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1.
Georgian Med News ; (349): 98-102, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38963211

ABSTRACT

We report a severe case of a 25-year-old girl presented with complaints of weakness, diarrhoea, vomiting, pain in abdomen and hypotension at Infectious Diseases and Clinical Immunology Research Center. From history on 25 February till 29 February she was in India and on 1 march this problem started with watery diarrhoea followed by vomiting. She ate pizza with mushroom following which her condition worsened. Stool culture revealed salmonella nontyphi (nonthyphodal Salmonella)and this is leading cause for gastroenteritis, bacteremia and affects several other bodily system. Her condition deteriorated due to the development of ARDS (acute respiratory distress syndrome) and for this she was on mechanical ventilation. Vitec machine was performed, which identified Salmonella typhi murium. Our goal is to manage and treat this patient well by early diagnosis. She was given ceftriaxone, iv fluids and symptomatic treatment but due to resistance meropenem was started and the patient's condition improved. From serology there was no evidence of immunocompromised state so being a severe case of immunocompetent patient this case reflects the importance of timely diagnosis and management together with food safety practices in population. On follow up she was stable and discharged after 3 weeks. Future research studies need to be continued regarding newer strains, effective treatment strategies and diagnostics to prevent morbidity and mortality.


Subject(s)
Salmonella Infections , Humans , Female , Adult , Salmonella Infections/diagnosis , Salmonella Infections/drug therapy , Salmonella Infections/microbiology , Salmonella Infections/complications , Ceftriaxone/therapeutic use , Anti-Bacterial Agents/therapeutic use , Respiratory Distress Syndrome/microbiology , Respiratory Distress Syndrome/etiology , Multiple Organ Failure/microbiology , Multiple Organ Failure/etiology , Salmonella/isolation & purification , Meropenem/therapeutic use , Salmonella typhi/isolation & purification , Salmonella typhi/pathogenicity , Diarrhea/microbiology
2.
Arch Virol ; 169(8): 156, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38967872

ABSTRACT

Infections caused by multidrug-resistant (MDR) bacteria are a growing global concern. Enterobacter cloacae complex (ECC) species are particularly adept at developing antibiotic resistance. Phage therapy is proposed as an alternative treatment for pathogens that no longer respond to antibiotics. Unfortunately, ECC phages are understudied when compared to phages of many other bacterial species. In this Ghanaian-Finnish study, we isolated two ECC strains from ready-to-eat food samples and three novel phages from natural waters against these strains. We sequenced the genomic DNA of the novel Enterobacter phages, fGh-Ecl01, fGh-Ecl02, and fGh-Ecl04, and assessed their therapeutic potential. All of the phages were found to be lytic, easy to propagate, and lacking any toxic, integrase, or antibiotic resistance genes and were thus considered suitable for therapy purposes. They all were found to be related to T4-type viruses: fGh-Ecl01 and fGh-Ecl04 to karamviruses and fGh-Ecl02 to agtreviruses. Testing of Finnish clinical ECC strains showed promising susceptibility to these novel phages. As many as 61.1% of the strains were susceptible to fGh-Ecl01 and fGh-Ecl04, and 7.4% were susceptible to fGh-Ecl02. Finally, we investigated the susceptibility of the newly isolated ECC strains to three antibiotics - meropenem, ciprofloxacin, and cefepime - in combination with the novel phages. The use of phages and antibiotics together had synergistic effects. When using an antibiotic-phage combination, even low concentrations of antibiotics fully inhibited the growth of bacteria.


Subject(s)
Anti-Bacterial Agents , Bacteriophages , Enterobacter cloacae , Enterobacter cloacae/virology , Enterobacter cloacae/drug effects , Ghana , Bacteriophages/genetics , Bacteriophages/isolation & purification , Bacteriophages/physiology , Bacteriophages/classification , Anti-Bacterial Agents/pharmacology , Phage Therapy/methods , Genome, Viral , Enterobacteriaceae Infections/therapy , Enterobacteriaceae Infections/microbiology , Drug Resistance, Multiple, Bacterial , Finland , Humans , Microbial Sensitivity Tests , Ciprofloxacin/pharmacology , Meropenem/pharmacology
3.
Clin Transl Sci ; 17(7): e13870, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38952168

