective adjuvant treatment for antibiotic-resistant infections. The mechanism may involve upregulation of AMP genes.
- MeSH
- Anti-Bacterial Agents pharmacology therapeutic use MeSH
- Antimicrobial Peptides MeSH
- Cephalosporins pharmacology MeSH
- Hepcidins pharmacology therapeutic use MeSH
- Humans MeSH
- Linezolid pharmacology therapeutic use MeSH
- Meropenem pharmacology therapeutic use MeSH
- Methicillin-Resistant Staphylococcus aureus * MeSH
- Mesenchymal Stem Cells * MeSH
- Microbial Sensitivity Tests MeSH
- Pseudomonas aeruginosa genetics MeSH
- Staphylococcal Infections * microbiology MeSH
- Vancomycin MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
This study aimed to characterize the impact of extracorporeal membrane oxygenation (ECMO) on the pharmacokinetics (PK) of meropenem in neonates and children and to provide recommendations for meropenem dosing in this specific population of patients. Therapeutic drug monitoring (152 meropenem plasma concentrations) data from 45 patients (38 received ECMO) with a body weight (BW) of 7.88 (3.62-11.97) kg (median (interquartile range)) and postnatal age of 3 (0-465) days were collected. The population PK analysis was performed using NONMEM V7.3.0. Monte Carlo simulations were performed to assess the probability of target achievement (PTA) for 40% of time the free drug remained above the minimum inhibitory concentration (fT > MIC) and 100% fT > MIC. BW was found to be a significant covariate for the volume of distribution (Vd) and clearance (CL). Additionally, continuous renal replacement therapy (CRRT) was associated with a two-fold increase in Vd. In the final model, the CL and Vd for a typical patient with a median BW of 7.88 kg that was off CRRT were 1.09 L/h (RSE = 8%) and 3.98 L (14%), respectively. ECMO did not affect meropenem PK, while superimposed CRRT significantly increased Vd. We concluded that current dosing regimens provide acceptably high PTA for MIC ≤ 4 mg/L for 40% fT > MIC, but individual dose adjustments are needed for 100% fT > MIC.
- Publication type
- Journal Article MeSH
OBJECTIVES: The objective of this study was to develop a population pharmacokinetic model of meropenem in a heterogeneous population of patients with a serious bacterial infection in order to propose dosing optimisation leading to improved achievement of the pharmacokinetic/pharmacodynamic (PK/PD) target. METHODS: A total of 174 meropenem serum levels obtained from 144 patients during therapeutic drug monitoring were analysed using a non-linear mixed-effects modelling approach and Monte Carlo simulation was then used to compare various dosing regimens in order to optimise PK/PD target attainment. RESULTS: The meropenem volume of distribution of the patient population was 54.95 L, while clearance started at 3.27 L/hour and increased by 0.91 L/hour with each 1 mL/s/1.73 m2 of estimated glomerular filtration rate. Meropenem clearance was also 0.31 L/hour higher in postoperative patients with central nervous system infection. Meropenem administration by continuous infusion showed a significantly higher probability of attaining the PK/PD target than a standard 30 min infusion (95.3% vs 49.5%). CONCLUSIONS: A daily meropenem dose of 3 g, 6 g and 10.5 g administered by continuous infusion was shown to be accurate for patients with moderate to severe renal impairment, normal renal function to mild renal impairment and augmented renal clearance, respectively.
- MeSH
- Anti-Bacterial Agents * pharmacokinetics administration & dosage MeSH
- Bacterial Infections * drug therapy MeSH
- Models, Biological * MeSH
- Adult MeSH
- Infusions, Intravenous MeSH
- Middle Aged MeSH
- Humans MeSH
- Meropenem * pharmacokinetics administration & dosage MeSH
- Monte Carlo Method MeSH
- Drug Monitoring methods MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Dose-Response Relationship, Drug MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Systemically administered antibiotics are thought to penetrate the wounds more effectively during negative pressure wound therapy (NPWT).To test this hypothesis total and free antibiotic concentrations were quantified in serum and wound exudate. METHODS: UHPLC-MS/MS methods were developed and validated for the determination of ceftazidime, cefepime, cefotaxime, cefuroxime, cefazolin, meropenem, oxacillin, piperacillin with tazobactam, clindamycin, ciprofloxacin, sulfamethoxazole/trimethoprim (cotrimoxazole), gentamicin, vancomycin, and linezolid. The unbound antibiotic fraction was obtained by ultrafiltration using a Millipore Microcon-30kda Centrifugal Filter Unit. Analysis was performed on a 1.7-μm Acquity UPLC BEH C18 2.1 × 100-mm column with a gradient elution. RESULTS: The validation was performed for serum, exudates and free fractions. For all matrices, requirements were met regarding linearity, precision, accuracy, limit of quantitation, and matrix effect. The coefficient of variation was in the range of 1.2-13.6%.and the recovery 87.6-115.6%, respectively. Among the 29 applications of antibiotics thus far, including vancomycin, clindamycin, ciprofloxacin, oxacillin, cefepime, cefotaxime, cotrimoxazole, and gentamicin, total and free antibiotic concentrations in serum and exudate were correlated. CONCLUSION: This method can accurately quantify the total and free concentrations of 16 antibiotics. Comparison of concentration ratios between serum and exudates allows for monitoring individual antibiotics' penetration capacity in patients receiving NPWT.
