-
Journal of Infection and Chemotherapy :... Oct 2022Sphingobacterium is an aerobic, glucose non-fermenting, Gram-negative rod bacterium that has been isolated from soil, plants, food, and water sources, including in...
INTRODUCTION
Sphingobacterium is an aerobic, glucose non-fermenting, Gram-negative rod bacterium that has been isolated from soil, plants, food, and water sources, including in hospitals. Reports of systemic infections caused by Sphingobacterium multivorum (S. multivorum) are rare, and their clinical and microbiological characteristics remain unclear. Moreover, conventional microbiological methods have limited ability to identify S. multivorum. We report the first case of obstructive cholangitis with bacteremia caused by S. multivorum in a patient with gastric cancer.
CASE REPORT
A 68-year-old woman with advanced gastric cancer, hypertension, and hyperlipidemia was admitted with obstructive jaundice, and subsequently developed obstructive cholangitis during the hospital stay. S. multivorum were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S ribosomal RNA sequencing of the patient's blood samples. Based on the antibiotic susceptibility results of the isolates, cefepime was administered intravenously for 14 days, with good therapeutic outcomes.
CONCLUSIONS
S. multivorum infection is rare, and its microbiology and pathogenicity in humans is mostly unknown. Therefore, multiple diagnostic approaches should be used to identify S. multivorum, and antimicrobial therapy should be selected based on the in vitro susceptibility. This report provides clinicians with novel information on the clinical manifestations and diagnostic methods for an accurate diagnosis of S. multivorum.
Topics: Acinetobacter; Aged; Bacteremia; Cholangitis; Female; Humans; RNA, Ribosomal, 16S; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sphingobacterium; Stomach Neoplasms
PubMed: 35718261
DOI: 10.1016/j.jiac.2022.06.005 -
International Journal of Molecular... Jul 2023Metal-Organic Frameworks (MOFs) offer new ideas for the design of antibacterial materials because of their antibacterial properties, high porosity and specific surface...
Metal-Organic Frameworks (MOFs) offer new ideas for the design of antibacterial materials because of their antibacterial properties, high porosity and specific surface area, low toxicity and good biocompatibility compared with other nanomaterials. Herein, a novel antimicrobial nanomaterial, MIL-101(Fe)@ZnO, has been synthesized by hydrothermal synthesis and characterized by FTIR, UV-vis, ICP-OES, XRD, SEM, EDS and BET to show that the zinc ions are doped into the crystal lattice of MIL-101(Fe) to form a Fe-Zn bimetallic structure. MIL-101(Fe)@ZnO was found to be effective against a wide range of antibacterial materials including , , , , and . It has a significant antibacterial effect, weak cytotoxicity, high safety performance and good biocompatibility. Meanwhile, MIL-101(Fe)@ZnO was able to achieve antibacterial effects by causing cells to produce ROS, disrupting the cell membrane structure, and causing protein leakage and lipid preoxidation mechanisms. In conclusion, MIL-101(Fe)@ZnO is an easy-to-prepare antimicrobial nanomaterial with broad-spectrum bactericidal activity and low toxicity.
Topics: Zinc Oxide; Metal-Organic Frameworks; Nanoparticles; Anti-Bacterial Agents
PubMed: 37569611
DOI: 10.3390/ijms241512238 -
Journal of Global Antimicrobial... Dec 2020The aim of this study was to identify Acinetobacter spp. strains from paediatric patients, to determine their genetic relationship, to detect antibiotic resistance genes...
OBJECTIVES
The aim of this study was to identify Acinetobacter spp. strains from paediatric patients, to determine their genetic relationship, to detect antibiotic resistance genes and to evaluate the role of efflux pumps in antibiotic resistance.
METHODS
A total of 54 non-duplicate, non-consecutive Acinetobacter spp. isolates were collected from paediatric patients. Their genetic relationship, antibiotic resistance profile, efflux pump activity, antibiotic resistance genes and plasmid profile were determined.
