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1.
Chemosphere ; 287(Pt 2): 132209, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826911

RESUMO

Soil cadmium (Cd) mobilized with phosphate-solubilizing bacteria (PSB), especially for strains effectively colonized in rhizosphere, is an important pathway for promoting its accumulation by Cd-hyperaccumulators. In this study, screened PSB strains, Acinetobacter pittii (AP) and Escherichia coli (EC), were used to evaluate their effects on Cd mobilization in rhizosphere, Cd accumulation by Solanum nigrum L., and rhizobacterial community and metabolic function under different colonization condition. Results indicated that AP or EC inoculated in soils significantly promoted plant growth, and simultaneously motivated Cd accumulation in S. nigrum L. by 119% and 88%, respectively, when compared with that of uninoculated treatment. Higher efficiency colonization of AP contributed to more organic acids (malic, l-proline, l-alanine, and γ-aminobutanoic) production in the rhizosphere soil and Cd accumulation by S. nigrum L., when compared with that of EC treatment. Taxonomic distribution and co-occurrence network analyses demonstrated that inoculation of AP or EC enriched dominant microbial taxa with plant growth promotion function and keystone taxa related to Cd mobilization in the rhizosphere soil, respectively. Inoculated strains up-regulated the expression of genes related to bacterial mobility, amino acid metabolism, and carbon metabolism among rhizobacterial community. Overall, this study provided a feasible method for soil Cd phytoremediation by promoting Cd mobilization with the enhancement of keystone taxa and organic acid secretion based on the high-efficiency colonization of PSB.


Assuntos
Poluentes do Solo , Solanum nigrum , Acinetobacter , Bactérias , Biodegradação Ambiental , Cádmio/análise , Fosfatos , Raízes de Plantas/química , Solo , Poluentes do Solo/análise
2.
Bioresour Technol ; 343: 126116, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34653622

RESUMO

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.


Assuntos
Desnitrificação , Nitrificação , Acinetobacter , Aerobiose , Processos Heterotróficos , Nitritos , Nitrogênio
3.
J Hazard Mater ; 421: 126728, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34339990

RESUMO

The increasing release of nanomaterials has attracted significant concerns for human and environmental health. Similarly, the dissemination of antimicrobial resistance (AMR) is a global health crisis affecting approximately 700,000 people a year. However, a knowledge gap persists between the spread of AMR and nanomaterials. This study aims to fill this gap by investigating whether and how nanomaterials could directly facilitate the dissemination of AMR through horizontal gene transfer. Our results show that commonly-used nanoparticles (NPs) (Ag, CuO and ZnO NPs) and their ion forms (Ag+, Cu2+ and Zn2+) at realistic concentrations within aquatic environments can significantly promote the transformation of extracellular antibiotic resistance genes in Acinetobacter baylyi ADP1 by a factor of 11.0-folds, which is comparable to the effects of antibiotics. The enhanced transformation by Ag NPs/Ag+ and CuO NPs/Cu2+ was primarily associated with the overproduction of reactive oxygen species and cell membrane damage. ZnO NPs/Zn2+ might increase the natural transformation rate by stimulating the stress response and ATP synthesis. All tested NPs/ions resulted in upregulating the competence and SOS response-associated genes. These findings highlight a new concern that nanomaterials can speed up the spread of AMR, which should not be ignored when assessing the holistic risk of nanomaterials.


Assuntos
Resistência Microbiana a Medicamentos , Íons , Nanopartículas Metálicas , Acinetobacter/genética , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Humanos , Íons/toxicidade , Nanopartículas Metálicas/toxicidade
4.
J Colloid Interface Sci ; 606(Pt 1): 628-634, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34416455

