Wild strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested in an experimental hyperbaric chamber to determine the possible effect of hyperbaric oxygen on the susceptibility of these strains to the antibiotics ampicillin, ampicillin + sulbactam, cefazolin, cefuroxime, cefoxitin, gentamicin, sulfamethoxazole + trimethoprim, colistin, oxolinic acid, ofloxacin, tetracycline, and aztreonam during their cultivation at 23 °C and 36.5 °C. Ninety-six-well inoculated microplates with tested antibiotics in Mueller-Hinton broth were cultured under standard incubator conditions (normobaric normoxia) for 24 h or in an experimental hyperbaric chamber (HAUX, Germany) for 24 h at 2.8 ATA of 100% oxygen (hyperbaric hyperoxia). The hyperbaric chamber was pressurised with pure oxygen (100%). Both cultures (normoxic and hyperoxic) were carried out at 23 °C and 36.5 °C to study the possible effect of the cultivation temperature. No significant differences were observed between 23 and 36.5 °C cultivation with or without the 2-h lag phase in Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Cultivation in a hyperbaric chamber at 23 °C and 36.5 °C with or without a 2-h lag phase did not produce significant changes in the minimum inhibitory concentration (MIC) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. For the tested strains of Pseudomonas aeruginosa, the possible effect of hyperbaric oxygen on their antibiotic sensitivity could not be detected because the growth of these bacteria was completely inhibited by 100% hyperbaric oxygen at 2.8 ATA under all hyperbaric conditions tested at 23 °C and 36.5 °C. Subsequent tests with wild strains of pseudomonads, burkholderias, and stenotrophomonads not only confirmed the fact that these bacteria stop growing under hyperbaric conditions at a pressure of 2.8 ATA of 100% oxygen but also indicated that inhibition of growth of these bacteria under hyperbaric conditions is reversible.
- MeSH
- ampicilin farmakologie MeSH
- anaerobní bakterie MeSH
- antibakteriální látky farmakologie MeSH
- Bacteria MeSH
- Escherichia coli MeSH
- hyperbarická oxygenace * MeSH
- Klebsiella pneumoniae MeSH
- kombinace léků trimethoprim a sulfamethoxazol farmakologie MeSH
- kyslík MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- oxidační stres MeSH
- pseudomonádové infekce * MeSH
- Pseudomonas aeruginosa MeSH
- sulbaktam MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Antimicrobial resistance is well-known to be a global health and development threat. Due to the decrease of effective antimicrobials, re-evaluation in clinical practice of old antibiotics, as fosfomycin (FOS), have been necessary. FOS is a phosphonic acid derivate that regained interest in clinical practice for the treatment of complicated infection by multi-drug resistant (MDR) bacteria. Globally, FOS resistant Gram-negative pathogens are raising, affecting the public health, and compromising the use of the antibiotic. In particular, the increased prevalence of FOS resistance (FOSR) profiles among Enterobacterales family is concerning. Decrease in FOS effectiveness can be caused by i) alteration of FOS influx inside bacterial cell or ii) acquiring antimicrobial resistance genes. In this review, we investigate the main components implicated in FOS flow and report specific mutations that affect FOS influx inside bacterial cell and, thus, its effectiveness. FosA enzymes were identified in 1980 from Serratia marcescens but only in recent years the scientific community has started studying their spread. We summarize the global epidemiology of FosA/C2/L1-2 enzymes among Enterobacterales family. To date, 11 different variants of FosA have been reported globally. Among acquired mechanisms, FosA3 is the most spread variant in Enterobacterales, followed by FosA7 and FosA5. Based on recently published studies, we clarify and represent the molecular and genetic composition of fosA/C2 genes enviroment, analyzing the mechanisms by which such genes are slowly transmitting in emerging and high-risk clones, such as E. coli ST69 and ST131, and K. pneumoniae ST11. FOS is indicated as first line option against uncomplicated urinary tract infections and shows remarkable qualities in combination with other antibiotics. A rapid and accurate identification of FOSR type in Enterobacterales is difficult to achieve due to the lack of commercial phenotypic susceptibility tests and of rapid systems for MIC detection.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- Escherichia coli genetika MeSH
- fosfomycin * farmakologie MeSH
- Klebsiella pneumoniae genetika MeSH
- proteiny z Escherichia coli * genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Hypervirulentní kmeny Klebsiella pneumoniae (hvKP) mohou způsobovat atypické multilokulární infekce u jinak zdravých pacientů. Diagnostika infekce vyvolané hvKP je založena především na klinickém nálezu a laboratorních výsledcích včetně detekce genů virulence. Typicky se projevuje jako jaterní absces s metastatickým šířením. Léčba je založena na chirurgickém řešení v kombinaci s cílenou antimikrobiální terapií. Výskyt infekce hvKP je relativně častý v Asii. V Evropě je sice stále vzácný, ale incidence onemocnění se zvyšuje. Cílem článku je poskytnout stručný přehled problematiky a upozornit na možný výskyt infekcí hvKP.
