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Frontiers in Microbiology 2020Bacteria of the genus , with their numerous species common in various habitats, play a significant role as pathogens. Their ability to adapt to different living...
Bacteria of the genus , with their numerous species common in various habitats, play a significant role as pathogens. Their ability to adapt to different living conditions is largely due to the presence of numerous plasmids containing the necessary adaptive genes. At the same time the diversity of plasmids and their evolutionary dynamics have not been sufficiently studied. Here, we characterized 44 plasmids isolated from five permafrost strains, examined their relationship with plasmids of modern strains and identified groups of related plasmids. For this purpose, we have developed a combined approach for classifying all known plasmids. The classification took into account the size of plasmids, the presence and structure of the and genes, as well as the structure of their backbone and accessory regions. Based on the analysis, 19 major groups (lineages) of plasmids were identified, of which more than half were small plasmids. The plasmids of each group have common features of the organization of the backbone region with a DNA identity level of at least 80%. In addition, plasmids of the same group have similarities in the organization of accessory regions. We also described a number of plasmids with a unique structure. The presence of plasmids in clinical strains that are closely related to those of environmental permafrost strains provides evidence of the origin of the former from the latter.
PubMed: 33304332
DOI: 10.3389/fmicb.2020.588410 -
Journal of Bacteriology Feb 2010Pseudomonas aeruginosa strain PP4 and Acinetobacter lwoffii strain ISP4 metabolize isophthalate as a sole source of carbon and energy. Isophthalate is known to be a...
Bypassing isophthalate inhibition by modulating glutamate dehydrogenase (GDH): purification and kinetic characterization of NADP-GDHs from isophthalate-degrading Pseudomonas aeruginosa strain PP4 and Acinetobacter lwoffii strain ISP4.
Pseudomonas aeruginosa strain PP4 and Acinetobacter lwoffii strain ISP4 metabolize isophthalate as a sole source of carbon and energy. Isophthalate is known to be a competitive inhibitor of glutamate dehydrogenase (GDH), which is involved in C and N metabolism. Strain PP4 showed carbon source-dependent modulation of NADP-GDH; GDH(I) was produced when cells were grown on isophthalate, while GDH(II) was produced when cells were grown on glucose. Strain ISP4 produced a single form of NADP-GDH, GDH(P), when it was grown on either isophthalate or rich medium (2YT). All of the forms of GDH were purified to homogeneity and characterized. GDH(I) and GDH(II) were found to be homotetramers, while GDH(P) was found to be a homohexamer. GDH(II) was more sensitive to inhibition by isophthalate (2.5- and 5.5-fold more sensitive for amination and deamination reactions, respectively) than GDH(I). Differences in the N-terminal sequences and electrophoretic mobilities in an activity-staining gel confirmed the presence of two forms of GDH, GDH(I) and GDH(II), in strain PP4. In strain ISP4, irrespective of the carbon source, the GDH(P) produced showed similar levels of inhibition with isophthalate. However, the specific activity of GDH(P) from isophthalate-grown cells was 2.5- to 3-fold higher than that of GDH(P) from 2YT-grown cells. Identical N-terminal sequences and electrophoretic mobilities in the activity-staining gel suggested the presence of a single form of GDH(P) in strain ISP4. These results demonstrate the ability of organisms to modulate GDH either by producing an entirely different form or by increasing the level of the enzyme, thus enabling strains to utilize isophthalate more efficiently as a sole source of carbon and energy.
Topics: Acinetobacter; Enzyme Activation; Glutamate Dehydrogenase (NADP+); Kinetics; Phthalic Acids; Pseudomonas aeruginosa
PubMed: 19933355
DOI: 10.1128/JB.01365-09 -
Revista Chilena de Infectologia :... Feb 2007
Topics: Acinetobacter Infections; Acinetobacter baumannii; Acinetobacter calcoaceticus; Drug Resistance, Microbial; History, 20th Century; Humans; Terminology as Topic
PubMed: 17369976
DOI: 10.4067/s0716-10182007000100016 -
BMC Veterinary Research May 2024Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In...