RESULTS
The isolates were identified as 24 Acinetobacter haemolyticus, 24 Acinetobacter calcoaceticus-baumannii (Acb) complex and 1 strain each of Acinetobacter junii, Acinetobacter radioresistens, Acinetobacter indicus, Acinetobacter lwoffii, Acinetobacter ursingii and Acinetobacter venetianus. The 24 A. haemolyticus were considered genetically unrelated. One strain was resistant to carbapenems, two to cephalosporins, two to ciprofloxacin and sixteen to aminoglycosides. The antibiotic resistance genes bla (29%), bla (4%), bla (8%), bla (29%), bla (4%), aac(6')-Ig (38%) and the novel variants bla (13%), bla (75%), aac(6')-Iga (4%), aac(6')-Igb (13%) and aac(6')-Igc (42%) were detected. Among 24 Acb complex, 5 were multidrug-resistant, carbapenem-resistant strains carrying bla and bla; they were genetically related and had the same plasmid profile. Other species were susceptible. In some strains of A. haemolyticus and Acb complex, the role of RND efflux pumps was evidenced by a decrease in the MICs for cefotaxime, amikacin and ciprofloxacin in the presence of an efflux pump inhibitor.
CONCLUSIONS
This study identified isolates of A. haemolyticus carrying new β-lactamase variants and shows for the first time the contribution of efflux pumps to antibiotic resistance in this species.
Topics: Acinetobacter; Acinetobacter Infections; Acinetobacter baumannii; Child; Hospitals, Pediatric; Humans; Mexico
PubMed: 32916332
DOI: 10.1016/j.jgar.2020.08.014 -
Urology Case Reports Sep 2020is one of more than 50 different species belonging to the genus . This bacterium is rarely reported to cause human infections. Here we described a rare case of , which...
is one of more than 50 different species belonging to the genus . This bacterium is rarely reported to cause human infections. Here we described a rare case of , which grew in urine culture approximately one month after the patient was discharged from the hospital with antibiotics for a urinary tract infection, which caused left obstructing renal calculi requiring nephrostomy tube placement.
PubMed: 32322533
DOI: 10.1016/j.eucr.2020.101209 -
Journal of Laboratory Physicians Sep 2023species has become a leading cause of nosocomial infections in recent years. The aim of the study was to establish the usefulness of matrix-assisted laser...
species has become a leading cause of nosocomial infections in recent years. The aim of the study was to establish the usefulness of matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS) for the identification of species with respect to conventional biochemical methods and MicroScan WalkAway 96 Plus system and to compare the antibiotic susceptibility test results Kirby-Bauer disk diffusion method with MicroScan WalkAway 96 Plus automated identification and antimicrobial susceptibility testing system. The study sample comprised 100 clinical isolates of species. They were all identified using MALDI-TOF MS and compared with other two identification systems. Comparison of categorical variables by Fisher's exact test or Pearson's chi-square test was done. All statistical tools were two tailed, and a significant level < 0.05 was used. All statistical tests were performed using SPSS v22.0 (Armonk IBM Corp., New York, United States). Cohen's kappa coefficients were also calculated and used as applicable. MALDI-TOF MS revealed 92 , 2 , 3 , and 1 each was identified as , , and . There was moderate agreement between identification by MicroScan WalkAway and MALDI-TOF, and substantial agreement between conventional biochemical tests and MALDI-TOF. We found that there was a 100% categorical agreement with respect to susceptibility of aminoglycosides (amikacin, gentamicin, tobramycin) and cephalosporins (ceftazidime, cefepime, cefotaxime) between disk diffusion method and MicroScan WalkAway 96 Plus system. Total of 16 errors were observed. Although MALDI-TOF MS could be useful to identify but not other species in the genus, it is a rapid, reliable method and can be routinely used in clinical laboratories.
PubMed: 37564221
DOI: 10.1055/s-0042-1760401 -
Communications Biology Oct 2022Incomplete documentary evidence, variable biomolecular preservation, and limited skeletal responses have hindered assessment of acute infections in the past. This study...
