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American Journal of Physiology. Renal... Feb 2020
Topics: Animals; Calcium; Infections; Ion Channels; Kidney Calculi; Rats; Urolithiasis
PubMed: 32045266
DOI: 10.1152/ajprenal.00016.2020 -
Frontiers in Microbiology 2024is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming... (Review)
Review
is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of infections, emphasizing its association with UTIs. The bacterium's genome analysis revealed the presence of resistance genes against commonly used antibiotics, an antibiotic-resistant phenotype that poses a serious clinical challenge. Particularly, the emergence of extended-spectrum β-lactamases (ESBLs) and carbapenemases resistant strains. On a molecular level, possesses a wide array of virulence factors including the production of fimbriae, urease, hemolysins, metallophores, and biofilm formation. This review thoroughly tackles a substantial gap in understanding the role of metallophores in shaping the virulence factors of virulence. Siderophores, iron metal chelating and transporting metallophores, particularly contribute to the complex pathogenic strategies, displaying a potential target for therapeutic intervention.
PubMed: 38646633
DOI: 10.3389/fmicb.2024.1383618 -
Acute and Critical Care May 2024Polymicrobial infections are the leading causes of complications incurred from injuries that burn patients develop. Such patients admitted to the hospital have a high...
Polymicrobial infections are the leading causes of complications incurred from injuries that burn patients develop. Such patients admitted to the hospital have a high risk of developing hospital-acquired infections, with longer patient stays leading to increased chances of acquiring such drug-resistant infections. Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis are the most common multidrug-resistant (MDR) Gram-negative bacteria identified in burn wound infections (BWIs). BWIs caused by viruses, like Herpes Simplex and Varicella Zoster, and fungi-like Candida spp. appear to occur occasionally. However, the preponderance of infection by opportunistic pathogens is very high in burn patients. Variations in the causative agents of BWIs are due to differences in geographic location and infection control measures. Overall, burn injuries are characterized by elevated serum cytokine levels, systemic immune response, and immunosuppression. Hence, early detection and treatment can accelerate the wound-healing process and reduce the risk of further infections at the site of injury. A multidisciplinary collaboration between burn surgeons and infectious disease specialists is also needed to properly monitor antibiotic resistance in BWI pathogens, help check the super-spread of MDR pathogens, and improve treatment outcomes as a result.
PubMed: 38863352
DOI: 10.4266/acc.2023.01571 -
Frontiers in Microbiology 2020spp. are commensal Enterobacterales of the human digestive tract. At the same time, is commonly involved in urinary tract infections (UTI). is naturally resistant to... (Review)
Review
spp. are commensal Enterobacterales of the human digestive tract. At the same time, is commonly involved in urinary tract infections (UTI). is naturally resistant to several antibiotics including colistin and shows reduced susceptibility to imipenem. However higher levels of resistance to imipenem commonly occur in isolates consecutively to the loss of porins, reduced expression of penicillin binding proteins (PBPs) PBP1a, PBP2, or acquisition of several antibiotic resistance genes, including carbapenemase genes. In addition, resistance to non-β-lactams is also frequently reported including molecules used for treating UTI infections (e.g., fluoroquinolones, nitrofurans). Emergence and spread of multidrug resistant isolates, including those producing ESBLs, AmpC cephalosporinases and carbapenemases, are being more and more frequently reported. This review covers spp. with a focus on the different genetic mechanisms involved in the acquisition of resistance genes to multiple antibiotic classes turning into a dreadful pandrug resistant bacteria and resulting in difficult to treat infections.
PubMed: 32153540
DOI: 10.3389/fmicb.2020.00256 -
BMC Microbiology Oct 2022Proteus mirabilis is an opportunistic pathogen, causing a variety of community-acquired and nosocomial illnesses. It poses a potential threat to patients via the...
BACKGROUND
Proteus mirabilis is an opportunistic pathogen, causing a variety of community-acquired and nosocomial illnesses. It poses a potential threat to patients via the production of β-lactamases, which decrease the efficacy of antimicrobial treatment and impair the management of its pathogenicity. Hence, this study was established to determine the prevalence of extended-spectrum β-lactamases (ESBLs), AmpC, and carbapenemases of P. mirabilis isolated from various clinical specimens.
