Molecular characterization and antibiotic resistance of clinical Bacteroides and related genera from a tertiary care center in Türkiye (Turkey).

Objectives: This study was conducted to measure the prevalence of antibiotic resistance, and corresponding resistance genes among Bacteroides and related genera in a tertiary hospital.

Methods: We examined 138 clinical strains of Bacteroides, Phocaeicola and Parabacteroides species isolated between July 2018 and June 2022. Antibiotic susceptibility tests were conducted using agar dilution.

Antimicrobial resistance surveillance of Bacteroides fragilis isolated from blood cultures, Europe, 2022 (ReSuBacfrag).

Objectives: Bacteroides fragilis is the most frequent cause of anaerobic bacteraemia. Although recent data suggest a rise in antimicrobial resistance (AMR) of this and other anaerobic bacteria, surveillance remains limited due to a lack of both data availability and comparability. However, a newly introduced standardised method for antimicrobial susceptibility testing (AST) of anaerobic bacteria has made larger scale surveillance possible for the first time.

Comparative evaluation of culture results and composition of microbiome of removed tonsils due to distant focal disease or other reasons. A prospective pilot study.

The aim of this prospective pilot study was to compare culture and microbiome results of the removed tonsils of patients with assumed distant focal disease (11 patients) and those who underwent a tonsillectomy, due to other reasons, such as recurrent tonsillitis, tonsil stones or snoring (nine patients). Aerobic culture was carried out for samples taken from the surface of the tonsils by swabs before tonsillectomy for all 20 patients. The squeezed detritus and the tissue samples of removed tonsils, taken separately for the right and left tonsils, were incubated aerobically and anaerobically.

Proteomics-Based RT-qPCR and Functional Analysis of 18 Genes in Metronidazole Resistance of .

Previously, we reported that metronidazole MICs are not dependent on the expression levels of genes in strains and we compared the proteomes of metronidazole-resistant laboratory strains to those of their susceptible parent strains. Here, we used RT-qPCR to correlate the expression levels of 18 candidate genes in a panel of selected, clinical gene-positive and -negative strains to their metronidazole MICs. Metronidazole MICs were correlated with the expression of certain tested genes.

Novel and rare β-lactamase genes of Bacteroides fragilis group species: Detection of the genes and characterization of their genetic backgrounds.

Objectives: This study screened the prevalence of rare β-lactamase genes in Bacteroides fragilis group strains from clinical specimens and normal microbiota and examined the genetic properties of the strains carrying these genes.

Methods: blaHGD1, blaOXA347, cblA, crxA, and pbbA were detected by real-time polymerase chain reaction in collections of Bacteroides strains from clinical (n = 406) and fecal (n = 184) samples. To examine the genetic backgrounds of the samples, end-point PCR, FT-IR, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were used.

Collateral sensitivity: An evolutionary trade-off between antibiotic resistance mechanisms, attractive for dealing with drug-resistance crisis.

Background: The discovery and development of antimicrobial drugs were one of the most significant advances in medicine, but the evolution of microbial resistance limited the efficiency of these drugs.

Aim: This paper reviews the collateral sensitivity in bacteria and its potential and limitation as a new target for treating infections.

Results And Discussion: Knowledge mechanisms of resistance to antimicrobial agents are useful to trace a practical approach to treat and control of resistant pathogens.

The effects of identical nim gene-insertion sequence combinations on the expression of the nim genes and metronidazole resistance in Bacteroides fragilis strains.

In this study we examined whether the same nim gene-insertion sequence (IS) element combinations give rise to the same expression levels as they harbor shared IS element-borne promoters. From our quantitative analysis, we found that the expressions of the nimB and nimE genes with their cognate IS elements were similar, but the metronidazole resistance of these strains were more diverse.

Proteomic analysis of metronidazole resistance in the human facultative pathogen .

The anaerobic gut bacteria and opportunistic pathogen can cause life-threatening infections when leaving its niche and reaching body sites outside of the gut. The antimicrobial metronidazole is a mainstay in the treatment of anaerobic infections and also highly effective against spp. Although resistance rates have remained low in general, metronidazole resistance does occur in .

Introduction of the Ellavi uterine balloon tamponade into the Kenyan and Ghanaian maternal healthcare package for improved postpartum haemorrhage management: an implementation research study.

Objectives: Use of intrauterine balloon tamponades for refractory postpartum haemorrhage (PPH) management has triggered recent debate since effectiveness studies have yielded conflicting results. Implementation research is needed to identify factors influencing successful integration into maternal healthcare packages. The Ellavi uterine balloon tamponade (UBT) (Ellavi) is a new low-cost, preassembled device for treating refractory PPH.

Machine learning-based typing of Salmonella enterica O-serogroups by the Fourier-Transform Infrared (FTIR) Spectroscopy-based IR Biotyper system.

Background: Salmonella enterica is among the major burdens for public health at global level. Typing of salmonellae below the species level is fundamental for different purposes, but traditional methods are expensive, technically demanding, and time-consuming, and therefore limited to reference centers. Fourier transform infrared (FTIR) spectroscopy is an alternative method for bacterial typing, successfully applied for classification at different infra-species levels.

Initial expression levels of nimA are decisive for protection against metronidazole in Bacteroides fragilis.

Objectives: In the genus Bacteroides, the nim genes are resistance determinants for metronidazole, a nitroimidazole drug widely used against anaerobic pathogens. The Nim proteins are considered to act as nitroreductases. However, data from several studies suggest that the expression levels of Nim do not increase with increasing resistance which is conflicting with this notion.

