-
Medicina (Kaunas, Lithuania) Feb 2022: and are related genera of opportunistic pathogens belonging to the family, often a cause of infections in the immunocompromised hosts, such as diabetic patients.... (Observational Study)
Observational Study
: and are related genera of opportunistic pathogens belonging to the family, often a cause of infections in the immunocompromised hosts, such as diabetic patients. Their clinical significance has increased due to their intrinsic resistance to polymyxins, which is often associated with acquired resistance mechanisms. In this study we evaluated the infections caused by and in two groups of patients, with diabetes (group 1) and without diabetes (group 2) admitted to the intensive care unit and surgical wards. The infections were investigated in terms of infection type, risk factors, clinical course, predictive factors for unfavourable outcomes and antibiotic resistance profile. : An observational, retrospective, cross-sectional study was conducted, comprising all patients infected with these pathogens. Bacterial identification and antibiotic sensitivity testing were performed using the Vitek2C automated system. : Comparison of the two groups showed that the statistically significant common infectious risk factors were found less frequently among diabetic patients when compared with non-diabetic patients, and that antimicrobial resistance was significantly lower in the diabetic patient group. However, survival rates did not differ between the two groups, drawing attention to the implications of diabetes as comorbidity. Additionally, with regard to the antibiotic resistance profile, 38.89% of strains isolated from diabetic patients belonged to the difficult-to-treat (DTR) phenotype, contributing to the severity of these infections compared with those caused by , of which 32% were wild type strains and 0% were DTR phenotype. The DTR/extended spectrum beta-lactamase producing isolates more than doubled the risk of mortality, while the presence of nasogastric nutrition tripled the risk. : infections that occurred in diabetic patients proved to be more difficult to treat, the majority of them being healthcare-associated bacteremias.
Topics: Cross-Sectional Studies; Diabetes Mellitus; Enterobacteriaceae Infections; Humans; Proteus Infections; Proteus mirabilis; Providencia; Retrospective Studies
PubMed: 35208593
DOI: 10.3390/medicina58020271 -
Food Technology and Biotechnology Mar 2022Shrimp shells contain chitin that can be further processed into acetylglucosamine, which has been extensively used to treat joint damage. has a strong chitinolytic...
RESEARCH BACKGROUND
Shrimp shells contain chitin that can be further processed into acetylglucosamine, which has been extensively used to treat joint damage. has a strong chitinolytic activity and may be utilized in the form of immobilized cells in repeated fermentation. Pumice is a porous and rigid stone that offers superior mechanical strength, making it suitable for immobilization.
EXPERIMENTAL APPROACH
In the research submerged fermentation with different pumice stone sizes and pumice stone/growth medium ratios (/) was carried out for 4 days at 37 °C and pH=7.0. The optimum pumice stone size and pumice stone/growth medium ratio (/) were used to determine the optimum fermentation cycle for the production of acetylglucosamine using immobilized .
RESULTS AND CONCLUSIONS
Pumice stones of 1.0 cm×1.0 cm×1.0 cm and pumice stone/growth medium ratio of 1:5 were found to be the optimum conditions for successful immobilization of (90.0±1.6) % cells and production of (331.4±7.3) g/L acetylglucosamine. The highest acetylglucosamine concentration of (323.0±2.5) g/L was obtained in the first fermentation cycle, which then decreased and remained stable throughout the last three cycles.
NOVELTY AND SCIENTIFIC CONTRIBUTION
, a strong chitinolytic bacterium previously isolated from rotten shrimp shells, was used for the first time in immobilized form to produce acetylglucosamine. The findings in this research showed the potential use of cells immobilized in pumice stone for continuous production of acetylglucosamine in repeated fermentation.
PubMed: 35440879
DOI: 10.17113/ftb.60.01.22.6994 -
Antimicrobial Agents and Chemotherapy Oct 2020Four isolates and one isolate were obtained from urine samples of five patients in 2018 in Japan. All of the isolates were resistant to imipenem and meropenem, and...