RESUMO

The sticky bacterium Acinetobacter sp. Tol 5 adheres to various material surfaces via its cell surface nanofiber protein, AtaA. This adhesiveness has only been evaluated based on the amount of cells adhering to a surface. In this study, the adhesion force mapping of a single Tol 5 cell in liquid using the quantitative imaging mode of atomic force microscopy (AFM) revealed that the adhesion of Tol 5 was near 2 nN, which was 1-2 orders of magnitude higher than that of other adhesive bacteria. The adhesion force of a cell became stronger with the increase in AtaA molecules present on the cell surface. Many fibers of peritrichate AtaA molecules simultaneously interact with a surface, strongly attaching the cell to the surface. The adhesion force of a Tol 5 cell was drastically reduced in the presence of 1% casamino acids but not in deionized water (DW), although both liquids decrease the adhesiveness of Tol 5 cells, suggesting that DW and casamino acids inhibit the cell approaching step and the subsequent direct interaction step of AtaA with surfaces, respectively. Heterologous production of AtaA provided non-adhesive Acinetobacter baylyi ADP1 cells with a strong adhesion force to AFM tip surfaces of silicon and gold.


Assuntos
Adesinas Bacterianas , Aderência Bacteriana , Acinetobacter , Bactérias , Adesão Celular , Microscopia de Força Atômica , Propriedades de Superfície
5.
Front Cell Infect Microbiol ; 11: 739211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722334

RESUMO

Acinetobacter sp. is among the ESKAPE organisms which represent the major nosocomial pathogens that exhibited a high resistance rate. A. pittii, frequently associated with antimicrobial resistance particularly to carbapenems, is one of the most common Acinetobacter species causing invasive infection. Pandrug resistant A. pittii has rarely been reported. Here, we report the case of a patient with acute exacerbations of chronic obstructive pulmonary disease three years after double lung transplantation and developed severe pneumonia associated with pandrug resistant A. pittii infection. Phenotypic and genomic characteristics of this pandrug resistant isolate (17-84) was identified, and the mechanisms underlying its resistance phenotypes were analyzed. Isolate 17-84 belonged to ST63, carried a non-typable and non-transferable plasmid encoding multiple acquired resistance genes including carbapenemase gene bla OXA-58. Point mutations and acquired resistance genes were identified which were associated with different drug resistance phenotypes. To our knowledge, this is the first detailed phenotypic and genomic characterization of PDR A. pittii causing severe infections in clinical settings. Findings from us and others indicate that A. pittii could serve as a reservoir for carbapenem determinants. The emergence of such a superbug could pose a serious threat to public health. Further surveillance of PDR A. pittii strains and implementation of stricter control measures are needed to prevent this emerging pathogen from further disseminating in hospital settings and the community.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Acinetobacter , Doença Pulmonar Obstrutiva Crônica , Acinetobacter/genética , Infecções por Acinetobacter/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , China , Humanos , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
6.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34633923

RESUMO

Two isolates of a non-fermenting, Gram-negative bacterial strain were cultured from two throat swabs that were taken from a pair of twins during routine microbiological surveillance screening. As these isolates could not be unambiguously identified using routine diagnostic methods, whole genome sequencing was performed followed by phylogenetic analysis based on the rpoB gene sequence and by whole genome datasets. The two strains compose a separate branch within the clade formed by the Acinetobacter calcoaceticus-baumannii (ACB) complex with Acinetobacter pittii CIP 70.29T as the most closely related species. The average nucleotide identity compared to all other species of the ACB complex was below 94.2% and digital DNA-DNA hybridization values were less than 60%. Biochemical characteristics confirm affiliation to the ACB complex with some specific phenotypic differences. As a result of the described data, a new Acinetobacter species is introduced, for which the name Acinetobacter geminorum sp. nov. is proposed. The type strain is J00019T with a G+C DNA content of 38.8 mol% and it is deposited in the DSMZ Germany (DSM 111094T) and CCUG Sweden (CCUG 74625T).


