Isolation of biosurfactant producers, optimization and properties of biosurfactant produced by Acinetobacter sp. from petroleum-contaminated soil.

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Chen, J; Huang, P T; Zhang, K Y; Ding, F R

2012-04-01

To screen and identify biosurfactant producers from petroleum-contaminated soil; to use response surface methodology (RSM) for medium optimization to enhance biosurfactant production; and to study the properties of the newly obtained biosurfactant towards pH, temperature and salinity. We successfully isolated three biosurfactant producers from petroleum-contaminated soil and identified them through 16S rRNA sequence analysis, which exhibit the highest similarities to Acinetobacter beijerinckii (100%), Kocuria marina (99%) and Kineococcus marinus (99%), respectively. A quadratic response model was constructed through RSM designs, leading to a 57·5% increase of the growth-associated biosurfactant production by Acinetobacter sp. YC-X 2 with an optimized medium: beef extract 3·12 g l(-1) ; peptone 20·87 g l(-1) ; NaCl 1·04 g l(-1); and n-hexadecane 1·86 g l(-1). Biosurfactant produced by Acinetobacter sp. YC-X 2 retained its properties during exposure to a wide range of pH values (5-11), high temperatures (up to 121°C) and high salinities [up to 18% (w/v) Na(+) and Ca(2+) ], which was more sensitive to Ca(2+) than Na(+). Two novel biosurfactant producers were isolated from petroleum-contaminated soil. Biosurfactant from Acinetobacter sp. YC-X 2 has good properties to a wide range of pH, high temperature and high salinity, and its production was optimized successfully through RSM. The fact, an increasing demand of high-quality surfactants and the lack of cost-competitive bioprocesses of biosurfactants for commercial utilization, motivates researchers to develop cost-effective strategies for biosurfactant production through isolating new biosurfactant producers with special surface-active properties and optimizing their cultural conditions. Two novel biosurfactant producers in this study will widen our knowledge about this kind of micro-organism. This work is the first application of RSM designs for cultural optimization of biosurfactant produced by Acinetobacter

Carbapenem-Resistant Acinetobacter baumannii: Concomitant Contamination of Air and Environmental Surfaces.

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Shimose, Luis A; Masuda, Eriko; Sfeir, Maroun; Berbel Caban, Ana; Bueno, Maria X; dePascale, Dennise; Spychala, Caressa N; Cleary, Timothy; Namias, Nicholas; Kett, Daniel H; Doi, Yohei; Munoz-Price, L Silvia

2016-07-01

OBJECTIVE To concomitantly determine the differential degrees of air and environmental contamination by Acinetobacter baumannii based on anatomic source of colonization and type of ICU layout (single-occupancy vs open layout). DESIGN Longitudinal prospective surveillance study of air and environmental surfaces in patient rooms. SETTING A 1,500-bed public teaching hospital in Miami, Florida. PATIENTS Consecutive A. baumannii-colonized patients admitted to our ICUs between October 2013 and February 2014. METHODS Air and environmental surfaces of the rooms of A. baumannii-colonized patients were sampled daily for up to 10 days. Pulsed-field gel electrophoresis (PFGE) was used to type and match the matching air, environmental, and clinical A. baumannii isolates. RESULTS A total of 25 A. baumannii-colonized patients were identified during the study period; 17 were colonized in the respiratory tract and 8 were colonized in the rectum. In rooms with rectally colonized patients, 38.3% of air samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 13.1% of air samples were positive (P=.0001). In rooms with rectally colonized patients, 15.5% of environmental samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 9.5% of environmental samples were positive (P=.02). The rates of air contamination in the open-layout and single-occupancy ICUs were 17.9% and 21.8%, respectively (P=.5). Environmental surfaces were positive in 9.5% of instances in open-layout ICUs versus 13.4% in single-occupancy ICUs (P=.09). CONCLUSIONS Air and environmental surface contaminations were significantly greater among rectally colonized patients; however, ICU layout did not influence the rate of contamination. Infect Control Hosp Epidemiol 2016;37:777-781.

Acinetobacter species as model microorganisms in environmental microbiology: current state and perspectives.

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Jung, Jaejoon; Park, Woojun

2015-03-01

Acinetobacter occupies an important position in nature because of its ubiquitous presence in diverse environments such as soils, fresh water, oceans, sediments, and contaminated sites. Versatile metabolic characteristics allow species of this genus to catabolize a wide range of natural compounds, implying active participation in the nutrient cycle in the ecosystem. On the other hand, multi-drug-resistant Acinetobacter baumannii causing nosocomial infections with high mortality has been raising serious concerns in medicine. Due to the ecological and clinical importance of the genus, Acinetobacter was proposed as a model microorganism for environmental microbiological studies, pathogenicity tests, and industrial production of chemicals. For these reasons, Acinetobacter has attracted significant attention in scientific and biotechnological fields, but only limited research areas such as natural transformation and aromatic compound degradation have been intensively investigated, while important physiological characteristics including quorum sensing, motility, and stress response have been neglected. The aim of this review is to summarize the recent achievements in Acinetobacter research with a special focus on strain DR1 and to compare the similarities and differences between species or other genera. Research areas that require more attention in future research are also suggested.

Drug-resistant post-neurosurgical nosocomial Acinetobacter ...

African Journals Online (AJOL)

Drug-resistant post-neurosurgical nosocomial Acinetobacter baumannii meningitis in two Iranian hospitals. ... Vol 11, No 17 (2012) >. Log in or Register to get access to full text downloads. ... Acinetobacter baumannii may cause meningitis and ventriculitis, particularly after head trauma and/or neurosurgery. The rate of ...

Evolution of a Pathogen: A Comparative Genomics Analysis Identifies a Genetic Pathway to Pathogenesis in Acinetobacter

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Sahl, Jason W.; Gillece, John D.; Schupp, James M.; Waddell, Victor G.; Driebe, Elizabeth M.; Engelthaler, David M.; Keim, Paul

2013-01-01

Acinetobacter baumannii is an emergent and global nosocomial pathogen. In addition to A. baumannii, other Acinetobacter species, especially those in the Acinetobacter calcoaceticus-baumannii (Acb) complex, have also been associated with serious human infection. Although mechanisms of attachment, persistence on abiotic surfaces, and pathogenesis in A. baumannii have been identified, the genetic mechanisms that explain the emergence of A. baumannii as the most widespread and virulent Acinetobacter species are not fully understood. Recent whole genome sequencing has provided insight into the phylogenetic structure of the genus Acinetobacter. However, a global comparison of genomic features between Acinetobacter spp. has not been described in the literature. In this study, 136 Acinetobacter genomes, including 67 sequenced in this study, were compared to identify the acquisition and loss of genes in the expansion of the Acinetobacter genus. A whole genome phylogeny confirmed that A. baumannii is a monophyletic clade and that the larger Acb complex is also a well-supported monophyletic group. The whole genome phylogeny provided the framework for a global genomic comparison based on a blast score ratio (BSR) analysis. The BSR analysis demonstrated that specific genes have been both lost and acquired in the evolution of A. baumannii. In addition, several genes associated with A. baumannii pathogenesis were found to be more conserved in the Acb complex, and especially in A. baumannii, than in other Acinetobacter genomes; until recently, a global analysis of the distribution and conservation of virulence factors across the genus was not possible. The results demonstrate that the acquisition of specific virulence factors has likely contributed to the widespread persistence and virulence of A. baumannii. The identification of novel features associated with transcriptional regulation and acquired by clades in the Acb complex presents targets for better understanding the

Acinetobacter spp. as nosocomial pathogens: Epidemiology and resistance features

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Saad B. Almasaudi

2018-03-01

Full Text Available The genus Acinetobacter is a major cause of nosocomial infections; it is increasingly being associated with various epidemics and has become a widespread concern in a variety of hospitals worldwide. Multi-antibiotic resistant Acinetobacter baumannii, is now recognized to be of great clinical significance. Numerous reports relay to the spread of A. baumannii in the hospital settings which leads to enhanced nosocomial outbreaks associated with high death rates. However, many other Acinetobacter spp. also can cause nosocomial infections. This review focused on the role of Acinetobacter spp. as nosocomial pathogens in addition to their persistence, antimicrobial resistance patterns and epidemiology. Keywords: Acinetobacter, Nosocomial infections, Multi-drug resistance, Epidemiology, Characteristics

Isolation, screening, and characterization of surface-active agent-producing, oil-degrading marine bacteria of Mumbai Harbor.

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Mohanram, Rajamani; Jagtap, Chandrakant; Kumar, Pradeep

2016-04-15

Diverse marine bacterial species predominantly found in oil-polluted seawater produce diverse surface-active agents. Surface-active agents produced by bacteria are classified into two groups based on their molecular weights, namely biosurfactants and bioemulsifiers. In this study, surface-active agent-producing, oil-degrading marine bacteria were isolated using a modified Bushnell-Haas medium with high-speed diesel as a carbon source from three oil-polluted sites of Mumbai Harbor. Surface-active agent-producing bacterial strains were screened using nine widely used methods. The nineteen bacterial strains showed positive results for more than four surface-active agent screening methods; further, these strains were characterized using biochemical and nucleic acid sequencing methods. Based on the results, the organisms belonged to the genera Acinetobacter, Alcanivorax, Bacillus, Comamonas, Chryseomicrobium, Halomonas, Marinobacter, Nesterenkonia, Pseudomonas, and Serratia. The present study confirmed the prevalence of surface-active agent-producing bacteria in the oil-polluted waters of Mumbai Harbor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative Analysis of 37 Acinetobacter Bacteriophages

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Dann Turner

2017-12-01

Full Text Available Members of the genus Acinetobacter are ubiquitous in the environment and the multiple-drug resistant species A. baumannii is of significant clinical concern. This clinical relevance is currently driving research on bacterial viruses infecting A. baumannii, in an effort to implement phage therapy and phage-derived antimicrobials. Initially, a total of 42 Acinetobacter phage genome sequences were available in the international nucleotide sequence databases, corresponding to a total of 2.87 Mbp of sequence information and representing all three families of the order Caudovirales and a single member of the Leviviridae. A comparative bioinformatics analysis of 37 Acinetobacter phages revealed that they form six discrete clusters and two singletons based on genomic organisation and nucleotide sequence identity. The assignment of these phages to clusters was further supported by proteomic relationships established using OrthoMCL. The 4067 proteins encoded by the 37 phage genomes formed 737 groups and 974 orphans. Notably, over half of the proteins encoded by the Acinetobacter phages are of unknown function. The comparative analysis and clustering presented enables an updated taxonomic framing of these clades.

Impact of terminal cleaning and disinfection on isolation of Acinetobacter baumannii complex from inanimate surfaces of hospital rooms by quantitative and qualitative methods.

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Manian, Farrin A; Griesnauer, Sandra; Senkel, Diane

2013-04-01

Quantitative broth cultures were obtained from hospital rooms newly vacated by patients positive for multidrug-resistant Acinetobacter baumannii complex (ABC) before and after terminal cleaning and disinfection. Of 10 ABC-positive precleaned room surfaces, 6 (60%) remained culture-positive after terminal cleaning and disinfection. Of a total of 16 room surfaces with detectable ABC by the quantitative method, 5 (31.2%; 95% confidence interval, 13.9%-55.8%) were also culture-positive by the qualitative technique. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

An MFS Transporter-Like ORF from MDR Acinetobacter baumannii AIIMS 7 Is Associated with Adherence and Biofilm Formation on Biotic/Abiotic Surface

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Praveen K. Sahu

2012-01-01

Full Text Available A major facilitator superfamily (MFS transporter-like open reading frame (ORF of 453 bp was identified in a pathogenic strain Acinetobacter baumannii AIIMS 7, and its association with adherence and biofilm formation was investigated. Reverse transcription PCR (RT-PCR showed differential expression in surface-attached biofilm cells than nonadherent cells. In vitro translation showed synthesis of a ∼17 kDa protein, further confirmed by cloning and heterologous expression in E. coli DH5. Up to 2.1-, 3.1-, and 4.1- fold biofilm augmentation was observed on abiotic (polystyrene and biotic (S. cerevisiae/HeLa surface, respectively. Scanning electron microscopy (SEM and gfp-tagged fluorescence microscopy revealed increased adherence to abiotic (glass and biotic (S. cerevisiae surface. Extracellular DNA(eDNA was found significantly during active growth; due to probable involvement of the protein in DNA export, strong sequence homology with MFS transporter proteins, and presence of transmembrane helices. In summary, our findings show that the putative MFS transporter-like ORF (pmt is associated with adherence, biofilm formation, and probable eDNA release in A. baumannii AIIMS 7.

Nosocomial infections due to Acinetobacter calcoaceticus.

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Zaer F

1989-01-01

Full Text Available Fifty four isolates of Acinetobacter calcoaceticus were studied in a period of 6 months. Maximum isolates were from burns cases and environmental sampling from burns ward also grew the same organism, indicating their role as nosocomial pathogen. Acinetobacter may initially be mistaken for Neisseria species. As the organisms show multidrug resistance to commonly used antibiotics their correct identification is important.

Nosocomial infections due to Acinetobacter calcoaceticus.

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Zaer, F; Deodhar, L

1989-01-01

Fifty four isolates of Acinetobacter calcoaceticus were studied in a period of 6 months. Maximum isolates were from burns cases and environmental sampling from burns ward also grew the same organism, indicating their role as nosocomial pathogen. Acinetobacter may initially be mistaken for Neisseria species. As the organisms show multidrug resistance to commonly used antibiotics their correct identification is important.

Copper Resistance of the Emerging Pathogen Acinetobacter baumannii

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Williams, Caitlin L.; Neu, Heather M.; Gilbreath, Jeremy J.; Michel, Sarah L. J.; Zurawski, Daniel V.

2016-01-01

ABSTRACT Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa. Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. IMPORTANCE Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic

Copper Resistance of the Emerging Pathogen Acinetobacter baumannii.

Science.gov (United States)

Williams, Caitlin L; Neu, Heather M; Gilbreath, Jeremy J; Michel, Sarah L J; Zurawski, Daniel V; Merrell, D Scott

2016-10-15

Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic, and treatment options

Green synthesis of selenium nanoparticles using Acinetobacter sp. SW30: optimization, characterization and its anticancer activity in breast cancer cells

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Wadhwani SA

2017-09-01

Full Text Available Sweety A Wadhwani,1 Mahadeo Gorain,2 Pinaki Banerjee,2 Utkarsha U Shedbalkar,3 Richa Singh,1 Gopal C Kundu,2 Balu A Chopade1,4 1Department of Microbiology, Savitribai Phule Pune University, 2Laboratory of Tumor Biology, Angiogenesis and Nanomedicine Research, National Center for Cell Science, Savitribai Phule Pune University Campus, Pune, 3Department of Biochemistry, The Institute of Science, Mumbai, 4Dr Babasaheb Ambedkar Marathwada University, Aurangabad, Maharashtra, India Abstract: The aim of this study was to synthesize selenium nanoparticles (SeNPs using cell suspension and total cell protein of Acinetobacter sp. SW30 and optimize its synthesis by studying the influence of physiological and physicochemical parameters. Also, we aimed to compare its anticancer activity with that of chemically synthesized SeNPs in breast cancer cells. Cell suspension of Acinetobacter sp. SW30 was exposed to various physiological and physicochemical conditions in the presence of sodium selenite to study their effects on the synthesis and morphology of SeNPs. Breast cancer cells (4T1, MCF-7 and noncancer cells (NIH/3T3, HEK293 were exposed to different concentrations of SeNPs. The 18 h grown culture with 2.7×109 cfu/mL could synthesize amorphous nanospheres of size 78 nm at 1.5 mM and crystalline nanorods at above 2.0 mM Na2SeO3 concentration. Polygonal-shaped SeNPs of average size 79 nm were obtained in the supernatant of 4 mg/mL of total cell protein of Acinetobacter sp. SW30. Chemical SeNPs showed more anticancer activity than SeNPs synthesized by Acinetobacter sp. SW30 (BSeNPs, but they were found to be toxic to noncancer cells also. However, BSeNPs were selective against breast cancer cells than chemical ones. Results suggest that BSeNPs are a good choice of selection as anticancer agents. Keywords: comparison, selective, 4T1, MCF7

Characterization of hydrogen peroxide-resistant Acinetobacter species isolated during the Mars Phoenix spacecraft assembly.

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Derecho, I; McCoy, K B; Vaishampayan, P; Venkateswaran, K; Mogul, R

2014-10-01

The microbiological inventory of spacecraft and the associated assembly facility surfaces represent the primary pool of forward contaminants that may impact the integrity of life-detection missions. Herein, we report on the characterization of several strains of hydrogen peroxide-resistant Acinetobacter, which were isolated during the Mars Phoenix lander assembly. All Phoenix-associated Acinetobacter strains possessed very high catalase specific activities, and the specific strain, A. gyllenbergii 2P01AA, displayed a survival against hydrogen peroxide (no loss in 100 mM H2O2 for 1 h) that is perhaps the highest known among Gram-negative and non-spore-forming bacteria. Proteomic characterizations reveal a survival mechanism inclusive of proteins coupled to peroxide degradation (catalase and alkyl hydroperoxide reductase), energy/redox management (dihydrolipoamide dehydrogenase), protein synthesis/folding (EF-G, EF-Ts, peptidyl-tRNA hydrolase, DnaK), membrane functions (OmpA-like protein and ABC transporter-related protein), and nucleotide metabolism (HIT family hydrolase). Together, these survivability and biochemical parameters support the hypothesis that oxidative tolerance and the related biochemical features are the measurable phenotypes or outcomes for microbial survival in the spacecraft assembly facilities, where the low-humidity (desiccation) and clean (low-nutrient) conditions may serve as selective pressures. Hence, the spacecraft-associated Acinetobacter, due to the conferred oxidative tolerances, may ultimately hinder efforts to reduce spacecraft bioburden when using chemical sterilants, thus suggesting that non-spore-forming bacteria may need to be included in the bioburden accounting for future life-detection missions.

Antimicrobial effects of Ferula gummosa Boiss gum against extended-spectrum β-lactamase producing Acinetobacter clinical isolates.

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Afshar, Fatemeh Farid; Saffarian, Parvaneh; Hosseini, Hamideh Mahmoodzadeh; Sattarian, Fereshteh; Amin, Mohsen; Fooladi, Abbas Ali Imani

2016-08-01

Acinetobacter spp. are important causes of nosocomial infections. They possess various antibiotic resistance mechanisms including extended spectrum beta lactamases (ESBLs). The aim of this study was to determine antibiotic resistance profile of Acinetobacter clinical isolates especially among ESBL-producing strains and to investigate the antimicrobial effects of oleo-gum-resin extract and essential oil of Ferula gummosa Boiss. 120 Acinetobacter strains were isolated from various clinical samples of hospitalized patients in Baqiyatallah hospital, Tehran during 2011-2012. Antibiotic susceptibility test was performed on the isolates using disk diffusion method. To detect and confirm the ESBL-positive isolates, phenotypic and genotypic tests were performed. Three types of F. gummosa oleo-gum-resin extracts and essential oils were prepared and the bioactive components of F. gummosa Boiss extracts were determined by GC-Mass chromatography. F. gummosa antimicrobial activity was evaluated against standard strain of Acinetobacter baumannii (ATCC19606) as well as Acinetobacter clinical isolates using well and disk diffusion methods. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution method. 46 isolates were resistant to all tested antibiotics. All clinical isolates were resistant to cefotaxime. 12.94% of the isolates were phenotypically ESBL-producing among which 94.2% carried ESBL genes ( bla PER-1 , bla OXA-4 and bla CTX-M ) detected by PCR. Oleo-gum-resin of F. gummosa had significant antibacterial activity and alcoholic essential oil had higher inhibitory effect on Acinetobacter strains (MIC of 18.75 mg/ml). Ferula gummosa extract contained components with well-known antimicrobial effects.

CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

OpenAIRE

Laura Ghibu; Egidia Miftode; Olivia Dorneanu; Carmen Dorobat

2011-01-01

Acinetobacter baumannii is an opportunistic pathogen of increasing relevance in hospital infections during the last 15 years.This organism causes a wide range of infection .Extensive use of antibiotics within hospitals has contribute to the emergence of multidrug-resistent A.baumannii strains that exhibit resistance to a wide range of antibiotics ,including carbapenems.We report the case of an 37 years old man diagnosed with Acinetobacter multidrug-resistant post-neurosurgical meningitis with...

[Community-acquired Acinetobacter pneumonia].

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Bernasconi, E; Wüst, J; Speich, R; Flury, G; Krause, M

1993-08-21

We report the history of a 38-year-old male native of Sri Lanka admitted to the emergency ward because of chest pain and shortness of breath. On physical and radiographic examination a bilateral predominantly right-sided pneumonia was found. The patient was admitted to the medical ICU and an antibiotic regimen with amoxicillin/clavulanic acid and erythromycin was initiated. Shortly afterwards septic shock developed. The patient was intubated and received high doses of catecholamines. He died 30 hours after admission to the hospital. Cultures from sputum, tracheal aspirate and blood grew Acinetobacter baumanni. Acinetobacter is an ubiquitous gram-negative rod with coccobacillary appearance in clinical specimens, that may appear gram-positive due to poor discoloration on Gram-stain. It is a well known causative agent of nosocomial infections, particularly in intensive care units. Community-acquired pneumonias, however, are quite rare. Sporadic cases have been reported from the US, Papua-New Guinea and Australia. Interestingly, these pneumonias are fulminant and have a high mortality. Chronic obstructive lung disease, diabetes, and tobacco and alcohol consumption appear to be predisposing factors. Due to the rapid course and poor prognosis, prompt diagnosis and adequate antibiotic treatment are indicated. Antibiotics use for community-acquired pneumonias, such as amoxicillin/clavulanic acid or macrolides, are not sufficient. Appropriate antibiotics for the initial treatment of suspected Acinetobacter infections include imipenem and carboxy- and ureidopenicillins combined with an aminoglycoside.

MICROORGANISMS’ SURFACE ACTIVE SUBSTANCES ROLE IN HYDROCARBONS BIODEGRADATION

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Оlga Vasylchenko

2012-09-01

Full Text Available  Existing data and publications regarding oil, hydrocarbon biodegradation, metabolism, and bioremediation were analyzed. Search of hydrocarbon degrading bacteria which are producers of biosurfactants was provided, types of microbial surfactants and their physiological role were analyzed and ordered. The study of factors affecting the surface active properties of producers’ cultures was done.

Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki.

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Dann Turner

Full Text Available Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA under the accession number LN890663.

Emerging Trend of Acinetobacter Nosocomial Infection in Northeast of Iran

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Samaneh Saed

2015-10-01

Full Text Available Background: Acinetobacter spp. emerged as an opportunistic pathogen for hospital-acquired infections. Recently, increasing antibiotic resistance among Acinetobacter spp. has worsened the problem. The aim of this study was to investigate  the  emerging  trend  of  infection  due  to Acinetobacter  in Ghaem University Hospital, Mashhad during 2006-2012.Methods: The demographic data and information about redisposing factors was collected. Appropriate bacteriological samples were collected and Acinetobacter spp. was isolated. Antibiotics susceptibility pattern of these isolates againstdifferent antimicrobials agents was determined.Results: Results confirmed that Acinetobacter spp. cause 20.9% of nosocomial infection during this period. The trend of Acinetobacter nosocomial infection was increasing and patients with risk factors such as COPD, bronchectasia, diabetes   mellitus   were   more   prone   to   infection.  There   was   significant association   between   these   infections   and   invasive   procedures   such   as catheterization, mechanical ventilation and broad-spectrum antibiotics usage. Conclusion:  Understanding  trends  in  causative  organisms  of  nosocomial infection can help us to better define our infection control policy.

Characterization of surface antigen protein 1 (SurA1) from Acinetobacter baumannii and its role in virulence and fitness.

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Liu, Dong; Liu, Zeng-Shan; Hu, Pan; Cai, Ling; Fu, Bao-Quan; Li, Yan-Song; Lu, Shi-Ying; Liu, Nan-Nan; Ma, Xiao-Long; Chi, Dan; Chang, Jiang; Shui, Yi-Ming; Li, Zhao-Hui; Ahmad, Waqas; Zhou, Yu; Ren, Hong-Lin

2016-04-15

Acinetobacter baumannii is a Gram-negative bacillus that causes nosocomial infections, such as bacteremia, pneumonia, and meningitis and urinary tract and wound infections. In the present study, the surface antigen protein 1 (SurA1) gene of A. baumannii strain CCGGD201101 was identified, cloned and expressed, and then its roles in fitness and virulence were investigated. Virulence was observed in the human lung cancer cell lines A549 and HEp-2 at one week after treatment with recombinant SurA1. One isogenic SurA1 knock-out strain, GR0015, which was derived from the A. baumannii strain CCGGD201101 isolated from diseased chicks in a previous study, highlighted the effect of SurA1 on fitness and growth. Its growth rate in LB broth and killing activity in human sera were significantly decreased compared with strain CCGGD201101. In the Galleria mellonella insect model, the isogenic SurA1 knock-out strain exhibited a lower survival rate and decreased dissemination. These results suggest that SurA1 plays an important role in the fitness and virulence of A. baumannii. Copyright © 2016 Elsevier B.V. All rights reserved.

Infections caused by Acinetobacter species and their susceptibility to ...

African Journals Online (AJOL)

Thirty-seven (63%) and 17 (30%) of the Acinetobacter isolates were from wound infections and UTI respectively. All the infections were nosocomially acquired and were associated with compromised host immunity, defective body defence, surgery or urinary catheterization; with Acinetobacter baumannii being the ...

Acinetobacter Peritoneal Dialysis Peritonitis: A Changing Landscape over Time

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Chao, Chia-Ter; Lee, Szu-Ying; Yang, Wei-Shun; Chen, Huei-Wen; Fang, Cheng-Chung; Yen, Chung-Jen; Chiang, Chih-Kang; Hung, Kuan-Yu; Huang, Jenq-Wen

2014-01-01

Background Acinetobacter species are assuming an increasingly important role in modern medicine, with their persistent presence in health-care settings and antibiotic resistance. However, clinical reports addressing this issue in patients with peritoneal dialysis (PD) peritonitis are rare. Methods All PD peritonitis episodes caused by Acinetobacter that occurred between 1985 and 2012 at a single centre were retrospectively reviewed. Clinical features, microbiological data, and outcomes were analysed, with stratifications based upon temporal periods (before and after 2000). Results Acinetobacter species were responsible for 26 PD peritonitis episodes (3.5% of all episodes) in 25 patients. A. baumannii was the most common pathogen (54%), followed by A. iwoffii (35%), with the former being predominant after 2000. Significantly more episodes resulted from breaks in exchange sterility after 2000, while those from exit site infections decreased (P = 0.01). The interval between the last and current peritonitis episodes lengthened significantly after 2000 (5 vs. 13.6 months; P = 0.05). All the isolates were susceptible to cefepime, fluoroquinolone, and aminoglycosides, with a low ceftazidime resistance rate (16%). Nearly half of the patients (46%) required hospitalisation for their Acinetobacter PD-associated peritonitis, and 27% required an antibiotic switch. The overall outcome was fair, with no mortality and a 12% technique failure rate, without obvious interval differences. Conclusions The temporal change in the microbiology and origin of Acinetobacter PD-associated peritonitis in our cohort suggested an important evolutional trend. Appropriate measures, including technique re-education and sterility maintenance, should be taken to decrease the Acinetobacter peritonitis incidence in PD patients. PMID:25314341

Acinetobacter peritoneal dialysis peritonitis: a changing landscape over time.

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Chia-Ter Chao

Full Text Available Acinetobacter species are assuming an increasingly important role in modern medicine, with their persistent presence in health-care settings and antibiotic resistance. However, clinical reports addressing this issue in patients with peritoneal dialysis (PD peritonitis are rare.All PD peritonitis episodes caused by Acinetobacter that occurred between 1985 and 2012 at a single centre were retrospectively reviewed. Clinical features, microbiological data, and outcomes were analysed, with stratifications based upon temporal periods (before and after 2000.Acinetobacter species were responsible for 26 PD peritonitis episodes (3.5% of all episodes in 25 patients. A. baumannii was the most common pathogen (54%, followed by A. iwoffii (35%, with the former being predominant after 2000. Significantly more episodes resulted from breaks in exchange sterility after 2000, while those from exit site infections decreased (P = 0.01. The interval between the last and current peritonitis episodes lengthened significantly after 2000 (5 vs. 13.6 months; P = 0.05. All the isolates were susceptible to cefepime, fluoroquinolone, and aminoglycosides, with a low ceftazidime resistance rate (16%. Nearly half of the patients (46% required hospitalisation for their Acinetobacter PD-associated peritonitis, and 27% required an antibiotic switch. The overall outcome was fair, with no mortality and a 12% technique failure rate, without obvious interval differences.The temporal change in the microbiology and origin of Acinetobacter PD-associated peritonitis in our cohort suggested an important evolutional trend. Appropriate measures, including technique re-education and sterility maintenance, should be taken to decrease the Acinetobacter peritonitis incidence in PD patients.

Acinetobacter infections as an emerging threat in intensive care units

International Nuclear Information System (INIS)

Tahseen, U.; Talib, M.T.

2015-01-01

Nosocomial infections caused by Acinetobacter species (Spp.) is an emerging threat in health care setups especially intensive care units (ICU). The objective of this observational study was to determine the pattern of Acinetobacter infections and its association with length of stay in patients admitted to our medical ICU from January to August 2011. Methods: All patients above 16 years of age with stay of more than 48 hours were checked for any development of new infections not present or incubating at the time of admission. Nosocomial infections were documented in the light of clinical findings and lab results. Data was analysed using statistical software SPSS 15.0. Results: A total of 146 patients had a stay of at least 48 hours; frequency of nosocomial infection was 30.8% out of which 57.8% were Acinetobacter infections. Respiratory system was most commonly involved. Acinetobacter Spp showed high resistance (96.2%) to penicillins, cephalosporins and even extended spectrum antibiotics including carbepenems, quinolones and piperacillin plus tazobactam. Extended drug resistance was seen in 92.3% isolates; while we found high susceptibility to tigecycline (88.5%) and polymyxins (100%). Acinetobacter Spp. infected patients had mean length of stay (LOS) of 12.92 days when compared to patients with other nosocomial infections and no infection with mean LOS of 7.05 days (p=0.05) and 4.86 days (p=0.00) respectively. Conclusions: Acinetobacter Spp infections increase with longer duration of stay in ICU. Emergence of multi-drug and extended-drug resistant Acinetobacter Spp is alarming and overwhelming at this rate for already stretched out health system with its economic and health implications. (author)

Quorum sensing molecules production by nosocomial and soil isolates Acinetobacter baumannii.

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Erdönmez, Demet; Rad, Abbas Yousefi; Aksöz, Nilüfer

2017-12-01

Acinetobacter species remain alive in hospitals on various surfaces, both dry and moist, forming an important source of hospital infections. These bacteria are naturally resistant to many antibiotic classes. Although the role of the quorum sensing system in regulating the virulence factors of Acinetobacter species has not been fully elucidated, it has been reported that they play a role in bacterial biofilm formation. The biofilm formation helps them to survive under unfavorable growth conditions and antimicrobial treatments. It is based on the accumulation of bacterial communication signal molecules in the area. In this study, we compared the bacterial signal molecules of 50 nosocomial Acinetobacter baumannii strain and 20 A. baumannii strain isolated from soil. The signal molecules were detected by the biosensor bacteria (Chromobacterium violaceum 026, Agrobacterium tumefaciens A136, and Agrobacterium tumefaciens NTL1) and their separation was determined by thin-layer chromatography. As a result, it has been found that soil-borne isolates can produce 3-oxo-C8-AHL and C8-AHL, whereas nosocomial-derived isolates can produce long-chain signals such as C10-AHL, C12-AHL, C14-AHL and C16-AHL. According to these results, it is possible to understand that these signal molecules are found in the infection caused by A. baumannii. The inhibition of this signaling molecules in a communication could use to prevent multiple antibiotic resistance of these bacteria.

Acinetobacter pneumonia: Is the outcome different from the pneumonias caused by other agents

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Edis Ebru

2010-01-01

Full Text Available Background : The principal aim of the present study was to determine whether Acinetobacter spp. pneumonia differs from hospital-acquired pneumonias (HAPs caused by other agents with respect to therapeutic success and survival rate. METHODS : This study includes 140 adult patients diagnosed with HAPs caused by identified etiologic agents between March 2005 and February 2006. These patients were divided into two groups according to the agent responsible for their infection (Acinetobacter spp. [n = 63] or non-Acinetobacter spp. [n = 77]. The groups were compared in terms of risk factors, therapeutic success and six-week survival rates. Results : Previous antibiotic use and the risk of aspiration were independent factors responsible for the development of Acinetobacter spp. pneumonia. Hypoalbuminemia, steroid use and the use of a mechanical ventilator were determined to be mortality-associated independent risk factors for Acinetobacter spp. pneumonia. The clinical success rate at the end of therapy was 41.6% and, at the sixth week, the survival rate was 35% among patients in whom Acinetobacter spp. was the causative agent. Conversely, in the control group, these values were 43 and 32%, respectively ( P > 0.05. We found that the use of the appropriate antibiotics for the treatment of Acinetobacter spp. pneumonia was an important factor in survival ( P < 0.001. Conclusion : The outcomes of Acinetobacter spp. pneumonia do not differ from HAPs associated with non-Acinetobacter spp. in terms of therapeutic success and survival rates.

Frequency and antimicrobial susceptibility of acinetobacter species isolated from blood samples of paediatric patients

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Javed, A.; Zafar, A.; Ejaz, H.; Zubair, M.

2012-01-01

Objective: Acinetobacter species is a major nosocomial pathogen causing serious infections in immuno-compromised and hospitalized patients. The aim of this study was to determine the frequency and antimicrobial susceptibility pattern of Acinetobacter species in blood samples of paediatric patients. Methodology: This cross sectional observational study was conducted during January to October, 2011 at The Children's Hospital and Institute of Child Health, Lahore. A total number of 12,032 blood samples were analysed during the study period. Acinetobacter species were Bauer disc diffusion method. Results: The blood cultures showed growth in 1,141 cultures out of which 46 (4.0%) were Acinetobacter species. The gender distribution of Acinetobacter species was 29 (63.0%) in males and 17 (37.0%) in females. A good antimicrobial susceptibility pattern of Acinetobacter species was seen with sulbactam-cefoperazone (93.0%), imepenem and meropenem (82.6% (30.4%) was poor. Conclusion: The results of the present study shows high rate of resistance of Acinetobacter species with cephalosporins in nosocomial infections. The sulbactam-cefoperazone, carbapenems and piperacillin-tazobactam showed effective antimicrobial susceptibility against Acinetobacter species. (author)

To ecological-sanitary essessment of the importance of surface-active substances as anthropogenic factor in the Chernobyl' NPP 30-km zone

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Mudryj, I.V.; Raetskaya, E.V.; Golenkova, L.G.

1992-01-01

Sociological analysis dealing with studying attitude of the personnel working in the duty-idle regime towards usage of special clothes treated with synthetic detergents is realized. The surface-active substances (SAS) arc adsorbed by laudered underclothes (8-17 mug/cm 2 ) and can cause skin irritation during wearing. 77% of personnel engaged in public catering and 86% of that working in special laundry were questioned. It is revealed that presence of SAS traces on special clothes gives unfavourable effect on skin covers of the persons questioned (>68%)

Use of a stainless steel washer platform to study Acinetobacter baumannii adhesion and biofilm formation on abiotic surfaces.

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Orsinger-Jacobsen, Samantha J; Patel, Shenan S; Vellozzi, Ernestine M; Gialanella, Phillip; Nimrichter, Leonardo; Miranda, Kildare; Martinez, Luis R

2013-12-01

Acinetobacter baumannii is a frequent cause of hospital-acquired pneumonia, and has recently increased in incidence as the causative agent of severe disease in troops wounded in Afghanistan and Iraq. Clinical approaches are limited since A. baumannii strains isolated from patients are extremely resistant to current antimicrobials. A. baumannii can survive desiccation and during outbreaks has been recovered from various sites in the patients' environment. To better understand its prevalence in hospital settings, we used a stainless steel washer (SSW) platform to investigate A. baumannii biofilm formation on abiotic surfaces. Scanning electron microscopy demonstrated that A. baumannii forms strong biofilms on stainless steel surfaces. This platform was combined with a colorimetric 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay to observe the metabolic activity of bacterial cells, and to facilitate the manipulation and comparison of multiple A. baumannii clinical strains. A strong correlation between XTT and c.f.u. assays was demonstrated. To complement the cell viability assays, A. baumannii biofilm mass was measured by crystal violet staining. Furthermore, the effect of commonly used disinfectants and environmental stressors on A. baumannii biofilms and planktonic cells was compared and characterized. Biofilms on SSWs were significantly more resistant than their planktonic counterparts, providing additional evidence that may allow us to understand the high prevalence of this microbe in hospital settings. Our results validate that SSWs are a simple, versatile and innovative method to study A. baumannii biofilms in vitro.

In vitro activity of aminoglycosides against clinical isolates of Acinetobacter baumannii complex and other nonfermentative Gram-negative bacilli causing healthcare-associated bloodstream infections in Taiwan.

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Liu, Jyh-You; Wang, Fu-Der; Ho, Mao-Wang; Lee, Chen-Hsiang; Liu, Jien-Wei; Wang, Jann-Tay; Sheng, Wang-Huei; Hseuh, Po-Ren; Chang, Shan-Chwen

2016-12-01

Aminoglycosides possess in vitro activity against aerobic and facultative Gram-negative bacilli. However, nationwide surveillance on susceptibility data of Acinetobacter baumannii complex and Pseudomonas aeruginosa to aminoglycosides was limited, and aminoglycoside resistance has emerged in the past decade. We study the in vitro susceptibility of A. baumannii complex and other nonfermentative Gram-negative bacilli (NFGNB) to aminoglycosides. A total of 378 NFGNB blood isolates causing healthcare-associated bloodstream infections during 2008 and 2013 at four medical centers in Taiwan were tested for their susceptibilities to four aminoglycosides using the agar dilution method (gentamicin, amikacin, tobramycin, and isepamicin) and disc diffusion method (isepamicin). A. baumannii was highly resistant to all four aminoglycosides (range of susceptibility, 0-4%), whereas >80% of Acinetobacter nosocomialis and Acinetobacter pittii blood isolates were susceptible to amikacin (susceptibility: 96% and 91%, respectively), tobramycin (susceptibility: 92% and 80%, respectively), and isepamicin (susceptibility: 96% and 80%, respectively). All aminoglycosides except gentamicin possessed good in vitro activity (>94%) against P. aeruginosa. Amikacin has the best in vitro activity against P. aeruginosa (susceptibility, 98%), followed by A. nosocomialis (96%), and A. pittii (91%), whereas tobramycin and isepamicin were less potent against A. pittii (both 80%). Aminoglycoside resistances were prevalent in Stenotrophomonas maltophilia and Burkholderia cepacia complex blood isolates in Taiwan. Genospecies among the A. baumannii complex had heterogeneous susceptibility profiles to aminoglycosides. Aminoglycosides, except gentamicin, remained good in vitro antimicrobial activity against P. aeruginosa. Further in vivo clinical data and continuous resistance monitoring are warranted for clinical practice guidance. Copyright © 2015. Published by Elsevier B.V.

Bactericidal activity of herbal volatile oil extracts against multidrug-resistant Acinetobacter baumannii.

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Intorasoot, Amornrat; Chornchoem, Piyaorn; Sookkhee, Siriwoot; Intorasoot, Sorasak

2017-01-01

The aim of the study is to investigate the antibacterial activity of 10 volatile oils extracted from medicinal plants, including galangal ( Alpinia galanga Linn.), ginger ( Zingiber officinale ), plai ( Zingiber cassumunar Roxb.), lime ( Citrus aurantifolia ), kaffir lime ( Citrus hystrix DC.), sweet basil ( Ocimum basilicum Linn.), tree basil ( Ocimum gratissimum ), lemongrass ( Cymbopogon citratus DC.), clove ( Syzygium aromaticum ), and cinnamon ( Cinnamomum verum ) against four standard strains of Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , Acinetobacter baumannii , and 30 clinical isolates of multidrug-resistant A. baumannii (MDR- A. baumannii ). Agar diffusion, minimum inhibitory concentration, and minimum bactericidal concentration (MBC) were employed for the determination of bactericidal activity of water distilled medicinal plants. Tea tree oil ( Melaleuca alternifolia ) was used as positive control in this study. The results indicated the volatile oil extracted from cinnamon exhibited potent antibacterial activity against the most common human pathogens, S. aureus , E. coli , P. aeruginosa , and A. baumannii . Most of volatile oil extracts were less effective against non-fermentative bacteria, P. aeruginosa . In addition, volatile oil extracted from cinnamon, clove, and tree basil possessed potent bactericidal activity against MDR- A. baumannii with MBC 90 of 0.5, 1, and 2 mg/mL, respectively. The volatile oil extracts would be useful as alternative natural product for the treatment of the most common human pathogens and MDR- A. baumannii infections.

Susceptibility to tigecycline of Acinetobacter baumannii strains isolated from intensive care unit patients.

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Talaga, Katarzyna; Krzyściak, Paweł; Bulanda, Małgorzata

2016-01-01

Infections caused by Acinetobacter baumannii are difficult to cure due to the acquisition of resistance by these bacteria and lead to an increase in the general costs of hospitalization. The aim of this study was to determine tigecycline susceptibility of Acinetobacter baumannii strains isolated from intensive care unit and non-intensive care unit patients with skin and soft tissue infections. MICs were tested by Etest among 70 Acinetobacter baumannii isolates. The MIC range was from 0.5 to 8.0 mg L⁻¹. For ESBL-producing Acinetobacter baumannii, as well as for strains without carbapenemases, the highest MIC to tigecycline value was 8.0 mg L⁻¹. For AmpC-producing Acinetobacter baumannii, the highest MIC to tigecycline value was 6.0 mg L⁻¹ and, for MBL-producing strains, 2.0 mg L⁻¹. The majority of Acinetobacter baumannii strains isolated from ICU and non-ICU patients demonstrated high values of MIC range, MIC50 and MIC90 to tigecycline.

Clinical and antimicrobial profile of Acinetobacter spp.: An emerging nosocomial superbug

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Purti C Tripathi

2014-01-01

Conclusion: Acinetobacter nosocomial infections resistant to most antimicrobials have emerged, especially in ICU. Early identification and continued surveillance of prevalent organism will help prevent the spread of Acinetobacter in hospital environment.

Phenotypic characterization and colistin susceptibilities of carbapenem-resistant of Pseudomonas aeruginosa and Acinetobacter spp.

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Mohanty, Srujana; Maurya, Vijeta; Gaind, Rajni; Deb, Monorama

2013-11-15

Pseudomonas aeruginosa and Acinetobcter spp. are important nosocomial pathogens and carbapenem resistance is an emerging threat. Therapeutic options for infections with these isolates include colistin. This study was conducted to determine the prevalence of carbapenem resistance in P. aeruginosa and Acinetobacter spp. bloodstream isolates, phenotypically characterize the resistance mechanisms and evaluate the in vitro activity of colistin. Consecutive 145 (95 P.aeruginosa and 50 Acinetobacter spp.) non-repeat isolates were included. Antibiotic susceptibility testing was performed per CLSI guidelines. MIC for carbapenems and colistin was performed using Etest. Isolates showing reduced susceptibility or resistance to the carbapenems were tested for metallo-β-lactamase (MBL) production using imipenem-EDTA combined disk and MBL Etest. Carbapenem resistance was observed in 40% P. aeruginosa and 66.0% Acinetobacter spp. Carbapenem-resistant (CA-R) isolates were significantly (p carbapenem-susceptible isolates. Approximately half of the CA-R strains were multidrug-resistant, and 3.1-5.5% were resistant to all antibiotics tested. MBL was found in 76.3% and 69.7% of the P. aeruginosa and Acinetobacter spp., respectively. Colistin resistance was observed in three (6.0%) Acinetobacter isolates and eight (8.4%) P. aeruginosa. MIC50 for carbapenems were two to four times higher for MBL-positive compared to MBL-negative isolates, but no difference was seen in MIC for colistin. Carbapenem resistance was observed to be mediated by MBL in a considerable number of isolates. Colistin is an alternative for infections caused by CA-R isolates; however, MIC testing should be performed whenever clinical use of colistin is considered.

Analysis of drug resistance in 1,861 strains of Acinetobacter baumannii.

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Jin, Hao; Qiu, Fan; Ji, Hong Jian; Lu, Qiang

2016-04-01

Acinetobacter baumannii is an emerging human pathogen that causes hospital-acquired infections. The trend in increased antimicrobial resistance limits the choice of effective antimicrobial agents. The present study reports the resistance to Acinetobacter baumannii and analyzes the associations between antibiotic use and resistance rates at a general hospital between 2010 and 2014. A total of 1,861 isolates were obtained from clinical cultures, accounting for 10.33% of all detected bacteria (1,861/18,016). The strains were mainly from respiratory samples (1,628 isolates, 87.5%) and the intensive care unit (696 isolates, 37.4%). The resistance rates of Acinetobacter baumannii to the majority of antibiotics were >50%, particularly the resistance rate to cefoperazone/sulbactam increased from 47.37 in 2011 to 89.25% in 2014. However, the rates of imipenem and cilastatin sodium decreased from 81.03 to 69.44% due to the antibiotic policy. There were Pearson significant associations between the use of three antibiotics and resistance in Acinetobacter baumannii to this drug, piperacillin/tazobactam (r=0.976, Ppolicies are essential to control the emergence of multidrug-resistance Acinetobacter baumannii .

Antimicrobial susceptibility pattern of Acinetobacter species isolated from infected wounds at a tertiary care hospital

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Rosić Ivana

2013-01-01

Full Text Available Bacteria of the genus Acinetobacter, especially species Acinetobacter baumanii, is one of the most important causes of infection in immunocompromised patients in hospital. The aim of this study was to determine susceptibility of Acinetobacter species isolated from swabs of inflamed wounds to antibiotics. The study was conducted in several departments of the Clinical Centre 'Kragujevac' through retrospective analysis of 220 Acinetobacter species isolates from surgical wounds in 2011. The isolates of Acinetobaster species were mostly sensitive to ampicillin-sulbactam, colistin and tigecycline in all hospital departments that were surveyed. Only minority of the isolated Acinetobacter species were susceptible to cotrimoxazole, amikacin, imipenem and/or meropenem. Antibiotics with the highest in vitro efficacy against Acinetobacter species were ampicillinsulbactam, colistin and tigecycline. Highly resistant Acinetobacter species were more frequently isolated from patients in Intensive Care Unit.

Investigations Of Powder Surface Properties Of Drug Substances ...

African Journals Online (AJOL)

In this study, Inverse Gas Chromatography (IGC) was used to characterize the surface energetics of different batches of two drug substances (Salmetrol Xinafoate, SX and Fluticasone Propionate, FP) manufactured under identical conditions. The results obtained demonstrate the potential of IGC technique to reveal ...

Mutations in the β-Subunit of the RNA Polymerase Impair the Surface-Associated Motility and Virulence of Acinetobacter baumannii.

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Pérez-Varela, María; Corral, Jordi; Vallejo, Juan Andrés; Rumbo-Feal, Soraya; Bou, Germán; Aranda, Jesús; Barbé, Jordi

2017-08-01

Acinetobacter baumannii is a major cause of antibiotic-resistant nosocomial infections worldwide. In this study, several rifampin-resistant spontaneous mutants obtained from the A. baumannii ATCC 17978 strain that differed in their point mutations in the rpoB gene, encoding the β-subunit of the RNA polymerase, were isolated. All the mutants harboring amino acid substitutions in position 522 or 540 of the RpoB protein were impaired in surface-associated motility and had attenuated virulence in the fertility model of Caenorhabditis elegans The transcriptional profile of these mutants included six downregulated genes encoding proteins homologous to transporters and metabolic enzymes widespread among A. baumannii clinical isolates. The construction of knockout mutants in each of the six downregulated genes revealed a significant reduction in the surface-associated motility and virulence of four of them in the A. baumannii ATCC 17978 strain, as well as in the virulent clinical isolate MAR002. Taken together, our results provide strong evidence of the connection between motility and virulence in this multiresistant nosocomial pathogen. Copyright © 2017 American Society for Microbiology.

Biochemical Characterization of Lipases Obtained from Acinetobacter psychrotolerans Strains

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Şule SEREN

2017-12-01

Full Text Available In this study, extracellular lipases obtained from Acinetobacter psychrotolerans strains (Xg1 and Xg2 were characterized. The effects of varying pH values (3.0-10.0 and various temperatures (10-90 °C on lipase activities were examined. Also the effects of different metal ions, organic solvents and detergents on lipases were studied. The extracellular crude lipases were concentrated using ultrafiltration. Zymogram analysis of these lipases was performed. Lipases exhibited maximum activity at pH 8 and 30 °C.  While lipase obtained from the Xg1 strain exhibited the highest stability in the presence of various organic solvents, including hexane, ethyl acetate, chloroform and N,N dietil formamide, lipase obtained from the Xg2 strain was sensitive in the presence of isopropanol, acetonitrile, and butan-1-ol. The lipases of the Xg1 and Xg2 strains were inhibited in the presence of Cu2+ and Zn2+. Also, the lipase of the Xg1 strain was inhibited in the presence of Fe3+. In the presence of EDTA, the lipase activities of the Xg1 and Xg2 strains were partially inhibited. In presence of SDS, they were exactly inhibited. According to the zymogram results, the molecular weights of the lipases obtained from the Acinetobacter psychrotolerans Xg1 and Xg2 strains have been found approximately 37 and 30 kDa, respectively.

Bactericidal activity of herbal volatile oil extracts against multidrug resistant Acinetobacter baumannii

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Amornrat Intorasoot

2017-06-01

Full Text Available Aim:\tTo investigate the antibacterial activity of ten volatile oils extracted from medicinal plants, including galangal (Alpinia galanga Linn., ginger (Zingiber officinale, plai (Zingiber cassumunar Roxb., lime (Citrus aurantifolia, kaffir lime (Citrus hystrix DC., sweet basil (Ocimum basilicum Linn., tree basil (Ocimum gratissimum, lemongrass (Cymbopogon citratus DC., clove (Syzygium aromaticum and cinnamon (Cinnamomum verum against four standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii and thirty clinical isolates of multidrug-resistant A. baumannii (MDR-A. baumannii. Methods:\tAgar diffusion, minimal inhibitory concentration (MIC and minimal bactericidal concentration (MBC were employed for determination of bactericidal activity of water distillated medicinal plants. Tea tree oil (Melaleuca alternifolia was used as positive control in this study. Results:\tThe results indicated the volatile oil extracted from cinnamon exhibited potent antibacterial activity against the most common human pathogens, S. aureus, E. coli, P. aeruginosa and A. baumannii. Most of volatile oil extracts were less effective against non-fermentative bacteria, P. aeruginosa. In addition, volatile oil extracted from cinnamon, clove and tree basil possessed potent bactericidal activity against MDR-A. baumannii with MBC90 of 0.5, 1 and 2 mg/mL, respectively. Conclusions: The volatile oil extracts would be useful as alternative natural product for treatment of the most common human pathogens and MDR-A. baumannii infections. [J Complement Med Res 2017; 6(2.000: 218-222

Antimicrobial susceptibility pattern of acinetobacter species-one year experience in a tertiary care setting

International Nuclear Information System (INIS)

Qureshi, Z.A.; Abbasi, S.A.; Mirza, I.A.; Malik, N.; Sattar, A.

2012-01-01

Objective: To find out antimicrobial susceptibility pattern of Acinetobacter species isolated from 1 January 2009 through 31 December 2009 at Department of Microbiology, Armed Forces Institute of Pathology Rawalpindi. Materials and Methods: A total of 276 isolates of Acinetobacter spp yielded from various clinical specimens during the study period were included Routine conventional methods were used to identify various species of Acinetobacter and modified Kirby-Bauer disk diffusion method was used for susceptibility testing. Out of total 276 isolates, 176 (63.8%) turned out to be Acinetobacter baumannii and 100 (36.2%) were Acinetobacter johnsonii. Overall sensitivity of Acinetobacter spp against piperacillin/sulbactam, tigecycline, sulbactam/cefoperazone, piperacillin/tazobactam, imipenem, doxycycline, ceftazidime, ciprofloxacin, chloramphenicol, trimethoprim /sulfamethoxazole, ampicillin, gentamycin, ceftriaxone, amoxicillin/clavulanic acid and ampicillin were 64%,63%, 48%, 47%, 41%,39%,35%, 34%, 32%, 31 %, 29%, 19%, 18% and 5% respectively. Out of 276 isolates, 181 (66 %) were multidrug resistant while 33 (18 %) isolates were pan-drug resistant. (author)

Iron-Regulated Phospholipase C Activity Contributes to the Cytolytic Activity and Virulence of Acinetobacter baumannii.

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Steven E Fiester

Full Text Available Acinetobacter baumannii is an opportunistic Gram-negative pathogen that causes a wide range of infections including pneumonia, septicemia, necrotizing fasciitis and severe wound and urinary tract infections. Analysis of A. baumannii representative strains grown in Chelex 100-treated medium for hemolytic activity demonstrated that this pathogen is increasingly hemolytic to sheep, human and horse erythrocytes, which interestingly contain increasing amounts of phosphatidylcholine in their membranes. Bioinformatic, genetic and functional analyses of 19 A. baumannii isolates showed that the genomes of each strain contained two phosphatidylcholine-specific phospholipase C (PC-PLC genes, which were named plc1 and plc2. Accordingly, all of these strains were significantly hemolytic to horse erythrocytes and their culture supernatants tested positive for PC-PLC activity. Further analyses showed that the transcriptional expression of plc1 and plc2 and the production of phospholipase and thus hemolytic activity increased when bacteria were cultured under iron-chelation as compared to iron-rich conditions. Testing of the A. baumannii ATCC 19606T plc1::aph-FRT and plc2::aph isogenic insertion derivatives showed that these mutants had a significantly reduced PC-PLC activity as compared to the parental strain, while testing of plc1::ermAM/plc2::aph demonstrated that this double PC-PLC isogenic mutant expressed significantly reduced cytolytic and hemolytic activity. Interestingly, only plc1 was shown to contribute significantly to A. baumannii virulence using the Galleria mellonella infection model. Taken together, our data demonstrate that both PLC1 and PLC2, which have diverged from a common ancestor, play a concerted role in hemolytic and cytolytic activities; although PLC1 seems to play a more critical role in the virulence of A. baumannii when tested in an invertebrate model. These activities would provide access to intracellular iron stores this pathogen

Phenotypic and genetic relationship of Acinetobacter Baumannii isolates.

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Trajkovska-Dokic, E; Kotevska, V; Kaftandzieva, A; Jankoska, G; Mircevska, G; Petrovska, M; Panovski, N

2011-01-01

The interest in Acinetobacter continues to rise. One of the main reasons is the emergence of multi-resistant strains, which cause outbreaks of infection involving several patients in a ward, in the intensive care unit and in different areas of the hospital. Many outbreaks of its infection or colonization in surgical, neonatal and burn intensive care units have been reported, but the epidemiology of these infections remains unclear. To investigate the relationship among the isolates of Acinetobacter baumannii, comparing some of their phenotypic and genetic features. A total of 20 Acinetobacter baumanni isolates were included in the study. 12 strains of Acinetobacter baumannii were obtained within a week in July 2010, from neonates hospitalized at the paediatric intensive care unit and on the neonatal ward. Three strains were isolated from neonates at the paediatric intensive care unit three months ago. All the Acinetobacter baumannii strains were isolated from tracheal aspirates obtained from neonates with infection of the lower respiratory tract. Five additional Acinetobacter baumannii strains were included in the study as controls. They were isolated from wound swabs taken from adult patients with wound infection, hospitalized at the University Traumatology Clinic. Susceptibility of the bacterial strains to 13 different antimicrobial agents was determined by the disk diffusion method (Kirby-Bauer). Additional testing of the susceptibility was performed by the VITEK 2 system. RAPD-PCR fingerprinting was carried out using the following primer (5' GAAACAGCTATGACCATG -3'). All A. baumannii isolates were multi-drug resistant. Antibiotic susceptibility-testing by the disk-diffusion method and automated VITEK 2 system showed 3 and 2 antimicrobial susceptibility patterns, respectively. RAPD-PCR assay of A. baumannii strains revealed two different RAPD-fingerprints. All the strains of A. baumannii isolated within a week in July 2010 from tracheal aspirates taken from

Commensal Staphylococcus spp., Acinetobacter spp. and ...

African Journals Online (AJOL)

ANTHONY

2012-07-31

Jul 31, 2012 ... Intermittent assessment of resistance genes in the ecosystem should be ..... among resistant Acinetobacter spp. isolated from integrated fish .... independent studies on the emerging phylogenetic view of bacterial .... Functional.

Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges

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Nielsen, Travis B.; Bonomo, Robert A.; Pantapalangkoor, Paul; Luna, Brian; Spellberg, Brad

2016-01-01

SUMMARY Acinetobacter is a complex genus, and historically, there has been confusion about the existence of multiple species. The species commonly cause nosocomial infections, predominantly aspiration pneumonia and catheter-associated bacteremia, but can also cause soft tissue and urinary tract infections. Community-acquired infections by Acinetobacter spp. are increasingly reported. Transmission of Acinetobacter and subsequent disease is facilitated by the organism's environmental tenacity, resistance to desiccation, and evasion of host immunity. The virulence properties demonstrated by Acinetobacter spp. primarily stem from evasion of rapid clearance by the innate immune system, effectively enabling high bacterial density that triggers lipopolysaccharide (LPS)–Toll-like receptor 4 (TLR4)-mediated sepsis. Capsular polysaccharide is a critical virulence factor that enables immune evasion, while LPS triggers septic shock. However, the primary driver of clinical outcome is antibiotic resistance. Administration of initially effective therapy is key to improving survival, reducing 30-day mortality threefold. Regrettably, due to the high frequency of this organism having an extreme drug resistance (XDR) phenotype, early initiation of effective therapy is a major clinical challenge. Given its high rate of antibiotic resistance and abysmal outcomes (up to 70% mortality rate from infections caused by XDR strains in some case series), new preventative and therapeutic options for Acinetobacter spp. are desperately needed. PMID:27974412

Study the properties of activated carbon and oxyhydroxide aluminum as sorbents for removal humic substances from natural waters

International Nuclear Information System (INIS)

Shiyan, L N; Machekhina, K I; Gryaznova, E N

2016-01-01

The present work relates to the problem of high-quality drinking water supply using processes of adsorption on activated carbon and aluminum oxyhydroxide for removal humic- type organic substances. Also the paper reports on sorbtion properties of the activeted carbon Norit SA UF and oxyhydroxide aluminum for removal humic substances. It was found out that the maximum adsorption capacity of activated carbon to organic substances is equal to 0.25 mg/mg and aluminum oxyhydroxide is equal to 0.3 mg/mg. It is shown that the maximum adsorption capacity of activated carbon Norit SA UF to iron (III) ions is equal to 0.0045 mg/mg and to silicon ions is equal to 0.024 mg/mg. Consequently, the aluminum oxyhydroxide has better adsorption characteristics in comparison with the activated carbon for removal of humic substances, iron and silicon ions. It is associated with the fact that activated carbon has a large adsorption surface, and this is due to its porous structure, but not all molecules can enter into these pores. Therefore, the fibrous structure of aluminum oxyhydroxide promotes better sorption capacity. The presented results suggest that activated carbon Norit SA UF and aluminum oxyhydroxide can be used as sorbents for removal humic substances or other organic substances from groundwater and natural waters. (paper)

Activities of colistin- and minocycline-based combinations against extensive drug resistant Acinetobacter baumannii isolates from intensive care unit patients

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Li Jian

2011-04-01

Full Text Available Abstract Background Extensive drug resistance of Acinetobacter baumannii is a serious problem in the clinical setting. It is therefore important to find active antibiotic combinations that could be effective in the treatment of infections caused by this problematic 'superbug'. In this study, we analyzed the in vitro activities of three colistin-based combinations and a minocycline-based combination against clinically isolated extensive drug resistant Acinetobacter baumannii (XDR-AB strains. Methods Fourteen XDR-AB clinical isolates were collected. The clonotypes were determined by polymerase chain reaction-based fingerprinting. Susceptibility testing was carried out according to the standards of the Clinical and Laboratory Standards Institute. Activities of drug combinations were investigated against four selected strains and analyzed by mean survival time over 12 hours (MST12 h in a time-kill study. Results The time-kill studies indicated that the minimum inhibitory concentration (MIC of colistin (0.5 or 0.25 μg/mL completely killed all strains at 2 to 4 hours, but 0.5×MIC colistin showed no bactericidal activity. Meropenem (8 μg/mL, minocycline (1 μg/mL or rifampicin (0.06 μg/mL did not show bactericidal activity. However, combinations of colistin at 0.5×MIC (0.25 or 0.125 μg/mL with each of the above were synergistic and shown bactericidal activities against all test isolates. A combination of meropenem (16 μg/mL with minocycline (0.5×MIC, 4 or 2 μg/mL was synergitic to all test isolates, but neither showed bactericidal activity alone. The MST12 h values of drug combinations (either colistin- or minocycline-based combinations were significantly shorter than those of the single drugs (p Conclusions This study indicates that combinations of colistin/meropenem, colistin/rifampicin, colistin/minocycline and minocycline/meropenem are synergistic in vitro against XDR-AB strains.

Perfluoroalkyl substances in the Maltese Environment - (I) Surface water and rain water

NARCIS (Netherlands)

Sammut, G.; Sinagra, E.; Helmus, R.; de Voogt, P.

2017-01-01

The presence of perfluoroalkyl substances (PFASs) in rain water on the Maltese Islands is reported here for the first time and an extensive survey of these substances in surface water also reported. The Maltese archipelago lies at the centre of the Mediterranean Sea and consists of three main

On the problem of radiation purification of waste waters containing synthetic surface-active agents

International Nuclear Information System (INIS)

Buslaeva, S.P.; Kon'kov, N.G.; Makarochkina, L.M.; Panin, Yu.A.; Upadyshev, L.B.; Filippov, M.T.

1975-01-01

Radiation decomposition of artificial solutions containing surface-active substances and the real sewage of textile factories is studied. Experiments on treatment of sewage in a foamed state were conducted (since the irradiation of sewage in a liquid form did not result in the desired effect) with a laboratory installation that made it possible to irradiate sewage by an electron beam both under stationary and flowing conditions. The dose rate was about 140 w/kg. The results of determination of the dependence of the decomposition rate for solutions that contain surface-active substances on the absorbed dose and the magnitude of the beam current are presented. It is demonstrated that the decrease of dose rate is accompanied by the increase of the yield of the surface-active substance decomposition in the foam. During irradiation of real sewage the improvement of their coloring as well as the acceleration of coagulation and the sedimentation of dissolved and suspended substances were observed. Recommendations are suggested for design of an experimental-industrial installation for irradiation of sewage. It is established that with the efficiency of 1000 m 3 /day the cost of sewage treatment will be 35-40 kop/m 3

Acinetobacter: environmental and biotechnological applications ...

African Journals Online (AJOL)

Among microbial communities involved in different ecosystems such as soil, freshwater, wastewater and solid wastes, several strains belonging to the genus of Acinetobacter have been attracting growing interest from medical, environmental and a biotechnological point of view. Bacteria of this genus are known to be ...

Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

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Chin-Soon Chee

2014-01-01

Full Text Available Glutathione transferases (GST were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW of 23 kDa. 2-dimensional (2-D gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5 and GST2 (pI 6.2 with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase and F0KKB0 (glutathione S-transferase III of Acinetobacter calcoaceticus strain PHEA-2, respectively.

Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

Science.gov (United States)

Chee, Chin-Soon; Tan, Irene Kit-Ping; Alias, Zazali

2014-01-01

Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively. PMID:24892084

Blood stream infections caused by Acinetobacter baumannii group in Japan - Epidemiological and clinical investigation.