BACKGROUND
Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In recent years, the infection rate and detection rate of A.lwoffii is increasing, especially in the breeding industry. Due to the presence of biofilms, it is difficult to eradicate and has become a potential super drug-resistant bacteria. Therefore, eradication of preformed biofilm is an alternative therapeutic action to control A.lwoffii infection. The present study aimed to clarify that baicalin could eradicate A.lwoffii biofilm in dairy cows, and to explore the mechanism of baicalin eradicating A.lwoffii.
RESULTS
The results showed that compared to the control group, the 4 MIC of baicalin significantly eradicated the preformed biofilm, and the effect was stable at this concentration, the number of viable bacteria in the biofilm was decreased by 0.67 LogCFU/mL. The total fluorescence intensity of biofilm bacteria decreased significantly, with a reduction rate of 67.0%. There were 833 differentially expressed genes (367 up-regulated and 466 down-regulated), whose functions mainly focused on oxidative phosphorylation, biofilm regulation system and trehalose synthesis. Molecular docking analysis predicted 11 groups of target proteins that were well combined with baicalin, and the content of trehalose decreased significantly after the biofilm of A.lwoffii was treated with baicalin.
CONCLUSIONS
The present study evaluated the antibiofilm potential of baicalin against A.lwoffii. Baicalin revealed strong antibiofilm potential against A.lwoffii. Baicalin induced biofilm eradication may be related to oxidative phosphorylation and TCSs. Moreover, the decrease of trehalose content may be related to biofilm eradication.
Topics: Biofilms; Animals; Flavonoids; Acinetobacter; Cattle; Milk; Anti-Bacterial Agents; Microbial Sensitivity Tests; Molecular Docking Simulation; Female; Acinetobacter Infections
PubMed: 38764041
DOI: 10.1186/s12917-024-04015-w -
Microbiology Spectrum Dec 2022New Delhi metallo-β-lactamase (NDM)-producing clinical strains in Acinetobacter spp. have been recently reported in many countries and have received considerable...
New Delhi metallo-β-lactamase (NDM)-producing clinical strains in Acinetobacter spp. have been recently reported in many countries and have received considerable attention. The vast majority of cases occur on conjugative plasmids, which play a vital role in disseminating . To characterize the conjugative plasmids bearing genes in Acinetobacter spp., we analyzed the variants of , conjugative transfer regions, genetic contexts of , and the phylogenetic pattern of the 62 predicted -positive plasmids, which were selected from 1,191 plasmids of Acinetobacter species from GenBank. We identified 30 conjugative plasmids from the 62 -harboring plasmids in Acinetobacter species, with the sites similar to plasmid pNDM-YR7 in our study, genes coding for relaxases of the MOB family, genes encoding type IV coupling proteins (T4CPs) of the TrwB/TraD subfamily, and VirB-like type IV secretion system (T4SS) gene clusters. The genome sizes of all 30 pNDM-YR7-like plasmids ranged from 39.36 kb to 49.65 kb, with a median size of 44.56 kb. The most common species of Acinetobacter containing the -positive conjugative plasmids was A. baumannii, followed by Acinetobacter lwoffii and Acinetobacter indicus. Notably, pNDM-YR7 is the first report on a -positive conjugative plasmid in Acinetobacter junii. Moreover, all 30 -positive conjugative plasmids in Acinetobacter species were found to contain genetic contexts with the structure IS--IS--. Our findings provide important insights into the phylogeny and evolution of -positive plasmids of Acinetobacter species and further address their role in acquiring and spreading genes in Acinetobacter species. Conjugative plasmids harboring the gene play a vital role in disseminating carbapenem resistance. In this study, we first report a conjugative plasmid, pNDM-YR7, in Acinetobacter junii. Based on the genomic characteristics of the -positive pNDM-YR7, we performed typing and comparative analysis of -positive plasmids using the 1,191 plasmids of Acinetobacter species available in the NCBI RefSeq database. We analyzed the characteristics of -positive plasmids, including the variants of , genetic features associated with , conjugative transfer regions, and the phylogenetic pattern of the -positive plasmids. All 30 -positive conjugative plasmids were found to contain an IS--IS-- region. This study provides novel insights into the phylogeny and evolution of -harboring conjugative plasmids and contributes to the repertoire of knowledge surrounding -positive plasmids in the genus Acinetobacter.