RESULTS
Proteus mirabilis was identified in 20.7% (58/280) of specimens. ESBL producers were present at a rate of 51.7% (30/58). All AmpC-positive isolates (n = 20) produced ESBLs as well, so 66.7% of ESBL-producing isolates coproduced AmpC enzymes. The modified Hodge test confirmed carbapenemase production in six out of seven imipenem nonsusceptible isolates. Of these, only two (5.7%) isolates were also ESBL-and AmpC-positive. Antibiotic resistance reached the highest level for cotrimoxazole (62.1%, n = 36/58 isolates) and the lowest for imipenem (12.1%, n = 7/58 isolates). The levels of multidrug-resistant (MDR) was 41.4% among the tested isolates. The bla (83.3%), bla (80%), and bla (50%) were the most detected genes in phenotypically confirmed ESBL-, AmpC-, and carbapenemase-producing isolates, respectively. Besides, more than a half of the tested P. mirabilis strains (53%) coproduced ESBLs and AmpC. Moreover, two isolates coproduced ESBLs and AmpC together with carbapenemases. Furthermore, dendrogram analysis showed great genetic divergence based on the 21 different enterobacterial repetitive intergenic consensus (ERIC) patterns (P1-P21) through the 34 β-lactamase producers. ERIC analysis distinguished clonal similarities between isolates 21 and 22 in P2 and 9 and 10 in P4, which were isolated from the same clinical source and possessed similar patterns of β-lactamase-encoding genes.
CONCLUSION
Hence, there is an urgent need to monitor hospitalized patients and improve healthcare in order to reduce the incidence of infection and outbreaks of infection with antibiotic-resistant Proteus.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Enterobacteriaceae; Humans; Imipenem; Microbial Sensitivity Tests; Prevalence; Proteus mirabilis; Trimethoprim, Sulfamethoxazole Drug Combination; beta-Lactamases
PubMed: 36221063
DOI: 10.1186/s12866-022-02662-3 -
Frontiers in Microbiology 2023is a multi-host pathogen that causes diseases of varying severity in a wide range of mammals, including humans. is resistant to multiple antibiotics and has acquired...
INTRODUCTION
is a multi-host pathogen that causes diseases of varying severity in a wide range of mammals, including humans. is resistant to multiple antibiotics and has acquired the ability to produce expanded spectrum of β-lactamases, leading to serious public health problems. However, the available information on isolated from feces of dogs, is still poorly understood, as is the correlation between its virulence-associated genes (VAGs) and antibiotic resistance genes (ARGs).
METHOD
In this study, we isolated 75 strains of from 241 samples, and investigated the swarming motility, biofilm formation, antimicrobial resistance (AMR), distribution of VAGs and ARGs, as well as the presence of class 1, 2, and 3 integrons in these isolates.
RESULTS
Our findings suggest a high prevalence of intensive swarming motility and strong biofilm formation ability among isolates. Isolates were primarily resistant to cefazolin (70.67%) and imipenem (70.67%). These isolates were found to carry , , , , , , , , , , and with varying prevalence levels of 100.00, 100.00, 100.00, 98.67, 98.67, 90.67, 90.67, 90.67, 90.67, 89.33, and 70.67%, respectively. Additionally, the isolates were found to carry , , , , , , , , and with varying prevalence levels of 38.67, 32.00, 25.33, 17.33, 16.00, 10.67, 5.33, 2.67, 1.33, and 1.33%, respectively. Among 40 MDR strains, 14 (35.00%) were found to carry class 1 integrons, 12 (30.00%) strains carried class 2 integrons, while no class 3 integrons was detected. There was a significant positive correlation between the class 1 integrons and three ARGs: , , and . This study revealed that strains isolated from domestic dogs exhibited a higher prevalence of MDR, and carried fewer VAGs but more ARGs compared to those isolated from stay dogs. Furthermore, a negative correlation was observed between VAGs and ARGs.