Assuntos
Acinetobacter , Faringe , Acinetobacter/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Humanos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
BMC Genomics ; 22(1): 713, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34600470

RESUMO

BACKGROUND: Abortion in horses leads to economic and welfare losses to the equine industry. Most cases of equine abortions are sporadic, and the cause is often unknown. This study aimed to detect potential abortigenic pathogens in equine abortion cases in Australia using metagenomic deep sequencing methods. RESULTS: After sequencing and analysis, a total of 68 and 86 phyla were detected in the material originating from 49 equine abortion samples and 8 samples from normal deliveries, respectively. Most phyla were present in both groups, with the exception of Chlamydiae that were only present in abortion samples. Around 2886 genera were present in the abortion samples and samples from normal deliveries at a cut off value of 0.001% of relative abundance. Significant differences in species diversity between aborted and normal tissues was observed. Several potential abortigenic pathogens were identified at a high level of relative abundance in a number of the abortion cases, including Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Streptococcus equi subspecies zooepidemicus, Pantoea agglomerans, Acinetobacter lwoffii, Acinetobacter calcoaceticus and Chlamydia psittaci. CONCLUSIONS: This work revealed the presence of several potentially abortigenic pathogens in aborted specimens. No novel potential abortigenic agents were detected. The ability to screen samples for multiple pathogens that may not have been specifically targeted broadens the frontiers of diagnostic potential. The future use of metagenomic approaches for diagnostic purposes is likely to be facilitated by further improvements in deep sequencing technologies.


Assuntos
Doenças dos Cavalos , Metagenômica , Acinetobacter , Animais , Austrália , Feminino , Feto , Cavalos , Metagenoma , Gravidez
8.
Pan Afr Med J ; 39: 208, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603589

RESUMO

Acinetobacter ursingii is an anaerobic gram negative opportunistic coccobacillus, rarely isolated in bacteremic patients. It is mainly found in immunocompromised and severely ill patients with no identifiable source of infection. When isolated into the bloodstream, it usually displays resistance to at least two antimicrobial agents. To date only seven cases of bacteremia due to this microorganism have been reported in adults, of which, this accounts for the second one associated to renal replacement therapy and the first case of a documented catheter-related bloodstream infection (CRBSI) in a patient with a hemodialysis catheter. A 78-year-old male presented into the emergency department with acute kidney injury requiring hemodialysis, later developing bacteremia due to Acinetobacter ursingii.


Assuntos
Infecções por Acinetobacter/diagnóstico , Acinetobacter/isolamento & purificação , Bacteriemia/diagnóstico , Infecções Relacionadas a Cateter/diagnóstico , Infecções por Acinetobacter/microbiologia , Injúria Renal Aguda/terapia , Idoso , Bacteriemia/microbiologia , Infecções Relacionadas a Cateter/microbiologia , Humanos , Masculino , Diálise Renal/efeitos adversos , Diálise Renal/métodos
9.
Front Public Health ; 9: 697917, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34604154

RESUMO

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 Micrococcus luteus (M. luteus), Staphylococcus warneri (S. warneri), Paracoccus yeei (P. yeei), Staphylococcus hominis ssp. hominis (S. hominis), Kocuria rhizophila (K. rhizophila), Kocuria rosea (K. rosea). In addition, Staphylococcus haemolyticus (S. haemolyticus), Acinetobacter lwoffii (A. lwoffii), Kocuria kristinae (K. kristinae), Lactococcus lactis ssp. lactis (L. lactis) were the most prevalent in kindergartens, whereas Kytococcus sedentarius (K. sedentarius) 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 (p < 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.


Assuntos
Ácido Peracético , Instituições Acadêmicas , Acinetobacter , Actinobacteria , Micrococcaceae , Paracoccus , Ácido Peracético/farmacologia , Staphylococcus
10.
Extremophiles ; 25(5-6): 425-436, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34542714

RESUMO

Extremophilic prokaryotes live under harsh environmental conditions which require far-reaching cellular adaptations. The acquisition of novel genetic information via natural transformation plays an important role in bacterial adaptation. This mode of DNA transfer permits the transfer of genetic information between microorganisms of distant evolutionary lineages and even between members of different domains. This phenomenon, known as horizontal gene transfer (HGT), significantly contributes to genome plasticity over evolutionary history and is a driving force for the spread of fitness-enhancing functions including virulence genes and antibiotic resistances. In particular, HGT has played an important role for adaptation of bacteria to extreme environments. Here, we present a survey of the natural transformation systems in bacteria that live under extreme conditions: the thermophile Thermus thermophilus and two desiccation-resistant members of the genus Acinetobacter such as Acinetobacter baylyi and Acinetobacter baumannii. The latter is an opportunistic pathogen and has become a world-wide threat in health-care institutions. We highlight conserved and unique features of the DNA transporter in Thermus and Acinetobacter and present tentative models of both systems. The structure and function of both DNA transporter are described and the mechanism of DNA uptake is discussed.