ABSTRACT

The AIDA randomized clinical trial found no significant difference in clinical failure or survival between colistin monotherapy and colistin-meropenem combination therapy in carbapenem-resistant Gram-negative infections. The aim of this reverse translational study was to integrate all individual preclinical and clinical pharmacokinetic-pharmacodynamic (PKPD) data from the AIDA trial in a pharmacometric framework to explore whether individualized predictions of bacterial burden were associated with the trial outcomes. The compiled dataset included for each of the 207 patients was (i) information on the infecting Acinetobacter baumannii isolate (minimum inhibitory concentration, checkerboard assay data, and fitness in a murine model), (ii) colistin plasma concentrations and colistin and meropenem dosing history, and (iii) disease scores and demographics. The individual information was integrated into PKPD models, and the predicted change in bacterial count at 24 h for each patient, as well as patient characteristics, was correlated with clinical outcomes using logistic regression. The in vivo fitness was the most important factor for change in bacterial count. A model-predicted growth at 24 h of ≥2-log10 (164/207) correlated positively with clinical failure (adjusted odds ratio, aOR = 2.01). The aOR for one unit increase of other significant predictors were 1.24 for SOFA score, 1.19 for Charlson comorbidity index, and 1.01 for age. This study exemplifies how preclinical and clinical anti-infective PKPD data can be integrated through pharmacodynamic modeling and identify patient- and pathogen-specific factors related to clinical outcomes - an approach that may improve understanding of study outcomes.


Subject(s)
Acinetobacter baumannii , Anti-Bacterial Agents , Meropenem , Microbial Sensitivity Tests , Humans , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/isolation & purification , Meropenem/pharmacokinetics , Meropenem/administration & dosage , Meropenem/pharmacology , Middle Aged , Female , Male , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Colistin/pharmacokinetics , Colistin/administration & dosage , Adult , Aged , Animals , Treatment Outcome , Mice , Acinetobacter Infections/drug therapy , Acinetobacter Infections/microbiology , Translational Research, Biomedical , Drug Therapy, Combination/methods , Models, Biological
4.
J Korean Med Sci ; 39(25): e208, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38952349

ABSTRACT

A 30-year-old Korean man with myelodysplastic syndrome admitted hospital due to undifferentiated fever and recurrent skin lesions. He received combination therapy with high doses of meropenem, tigecycline and amikacin, yielding carbapenem resistant Klebsiella pneumoniae (CRKP) harboring K. pneumoniae carbapenemase (KPC)-2 from blood cultures on hospital day (HD) 23. Ceftazidime/avibactam was started at HD 37 and CRKP was eradicated from blood cultures after 5 days. However, ceftazidime/avibactam-resistant CRKP carrying KPC-44 emerged after 26 days of ceftazidime/avibactam treatment and then ceftazidime/avibactam-resistant, carbapenem-susceptible K. pneumoniae carrying KPC-135 was isolated on HD 65. The 3-D homology of KPC protein showed that hot spot changes in the omega loop could be attributed to ceftazidime/avibactam resistance and loss of carbapenem resistance. Whole genome sequencing of serial isolates supported that phenotypic variation was due to clonal evolution than clonal replacement. The treatment regimen was changed from CAZ/AVI to meropenem-based therapy (meropenem 1 g iv q 8 hours and amikacin 600 mg iv per day) starting with HD 72. CAZ/AVI-susceptible CRKP was presented again from blood cultures on HD 84, and the patient expired on HD 85. This is the first Korean report on the acquisition of ceftazidime/avibactam resistance through the emergence of blaKPC variants.


Subject(s)
Anti-Bacterial Agents , Azabicyclo Compounds , Bacteremia , Ceftazidime , Drug Combinations , Klebsiella Infections , Klebsiella pneumoniae , Microbial Sensitivity Tests , beta-Lactamases , Humans , Ceftazidime/therapeutic use , Ceftazidime/pharmacology , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/drug effects , Male , Azabicyclo Compounds/therapeutic use , Adult , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , beta-Lactamases/genetics , beta-Lactamases/metabolism , Klebsiella Infections/drug therapy , Klebsiella Infections/microbiology , Bacteremia/drug therapy , Bacteremia/microbiology , Carbapenems/therapeutic use , Carbapenems/pharmacology , Whole Genome Sequencing , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Meropenem/therapeutic use , Meropenem/pharmacology , Drug Resistance, Multiple, Bacterial/genetics
5.
Medicina (Kaunas) ; 60(6)2024 Jun 02.
Article in English | MEDLINE | ID: mdl-38929546