Science.gov (United States)

Fujikura, Yuji; Yuki, Atsushi; Hamamoto, Takaaki; Kawana, Akihiko; Ohkusu, Kiyofumi; Matsumoto, Tetsuya

2016-06-01

Acinetobacter calcoaceticus-Acinetobacter baumannii complex, especially A. baumannii, Acinetobacter pittii and Acinetobacter nosocomialis, constitutes an important group of nosocomial pathogens; however, epidemiological or clinical characteristics and prognosis is limited in Japan. From 2009 to 2013, 47 blood stream infection cases resulting from A. baumannii group were reviewed at the National Defense Medical College, an 800-bed tertiary hospital. To determine the genospecies, further comparative nucleotide sequence analyses of the RNA polymerase b-subunit (rpoB) gene were performed. Sequence analysis of rpoB gene showed that 25 (49.0%), 17 (33.3%) and 5 (9.8%) cases were caused by A. baumannii, A. pittii and A. nosocomialis, respectively. The 30-day and in-hospital mortality rates of A. baumannii were 8.5% and 25.5%, respectively, and there were no significant differences between Acinetobacter species. Clinical characteristics were statistically insignificant. Multidrug-resistant Acinetobacter species were detected in 3 cases (5.9%) with same pulsed-field gel electrophoresis (PFGE) pattern and A. baumannii was less susceptible to amikacin and levofloxacin. In this study, the mortality and clinical characteristics were similar among A. baumannii group isolate cases despite some showing drug resistance. However, identification of Acinetobacter species helps to initiate appropriate antibiotic therapy in earlier treatment phase, because A. baumannii shows some drug resistance. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Antibacterial activity of a newly developed peptide-modified lysin against Acinetobacter baumannii and Pseudomonas aeruginosa

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Hang eYang

2015-12-01

Full Text Available The global emergence of multidrug-resistant (MDR bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs and stationary phase (with OMPs A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices.

[Non-drug psycho-active substance use and pregnancy].

Science.gov (United States)

El Ammouri, A; Sabir, M; Ahid, S; Toufiq, J; El Omari, F

2015-09-01

The consumption of psycho-active substances (PAS) by pregnant women is in a growing increase around the world. It is a major problem of public health in some countries due to serious and negative consequences for children and society as well as for pregnant women. This problem has also increased among women in Morocco. However, it is still neglected and underrated in the absence of any official statistical data. This is the first study leading to a better profiling of pregnant women who may consume psycho-active substances during their pregnancy; it would permit better medical and psychosocial care of both women and children. To determine the prevalence and the factors associated with the psycho-active substances used by pregnant women and describe their socio-demographic characteristics. A trans-sectional study was carried out from September to October 2010, including pregnant women consulting at the obstetrical service of the provincial hospital Moulay Abdellah in the city of Salé. The study included women who were pregnant or had recently given birth, and not having any serious mental disorders that could have upset their cognitive abilities. The data was collected through a straight questionnaire of 25 items specifying the socio-demographic characteristics, data about pregnancy and habits of using psycho-active substances. One hundred and fifty pregnant women were included in the study. The majority of them (83.2%) were aged 20 to 40 years old, 94.6% were married, 96% were unemployed and depended on their spouses for their financial resources and 80% had normal domestic relationships (from average to good quality). Among the women, 31.3% of them reported traumatic events in the past. The prevalence of psycho-active substance consumption by the pregnant women of our sample was 11.3%. The used substances were tobacco (9.3%) and cannabis (4%). These women were more likely to have a low level of education (47.1 vs 16.5). They were victims of abuse or neglect in

Radiotracer studies of the adsorption of surface active substances at aqueous surfaces, 6

International Nuclear Information System (INIS)

Tajima, Kazuo

1976-01-01

The surface tension and adsorption were observed by the Wilhelmy plate and radiotracer methods at the air-solution interface of an aqueous solution of urea and α-dodecyl-ω-hydroxyhexa(oxyethylene) (D(EO) 6 ). The adsorption of D(EO) 6 was dependent on the concentration of urea below the CMC values, but above the values it was independent of the concentration. Urea adsorption occurs positively for low-surface packing of the poly(oxyethylene) group of D(EO) 6 , but negatively for the closest packing of the group and high concentrations of urea. It was confirmed that D(EO) 6 adsorption took place at the solution surface according to the Gibbs adsorption isotherm, which was taken into account as an activity coefficient in an empirical equation for the interactions of D(EO) 6 and urea in solution. Urea adsorption for the adsorbed monolayer of D(EO) 6 above the CMC value was interpreted assuming that urea, as for the nonionic micelle, was nonpenetrating, which was examined by gel permeation. (auth.)

Improvement of MALDI-TOF MS profiling for the differentiation of species within the Acinetobacter calcoaceticus-Acinetobacter baumannii complex.

Science.gov (United States)

Šedo, Ondrej; Nemec, Alexandr; Křížová, Lenka; Kačalová, Magdaléna; Zdráhal, Zbyněk

2013-12-01

MALDI-TOF MS is currently becoming the method of choice for rapid identification of bacterial species in routine diagnostics. Yet, this method suffers from the inability to differentiate reliably between some closely related bacterial species including those of the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex, namely A. baumannii and Acinetobacter nosocomialis. In the present study, we evaluated a protocol which was different from that used in the Bruker Daltonics identification system (MALDI BioTyper) to improve species identification using a taxonomically precisely defined set of 105 strains representing the four validly named species of the ACB complex. The novel protocol is based on the change in matrix composition from alpha-cyano-4-hydroxycinnamic acid (saturated solution in water:acetonitrile:trifluoroacetic acid, 47.5:50:2.5, v/v) to ferulic acid (12.5mgml(-1) solution in water:acetonitrile:formic acid 50:33:17, v/v), while the other steps of sample processing remain unchanged. Compared to the standard protocol, the novel one extended the range of detected compounds towards higher molecular weight, produced signals with better mass resolution, and allowed the detection of species-specific signals. As a result, differentiation of A. nosocomialis and A. baumannii strains by cluster analysis was improved and 13 A. nosocomialis strains, assigned erroneously or ambiguously by using the standard protocol, were correctly identified. Copyright © 2013 Elsevier GmbH. All rights reserved.

Effect of multipurpose solutions against Acinetobacter carrying QAC genes.

Science.gov (United States)

Boost, Maureen V; Chan, Jessica; Shi, Guang-sen; Cho, Pauline

2014-03-01

Acinetobacter has low virulence but causes infections in subjects with reduced immunity. It has been reported in ocular infections including those of patients using contact lenses. Treatment is difficult because Acinetobacter is frequently multidrug resistant. Antibiotic-resistant strains frequently also harbor genes for antiseptic resistance (quaternary ammonium compound [QAC]) genes. Because Acinetobacter is part of the normal flora, it may contaminate contact lens and accessories. This study aims to investigate carriage rates of QAC genes in household and clinical isolates of Acinetobacter and to determine the effectiveness of two multipurpose solutions (MPSs) for soft lenses against organisms carrying QAC genes. DNA was extracted from 11 bathroom isolates and 15 clinical isolates and amplified by polymerase chain reaction to determine the presence of qacEΔ1. Gene-positive and gene-negative control strains were used to challenge the two MPSs, and minimum inhibitory concentrations (MICs) of these organisms to benzalkonium chloride and chlorhexidine gluconate were determined. More than 90% of isolates carried qacEΔ1. The MICs of clinical isolates were higher than those of isolates of bathrooms. Both MPSs were able to produce a 3-log reduction in the numbers of all isolates. Although most isolates carried qacEΔ1 and elevated MICs to benzalkonium chloride and chlorhexidine gluconate were observed, all were susceptible to both MPSs tested. However, if there were to be poor compliance with care procedures, it is probable that such organisms could survive in the presence of diluted or expired solutions.

In vitro and in vivo analysis of antimicrobial agents alone and in combination against multi-drug resistant Acinetobacter baumannii

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Songzhe eHE

2015-05-01

Full Text Available Objective To investigate the in vitro and in vivo antibacterial activities of tigecycline and other 13 common antimicrobial agents, alone or in combination, against multi-drug resistant Acinetobacter baumannii.MethodsAn in vitro susceptibility test of 101 Acinetobacter baumannii was used to detect minimal inhibitory concentrations (MICs. A mouse lung infection model of multi-drug resistant Acinetobacter baumannii,established by the ultrasonic atomization method, was used to define in vivo antimicrobial activities.Results Multi-drug resistant Acinetobacter baumannii showed high sensitivity to tigecycline (98% inhibition, polymyxin B (78.2% inhibition, and minocycline (74.2% inhibition. However, the use of these antimicrobial agents in combination with other antimicrobial agents produced synergistic or additive effects. In vivo data showed that white blood cell (WBC counts in drug combination groups C (minocycline + amikacin and D (minocycline + rifampicin were significantly higher than in groups A (tigecycline and B (polymyxin B (P < 0.05, after administration of the drugs 24h post-infection. Lung tissue inflammation gradually increased in the model group during the first 24h after ultrasonic atomization infection; vasodilation, congestion with hemorrhage were observed 48h post infection. After three days of anti-infective therapy in groups A, B, C and D, lung tissue inflammation in each group gradually recovered with clear structures. The mortality rates in drug combination groups (groups C and D were much lower than in groups A and B.ConclusionThe combination of minocycline with either rifampicin or amikacin is more effective against multidrug-resistant Acinetobacter baumannii than single-agent tigecycline or polymyxin B. In addition, the mouse lung infection by ultrasonic atomization is a suitable model for drug screening and analysis of infection mechanism.

Activation of Microglia by Histamine and Substance P

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Jin Zhu

2014-08-01

Full Text Available Background: Activated microglia perform many of the immune effector functions typically associated with macrophages. However, the regulators involved in microglial activation are not well defined. Because microglia play a pivotal role in immune surveillance of the CNS, we studied the effect of the neuromediators histamine and substance P on microglia. Methods: The induction of microglial activation by histamine and substance P was examined using primary cultured microglia. Fluorescent images were acquired with a confocal microscope. The levels of TNF-α and IL-6 were measured with a commercial ELISA kit. Intracellular reactive oxygen species (ROS levels were determined by dichlorodihydrofluorescein oxidation. The mitochondrial membrane potential was assessed with the MitoProbe™ JC-1 assay kit. Results: We found that the neuromediators histamine and substance P were able to stimulate microglial activation and the subsequent production of ROS and proinflammatory factors TNF-α and IL-6. These effects were partially abolished by antagonists of the histamine receptors H1 and H4 and of the substance P receptors NK-1, NK-2 and NK-3. Histamine induced mitochondrial membrane depolarization in microglia. Conclusions: These results indicate that the neuromediators histamine and SP can trigger microglial activation and release of pro-inflammatory factors from microglia, thus contributing to the development of microglia-mediated inflammation in the brain.

Identification of genus Acinetobacter: Standardization of in-house PCR and its comparison with conventional phenotypic methods.

Science.gov (United States)

Kulkarni, Sughosh S; Madalgi, Radhika; Ajantha, Ganavalli S; Kulkarni, Raghavendra D

2017-01-01

Acinetobacter is grouped under nonfermenting Gram-negative bacilli. It is increasingly isolated from pathological samples. The ability of this genus to acquire drug resistance and spread in the hospital settings is posing a grave problem in healthcare. Specific treatment protocols are advocated for Acinetobacter infections. Hence, rapid identification and drug susceptibility profiling are critical in the management of these infections. To standardize an in-house polymerase chain reaction (PCR) for identification of genus Acinetobacter and to compare PCR with two protocols for its phenotypic identification. A total of 96 clinical isolates of Acinetobacter were included in the study. An in-house PCR for genus level identification of Acinetobacter was standardized. All the isolates were phenotypically identified by two protocols. The results of PCR and phenotypic identification protocols were compared. The in-house PCR standardized was highly sensitive and specific for the genus Acinetobacter . There was 100% agreement between the phenotypic and molecular identification of the genus. The preliminary identification tests routinely used in clinical laboratories were also in complete agreement with phenotypic and molecular identification. The in-house PCR for genus level identification is specific and sensitive. However, it may not be essential for routine identification as the preliminary phenotypic identification tests used in the clinical laboratory reliably identify the genus Acinetobacter .

Virulence factors and antibiotic susceptibility pattern of Acinetobacter species in a tertiary care hospital in Bangladesh

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Azizun Nahar

2012-01-01

Full Text Available Acinetobacter species are aerobic Gram variable coccobacilli that are now emerging as an important nosocomial pathogen. Infections caused by them are difficult to control due to multidrug resistance. The purpose of this study was to detect virulence factors namely gelatinase production, biofilm formation and antibiotic susceptibility of Acinetobacter species. Two hundred fifty six clinical samples collected from Bangabandhu Sheikh Mujib medical University (BSMMU and from burn unit of Dhaka Medical College Hospital were included in the study. Gelatinase production was seen on Luria Bertani agar media containing gelatin (30 gm/l and biofilm formation was detected in microtiter plate assay. Out of 256 clinical samples, 52 (20.3% were Acinetobacter species. Out of 52 Acinetobacter isolates, none were gelatinase producer but 39 (75% were found biofilm producers. Acinetobacter isolates were 100% resistant to ceftazidime, cefotaxime cefuroxime and ceftriaxone. High level of resistance was also recorded for amoxicillin (98.1%, aztreonam (98.1%, gentamicin (90.4%, ciprofloxacin (73.1%, amikacin (57.6%, netilmicin (53.8% and imipenem (44.2%. Susceptibility to colistin was maximum (96.2%. The present study demonstrated a high propensity of biofilm formation by the clinical isolates of Acinetobacter species and most of the Acinetobacter were multidrug resistant. Ibrahim Med. Coll. J. 2012; 6(1: 27-30

Acinetobacter lactucae sp. nov., isolated from iceberg lettuce (Asteraceae: Lactuca sativa).

Science.gov (United States)

Rooney, Alejandro P; Dunlap, Christopher A; Flor-Weiler, Lina B

2016-09-01

Strain NRRL B-41902T and three closely related strains were isolated from iceberg lettuce. The strain was found to consist of strictly aerobic, Gram-stain-negative rods that formed cocci in late stationary phase. 16S rRNA gene sequence analysis showed that strain NRRL B-41902T was most closely related to species within the genera Acinetobacter, and that a grouping of it and the three other closely related strains was most closely related to the type strain of Acinetobacter pittii, which was also confirmed through a phylogenomic analysis. Moreover, in silico DNA-DNA hybridization analysis revealed a substantial amount of genomic divergence (39.1 %) between strain NRRL B-41902T and the type strain of A. pittii, which is expected if the strains represent distinct species. Further phenotypic analysis revealed that strain NRRL B-41902T was able to utilize a combination of l-serine, citraconic acid and citramalic acid, which differentiated it from other, closely related Acinetobacter species. Therefore, strain NRRL B-41902T (=CCUG 68785T) is proposed as the type strain of a novel species, Acinetobacter lactucae sp. nov.

An update on the arsenal for multidrug-resistant Acinetobacter infections: polymyxin antibiotics.

Science.gov (United States)

Kassamali, Zahra; Jain, Rupali; Danziger, Larry H

2015-01-01

To review recent clinical pharmacokinetic and pharmacodynamic data to optimize dosing regimens for polymyxin B and colistin for treatment of infections due to A. baumannii. A literature search was performed using the search terms Acinetobacter, polymyxin, colistin, polymyxin B on MEDLINE. Additional references were identified from the resulting citations. Increasing the dose of polymyxin B or colistin and using either in combination with other antibiotic agents demonstrates improved antimicrobial activity against Acinetobacter spp. Polymyxin B, unlike colistin, is available as an active drug and appears to be relatively unaffected by renal function. This is advantageous both for patients with renal impairment and for those with intact renal function. Achieving therapeutic serum concentrations of colistin may be difficult for those with intact renal function due to rapid clearance of the prodrug, colistimethate sodium (CMS). Clinical data are still lacking for polymyxin B, and it remains to be seen whether advantages demonstrated in PK/PD analyses will persist in the larger scale of patient care and safety. The use of higher doses of either colistin or polymyxin B, as well as combination with other antibiotics, may prevent emerging resistance and preserve the activity of polymyxins against A. baumannii. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Genome sequencing and annotation of Acinetobacter gerneri strain MTCC 9824T

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Nitin Kumar Singh

2014-12-01

Full Text Available The genus Acinetobacter consists of 31 validly published species ubiquitously distributed in nature and primarily associated with nosocomial infection. We report the 4.4 Mb genome of Acinetobacter gerneri strain MTCC 9824T. The genome has a G + C content of 38.0% and includes 3 rRNA genes (5S, 23S16S and 64 aminoacyl-tRNA synthetase genes.

Evaluation of antibacterial effect of Myrtus communis against Acinetobacter baumannii clinical strains

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Venous Akhavan

2016-09-01

Full Text Available Because of inappropriate use of antibiotics and prevalence of resistant bacteria, there is urgent need for antibacterial drugs that have fewer side effects than antibiotics. Myrtus communis is a medicinal plant which had many uses in traditional medicine. In this study, ethanol leave extract of this plant is tested on Acinetobacter baumannii. In the case of antimicrobial evaluation of plants, one of the effecting factors on effectiveness of the microbial inhibition is extraction techniques. In the presents study, the antibacterial activity of the Ethanol, Methanol, and Ethyl acetate extracts of M. communis plant was evaluated at seven different concentrations by broth microdilution method. The results of this study showed that the antimicrobial effect of M. communis extract is concentration dependent. Different extracts were obtained by the maceration method. Extracts of the plant exhibited antibacterial activity at varied levels against A. baumannii. Obtained results from our antibacterial experiments showed that all extracts have anti-bacterial activity against tested bacterial isolates According to the results, the ethyl acetate extracted fraction showed the highest level of activity at a MIC 400 mg/ml for A. baumannii. The results of this study indicate that, different extracts had growth inhibitory effect on A. baumannii. Therefore this plant has the potential to be evaluated as an alternative or adjunct to antibiotics to treat Acinetobacter infections.

SiC nanoparticles as potential carriers for biologically active substances

Science.gov (United States)

Guevara-Lora, Ibeth; Czosnek, Cezary; Smycz, Aleksandra; Janik, Jerzy F.; Kozik, Andrzej

2009-01-01

Silicon carbide SiC thanks to its many advantageous properties has found numerous applications in diverse areas of technology. In this regard, its nanosized forms often with novel properties have been the subject of intense research in recent years. The aim of this study was to investigate the binding of biologically active substances onto SiC nanopowders as a new approach to biomolecule immobilization in terms of their prospective applications in medicine or for biochemical detection. The SiC nanoparticles were prepared by a two-stage aerosol-assisted synthesis from neat hexamethyldisiloxane. The binding of several proteins (bovine serum albumin, high molecular weight kininogen, immunoglobulin G) on SiC particle surfaces was demonstrated at the levels of 1-2 nanograms per mg of SiC. These values were found to significantly increase after suitable chemical modifications of nanoparticle surfaces (by carbodiimide or 3-aminopropyltrietoxysilane treatment). The study of SiC biocompatibility showed a lack of cytotoxicity against macrophages-like cells below the concentration of 1 mg nanoparticles per mL. In summary, we demonstrated the successful immobilization of the selected substances on the SiC nanoparticles. These results including the cytotoxicity study make nano-SiC highly attractive for potential applications in medicine, biotechnology or molecular detection.

Molecular characterization of carbapenem-resistant Acinetobacter ...

African Journals Online (AJOL)

Purpose: To survey the molecular characteristics of imipenem-resistant Acinetobacter baumannii obtained from pediatric burns patients in a teaching hospital in Tehran, Iran. Methods: Over a 10-month period, 73 non-duplicate A. baumannii strains were collected from pediatric burns patients admitted to Motahari Burn and ...

Nosocomial imipenem-resistant Acinetobacter baumannii infections ...

African Journals Online (AJOL)

Imipenem-resistant Acinetobacter baumannii (A. baumannii) (IRAB) has emerged as a challenging nosocomial pathogen particularly in intensive care units (ICUs). Studying the risk factors associated with IRAB infection is of paramount importance for appropriate control of IRAB spread. The aim of this study was to assess ...

Activity of levofloxacin in combination with colistin against Acinetobacter baumannii: In vitro and in a Galleria mellonella model

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Wenjuan Wei

2017-12-01

Full Text Available Background/Purpose: Treatment of Acinetobacter baumannii infections is challenging owing to widespread multidrug-resistant A. baumannii (MDR-AB and the lack of novel agents. Although recent data suggest that levofloxacin (LVX may have unique activity against MDR-AB in combination with colistin (CST, further preclinical work is needed. Methods: We used a A. baumannii type strain ATCC19606, a CST-resistant strain AB19606R, and two clinical isolates (GN0624 and GN1115 of MDR-AB to investigate the in vitro and in vivo efficacy of LVX–CST combination. Synergy studies were performed using the microtiter plate chequerboard assay and time–kill methodology. Inhibitory activity of antibiotics against biofilms and the mutant prevention concentrations were also studied in vitro. A simple invertebrate model (Galleria mellonella has been used to assess the in vivo activity of antimicrobial therapies. Results: The LVX–CST combination was bactericidal against the CST-susceptible clinical isolate (GN0624. In checkerboard assays, synergy (defined as a fractional inhibitory concentration index of < 0.5 was observed between CST and LVX in GN0624. The combination had antibiofilm properties on the preformed biofilms of four tested strains and could prevent the emergence of CST-resistant A. baumanni. Treatment of G. mellonella larvae infected with lethal doses of A. baumannii resulted in significantly enhanced survival rates when LVX was given with CST compared with CST treatment alone (p < 0.05. Conclusion: In summary, a synergistic or additive effect between CST and LVX was observed in vitro and in vivo against CST-susceptible A. baumannii strains, although not against CST-resistant ones. Keywords: Acinetobacter baumannii, antimicrobial synergy, invertebrate model, levofloxacin, polymyxins

PREVALENCE OF ACINETOBACTER BAUMANNII ISOLATED FROM CLINICAL SPECIMENS IN ADAM MALIK HOSPITAL

OpenAIRE

Evita Mayasari; Cherry Siregar

2014-01-01

AbstrakAcinetobacter baumannii merupakan spesies Acinetobacter spp. tersering diisolasi darimanusia, dan lebih sering dijumpai pada infeksi nosokomial dibandingkan dengan infeksi dikomunitas. Eksistensi bakteri ini di lingkungan terkait dengan keragaman reservoir, kemampuanmemperoleh gen pembawa sifat resisten antimikroba, dan sifat resisten terhadap pengeringan.Infeksi disebabkan strain A.baumannii yang resisten terhadap banyak antibiotik tidak mudahdikendalikan dan menjadi permasalahan di b...

Genome sequencing and annotation of Acinetobacter gyllenbergii strain MTCC 11365T

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Nitin Kumar Singh

2014-12-01

Full Text Available The genus Acinetobacter consists of 31 validly published species ubiquitously distributed in nature and primarily associated with nosocomial infection. We report 4.3 Mb genome of the Acinetobacter gyllenbergii strain MTCC 11365T. The draft genome of A. gyllenbergii has a G + C content of 41.0% and includes 3 rRNA genes (5S, 23S, 16S and 67 aminoacyl-tRNA synthetase genes.

Amide side chain amphiphilic polymers disrupt surface established bacterial bio-films and protect mice from chronic Acinetobacter baumannii infection.

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Uppu, Divakara S S M; Samaddar, Sandip; Ghosh, Chandradhish; Paramanandham, Krishnamoorthy; Shome, Bibek R; Haldar, Jayanta

2016-01-01

Bacterial biofilms represent the root-cause of chronic or persistent infections in humans. Gram-negative bacterial infections due to nosocomial and opportunistic pathogens such as Acinetobacter baumannii are more difficult to treat because of their inherent and rapidly acquiring resistance to antibiotics. Due to biofilm formation, A. baumannii has been noted for its apparent ability to survive on artificial surfaces for an extended period of time, therefore allowing it to persist in the hospital environment. Here we report, maleic anhydride based novel cationic polymers appended with amide side chains that disrupt surface established multi-drug resistant A. baumannii biofilms. More importantly, these polymers significantly (p polymers also show potent antibacterial efficacy against methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococci (VRE) and multi-drug resistant clinical isolates of A. baumannii with minimal toxicity to mammalian cells. We observe that optimal hydrophobicity dependent on the side chain chemical structure of these polymers dictate the selective toxicity to bacteria. Polymers interact with the bacterial cell membranes by causing membrane depolarization, permeabilization and energy depletion. Bacteria develop rapid resistance to erythromycin and colistin whereas no detectable development of resistance occurs against these polymers even after several passages. These results suggest the potential use of these polymeric biomaterials in disinfecting biomedical device surfaces after the infection has become established and also for the topical treatment of chronic bacterial infections. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acinetobacter baumannii and A. pittii clinical isolates lack adherence and cytotoxicity to lung epithelial cells in vitro.

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Lázaro-Díez, María; Navascués-Lejarza, Teresa; Remuzgo-Martínez, Sara; Navas, Jesús; Icardo, José Manuel; Acosta, Felix; Martínez-Martínez, Luis; Ramos-Vivas, José

2016-09-01

The molecular and genetic basis of Acinetobacter baumannii and Acinetobacter pittii virulence remains poorly understood, and there is still lack of knowledge in host cell response to these bacteria. In this study, we have used eleven clinical Acinetobacter strains (A. baumannii n = 5; A. pittii n = 6) to unravel bacterial adherence, invasion and cytotoxicity to human lung epithelial cells. Our results showed that adherence to epithelial cells by Acinetobacter strains is scarce and cellular invasion was not truly detected. In addition, all Acinetobacter strains failed to induce any cytotoxic effect on A549 cells. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

A novel bacterial transport mechanism of Acinetobacter baumannii via activated human neutrophils through interleukin-8.

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Kamoshida, Go; Tansho-Nagakawa, Shigeru; Kikuchi-Ueda, Takane; Nakano, Ryuichi; Hikosaka, Kenji; Nishida, Satoshi; Ubagai, Tsuneyuki; Higashi, Shouichi; Ono, Yasuo

2016-12-01

Hospital-acquired infections as a result of Acinetobacter baumannii have become problematic because of high rates of drug resistance. Although neutrophils play a critical role in early protection against bacterial infection, their interactions with A. baumannii remain largely unknown. To elucidate the interactions between A. baumannii and human neutrophils, we cocultured these cells and analyzed them by microscopy and flow cytometry. We found that A. baumannii adhered to neutrophils. We next examined neutrophil and A. baumannii infiltration into Matrigel basement membranes by an in vitro transmigration assay. Neutrophils were activated by A. baumannii, and invasion was enhanced. More interestingly, A. baumannii was transported together by infiltrating neutrophils. Furthermore, we observed by live cell imaging that A. baumannii and neutrophils moved together. In addition, A. baumannii-activated neutrophils showed increased IL-8 production. The transport of A. baumannii was suppressed by inhibiting neutrophil infiltration by blocking the effect of IL-8. A. baumannii appears to use neutrophils for transport by activating these cells via IL-8. In this study, we revealed a novel bacterial transport mechanism that A. baumannii exploits human neutrophils by adhering to and inducing IL-8 release for bacterial portage. This mechanism might be a new treatment target. © Society for Leukocyte Biology.

Substance P receptor desensitization requires receptor activation but not phospholipase C

International Nuclear Information System (INIS)

Sugiya, Hiroshi; Putney, J.W. Jr.

1988-01-01

Previous studies have shown that exposure of parotid acinar cells to substance P at 37 degree C results in activation of phospholipase C, formation of [ 3 H]inositol 1,4,5-trisphosphate (IP 3 ), and persistent desensitization of the substance P response. In cells treated with antimycin in medium containing glucose, ATP was decreased to ∼20% of control values, IP 3 formation was completely inhibited, but desensitization was unaffected. When cells were treated with antimycin in the absence of glucose, cellular ATP was decreased to ∼5% of control values, and both IP 3 formation and desensitization were blocked. A series of substance P-related peptides increased the formation of [ 3 H]IP 3 and induced desensitization of the substance P response with a similar rank order of potencies. The substance P antagonist, [D-Pro 2 , D-Try 7,9 ]-substance P, inhibited substance P-induced IP 3 formation and desensitization but did not induce desensitization. These results suggest that the desensitization of substance P-induced IP 3 formation requires agonist activation of a P-type substance P receptor, and that one or more cellular ATP-dependent processes are required for this reaction. However, activation of phospholipase C and the generation of inositol phosphates does not seem to be a prerequisite for desensitization

Genomic sequencing of a strain of Acinetobacter baumannii and potential mechanisms to antibiotics resistance.

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Zhao, Lei; Li, Hongru; Zhu, Ziwen; Wakefield, Mark R; Fang, Yujiang; Ye, Ying

2017-06-01

Acinetobacter baumannii has been becoming a great challenge to clinicians due to their resistance to almost all available antibiotics. In this study, we sequenced the genome from a multiple antibiotics resistant Acinetobacter baumannii stain which was named A. baumannii-1isolated from China by SMRT sequencing technology to explore its potential mechanisms to antibiotic resistance. We found that several mechanisms might contribute to the antibiotic resistance of Acinetobacter baumannii. Specifically, we found that SNP in genes associated with nucleotide excision repair and ABC transporter might contribute to its resistance to multiple antibiotics; we also found that specific genes associated with bacterial DNA integration and recombination, DNA-mediated transposition and response to antibiotics might contribute to its resistance to multiple antibiotics; Furthermore, specific genes associated with penicillin and cephalosporin biosynthetic pathway and specific genes associated with CHDL and MBL β-lactamase genes might contribute to its resistance to multiple antibiotics. Thus, the detailed mechanisms by which Acinetobacter baumannii show extensive resistance to multiple antibiotics are very complicated. Such a study might be helpful to develop new strategies to control Acinetobacter baumannii infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanodiamonds as Carriers for Address Delivery of Biologically Active Substances

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Petunin AI

2010-01-01

Full Text Available Abstract Surface of detonation nanodiamonds was functionalized for the covalent attachment of immunoglobulin, and simultaneously bovine serum albumin and Rabbit Anti-Mouse Antibody. The nanodiamond-IgGI125 and RAM-nanodiamond-BSAI125 complexes are stable in blood serum and the immobilized proteins retain their biological activity. It was shown that the RAM-nanodiamond-BSAI125 complex is able to bind to the target antigen immobilized on the Sepharose 6B matrix through antibody–antigen interaction. The idea can be extended to use nanodiamonds as carriers for delivery of bioactive substances (i.e., drugs to various targets in vivo.

Determination antimicrobial resistance profile of Acinetobacter strains isolated from hospitalized patients in Different Part of Taleghani Hospital (Ahvaz, Iran

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Khadijah Ahmadi

2014-10-01

Full Text Available Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections such as meningitis, endocarditis, skin and soft tissue infections, urinary tract infection, conjunctivitis, burn wound infection and bacteremia. This organism has been shown resistance to different antimicrobial agents. The aim of this study was to determination antibiotic resistance profile of Acinetobacter strains isolated from hospitalized patients in Taleghani hospital (Ahvaz, Iran. Materials and Methods: This cross-sectional study was conducted on 43 Acinetobacter strains isolated from hospitalized patients. Clinical specimens were cultured on microbiological media. Subsequently, drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Results: Acinetobacter strains were isolated from different specimens consisting biopsy 24 (55.8%, wound 13 (30/2% and blood 6 (14%. In antimicrobial susceptibility testing, colistin exhibited the greatest activity (60.5% against isolated strains. 33 (76/7% isolates demonstrated resistance to imipenem. Conclusion: In outbreak situations, surveillance cultures of patients involved in the outbreak or who are deemed at risk for colonization/infection with the outbreak organism are often parts of the planned intervention.

Frequency and Antimicrobial Susceptibility Pattern of Acinetobacter Species Isolated from Pus and Pus Swab Specimens

International Nuclear Information System (INIS)

Fayyaz, M.; Akbar, N.; Khan, I. U.; Hussain, A.; Ali, S.; Mirza, I. A.

2015-01-01

Objective: To evaluate the frequency and antimicrobial susceptibility pattern of Acinetobacter species isolated from pus and pus swab specimens at a tertiary care setting. Study Design: Cross-sectional observational study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from July 2008 to July 2012. Methodology: Data regarding positive culture and antimicrobial sensitivity pattern was retrieved from the pus and pus swab culture records of the Microbiology Department, AFIP, Rawalpindi. Only those pus and pus swab specimens which yielded the growth of Acinetobacter species were included in the study. Results:Out of 2781, 1848 were of pure pus while 933 were pus swab specimens. Out of 2538 culture positive isolates, 276 (10.9 percentage) were identified as Acinetobacterspecies. Among 276 Acinetobacter species, 245 (88.8 percentage) were Acinetobacter baumannii and 31 (11.2 percentage) were Acinetobacter johnsonii. Male/female ratio of the affected patients was 5.6:1. Doxycycline was the most sensitive antibiotic to which 45 percentage of the tested isolates were sensitive. Sensitivity to all other antimicrobials was 15 percentage or less. Conclusion: About 11 percentage of soft tissue and wound infections are caused by Acinetobacter species in our set up particularly in male. Doxycycline was the most sensitive antibiotic. Sensitivity to all other antimicrobials was 15 percentage or less. In vitro sensitivity to carbapenems is very low. (author)

Contribution of Acinetobacter-derived cephalosporinase-30 to sulbactam resistance in Acinetobacter baumannii

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Shu-Chen eKuo

2015-03-01

Full Text Available The sulbactam resistance rate in Acinetobacter baumannii has increased worldwide. Previous reports have shown that the β-lactamase blaTEM-1 confers resistance to sulbactam in A. baumannii. The purpose of this study was to examine whether other β-lactamases including, the Acinetobacter-derived cephalosporinase (ADC, OXA-23, OXA-24/72, and OXA-58 families, also contribute to sulbactam resistance in A. baumannii. The correlation between these β-lactamases and the sulbactam minimal inhibitory concentration (MIC was determined using A. baumannii clinical isolates from diverse clonality, which were collected in a nationwide surveillance program from 2002 to 2010 in Taiwan. A possible association between the genetic structure of ISAba1-blaADC-30 and sulbactam resistance was observed because this genetic structure was detected in 97% of sulbactam-resistant strains compared with 10% of sulbactam-susceptible strains. Transformation of ISAba1-blaADC-30 into susceptible strains increased the sulbactam MIC from 2 to 32 μg/ml, which required blaADC-30 overexpression using an upstream promoter in ISAba1. Flow cytometry showed that ADC-30 production increased in response to sulbactam, ticarcillin, and ceftazidime treatment. This effect was regulated at the RNA level but not by an increase in the blaADC-30 gene copy number as indicated by quantitative PCR. Purified ADC-30 decreased the inhibitory zone created by sulbactam or ceftazidime, similarly to TEM-1. In conclusion, ADC-30 overexpression conferred resistance to sulbactam in diverse clinical A. baumannii isolates.

First case of bacteraemia due to Acinetobacter schindleri harbouring blaNDM-1 in an immunocompromised patient

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S. Montaña

2018-01-01

Full Text Available Clinically significant NDM-1-producing Acinetobacter schindleri has not yet been described in the literature. We report the first case of bacteraemia due to an A. schindleri strain harbouring blaNDM-1 recovered from an immunocompromised patient. Our report reinforces the fact that NDM-1 can easily be acquired by Acinetobacter species. Keywords: Acinetobacter schindleri, bacteraemia, blaNDM-1, clinically significant isolate, immunocompromised patient

Acinetobacter spp. Infections in Malaysia: A Review of Antimicrobial Resistance Trends, Mechanisms and Epidemiology.

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Mohd Rani, Farahiyah; A Rahman, Nor Iza; Ismail, Salwani; Alattraqchi, Ahmed Ghazi; Cleary, David W; Clarke, Stuart C; Yeo, Chew Chieng

2017-01-01

Acinetobacter spp. are important nosocomial pathogens, in particular the Acinetobacter baumannii - calcoaceticus complex, which have become a global public health threat due to increasing resistance to carbapenems and almost all other antimicrobial compounds. High rates of resistance have been reported among countries in Southeast Asia, including Malaysia. In this review, we examine the antimicrobial resistance profiles of Acinetobacter spp. hospital isolates from Malaysia over a period of nearly three decades (1987-2016) with data obtained from various peer-reviewed publications as well as the Malaysian National Surveillance on Antibiotic Resistance (NSAR). NSAR data indicated that for most antimicrobial compounds, including carbapenems, the peak resistance rates were reached around 2008-2009 and thereafter, rates have remained fairly constant (e.g., 50-60% for carbapenems). Individual reports from various hospitals in Peninsular Malaysia do not always reflect the nationwide resistance rates and often showed higher rates of resistance. We also reviewed the epidemiology and mechanisms of resistance that have been investigated in Malaysian Acinetobacter spp. isolates, particularly carbapenem resistance and found that bla OXA-23 is the most prevalent acquired carbapenemase-encoding gene. From the very few published reports and whole genome sequences that are available, most of the Acinetobacter spp. isolates from Malaysia belonged to the Global Clone 2 (GC2) CC92 group with ST195 being the predominant sequence type. The quality of data and analysis in the national surveillance reports could be improved and more molecular epidemiology and genomics studies need to be carried out for further in-depth understanding of Malaysian Acinetobacter spp. isolates.

Contamination of Ambient Air with Acinetobacter baumannii on Consecutive Inpatient Days.

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Shimose, Luis A; Doi, Yohei; Bonomo, Robert A; De Pascale, Dennise; Viau, Roberto A; Cleary, Timothy; Namias, Nicholas; Kett, Daniel H; Munoz-Price, L Silvia

2015-07-01

Acinetobacter-positive patients had their ambient air tested for up to 10 consecutive days. The air was Acinetobacter positive for an average of 21% of the days; the rate of contamination was higher among patients colonized in the rectum than in the airways (relative risk [RR], 2.35; P = 0.006). Of the 6 air/clinical isolate pairs available, 4 pairs were closely related according to rep-PCR results. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Host-microbe interactions that shape the pathogenesis of Acinetobacter baumannii infection

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Mortensen, Brittany L.; Skaar, Eric P.

2013-01-01

Summary Acinetobacter baumannii is an opportunistic pathogen that has emerged as a prevalent source of nosocomial infections, most frequently causing ventilator-associated pneumonia. The emergence of pan-drug resistant strains magnifies the problem by reducing viable treatment options and effectively increasing the mortality rate associated with Acinetobacter infections. In light of this rising threat, research on A. baumannii epidemiology, antibiotic resistance, and pathogenesis is accelerating. The recent development of both in vitro and in vivo models has enabled studies probing the host-Acinetobacter interface. Bacterial genetic screens and comparative genomic studies have led to the identification of several A. baumannii virulence factors. Additionally, investigations into host defense mechanisms using animal models or cell culture have provided insight into the innate immune response to infection. This review highlights some of the key attributes of A. baumannii virulence with an emphasis on bacterial interactions with the innate immune system. PMID:22640368

Multidrug Resistant Acinetobacter Infection and Their Antimicrobial ...

African Journals Online (AJOL)

Background: Acinetobacter baumannii, a non-glucose fermenting Gram negative bacillus, has emerged in the last three decades as a major etiological agent of hospital-associated infections giving rise to significant morbidity and mortality particularly in immunocompromised patients. Multidrug resistant A. baumannii ...

Acinetobacter Infection and Resistance Profile of Intensive Care Units In a City of Northwestern Anatolia

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İsa Yıldız

2016-09-01

Full Text Available INTRODUCTION: Determination of suitable antibiotics in treatment of Acinetobacter infections is through the hospital ascertaining the resistance state to bacteria causing the problem. In this study, the evaluation of antibiotics sensitivity of Acinetobacter strains isolated as infection factor in patients hospitalized in intensive care units is aimed. METHODS: Acinetobacter strains isolated from the samples of patients hospitalized in the 2nd and 3rd Stage adult intensive care units of a province in in northwestern Anatolia have been studied. RESULTS: A total of 165 patients were included in the study. The most isolated samples were respiratory tract samples, blood and urine. The antibiotics which the factors were most sensitive were cholistin (66,1% gentamicin (22,4% and trimethoprim sulfamethoxazole (18,2%. DISCUSSION AND CONCLUSION: We face increasing resistance ratios in Acinetobacter strains. Necessary precautions should be taken for this.

Production of humic substances through coal-solubilizing bacteria

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Nelson Valero

2014-09-01

Full Text Available In this paper, the production of humic substances (HS through the bacterial solubilization of low rank coal (LRC was evaluated. The evaluation was carried out by 19 bacterial strains isolated in microenvironments with high contents of coal wastes. The biotransformed LRC and the HS produced were quantified in vitro in a liquid growth medium. The humic acids (HA obtained from the most active bacterial strain were characterized via elemental composition (C, H, N, O, IR analyses, and the E4/E6 ratio; they were then compared with the HA extracted chemically using NaOH. There was LRC biotransformation ranged from 25 to 37%, and HS production ranged from 127 to 3100 mg.L-1. More activity was detected in the isolated strains of Bacillus mycoides, Microbacterium sp, Acinetobacter sp, and Enterobacter aerogenes. The HA produced by B. mycoides had an IR spectrum and an E4/E6 ratio similar to those of the HA extracted with NAOH, but their elemental composition and their degree of aromatic condensation was different. Results suggest that these bacteria can be used to exploit the LRC resulting from coal mining activities and thus produce HS in order to improve the content of humified organic matter in soils.

Phytotoxic substance with allelopathic activity in Brachiaria decumbens.

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Kobayashi, Ai; Kato-Noguchi, Hisashi

2015-05-01

The grass Brachiaria decumbens becomes naturalized and quickly dominant in non-native areas. It was hypothesized that phytotoxic substances of plants may contribute to the domination and invasion of the plants. However, no potent phytotoxic substance has been reported in B. decumbens. Therefore, we searched for phytotoxic substances with allelopathic activity in this species. An aqueous methanol extract of B. decumbens inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was then purified using chromatographic methods and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as (6R,9S)-3-oxo-α-ionol. These results suggest that this compound may contribute to the allelopathic effect caused by the B. decumbens extract and may be in part responsible for the invasion and domination of B. decumbens. Two other Brachiaria species, B. brizantha and a Brachiaria hybrid were also confirmed to contain (6R,9S)-3-oxo-α-ionol. Therefore, this compound may play an important role in the phytotoxicity of the Brachiaria species.

Biodegradation of 4-nitroaniline by plant-growth promoting Acinetobacter sp. AVLB2 and toxicological analysis of its biodegradation metabolites

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Silambarasan, Sivagnanam [Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Vangnai, Alisa S., E-mail: alisa.v@chula.ac.th [Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok 10330 (Thailand)

2016-01-25

Highlights: • Acinetobacter sp. AVLB2 is a PGPB able to degrade high concentration of 4-NA. • Growth and degradation kinetics for 4-NA removal by AVLB2 were studied. • A novel biodegradation pathway for 4-nitroaniline has been proposed. • Toxicological studies revealed non-toxic nature of 4-NA biodegraded metabolites. • Acinetobacter sp. AVLB2 could maintain PGP traits under 4-NA stress. - Abstract: 4-nitroaniline (4-NA) is one of the major priority pollutants generated from industrial productions and pesticide transformation; however very limited biodegradation details have been reported. This work is the first to report 4-NA biodegradation kinetics and toxicity reduction using a newly isolated plant-growth promoting bacterium, Acinetobacter sp. AVLB2. The 4-NA-dependent growth kinetics parameters: μ{sub max}, K{sub s} and K{sub i}, were determined to be 0.039 h{sup −1}, 6.623 mg L{sup −1} and 25.57 mg L{sup −1}, respectively using Haldane inhibition model, while the maximum biodegradation rate (V{sub max}) of 4-NA was at 0.541 mg L{sup −1} h{sup −1} and 0.551 mg L{sup −1} h{sup −1}, following Michaelis–Menten and Hanes–Woolf models, respectively. Biodegradation pathway of 4-NA by Acinetobacter sp. AVLB2 was proposed, and successfully led to the reduction of 4-NA toxicity according to the following toxicity assessments: microbial toxicity using Escherichia coli DH5α, phytotoxicity with Vigna radiata and Crotalaria juncea, and cytogenotoxicity with Allium cepa root-tip cells. In addition, Acinetobacter sp. AVLB2 possess important plant-growth promoting traits, both in the presence and absence of 4-NA. This study has provided a new insight into 4-NA biodegradation ability and concurrent plant-growth promoting activities of Acinetobacter sp. AVLB2, which may indicate its potential role for rhizoremediation, while sustaining crop production even under 4-NA stressed environment.

Comparison of Disk Diffusion and E-Test Methods for Doripenem Susceptibility of Nosocomial Acinetobacter Baumannii Strains

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Yesim Cekin

2014-03-01

Full Text Available Aim: Acinetobacter species are amoung the most common two cause of infections isolated from patients of intensive care unit in our hospital. Doripenem which acts by inhibiting cell wall synthesis is resently introduced for use in our country is broad spectrum antibiotic belonging to carbapenems. There are many studies investigating the susceptibility of doripenem of Acinetobacter baumannii which is isolated as a cause of ventilatory associated pneumonia in the literature. We aimed to compare e-test and disc diffusion methods for doripenem susceptibility of acinetobacter baumannii strains as nosocomial infections Acinetobacter baumanni isolates detected as nosocomial infection. Material and Method:. Between January to December, 2009 a total of 94 Acinetobacter baumanni strains isolated from different clinical specimens from intensive care units have been studied for doripenem susceptibility by disc diffusion and E-test methods. Minimal inhibitory consantrations (MIC were accepted as; sensitive %u22641 %u03BCg/ml, intermadiate 2-4 %u03BCg/ml, resistant >4 %u03BCg/ml and diameters of inhibition zone with 10 µg disc; sensitive

Synergy and mechanism of action of α-mangostin and ceftazidime against ceftazidime-resistant Acinetobacter baumannii.

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Pimchan, T; Maensiri, D; Eumkeb, G

2017-10-01

To address the resistance of Acinetobacter baumannii to β-lactam antibiotics, combination therapy between different antibiotic classes is increasingly used. The antibacterial activity of α-mangostin (AMT) alone or in combination with ceftazidime (CTZ) was investigated against ceftazidime-resistant A. baumannii DMST 45378 (CRAB). Initial screening showed that A. baumannii strains possessed AmpC β-lactamase (AmpC), extended-spectrum beta-lactamase (ESBL) and metallo-β-lactamases (MBL). Minimum inhibitory concentrations (MICs) of all test agents were >800 μg ml -1 against CRAB. The combination of AMT/CTZ exhibited a fractional inhibitory concentration index (FICI) of Type IV β-lactamase was inhibited by AMT. The data suggest that AMT in combination with CTZ is synergistic and efficient against CRAB. The data also indicate that the AMT/CTZ combination may target multiple structures on the bacterial cell surface. This represents the first report of this effect on CRAB and could potentially be expanded into in vivo studies. Significance and Impact of the Study: Acinetobacter baumannii strains cause serious infections, patient mortality, and have been reported to rise of multidrug resistance. This article represents the first report of using α-mangostin plus ceftazidime against these resistant strains and its mechanism of action. α-mangostin has no cytotoxic effects. Therefore, α-mangostin has strong potential for development as a useful, novel adjunct phytopharmaceutical to ceftazidime synergistically for the treatment of these strains. The synergy approach could potentially be a novel tool to combat the resistant strains. © 2017 The Society for Applied Microbiology.

Diversity Within the O-linked Protein Glycosylation Systems of Acinetobacter Species

DEFF Research Database (Denmark)

Scott, N. E.; Kinsella, R. L.; Edwards, A. V. G.

2014-01-01

nature of glycan biogenesis we investigated the composition, diversity, and properties of the Acinetobacter glycoproteome. Utilizing global and targeted mass spectrometry methods, we examined 15 strains and found extensive glycan diversity in the O-linked glycoproteome of Acinetobacter. Comparison......-linked glycosylation favors short (three to five residue) glycans with limited branching containing negatively charged sugars such as GlcNAc3NAcA4OAc or legionaminic/pseudaminic acid derivatives. These observations suggest that although highly diverse, the capsule/O-linked glycan biosynthetic pathways generate glycans...

In vitro efficacy of doripenem against pseudomonas aeruginosa and acinetobacter baumannii by e-test

International Nuclear Information System (INIS)

Gilani, M.; Munir, T.; Latif, M.; Rehman, S.

2015-01-01

To assess the in vitro efficacy of doripenem against Pseudomonas aeruginosa and Acinetobacter baumannii using Epsilometer strips. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Army Medical College, Rawalpindi and National University of Sciences and Technology, Islamabad, from May 2014 to September 2014. Methodology: A total of 60 isolates of Acinetobacter baumannii and Pseudomonas aeruginosa collected from various clinical samples received from Military Hospital were included in the study. The specimens were inoculated onto blood, MacConkey and chocolate agars. The isolates were identified using Gram staining, motility, catalase test, oxidase test and API 20NE (Biomeriux, France). Organisms identified as Acinetobacter baumannii and Pseudomonas aeruginosa were included in the study. Bacterial suspensions equivalent to 0.5 McFarland turbidity standard of the isolates were prepared and applied on Mueller Hinton agar. Epsilometer strip was placed in the center of the plate and incubated for 18-24 hours. Minimum Inhibitory Concentration (MIC) was taken to be the point where the epsilon intersected the E-strip. MIC of all the isolates was noted. Results: For Pseudomonas aeruginosa isolates, MIC50 was 12 micro g/mL and MIC90 was 32 micro g/mL. For Acinetobacter baumannii MIC 50 and MIC90 was 32 micro g/mL. Conclusion: Doripenem is no more effective against Pseudomonas aeruginosa and Acinetobacter baumannii in our setting. (author)

Genome Sequence of Jumbo Phage vB_AbaM_ME3 of Acinetobacter baumanni

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Buttimer, Colin; O?Sullivan, Lisa; Elbreki, Mohamed; Neve, Horst; McAuliffe, Olivia; Ross, R. Paul; Hill, Colin; O?Mahony, Jim; Coffey, Aidan

2016-01-01

Bacteriophage (phage) vB_AbaM_ME3 was previously isolated from wastewater effluent using the propagating host Acinetobacter baumannii DSM 30007. The full genome was sequenced, revealing it to be the largest Acinetobacter bacteriophage sequenced to date with a size of 234,900 bp and containing 326 open reading frames (ORFs).

Antibacterial activity of Hibiscus sabdariffa L. calyces against hospital isolates of multidrug resistant Acinetobacter baumannii

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Emad Mohamed Abdallah

2016-11-01

Full Text Available Objective: To evaluate the antibacterial activity of methanol extract of Hibiscus sabdariffa (H. sabdariffa calyces employed in Sudanese folk medicine against five hospital isolates of multidrug resistant Acinetobacter baumannii (MDR A. baumannii. Methods: The antibacterial activity of 80% methanol extract (v/v of H. sabdariffa calyces was evaluated by agar disc diffusion, minimum inhibitory concentration and minimum bactericidal concentration methods. Antibiotic susceptibility of selected A. baumannii strains was tested. Results: In the present investigation, the methanol extract from the calyces of H. sabdariffa exhibited significant antibacterial properties against the non-MDR A. baumannii as well as the MDR A. baumannii strains with a zone of inhibition ranging from (11.3 ± 0.3 to (13.6 ± 0.3 mm. The relative percentage inhibition of H. sabdariffa extract (10 mg/disc with respect to gentamicin (10 mg/disc had potent antibacterial properties and was much more effective than gentamicin. Values of minimum inhibitory concentration and minimum bactericidal concentration ranged from 25 to 50 and 50 to 100 mg/mL, respectively, revealing the potential bactericidal properties of the extract. Conclusions: According to the present study, the calyces of H. sabdariffa can be used as a substitute source of the current ineffective synthetic antibiotics used against MDR A. baumannii.

Genome sequencing and annotation of Acinetobacter guillouiae strain MSP 4-18

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Nitin Kumar Singh

2014-12-01

Full Text Available The genus Acinetobacter consists of 31 validly published species ubiquitously distributed in nature and primarily associated with nosocomial infection. We report the 4.8 Mb genome of Acinetobacter guillouiae MSP 4-18, isolated from a mangrove soil sample from Parangipettai (11°30′N, 79°47′E, Tamil Nadu, India. The draft genome of A. guillouiae MSP 4-18 has a G + C content of 38.0% and includes 3 rRNA genes (5S, 23S, 16S and 69 aminoacyl-tRNA synthetase genes.

Staring at the cold sun: blue light regulation is distributed within the genus Acinetobacter.

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Adrián Golic

Full Text Available We previously showed that the opportunistic nosocomial pathogen Acinetobacter baumannii is able to sense and respond to light via BlsA, a BLUF (Blue-Light-sensing Using FAD-domain photoreceptor protein. Here, we extend our previous studies showing that light regulation is not restricted to A. baumannii, but rather widespread within the genus Acinetobacter. First, we found that blue light modulates motility and biofilm formation in many species of the genus, including members of the Acinetobacter calcoaceticus-A. baumannii complex. In many of these species blue light acts as a key factor guiding the decision between motility or sessility at 24°C, whereas in A. baumannii, light inhibits both motility and biofilm formation. We also show that light regulation of motility occurred not only at 24°C but also at 37°C in non-A. baumannii species, contrasting the situation of A. baumannii which only shows photoregulation at 24°C. Second, we show that Acinetobacter baylyi (strain ADP1 BLUF-photoreceptors can functionally replace in vivo the A. baumannii 17978 BlsA protein and that the pathways leading to biofilm formation are inversely regulated at 24°C between these two microorganisms. Finally, we found the presence of predicted genes coding BLUF-containing proteins in all Acinetobacter sequenced genomes, even though the copy number is variable among them. Phylogenetic analysis suggests a common origin for all BLUF domains present in members of this genus, and could distinguish well-differentiated clusters that group together BLUF homologs from different species, a situation particularly clear for members of the ACB complex. Despite a role played by these BLUF domain-containing proteins in the photoregulation observed in the members of the genus Acinetobacter is a likely scenario given our findings in A. baumannii and A. baylyi, further research will contribute to confirm this possibility.

Staring at the Cold Sun: Blue Light Regulation Is Distributed within the Genus Acinetobacter

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Golic, Adrián; Vaneechoutte, Mario; Nemec, Alexandr; Viale, Alejandro M.; Actis, Luis A.; Mussi, María Alejandra

2013-01-01

We previously showed that the opportunistic nosocomial pathogen Acinetobacter baumannii is able to sense and respond to light via BlsA, a BLUF (Blue-Light-sensing Using FAD)-domain photoreceptor protein. Here, we extend our previous studies showing that light regulation is not restricted to A. baumannii, but rather widespread within the genus Acinetobacter. First, we found that blue light modulates motility and biofilm formation in many species of the genus, including members of the Acinetobacter calcoaceticus-A. baumannii complex. In many of these species blue light acts as a key factor guiding the decision between motility or sessility at 24°C, whereas in A. baumannii, light inhibits both motility and biofilm formation. We also show that light regulation of motility occurred not only at 24°C but also at 37°C in non-A. baumannii species, contrasting the situation of A. baumannii which only shows photoregulation at 24°C. Second, we show that Acinetobacter baylyi (strain ADP1) BLUF-photoreceptors can functionally replace in vivo the A. baumannii 17978 BlsA protein and that the pathways leading to biofilm formation are inversely regulated at 24°C between these two microorganisms. Finally, we found the presence of predicted genes coding BLUF-containing proteins in all Acinetobacter sequenced genomes, even though the copy number is variable among them. Phylogenetic analysis suggests a common origin for all BLUF domains present in members of this genus, and could distinguish well-differentiated clusters that group together BLUF homologs from different species, a situation particularly clear for members of the ACB complex. Despite a role played by these BLUF domain-containing proteins in the photoregulation observed in the members of the genus Acinetobacter is a likely scenario given our findings in A. baumannii and A. baylyi, further research will contribute to confirm this possibility. PMID:23358859

Polyvinylpyrrolidone-Capped Silver Nanoparticle Inhibits Infection of Carbapenem-Resistant Strain of Acinetobacter baumannii in the Human Pulmonary Epithelial Cell

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Vishvanath Tiwari

2017-08-01

Full Text Available Acinetobacter baumannii, an opportunistic ESKAPE pathogen, causes respiratory and urinary tract infections. Its prevalence increases gradually in the clinical setup. Pathogenicity of Acinetobacter is significantly influenced by its ability to infect and survive in human pulmonary cells. Therefore, it is important to study the infection of A. baumannii in human pulmonary host cell (A-549, monitoring surface interacting and internalized bacteria. It was found that during infection of A. baumannii, about 40% bacteria adhered to A-549, whereas 20% got internalized inside pulmonary cell and induces threefold increase in the reactive oxygen species production. We have synthesized polyvinylpyrrolidone (PVP-capped AgNPs using chemical methods and tested its efficacy against carbapenem-resistant strain of A. baumannii. PVP-capped silver nanoparticles (PVP-AgNPs (30 µM have shown antibacterial activity against carbapenem-resistant strain of A. baumannii and this concentration does not have any cytotoxic effect on the human pulmonary cell line (IC50 is 130 µM. Similarly, PVP-AgNPs treatment decreases 80% viability of intracellular bacteria, decreases adherence of A. baumannii to A-549 (40 to 2.2%, and decreases intracellular concentration (20 to 1.3% of A. baumannii. This concludes that PVP-AgNPs can be developed as a substitute for carbapenem to control the infection caused by carbapenem-resistant A. baumannii.

Antimicrobial resistance and clonality in Acinetobacter baumannii

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Nemec, Alexandr

2009-01-01

The aim of this thesis was to obtain insight into the epidemiology and molecular basis of multidrug resistance of Acinetobacter baumannii at the population level. To this aim a number of studies were performed on strains mainly from the Czech Republic (CR) which have shown in particular that (i) the

Neutron activation analysis of biological substances

International Nuclear Information System (INIS)

Ordogh, M.

1978-08-01

A Bowen cabbage sample was used as a reference material for the neutron activation studies, and the method was checked by the analysis of other biological substances (blood or serum etc.). For nondestructive measurements also some non-trace elements were determined in order to decide whether the activation analysis is a useful means for such measurements. The new activation analysis procedure was used for biomedical studies as, e.g., for trace element determination in body fluids, and for the analysis of inorganic components in air samples. (R.P.)

Genome Sequence of Jumbo Phage vB_AbaM_ME3 of Acinetobacter baumanni.

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Buttimer, Colin; O'Sullivan, Lisa; Elbreki, Mohamed; Neve, Horst; McAuliffe, Olivia; Ross, R Paul; Hill, Colin; O'Mahony, Jim; Coffey, Aidan

2016-08-25

Bacteriophage (phage) vB_AbaM_ME3 was previously isolated from wastewater effluent using the propagating host Acinetobacter baumannii DSM 30007. The full genome was sequenced, revealing it to be the largest Acinetobacter bacteriophage sequenced to date with a size of 234,900 bp and containing 326 open reading frames (ORFs). Copyright © 2016 Buttimer et al.

Heavy metal and antibiotic resistance of Acinetobacter spp. isolated from diesel fuel polluted

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Kais Kassim Ghaima

2018-04-01

Full Text Available Heavy metals pollution of soil and wastewater is a global problem that threatens the environment as they are not degraded or removed and the potential threat to human health comes from the multiple resistances to heavy metals and antibiotics among bacterial populations. The present study was aimed to isolate and identify multiple metal/antibiotic resistant Acinetobacter spp. from diesel fuel polluted soil of Al-Dora, Baghdad, Iraq. Initially, a total of 24 bacterial cultures (coded KNZ–1 to KNZ–24 were isolated and identified up to genus level as Acinetobacter by morphological, physiological and biochemical characteristics. Screening of heavy metals resistant Acinetobacter were conducted by streaking the isolates on nutrient agar plates supplemented with different concentrations: 10, 25, 50 and 100mg/L of the three heavy metals; Hg2+, Cd2+ and Pb2+. Out of 24 isolates, 6 (25% isolates (KNZ–3, KNZ–5, KNZ–8, KNZ–12, KNZ–16 and KNZ–21 were selected as a multiple heavy metal resistant (MHMR Acinetobacter with maximum tolerable concentrations (MTCs; 100–200mg/L for Hg2+, 300-600mg/L for Cd2+ and 100–300mg/L for Pb2+. Antibiotic resistance pattern of the selected MHMR isolates was determined by Kirby-Bauer disc diffusion method against 12 different antibiotics belonging to 7 classes. Out of 6 isolates, 4 isolates were multidrug resistance (MDR with varying degrees. Among them isolate, KNZ–16 showed a wide range of resistance to all tested antibiotics except Levofloxacin and Imipenem. It was concluded that dual resistant Acinetobacter is useful in the bioremediation of environments polluted with heavy metals especially the biodegradation of organic pollutants.

Mutant Prevention Concentrations of Imipenem and Meropenem against Pseudomonas aeruginosa and Acinetobacter baumannii

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E. Dahdouh

2014-01-01

Full Text Available The aim of this study was to determine the usefulness of the MPC of carbapenems against clinical isolates of Pseudomonas spp. and Acinetobacter spp. and to assess its possible relationship with mechanisms of resistance. Detection of the mechanisms of resistance was performed using Antibiotic Susceptibility Testing, Double Disk Synergy, disk antagonism, addition of NaCl to the medium, addition of PBA or EDTA to Carbapenem disks, addition of PBA to Cefoxitin disks, and CCCP test for 10 Pseudomonas spp. and Acinetobacter baumannii strains. The MIC and MPC were determined using the broth macrodilution and plate dilution methods, respectively. Four Acinetobacter baumannii strains produced MBL. Two of them produced Oxacillinase and one produced ESBL. Two Pseudomonas spp. isolates produced both KPC and MBL. The resistant Acinetobacter spp. and Pseudomonas spp. strains had higher MPC values than susceptible ones. However, the Mutant Selection Window was found to be dependent on the degree of resistance but not on a particular mechanism of resistance. The usefulness of the MPC was found to be dependent on its value. Based on our data, we recommend determining the MPC for each isolate before using it during treatment. Furthermore, the use of T>MSW instead of T>MIC is suggested.

Biosurfactants from Acinetobacter calcoaceticus BU03 enhance the solubility and biodegradation of phenanthrene.

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Zhao, Zhenyong; Wong, Jonathan W C

2009-03-01

A thermophilic bacterial strain, Acinetobacter calcoaceticus BU03, with a biosurfactant-producing capability, was isolated from petroleum-contaminated soil with an improved procedure which employed the solubilization of polycyclic aromatic hydrocarbons (PAHs), i.e. naphthalene in agar plate, as a selection criterion. Crude biosurfactant was recovered from the culture of BU03 by extraction with n-hexane, and its properties were investigated. Biosurfactants from A. calcoaceticus BU03 constitute a thermo-stable mixture, composed of different agents with surface activities. At their critical micelle concentration (CMC) of 152.4 mg L(-1), the crude biosurfactants produced from A. calcoaceticus BU03 decreased the air-water surface tension to 38.4 mN m(-1). In thermophilic conditions, the emulsifying activity is 2.8 times that of Tween 80. The effects of the biosurfactants produced by A. calcoaceticus on the solubility and biodegradation of PAHs were investigated in batch systems. Biosurfactants produced by A. calcoaceticus BU03 at 25 times their CMC significantly increased the apparent aqueous solubility of phenanthrene (PHE), pyrene (PYR) and benzo(a)pyrene (B[a]P) to 54.3, 6.33 and 2.08 mg L(-1), respectively. In aqueous system, the biosurfactants at concentrations of 0.5 CMC and 1 CMC slightly enhanced the biodegradation of PHE by a consortium of PAH-degrading microrganisms. Results indicate that biosurfactants from A. calcoaceticus BU03 have potential to enhance the removal of PAHs from contaminated sites.

Genomic and proteomic evidences unravel the UV-resistome of the poly-extremophile Acinetobacter sp. Ver3.