Assuntos
Acinetobacter , Acinetobacter/genética , Ambientes Extremos , Transferência Genética Horizontal , Thermus thermophilus
11.
J Hazard Mater ; 416: 126239, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492990

RESUMO

Polystyrene (PS), a major plastic waste, is difficult to biodegrade due to its unique chemical structure that comprises phenyl moieties attached to long linear alkanes. In this study, we investigated the biodegradation of PS by mesophilic bacterial cultures obtained from various soils in common environments. Two new strains, Pseudomonas lini JNU01 and Acinetobacter johnsonii JNU01, were specifically enriched in non-carbonaceous nutrient medium, with PS as the only source of carbon. Their growth after culturing in basal media increased more than 3-fold in the presence of PS. Fourier transform infrared spectroscopy analysis, used to confirm the formation of hydroxyl groups and potentially additional chemical bond groups, showed an increase in the amount of oxidized PS samples. Moreover, field emission scanning electron microcopy analysis confirmed PS biodegradation by biofilms of the screened microbes. Water contact angle measurement additionally offered insights into the increased hydrophilic characteristics of PS films. Bioinformatics and transcriptional analysis of A. johnsonii JNU01 revealed alkane-1-monooxygenase (AlkB) to be involved in PS biodegradation, which was confirmed by the hydroxylation of PS using recombinant AlkB. These results provide significant insights into the discovery of novel functions of Pseudomonas sp. and Acinetobacter sp., as well as their potential as PS decomposers.


Assuntos
Poliestirenos , Solo , Acinetobacter , Bactérias , Biodegradação Ambiental , Pseudomonas
12.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34431761

RESUMO

Acinetobacter variabilis (formerly genospecies 15 sensu Tjernberg and Ursing) has been isolated from humans and animals and was proposed to be a novel species in 2015. A multidrug-resistant A. variabilis isolate, RYU24, was obtained in 2012 from an inpatient in Okinawa, Japan, with no record of overseas travel. The isolate was resistant to carbapenems, aminoglycosides and ciprofloxacin, with minimum inhibitory concentrations (MICs) of 32 µg ml-1 for imipenem and meropenem; > 1024 µg ml-1 for amikacin, arbekacin, gentamicin and tobramycin; and 8 µg ml-1 for ciprofloxacin. The isolate was found to harbour a 68-kbp plasmid carrying bla NDM-1, which encodes New Delhi metallo-ß-lactamase-1 (NDM-1); bla OXA-420, which encodes an OXA-58-like carbapenemase and; armA, which encodes ArmA 16S rRNA methylase conferring pan-aminoglycoside resistance. To our knowledge, this is the first report of a plasmid harbouring the three major drug-resistance genes, bla NDM-1, bla OXA-420 and armA.


Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter/genética , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/microbiologia , Farmacorresistência Bacteriana Múltipla , beta-Lactamases/genética , Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Humanos , Japão/epidemiologia , Metiltransferases/genética , Testes de Sensibilidade Microbiana , Vigilância em Saúde Pública , RNA Ribossômico 16S/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-34444543