ABSTRACT

Background and Objectives: The prolonged infusion of meropenem is recommended by guidelines for the treatment of sepsis. However, studies provide controversial data on the advantages of prolonged infusions over intermittent ones. In our opinion, this can be related to age, which possibly distorts the final data, as older people have age-related characteristics. In our study, we analyzed the ventilatory status, laboratory tests and vital signs of the patient and carried out microbiological cultures. Materials and Methods: This was a prospective single-center case series investigation conducted from June 2022 to June 2023. The objective of this study was to evaluate the effectiveness of continuous infusion in elderly patients with severe infectious complications after orthopedic interventions. The primary endpoints were 28-day survival and the emergence of new multidrug-resistant strains. Secondary endpoints were long-term mortality and length of stay in the ICU. Results: Three patients (median age 65, 100% female) received a continuous infusion of meropenem. Two patients were alive at hospital discharge, and one patient died on the 105th day of hospitalization. Multi-resistant bacteria were observed in one patient. Conclusions: The use of a continuous meropenem infusion in the complex treatment of purulent-septic complications in elderly patients with periprosthetic infection and anemia probably led to clinical improvement in these case reports. However, the emergence of new pan-resistant strains and overall mortality using this infusion technique remains unclear. Further, high-quality RCTs for the elderly are needed.


Subject(s)
Anemia , Anti-Bacterial Agents , Meropenem , Humans , Meropenem/administration & dosage , Meropenem/therapeutic use , Aged , Female , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Prospective Studies , Male , Anemia/drug therapy , Infusions, Intravenous , Middle Aged , Aged, 80 and over , Sepsis/drug therapy
6.
Eur J Med Res ; 29(1): 331, 2024 Jun 16.
Article in English | MEDLINE | ID: mdl-38880888

ABSTRACT

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) infections are one of the most common causes of nosocomial infections and have high mortality rates due to difficulties in treatment. In this study, the in vitro synergistic interactions of the colistin (CT)-meropenem (MEM) combination and patient clinical outcomes were compared in CRAB-infected patients that receive CT-MEM antimicrobial combination therapy. In addition, in vitro synergistic interactions of MEM-ertapenem (ETP), MEM-fosfomycin (FF) and CT-FF antimicrobial combinations were investigated. Finally, the epsilometer (E) test and checkerboard test results were compared and the compatibility of these two tests was evaluated. METHODS: Twenty-one patients were included in the study. Bacterial identification was performed with MALDI-TOF, and antimicrobial susceptibility was assessed with an automated system. Synergy studies were performed using the E test and checkerboard method. RESULTS: For the checkerboard method, the synergy rates for CT-MEM, MEM-FF, MEM-ETP and CT-FF were 100%, 52.3%, 23.8% and 28.5%, respectively. In the E test synergy tests, synergistic effects were detected for two isolates each in the CT-MEM and CT-FF combinations. Microbial eradication was achieved in nine (52.9%) of the 17 patients that received CT-MEM combination therapy. The agreement between the E test and the checkerboard test was 6.5%. CONCLUSIONS: A synergistic effect was found with the checkerboard method for the CT-MEM combination in all isolates in our study, and approximately 70% of the patients benefited from treatment with this combination. In addition, more than half of the isolates showed a synergistic effect for the MEM-FF combination. Combinations of CT-MEM and MEM-FF may be options for the treatment of CRAB infections. However, a comprehensive understanding of the potential of the microorganism to develop resistant mutants under applied exposures, as well as factors that directly affect antimicrobial activity, such as pharmacokinetics/pharmacodynamics, is essential for providing treatment advice. We found a low rate of agreement between the E test method and the checkerboard test method in our study, in contrast to the literature. Comprehensive studies that compare clinical results with methods are needed to determine the ideal synergy test and interpretation method.


Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Anti-Bacterial Agents , Carbapenems , Colistin , Microbial Sensitivity Tests , Acinetobacter baumannii/drug effects , Humans , Colistin/pharmacology , Carbapenems/pharmacology , Male , Female , Middle Aged , Microbial Sensitivity Tests/methods , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/administration & dosage , Aged , Acinetobacter Infections/drug therapy , Acinetobacter Infections/microbiology , Adult , Drug Synergism , Aged, 80 and over , Drug Therapy, Combination/methods , Meropenem/pharmacology , Meropenem/administration & dosage
7.
BMC Infect Dis ; 24(1): 599, 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38898413

ABSTRACT

BACKGROUND: Phytobacter diazotrophicus (P. diazotrophicus) is an opportunistic pathogen that causes nosocomial outbreaks and sepsis. However, there are no reports of P. diazotrophicus isolated from human blood in China. CASE PRESENTATION: A 27-day-old female infant was admitted to our hospital with fever and high bilirubin levels. The clinical features included jaundice, abnormal coagulation, cholestasis, fever, convulsions, weak muscle tension, sucking weakness, ascites, abnormal tyrosine metabolism, cerebral oedema, abnormal liver function, clavicle fracture, and haemolytic anaemia. The strain isolated from the patient's blood was identified as P. diazotrophicus by whole-genome sequencing (WGS). Galactosemia type 1 (GALAC1) was diagnosed using whole-exome sequencing (WES). Based on drug sensitivity results, 10 days of anti-infective treatment with meropenem combined with lactose-free milk powder improved symptoms. CONCLUSION: P. diazotrophicus was successfully identified in a patient with neonatal sepsis combined with galactosemia. Galactosemia may be an important factor in neonatal sepsis. This case further expands our understanding of the clinical characteristics of GALAC1.


Subject(s)
Galactosemias , Sepsis , Humans , Female , China , Galactosemias/complications , Galactosemias/microbiology , Sepsis/microbiology , Sepsis/drug therapy , Sepsis/complications , Infant, Newborn , Anti-Bacterial Agents/therapeutic use , Meropenem/therapeutic use , Whole Genome Sequencing , Gammaproteobacteria/genetics , Gammaproteobacteria/isolation & purification
8.
BMC Infect Dis ; 24(1): 631, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38914964

ABSTRACT

BACKGROUND: Acinetobacter baumannii is a health threat due to its antibiotic resistance. Herein, antibiotic susceptibility and its association with the Toxin-antitoxin (TA) system genes in A. baumannii clinical isolates from Iran were investigated. Next, we prepared meropenem-loaded chitosan nanoparticles (MP-CS) and investigated their antibacterial effects against meropenem-susceptible bacterial isolates. METHODS: Out of 240 clinical specimens, 60 A. baumannii isolates were assessed. Antibiotic resistance of the isolates against conventional antibiotics was determined alongside investigating the presence of three TA system genes (mazEF, relBE, and higBA). Chitosan nanoparticles were characterized in terms of size, zeta potential, encapsulation efficiency, and meropenem release activity. Their antibacterial effects were assessed using the well diffusion method, minimum inhibitory concentration (MIC), and colony-forming unit (CFU) counting. Their cytotoxic effects and biocompatibility index were determined via the MTT, LDH, and ROS formation assays. RESULTS: Ampicillin, ceftazidime, and colistin were the least effective, and amikacin and tobramycin were the most effective antibiotics. Out of the 60 isolates, 10 (16.7%), 5 (8.3%), and 45 (75%) were multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR), respectively. TA system genes had no significant effect on antibiotic resistance. MP-CS nanoparticles demonstrated an average size of 191.5 and zeta potential of 27.3 mV alongside a maximum encapsulation efficiency of 88.32% and release rate of 69.57%. MP-CS nanoparticles mediated similar antibacterial effects, as compared with free meropenem, against the A. baumannii isolates with significantly lower levels of meropenem. MP-CS nanoparticles remarkably prevented A549 and NCI-H292 cell infection by the A. baumannii isolates alongside demonstrating a favorable biocompatibility index. CONCLUSION: Antibiotic-loaded nanoparticles should be further designed and investigated to increase their antibacterial effect against A. baumannii and assess their safety and applicability in vivo settings.


Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Anti-Bacterial Agents , Chitosan , Meropenem , Microbial Sensitivity Tests , Nanoparticles , Acinetobacter baumannii/drug effects , Meropenem/pharmacology , Chitosan/pharmacology , Chitosan/chemistry , Chitosan/analogs & derivatives , Anti-Bacterial Agents/pharmacology , Humans , Nanoparticles/chemistry , Acinetobacter Infections/microbiology , Acinetobacter Infections/drug therapy , Iran , Polyphosphates/pharmacology , Polyphosphates/chemistry
9.
Ann Intern Med ; 177(6): JC67, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38830218

ABSTRACT

SOURCE CITATION: Wagenlehner FM, Gasink LB, McGovern PC, et al; CERTAIN-1 Study Team. Cefepime-taniborbactam in complicated urinary tract infection. N Engl J Med. 2024;390:611-622. 38354140.