DISCUSSION
Given the increasing antimicrobial resistance of , veterinarians should adopt a prudent approach towards antibiotics administration in dogs to mitigate the emergence and dissemination of MDR strains that pose a potential threat to public health.
PubMed: 37234544
DOI: 10.3389/fmicb.2023.1141418 -
Journal of Microbiology, Immunology,... Apr 2023New tetracycline derivatives exhibit broad-spectrum antimicrobial activities. This study aimed to assess the in vitro activity of eravacycline against common...
BACKGROUND
New tetracycline derivatives exhibit broad-spectrum antimicrobial activities. This study aimed to assess the in vitro activity of eravacycline against common Enterobacterales.
METHODS
Clinical Enterobacterales isolates were collected between 2017 and 2021. The minimum inhibitory concentration (MIC) was determined using a broth microdilution test.
RESULTS
We identified Klebsiella pneumoniae (n = 300), Escherichia coli (n = 300), Klebsiella oxytoca (n = 100), Enterobacter cloacae complex (n = 100), Citrobacter freundii (n = 100), and Proteus mirabilis (n = 100). All P. mirabilis strains were resistant to eravacycline. Excluding P. mirabilis, the susceptibility rates to eravacycline, omadacycline, and tigecycline were 75.2%, 66.9%, and 73%, respectively. The MIC and MIC (mg/L) of eravacycline were 0.5 and 4 for K. pneumoniae, 0.5 and 1 for E. coli, 0.5 and 1 for K. oxytoca, 0.5 and 2 for E. cloacae complex, and 0.25 and 1 for C. freundii. In cefotaxime non-susceptible and meropenem susceptible Enterobacterales, excluding P. mirabilis, the susceptibility rates of eravacycline, omadacycline, and tigecycline were 69.7%, 57.1%, and 66.2%. We found decreased susceptibility rates of three new tetracycline derivatives against meropenem non-susceptible Enterobacterales (eravacycline: 47.1%, omadacycline: 39.4%, and tigecycline: 39.4%). Eravacycline showed a high susceptibility rate against cefotaxime non-susceptible and meropenem susceptible K. oxytoca (100%), C. freundii (93.2%), E. coli (85.9%), and meropenem non-susceptible E. coli (100%).
CONCLUSION
This study provides the MIC and susceptibility rate of eravacycline for common Enterobacterales. Eravacycline could be a therapeutic choice for cefotaxime non-susceptible or meropenem non-susceptible Enterobacterales, especially K. oxytoca, C. freundii, and E. coli.
Topics: Humans; Meropenem; Tigecycline; Escherichia coli; Taiwan; Anti-Bacterial Agents; Klebsiella pneumoniae; Klebsiella oxytoca; Cefotaxime; Microbial Sensitivity Tests
PubMed: 36243669
DOI: 10.1016/j.jmii.2022.09.009 -
MBio Oct 2019Swarmer cells of the Gram-negative uropathogenic bacteria and become long (>10 to 100 μm) and multinucleate during their growth and motility on polymer surfaces. We...