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Kurth, Daniel; Belfiore, Carolina; Gorriti, Marta F; Cortez, Néstor; Farias, María E; Albarracín, Virginia H

2015-01-01

Ultraviolet radiation can damage biomolecules, with detrimental or even lethal effects for life. Even though lower wavelengths are filtered by the ozone layer, a significant amount of harmful UV-B and UV-A radiation reach Earth's surface, particularly in high altitude environments. high-altitude Andean lakes (HAALs) are a group of disperse shallow lakes and salterns, located at the Dry Central Andes region in South America at altitudes above 3,000 m. As it is considered one of the highest UV-exposed environments, HAAL microbes constitute model systems to study UV-resistance mechanisms in environmental bacteria at various complexity levels. Herein, we present the genome sequence of Acinetobacter sp. Ver3, a gammaproteobacterium isolated from Lake Verde (4,400 m), together with further experimental evidence supporting the phenomenological observations regarding this bacterium ability to cope with increased UV-induced DNA damage. Comparison with the genomes of other Acinetobacter strains highlighted a number of unique genes, such as a novel cryptochrome. Proteomic profiling of UV-exposed cells identified up-regulated proteins such as a specific cytoplasmic catalase, a putative regulator, and proteins associated to amino acid and protein synthesis. Down-regulated proteins were related to several energy-generating pathways such as glycolysis, beta-oxidation of fatty acids, and electronic respiratory chain. To the best of our knowledge, this is the first report on a genome from a polyextremophilic Acinetobacter strain. From the genomic and proteomic data, an "UV-resistome" was defined, encompassing the genes that would support the outstanding UV-resistance of this strain.

Genomic and proteomic evidences unravel the UV-resistome of the poly-extremophile Acinetobacter sp. Ver3

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Daniel eKurth

2015-04-01

Full Text Available Ultraviolet radiation can damage biomolecules, with detrimental or even lethal effects for life. Even though lower wavelengths are filtered by the ozone layer, a significant amount of harmful UV-B and UV-A radiation reach Earth’s surface, particularly in high altitude environments. High-Altitude Andean Lakes (HAAL are a group of disperse shallow lakes and salterns, located at the Dry Central Andes region in South America at altitudes above 3,000 m. As it is considered one of the highest UV-exposed environments, HAAL microbes constitute model systems to study UV-resistance mechanisms in environmental bacteria at various complexity levels. Herein, we present the genome sequence of Acinetobacter sp. Ver3, a gammaproteobacterium isolated from Lake Verde (4,400 m, together with further experimental evidence supporting the phenomenological observations regarding this bacterium ability to cope with increased UV-induced DNA damage. Comparison with the genomes of other Acinetobacter strains highlighted a number of unique genes, such as a novel cryptochrome. Proteomic profiling of UV-exposed cells identified up-regulated proteins such as a specific cytoplasmic catalase, a putative regulator, and proteins associated to amino acid and protein synthesis. Down-regulated proteins were related to several energy-generating pathways such as glycolysis, beta-oxidation of fatty acids and electronic respiratory chain. To the best of our knowledge, this is the first report on a genome from a polyextremophilic Acinetobacter strain. From the genomic and proteomic data, an UV-resistome was defined, encompassing the genes that would support the outstanding UV-resistance of this strain.

Epidemiology of nosocomial colonization/infection caused by Acinetobacter spp. in patients of six surgical clinics in war and peacetime.

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Suljagić, Vesna; Jevtić, Miodrag; Djordjević, Boban; Romić, Predrag; Ilić, Radoje; Stanković, Nebojsa; Milović, Novak; Novaković, Marijan; Kozarski, Jefta; Roganović, Zoran; Popović, Zoran; Jovelić, Aleksandra

2011-08-01

Acinetobacter spp. has emerged as nosocomial pathogen during the past few decades in hospitals all over the world, but it has increasingly been implicated as a serious nosocomial pathogen in military hospitals. The aim of this study was to analyse and compare the surveillance data on Acinetobacter nosocomial colonization/infection (NCI) collected during the wartime with the data collected in peacetime. We conducted a prospective study of incidence of Acinetobacter spp. colonization/infection. Also, the two nested case-control studies were conducted. The patients with nosocomial infection (cases) were compared with those with nosocomial colonization (controls) during the two different periods, wartime and peacetime. The patients with NCI by Acinetobacter spp. were identified by the case-based surveillance. The surveillance covered all the patients in 6 surgical clinics. During the study periods a total of 166 patients had cultures that grew Acinetobacter spp. and the pooled rates of Acinetobacter spp. colonization and infection were significantly higher in wartime. When patients with NCI in wartime were compared with those with NCI in peacetime significant differences were observed. In the war year, the patients were more significantly males (p war and peace period.

INFLUENCE OF SPEED, TIME OF HOMOGENIZATION, TYPE OF SURFACE ACTIVE SUBSTANCE ON THE SIZE OF PENTOXYPHILLINE NANOPARTICLES BASED ON POLY-DL-LAKTIDE-CO-GLICOLIDE

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T. V. Timchenko

2017-01-01

Full Text Available Nanopharmacology is a set of methods and techniques used in the creation, study, production and use of nanostructures (size about 1–700 nm with new chemical, physical, and biological properties. For a long time pharmacologists have been working on molecular, and sometimes even on a submolecular level for synthesizing new drugs and explaining their mechanism of action. Thanks to this, the interest of pharmacology in nanotechnology is connected with new ways of obtaining and using medicines. One way of obtaining new forms of drugs is the synthesis of nanoparticles, since they allow the active substance to overcome the protective barriers of the body such as, for example, the immune system. Due to the fact that the surface of nanoparticles (nanocapsules is multilayered, their resistance to the action of the protective mechanisms of the body increases, which allows the drug to retain the activity of the pharmacological action, as well as its structure for a longer time. The possibility of penetration through biological barriers, tissue-specificity, rate of drug release depends largely on the size and surface properties of nanoparticles.The aim of our study was to study the influence of such important factors as time, homogenization rate and the type of surface active substance, on the size of the obtained nanoparticles of pentoxifylline based on poly-DL-lactide-co-glycolide (PLGA.Materials and methods. The research was carried out using the information retrieval database (PubMed, as well as the results of our own research.Results and discussion. It has been found that the dispersion phase of the sample, in which polyvinyl alcohol was used as the surfactant, had the smallest size, particularly, the average hydrodynamic radius of the particles amounted to 175.4 nm. The influence of the speed and time of homogenization on the size of nano particles of pentoxifylline based on PLGA was experimentally proved. Also, microphotographs of nanoparticles of

WCK 4234, a novel diazabicyclooctane potentiating carbapenems against Enterobacteriaceae, Pseudomonas and Acinetobacter with class A, C and D β-lactamases.

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Mushtaq, Shazad; Vickers, Anna; Woodford, Neil; Livermore, David M

2017-06-01

Several diazabicyclooctanes (DBOs) are under development as inhibitors of class A and C β-lactamases. Inhibition of OXA (class D) carbapenemases is variable, with those of Acinetobacter spp. remaining notably resistant. We describe a novel DBO, WCK 4234 (Wockhardt), with distinctive activity against OXA carbapenemases. MICs of imipenem and meropenem were determined by CLSI agar dilution with WCK 4234 added at 4 or 8 mg/L. Test organisms were clinical Enterobacteriaceae, Acinetobacter baumannii and Pseudomonas aeruginosa with carbapenemases or carbapenem resistance via porin loss plus AmpC or ESBL activity. AmpC mutants were also tested. WCK 4234, which lacked direct antibacterial activity, strongly potentiated imipenem and meropenem against Enterobacteriaceae with OXA-48/OXA-181 or KPC enzymes, or with combinations of impermeability and AmpC or ESBL activity, with MICs reduced to ≤2 mg/L in almost all cases. Carbapenems likewise were potentiated against P. aeruginosa ( n  =   2) with OXA-181 enzyme, with MICs reduced from 64-128 to 2-8 mg/L and against A. baumannii with OXA carbapenemases, particularly OXA-23 or hyperproduced OXA-51, with MICs reduced to ≤2 mg/L for 9/10 acinetobacters with OXA-23 enzyme. Carbapenems were not potentiated against Enterobacteriaceae or non-fermenters with metallo-β-lactamases. WCK 4234 distinctively overcame resistance mediated by OXA-type carbapenemases, including those of A. baumannii . It behaved similarly to other DBOs against strains with KPC carbapenemases or combinations of impermeability and ESBL or AmpC activity. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Caspase-11 Plays a Protective Role in Pulmonary Acinetobacter baumannii Infection.

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Wang, Wei; Shao, Yue; Li, Shengjun; Xin, Na; Ma, Tingxian; Zhao, Chenghai; Song, Min

2017-10-01

Activation of caspase-11 by some Gram-negative bacteria triggers the caspase-1/interleukin 1β (IL-1β) pathway, independent of canonical inflammasomes. Acinetobacter baumannii is a Gram-negative, conditionally pathogenic bacterium that can cause severe pulmonary infection in hospitalized patients. A. baumannii was revealed to activate canonical and noncanonical inflammasome pathways in bone marrow-derived macrophages (BMDMs). Pulmonary infection of caspase-11 -/- mice with A. baumannii showed that caspase-11 deficiency impaired A. baumannii clearance, exacerbated pulmonary pathological changes, and enhanced susceptibility to A. baumannii These data indicate that the caspase-11-mediated innate immune response plays a crucial role in defending against A. baumannii . Copyright © 2017 American Society for Microbiology.

Quorum sensing in Acinetobacter: with special emphasis on antibiotic resistance, biofilm formation and quorum quenching

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Bindu Subhadra

2016-02-01

Full Text Available Acinetobacter is an important nosocomial, opportunistic human pathogen that is gradually gaining more attention as a major health threat worldwide. Quorum sensing (QS is a cell-cell communication system in which specific signaling molecules called autoinducers accumulate in the medium as the population density grows and control various physiological processes including production of virulence factors, biofilm and development of antibiotic resistance. The complex QS machinery in Acinetobacter is mediated by a two-component system which is homologous to the typical LuxI/LuxR system found in Gram-negative bacteria. This cell signaling system comprises of a sensor protein that functions as autoinducer synthase and a receptor protein which binds to the signal molecules, acyl homoserine lactones inducing a cascade of reactions. Lately, disruption of QS has emerged as an anti-virulence strategy with great therapeutic potential. Here, we depict the current understanding of the existing QS network in Acinetobacter and describe important anti-virulent strategies developed in order to effectively tackle this pathogen. In addition, the prospects of quorum quenching to control Acinetobacter infections is also been discussed.

Occurrence of bla genes encoding carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii from Intensive Care Unit in a tertiary care hospital.

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Subramaniyan, Jayanthi Siva; Sundaram, Jeya Meenakshi

2018-01-01

ICU shows increasing incidence of infection associated with the use of invasive procedures for the diagnostic purpose as well as the indiscriminate use of antibiotics. Pseudomonas aeruginosa and Acinetobacter species are "very successful" pathogen and the emergence of the Metallo-β-Lactamases (MBL) is becoming a therapeutic challenge. To isolate the Nonfermenting Gram negative bacilli from the ICU samples. To identify the metallo betalactamase producers and to detect the bla gene presence among the Pseudomonas aeruginosa and Acinetobacter baumannii . The Nonfermenting Gram negative bacilli isolates from the ICU samples were taken over for 5 years (2009-2014) in a tertiary care hospital. The isolates of Pseudomonas species and Acinetobacter species were confirmed by API analyser and processed according to standard procedures. Detection of the MBL producers were done by E strip method and subjected for bla gene detection by PCR method. In our study a total of 195 isolates of NFGNB were obtained from various ICU. Of these MBL producers, 26 % were Pseudomonas aeruginosa and 25 % were Acinetobacter baumannii . The subtypes of bla VIM MBL producing P.aeruginosa were 26%. The predominant gene coding for MBL activity in A.baumannii were found to be bla OXA gene 11.9%. The gene accession numbers were KF975367, KF975372. We have to control the development and dissemination of these superbugs among the ICU's.

Distribution and Molecular Characterization of Acinetobacter baumannii International Clone II Lineage in Japan.

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Matsui, Mari; Suzuki, Masato; Suzuki, Masahiro; Yatsuyanagi, Jun; Watahiki, Masanori; Hiraki, Yoichi; Kawano, Fumio; Tsutsui, Atsuko; Shibayama, Keigo; Suzuki, Satowa

2018-02-01

Multidrug-resistant (MDR) Acinetobacter spp. have been globally disseminated in association with the successful clonal lineage Acinetobacter baumannii international clone II (IC II). Because the prevalence of MDR Acinetobacter spp. in Japan remains very low, we characterized all Acinetobacter spp. ( n = 866) from 76 hospitals between October 2012 and March 2013 to describe the entire molecular epidemiology of Acinetobacter spp. The most prevalent species was A. baumannii ( n = 645; 74.5%), with A. baumannii IC II ( n = 245) accounting for 28.3% of the total. Meropenem-resistant isolates accounted for 2.0% ( n = 17) and carried IS Aba1-bla OXA-23-like ( n = 10), bla IMP ( n = 4), or IS Aba1-bla OXA-51-like ( n = 3). Multilocus sequence typing of 110 representative A. baumannii isolates revealed the considerable prevalence of domestic sequence types (STs). A. baumannii IC II isolates were divided into the domestic sequence type 469 (ST469) ( n = 18) and the globally disseminated STs ST208 ( n = 14) and ST219 ( n = 4). ST469 isolates were susceptible to more antimicrobial agents, while ST208 and ST219 overproduced the intrinsic AmpC β-lactamase. A. baumannii IC II and some A. baumannii non-IC II STs (e.g., ST149 and ST246) were associated with fluoroquinolone resistance. This study revealed that carbapenem-susceptible A. baumannii IC II was moderately disseminated in Japan. The low prevalence of acquired carbapenemase genes and presence of domestic STs could contribute to the low prevalence of MDR A. baumannii A similar epidemiology might have appeared before the global dissemination of MDR epidemic lineages. In addition, fluoroquinolone resistance associated with A. baumannii IC II may provide insight into the significance of A. baumannii epidemic clones. Copyright © 2018 American Society for Microbiology.

[Identification and typing of hospital strains of Acinetobacter calcoaceticus-Acinetobacter baumanni complex].

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Nemec, A; Urbásková, P; Grimont, F; Vránková, J; Melter, O; Schindler, J

1996-05-01

A collection of 95 strains of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex, isolated between 1991 and 1993 in the Prague Burn Center (BC), was studied. Ninety-one strains were isolated from 43 patients: 50 of them from burnt sites, 22 from endotracheal tube, 13 from urine, 3 from blood and 3 from venous catheter, and 4 strains were isolated from the hospital environment and the nursing staff. The strains were classified by restriction endonuclease fingerprinting of total DNA, plasmid profile analysis, ribotyping, comparison of antibiograms, biotyping and according to epidemiological data, into 31 relatedness groups each of them including 1 to 29 strains, likely to be isolates of the same strain. None of the methods used enabled to distinguish all groups. The importance of the polyphasic approach is emphasized since three multiresistant strains, isolated almost simultaneously in the BC, needed at least two methods to be distinguished (e.g. ribotyping and biotyping). Twenty-eight representative strains of different groups were identified by ribotyping: 18 of them were allocated to genomospecies 2 (A. baumannii), 5 to genomospecies 3 and 5 to genomospecies 13 sensu Tjernberg and Ursing. Only A. baumannii was found to spread among patients. Strains of two multiresistant groups persisted in the BC throughout the period studied and strains of one of these groups were responsible for an outbreak in the autumn of 1993. The methods mentioned above were used to describe 12 multiresistant strains isolated in three hospital wards in other localities. When ribotyped these strains were identified as A. baumannii. The strains of the same origin were identical in their typing profiles while the strains of different origins were easy to differentiate using any of the above methods; nevertheless, 2 of these groups were almost identical to 2 groups of multiresistant strains isolated in the BC.

Modelling metal-humic substances-surface systems: reasons for success, failure and possible routes for peace of mind

International Nuclear Information System (INIS)

Reiller, P.E.

2012-01-01

Iron oxides and oxy-hydroxides are commonly of considerable importance in the sorption of ions onto rocks, soils and sediments. They can be the controlling sorptive phases even if they are present in relatively small quantities. In common with other oxides and clay minerals, the sorption pH-edge of metals is directly linked to their hydrolysis: the higher the residual charge on the metal ion, the lower the pH-edge. Modelling of this process has been successfully carried out using different microscopic or macroscopic definitions of the interface (e.g. surface complexation or ion exchange models that may or may not include mineralogical descriptions). The influence of organic material on the sorption of many metals is of significant. This organic material includes simple organic molecules and more complex exo-polymeric substances (e.g. humic substances) produced by the decay of natural organic matter. Sorption of this organic material to mineral surfaces has been the subject of a large body of work. The various types of organic substances do not share the same affinities for mineral surfaces in general, and for iron oxides and oxy-hydroxides in particular. In those cases in which successful models of the component binary systems (i.e. metal-surface, metal-organic, organic-surface) have been developed, the formation of mixed surface complexes, the evolution of the surface itself, the addition order in laboratory systems, and the evolution of natural organic matter fractions during sorption, have often precluded a satisfactory description of metal-surface-organic ternary systems over a sufficiently wide range of parameter values (i.e. pH, ionic strength, concentration of humic substances). This manuscript describes the reasons for some successes and failures in the modelling of the ternary systems. Promising recent advances and possible methods of providing more complete descriptions of these intricate systems are also discussed. (author)

The effect of cleaning substances on the surface of denture base material.

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Žilinskas, Juozas; Junevičius, Jonas; Česaitis, Kęstutis; Junevičiūtė, Gabrielė

2013-12-11

The aim of this study was to evaluate the effect of substances used for hygienic cleaning of dentures on the surface of the denture base material. Meliodent Heat Cure (Heraeus-Kulzer, Germany) heat-polymerized acrylic resin was used to produce plates with all the characteristics of removable denture bases (subsequently, "plates"). Oral-B Complete toothbrushes of various brush head types were fixed to a device that imitated tooth brushing movements; table salt and baking soda (frequently used by patients to improve tooth brushing results), toothpaste ("Colgate Total"), and water were also applied. Changes in plate surfaces were monitored by measuring surface reflection alterations on spectrometry. Measurements were conducted before the cleaning and at 2 and 6 hours after cleaning. No statistically significant differences were found between the 3 test series. All 3 plates used in the study underwent statistically significant (pbaking soda--the total reflection reduction was 4.82 ± 0.1%; among toothbrushes with toothpaste, the hard-type toothbrush had the greatest reflection-reducing effect--4.6 ± 0.05%, while the toothbrush with table salt inflicted the least damage (3.5 ± 0.16%) due to the presence of rounded crystals between the bristles and the resin surface. Toothbrushes with water had a uniform negative effect on the plate surface - 3.8 9 ± 0.07%. All substances used by the patients caused surface abrasion of the denture base material, which reduced the reflection; a hard toothbrush with toothpaste had the greatest abrasive effect, while soft toothbrushes inflicted the least damage.

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with chronic periodontal infection

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Renata Souto

2014-06-01

Full Text Available P. aeruginosa and Acinetobacter spp. are important pathogens associated with late nosocomial pneumonia in hospitalized and institutionalized individuals. The oral cavity may be a major source of these respiratory pathogens, particularly in the presence of poor oral hygiene and periodontal infection. This study investigated the prevalence of P. aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with periodontal disease or health. Samples were obtained from 55 periodontally healthy (PH and 169 chronic periodontitis (CP patients. DNA was obtained from the samples and detection of P. aeruginosa and Acinetobacter spp. was carried out by multiplex and nested PCR. P. aeruginosa and Acinetobacter spp. were detected in 40% and 45% of all samples, respectively. No significant differences in the distribution of these microorganisms between men and women, subgingival biofilm and saliva samples, patients 35 years of age, and smokers and non-smokers were observed regardless periodontal status (p > 0.05. In contrast, the frequencies of P. aeruginosa and Acinetobacter spp. in saliva and biofilm samples were significantly greater in CP than PH patients (p < 0.01. Smokers presenting P. aeruginosa and high frequencies of supragingival plaque were more likely to present CP than PH. P. aeruginosa and Acinetobacter spp. are frequently detected in the oral microbiota of CP. Poor oral hygiene, smoking and the presence of P. aeruginosa are strongly associated with periodontitis.

A novel substance with allelopathic activity in Ginkgo biloba.

Science.gov (United States)

Kato-Noguchi, Hisashi; Takeshita, Sayaka; Kimura, Fukiko; Ohno, Osamu; Suenaga, Kiyotake

2013-12-15

Ginkgo (Ginkgo biloba) is one of the oldest living tree species and has been widely used in traditional medicine. Leaf extracts of ginkgo, such as the standardized extract EGb761, have become one of the best-selling herbal products. However, no bioactive compound directed at plants has been reported in this species. Therefore, we investigated possible allelopathic activity and searched for allelopathically active substances in ginkgo leaves. An aqueous methanol leaf extract inhibited the growth of roots and shoots of garden cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was purified by several chromatographic runs and an allelopathically active substance was isolated and identified by spectral analysis to be the novel compound 2-hydroxy-6-(10-hydroxypentadec-11-enyl)benzoic acid. The compound inhibited root and shoot growth of garden cress and timothy at concentrations greater than 3 μM. The activity of the compound was 10- to 52-fold that of nonanoic acid. These results suggest that 2-hydroxy-6-(10-hydroxypentadec-11-enyl)benzoic acid may contribute to the allelopathic effect caused by ginkgo leaf extract. The compound may also have potential as a template for the development of new plant control substances. Copyright © 2013 Elsevier GmbH. All rights reserved.

Species distribution, virulence factors, and antimicrobial resistance of Acinetobacter spp. isolates from dogs and cats: a preliminary study.

Science.gov (United States)

Kimura, Yui; Harada, Kazuki; Shimizu, Takae; Sato, Tomomi; Kajino, Akari; Usui, Masaru; Tamura, Yutaka; Tsuyuki, Yuzo; Miyamoto, Tadashi; Ohki, Asami; Watarai, Masahisa

2018-05-12

We investigated the prevalence of virulence factors and antimicrobial resistance among 67 Acinetobacter spp. isolates, consisting of 21 Acinetobacter baumannii and 46 non-baumannii Acinetobacter from companion animals. The PCR analysis showed that the most prevalent virulence gene was afa/draBC (29.9%), followed by papC (22.4%) and cvaC (20.9%). Antimicrobial susceptibility testing revealed that resistance to gentamicin (14.9%) and ciprofloxacin (11.9%) was relatively prevalent. Five gentamicin- and/or ciprofloxacin-resistant A. baumannii strains were assigned to ST25, ST149, ST164, ST203, and ST1198. All ciprofloxacin-resistant isolates harbored point mutations in gyrA and/or parC. This is the first preliminary monitoring of animal-origin Acinetobacter spp. in Japan. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

Weigle Reactivation in Acinetobacter Calcoaceticus

DEFF Research Database (Denmark)

Berenstein, Dvora

1982-01-01

phage and host survivals of about 5 times 10-6 and 1 times 10-1, respectively. Intracellular development of W-reactivated P78 was followed by one-step growth experiments. Conditions which allowed maximal W-reactivation also extended the period of phage production and yielded a somewhat reduced burst......Weigle (W)-reactivation was demonstrated in Acinetobacter calcoaceticus for the UV-irra-diated lysogenic phage P78. The reactivation factor (survival of irradiated phage on irradiated bacteria/ survival on unirradiated bacteria) reached a maximum value of 20. This was obtained at UV-doses giving...

Potential of a lytic bacteriophage to disrupt Acinetobacter baumannii biofilms in vitro.

Science.gov (United States)

Liu, Yannan; Mi, Zhiqiang; Niu, Wenkai; An, Xiaoping; Yuan, Xin; Liu, Huiying; Wang, Yong; Feng, Yuzhong; Huang, Yong; Zhang, Xianglilan; Zhang, Zhiyi; Fan, Hang; Peng, Fan; Li, Puyuan; Tong, Yigang; Bai, Changqing

2016-10-01

The ability of Acinetobacter baumannii to form biofilms and develop antibiotic resistance makes it difficult to control infections caused by this bacterium. In this study, we explored the potential of a lytic bacteriophage to disrupt A. baumannii biofilms. The potential of the lytic bacteriophage to disrupt A. baumannii biofilms was assessed by performing electron microscopy, live/dead bacterial staining, crystal violet staining and by determining adenosine triphosphate release. The bacteriophage inhibited the formation of and disrupted preformed A. baumannii biofilms. Results of disinfection assay showed that the lytic bacteriophage lysed A. baumannii cells suspended in blood or grown on metal surfaces. These results suggest the potential of the lytic bacteriophage to disrupt A. baumannii biofilms.

CipA of Acinetobacter baumannii Is a Novel Plasminogen Binding and Complement Inhibitory Protein.

Science.gov (United States)

Koenigs, Arno; Stahl, Julia; Averhoff, Beate; Göttig, Stephan; Wichelhaus, Thomas A; Wallich, Reinhard; Zipfel, Peter F; Kraiczy, Peter

2016-05-01

Acinetobacter baumannii is an emerging opportunistic pathogen, responsible for up to 10% of gram-negative, nosocomial infections. The global increase of multidrug-resistant and pan-resistant Acinetobacter isolates presents clinicians with formidable challenges. To establish a persistent infection,A. baumannii must overcome the detrimental effects of complement as the first line of defense against invading microorganisms. However, the immune evasion principles underlying serum resistance inA. baumannii remain elusive. Here, we identified a novel plasminogen-binding protein, termed CipA. Bound plasminogen, upon conversion to active plasmin, degraded fibrinogen and complement C3b and contributed to serum resistance. Furthermore, CipA directly inhibited the alternative pathway of complement in vitro, irrespective of its ability to bind plasminogen. A CipA-deficient mutant was efficiently killed by human serum and showed a defect in the penetration of endothelial monolayers, demonstrating that CipA is a novel multifunctional protein that contributes to the pathogenesis ofA. baumannii. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

A Pathogenic Potential of Acinetobacter baumannii-Derived Membrane Vesicles

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Jong Suk Jin

2011-12-01

Full Text Available Acinetobacter baumannii secretes outer membrane vesicles (OMVs. A. baumannii OMVs deliver many virulence factors to host cells and then induce cytotoxicity and innate immune response. OMVs secreted from bacteria contribute directly to host pathology during A. baumannii infection.

The Genomic Diversification of the Whole Acinetobacter Genus: Origins, Mechanisms, and Consequences

Science.gov (United States)

Touchon, Marie; Cury, Jean; Yoon, Eun-Jeong; Krizova, Lenka; Cerqueira, Gustavo C.; Murphy, Cheryl; Feldgarden, Michael; Wortman, Jennifer; Clermont, Dominique; Lambert, Thierry; Grillot-Courvalin, Catherine; Nemec, Alexandr; Courvalin, Patrice; Rocha, Eduardo P.C.

2014-01-01

Bacterial genomics has greatly expanded our understanding of microdiversification patterns within a species, but analyses at higher taxonomical levels are necessary to understand and predict the independent rise of pathogens in a genus. We have sampled, sequenced, and assessed the diversity of genomes of validly named and tentative species of the Acinetobacter genus, a clade including major nosocomial pathogens and biotechnologically important species. We inferred a robust global phylogeny and delimited several new putative species. The genus is very ancient and extremely diverse: Genomes of highly divergent species share more orthologs than certain strains within a species. We systematically characterized elements and mechanisms driving genome diversification, such as conjugative elements, insertion sequences, and natural transformation. We found many error-prone polymerases that may play a role in resistance to toxins, antibiotics, and in the generation of genetic variation. Surprisingly, temperate phages, poorly studied in Acinetobacter, were found to account for a significant fraction of most genomes. Accordingly, many genomes encode clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems with some of the largest CRISPR-arrays found so far in bacteria. Integrons are strongly overrepresented in Acinetobacter baumannii, which correlates with its frequent resistance to antibiotics. Our data suggest that A. baumannii arose from an ancient population bottleneck followed by population expansion under strong purifying selection. The outstanding diversification of the species occurred largely by horizontal transfer, including some allelic recombination, at specific hotspots preferentially located close to the replication terminus. Our work sets a quantitative basis to understand the diversification of Acinetobacter into emerging resistant and versatile pathogens. PMID:25313016

Characterization and identification of newly isolated Acinetobacter baumannii strain serdang 1 for phenol removal

Science.gov (United States)

Yadzir, Z. H. M.; Shukor, M. Y.; Nazir, M. S.; Abdullah, M. A.

2012-09-01

A new indigenous bacterial strain from Malaysian soil contaminated with petroleum waste had been successfully isolated, characterized and identified for phenol removal. The gram negative bacteria showed 98% identity with Acinetobacter baumannii based on Biolog{trade mark, serif} Identification System and the determination of a partial 16S ribosomal RNA (rRNA) sequence. The isolate clustered with species belonging to Acinetobacter clade in a 16S rDNA-based neighbour-joining phylogenetic tree.

High-surface-area active carbon

International Nuclear Information System (INIS)

O'Grady, T.M.; Wennerberg, A.N.

1986-01-01

This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

Rare cutaneous infection by Acinetobacter baumannii in an immunocompetent patient: a case report

OpenAIRE

Cirino, Pablo Vitoriano; Guimarães, Newton Sales; Follador, Ivonise

2008-01-01

O Acinetobacter baumanni é patógeno oportunista antigamente considerado de baixa virulência. Atualmente está envolvido em processos infecciosos que acometem pacientes imunocomprometidos,grandes queimados e pacientes em unidades de terapia intensiva que fazem uso de ventilação mecânica. Esse relato de caso chama atenção para infecção cutânea rara por essa bactéria em paciente imunocompetente.Acinetobacter baumannii is an oportunistic pathogen that used to be considered as having low virulence;...

Occurrence of an Environmental Acinetobacter baumannii Strain Similar to a Clinical Isolate in Paleosol from Croatia

Science.gov (United States)

Durn, Goran; Goic-Barisic, Ivana; Kovacic, Ana

2014-01-01

Over the past decade, bacteria of the genus Acinetobacter have emerged as a leading cause of hospital-acquired infections. Outbreaks of Acinetobacter infections are considered to be caused exclusively by contamination and transmission in hospital environments. The natural habitats of clinically important multiresistant Acinetobacter spp. remain to be defined. In this paper, we report an incidental finding of a viable multidrug-resistant strain of Acinetobacter baumannii, related to clinical isolates, in acid paleosol from Croatia. The environmental isolate of A. baumannii showed 87% similarity to a clinical isolate originating from a hospital in this geographic area and was resistant to gentamicin, trimethoprim-sulfamethoxazole, ciprofloxacin, and levofloxacin. In paleosol, the isolate was able to survive a low pH (3.37), desiccation, and a high temperature (50°C). The probable source of A. baumannii in paleosol is illegally disposed waste of external origin situated in the abandoned quarry near the sampling site. The bacteria could have been leached from waste by storm water and thus infiltrated the paleosol. PMID:24584245

Carbapenem-resistance and pathogenicity of bovine Acinetobacter indicus-like isolates.

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Peter Klotz

Full Text Available The objective of this study was to characterize blaOXA-23 harbouring Acinetobacter indicus-like strains from cattle including genomic and phylogenetic analyses, antimicrobial susceptibility testing and evaluation of pathogenicity in vitro and in vivo. Nasal and rectal swabs (n = 45 from cattle in Germany were screened for carbapenem-non-susceptible Acinetobacter spp. Thereby, two carbapenem resistant Acinetobacter spp. from the nasal cavities of two calves could be isolated. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified these isolates as A. indicus-like. A phylogenetic tree based on partial rpoB sequences indicated closest relation of the two bovine isolates to the A. indicus type strain A648T and human clinical A. indicus isolates, while whole genome comparison revealed considerable intraspecies diversity. High mimimum inhibitory concentrations were observed for carbapenems and other antibiotics including fluoroquinolones and gentamicin. Whole genome sequencing and PCR mapping revealed that both isolates harboured blaOXA-23 localized on the chromosome and surrounded by interrupted Tn2008 transposon structures. Since the pathogenic potential of A. indicus is unknown, pathogenicity was assessed employing the Galleria (G. mellonella infection model and an in vitro cytotoxicity assay using A549 human lung epithelial cells. Pathogenicity in vivo (G. mellonella killing assay and in vitro (cytotoxicity assay of the two A. indicus-like isolates was lower compared to A. baumannii ATCC 17978 and similar to A. lwoffii ATCC 15309. The reduced pathogenicity of A. indicus compared to A. baumannii correlated with the absence of important virulence genes encoding like phospholipase C1+C2, acinetobactin outer membrane protein BauA, RND-type efflux system proteins AdeRS and AdeAB or the trimeric autotransporter adhesin Ata. The emergence of carbapenem-resistant A. indicus-like strains from cattle carrying blaOXA-23 on transposable elements and

Isolation of a bacterial strain, Acinetobacter sp. from centrate wastewater and study of its cooperation with algae in nutrients removal.

Science.gov (United States)

Liu, Hui; Lu, Qian; Wang, Qin; Liu, Wen; Wei, Qian; Ren, Hongyan; Ming, Caibing; Min, Min; Chen, Paul; Ruan, Roger

2017-07-01

Algae were able to grow healthy on bacteria-containing centrate wastewater in a pilot-scale bioreactor. The batch experiment indicated that the co-cultivation of algae and wastewater-borne bacteria improved the removal efficiencies of chemical oxygen demand and total phosphorus in centrate wastewater to 93.01% and 98.78%, respectively. A strain of beneficial aerobic bacteria, Acinetobacter sp., was isolated and its biochemical characteristics were explored. Synergistic cooperation was observed in the growth of algae and Acinetobacter sp. Removal efficiencies of some nutrients were improved significantly by the co-cultivation of algae and Acinetobacter sp. After treatment, residual nutrients in centrate wastewater reached the permissible discharge limit. The cooperation between algae and Acinetobacter sp. was in part attributed to the exchange of carbon dioxide and oxygen between the algae and bacteria. This synergetic relationship between algae and Acinetobacter sp. provided a promising way to treat the wastewater by improving the nutrients removal and biomass production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibacterial Activity of Pinus pinaster Bark Extract and its Components Against Multidrug-resistant Clinical Isolates of Acinetobacter baumannii

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Mirna Ćurković-Perica

2015-07-01

Full Text Available The aim of this research was to test the antibacterial activity of Pinus pinaster aqueous bark extract (PABE and its basic components against multidrug-resistant isolates of Acinetobacter baumannii belonging to European clone I and II, isolated previously from the clinical outbreaks. The minimum bactericidal concentration of PABE against both clones of A. baumannii was 200 mg ml–1, while lower concentrations showed high antibacterial activity. After 24 h of treatment with 100, 50 or 10 mg ml–1 of extract, the reduction in the number of A. baumannii isolates belonging to European clone I and II was 85.8 ± 2.5 %, 78.5 ± 1.1 %, 66.3 ± 2.5 % and 90.2 ± 1.7 %, 78.6 ± 1.2 %, 69.8 ± 0.7 %, respectively. Several basic components: caffeic acid, catechin, epicatechin, gallic acid and vanillin, detected in the extract by high performance liquid chromatography, contributed to the antibacterial activity of the extract against both clones of A. baumannii. However, the antibacterial activity of extract was higher than that of each tested basic component suggesting that proanthocyanidins, which were present in quite a large amount in the extract, might have also contributed to the activity of the extract. Antibacterial activity of PABE against A. baumannii reveals that complex and inexpensive natural product might be useful in combat against naturally competent bacteria that easily acquire resistance against antibiotics.

Molecular detection of Acinetobacter species in lice and keds of domestic animals in Oromia Regional State, Ethiopia.

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Bersissa Kumsa

Full Text Available This study was conducted to determine the presence of Acinetobacter and Rickettsia species DNA in lice and Melophagus ovinus (sheep ked of animals from Oromia Regional State in Ethiopia. From September through November 2011, a total of 207 cattle, 85 sheep, 47 dogs and 16 cats were examined for ectoparasites. Results of morphological identification revealed several species of ectoparasites: Linognathus vituli (L. vituli, Bovicola bovis (B. bovis and Solenopotes capillatus (S. capillatus on cattle; B. ovis and Melophagus ovinus (M. ovinus on sheep; and Heterodoxus spiniger (H. spiniger on dogs. There was a significantly (p≤0.0001 higher prevalence of L. vituli observed in cattle than both S. capillatus and B. bovis. Molecular identification of lice using an 18S rRNA gene analysis confirms the identified lice species by morphological methods. We detected different Acinetobacter species among lice (11.1% and keds (86.4% including A. soli in L. vituli of cattle, A. lowffii in M. ovinus of sheep, A. pittii in H. spiniger of dogs, 1 new Acinetobacter spp. in M. ovinus and 2 new Acinetobacter spp. in H. spiniger of dogs using partial rpoB gene sequence analysis. There was a significantly higher prevalence of Acinetobacter spp. in keds than in lice (p≤0.00001. Higher percentage of Acinetobacter spp. DNA was detected in H. spiniger than in both B. ovis and L. vituli (p≤0.00001. Carbapenemase resistance encoding genes for blaOXA-23, blaOXA-24, blaOXA-58, blaNDM-1 and blaOXA-51 were not found in any lice and keds. These findings suggest that synanthropic animals and their ectoparasites might increase the risk of human exposure to zoonotic pathogens and could be a source for Acinetobacter spp. infections in humans. However, additional epidemiological data are required to determine whether ectoparasites of animals can act as environmental reservoirs and play a role in spreading these bacteria to both animal and human hosts.

Molecular detection of Acinetobacter species in lice and keds of domestic animals in Oromia Regional State, Ethiopia.

Science.gov (United States)

Kumsa, Bersissa; Socolovschi, Cristina; Parola, Philippe; Rolain, Jean-Marc; Raoult, Didier

2012-01-01

This study was conducted to determine the presence of Acinetobacter and Rickettsia species DNA in lice and Melophagus ovinus (sheep ked) of animals from Oromia Regional State in Ethiopia. From September through November 2011, a total of 207 cattle, 85 sheep, 47 dogs and 16 cats were examined for ectoparasites. Results of morphological identification revealed several species of ectoparasites: Linognathus vituli (L. vituli), Bovicola bovis (B. bovis) and Solenopotes capillatus (S. capillatus) on cattle; B. ovis and Melophagus ovinus (M. ovinus) on sheep; and Heterodoxus spiniger (H. spiniger) on dogs. There was a significantly (p≤0.0001) higher prevalence of L. vituli observed in cattle than both S. capillatus and B. bovis. Molecular identification of lice using an 18S rRNA gene analysis confirms the identified lice species by morphological methods. We detected different Acinetobacter species among lice (11.1%) and keds (86.4%) including A. soli in L. vituli of cattle, A. lowffii in M. ovinus of sheep, A. pittii in H. spiniger of dogs, 1 new Acinetobacter spp. in M. ovinus and 2 new Acinetobacter spp. in H. spiniger of dogs using partial rpoB gene sequence analysis. There was a significantly higher prevalence of Acinetobacter spp. in keds than in lice (p≤0.00001). Higher percentage of Acinetobacter spp. DNA was detected in H. spiniger than in both B. ovis and L. vituli (p≤0.00001). Carbapenemase resistance encoding genes for blaOXA-23, blaOXA-24, blaOXA-58, blaNDM-1 and blaOXA-51 were not found in any lice and keds. These findings suggest that synanthropic animals and their ectoparasites might increase the risk of human exposure to zoonotic pathogens and could be a source for Acinetobacter spp. infections in humans. However, additional epidemiological data are required to determine whether ectoparasites of animals can act as environmental reservoirs and play a role in spreading these bacteria to both animal and human hosts.

Celulitis por Acinetobacter junii-johnsonii adquirida en la comunidad: una presentación de caso

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Andrés F. Henao-Martínez

2012-06-01

Full Text Available La infección de piel y tejidos blandos por Acinetobacter no relacionada con trauma es una presentación inusual. La mayoría de los casos descritos presentan enfermedades concomitantes y son causados por Acinetobacter baumanii. Se describe un caso de celulitis no traumática por A. junii-johnsonii con bacteriemia, de inicio en la comunidad y asociado con el tratamiento médico. De acuerdo con nuestro conocimiento, éste sería el primer caso reportado de infección de tejidos blandos y piel por A. juniijohnsonii.La vesícula hemorrágica podría ser una característica clínica de celulitis por Acinetobacter.   doi: http://dx.doi.org/10.7705/biomedica.v32i2.652

Pneumonia adquirida na comunidade numa criança saudável por Acinetobacter

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G. Moreira Silva

2012-03-01

Full Text Available Resumo: O género Acinetobacter tem sido implicado numa grande variedade de doenças infecciosas, em particular, nas infecções associadas aos cuidados de saúde. Actualmente há evidência a enfatizar o papel deste microrganismo nas infecções adquiridas na comunidade.É relatado o caso de uma criança previamente saudável, de 28 meses de idade, internada por febre associada a tosse e dor localizada no hemitórax esquerdo e cuja radiografia torácica revelou pneumonia necrotisante do lobo inferior. A investigação diagnóstica efetuada permitiu o diagnóstico de Pneumonia adquirida na comunidade a Acinetobacter lwoffii.A criança partilhava frequentemente o seu equipamento respiratório com familiares idosos com doença pulmonar crónica obstrutiva. Dado não terem sido apurados outros factores de risco, considera-se que a partilha do equipamento poderá ter sido o foco infeccioso.Os autores pretendem alertar para a possibilidade de Pneumonia adquirida na comunidade por Acinetobacter lwoffii, numa criança previamente saudável, relacionada com o mau uso e limpeza dos nebulizadores. Este caso realça o papel emergente desta bactéria, mesmo no contexto comunitário. Abstract: Acinetobacter is involved in a variety of infectious diseases primarily associated with healthcare. Recently there has been increasing evidence of the important role these pathogens play in community acquired infections.We report on the case of a previously healthy child, aged 28 months, admitted for fever, cough and pain on the left side of the chest, which on radiographic examination corresponded to a lower lobe necrotizing pneumonia. After detailed diagnostic work–up, community acquired Acinetobacter lwoffii pneumonia was diagnosed.The child had frequently shared respiratory equipment with elderly relatives with chronic obstructive pulmonary disease. As there were no other apparent risk factors, it could

Simple screening tests for the detection of metallo-β-lactamase (MBL production in clinical isolates of Pseudomonas and Acinetobacter

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Shaheda Anwar

2010-01-01

Full Text Available There are no standard methods for the detection of metallo-b-lactamase (MBL production in gram negative organism in routine microbiology practice. The present study was undertaken to evaluate the screening tests like double disk synergy test (DDST and disk potentiation test (DPT using ceftazidime (CAZ and imipenem (IPM disks with chelating agents like EDTA, 2-mercaptopropionic acid (2-MPA. A total of 132 Pseudomonas and 76 Acinetobacter isolates were obtained from Bangabandhu Sheikh Mujib Medical University (BSMMU and Bangladesh Institute of Research and Rehabilitation for Diabetes, Endocrine and Metabolic Disorders (BIRDEM hospitals of Dhaka city. A total of 53 and 29 IPM resistant Pseudomonas and Acinetobacter isolates were selected. EDTA-IPM microdilution minimum inhibitory concentration (EDTA-IPM MIC method detected MBL in 44 (83% IPM resistant Pseudomonas and 19 (65.5% Acinetobacter isolates. DDST with CAZ-0.1M EDTA and CAZ-2-MPA detected MBL in 73.6% and 67.9% of IPM resistant Pseudomonas and 55.2% and 48.3% of Acinetobacter isolates respectively. The detection rate was 67.9% and 66.1% in Pseudomonas and 51.7% and 44.8% in Acinetobacter isolates by EDTA-IPM and IPM-2-MPA methods respectively. In comparison to DDST, DPT with CAZ-0.1M EDTA showed higher sensitivity (89.7% and specificity (100% for detection of MBL in Pseudomonas and Acinetobacter. The results showed that simple screening tests like DPT with 0.1M EDTA was able to detect MBL producing Pseudomonas and Acinetobacter from clinical samples with high sensitivity and specificity. Ibrahim Med. Coll. J. 2010; 4(1: 26-30

Acinetobacter species in the hospital environment : tracing and epidemiology.

NARCIS (Netherlands)

L. Dijkshoorn-de Bruin (Lenie)

1990-01-01

textabstractIn the course of the investigation a new taxonomic classification of Acinetobacter strains was introduced. The groups of this classification were established on the basis of DNA-DNA hybridization data of strains. In a final study of the present thesis, we investigated whether cell

Endophthalmitis caused by Acinetobacter baumanni: a case series.

Science.gov (United States)

Roy, R; Panigrahi, P; Malathi, J; Pal, S S; Nandi, K; Patil, A; Nigam, E; Arora, V

2013-03-01

To profile the etiology, clinical outcomes and drug sensitivity patterns in endophthalmitis caused by Acinetobacter baumanni. Retrospective analysis of all the cases of Acinetobacter baumanni endophthalmitis presenting to tertiary referral care ophthalmic hospital in Eastern India from January 2009 to December 2011 were done. A total of four cases were included in the study. Out of the four cases one was post traumatic and the rest were post cataract surgery. All the cases underwent vitreoretinal surgical intervention followed by intravitreal antibiotics. A. Baumanni was isolated from vitreous in all the cases. Among all the drugs tested bacteria were found sensitive to ciprofloxacin (100 %) whereas all tested resistant to ceftazidime. Out of the four cases one had to be eviscerated, another developed retinal detachment post vitrectomy, one was phthisical at final followup, and only one patient achieved a vision of 20/200 with clear media and attached retina at final visit. A. Baumanni is a very rare cause of endophthalmitis with poor visual and anatomical outcomes. Ciprofloxacin should be considered as first the line intravitreal antibiotic.

Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii on computer interface surfaces of hospital wards and association with clinical isolates

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Ma Ling

2009-10-01

Full Text Available Abstract Background Computer keyboards and mice are potential reservoirs of nosocomial pathogens, but routine disinfection for non-water-proof computer devices is a problem. With better hand hygiene compliance of health-care workers (HCWs, the impact of these potential sources of contamination on clinical infection needs to be clarified. Methods This study was conducted in a 1600-bed medical center of southern Taiwan with 47 wards and 282 computers. With education and monitoring program of hand hygiene for HCWs, the average compliance rate was 74% before our surveillance. We investigated the association of methicillin-resistant Staphylococcus aureus (MRSA, Pseudomonas aeruginosa and Acinetobacter baumannii, three leading hospital-acquired pathogens, from ward computer keyboards, mice and from clinical isolates in non-outbreak period by pulsed field gel electrophoresis and antibiogram. Results Our results revealed a 17.4% (49/282 contamination rate of these computer devices by S. aureus, Acinetobacter spp. or Pseudomonas spp. The contamination rates of MRSA and A. baumannii in the ward computers were 1.1% and 4.3%, respectively. No P. aeruginosa was isolated. All isolates from computers and clinical specimens at the same ward showed different pulsotypes. However, A. baumannii isolates on two ward computers had the same pulsotype. Conclusion With good hand hygiene compliance, we found relatively low contamination rates of MRSA, P. aeruginosa and A. baumannii on ward computer interface, and without further contribution to nosocomial infection. Our results suggested no necessity of routine culture surveillance in non-outbreak situation.

The genomic diversification of the whole Acinetobacter genus: origins, mechanisms, and consequences.

Science.gov (United States)

Touchon, Marie; Cury, Jean; Yoon, Eun-Jeong; Krizova, Lenka; Cerqueira, Gustavo C; Murphy, Cheryl; Feldgarden, Michael; Wortman, Jennifer; Clermont, Dominique; Lambert, Thierry; Grillot-Courvalin, Catherine; Nemec, Alexandr; Courvalin, Patrice; Rocha, Eduardo P C

2014-10-13

Bacterial genomics has greatly expanded our understanding of microdiversification patterns within a species, but analyses at higher taxonomical levels are necessary to understand and predict the independent rise of pathogens in a genus. We have sampled, sequenced, and assessed the diversity of genomes of validly named and tentative species of the Acinetobacter genus, a clade including major nosocomial pathogens and biotechnologically important species. We inferred a robust global phylogeny and delimited several new putative species. The genus is very ancient and extremely diverse: Genomes of highly divergent species share more orthologs than certain strains within a species. We systematically characterized elements and mechanisms driving genome diversification, such as conjugative elements, insertion sequences, and natural transformation. We found many error-prone polymerases that may play a role in resistance to toxins, antibiotics, and in the generation of genetic variation. Surprisingly, temperate phages, poorly studied in Acinetobacter, were found to account for a significant fraction of most genomes. Accordingly, many genomes encode clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems with some of the largest CRISPR-arrays found so far in bacteria. Integrons are strongly overrepresented in Acinetobacter baumannii, which correlates with its frequent resistance to antibiotics. Our data suggest that A. baumannii arose from an ancient population bottleneck followed by population expansion under strong purifying selection. The outstanding diversification of the species occurred largely by horizontal transfer, including some allelic recombination, at specific hotspots preferentially located close to the replication terminus. Our work sets a quantitative basis to understand the diversification of Acinetobacter into emerging resistant and versatile pathogens. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society

Activation of non-sensitizing or low-sensitizing fragrance substances into potent sensitizers - prehaptens and prohaptens.

Science.gov (United States)

Karlberg, Ann-Therese; Börje, Anna; Duus Johansen, Jeanne; Lidén, Carola; Rastogi, Suresh; Roberts, David; Uter, Wolfgang; White, Ian R

2013-12-01

Experimental and clinical studies have shown that fragrance substances can act as prehaptens or prohaptens. They form allergens that are more potent than the parent substance by activation outside or in the skin via abiotic (chemical and physical factors) and/or biotic activation, thus, increasing the risk of sensitization. In the present review a series of fragrance substances with well documented abiotic and/or biotic activation are given as indicative and illustrative examples of the general problem. Commonly used fragrance substances, also found in essential oils, autoxidize on contact with air, forming potent sensitizers that can be an important source for contact allergy to fragrances and fragranced products. Some of them can act as prohaptens and be activated in the skin as well. The experimental findings are confirmed in large clinical studies. When substances with structural alerts for acting as prohaptens and/or prehaptens are identified, the possibility of generating new potent allergens should be considered. Predictive testing should include activation steps. Further experimental and clinical research regarding activation of fragrance substances is needed to increase consumer safety. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Acinetobacter infections prevalence and frequency of the antibiotics ...

African Journals Online (AJOL)

More than a half of the isolates were from the ICUs and were obtained from 293 infected patients of which 65, 2% (191 cases) were males (sex ratio = 1.9) and the median age was 56 years (interquartile range: 42-68 years). Acinetobacter clinical isolates were obtained from respiratory samples (44.67%) followed by blood ...

First report of an OXA-58 carbapenemase-producing Acinetobacter ...

African Journals Online (AJOL)

S. Natoubi

2016-11-18

Nov 18, 2016 ... urinary tract infection, in Morocco. Acinetobacter baumannii are organisms frequently found in the environment. This bacterium causes several types of infections, such as bacteremia, pneumonia and urinary tract infection [1]. Carbapenem resistance in A. baumannii is more often caused by the production of ...

Isolation of a substance activating foot formation in hydra

DEFF Research Database (Denmark)

Grimmelikhuijzen, C J; Schaller, H C

1977-01-01

-forming potential of the tissue (2) It does not accelerate head regeneration, nor do the head factors of hydra discovered by Schaller (1973) and Berking (1977) accelerate foot regeneration. We propose that the foot-activating substance is a morphogen responsible for foot formation in hydra. The foot activator can...

Propolis as an antibacterial agent against clinical isolates of mdr-acinetobacter baumannii

International Nuclear Information System (INIS)

Hannan, A.; Batool, A.; Qamar, U.; Khalid, F.

2015-01-01

Multidrug resistant (MDR) Acinetobacter baumannii has emerged as an important health care problem. The organism is now identified as an important nosocomial pathogen particularly in the intensive care settings. The therapeutic options to treat this pathogen are limited; thus it needs testing for alternatives, like those of plant origin or natural products. Propolis is one of such products which have been tested against this organism. Methods: A. baumannii (n=32) were collected from Fatima Memorial Hospital, Lahore. The isolates were identified on the basis of their morphology, cultural characteristics and biochemical profile. The susceptibility of the isolates to various antimicrobials was evaluated as per Kirby-Bauer disc diffusion method according to (CLSI 2010). An ethanolic extract of propolis was prepared by the ultrasonic extraction method and its antibacterial activity was evaluated by the agar well diffusion technique. Minimum inhibitory concentration (MIC) was also determined by the agar dilution technique. Results: The isolates were found to be resistant to most of the commonly used anti-acinetobacter antimicrobials; doxycycline however was the exception. Propolis from Sargodha (EPS) and Lahore (EPL) showed zones of inhibition of 21.8 ± .29 mm and 15.66 ± 2.18 mm respectively. MIC ranges of EPS and EPL similarly was from 1.5-2.0 mg/ml and 4.0-4.5 mg/ml respectively. Conclusion: It is clear that EPS has potential edge of activity as compared to EPL. Nevertheless the potential efficacy of propolis must be subjected to pharmaceutical kinetics and dynamics to precisely determine its potential antimicrobial usefulness. (author)

Structure-reactivity relationships in the interactions between humic substances, pollutants from the nuclear cycle, and mineral surfaces

International Nuclear Information System (INIS)

Reiller, Pascal

2015-01-01

This document proposes an analysis of the structure-reactivity relationships in the interaction between humic substances, metallic pollutants from the nuclear cycle, and mineral surfaces. It composes the scientific document, which allowed the author to defend a Habilitation degree. It is mainly focused on the research works into which the author have been involved in on this particular thematic. Humic substances are issued from the degradation of the living. They have an important influence onto migration of metals in the environment. They are showing particular intrinsic physic and chemical, metal complexation, and adsorption onto mineral surfaces properties, which render the global comprehension of the different mechanisms somehow difficult. These three aspects are covered in this document. The first part is dedicated to the studies on composition, structure, and organization of humic substances, which cannot be considered as a well-defined type of chemical. They are a heterogeneous degradation product with a supramolecular organization, which is showing fractal properties from fractions up to several nanometers. Second part is on the complexation reactions. The different modelling strategies come from the difficulties on apprehending composition, structure, and organization of humic substances. The different models used are showing more or less strongly empiric characteristics. They can be derived from the mass action law, or explicitly account for heterogeneity, acid-basic, or ionic strength related parameters. The third and latter part covers the adsorption studies. The main property is adsorptive fractionation, which induces modification of chemical composition of humic substances between the surface and the solution. It also induces modification of complexation properties between the adsorbed and non-adsorbed fractions. Because of adsorptive fractionation, and the particular influence of ionic strength on humic substances, and of complexed metals, adsorption

A distinct alleles and genetic recombination of pmrCAB operon in species of Acinetobacter baumannii complex isolates.

Science.gov (United States)

Kim, Dae Hun; Ko, Kwan Soo

2015-07-01

To investigate pmrCAB sequence divergence in 5 species of Acinetobacter baumannii complex, a total of 80 isolates from a Korean hospital were explored. We evaluated nucleotide and amino acid polymorphisms of pmrCAB operon, and phylogenetic trees were constructed for each gene of prmCAB operon. Colistin and polymyxin B susceptibility was determined for all isolates, and multilocus sequence typing was also performed for A. baumannii isolates. Our results showed that each species of A. baumannii complex has divergent pmrCAB operon sequences. We identified a distinct pmrCAB allele allied with Acinetobacter nosocomialis in gene trees. Different grouping in each gene tree suggests sporadic recombination or emergence of pmrCAB genes among Acinetobacter species. Sequence polymorphisms among Acinetobacter species might not be associated with colistin resistance. We revealed that a distinct pmrCAB allele may be widespread across the continents such as North America and Asia and that sporadic genetic recombination or emergence of pmrCAB genes might occur. Copyright © 2015 Elsevier Inc. All rights reserved.

Utility of Whole-Genome Sequencing in Characterizing Acinetobacter Epidemiology and Analyzing Hospital Outbreaks

Science.gov (United States)

Fitzpatrick, Margaret A.; Hauser, Alan R.

2015-01-01

Acinetobacter baumannii frequently causes nosocomial infections and outbreaks. Whole-genome sequencing (WGS) is a promising technique for strain typing and outbreak investigations. We compared the performance of conventional methods with WGS for strain typing clinical Acinetobacter isolates and analyzing a carbapenem-resistant A. baumannii (CRAB) outbreak. We performed two band-based typing techniques (pulsed-field gel electrophoresis and repetitive extragenic palindromic-PCR), multilocus sequence type (MLST) analysis, and WGS on 148 Acinetobacter calcoaceticus-A. baumannii complex bloodstream isolates collected from a single hospital from 2005 to 2012. Phylogenetic trees inferred from core-genome single nucleotide polymorphisms (SNPs) confirmed three Acinetobacter species within this collection. Four major A. baumannii clonal lineages (as defined by MLST) circulated during the study, three of which are globally distributed and one of which is novel. WGS indicated that a threshold of 2,500 core SNPs accurately distinguished A. baumannii isolates from different clonal lineages. The band-based techniques performed poorly in assigning isolates to clonal lineages and exhibited little agreement with sequence-based techniques. After applying WGS to a CRAB outbreak that occurred during the study, we identified a threshold of 2.5 core SNPs that distinguished nonoutbreak from outbreak strains. WGS was more discriminatory than the band-based techniques and was used to construct a more accurate transmission map that resolved many of the plausible transmission routes suggested by epidemiologic links. Our study demonstrates that WGS is superior to conventional techniques for A. baumannii strain typing and outbreak analysis. These findings support the incorporation of WGS into health care infection prevention efforts. PMID:26699703

In vitro synergistic antibacterial activity of the essential oil from Zingiber cassumunar Roxb against extensively drug-resistant Acinetobacter baumannii strains.

Science.gov (United States)

Boonyanugomol, Wongwarut; Kraisriwattana, Kairin; Rukseree, Kamolchanok; Boonsam, Kraisorn; Narachai, Panchaporn

In this study, we determined the antibacterial and synergistic activities of the essential oil from Zingiber cassumunar against the extensively drug-resistant (XDR) Acinetobacter baumannii strains. The antibacterial and synergistic properties of the essential oil from Z. cassumunar were examined by agar disc diffusion tests. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated by broth microdilution using the resazurin assay. The in vitro time-kill antibacterial kinetics was analyzed using the plate count technique. We found that the essential oil from Z. cassumunar had antibacterial activity against A. baumannii, with MIC and MBC ranging from 7.00 to 9.24mg/ml. The essential oil could completely inhibit A. baumannii at 1h, and coccoid-shaped bacteria were found after treatment. In addition, the essential oil had a synergistic effect when combined with antibiotics, e.g., aminoglycosides, fluoroquinolones, tetracyclines, and folate pathway inhibitors. Thus, the essential oil from Z. cassumunar has strong antibacterial and synergistic activities against XDR A. baumannii, which may provide the basis for the development of a new therapy against drug-resistant bacteria. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Novel Low-Temperature Alkaline Lipase from Acinetobacter johnsonii LP28 Suitable for Detergent Formulation

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Hai Kuan Wang

2011-01-01

Full Text Available A strain LP28 that produces alkaline and low-temperature lipase was isolated from the soil collected from the Bay of Bohai, PR China and identified as Acinetobacter johnsonii using 16S rDNA sequencing. The lipase was purified to homogeneity by centrifugation, followed by ammonium sulphate precipitation, dialysis, ion exchange chromatography on cellulose DE-52 and gel filtration chromatography on Sephadex G-75. The enzyme was purified about 34-fold with a final yield of 13 % and the relative molecular mass of the enzyme was determined to be 53 kDa by SDS-PAGE. The purified enzyme exhibited maximum activity at 30 °C and pH=9.0, and retained 94.53 % of its maximum activity at 20 °C. The enzyme was stable at 50 °C and retained 80.9 % of its original activity for 30 min. It was also highly stable in a pH range of 8.0–11.0. The enzyme hydrolyzed a wide range of oils and showed a high level of lipase activity in hydrolyzing tributyrin. The enzyme activity was promoted in the presence of Na+, Ca2+, K+, Mg2+ and sodium citrate. Ba2+, Mn2+, Cr3+ and Co2+ did not affect the enzyme activity, whereas the presence of Al3+, Cu2+, Fe2+, Fe3+, Zn2+ and EDTA reduced the enzyme activity. Regarding the stability of detergent process, the enzyme was highly stable in the presence of various oxidizing agents, some commercial detergents and alkaline protease, and its activity was also promoted by most of the surfactants, viz. Tween 20, Tween 80, sodium cholate, sodium taurocholate and saponin. For these characteristics, the lipase from Acinetobacter johnsonii LP28 showed good potential as an additive in laundry detergent formulation.

Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities.

Science.gov (United States)

Falghoush, Azeza; Beyenal, Haluk; Besser, Thomas E; Omsland, Anders; Call, Douglas R

2017-10-01

Biofilm-associated infections are a clinical challenge, in part because a hydrated matrix protects the bacterial community from antibiotics. Herein, we evaluated how different osmotic compounds (maltodextrin, sucrose, and polyethylene glycol [PEG]) enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities. Established (24-h) test tube biofilms (strain ATCC 17978) were treated with osmotic compounds in the presence or absence of 10× the MIC of different antibiotics (50 μg/ml tobramycin, 20 μg/ml ciprofloxacin, 300 μg/ml chloramphenicol, 30 μg/ml nalidixic acid, or 100 μg/ml erythromycin). Combining antibiotics with hypertonic concentrations of the osmotic compounds for 24 h reduced the number of biofilm bacteria by 5 to 7 log ( P baumannii strains were similarly treated with 400-Da PEG and tobramycin, resulting in a mean 2.7-log reduction in recoverable bacteria compared with tobramycin treatment alone. Multivariate regression models with data from different osmotic compounds and nine antibiotics demonstrated that the benefit from combining hypertonic treatments with antibiotics is a function of antibiotic mass and lipophilicity ( r 2 > 0.82; P baumannii and Escherichia coli K-12. Augmenting topical antibiotic therapies with a low-mass hypertonic treatment may enhance the efficacy of antibiotics against wound biofilms, particularly when using low-mass hydrophilic antibiotics. IMPORTANCE Biofilms form a barrier that protects bacteria from environmental insults, including exposure to antibiotics. We demonstrated that multiple osmotic compounds can enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities, but viscosity is a limiting factor, and the most effective compounds have lower molecular mass. The synergism between osmotic compounds and antibiotics is also dependent on the hydrophobicity and mass of the antibiotics. The statistical models presented herein provide a basis for predicting the optimal combination of

Study of the processes of adsorption of amine-containing surface-active substance on the surface of Aluminum powder

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Antonina Dyuryagina

2012-03-01

Full Text Available Equilibrium characteristics of adsorption on a surface of a pigment depending on concentration factors and temperature of the dispersive environment are defined. Kinetic laws of superficial activity of binary, threefold homogeneous and heterogeneous modeling systems are studied. The estimation of mechanisms of process of adsorption is carried out.

Method of treating the waste liquid of a washing containing a radioactive substance

International Nuclear Information System (INIS)

Sawaguchi, Yusuke; Tsuyuki, Takashi; Kaneko, Masato; Sato, Yasuhiko; Yamaguchi, Takashi.

1975-01-01

Object: To separate waste liquid resulting from washing and which contains a radioactive substance and surface active agent into high purity water and a solid waste substance containing a small quantity of surface active agent. Structure: To waste liquid from a waste liquid tank is added a pH adjusting agent for adjusting the pH to 5.5, and the resultant liquid is sent to an agglomeration reaction tank, in which an inorganic agglomerating agent is added to the waste liquid to cause a major proportion of the radioactive substance and surface active agent to form flocks produced through agglomeration. Then, the waste liquid is sent from the agglomeration reaction tank to a froth separation tank, to which air is supplied through a perforated plate to cause frothing. The over-flowing liquid is de-frothed, and then the insoluble matter is separated as sludge, followed by hydroextraction and drying for solidification. The treated liquid extracted from a froth separation tank is sent to an agglomerating agent recovery tank for separation of the agglomeration agent, and then the residual surface active agent is removed by adsorption in an active carbon adsorption tower, followed by concentration by evaporation in an evaporating can. The concentrated liquid is extracted and then solidified with cement or asphalt. (Kamimura, M.)

Distribution of adeB and NDM-1 genes in multidrug resistant Acinetobacter baumannii isolated from infected wound of patients admitted in a tertiary care hospital in Bangladesh.