Subject(s)
Anti-Bacterial Agents , Cefepime , Meropenem , Urinary Tract Infections , Cefepime/therapeutic use , Humans , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/adverse effects , Urinary Tract Infections/drug therapy , Meropenem/therapeutic use , Treatment Outcome , Female , Male , Middle Aged , Drug Combinations
10.
Assist Inferm Ric ; 43(2): 83-90, 2024.
Article in Italian | MEDLINE | ID: mdl-38873717

ABSTRACT

. The overlap Stevens-Johnson syndrome due to meropenem administration. Clinical case and nursing care. A case of overlap Stevens-Johnson syndrome caused by meropenem administration is described. It is a rare cutaneous reaction due to delayed hypersensitivity to drugs characterised by the destruction and separation of the skin epithelium and mucous membranes, affecting between 10% and 29% of the body surface area. The clinical description of the case and a detailed description of nursing management and interventions based on the available literature are reported.


Subject(s)
Anti-Bacterial Agents , Meropenem , Stevens-Johnson Syndrome , Stevens-Johnson Syndrome/nursing , Stevens-Johnson Syndrome/etiology , Humans , Meropenem/administration & dosage , Meropenem/adverse effects , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Female , Male , Thienamycins/administration & dosage , Thienamycins/adverse effects
11.
Vestn Otorinolaringol ; 89(2): 88-94, 2024.
Article in Russian | MEDLINE | ID: mdl-38805469

ABSTRACT

According to the literature, acute otitis media is complicated by mastoiditis in 0.15-1% of cases. In turn, mastoiditis can be complicated by meningitis, encephalitis, abscess of temporal lobe of brain and cerebellum, epidural and subdural abscesses, facial nerve paresis, labyrinthitis, phlegmon of soft tissues of neck, as well as subperiosteal abscess, which makes 7% in the structure of mastoiditis complications. Nowadays, when doctors have a wide range of antibacterial preparations at their disposal, a complicated course of acute otitis media and further mastoiditis is caused both by an aggressive atypical infectious agent and immunocompromised status of a patient. The article deals with a clinical case of a prolonged course of acute otitis media complicated by mastoiditis and subperiosteal abscess against the background of outpatient courses of antibacterial therapy. The examination revealed an atypical pathogen of otitis media Pseudomonas aeruginosa and HIV-positive status of the patient, previously unknown. Timely surgical intervention and the right combination of antibacterial drugs, meropenem and ciprofloxacin, prevented the development of intracranial and septic complications, despite the presence of multiple foci of bone destruction of the mastoid process and temporal bone pyramid, bordering the middle fossa and sigmoid sinus, according to multispiral head computed tomography. As a part of additional examination in the Center for AIDS and Infectious Diseases Prevention and Control, the patient was diagnosed with HIV infection, clinical stage 4C, progressing phase on the background of absence of antiretroviral therapy, and the necessary amount of treatment was prescribed.


Subject(s)
Anti-Bacterial Agents , Mastoiditis , Otitis Media, Suppurative , Adult , Humans , Male , Acute Disease , Anti-Bacterial Agents/therapeutic use , HIV Infections/complications , Mastoiditis/etiology , Mastoiditis/diagnosis , Meropenem/administration & dosage , Meropenem/therapeutic use , Otitis Media, Suppurative/diagnosis , Pseudomonas aeruginosa/isolation & purification , Pseudomonas Infections/diagnosis , Tomography, X-Ray Computed/methods , Treatment Outcome
12.
Microbiol Res ; 285: 127769, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38797112

