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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 -
PeerJ 2020Sanguinarine (SAG), a benzophenanthridine alkaloid, occurs in , and families. Studies have found that SAG has antioxidant, anti-inflammatory, and antiproliferative...
BACKGROUND
Sanguinarine (SAG), a benzophenanthridine alkaloid, occurs in , and families. Studies have found that SAG has antioxidant, anti-inflammatory, and antiproliferative activities in several malignancies and that it exhibits robust antibacterial activities. However, information reported on the action of SAG against is limited in the literature. Therefore, the present study aimed to evaluate the antimicrobial and antibiofilm activities of SAG against in vitro.
METHODS
The agar dilution method was used to determine the minimum inhibitory concentration (MIC) of SAG against . The intracellular ATP concentration, intracellular pH (pH), and cell membrane integrity and potential were measured. Confocal laser scanning microscopy (CLSM), field emission scanning electron microscopy (FESEM), and crystal violet staining were used to measure the antibiofilm formation of SAG.
RESULTS
The MIC of SAG against was 7.8 μg/mL. SAG inhibited the growth of and destroyed the integrity of cell membrane, as reflected mainly through the decreases in the intracellular ATP concentration, pH and cell membrane potential and significant changes in cellular morphology. The findings of CLSM, FESEM and crystal violet staining indicated that SAG exhibited strong inhibitory effects on the biofilm formation of and led to the inactivity of biofilm-related cells.
PubMed: 32864203
DOI: 10.7717/peerj.9543 -
Infection and Drug Resistance 2023The coexistence of with other resistance determinants is rarely reported for . Therefore, this study investigates the phenotypic and genetic characteristics of a...
BACKGROUND
The coexistence of with other resistance determinants is rarely reported for . Therefore, this study investigates the phenotypic and genetic characteristics of a multidrug-resistant strain YQ150713.
METHODS
YQ150713 was identified as carrying . S1-pulsed-field gel electrophoresis (S1-PFGE), Southern blotting, and conjugation experiments were used to determine plasmid characteristics. An antimicrobial susceptibility test was conducted. The complete genomic sequence of YQ150713 was obtained using Illumina NovaSeq 6000 and Oxford nanopore platforms. To further characterize the phylogenetic structure of YQ150713, average nucleotide identity (ANI) and phylogenetic analyses were conducted.
RESULTS
The S1-PFGE, Southern blot, and conjugation assays have confirmed that the isolate YQ150713 contains the gene on a conjugative plasmid pYQ150713-NDM-1. Antimicrobial susceptibility testing has indicated that strain YQ150713 was resistant to various common antibiotics, except aztreonam and fosfomycin. Bioinformatics analysis has further shown that pYQ150713-NDM-1 was a novel plasmid with a size of 265,883 bp, and and were co-located on it. Phylogenetic analysis suggesting has spread widely throughout the world.
CONCLUSION
In this study, and were co-localized on a novel plasmid pYQ150713-NDM-1 with a horizontal transfer function. To reduce the risk of the dissemination of such isolates in clinical settings, more surveillance will be required in the future.
PubMed: 37601562
DOI: 10.2147/IDR.S418131 -
Journal of Food Protection May 2022Providencia rettgeri is an opportunistic foodborne pathogen with a strong biofilm-forming ability in low-nutrition environments. However, information regarding the...
