-
Journal of Global Antimicrobial... Jun 2023Colistin-resistant Gram-negative pathogens have become a serious worldwide medical problem. This study was designed to reveal the effects of an intrinsic...
OBJECTIVES
Colistin-resistant Gram-negative pathogens have become a serious worldwide medical problem. This study was designed to reveal the effects of an intrinsic phosphoethanolamine transferase from Acinetobacter modestus on Enterobacterales.
METHODS
A strain of colistin-resistant A. modestus was isolated from a sample of nasal secretions taken in 2019 from a hospitalised pet cat in Japan. The whole genome was sequenced by next generation sequencing, and transformants of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae harbouring the phosphoethanolamine transferase-encoding gene from A. modestus were constructed. Lipid A modification in E. coli transformants was analysed using electrospray ionization mass spectrometry.
RESULTS
Sequencing of the entire genome revealed that the isolate harboured a phosphoethanolamine transferase-encoding gene, eptA_AM, on its chromosome. Transformants of E. coli, K. pneumoniae, and E. cloacae harbouring both the promoter and eptA_AM gene from A. modestus had 32-fold, 8-fold, and 4-fold higher minimum inhibitory concentrations (MICs) for colistin, respectively, than transformants harbouring a control vector. The genetic environment surrounding eptA_AM in A. modestus was similar to that surrounding eptA_AM in Acinetobacter junii and Acinetobacter venetianus. Electrospray ionization mass spectrometry analysis revealed that EptA_AM modified lipid A in Enterobacterales.
CONCLUSION
This is the first report to describe the isolation of an A. modestus strain in Japan and show that its intrinsic phosphoethanolamine transferase, EptA_AM, contributes to colistin resistance in Enterobacterales and A. modestus.
Topics: Animals; Cats; Colistin; Escherichia coli; Lipid A; Ethanolaminephosphotransferase; Bacterial Proteins; Drug Resistance, Bacterial; Anti-Bacterial Agents; Klebsiella pneumoniae
PubMed: 36906175
DOI: 10.1016/j.jgar.2023.02.023 -
Cureus Nov 2021genus includes multiple species, most notably that constitutes a common cause of nosocomial infections worldwide, particularly in patients with underlying...
genus includes multiple species, most notably that constitutes a common cause of nosocomial infections worldwide, particularly in patients with underlying immunodeficiency and risk factors (e.g., prior broad-spectrum antibiotic therapy, central venous catheter, mechanical ventilation). is a very rare human pathogen that is particularly associated with outbreaks of sepsis in immunocompromised neonates and pediatric oncology patients and rarely in immunocompromised adults. To our knowledge, this is the first case report of cavitary pneumonia with bacteremia secondary to in a patient with systemic lupus erythematosus (SLE).
PubMed: 34976481
DOI: 10.7759/cureus.19711 -
MicrobiologyOpen Mar 2021The intestinal symbiotic bacteria of Aedes albopictus play a potential role in host resistance to insecticides. In this study, we sequenced the full-length of 16S rRNA... (Comparative Study)
Comparative Study
The intestinal symbiotic bacteria of Aedes albopictus play a potential role in host resistance to insecticides. In this study, we sequenced the full-length of 16S rRNA and analyzed the differences in the intestinal microbiota between deltamethrin-resistant and -sensitive Ae. albopictus. Symbiotic bacteria were cultured and analyzed using six types of culture media in aerobic and anaerobic environments. We found significant differences in the diversity and abundance of the intestinal microbiota of the two strains of Ae. albopictus. The symbiotic bacteria cultured in vitro were found to be mainly facultative anaerobes. The cultured bacteria such as Serratia oryzae and Acinetobacter junii may function to promote the development of insecticide resistance. This work indicates that intestinal bacteria may contribute to the enhancement of insecticide resistance of Ae. albopictus It also highlights the analytical advantage of full-length 16S rRNA sequencing to study the intestinal microbiota of mosquitoes.
Topics: Aedes; Animals; Bacteria; Biodiversity; DNA, Bacterial; Gastrointestinal Microbiome; Insecticide Resistance; Insecticides; Larva; Nitriles; Pyrethrins; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Symbiosis
PubMed: 33970535
DOI: 10.1002/mbo3.1177 -
Microbiology Spectrum Apr 2024Tigecycline is an antibiotic of last resort for infections with carbapenem-resistant . Plasmids harboring variants of the tetracycline destructase gene promote rising...
UNLABELLED
Tigecycline is an antibiotic of last resort for infections with carbapenem-resistant . Plasmids harboring variants of the tetracycline destructase gene promote rising tigecycline resistance rates. We report the earliest observation of ) in a clinical strain predating tigecycline's commercialization, suggesting selective pressures other than tigecycline contributed to its emergence.
IMPORTANCE
We present the earliest observation of a ()-positive bacterial strain, predating by many years the earliest reports of this gene so far. This finding is significant as tigecycline is an antibiotic of last resort for carbapenem-resistant (CRAB), which the World Health Organization ranks as one of its top three critical priority pathogens, and () variants have become the most prevalent genes responsible for enabling CRAB to become tigecycline resistant. Moreover, the ()-positive strain we report is the first and only to be found that predates the commercialization of tigecycline, an antibiotic that was thought to have contributed to the emergence of this resistance gene. Understanding the factors contributing to the origin and spread of novel antibiotic resistance genes is crucial to addressing the major global public health issue, which is antimicrobial resistance.
