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Journal of Global Antimicrobial... May 2024Klebsiella aerogenes is a largely understudied opportunistic pathogen that can cause sepsis and lead to high mortality rates. In this study, we reported the occurrence...
OBJECTIVES
Klebsiella aerogenes is a largely understudied opportunistic pathogen that can cause sepsis and lead to high mortality rates. In this study, we reported the occurrence of carbapenem-resistant bla-carrying Klebsiella aerogenes from swine in China and elucidate their genomic characteristics.
METHODS
A total of 126 samples, including 109 swine fecal swabs, 14 environmental samples, and 3 feed samples were collected from a pig farm in China. The samples were enriched with LB broth culture and then inoculated into MacConkey agar plates for bacterial isolation. After PCR detection of carbapenemases genes, the bla-carrying isolates were subjected to antimicrobial susceptibility testing, and whole-genome sequence analysis.
RESULTS
Four Klebsiella aerogenes isolates carrying the bla gene were obtained from swine fecal samples. All the four strains were belonged to ST438. The bla genes were located in IncX3-ColKP3 hybrid plasmids with the core genetic structure of IS26-ΔIS3000-ΔISEcp1-bla-ΔlysR-ΔereA-ΔrepA-ISKpn19-tinR-qnrS1-ΔIS2-IS26, which suggests the potential for horizontal transfer and further dissemination of this resistance gene among Enterobacteriaceae and other sources.
CONCLUSIONS
This study represents the first instance of OXA-181-producing K. aerogenes being identified from swine feces in China. It is crucial to maintain continuous monitoring and ongoing attention to the detection of K. aerogenes carrying bla and other resistance genes in pigs.
PubMed: 38763331
DOI: 10.1016/j.jgar.2024.04.009 -
Communications Biology May 2024In gram-negative bacteria, IS26 often exists in multidrug resistance (MDR) regions, forming a pseudocompound transposon (PCTn) that can be tandemly amplified. It also...
In gram-negative bacteria, IS26 often exists in multidrug resistance (MDR) regions, forming a pseudocompound transposon (PCTn) that can be tandemly amplified. It also generates a circular intermediate called the "translocatable unit (TU)", but the TU has been detected only by PCR. Here, we demonstrate that in a Klebsiella pneumoniae MDR clone, mono- and multimeric forms of the TU were generated from the PCTn in a preexisting MDR plasmid where the inserted form of the TU was also tandemly amplified. The two modes of amplification were reproduced by culturing the original clone under antimicrobial selection pressure, and the amplified state was maintained in the absence of antibiotics. Mono- and multimeric forms of the circularized TU were generated in a RecA-dependent manner from the tandemly amplified TU, which can be generated in RecA-dependent and independent manners. These findings provide novel insights into the dynamic processes of genome amplification in bacteria.
Topics: Klebsiella pneumoniae; Drug Resistance, Multiple, Bacterial; DNA Transposable Elements; Rec A Recombinases; Plasmids; Anti-Bacterial Agents
PubMed: 38762617
DOI: 10.1038/s42003-024-06312-4 -
Scientific Reports May 2024According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion...
According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.
Topics: Metal Nanoparticles; Silver; Pectobacterium carotovorum; Green Chemistry Technology; Copper; Escherichia coli; Plant Extracts; Animals; Staphylococcus aureus; Anti-Bacterial Agents; Microbial Sensitivity Tests; Humans; Plant Diseases
PubMed: 38762576
DOI: 10.1038/s41598-024-61920-8 -
BMC Infectious Diseases May 2024Urinary tract infections (UTIs) are one of the most common health problems worldwide and mainly affect women. This study aimed to evaluate the prevalence of UTIs in...
BACKGROUND
Urinary tract infections (UTIs) are one of the most common health problems worldwide and mainly affect women. This study aimed to evaluate the prevalence of UTIs in pregnant women and determine the antimicrobial resistance patterns of bacterial pathogens isolated from pregnant and nonpregnant women in Riyadh, Saudi Arabia.
METHODS
This retrospective cohort study was conducted at an academic medical center in Riyadh, Saudi Arabia, from January to June 2022. The study included all urine cultures performed for adult women during the study period. We excluded urine culture performed for women on antibiotics prescribed for any infection, children, and men. Using the SPSS (version 27) package, descriptive statistics and chi-square tests were used to analyze the data, and p < 0.05 was considered to indicate statistical significance.
