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Frontiers in Public Health 2021The genus was established in 2001. Species of and share many ecological, biochemical, clinical, and microbiological features. Given the shortcomings of available... (Review)
Review
The genus was established in 2001. Species of and share many ecological, biochemical, clinical, and microbiological features. Given the shortcomings of available technology for species identification in the clinical microbiology laboratory, are practically indistinguishable. Since the late 2000s there has been an increase in case reports of human infections. Therefore, several authors are postulating that spp. are rare and/or emerging pathogens. spp. are very similar to . The epidemiology and the clinical relevance of the human spp. infections is uncertain and further studies are required. The previous difficulties in the identification of spp. and the introduction of more precise identification techniques may explain the recent increase in the number of case reports. spp. might be rather underdiagnosed than rare or emerging pathogens.
Topics: Enterobacteriaceae Infections; Humans; Klebsiella
PubMed: 34409007
DOI: 10.3389/fpubh.2021.686789 -
Scientific Reports Mar 2022Raoultella planticola is an emerging pathogen causing several infections in humans, and its roles in the propagation of antibiotic resistance genes (ARGs) remain...
Raoultella planticola is an emerging pathogen causing several infections in humans, and its roles in the propagation of antibiotic resistance genes (ARGs) remain uncharacterized. In this study, a carbapenem and tigecycline-resistant R. planticola isolate was recovered from hospital sewage. It carried nine plasmids, bearing 30 ARGs, including one bla and two bla. It also contained a plasmid-borne efflux pump gene cluster, tmexCD1-toprJ, conferring resistance to tigecycline. Analysis of plasmid sequences revealed that both bla-carrying plasmids were highly similar to those recovered from humans, reinforcing the close relatedness of environmental and clinical isolates. We also identified that plasmid bearing bla or tmexCD1-toprJ1 was transferable, and can be stabilized in the host bacteria, indicating that the R. planticola isolate has a considerable potential in the dissemination of ARGs. Besides, we found that this isolate could produce biofilm and was virulent in a Galleria mellonella infection model. In conclusion, our study shows the convergence of virulence and multidrug resistance in a R. planticola isolate. This potentially virulent superbug may disseminate into its receiving rivers, and finally to humans through cross-contamination during recreation activities or daily use of water, which poses a risk to public health.
Topics: Anti-Bacterial Agents; Carbapenems; Enterobacteriaceae; Humans; Klebsiella pneumoniae; Microbial Sensitivity Tests; Plasmids; Tigecycline; Virulence; beta-Lactamases
PubMed: 35264602
DOI: 10.1038/s41598-022-07778-0 -
Iranian Journal of Biotechnology Oct 2022Nanoparticles can be chemically, physically, or biologically synthesized. Biosynthesis of silver nanoparticles (AgNPs) utilizing microbes is a promising process due to...
BACKGROUND
Nanoparticles can be chemically, physically, or biologically synthesized. Biosynthesis of silver nanoparticles (AgNPs) utilizing microbes is a promising process due to the low toxicity and high stability of AgNPs. Here, AgNPs were fabricated by Gram-negative .
OBJECTIVES
This study aimed to assess the ability of to produce nanoparticles (NPs) and evaluate their antibacterial potential against multidrug-resistant pathogens (MDR). Additionally, the study aimed to compare the antibacterial activity of biosynthesized nanoparticles to well-known conventional antibiotics Azithromycin and Tetracycline.
MATERIALS AND METHODS
AgNPs were characterized using visual observation, UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The TEM and SEM were used to determine the size and shape of the nanoparticles. The XRD data were recorded in the 2θ ranging from 20-80° to analyze the crystalline structure of nanoparticles. The antibacterial activity was detected using a 96-well microtiter plate.