RESUMO

This paper analyzed the degradation pathways of petroleum hydrocarbon degradation bacteria, screened the main degradation pathways, and found the petroleum hydrocarbon degradation enzymes corresponding to each step of the degradation pathway. Through the Copeland method, the best inoculation program of petroleum hydrocarbon degradation bacteria in a polluted site was selected as follows: single oxygenation path was dominated by Streptomyces avermitilis, hydroxylation path was dominated by Methylosinus trichosporium OB3b, secondary oxygenation path was dominated by Pseudomonas aeruginosa, secondary hydroxylation path was dominated by Methylococcus capsulatus, double oxygenation path was dominated by Acinetobacter baylyi ADP1, hydrolysis path was dominated by Rhodococcus erythropolis, and CoA path was dominated by Geobacter metallireducens GS-15 to repair petroleum hydrocarbon contaminated sites. The Copeland method score for this solution is 22, which is the highest among the 375 solutions designed in this paper, indicating that it has the best degradation effect. Meanwhile, we verified its effect by the Cdocker method, and the Cdocker energy of this solution is -285.811 kcal/mol, which has the highest absolute value. Among the inoculation programs of the top 13 petroleum hydrocarbon degradation bacteria, the effect of the best inoculation program of petroleum hydrocarbon degradation bacteria was 18% higher than that of the 13th group, verifying that this solution has the best overall degradation effect. The inoculation program of petroleum hydrocarbon degradation bacteria designed in this paper considered the main pathways of petroleum hydrocarbon pollutant degradation, especially highlighting the degradability of petroleum hydrocarbon intermediate degradation products, and enriching the theoretical program of microbial remediation of petroleum hydrocarbon contaminated sites.


Assuntos
Petróleo , Rhodococcus , Poluentes do Solo , Acinetobacter , Biodegradação Ambiental , Geobacter , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Streptomyces
14.
J Water Health ; 19(4): 592-603, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34371496

RESUMO

Antimicrobial resistance is not restricted to clinics but also spreading fast in the aquatic environment. This study focused on the prevalence and diversity of extended-spectrum ß-lactamase (ESBL) genes among bacteria from lentic and effluent water in Delhi-NCR, India. Phenotypic screening of 436 morphologically distinct bacterial isolates collected from diverse sites revealed that 106 (∼24%) isolates were ESBL positive. Antibiotic profiling showed that 42, 60, 78 and 59% ESBL producing isolates collected from Ghazipur slaughterhouse, Lodhi garden pond, Hauz Khas lake and Jasola wastewater treatment plant, respectively, were multidrug-resistant (MDR). The multiple antibiotic resistance (MAR) index varied from 0.20 to 0.32 among selected locations. The prevalence of ESBL gene variants blaSHV, blaTEM and blaCTX-M were found to be 17.64, 35.29 and 64%, respectively. Furthermore, the analysis of obtained gene sequences showed three variants of blaCTX-M (15, 152 and 205) and two variants of blaTEM (TEM-1 and TEM-116) among ESBL producers. The co-existence of 2-3 gene variants was recorded among 48% ESBL positive isolates. New reports from this study include the blaCTX-M gene in Acinetobacter lwoffii, Enterobacter ludwigii, Exiguobacterium mexicanum and Aeromonas caviae. Furthermore, the identification of blaTEM and blaSHV in an environmental isolate of A. caviae is a new report from India.


Assuntos
Água , beta-Lactamases , Acinetobacter , Antibacterianos/farmacologia , Enterobacter , Índia , beta-Lactamases/genética
15.
Mar Pollut Bull ; 172: 112850, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34391012

RESUMO

This study investigates bacterial diversity and potential pathogens in the international ships' ballast water at Tanjung Pelepas Port, Malaysia, using 16S rRNA amplicon sequencing. Thirty-four bacterial phylum, 305 families, 577 genera, and 941 species were detected in eight ballast water samples of different origins. The similarity of the bacterial composition between samples was found to be random and not tied to geographical locations. The bacterial abundance did not seem to be affected by related physicochemical except for temperature. Ballast water samples with a temperature lower than 25 °C showed a relatively lower bacterial abundance. A total of 33 potential pathogens were detected from all ballast water samples. Pseudomonas spp., Tenacibaculum spp., Flavobacteriaceae spp., Halomonas spp., and Acinetobacter junii are the potential pathogens with more than 10% OTU prevalence. This study would provide beneficial information for further enhancing ballast water microorganism guidelines in Malaysia.