Incomplete documentary evidence, variable biomolecular preservation, and limited skeletal responses have hindered assessment of acute infections in the past. This study was initially developed to explore the diagnostic potential of dental calculus to identify infectious diseases, however, the breadth and depth of information gained from a particular individual, St. Louis Individual (St.LI), enabled an individualized assessment and demanded broader disciplinary introspection of ethical research conduct. Here, we document the embodiment of structural violence in a 23-year-old Black and/or African American male, who died of lobar pneumonia in 1930s St. Louis, Missouri. St.LI exhibits evidence of systemic poor health, including chronic oral infections and a probable tuberculosis infection. Metagenomic sequencing of dental calculus recovered three pre-antibiotic era pathogen genomes, which likely contributed to the lobar pneumonia cause of death (CoD): Klebsiella pneumoniae (13.8X); Acinetobacter nosocomialis (28.4X); and Acinetobacter junii (30.1X). Ante- and perimortem evidence of St.LI's lived experiences chronicle the poverty, systemic racism, and race-based structural violence experienced by marginalized communities in St. Louis, which contributed to St.LI's poor health, CoD, anatomization, and inclusion in the Robert J. Terry Anatomical Collection. These same embodied inequalities continue to manifest as health disparities affecting many contemporary communities in the United States.
Topics: Adult; Black or African American; Anti-Bacterial Agents; Bacterial Infections; Dental Calculus; Humans; Male; United States; Violence; Young Adult
PubMed: 36192528
DOI: 10.1038/s42003-022-03890-z -
MSphere Jan 2021nasal carriage provides the bacterial reservoir for opportunistic infection. In comparing the nasal microbiomes of culture-defined persistent carriers versus...
nasal carriage provides the bacterial reservoir for opportunistic infection. In comparing the nasal microbiomes of culture-defined persistent carriers versus noncarriers, we detected DNA in all noses, including those with an established history of negativity based on culture. Colonization with , including , , , and select spp., was associated with noncarriage. We next developed physiological competition assays for testing anti- activity of isolated nasal species, utilizing medium modeling the nutrient-limited fluid of the nasal mucosa, polarized primary nasal epithelia, and nasal secretions. from the nose of an noncarrier demonstrated >99% inhibition of recovery in all assays, even when was coincubated in 9-fold excess. Secreted inhibitory proteins from and were heat-stable and <30 kDa, fitting the profile of antimicrobial peptides. , , , and inhibited recovery on nasal epithelia in a contact-dependent manner, while several other species either had no effect or promoted growth. Collectively, this project is one of the first to identify resident nasal microbial species that impede survival, and it implies that detectable nasal results from shifts in microbial community composition. Nasal carriage of is a risk factor for infection, but it is not yet understood why some individuals carry nasal persistently, intermittently, or seemingly not at all when tested via culture methods. This study compared the nasal microbiomes of established carriers and noncarriers, identified species associated with noncarriage, and tested them for anti- activity using assays developed to model the nutrient-limited nasal mucosa. We determined that all nostril swabs contain DNA, even swabs from hosts considered to be long-term noncarriers. Select members of the class were more prevalent in noncarrier than carrier nostrils and demonstrated potent activity against multiple strains of The results described here provide a better understanding of how the nasal microbiome controls growth and viability and may be useful in the design of improved decolonization strategies.
Topics: Anti-Bacterial Agents; Antibiosis; Carrier State; Cells, Cultured; Epithelial Cells; Gammaproteobacteria; Humans; Microbiota; Nasal Cavity; Staphylococcus aureus
PubMed: 33408227
DOI: 10.1128/mSphere.01015-20 -
Annales Pharmaceutiques Francaises Nov 2023Nanofibers are a class of nanomaterial with specific physicochemical properties and characteristics making them quite sought after and investigated by researchers....