- MeSH
- Anti-Bacterial Agents MeSH
- Cefepime MeSH
- Cefotaxime MeSH
- Chromatography, Liquid methods MeSH
- Ciprofloxacin MeSH
- Exudates and Transudates MeSH
- Gentamicins MeSH
- Wound Infection * MeSH
- Clindamycin MeSH
- Trimethoprim, Sulfamethoxazole Drug Combination MeSH
- Humans MeSH
- Oxacillin MeSH
- Sternotomy MeSH
- Tandem Mass Spectrometry methods MeSH
- Negative-Pressure Wound Therapy * MeSH
- Vancomycin MeSH
- Chromatography, High Pressure Liquid methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Delftia acidovorans je gramnegatívna aeróbna tyčinkovitá baktéria. Ochorenia u ľudí vyvoláva len raritne. Spôsobuje predovšetkým nozokomiálne nákazy, opisované častejšie u imunokompromitovaných pacientov v rámci všetkých vekových skupín. V odbornej literatúre bolo v posledných rokoch publikovaných niekoľko prípadov, v rámci ktorých sa uplatnila pri vzniku infekcií postihujúcich rôzne orgánové systémy. S ohľadom na častú rezistenciu voči aminoglykozidom a polymyxínom, ktoré mnohokrát slúžia ako záchranné liečivá pri komplikovaných infekciách gramnegatívnymi baktériami, nastáva nevyhnutne potreba jej rýchlej identifikácie s následne správne zvolenou liečbou. V kazuistike opisujeme prípad pacientky s rozsiahlym fluidothoraxom hrudníka v dôsledku infekcie baktériou Delftia acidovorans a sumarizujeme aktuálne dostupné informácie o infekciách spôsobených týmto zriedkavým patogénom.
Delftia acidovorans is a Gram-negative, aerobic, rod-shaped bacterium which causes infections in humans only rarely. It causes mostly nosocomial infections, described more frequently in immunocompromised patients across all age groups. In recent years, several cases involving this bacterium in infections affecting various organ systems have been published in the literature. With regard to its common resistance to aminoglycosides and polymyxins, which oftentimes serve as salvage therapy for complicated Gram-negative bacterial infections, there is inevitably a need for its quick identification followed by a correctly chosen treatment. This article describes a case of a patient with extensive pleural effusion due to Delftia acidovorans infection and also summarizes the currently available information on infections caused by this rare pathogen.
- MeSH
- Delftia acidovorans isolation & purification MeSH
- Empyema, Pleural * diagnosis etiology therapy MeSH
- Comorbidity MeSH
- Middle Aged MeSH
- Humans MeSH
- Meropenem administration & dosage therapeutic use MeSH
- Microbiological Techniques methods MeSH
- Pleural Effusion diagnosis therapy MeSH
- Tomography, X-Ray Computed methods MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
The objective of this study was to assess the susceptibility of cefiderocol against multidrug-resistant carbapenemase-producing and nonproducing bacteria. The panel comprised 182 isolates of the order Enterobacterales, and 40 strains of Pseudomonas aeruginosa. Antimicrobial susceptibility testing has been performed using broth microdilution method according to the European Committee on Antimicrobial Susceptibility Testing recommendations. Mass spectrometry matrix-assisted laser desorption/ionization-time of flight mass spectrometry and carbapenemase-producing test were used to verify the presence of carbapenemases in clinical isolates. The genetic expression of single carbapenemases (blaKPC, blaOXA-48, blaNDM, blaVIM, blaIMP, blaGES) was determined by real-time polymerase chain reaction. Cefiderocol exhibited a good activity against the majority of strains tested in this study. Altogether, growth of 81.9% (n = 149) strains of the order Enterobacterales and 77.5% (n = 31) of P. aeruginosa isolates were inhibited at minimal inhibitory concentration (MIC) ≤2 mg/L. Values MIC50/MIC90 were 0.5/8 mg/L for enterobacteria, and 1/8 mg/L for P. aeruginosa. One isolate (Klebsiella pneumoniae) harboring two carbapenemases (blaOXA-48, blaNDM) had cefiderocol MIC 0.5 mg/L. In enterobacteria resistant to cefiderocol, blaNDM carbapenemase prevailed (43.3%, n = 29), followed by blaOXA-48 (31.3%, n = 21) and blaKPC (4.5%, n = 3). blaIMP (n = 8) and blaVIM (n = 1) metallo-β-lactamases dominated in cefiderocol-resistant P. aeruginosa (n = 9) isolates. Very good susceptibility (100%) to this drug showed blaGES-positive strains of P. aeruginosa (n = 8) and isolates resistant to meropenem without confirmed carbapenemase gene (n = 10). In this study, cefiderocol demonstrated potent activity against important nosocomial pathogens, therefore, therapeutic options of this drug against multidrug-resistant bacteria should be considered.