ABSTRACT
Providencia rettgeri is an opportunistic foodborne pathogen with a strong biofilm-forming ability in low-nutrition environments. However, information regarding the impact of simulated food processing conditions on P. rettgeri planktonic growth and biofilm formation is limited. Using response surface methodology (RSM), the combined effects of temperature (19 to 37°C), pH (5 to 9), and sodium chloride (NaCl) concentration (0.50 to 2.0%, w/v) were applied to construct planktonic growth and biofilm formation models for P. rettgeri. For both RSM models, an increase in NaCl concentration restricted P. rettgeri growth. Planktonic growth and biofilm formation were maximum at 27.83 and 25.41°C, respectively. Tannic acid (TA) is a highly effective antibacterial agent that inhibited planktonic and biofilm P. rettgeri under optimal growth conditions. The viability of P. rettgeri cells was decreased by TA treatment, which caused destruction of the cell membrane and production of endogenous reactive oxygen species. TA significantly inactivated P. rettgeri biofilms, as verified by observation. The obtained models in this study may be useful for describing the impact of temperature, pH, and NaCl concentration on the growth by P. rettgeri in the food processing environment and better understanding the impacts of food-related conditions on bacterial planktonic growth and biofilm formation. These results obtained for P. rettgeri planktonic cells and biofilms can provide a framework for removal strategies for other foodborne pathogens.
Topics: Biofilms; Plankton; Providencia; Sodium Chloride; Tannins
PubMed: 35271716
DOI: 10.4315/JFP-21-289 -
Microbiology Spectrum Aug 2022Although the prevalence of carbapenem-resistant Enterobacterales remains low in Japan, these bacteria are a growing problem worldwide, owing to their multidrug...
Although the prevalence of carbapenem-resistant Enterobacterales remains low in Japan, these bacteria are a growing problem worldwide, owing to their multidrug resistance phenotype. We isolated a multidrug-resistant Providencia rettgeri strain, NR1418, harboring a rare variant, , a novel variant, designated , and . This strain is resistant to β-lactams, amikacin, levofloxacin, and colistin. Genomic analysis revealed that NR1418 carries two plasmids, designated pNR1418-1 and pNR1418-2. The pNR1418-1 plasmid harbors , , and , while the pNR1418-2 plasmid harbors , which is located in a class 1 integron. Both plasmids exhibit high similarities with the plasmid of the isolate BML2526, which also harbors and was identified in the same region of Japan as NR1418 at a different point in time. This indicates the possibility of the emergence and evolution of IMP-70-producing and suggests that the plasmid of BML2526 may have occurred following recombination of the two plasmids harbored by NR1418. Further, and were found on unique plasmids, indicating that they likely evolved through mutations and recombination. Although Providencia rettgeri is an opportunistic pathogen, its intrinsic resistance to colistin and tigecycline makes the treatment of carbapenem-resistant challenging. We isolated a multidrug-resistant strain which harbored a rare variant, , a novel variant, , and from a urinary sample obtained in Osaka, Japan. We investigated its genetic structure and evaluated the evolution of the plasmids carrying these genes. We show that , , and are present on unique plasmids and that they have high similarities to the plasmid of another IMP-70-producing isolate that was identified as being from the same location. The evolution of plasmids through mutations and recombination may play a role in the development and spread of multidrug resistance.
Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Colistin; Microbial Sensitivity Tests; Plasmids; Providencia
PubMed: 35862988
DOI: 10.1128/spectrum.01204-22 -
Frontiers in Cellular and Infection... 2021is a nosocomial pathogen associated with urinary tract infections related to hospital-acquired Infections. In recent years, clinical strains producing New Delhi...
is a nosocomial pathogen associated with urinary tract infections related to hospital-acquired Infections. In recent years, clinical strains producing New Delhi Metallo-β-lactamase (NDM) and other β-lactamase which reduce the efficiency of antimicrobial therapy have been reported. However, there are few reports of co-producing two metallo-β-lactamases in one isolate. Here, we first reported a strain (P138) co-harboring , , and . The specie were identified using MALDI-TOF MS. The results of antimicrobial susceptibility testing by broth microdilution method indicated that P138 was resistant to meropenem (MIC = 64μg/ml), imipenem (MIC = 64μg/ml), and aztreonam (MIC = 32μg/ml). Conjugation experiments revealed that the -carrying plasmid was transferrable. The carbapenemase genes were detected using PCR and confirmed by PCR-based sequencing. The complete genomic sequence of the was identified using Illumina (Illumina, San Diego, CA, USA) short-read sequencing (150bp paired-end reads), and many common resistance genes had been identified, including , , , , , , and . The gene was characterized by the following structure: IS-TnpA-IntI1-aadB-IS-GroEL-GroES-DsbD-PAI-ble--IS-QnrS1-IS. Blast comparison revealed that the gene structure shared >99% similarity with plasmid p5_SCLZS62 (99% nucleotide identity and query coverage). In summary, we isolated a strain coproducing , , and blaOXA-10. To the best of our acknowledge, this was first reported in the world. The occurrence of the strain needs to be closely monitored.