ABSTRACT

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a global threat due to its high mortality in clinical patients. However, the specific mechanisms underlying this increased mortality remain unclear. The objective of this study is to investigate how the development of a resistance phenotype contributes to the significantly higher mortality associated with this pathogen. To achieve this, a collection of isogeneic strains was generated. The clinical carbapenem-susceptible K. pneumoniae (CSKP) strain HKU3 served as the control isolate, while HKU3-KPC was created through conjugation with a blaKPC-2-bearing plasmid and served as clinical CRKP strain. Using a sepsis model, it was demonstrated that both HKU3 and HKU3-KPC exhibited similar levels of virulence. Flow cytometry, RNA-seq, and ELISA analysis were employed to assess immune cell response, M1 macrophage polarization, and cytokine storm induction, revealing that both strains elicited comparable types and levels of these immune responses. Subsequently, meropenem was utilized to treat K. pneumoniae infection, and it was found that meropenem effectively reduced bacterial load, inhibited M1 macrophage polarization, and suppressed serum cytokine production during HKU3 (CSKP) infection. However, these effects were not observed in the case of HKU3-KPC (CRKP) infection. These findings provide evidence that the high mortality associated with CRKP is attributed to its enhanced survival within the host during antibiotic treatment, resulting in a cytokine storm and subsequent host death. The development of an effective therapy for CRKP infections could significantly reduce the mortality caused by this pathogen.


Subject(s)
Anti-Bacterial Agents , Carbapenem-Resistant Enterobacteriaceae , Carbapenems , Klebsiella Infections , Klebsiella pneumoniae , Meropenem , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/pathogenicity , Klebsiella pneumoniae/genetics , Klebsiella Infections/microbiology , Klebsiella Infections/mortality , Klebsiella Infections/drug therapy , Virulence , Anti-Bacterial Agents/pharmacology , Meropenem/pharmacology , Carbapenems/pharmacology , Animals , Mice , Carbapenem-Resistant Enterobacteriaceae/drug effects , Carbapenem-Resistant Enterobacteriaceae/genetics , Humans , Macrophages/microbiology , Macrophages/immunology , beta-Lactamases/genetics , beta-Lactamases/metabolism , Sepsis/microbiology , Sepsis/mortality , Sepsis/drug therapy , Cytokines/metabolism , Microbial Sensitivity Tests , Bacterial Proteins/genetics , Disease Models, Animal , Bacterial Load
16.
Microbiology (Reading) ; 170(5)2024 May.
Article in English | MEDLINE | ID: mdl-38739119

ABSTRACT

Introduction. Bacterial keratitis, particularly caused by Pseudomonas aeruginosa, is challenging to treat because of multi-drug tolerance, often associated with the formation of biofilms. Antibiotics in development are typically evaluated against planktonic bacteria in a culture medium, which may not accurately represent the complexity of infections in vivo.Hypothesis/Gap Statement. Developing a reliable, economic ex vivo keratitis model that replicates some complexity of tissue infections could facilitate a deeper understanding of antibiotic efficacy, thus aiding in the optimization of treatment strategies for bacterial keratitis.Methodology. Here we investigated the efficacy of three commonly used antibiotics (gentamicin, ciprofloxacin and meropenem) against Pseudomonas aeruginosa cytotoxic strain PA14 and invasive strain PA01 using an ex vivo porcine keratitis model.Results. Both strains of P. aeruginosa were susceptible to the MIC of the three tested antibiotics. However, significantly higher concentrations were necessary to inhibit bacterial growth in the minimum biofilm eradication concentration (MBEC) assay, with both strains tolerating concentrations greater than 512 mg l-1 of meropenem. When MIC and higher concentrations than MBEC (1024 mg l-1) of antibiotics were applied, ciprofloxacin exhibited the highest potency against both P. aeruginosa strains, followed by meropenem, while gentamicin showed the least potency. Despite this, none of the antibiotic concentrations used effectively cleared the infection, even after 18 h of continuous exposure.Conclusions. Further exploration of antibiotic concentrations and aligning dosing with clinical studies to validate the model is needed. Nonetheless, our ex vivo porcine keratitis model could be a valuable tool for assessing antibiotic efficacy.