RESULTS
The UV-vis absorption recorded from the 300 - 900 nm spectrum was well defined at 420 nm, and the XRD pattern was compatible with Braggs's reflection of the silver nanocrystals. FTIR showed absorbance bands corresponding to different functional groups. TEM and SEM images showed non-uniform spherical and AgNPs of 10-80 nm. XRD data confirmed that the resultant particles are AgNPs. The AgNPs showed effective activity against multi-drug resistant (MDR) , sp., sp., , sp., , and . The AgNPs demonstrated effectiveness in lower concentrations compared to broad-spectrum antibiotics.
CONCLUSION
These data reveal that AgNP generated by was more efficient against MDR microorganisms than commercial antibiotics. However, the cytotoxicity of these nanoparticles must be further studied.
PubMed: 38344316
DOI: 10.30498/ijb.2022.298773.3121 -
Cureus Sep 2021is a gram-negative, aerobic, nonmotile bacteria that can be found in soil and water. This is a relatively rare organism with few case reports on it and only three...
is a gram-negative, aerobic, nonmotile bacteria that can be found in soil and water. This is a relatively rare organism with few case reports on it and only three reports of -induced urinary tract infection (UTI) have been reported. Here we present a case of acute cystitis caused by in a woman with atrial fibrillation and recurrent UTIs.
PubMed: 34660160
DOI: 10.7759/cureus.17985 -
Infection and Drug Resistance 2021is an aerobic gram-negative rod predominantly found in soil and aquatic environments. The typical reservoirs of spp. include the gastrointestinal tract and the upper...
INTRODUCTION
is an aerobic gram-negative rod predominantly found in soil and aquatic environments. The typical reservoirs of spp. include the gastrointestinal tract and the upper respiratory tract. It usually causes pneumonia, biliary tract infections, and bacteremia. Urinary tract infection (UTI) secondary to is an uncommon entity. Less than 10 cases of -associated UTIs in adults have been published in the literature to date.
OBJECTIVE
This is a single institution retrospective study undertaken to identify the epidemiology, patient characteristics, clinical spectrum, predisposing risk factors and the outcome of patients with UTI caused by
RESULTS
A total of 37 isolates were identified in urine samples over a 5-year study period. The mean age of the patient population was 77 years. The most common comorbidity was diabetes mellitus, which was present in 16 patients. Only 3 patients had a history of steroid use, an immunosuppressive condition, or were on chemotherapy. The most common presenting complaint was altered mental status followed by fever. Resistance to ampicillin was found in 35 isolates which seems to be an intrinsic characteristic of spp. and 2 isolates were multidrug-resistant, but still susceptible to ciprofloxacin. The average length of stay was 3 days, and the average duration of antibiotic administration was 8 days. Ciprofloxacin was the most frequently prescribed antibiotic (9 patients). The severity of infection ranged from simple cystitis in 15 patients to urosepsis in 2 patients and septic shock in 2 patients. There were no mortalities in our cohort.
CONCLUSION
Our study revealed that patients with UTI had higher proportion of diabetes mellitus, renal failure compared to the general population. Our study also confirms the intrinsic resistance to ampicillin of spp., which has been documented previously in the literature.
PubMed: 34103946
DOI: 10.2147/IDR.S306632 -
Journal of Thoracic Disease Apr 2020, considered to be an environmental organism, is a rare cause of human infections. Although in recent years the frequency of infections reported in the literature has...
BACKGROUND
, considered to be an environmental organism, is a rare cause of human infections. Although in recent years the frequency of infections reported in the literature has increased, few cases of pneumonia caused by have been described. Here, we investigate the clinical characteristics, management, and clinical outcomes of pneumonia caused by .
METHODS
Consecutive patients with pneumonia caused by were included. The medical records of patients with pneumonia treated at Dankook University Hospital from January 2011 to December 2017 were collected.