Science.gov (United States)

Hasan, M J; Shamsuzzaman, S M

2017-12-01

The adeB gene in Acinetobacter baumannii regulates the bacterial internal drug efflux pump that plays a significant role in drug resistance. The aim of our study was to determine the occurrence of adeB gene in multidrug resistant and New Delhi metallo-beta-lactamase-1 (NDM- 1) gene in imipenem resistant Acinetobacter baumannii isolated from wound swab samples in a tertiary care hospital of Bangladesh. A total of 345 wound swab samples were tested for bacterial pathogens. Acinetobacter baumannii was identified by culture and biochemical tests. Antimicrobial susceptibility pattern was determined by the disc diffusion method according to CLSI standards. Extended spectrum beta-lactamases were screened using the double disc synergy technique. Gene encoding AdeB efflux pump and NDM-1 were detected by Polymerase Chain Reaction (PCR). A total 22 (6.37%) Acinetobacter baumannii were identified from 345 wound swab samples and 20 (91%) of them were multidrug resistant. High resistance rates to some antibiotics were seen namely, cefotaxime (95%), amoxyclavulanic acid (90%) and ceftriaxone (82%). All the identified Acinetobacter baumannii were sensitive to colistin and 82% to imipenem. Two (9%) ESBL producing Acinetobacter baumannii strains were detected. adeB gene was detected in 16 (80%) out of 20 multidrug resistant Acinetobacter baumannii. 4 (18%) of 22 Acinetobacter baumannii were imipenem resistant. NDM-1 gene was detected in 2 (50%) of the imipenem resistant strains of Acinetobacter baumannii. The results of this study provide insight into the role of adeB gene as a potential regulator of drug resistance in Acinetobacter baumanni in Bangladesh. NDM-1 gene also contributes in developing such resistance for Acinetobacter baumannii.

Mushrooms as a source of substances with antiviral activity

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Martyna Kandefer-Szerszeń

2014-08-01

Full Text Available Water extracts the fructifications of 56 species of fungi were examined as a source of antiviral substances with activity against VS and vaccinia viruses. Extracts from 16 fungal species exhibited the antiviral activity. Water extracts from Boletus edulis active against vaccinia virus and extract from Armillariella mellea active against VS virus are particularly worth nothing. Both of them in applied concentrations were not toxic in chick embryo fibroblasts tissue culture.

Acinetobacter baumannii in Localised Cutaneous Mycobacteriosis in Falcons

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Margit Gabriele Muller

2010-01-01

Full Text Available Between May 2007 and April 2009, 29 falcons with identically localized, yellowish discolored cutaneous lesions in the thigh and lateral body wall region were presented at Abu Dhabi Falcon Hospital. Out of 18 falcons integrated in this study, 16 tested positive to Mycobacterium. avium complex. The 2 negative falcons tested positive in the Mycobacterium genus PCR. Moreover, 1 falcon tested positive to M. avium. paratuberculosis in tissue samples by PCR. In all cases, blood and fecal samples tested negative. In the acid-fast stain, all samples showed the for mycobacteriosis typical rods. Moreover, in 13 samples Acinetobacter baumannii was detected by PCR and proven by DNA sequencing. Clinical features included highly elevated WBCs, heterophilia, lymphocytopenia, monocytosis, severe anemia and weight loss. A. baumannii, a gram-negative bacillus with the ability to integrate foreign DNA, has emerged as one of the major multidrug resistant bacteria. In veterinary medicine, it has so far been detected in dogs, cats, horses and wild birds. To the authors' knowledge, this is the first report of an A. baumannii infection in falcons and of a veterinary Mycobacterium-Acinetobacter coinfection.

Place of Colistin-Rifampicin Association in the Treatment of Multidrug-Resistant Acinetobacter Baumannii Meningitis: A Case Study

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Dahraoui Souhail

2016-01-01

Full Text Available Treatment of Acinetobacter baumannii meningitis is an important challenge due to the accumulation of resistance of this bacteria and low meningeal diffusion of several antimicrobial requiring use of an antimicrobial effective combination to eradicate these species. We report a case of Acinetobacter baumannii multidrug-resistant nosocomial meningitis which was successfully treated with intravenous and intrathecal colistin associated with rifampicin.

The success of acinetobacter species; genetic, metabolic and virulence attributes.

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Anton Y Peleg

Full Text Available An understanding of why certain Acinetobacter species are more successful in causing nosocomial infections, transmission and epidemic spread in healthcare institutions compared with other species is lacking. We used genomic, phenotypic and virulence studies to identify differences between Acinetobacter species. Fourteen strains representing nine species were examined. Genomic analysis of six strains showed that the A. baumannii core genome contains many genes important for diverse metabolism and survival in the host. Most of the A. baumannii core genes were also present in one or more of the less clinically successful species. In contrast, when the accessory genome of an individual A. baumannii strain was compared to a strain of a less successful species (A. calcoaceticus RUH2202, many operons with putative virulence function were found to be present only in the A. baumannii strain, including the csu operon, the acinetobactin chromosomal cluster, and bacterial defence mechanisms. Phenotype microarray analysis showed that compared to A. calcoaceticus (RUH2202, A. baumannii ATCC 19606(T was able to utilise nitrogen sources more effectively and was more tolerant to pH, osmotic and antimicrobial stress. Virulence differences were also observed, with A. baumannii ATCC 19606(T, A. pittii SH024, and A. nosocomialis RUH2624 persisting and forming larger biofilms on human skin than A. calcoaceticus. A. baumannii ATCC 19606(T and A. pittii SH024 were also able to survive in a murine thigh infection model, whereas the other two species were eradicated. The current study provides important insights into the elucidation of differences in clinical relevance among Acinetobacter species.

The Success of Acinetobacter Species; Genetic, Metabolic and Virulence Attributes

Science.gov (United States)

Peleg, Anton Y.; de Breij, Anna; Adams, Mark D.; Cerqueira, Gustavo M.; Mocali, Stefano; Galardini, Marco; Nibbering, Peter H.; Earl, Ashlee M.; Ward, Doyle V.; Paterson, David L.; Seifert, Harald; Dijkshoorn, Lenie

2012-01-01

An understanding of why certain Acinetobacter species are more successful in causing nosocomial infections, transmission and epidemic spread in healthcare institutions compared with other species is lacking. We used genomic, phenotypic and virulence studies to identify differences between Acinetobacter species. Fourteen strains representing nine species were examined. Genomic analysis of six strains showed that the A. baumannii core genome contains many genes important for diverse metabolism and survival in the host. Most of the A. baumannii core genes were also present in one or more of the less clinically successful species. In contrast, when the accessory genome of an individual A. baumannii strain was compared to a strain of a less successful species (A. calcoaceticus RUH2202), many operons with putative virulence function were found to be present only in the A. baumannii strain, including the csu operon, the acinetobactin chromosomal cluster, and bacterial defence mechanisms. Phenotype microarray analysis showed that compared to A. calcoaceticus (RUH2202), A. baumannii ATCC 19606T was able to utilise nitrogen sources more effectively and was more tolerant to pH, osmotic and antimicrobial stress. Virulence differences were also observed, with A. baumannii ATCC 19606T, A. pittii SH024, and A. nosocomialis RUH2624 persisting and forming larger biofilms on human skin than A. calcoaceticus. A. baumannii ATCC 19606T and A. pittii SH024 were also able to survive in a murine thigh infection model, whereas the other two species were eradicated. The current study provides important insights into the elucidation of differences in clinical relevance among Acinetobacter species. PMID:23144699

On the possibility of biologically active fenole substances forming during irradiation of vegetable origin products

International Nuclear Information System (INIS)

Koval'skaya, L.P.; Petrash, I.P.; Medvedeva, T.N.; Lezhneva, M.L.; Shchegoleva, G.I.

1974-01-01

The purpose of this study was to find out whether biologically active substances of phenol nature can form upon irradiation of fresh fruits and vegetables with doses of 200-300 Krad, to ascertain the stability of these substances during storage and processing, and to see whether they display cytostatic effects. The results of the study led to modifications and improvements in the methods used to study biologically active substances of phenol nature in fresh fruits irradiated with 200-300 krad. The total amount of phenolic compounds was found to be somewhat increased upon their extraction with cold ethanol. Of the substances detected in extracts from red tomatoes, the contens of chlorogenic acid, caffeic acid, and naranguenine were appreciably increased. Neither chemical methods nor bioassays revealed in irradiated juices and fruits any biologically active substances affecting the living organism. (E.T.)

Effect of Acinetobacter sp on metalaxyl degradation and metabolite profile of potato seedlings (Solanum tuberosum L. alpha variety.

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Fabiola G Zuno-Floriano

Full Text Available One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC-TOF-MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism.

PREVALENCE OF MBL AND ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF ACINETOBACTER ISOLATES FROM A TERTIARY CARE HOSPITAL, ASSAM, INDIA

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Monjuri Kataki

2017-02-01

Full Text Available BACKGROUND Acinetobacter infection have been clinically prominent pathogen in tropical countries have caused recurrent problems during wars and natural disasters and have recently caused multihospital outbreaks. Rational use of antimicrobial agents is clinically important to prevent Acinetobacter infections as well as to avoid poor outcomes. 1 The aim of the study is to see the prevalence of Acinetobacter as a pathogen in this tertiary care hospital, their susceptibility pattern along with prevalence of metallo-beta-lactamase. MATERIALS AND METHODS The samples were processed for a period of one year. Samples were collected from ICU including urine, sputum, endotracheal aspirate, BAL, blood, pus, body fluids (pleural fluid, CSF, etc. and the stool specimens were plated using appropriate culture media (MAC, BA, CLED, XLD. RESULTS Shows Acinetobacter baumannii is the significant species isolated is ICU among 700 cases, which yielded only 100% sensitivity to commonly used antibiotics. So, it is the need of the hour to implement infection control measures in a serious and intensive way. CONCLUSION So, it is the need of the hour to implement infection control measures in a serious and intensive way.

Phenotypic detection of metallo-β-lactamase among the clinical isolates of imipenem resistant Pseudomonas and Acinetobacter in tertiary care hospitals of Dhaka city

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Shaheda Anwar

2010-07-01

Full Text Available The rapid spread of Metallo-b-lactamase (MBL producing Gram negative bacilli represents a matter of great concern worldwide. The study analyzed the occurrence of MBL production in carbapenem resistant Pseudomonas and Acinetobacter isolates over one year period. A total of 132 Pseudomonas and 76 Acinetobacter isolates were obtained from two tertiary care hospitals of Dhaka city. A total of 53 Pseudomonas and 29 Acinetobacter isolates were selected because of their resistance to carbapenem specially imipenem (IPM. Screening for MBL production was performed in these isolates by IPM-EDTA microdilution MIC method. 44 (83% IPM resistant Pseudomonas and 19 (65.5% Acinetobacter isolates were MBL producer by IPM-EDTA microdilution MIC method. These results suggest that MBL producing Pseudomonas and Acinetobacter isolates are emerging in our country and it is essential to screen carbapenem resistant isolates for MBL production. Ibrahim Med. Coll. J. 2010; 4(2: 63-65

Comparison of Disk Diffusion and E-Test Methods for Doripenem Susceptibility of Nosocomial Acinetobacter Baumannii Strains

OpenAIRE

Yesim Cekin

2014-01-01

Aim: Acinetobacter species are amoung the most common two cause of infections isolated from patients of intensive care unit in our hospital. Doripenem which acts by inhibiting cell wall synthesis is resently introduced for use in our country is broad spectrum antibiotic belonging to carbapenems. There are many studies investigating the susceptibility of doripenem of Acinetobacter baumannii which is isolated as a cause of ventilatory associated pneumonia in the literature. We aimed to compare ...

Structural Basis for Toughness and Flexibility in the C-terminal Passenger Domain of an Acinetobacter Trimeric Autotransporter Adhesin*

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Koiwai, Kotaro; Hartmann, Marcus D.; Linke, Dirk; Lupas, Andrei N.; Hori, Katsutoshi

2016-01-01

Trimeric autotransporter adhesins (TAAs) on the cell surface of Gram-negative pathogens mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific high adhesiveness to abiotic material surfaces as well as to biotic surfaces. It consists of a passenger domain secreted by the C-terminal transmembrane anchor domain (TM), and the passenger domain contains an N-terminal head, N-terminal stalk, C-terminal head (Chead), and C-terminal stalk (Cstalk). The Chead-Cstalk-TM fragment, which is conserved in many Acinetobacter TAAs, has by itself the head-stalk-anchor architecture of a complete TAA. Here, we show the crystal structure of the Chead-Cstalk fragment, AtaA_C-terminal passenger domain (CPSD), providing the first view of several conserved TAA domains. The YadA-like head (Ylhead) of the fragment is capped by a unique structure (headCap), composed of three β-hairpins and a connector motif; it also contains a head insert motif (HIM1) before its last inner β-strand. The headCap, Ylhead, and HIM1 integrally form a stable Chead structure. Some of the major domains of the CPSD fragment are inherently flexible and provide bending sites for the fiber between segments whose toughness is ensured by topological chain exchange and hydrophobic core formation inside the trimer. Thus, although adherence assays using in-frame deletion mutants revealed that the characteristic adhesive sites of AtaA reside in its N-terminal part, the flexibility and toughness of the CPSD part provide the resilience that enables the adhesive properties of the full-length fiber across a wide range of conditions. PMID:26698633

Draft Genome Sequence of the Plant Growth–Promoting Rhizobacterium Acinetobacter radioresistens Strain SA188 Isolated from the Desert Plant Indigofera argentea

KAUST Repository

Lafi, Feras Fawzi; Alam, Intikhab; Bisseling, Ton; Geurts, Rene; Bajic, Vladimir B.; Hirt, Heribert; Saad, Maged

2017-01-01

Acinetobacter radioresistens strain SA188 is a plant endophytic bacterium, isolated from root nodules of the desert plants Indigofera spp., collected in Jizan, Saudi Arabia. Here, we report the 3.2-Mb draft genome sequence of strain SA188, highlighting characteristic pathways for plant growth–promoting activity and environmental adaptation.

Draft Genome Sequence of the Plant Growth–Promoting Rhizobacterium Acinetobacter radioresistens Strain SA188 Isolated from the Desert Plant Indigofera argentea

KAUST Repository

Lafi, Feras Fawzi

2017-03-03

Acinetobacter radioresistens strain SA188 is a plant endophytic bacterium, isolated from root nodules of the desert plants Indigofera spp., collected in Jizan, Saudi Arabia. Here, we report the 3.2-Mb draft genome sequence of strain SA188, highlighting characteristic pathways for plant growth–promoting activity and environmental adaptation.

Clonal relatedness and biofilm formation of OXA-23-producing carbapenem resistant Acinetobacter baumannii isolates from hospital environment.

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Aliramezani, Amir; Douraghi, Masoumeh; Hajihasani, Azade; Mohammadzadeh, Mona; Rahbar, Mohammad

2016-10-01

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a serious threat for hospitalized patients and it can survive for long periods in hospital settings, particularly on inanimate surfaces. The environment occupied by these resistant and resilient isolates may act as a reservoir for cross-colonization and outbreaks. Here, we aimed to determine the distribution of CRAB in the hospital environment and to characterize their clonal relatedness, susceptibility profile, carriage of bla OXA genes, and biofilm formation. A total of 1080 samples were collected from various environmental surfaces and equipment of two referral hospitals in Tehran, Iran. The A. baumannii isolates were subjected to gyrB multiplex PCR, antibiotic susceptibility testing, biofilm formation assay, pulsed field gel electrophoresis (PFGE), and multiplex PCR for bla OXA-58 , bla OXA-24 , and bla OXA-23 genes. Eighteen Acinetobacter spp. were isolated; 8 were identified as A. baumannii and 10 as A. lwoffii. Five of A. baumannii isolates were CRAB and exhibited the multidrug-resistant (MDR) phenotype as well. All CRAB isolates produced biofilm, albeit with different levels. Four of CRAB isolates harbored the bla OXA-23 . The CRAB isolates were clustered into 3 distinct pulsotypes (PTs). The CRAB isolates belonging to PT1 were detected in two geographically distinct hospitals whereas those belonging to PT3 were found in two different units of same hospital. This study revealed the presence of clonally related OXA-23-producing CRAB in high risk units of referral hospitals as inter- or intra-hospital dissemination. The distribution of multiresistant A. baumannii on several surfaces and areas may increase the risk of transmission of resistant isolates to vulnerable patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Egyptian Environmental Activities and Regulations for Management of Hazardous Substances and Hazardous Wastes

International Nuclear Information System (INIS)

El Zarka, M.

1999-01-01

A substantial use of hazardous substances is essential to meet the social and economic goals of the community in Egypt. Agrochemicals are being used extensively to increase crop yield. The outdated agrochemicals and their empty containers represent a serious environmental problem. Industrial development in different sectors in Egypt obligates handling of huge amounts of hazardous substances and hazardous wastes. The inappropriate handling of such hazardous substances creates several health and environmental problems. Egypt faces many challenges to control safe handling of such substances and wastes. Several regulations are governing handling of hazardous substances in Egypt. The unified Environmental Law 4 for the year 1994 includes a full chapter on the Management of Hazardous Substances and Hazardous Wastes. National and international activities have been taken to manage hazardous substances and hazardous wastes in an environmental sound manner

Glucose availability enhances lipopolysaccharide production and immunogenicity in the opportunistic pathogen Acinetobacter baumannii.

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Rossi, Elio; Longo, Francesca; Barbagallo, Marialuisa; Peano, Clelia; Consolandi, Clarissa; Pietrelli, Alessandro; Jaillon, Sebastian; Garlanda, Cecilia; Landini, Paolo

2016-01-01

Acinetobacter baumannii can cause sepsis with high mortality rates. We investigated whether glucose sensing might play a role in A. baumannii pathogenesis. We carried out transcriptome analysis and extracellular polysaccharide determination in an A. baumannii clinical isolate grown on complex medium with or without glucose supplementation, and assessed its ability to induce production of inflammatory cytokines in human macrophages. Growth in glucose-supplemented medium strongly enhanced A. baumannii sugar anabolism, resulting in increasing lipopolysaccharide biosynthesis. In addition, glucose induced active shedding of lipopolysaccharide, in turn triggering a strong induction of inflammatory cytokines in human macrophages. Finally, hemolytic activity was strongly enhanced by growth in glucose-supplemented medium. We propose that sensing of exogenous glucose might trigger A. baumannii pathogenesis during sepsis.

Resistência a β-lactâmicos em Acinetobacter spp isolados de efluente hospitalar no sul do Brasil Resistance to β-lactams among Acinetobacter spp isolated from hospital sewage in southern Brazil

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Carolina de Souza Gusatti

2009-04-01

Full Text Available Acinetobacter spp é um importante patógeno causador de infecções nosocomiais que acomete pacientes imunocomprometidos e capaz de adquirir resistência a antimicrobianos com facilidade. Os esgotos hospitalares são importantes disseminadores de genes de resistência a antimicrobianos para a microbiota ambiental. Neste contexto, 30 cepas de Acinetobacter spp provenientes de efluente de um hospital em Porto Alegre, RS, foram analisados quanto ao perfil de susceptibilidade a β-lactamases, quinolonas e aminoglicosídeos através de antibiograma e testes de triagem para metalo beta-lactamases e β-lactamases de espectro estendido. O perfil encontrado revela cepas multi-resistentes e que mecanismos de resistência como a produção de β-lactamases de espectro estendido e bombas de efluxo podem estar presentes nesses isolados.Acinetobacter spp is an important pathogen that is responsible for nosocomial infections affecting immunocompromised patients, and it can easily acquire resistance to antimicrobial agents. Hospital sewage is an important means for disseminating genes for resistance to antimicrobial agents, to the microbiota of the environment. Within this context, 30 strains of Acinetobacter spp from the sewage of a hospital in Porto Alegre, Rio Grande do Sul, were analyzed regarding their profile of susceptibility to β-lactams, quinolones and aminoglycosides, by means of an antibiogram and tests to screen for metallo-β-lactamases and extended-spectrum β-lactamases. The profile obtained revealed the presence of multidrug-resistant strains and showed that resistance mechanisms such as the production of extended-spectrum β-lactamases and efflux pumps may be present in these strains.

Stereochemical insignificance discovered in Acinetobacter baumannii quorum sensing.

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Amanda L Garner

Full Text Available Stereochemistry is a key aspect of molecular recognition for biological systems. As such, receptors and enzymes are often highly stereospecific, only recognizing one stereoisomer of a ligand. Recently, the quorum sensing signaling molecules used by the nosocomial opportunistic pathogen, Acinetobacter baumannii, were identified, and the primary signaling molecule isolated from this species was N-(3-hydroxydodecanoyl-L-homoserine lactone. A plethora of bacterial species have been demonstrated to utilize 3-hydroxy-acylhomoserine lactone autoinducers, and in virtually all cases, the (R-stereoisomer was identified as the natural ligand and exhibited greater autoinducer activity than the corresponding (S-stereoisomer. Using chemical synthesis and biochemical assays, we have uncovered a case of stereochemical insignificance in A. baumannii and provide a unique example where stereochemistry appears nonessential for acylhomoserine lactone-mediated quorum sensing signaling. Based on previously reported phylogenetic studies, we suggest that A. baumannii has evolutionarily adopted this unique, yet promiscuous quorum sensing system to ensure its survival, particularly in the presence of other proteobacteria.

41 CFR 102-75.340 - Where hazardous substance activity has been identified on property proposed for disposal, what...

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2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Where hazardous... Provisions Relating to Hazardous Substance Activity § 102-75.340 Where hazardous substance activity has been... offer to purchase and the conveyance document? Where the existence of hazardous substance activity has...

Infection with Acinetobacter baumannii in an intensive care unit in the Western part of Romania.

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Lăzureanu, Voichița; Poroșnicu, Mirela; Gândac, Ciprian; Moisil, Teodora; Bădițoiu, Luminița; Laza, Ruxandra; Musta, Virgil; Crișan, Alexandru; Marinescu, Adelina-Raluca

2016-03-08

Acinetobacter baumannii is one of the main causes of morbidity and mortality in critical condition patients. The pathogen's ability to survive under a wide range of environment conditions and to persist for long periods of time on areas represents a frequent cause of endemic infection hotbeds especially in the Intensive Care Unit. The objectives of the study are: determining the 5-year incidence of A. baumannii infection in patients admitted in the ICU which needed mechanical ventilation; the analysis of these cases regarding pathological antecedents; processing the data regarding these cases; gradual analysis of the susceptibility/resistance of isolated A. baumannii strains; observing the emergence of A. baumannii infection in patients transferred into the ICU. We have performed an observational retrospective study regarding the incidence of Acinetobacter baumannii infections in the Intensive Care Unit of the Hospital of Infectious Diseases and Pneumophtisiology "Victor Babes" Timisoara, Clinic II Infectious Diseases, during June 2011 - June 2015. We have identified a high prevalence of Acinetobacter baumannii infection, with an average period of 6 days. Bronchial suction was the most common pathological product in the study (90 % of the cases). Resistance to antimicrobials has been determined: the lowest resistance was recorded for ampicillin + sulbactam (81.1 %), and the highest resistance rate was recorded for ceftazidime and imipenem (94.6 % each). When comparing resistance to third generation cephalosporins, the difference was not statistically significant (94.6 % for ceftazidime vs. 86.5 % for cefoperazone, p = 0.117). Within the present study we were able to observe a significantly high resistance of the germ to carbapenems, with a good sensitivity to aminoglycosides, and to colistin. Only one strain of Acinetobacter baumannii was resistant to all classes of tested antibiotics. Generally, carbapenems represented the elective treatment in

Effects of Carbapenem consumption on the prevalence of Acinetobacter infection in intensive care unit patients.

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Ogutlu, Aziz; Guclu, Ertugrul; Karabay, Oguz; Utku, Aylin Calica; Tuna, Nazan; Yahyaoglu, Mehmet

2014-01-09

The consumption of carbapenems has increased worldwide, together with the increase in resistant gram negative bacilli. Subsequently, the prevalence of carbapenem-resistant Acinetobacter infections has increased rapidly and become a significant problem particularly in intensive care unit patients. The aim of the present study was to evaluate the changes in the prevalence of Acinetobacter infection by restricting the consumption of carbapenems in intensive care unit patients. This study was conducted between May 1, 2011 and February 28, 2013. The amount of carbapenem consumption and the number of patients with multi-drug resistant Acinetobacter baumannii (MDRAB) isolates during the study period were retrospectively obtained from the records of the patients, who were hospitalized in the intensive care unit. The study period was divided into two periods named as: Carbapenem non-restricted period (CNRP) and carbapenem-restricted period (CRP). During CNRP, no restrictions were made on the use of carbapenems. During CRP, the use of carbapenems was not allowed if there was an alternative to carbapenems. Primary Endpoint: MDRAB infection after ICU admission. The definition of nosocomial infections related to Acinetobacter spp. was based on the criteria of the Center for Disease Control (CDC). The correlation between the amount of carbapenem consumption and the number of infections with MDRAB strains between the two periods were evaluated. During the study period, a total of 1822 patients' (1053 patients in CNRP and 769 patients in CRP) records were evaluated retrospectively. A total of 10.82 defined daily dose (DDD/100 ICU days) of anti-pseudomonal carbapenem were used in CNRP, and this figure decreased to 6.95 DDD/100 ICU days in CRP. In the 8-month CNRP, 42 (3.98%) MDRAB-related nosocomial infections were detected, and 14 (1.82%) infections were detected in CRP (p = 0.012). The prevalence of MDRAB strains isolated in the CNRP was 2.24-fold higher than the prevalence in

Social Activity, School-Related Activity, and Anti-Substance Use Media Messages on Adolescent Tobacco and Alcohol Use.

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Moon, Sung Seek; Rao, Uma

2011-01-01

In this article, we present the effects of three hypothesized protective factors: social activities, school-related activities, and anti-substance use media messages on adolescent tobacco and alcohol use. Data were drawn from the "Monitoring the Future" (MTF) research project, which was conducted by the Institute for Social Research at the University of Michigan. The sample included 2,551 twelfth-grade students. The results of the structural equation model showed that exposure to media anti-drug messages had an indirect negative effect on tobacco and alcohol use through school-related activity and social activity. The results suggest that comprehensive ecological interventions encompassing media, family, and school can increase on the preventive effects of adolescent's substance use.

Simultaneous Microcystis Algicidal and Microcystin Degrading Capability by a Single Acinetobacter Bacterial Strain.

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Li, Hong; Ai, Hainan; Kang, Li; Sun, Xingfu; He, Qiang

2016-11-01

Measures for removal of toxic harmful algal blooms often cause lysis of algal cells and release of microcystins (MCs). In this study, Acinetobacter sp. CMDB-2 that exhibits distinct algal lysing activity and MCs degradation capability was isolated. The physiological response and morphological characteristics of toxin-producing Microcystis aeruginosa, the dynamics of intra- and extracellular MC-LR concentration were studied in an algal/bacterial cocultured system. The results demonstrated that Acinetobacter sp. CMDB-2 caused thorough decomposition of algal cells and impairment of photosynthesis within 24 h. Enhanced algal lysis and MC-LR release appeared with increasing bacterial density from 1 × 10 3 to 1 × 10 7 cells/mL; however, the MC-LR was reduced by nearly 94% within 14 h irrespective of bacterial density. Measurement of extracellular and intracellular MC-LR revealed that the toxin was decreased by 92% in bacterial cell incubated systems relative to control and bacterial cell-free filtrate systems. The results confirmed that the bacterial metabolite caused 92% lysis of Microcystis aeruginosa cells, whereas the bacterial cells were responsible for approximately 91% reduction of MC-LR. The joint efforts of the bacterium and its metabolite accomplished the sustainable removal of algae and MC-LR. This is the first report of a single bacterial strain that achieves these dual actions.

Not only biocidal products: Washing and cleaning agents and personal care products can act as further sources of biocidal active substances in wastewater.

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Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2018-06-01

The emission sources of biocidal active substances in households have been under discussion since these substances have been detected frequently in municipal wastewater and receiving surface water bodies. Therefore, the goal of this study was to investigate the products responsible for the emission of these substances to wastewater. We analysed the wastewater of two streets for a set of biocidal active substances. Time-proportional sampling was conducted for one week of each season during one year in each street. The 14 substances analysed with liquid chromatography coupled with tandem mass spectrometry were 1,2-benzisothiazol-3(2H)-one (BIT), C 12 -benzalkonium chloride, carbendazim, 5-chloro-2-methyl-2H-isothiazol-3-one (CMIT), dichlorooctylisothiazolinone (DCOIT), N,N-diethyl-meta-toluamide (DEET), diuron, icaridine, 2-octyl-2H-isothiazol-3-one (OIT), piperonyl butoxide (PBO), triclosan, tebuconazole, terbutryn and tetramethrin. Using data available from household product inventories of the two streets, we searched the lists of ingredients for the products possibly being responsible for the emissions. Except for four substances, all substances have been detected in at least 10% of the samples. Highest concentrations were measured for C 12 -benzalkonium chloride with an average concentration in the daily samples of 7.7 μg/L in one of the streets. Next to C 12 -benzalkonium chloride, BIT, DEET and icaridine were detected in all samples in average concentrations above 1 μg/L in at least one street. The results show that washing and cleaning agents were important sources for preservatives such as BIT and OIT, while triclosan was apparently mainly emitted through personal care products. The mosquito repelling substances DEET and icaridine were found throughout the year, with highest emissions in summer and autumn. In conclusion, the results demonstrate that the sources of biocidal active substances in municipal wastewater are complex and that measures for the

In vitro activity of tigecycline and comparators against carbapenem-susceptible and resistant Acinetobacter baumannii clinical isolates in Italy

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Carattoli Alessandra

2008-02-01

Full Text Available Abstract Background In a recent multi-centre Italian survey (2003–2004, conducted in 45 laboratories throughout Italy with the aim of monitoring microorganisms responsible for severe infections and their antibiotic resistance, Acinetobacter baumannii was isolated from various wards of 9 hospitals as one of the most frequent pathogens. One hundred and seven clinically significant strains of A. baumannii isolates were included in this study to determine the in vitro activity of tigecycline and comparator agents. Methods Tests for the susceptibility to antibiotics were performed by the broth microdilution method as recommended by CLSI guidelines. The following antibiotics were tested: aztreonam, piperacillin/tazobactam, ampicillin/sulbactam, ceftazidime, cefepime, imipenem, meropenem tetracycline, doxycycline, tigecycline, gentamicin, amikacin, ciprofloxacin, colistin, and trimethoprim/sulphametoxazole. The PCR assay was used to determine the presence of OXA, VIM, or IMP genes in the carbapenem resistant strains. Results A. baumannii showed widespread resistance to ceftazidime, ciprofloxacin and aztreonam in more than 90% of the strains; resistance to imipenem and meropenem was 50 and 59% respectively, amikacin and gentamicin were both active against about 30% of the strains and colistin about 99%, with only one strain resistant. By comparison with tetracyclines, tigecycline and doxycycline showed a higher activity. In particular, tigecycline showed a MIC90 value of 2 mg/L and our strains displayed a unimodal distribution of susceptibility being indistinctly active against carbapenem-susceptible and resistant strains, these latter possessed OXA-type variant enzymes. Conclusion In conclusion, tigecycline had a good activity against the MDR A. baumannii strains while maintaining the same MIC90 of 2 mg/L against the carbapenem-resistant strains.

Bacillus subtilis from Soybean Food Shows Antimicrobial Activity for Multidrug-Resistant Acinetobacter baumannii by Affecting the adeS Gene.

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Wang, Tieshan; Su, Jianrong

2016-12-28

Exploring novel antibiotics is necessary for multidrug-resistant pathogenic bacteria. Because the probiotics in soybean food have antimicrobial activities, we investigated their effects on multidrug-resistant Acinetobacter baumannii . Nineteen multidrug-resistant A. baumannii strains were clinifcally isolated as an experimental group and 11 multidrug-sensitive strains as controls. The growth rates of all bacteria were determined by using the analysis for xCELLigence Real-Time Cell. The combination of antibiotics showed synergistic effects on the strains in the control group but no effect on the strains in the experimental group. Efflux pump gene adeS was absent in all the strains from the control group, whereas it exists in all the strains from the experimental group. Furthermore, all the strains lost multidrug resistance when an adeS inhibitor was used. One strain of probiotics isolated from soybean food showed high antimicrobial activity for multidrug-resistant A. baumannii . The isolated strain belongs to Bacillus subtilis according to 16S RNA analysis. Furthermore, E. coli showed multidrug resistance when it was transformed with the adeS gene from A. baumannii whereas the resistant bacteria could be inhibited completely by isolated Bacillus subtilis . Thus, probiotics from soybean food provide potential antibiotics against multidrug-resistant pathogenic bacteria.

Dendrimer and an active substance occluded in the dendrimer : a process for the preparation thereof and a process for releasing the active substance

NARCIS (Netherlands)

1998-01-01

The invention relates to a dendrimer composition in which an effective number of the terminal functionalities are provided with blocking agents, and at least one active substance species is occluded in the dendrimer. A blocking agent is a sufficiently sterically sized compound which readily enters

Composition consisting of a dendrimer and an active substance

NARCIS (Netherlands)

1995-01-01

The invention relates to a composition consisting of a dendrimer provided with blocking agents and an active substance occluded in the dendrimer. According to the invention a blocking agent is a compound which is sterically of sufficient size, which readily enters into a chemical bond with the

Acinetobacter baumannii-Infected Vascular Catheters Collected from Horses in an Equine Clinic

OpenAIRE

Vaneechoutte, Mario; Devriese, Luc A.; Dijkshoorn, Lenie; Lamote, Benedicte; Deprez, Piet; Verschraegen, Gerda; Haesebrouck, Freddy

2000-01-01

Acinetobacter baumannii was isolated from tips clipped from seven intravenous jugular catheters collected from horses in the Ghent University equine clinic. They originated from seven different horses. Three of the seven showed evidence of local infection.

Single-step selection of drug resistant Acinetobacter baylyi ADP1 mutants reveals a functional redundancy in the recruitment of multidrug efflux systems.

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Anthony J Brzoska

Full Text Available Members of the genus Acinetobacter have been the focus recent attention due to both their clinical significance and application to molecular biology. The soil commensal bacterium Acinetobacter baylyi ADP1 has been proposed as a model system for molecular and genetic studies, whereas in a clinical environment, Acinetobacter spp. are of increasing importance due to their propensity to cause serious and intractable systemic infections. Clinically, a major factor in the success of Acinetobacter spp. as opportunistic pathogens can be attributed to their ability to rapidly evolve resistance to common antimicrobial compounds. Whole genome sequencing of clinical and environmental Acinetobacter spp. isolates has revealed the presence of numerous multidrug transporters within the core and accessory genomes, suggesting that efflux is an important host defense response in this genus. In this work, we used the drug-susceptible organism A. baylyi ADP1 as a model for studies into the evolution of efflux mediated resistance in genus Acinetobacter, due to the high level of conservation of efflux determinants across four diverse Acinetobacter strains, including clinical isolates. A single exposure of therapeutic concentrations of chloramphenicol to populations of A. baylyi ADP1 cells produced five individual colonies displaying multidrug resistance. The major facilitator superfamily pump craA was upregulated in one mutant strain, whereas the resistance nodulation division pump adeJ was upregulated in the remaining four. Within the adeJ upregulated population, two different levels of adeJ mRNA transcription were observed, suggesting at least three separate mutations were selected after single-step exposure to chloramphenicol. In the craA upregulated strain, a T to G substitution 12 nt upstream of the craA translation initiation codon was observed. Subsequent mRNA stability analyses using this strain revealed that the half-life of mutant craA mRNA was significantly

Homologs of the Acinetobacter baumannii AceI transporter represent a new family of bacterial multidrug efflux systems.

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Hassan, Karl A; Liu, Qi; Henderson, Peter J F; Paulsen, Ian T

2015-02-10

Multidrug efflux systems are a major cause of resistance to antimicrobials in bacteria, including those pathogenic to humans, animals, and plants. These proteins are ubiquitous in these pathogens, and five families of bacterial multidrug efflux systems have been identified to date. By using transcriptomic and biochemical analyses, we recently identified the novel AceI (Acinetobacter chlorhexidine efflux) protein from Acinetobacter baumannii that conferred resistance to the biocide chlorhexidine, via an active efflux mechanism. Proteins homologous to AceI are encoded in the genomes of many other bacterial species and are particularly prominent within proteobacterial lineages. In this study, we expressed 23 homologs of AceI and examined their resistance and/or transport profiles. MIC analyses demonstrated that, like AceI, many of the homologs conferred resistance to chlorhexidine. Many of the AceI homologs conferred resistance to additional biocides, including benzalkonium, dequalinium, proflavine, and acriflavine. We conducted fluorimetric transport assays using the AceI homolog from Vibrio parahaemolyticus and confirmed that resistance to both proflavine and acriflavine was mediated by an active efflux mechanism. These results show that this group of AceI homologs represent a new family of bacterial multidrug efflux pumps, which we have designated the proteobacterial antimicrobial compound efflux (PACE) family of transport proteins. Bacterial multidrug efflux pumps are an important class of resistance determinants that can be found in every bacterial genome sequenced to date. These transport proteins have important protective functions for the bacterial cell but are a significant problem in the clinical setting, since a single efflux system can mediate resistance to many structurally and mechanistically diverse antibiotics and biocides. In this study, we demonstrate that proteins related to the Acinetobacter baumannii AceI transporter are a new class of multidrug

In vitro activities of carbapenems in combination with amikacin, colistin, or fosfomycin against carbapenem-resistant Acinetobacter baumannii clinical isolates.

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Singkham-In, Uthaibhorn; Chatsuwan, Tanittha

2018-01-31

Carbapenem-resistant Acinetobacter baumannii clinical isolates (n=23) were investigated for carbapenem resistance mechanisms and in vitro activities of carbapenems in combination with amikacin, colistin, or fosfomycin. Major carbapenem resistance mechanism was OXA-23 production. The vast majority of these isolates were OXA-23-producing A. baumannii ST195 and ST542, followed by novel STs, ST1417, and ST1423. The interuption of carO by a novel insertion sequence, ISAba40, was found in two isolates. The combinations of imipenem and fosfomycin, meropenem and amikacin, imipenem and amikacin, and imipenem and colistin were synergistic against carbapenem-resistant A. baumannii by 65.2%, 46.2%, 30.8%, and 17.4%, respectively. Surprisingly, the combination of imipenem and fosfomycin was the most effective in this study against A. baumannii, which is intrinsically resistant to fosfomycin. Imipenem and fosfomycin inhibit cell wall synthesis; therefore, fosfomycin may be an adjuvant and enhance the inhibition of cell wall synthesis of carbapenem-resistant A. baumannii when combined with imipenem. Copyright © 2018. Published by Elsevier Inc.

Use of Comparative Genomics To Characterize the Diversity of Acinetobacter baumannii Surveillance Isolates in a Health Care Institution

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Wallace, Lalena; Daugherty, Sean C.; Nagaraj, Sushma; Johnson, J. Kristie; Harris, Anthony D.

2016-01-01

Despite the increasing prevalence of the nosocomial pathogen Acinetobacter baumannii, little is known about which genomic components contribute to clinical presentation of this important pathogen. Most whole-genome comparisons of A. baumannii have focused on specific genomic regions associated with phenotypes in a limited number of genomes. In this work, we describe the results of a whole-genome comparative analysis of 254 surveillance isolates of Acinetobacter species, 203 of which were A. baumannii, isolated from perianal swabs and sputum samples collected as part of an infection control active surveillance program at the University of Maryland Medical Center. The collection of surveillance isolates includes both carbapenem-susceptible and -resistant isolates. Based on the whole-genome phylogeny, the A. baumannii isolates collected belong to two major phylogenomic lineages. Results from multilocus sequence typing indicated that one of the major phylogenetic groups of A. baumannii was comprised solely of strains from the international clonal lineage 2. The genomic content of the A. baumannii isolates was examined using large-scale BLAST score ratio analysis to identify genes that are associated with carbapenem-susceptible and -resistant isolates, as well as genes potentially associated with the source of isolation. This analysis revealed a number of genes that were exclusive or at greater frequency in each of these classifications. This study is the most comprehensive genomic comparison of Acinetobacter isolates from a surveillance study to date and provides important information that will contribute to our understanding of the success of A. baumannii as a human pathogen. PMID:27458211

The lytic transglycosylase MltB connects membrane homeostasis and in vivo fitness of Acinetobacter baumannii.

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Crépin, Sébastien; Ottosen, Elizabeth N; Peters, Katharina; Smith, Sara N; Himpsl, Stephanie D; Vollmer, Waldemar; Mobley, Harry L T

2018-06-08

Acinetobacter baumannii has emerged as a leading nosocomial pathogen, infecting a wide range of anatomic sites including the respiratory tract and the bloodstream. In addition to being multi-drug resistant, little is known about the molecular basis of A. baumannii pathogenesis. To better understand A. baumannii virulence, a combination of a transposon-sequencing (TraDIS) screen and the neutropenic mouse model of bacteremia was used to identify the full set of fitness genes required during bloodstream infection. The lytic transglycosylase MltB was identified as a critical fitness factor. MltB cleaves the MurNAc-GlcNAc bond of peptidoglycan, which leads to cell wall remodeling. Here we show that MltB is part of a complex network connecting resistance to stresses, membrane homeostasis, biogenesis of pili and in vivo fitness. Indeed, inactivation of mltB not only impaired resistance to serum complement, cationic antimicrobial peptides and oxygen species, but also altered the cell envelope integrity, activated the envelope stress response, drastically reduced the number of pili at the cell surface and finally, significantly decreased colonization of both the bloodstream and the respiratory tract. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

The role of the genetic elements bla oxa and IS Aba 1 in the Acinetobacter calcoaceticus-Acinetobacter baumannii complex in carbapenem resistance in the hospital setting.

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Kobs, Vanessa Cristine; Ferreira, Jéssica Augustini; Bobrowicz, Thaís Alexandra; Ferreira, Leslie Ecker; Deglmann, Roseneide Campos; Westphal, Glauco Adrieno; França, Paulo Henrique Condeixa de

2016-01-01

Members of the Acinetobacter genus are key pathogens that cause healthcare-associated infections, and they tend to spread and develop new antibiotic resistance mechanisms. Oxacillinases are primarily responsible for resistance to carbapenem antibiotics. Higher rates of carbapenem hydrolysis might be ascribed to insertion sequences, such as the ISAba1 sequence, near bla OXA genes. The present study examined the occurrence of the genetic elements bla OXA and ISAba1 and their relationship with susceptibility to carbapenems in clinical isolates of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. Isolates identified over 6 consecutive years in a general hospital in Joinville, Southern Brazil, were evaluated. The investigation of 5 families of genes encoding oxacillinases and the ISAba1 sequence location relative to bla OXA genes was conducted using polymerase chain reaction. All isolates presented the bla OXA-51-like gene (n = 78), and 91% tested positive for the bla OXA-23-like gene (n = 71). The presence of ISAba1 was exclusively detected in isolates carrying the bla OXA-23-like gene. All isolates in which ISAba1 was found upstream of the bla OXA-23-like gene (n = 69) showed resistance to carbapenems, whereas the only isolate in which ISAba1 was not located near the bla OXA-23-like gene was susceptible to carbapenems. The ISAba1 sequence position of another bla OXA-23-like-positive isolate was inconclusive. The isolates exclusively carrying the bla OXA-51-like gene (n = 7) showed susceptibility to carbapenems. The presence of the ISAba1 sequence upstream of the bla OXA-23-like gene was strongly associated with carbapenem resistance in isolates of the A. calcoaceticus-A. baumannii complex in the hospital center studied.

Quorum sensing signal profile of Acinetobacter strains from nosocomial and environmental sources Perfil de sensores de quórum en cepas nosocomiales y ambientales de Acinetobacter

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R. H. González

2009-06-01

Full Text Available A set of 43 strains corresponding to 20 classified and unclassified genomic Acinetobacter species was analyzed for the production of typical N-acyl homoserine lactone quorum sensing molecules in culture broths. A large percentage of the strains (74% displayed quorum sensing signals that could be separated into three statistically significantly different chromatographic groups (p Rf2 > Rf1. None of the three signals could be specifically assigned to a particular species in the genus; furthermore, no distinction could be made between the quorum sensing signals secreted by typical opportunistic strains of the A. calcoaceticus-A. baumannii complex, isolated from patients, with respect to the other species of the genus, except for the Rf1 signal which was present in all the QS positive strains belonging to this complex and DNA group 13 TU. In conclusion, quorum sensors in Acinetobacter are not homogenously distributed among species and one of them is present in most of the A. calcoaceticus-baumannii complex.Se analizó la producción de moléculas típicas de N-acil homoserina lactona con actividad de quorum sensing en cultivos líquidos de un grupo de 43 cepas correspondientes a 20 especies genómicas clasificadas y no clasificadas de Acinetobacter. Un porcentaje alto de las cepas (74% mostraron señales de quorum sensing que pudieron ser separadas en tres grupos cromatográficos significativamente diferentes entre sí (p Rf2 > Rf1. Ninguna de las tres señales pudo ser asignada a una especie en particular dentro del género; es más, no se encontró diferencia entre las señales producidas por las cepas típicamente oportunistas (complejo A. calcoaceticus-A. baumannii aisladas de pacientes respecto de las producidas por otras cepas del mismo género, excepto para el caso de Rf1, que se encontró presente en todos los aislamientos quorum sensing positivos del mencionado complejo y en las cepas del grupo de DNA 13TU. En conclusión, los sensores de

Draft Genome Sequence of Acinetobacter johnsonii C6, an Environmental Isolate Engaging in Interspecific Metabolic Interactions

DEFF Research Database (Denmark)

Kaas, Rolf Sommer; Mordhorst, Hanne; Leekitcharoenphon, Pimlapas

2017-01-01

Acinetobacter johnsonii C6 originates from creosote-polluted groundwater and performs ecological and evolutionary interactions with Pseudomonas putida in biofilms. The draft genome of A. johnsonii C6 is 3.7 Mbp and was shaped by mobile genetic elements. It reveals genes facilitating the biodegrad......Acinetobacter johnsonii C6 originates from creosote-polluted groundwater and performs ecological and evolutionary interactions with Pseudomonas putida in biofilms. The draft genome of A. johnsonii C6 is 3.7 Mbp and was shaped by mobile genetic elements. It reveals genes facilitating...

Regulation of the aceI multidrug efflux pump gene in Acinetobacter baumannii.

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Liu, Qi; Hassan, Karl A; Ashwood, Heather E; Gamage, Hasinika K A H; Li, Liping; Mabbutt, Bridget C; Paulsen, Ian T

2018-06-01

To investigate the function of AceR, a putative transcriptional regulator of the chlorhexidine efflux pump gene aceI in Acinetobacter baumannii. Chlorhexidine susceptibility and chlorhexidine induction of aceI gene expression were determined by MIC and quantitative real-time PCR, respectively, in A. baumannii WT and ΔaceR mutant strains. Recombinant AceR was prepared as both a full-length protein and as a truncated protein, AceR (86-299), i.e. AceRt, which has the DNA-binding domain deleted. The binding interaction of the purified AceR protein and its putative operator region was investigated by electrophoretic mobility shift assays and DNase I footprinting assays. The binding of AceRt with its putative ligand chlorhexidine was examined using surface plasmon resonance and tryptophan fluorescence quenching assays. MIC determination assays indicated that the ΔaceI and ΔaceR mutant strains both showed lower resistance to chlorhexidine than the parental strain. Chlorhexidine-induced expression of aceI was abolished in a ΔaceR background. Electrophoretic mobility shift assays and DNase I footprinting assays demonstrated chlorhexidine-stimulated binding of AceR with two sites upstream of the putative aceI promoter. Surface plasmon resonance and tryptophan fluorescence quenching assays suggested that the purified ligand-binding domain of the AceR protein was able to bind with chlorhexidine with high affinity. This study provides strong evidence that AceR is an activator of aceI gene expression when challenged with chlorhexidine. This study is the first characterization, to our knowledge, of a regulator controlling expression of a PACE family multidrug efflux pump.

Infecção cutânea rara por Acinetobacter baumannii em imunocompetente: relato de um caso Rare cutaneous infection by Acinetobacter baumannii in an immunocompetent patient: a case report

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Pablo Vitoriano Cirino

2008-08-01

Full Text Available O Acinetobacter baumanni é patógeno oportunista antigamente considerado de baixa virulência. Atualmente está envolvido em processos infecciosos que acometem pacientes imunocomprometidos,grandes queimados e pacientes em unidades de terapia intensiva que fazem uso de ventilação mecânica. Esse relato de caso chama atenção para infecção cutânea rara por essa bactéria em paciente imunocompetente.Acinetobacter baumannii is an oportunistic pathogen that used to be considered as having low virulence; however, it is currently known to be involved in infectious processes in patients with immunosuppression, large burns and those under mechanical ventilation in intensive care units. This case report emphasizes the possibility of cutaneous infection by A. baumanni in immunocompetent patients.

Characterization of a novel plasmid type and various genetic contexts of bla OXA-58 in Acinetobacter spp. from multiple cities in China.

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Yiqi Fu

Full Text Available BACKGROUND/OBJECTIVE: Several studies have described the epidemiological distribution of blaOXA-58-harboring Acinetobacter baumannii in China. However, there is limited data concerning the replicon types of blaOXA-58-carrying plasmids and the genetic context surrounding blaOXA-58 in Acinetobacter spp. in China. METHODOLOGY/PRINCIPAL FINDINGS: Twelve non-duplicated blaOXA-58-harboring Acinetobacter spp. isolates were collected from six hospitals in five different cities between 2005 and 2010. The molecular epidemiology of the isolates was carried out using PFGE and multilocus sequence typing. Carbapenemase-encoding genes and plasmid replicase genes were identified by PCR. The genetic location of blaOXA-58 was analyzed using S1-nuclease method. Plasmid conjugation and electrotransformation were performed to evaluate the transferability of blaOXA-58-harboring plasmids. The genetic structure surrounding blaOXA-58 was determined by cloning experiments. The twelve isolates included two Acinetobacter pittii isolates (belong to one pulsotype, three Acinetobacter nosocomialis isolates (belong to two pulsotypes and seven Acinetobacter baumannii isolates (belong to two pulsotypes/sequence types. A. baumannii ST91 was found to be a potential multidrug resistant risk clone carrying both blaOXA-58 and blaOXA-23. blaOXA-58 located on plasmids varied from ca. 52 kb to ca. 143 kb. All plasmids can be electrotransformed to A. baumannii recipient, but were untypeable by the current replicon typing scheme. A novel plasmid replicase named repAci10 was identified in blaOXA-58-harboring plasmids of two A. pittii isolates, three A. nosocomialis isolates and two A. baumannii isolates. Four kinds of genetic contexts of blaOXA-58 were identified. The transformants of plasmids with structure of IS6 family insertion sequence (ISOur1, IS1008 or IS15-ΔISAba3-like element-blaOXA-58 displayed carbapenem nonsusceptible, while others with structure of intact ISAba3-like element

Colistin-Resistant Acinetobacter baumannii Clinical Strains with Deficient Biofilm Formation

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Dafopoulou, Konstantina; Xavier, Basil Britto; Hotterbeekx, An; Janssens, Lore; Lammens, Christine; Dé, Emmanuelle; Goossens, Herman; Tsakris, Athanasios; Malhotra-Kumar, Surbhi

2015-01-01

In two pairs of clinical colistin-susceptible/colistin-resistant (Csts/Cstr) Acinetobacter baumannii strains, the Cstr strains showed significantly decreased biofilm formation in static and dynamic assays (P Cstr strain and a frameshift mutation in CarO and the loss of a 47,969-bp element containing multiple genes associated with biofilm production in the other. PMID:26666921

Nimbolide B and Nimbic Acid B, Phytotoxic Substances in Neem Leaves with Allelopathic Activity

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Hisashi Kato-Noguchi

2014-05-01

Full Text Available Neem (Azadirachta indica has been widely used as a traditional medicine and several bioactive compounds have been isolated from this species, but to date no potent allelopathic active substance has been reported. Therefore, we investigated possible allelopathic property and phytotoxic substances with allelopathic activity in neem. An aqueous methanol extract of neem leaves inhibited the growth of roots and shoots of cress, lettuce, alfalfa, timothy, crabgrass, ryegrass, barnyard grass and jungle rice. The extracts were then purified by several chromatographic runs while monitoring the inhibitory activity and two phytotoxic substances were isolated. The chemical structures of the two substances were determined by spectral data to correspond to novel compounds, nimbolide B (1 and nimbic acid B (2. Nimbolide B inhibited the growth of cress and barnyard grass at concentrations greater than 0.1‒3.0 μM. Nimbic acid B inhibited the growth of cress and barnyard grass at concentrations greater than 0.3–1.0 μM. These results suggest that nimbolide B and nimbic acid B may contribute to the allelopathic effects caused by neem leaves.

Effect of Drug Active Substance Particles on Wet Granulation Process.

Czech Academy of Sciences Publication Activity Database

Bělohlav, Z.; Břenková, L.; Hanika, Jiří; Durdil, P.; Rapek, P.; Tomášek, V.

2007-01-01

Roč. 85, A7 (2007) , s. 974-980 ISSN 0263-8762 Institutional research plan: CEZ:AV0Z40720504 Keywords : wet granulation * control * active substance Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.837, year: 2007

Acinetobacter baumannii displays inverse relationship between meropenem resistance and biofilm production.

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Perez, Leandro Reus Rodrigues

2015-02-01

In this study the ability for biofilm production among meropenem (MEM)-resistant and -susceptible Acinetobacter baumannii isolates was verified. MEM susceptibility and biofilm production were screened in 116 isolates. Meropenem-resistant A. baumannii isolates showed a reduced ability to produce biofilms compared to those susceptible to MEM (Pbaumanni isolates.

Antimicrobial activity of the imipenem/rifampicin combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures.

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Wang, Yang; Bao, Wanguo; Guo, Na; Chen, Haiying; Cheng, Wei; Jin, Kunqi; Shen, Fengge; Xu, Jiancheng; Zhang, Qiaoli; Wang, Chao; An, Yanan; Zhang, Kaiyu; Wang, Feng; Yu, Lu

2014-12-01

To investigate the antimicrobial activity of imipenem and rifampicin alone and in combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures. Minimum inhibitory concentrations were determined for each isolate grown in suspension and in biofilm using a microbroth dilution method. Chequerboard assays and the agar disk diffusion assay were used to determine synergistic, indifferent or antagonistic interactions between imipenem and rifampicin. We used the tissue culture plate method for A. baumannii biofilm formation to measure the percentage of biofilm inhibition and the amount of extracellular DNA after the treatment. To understand the synergistic mechanisms, we conducted hydroxyl radical formation assays. The results were verified by confocal laser scanning microscopy. Imipenem and rifampicin showed effective antimicrobial activity against suspensions and biofilm cultures of A. baumannii, respectively. Synergistic antimicrobial effects between imipenem and rifampicin were observed in 13 and 17 of the 20 clinical isolates when in suspension and in biofilms, respectively. Imipenem and rifampicin alone and in combination generated hydroxyl radicals, which are highly reactive oxygen forms and the major components of bactericidal agents. Furthermore, treatment with imipenem and rifampicin individually or in combination has obvious antibiofilm effects. The synergistic activity of imipenem and rifampicin against clinical isolates of A. baumannii (in suspension and in biofilms) was observed in vitro. Therefore, we conclude that imipenem combined with rifampicin has the potential to be used as a combinatorial therapy for the treatment of infectious diseases caused by A. baumannii.

Activity of levofloxacin in combination with colistin against Acinetobacter baumannii: In vitro and in a Galleria mellonella model.

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Wei, Wenjuan; Yang, Haifei; Hu, Lifen; Ye, Ying; Li, Jiabin

2017-12-01

Treatment of Acinetobacter baumannii infections is challenging owing to widespread multidrug-resistant A. baumannii (MDR-AB) and the lack of novel agents. Although recent data suggest that levofloxacin (LVX) may have unique activity against MDR-AB in combination with colistin (CST), further preclinical work is needed. We used a A. baumannii type strain ATCC19606, a CST-resistant strain AB19606R, and two clinical isolates (GN0624 and GN1115) of MDR-AB to investigate the in vitro and in vivo efficacy of LVX-CST combination. Synergy studies were performed using the microtiter plate chequerboard assay and time-kill methodology. Inhibitory activity of antibiotics against biofilms and the mutant prevention concentrations were also studied in vitro. A simple invertebrate model (Galleria mellonella) has been used to assess the in vivo activity of antimicrobial therapies. The LVX-CST combination was bactericidal against the CST-susceptible clinical isolate (GN0624). In checkerboard assays, synergy (defined as a fractional inhibitory concentration index of baumanni. Treatment of G. mellonella larvae infected with lethal doses of A. baumannii resulted in significantly enhanced survival rates when LVX was given with CST compared with CST treatment alone (p < 0.05). In summary, a synergistic or additive effect between CST and LVX was observed in vitro and in vivo against CST-susceptible A. baumannii strains, although not against CST-resistant ones. Copyright © 2015. Published by Elsevier B.V.

Biofilm and metallo beta-lactamase production among the strains of Pseudomonas aeruginosa and Acinetobacter spp. at a Tertiary Care Hospital in Kathmandu, Nepal

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Bandana Baniya

2017-11-01

Full Text Available Abstract Introduction Pseudomonas aeruginosa and Acinetobacter spp. are found to be associated with biofilm and metallo-β-lactamase production and are the common causes of serious infections mainly in hospitalized patients. So, the main aims of this study were to determine the rates of biofilm production and metallo beta-lactamase production (MBL among the strains of Pseudomonas aeruginosa and Acinetobacter spp. isolated from hospitalized patients. Methods A total of 85 P. aeruginosa isolates and 50 Acinetobacter spp. isolates isolated from different clinical specimens from patients admitted to Shree Birendra Hospital, Kathmandu, Nepal from July 2013 to May 2014 were included in this study. The bacterial isolates were identified with the help of biochemical tests. Modified Kirby-Bauer disc diffusion technique was used for antimicrobial susceptibility testing. Combined disc diffusion technique was used for the detection of MBL production, while Congo red agar method and tube adherence method were used for detection of biofilm production. Results Around 16.4% of P. aeruginosa isolates and 22% of the strains of Acinetobacter spp. were metallo β-lactamase producers. Out of 85 P. aeruginosa isolates, 23 (27.05% were biofilm producers according to tube adherence test while, only 13 (15.29% were biofilm producers as per Congo red agar method. Similarly, out of 50 Acinetobacter spp. 7 (14% isolates were biofilm producers on the basis of tube adherence test, while only 5 (10% were positive for biofilm production by Congo red agar method. Highest rates of susceptibility of P. aeruginosa as well as Acinetobacter spp. were seen toward colistin. Conclusion In our study, biofilm production and metallo beta-lactamase production were observed among Pseudomonas aeruginosa and Acinetobacter spp. However, no statistically significant association could be established between biofilm production and metallo beta-lactamase production.

Surface tension of compositions of polyhexametyleneguanidine hydrochloride - surfactants

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S. Kumargaliyeva

2012-12-01

Full Text Available We made up songs bactericidal polyhexamethyleneguanidine hydrochloride (metacyde with the surface-active substances - anionic sodium dodecylsulfate, cationic cetylpyridinium bromide, and nonionic Tween-80 and measured the surface tension of water solutions. The study showed that the composition metacyde with surface-active agents have a greater surface activity than the individual components.

Substance use disorders in Arab countries: research activity and bibliometric analysis

Science.gov (United States)

2014-01-01

Background Substance use disorders, which include substance abuse and substance dependence, are present in all regions of the world including Middle Eastern Arab countries. Bibliometric analysis is an increasingly used tool for research assessment. The main objective of this study was to assess research productivity in the field of substance use disorders in Arab countries using bibliometric indicators. Methodology Original or review research articles authored or co-authored by investigators from Arab countries about substance use disorders during the period 1900 – 2013 were retrieved using the ISI Web of Science database. Research activity was assessed by analyzing the annual research productivity, contribution of each Arab country, names of journals, citations, and types of abused substances. Results Four hundred and thirteen documents in substance use disorders were retrieved. Annual research productivity was low but showed a significant increase in the last few years. In terms of quantity, Kingdom of Saudi Arabia (83 documents) ranked first in research about substance use disorders while Lebanon (17.4 documents per million) ranked first in terms of number of documents published per million inhabitants. Retrieved documents were found in different journal titles and categories, mostly in Drug and Alcohol Dependence Journal. Authors from USA appeared in 117 documents published by investigators from Arab countries. Citation analysis of retrieved documents showed that the average citation per document was 10.76 and the h - index was 35. The majority of retrieved documents were about tobacco and smoking (175 documents) field while alcohol consumption and abuse research was the least with 69 documents. Conclusion The results obtained suggest that research in this field was largely neglected in the past. However, recent research interest was observed. Research output on tobacco and smoking was relatively high compared to other substances of abuse like illicit drugs

Real-Time Fluorescence Loop Mediated Isothermal Amplification for the Detection of Acinetobacter baumannii

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Wang, Qinqin; Zhou, Yanbin; Li, Shaoli; Zhuo, Chao; Xu, Siqi; Huang, Lixia; Yang, Ling; Liao, Kang

2013-01-01

Background Detection of Acinetobacter baumannii has been relying primarily on bacterial culture that often fails to return useful results in time. Although DNA-based assays are more sensitive than bacterial culture in detecting the pathogen, the molecular results are often inconsistent and challenged by doubts on false positives, such as those due to system- and environment-derived contaminations. In addition, these molecular tools require expensive laboratory instruments. Therefore, establishing molecular tools for field use require simpler molecular platforms. The loop-mediated isothermal amplification method is relatively simple and can be improved for better use in a routine clinical bacteriology laboratory. A simple and portable device capable of performing both the amplification and detection (by fluorescence) of LAMP in the same platform has been developed in recent years. This method is referred to as real-time loop-mediated isothermal amplification. In this study, we attempted to utilize this method for rapid detection of A. baumannii. Methodology and Significant Findings Species-specific primers were designed to test the utility of this method. Clinical samples of A. baumannii were used to determine the sensitivity and specificity of this system compared to bacterial culture and a polymerase chain reaction method. All positive samples isolated from sputum were confirmed to be the species of Acinetobacter by 16S rRNA gene sequencing. The RealAmp method was found to be simpler and allowed real-time detection of DNA amplification, and could distinguish A. baumannii from Acinetobacter calcoaceticus and Acinetobacter genomic species 3. DNA was extracted by simple boiling method. Compared to bacterial culture, the sensitivity and specificity of RealAmp in detecting A. baumannii was 98.9% and 75.0%, respectively. Conclusion The RealAmp assay only requires a single unit, and the assay positivity can be verified by visual inspection. Therefore, this assay has

Multidrug-resistant Acinetobacter meningitis in neurosurgical patients with intraventricular catheters: assessment of different treatments.

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Rodríguez Guardado, A; Blanco, A; Asensi, V; Pérez, F; Rial, J C; Pintado, V; Bustillo, E; Lantero, M; Tenza, E; Alvarez, M; Maradona, J A; Cartón, J A

2008-04-01

The treatment of multidrug-resistant Acinetobacter baumannii meningitis is a serious therapeutic problem due to the limited penetration of antibiotics into the CSF. We describe the clinical features and the outcome of a group of patients with nosocomial neurosurgical meningitis treated with different therapeutic options. All patients with nosocomial post-surgical meningitis due to A. baumannii diagnosed between 1990 and 2004 were retrospectively reviewed. During the period of study, 51 cases of this nosocomial infection were identified. Twenty-seven patients were treated with intravenous (iv) monotherapy: carbapenems (21 cases), ampicillin/sulbactam (4 cases) and other antibiotics (2 cases). Four patients were treated with iv combination therapy. Nineteen patients were treated with iv and intrathecal regimens: colistin by both routes (8 cases), carbapenems plus iv and intrathecal (4 cases) or only intrathecal (5 cases) aminoglycosides, and others (2 cases). Seventeen patients died due to the infection. One patient died without treatment. The mean (SD) duration of therapy was 17.4 (8.3) days (range 3-44). Although no patients treated with colistin died, we did not observe statistically significant differences in the mortality among the groups with different treatments. Nosocomial Acinetobacter meningitis has a high mortality. Combined therapy with iv and intrathecal colistin is a useful and safe option in the treatment of nosocomial Acinetobacter meningitis.