Hypervirulent strains of Klebsiella pneumoniae (hvKP) can cause atypical multilocular infections in otherwise healthy patients. Diagnosis of infection caused by hvKP is based mainly on clinical findings and laboratory results, including detection of virulence genes. It typically manifests as hepatic abscess with metastatic spread. Treatment is based on surgical intervention in combination with targeted antimicrobial therapy. The occurrence of hvKP infection is relatively common in Asia, and while still rare in Europe, incidence is increasing. The article aims to provide a short overview of the issue and increase awareness of the possible occurrence of hvKP infections.
- MeSH
- amputace MeSH
- antibakteriální látky terapeutické užití MeSH
- dospělí MeSH
- faktory virulence MeSH
- infekce bakteriemi rodu Klebsiella * diagnóza epidemiologie terapie MeSH
- infekce měkkých tkání chirurgie diagnóza etiologie farmakoterapie MeSH
- Klebsiella pneumoniae MeSH
- lidé MeSH
- sepse MeSH
- virulence MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
Klebsiella spp. is a commensal gram-negative bacterium and a member of the human microbiota. It is the leading cause of various hospital-acquired infections. The occurrence of multi-drug drug resistance and carbapenemase-producing strains of Klebsiella pneumoniae producing weighty contaminations is growing, and Klebsiella oxytoca is an arising bacterium. Alternative approaches to tackle contaminations led by these microorganisms are necessary as strains enhance opposing to last-stage antibiotics in the way that Colistin. The lytic bacteriophages are viruses that infect and rapidly eradicate bacterial cells and are strain-specific to their hosts. They and their proteins are immediately deliberate as opportunities or adjuncts to antibiotic therapy. There are several reports in vitro and in vivo form that proved the potential use of lytic phages to combat superbug stains of K. pneumoniae. Various reports dedicated that the phage area can be returned to the elimination of multi-drug resistance and carbapenemase resistance isolates of K. pneumoniae. This review compiles our current information on phages of Klebsiella spp. and highlights technological and biological issues related to the evolution of phage-based therapies targeting these bacterial hosts.
- MeSH
- antibakteriální látky MeSH
- bakteriofágy * MeSH
- fágová terapie * MeSH
- infekce bakteriemi rodu Klebsiella * mikrobiologie MeSH
- Klebsiella pneumoniae MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Klebsiella pneumoniae is an important cause of nosocomial infections and displays increasing resistance to fluoroquinolones (FQ). This study surveyed the mechanisms of FQ resistance and molecular typing of K. pneumoniae isolates from intensive care units patients in Tehran, Iran. A total of 48 ciprofloxacin (CIP) resistant K. pneumoniae isolates from urine samples were included in this study. Broth microdilution assays revealed high-level CIP resistance (MIC > 32 μg/mL) in 31.25% of the isolates. Plasmid-mediated quinolone resistance genes were detected in 41 (85.4%) isolates. Among which, qnrS (41.67%) was the most prevalent followed by qnrD (35.42%), qnrB (27.1%), qnrA (25%), qepA (22.9%), aac(6')-Ib-cr (20.83%), and qnrC (6.25%). Target site mutations (gyrA and parC) were assessed using PCR and sequencing on all isolates. A single mutation in gyrA (S83I) was found in 13 (27.1%) isolates and two isolates harbored six simultaneous mutations. Fourteen isolates (29.2%) had mutations in parC and S129A and A141V mutations were the most prevalent. Real time PCR showed an increase in the expression level of acrB and oqxB efflux genes in 68.75 and 29.16% isolates, respectively. Enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed 14 genotypes and 11 of them were classified by multilocus sequence typing (MLST) into 11 different sequence types belonging to seven clonal complexes and two singletons, most of them have not been reported in Iran yet. We are concerned about the spread of these clones throughout our country. Most FQ resistance mechanisms were detected among our isolates. However, target site mutation had the greatest effect on CIP resistance among our isolates.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- ciprofloxacin * farmakologie MeSH
- DNA gyráza genetika MeSH
- fluorochinolony * farmakologie MeSH
- Klebsiella pneumoniae genetika MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- molekulární epidemiologie MeSH
- multilokusová sekvenční typizace MeSH
- plazmidy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Írán MeSH