Four isolates and one isolate were obtained from urine samples of five patients in 2018 in Japan. All of the isolates were resistant to imipenem and meropenem, and three were highly resistant to both carbapenems, with MICs of 512 μg/ml. The three highly carbapenem-resistant isolates harbored , encoding a variant of IMP-1 metallo-β-lactamase with two amino acid substitutions (Val67Phe and Phe87Val), and the other two harbored and , respectively. Whole-genome sequencing revealed that an isolate harbored two copies of on the chromosome and that the other four harbored a copy of or in a plasmid. Expression of conferred carbapenem resistance in Recombinant IMP-70 and an IMP-1 variant with Val67Phe but without Phe87Val had significant higher hydrolytic activities against meropenem than recombinant IMP-1, indicating that an amino acid substitution of Val67Phe affects increased activities against meropenem in IMP-70. These results suggest that spp. become more highly resistant to carbapenems by acquisition of two copies of or by mutation of genes with amino acid substitutions, such as .
Topics: Humans; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Japan; Microbial Sensitivity Tests; Providencia
PubMed: 32816727
DOI: 10.1128/AAC.00382-20 -
The Journal of International Medical... Oct 2020To investigate the clinical and drug resistance characteristics of infections in the Huainan region of Anhui and provide a reference for the clinical selection of...
OBJECTIVES
To investigate the clinical and drug resistance characteristics of infections in the Huainan region of Anhui and provide a reference for the clinical selection of antimicrobial agents.
METHODS
This single-center retrospective analysis included 76 patients with infection in Huainan during the period from October 2018 to March 2020. The hospital department in which the patients were treated and the drug susceptibility characteristics of the isolates were recorded.
RESULTS
Among the 76 patients, the lung was the most common site of infection, and intensive care unit was the main hospital department. Extended spectrum beta-lactamase screening revealed expression by all 76 isolates of . Of the 76 isolates, 92.1% exhibited multiple drug resistance or extensive drug resistance. isolates were sensitive to cefepime and imipenem, but not to other beta-lactam antibiotics. Twenty isolates were resistant to all 21 types of antibiotics. Of the 20 patients infected with extensively drug-resistant isolates, nine (45%) died.
CONCLUSIONS
Drug resistance is increasing in . The antimicrobial agent imipenem may be effective for treatment of infections. Fluoroquinolones, aminoglycosides, and fourth-generation cephalosporins are suitable options for antibiotic therapy.
Topics: Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae Infections; Humans; Microbial Sensitivity Tests; Providencia; Retrospective Studies
PubMed: 33081537
DOI: 10.1177/0300060520962296 -
Microorganisms Apr 2022is a highly social pathogen responsible for nosocomial chronic urinary tract infections. The bacterium indeed forms floating communities of cells (FCC) besides and...
is a highly social pathogen responsible for nosocomial chronic urinary tract infections. The bacterium indeed forms floating communities of cells (FCC) besides and prior-to canonical surface-attached biofilms (SAB). Within FCC, cells are riveted one to another owing to by self-interactions between its porins, viz. Omp-Pst1 and Omp-Pst2. In pathophysiological conditions, is principally exposed to high concentrations of urea, ammonia, bicarbonate, creatinine and to large variations of pH, questioning how these environmental cues affect socialization, and whether formation of SAB and FCC protects cells against those. Results from our investigations indicate that FCC and SAB can both form in the urinary tract, endowing cells with increased resistance and fitness. They additionally show that while Omp-Pst1 is the main gateway allowing penetration of urea, bicarbonate and ammonia into the periplasm, expression of Omp-Pst2 enables resistance to them.
PubMed: 35630346
DOI: 10.3390/microorganisms10050901 -
Diagnostics (Basel, Switzerland) Mar 2023Microbiota are ecological communities of commensal, symbiotic, and pathogenic microorganisms. The microbiome could be involved in kidney stone formation through... (Review)
Review
Microbiota are ecological communities of commensal, symbiotic, and pathogenic microorganisms. The microbiome could be involved in kidney stone formation through hyperoxaluria and calcium oxalate supersaturation, biofilm formation and aggregation, and urothelial injury. Bacteria bind to calcium oxalate crystals, which causes pyelonephritis and leads to changes in nephrons to form Randall's plaque. The urinary tract microbiome, but not the gut microbiome, can be distinguished between cohorts with urinary stone disease (USD) and those without a history of the disease. In the urine microbiome, the role is known of urease-producing bacteria (, , , , , , and ) in stone formation. Calcium oxalate crystals were generated in the presence of two uropathogenic bacteria ( and . Non-uropathogenic bacteria ( and ) exhibit calcium oxalate lithogenic effects. The taxa and best distinguished the healthy cohort from the USD cohort, respectively. Standardization is needed in urine microbiome research for urolithiasis. Inadequate standardization and design of urinary microbiome research on urolithiasis have hampered the generalizability of results and diminished their impact on clinical practice.