Molecular epidemiology of Acinetobacter baumannii in central intensive care unit in Kosova teaching hospital

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Lul Raka

Full Text Available Infections caused by bacteria of genus Acinetobacter pose a significant health care challenge worldwide. Information on molecular epidemiological investigation of outbreaks caused by Acinetobacter species in Kosova is lacking. The present investigation was carried out to enlight molecular epidemiology of Acinetobacterbaumannii in the Central Intensive Care Unit (CICU of a University hospital in Kosova using pulse field gel electrophoresis (PFGE. During March - July 2006, A. baumannii was isolated from 30 patients, of whom 22 were infected and 8 were colonised. Twenty patients had ventilator-associated pneumonia, one patient had meningitis, and two had coinfection with bloodstream infection and surgical site infection. The most common diagnoses upon admission to the ICU were politrauma and cerebral hemorrhage. Bacterial isolates were most frequently recovered from endotracheal aspirate (86.7%. First isolation occurred, on average, on day 8 following admission (range 1-26 days. Genotype analysis of A. baumannii isolates identified nine distinct PFGE patterns, with predominance of PFGE clone E represented by isolates from 9 patients. Eight strains were resistant to carbapenems. The genetic relatedness of Acinetobacter baumannii was high, indicating cross-transmission within the ICU setting. These results emphasize the need for measures to prevent nosocomial transmission of A. baumannii in ICU.

The seasonal variations of allelopathic activity and allelopathic substances in Brachiaria brizantha.

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Kobayashi, Ai; Kato-Noguchi, Hisashi

2015-12-01

Controlling weeds through allelopathy is one strategy to reduce dependency on synthetic herbicides. The plant shoots of the grass Brachiaria brizantha incorporated into the field soil were found to inhibit the growth of several plant species. We investigated the variations of allelopathic activity and allelopathic substances in B. brizantha harvested in June, October and January. All extracts of B. brizantha obtained from June, October and January inhibited the root and shoot growth of cress, lettuce, Phleum pretense and Lolium multiflorum in a concentration dependent manner. However, the inhibitory activity of B. brizantha of June and October was greater than that of B. brizantha of January. Concentrations of three potent allelopathic active substances, (6R,9S)-3-oxo-α-ionol, (6R,9R)-3-oxo-α-ionol and 4-ketopinoresinol were also greater in B. brizantha of June and October than those in B. brizantha of January. The results suggest that the allelopathic activity and the levels of those allelopathic active substances are greater in B. brizantha of June and October than those in B. brizantha of January. It is possible that B. brizantha could be useful for a weed suppressive residue or soil additive materials in the variety of agricultural settings to develop sustainable agriculture options. The effectiveness of B. brizantha of June and October as a weed suppressive agent may be greater than that of January.

Model tests for the efficacy of disinfectants on surfaces. IV. Communication: dependence of test results on the amount of contamination and the kind of active substance.

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Peters, J; Spicher, G

1998-12-01

In the assessment of efficacy of surface disinfectants, many influencing factors have to be taken into account. One essential item is whether the surface to be disinfected is clean or soiled. Among the feasible soilings, the blood is of particular consequences because it ads impediments to many disinfecting agents. This paper shows to what extent the impairment of the efficacy of typical active agents depends on the blood burden of the surfaces. Therefore, test surfaces (varnished plywood) were contaminated with 0.01 to 0.08 ml of coagulating blood per test area (3 cm2). The blood contained cells of Staphylococcus aureus as test germs. The disinfection was effected by immersing the test objects in the disinfecting solution for 5 seconds and mingling the adhering disinfecting solution (about 0.02 ml) with the coagulated blood on the test surface with a glass spatula for about 20 seconds. Subsequently, the test objects remained in a horizontal position at room conditions for 4 hours and then the numbers of surviving test germs were determined. The graphical representation of the results shows that the efficacy curves of formaldehyde and phenol lie very closely together, i.e. their effect is hardly impaired by the different blood burdens of the test areas. The efficacy curves of glutaraldehyde, peracetic acid, chloramine T, and quaternary ammonium compounds lie very far apart from each other. To achieve the same microbicidal effect (log N/N0 = -5) when the contaminating amount is raised from 10 microliters/3 cm2 to 80 microliters/3 cm2, the concentration of chloramine T has to be raised by a factor of 5.4, peracetic acid by a factor of 9, glutaraldehyde by a factor of 24, quaternary ammonium compound even by a factor of 67. Ethanol and sodium hypochlorite showed a divergent behaviour. For ethanol, the efficacy diminution produced by increasing the contamination amount by a factor of 4 can be compensated by raising the concentration from 50% to about 70%. But again and

PREVALENCE OF ACINETOBACTER BAUMANNII ISOLATED FROM CLINICAL SPECIMENS IN ADAM MALIK HOSPITAL

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Evita Mayasari

2014-05-01

Full Text Available AbstrakAcinetobacter baumannii merupakan spesies Acinetobacter spp. tersering diisolasi darimanusia, dan lebih sering dijumpai pada infeksi nosokomial dibandingkan dengan infeksi dikomunitas. Eksistensi bakteri ini di lingkungan terkait dengan keragaman reservoir, kemampuanmemperoleh gen pembawa sifat resisten antimikroba, dan sifat resisten terhadap pengeringan.Infeksi disebabkan strain A.baumannii yang resisten terhadap banyak antibiotik tidak mudahdikendalikan dan menjadi permasalahan di berbagai negara. Penelitian ini bertujuan untukmengetahui prevalensi A.baumannii dari spesimen klinis di instalasi mikrobiologi klinik RSUPHaji Adam Malik serta pola kepekaannya terhadap berbagai antibiotik. Identifikasi dan ujikepekaan menggunakan mesin otomatis Vitek 2 dengan Advanced Expert System (AES.Penelitian ini menemukan 644/3693 (17,44% isolat A.baumannii dari berbagai spesimen klinis.A.baumannii paling banyak diisolasi dari spesimen dahak. Penelitian ini menemukan 147/644(23% bahwa isolat carbapenem-resistent A.baumannii (imipenem dan meropenem. Sebagianbesar isolat sensitif terhadap colistin, amikacin dan tigecycline. Prevalensi A.baumanni yangditemukan pada penelitian ini adalah rendah namun resistensinya tinggi terhadap antibiotikterutama golongan penicillin, cephalosporin dan fluoroquinolon.AbstractAcinetobacter baumannii is the most frequent species of Acinetobacter spp. isolated fromhumans and more common in nosocomial infection than it is in community acquired infection.A.baumannii existence in environment is associated with the diversity of its reservoirs, itscapacity to accumulate genes of antimicrobial resistence, and its resistence to desiccation.Infection of Multidrug resistent (MDR strain of A.baumannii is not easy to manage and it hasbecome a problem in many countries. The aim of this retrospective study was to investigatethe prevalence of A.baumannii from routine clinical specimens sent to clinical microbiologylaboratory RSUP HAM

Extrahuman Epidemiology of Acinetobacter baumannii in Lebanon

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Rafei, Rayane; Hamze, Monzer; Pailhoriès, Hélène; Eveillard, Matthieu; Marsollier, Laurent; Joly-Guillou, Marie-Laure; Dabboussi, Fouad

2015-01-01

The presence of Acinetobacter baumannii outside hospitals is still a controversial issue. The objective of our study was to explore the extrahospital epidemiology of A. baumannii in Lebanon. From February 2012 to October 2013, a total of 73 water samples, 51 soil samples, 37 raw cow milk samples, 50 cow meat samples, 7 raw cheese samples, and 379 animal samples were analyzed by cultural methods for the presence of A. baumannii. Species identification was performed by rpoB gene sequencing. Antibiotic susceptibility was investigated, and the A. baumannii population was studied by two genotyping approaches: multilocus sequence typing (MLST) and blaOXA-51 sequence-based typing (SBT). A. baumannii was detected in 6.9% of water samples, 2.7% of milk samples, 8.0% of meat samples, 14.3% of cheese samples, and 7.7% of animal samples. All isolates showed a susceptible phenotype against most of the antibiotics tested and lacked carbapenemase-encoding genes, except one that harbored a blaOXA-143 gene. MLST analysis revealed the presence of 36 sequence types (STs), among which 24 were novel STs reported for the first time in this study. blaOXA-51 SBT showed the presence of 34 variants, among which 21 were novel and all were isolated from animal origins. Finally, 30 isolates had new partial rpoB sequences and were considered putative new Acinetobacter species. In conclusion, animals can be a potential reservoir for A. baumannii and the dissemination of new emerging carbapenemases. The roles of the novel animal clones identified in community-acquired infections should be investigated. PMID:25616788

Extremophilic Acinetobacter Strains from High-Altitude Lakes in Argentinean Puna: Remarkable UV-B Resistance and Efficient DNA Damage Repair

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Albarracín, Virginia Helena; Pathak, Gopal P.; Douki, Thierry; Cadet, Jean; Borsarelli, Claudio Darío; Gärtner, Wolfgang; Farias, María Eugenia

2012-06-01

High-Altitude Andean Lakes (HAAL) of the South American Andes are almost unexplored ecosystems of shallow lakes. The HAAL are recognized by a remarkably high UV exposure, strong changes in temperature and salinity, and a high content of toxic elements, especially arsenic. Being exposed to remarkably extreme conditions, they have been classified as model systems for the study of life on other planets. Particularly, Acinetobacter strains isolated from the HAAL were studied for their survival competence under strong UV-B irradiation. Clinical isolates, Acinetobacter baumannii and Acinetobacter johnsonii, served as reference material. Whereas the reference strains rapidly lost viability under UV-B irradiation, most HAAL-derived strains readily survived this exposure and showed less change in cell number after the treatment. Controls for DNA repair activity, comparing dark repair (DR) or photo repair (PR), gave evidence for the involvement of photolyases in the DNA repair. Comparative measurements by HPLC-mass spectrometry detected the number of photoproducts: bipyrimidine dimers under both PR and DR treatments were more efficiently repaired in the HAAL strains (up to 85 % PR and 38 % DR) than in the controls (31 % PR and zero DR ability). Analysis of cosmid-cloned total genomic DNA from the most effective DNA-photorepair strain (Ver3) yielded a gene (HQ443199) encoding a protein with clear photolyase signatures belonging to class I CPD-photolyases. Despite the relatively low sequence similarity of 41 % between the enzymes from Ver3 and from E. coli (PDB 1DNPA), a model-building approach revealed a high structural homology to the CPD-photolyase of E. coli.

Characterization of Acinetobacter baumannii biofilm associated components

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Brossard, Kari A.

Acinetobacter baumannii is a Gram-negative aerobic coccobaccillus that is a major cause of nosocomial infections worldwide. Infected individuals may develop pneumonia, urinary tract, wound, and other infections that are associated with the use of indwelling medical devices such as catheters and mechanical ventilation. Treatment is difficult because many A. baumannii isolates have developed multi-drug resistance and the bacterium can persist on abiotic surfaces. Persistence and resistance may be due to formation of biofilms, which leads to long-term colonization, evasion of the host immune system and resistance to treatment with antibiotics and disinfectants. While biofilms are complex multifaceted structures, two bacterial components that have been shown to be important in formation and stability are exopolysaccharides (EPS) and the biofilm-associated protein (Bap). An EPS, poly-beta-1,6-N-acetylglucosamine, PNAG, has been described for E. coli and S. epidermidis. PNAG acts as an intercellular adhesin. Production of this adhesin is dependent on the pga/icaABCD locus. We have identified a homologous locus in A. baumannii 307-0294 that is involved in production of an exopolysaccharide, recognized by an anti-PNAG antibody. We hypothesized that the A. baumannii pgaABCD locus plays a role in biofilm formation, and protection against host innate defenses and disinfectants suggesting that PNAG is a possible virulence factor for the organism. The first aim of this thesis will define the pgaABCD locus. We have previously identified Bap, a protein with similarity to those described for S. aureus and we have demonstrated that this protein is involved in maintaining the stability of biofilms on glass. We hypothesized that A. baumannii Bap plays a role in persistence and pathogenesis and is regulated by quorum sensing. In our second aim we will examine the role of Bap in attachment and biofilm formation on medically relevant surfaces and also determine if Bap is involved in

The role of the genetic elements bla oxa and IS Aba 1 in the Acinetobacter calcoaceticus-Acinetobacter baumannii complex in carbapenem resistance in the hospital setting

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Vanessa Cristine Kobs

Full Text Available Abstract: INTRODUCTION: Members of the Acinetobacter genus are key pathogens that cause healthcare-associated infections, and they tend to spread and develop new antibiotic resistance mechanisms. Oxacillinases are primarily responsible for resistance to carbapenem antibiotics. Higher rates of carbapenem hydrolysis might be ascribed to insertion sequences, such as the ISAba1 sequence, near bla OXA genes. The present study examined the occurrence of the genetic elements bla OXA and ISAba1 and their relationship with susceptibility to carbapenems in clinical isolates of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. METHODS: Isolates identified over 6 consecutive years in a general hospital in Joinville, Southern Brazil, were evaluated. The investigation of 5 families of genes encoding oxacillinases and the ISAba1 sequence location relative to bla OXA genes was conducted using polymerase chain reaction. RESULTS: All isolates presented the bla OXA-51-like gene (n = 78, and 91% tested positive for the bla OXA-23-like gene (n = 71. The presence of ISAba1 was exclusively detected in isolates carrying the bla OXA-23-like gene. All isolates in which ISAba1 was found upstream of the bla OXA-23-like gene (n = 69 showed resistance to carbapenems, whereas the only isolate in which ISAba1 was not located near the bla OXA-23-like gene was susceptible to carbapenems. The ISAba1 sequence position of another bla OXA-23-like-positive isolate was inconclusive. The isolates exclusively carrying the bla OXA-51-like gene (n = 7 showed susceptibility to carbapenems. CONCLUSIONS: The presence of the ISAba1 sequence upstream of the bla OXA-23-like gene was strongly associated with carbapenem resistance in isolates of the A. calcoaceticus-A. baumannii complex in the hospital center studied.

Mechanics of active surfaces

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Salbreux, Guillaume; Jülicher, Frank

2017-09-01

We derive a fully covariant theory of the mechanics of active surfaces. This theory provides a framework for the study of active biological or chemical processes at surfaces, such as the cell cortex, the mechanics of epithelial tissues, or reconstituted active systems on surfaces. We introduce forces and torques acting on a surface, and derive the associated force balance conditions. We show that surfaces with in-plane rotational symmetry can have broken up-down, chiral, or planar-chiral symmetry. We discuss the rate of entropy production in the surface and write linear constitutive relations that satisfy the Onsager relations. We show that the bending modulus, the spontaneous curvature, and the surface tension of a passive surface are renormalized by active terms. Finally, we identify active terms which are not found in a passive theory and discuss examples of shape instabilities that are related to active processes in the surface.

RESISTENCIA A LOS ANTIBIÓTICOS EN CEPAS DE KLEBSIELLA PNEUMONIAE, SERRATIA SPP. Y ACINETOBACTER SPP.AISLADAS DE PACIENTES CON INFECCIÓN DEL TRACTO URINARIO - LIMA, PERU

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Luján Roca DA

2013-01-01

Full Text Available INFECTION - LIMA, PERU Introduction: Urinary tract infection (UTI is one of the most common infections in clinical practice. Gram negative bacteria as Klebsiella pneumoniae, Serratia spp. and Acinetobacter spp. can cause UTI. Objective: To study antibiotic resistance in K. pneumoniae, Serratia spp. and Acinetobacter spp. strains isolated from UTI Material and methods: Urine cultures were collected from January 2003 to December 2003. Identification of isolated bacteria included biochemical characteristics. Bauer-Kirby disc diffusion test was performed. Results: A total of 106 strains were evaluated (41 of K. pneumoniae, 28 of Serratia spp. and 37 of Acinetobacter spp.. Among K. pneumoniae isolates resistance to ampicillin (83% was remarkable. The Serratia spp. isolates displayed a high level of resistance to nalidixic acid (79% and gentamicin (75%. In Acinetobacter spp. isolates high resistance rates were observed against amikacin (81%, gentamicin (67% and trimethoprim/sulfamethoxazole(71%. Conclusions: In general, antibiotic resistance patterns were high. Acinetobacter spp. showed elevated resistance rates (>50% against antibiotics included.

Pesquisa de Acinetobacter sp e Pseudomonas aeruginosa produtores de metalo-β-lactamase em hospital de emergência de Porto Alegre, Estado do Rio Grande do Sul, Brasil Investigation of metallo-β-lactamase-producing Acinetobacter sp and Pseudomonas aeruginosa at an emergency hospital in Porto Alegre, State of Rio Grande do Sul, Brazil

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Vani Dos Santos Laranjeira

2010-08-01

Full Text Available INTRODUÇÃO: O aparecimento de Pseudomonas aeruginosa e Acinetobacter sp produtores de metalo-β-lactamases (MBLs é um desafio para os hospitais. MÉTODOS: Verificou-se a produção de MBL em cepas clínicas de Pseudomonas aeruginosa e Acinetobacter sp de um hospital de emergência de Porto Alegre pelo método de aproximação de disco e E-test MBL. Os genes bla foram pesquisados pela PCR. RESULTADOS: Duas cepas de Pseudomonas aeruginosa e oito Acinetobacter sp demonstraram fenótipo de MBLs. A amplificação do gene blaSPM-1 confirmou a enzima em P. aeruginosa.. CONCLUSÕES: Deve-se ter cautela ao avaliar testes fenotípicos utilizados na detecção rotineira de metalo-enzima.INTRODUCTION: The appearance of metallo-β-lactamase (MBL-producing Pseudomonas aeruginosa and Acinetobacter sp. is a challenge for hospitals. METHODS: The production of MBL in clinical isolates of Pseudomonas aeruginosa and Acinetobacter sp. From an emergency hospital in Porto Alegre was investigated using the disk approximation test and MBL E-test. The bla genes were determined using PCR. RESULTS: Two strains of Pseudomonas aeruginosa and eight of Acinetobacter sp were shown to be MBL phenotypes. Amplification of the blaSPM-1 gene confirmed the presence of the enzyme in P. aeruginosa. CONCLUSIONS: Caution is needed in evaluating phenotype tests used for routine detection of metallo-β-lactamases.

Tn7::In2-8 dispersion in multidrug resistant isolates of Acinetobacter baumannii from Chile Dispersión de Tn7::In2-8 en aislamientos multirresistentes de Acinetobacter baumannii de Chile

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M. S. Ramírez

2010-06-01

Full Text Available Acinetobacter baumannii is considered an important pathogen in our hospital environment having a well-known capacity to acquire different mechanisms of antibiotic resistance. Previous studies in our laboratory had exposed the high dispersion of class 2 integrons in this species. In the present study, we analyzed 7 multiresistant intI2 positive A. baumannii isolates, 6 of which were found to harbour the Tn7::In2-8 element. Our results demonstrate the unusually high distribution of Tn7::In2-8 among different A. baumannii clones from Chile, suggesting a particular behavior of these elements at geographical level.Acinetobacter baumannii, patógeno de importancia clínica en el ámbito hospitalario, es reconocido como un microorganismo que posee la capacidad de evolucionar rápidamente hacia la multirresistencia. Estudios previos efectuados en nuestro laboratorio han demostrado la alta dispersión de los integrones de clase 2 en aislamientos de esta especie. En el presente trabajo se analizaron 7 aislamientos de Acinetobacter baumannii multirresistentes portadores de la integrasa de clase 2, 6 de los cuales portaban el inusual arreglo Tn7::In2-8. Nuestros resultados muestran una elevada frecuencia de dispersión del elemento Tn7::In2-8 en diferentes clones circulantes en Chile, lo que sugiere un comportamiento geográfico particular.

[Biologically active substances of black currant of new varieties].

Science.gov (United States)

Miasishcheva, N V; Artemova, E N

2013-01-01

The assortment of black currant actively replenishes and is constantly updated as a result of successful work of domestic and foreign selectors. New grades of black currant are characterized by the raised content of biologically active substances, including vitamin C, P-active agents, pectin and are of special interest for studying. Fresh berries of seven grades (Azhurnaya, Arapka, Iskushenie, Kreolka, Ladushka, Orel serenade, Ocharovanie) of black currant which were selected by the All-Russian research institute of selection of fruit crops and are perspective for cultivation in the Central Chernozem Region of Russia were chosen as objects for research. The nutritional value of fresh berries was found to vary. Average content of soluble solids was 14.1%, while those below the average were observed in Kreolka (12.1%). The maximum amount of sugars characterized Ladushka grade (11.05%), minimum--Kreolka (9.00%). It has been found that most varieties have fairly high acidity. It is worth noting grade Ladushka, which had the highest sugar-acid index (4.39), with the lowest acidity (2.51%). The highest content of ascorbic acid was found in varieties Orel Serenade--183.7 mg/100 g, the smallest--Ocharovanie--110 mg/100 g, grade Azhurnaya, Kreolka, Ladushka exceeded this indicator average value (144.9 mg/100 g). In terms of the amount of P-active substances stood grades having values above the average (722.2 mg/100 g): Azhurnaya (789.8 mg/100 g), Kreolka (864.5 mg/100 g), Oryol serenade (765.6 mg/100 g). The average content of pectin in the studied berries of black currant was 7.92%, with a minimum of 6.30% was observed in grades Azhurnaya, maximum 9.90%--the kind Oryol serenade. High values of this index were characterized by grade Ladushka, Ocharovanie. Azhurnaya varieties, Creole, Orel serenade had high levels of ascorbic acid and P-active substances. Sort Ladushka marked as a dessert due to the largest sugar-acid ratio. Ladushka, Orel Serenade, Ocharovanie have the

Evaluation of the Removal Efficiency of Per- and Polyfluoroalkyl Substances in Drinking Water using Nanofiltration Membranes, Active Carbon and Anion Exchange

OpenAIRE

Lindegren, Klara

2015-01-01

Per- and polyfluoroalkyl substances (PFASs) is a group of man-made, highly persistent chemicals. Due to the specific surface-active attributes of these molecules, applications are numerous and feed an economically important industry. During the last decade, PFASs have been detected globally in the environment, living organisms and tap water. The combination of toxic properties and high bioaccumulative potential, together with the discovery that conventional water treatment methods do not remo...

Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii

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Kröger, Carsten; Kary, Stefani C.; Schauer, Kristina; Cameron, Andrew D. S.

2016-01-01

Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance. PMID:28036056

Acinetobacter Prosthetic Joint Infection Treated with Debridement and High-Dose Tigecycline.

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Vila, Andrea; Pagella, Hugo; Amadio, Claudio; Leiva, Alejandro

2016-12-01

Prosthesis retention is not recommended for multidrug-resistant Acinetobacter prosthetic joint infection due to its high failure rate. Nevertheless, replacing the prosthesis implies high morbidity and prolonged hospitalization. Although tigecycline is not approved for the treatment of prosthetic joint infection due to multidrug resistant Acinetobacter baumannii, its appropriate use may preclude prosthesis exchange. Since the area under the curve divided by the minimum inhibitory concentration is the best pharmacodynamic predictor of its efficacy, we used tigecycline at high dose, in order to optimize its efficacy and achieve implant retention in 3 patients who refused prosthesis exchange. All patients with prosthetic joint infections treated at our Institution are prospectively registered in a database. Three patients with early prosthetic joint infection of total hip arthroplasty due to multidrug resistant A. baumannii were treated with debridement, antibiotics and implant retention, using a high maintenance dose of tigecycline (100 mg every 12 hours). The cases were retrospectively reviewed. All patients signed informed consent for receiving off-label use of tigecycline. Tigecycline was well tolerated, allowing its administration at high maintenance dose for a median of 40 days (range 30-60). Two patients were then switched to minocycline at standard doses for a median of 3.3 months in order to complete treatment. Currently, none of the patients showed relapse. Increasing the dose of tigecycline could be considered as a means to better attain pharmacodynamic targets in patients with severe or difficult-to-treat infections. Tigecycline at high maintenance dose might be useful when retention of the implant is attempted for treatment for prosthetic joint infections due to multidrug resistant Acinetobacter. Although this approach might be promising, off-label use of tigecycline should be interpreted cautiously until prospective data are available. Tigecycline is

Characterization of rhamnolipids produced by non-pathogenic Acinetobacter and Enterobacter bacteria

Czech Academy of Sciences Publication Activity Database

Hošková, M.; Schreiberová, O.; Ježdík, R.; Chudoba, J.; Masák, M.; Sigler, Karel; Řezanka, Tomáš

2013-01-01

Roč. 130, FEB 2013 (2013), s. 510-516 ISSN 0960-8524 R&D Projects: GA ČR(CZ) GAP503/11/0215 Grant - others:GA MPO(CZ) FR-TI1/456 Institutional support: RVO:61388971 Keywords : Pseudomonas aeruginosa * Acinetobacter calcoaceticus * Enterobacter asburiae Subject RIV: EE - Microbiology, Virology Impact factor: 5.039, year: 2013

Ecology and resistance of Moraxella-Acinetobacter

International Nuclear Information System (INIS)

Gulistani, A.W.

1977-01-01

The diverse microenvironments of foods, changing with processing and preservation, might provide conditions that would enhance the growth of microorganisms which are the principal cause of spoilage, off-odor and unpleasant flavor in foods. Radiation is a potential process which may provide a product with far superior microbial quality for food preservation, by reduction of microbial population; elimination of food-borne pathogens; extension of shelf-life; and reduction of spoilage. The aim of irradiation at low dose level is to eliminate certain microorganisms, especially spoilage types and those of public health significance. But, the radurization dose allows the outgrowth of radioresistant bacteria. Certain strains of Moraxella-Acinetobacter (M-A) groups have been recognized as radioresistant bacteria (Welch and Maxcy, 1975), which may have gone unnoticed by food microbiologists, since these bacteria have not been associated with problems and are present in relatively small numbers. However, irrradiation with radurization doses reduces the number of organisms and brings the M-A group into prominence, which may cause problems in irradiated foods. When M-A isolate No. 4 was grown in PCB and TSB media at 32 0 C and on PCA at ambient temperature and ambient RH, as well as when its resistance was observed in a film of various soiling materials on stainless steel surfaces at ambient temperature and room RH, it was concluded that these bacteria were resistant under various conditions for long periods of time. Other tests in which M-A isolates were observed were salt tolerance, various pH levels, quats, chlorine, antibiotic sensitivity, effects of dyes and hydrogen peroxide

Surface tension of droplets and Tolman lengths of real substances and mixtures from density functional theory

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Rehner, Philipp; Gross, Joachim

2018-04-01

The curvature dependence of interfacial properties has been discussed extensively over the last decades. After Tolman published his work on the effect of droplet size on surface tension, where he introduced the interfacial property now known as Tolman length, several studies were performed with varying results. In recent years, however, some consensus has been reached about the sign and magnitude of the Tolman length of simple model fluids. In this work, we re-examine Tolman's equation and how it relates the Tolman length to the surface tension and we apply non-local classical density functional theory (DFT) based on the perturbed chain statistical associating fluid theory (PC-SAFT) to characterize the curvature dependence of the surface tension of real fluids as well as mixtures. In order to obtain a simple expression for the surface tension, we use a first-order expansion of the Tolman length as a function of droplet radius Rs, as δ(Rs) = δ0 + δ1/Rs, and subsequently expand Tolman's integral equation for the surface tension, whereby a second-order expansion is found to give excellent agreement with the DFT result. The radius-dependence of the surface tension of increasingly non-spherical substances is studied for n-alkanes, up to icosane. The infinite diameter Tolman length is approximately δ0 = -0.38 Å at low temperatures. For more strongly non-spherical substances and for temperatures approaching the critical point, however, the infinite diameter Tolman lengths δ0 turn positive. For mixtures, even if they contain similar molecules, the extrapolated Tolman length behaves strongly non-ideal, implying a qualitative change of the curvature behavior of the surface tension of the mixture.

Molecular Typing of Acinetobacter Baumannii Clinical Strains in Tehran by Pulsed-Field Gel Electrophoresis

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Neda Farahani

2013-03-01

Full Text Available Background & Objective : Currently, Acinetobacter baumannii is an important nosocomial pathogen insofar as its hospital outbreaks have been described from various geographical areas. Since the discrimination of strains within a species is important for delineating nosocomial outbreaks, this study was conducted with the aim of genotyping the A. baumannii clinical strains in Tehran via the pulsed-field gel electrophoresis (PFGE method, which is the most accurate method used for the typing of bacterial species.   Materials & methods: This study was performed on 70 isolates of acinetobacter baumannii isolated from patients from Baqiyatallah, Rasoole Akram, and Milad hospitals in Tehran. Cultural and biochemical methods were used for the identification of the isolates in species level, and then susceptibility tests were carried out on 50 isolates of A. baumannii using the disk diffusion method. The PFGE method was performed on the isolates by Apa I restriction enzyme. Finally, the results of the PFGE were analyzed. Result: Acinetobacter baumannii strains isolated from hospitals in Tehran showed seven different genetic patterns, two of which were sporadic . Also, genotypic profiles were different in each hospital, and different patterns of genetic resistance to common antibiotics were observed. Conclusion: A lthough diversity was observed among the strains of A. baumannii by the PFGE method in Tehran, no epidemic strains were found among them.  

Antimicrobial susceptibility pattern in nosocomial infections caused by Acinetobacter species in Asir Region, Saudi Arabia.

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Abdalla, Nazar M; Osman, Amani A; Haimour, Waleed O; Sarhan, Mohammed A A; Mohammed, Mohammed N; Zyad, Eyhab M; Al-Ghtani, Abdalla M

2013-03-15

This study aimed at evaluating the sensitivity of antibiotics towards nosocomial infections caused by Acinetobacter species. The study took place during the period Dec. 2011- Dec. 2012 at Assir Central Hospital in collaboration with the department of microbiology, college of medicine, King Khalid University, Abha. A prospective study involving 150 patients presented with nosocomial infections due to Acinetobacter species detected by bacteriological tests; direct microscopy, culture in blood agar media, fermentation test in MacConkey media and MIC (minimum inhibitory concentration) for antibiotics sensitivity using Muller Hinton media and Chemical test using API 20. A 150 nosocomial infections in this study showed gram-negative coccobacilli, non motile, glucose-negative fermentor and oxidase negative. All isolates showed 100% sensitivity to: Imipramine, Meropenem, Colistin. From the rest of tested antibiotics the higher resistant ones were; Nitrofurantoin 87% and Cefoxitin 85%. The least resistant antibiotics; Imipenem 3% and Ticarcillin 7%. While variable resistance in the rest of tested antimicrobials. A 47 patients (31.3%) have used antibiotics prior to this study. The high rate of usage occurred in elder patients. The frequency of Acinetobacter calcoaceticus baumannii complex multi-drugs resistance ABCMDR is rising including almost all commonly used antibiotics. Only few antibiotics exert 100% sensitivity towards these bacteria.

Variation in the complex carbohydrate biosynthesis loci of Acinetobacter baumannii genomes.

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Johanna J Kenyon

Full Text Available Extracellular polysaccharides are major immunogenic components of the bacterial cell envelope. However, little is known about their biosynthesis in the genus Acinetobacter, which includes A. baumannii, an important nosocomial pathogen. Whether Acinetobacter sp. produce a capsule or a lipopolysaccharide carrying an O antigen or both is not resolved. To explore these issues, genes involved in the synthesis of complex polysaccharides were located in 10 complete A. baumannii genome sequences, and the function of each of their products was predicted via comparison to enzymes with a known function. The absence of a gene encoding a WaaL ligase, required to link the carbohydrate polymer to the lipid A-core oligosaccharide (lipooligosaccharide forming lipopolysaccharide, suggests that only a capsule is produced. Nine distinct arrangements of a large capsule biosynthesis locus, designated KL1 to KL9, were found in the genomes. Three forms of a second, smaller variable locus, likely to be required for synthesis of the outer core of the lipid A-core moiety, were designated OCL1 to OCL3 and also annotated. Each K locus includes genes for capsule export as well as genes for synthesis of activated sugar precursors, and for glycosyltransfer, glycan modification and oligosaccharide repeat-unit processing. The K loci all include the export genes at one end and genes for synthesis of common sugar precursors at the other, with a highly variable region that includes the remaining genes in between. Five different capsule loci, KL2, KL6, KL7, KL8 and KL9 were detected in multiply antibiotic resistant isolates belonging to global clone 2, and two other loci, KL1 and KL4, in global clone 1. This indicates that this region is being substituted repeatedly in multiply antibiotic resistant isolates from these clones.

Tigecycline use in two cases with multidrug-resistant Acinetobacter baumannii meningitis.

Science.gov (United States)

Tutuncu, E Ediz; Kuscu, Ferit; Gurbuz, Yunus; Ozturk, Baris; Haykir, Asli; Sencan, Irfan

2010-09-01

The treatment of post-surgical meningitis due to multidrug-resistant (MDR) Acinetobacter baumannii is a therapeutic dilemma. The cases of two patients with MDR A. baumannii meningitis secondary to surgical site infections, successfully treated with combination regimens including tigecycline, are presented. Copyright © 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Reward salience and risk aversion underlie differential ACC activity in substance dependence.

Science.gov (United States)

Alexander, William H; Fukunaga, Rena; Finn, Peter; Brown, Joshua W

2015-01-01

The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC), has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs), while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed.

Road surface washing system for decontaminating radioactive substances. Experiment of radioactive decontamination

International Nuclear Information System (INIS)

Endo, Mitsuru; Endo, Mai; Kakizaki, Takao

2015-01-01

The Great East Japan Earthquake that occurred on March 11, 2011 resulted in the explosion of the TEPCO Fukushima 1st Nuclear Power Plant and the global dispersion of a large quantity of radioactive substances. A high radiation dose was particularly recorded in Fukushima prefecture several weeks after the accident, although the level is presently sufficiently low. However, considering that the adverse effects of low but extended exposure to radiation are yet to be negated, there is the urgent need for further decontamination. In our study, we focused on the efficient decontamination of radioactive substances in residential areas, for which we propose a high-pressure water jet system for washing road surfaces. The system differs from conventional systems of its type that were initially designed for use in the immediate environment of the nuclear reactors of the TEPCO Fukushima 1st Nuclear Power Plant. The proposed system consists of multiple washing, transporter, and server robots. The washing robots decontaminate the road surface using high-pressure water jets and are transported between washed and unwashed areas by the transporter robots. The server robots supply the water used for washing and absorb the polluted water together with ground dust. In this paper, we describe the concept of the system and present the results of decontamination experiments. Particular attention is given to the washing robot and its mechanism and control method. The results of the integration of the washing robot in an experimental system confirmed the feasibility of the proposed system. (author)

Cryo-electron tomography analysis of membrane vesicles from Acinetobacter baumannii ATCC19606(T)

NARCIS (Netherlands)

Koning, Roman I.; de Breij, Anna; Oostergetel, Gert T.; Nibbering, Peter H.; Koster, Abraham J.; Dijkshoorn, Lenie

Acinetobacter baumannii is an important nosocomial pathogen responsible for colonization and infection of critically ill patients. Its virulence attributes together with the condition of the host determine the pathogenicity of A. baumannii. These virulence factors may be delivered to host cells by

Towards an explanation for the success of Acinetobacter baumannii in the human host

NARCIS (Netherlands)

Breij, Anastasia (Anna)

2012-01-01

Acinetobacter baumannii is an important nosocomial pathogen responsible for outbreaks of infection worldwide. The studies presented in this thesis aimed to gain further insight into the bacterial and host factors associated with the pathogenesis of A. baumannii to seek an explanation for the

PCR Assay Based on the gyrB Gene for Rapid Identification of Acinetobacter baumannii-calcoaceticus Complex at Specie Level.

Science.gov (United States)

Teixeira, Aline B; Barin, Juliana; Hermes, Djuli M; Barth, Afonso L; Martins, Andreza F

2017-05-01

The genus Acinetobacter sp. comprises more than 50 species, and four are closely related and difficult to be distinguished by either phenotypic or genotypic methods: the Acinetobacter calcoaceticus-baumannii complex (ABC). The correct identification at species level is necessary mainly due to the epidemiological aspects. We evaluated a multiplex PCR for gyrB gene to identify the species of the ABC using the sequencing of the ITS 16S-23S fragment as a gold standard. Isolates identified as Acinetobacter calcoaceticus-baumannii from three hospitals at southern Brazil in 2011 were included in this study. A total of 117 isolates were obtained and 106 (90.6%) were confirmed as A. baumannii, 6 (5.1%) as A. nosocomialis and 4 (3.4%) as A. pittii by PCR for gyrB gene. Only one isolate did not present a product of the PCR for the gyrB gene; this isolate was identified as Acinetobacter genospecie 10 by sequencing of ITS. We also noted that the non-A. baumannii isolates were recovered from respiratory tract (8/72.7%), blood (2/18.2%) and urine (1/9.1%), suggesting that these species can cause serious infection. These findings evidenced that the multiplex PCR of the gyrB is a feasible and simple method to identify isolates of the ABC at the species level. © 2016 Wiley Periodicals, Inc.

Does incentive-elicited nucleus accumbens activation differ by substance of abuse? An examination with adolescents

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Hollis C. Karoly

2015-12-01

Full Text Available Numerous questions surround the nature of reward processing in the developing adolescent brain, particularly in regard to polysubstance use. We therefore sought to examine incentive-elicited brain activation in the context of three common substances of abuse (cannabis, tobacco, and alcohol. Due to the role of the nucleus accumbens (NAcc in incentive processing, we compared activation in this region during anticipation of reward and loss using a monetary incentive delay (MID task. Adolescents (ages 14–18; 66% male were matched on age, gender, and frequency of use of any common substances within six distinct groups: cannabis-only (n = 14, tobacco-only (n = 34, alcohol-only (n = 12, cannabis + tobacco (n = 17, cannabis + tobacco + alcohol (n = 17, and non-using controls (n = 38. All groups showed comparable behavioral performance on the MID task. The tobacco-only group showed decreased bilateral nucleus accumbens (NAcc activation during reward anticipation as compared to the alcohol-only group, the control group, and both polysubstance groups. Interestingly, no differences emerged between the cannabis-only group and any of the other groups. Results from this study suggest that youth who tend toward single-substance tobacco use may possess behavioral and/or neurobiological characteristics that differentiate them from both their substance-using and non-substance-using peers.

The role of the surface environment in healthcare-associated infections.

Science.gov (United States)

Weber, David J; Anderson, Deverick; Rutala, William A

2013-08-01

This article reviews the evidence demonstrating the importance of contamination of hospital surfaces in the transmission of healthcare-associated pathogens and interventions scientifically demonstrated to reduce the levels of microbial contamination and decrease healthcare-associated infections. The contaminated surface environment in hospitals plays an important role in the transmission of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp. (VRE), Clostridium difficile, Acinetobacter spp., and norovirus. Improved surface cleaning and disinfection can reduce transmission of these pathogens. 'No-touch' methods of room disinfection (i.e., devices which produce ultraviolet light or hydrogen peroxide) and 'self-disinfecting' surfaces (e.g., copper) also show promise to decrease contamination and reduce healthcare-associated infections. Hospital surfaces are frequently contaminated with important healthcare-associated pathogens. Contact with the contaminated environment by healthcare personnel is equally as likely as direct contact with a patient to lead to contamination of the healthcare provider's hands or gloves that may result in patient-to-patient transmission of nosocomial pathogens. Admission to a room previously occupied by a patient with MRSA, VRE, Acinetobacter, or C. difficile increases the risk for the subsequent patient admitted to the room to acquire the pathogen. Improved cleaning and disinfection of room surfaces decreases the risk of healthcare-associated infections.

Eradication of multidrug-resistant Acinetobacter baumannii in a female patient with total hip arthroplasty, with debridement and retention: a case report

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Beieler Alison M

2009-02-01

Full Text Available Abstract Introduction Multidrug-resistant Acinetobacter baumannii has become a significant cause of healthcare-associated infections, but few reports have addressed Acinetobacter baumannii infections associated with orthopedic devices. The current recommended treatment for complicated infections due to orthopedic devices, including resistant gram-negative rods, consists of antimicrobial therapy with debridement and removal of implants. Case presentation The patient, a 47-year-old woman, had previously had a prior total hip arthroplasty at 16 years of age for a complex femoral neck fracture, and multiple subsequent revisions. This time, she underwent a fifth revision secondary to pain. Surgery was complicated by hypotension resulting in transfer to the intensive care unit and prolonged respiratory failure. She received peri-operative cefazolin but postoperatively developed surgical wound drainage requiring debridement of a hematoma. Cultures of this grew ampicillin-sensitive Enterococcus and Acinetobacter baumannii (sensitive only to amikacin and imipenem. The patient was started on imipenem. Removal of the total hip arthroplasty was not recommended because of the recent surgical complications, and the patient was eventually discharged home. She was seen weekly for laboratory tests and examinations and, after 4 months of therapy, the imipenem was discontinued. She did well clinically for 7 months before recurrent pain led to removal of the total hip arthroplasty. Intra-operative cultures grew ampicillin-sensitive Enterococcus and coagulase-negative Staphylococcus but no multidrug-resistant Acinetobacter baumannii. The patient received ampicillin for 8 weeks and had not had recurrent infection at the time of writing, 37 months after discontinuing imipenem. Conclusion We describe the successful treatment of an acute infection from multidrug-resistant Acinetobacter baumannii with debridement and retention of the total hip arthroplasty, using

Chitosan as an effective inhibitor of multidrug resistant Acinetobacter baumannii.

Science.gov (United States)

Costa, E M; Silva, S; Vicente, S; Veiga, M; Tavaria, F; Pintado, M M

2017-12-15

Over the last two decades worldwide levels of antibiotic resistance have risen leading to the appearance of multidrug resistant microorganisms. Acinetobacter baumannii is a known skin pathogen which has emerged as a major cause of nosocomial outbreaks due to its capacity to colonize indwelling medical devices and natural antibiotic resistance. With chitosan being an effective antimicrobial agent against antibiotic resistant microorganisms, the aim of this work was to access its potential as an alternative to traditional antimicrobials in the management of A. baumannii growth. What the results showed was that both chitosan MW's tested were active upon A. baumannii's planktonic and sessile growth. For planktonic growth MICs and MBCs were obtained at relatively low concentrations (0.5-2mg/mL) while for sessile growth chitosan proved to be an effective inhibitor of A. baumannii's adhesion and biofilm formation. Considering these results chitosan shows a high potential for control of A. baumannii infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Why do games work? In search of the active substance

NARCIS (Netherlands)

Hofstede, G.J.; Peters, V.; Caluwé, de L.; Martens, D.

2009-01-01

During the ISAGA2007 conference in Nijmegen, The Netherlands, the foundation was laid for a book that tries to find answers to the questions "Why do games work? What is the active substance that makes them do what they do?" Now, one year later, over 20 authors from different fields, from different

Active substance from some blue green algal species used as ...

African Journals Online (AJOL)

The concept of biological control for health maintenance has received widespread attention during the last few years. Therefore, the main objective of this work was to look for active substances that could be used as antimicrobial agents in an efficient and safe manner. To achieve this target, five different extracts (ethyl ...

Activation of non-sensitizing or low-sensitizing fragrance substances into potent sensitizers - prehaptens and prohaptens

DEFF Research Database (Denmark)

Karlberg, Ann-Therese; Börje, Anna; Duus Johansen, Jeanne

2013-01-01

the risk of sensitization. In the present review a series of fragrance substances with well documented abiotic and/or biotic activation are given as indicative and illustrative examples of the general problem. Commonly used fragrance substances, also found in essential oils, autoxidize on contact with air...

Epidemiology of multiple Acinetobacter outbreaks in The Netherlands during the period 1999-2001

NARCIS (Netherlands)

van den Broek, P. J.; Arends, J.; Bernards, A. T.; De Brauwer, E.; Mascini, E. M.; van der Reijden, T. J. K.; Spanjaard, L.; Thewessen, E. A. P. M.; van der Zee, A.; van Zeijl, J. H.; Dijkshoorn, L.

An increase in the number of outbreaks of Acinetobacter infection was notified in The Netherlands during 1999-2001. The present study compared the outbreaks at the species and strain levels, and analysed the epidemiology and control measures at the different locations. For each institute, three

Effect of Extracellular Polymeric Substances on Surface Properties and Attachment Behavior of Acidithiobacillus ferrooxidans

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Qian Li

2016-09-01

Full Text Available Bacterial contact leaching of ores is more effective than non-contact leaching. Adhesion is the first step for leaching bacteria to form a biofilm on a mineral surface. Extracellular polymeric substances (EPS are pivotal for mediating bacterial adhesion to a substratum. In order to clarify the role of EPS, we measured the adhesion forces between chalcopyrite-, sulfur- or FeSO4·7H2O-grown cells of Acidithiobacillus ferrooxidans and chalcopyrite by an atomic force microscope (AFM before and after EPS removal. Surface properties of these cells were assessed by measurements of the contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR and acid-base titration. Bacterial attachment to chalcopyrite was monitored for 140 min. The results indicate that the EPS control the surface properties of the cells. In addition, the surface properties are decisive for adhesion. The adhesion forces and the amounts of attached cells decreased dramatically after removing EPS, which was not dependent on the preculture.

Antibiotic Resistance and Carriage Integron Classes in Clinical Isolates of Acinetobacter Baumannii from Isfahan Hospitals, Iran

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Fahimeh Nourbakhsh

2017-01-01

Full Text Available Background Acinetobacter baumannii is a significant nosocomial pathogen around the world, especially in the intensive care unit that most A. baumannii infections are caused by the outbreak strains. Objectives This study has been performed in Acinetobacter baumannii isolates, aimed to detect integron classes I, II, III and molecular typing of A. baumannii genes. Methods In this Cross-sectional study, Acinetobacter baumannii isolated from 150 patients in Isfahan hospitals then antibiotic resistance pattern was determined by disk diffusion method (Kirby Bauer. The presence of genes coding in antibiotic resistance and integrons class I, II, III were analyzed by using of M-PCR method. The data were analyzed by Chi-square, Fischer’s test and SPSS statistical software version 16. Results Antibiotic resistance pattern for Acinetobacter baumannii show that the high resistance was for ciprofloxacin with frequency of 98.3%, ceftazidime with 89.4%, and tetracycline with frequency of 87.3%. The most sensitive antibiotics were chloramphenicol, and nitrofurantoin with frequency of 3.5% and 3.2% resistance. The detection of dfrA1 (63.7%, sul1 (68.6%, aac (3-IV (54.4%, tet (B (22.4%, tet (A (78.3%, aadA1 (15.4%, CITM (17. %, vim (12.2%, Qnr (17.1%, blaSHV (19.8%, sim (7.8%, Oxa-24-like (13.2%, Oxa-51-like (11.9%, Oxa-58-like (39.4%, Oxa-23-like (12.6%, imp (9.2%, cmlA (19% and cat1 (8.6% were respectively reported too. Also in this study Frequency of integrons class 1, 2, 3 were (100%, (28%, (6.6% respectively. Conclusions High prevalence of integrons among Acinetobater baumannii isolated from Isfahan hospitals indicate the importance role of integron classes in multidrug resistance. Considering the increasing pattern of MDR infections is one of the important issues of treatment which can be effective strategy for curing.

Drug resistance patterns of acinetobacter baumannii in makkah, saudi arabia

International Nuclear Information System (INIS)

Khan, M.A.; Ashshi, A.M.; Mahomed, M.F.

2012-01-01

Background: Acinetobacter baumannii causes infections of respiratory, urinary tract, blood stream and surgical sites. Its clinical significance has increased due to its rapidly developing resistance to major groups of antibiotics used for its treatment. There is limited data available on antimicrobial susceptibility of A. baumannii from Saudi Arabia. Objectives: To determine the patterns of drug resistance of Acinetobacter baumannii and predisposing factors for its acquisition.Subjects and Methods: In this descriptive study, 72 hospitalized patients infected with A baumannii were studied. The clinical and demographic data of the patients were collected using a predesigned questionnaire. Isolation and identification of A.baumannii from all clinical specimens were done using standard microbiological methods. Antibiotic susce ptibility testing was performed by disk diffusion method recommended by Clinical Laboratory Standards Institute. Results: Majority of the isolates (61.1%) were from respiratory tract infections. A.baumannii isolates showed high drug resistance to piperacil lin (93.1%), aztreonam (80.5%), ticarcillin, ampicillin, and tetracycline (76.4%, each) and cefotaxime (75%). Only amikacin showed low rate of resistance compared to other antibiotics (40.3%). About 36% patients had some underlying diseases with diabetes mellitus (11%) being the predominant underlying disease. Conclusions: High antimicrobial resistance to commonly used antibiotics was seen against A.baumannii isolates. Only amikacin was most effective against it. (author)

Prophage induction by ultraviolet light in Acinetobacter calcoaceticus

Energy Technology Data Exchange (ETDEWEB)

Berenstein, D.

1986-09-01

UV-induction of prophage P78 of Acinetobacter calcoaceticus increased with the UV-dose given to the lysogenic strain from the spontaneous induction frequency of about 0.8% to a maximal frequency of 10%. This 10- to 20-fold increase of induction frequency, as measured by the number of infective centres, was accompanied by a 1000-fold increase in the yield of free phage. This effect was probably due to an increase in burst size under the conditions of lysogenic induction. Unusually, the lysogen was more resistant to UV-irradiation than the corresponding non-lysogenic strain.

Prophage Induction by Ultraviolet Light in Acinetobacter calcoaceticus

DEFF Research Database (Denmark)

Berenstein, D.

1986-01-01

UV-induction of prophage P78 of Acinetobacter calcoaceticus increased with the UV-dose given to the lysogenic strain from the spontaneous induction frequency of about 0.8% to a maximal frequency of 10%. This 10- to 20-fold increase of induction frequency, as measured by the number of infective...... centres, was accompanied by a 1000-fold increase in the yield of free phage. This effect was probably due to an increase in burst size under the conditions of lysogenic induction. Unusually, the lysogen was more resistant to UV-irradiation than the corresponding non-lysogenic strain....

A medically relevant capsular polysaccharide in Acinetobacter baumannii is a potential vaccine candidate.

Science.gov (United States)

Yang, Feng-Ling; Lou, Tze-Chi; Kuo, Shu-Chen; Wu, Wan-Ling; Chern, Jeffy; Lee, Yi-Tzu; Chen, Shui-Tsung; Zou, Wei; Lin, Nien-Tsung; Wu, Shih-Hsiung

2017-03-07

Concerns of Acinetobacter baumannii infection have increased due to the emergence of multi-drug resistance. In the present study, we determined the capsular polysaccharide (CPS) structure of A. baumannii SK44, a clinical isolate from Taiwan, to consist of pentasaccharide repeats. We found that CPS-induced antibody provided 55% protection against challenge in an animal model. The CPS-specific antibody reacted with the surface components of about 62% clinical isolates (342/554 strains) from cross-sectional and longitudinal studies by dot-immunoassay. Pulsed-field gel electrophoresis of positive strains showed the antibody covered different clonalites of A. baumannii clinical isolates. Meanwhile, using the CPS antibody as a probe, we found a number of outer membrane proteins bound to the antibody, including OmpA/motB, TonB-dependent receptor, and Omp38, indicating their association with CPS. These results might lead to the use of the capsular polysaccharide as a vaccine to prevent A. baumannii infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ozone oxidation of oestrogenic active substances in wastewater and drinking water.

Science.gov (United States)

Baig, S; Hansmann, G; Paolini, B

2008-01-01

Ozone oxidation is proven to be an effective solution for the degradation of selected oestrogenic active substances detected in secondary wastewaters such as beta-oestradiol, oestrone, oestriol, 17-alpha-ethinyloestradiol, mestranol, daidzeine, beta-sitosterol, bisphenol A, norethisterone, 4-tert-octylphenol and 4-iso-nonylphenol, up to their limit of detection. The matrix-effect of wastewater was investigated performing ozone experiments under batch mode and continuous mode using drinking water and a wastewater issued from a local plant both spiked with the non-detected substances. The results obtained indicate that the wastewater matrix greatly affects the kinetics of ozone reaction with these substances but does not really change the related reactivity scale. The ozone dose corresponding to the full conversion of target EDCs consequently increases as their oxidation takes place competing with reactions of background pollutants represented by the COD and DOC content. However, a usual dose close to 12 mg/L was found sufficient to provide high degradation yields for all substances studied while 35% of COD was removed. This is a contribution to the numerous current works focused on technologies able to improve the quality of water discharged from wastewater treatment plants, both considering conventional parameters and emerging contaminants. IWA Publishing 2008.

Increased activity of digoxin-like substance in low-renin hypertension in acromegaly

Energy Technology Data Exchange (ETDEWEB)

Soszynski, P.; Slowinska-Srzednicka, J.; Zgliczynski, S. (Medical Center for Postgraduate Education, Warsaw (Poland))

1990-01-01

Arterial hypertension is common in acromegaly, but the pathogenesis of this complication remains unknown. To determine the role of an endogenous Na,K pump inhibitor/digoxin-like substance (DLS) in the pathogenesis of hypertension in acromegaly 76 subjects: 28 with acromegaly, 20 with essential hypertension and 28 healthy controls were studied. Serum DLS was measured with the use of radioimmunoassay and bioassay by the inhibition of digoxin-sensitive erythrocyte 86-Rb uptake. In acromegaly, the activity of DLS was significantly increased and plasma renin activity decreased in the hypertensive group, as compared with that of the normotensive group and controls. Moreover, DLS was elevated in the low-renin group of essential hypertension, as compared with that of the normal/high-renin group or controls. The activity of DLS correlated positively with mean arterial pressure and negatively with plasma renin activity, but not with growth hormone levels. In conclusion, an endogenous sodium pump inhibitor/digoxin-like substance may play a role in the pathogenesis of low-renin hypertension in acromegaly.

Increased activity of digoxin-like substance in low-renin hypertension in acromegaly

International Nuclear Information System (INIS)

Soszynski, P.; Slowinska-Srzednicka, J.; Zgliczynski, S.

1990-01-01

Arterial hypertension is common in acromegaly, but the pathogenesis of this complication remains unknown. To determine the role of an endogenous Na,K pump inhibitor/digoxin-like substance (DLS) in the pathogenesis of hypertension in acromegaly 76 subjects: 28 with acromegaly, 20 with essential hypertension and 28 healthy controls were studied. Serum DLS was measured with the use of radioimmunoassay and bioassay by the inhibition of digoxin-sensitive erythrocyte 86-Rb uptake. In acromegaly, the activity of DLS was significantly increased and plasma renin activity decreased in the hypertensive group, as compared with that of the normotensive group and controls. Moreover, DLS was elevated in the low-renin group of essential hypertension, as compared with that of the normal/high-renin group or controls. The activity of DLS correlated positively with mean arterial pressure and negatively with plasma renin activity, but not with growth hormone levels. In conclusion, an endogenous sodium pump inhibitor/digoxin-like substance may play a role in the pathogenesis of low-renin hypertension in acromegaly

Studying the Relationship between the Ability of Biofilm Formation and Antibiotic Resistance in Acinetobacter baumannii Clinical and Environmental Isolates in Tehran, 2015

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Faegheh Teymori

2017-07-01

Full Text Available Abstract Background: Acinetobacters are aerobic gram-negative bacteria which are distributed widespread in soil and water. The bacteria are isolated from cultured skin, mucous membranes, secretions and hospital environment. Acinetobacter baumannii, is a strain that more frequently isolated. Acinetobacter strains are often resistant against antimicrobial agents. Materials and Methods: The method of this study was based on field, observation and test. On August and October 2015, samples were isolated from the soil and water of the Sadeghieh Square river in Tehran, respectively, and were transferred to the laboratory in the ice pack. 50 baumannii samples were isolated by biochemical methods (TSI, SIM, OF and gram test. November 1394, 100 clinical samples were isolated from Imam Khomeini hospital by biochemical method, and in the culture media Mueller Hinton agar plates were transferred to the laboratory. Antibiogram test for 150 baumannii samples was performed. Biofilms formation of Acinetobacter baumannii environmental and clinical samples was investigated by Congo red agar and culture plate methods. Results: In all samples (clinical and soil, most of antibiotic resistance was 92% for imipenem and the resistance of water samples to imipenem was 99.9%. Biofilm formation by Congo red agar in water, soil, and clinical samles was resprctively 44%, 40% and 1%. All isolates were negative biofilm culture plate. Conclusion: Considering Acinetobacter baumannii resistance to antibiotics and the lack of biofilm formation of in clinical and environmental isolates, it was concluded that there wasn’t any relationship between antibiotic resistance and biofilm formation.

Effect of secondary metabolite of Actinidia deliciosa on the biofilm and extra-cellular matrix components of Acinetobacter baumannii.

Science.gov (United States)

Tiwari, Vishvanath; Tiwari, Deepika; Patel, Varsha; Tiwari, Monalisa

2017-09-01

Acinetobacter baumannii, opportunistic nosocomial pathogen, increases gradually in the clinical setup. The high level of resistance mechanisms acquired by these bacteria makes their eradication difficult and biofilm formation is one of them. Biofilm comprises of closely packed bacterial population crowded together by extra-cellular matrix (ECM). ECM contains bacterial secreted polymers such as exopolysaccharides (EPS), proteins and extracellular-DNA (e-DNA) and rarely amyloidogenic proteins. Biofilm offers protection of underlying bacterial population against chemotherapeutic agents and host immune system. Therefore, present efforts are focused to find a novel therapeutic that targets biofilm-associated infections. Plants are used as a natural therapeutic for numerous ailments. In order to find an alternative of the available antibacterial drugs, we have focused on the natural herbal active compounds. In this study, we have extracted active compounds from various medicinal plants and screened its anti-biofilm activity against carbapenem resistant strain of A. baumannii. Results showed that polar extract of kiwi (Actinidia deliciosa) and clove (Syzygium aromaticum) exhibit effective anti-biofilm activity. These two plants were also used for their phytochemical screening and TLC profiling to find out the constituting secondary metabolites. Actinidia deliciosa extract contains an alkaloid (sanquinarine) as well as a flavonoid (hydroxyflavone). Anti-biofilm effect of this extract on the ECM of A. baumannii showed that it reduces EPS, protein and eDNA contents in the ECM. Proteins of ECM have also shown to form amyloid like structure, which was evident from its interaction with the Congo Red. CFU counting after Actinidia deliciosa extract treatment also supported the results. Therefore, it can be concluded that polar extract of A. deliciosa can be used to find suitable alternative therapeutic to control biofilm formation by carbapenem resistant strain of

Acinetobacter Species Infections among Navy and Marine Corps Beneficiaries: 2014 Annual Report

Science.gov (United States)

2015-07-20

microbiology data were used to identify Acinetobacter cases. These isolates were matched to three databases. Microbiology records were matched to...Data Record (SIDR) database to determine exposure associations within the healthcare system. Microbiology records were matched to the Defense...that they could establish a community reservoir. Veterinary nosocomial spread has been described among animals, mainly in veterinary hospital intensive

Acceptability and characteristics of 124 human bioequivalence studies with active substances classified according to the Biopharmaceutic Classification System

Science.gov (United States)

Ramirez, Elena; Laosa, Olga; Guerra, Pedro; Duque, Blanca; Mosquera, Beatriz; Borobia, Alberto M; Lei, Suhua H; Carcas, Antonio J; Frias, Jesus

2010-01-01

AIM The aim of this study was to evaluate the acceptability of 124 bioequivalence (BE) studies with 80 active substances categorized according to the Biopharmaceutics Classification System (BCS) in order to establish if there were different probabilities of proving BE between the different BCS classes. METHODS We evaluated the differences between pharmaceutical products with active substances from different BCS classes in terms of acceptability, number of subjects in the study (n), the point estimates, and intra- and inter-subject coefficients of variation data from BE studies with generic products. RESULTS Out of 124 BE studies 89 (71.77%) were performed with pharmaceutical products containing active substances classified by the BCS. In all BCS classes there were non-bioequivalent pharmaceutical products: 4 out of 26 (15.38%) in class 1, 14 out of 28 (50%) in class 2, 3 out of 22 (13.63%) in class 3 and 1 out of 13 (7.69%) in class 4. When we removed those pharmaceutical products in which intra-subject variability was higher than predicted (2 in class 1 active substances, 9 in class 2 and 2 in class 3) there were still non-BE pharmaceutical products in classes 1, 2 and 3. CONCLUSIONS Comparisons between pharmaceutical products with active substances from the four BCS classes have not allowed us to define differential characteristics of each class in terms of n, inter and intra-subject variability for Cmax or AUC. Despite the usually employed test dissolution methodology proposed as quality control, pharmaceutical products with active substances from the four classes of BCS showed non-BE studies. PMID:21039763

Plant derived substances with anti-cancer activity: from folklore to practice

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Marcelo eFridlender

2015-10-01

Full Text Available Plants have had an essential role in the folklore of ancient cultures. In addition to the use as food and spices, plants have also been utilized as medicines for over 5000 years. It is estimated that 70-95% of the population in developing countries continues to use traditional medicines even today. A new trend, that involved the isolation of plant active compounds begun during the early 19th century. This trend led to the discovery of different active compounds that are derived from plants. In the last decades, more and more new materials derived from plants have been authorized and subscribed as medicines, including those with anti-cancer activity. Cancer is among the leading causes of morbidity and mortality worldwide. The number of new cases is expected to rise by about 70% over the next 2 decades. Thus, there is a real need for new efficient anti-cancer drugs with reduced side effects, and plants are a promising source for such entities. Here we focus on some plant-derived substances exhibiting anti-cancer and chemoprevention activity, their mode of action and bioavailability. These include paclitaxel, curcumin and cannabinoids. In addition, development and use of their synthetic analogs, and those of strigolactones, are discussed. Also discussed are commercial considerations and future prospects for development of plant derived substances with anti-cancer activity.

The Influence of Interfering Substances on the Antimicrobial Activity of Selected Quaternary Ammonium Compounds

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Paula A. Araújo

2013-01-01

Full Text Available Standard cleaning processes may not remove all the soiling typically found in food industry, such as carbohydrates, fats, or proteins. Contaminants have a high impact in disinfection as their presence may reduce the activity of disinfectants. The influence of alginic acid, bovine serum albumin, yeast extract, and humic acids was assessed on the antimicrobial activities of benzalkonium chloride and cetyltrimethyl ammonium bromide against Bacillus cereus vegetative cells and Pseudomonas fluorescens. The bacteria (single and consortium were exposed to surfactants (single and combined in the absence and presence of potential disinfection interfering substances. The antimicrobial effects of the surfactants were assessed based on the bacterial respiratory activity measured by oxygen uptake rate due to glucose oxidation. The tested surfactants were efficient against both bacteria (single and consortium with minimum bactericidal concentrations ranging from 3 to 35 mg·L−1. The strongest effect was caused by humic acids that severely quenched antimicrobial action, increasing the minimum bactericidal concentration of the surfactants on P. fluorescens and the consortium. The inclusion of the other interfering substances resulted in mild interferences in the antibacterial activity. This study clearly demonstrates that humic acids should be considered as an antimicrobial interfering substance in the development of disinfection strategies.

Shared Substance

DEFF Research Database (Denmark)

Gjerlufsen, Tony; Klokmose, Clemens Nylandsted; Eagan, James

2011-01-01

This paper presents a novel middleware for developing flexible interactive multi-surface applications. Using a scenario-based approach, we identify the requirements for this type of applications. We then introduce Substance, a data- oriented framework that decouples functionality from data, and S...

Natural genetic transformation in Acinetobacter sp. BD413 Biofilms: introducing natural genetic transformation as a tool for bioenhancement of biofilm reactors

Energy Technology Data Exchange (ETDEWEB)

Hendrickx, L

2002-07-01

This study focussed on the localization and quantification of natural genetic transformation using neutral and disadvantageous genes in monoculture biofilms to investigate gene transfer and expression of the transferred genes in the absence of a selective advantage. Data obtained by this investigation were regarded as initial steps for evaluating the applicability of adding catabolic traits into the indigenous bacterial community of biofilm reactors by in situ natural genetic transformation. Because Acinetobacter spp. strains are readily found in waste water treatment plants and because Acinetobacter sp. BD413 possesses a high effective level of competence, natural genetic transformation was investigated in monoculture Acinetobacter sp. BD413 biofilms. The genes used for transformation encoded for the green fluorescent protein (GFP) and its variants. Monitoring of transformation events were performed with the use of automated confocal laser scanning microscopy (CLSM) and semi automated digital image processing and analysis. (orig.)

Substance P spinal signaling induces glial activation and nociceptive sensitization after fracture

OpenAIRE

Li, Wen-Wu; Guo, Tian-Zhi; Shi, Xiaoyou; Sun, Yuan; Wei, Tzuping; Clark, David J; Kingery, Wade S

2015-01-01

Tibia fracture in rodents induces substance P (SP)-dependent keratinocyte activation and inflammatory changes in the hindlimb, similar to those seen in complex regional pain syndrome (CRPS). In animal pain models spinal glial cell activation results in nociceptive sensitization. This study tested the hypothesis that limb fracture triggers afferent C-fiber SP release in the dorsal horn, resulting in chronic glia activation and central sensitization. At 4 weeks after tibia fracture and casting ...