Topics: Tigecycline; Microbial Sensitivity Tests; Anti-Bacterial Agents; Tetracycline; Plasmids; Carbapenems
PubMed: 38412527
DOI: 10.1128/spectrum.03327-23 -
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 -
Infection Dec 2014Rods of the Acinetobacter genus are present mainly in the external environment (e.g. water, soil) and in animals, while in humans they may comprise physiological flora....
Rods of the Acinetobacter genus are present mainly in the external environment (e.g. water, soil) and in animals, while in humans they may comprise physiological flora. The main pathogenic species is Acinetobacter baumannii complex, which constitutes a common cause of nosocomial infections, particularly in patients with underlying diseases and risk factors (e.g. prior broad-spectrum antibiotic therapy, malignancy, central venous catheter, mechanical ventilation); however, infections of the eye caused by strains of Acinetobacter spp. are very rare. We report a unique case of community-acquired corneal ulcer caused by Acinetobacter non-baumannii (possibly A. junii), in a patient with no risk factors identified. The case highlights the need for obtaining a sample from the cornea for bacteriological culture in the case of suspected ophthalmic infection as identification of the pathogen, and assessment of its susceptibility profile enables proper antibiotic therapy, improves the outcome and may constitute an eyesight-saving management.
Topics: Acinetobacter; Acinetobacter Infections; Anti-Bacterial Agents; Corneal Ulcer; Female; Humans; Middle Aged
PubMed: 25056128
DOI: 10.1007/s15010-014-0647-8 -
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 -
Antimicrobial Agents and Chemotherapy Sep 2000The mef gene, originally described for gram-positive organisms and coding for an efflux pump, has been identified in clinical isolates of Acinetobacter junii and...
The mef gene, originally described for gram-positive organisms and coding for an efflux pump, has been identified in clinical isolates of Acinetobacter junii and Neisseria gonorrhoeae. These strains could transfer the mef gene at frequencies ranging from 10(-6) to 10(-9) into one or more of the following recipients: gram-negative Moraxella catarrhalis, Neisseria perflava/sicca and Neisseria mucosa and gram-positive Enterococcus faecalis. Three Streptococcus pneumoniae strains could transfer the mef gene into Eikenella corrodens, Haemophilus influenzae, Kingella denitrificans, M. catarrhalis, Neisseria meningitidis, N. perflava/sicca, and N. mucosa at similar frequencies. The mef gene can thus be transferred to and expressed in a variety of gram-negative recipients.
Topics: Acinetobacter; Conjugation, Genetic; DNA-Binding Proteins; Humans; Neisseria gonorrhoeae; Streptococcus pneumoniae; Transcription Factors
PubMed: 10952602
DOI: 10.1128/AAC.44.9.2503-2506.2000 -
European Journal of Biochemistry Apr 1997A polysaccharide containing rhamnose (Rha) and Gal was isolated by acetic acid hydrolysis, followed by gel-permeation chromatography, from the water-soluble...
A polysaccharide containing rhamnose (Rha) and Gal was isolated by acetic acid hydrolysis, followed by gel-permeation chromatography, from the water-soluble lipopolysaccharide (phenol/water extracted) from Acinetobacter junii strain 65. The polysaccharide was characterised by means of monosaccharide analyses, Smith degradation, and NMR studies, and was shown to have a linear pentasaccharide repeating unit, as depicted below. This structure was specifically recognised in western blots and enzyme immunoassays by polyclonal rabbit antisera. [structure in text]
Topics: Acinetobacter; Animals; Blotting, Western; Carbohydrate Sequence; Electrophoresis, Polyacrylamide Gel; Galactose; Gas Chromatography-Mass Spectrometry; Immunoenzyme Techniques; Magnetic Resonance Spectroscopy; Molecular Sequence Data; O Antigens; Rabbits; Rhamnose
PubMed: 9151982
DOI: 10.1111/j.1432-1033.1997.t01-1-00477.x -
Journal of Infection in Developing... May 2014Infections caused by Acinetobacter junii are rarely reported. However, some outbreaks of septicemia in neonates and pediatric oncology patients, as well as meningitis,...
INTRODUCTION
Infections caused by Acinetobacter junii are rarely reported. However, some outbreaks of septicemia in neonates and pediatric oncology patients, as well as meningitis, peritonitis, and ocular infection have been described. Since it is highly infrequent to find the molecular characterization of A. junii strains in literature, in this study we described the molecular characterization of A. junii isolates recovered from blood samples of a renal transplant patient.
METHODOLOGY
The case was defined as a catheter-related bacteremia caused by A. junii. The patient responded favorably after catheter removal and treatment with ciprofloxacin.
RESULTS AND CONCLUSION
The complete molecular characterization of the isolate showed that it harbored a class 1 integron and diverse DNA mobile elements. This explains its genomic plasticity for acquiring antimicrobial resistance determinants and for adapting to a nosocomial niche.
Topics: Acinetobacter; Acinetobacter Infections; Adult; Anti-Bacterial Agents; Bacteremia; Catheter-Related Infections; Ciprofloxacin; DNA, Bacterial; Female; Humans; Integrons; Interspersed Repetitive Sequences; Kidney Transplantation; Transplant Recipients; Treatment Outcome
PubMed: 24820473
DOI: 10.3855/jidc.3747