Subject(s)
Anti-Bacterial Agents , Biofilms , Ciprofloxacin , Disease Models, Animal , Keratitis , Microbial Sensitivity Tests , Pseudomonas Infections , Pseudomonas aeruginosa , Animals , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Anti-Bacterial Agents/pharmacology , Swine , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Biofilms/drug effects , Keratitis/microbiology , Keratitis/drug therapy , Ciprofloxacin/pharmacology , Gentamicins/pharmacology , Meropenem/pharmacology
17.
Emerg Microbes Infect ; 13(1): 2352432, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38712634

ABSTRACT

This study investigated resistance evolution mechanisms of conjugated plasmids and bacterial hosts under different concentrations of antibiotic pressure. Ancestral strain ECNX52 was constructed by introducing the blaNDM-5-carrying IncX3 plasmid into E. coli C600, and was subjected to laboratory evolution under different concentrations of meropenem pressure. Minimal inhibitory concentrations and conjugation frequency were determined. Fitness of these strains was assessed. Whole genome sequencing and transcriptional changes were performed. Ancestral host or plasmids were recombined with evolved hosts or plasmids to verify plasmid or host factors in resistance evolution. Role of the repA mutation on plasmid copy number was determined. Two out of the four clones (EM2N1 and EM2N3) exhibited four-fold increase in MIC when exposed to a continuous pressure of 2 µg/mL MEM (1/32 MIC), by down regulating expression of outer membrane protein ompF. Besides, all four clones displayed four-fold increase in MIC and higher conjugation frequency when subjected to a continuous pressure of 4 µg/mL MEM (1/16 MIC), attributing to increasing plasmid copy number generated by repA D140Y (GAT→TAT) mutation. Bacterial hosts and conjugative plasmids can undergo resistance evolution under certain concentrations of antimicrobial pressure by reducing the expression of outer membrane proteins or increasing plasmid copy numbers.


Subject(s)
Anti-Bacterial Agents , Escherichia coli Proteins , Escherichia coli , Microbial Sensitivity Tests , Plasmids , Porins , Escherichia coli/genetics , Escherichia coli/drug effects , Plasmids/genetics , Anti-Bacterial Agents/pharmacology , Porins/genetics , Porins/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Carbapenems/pharmacology , Meropenem/pharmacology , Mutation , Evolution, Molecular , Conjugation, Genetic , Carbapenem-Resistant Enterobacteriaceae/genetics , Carbapenem-Resistant Enterobacteriaceae/drug effects , Whole Genome Sequencing , Gene Dosage , beta-Lactamases/genetics
18.
Sci Rep ; 14(1): 10173, 2024 05 03.
Article in English | MEDLINE | ID: mdl-38702351

ABSTRACT

This study aimed to explore the changes of pharmacokinetic parameters after meropenem in patients with abdominal septic shock after gastrointestinal perforation, and to simulate the probability of different dosing regimens achieving different pharmacodynamic goals. The study included 12 patients, and utilized high performance liquid chromatography-tandem mass spectrometry to monitor the plasma concentration of meropenem. The probability of target attainment (PTA) for different minimum inhibitory concentration (MIC) values and %fT > 4MIC was compared among simulated dosing regimens. The results showed that in 96 blood samples from 12 patients, the clearance (CL) of meropenem in the normal and abnormal creatinine clearance subgroups were 7.7 ± 1.8 and 4.4 ± 1.1 L/h, respectively, and the apparent volume of distribution (Vd) was 22.6 ± 5.1 and 17.2 ± 5.8 L, respectively. 2. Regardless of the subgroup, 0.5 g/q6h infusion over 6 h regimen achieved a PTA > 90% when MIC ≤ 0.5 mg/L. 1.0 g/q6h infusion regimen compared with other regimen, in most cases, the probability of making PTA > 90% is higher. For patients at low MIC, 0.5 g/q6h infusion over 6 h may be preferable. For patients at high MIC, a dose regimen of 1.0 g/q6 h infusion over 6 h may be preferable. Further research is needed to confirm this exploratory result.


Subject(s)
Anti-Bacterial Agents , Meropenem , Microbial Sensitivity Tests , Shock, Septic , Humans , Meropenem/pharmacokinetics , Meropenem/administration & dosage , Meropenem/therapeutic use , Shock, Septic/drug therapy , Male , Female , Middle Aged , Aged , Prospective Studies , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Adult , Intestinal Perforation , Aged, 80 and over
19.
J Assoc Physicians India ; 72(1): 43-46, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38736073