Assuntos
Navios , Água , Acinetobacter , Humanos , Malásia , RNA Ribossômico 16S
16.
Int J Mol Sci ; 22(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34298891

RESUMO

The genus Acinetobacter consists of Gram-negative obligate aerobic pathogens, including clinically relevant species, such as A. baumannii, which frequently cause hospital infections, affecting debilitated patients. The growing resistance to antimicrobial therapies shown by A. baumannii is reaching unacceptable levels in clinical practice, and there is growing concern that the serious conditions it causes may soon become incurable. New therapeutic possibilities are, therefore, urgently needed to circumvent this important problem. Synthetic cationic macromolecules, such as cationic antimicrobial peptides (AMPs), which act as membrane disrupters, could find application in these conditions. A lysine-modified cationic polyester-based dendrimer (G5-PDK), capable of electrostatically interacting with bacterial surfaces as AMPs do, has been synthesized and characterized here. Given its chemical structure, similar to that of a fifth-generation lysine containing dendrimer (G5K) with a different core, and previously found inactive against Gram-positive bacterial species and Enterobacteriaceae, the new G5-PDK was also ineffective on the species mentioned above. In contrast, it showed minimum inhibitory concentration values (MICs) lower than reported for several AMPs and other synthetic cationic compounds on Acinetobacter genus (3.2-12.7 µM). Time-kill experiments on A. baumannii, A. pittii, and A. ursingii ascertained the rapid bactericidal effects of G5-PDK, while subsequent bacterial regrowth supported its self-biodegradability.


Assuntos
Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Dendrímeros/farmacologia , Lisina/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos
17.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299184

RESUMO

Quorum sensing of Acinetobacter nosocomialis for cell-to-cell communication produces N-3-hydroxy dodecanoyl-DL-homoserine lactone (OH-dDHL) by an AnoR/I two-component system. However, OH-dDHL-driven apoptotic mechanisms in hosts have not been clearly defined. Here, we investigated the induction of apoptosis signaling pathways in bone marrow-derived macrophages treated with synthetic OH-dDHL. Moreover, the quorum-sensing system for virulence regulation was evaluated in vivo using wild-type and anoI-deletion mutant strains. OH-dDHL decreased the viability of macrophage and epithelial cells in dose- and time-dependent manners. OH-dDHL induced Ca2+ efflux and caspase-12 activation by ER stress transmembrane protein (IRE1 and ATF6a p50) aggregation and induced mitochondrial dysfunction through reactive oxygen species (ROS) production, which caused cytochrome c to leak. Pretreatment with a pan-caspase inhibitor reduced caspase-3, -8, and -9, which were activated by OH-dDHL. Pro-inflammatory cytokine and paraoxonase-2 (PON2) gene expression were increased by OH-dDHL. We showed that the anoI-deletion mutant strains have less intracellular invasion compared to the wild-type strain, and their virulence, such as colonization and dissemination, was decreased in vivo. Consequently, these findings revealed that OH-dDHL, as a virulence factor, contributes to bacterial infection and survival as well as the modification of host responses in the early stages of infection.


Assuntos
4-Butirolactona/análogos & derivados , Acinetobacter/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Homosserina/análogos & derivados , Macrófagos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , 4-Butirolactona/farmacologia , Acinetobacter/isolamento & purificação , Acinetobacter/patogenicidade , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Feminino , Homosserina/farmacologia , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Mitocôndrias/metabolismo , Percepção de Quorum , Espécies Reativas de Oxigênio/metabolismo , Fatores de Virulência/farmacologia
18.
Bioresour Technol ; 339: 125620, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34311410

RESUMO

A novel strain was isolated from swinewastewater and identified as Acinetobacter sp. TAC-1 based on its phylogenetic and phenotypic characteristics. The strain TAC-1 was found to have a high ability to metabolize ammonium-N under low temperature condition. The strain TAC-1 could remove approximately 94.6% of ammonium-N (400 mg/L), 93.3% of nitrate-N (400 mg/L) and 42.4% of nitrite-N (400 mg/L) at 5 °C. The functional genes nitrate reductase gene (narG) and nitrite reductase gene (nirK, nirS) were successfully amplified by qPCR, further evidencing the heterotrophic nitrification and aerobic denitrification capability of Acinetobacter sp. TAC-1. The transcriptome data confirmed that the membrane transport protein and unsaturated fatty acid dehydrogenase-related genes of the strain TAC-1 were significantly up-regulated at 5 °C, enabling it to survive low temperatures. The high nitrogen removal ability at 5 °C makes this strain have a good application prospect.