Topics: Anti-Bacterial Agents; China; Enterobacteriaceae Infections; Humans; Microbial Sensitivity Tests; Providencia; beta-Lactamases
PubMed: 35047418
DOI: 10.3389/fcimb.2021.789646 -
Vaccines Jan 2022Antibiotic resistance (AR) is the resistance mechanism pattern in bacteria that evolves over some time, thus protecting the bacteria against antibiotics. AR is due to...
Antibiotic resistance (AR) is the resistance mechanism pattern in bacteria that evolves over some time, thus protecting the bacteria against antibiotics. AR is due to bacterial evolution to make itself fit to changing environmental conditions in a quest for survival of the fittest. AR has emerged due to the misuse and overuse of antimicrobial drugs, and few antibiotics are now left to deal with these superbug infections. To combat AR, vaccination is an effective method, used either therapeutically or prophylactically. In the current study, an in silico approach was applied for the design of multi-epitope-based vaccines against , a major cause of traveler's diarrhea. A total of six proteins: fimbrial protein, flagellar hook protein (FlgE), flagellar basal body L-ring protein (FlgH), flagellar hook-basal body complex protein (FliE), flagellar basal body P-ring formation protein (FlgA), and Gram-negative pili assembly chaperone domain proteins, were considered as vaccine targets and were utilized for B- and T-cell epitope prediction. The predicted epitopes were assessed for allergenicity, antigenicity, virulence, toxicity, and solubility. Moreover, filtered epitopes were utilized in multi-epitope vaccine construction. The predicted epitopes were joined with each other through specific GPGPG linkers and were joined with cholera toxin B subunit adjuvant via another EAAAK linker in order to enhance the efficacy of the designed vaccine. Docking studies of the designed vaccine construct were performed with MHC-I (PDB ID: 1I1Y), MHC-II (1KG0), and TLR-4 (4G8A). Findings of the docking study were validated through molecular dynamic simulations, which confirmed that the designed vaccine showed strong interactions with the immune receptors, and that the epitopes were exposed to the host immune system for proper recognition and processing. Additionally, binding free energies were estimated, which highlighted both electrostatic energy and van der Waals forces to make the complexes stable. Briefly, findings of the current study are promising and may help experimental vaccinologists to formulate a novel multi-epitope vaccine against .
PubMed: 35214648
DOI: 10.3390/vaccines10020189 -
Frontiers in Microbiology 2022In this study, a multi-metal-tolerant natural bacterial isolate strain KDM3 from an industrial effluent in Mumbai, India, showed high cadmium (Cd) tolerance. grew in...
In this study, a multi-metal-tolerant natural bacterial isolate strain KDM3 from an industrial effluent in Mumbai, India, showed high cadmium (Cd) tolerance. grew in the presence of more than 100 ppm (880 μM) Cd (LD = 100 ppm) and accumulated Cd intracellularly. Following Cd exposure, a comparative proteome analysis revealed molecular mechanisms underlying Cd tolerance. Among a total of 69 differentially expressed proteins (DEPs) in Cd-exposed cells, induction of operon proteins and L-cysteine/L-cystine shuttle protein FliY was observed, while Dps and superoxide dismutase proteins were overexpressed, indicating upregulation of a robust oxidative stress defense. ENTRA1, a membrane transporter showing homology to heavy metal transporter, was also induced . In addition, the protein disaggregation chaperone ClpB, trigger factor, and protease HslU were also overexpressed. Notably, 46 proteins from the major functional category of energy metabolism were found to be downregulated. Furthermore, the addition of to Cd-spiked soil resulted in a significant reduction in the Cd content [roots (11%), shoot (50%), and grains (46%)] of the rice plants. Cd bioaccumulation of improved plant growth and grain yield. We conclude that , a highly Cd-tolerant bacterium, is an ideal candidate for bioremediation of Cd-contaminated agricultural soils.