Enterobacter spp. and Klebsiella aerogenes are rod-shaped Gram-negative opportunistic pathogens. This study aimed at the molecular and genomic characterization of multidrug resistant Enterobacter spp. and K. aerogenes isolates recovered from hospitalized patients in a tertiary care hospital in Lebanon. A total of 59 Enterobacter spp. clinical isolates consisting of 41 carbapenem-resistant and 18 susceptible by Etest were included in this study. Genotypic identification through whole-genome sequencing (WGS) was performed and confirmed in silico. Resistance and plasmid profiles were studied using ResFinder4.0 and Plasmid-Finder2.1. Multilocus sequence typing (MLST) was used to determine the isolates' clonality. Using the average nucleotide identity (ANI) we identified and confirmed that 47 (80%) isolates were E. hormaechei, 11 (18%) were Klebsiella aerogenes and 1 (2%) was an E. cloacae. Carbapenem-resistance was detected among 41 isolates all showing an MIC90 of ≥ 32 μg/mL for ertapenem, imipenem, and meropenem. blaNDM-1 (58.5%), blaACT-16 (54%), and blaOXA-1 (54%) were the most common detected β-lactamases, while blaCTX-M-15 (68%) was the main detected extended-spectrum β-lactamase (ESBL) encoding gene. Chromosomal ampC, carbapenemase encoding genes, and porin modifications were among the detected carbapenem resistance determinants. The carbapenemase encoding genes were linked to three well-defined plasmid Inc groups, IncFII/IncFIB, IncX3, and IncL. MLST typing revealed the diversity within the studied isolates, with ST114 being the most common among the studied E. hormaechei.: The spread of carbapenem-resistant isolates in clinical settings in Lebanon is a serious challenge. Screening and continuous monitoring through WGS analysis could effectively limit the dissemination of drug-resistant isolates in hospitalized patients. IMPORTANCE Drug resistance is an increasing global public health threat that involves most disease-causing organisms and antimicrobial drugs. Drug-resistant organisms spread in health care settings, and resistance to multiple drugs is common. Our study demonstrated the mechanisms leading to resistance against the last resort antimicrobial agents among members of the Enterobacteriaceae family. The spread of carbapenem-resistant bacteria in clinical settings is a serious challenge. Screening and continuous monitoring could effectively limit the dissemination of drug-resistant isolates in hospitalized patients.
- MeSH
- antibakteriální látky farmakologie terapeutické užití MeSH
- bakteriální proteiny genetika MeSH
- beta-laktamasy genetika MeSH
- Enterobacter aerogenes * genetika MeSH
- Enterobacter genetika MeSH
- karbapenemy farmakologie MeSH
- Klebsiella pneumoniae genetika MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- multilokusová sekvenční typizace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Libanon MeSH
Carbapenem resistance observed in Klebsiella pneumoniae strains limits treatment options. Therefore, use of antibiotics combined with bioactive compounds may be an important strategy to control K. pneumoniae. The purpose of this study was to evaluate the activity of combination of carvacrol and meropenem on carbapenem-resistant K. pneumoniae (CRKP) strains. The presence of blaOXA-48 carbapenemase in all 25 CRKP strains was identified using the PCR technique. The combination of carvacrol and meropenem was tested for antimicrobial activity on CRKP strains. The minimum inhibitory concentrations of carvacrol and meropenem were detected within a range of 32-128 μg/mL using the broth microdilution method. Synergy between carvacrol and meropenem was observed on 8 of the 25 CRKP strains by checkerboard assay (FICI = 0.5) and confirmed by time-kill assay. According to the live-dead test results, the viability percentage of the cells exposed to synergistic combination was 35.47% at the end of 24 h. The membrane damage caused by the synergistic combination was spectrophotometrically measured (A = 0.21) and further confirmed by SEM analysis. According to the MTT assay, both carvacrol and meropenem did not show any statistically significant cytotoxic effect on Vero cells (p > 0.05). In conclusion, the results suggest that carvacrol and meropenem can act synergistically to inhibit the growth of CRKP.
- MeSH
- antibakteriální látky farmakologie MeSH
- beta-laktamasy * genetika MeSH
- Cercopithecus aethiops MeSH
- cymeny MeSH
- karbapenemy farmakologie MeSH
- Klebsiella pneumoniae * MeSH
- meropenem farmakologie MeSH
- mikrobiální testy citlivosti MeSH
- synergismus léků MeSH
- Vero buňky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Aim: Colistin resistance poses a serious clinical problem. This study aims to investigate the presence of plasmid-mediated resistance and heteroresistance among Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) clinical isolates at intensive care units of Main Alexandria University Hospital. Material and Methods: Seventy colistin-resistant and 30 colistin-susceptible K. pneumoniae and E. coli isolates constituted the material of the study. The rapid polymyxin NP (Nordmann Poirel) test was performed. Heteroresistance in colistin-susceptible isolates was investigated by population analysis profile. mcr-1 and mcr-2 genes were amplified by polymerase chain reaction (PCR). Results: The rapid polymyxin NP test showed 100% concordance with the results of BMD (broth microdilution method). Heteroresistance to colistin was detected in 23.3% of colistin-susceptible K. pneumoniae isolates. All colistin-resistant isolates were negative for mcr-1 and mcr-2 genes. Conclusions: The rapid polymyxin NP test is a reliable screening tool for colistin resistance, but not for heteroresistance. Other colistin resistance mechanisms should be investigated.