Interactions of rice (Oryza sativa L.) and PAH-degrading bacteria (Acinetobacter sp.) on enhanced dissipation of spiked phenanthrene and pyrene in waterlogged soil.

Science.gov (United States)

Gao, Y; Yu, X Z; Wu, S C; Cheung, K C; Tam, N F Y; Qian, P Y; Wong, M H

2006-12-15

The effects of cultivation of rice (Oryza sativa L.) and PAH-degrading bacteria (Acinetobacter sp.) separately, and in combination, on the dissipation of spiked phenanthrene and pyrene (0, 50+50, 100+100, 200+200 mg kg(-1)) in waterlogged soil were studied using pot trials. The population of introduced PAH-degrading bacteria remained at 10(5) CFU g(-1) dry soil after 20 days of treatment with Acinetobacter sp. only, but increased to 10(6) when planted with rice simultaneously. Shoot and root biomass of rice when grown alone was adversely affected by spiked PAHs, but significantly increased by 2-55% and 8-409%, respectively, when inoculated with Acinetobacter sp.. Phenanthrene and pyrene concentrations in roots ranged from 1-27 and 20-98 mg kg(-1), respectively, while their concentrations in shoots were generally lower than 0.2 mg kg(-1). The dissipation of phenanthrene was mainly due to abiotic loss as 70-78% phenanthrene was lost from the control soil at the end of 80 days, while removal of 86-87% phenanthrene had been achieved after 40 days in the treatment co-cultivated with Acinetobacter sp. and rice. Compared with the control where only 6-15% of pyrene was removed from soil, a much higher dissipation of pyrene (43-62%) was attained for the treatments co-cultivated with Acinetobacter sp. and rice at the end of 80 days. The results demonstrated that co-cultivation of rice and PAH-degrading bacteria may have a great potential to accelerate the bioremediation process of PAH-contaminated soil under waterlogged conditions.

Differential Role of the T6SS in Acinetobacter baumannii Virulence

Science.gov (United States)

Foucault-Grunenwald, Marie-Laure; Borges, Vitor; Charpentier, Xavier; Limansky, Adriana S.; Gomes, João Paulo; Viale, Alejandro M.; Salcedo, Suzana P.

2015-01-01

Gram-negative bacteria, such as Acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (MDR) strains. Herein, we compared a type strain (ATCC17978), a non-clinical isolate (DSM30011) and MDR strains of A. baumannii implicated in hospital outbreaks (Ab242, Ab244 and Ab825), revealing distinct patterns of type VI secretion system (T6SS) functionality. The T6SS genomic locus is present and was actively transcribed in all of the above strains. However, only the A. baumannii DSM30011 strain was capable of killing Escherichia coli in a T6SS-dependent manner, unlike the clinical isolates, which failed to display an active T6SS in vitro. In addition, DSM30011 was able to outcompete ATCC17978 as well as Pseudomonas aeruginosa and Klebsiella pneumoniae, bacterial pathogens relevant in mixed nosocomial infections. Finally, we found that the T6SS of DSM30011 is required for host colonization of the model organism Galleria mellonella suggesting that this system could play an important role in A. baumannii virulence in a strain-specific manner. PMID:26401654

Differential Role of the T6SS in Acinetobacter baumannii Virulence.

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Guillermo D Repizo

Full Text Available Gram-negative bacteria, such as Acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (MDR strains. Herein, we compared a type strain (ATCC17978, a non-clinical isolate (DSM30011 and MDR strains of A. baumannii implicated in hospital outbreaks (Ab242, Ab244 and Ab825, revealing distinct patterns of type VI secretion system (T6SS functionality. The T6SS genomic locus is present and was actively transcribed in all of the above strains. However, only the A. baumannii DSM30011 strain was capable of killing Escherichia coli in a T6SS-dependent manner, unlike the clinical isolates, which failed to display an active T6SS in vitro. In addition, DSM30011 was able to outcompete ATCC17978 as well as Pseudomonas aeruginosa and Klebsiella pneumoniae, bacterial pathogens relevant in mixed nosocomial infections. Finally, we found that the T6SS of DSM30011 is required for host colonization of the model organism Galleria mellonella suggesting that this system could play an important role in A. baumannii virulence in a strain-specific manner.

Annual Surveillance Summary: Acinetobacter Species Infections in the Military Health System (MHS), 2016

Science.gov (United States)

2017-06-01

Infection Classifications .................................................................. 7 Section B – Antimicrobial Resistance and Use... Antimicrobial Resistance and Use Regional Multidrug Resistance In 2016, the IR of Acinetobacter species infection was 5.34 infections per 100,000 persons...et al. Antimicrobial - resistant pathogens associated with health-associated infections: annual summary of data reported to the National Healthcare

Active-learning Strategies for Legal Topics and Substance Abuse in a Pharmacy Curriculum.

Science.gov (United States)

Steinhardt, Sarah J; Clark, John E; Kelly, William N; Hill, Angela M

2017-02-25

Objective. To implement active-learning strategies to engage students in learning, applying, and teaching legal and substance abuse topics. Design. Medication Safety course student groups created films on a National Patient Safety Goal (NPSG) using a movie genre and presented them in film festival format. Pharmacogenomics course student groups taught ethical, legal, and social implications (ELSI) topics through presentation of short stories about comic book characters with genetic mutations. Students in the Drugs of Abuse course composed and performed dances depicting the mechanism of action of a drug in an in-class rave dance format. Assessment. Course evaluations revealed student engagement with subject material and enjoyment of the creative applications, critical thinking, and collaborative aspects of the activities. Students performed well on examination questions and graded assignments. Conclusion. These active-learning strategies facilitated students' abilities to learn, apply, and teach material in medication safety, pharmacogenomics, and substance abuse courses.

Acinetobacter baumannii: Evolution of Antimicrobial Resistance—Treatment Options

Science.gov (United States)

Doi, Yohei; Murray, Gerald L.; Peleg, Anton Y.

2015-01-01

The first decade of the 20th century witnessed a surge in the incidence of infections due to several highly antimicrobial-resistant bacteria in hospitals worldwide. Acinetobacter baumannii is one such organism that turned from an occasional respiratory pathogen into a major nosocomial pathogen. An increasing number of A. baumannii genome sequences have broadened our understanding of the genetic makeup of these bacteria and highlighted the extent of horizontal transfer of DNA. Animal models of disease combined with bacterial mutagenesis have provided some valuable insights into mechanisms of A. baumannii pathogenesis. Bacterial factors known to be important for disease include outer membrane porins, surface structures including capsule and lipopolysaccharide, enzymes such as phospholipase D, iron acquisition systems, and regulatory proteins. A. baumannii has a propensity to accumulate resistance to various groups of antimicrobial agents. In particular, carbapenem resistance has become commonplace, accounting for the majority of A. baumannii strains in many hospitals today. Carbapenem-resistant strains are often resistant to all other routinely tested agents. Treatment of carbapenem-resistant A. baumannii infection therefore involves the use of combinations of last resort agents such as colistin and tigecycline, but the efficacy and safety of these approaches are yet to be defined. Antimicrobial-resistant A. baumannii has high potential to spread among ill patients in intensive care units. Early recognition and timely implementation of appropriate infection control measures is crucial in preventing outbreaks. PMID:25643273

Isolation and characterization of Acinetobacter baumannii recovered from Campylobacter selective medium.

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Dinesh M Fernando

2016-11-01

Full Text Available Acinetobacter baumannii, a Gram-negative opportunistic pathogen, is known to cause multidrug resistant infections. This organism has primarily been isolated from clinical environments and its environmental reservoirs remain largely unknown. In the present study, we recovered seven isolates of A. baumannii growing under conditions selective for Campylobacter spp. (microaerophilic at 42 oC and in the presence of antibiotics from dairy cattle manure storage tank or surface water impacted by livestock effluents. Antibiotic susceptibility tests revealed that all of these isolates were less susceptible to at least two different clinically relevant antibiotics, compared to the type strain A. baumannii ATCC17978. Expression of resistance-nodulation-division efflux pumps, an important mechanism of intrinsic resistance in these organisms, was analyzed and adeB was found to be overexpressed in one and adeJ was overexpressed in three isolates. Comparison of these isolates using genomic DNA Macro-Restriction Fragment Pattern Analysis (MRFPA revealed relatively low relatedness among themselves or with some of the clinical isolates from previous studies. This study suggests that A. baumannii isolates are capable of growing under selective conditions for Campylobacter spp. and that this organism can be present in manure and water.

Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

International Nuclear Information System (INIS)

Patters, M.R.; Landsberg, R.L.; Johansson, L.-A.; Trummel, C.L.; Robertson, P.R.

1982-01-01

Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated 45 Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis. (author)

Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

Energy Technology Data Exchange (ETDEWEB)

Patters, M R; Landsberg, R L; Johansson, L A; Trummel, C L; Robertson, P R [Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.

1982-01-01

Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

Exercise and Physical Activity in the Therapy of Substance Use Disorders

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Elisabeth Zschucke

2012-01-01

Full Text Available Exercise and physical activity are constantly gaining attention as adjuvant treatment for substance use disorders, supplementing classical pharmacological and psychotherapeutic approaches. The present work reviews studies addressing the therapeutic effects of exercise in alcohol abuse/dependence, nicotine abuse/dependence, and illicit drug abuse/dependence. In the field of smoking cessation, evidence is strong for exercise as an effective adjuvant treatment, whereas no generalizable and methodologically strong studies have been published for alcohol and drug treatment so far, allowing only preliminary conclusions about the effectiveness of exercise in these disorders. A couple of potential mechanisms are discussed, by which exercise may act as an effective treatment, as well as future directions for studies investigating exercise as a treatment strategy for substance use disorders.

Facial ulcerations due to Acinetobacter baumannii: Vessel thrombosis with bacterial mycelia

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Dong Ming Li

2014-01-01

Full Text Available A 14-year-old girl presented with a 2-week history of progressive facial ulcerations that did not respond to cephalexin and topical dexamethasone. Biopsy on the ulcer showed rod-shaped bacteria and actinomycetes-like mycelia in the vessel walls and within thrombi. Tissue culture yielded Acinetobacter baumannii, which was resistant to cephalexin. A favourite outcome was achieved with minocycline treatment. This is the first case report of A. baumannii-related vasculitis.

Substance Use, Dental Hygiene, and Physical Activity in Adult Patients with Single Ventricle Physiology

DEFF Research Database (Denmark)

Schrader, Anne-Marie Voss

2013-01-01

% are not flossing their teeth (32% in controls; OR = 1.32; P = 0.239); and 39% are not physically active (24% in controls; OR = 1.63; P = 0.069). CONCLUSIONS: While in general there was no significant differences in overall health behaviors between SVP patients and controls, SVP patients are less physically active......Substance Use, Dental Hygiene, and Physical Activity in Adult Patients with Single Ventricle Physiology. Overgaard D, Schrader AM, Lisby KH, King C, Christensen RF, Jensen HF, Moons P. Author information OBJECTIVES: The study aims to describe substance use, dental hygiene, and physical activity...... in adult survivors with single ventricle physiology (SVP) and to compare the behaviors with matched controls, while the patients are particularly at risk for general health problems. DESIGN: The present study is part of a larger research project on long-term outcomes in adult patients with SVP. A cross...

Plant growth-promoting bacterium Acinetobacter calcoaceticus P23 increases the chlorophyll content of the monocot Lemna minor (duckweed) and the dicot Lactuca sativa (lettuce).

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Suzuki, Wakako; Sugawara, Masayuki; Miwa, Kyoko; Morikawa, Masaaki

2014-07-01

Acinetobacter calcoaceticus P23 is a plant growth-promoting bacterium that was isolated from the surface of duckweed (Lemna aoukikusa). The bacterium was observed to colonize on the plant surfaces and increase the chlorophyll content of not only the monocotyledon Lemna minor but also the dicotyledon Lactuca sativa in a hydroponic culture. This effect on the Lactuca sativa was significant in nutrient-poor (×1/100 dilution of H2 medium) and not nutrient-rich (×1 or ×1/10 dilutions of H2 medium) conditions. Strain P23 has the potential to play a part in the future development of fertilizers and energy-saving hydroponic agricultural technologies. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Ecotoxicological hazard and risk assessment of endocrine active substances.

Science.gov (United States)

Leopold, Annegaaike; Roberts, Mike; Matthiessen, Peter

2017-03-01

This collection of papers provides state-of-the-art science on a complex topic that has been challenging for scientists and regulators for a long time. The papers emanated from the Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop ® Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA). Forty-eight international experts met in early February 2016 to discuss whether the environmental risks posed by endocrine-disrupting substances (EDS) can be reliably assessed. The primary conclusion of the workshop was that if data on environmental exposure, effects on sensitive species and life-stages, delayed effects, and effects at low concentrations are robust, initiating environmental risk assessment of EDS is scientifically sound and reliable. Integr Environ Assess Manag 2017;13:264-266. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Neutron activation analysis of high purity substances

International Nuclear Information System (INIS)

Gil'bert, Eh.N.

1987-01-01

Peculiarities of neutron-activation analysis (NAA) of high purity substances are considered. Simultaneous determination of a wide series of elements, high sensitivity (the lower bound of determined contents 10 -9 -10 -10 %), high selectivity and accuracy (Sr=0.10-0.15, and may be decreased up to 0.001), possibility of analysis of the samples from several micrograms to hundreds of grams, simplicity of calibration may be thought NAA advantages. Questions of accounting of NAA systematic errors associated with the neutron flux screening by the analysed matrix and with production of radionuclides of determined elements from accompanying elements according to concurrent nuclear reactions, as well as accounting of errors due to self-absorption of recorded radiation by compact samples, are considered

Hazardous substances in the aquatic environment of Estonia.

Science.gov (United States)

Roots, Ott; Roose, Antti

2013-09-01

The Water Framework Directive (WFD) aims to regulate the management of European surface water bodies. Directive 2008/105/EC, which establishes the environmental quality standards of priority substances and certain other pollutants, the content of which in the surface water should be monitored, has been transposed by the Estonian Ministry of Environment 9 September 2010 Regulation No. 49. Sampled hazardous substances were selected primarily based on their toxicity, as well as their lifetime in environment and ability to accumulate in living organisms (bioaccumulation). The contents of hazardous substances and their groups determined from Estonian surface waters remained below the limits of quantifications of used analysis methods in most cases. However, the content of some heavy metals, mono- and dibasic phenols in the surface water/waste water and sewage sludge/bottom sediments can still reach the delicate levels in the Estonian oil shale region in particular. Among new substances analysed in Estonia historically first time in 2010, amounts of organotin compounds in sediments and some alkylphenols, their ethoxylates and phthalates were found in various sample matrices. Copyright © 2013 Elsevier Ltd. All rights reserved.

Perfluoroalkyl and polyfluoroalkyl substances in the lower atmosphere and surface waters of the Chinese Bohai Sea, Yellow Sea, and Yangtze River estuary.

Science.gov (United States)

Zhao, Zhen; Tang, Jianhui; Mi, Lijie; Tian, Chongguo; Zhong, Guangcai; Zhang, Gan; Wang, Shaorui; Li, Qilu; Ebinghaus, Ralf; Xie, Zhiyong; Sun, Hongwen

2017-12-01

Polyfluoroalkyl and perfluoroalkyl substances (PFASs), in the forms of neutral polyfluoroalkyl substances in the gas phase of air and ionic perfluoroalkyl substances in the dissolved phase of surface water, were investigated during a sampling campaign in the Bohai Sea, Yellow Sea, and Yangtze River estuary in May 2012. In the gas phase, the concentrations of neutral ∑PFASs were within the range of 76-551pg/m 3 . Higher concentrations were observed in the South Yellow Sea. 8:2 fluorotelomer alcohol (FTOH) was the predominant compound as it accounted for 92%-95% of neutral ∑PFASs in all air samples. Air mass backward trajectory analysis indicated that neutral ∑PFASs came mainly from the coast of the Yellow Sea, including the Shandong, Jiangsu, and Zhejiang provinces of China, and the coastal region of South Korea. The fluxes of gas phase dry deposition were simulated for neutral PFASs, and neutral ∑PFASs fluxes varied from 0.37 to 2.3pg/m 2 /s. In the dissolved phase of the surface water, concentrations of ionic ∑PFASs ranged from 1.6 to 118ng/L, with the Bohai Sea exhibiting higher concentrations than both the Yellow Sea and the Yangtze River estuary. Perfluorooctanoic acid (PFOA) was the predominant compound accounting for 51%-90% of the ionic ∑PFAS concentrations. Releases from industrial and domestic activities as well as the semiclosed geographical conditions increased the level of ionic ∑PFASs in the Bohai Sea. The spatial distributions of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) were different significantly. The Laizhou Bay was the major source region of PFCAs and the Yangtze River estuary was the major source of PFSAs. Copyright © 2017 Elsevier B.V. All rights reserved.

Wetted surface area of recreational boats

NARCIS (Netherlands)

Bakker J; van Vlaardingen PLA; ICH; VSP

2018-01-01

The wetted surface area of recreational craft is often treated with special paint that prevents growth of algae and other organisms. The active substances in this paint (antifouling) are also emitted into the water. The extent of this emission is among others determined by the treated surface area.

Escherichia coli Overexpressing a Baeyer-Villiger Monooxygenase from Acinetobacter radioresistens Becomes Resistant to Imipenem.

Science.gov (United States)

Minerdi, Daniela; Zgrablic, Ivan; Castrignanò, Silvia; Catucci, Gianluca; Medana, Claudio; Terlizzi, Maria Elena; Gribaudo, Giorgio; Gilardi, Gianfranco; Sadeghi, Sheila J

2016-01-01

Antimicrobial resistance is a global issue currently resulting in the deaths of hundreds of thousands of people a year worldwide. Data present in the literature illustrate the emergence of many bacterial species that display resistance to known antibiotics; Acinetobacter spp. are a good example of this. We report here that Acinetobacter radioresistens has a Baeyer-Villiger monooxygenase (Ar-BVMO) with 100% amino acid sequence identity to the ethionamide monooxygenase of multidrug-resistant (MDR) Acinetobacter baumannii. Both enzymes are only distantly phylogenetically related to other canonical bacterial BVMO proteins. Ar-BVMO not only is capable of oxidizing two anticancer drugs metabolized by human FMO3, danusertib and tozasertib, but also can oxidize other synthetic drugs, such as imipenem. The latter is a member of the carbapenems, a clinically important antibiotic family used in the treatment of MDR bacterial infections. Susceptibility tests performed by the Kirby-Bauer disk diffusion method demonstrate that imipenem-sensitive Escherichia coli BL21 cells overexpressing Ar-BVMO become resistant to this antibiotic. An agar disk diffusion assay proved that when imipenem reacts with Ar-BVMO, it loses its antibiotic property. Moreover, an NADPH consumption assay with the purified Ar-BVMO demonstrates that this antibiotic is indeed a substrate, and its product is identified by liquid chromatography-mass spectrometry to be a Baeyer-Villiger (BV) oxidation product of the carbonyl moiety of the β-lactam ring. This is the first report of an antibiotic-inactivating BVMO enzyme that, while mediating its usual BV oxidation, also operates by an unprecedented mechanism of carbapenem resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A case of community-acquired Acinetobacter baumannii meningitis - has the threat moved beyond the hospital?

NARCIS (Netherlands)

Lowman, Warren; Kalk, Thomas; Menezes, Colin N.; John, Melanie A.; Grobusch, Martin P.

2008-01-01

Acinetobacter baumannii is a prolific nosocomial pathogen renowned for its multidrug-resistant nature. We report a case of community-acquired meningitis due to A. baumannii. The case highlights the potential pathogenicity of this organism and raises concerns that this highly adaptable organism may

Efficacy Evaluation of a Multifunctional Cosmetic Formulation: The Benefits of a Combination of Active Antioxidant Substances

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Mirela D. Gianeti

2014-11-01

Full Text Available This study presents the association of active antioxidants substances in a multifunctional cosmetic formulation with established efficacy against signs of aging. A multifunctional cosmetic formulation containing an association of UV filters and antioxidant substances (liposoluble vitamins A, C and E, Ginkgo biloba and Phorphyra umbilicalis extracts was evaluated. This formulation was submitted to a clinical efficacy study using biophysics techniques and skin images analysis (digital photography imaging systems, 20 MHz ultrasound, and reflectance confocal microscopy. The volunteers applied the formulation containing the UV filters and antioxidant substances during the day and the formulation with antioxidant substances and without the UV filters at night, for 90 days. The formulation increased the hydration and protected the skin barrier function after a single application. At the long term assessment the formulation provided an improvement in skin barrier function and skin hydration to the deeper layers of the epidermis, leading to an improvement in skin appearance by reducing wrinkles and skin roughness. The multifunctional cosmetic formulation studied can be suggested to preventing signs of aging and improving skin conditions. In addition, this study presents the benefits of associating different active antioxidants substances in a single cosmetic formulation to prevent skin aging.

SHORT COMMUNICATION: Non-Fermenters in Human Infections with Special Reference to Acinetobacter Species in a Tertiary Care Hospital from North Karnataka, India

Directory of Open Access Journals (Sweden)

Prashant K. Parandekar

2012-01-01

Full Text Available Background: Non-fermenters are a group of aerobic non-spore forming gram negative bacilli that are either incapable of utilizingcarbohydrates as a source of energy or degrade them via oxidative rather than fermentative pathway. These are increasingly been reported from the cases of nosocomial infections. Aims and Objectives: This study was undertaken aiming to identify, characterize all nonfermenters and further study of Acinetobacterisolates. Materials and Methods: A total 116 non-fermenters isolated from various specimens obtained from the patients in tertiarycare hospital. Gram negative bacilli which failed to produce acid on Triple Sugar Iron Agar (TSI were identified by employing battery oftests. The Acinetobacter isolates were further speciated and antimicrobial susceptibility testing done by Kirby Bauer disc diffusion technique. Results: Non-fermenters isolated were Pseudomonas aerugionsa (69.8%, Acinetobacter species (18.9%,Stenotrophomonas maltophilia (4.3%, Burkholderia cepacia (3.4%, Alcaligenes fecalis (1.7% and Pseudomonas fluorescens (1.7%. Most of the isolates showed susceptibility to imipenem (86.3% whereasnone of the isolates were sensitive to cephalexin and co-trimoxazole. Conclusion: This study highlights that, after Pseudomonas aeruginosa, Acinetobacter species is the most common non-fermenter. Majority of the isolates of Acinetobacter Species were ofnosocomial origin and were multidrug resistant, which underlines the importance of proper vigilance of these infections in hospital setting.

Infrequent air contamination with Acinetobacter baumannii of air surrounding known colonized or infected patients.

Science.gov (United States)

Rock, Clare; Harris, Anthony D; Johnson, J Kristie; Bischoff, Werner E; Thom, Kerri A

2015-07-01

Using a validated air sampling method we found Acinetobacter baumannii in the air surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients' closed-circuit ventilator status, frequent air exchanges in patient rooms, and short sampling time may have contributed to this low burden.

Informing Antibiotic Treatment Decisions: Evaluating Rapid Molecular Diagnostics To Identify Susceptibility and Resistance to Carbapenems against Acinetobacter spp. in PRIMERS III.

Science.gov (United States)

Evans, Scott R; Hujer, Andrea M; Jiang, Hongyu; Hill, Carol B; Hujer, Kristine M; Mediavilla, Jose R; Manca, Claudia; Tran, Thuy Tien T; Domitrovic, T Nicholas; Higgins, Paul G; Seifert, Harald; Kreiswirth, Barry N; Patel, Robin; Jacobs, Michael R; Chen, Liang; Sampath, Rangarajan; Hall, Thomas; Marzan, Christine; Fowler, Vance G; Chambers, Henry F; Bonomo, Robert A

2017-01-01

The widespread dissemination of carbapenem-resistant Acinetobacter spp. has created significant therapeutic challenges. At present, rapid molecular diagnostics (RMDs) that can identify this phenotype are not commercially available. Two RMD platforms, PCR combined with electrospray ionization mass spectrometry (PCR/ESI-MS) and molecular beacons (MB), for detecting genes conferring resistance/susceptibility to carbapenems in Acinetobacter spp. were evaluated. An archived collection of 200 clinical Acinetobacter sp. isolates was tested. Predictive values for susceptibility and resistance were estimated as a function of susceptibility prevalence and were based on the absence or presence of beta-lactamase (bla) NDM, VIM, IMP, KPC, and OXA carbapenemase genes (e.g., bla OXA-23 , bla OXA-24/40 , and bla OXA-58 found in this study) against the reference standard of MIC determinations. According to the interpretation of MICs, 49% (n = 98) of the isolates were carbapenem resistant (as defined by either resistance or intermediate resistance to imipenem). The susceptibility sensitivities (95% confidence interval [CI]) for imipenem were 82% (74%, 89%) and 92% (85%, 97%) for PCR/ESI-MS and MB, respectively. Resistance sensitivities (95% CI) for imipenem were 95% (88%, 98%) and 88% (80%, 94%) for PCR/ESI-MS and MB, respectively. PRIMERS III establishes that RMDs can discriminate between carbapenem resistance and susceptibility in Acinetobacter spp. In the context of a known prevalence of resistance, SPVs and RPVs can inform clinicians regarding the best choice for empiric antimicrobial therapy against this multidrug-resistant pathogen. Copyright © 2016 American Society for Microbiology.

41 CFR 102-75.130 - If hazardous substance activity took place on the property, what specific information must an...

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false If hazardous substance... Utilization of Excess Real Property Title Report § 102-75.130 If hazardous substance activity took place on... quantity of such hazardous substance and the time at which such storage, release, or disposal took place...

Structural characterization of humic-like substances with conventional and surface-enhanced spectroscopic techniques

Science.gov (United States)

Carletti, Paolo; Roldán, Maria Lorena; Francioso, Ornella; Nardi, Serenella; Sanchez-Cortes, Santiago

2010-10-01

Emission-excitation, synchronous fluorescence spectroscopy and surface-enhanced Raman scattering (SERS) combined with surface-enhanced fluorescence (SEF) were applied to aqueous solutions of a humic-like substance (HLS) extracted from earthworm faeces. All measurements were acquired in a wide range of pH (4-12) and analysed by the linear regression analysis. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra were also acquired to assist in the structural characterization of this HLS. The emission and excitation spectra allowed the identification of two main fluorophores in the analysed sample. Moreover, a close correlation between fluorescence intensities of each fluorophore with pH variation was observed. SERS and SEF, in agreement with the fluorescence spectroscopy, showed that the HLS at low pH values exists in an aggregated and coiled molecular structure while it is dispersed and uncoiled at alkaline conditions. The obtained spectra also evidenced that different conditions modify the functional groups exposed to the surrounding aqueous environment.

Blue light irradiation triggers the antimicrobial potential of ZnO nanoparticles on drug-resistant Acinetobacter baumannii.

Science.gov (United States)

Yang, Ming-Yeh; Chang, Kai-Chih; Chen, Liang-Yu; Wang, Po-Ching; Chou, Chih-Chiang; Wu, Zhong-Bin; Hu, Anren

2018-03-01

Photodynamic inactivation (PDI) is a non-invasive and safe therapeutic method for microbial infections. Bacterial antibiotic resistance is caused by antibiotics abuse. Drug-resistant Acinetobacter spp. is a serious problem in hospitals around the world. These pathogens from nosocomial infections have high mortality rates in frailer people, and Acinetobacter spp. is commonly found in immunocompromised patients. Visible light is safer than ultraviolet light (UV) for PDI of nosocomial pathogens with mammalian cells. Zinc oxide nanoparticles (ZnO-NPs) were used in this study as an antimicrobial agent and a photosensitizer. ZnO is recognized as safe and has extensive usage in food additives, medical and cosmetic products. In this study, we used 0.125 mg/ml ZnO-NPs combined with 10.8 J/cm 2 blue light (BL) on Acinetobacter baumannii (A. baumannii) that could significantly reduce microbial survival. However, individual exposure to ZnO-NPs does not affect the viability of A. baumannii. BL irradiation could trigger the antimicrobial ability of ZnO nanoparticles on A. baumannii. The mechanism of photocatalytic ZnO-NPs treatment for sterilization occurs through bacterial membrane disruptions. Otherwise, the photocatalytic ZnO-NPs treatment showed high microbial eradication in nosocomial pathogens, including colistin-resistant and imipenem-resistant A. baumannii and Klebsiella pneumoniae. Based on our results, the photocatalytic ZnO-NPs treatment could support hygiene control and clinical therapies without antibiotics to nosocomial bacterial infections. Copyright © 2018. Published by Elsevier B.V.

ANTIMICROBIAL ACTIVITY OF THE SUBSTANCES RECEIVED FROM RAW MATERIALS OF BIRCH FAMILY PLANTS

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Fedchenkova Yu.A

2016-12-01

Full Text Available Introduction. In accordance with the last events in Ukraine (considering military operations in anti-terrorist operation in the Luhansk and Donetsk regions the domestic medicine is in great need in preparations with antimicrobial activity. Our attention as the sources of receiving biologically active substances with antimicrobial activity was drawn with birch Betulaceae family plants – hazel ordinary Corylus avellana L. and black alder Alnus glutinosa (L. Gaertn. It is known that in medicine the leaves of hazel ordinary are used as antiseptic, anti-inflammatory, vesselrestorative drug, and the leaves of black alder reveal the antiinflammatory, astringent, wound healing, spasmolytic and choleretic action. However, the drugs with antimicrobial action received from the leaves of these plants are absent on the market of Ukraine. Therefore the studying of antimicrobial activity of this type of raw materials received from hazel ordinary and black alder, for creation of new medicines, is now one of the main directions in pharmacy. For this purpose we have revealed tinctures, spirit, lipophilic and polysacharid fractions received from the leaves of hazel ordinary and black alder. The purpose of our research is studying of antimicrobial activity of revealed substance received from the leaves of black alder and hazel ordinary. Materials and methods. There were being examined tinctures, lipophilic, spirit and polysacharid fractions received from the leaves of hazel ordinary and black alder. The test of antimicrobial effect of substances was carried out by means of serial dilution concerning the following six reference cultures: Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 885-653, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6833, Bacillus cereus ATCC 10702, Pseudomonas aeruginosa ATCC 9027, according to the State Pharmacopoeia of Ukraine, in the Department of Microbiology and Immunology of KMAPE. For the experiment there was prepared

Development of Novel Antibiotics for the Treatment of Acinetobacter and Related Pathogens

Science.gov (United States)

2012-07-07

8217]’ . [ugmL ’] Staphylococcus aureus Enterococcus faecalis JH2-2 32 ATCC 12608 2 ATCC 12608+10% serum 2 Bacillus subtilis ATCC 12608 +50% serum...March 1, 2009 to February 28, 2012 4. TITLE AND SUBTITLE Development of Novel Antibiotics for the Treatment of Acinetobacter and Related Pathogens...novel antibacterial agents. 15. SUBJECT TERMS antibiotics , compound screening, complex small molecules 16. SECURITY CLASSIFICATION OF: a. REPORT U

Surface Chemical Characterisation of Pyrite Exposed to Acidithiobacillus ferrooxidans and Associated Extracellular Polymeric Substances

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Sian M. La Vars

2018-03-01

Full Text Available A. ferrooxidans and their metabolic products have previously been explored as a viable alternative depressant of pyrite for froth flotation; however, the mechanism by which separation is achieved is not completely understood. Scanning electron microscopy (SEM, photoemission electron microscopy (PEEM, time-of-flight secondary ion mass spectrometry (ToF-SIMS and captive bubble contact angle measurements have been used to examine the surface physicochemical properties of pyrite upon exposure to A. ferrooxidans grown in HH medium at pH 1.8. C K-edge near edge X-ray absorption fine structure (NEXAFS spectra collected from PEEM images indicate hydrophilic lipids, fatty acids and biopolymers are formed at the mineral surface during early exposure. After 168 h, the spectra indicate a shift towards protein and DNA, corresponding to an increase in cell population and biofilm formation on the surface, as observed by SEM. The Fe L-edge NEXAFS show gradual oxidation of the mineral surface from Fe(II sulfide to Fe(III oxyhydroxides. The oxidation of the iron species at the pyrite surface is accelerated in the presence of A. ferrooxidans and extracellular polymeric substances (EPS as compared to HH medium controls. The surface chemical changes induced by the interaction with A. ferrooxidans show a significant decrease in surface hydrophobicity within the first 2 h of exposure. The implications of these findings are the potential use of EPS produced during early attachment of A. ferrooxidans, as a depressant for bioflotation.

Purification and Characterization of Catalase from Marine Bacterium Acinetobacter sp. YS0810

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Xinhua Fu

2014-01-01

Full Text Available The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability.

Differential roles of CD14 and toll-like receptors 4 and 2 in murine Acinetobacter pneumonia

NARCIS (Netherlands)

Knapp, Sylvia; Wieland, Catharina W.; Florquin, Sandrine; Pantophlet, Ralph; Dijkshoorn, Lenie; Tshimbalanga, Ntambua; Akira, Shizuo; van der Poll, Tom

2006-01-01

RATIONALE: Acinetobacter baumannii is an opportunistic bacterial pathogen that is increasingly associated with gram-negative nosocomial pneumonia, but the molecular mechanisms that play a role in innate defenses during A. baumannii infection have not been elucidated. OBJECTIVE: To gain first insight

Gamma radiation (Co60) effects on active substances and microbe burden of medicinal plants

International Nuclear Information System (INIS)

Dall'Agnol, L.

2001-01-01

In order to evaluate the effects of radioactivity on active vegetal substances, samples of Fennel (Foeniculum vulgare Miller., fructus), Guarana (Paulinia cupana, Kunth, semen), Gingko (gingko biloba, L., folium), and Kawa-Kawa (Piper methysticum G. Forst, rhizoma), were treated with scaling doses (0 to 25 KGy) of gamma radiation (Co 60 ). The 'blind test' methodology was used. The active substances from each sample were analysed by qualitative and quantitative methods after radiation. There were no significant differences seen between the control sample (0 KGy) and the irradiated samples. Microbe contamination was significantly reduced, about 10000 CFU/g, with the initial 5 KGy dose. It was concluded that gamma radiation can be used as an alternative procedure to reduce microbiologic contamination in medicinal plants. Before this procedure can be extended to other medicinal plants, more specific analytical methods are recommended to verify possible structural alterations in active vegetal molecules. (author)

Antimicrobial photodynamic therapy in a mouse model of Acinetobacter baumannii burn infection

Science.gov (United States)

Dai, Tianhong; Tegos, George P.; Lu, Zongshun; Zhiyentayev, Timur; Huang, Liyi; Franklin, Michael J.; Baer, David G.; Hamblin, Michael R.

2009-06-01

Multi-drug resistant Acinetobacter baumanii infections represent a growing problem, especially in traumatic wounds and burns suffered by military personnel injured in Middle Eastern conflicts. Effective treatment using traditional antibiotics can be extremely difficult and new antimicrobial approaches are being investigated. One of these antimicrobial alternatives could be the combination of non-toxic photosensitizers (PS) and visible light known as photodynamic therapy (PDT). We report on the establishment of a new mouse model of full thickness thermal burns infected with a bioluminescent derivative of a clinical Iraqi isolate of A. baumannii and its PDT treatment by topical application of a PS produced by covalent conjugation chlorin(e6) to polyethylenimine followed by illumination of the burn surface with red light. Application of 108 A. baumannii cells to the surface of 10-second burns made on the dorsal surface of shaved female BALB/c mice led to chronic infections that lasted on average 22 days characterized by a remarkably stable bacterial bioluminescence. PDT carried out on day 0 soon after applying bacteria gave over three logs of loss of bacterial luminescence in a light exposure dependent manner, while PDT carried out on day 1 and day 2 gave approximately a 1.7-log reduction. Application of PS dissolved in 10% or 20% DMSO without light gave only modest reduction in bacterial luminescence from mouse burns. Some bacterial regrowth in the treated burn was observed but was generally modest. It was also found that PDT did not lead to inhibition of wound healing. The data suggest that PDT may be an effective new treatment for multi-drug resistant localized A. baumannii infections.

Phytotoxic substances with allelopathic activity may be central to the strong invasive potential of Brachiaria brizantha.

Science.gov (United States)

Kato-Noguchi, Hisashi; Kobayashi, Ai; Ohno, Osamu; Kimura, Fukiko; Fujii, Yoshiharu; Suenaga, Kiyotake

2014-04-15

The grass Brachiaria brizantha, native to eastern Africa, becomes naturalized and dominant quickly in the non-native areas. It was hypothesized that phytotoxic chemical interaction between this plant and native plants may play an important role in the invasion of B. brizantha. However, no potent phytotoxic substance has been reported in this species. Therefore, we investigated possible allelopathic activity and searched for phytotoxic substances with allelopathic activity in B. brizantha. An aqueous methanol extract of B. brizantha inhibited the growth of roots and shoots of garden cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense) and ryegrass (Lolium multiflorum) seedlings. The extract was purified by several chromatographic runs and three allelopathically active substances were isolated and identified by spectral analysis as (6R,9R)-3-oxo-α-ionol, (6R,9S)-3-oxo-α-ionol and 4-ketopinoresinol. (6R,9R)-3-Oxo-α-ionol and (6R,9S)-3-oxo-α-ionol inhibited root and shoot growth of garden cress at concentrations greater than 30 and 10 μM, respectively. The activity of (6R,9S)-3-oxo-α-ionol was 5.3- to 6.2-fold that of (6R,9R)-3-oxo-α-ionol. The stereochemistry of the hydroxyl group at position C-9 may be important for the inhibitory activities of those compounds. 4-Ketopinoresinol inhibited root and shoot growth of garden cress at concentrations greater than 30 μM. The growth inhibitory activity of (6R,9S)-3-oxo-α-ionol was the greatest and followed by 4-ketopinoresinol and (6R,9R)-3-oxo-α-ionol. These results suggest that those phytotoxic substances may contribute to the allelopathic effect caused by B. brizantha and may be involved in the invasion of B. brizantha. Copyright © 2013 Elsevier GmbH. All rights reserved.

CONCENTRATION OF HARMFUL SUBSTANCES REDUCING IN SURFACE LAYER OF ATMOSPHERE AT RHEOSTAT LOCOMOTIVE TESTS

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E. A. Bondar

2010-06-01

Full Text Available It is shown that at present an acceptable way of reducing the concentration of harmful substances in the surface layer of the atmosphere at rheostat tests of locomotives is their dispersion in a large volume of air. Channels, installed above an exhaust pipe of diesel locomotive with a break at the gas flow, work as ejectors. We have solved jointly the equation of aerodynamic characteristics of the ejector device and the equation of diffusion of gases; as a result the calculated dependence for determining the necessary height of ejector device has been obtained.

Factor analysis in optimization of formulation of high content uniformity tablets containing low dose active substance.

Science.gov (United States)

Lukášová, Ivana; Muselík, Jan; Franc, Aleš; Goněc, Roman; Mika, Filip; Vetchý, David

2017-11-15

Warfarin is intensively discussed drug with narrow therapeutic range. There have been cases of bleeding attributed to varying content or altered quality of the active substance. Factor analysis is useful for finding suitable technological parameters leading to high content uniformity of tablets containing low amount of active substance. The composition of tabletting blend and technological procedure were set with respect to factor analysis of previously published results. The correctness of set parameters was checked by manufacturing and evaluation of tablets containing 1-10mg of warfarin sodium. The robustness of suggested technology was checked by using "worst case scenario" and statistical evaluation of European Pharmacopoeia (EP) content uniformity limits with respect to Bergum division and process capability index (Cpk). To evaluate the quality of active substance and tablets, dissolution method was developed (water; EP apparatus II; 25rpm), allowing for statistical comparison of dissolution profiles. Obtained results prove the suitability of factor analysis to optimize the composition with respect to batches manufactured previously and thus the use of metaanalysis under industrial conditions is feasible. Copyright © 2017 Elsevier B.V. All rights reserved.

Research of Acinetobacter Baumannii Isolation From Clinical Samples in Second Step Hospital

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Keramettin Yanik

2015-11-01

Full Text Available Aim: Due to existing multi drug resistance and subsequently acquired resistance Acinetobacter genus bacteria continuously actual. Other characteristics are increasing treatment costs, patient hospitalization period, mortality and morbidity. Risk factors like extended hospitalization period, background immune system disorders are increasing isolation frequency of this bacteria from patients. Extended spectrum antibiotic usage is known to be a major risk factor. Aim of our study is to investigate cause of growing A.baumanii isolation rate and cross contamination between this isolates in a state hospital. Material and Method: In this study analysed increasing isolation frequency by years and specimen occurrence in level 2 hospital. At the same time detected amount of used imipenem and meropenem in hospital during last three years. A.baumanii strains isolated from respiratory and sputum specimens of patients from intensive care unit and thoracal departament during last month of 2013 year%u2019s were tested using PFGE method for genotypic similarity. Results: Acinetobacters isolation frequency in years and carbapenem usage are subsequently increased. Specimens are generally from respiratory tract. Genotypic similarity not detected on studied 6 A.baumanii strain%u2019s PFGE image. This condition interpreted like this strains origins not from cross contamination.

41 CFR 102-75.135 - If no hazardous substance activity took place on the property, what specific information must an...

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false If no hazardous... DISPOSAL Utilization of Excess Real Property Title Report § 102-75.135 If no hazardous substance activity... hazardous substance activity took place, the reporting agency must include the following statement: The...

Levels of surface contamination with radioactive materials at workplaces of nuclear research centre at Rez

International Nuclear Information System (INIS)

Hoelgye, Z.; Nemcova, I.; Kasikova, M.; Popper, J.; Chysky, J.

1983-01-01

A hygiene supervision unit at workplaces of the nuclear Research Institute in Rez monitored on a long-term basis surface contamination with radioactive substances. Surface contamination was found at workplaces with open sources. Of the 4343 monitored places action levels were only exceeded in 13 cases. The obtained data were used for typifying workplaces with the highest level of surface contamination, to determine in certain instances the mechanism of the escape of radioactive substances from insulating facilities and to determine the rate of the spread of the radioactive substance into adjacent non-active workplaces. (author)

Phenolic acids potentiate colistin-mediated killing of Acinetobacter baumannii by inducing redox imbalance.

Science.gov (United States)

Ajiboye, Taofeek O; Skiebe, Evelyn; Wilharm, Gottfried

2018-05-01

Phenolic acids with catechol groups are good prooxidants because of their low redox potential. In this study, we provided data showing that phenolic acids, caffeic acid, gallic acid and protocatechuic acid, enhanced colistin-mediated bacterial death by inducing redox imbalance. The minimum inhibitory concentrations of these phenolic acids against Acinetobacter baumannii AB5075 were considerably lowered for ΔsodB and ΔkatG mutants. Checkerboard assay shows synergistic interactions between colistin and phenolic acids. The phenolic acids exacerbated colistin-induced oxidative stress in A. baumannii AB5075 through increased superoxide anion generation, NAD + /NADH and ADP/ATP ratio. In parallel, the level of reduced glutathione was significantly lowered. We conclude that phenolic acids potentiate colistin-induced oxidative stress in A. baumannii AB5075 by increasing ROS generation, energy metabolism and electron transport chain activity with a concomitant decrease in glutathione. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A novel mutation in pmrB mediates colistin resistance during therapy of Acinetobacter baumannii.

Science.gov (United States)

Dahdouh, Elias; Gómez-Gil, Rosa; Sanz, Sonia; González-Zorn, Bruno; Daoud, Ziad; Mingorance, Jesús; Suárez, Monica

2017-06-01

Acinetobacter baumannii is a highly versatile nosocomial pathogen. Multidrug resistance among A. baumannii isolates led to the use of colistin, subsequently giving rise to colistin-resistant strains. In this study, the genetic and phenotypic profiles of two colistin-resistant A. baumannii isolates were investigated. Two A. baumannii isolates were obtained from Patient 1 (C071 and C440) and three isolates were obtained from Patient 2 (C080, C314 and C428). Susceptibility profiles were determined by VITEK ® 2 and Etest. Clonality was determined by RAPD analysis and trilocus multiplex PCR. The pmrCAB operon was sequenced and common carbapenemase genes were screened for by PCR. Doubling times, haemolysis, surface motility, biofilm formation, siderophore production and proteolytic activity were phenotypically determined. Finally, whole-genome sequencing was performed for all five isolates. Isolates C440 and C428 were resistant to colistin and were clonally identical to their sensitive counterparts. The cause of colistin resistance was traced to the previously described P233S mutation in pmrB of C440 and to a novel ΔI19 mutation in pmrB of C428. bla OXA-58-like and bla GES-5 from the strains of Patients 1 and 2, respectively, were also detected. C440 had attenuated proteolytic activity and was positive for siderophore production compared with C071. No difference in in vitro virulence was detected between isolates C080, C314 and C428. In conclusion, one common and one novel mutation were encountered in pmrB from two distinct colistin-resistant A. baumannii isolates. These mutations caused colistin resistance during therapy in two distinct clones, and only one of them had altered in vitro virulence. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Humic substances in ground waters

International Nuclear Information System (INIS)

Paxeus, N.; Allard, B.; Olofsson, U.; Bengtsson, M.

1986-01-01

The presence of naturally occurring complexing agents that may enhance the migration of disposed radionuclikes and thus facilitate their uptake by plantsis a problem associated with the underground disposal of radioactive wastes in bedrock. The main purpose of this work is to characterized humic substances from ground water and compare them with humic substances from surface water. The humic materials isolated from ground waters of a borehole in Fjaellveden (Sweden) were characterized by elemental and functional group analyses. Spectroscopic properties, molecular weight distributions as well as acid-base properties of the fulvic and humic fractions were also studied. The ground water humic substances were found to be quite similar in many respects (but not identical) to the Swedish surface water humics concentrated from the Goeta River but appeared to be quite different from the American ground water humics from Biscayne Florida Aquifer or Laramie Fox-Hills in Colorado. The physico-chemical properties of the isolated humic materials are discussed

Enhancement mechanisms of short-time aerobic digestion for waste activated sludge in the presence of cocoamidopropyl betaine.

Science.gov (United States)

Xia, Siqing; Zhou, Yun; Eustance, Everett; Zhang, Zhiqiang

2017-10-18

Cocoamidopropyl betaine (CAPB), which is a biodegradable ampholytic surfactant, has recently been found to dramatically enhance the aerobic digestion of waste activated sludge (WAS) in short-time aerobic digestion (STAD) systems. Therefore, it is important to understand the mechanisms in which CAPB enhances WAS aerobic digestion performance. Results showed that CAPB could dramatically enhance the solubilization of soluble proteins (PN), polysaccharides (PS), nucleic acids (NA) and humic-like substances (HS) in the STAD system within the initial 2 h. Then PN, PS and NA gradually decreased, while HS showed only minor decease. In addition, CAPB increased the proportion of low MW fractions (biodegradable. Specific oxygen uptake rates and dehydrogenase enzyme activity results indicated that CAPB markedly improved the aerobic microorganism activities. Microbial community analyses and principle coordinate analyses (PCoA) revealed that CAPB increased the proportion of some functional microorganisms, including Proteobacteria, Planctomycetales, Acinetobacter, Pseudomonas and Aeromonas. The changes driven by CAPB could explain the enhanced performance of the STAD system for WAS aerobic treatment.

Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

Science.gov (United States)

Sand, Wolfgang; Gehrke, Tilman

2006-01-01

Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

The acute-phase response and serum amyloid A inhibit the inflammatory response to Acinetobacter baumannii Pneumonia

NARCIS (Netherlands)

Renckens, Rosemarijn; Roelofs, Joris J. T. H.; Knapp, Sylvia; de Vos, Alex F.; Florquin, Sandrine; van der Poll, Tom

2006-01-01

BACKGROUND: Acinetobacter baumannii is an emerging pathogen in nosocomial pneumonia. Trauma and postsurgical patients display a profound acute-phase protein response and are susceptible to pneumonia. METHODS: To study the way in which the acute-phase response induced by sterile tissue injury

Social Activity, School-Related Activity, and Anti-Substance Use Media Messages on Adolescent Tobacco and Alcohol Use

OpenAIRE

Moon, Sung Seek; Rao, Uma

2011-01-01

In this article, we present the effects of three hypothesized protective factors: social activities, school-related activities, and anti-substance use media messages on adolescent tobacco and alcohol use. Data were drawn from the “Monitoring the Future” (MTF) research project, which was conducted by the Institute for Social Research at the University of Michigan. The sample included 2,551 twelfth-grade students. The results of the structural equation model showed that exposure to media anti-d...

Surface-Activated Coupling Reactions Confined on a Surface.

Science.gov (United States)

Dong, Lei; Liu, Pei Nian; Lin, Nian

2015-10-20

Chemical reactions may take place in a pure phase of gas or liquid or at the interface of two phases (gas-solid or liquid-solid). Recently, the emerging field of "surface-confined coupling reactions" has attracted intensive attention. In this process, reactants, intermediates, and products of a coupling reaction are adsorbed on a solid-vacuum or a solid-liquid interface. The solid surface restricts all reaction steps on the interface, in other words, the reaction takes place within a lower-dimensional, for example, two-dimensional, space. Surface atoms that are fixed in the surface and adatoms that move on the surface often activate the surface-confined coupling reactions. The synergy of surface morphology and activity allow some reactions that are inefficient or prohibited in the gas or liquid phase to proceed efficiently when the reactions are confined on a surface. Over the past decade, dozens of well-known "textbook" coupling reactions have been shown to proceed as surface-confined coupling reactions. In most cases, the surface-confined coupling reactions were discovered by trial and error, and the reaction pathways are largely unknown. It is thus highly desirable to unravel the mechanisms, mechanisms of surface activation in particular, of the surface-confined coupling reactions. Because the reactions take place on surfaces, advanced surface science techniques can be applied to study the surface-confined coupling reactions. Among them, scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) are the two most extensively used experimental tools. The former resolves submolecular structures of individual reactants, intermediates, and products in real space, while the latter monitors the chemical states during the reactions in real time. Combination of the two methods provides unprecedented spatial and temporal information on the reaction pathways. The experimental findings are complemented by theoretical modeling. In particular, density

Insect-derived cecropins display activity against Acinetobacter baumannii in a whole-animal high-throughput Caenorhabditis elegans model.

Science.gov (United States)

Jayamani, Elamparithi; Rajamuthiah, Rajmohan; Larkins-Ford, Jonah; Fuchs, Beth Burgwyn; Conery, Annie L; Vilcinskas, Andreas; Ausubel, Frederick M; Mylonakis, Eleftherios

2015-03-01

The rise of multidrug-resistant Acinetobacter baumannii and a concomitant decrease in antibiotic treatment options warrants a search for new classes of antibacterial agents. We have found that A. baumannii is pathogenic and lethal to the model host organism Caenorhabditis elegans and have exploited this phenomenon to develop an automated, high-throughput, high-content screening assay in liquid culture that can be used to identify novel antibiotics effective against A. baumannii. The screening assay involves coincubating C. elegans with A. baumannii in 384-well plates containing potential antibacterial compounds. At the end of the incubation period, worms are stained with a dye that stains only dead animals, and images are acquired using automated microscopy and then analyzed using an automated image analysis program. This robust assay yields a Z' factor consistently greater than 0.7. In a pilot experiment to test the efficacy of the assay, we screened a small custom library of synthetic antimicrobial peptides (AMPs) that were synthesized using publicly available sequence data and/or transcriptomic data from immune-challenged insects. We identified cecropin A and 14 other cecropin or cecropin-like peptides that were able to enhance C. elegans survival in the presence of A. baumannii. Interestingly, one particular hit, BR003-cecropin A, a cationic peptide synthesized by the mosquito Aedes aegypti, showed antibiotic activity against a panel of Gram-negative bacteria and exhibited a low MIC (5 μg/ml) against A. baumannii. BR003-cecropin A causes membrane permeability in A. baumannii, which could be the underlying mechanism of its lethality. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Spread of carbapenem-resistant international clones of Acinetobacter baumannii in Turkey and Azerbaijan: a collaborative study

NARCIS (Netherlands)

Ahmed, S.S.; Alp, E.; Ulu-Kilic, A.; Dinc, G.; Aktas, Z.; Ada, B.; Bagirova, F.; Baran, I.; Ersoy, Y.; Esen, S.; Guven, T.G.; Hopman, J.; Hosoglu, S.; Koksal, F.; Parlak, E.; Yalcin, A.N.; Yilmaz, G.; Voss, A.; Melchers, W.J.

2016-01-01

Epidemic clones of Acinetobacter baumannii, described as European clones I, II, and III, are associated with hospital epidemics throughout the world. We aimed to determine the molecular characteristics and genetic diversity between European clones I, II, and III from Turkey and Azerbaijan. In this

Did Mineral Surface Chemistry and Toxicity Contribute to Evolution of Microbial Extracellular Polymeric Substances?

Science.gov (United States)

Campbell, Jay M.; Zhang, Nianli; Hickey, William J.

2012-01-01

Abstract Modern ecological niches are teeming with an astonishing diversity of microbial life in biofilms closely associated with mineral surfaces, which highlights the remarkable success of microorganisms in conquering the challenges and capitalizing on the benefits presented by the mineral–water interface. Biofilm formation capability likely evolved on early Earth because biofilms provide crucial cell survival functions. The potential toxicity of mineral surfaces toward cells and the complexities of the mineral–water–cell interface in determining the toxicity mechanisms, however, have not been fully appreciated. Here, we report a previously unrecognized role for extracellular polymeric substances (EPS), which form biofilms in shielding cells against the toxicity of mineral surfaces. Using colony plating and LIVE/DEAD staining methods in oxide suspensions versus oxide-free controls, we found greater viability of wild-type, EPS-producing strains of Pseudomonas aeruginosa PAO1 compared to their isogenic knockout mutant with defective biofilm-producing capacity. Oxide toxicity was specific to its surface charge and particle size. High resolution transmission electron microscopy (HRTEM) images and assays for highly reactive oxygen species (hROS) on mineral surfaces suggested that EPS shield via both physical and chemical mechanisms. Intriguingly, qualitative as well as quantitative measures of EPS production showed that toxic minerals induced EPS production in bacteria. By determining the specific toxicity mechanisms, we provide insight into the potential impact of mineral surfaces in promoting increased complexity of cell surfaces, including EPS and biofilm formation, on early Earth. Key Words: Mineral toxicity—Bacteria—EPS evolution—Biofilms—Cytotoxicity—Silica—Anatase—Alumina. Astrobiology 12, 785–798. PMID:22934560

A container for containing and protecting a radioactive substance

International Nuclear Information System (INIS)

1974-01-01

The invention relates to a container adapted to contain and protect a radio-active substance. That container comprises a heat sensitive device for automatically (and, preferably, sealingly) enclosing and protecting the radio-active substance, should room temperature reach a predetermined level. Thus, the radio-active substance cannot escape in case of fire. Preferably, a bolt is also provided, capable of being actuated at a temperature slightly above the temperature actuating the protective device so as to maintain the radioactive substance protected. This can be applied to containers containing a radio-active substance such as polonium 210 [fr

Recommended approaches to the scientific evaluation of ecotoxicological hazards and risks of endocrine-active substances

DEFF Research Database (Denmark)

Matthiessen, Peter; Ankley, Gerald T.; Biever, Ronald C

2017-01-01

A SETAC Pellston Workshop(®) "Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA)" was held in February 2016 in Pensacola, Florida, USA. The primary objective of the workshop was to provide advice, based on current scientific understanding, to regulators...... and policy makers; the aim being to make considered, informed decisions on whether to select an ecotoxicological hazard- or a risk-based approach for regulating a given endocrine-disrupting substance (EDS) under review. The workshop additionally considered recent developments in the identification of EDS...... at multiple biological levels of organization for 1 or more ecologically relevant taxa. The substances selected were 17α-ethinylestradiol, perchlorate, propiconazole, 17β-trenbolone, tributyltin, and vinclozolin. The 6 case studies were not comprehensive safety evaluations but provided foundations...

Comparative analysis of Acinetobacters: three genomes for three lifestyles.

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David Vallenet

Full Text Available Acinetobacter baumannii is the source of numerous nosocomial infections in humans and therefore deserves close attention as multidrug or even pandrug resistant strains are increasingly being identified worldwide. Here we report the comparison of two newly sequenced genomes of A. baumannii. The human isolate A. baumannii AYE is multidrug resistant whereas strain SDF, which was isolated from body lice, is antibiotic susceptible. As reference for comparison in this analysis, the genome of the soil-living bacterium A. baylyi strain ADP1 was used. The most interesting dissimilarities we observed were that i whereas strain AYE and A. baylyi genomes harbored very few Insertion Sequence elements which could promote expression of downstream genes, strain SDF sequence contains several hundred of them that have played a crucial role in its genome reduction (gene disruptions and simple DNA loss; ii strain SDF has low catabolic capacities compared to strain AYE. Interestingly, the latter has even higher catabolic capacities than A. baylyi which has already been reported as a very nutritionally versatile organism. This metabolic performance could explain the persistence of A. baumannii nosocomial strains in environments where nutrients are scarce; iii several processes known to play a key role during host infection (biofilm formation, iron uptake, quorum sensing, virulence factors were either different or absent, the best example of which is iron uptake. Indeed, strain AYE and A. baylyi use siderophore-based systems to scavenge iron from the environment whereas strain SDF uses an alternate system similar to the Haem Acquisition System (HAS. Taken together, all these observations suggest that the genome contents of the 3 Acinetobacters compared are partly shaped by life in distinct ecological niches: human (and more largely hospital environment, louse, soil.

Improved Triacylglycerol Production in Acinetobacter baylyi ADP1 by Metabolic Engineering

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Karp Matti

2011-05-01

Full Text Available Abstract Background Triacylglycerols are used in various purposes including food applications, cosmetics, oleochemicals and biofuels. Currently the main sources for triacylglycerol are vegetable oils, and microbial triacylglycerol has been suggested as an alternative for these. Due to the low production rates and yields of microbial processes, the role of metabolic engineering has become more significant. As a robust model organism for genetic and metabolic studies, and for the natural capability to produce triacylglycerol, Acinetobacter baylyi ADP1 serves as an excellent organism for modelling the effects of metabolic engineering for energy molecule biosynthesis. Results Beneficial gene deletions regarding triacylglycerol production were screened by computational means exploiting the metabolic model of ADP1. Four deletions, acr1, poxB, dgkA, and a triacylglycerol lipase were chosen to be studied experimentally both separately and concurrently by constructing a knock-out strain (MT with three of the deletions. Improvements in triacylglycerol production were observed: the strain MT produced 5.6 fold more triacylglycerol (mg/g cell dry weight compared to the wild type strain, and the proportion of triacylglycerol in total lipids was increased by 8-fold. Conclusions In silico predictions of beneficial gene deletions were verified experimentally. The chosen single and multiple gene deletions affected beneficially the natural triacylglycerol metabolism of A. baylyi ADP1. This study demonstrates the importance of single gene deletions in triacylglycerol metabolism, and proposes Acinetobacter sp. ADP1 as a model system for bioenergetic studies regarding metabolic engineering.

Actividad "in vitro" de diferentes antibacterianos sobre bacilos gram-negativos no fermentadores, excluidos Pseudomonas aeruginosa y Acinetobacter spp ‘In vitro' activity of different antimicrobial agents on gram-negative nonfermentative bacilli, excluding Pseudomonas aeruginosa and Acinetobacter spp

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C.A. Vay

2005-03-01

antibacterianos a fin de abordar la elección correcta del mismo. Debido a la marcada multirresistencia de algunas especies, surge la necesidad del desarrollo de nuevos agentes antimicrobianos que posean actividad sobre este grupo de bacterias, así como tambien la búsqueda de combinaciones sinérgicas.Gram-negative nonfermentative bacilli (NFB are widely spread in the environment. Besides of difficulties for identification, they often have a marked multiresistance to antimicrobial agents, including those active against Pseudomonas aeruginosa. The objective of this study was to evaluate the ‘in vitro' activity of different antimicrobial agents on 177 gram-negative nonfermentative bacilli isolates (excluding Pseudomonas aeruginosa and Acinetobacter spp. isolated from clinical specimens. Minimum inhibitory concentrations (MIC were determined according to the Mueller Hinton agar dilution method against the following antibacterial agents: ampicillin, piperacillin, piperacillin-tazobactam, sulbactam, cefoperazone, cefoperazone-sulbactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, colistin, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, rifampin, norfloxacin, ciprofloxacin and minocycline. Seven isolates: Sphingobacterium multivorum (2 , Sphingobacterium spiritivorum (1, Empedobacter brevis (1, Weeksella virosa (1, Bergeyella zoohelcum (1 and Oligella urethralis (1, were tested for amoxicillin-clavulanic acid and ampicillin-sulbactam susceptibility, and susceptibility to cefoperazone or sulbactam was not determined. Multiresistance was generally found in Stenotrophomonas maltophilia, Burkholderia cepacia, Chryseobacterium spp., Myroides spp., Achromobacter xylosoxidans, and Ochrobactrum anthropi isolates. On the other hand, Pseudomonas stutzeri, Shewanella putrefaciens-algae, Sphingomonas paucimobilis, and Pseudomonas oryzihabitans, Bergeyella zoohelcum, Weeksella virosa and Oligella urethralis were widely susceptible to the

OXA-carbapenemases present in clinical acinetobacter baumannii-calcoaceticus complex isolates from patients in kurdistan region, Iraq

NARCIS (Netherlands)

Ganjo, A.R. (Aryann R.); D.M. Maghdid (Delshad); Mansoor, I.Y. (Isam Y.); Kok, D.J. (Dik J.); J.A. Severin (Juliëtte); H.A. Verbrugh (Henri); D. Kreft; Fatah, M.H.; Alnakshabandi, A.A.; Dlnya, A. (Asad); Hammerum, A.M. (Anette M.); Ng, K. (Kim); W.H.F. Goessens (Wil)

2016-01-01

markdownabstractIn addition to intrinsic resistance in Acinetobacter baumannii, many different types of acquired resistance mechanisms have been reported, including the presence of VIM and IMP metallo β-lactamases and also of blaOXA-23-like and blaOXA-58-like enzymes. In the Kurdistan region of

Molecular characterization of Ambler class A to D β-lactamases, ISAba1, and integrons reveals multidrug-resistant Acinetobacter spp. isolates in northeastern China.

Science.gov (United States)

Sun, Xiaoyu; Liu, Bin; Chen, Yan; Huang, Honglan; Wang, Guoqing; Li, Fan; Ni, Zhaohui

2016-12-01

The prevalence of various Ambler class A to D β-lactamases, ISAba1, and class 1 and 2 integrons as well as the clonal relatedness in 105 Acinetobacter spp. isolates found in northeastern China was investigated. All 105 Acinetobacter spp. isolates were determined to be multidrug resistant (MDR), and the resistance rates to carbapenem agents were approximately 50%. PER, IMP, AmpC, and OXA-23 were found to be dominant β-lactamases belonging to different classes, respectively. This is the first report of the coexistence of bla PER , bla IMP , bla AmpC , and bla OXA-23-like genes in Acinetobacter spp. isolates from northeastern China. ISAba1 was found upstream of the bla OXA-23-like gene in 87.8% (36/41) strains and upstream of the bla OXA-51-like gene in 26.5% (13/49) strains. ISAba3-like element was found upstream of the bla OXA-58-like gene in one bla OXA-58-like -positive strain. The presence of IntI1 was detected in 63.8% (67/105) of the isolates and the most prevalent gene cassettes were aacA4, aadA1, and catB8. The highly prevalent isolates belong to international clonal lineage (ICL)-II. These results indicate that the wide horizontal and clonal spread of MDR Acinetobacter spp. isolates harbouring multiple β-lactamase genes has become a serious problem in northeastern China.

Influence of regular reporting on local Pseudomonas aeruginosa and Acinetobacter spp. sensitivity to antibiotics on consumption of antibiotics and resistance patterns.