Topics: Phylogeny; Acinetobacter; Plasmids; beta-Lactamases; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 36301090
DOI: 10.1128/spectrum.02102-22 -
Polish Journal of Microbiology Sep 2020Ligninolytic bacteria degrading lignin were isolates and identified, and their biodegradation mechanism of alkaline-lignin was investigated. Four strains with lignin...
Ligninolytic bacteria degrading lignin were isolates and identified, and their biodegradation mechanism of alkaline-lignin was investigated. Four strains with lignin degradation capability were screened and identified from the soil, straw, and silage based on their decolorizing capacity of aniline blue and colony size on alkaline-lignin medium. The degradation ratio of BY5, LN2, LN4, and CL32 have been assayed using alkaline-lignin as the unique carbon source. Further, the Lip (lignin peroxidase) and Mnp (manganese peroxidase) activities of strains were investigated. Lip activity of LN4 was highest after 72 h of incubation and reached 7151.7 U · l. Mnp activity of CL32 was highest after 48 h and reached 12533 U · l. The analysis of alkaline-lignin degradation products by GC-MS revealed that the strains screened could utilize aromatic esters compounds such as dibutyl phthalate (DBP), and decomposite monocyclic aromatic compounds through the DBP aerobic metabolic pathway. The results indicate that BY5, LN2, LN4, and CL32 have high potential to degrade alkaline-lignin, and might utilize aromatic compounds by DBP aerobic metabolic pathway in the process of lignin degradation.
Topics: Alkalies; Bacteria; Bacterial Proteins; Biodegradation, Environmental; Lignin; Metabolic Networks and Pathways; Peroxidases; Phylogeny; RNA, Ribosomal, 16S
PubMed: 33574863
DOI: 10.33073/pjm-2020-037 -
Frontiers in Public Health 2021Disinfection is a key element in controlling infections. Fogging, also known as fumigation, is one of the most effective chemical disinfection methods. Peracetic acid...
Disinfection is a key element in controlling infections. Fogging, also known as fumigation, is one of the most effective chemical disinfection methods. Peracetic acid (PAA) is a powerful oxidant with bactericidal and fungicidal properties. The aim of this study is to determine the type of bacteria and fungi present in educational institutions and whether disinfection by PAA fumigation in these institutions is also effective and useful, as demonstrated previously in healthcare centers. This study was carried out in five kindergartens and five primary schools in Bialystok, Poland. Three rooms have been selected in each of these educational institutions, and the disinfection was carried out in 30 rooms in total. Fogging with PAA was performed in selected rooms. Before and after disinfection, samples were collected from four surfaces: walls, tables, doors, and chair backs. Most frequently detected microorganisms in schools and kindergartens were ssp. . In addition, ssp. were the most prevalent in kindergartens, whereas was the most prevalent in schools. Comparison of the bacterial flora of schools and kindergartens showed statistically significant differences in the prevalence of bacteria on different surfaces. A significant decrease in the number of colonies after disinfection was observed on all surfaces ( < 0.05). In addition, the calculated effectiveness of disinfection was 99.7% in kindergartens and 99.3% in schools. The results indicate that fogging of PAA is a highly effective method of surface disinfection in kindergartens and schools.
Topics: Acinetobacter; Actinobacteria; Micrococcaceae; Paracoccus; Peracetic Acid; Schools; Staphylococcus
PubMed: 34604154
DOI: 10.3389/fpubh.2021.697917 -
Frontiers in Microbiology 2017South American Camelids have an increasing relevance in local economies, worldwide. These animals are bred for their meat, fur and as companion and therapy animals....
South American Camelids have an increasing relevance in local economies, worldwide. These animals are bred for their meat, fur and as companion and therapy animals. Thus, their sanitary status should be well-established. According to the OIE (World Organization for Animal Health), respiratory infections mainly produced by spp. have been reported for camelids. It has been stated that this microorganism causes a mild disease, although many authors report it is an important cause of mortality among alpacas. Nevertheless, the incidence of infection by spp. in camelids still needs to be investigated. The aim of the present study was to analyze the occurrence of nasopharyngeal colonization of by respiratory bacteria, and to assess the usefulness of serological tests for clinical diagnosis. The colonization was studied by culture techniques carried out with material taken by nasopharyngeal swabs. Bacterial isolates were first phenotypically characterized and then identified by MALDI/TOF-MS. The presence of specific serum antibodies was studied by ELISA and Western blot. In the present work spp. was not found. Nevertheless, we report for the first time, the colonization of by bacteria of the , at a reliable level in 19.4% of the animals. species are found in different environmental sources, as well as vegetables, animals, and humans, and their role in infections has recently gained relevance. The results presented herein contribute to a better understanding of the respiratory microbiota in camelids, and increase the knowledge about environmental distribution of non- species. Given that these respiratory bacteria might be the cause of infection among cattle, and even humans, this report highlights the need for further research.