RESULTS
A total of 11 adult patients with pneumonia were diagnosed and treated [10 males and 1 female; median age, 70 years (range: 51-79 years)]; 5 patients had underlying malignant conditions (45.5%). Antibacterial susceptibility testing showed that all isolates of were susceptible to cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, and beta-lactams/beta-lactamase inhibitors. Chest imaging revealed consolidation (8/11, 72.7%), ground-glass opacity (5/11, 45.5%), pleural effusion (5/11, 45.5%), and micronodules (3/11, 27.3%). Four patients (36.4%) required mechanical ventilation; three survived but one died of multiple organ dysfunction syndrome (principally pneumonia and septic shock).
CONCLUSIONS
pneumonia occurred mainly in patients with underlying risk factors such as malignant disease, cerebral infarction or hemorrhage, and chronic obstructive pulmonary disease. The organism was sensitive to most antibiotics, and the clinical outcomes were favorable after empirical antibiotic therapy.
PubMed: 32395267
DOI: 10.21037/jtd.2020.02.56 -
Diseases (Basel, Switzerland) Oct 2018is a gram-negative bacterium of the family that is usually found in soil, plant and aquatic environments. It is an uncommon human pathogen and has been associated with...
is a gram-negative bacterium of the family that is usually found in soil, plant and aquatic environments. It is an uncommon human pathogen and has been associated with cases of bacteremia, pneumonia, urinary tract infections, among others. Here, we present the case of an 85-year-old female that developed nosocomial pneumonia and bacteremia caused by . Pertinent microbiological studies detected carbapenemase production codified by the bla gene. The patient was successfully treated with ceftazidime/avibactam and polymyxin. Our case illustrates the pathogenic potential of this organism and highlights the importance of phenotypic and genotypic assays for the appropriate identification of carbapenemase production.
PubMed: 30336607
DOI: 10.3390/diseases6040094 -
Journal of Infection in Developing... May 2022Raoultella planticola is a Gram-negative, aerobic, non-motile bacterium, abundant in the environment, but rarely associated with pathology in humans. Notably, few...
Raoultella planticola is a Gram-negative, aerobic, non-motile bacterium, abundant in the environment, but rarely associated with pathology in humans. Notably, few urinary tract infections caused by R. planticola have been reported. To our knowledge, we are presenting here the first case of urinary tract infection caused by R. planticola in an HIV-infected individual. It is a 50-year-old female, with a history of HIV-1 infection treated for three years. At admission, her CD4 count was 70 cells/mL, and the main complaints were severe diarrhea and cough. She was diagnosed and treated for pulmonary tuberculosis (TB) and E. Coli enteritis. Initially, we observed a good evolution. However, on day 21 of hospitalization, she presented with fever and dysuria. Urinalysis revealed the presence of R. planticola with resistance to multiple antibiotics. We also detected that she has an HIV-2 but not HIV-1 infection. After receiving the right regimen, she was confirmed cured of her bacterial infections.
Topics: Enterobacteriaceae; Escherichia coli; Female; Gram-Negative Bacteria; Humans; Mali; Middle Aged; Urinary Tract Infections
PubMed: 35656965
DOI: 10.3855/jidc.15688 -
Microorganisms Jun 2022Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as ,... (Review)
Review
Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as , , , , , , , , spp., , , , , , , , , , spp., , , , , , and In this review, the role of these bacteria in histamine production in fish and seafood products with consequences for human food poisoning following consumption are discussed. In addition, methods to control their activity in countering histamine production are proposed.
PubMed: 35744715
DOI: 10.3390/microorganisms10061197 -
Case Reports in Infectious Diseases 2022, a Gram-negative bacterium, is a nonmotile rod usually found in soil and aquatic environments. It can be found in association with gastrointestinal malignancy. is a...
, a Gram-negative bacterium, is a nonmotile rod usually found in soil and aquatic environments. It can be found in association with gastrointestinal malignancy. is a rare vancomycin-resistant that is responsible for some bacteremia. Our case describes a unique presentation of colonization with both and isolated from the biliary stent isolates of a patient with known pancreatic malignancy and concomitant bacteremia. This is the first case ever reported of infection with both species.
PubMed: 35656361
DOI: 10.1155/2022/3377331