Swarmer cells of the Gram-negative uropathogenic bacteria and become long (>10 to 100 μm) and multinucleate during their growth and motility on polymer surfaces. We demonstrated that the increasing cell length is accompanied by a large increase in flexibility. Using a microfluidic assay to measure single-cell mechanics, we identified large differences in the swarmer cell stiffness (bending rigidity) of (5.5 × 10 N m) and (1.0 × 10 N m) compared to vegetative cells (1.4 × 10 N m and 2.2 × 10 N m, respectively). The reduction in bending rigidity (∼2-fold to ∼26-fold) was accompanied by a decrease in the average polysaccharide strand length of the peptidoglycan layer of the cell wall from 28 to 30 disaccharides to 19 to 22 disaccharides. Atomic force microscopy revealed a reduction in peptidoglycan thickness from 1.5 nm (vegetative cells) to 1.0 nm (swarmer cells), and electron cryotomography indicated changes in swarmer cell wall morphology. and swarmer cells became increasingly sensitive to osmotic pressure and susceptible to cell wall-modifying antibiotics (compared to vegetative cells)-they were ∼30% more likely to die after 3 h of treatment with MICs of the β-lactams cephalexin and penicillin G. The adaptive cost of "swarming" was offset by the increase in cell susceptibility to physical and chemical changes in their environment, thereby suggesting the development of new chemotherapies for bacteria that leverage swarming for the colonization of hosts and for survival. and are bacteria that infect humans. To adapt to environmental changes, these bacteria alter their cell morphology and move collectively to access new sources of nutrients in a process referred to as "swarming." We found that changes in the composition and thickness of the peptidoglycan layer of the cell wall make swarmer cells of and more flexible (i.e., reduce cell stiffness) and that they become more sensitive to osmotic pressure and cell wall-targeting antibiotics (e.g., β-lactams). These results highlight the importance of assessing the extracellular environment in determining antibiotic doses and the use of β-lactam antibiotics for treating infections caused by swarmer cells of and .
Topics: Anti-Bacterial Agents; Chemical Phenomena; Locomotion; Mechanical Phenomena; Microbial Viability; Microfluidics; Osmotic Pressure; Peptidoglycan; Polysaccharides, Bacterial; Proteus mirabilis; Single-Cell Analysis; Vibrio parahaemolyticus; beta-Lactams
PubMed: 31594808
DOI: 10.1128/mBio.00210-19 -
Revista Argentina de Microbiologia 2023Proteus mirabilis(P. mirabilis) is a common etiological agent of urinary tract infections, particularly those associated with catheterization. P. mirabilis efficiently...
Proteus mirabilis(P. mirabilis) is a common etiological agent of urinary tract infections, particularly those associated with catheterization. P. mirabilis efficiently forms biofilms on different surfaces and shows a multicellular behavior called 'swarming', mediated by flagella. To date, the role of flagella in P. mirabilis biofilm formation has been under debate. In this study, we assessed the role of P. mirabilis flagella in biofilm formation using an isogenic allelic replacement mutant unable to express flagellin. Different approaches were used, such as the evaluation of cell surface hydrophobicity, bacterial motility and migration across catheter sections, measurements of biofilm biomass and biofilm dynamics by immunofluorescence and confocal microscopy in static and flow models. Our findings indicate that P. mirabilis flagella play a role in biofilm formation, although their lack does not completely avoid biofilm generation. Our data suggest that impairment of flagellar function can contribute to biofilm prevention in the context of strategies focused on particular bacterial targets.
Topics: Humans; Proteus mirabilis; Biofilms; Urinary Tract Infections; Flagella
PubMed: 37076397
DOI: 10.1016/j.ram.2023.01.005 -
Diagnostics (Basel, Switzerland) Oct 2022and are common single- and polymicrobial urinary tract infections which can survive under various oxygen levels, including inside of stone matrices. Therefore, we...
and are common single- and polymicrobial urinary tract infections which can survive under various oxygen levels, including inside of stone matrices. Therefore, we aimed to investigate and compare the calcium oxalate monohydrate (COM) lithogenic activities including COM crystal growth and aggregation under microaerobic conditions of and isolated from the same stone matrix. The crystal growth was analyzed at the delta crystal area while the crystal aggregation was analyzed as the number of crystal aggregates. The results showed that compared to blank control, , and the co-culture of and were able to significantly promote COM crystal growth under microaerobic conditions. Interestingly, the delta crystal area in the co-culture under microaerobic conditions was larger than that of alone and alone. In addition, only alone and the co-culture were able to significantly increase COM aggregates. This study demonstrated that single- and co-culture of and could promote COM crystal growth and aggregation under microaerobic conditions. The co-culture of and may provide the combination effect on COM crystal interactions. The bacterial surfaces and the important effects on bacteria-crystal interactions should be further evaluated.
PubMed: 36359494
DOI: 10.3390/diagnostics12112651