- MeSH
- antibakteriální látky imunologie MeSH
- bakteriální léková rezistence * MeSH
- Escherichia coli * genetika MeSH
- jednotky intenzivní péče MeSH
- Klebsiella pneumoniae * genetika MeSH
- klinická studie jako téma MeSH
- kolistin farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- polymyxiny MeSH
- proteiny z Escherichia coli genetika MeSH
- Check Tag
- lidé MeSH
In response to the emergence of drug resistance and limited therapeutic options, researchers are in action to look for more effective and sustainable antimicrobial practices. Over few years, novel nanoparticles are proving to be potent and promising for effectively dealing with ever- evolving microbial pathogens and diseases. In the present investigation, antibacterial and anti-biofilm efficiencies of zinc ferrite nanoparticles (ZnFe2O4 NPs) are explored against opportunistic pathogens Klebsiella pneumoniae (K. pneumoniae). Results of the present study demonstrate that the ZnFe2O4 NPs endow an excellent antibacterial efficiency with a maximum zone of inhibition i.e.16 mm. The reactive oxygen species (ROS)-induced bacterial damage is caused by the ZnFe2O4 NPs. Subsequently, intracellular cytoplasmic leakage of sugar and protein confirms their ability to disturb the membrane integrity of bacteria. This study also demonstrates the prominent efficiency of ZnFe2O4 NPs in an anti-biofilm study by inhibiting biofilm formation up to 81.76% and reducing mature biofilm up to 56.22% at 75 μg/mL the minimum inhibitory concentration value. Therapeutic possibilities of the ZnFe2O4 NPs in antimicrobial applications are discussed which are helpful to overcome the challenges associated with biofilm infectivity.
- MeSH
- antibakteriální látky farmakologie terapeutické užití MeSH
- antiinfekční látky * farmakologie MeSH
- Bacteria metabolismus MeSH
- biofilmy MeSH
- cukry farmakologie MeSH
- Klebsiella pneumoniae MeSH
- mikrobiální testy citlivosti MeSH
- nanočástice * MeSH
- reaktivní formy kyslíku metabolismus MeSH
- železité sloučeniny MeSH
- zinek farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
As resistance of bacterial strains to antibiotics is a major problem, there is a need to look for alternative treatments. One option is antimicrobial photodynamic inactivation (aPDI). The pathogenic cells are targeted by a nontoxic photosensitizer while the surrounding healthy tissue is relatively unaffected. The photosensitizer is activated by light of t appropriate wavelength resulting in the generation of reactive oxygen species that are cytotoxic for the pathogens. In this work, the photosensitizer TMPyP and silver nanoparticles (AgNPs) were investigated for their synergistic antibacterial effect. We tested these two substances on two bacterial strains, methicillin-resistant Staphylococcus aureus 4591 (MRSA) and extended-spectrum beta-lactamases-producing Klebsiella pneumoniae 2486 (ESBL-KP), to compare their effectiveness. The bacteria were first incubated with TMPyP for 45 min or 5 h, then irradiated with a LED source with the total fluence of 10 or 20 J/cm2 and then placed in a microbiological growth medium supplemented with AgNPs. To accomplish the synergistic effect, the optimal combination of TMPyP and AgNPs was estimated as 1.56-25 μM for TMPyP and 3.38 mg/l for AgNPs in case of MRSA and 1.56-50 μM for TMPyP and 3.38 mg/l for AgNPs in case of ESBL-KP at 45 min incubation with TMPyP and fluence of 10 J/cm2. Longer incubation and/or longer irradiation led to a decrease in the maximum values of the photosensitizer concentration to produce the synergistic effect. From this work it can be concluded that the combination of antimicrobial photodynamic inactivation with a treatment including silver nanoparticles could be a promising approach to treat bacterial infection.
- MeSH
- antibakteriální látky farmakologie MeSH
- antiinfekční látky * farmakologie MeSH
- fotochemoterapie * metody MeSH
- fotosenzibilizující látky farmakologie MeSH
- Klebsiella pneumoniae MeSH
- kovové nanočástice * MeSH
- methicilin rezistentní Staphylococcus aureus * MeSH
- porfyriny * farmakologie MeSH
- rezistence na methicilin MeSH
- stříbro farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