RESULTS
A total of 2,418 urine cultures performed during the study period were included (985 and 1,433 for pregnant and nonpregnant women, respectively). The overall prevalence of UTIs in pregnant women was 5% (95% CI 3.6-6.4); 10 (1%) women were symptomatic, and 40 (4%) women were asymptomatic. Of the entire cohort, 244 (10.1%) women were diagnosed with UTIs based on bacterial cultures. The predominant bacteria in both pregnant and nonpregnant women were Escherichia coli (134, 54.9%), followed by Klebsiella pneumoniae (48, 19.6%). The antibiotic susceptibility criteria for Escherichia coli and Klebsiella pneumoniae were as follows: nitrofurantoin (94% and 18.8%, respectively), amoxicillin-clavulanic acid (82.8% and 70.8%, respectively), ciprofloxacin (65.7% and 83.3%, respectively), trimethoprim-sulfamethoxazole (65.7% and 79.2%, respectively) and cephalothin (47% and 68.8%, respectively).
CONCLUSION
Compared to the findings of other similar studies, the prevalence of UTIs was lower in pregnant women. This may be because the patient population was composed of healthy and educated women who received prenatal education and underwent prenatal assessment as per institutional guidelines. Nitrofurantoin and amoxicillin-clavulanic acid are recommended for use as an empirical therapy for UTIs in pregnant and nonpregnant women because bacteria have the least amount of resistance to these drugs.
Topics: Humans; Female; Urinary Tract Infections; Saudi Arabia; Pregnancy; Retrospective Studies; Adult; Prevalence; Anti-Bacterial Agents; Drug Resistance, Bacterial; Young Adult; Pregnancy Complications, Infectious; Microbial Sensitivity Tests; Escherichia coli; Bacteria; Middle Aged
PubMed: 38762526
DOI: 10.1186/s12879-024-09385-y -
Nature Communications May 2024Glioblastoma multiforme (GBM) is a highly aggressive brain tumor characterized by invasive behavior and a compromised immune response, presenting treatment challenges....
Glioblastoma multiforme (GBM) is a highly aggressive brain tumor characterized by invasive behavior and a compromised immune response, presenting treatment challenges. Surgical debulking of GBM fails to address its highly infiltrative nature, leaving neoplastic satellites in an environment characterized by impaired immune surveillance, ultimately paving the way for tumor recurrence. Tracking and eradicating residual GBM cells by boosting antitumor immunity is critical for preventing postoperative relapse, but effective immunotherapeutic strategies remain elusive. Here, we report a cavity-injectable bacterium-hydrogel superstructure that targets GBM satellites around the cavity, triggers GBM pyroptosis, and initiates innate and adaptive immune responses, which prevent postoperative GBM relapse in male mice. The immunostimulatory Salmonella delivery vehicles (SDVs) engineered from attenuated Salmonella typhimurium (VNP20009) seek and attack GBM cells. Salmonella lysis-inducing nanocapsules (SLINs), designed to trigger autolysis, are tethered to the SDVs, eliciting antitumor immune response through the intracellular release of bacterial components. Furthermore, SDVs and SLINs administration via intracavitary injection of the ATP-responsive hydrogel can recruit phagocytes and promote antigen presentation, initiating an adaptive immune response. Therefore, our work offers a local bacteriotherapy for stimulating anti-GBM immunity, with potential applicability for patients facing malignancies at a high risk of recurrence.
Topics: Glioblastoma; Animals; Mice; Salmonella typhimurium; Male; Neoplasm Recurrence, Local; Brain Neoplasms; Humans; Cell Line, Tumor; Mice, Inbred C57BL; Pyroptosis; Adaptive Immunity; Immunity, Innate; Hydrogels; Immunotherapy
PubMed: 38762500
DOI: 10.1038/s41467-024-48606-5 -
BMC Microbiology May 2024This study aimed to discuss the distinctive features of the intestinal microbiota in neonates with hyperbilirubinemia and to comprehensively analyse the composition of...
OBJECTIVE
This study aimed to discuss the distinctive features of the intestinal microbiota in neonates with hyperbilirubinemia and to comprehensively analyse the composition of the intestinal microbiota as well as the levels of free amino acids and acylcarnitines in the peripheral blood of neonates experiencing hyperbilirubinemia.
RESULTS
At the phylum level, Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Chloroflexi were the five predominant microbial groups identified in both the hyperbilirubinemia and control groups. Alpha diversity analysis, encompassing seven indices, showed no statistically significant differences between the two groups. However, Beta diversity analysis revealed a significant difference in intestinal microbiota structure between the groups. Linear discriminant analysis effect size (LEfSe) indicated a significant reduction in the abundance of Gammaproteobacteria and Enterobacteriaceae within the hyperbilirubinemia group compared to that in the control group. The heatmap revealed that the control group exhibited increased abundances of Escherichia and Bifidobacterium, while the hyperbilirubinemia group exhibited increased levels of Enterococcus and Streptococcus. Regarding blood amino acids and acylcarnitines, there were greater concentrations of citrulline (Cit), arginine (Arg), ornithine (Orn), and valine (Val) in the hyperbilirubinemia group than in the control group. The hyperbilirubinemia group also exhibited significant increases in medium-chain fatty acids (C6, C8), long-chain fatty acids (C18), and free carnitine (C0).