Assuntos
Acinetobacter , Nitrificação , Acinetobacter/genética , Aerobiose , Amônia , Desnitrificação , Processos Heterotróficos , Nitritos , Nitrogênio , Filogenia , Temperatura
19.
Artigo em Inglês | MEDLINE | ID: mdl-34208169

RESUMO

The increasing number of endoscopic procedures performed and their increasing invasiveness mean that endoscopy of the gastrointestinal tract is associated with the risk of transmitting pathogenic microorganisms through infected equipment or contact with other patients and medical staff. In order to ensure protection of the health of both patients and medical staff, endoscopy laboratories should meet high hygiene standards. The results of tests of the microbiological cleanliness of surfaces and equipment of an endoscopic examination laboratory performed in the period from January to December 2019 at the Provincial Clinical Hospital No. 2 in Rzeszow were assessed retrospectively. Samples for testing were collected by swabbing from places where microbiological contamination was the most likely and cleaning was the most difficult. In the analyzed period, a total of 86 samples were collected for microbiological tests, of which positive results accounted for 6.9%. Positive results were obtained mainly from swabs collected from wet surfaces (66.7%). Most of the isolated microorganisms were Gram-negative bacteria (66.7% of all positive tests) and they were: Acinetobacter junii, Ralstonia pickettii, and Achromobacter denitrificans. The condition of the microbiological cleanliness of the surfaces and equipment of the endoscopic examination laboratory was satisfactory. A very low level of microbiological contamination of the tested items indicates occasional shortcomings in the decontamination processes. Since microorganisms isolated from the collected samples may be the cause of infection in patients and medical personnel, it is necessary to verify the decontamination procedures applied and to continue periodic microbiological monitoring of their effectiveness.


Assuntos
Endoscopia , Laboratórios , Acinetobacter , Contaminação de Equipamentos , Humanos , Polônia , Estudos Retrospectivos
20.
Artigo em Inglês | MEDLINE | ID: mdl-34208299

RESUMO

Strain sw-1, isolated from 7619-m seawater of the Mariana Trench, was identified as Acinetobacter pittii by 16S rRNA gene and whole-genome sequencing. A. pittii sw-1 was able to efficiently utilize long-chain n-alkanes (C18-C36), but not short- and medium-chain n-alkanes (C8-C16). The degradation rate of C20 was 91.25%, followed by C18, C22, C24, C32, and C36 with the degradation rates of 89.30%, 84.03%, 80.29%, 30.29%, and 13.37%, respectively. To investigate the degradation mechanisms of n-alkanes for this strain, the genome and the transcriptome analyses were performed. Four key alkane hydroxylase genes (alkB, almA, ladA1, and ladA2) were identified in the genome. Transcriptomes of strain sw-1 grown in C20 or CH3COONa (NaAc) as the sole carbon source were compared. The transcriptional levels of alkB and almA, respectively, increased 78.28- and 3.51-fold in C20 compared with NaAc, while ladA1 and ladA2 did not show obvious change. The expression levels of other genes involved in the synthesis of unsaturated fatty acids, permeases, membrane proteins, and sulfur metabolism were also upregulated, and they might be involved in n-alkane uptake. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that alkB expression was significantly induced by C20, C24, and C32, and almA induction extent by C24 and C32 was higher than that with C20. Furthermore, ladA2 expression was only induced by C32, and ladA1 expression was not induced by any of n-alkanes. In addition, A. pittii sw-1 could grow with 0%-3% NaCl or 8 out of 10 kinds of the tested heavy metals and degrade n-alkanes at 15 °C. Taken together, these results provide comprehensive insights into the degradation of long-chain n-alkanes by Acinetobacter isolated from the deep ocean environment.


Assuntos
Acinetobacter , Alcanos , Acinetobacter/genética , Biodegradação Ambiental , Perfilação da Expressão Gênica , RNA Ribossômico 16S
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