PubMed: 36900094
DOI: 10.3390/diagnostics13050951 -
Access Microbiology 2023This study aimed to characterize the virulence factors and antimicrobial resistance of , an opportunistic pathogen that causes human infections. We examined 45 isolates...
This study aimed to characterize the virulence factors and antimicrobial resistance of , an opportunistic pathogen that causes human infections. We examined 45 isolates of both genotypically and phenotypically by studying their adherence to HeLa cells, biofilm formation, cytotoxicity and antimicrobial resistance, and analysed their genomes for putative virulence and resistance genes. This study found that most isolates possessed multiple virulence genes, including A, A, A, A, A and A, and were cytotoxic to Vero cells. All the isolates were resistant to amoxicillin plus clavulanic acid, levofloxacin and sulfamethoxazole plus trimethoprim, and most were resistant to ceftriaxone and cefepime. All isolates harboured extended-spectrum beta-lactamase coding genes such as and 23/45(51.11 %) of them also harboured . The gene KPC-2 (carbapenemase) was detected in 8/45(17.77 %) isolates. This study also found clonality among the isolates, indicating the possible spread of the pathogen among patients at the hospital. These results have significant clinical and epidemiological implications and emphasize the importance of a continued understanding of the virulence and antimicrobial resistance of this pathogen for the prevention and treatment of future infections.
PubMed: 37970084
DOI: 10.1099/acmi.0.000652.v4 -
Communications Biology Apr 2022Bacterial homologous lysine and arginine decarboxylases play major roles in the acid stress response, physiology, antibiotic resistance and virulence. The Escherichia...
Bacterial homologous lysine and arginine decarboxylases play major roles in the acid stress response, physiology, antibiotic resistance and virulence. The Escherichia coli enzymes are considered as their archetypes. Whereas acid stress triggers polymerisation of the E. coli lysine decarboxylase LdcI, such behaviour has not been observed for the arginine decarboxylase Adc. Here we show that the Adc from a multidrug-resistant human pathogen Providencia stuartii massively polymerises into filaments whose cryo-EM structure reveals pronounced differences between Adc and LdcI assembly mechanisms. While the structural determinants of Adc polymerisation are conserved only in certain Providencia and Burkholderia species, acid stress-induced polymerisation of LdcI appears general for enterobacteria. Analysis of the expression, activity and oligomerisation of the P. stuartii Adc further highlights the distinct properties of this unusual protein and lays a platform for future investigation of the role of supramolecular assembly in the superfamily or arginine and lysine decarboxylases.
Topics: Carboxy-Lyases; Escherichia coli; Providencia
PubMed: 35383285
DOI: 10.1038/s42003-022-03276-1 -
JAAD Case Reports May 2020
PubMed: 32382635
DOI: 10.1016/j.jdcr.2020.02.043 -
Antibiotics (Basel, Switzerland) Apr 2021spp. are emerging pathogens mainly in nosocomial infections. in particular is involved in urinary tract infections and contributes significantly to the high incidence...
spp. are emerging pathogens mainly in nosocomial infections. in particular is involved in urinary tract infections and contributes significantly to the high incidence of biofilm-formation in catheterized patients. Furthermore, recent reports suggested a role for multiple drug resistant (MDR) in hospital-associated outbreaks which leads to excessive complications resulting in challenging treatments. Phage therapy is currently one of the most promising solutions to combat antibiotic-resistant infections. However, the number of available phages targeting spp. is extremely limited, restricting the use of phage therapy in such cases. In the present study, we describe the isolation and characterization of 17 lytic and temperate bacteriophages targeting clinical isolates of spp. as part of the Israeli Phage Bank (IPB). These phages, isolated from sewage samples, were evaluated for host range activity and effectively eradicated 95% of the tested bacterial strains isolated from different geographic locations and displaying a wide range of antibiotic resistance. Their lytic activity is demonstrated on agar plates, planktonic cultures, and biofilm formed in a catheter model. The results suggest that these bacteriophages can potentially be used for treatment of antibiotic-resistant spp. infections in general and of urinary tract infections in particular.
PubMed: 33918377
DOI: 10.3390/antibiotics10040375