CONCLUSION
By comparing neonates with hyperbilirubinemia to those without, a significant disparity in the community structure of the intestinal microbiota was observed. The intestinal microbiota plays a crucial role in the bilirubin metabolism process. The intestinal microbiota of neonates with hyperbilirubinemia exhibited a certain degree of dysbiosis. The abundances of Bacteroides and Bifidobacterium were negatively correlated with the bilirubin concentration. Therefore, the fact that neonates with hyperbilirubinemia exhibit some variations in blood amino acid and acylcarnitine levels may provide, to a certain degree, a theoretical basis for clinical treatment and diagnosis.
Topics: Humans; Carnitine; Gastrointestinal Microbiome; Amino Acids; Infant, Newborn; Male; Female; Bacteria; RNA, Ribosomal, 16S
PubMed: 38760685
DOI: 10.1186/s12866-024-03328-y -
BMC Microbiology May 2024We aimed to compare the performance of carbapenemase classification in carbapenem-resistant Klebsiella pneumoniae (CRKP) obtained using the BD Phoenix CPO Detect panel... (Comparative Study)
Comparative Study
BACKGROUND
We aimed to compare the performance of carbapenemase classification in carbapenem-resistant Klebsiella pneumoniae (CRKP) obtained using the BD Phoenix CPO Detect panel (CPO panel) and Cepheid Xpert Carba-R assays. We analyzed 55 CRKP strains from clinical specimens collected between November 2020 and November 2022. The CPO panel was used to detect both antibiotic susceptibility and phenotypic carbapenemase classes, while Xpert Carba-R was employed to identify KPC, NDM, VIM, OXA-48, and IMP genes. Due to the limited availability of molecular kits, we arbitrarily selected 55 isolates, identified as carbapenemase-producing according to the CPO panel and with meropenem minimum inhibitory concentration values > 8 mg/L.
RESULTS
According to the Xpert Carba-R assay, 16 of the 55 isolates (29.1%) were categorised as Ambler Class A (11 of which matched CPO panel Class A identification); three isolates (5.5%) were identified as Class B and 27 isolates (49.1%) as Class D (in both cases consistent with CPO panel B and D classifications). A further eight isolates (14.5%) exhibited multiple carbapenemase enzymes and were designated as dual-carbapenemase producers, while one isolate (1.8%) was identified as a non-carbapenemase-producer. The CPO panel demonstrated positive and negative percent agreements of 100% and 85.7% for Ambler Class A, 100% and 100% for Class B, and 96.4% and 100% for Class D carbapenemase detection, respectively.
CONCLUSION
While the CPO panel's phenotypic performance was satisfactory in detecting Class B and D carbapenemases, additional confirmatory testing may be necessary for Class A carbapenemases as part of routine laboratory procedures.
Topics: beta-Lactamases; Klebsiella pneumoniae; Bacterial Proteins; Humans; Microbial Sensitivity Tests; Klebsiella Infections; Anti-Bacterial Agents; Carbapenem-Resistant Enterobacteriaceae
PubMed: 38760674
DOI: 10.1186/s12866-024-03311-7 -
Nature Communications May 2024Hypervirulent Klebsiella pneumoniae (hvKp) is a significant cause of severe invasive infections in Vietnam, yet data on its epidemiology, population structure and...
Hypervirulent Klebsiella pneumoniae (hvKp) is a significant cause of severe invasive infections in Vietnam, yet data on its epidemiology, population structure and dynamics are scarce. We screened hvKp isolates from patients with bloodstream infections (BSIs) at a tertiary infectious diseases hospital in Vietnam and healthy individuals, followed by whole genome sequencing and plasmid analysis. Among 700 BSI-causing Kp strains, 100 (14.3%) were hvKp. Thirteen hvKp isolates were identified from 350 rectal swabs of healthy adults; none from 500 rectal swabs of healthy children. The hvKp isolates were genetically diverse, encompassing 17 sequence types (STs), predominantly ST23, ST86 and ST65. Among the 113 hvKp isolates, 14 (12.6%) carried at least one antimicrobial resistance (AMR) gene, largely mediated by IncFII, IncR, and IncA/C plasmids. Notably, the acquisition of AMR conjugative plasmids facilitated horizontal transfer of the non-conjugative virulence plasmid between K. pneumoniae strains. Phylogenetic analysis demonstrated hvKp isolates from BSIs and human carriage clustered together, suggesting a significant role of intestinal carriage in hvKp transmission. Enhanced surveillance is crucial to understand the factors driving intestinal carriage and hvKp transmission dynamics for informing preventive measures. Furthermore, we advocate the clinical use of our molecular assay for diagnosing hvKp infections to guide effective management.