PubMed: 28303121
DOI: 10.3389/fmicb.2017.00278 -
Journal of Bacteriology Aug 1997Two novel type I catechol 1,2-dioxygenases inducible on aniline media were isolated from Acinetobacter lwoffii K24. Although the two purified enzymes, CD I1 and CD I2,...
Two novel type I catechol 1,2-dioxygenases inducible on aniline media were isolated from Acinetobacter lwoffii K24. Although the two purified enzymes, CD I1 and CD I2, had similar intradiol cleavage activities, they showed different substrate specificities for catechol analogs, physicochemical properties, and amino acid sequences. Two catA genes, catA1 and catA2, encoding by CD I1 and CD I2, respectively, were isolated from the A. lwoffii K24 genomic library by using colony hybridization and PCR. Two DNA fragments containing the catA1 and catA2 genes were located on separate regions of the chromosome. They contained open reading frames encoding 33.4- and 30.4-kDa proteins. The amino acid sequences of the two proteins matched well with previously determined sequences. Interestingly, further analysis of the two DNA fragments revealed the locations of the catB and catC genes as well. Moreover, the DNA fragment containing catA1 had a cluster of genes in the order catB1-catC1-catA1 while the catB2-catA2-catC2 arrangement was found in the catA2 DNA fragment. These results may provide an explanation of the different substrate specificities and physicochemical properties of CD I1 and CD I2.
Topics: Acinetobacter; Amino Acid Sequence; Base Sequence; Catechol 1,2-Dioxygenase; Catechols; Chromosome Mapping; Chromosomes, Bacterial; Cloning, Molecular; Dioxygenases; Genes, Bacterial; Isoelectric Point; Kinetics; Molecular Sequence Data; Molecular Weight; Oxygenases; Substrate Specificity
PubMed: 9260969
DOI: 10.1128/jb.179.16.5226-5231.1997 -
Antimicrobial Agents and Chemotherapy Apr 2020Tigecycline serves as one of the antibiotics of last resort to treat multidrug-resistant (including carbapenem-resistant) pathogens. However, the recently emerged...
Tigecycline serves as one of the antibiotics of last resort to treat multidrug-resistant (including carbapenem-resistant) pathogens. However, the recently emerged plasmid-mediated tigecycline resistance mechanism, Tet(X), challenges the clinical efficacy of this class of antibiotics. In this study, we detected 180 (X)-harboring isolates (8.9%, = 180) from 2,018 samples collected from avian farms and adjacent environments in China. Eighteen (X)-harboring isolates (10.0%) were found to cocarry the carbapenemase gene , mostly from waterfowl samples (94.4%, 17/18). Interestingly, among six strains, (X) and were found to colocalize on the same plasmids. Moreover, whole-genome sequencing (WGS) revealed a novel orthologue of (X) in the six isolates coharboring (X) and Inverse PCR suggested that the two (X) genes form a single transposable unit and may be cotransferred. Sequence comparison between six (X)- and -coharboring plasmids showed that they shared a highly homologous plasmid backbone even though they were isolated from different species (three from , two from , and one from ) from various sources and from different geological regions, suggesting the horizontal genetic transfer of a common (X)- and -coharboring plasmid among species in China. Emergence and spread of such plasmids and strains are of great clinical concern, and measures must be implemented to avoid their dissemination.
Topics: Acinetobacter; Acinetobacter Infections; Animals; Anti-Bacterial Agents; Bird Diseases; Birds; Carbapenems; China; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Microbial Sensitivity Tests; Molecular Epidemiology; Plasmids; Tetracycline Resistance; Tigecycline; Whole Genome Sequencing
PubMed: 32122894
DOI: 10.1128/AAC.02502-19