Science.gov (United States)

Djordjevic, Z M; Folic, M M; Jankovic, S M

2017-10-01

Regular surveillance of antimicrobial resistance is an important component of multifaceted interventions directed at the problem with resistance of bacteria causing healthcare-associated infections (HAIs) in intensive care units (ICUs). Our aim was to analyse antimicrobial consumption and resistance among isolates of Pseudomonas aeruginosa and Acinetobacter spp. causing HAIs, before and after the introduction of mandatory reporting of resistance patterns to prescribers. A retrospective observational study was conducted between January 2011 and December 2015, at an interdisciplinary ICU of the Clinical Centre Kragujevac, Serbia. The intervention consisted of continuous resistance monitoring of all bacterial isolates from ICU patients and biannual reporting of results per isolate to prescribers across the hospital. Both utilization of antibiotics and density of resistant isolates of P. aeruginosa and Acinetobacter spp. were followed within the ICU. Resistance densities of P. aeruginosa to all tested antimicrobials were lower in 2015, in comparison with 2011. Although isolates of Acinetobacter spp. had lower resistance density in 2015 than in 2011 to the majority of investigated antibiotics, a statistically significant decrease was noted only for piperacillin/tazobactam. Statistically significant decreasing trends of consumption were recorded for third-generation cephalosporins, aminoglycosides and fluoroquinolones, whereas for the piperacillin/tazobactam, ampicillin/sulbactam and carbapenems, utilization trends were decreasing, but without statistical significance. In the same period, increasing trends of consumption were observed for tigecycline and colistin. Regular monitoring of resistance of bacterial isolates in ICUs and reporting of summary results to prescribers may lead to a significant decrease in utilization of some antibiotics and slow restoration of P. aeruginosa and Acinetobacter spp. susceptibility. © 2017 John Wiley & Sons Ltd.

Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. II. Radiation-induced polymerization of methyl methacrylate adsorbed on several inorganic substances

International Nuclear Information System (INIS)

Fukano, K.; Kageyama, E.

1975-01-01

The radiation-induced polymerization of methyl methacrylate (MMA) adsorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO 2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond

Nrf2 pathway modulates Substance P-induced human mast cell activation and degranulation in the hair follicle.

Science.gov (United States)

Jadkauskaite, Laura; Bahri, Rajia; Farjo, Nilofer; Farjo, Bessam; Jenkins, Gail; Bhogal, Ranjit; Haslam, Iain; Bulfone-Paus, Silvia; Paus, Ralf

2018-05-30

Activation of Nrf2 in primary human mast cells exposed to oxidative stress induced by substance P suppresses pro-inflammatory gene transcription, activation and degranulation. Copyright © 2018. Published by Elsevier Inc.

Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07

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P. Gururaj

Full Text Available ABSTRACT The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 ºC and pH 7, using a 0.5% (v/v inoculum, 2% (v/v castor oil (inducer, and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 ºC and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.

Radioactive substances found on the contaminated fish

Energy Technology Data Exchange (ETDEWEB)

Kiba, T; Ohashi, S; Shibata, M; Mizube, T

1954-01-01

Radiochemical investigation of the substance collected from the surface of tuna fish which were brought back by the No. 5 Fukuryu Maru was performed. Most of the radioactivity was found on the scales which could not be decontaminated by treating with H/sub 2/O; 80% of the activity was removed by washing the dried scales with 3N HCl. Paper chromatographic separation of the HCl fraction showed the presence of /sup 140/Ba, /sup 89/Sr, /sup 132/Te, and probably /sup 95/Zr, /sup 140/La, and rare earths.

Epidemiological characteristics of blaNDM-1 in Enterobacteriaceae and the Acinetobacter calcoaceticus-Acinetobacter baumannii complex in China from 2011 to 2012.

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Weimei Ou

Full Text Available The study aimed to investigate the prevalence and epidemiological characteristics of blaNDM-1 (encoding New Delhi metallo-β-lactamase 1 in Enterobacteriaceae and the Acinetobacter calcoaceticus-Acinetobacter baumannii complex (ABC in China from July 2011 to June 2012.PCR was used to screen for the presence of blaNDM-1 in all organisms studied. For blaNDM-1-positive strains, 16S rRNA analysis and Analytical Profile Index (API strips were used to identify the bacterial genus and species. The ABCs were reconfirmed by PCR detection of blaOXA-51-like. Antibiotic susceptibilities of the bacteria were assessed by determining minimum inhibitory concentration (MIC of them using two-fold agar dilution test, as recommended by the Clinical and Laboratory Standards Institute (CLSI. Molecular typing was performed using pulsed-field gel electrophoresis (PFGE. S1 nuclease-pulsed-field gel electrophoresis (S1-PFGE and Southern blot hybridization were conducted to ascertain the gene location of blaNDM-1. Conjugation experiments were conducted to determine the transmission of blaNDM-1-positive strains.Among 2,170 Enterobacteriaceae and 600 ABCs, seven Enterobacteriaceae strains and two A. calcoaceticus isolates from five different cities carried the blaNDM-1 gene. The seven Enterobacteriaceae strains comprised four Klebsiella pneumoniae, one Enterobacter cloacae, one Enterobacter aerogen and one Citrobacter freundii. All seven were non-susceptible to imipenem, meropenem or ertapenem. Two A. calcoaceticus species were resistant to imipenem and meropenem. Three K. pneumoniae showed the same PFGE profiles. The blaNDM-1 genes of eight strains were localized on plasmids, while one was chromosomal.Compared with previous reports, the numbers and species containing the blaNDM-1 in Enterobacteriaceae have significantly increased in China. Most of them are able to disseminate the gene, which is cause for concern. Consecutive surveillance should be implemented and should

Mortalidad por Acinetobacter baumannii en unidades de cuidados intensivos en Colombia Acinetobacter baumannii - related mortality in intensive care units in Colombia

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Elkin V Lemos

2011-10-01

Full Text Available OBJETIVO: Comparar la mortalidad en pacientes infectados por Acinetobacter baumannii multisensibles con pacientes infectados por A. baumannii multirresistentes hospitalizados en unidades de cuidados intensivos (UCI de Colombia. MÉTODOS: Estudio prospectivo, observacional y multicéntrico. Se incluyó a 165 pacientes ingresados en las UCIs participantes entre abril de 2006 y abril de 2010. Se comparó la mortalidad de los pacientes con aislamientos clínicos de A. baumannii multirresistentes frente a aquellos multisensibles al día 14 y 30 de hospitalización. RESULTADOS: De los 165 pacientes adultos que presentaron infecciones asociadas al cuidado en salud (IACS por A. baumannii, en 62 se encontraron bacterias multisensibles y en 103, multirresistentes. No se hallaron diferencias estadísticamente significativas en la mortalidad al día 14 de hospitalización en UCI. Sí se observaron en cambio diferencias significativas (P OBJECTIVE: Compare mortality in multidrug-susceptible Acinetobacter baumannii infected patients and multidrug-resistant A. baumannii-infected patients hospitalized in intensive care units (ICUs in Colombia. METHODS: A prospective, observational, and multicenter study. A total of 165 patients admitted to the participating ICUs from April 2006 to April 2010 were included. On day 14 and day 30 of hospitalization, mortality in multidrug-resistant patients with clinical isolates of A. baumannii was compared with that in multidrug-susceptible patients. RESULTS: Of the 165 adult patients who had health care-associated infections (HAI caused by A. baumannii, multidrug-susceptible bacteria were found in 62 patients and multidrug-resistant bacteria in 103. Statistically significant differences in mortality on day 14 of hospitalization in the ICU were not found. On the other hand, significant differences (P < 0.05 in mortality on day 30 of hospitalization were observed between patients with multidrug-resistant isolates and those with

A data-driven mathematical model of multi-drug resistant Acinetobacter baumannii transmission in an intensive care unit

NARCIS (Netherlands)

Wang, Xia; Chen, Yong; Zhao, Wei; Wang, Yan; Song, Qing; Liu, Hui; Zhao, Jingya; Han, Xuelin; Hu, Xiaohua; Grundmann, Hajo; Xiao, Yanni; Han, Li

2015-01-01

Major challenges remain when attempting to quantify and evaluate the impacts of contaminated environments and heterogeneity in the cohorting of health care workers (HCWs) on hospital infections. Data on the detection rate of multidrug-resistant Acinetobacter baumannii (MRAB) in a Chinese intensive

Specific activity isolation and determination of radioactive Estrogenic Substances in White Clover

International Nuclear Information System (INIS)

Pupiales T, G.; Mejia M, G.

1986-01-01

Due to high number of leguminous that exhibit estrogenic activity, subterranean clover between others, which causes infertility in sheep that eat it. It has been considered that white clover (Trifolium repens, variety Ladino, is an specie of low estrogenic activity, however at Bogota City (Colombia) it has high estrogenic activity and may cause reduction in the dairy cattle fertility. Research done in the IAN (today Ingeominas) over this clover variety, showed that the radioactivity substances presents in the white clover have high activity for stradiol, affecting organs from mouse females; Isoflavonoids from vegetables have an anabolism and utero tropic action; estrogenic activity of clover leaves, was exponentially proportional to the amount of ultraviolet radioactivity, falling upon plants during leaves development stage

Kinetics and Novel Degradation Pathway of Permethrin in Acinetobacter baumannii ZH-14

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Hui Zhan

2018-02-01

Full Text Available Persistent use of permethrin has resulted in its ubiquitous presence as a contaminant in surface streams and soils, yet little is known about the kinetics and metabolic behaviors of this pesticide. In this study, a novel bacterial strain Acinetobacter baumannii ZH-14 utilizing permethrin via partial hydrolysis pathways was isolated from sewage sludge. Response surface methodology based on Box-Behnken design of cultural conditions was used for optimization resulting in 100% degradation of permethrin (50 mg·L−1 within 72 h. Strain ZH-14 degraded permethrin up to a concentration of 800 mg·L−1. Biodegradation kinetics analysis indicated that permethrin degradation by this strain was concentration dependent, with a maximum specific degradation rate, half-saturation constant, and inhibition constant of 0.0454 h−1, 4.7912 mg·L−1, and 367.2165 mg·L−1, respectively. High-performance liquid chromatography and gas chromatography-mass spectrometry identified 3-phenoxybenzenemethanol and 3-phenoxybenzaldehyde as the major intermediate metabolites of the permethrin degradation pathway. Bioaugmentation of permethrin-contaminated soils with strain ZH-14 significantly enhanced degradation, and over 85% of permethrin was degraded within 9 days with the degradation process following the first-order kinetic model. In addition to degradation of permethrin, strain ZH-14 was capable of degrading a large range of synthetic pyrethroids such as deltamethrin, bifenthrin, fenpropathrin, cyhalothrin, and beta-cypermethrin which are also widely used pesticides with environmental contamination problems, suggesting the promising potentials of A. baumannii ZH-14 in bioremediation of pyrethroid-contaminated terrestrial and aquatic environments.

Effect of BCAA intake during endurance exercises on fatigue substances, muscle damage substances, and energy metabolism substances.

Science.gov (United States)

Kim, Dong-Hee; Kim, Seok-Hwan; Jeong, Woo-Seok; Lee, Ha-Yan

2013-12-01

The increase rate of utilization of branched-chain amino acids (BCAA) by muscle is reduced to its plasma concentration during prolonged exercise leading to glycogen. BCAA supplementation would reduce the serum activities of intramuscular enzymes associated with muscle damage. To examine the effects of BCAA administration on fatigue substances (serotonin, ammonia and lactate), muscle damage substances (CK and LDH) and energy metabolism substances (FFA and glucose) after endurance exercise. Subjects (n = 26, college-aged males) were randomly divided into an experimental (n = 13, EXP) and a placebo (n = 13, CON) group. Subjects both EXP and CON performed a bout of cycle training (70% VO2max intensity) to exhaustion. Subject in the EXP were administrated BCAA (78ml/kg·w) prior to the bout of cycle exercise. Fatigue substances, muscle damage substances and energy metabolism substances were measured before ingesting BCAAs and placebos, 10 min before exercise, 30 min into exercise, immediately after exercise, and 30 min after exercise. Data were analyzed by two-way repeated measure ANCOVA, correlation and statistical significance was set at p BCAA decreased serum concentrations of the intramuscular enzymes as CK and LDH following exhaustive exercise. This observation suggests that BCAA supplementation may reduce the muscle damage associated with endurance exercise.

Characterization of Acinetobacter baumannii strain PS3 in degradation of food emulsifiers

Science.gov (United States)

Nguyen, Ngoc Tuan; Tran, Tuyet Nhung; Ha, Thi Bich Ngoc

2018-04-01

Strain SP3 revealed the abilty to utilizes emulsifier which is widely used in the preparation of drugs, vaccines, food, cosmetics and skin care products as its sole carbon and energy source. Generation time ranges from 1.4 to 2.1 h on the polysorbate family. Strain was identified as Acinetobacter baumannii based on 16S rRNA gene and it could dispose 27 % polysorbate 80 within a day. The proposed mechanism for polysorbate utilization belongs to the β-oxidation.

Extracellular Polymeric Substances Govern the Surface Charge of Biogenic Elemental Selenium Nanoparticles

KAUST Repository

Jain, Rohan

2015-02-03

© 2014 American Chemical Society. The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies.

Prevalence and risk factors of metallo β-lactamase producing Pseudomonas aeruginosa and Acinetobacter species in burns and surgical wards in a tertiary care hospital

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Simit H Kumar

2012-01-01

Full Text Available Introduction: The production of Metallo-β-lactamases (MBLs is one of the resistance mechanisms of Pseudomonas aeruginosa and Acinetobacter species. There is not much Indian data on the prevalence of MBLs in burns and surgical wards. Materials and Methods: A total of 145 non-duplicate isolates of carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter species, isolated from pus/wound swabs and endotracheal secretions from burns and surgical wards, were tested for MBL production by modified ethylene diamine tetra acetic acid (EDTA disc synergy and double disc synergy tests. Results: Prevalence of MBLs was 26.9% by both the above tests. All MBL-positive isolates were multidrug resistant. Only 6.06% (2/33 P.aeruginosa and 16.67% (1/06 Acinetobacter species were susceptible to piperacillin-tazobactam and netilmycin, respectively. These patients had multiple risk factors like >8 days hospital stay, catheterization, IV lines, previous antibiotic use, mechanical ventilation, etc. Graft application and surgical intervention were significant risk factors in MBL-positive patients. Overall mortality in MBL-positive patients was 34.21%. Conclusion: Emergence of MBL-producing Pseudomonas aeruginosa and Acinetobacter species in this hospital is alarming, which reflect excessive use of carbapenems and at the same time, pose a therapeutic challenge to clinicians as well as to microbiologists. Therefore, a strict antibiotic policy and implementation of proper infection control practices will go a long way to prevent further spread of MBLs. Detection of MBLs should also become mandatory in all hospitals.

Insight into Identification of Acinetobacter Species by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) in the Clinical Laboratory

Science.gov (United States)

Li, Xiuyuan; Tang, Yanyan; Lu, Xinxin

2018-04-01

Currently, the capability of identification for Acinetobacter species using MALDI-TOF MS still remains unclear in clinical laboratories due to certain elusory phenomena. Thus, we conducted this research to evaluate this technique and reveal the causes of misidentification. Briefly, a total of 788 Acinetobacter strains were collected and confirmed at the species level by 16S rDNA and rpoB sequencing, and subsequently compared to the identification by MALDI-TOF MS using direct smear and bacterial extraction pretreatments. Cluster analysis was performed based on the mass spectra and 16S rDNA to reflect the diversity among different species. Eventually, 19 Acinetobacter species were confirmed, including 6 species unavailable in Biotyper 3.0 database. Another novel species was observed, temporarily named A. corallinus. The accuracy of identification for Acinetobacter species using MALDI-TOF MS was 97.08% (765/788), regardless of which pretreatment was applied. The misidentification only occurred on 3 A. parvus strains and 20 strains of species unavailable in the database. The proportions of strains with identification score ≥ 2.000 using direct smear and bacterial extraction pretreatments were 86.04% (678/788) and 95.43% (752/788), χ 2 = 41.336, P clinical samples was deemed reliable. Misidentification occurred occasionally due to the insufficiency of the database rather than sample extraction failure. We suggest gene sequencing should be performed when the identification score is under 2.000 even when using bacterial extraction pretreatment. [Figure not available: see fulltext.

QSAR development and profiling of 72,524 REACH substances for PXR activation and CYP3A4 induction

DEFF Research Database (Denmark)

Abildgaard Rosenberg, Sine; Xia, M.; Huang, R.

2017-01-01

,524 substances pre-registered under the EU chemicals regulation, REACH, and the models could predict 52.5% to 71.9% of the substances within their respective applicability domains. These predictions can, for example, be used for priority setting and in weight-of-evidence assessments of chemicals. Statistical...... analyses of the experimental drug dataset and the QSAR-predicted set of REACH substances were performed to identify similarities and differences in frequencies of overlapping positive results for PXR binding, PXR activation and CYP3A4 induction between the two datasets....

Epidemiology of Multiresistant Acinetobacter Infections in Bulgaria

International Nuclear Information System (INIS)

Savov, E.; Borisova, M.; Michailova, G.

2007-01-01

Evolution of bacteria towards resistance to antimicrobial drugs, including these with multidrug resistance, is very important issue for hospital epidemiology in all over the world. There are many papers about an increasing number of Acinetobacter baumannii blood stream and other type of infections in patients at military medical facilities in the Iraq / Kuwait region and in Afghanistan during Operation Enduring Freedom /OEF /. It has now become also a one of the major cause of hospital acquired infections in Bulgaria which due to its remarkable propensity to rapidly acquire resistance determinants to a wide range of antimicrobial drugs. According to the data obtained in Bulgaria, it can be concluded that the majority of the A.baumannii isolates was strikingly resistant, including the 3rd generation of cephalosporins, quinolones and also carbapenems, in the last years. Different methods / phenotypical and molecular methods, including PCR/ for a multidrug A.baumannii investigation and its clonality determination are needed, especially when the strains are not epidemiological related.(author)

Comparison of the bony remodelling of two synthetic biomaterials: aragonite 55% and aragonite 55% with active substance

International Nuclear Information System (INIS)

Oudadesse, H; Derrien, A C; Martin, S; Lucas-Girot, A; Cathelineau, G

2007-01-01

In this work, the in vivo behaviour of pure aragonite and vectabone, which is an association of aragonite and an active substance such as gentamicin, was studied to highlight the kinetic resorption of these two biomaterials with 55% of porosity destined for the filling or replacement of bony defects. The synthesis conditions and parameters we used permit us to obtain a biomaterial without a sintering stage. These conditions allow introducing of active substances at the first stage of the elaboration. In this work, the gentamycin antibiotic was associated with calcium carbonate (aragonite 55% with gentamycin) to deliver this active substance on the surgical site for local treatment. The tricalcium phosphate biomaterial was used as the control because of its high biocompatibility. The bony remodelling of these three biomaterials was studied by in vivo experiments. This study was ensured with neutron activation analysis (NAA). The resorption kinetic was elaborated and comparisons of the remodelling biomaterials CaCO 3 55% and CaCO 3 55% with gentamicin (vectabone) and tricalcium phosphate were carried out. The obtained results show that, 6 months after implantation, the mineral composition of vectabone and tricalcium phosphate becomes close to that of young bone. Twelve months after implantation, it becomes similar to that of mature bone

Specific binding of an immunoreactive and biologically active 125I-labeled substance P derivative to mouse mesencephalic cells in primary culture

International Nuclear Information System (INIS)

Beaujouan, J.C.; Torrens, Y.; Herbet, A.; Daguet, M.C.; Glowinski, J.; Prochiantz, A.

1982-01-01

Binding characteristics of 125 I-labeled Bolton-Hunter substance P ([ 125 I]BHSP), a radioactive analogue of substance P, were studied with mesencephalic primary cultures prepared from embryonic mouse brain. Nonspecific binding represented no more than 20% of the total binding observed on the cells. In contrast, significant specific binding--saturable, reversible, and temperature-dependent--was demonstrated. Scatchard analysis of concentration-dependent binding saturation indicates a single population of noninteracting sites with a high affinity (Kd . 169 pM). Substance P and different substance P analogues were tested for their competitive potencies with regard to [ 125 I]BHSP binding. BHSP itself, substance P, (Tyr8)-substance P, and (nor-Leu11)-substance P strongly inhibited the binding. Good inhibition was also obtained with physalaemin and eledoisin, two peptides structurally related to substance P. When substance P C-terminal fragments were tested for their ability to compete with [ 125 I]BHSP binding, a good relationship was found between competitive activity and peptide length. Regional distribution of [ 125 I]BHSP binding sites was found using primary cultures obtained from different regions of embryonic mouse brain. Mesencephalic, hypothalamic, and striatal cultures had the highest [ 125 I]BHSP binding capacities, whereas cortical, hippocampal, and cerebellar cells shared only little binding activity. Finally, when mesencephalic cells were grown under conditions impairing glial development, [ 125 I]BHSP binding was not affected, demonstrating that binding sites are located on neuronal cells

Evaluation of carriage and environmental contamination by carbapenem-resistant Acinetobacter baumannii.

Science.gov (United States)

Nutman, A; Lerner, A; Schwartz, D; Carmeli, Y

2016-11-01

We evaluated the sensitivity of surveillance cultures for carbapenem-resistant Acinetobacter baumannii (CRAB) in patients and in their environment. Patients with a CRAB-positive clinical culture were sampled within 7 days; the buccal mucosa and rectum were sampled using swabs, and skin was sampled using pre-moistened sterile sponges. Sponges were also used to sample the surrounding environment. Specimens were inoculated onto CHROMagar MDR Acinetobacter plates both directly and after overnight enrichment. CRAB load was scored semi-quantitatively and composite scores for patient colonization and environmental contamination were calculated. Thirty-four patients were included. Screening sensitivity was 28/34 (82%) for buccal mucosa, 30/34 (88%) for skin, and 25/34 (74%) for rectum. Combined sensitivity was 32/34 (94%). Among patients with CRAB-positive respiratory cultures, sensitivity for buccal mucosa was 20/20 (100%). Direct inoculation had excellent sensitivity: 25/28 (89%) for all three sites combined. In the subgroup of patients who did not have a respiratory source for CRAB, direct inoculation sensitivity was lower than among patients with CRAB-positive respiratory cultures: 5/8 (63%) versus 20/20 (100%). The environment of all patients was contaminated with CRAB. There was a positive correlation between the patient colonization score and the environmental contamination score (r = 0.63, p Environmental contamination is common and can be monitored. Implementing screening may facilitate infection control efforts to limit the spread of CRAB. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Explorando el plegamiento metallo-beta-lactamasa en el genoma de Acinetobacter baumanni

OpenAIRE

Rodríguez Calviño, Fabiola

2012-01-01

Acinetobacter baumannii fue considerado siempre como un patógeno de relativa baja virulencia, pero durante las dos últimas décadas, este microorganismo oportunista ha emergido como uno de los mayores problemas encarados por el sistema clínico en hospitales de todo el mundo. Como consecuencia inevitable de la presión selectiva impuesta por el uso abusivo de antibióticos en el tratamiento de infecciones, se han descrito cepas clínicas multirresistentes de A. baumannii, con una alta capacidad...

Improved PVDF membrane performance by doping extracellular polymeric substances of activated sludge.

Science.gov (United States)

Guan, Yan-Fang; Huang, Bao-Cheng; Qian, Chen; Wang, Long-Fei; Yu, Han-Qing

2017-04-15

Polyvinylidene fluoride (PVDF) membrane has been widely applied in water and wastewater treatment because of its high mechanical strength, thermal stability and chemical resistance. However, the hydrophobic nature of PVDF membrane makes it readily fouled, substantially reducing water flux and overall membrane rejection ability. In this work, an in-situ blending modifier, i.e., extracellular polymeric substances (EPS) from activated sludge, was used to enhance the anti-fouling ability of PVDF membrane. Results indicate that the pure water flux of the membrane and its anti-fouling performance were substantially improved by blending 8% EPS into the membrane. By introducing EPS, the membrane hydrophilicity was increased and the cross section morphology was changed when it interacted with polyvinl pyrrolidone, resulting in the formation of large cavities below the finger-like pores. In addition, the fraction of pores with a size of 100-500 nm increased, which was also beneficial to improving membrane performance. Surface thermodynamic calculations indicate the EPS-functionalized membrane had a higher cohesion free energy, implying its good pollutant rejection and anti-fouling ability. This work provides a simple, efficient and cost-effective method to improve membrane performance and also extends the applications of EPS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using the Chinese herb Scutellaria barbata against extensively drug-resistant Acinetobacter baumannii infections: in vitro and in vivo studies.

Science.gov (United States)

Tsai, Chin-Chuan; Lin, Chi-Shiuan; Hsu, Chun-Ru; Chang, Chiu-Ming; Chang, I-Wei; Lin, Li-Wei; Hung, Chih-Hsin; Wang, Jiun-Ling

2018-03-20

No animal model studies have been conducted in which the efficacy of herbal compounds has been tested against multidrug-resistant Acinetobacter baumannii infections. Very few antibiotics are available for the treatment of pulmonary infections caused by extensively drug-resistant Acinetobacter baumannii (XDRAB). To find alternative treatments, traditional Chinese herbs were screened for their antimicrobial potential. The present study screened 30 herbs that are traditionally used in Taiwan and that are commonly prescribed for heat clearing and detoxification. The herbs with antibacterial activities were analysed by disc diffusion assays, time-kill assays and a murine lung infection model. Of the 30 herbs tested, only Scutellaria barbata demonstrated 100% in vitro activity against XDRAB. Furthermore, we compared the antibacterial effect of the S. barbata extract with that of colistin, and the S. barbata extract showed better antibacterial effect. In the XDRAB pneumonia murine model, we compared the antimicrobial effects of the orally administered S. barbata extract (200 mg/kg, every 24 h), the intratracheally administered colistin (75,000 U/kg, every 12 h), and the control group. The bacterial load in the lungs of the treatment group that received the oral S. barbata extract showed a significant decrease in comparison to that in the lungs of the control group. In addition, histopathological examinations also revealed better resolution of perivascular, peribronchial, and alveolar inflammation in the oral S. barbata extract-treated group. Our in vitro and in vivo data from the animal model support the use of S. barbata as an alternate drug to treat XDRAB pulmonary infections. However, detailed animal studies and clinical trials are necessary to establish the clinical utility of S. barbata in treating XDRAB pulmonary infections.

Antimicrobial activity of Eucalyptus camaldulensis essential oils and their interactions with conventional antimicrobial agents against multi-drug resistant Acinetobacter baumannii.

Science.gov (United States)

Knezevic, Petar; Aleksic, Verica; Simin, Natasa; Svircev, Emilija; Petrovic, Aleksandra; Mimica-Dukic, Neda

2016-02-03

Traditional herbal medicine has become an important issue on the global scale during the past decade. Among drugs of natural origin, special place belongs to essential oils, known as strong antimicrobial agents that can be used to combat antibiotic-resistant bacteria. Eucalyptus camaldulensis leaves are traditional herbal remedy used for various purposes, including treatment of infections. The aim of this study was to determine antimicrobial potential of two E. camaldulensis essential oils against multi-drug resistant (MDR) Acinetobacter baumannii wound isolates and to examine possible interactions of essential oils with conventional antimicrobial agents. Chemical composition of essential oils was determined by gas chromatography-mass spectrometry analysis (GC-MS). MIC values of essential oils against A. baumannii strains were estimated by modified broth microdilution method. The components responsible for antimicrobial activity were detected by bioautographic analysis. The potential synergy between the essential oils and antibiotics (ciprofloxacin, gentamicin and polymyxin B) was examined by checkerboard method and time kill curve. The dominant components of both essential oils were spatulenol, cryptone, p-cimene, 1,8-cineole, terpinen-4-ol and β-pinene. The detected MICs for the E. camaldulensis essential oils were in range from 0.5 to 2 μl mL(-1). The bioautographic assay confirmed antibacterial activity of polar terpene compounds. In combination with conventional antibiotics (ciprofloxacin, gentamicin and polymyxin B), the examined essential oils showed synergistic antibacterial effect in most of the cases, while in some even re-sensitized MDR A. baumannii strains. The synergistic interaction was confirmed by time-kill curves for E. camaldulensis essential oil and polymyxin B combination which reduced bacterial count under detection limit very fast, i.e. after 6h of incubation. The detected anti-A. baumannii activity of E. camaldulensis essential oils

Hubungan antara Sepsis Akibat Acinetobacter baumannii dan Mortalitas pada Pasien Anak dengan Penyakit Kritis di Pediatric Intensive Care Unit (PICU) RSUP Haji Adam Malik Medan, 2011-201

OpenAIRE

Sardini, Rima Novia

2015-01-01

Acinetobacter sp. is one of the major pathogenic bacteria which are endemic throughout the world. Acinetobacter baumannii’s infections are often involved in a variety of nosocomial infections in the urinary tract, surgical wound infection, infection of the blood vessels, ventilator-associated pneumonia (VAP) and meningitis in particular patients with a low immune system that are in the intensive care unit (ICU). This study aimed to determine the relationship of the number of primary disease...

Isolation and characterization of antimicrobial compounds in plant extracts against multidrug-resistant Acinetobacter baumannii.

Directory of Open Access Journals (Sweden)

Yoko Miyasaki

Full Text Available The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii.

Molecular Epidemiology and Clinical Impact of Acinetobacter calcoaceticus-baumannii Complex in a Belgian Burn Wound Center.

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Daniel De Vos

Full Text Available Multidrug resistant Acinetobacter baumannii and its closely related species A. pittii and A. nosocomialis, all members of the Acinetobacter calcoaceticus-baumannii (Acb complex, are a major cause of hospital acquired infection. In the burn wound center of the Queen Astrid military hospital in Brussels, 48 patients were colonized or infected with Acb complex over a 52-month period. We report the molecular epidemiology of these organisms, their clinical impact and infection control measures taken. A representative set of 157 Acb complex isolates was analyzed using repetitive sequence-based PCR (rep-PCR (DiversiLab and a multiplex PCR targeting OXA-51-like and OXA-23-like genes. We identified 31 rep-PCR genotypes (strains. Representatives of each rep-type were identified to species by rpoB sequence analysis: 13 types to A. baumannii, 10 to A. pittii, and 3 to A. nosocomialis. It was assumed that isolates that belonged to the same rep-type also belonged to the same species. Thus, 83.4% of all isolates were identified to A. baumannii, 9.6% to A. pittii and 4.5% to A. nosocomialis. We observed 12 extensively drug resistant Acb strains (10 A. baumannii and 2 A. nosocomialis, all carbapenem-non-susceptible/colistin-susceptible and imported into the burn wound center through patients injured in North Africa. The two most prevalent rep-types 12 and 13 harbored an OXA-23-like gene. Multilocus sequence typing allocated them to clonal complex 1 corresponding to EU (international clone I. Both strains caused consecutive outbreaks, interspersed with periods of apparent eradication. Patients infected with carbapenem resistant A. baumannii were successfully treated with colistin/rifampicin. Extensive infection control measures were required to eradicate the organisms. Acinetobacter infection and colonization was not associated with increased attributable mortality.

Molecular Epidemiology and Clinical Impact of Acinetobacter calcoaceticus-baumannii Complex in a Belgian Burn Wound Center

Science.gov (United States)

Bilocq, Florence; Jennes, Serge; Verbeken, Gilbert; Rose, Thomas; Keersebilck, Elkana; Bosmans, Petra; Pieters, Thierry; Hing, Mony; Heuninckx, Walter; De Pauw, Frank; Soentjens, Patrick; Merabishvili, Maia; Deschaght, Pieter; Vaneechoutte, Mario; Bogaerts, Pierre; Glupczynski, Youri; Pot, Bruno; van der Reijden, Tanny J.; Dijkshoorn, Lenie

2016-01-01

Multidrug resistant Acinetobacter baumannii and its closely related species A. pittii and A. nosocomialis, all members of the Acinetobacter calcoaceticus-baumannii (Acb) complex, are a major cause of hospital acquired infection. In the burn wound center of the Queen Astrid military hospital in Brussels, 48 patients were colonized or infected with Acb complex over a 52-month period. We report the molecular epidemiology of these organisms, their clinical impact and infection control measures taken. A representative set of 157 Acb complex isolates was analyzed using repetitive sequence-based PCR (rep-PCR) (DiversiLab) and a multiplex PCR targeting OXA-51-like and OXA-23-like genes. We identified 31 rep-PCR genotypes (strains). Representatives of each rep-type were identified to species by rpoB sequence analysis: 13 types to A. baumannii, 10 to A. pittii, and 3 to A. nosocomialis. It was assumed that isolates that belonged to the same rep-type also belonged to the same species. Thus, 83.4% of all isolates were identified to A. baumannii, 9.6% to A. pittii and 4.5% to A. nosocomialis. We observed 12 extensively drug resistant Acb strains (10 A. baumannii and 2 A. nosocomialis), all carbapenem-non-susceptible/colistin-susceptible and imported into the burn wound center through patients injured in North Africa. The two most prevalent rep-types 12 and 13 harbored an OXA-23-like gene. Multilocus sequence typing allocated them to clonal complex 1 corresponding to EU (international) clone I. Both strains caused consecutive outbreaks, interspersed with periods of apparent eradication. Patients infected with carbapenem resistant A. baumannii were successfully treated with colistin/rifampicin. Extensive infection control measures were required to eradicate the organisms. Acinetobacter infection and colonization was not associated with increased attributable mortality. PMID:27223476

Novel use of antimicrobial hand sanitizer in treatment of nosocomial acinetobacter infection.

Science.gov (United States)

Donahue, Meghan; Watson, Luke R; Torress-Cook, Alfonso; Watson, Paul A

2009-01-01

Colonization of wounds with multidrug-resistant organisms is a difficult orthopedic problem. Acinetobacter infections are especially difficult because they are resistant to all currently available antibiotics. We present the use of a novel skin sanitizer, Stay Byotrol Clean (Byotrol Inc, Spartanburg, South Carolina), to treat a multidrug-resistant wound infection. A 31-year-old T10 paraplegic man presented with chronic bilateral stage IV decubitus trochanteric ulcers. Cultures grew methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The ulcers were initially treated with irrigation and debridement and vancomycin, levaquin, and cefepime. After 4 months of aggressive treatment, the cultures continued to be positive for Escherichia coli and Acinetobacter baumannii. The patient was started on amikacin and tigecycline. Despite 1 additional month of aggressive wound care, debridements, and intravenous antibiotics, the cultures continued to grow A baumannii and Pseudomonas aerug. The A baumannii was resistant to all available antibiotics tested. The ulcers were then treated with daily application of Stay Byotrol Clean hand and skin sanitizer. Four days later, cultures were negative for any bacterial growth, with no A baumannii. After 1 week, the ulcers showed new granulation tissue with no visible necrotic tissue. After 3 months of treatment, the ulcers had healed. Stay Byotrol Clean is nonirritating and contains no iodine or alcohol. It is currently being used for decolonization of patients on admission to the hospital, however, there is great potential for its use in wound treatment, preoperative surgical sterilization, and orthopedic devices.

The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii.

Science.gov (United States)

Ghafourian, Sobhan; Good, Liam; Sekawi, Zamberi; Hamat, Rukman Awang; Soheili, Sara; Sadeghifard, Nourkhoda; Neela, Vasanthakumari

2014-07-01

Although analysis of toxin-antitoxin (TA) systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems' locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium.

Surface active monomers synthesis, properties, and application

CERN Document Server

Borzenkov, Mykola

2014-01-01

This brief includes information on the background?of and development of synthesis of various types of surface active monomers. The authors explain the importance of utilization of surface active monomers for creation of surface active polymers? and the various biomedical applications of such compounds . This brief introduces techniques for the synthesis of novel types of surface active monomers, their colloidal and polymerizable properties and application for needs of medicine and biology.

UV light-induced survival response in a highly radiation-resistant isolate of the Moraxella-acinetobacter group

International Nuclear Information System (INIS)

Keller, L.C.; Thompson, T.L.; Maxcy, R.B.

1982-01-01

A highly radiation-resistant member of the Moraxella-Acinetobacter group, isolate 4, obtained from meat, was studied to determine the effect of preexposure to UV radiation on subsequent UV light resistance. Cultures that were preexposed to UV light and incubated for a short time in plate count broth exhibited increased survival of a UV light challenge dose. This response was inhibited in the presence of chloramphenicol. Frequencies of mutation to streptomycin, trimethoprim, and sulfanilamide resistance remained the same after the induction of this survival response and were not altered by treatment with mutagens, with the exception of mutation to streptomycin resistance after γ-irradiation or nitrosoguanidine or methyl methane sulfonate treatment. The results indicated that isolate 4 has a UV light-inducible UV light resistance mechanism which is not associated with increased mutagenesis. The characteristics of the radiation resistance response in this organism are similar to those of certain other common food contaminants. Therefore, considered as part of the total microflora of meat, isolate 4 and the other radiation-resistant Moraxella-Acinetobacter isolates should not pose unique problems in a proposed radappertizaton process

Prevalence of metallo-beta-lactamase among Pseudomonas aeruginosa and Acinetobacter baumannii isolated from burn wounds and in vitro activities of antibiotic combinations against these isolates.

Science.gov (United States)

Altoparlak, Ulku; Aktas, Ferda; Celebi, Demet; Ozkurt, Zulal; Akcay, Mufide N

2005-09-01

The prevalence of metallo-beta-lactamases (MBLs) produced by isolates of Pseudomonas aeruginosa and Acinetobacter baumannii and the activities of various antmicrobial combinations against MBL producer strains were investigated. During the period from June 2003 till July 2004, 120 P. aeruginosa and 9 A. baumannii nonduplicate isolates were obtained from burn wounds. Forty strains (37 P. aeruginosa, 3 A. baumannii) were selected because of resistance to carbapenems. Screening for MBL production was performed in the latter isolates by the combined disk method which depends on comparing the zones given by disks containing imipenem with and without ethylenediaminetetraacetic acid (EDTA). Of imipenem resistant P. aeruginosa strains, 21 and 1 of A. baumannii were found metallo-beta-lactamase producers. Disk approximation studies were then performed to test for in vitro activities of various antimicrobial combinations. For a total of 21 P. aeruginosa strains, synergy was demonstrated predominantly by ciprofloxacin in combination with ceftazidime and imipenem, by ofloxacin in combination with astreonam. Against MBL producer A. baumannii strain, synergy was detected only with imipenem-ofloxacin combination. None of the combinations were antagonistic. These results suggest that MBL producing P. aeruginosa and A. baumanni strains have been introduced into burn centers, and to prevent the further spread of MBL producers, it is essential for carbapenem resistant isolates to be screened for MBLs.

KatG and KatE Confer Acinetobacter Resistance to Hydrogen Peroxide but Sensitize Bacteria to Killing by Phagocytic Respiratory Burst

Science.gov (United States)

Sun, Daqing; Crowell, Sara A.; Harding, Christian M.; De Silva, P. Malaka; Harrison, Alistair; Fernando, Dinesh M.; Mason, Kevin M.; Santana, Estevan; Loewen, Peter C.; Kumar, Ayush; Liu, Yusen

2016-01-01

Aims Catalase catalyzes the degradation of H2O2. Acinetobacter species have four predicted catalase genes, katA, katE, katG, and katX. The aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to H2O2, and to assess the role of catalase in Acinetobacter virulence. Main Methods Mutants of A. baumannii and A. nosocomialis with deficiencies in katA, katE, katG, and katX were tested for sensitivity to H2O2, either by halo assays or by liquid culture assays. Respiratory burst of neutrophils, in response to A. nosocomialis, was assessed by chemiluminescence to examine the effects of catalase on the production of reactive oxygen species (ROS)1 in neutrophils. Bacterial virulence was assessed using a Galleria mellonella larva infection model. Key findings The capacities of A. baumannii and A. nosocomialis to degrade H2O2 are largely dependent on katE. The resistance of both A. baumannii and A. nosocomialis to H2O2 is primarily determined by the katG gene, although katE also plays a minor role in H2O2 resistance. Bacteria lacking both the katG and katE genes exhibit the highest sensitivity to H2O2. While A. nosocomialis bacteria with katE and/or katG were able to decrease ROS production by neutrophils, these cells also induced a more robust respiratory burst in neutrophils than did cells deficient in both katE and katG. We also found that A. nosocomialis deficient in both katE and katG was more virulent than the wildtype A. nosocomialis strain. Significance Our findings suggest that inhibition of Acinetobacter catalase may help to overcome the resistance of Acinetobacter species to microbicidal H2O2 and facilitate bacterial disinfection. PMID:26860891

Bioinformatic analysis of phage AB3, a phiKMV-like virus infecting Acinetobacter baumannii.

Science.gov (United States)

Zhang, J; Liu, X; Li, X-J

2015-01-16

The phages of Acinetobacter baumannii has drawn increasing attention because of the multi-drug resistance of A. baumanni. The aim of this study was to sequence Acinetobacter baumannii phage AB3 and conduct bioinformatic analysis to lay a foundation for genome remodeling and phage therapy. We isolated and sequenced A. baumannii phage AB3 and attempted to annotate and analyze its genome. The results showed that the genome is a double-stranded DNA with a total length of 31,185 base pairs (bp) and 97 open reading frames greater than 100 bp. The genome includes 28 predicted genes, of which 24 are homologous to phage AB1. The entire coding sequence is located on the negative strand, representing 90.8% of the total length. The G+C mol% was 39.18%, without areas of high G+C content over 200 bp in length. No GC island, tRNA gene, or repeated sequence was identified. Gene lengths were 120-3099 bp, with an average of 1011 bp. Six genes were found to be greater than 2000 bp in length. Genomic alignment and phylogenetic analysis of the RNA polymerase gene showed that similar to phage AB1, phage AB3 is a phiKMV-like virus in the T7 phage family.

Code blue: Acinetobacter baumannii, a nosocomial pathogen with a role in the oral cavity

Science.gov (United States)

Richards, A.M.; Kwaik, Y. Abu; Lamont, R.J.

2015-01-01

SUMMARY Actinetobacter baumannii is an important nosocomial pathogen that can cause a wide range of serious conditions including pneumonia, meningitis, necrotizing fasciitis and sepsis. It is also a major cause of wound infections in military personnel injured during the conflicts in Afghanistan and Iraq, leading to its popular nickname of ‘Iraqibacter’. Contributing to its success in clinical settings is resistance to environmental stresses such as desiccation and disinfectants. Moreover, in recent years there has been a dramatic increase in the number of A. baumannii strains with resistance to multiple antibiotic classes. Acinetobacter baumannii is an inhabitant of oral biofilms, which can act as a reservoir for pneumonia and chronic obstructive pulmonary disease. Subgingival colonization by A. baumannii increases the risk of refractory periodontitis. Pathogenesis of the organism involves adherence, biofilm formation and iron acquisition. In addition, A. baumannii can induce apoptotic cell death in epithelial cells and kill hyphal forms of Candida albicans. Virulence factors that have been identified include pili, the outer membrane protein OmpA, phospholipases and extracellular polysaccharide. Acinetobacter baumannii can sense blue light through a blue-light sensing using flavin (BLUF) domain protein, BlsA. The resulting conformational change in BlsA leads to changes in gene expression, including virulence genes. PMID:25052812

Association Between Substance Use and Gun-Related Behaviors.

Science.gov (United States)

Chen, Danhong; Wu, Li-Tzy

2016-01-01

Gun-related violence is a public health concern. This study synthesizes findings on associations between substance use and gun-related behaviors. Searches through PubMed, Embase, and PsycINFO located 66 studies published in English between 1992 and 2014. Most studies found a significant bivariate association between substance use and increased odds of gun-related behaviors. However, their association after adjustment was mixed, which could be attributed to a number of factors such as variations in definitions of substance use and gun activity, study design, sample demographics, and the specific covariates considered. Fewer studies identified a significant association between substance use and gun access/possession than other gun activities. The significant association between nonsubstance covariates (e.g., demographic covariates and other behavioral risk factors) and gun-related behaviors might have moderated the association between substance use and gun activities. Particularly, the strength of association between substance use and gun activities tended to reduce appreciably or to become nonsignificant after adjustment for mental disorders. Some studies indicated a positive association between the frequency of substance use and the odds of engaging in gun-related behaviors. Overall, the results suggest a need to consider substance use in research and prevention programs for gun-related violence. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Whole-genome pyrosequencing of an epidemic multidrug-resistant Acinetobacter baumannii strain belonging to the European clone II group

DEFF Research Database (Denmark)

Iacono, M.; Villa, L.; Fortini, D.

2008-01-01

The whole-genome sequence of an epidemic, multidrug-resistant Acinetobacter baumannii strain (strain ACICU) belonging to the European clone II group and carrying the plasmid-mediated bla(OXA-58) carbapenem resistance gene was determined. The A. baumannii ACICU genome was compared with the genomes...

A Case of Acinetobacter Septic Pulmonary Embolism in an Infant

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Poonam Wade

2016-01-01

Full Text Available Case Characteristics. An 11-month-old girl presented with fever and breathlessness for 5 days. Patient had respiratory distress with bilateral coarse crepitations. Chest radiograph revealed diffuse infiltrations in the right lung with thick walled cavities in mid and lower zone. Computed tomography showed multiple cystic spaces and emboli. Blood culture grew Acinetobacter species. Intervention. Patient was treated with Meropenem and Vancomycin. Outcome. Complete clinical and radiological recovery was seen in child. Message. Blood cultures and CT of the chest are invaluable in the evaluation of a patient with suspected septic pulmonary embolism. With early diagnosis and appropriate antimicrobial therapy, complete recovery can be expected in patients with septic pulmonary embolism.

OXA beta-lactamase-mediated carbapenem resistance in Acinetobacter baumannii

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S M Amudhan

2011-01-01

Full Text Available Objectives: Acinetobacter baumannii is a significant pathogen in health care settings. In recent years, an increase in carbapenem resistance among A. baumannii due to Ambler class B metallo-beta-lactamases or class D OXA carbapenamases has been reported. In this study we detected the presence of OXA carbapenamases and coproduction of metallo-beta-lactamases (blaVIM and blaIMP by phenotypic and genotypic methods in carbapenem resistant clinical isolates of Acinetobacter baumannii. Materials and Methods: A total of 116 consecutive, non-duplicate carbapenem resistant A. baumannii isolated from various clinical specimens were included in the study. The modified Hodge test and inhibitor potentiated disk diffusion tests were done for the screening of carbapenamase and metallo-beta-lactamase production, respectively. Polymerase chain reaction (PCR was performed for the detection of OXA (blaOXA 23 like, blaOXA 24 like, blaOXA-51 like and blaOXA-58 like genes and metallo-beta-lactamases (blaVIM and blaIMP genes. Gene sequencing was performed for representative isolates. Results: Among 116 A. baumannii, OXA genes were detected in 106 isolates. BlaOXA 51 like (n = 99 and blaOXA -23 like (n = 95 were the most common and they coexisted in 89 isolates. blaOXA-24 like gene was detected in two isolates of which one also carried blaOXA-51 like and blaOXA-58 like genes. The modified Hodge test was positive in 113 isolates. The metallo-beta-lactamase screening test was positive in 92 isolates. blavim was detected in 54 isolates of which 1 also carried the blaIMP gene. Conclusions: blaOXA-23 like and bla OXA 51 like genes are the most common types of OXA carbapenamases while the blaVIM type is the most common type of metallo-beta-lactamase contributing to carbapenem resistance in clinical isolates of A. baumannii. The coproduction of OXA and metallo-beta-lactamases is not an uncommon phenomenon in A. baumannii.

Decisions during Negatively-Framed Messages Yield Smaller Risk-Aversion-Related Brain Activation in Substance-Dependent Individuals

Science.gov (United States)

Fukunaga, Rena; Bogg, Tim; Finn, Peter R.; Brown, Joshua W.

2012-01-01

A sizable segment of addiction research investigates the effects of persuasive message appeals on risky and deleterious behaviors. However, to date, little research has examined how various forms of message framing and corresponding behavioral choices might by mediated by risk-related brain regions. Using event-related functional magnetic resonance imaging, we investigated brain regions hypothesized to mediate the influence of message appeals on decision making in substance-dependent (SD) compared to non-substance-dependent (non-SD) individuals. The Iowa Gambling Task (IGT) was modified to include positively-framed, negatively-framed, and control messages about long-term deck payoffs. In the positively-framed condition, the SD and non-SD groups showed improved decision-making performance that corresponded to higher risk-aversion-related brain activity in the anterior cingulate cortex (ACC) and anterior insula (AI). In contrast, in the negatively-framed condition, the SD group showed poorer performance that corresponded to lower risk-aversion-related brain activity in the AI region. In addition, only the non-SD group showed a positive association between decision quality and greater risk-related activity in the ACC, regardless of message type. The findings suggest substance-dependent individuals may have reduced neurocognitive sensitivity in the ACC and AI regions involved in risk perception and aversion during decision-making, especially in response to framed messages that emphasize reduced prospects for long-term gains. PMID:23148798

PC-3 prostate carcinoma cells release signal substances that influence the migratory activity of cells in the tumor's microenvironment

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Zänker Kurt S

2010-07-01

Full Text Available Abstract Background Tumor cells interact with the cells of the microenvironment not only by cell-cell-contacts but also by the release of signal substances. These substances are known to induce tumor vascularization, especially under hypoxic conditions, but are also supposed to provoke other processes such as tumor innervation and inflammatory conditions. Inflammation is mediated by two organ systems, the neuroendocrine system and the immune system. Therefore, we investigated the influence of substances released by PC-3 human prostate carcinoma cells on SH-SY5Y neuroblastoma cells as well as neutrophil granulocytes and cytotoxic T lymphocytes, especially with regard to their migratory activity. Results PC-3 cells express several cytokines and growth factors including vascular endothelial growth factors, fibroblast growth factors, interleukins and neurotrophic factors. SH-SY5Y cells are impaired in their migratory activity by PC-3 cell culture supernatant, but orientate chemotactically towards the source. Neutrophil granulocytes increase their locomotory activity only in response to cell culture supernantant of hypoxic but not of normoxic PC-3 cells. In contrast, cytotoxic T lymphocytes do not change their migratory activity in response to either culture supernatant, but increase their cytotoxicity, whereas supernatant of normoxic PC-3 cells leads to a stronger increase than that of hypoxic PC-3 cells. Conclusions PC-3 cells release several signal substances that influence the behavior of the cells in the tumor's microenvironment, whereas no clear pattern towards proinflammatory or immunosuppressive conditions can be seen.

The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

DEFF Research Database (Denmark)

Agersø, Yvonne; Petersen, Andreas

2007-01-01

Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... and Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

OpenAIRE

Copley, Shelley D.; Crooks, Gwen P.

1992-01-01

4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed.

Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

Science.gov (United States)

Copley, Shelley D.; Crooks, Gwen P.

1992-01-01

4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed. PMID:16348702

Recommended approaches to the scientific evaluation of ecotoxicological hazards and risks of endocrine-active substances

Science.gov (United States)

Matthiessen, Peter; Ankley, Gerald T.; Biever, Ronald C.; Bjerregaard, Poul; Borgert, Christopher; Brugger, Kristin; Blankinship, Amy; Chambers, Janice; Coady, Katherine K.; Constantine, Lisa; Dang, Zhichao; Denslow, Nancy D.; Dreier, David; Dungey, Steve; Gray, L. Earl; Gross, Melanie; Guiney, Patrick D.; Hecker, Markus; Holbech, Henrik; Iguchi, Taisen; Kadlec, Sarah; Karouna-Renier, Natalie K.; Katsiadaki, Ioanna; Kawashima, Yukio; Kloas, Werner; Krueger, Henry; Kumar, Anu; Lagadic, Laurent; Leopold, Annegaaike; Levine, Steven L.; Maack, Gerd; Marty, Sue; Meador, James P.; Mihaich, Ellen; Odum, Jenny; Ortego, Lisa; Parrott, Joanne L.; Pickford, Daniel; Roberts, Mike; Schaefers, Christoph; Schwarz, Tamar; Solomon, Keith; Verslycke, Tim; Weltje, Lennart; Wheeler, James R.; Williams, Mike; Wolf, Jeffery C.; Yamazaki, Kunihiko

2017-01-01

A SETAC Pellston Workshop® “Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA)” was held in February 2016 in Pensacola, Florida, USA. The primary objective of the workshop was to provide advice, based on current scientific understanding, to regulators and policy makers; the aim being to make considered, informed decisions on whether to select an ecotoxicological hazard- or a risk-based approach for regulating a given endocrine-disrupting substance (EDS) under review. The workshop additionally considered recent developments in the identification of EDS. Case studies were undertaken on 6 endocrine-active substances (EAS—not necessarily proven EDS, but substances known to interact directly with the endocrine system) that are representative of a range of perturbations of the endocrine system and considered to be data rich in relevant information at multiple biological levels of organization for 1 or more ecologically relevant taxa. The substances selected were 17α-ethinylestradiol, perchlorate, propiconazole, 17β-trenbolone, tributyltin, and vinclozolin. The 6 case studies were not comprehensive safety evaluations but provided foundations for clarifying key issues and procedures that should be considered when assessing the ecotoxicological hazards and risks of EAS and EDS. The workshop also highlighted areas of scientific uncertainty, and made specific recommendations for research and methods-development to resolve some of the identified issues. The present paper provides broad guidance for scientists in regulatory authorities, industry, and academia on issues likely to arise during the ecotoxicological hazard and risk assessment of EAS and EDS. The primary conclusion of this paper, and of the SETAC Pellston Workshop on which it is based, is that if data on environmental exposure, effects on sensitive species and life-stages, delayed effects, and effects at low concentrations are robust, initiating environmental risk

A Nanosecond Pulsed Plasma Brush for Surface Decontamination

Science.gov (United States)

Neuber, Johanna; Malik, Muhammad; Song, Shutong; Jiang, Chunqi

2015-11-01

This work optimizes a non-thermal, atmospheric pressure plasma brush for surface decontamination. The generated plasma plumes with a maximum length of 2 cm are arranged in a 5 cm long, brush-like array. The plasma was generated in ambient air with Acinetobacter baumannii. Laminate surfaces inoculated with over-night cultured bacteria were subject to the plasma treatment for varying water concentrations in He, flow rates and discharge voltages. It was found that increasing the water content of the feed gas greatly enhanced the bactericidal effect. Emission spectroscopy was performed to identify the reactive plasma species that contribute to this variation. Additional affiliation: Frank Reidy Research Center for Bioelectrics

ISAba1 Regulated OXA-23 Carbapenem Resistance in Acinetobacter baumannii Strains in Durban, South Africa.

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Agoba, Esther Eyram; Govinden, Usha; Peer, Abdool Kader Cassim; Osei Sekyere, John; Essack, Sabiha Yusuf

2018-03-20

This study investigated the molecular mechanisms of resistance to carbapenems and cephalosporins in 24 consecutive, multidrug-resistant Acinetobacter baumannii (MDRAB) isolates collected between January and April 2015 by a private sector laboratory in Durban, South Africa. All isolates were resistant to all carbapenems tested. bla OXA-23 and bla OXA-51 genes were found in 23 isolates, while bla OXA-24 , bla OXA-48 , and bla OXA-58 were absent in all isolates. The most prevalent extended-spectrum β-lactamase was TEM-116 (92%). bla ADC was present in 83.3% of isolates, of which two were new variants with three and five amino acid differences compared to Acinetobacter-derived cephalosporinase (ADC)-1, the first at positions 64E → K, 341N → T, and 342R → G and the second at positions 24G → D, 167S → P, 283R → F, 341N → T, and 342R → G, respectively. All isolates were negative for bla PER , bla CMY , bla GES , bla KPC , bla CTX-M , and bla SHV . Metallo-β-lactamase IMP and VIM were absent in all isolates, and NDM-1 was present in 1 isolate. ISAba1 was located upstream bla OXA-23 in all isolates and upstream bla ADC (30, 78, 79, 87 and the ADC variants) in 54.2% of the ADC-carrying isolates. None of the isolates had ISAba1 inserted upstream bla OXA-51 gene. Four isolates were clonally related and showed two clusters (A and B), while 20 isolates remained unclustered. There was no direct relationship between the clusters and the hospitals they were isolated from. This study reports the first NDM-1-producing carbapenem resistant Acinetobacter baumannii isolate in South Africa and highlights the presence of OXA-23, the known ADCs (ADC-30, ADC-78, ADC-79, and ADC-87), and two new ADC variants associated with ISAba1 from the private health sector in Durban, South Africa. The complexity and diversity of MDRAB severely limit treatment options.

Molecular catchers for pharmacologically active substances in wastewaters, a theoretical study

International Nuclear Information System (INIS)

Salazar Valencia, P J; Pérez Merchancano, S T; Bolívar Marinez, L E; Paredes, H

2016-01-01

A basic and pressing need in the treatment of residual waste waters for urban and rural centers is the removal of pharmacological active residues from them, these resides are originated in a wide array of domestic, agricultural and industrial sources and can't be removed in the residual waters treatment plants by conventional methods, the result is the incorporation of them into the ecosystem altering the physiology and behavior of living organisms. Among the most active pharmacological substances found in very high concentration in residual waters is paracetamol, an analgesic of very wide excessive use due to its ease of access and low cost [1]. No pharmacological substance is entirely absorbed by the human organism and therefore a wide family of molecular residues is excreted by the urinary tract. In this work we have used the AM1 (Austin Model 1), PM3 (Parametric Method 3) and ZINDO/CI semiempirical methods, from the NDO (Neglect Differential Overlap) family [2] to study and observe the structural, electronic and optical characteristics of paracetamol while immersed in different basic and acidic aqueous environments, either alone or interacting with lignosulphonates. We have previously found that lignosulphonates, a lignin derivatives of wide industrial applications, can be engineered as a binding and flocculant agent and acts as molecular catchers therefore showing the potential to be used as a mean to filter and eliminate molecular residues from the residual waters [3]. (paper)

First Evaluation of the Biologically Active Substances and Antioxidant Potential of Regrowth Velvet Antler by means of Multiple Biochemical Assays

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Yujiao Tang

2015-01-01

Full Text Available We investigated the biologically active substances contained in RVA (regrowth velvet antler by comparing the composition of biologically active substances and antioxidant potential of different antler segments. RVA was subjected to extraction using DW (distilled water. RVA was divided into 3 segments: T-RVA (top RVA, M-RVA (middle RVA, and B-RVA (base RVA. The T-RVA section possessed the greatest amounts of uronic acid (36.251 mg/g, sulfated GAGs (sulfated glycosaminoglycans (555.76 mg/g, sialic acid (111.276 mg/g, uridine (0.957 mg/g, uracil (1.084 mg/g, and hypoxanthine (1.2631 mg/g. In addition, the T-RVA section possessed the strongest antioxidant capacity as determined by DPPH, H2O2 (hydrogen peroxide, hydroxyl, and ABTS (2,2′-azinobis-3-ethylbenzthiazoline-6-sulphonate radical scavenging activity as well as FRAP (ferric reducing antioxidant power and ORAC (oxygen radical absorbance capacity. The values of those were 53.44, 23.09, 34.12, 60.31, and 35.81 TE/μM at 1 mg/mL and 113.57 TE/μM at 20 μg/mL. These results indicate that the T-RVA section possesses the greatest amount of biologically active substances and highest antioxidant potential. This is the first report on the biologically active substances and antioxidant potential of RVA.

Acinetobacter calcoaceticus CSY-P13 Mitigates Stress of Ferulic and p-Hydroxybenzoic Acids in Cucumber by Affecting Antioxidant Enzyme Activity and Soil Bacterial Community

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Fenghui Wu

2018-06-01

Full Text Available Ferulic acid (FA and p-hydroxybenzoic acid (PHBA are main phenolic compounds accumulated in rhizosphere of continuously cropped cucumber, causing stress in plants. Microbial degradation of a mixture of FA and PHBA is not well understood in soil. We isolated a strain CSY-P13 of Acinetobacter calcoaceticus, inoculated it into soil to protect cucumber from FA and PHBA stress, and explored a mechanism underlying the protection. CSY-P13 effectively degraded a mixture of FA and PHBA in culture solution under conditions of 39.37°C, pH 6.97, and 21.59 g L-1 potassium dihydrogen phosphate, giving rise to 4-vinyl guaiacol, vanillin, vanillic acid, and protocatechuic acid. During FA and PHBA degradation, activities of superoxide dismutase (SOD, catalase, ascorbate peroxidase, and dehydroascorbate reductase in CSY-P13 were induced. Inoculated into cucumber-planted soil containing 220 μg g-1 mixture of FA and PHBA, CSY-P13 degraded FA and PHBA in soil, increased plant height, and decreased malonaldehyde, superoxide radical, and hydrogen peroxide levels in leaves. CSY-P13 also enhanced SOD, guaiacol peroxidase, catalase, glutathione peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activities; increased ascorbate and glutathione contents; and elevated transcript levels of copper/zinc SOD, manganese SOD, and catalase in leaves under FA and PHBA. Moreover, CSY-P13 increased phosphatase, catalase, urease, and sucrase activities and changed bacterial richness, diversity, and community composition by high throughput sequencing in cucumber-planted soil supplemented with the mixture of FA and PHBA. So CSY-P13 degrades the mixture of FA and PHBA in soil and mitigates stress from the two phenolic compounds in cucumber by activating antioxidant enzymes, changing soil bacterial community, and inducing soil enzymes.

Clinical and molecular epidemiology of Acinetobacter baumannii bloodstream infections in an endemic setting.

Science.gov (United States)

Marchaim, Dror; Levit, Dana; Zigron, Roy; Gordon, Michal; Lazarovitch, Tsillia; Carrico, Joao A; Chalifa-Caspi, Vered; Moran-Gilad, Jacob

2017-03-01

The transmission dynamics of Acinetobacter baumannii in endemic settings, and the relation between microbial properties and patients' clinical outcomes, are yet obscure and hampered by insufficient metadata. Of 20 consecutive patients with A. baumannii bloodstream infection that were thoroughly analyzed at a single center, at least one transmission opportunity was evident for 85% of patients. This implies that patient-to-patient transmission is the major mode of A. baumannii acquisitions in health facilities. Moreover, all patients who died immediately (baumannii ST457 lineage compared with other strains.