Nanofibers are a class of nanomaterial with specific physicochemical properties and characteristics making them quite sought after and investigated by researchers. Lipopeptide biosurfactant (LPB) formulation properties were previously established in wound healing. LPB were isolated from in vitro culture of Acinetobacter junii B6 and loaded on nanofibers formulation produced by electrospinning method with different ratios of carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), and Poloxamer. Numerous experimental control tests were carried out on formulations, including physicochemical properties which were evaluated by using dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), morphology study by scanning electron microscopy (SEM), and thermal stability. The best nanofibers formulation was obtained by the electrospinning method, with a voltage of 19.8 volts, a discharge capacity of 1cm/h, a cylindrical rotating velocity of 100rpm, and a needle interval of 7cm from the cylinder, which continued for 7hours. The formulation contained 2% (w/v) CMC, 10% (w/v) poloxamer, 9% (w/v) PVA, and 5% (w/v) LPB. This formula had desirable physicochemical properties including spreadability, stability, and uniformity with the particle size of about 590nm.
PubMed: 37633459
DOI: 10.1016/j.pharma.2023.08.008 -
Bioresource Technology Jan 2022A heterotrophic nitrification- aerobic denitrification (HNAD) bacterium, Acinetobacter junii ZHG-1, was isolated, meanwhile, the optimal conditions for the strain were...
A heterotrophic nitrification- aerobic denitrification (HNAD) bacterium, Acinetobacter junii ZHG-1, was isolated, meanwhile, the optimal conditions for the strain were evaluated, moreover, the influence mechanism of the C/N ratio on the HNAD process was investigated from the perspective of electron transport and energy level. The increasing of C/N ratio enhanced the reduced/oxidized nicotinamide adenine dinucleotide (NADH/NAD) ratio, NADH concentration, electron transport system activity (ETSA), ATP content, as well as enzymes activities, consequently, the HNAD performance of the strain can be improved, however, when the C/N ratio was higher than 30, the activities of enzymes relating to the HNAD process and the ETSA had reached the maximum, which might limit the further improvement of the nitrogen removal with the increasing of C/N ratio. As the interaction between different biochemical reactions in HNAD process, more efforts should be devoted to the influent mechanism of different environmental factors on the HNAD process.
Topics: Acinetobacter; Aerobiosis; Denitrification; Heterotrophic Processes; Nitrification; Nitrites; Nitrogen
PubMed: 34653622
DOI: 10.1016/j.biortech.2021.126116 -
Environmental Research Sep 2022Converting renewable biomass into carbon-neutral biofuels is one of the most effective strategies to achieve zero carbon emissions and contribute to environmental...
Converting renewable biomass into carbon-neutral biofuels is one of the most effective strategies to achieve zero carbon emissions and contribute to environmental protection. Microorganisms from the soil were primarily screened on the rhodamine B-plate for highly-active lipase producing strains and re-screened on a tributyrin-methanol plate using crude lipases produced from the initially screened-out strains. The lipase-producing strains with higher methanol-tolerant lipase were identified based on morphological characteristics and 16S rDNA sequencing. The crude lipases with much higher methanol-tolerance from screened top-4 strains, Stenotrophomonas maltophilia D18, Lysinibacillus fusiformis B23, Acinetobacter junii C69, and A. pittii C95 showed temperature optima of 25 °C, 35 °C, 30 °C, and 30 °C at pH 7.0, respectively, while their pH optima were 8.0, 7.0, 7.5, and 7.5 at each optimum temperature, respectively. After 24-h incubation, they retained more than 85% of their original activities in 25%, 15%, 20%, and 20% of methanol, respectively. They catalyzed the conversion of soybean oil into biodiesel by yields of 63.1%, 35.4%, 74.6%, and 78.5% after 24-h reactions, respectively. In conclusion, the as-isolated microorganisms producing high methanol-tolerant lipase are considered promising to provide robust biocatalyst for efficient biodiesel preparation and other industrial applications.
Topics: Biofuels; Carbon; Lipase; Methanol; Soil
PubMed: 35671798
DOI: 10.1016/j.envres.2022.113570