Modulation of Iron Import and Metronidazole Resistance in Harboring a Gene.

is a commensal of the human gut but can also cause severe infections when reaching other body sites, especially after surgery or intestinal trauma. is an anaerobe innately susceptible to metronidazole, a 5-nitroimidazole drug that is prescribed against the majority of infections caused by anaerobic bacteria. In most of the cases, metronidazole treatment is effective but a fraction of .

-Got Worse by a Pandemic?

The role of has been demonstrated in different nosocomial infections. An increasing number of publications have demonstrated its virulence in the respiratory tract, especially in the immunosuppressed patient population. The number of these patients has increased significantly during the COVID-19 pandemic.

Carbapenem resistance in Bacteroides fragilis: A review of molecular mechanisms.

Carbapenems are an applicable subclass of β-lactam drugs in the antibiotic therapy of anaerobic infections, especially for poly-microbial cases, due to their broad antimicrobial spectrum on aerobic and anaerobic bacteria. Bacteroides fragilis is the most commonly recovered anaerobic bacteria in the clinical laboratories from mono- and poly-microbial infections. B.

Phenotypic and Molecular Characterization of Carbapenem-Heteroresistant Strains.

Carbapenem-resistant strains usually emerge by an insertion sequence (IS) jump into the upstream region of the carbapenemase gene. However, intermediate or fully resistant -positive strains also exist. These do not have such IS element activations, but usually have heterogeneous resistance (HR) phenotypes, as detected by a disc diffusion or gradient tests.

A Porcine Sepsis Model With Numerical Scoring for Early Prediction of Severity.

Introduction: Sepsis can lead to organ dysfunctions with disturbed oxygen dynamics and life-threatening consequences. Since the results of organ-protective treatments cannot always be transferred from laboratory models into human therapies, increasing the translational potential of preclinical settings is an important goal. Our aim was to develop a standardized research protocol, where the progression of sepsis-related events can be characterized reproducibly in model experiments within clinically-relevant time frames.

A novel Bacteroides metallo-β-lactamase (MBL) and its gene (crxA) in Bacteroides xylanisolvens revealed by genomic sequencing and functional analysis.

Objectives: We sought to characterize the carbapenem resistance mechanism of Bacteroides xylanisolvens 14880, an imipenem-resistant strain from Germany, and assess its prevalence.

Methods: Antimicrobial susceptibilities were determined using agar dilution or Etest methodology and specific imipenemase activity was detected. The genomic sequence of B.

Haemin deprivation renders Bacteroides fragilis hypersusceptible to metronidazole and cancels high-level metronidazole resistance.

Background: Infections with Bacteroides fragilis are routinely treated with metronidazole, a 5-nitroimidazole antibiotic that is active against most anaerobic microorganisms. Metronidazole has remained a reliable treatment option, but resistance does occur, including in B. fragilis.

Characterization of the components of the thioredoxin system in Bacteroides fragilis and evaluation of its activity during oxidative stress.

Objectives: Bacteroides fragilis has a pronounced ability to survive prolonged exposure to atmospheric oxygen. The major objective of this study was to biochemically characterize the components of the thioredoxin system in B. fragilis.

The microbial composition of the initial insult can predict the prognosis of experimental sepsis.

We hypothesized that the composition of sepsis-inducing bacterial flora influences the course of fecal peritonitis in rodents. Saline or fecal suspensions with a standardized dose range of bacterial colony-forming units (CFUs) were injected intraperitoneally into Sprague-Dawley rats. The qualitative composition of the initial inoculum and the ascites was analyzed separately by MALDI-TOF mass spectrometry.

A comparison of the antimicrobial resistance of fecal Bacteroides isolates and assessment of the composition of the intestinal microbiotas of carbapenem-treated and non-treated persons from Belgium and Hungary.

The antimicrobial susceptibilities of Bacteroides strains isolated from the feces of imipenem-treated patients from Belgium and Hungary were compared with those isolated from the normal microbiota from these two and five other European countries and assessed. Of the 10 antibiotics tested, highly significant differences were found with cefoxitin (decrease for Belgium and for this two and the five countries from the previous study), clindamycin (decrease for Belgium and for this two and the five countries from the previous study) and moxifloxacin (increase for Belgium and for this two and the five countries from the previous study) relative to normal microbiota strains reported earlier. Imipenem treatment brought about modest, but notable differences in the compositions of the microbiomes where there was less diversity in the treated group relative to the non-treated group.

Correlation between antibiotic resistance and clinical outcome of anaerobic infections; mini-review.

In anaerobic infections, the relationship between clinical failure and antibiotic resistance is difficult to demonstrate, especially in mixed anaerobic-aerobic infections. Single isolates of anaerobes in cases of bacteraemia revealed that treatment failures were due to inappropriate therapy. We review here cases, where the empiric treatment was unsuccessful due to resistance of anaerobic bacteria to the administered agents and where the change of the antibiotic allowed the patients to be cured.

An update on ampicillin resistance and β-lactamase genes of spp.

There are several β-lactamase genes described for s strains, of which and are specific for and define two genetic divisions. The expression and phenotypic effects of these genes are usually regulated by insertional activation. Information is lacking about how is regulated for most of the strains and whether there could be a genetic element for it.

Molecular characterization of metronidazole resistant Bacteroides strains from Kuwait.

Eleven metronidazole resistant Bacteroides and one newly classified Phocaeicola dorei strain from Kuwait were investigated for their resistance mechanisms and the emergence of their resistant plasmids. All but one strain harbored nimE genes on differently sized plasmids. Of the 11 nimE genes, 9 were preceded by full copies of the prototype ISBf6 insertion sequence element, one carried a truncated ISBf6 and one was activated by an additional copy of IS612B.