PubMed: 35558133
DOI: 10.3389/fmicb.2022.852697 -
Viruses Mar 2022is an emerging opportunistic Gram-negative pathogen with reports of increasing antibiotic resistance. Pan-drug resistant (PDR) infections are a growing concern,...
is an emerging opportunistic Gram-negative pathogen with reports of increasing antibiotic resistance. Pan-drug resistant (PDR) infections are a growing concern, demonstrating a need for the development of alternative treatment options which is fueling a renewed interest in bacteriophage (phage) therapy. Here, we identify and characterize phage vB_PreP_EPr2 (EPr2) with lytic activity against PDR MRSN 845308, a clinical isolate that carries multiple antibiotic resistance genes. EPr2 was isolated from an environmental water sample and belongs to the family , subfamily and genus , with a genome size of 41,261 base pairs. Additional phenotypic characterization showed an optimal MOI of 1 and a burst size of 12.3 ± 3.4 PFU per bacterium. EPr2 was determined to have a narrow host range against a panel of clinical strains. Despite this fact, EPr2 is a promising lytic phage with potential for use as an alternative therapeutic for treatment of PDR infections.
Topics: Anti-Bacterial Agents; Bacteriophages; Host Specificity; Providencia
PubMed: 35458437
DOI: 10.3390/v14040708 -
Clinical Microbiology and Infection :... Sep 2018A carbapenem-resistant Providencia rettgeri (PR1) isolate was recovered from a wound infection in Missouri, USA. This isolate possessed an EDTA-inhibitable carbapenemase...
OBJECTIVES
A carbapenem-resistant Providencia rettgeri (PR1) isolate was recovered from a wound infection in Missouri, USA. This isolate possessed an EDTA-inhibitable carbapenemase that was unidentified using the Xpert CARBA-R assay. Our objective was to elucidate the molecular determinant of carbapenem resistance in this isolate. We then sought to test the transmissibility of bla loci in clinical P. rettgeri and Proteus mirabilis isolates.
METHODS
In October 2016 the novel ambler Class B carbapenemase bla, was reported in two different Proteus mirabilis (PM185 and PM187) isolates. Broth mating assays for transfer of carbapenemase activity were performed for the three clinical isolates with recipient sodium azide-resistant Escherichia coli J53. Antibiotic susceptibility testing and phenotypic carbapenemase activity testing were performed on the clinical isolates, J53 and transconjugants using the Kirby-Bauer disc diffusion method according to CLSI guidelines. Plasmid DNA from PM187, PR1 and their transconjugants were used as input for Nextera Illumina sequencing libraries and sequenced on a NextSeq platform.
RESULTS
PR1 was resistant to both imipenem and meropenem. PM187 and PR1 could transfer resistance to E. coli through plasmid conjugation (pPM187 and pPR1). pPM187 had a virB/virD4 type IV secretion system whereas pPR1 had a traB/traD type IV secretion system.
CONCLUSION
Two of three bla-bearing clinical isolates tested could conjugate resistance into E. coli. The resulting transconjugants became positive for phenotypic carbapenemase production but did not pass clinical resistance breakpoints. bla can be transmitted on different plasmid replicon types that rely on distinct classes of type IV secretion system for horizontal transfer.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Disk Diffusion Antimicrobial Tests; Gene Transfer, Horizontal; High-Throughput Nucleotide Sequencing; Humans; Imipenem; Meropenem; Plasmids; Proteus mirabilis; Providencia; Sequence Analysis, DNA; Thienamycins; beta-Lactamases
PubMed: 29496594
DOI: 10.1016/j.cmi.2018.02.018