Topics: Klebsiella pneumoniae; Vietnam; Humans; Plasmids; Klebsiella Infections; Phylogeny; Whole Genome Sequencing; Virulence; Adult; Female; Gene Transfer, Horizontal; Male; Genome, Bacterial; Middle Aged; Anti-Bacterial Agents; Child; Genomics; Drug Resistance, Bacterial
PubMed: 38760381
DOI: 10.1038/s41467-024-48206-3 -
Nature Communications May 2024Bacteriophage infection, a pivotal process in microbiology, initiates with the phage's tail recognizing and binding to the bacterial cell surface, which then mediates...
Bacteriophage infection, a pivotal process in microbiology, initiates with the phage's tail recognizing and binding to the bacterial cell surface, which then mediates the injection of viral DNA. Although comprehensive studies on the interaction between bacteriophage lambda and its outer membrane receptor, LamB, have provided rich information about the system's biochemical properties, the precise molecular mechanism remains undetermined. This study revealed the high-resolution cryo-electron microscopy (cryo-EM) structures of the bacteriophage lambda tail complexed with its irreversible Shigella sonnei 3070 LamB receptor and the closed central tail fiber. These structures reveal the complex processes that trigger infection and demonstrate a substantial conformational change in the phage lambda tail tip upon LamB binding. Providing detailed structures of bacteriophage lambda infection initiation, this study contributes to the expanding knowledge of lambda-bacterial interaction, which holds significance in the fields of microbiology and therapeutic development.
Topics: Bacteriophage lambda; Cryoelectron Microscopy; Shigella sonnei; Viral Tail Proteins; Porins; Bacterial Outer Membrane Proteins; Protein Binding; Models, Molecular; Protein Conformation; Receptors, Virus
PubMed: 38760367
DOI: 10.1038/s41467-024-48686-3 -
PloS One 2024The primary objective of this study was to isolate bacteria from diabetic foot ulcers and subsequently assess their antibiotic resistance capabilities. Seventy-five...
The primary objective of this study was to isolate bacteria from diabetic foot ulcers and subsequently assess their antibiotic resistance capabilities. Seventy-five patients diagnosed with diabetic foot ulcers were investigated. A number of these patients (97.33%) had type 2 diabetes, with a significant proportion of them having been diagnosed for 1-5 years (29.33%). Notably, a substantial number of these individuals were on insulin usage (78.66%). Among the patients under examination, 49.33% reported having no use of tobacco products, alcohol, or betel leaf. The ulcers analyzed in this study were classified into grades 1-5 according to the Wagner scale. Wagner grade 2 diabetic foot ulcers had the highest number of culture-positive patients, at 33.33%. Pus samples collected from patients were cultured on selective media, and bacterial identity was confirmed by biochemical tests and polymerase chain reaction. A total of 141 isolates were isolated. Among the isolates, 82.97% gram-negative bacteria and 17.02% gram-positive bacteria were detected. Klebsiella pneumoniae was the most common isolate. Proteus spp., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were also detected. Approximately 61.33% of the ulcers exhibited were polybacterial. In this study, it was observed that all bacterial isolates, except for Proteus spp., were primarily detected in patients classified under Wagner's grade 2. Moreover, antibiotic susceptibility was also tested on these 141 isolates. Among them, Escherichia coli showed the highest multidrug resistance, 81.81%. Most of the gram-negative bacteria were resistant to ampicillin. All of the gram-negative isolates exhibited high levels of susceptibility to piperacillin-tazobactam, and these levels were Klebsiella pneumoniae (97.56%), Pseudomonas aeruginosa (95.24%), Escherichia coli (81.82%), and Proteus spp. (80%). On the other hand, gram-positive Staphylococcus aureus mostly showed sensitivity towards vancomycin and norfloxacin (79.17%).
Topics: Humans; Diabetic Foot; Male; Female; Middle Aged; Anti-Bacterial Agents; Microbial Sensitivity Tests; Bangladesh; Aged; Adult; Drug Resistance, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Escherichia coli; Diabetes Mellitus, Type 2; Staphylococcus aureus
PubMed: 38758936
DOI: 10.1371/journal.pone.0301767