ABSTRACT

INTRODUCTION: A survey-based approach to managing antibiotic-resistant infections in the intensive care unit (ICU) setting, with a focus on carbapenem-resistant Enterobacteriaceae (CRE) cases, was conducted. Among CRE, New Delhi metallo-ß-lactamase 1 (NDM-1) is a carbapenemase that is resistant to ß-lactam antibiotics and has a broader spectrum of antimicrobial resistance than other carbapenemase types. The article explains that healthcare-associated infections (HAIs) are a significant problem, particularly in low- and middle-income countries, and that carbapenem in combination with other antibiotics are the most potent class of antimicrobial agents effective in treating life-threatening bacterial infections, including those caused by resistant strains. AIM: The survey aimed to gather critical care healthcare professionals (HCPs') opinions on their current practices in managing infections acquired in the hospital and ICU settings, with a focus on CRE cases, specifically NDM-1 and other antibiotic-resistant infections. METHODS: Responses from critical care healthcare professionals, including online surveys and in-person interviews, to gain insights into the management of infections caused by multidrug-resistant bacteria. The findings related to the insights on the prevalence of bacterial flora, clinical experiences on efficacy and safety of meropenem sulbactam ethylenediaminetetraacetic acid (EDTA) (MSE) in CRE cases, and various combination therapies of antibiotics used to treat antibiotic-resistant infections in ICU setting were evaluated. RESULTS: Klebsiella pneumoniae bacteria were the most common bacteria in cultures, followed by Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. NDM-1 was the type of carbapenemase found in around 50% of CRE patients. MSE is among the most preferred antibiotics besides colistin, polymyxin B, and ceftazidime avibactum for CRE cases and specifically for NDM-1 cases due to its high rate of efficacy and safety. CONCLUSION: The article concludes with a discussion on the antibiotics used in response to CRE cases, reporting that critical care HCP considers MSE with high efficacy and safe antibiotic combination and was used as both monotherapy and in combination with other antibiotics. The survey highlights the need for exploring and better understanding the role of MSE in the management of CRE infections, especially in NDM-1.


Subject(s)
Anti-Bacterial Agents , Carbapenem-Resistant Enterobacteriaceae , Critical Care , Enterobacteriaceae Infections , Intensive Care Units , Humans , Anti-Bacterial Agents/therapeutic use , Enterobacteriaceae Infections/drug therapy , Critical Care/methods , Cross Infection/drug therapy , Cross Infection/microbiology , Surveys and Questionnaires , beta-Lactamases , Drug Resistance, Multiple, Bacterial , Meropenem/therapeutic use , India , Attitude of Health Personnel , Polymyxin B/therapeutic use , Carbapenems/therapeutic use , Carbapenems/pharmacology , Klebsiella pneumoniae/drug effects , Health Personnel
20.
Environ Int ; 187: 108729, 2024 May.
Article in English | MEDLINE | ID: mdl-38735077

ABSTRACT

Due to the specific action on bacterial cell wall, ß-lactam antibiotics have gained widespread usage as they exhibit a high degree of specificity in targeting bacteria, but causing minimal toxicity to host cells. Under antibiotic pressure, bacteria may opt to shed their cell walls and transform into L-form state as a means to evade the antibiotic effects. In this study, we explored and identified diverse optimal conditions for both Gram-negative bacteria (E. coli DH5α (CTX)) and Gram-positive bacteria (B. subtilis ATCC6633), which were induced to L-form bacteria using lysozyme (0.5 ppm) and meropenem (64 ppm). Notably, when bacteria transformed into L-form state, both bacterial strains showed varying degrees of increased resistance to antibiotics polymyxin E, meropenem, rifampicin, and tetracycline. E. coli DH5α (CTX) exhibited the most significant enhancement in resistance to tetracycline, with a 128-fold increase, while B. subtilis ATCC6633 showed a 32-fold increase in resistance to tetracycline and polymyxin E. Furthermore, L-form bacteria maintained their normal metabolic activity, combined with enhanced oxidative stress, served as an adaptive strategy promoting the sustained survival of L-form bacteria. This study provided a theoretical basis for comprehending antibiotic resistance mechanisms, developing innovative treatment strategies, and confronting global antibiotic resistance challenges.


Subject(s)
Anti-Bacterial Agents , Bacillus subtilis , Escherichia coli , Oxidative Stress , Anti-Bacterial Agents/pharmacology , Oxidative Stress/drug effects , Escherichia coli/drug effects , Bacillus subtilis/drug effects , Drug Resistance, Bacterial , Microbial Sensitivity Tests , Tetracycline/pharmacology , Meropenem/pharmacology
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