Virulence profiles and innate immune responses against highly lethal, multidrug-resistant nosocomial isolates of Acinetobacter baumannii from a tertiary care hospital in Mexico

Science.gov (United States)

Gayosso-Vázquez, Catalina; Fernández-Vázquez, José Luis; Jarillo-Quijada, Ma Dolores; Rivera-Benítez, César; Santos-Preciado, José Ignacio

2017-01-01

Virulence profiles and innate immune responses were studied in Acinetobacter baumannii from nosocomial infections collected over one year in a tertiary care hospital in Mexico. A. baumannii were identified by VITEK 2 System followed by susceptibility tests. Carbapenemase genes, active efflux mechanism to imipenem and meropenem and outer membrane proteins profile were analyzed to evaluate their role on the activity of carbapenem resistance. All isolates were genotyped by pulsed field gel electrophoresis. The ability to form biofilm was determined on a polystyrene surface. The resistance to complement was determined with a pooled human normal serum and TNFα release by infected macrophages was determined by ELISA. The 112 isolates from this study were associated with a 52% of mortality. All were resistance to β-lactams, fluoroquinolones, and trimethroprim-sulfamethoxal, 96 and 90% were resistant to meropenem and imipenem, respectively, but with high susceptibility to polymyxin B, colistin and tigecyclin. Isolates were classified in 11 different clones. Most isolates, 88% (99/112), were metallo-β-lactamases and carbapenemases producers, associated in 95% with the presence of blaOXA-72 gene. Only 4/99 and 1/99 of the carbapenem-resistant isolates were related to efflux mechanism to meropenem or imipenem resistance, respectively. The loss of expression of 22, 29, and/or 33-36-kDa proteins was detected in 8/11 of the clinical isolates with resistance to carbapenem. More than 96% (108/112) of the isolates were high producers of biofilms on biotic surfaces. Finally, all isolates showed variable resistance to normal human serum activity and were high inductors of TNFα release by macrophages. In summary, these results suggest that multidrug-resistant A. baumannii can persist in the hospital environment through its ability to form biofilms. The high mortality observed was due to their ability to survive normal human serum activity and capability to induce potent

The Immune Response against Acinetobacter baumannii, an Emerging Pathogen in Nosocomial Infections

Science.gov (United States)

García-Patiño, María Guadalupe; García-Contreras, Rodolfo; Licona-Limón, Paula

2017-01-01

Acinetobacter baumannii is the etiologic agent of a wide range of nosocomial infections, including pneumonia, bacteremia, and skin infections. Over the last 45 years, an alarming increase in the antibiotic resistance of this opportunistic microorganism has been reported, a situation that hinders effective treatments. In order to develop effective therapies against A. baumannii it is crucial to understand the basis of host–bacterium interactions, especially those concerning the immune response of the host. Different innate immune cells such as monocytes, macrophages, dendritic cells, and natural killer cells have been identified as important effectors in the defense against A. baumannii; among them, neutrophils represent a key immune cell indispensable for the control of the infection. Several immune strategies to combat A. baumannii have been identified such as recognition of the bacteria by immune cells through pattern recognition receptors, specifically toll-like receptors, which trigger bactericidal mechanisms including oxidative burst and cytokine and chemokine production to amplify the immune response against the pathogen. However, a complete picture of the protective immune strategies activated by this bacteria and its potential therapeutic use remains to be determined and explored. PMID:28446911

LEVANTAMENTO EPIDEMIOLÓGICO DE INFECÇÃO POR ACINETOBACTER SPP EM AMOSTRAS DE HEMOCULTURAS DE UM LABORATÓRIO DE SÃO JOSÉ DOS CAMPOS

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Vânia Waleska Sousa da Cunha

2015-01-01

Full Text Available A presença de infecções na corrente sanguínea representa uma grave complicação na situação de pacientes críticos, podendo aumentar os riscos de morbidade e mortalidade, sendo a hemocultura um importante recurso no diagnóstico do agente microbiano. Entre as bactérias causadoras de bacteriemia, encontramos, frequentemente, a Acinetobacter spp, sendo um patógeno de grande importância clínica devido ao aumento de sua frequência como causa de infecções hospitalares e, também, por, normalmente, apresentar multirresistência aos agentes antimicrobianos de prática clínica. O presente estudo teve como finalidade o levantamento epidemiológico de infecções em hemoculturas causadas pelo gênero Acinetobacter spp em pacientes internados, em hospitais de São José dos Campos-SP, demonstrando sua prevalência no munícipio. Os dados analisados foram fornecidos pelo sistema de um laboratório de análises microbiológicas e utilizados para o levantamento de infecções por Acinetobacter spp em hemoculturas, no período de agosto de 2012 a agosto de 2013. Foram avaliados 5.759 exames de hemocultura, com 1.019 resultados positivos, sendo que Acinetobacter baumannii foi identificada em 31 amostras, correspondendo ao sexto patógeno mais isolado (3,04% das hemoculturas positivas. A. baumannii se tornou um patógeno de grande preocupação hospitalar, devido à sua crescente colonização nas Unidades de Tratamento Intensivo e sua multirresistência aos antimicrobianos.

Acinetobacter phage genome is similar to Sphinx 2.36, the circular DNA copurified with TSE infected particles.

Science.gov (United States)

Longkumer, Toshisangba; Kamireddy, Swetha; Muthyala, Venkateswar Reddy; Akbarpasha, Shaikh; Pitchika, Gopi Krishna; Kodetham, Gopinath; Ayaluru, Murali; Siddavattam, Dayananda

2013-01-01

While analyzing plasmids of Acinetobacter sp. DS002 we have detected a circular DNA molecule pTS236, which upon further investigation is identified as the genome of a phage. The phage genome has shown sequence similarity to the recently discovered Sphinx 2.36 DNA sequence co-purified with the Transmissible Spongiform Encephalopathy (TSE) particles isolated from infected brain samples collected from diverse geographical regions. As in Sphinx 2.36, the phage genome also codes for three proteins. One of them codes for RepA and is shown to be involved in replication of pTS236 through rolling circle (RC) mode. The other two translationally coupled ORFs, orf106 and orf96, code for coat proteins of the phage. Although an orf96 homologue was not previously reported in Sphinx 2.36, a closer examination of DNA sequence of Sphinx 2.36 revealed its presence downstream of orf106 homologue. TEM images and infection assays revealed existence of phage AbDs1 in Acinetobacter sp. DS002.

Assessment of intra-species diversity among strains of Acinetobacter baumannii isolated from sites contaminated with petroleum hydrocarbons

International Nuclear Information System (INIS)

Manab Sarma, P.; Bhattacharya, D.; Krishnan, S.; Lal, B.

2004-01-01

Intra-species diversity among Acinetobacter baumannii strains isolated from crude oil-contaminated soils from different geographic regions in India was assessed, including their capability to degrade different fractions of total petroleum hydrocarbons. A total of 96 strains were isolated from five different sites. Of the 96 isolates, 25 strains were identified as Acinetobacter baumannii; all of these strains were biochemically profiled and grouped into eight phenovars on the basis of multivariate analysis of their substrate utilization profiles. All strains were able to degrade the total petroleum hydrocarbon fractions of crude oil. Intraspecies relatedness among the 25 strains was determined using tRNA intergenic spacer length polymorphism. Specific variants among the strains with different degradation capacities for different fractions of crude oil were detected. Environmental influences that cause intra-species diversity, such as functional resilience, within the selected strains of A. baumannii were also noted. It is suggested that such diversities may make it possible to select contaminant-specific strains for efficient biotechnological strategies in environmental remediation. 19 refs., 4 tabs., 3 figs

Assessment of intra-species diversity among strains of Acinetobacter baumannii isolated from sites contaminated with petroleum hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Manab Sarma, P.; Bhattacharya, D.; Krishnan, S. [TERI School of Advanced Studies, Center of Bioresources and Biotechnology, New Delhi (India); Lal, B. [TERI School of Advanced Studies, Microbial Biotechnology Division, New Delhi (India)

2004-06-01

Intra-species diversity among Acinetobacter baumannii strains isolated from crude oil-contaminated soils from different geographic regions in India was assessed, including their capability to degrade different fractions of total petroleum hydrocarbons. A total of 96 strains were isolated from five different sites. Of the 96 isolates, 25 strains were identified as Acinetobacter baumannii; all of these strains were biochemically profiled and grouped into eight phenovars on the basis of multivariate analysis of their substrate utilization profiles. All strains were able to degrade the total petroleum hydrocarbon fractions of crude oil. Intraspecies relatedness among the 25 strains was determined using tRNA intergenic spacer length polymorphism. Specific variants among the strains with different degradation capacities for different fractions of crude oil were detected. Environmental influences that cause intra-species diversity, such as functional resilience, within the selected strains of A. baumannii were also noted. It is suggested that such diversities may make it possible to select contaminant-specific strains for efficient biotechnological strategies in environmental remediation. 19 refs., 4 tabs., 3 figs.

Does substance use moderate the association of neighborhood disadvantage with perceived stress and safety in the activity spaces of urban youth?

Science.gov (United States)

Mennis, Jeremy; Mason, Michael; Light, John; Rusby, Julie; Westling, Erika; Way, Thomas; Zahakaris, Nikola; Flay, Brian

2016-08-01

This study investigates the association of activity space-based exposure to neighborhood disadvantage with momentary perceived stress and safety, and the moderation of substance use on those associations, among a sample of 139 urban, primarily African American, adolescents. Geospatial technologies are integrated with Ecological Momentary Assessment (EMA) to capture exposure to neighborhood disadvantage and perceived stress and safety in the activity space. A relative neighborhood disadvantage measure for each subject is calculated by conditioning the neighborhood disadvantage observed at the EMA location on that of the home neighborhood. Generalized estimating equations (GEE) are used to model the effect of relative neighborhood disadvantage on momentary perceived stress and safety, and the extent to which substance use moderates those associations. Relative neighborhood disadvantage is significantly associated with higher perceived stress, lower perceived safety, and greater substance use involvement. The association of relative neighborhood disadvantage with stress is significantly stronger among those with greater substance use involvement. This research highlights the value of integrating geospatial technologies with EMA and developing personalized measures of environmental exposure for investigating neighborhood effects on substance use, and suggests substance use intervention strategies aimed at neighborhood conditions. Future research should seek to disentangle the causal pathways of influence and selection that relate neighborhood environment, stress, and substance use, while also accounting for the role of gender and family and peer social contexts. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Recommended approaches to the scientific evaluation of ecotoxicological hazards and risks of endocrine‐active substances

Science.gov (United States)

A SETAC Pellston Workshop™ ?‘Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA)’ was held from 31st January to 5th February 2016 in Pensacola, Florida, USA. The primary aim of the workshop was to provide objective advice, based on current s...

Selection of organic process and source indicator substances for the anthropogenically influenced water cycle.

Science.gov (United States)

Jekel, Martin; Dott, Wolfgang; Bergmann, Axel; Dünnbier, Uwe; Gnirß, Regina; Haist-Gulde, Brigitte; Hamscher, Gerd; Letzel, Marion; Licha, Tobias; Lyko, Sven; Miehe, Ulf; Sacher, Frank; Scheurer, Marco; Schmidt, Carsten K; Reemtsma, Thorsten; Ruhl, Aki Sebastian

2015-04-01

An increasing number of organic micropollutants (OMP) is detected in anthropogenically influenced water cycles. Source control and effective natural and technical barriers are essential to maintain a high quality of drinking water resources under these circumstances. Based on the literature and our own research this study proposes a limited number of OMP that can serve as indicator substances for the major sources of OMP, such as wastewater treatment plants, agriculture and surface runoff. Furthermore functional indicators are proposed that allow assessment of the proper function of natural and technical barriers in the aquatic environment, namely conventional municipal wastewater treatment, advanced treatment (ozonation, activated carbon), bank filtration and soil aquifer treatment as well as self-purification in surface water. These indicator substances include the artificial sweetener acesulfame, the anti-inflammatory drug ibuprofen, the anticonvulsant carbamazepine, the corrosion inhibitor benzotriazole and the herbicide mecoprop among others. The chemical indicator substances are intended to support comparisons between watersheds and technical and natural processes independent of specific water cycles and to reduce efforts and costs of chemical analyses without losing essential information. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation, Surface and Pore Structure of High Surface Area Activated Carbon Fibers from Bamboo by Steam Activation

Directory of Open Access Journals (Sweden)

Xiaojun Ma

2014-06-01

Full Text Available High surface area activated carbon fibers (ACF have been prepared from bamboo by steam activation after liquefaction and curing. The influences of activation temperature on the microstructure, surface area and porosity were investigated. The results showed that ACF from bamboo at 850 °C have the maximum iodine and methylene blue adsorption values. Aside from the graphitic carbon, phenolic and carbonyl groups were the predominant functions on the surface of activated carbon fiber from bamboo. The prepared ACF from bamboo were found to be mainly type I of isotherm, but the mesoporosity presented an increasing trend after 700 °C. The surface area and micropore volume of samples, which were determined by application of the Brunauer-Emmett-Teller (BET and t-plot methods, were as high as 2024 m2/g and 0.569 cm3/g, respectively. It was also found that the higher activation temperature produced the more ordered microcrystalline structure of ACF from bamboo.

Effects of Psychrotrophic Bacteria, Serratia liquefaciens and Acinetobacter genomospecies 10 on Yogurt Quality

Science.gov (United States)

Shin, Yong Kook; Oh, Nam Su; Lee, Hyun Ah; Choi, Jong-Woo

2014-01-01

The aim of this study was to evaluate the effect of proteolytic (Serratia liquefaciens, match %: 99.39) or lipolytic (Acinetobacter genomospecies 10, match %: 99.90) psychrotrophic bacteria (bacterial counts, analysis of free fatty acids (FFA) and analysis of free amino acids) on the microbial and chemical properties (yogurt composition), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of yogurt during storage. Yogurts were prepared with raw milk preinoculated with each psychrotrophic bacteria. The total solid, fat, and protein content were not affected by preinoculation, but the pH of yogurt preinoculated with psychrotrophic bacteria was higher than in control. There was a dramatic increase in short chain free fatty acids among FFA in yogurt with Acinetobacter genomospecies 10. For 14 d of cold storage condition, SCFFA was 25.3 mg/kg to 34.4 mg/kg (1.36 times increased), MCFFA was 20.4 mg/kg to 25.7 mg/kg (1.26 times increased), and LCFFA was 240.2 mg/kg to 322.8 mg/kg (1.34 times increased). Serratia liquefaciens (match %: 99.39) in yogurt caused a greater accumulation of free amino acids (FAA), especially bitter peptides such as leucine, valine, arginine, and tyrosine, but SDS-PAGE showed that the inoculation of Serratia liquefaciens did not affect the degree of casein degradation during storage. Taken together, the excessive peptides and FFA in yogurt generated from psychrotrophic bacteria could develop off-flavors that degrade the quality of commercial yogurt products. PMID:26761293

Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

Science.gov (United States)

Zhang, Qiuzhuo; Wang, Duanchao; Li, Mengmeng; Xiang, Wei-Ning; Achal, Varenyam

2014-03-01

Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

Volumetric and superficial characterization of carbon activated

International Nuclear Information System (INIS)

Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T.

2000-01-01

The activated carbon is the resultant material of the calcination process of natural carbonated materials as coconut shells or olive little bones. It is an excellent adsorbent of diluted substances, so much in colloidal form, as in particles form. Those substances are attracted and retained by the carbon surface. In this work is make the volumetric and superficial characterization of activated carbon treated thermically (300 Centigrade) in function of the grain size average. (Author)

Imipenem Treatment Induces Expression of Important Genes and Phenotypes in a Resistant Acinetobacter baumannii Isolate.

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Dhabaan, Ghulam Nasser; AbuBakar, Sazaly; Cerqueira, Gustavo Maia; Al-Haroni, Mohammed; Pang, Sui Ping; Hassan, Hamimah

2015-12-14

Acinetobacter baumannii has emerged as a notorious multidrug-resistant pathogen, and development of novel control measures is of the utmost importance. Understanding the factors that play a role in drug resistance may contribute to the identification of novel therapeutic targets. Pili are essential for A. baumannii adherence to and biofilm formation on abiotic surfaces as well as virulence. In the present study, we found that biofilm formation was significantly induced in an imipenem-resistant (Imp(r)) strain treated with a subinhibitory concentration of antibiotic compared to that in an untreated control and an imipenem-susceptible (Imp(s)) isolate. Using microarray and quantitative PCR analyses, we observed that several genes responsible for the synthesis of type IV pili were significantly upregulated in the Imp(r) but not in the Imp(s) isolate. Notably, this finding is corroborated by an increase in the motility of the Imp(r) strain. Our results suggest that the ability to overproduce colonization factors in response to imipenem treatment confers biological advantage to A. baumannii and may contribute to clinical success. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Parental knowledge of adolescent activities: links with parental attachment style and adolescent substance use.

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Jones, Jason D; Ehrlich, Katherine B; Lejuez, C W; Cassidy, Jude

2015-04-01

Parents' knowledge of their adolescents' whereabouts and activities is a robust predictor of adolescent risk behavior, including the use of drugs and alcohol. Surprisingly few studies have attempted to identify parental characteristics that are associated with the degree of parental knowledge. The present study is the first to examine how parental attachment style relates to mother, father, and adolescent reports of parental knowledge. Further, we used structural equation modeling to test the associations among parents' attachment styles, reports of parental knowledge, and adolescents' alcohol and marijuana use. Participants included 203 adolescents (M age = 14.02, SD = .91) living in 2-parent households and their parent(s). As predicted, mothers' and fathers' insecure attachment styles were negatively associated with self-reported and adolescent-reported parental knowledge, and all 3 reports of parental knowledge were negatively related to adolescent substance use. Mothers' and fathers' attachment styles were unrelated to adolescent substance use. However, evidence emerged for indirect effects of parental attachment style on adolescent substance use through reports of parental knowledge. Implications for prevention efforts and the importance of multiple reporters within the family are discussed. (c) 2015 APA, all rights reserved).

Harsh parenting, parasympathetic activity, and development of delinquency and substance use.

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Hinnant, J Benjamin; Erath, Stephen A; El-Sheikh, Mona

2015-02-01

Stress response systems are thought to play an important role in the development of psychopathology. In addition, family stress may have a significant influence on the development of stress response systems. One potential avenue of change is through alterations to thresholds for the activation of stress responses: Decreased threshold for responding may mark increased stress sensitivity. Our first aim was to evaluate the interaction between thresholds for parasympathetic nervous system (PNS) responding, operationalized as resting respiratory sinus arrhythmia (RSA), and harsh parenting in the prediction of development of delinquency and adolescent substance use (resting RSA as a biomarker of risk). The second aim was to evaluate if resting RSA changes over time as a function of harsh parenting and stress reactivity indexed by RSA withdrawal (altered threshold for stress responding). Our third aim was to evaluate the moderating role of sex in these relations. We used longitudinal data from 251 children ages 8-16 years. Mother-reports of child delinquency and RSA were acquired at all ages. Adolescents self-reported substance use at age 16 years. Family stress was assessed with child-reported harsh parenting. Controlling for marital conflict and change over time in harsh parenting, lower resting RSA predicted increases in delinquency and increased likelihood of drug use in contexts of harsh parenting, especially for boys. Harsh parenting was associated with declining resting RSA for children who exhibited greater RSA withdrawal to stress. Findings support resting PNS activity as a moderator of developmental risk that can be altered over time. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Synthesis and antimicrobial studies of novel derivatives of 4-(4-formyl-3-phenyl-1H-pyrazol-1-yl)benzoic acid as potent anti-Acinetobacter baumanni agents

Science.gov (United States)

Allison, Devin; Delancey, Evan; Ramey, Hunter; Williams, Conrad; Alsharif, Zakeyah Ali; Al-khattabi, Hessa; Ontko, Allyn; Gilmore, David

2017-01-01

Microbial resistance to antibiotics is a global concern. The World Health Organization (WHO) has identified antimicrobial resistance as one the three greatest threats for human beings in the 21st century. Without urgent and coordinated action, the world is moving toward a post-antibiotic era, in which normal infections or minor injuries may become fatal. In an effort to find new agents, we report the synthesis and antimicrobial activities of 40 novel 1,3-diphenyl pyrazole derivatives. These compounds have shown zones of growth inhibition up to 85 mm against Acinetobacter baumannii. We tested the active compounds against this Gram-negative bacterium in minimum inhibitory concentration (MIC) tests and found activity with concentration as low as 4 μg/mL. PMID:28065568

Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin

DEFF Research Database (Denmark)

Agersø, Yvonne; Guardabassi, L.

2005-01-01

A novel tetracycline resistance determinant named Tet 39 was found in unrelated Acinetobacter strains isolated from freshwater trout farms (n=4) and sewage (n=6) in Denmark, and from a clinical specimen in the Netherlands (n=1). The determinant was located on transferable plasmids and consisted o...

High prevalence of the PER-1 gene among carbapenem-resistant Acinetobacter baumannii in Riyadh, Saudi Arabia.

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Aly, M M; Abu Alsoud, N M; Elrobh, M S; Al Johani, S M; Balkhy, H H

2016-11-01

The prevalence of carbapenem-resistant Acinetobacter baumannii in Saudi Arabia and their resistance genetic mechanisms are yet to be identified. We studied the prevalence and genetic diversity of extended-spectrum beta-lactamase genes, particularly the PER-1 gene, among carbapenem-resistant A. baumannii strains from patients at a tertiary care hospital in Riyadh, Saudi Arabia between 2006 and 2014. Fresh subcultured samples were tested for antimicrobial susceptibility minimum inhibitory concentration (MIC). Total genomic DNA was extracted from each isolate and further used for polymerase chain reaction (PCR) genotyping, sequence-based typing (SBT) of PER-1 and OXA-51-like gene, and multilocus sequence typing (MLST) of positive isolates. Randomly selected clinical isolates (n = 100) were subjected to MLST. A total of 503 isolates were characterized as multidrug-resistant (MDR) using the MIC. Isolates were further PCR tested for bla -TEM and bla -PER-1 resistance genes (n = 503). The genotyping results showed that 68/503 (14 %) isolates were positive to bla TEM. The genotyping results of PER-1-like genes showed that 384/503 (76.3 %) were positive among MDR Acinetobacter isolates. Based on SBT, the majority of these isolates were clustered into three main groups including isolates harboring PER-1: AB11 (bla -PER-1 ), isolate AB16 (bla -PER-1 ), and, finally, the plasmid pAB154 (bla -PER-7 ). Remarkably, many isolates were concealing the PER-1 gene and harboring the TEM resistance genes as well. MLST results for selected isolates (n = 100) identified four main sequence types (STs: 2, 19, 20, and 25) and four novel isolates (ST 486-489). We report 76.3 % prevalence of the PER-1 resistance gene among Acinetobacter clinical isolates from Riyadh, Saudi Arabia. Further work is needed to explore the clinical risks and patient outcome with such resistance related to healthcare-associated infections and investigate the genetic and molecular mechanisms that confer the MDR

Substance abuse: medical and slang terminology.

Science.gov (United States)

Hamid, Humera; El-Mallakh, Rif S; Vandeveir, Keith

2005-03-01

Substance abuse is among one of the major problems plaguing our society. It has come to the attention of several healthcare professionals that a communication gap exists between themselves and substance abusers. Most of the time the substance abusers are only familiar with the slang terms of abused substances, a terminology that medical professionals are usually unaware of. This paper is an attempt to close that communication gap, allowing health care professionals to understand the slang terminology that their patients use, thus enabling them to make appropriate treatment decisions. In addition, the article presents some key features (including active ingredient, pharmacological classification, medical use, abuse form, usage method, combinations used, effects sought, long-term possible effects, and detectability in urine) of the most commonly abused substances.

Understanding the risks associated with the use of new psychoactive substances (NPS): high variability of active ingredients concentration, mislabelled preparations, multiple psychoactive substances in single products.

Science.gov (United States)

Zamengo, Luca; Frison, Giampietro; Bettin, Chiara; Sciarrone, Rocco

2014-08-17

New psychoactive substances (NPS), are now a large group of substances of abuse not yet completely controlled by international drug conventions, which may pose a public health threat. Anxiety, paranoia, hallucinations, seizures, hyperthermia and cardiotoxicity are some of the common adverse effects associated with these compounds. In this paper, three case reports taken from the archive of processed cases of the authors' laboratory are presented and discussed to stress the risks of possible adverse consequences for NPS users: in particular, (i) the risk deriving from the difficulty of predicting the actual consumed dose, due to variability of active ingredients concentration in consumed products, (ii) the risk deriving from the difficulty of predicting the actual active ingredients present in consumed products, as opposed to those claimed by the manufacturer, and (iii) the risk deriving from the difficulty of predicting the actual pharmacological and toxicological effects related to the simultaneous consumption of different psychoactive ingredients contained in single products, whose interactions are mostly unknown. Each of them individually provide a source of concern for possible serious health related consequences. However, they should be considered in conjunction with each others, with the worldwide availability of NPS through the web and also with the incessantly growing business derived from the manipulation and synthesis of new substances. The resulting scenario is that of a cultural challenge which demands a global approach from different fields of knowledge. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii

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Sobhan Ghafourian

2014-07-01

Full Text Available Although analysis of toxin-antitoxin (TA systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems’ locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium.

Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro.

Science.gov (United States)

Buist, Harrie E; van de Sandt, Johannes J M; van Burgsteden, Johan A; de Heer, Cees

2005-10-01

The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeated exposure. The influence of repeated and single exposure to representative biocidal active substances on the skin barrier was investigated in vitro. The biocidal active substances selected were alkyldimethylbenzylammonium chloride (ADBAC), boric acid, deltamethrin, dimethyldidecylammonium chloride (DDAC), formaldehyde, permethrin, piperonyl butoxide, sodium bromide, and tebuconazole. Of these nine compounds, only the quaternary ammonium chlorides ADBAC and DDAC had a clear and consistent influence on skin permeability of the marker compounds tritiated water and [(14)C]propoxur. For these compounds, repeated exposure increased skin permeability more than single exposure. At high concentrations the difference between single and repeated exposure was quantitatively significant: repeated exposure to 300 mg/L ADBAC increased skin permeability two to threefold in comparison to single exposure. Therefore, single and repeated exposure to specific biocidal products may significantly increase skin permeability, especially when used undiluted.

Influence of ecological factors on the production of active substances in the anti-cancer plant Sinopodophyllum hexandrum (Royle T.S. Ying.

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Wei Liu

Full Text Available The quality of traditional Chinese herbal medicine, which plays a very important role in the health system of China, is determined by the active substances produced by the plants. The type, content, and proportion of these substances may vary depending on ecological factors in areas where the plants are grown. Sinopodophyllum hexandrum (Royle T.S. Ying, an endangered plant species with great medical value, was investigated in eight production locations representative of its natural geographical distribution range in China. The correlation between the contents of the active ingredients extracted from the roots and rhizomes of S. hexandrum and the ecological factors were evaluated step-by-step using a series of computational biology methodologies. The results showed that ecological factors had significant effects on the contents but not on the types of the active ingredients in eight production locations. The primary ecological factors influencing the active substances included the annual average precipitation, July mean temperature, frost-free period, sunshine duration, soil pH, soil organic matter, and rapidly available potassium in the soil. The annual average precipitation was the most important determinant factor and was significantly and negatively correlated with the active ingredient contents (P < 0.001. In contrast, organic matter was the most important limiting factor and was significantly and positively correlated with the active substances. These ecological factors caused 98.13% of the total geographical variation of the active ingredient contents. The climate factors contributed more to the active ingredient contents than did the soil factors. It was concluded that from the view of the contents of the secondary metabolites and ecological factors of each growing location, in Jingyuan, Ningxia Province, and Yongdeng, Gansu Province, conditions were favorable to the production of podophyllotoxin and lignans, whereas in Shangri-La, Yunnan

Antimicrobial activity of photodynamic therapy in combination with colistin against a pan-drug resistant Acinetobacter baumannii isolated from burn patient.

Science.gov (United States)

Boluki, Ebrahim; Kazemian, Hossein; Peeridogaheh, Hadi; Alikhani, Mohammad Yousef; Shahabi, Sima; Beytollahi, Leili; Ghorbanzadeh, Roghayeh

2017-06-01

Nosocomially-acquired multi-, extensively-, and pandrug resistant (MDR, XDR, and PDR) strains of microorganisms such as Acinetobacter baumannii remain a serious cause of infection and septic mortality in burn patients. Treatment of patients with nosocomial burn wound infections is often complicated by drug-resistant strains of A. baumannii. Today, many researchers are focusing on the investigation of novel non-antibiotic strategies such as photodynamic therapy (PDT). We report a new PDT strategy that suppresses colistin resistance in PDR A. baumannii by interfering with the expression of a pmrA/pmrB two-component system. In the current study, A. baumannii with a PDR feature isolated from a burn patient was used as a test strain. PDT was carried out using toluidine blue O (TBO) and light-emitting diode (LED) as a photosensitizer and radiation source, respectively. The antimicrobial susceptibility profiles were assessed for cells surviving PDT. The effects of sub-lethal PDT (sPDT) on the expression of the pmrA/pmrB two-component signal transduction system were evaluated by real-time quantitative reverse transcription PCR. Results of drug susceptibly testing (DST) in LED and TBO groups separately showed that the bacteria were resistant to all tested antibiotics, while the DST result of the LED+TBO group showed highly declining bacterial growth when compared with the control group. Reduction in the expression of pmrA and pmrB was observed in the treated strains after sPDT. This represents the first conclusive example of a direct role for the PDT in breaking antibiotic resistance by directly modulating two-component system activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Breathing rates and daily activities: parameters of exposure to inhaled substances

International Nuclear Information System (INIS)

Roy, M.; Malarbet, J.L.; Courtay, C.

1993-01-01

The intake of inhaled toxic substances is based upon the air volumes breathed every day by people under exposure to gases and aerosols. On the occasion of the revision of the respiratory tract model by the International Commission on Radiological Protection (ICRP), modern standards have been assessed for average inspired air volumes according to age and sex. Recent data of breathing rates as a function of physical activity have been recorded, and economical surveys recently published by the National Institute of Statistics and Economical studies (INSEE) provided time budgets and activities of specific categories of the population. The results were calculated for adults and children, 3 months, 1, 5, 10 and 15 years old. These values are slightly different from those formerly published by ICRP and the United Nations scientific committee on the effects of atomic radiation (UNSCEAR). (author). 27 refs., 6 tabs

BIOLOGICALLY ACTIVE SUBSTANCES OF THE LAURUS NOBILIS LEAVES

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N. M. Nasukhova

2017-01-01

Full Text Available Laurus nobilis L. is an evergreen dioecious, rarely monecious plant up to 12-15 m high. The plant’s name is devoted to an Ancient Greek God of Sun Apollo and is a symbol of peace and victory. It was used in making up wreaths for emperors, generals, and poets. Its natural area includes Mediterranean countries with high level of annual precipitation. It is actively cultivated as a decorative plant in Europe, Russia, USA and other countries. It is cultivated in Turkey, Algeria, Morocco, Portugal, Spain, Italy, France, Russia, and Mexico. The aim of the study is the review of available literature about isolation, identification, quantitative determination of biologically active compounds of the Laurus nobilis leaves in the established species and their pharmacological activity. Materialsand methods. The study was carried out using searching (PubMed, CiteSeer, arXiv, library databases (eLibrary, Cyberleninka, and ResearchGate free social network. Results and discussion. We have established that Laurus nobilis leaves have components of essential oil, phenolic compounds, and sesquiterpenic lactones as the principal active substances. Qualitative composition and quantitative content of these compound groups in these raw materials varies depending on the ecological and geographical, edaphic, climatic factors, phase of the plant growth, cultivation technology, drying method etc. The results of the pharmacological studies of the extracts, summary fractions, and individual compounds of Laurus nobilis leaves characterize this type of raw materials as a perspective source for a more profound study. Conclusion. As the available open review data showed, the essential oil components, phenolic compounds (phenolic acids, flavonoids, etc, sesquiterpenic lactones of Laurus nobilis exhibit a diverse spectrum of pharmacological activity. Antimicrobial (widely, anti-virus, anti-inflammatory, anti-diabetic, and cytoxic (anticancer activities, established in extracts

Homogeneous near surface activity distribution by double energy activation for TLA

International Nuclear Information System (INIS)

Takacs, S.; Ditroi, F.; Tarkanyi, F.

2007-01-01

Thin layer activation (TLA) is a versatile tool for activating thin surface layers in order to study real-time the surface loss by wear, corrosion or erosion processes of the activated parts, without disassembling or stopping running mechanical structures or equipment. The research problem is the determination of the irradiation parameters to produce point-like or large area optimal activity-depth distribution in the sample. Different activity-depth profiles can be produced depending on the type of the investigated material and the nuclear reaction used. To produce activity that is independent of the depth up to a certain depth is desirable when the material removed from the surface by wear, corrosion or erosion can be collected completely. By applying dual energy irradiation the thickness of this quasi-constant activity layer can be increased or the deviation of the activity distribution from a constant value can be minimized. In the main, parts made of metals and alloys are suitable for direct activation, but by using secondary particle implantation the wear of other materials can also be studied in a surface range a few micrometers thick. In most practical cases activation of a point-like spot (several mm 2 ) is enough to monitor the wear, corrosion or erosion, but for special problems relatively large surfaces areas of complicated spatial geometry need to be activated uniformly. Two ways are available for fulfilling this task, (1) production of large area beam spot or scanning the beam over the surface in question from the accelerator side, or (2) a programmed 3D movement of the sample from the target side. Taking into account the large variability of tasks occurring in practice, the latter method was chosen as the routine solution in our cyclotron laboratory

Perfluoroalkylated substances in the global tropical and subtropical surface oceans.

Science.gov (United States)

González-Gaya, Belén; Dachs, Jordi; Roscales, Jose L; Caballero, Gemma; Jiménez, Begoña

2014-11-18

In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability

Vitroprocines, new antibiotics against Acinetobacter baumannii, discovered from marine Vibrio sp. QWI-06 using mass-spectrometry-based metabolomics approach

Science.gov (United States)

Liaw, Chih-Chuang; Chen, Pei-Chin; Shih, Chao-Jen; Tseng, Sung-Pin; Lai, Ying-Mi; Hsu, Chi-Hsin; Dorrestein, Pieter C.; Yang, Yu-Liang

2015-08-01

A robust and convenient research strategy integrating state-of-the-art analytical techniques is needed to efficiently discover novel compounds from marine microbial resources. In this study, we identified a series of amino-polyketide derivatives, vitroprocines A-J, from the marine bacterium Vibrio sp. QWI-06 by an integrated approach using imaging mass spectroscopy and molecular networking, as well as conventional bioactivity-guided fractionation and isolation. The structure-activity relationship of vitroprocines against Acinetobacter baumannii is proposed. In addition, feeding experiments with 13C-labeled precursors indicated that a pyridoxal 5‧-phosphate-dependent mechanism is involved in the biosynthesis of vitroprocines. Elucidation of amino-polyketide derivatives from a species of marine bacteria for the first time demonstrates the potential of this integrated metabolomics approach to uncover marine bacterial biodiversity.

Surface tension of calcium hydroxide associated with different substances Tensão superficial do hidróxido de cálcio associado a diferentes substâncias

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Carlos Estrela

2005-06-01

Full Text Available The purpose of this study was to evaluate the surface tension of calcium hydroxide (CH associated with different substances (deionized distilled water, camphorated paramonochlorophenol, 2% chlorhexidine digluconate, Otosporin, 3% sodium lauryl ether sulphate; Furacin, PMC Furacin using tensiometer. The action of the substances studied on the dentinal structure enhances the property of surface tension. This method consists in the application of force to separate a platinum ring immersed in the substances. Thus, torsion was applied to the screw until the platinum ring separated during substances testing. Considering the methodology applied, the following can be concluded: distilled water alone or associated with CH presented a high surface tension (70.00 and 68.40 dynes/cm; calcium hydroxide in association with anionic detergent showed low surface tension (31.60 dynes/cm; camphorated paramonochlorophenol plus CH presented low surface tension (37.50 dynes/cm; 2% chlorhexidine associated with calcium hydroxide showed high surface tension values (58.00 dynes/cm; Otosporin plus calcium hydroxide showed low surface tension (35.40 dynes/cm; paramonochlorophenol Furacin mixed with calcium hydroxide presented surface tension equal to 45.50 dynes/cm; sodium hypochlorite presented high surface tension (75.00 dynes/cm. Antimicrobial agents more indicated in endodontics, i.e. CH, chlorhexidine and hypochlorite, presented the highest surface tension.Estudou-se a tensão superficial do hidróxido de cálcio associado a diferentes substâncias (água destilada deionizada, paramonoclorofenol canforado, digluconato de clorexidina 2%, Otosporin, sulfato éter lauril sódio 3%, furacin, PMC furacin usando tensiômetro. O modelo experimental consistiu na aplicação de uma força para separar um anel de platina imerso na superfície das substâncias, exercido por um tensiômetro. Considerando a metodologia aplicada, pode-se concluir: a água destilada isolada ou

Molecular epidemiology of multidrug-resistant Acinetobacter baumannii isolates in a university hospital in Nepal reveals the emergence of a novel epidemic clonal lineage.

Science.gov (United States)

Shrestha, Shovita; Tada, Tatsuya; Miyoshi-Akiyama, Tohru; Ohara, Hiroshi; Shimada, Kayo; Satou, Kazuhito; Teruya, Kuniko; Nakano, Kazuma; Shiroma, Akino; Sherchand, Jeevan Bdr; Rijal, Basista Psd; Hirano, Takashi; Kirikae, Teruo; Pokhrel, Bharat Mani

2015-11-01

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii has become a serious medical problem worldwide. To clarify the genetic and epidemiological properties of MDR A. baumannii strains isolated from a medical setting in Nepal, 246 Acinetobacter spp. isolates obtained from different patients were screened for MDR A. baumannii by antimicrobial disk susceptibility testing. Whole genomes of the MDR A. baumannii isolates were sequenced by MiSeq™ (Illumina), and the complete genome of one isolate (IOMTU433) was sequenced by PacBio RS II. Phylogenetic trees were constructed from single nucleotide polymorphism concatemers. Multilocus sequence types were deduced and drug resistance genes were identified. Of the 246 Acinetobacter spp. isolates, 122 (49.6%) were MDR A. baumannii, with the majority being resistant to aminoglycosides, carbapenems and fluoroquinolones but not to colistin and tigecycline. These isolates harboured the 16S rRNA methylase gene armA as well as bla(NDM-1), bla(OXA-23) or bla(OXA-58). MDR A. baumannii isolates belonging to clonal complex 1 (CC1) and CC2 as well as a novel clonal complex (CC149) have spread throughout a medical setting in Nepal. The MDR isolates harboured genes encoding carbapenemases (OXA and NDM-1) and a 16S rRNA methylase (ArmA). Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates

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Jin Jing

2012-07-01

Full Text Available Abstract Background Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Results Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min and a large burst size (200 PFU/cell. It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9 and at extreme temperatures (between 50°C and 60°C. ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. Conclusion The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent

Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates.

Science.gov (United States)

Jin, Jing; Li, Zhen-Jiang; Wang, Shu-Wei; Wang, Shan-Mei; Huang, De-Hai; Li, Ya-Hui; Ma, Yun-Yun; Wang, Jin; Liu, Fang; Chen, Xiang-Dong; Li, Guang-Xing; Wang, Xiao-Ting; Wang, Zhong-Quan; Zhao, Guo-Qiang

2012-07-28

Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min) and a large burst size (200 PFU/cell). It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9) and at extreme temperatures (between 50°C and 60°C). ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent; thus, it should be further investigated.

Reduced Mutation Rate and Increased Transformability of Transposon-Free Acinetobacter baylyi ADP1-ISx.

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Suárez, Gabriel A; Renda, Brian A; Dasgupta, Aurko; Barrick, Jeffrey E

2017-09-01

The genomes of most bacteria contain mobile DNA elements that can contribute to undesirable genetic instability in engineered cells. In particular, transposable insertion sequence (IS) elements can rapidly inactivate genes that are important for a designed function. We deleted all six copies of IS 1236 from the genome of the naturally transformable bacterium Acinetobacter baylyi ADP1. The natural competence of ADP1 made it possible to rapidly repair deleterious point mutations that arose during strain construction. In the resulting ADP1-ISx strain, the rates of mutations inactivating a reporter gene were reduced by 7- to 21-fold. This reduction was higher than expected from the incidence of new IS 1236 insertions found during a 300-day mutation accumulation experiment with wild-type ADP1 that was used to estimate spontaneous mutation rates in the strain. The extra improvement appears to be due in part to eliminating large deletions caused by IS 1236 activity, as the point mutation rate was unchanged in ADP1-ISx. Deletion of an error-prone polymerase ( dinP ) and a DNA damage response regulator ( umuD Ab [the umuD gene of A. baylyi ]) from the ADP1-ISx genome did not further reduce mutation rates. Surprisingly, ADP1-ISx exhibited increased transformability. This improvement may be due to less autolysis and aggregation of the engineered cells than of the wild type. Thus, deleting IS elements from the ADP1 genome led to a greater than expected increase in evolutionary reliability and unexpectedly enhanced other key strain properties, as has been observed for other clean-genome bacterial strains. ADP1-ISx is an improved chassis for metabolic engineering and other applications. IMPORTANCE Acinetobacter baylyi ADP1 has been proposed as a next-generation bacterial host for synthetic biology and genome engineering due to its ability to efficiently take up DNA from its environment during normal growth. We deleted transposable elements that are capable of copying themselves

Successfull Treatment of Ventriculitis Caused by Extensively Drug Resistant (XDR Acinetobacter Baumannii with Intraventriculer Colistin Administration: Report of Two Cases

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Gokhan Karaahmetoglu

2014-08-01

Full Text Available Acinetobacter baumanni is an important nosocomial infection pathogen has emerged worldwide and can causes life-threatening hospital acquired infections, particularly in intensive care units (ICU. After post neurosurgical operations or procedures, this pathogen consists with central nervous system (CNS infections, also. Resistance mechanism of these pathogens against broad-spectrum antimicrobials is the challenging problem and limited penetration of antibiotics to achieve therapeutic concentrations in cerebrospinal fluid (CSF has been still controversial issue. Here we report two cases who had ventriculitis after external ventricular drainage (EVD placement procedures. Both of CSF of two cases yielded XDR (Extensively drug resistant Acinetobacter baumanni. Traditional intravenous treatment did not eradicate pathogen exactly, at first. Adjunctive colistimetat sodium every 12 h (10 mg/kg/day by the route of intraventriculer (IVT was admitted and CSF sterilization was achieved thereafter. The option of IVT colistin administration must be considered with IV antibiotherapy to provide satisfactory treatment of those complicated CNS infections. [Dis Mol Med 2014; 2(4.000: 65-69

Molecular detection of aminoglycoside-modifying enzyme genes in Acinetobacter baumannii clinical isolates.

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Heidary, Mohsen; Salimi Chirani, Alireza; Khoshnood, Saeed; Eslami, Gita; Atyabi, Seyyed Mohammad; Nazem, Habibollah; Fazilati, Mohammad; Hashemi, Ali; Soleimani, Saleh

2017-06-01

Acinetobacter baumannii is a major opportunistic pathogen in healthcare settings worldwide. In Iran, there are only few reports on the prevalence of aminoglycoside resistance genes among A. baumannii isolates. The aim of this study was to investigate the existence of aminoglycoside-modifying enzyme (AME) genes from A. baumannii strains collected at a university teaching hospital in Iran. One hundred A. baumannii strains were collected between 2014 and 2015 from hospitalized patients at Loghman Hakim Hospital, Tehran, Iran. Antimicrobial susceptibility was determined by disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. The DNA was extracted using a kit obtained from Bioneer Co. (Korea) and was used as a template for polymerase chain reaction. The most active antimicrobial agent against these strains was colistin. The rate of extended-spectrum cephalosporin resistance was 97%. The aadA1, aadB, aac(6')-Ib, and aac(3)-IIa genes were found in 85%, 77%, 72%, and 68% of A. baumannii isolates, respectively. This study showed a high prevalence rate of AME genes in A. baumannii. This prevalence rate has explained that further aminoglycoside resistance genes may have role in the resistance of clinical isolates of A. baumannii. Therefore, control and treatment of serious infections caused by this opportunistic pathogen should be given more consideration.

Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

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Lin, Johnson; Sharma, Vikas; Milase, Ridwaan; Mbhense, Ntuthuko

2016-06-01

Phenol degradation enhancement of Acinetobacter strain V2 by a step-wise continuous acclimation process was investigated. At the end of 8 months, three stable adapted strains, designated as R, G, and Y, were developed with the sub-lethal concentration of phenol at 800, 1100, and 1400 mg/L, respectively, from 400 mg/L of V2 parent strain. All strains degraded phenol at their sub-lethal level within 24 h, their growth rate increased as the acclimation process continued and retained their degradation properties even after storing at -80 °C for more than 3 years. All adapted strains appeared coccoid with an ungranulated surface under electron microscope compared to typical rod-shaped parental strain V2 . The adapted Y strain also possessed superior degradation ability against aniline, benzoate, and toluene. This study demonstrated the use of long term acclimation process to develop efficient and better pollutant degrading bacterial strains with potentials in industrial and environmental bioremediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantification of potential exposure of gray partridge (Perdix perdix) to pesticide active substances in farmlands

International Nuclear Information System (INIS)

Bro, Elisabeth; Millot, Florian; Decors, Anouk; Devillers, James

2015-01-01

Estimating exposure of wild birds to plant protection products is of key importance in the risk assessment process evaluating their harmful potential. In this paper, we propose an ecologically-relevant methodology to estimate potential exposure to active substances (ASs) of a farmland focal bird, the gray partridge Perdix perdix. It is based on bird habitat use of fields at the time of pesticide applications. It accounts for spatio-temporal heterogeneity at population and landscape scales. We identify and quantify the potential exposure to 179 ASs of 140 clutches during pre-laying, laying, and incubation phases, and of 75 coveys. The data come from a large scale field study combining radiotelemetry and a farmer survey. They were collected in 12 different representative sites. The proportion of clutches potentially exposed to a given chemical was ≥ 5% for 32 ASs; prothioconazole and epoxiconazole ranking first. 71% of clutches were potentially exposed to ≥ 1 AS and 67% to ≥ 2 ASs. Mixtures involved 2 to 22 ASs. They emerged from commercial formulations, tank mixtures, bird habitat use, and combinations. ASs were fungicides (53%), herbicides (25%), and insecticides (16%) used on a variety of crops in April–June, when ground-nesting birds are breeding. The European Food Safety Authority conclusions report a long-term first-tier toxicity-to-exposure ratio (TER lt ) < 5 for 11 out of 19 documented ASs, and higher-tier TER lt < 5 for 5 out of 10 ASs. This suggests a potential risk for bird reproduction in farmlands. Globally 13% of coveys were potentially exposed to 18 ASs during the first month (1–4 coveys per AS). The use of our field data in future research and risk assessment is discussed. - Highlights: • 71% of clutches and 13% of coveys are exposed to active substances. • Partridge clutches/coveys are mostly exposed to 32/3 substances. • Fungicides (53%), herbicides (25%), and insecticides (16%) dominate. • Some substances have the potential to

In vitro metabolism and bioavailability tests for endocrine active substances: What is needed next for regulatory purposes?

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Legistation and prospective legislative proposals internationally (may) require that chemicals be tested for their ability to disrupt the hormonal systems of mammals. Chemicals found to test positive in vitro are considered to be endocrine active substances (EAS) and may be puta...

Huellas digitales de cepas de Acinetobacter baumannii procedentes de pacientes hospitalizados en la Caja Petrolera de Salud de Obrajes, mediante el método de Pulsed Field Gel Electrophoresis (PFGE, La Paz, Bolivia. Marzo 2015

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García-Rada Giovanni

2017-08-01

Full Text Available Acinetobacter baumannii, worldwide is considered an opportunistic microorganism, present in several cases of hospital-acquired infections. In the Caja Petrolera de Salud of Obrajes Hospital was made the isolation of four Acinetobacter baumannii strains. Identification was confirmed by biochemical tests. Then, the PFGE molecular technique was applied for the identification of genomic fingerprints using Apa I restriction en-zyme.

Antimicrobial activity against gram negative bacilli from Yaounde ...

African Journals Online (AJOL)

Pseudomonas aeruginosa was less susceptible to cefotaxime (2%) and aztreonam (33%), and highly susceptible to ceftazidime (72%) whereas Acinetobacter baumannii was highly resistant to aztreonam (100%), to cefotaxime (96%) and cetazidime (62%). Imipenem (98%) was the most active antibiotic followed by the ...

Amphoteric surface active agents

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Eissa, A.M. F.

1995-10-01

Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C₁₂, C₁₄, C₁₆ and C₁₈carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.

Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C₁₂, C₁₄, C₁₆ y C₁₈ átomos de carbono.
Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.

Influence of ecological factors on the production of active substances in the anti-cancer plant Sinopodophyllum hexandrum (Royle) T.S. Ying.

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Liu, Wei; Liu, Jianjun; Yin, Dongxue; Zhao, Xiaowen

2015-01-01

The quality of traditional Chinese herbal medicine, which plays a very important role in the health system of China, is determined by the active substances produced by the plants. The type, content, and proportion of these substances may vary depending on ecological factors in areas where the plants are grown. Sinopodophyllum hexandrum (Royle) T.S. Ying, an endangered plant species with great medical value, was investigated in eight production locations representative of its natural geographical distribution range in China. The correlation between the contents of the active ingredients extracted from the roots and rhizomes of S. hexandrum and the ecological factors were evaluated step-by-step using a series of computational biology methodologies. The results showed that ecological factors had significant effects on the contents but not on the types of the active ingredients in eight production locations. The primary ecological factors influencing the active substances included the annual average precipitation, July mean temperature, frost-free period, sunshine duration, soil pH, soil organic matter, and rapidly available potassium in the soil. The annual average precipitation was the most important determinant factor and was significantly and negatively correlated with the active ingredient contents (P Shangri-La, Yunnan Province, and Nyingchi, Tibet, conditions were favorable to the production of quercetin and kaempferol.

Recommended approaches to the scientific evaluation of ecotoxicological hazards and risks of endocrine-active substances.

Science.gov (United States)

Matthiessen, Peter; Ankley, Gerald T; Biever, Ronald C; Bjerregaard, Poul; Borgert, Christopher; Brugger, Kristin; Blankinship, Amy; Chambers, Janice; Coady, Katherine K; Constantine, Lisa; Dang, Zhichao; Denslow, Nancy D; Dreier, David A; Dungey, Steve; Gray, L Earl; Gross, Melanie; Guiney, Patrick D; Hecker, Markus; Holbech, Henrik; Iguchi, Taisen; Kadlec, Sarah; Karouna-Renier, Natalie K; Katsiadaki, Ioanna; Kawashima, Yukio; Kloas, Werner; Krueger, Henry; Kumar, Anu; Lagadic, Laurent; Leopold, Annegaaike; Levine, Steven L; Maack, Gerd; Marty, Sue; Meador, James; Mihaich, Ellen; Odum, Jenny; Ortego, Lisa; Parrott, Joanne; Pickford, Daniel; Roberts, Mike; Schaefers, Christoph; Schwarz, Tamar; Solomon, Keith; Verslycke, Tim; Weltje, Lennart; Wheeler, James R; Williams, Mike; Wolf, Jeffrey C; Yamazaki, Kunihiko

2017-03-01

A SETAC Pellston Workshop ® "Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA)" was held in February 2016 in Pensacola, Florida, USA. The primary objective of the workshop was to provide advice, based on current scientific understanding, to regulators and policy makers; the aim being to make considered, informed decisions on whether to select an ecotoxicological hazard- or a risk-based approach for regulating a given endocrine-disrupting substance (EDS) under review. The workshop additionally considered recent developments in the identification of EDS. Case studies were undertaken on 6 endocrine-active substances (EAS-not necessarily proven EDS, but substances known to interact directly with the endocrine system) that are representative of a range of perturbations of the endocrine system and considered to be data rich in relevant information at multiple biological levels of organization for 1 or more ecologically relevant taxa. The substances selected were 17α-ethinylestradiol, perchlorate, propiconazole, 17β-trenbolone, tributyltin, and vinclozolin. The 6 case studies were not comprehensive safety evaluations but provided foundations for clarifying key issues and procedures that should be considered when assessing the ecotoxicological hazards and risks of EAS and EDS. The workshop also highlighted areas of scientific uncertainty, and made specific recommendations for research and methods-development to resolve some of the identified issues. The present paper provides broad guidance for scientists in regulatory authorities, industry, and academia on issues likely to arise during the ecotoxicological hazard and risk assessment of EAS and EDS. The primary conclusion of this paper, and of the SETAC Pellston Workshop on which it is based, is that if data on environmental exposure, effects on sensitive species and life-stages, delayed effects, and effects at low concentrations are robust, initiating environmental risk

Brief Family Based Intervention for Substance Abusing Adolescents

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Hernandez, Lynn; Rodriguez, Ana Maria; Spirito, Anthony

2015-01-01

Synopsis Research has consistently shown that a lack of parental involvement in the activities of their children predicts initiation and escalation of substance use. Parental monitoring, as well as youth disclosure about their whereabouts, parent child communication, positive parenting and family management strategies, e.g., consistent limit setting, and parental communication about and disapproval of substance use, have all been shown to protect against adolescent substance abuse and substance problems. Given the empirical evidence, family and parenting approaches to preventing and intervening on adolescent substance misuse have received support in the literature. This article discusses the theoretical foundations as well as the application of the Family Check-up, a brief family-based intervention for adolescent substance use. PMID:26092741

Short communication: Biochemically active humic substances in contrasting agricultural managements

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Emilio Benitez

2016-08-01

Full Text Available Because their crucial role in several soil biochemical cycles and their fast response to changes in soil management, extracellular enzymes activities are widely used as sensitive indicators of ecological change and soil quality. The aim of this work was to determine the effects of soil management on the stable pool of soil carbon cycling enzymes as indicators of essential functions. For this, extracellular β-glucosidase enzymes bounded by humic acids (C higher than 104 Da were used to compare four long-term contrasting agricultural managements in a rainfed olive orchard representative of semi-arid Mediterranean habitats. The study was conducted for 30 years by designing a random-block of four treatments (nude vs. covered soils and four replicates. Maintaining cover crops through fall, winter and early spring provoked a more stable and active pool of extracellular β-glucosidase in soils only if spontaneous vegetation was managed with mechanical methods. When herbicides were used during 30 years, the pattern of the molecular composition and activity of humus β-glucosidase complexes were similar in covered and nude soils, although higher activity was retrieved in the former. Tillage management increased carbon mineralization and the level of humic substances and the activity of β-glucosidase humic-bound were quite lower than in the rest of treatments. Given the ecological role of extracellular soil carbon cycling enzymes, the characterization of humus β-glucosidase complexes could be an adequate indicator of sustainability of agricultural management systems.

Short communication: Biochemically active humic substances in contrasting agricultural managements

Energy Technology Data Exchange (ETDEWEB)

Benitez, E.; Nogales, R.; Doni, S.; Masciandaro, G.; Moreno, B.

2016-11-01

Because their crucial role in several soil biochemical cycles and their fast response to changes in soil management, extracellular enzymes activities are widely used as sensitive indicators of ecological change and soil quality. The aim of this work was to determine the effects of soil management on the stable pool of soil carbon cycling enzymes as indicators of essential functions. For this, extracellular β-glucosidase enzymes bounded by humic acids (C higher than 104 Da) were used to compare four long-term contrasting agricultural managements in a rainfed olive orchard representative of semi-arid Mediterranean habitats. The study was conducted for 30 years by designing a random-block of four treatments (nude vs. covered soils) and four replicates. Maintaining cover crops through fall, winter and early spring provoked a more stable and active pool of extracellular β-glucosidase in soils only if spontaneous vegetation was managed with mechanical methods. When herbicides were used during 30 years, the pattern of the molecular composition and activity of humus β-glucosidase complexes were similar in covered and nude soils, although higher activity was retrieved in the former. Tillage management increased carbon mineralization and the level of humic substances and the activity of β-glucosidase humic-bound were quite lower than in the rest of treatments. Given the ecological role of extracellular soil carbon cycling enzymes, the characterization of humus β-glucosidase complexes could be an adequate indicator of sustainability of agricultural management systems. (Author)

TNF-α inhibits SCF, ghrelin, and substance P expressions through the NF-κB pathway activation in interstitial cells of Cajal.

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Ren, Keyu; Yong, Chunming; Yuan, Hao; Cao, Bin; Zhao, Kun; Wang, Jin

2018-01-01

Ulcerative colitis is a chronic inflammatory disease of the colon where intestinal motility is disturbed. Interstitial cells of Cajal (ICC) are required to maintain normal intestinal motility. In the present study, we assessed the effect of tumor necrosis factor-alpha (TNF-α) on viability and apoptosis of ICC, as well as on the expression of stem cell factor (SCF), ghrelin, and substance P. ICC were derived from the small intestines of Swiss albino mice. Cell viability and apoptosis were measured using CCK-8 assay and flow cytometry, respectively. ELISA was used to measure the concentrations of IL-1β, IL-6, ghrelin, substance P, and endothelin-1. Quantitative RT-PCR was used to measure the expression of SCF. Western blotting was used to measure the expression of apoptosis-related proteins, interleukins, SCF, and NF-κB signaling pathway proteins. TNF-α induced inflammatory injury in ICC by decreasing cell viability and increasing apoptosis and levels of IL-1β and IL-6. TNF-α decreased the levels of SCF, ghrelin, and substance P, but had no effect on endothelin-1. TNF-α down-regulated expressions of SCF, ghrelin, and substance P by activating the NF-κB pathway in ICC. In conclusion, TNF-α down-regulated the expressions of SCF, ghrelin, and substance P via the activation of the NF-κB pathway in ICC.

Role of Extracellular Polymeric Substances in the Surface Chemical Reactivity of Hymenobacter aerophilus, a Psychrotolerant Bacterium▿

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Baker, M. G.; Lalonde, S. V.; Konhauser, K. O.; Foght, J. M.

2010-01-01

Bacterial surface layers, such as extracellular polymeric substances (EPS), are known to play an important role in metal sorption and biomineralization; however, there have been very few studies investigating how environmentally induced changes in EPS production affect the cell's surface chemistry and reactivity. Acid-base titrations, cadmium adsorption assays, and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the surface reactivities of Hymenobacter aerophilus cells with intact EPS (WC) or stripped of EPS (SC) and purified EPS alone. Linear programming modeling of titration data showed SC to possess functional groups corresponding to phosphoryl (pKa ∼6.5), phosphoryl/amine (pKa ∼7.9), and amine/hydroxyl (pKa ∼9.9). EPS and WC both possess carboxyl groups (pKa ∼5.1 to 5.8) in addition to phosphoryl and amine groups. FT-IR confirmed the presence of polysaccharides and protein in purified EPS that can account for the additional carboxyl groups. An increased ligand density was observed for WC relative to that for SC, leading to an increase in the amount of Cd adsorbed (0.53 to 1.73 mmol/liter per g [dry weight] and 0.53 to 0.59 mmol/liter per g [dry weight], respectively). Overall, the presence of EPS corresponds to an increase in the number and type of functional groups on the surface of H. aerophilus that is reflected by increased metal adsorption relative to that for EPS-free cells. PMID:19915039

Role of extracellular polymeric substances in the surface chemical reactivity of Hymenobacter aerophilus, a psychrotolerant bacterium.

Science.gov (United States)

Baker, M G; Lalonde, S V; Konhauser, K O; Foght, J M

2010-01-01

Bacterial surface layers, such as extracellular polymeric substances (EPS), are known to play an important role in metal sorption and biomineralization; however, there have been very few studies investigating how environmentally induced changes in EPS production affect the cell's surface chemistry and reactivity. Acid-base titrations, cadmium adsorption assays, and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the surface reactivities of Hymenobacter aerophilus cells with intact EPS (WC) or stripped of EPS (SC) and purified EPS alone. Linear programming modeling of titration data showed SC to possess functional groups corresponding to phosphoryl (pKa approximately 6.5), phosphoryl/amine (pKa approximately 7.9), and amine/hydroxyl (pKa approximately 9.9). EPS and WC both possess carboxyl groups (pKa approximately 5.1 to 5.8) in addition to phosphoryl and amine groups. FT-IR confirmed the presence of polysaccharides and protein in purified EPS that can account for the additional carboxyl groups. An increased ligand density was observed for WC relative to that for SC, leading to an increase in the amount of Cd adsorbed (0.53 to 1.73 mmol/liter per g [dry weight] and 0.53 to 0.59 mmol/liter per g [dry weight], respectively). Overall, the presence of EPS corresponds to an increase in the number and type of functional groups on the surface of H. aerophilus that is reflected by increased metal adsorption relative to that for EPS-free cells.

Pan Drug-Resistant Environmental Isolate of Acinetobacter baumannii from Croatia.

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Goic-Barisic, Ivana; Seruga Music, Martina; Kovacic, Ana; Tonkic, Marija; Hrenovic, Jasna

2017-06-01

Acinetobacter baumannii is an emerging nosocomial pathogen with also emerging resistance to different antibiotics. Multidrug and pan drug-resistant clinical isolates were reported worldwide. Here we report the first evidence of pan drug-resistant environmental isolate of A. baumannii. The isolate was recovered from the effluent of secondary treated municipal wastewater of the City of Zagreb, Croatia. The isolate was resistant to penicillins/β-lactamase inhibitors, carbapenems, fluoroquinolones, aminoglycosides, folate pathway inhibitors, and polymyxins, except intermediately susceptible to minocycline and tigecycline. Intrinsic chromosomally located bla OXA-51-like gene and acquired plasmid-located bla OXA-23-like gene were related to clinical isolates. Pan drug-resistant A. baumannii can occur in natural environments outside of the hospital. Secondary treated municipal wastewater represents a potential epidemiological reservoir of pan drug-resistant A. baumannii and carbapenem resistance gene.

Activity of Colistin in Combination with Meropenem, Tigecycline, Fosfomycin, Fusidic Acid, Rifampin or Sulbactam against Extensively Drug-Resistant Acinetobacter baumannii in a Murine Thigh-Infection Model.

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Bing Fan

Full Text Available Few effective therapeutic options are available for treating severe infections caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB. Using a murine thigh-infection model, we examined the in vivo efficacy of colistin in combination with meropenem, tigecycline, fosfomycin, fusidic acid, rifampin, or sulbactam against 12 XDR-AB strains. Colistin, tigecycline, rifampin, and sulbactam monotherapy significantly decreased bacterial counts in murine thigh infections compared with those observed in control mice receiving no treatment. Colistin was the most effective agent tested, displaying bactericidal activity against 91.7% of strains at 48 h post-treatment. With strains showing a relatively low minimum inhibitory concentration (MIC for meropenem (MIC ≤ 32 mg/L, combination therapy with colistin plus meropenem caused synergistic inhibition at both 24 h and 48 h post-treatment. However, when the meropenem MIC was ≥64 mg/L, meropenem did not significantly alter the efficacy of colistin. The addition of rifampin and fusidic acid significantly improved the efficacy of colistin, showing a synergistic effect in 100% and 58.3% of strains after 24 h of treatment, respectively, while the addition of tigecycline, fosfomycin, or sulbactam did not show obvious synergistic activity. No clear differences in activities were observed between colistin-rifampin and colistin-fusidic acid combination therapy with most strains. Overall, our in vivo study showed that administering colistin in combination with rifampin or fusidic acid is more efficacious in treating XDR-AB infections than other combinations. The colistin-meropenem combination may be another appropriate option if the MIC is ≤32 mg/L. Further clinical studies are urgently needed to confirm the relevance of these findings.

Radioactive substance solidifying device

International Nuclear Information System (INIS)

Sakoda, Kotaro.

1979-01-01

Purpose: To easily solidify radioactive substances adhering to the surfaces of solid wastes without scattering in the circumference by paints, and further to reduce surface contamination concentrations. Constitution: Solid wastes are placed on a hanging plate, and dipped in paints within a paint dipping treatment tank installed at the lower part of a treatment tank by means of a monorail hoist, and the surfaces of said solid wastes are coated with paints, thereby to solidify the radioactivity on the surfaces of the solid wastes. After dipping, the solid wastes are suspended up to a paint spraying tank to dry the paints. After drying, non-contaminated paints are atomized to apply through an atomizing tube onto the solid wastes. After drying the atomized paints, the solid wastes are carried outside the treatment tank by means of the monorail hoist. (Yoshino, Y.)

Characterization and plasmid elimination of NDM-1-producing Acinetobacter calcoaceticus from China.

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Yang Sun

Full Text Available The presence of multidrug-resistant bacterial pathogens in the environment poses a serious threat to public health. The opportunistic Acinetobacter spp. are among the most prevalent causes of nosocomial infections. Here, we performed complete genome sequencing of the Acinetobacter calcoaceticus strain XM1570, which was originally cultivated from the sputum of a patient diagnosed with pneumonia in Xiamen in 2010. We identified carbapenem resistance associated gene bla(NDM-1 located on a 47.3-kb plasmid. Three methods--natural reproduction, sodium dodecyl sulfate treatment and nalidixic acid treatment--were used to eliminate the bla(NDM-1-encoding plasmid, which achieved elimination rates of 3.32% (10/301, 83.78% (278/332, and 84.17% (298/354, respectively. Plasmid elimination dramatically increased antibiotic sensitivity, reducing the minimum bacteriostatic concentration of meropenem from 256 µg/ml in the clinical strain to 0.125 µg/ml in the plasmid-eliminated strain. Conjugation transfer assays showed that the bla(NDM-1-containing plasmid could be transferred into Escherichia coli DH5α:pBR322 in vitro as well as in vivo in mice. The bla(NDM-1 genetic environment was in accordance with that of other bla(NDM-1 genes identified from India, Japan, and Hong-Kong. The multilocus sequence type of the isolate was identified as ST-70. Two novel genes encoding intrinsic OXA and ADC were identified and named as OXA-417 and ADC-72. The finding of bla(NDM-1 in species like A. calcoaceticus demonstrates the wide spread of this gene in gram-negative bacteria which is possible by conjugative plasmid transfer. The results of this study may help in the development of a treatment strategy for controlling NDM-1 bacterial infection and transmission.

Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

International Nuclear Information System (INIS)

Allen, C. Leigh; Gulick, Andrew M.

2014-01-01

The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins

Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

Energy Technology Data Exchange (ETDEWEB)

Allen, C. Leigh; Gulick, Andrew M., E-mail: gulick@hwi.buffalo.edu [University at Buffalo, Buffalo, NY 14203 (United States)

2014-06-01

The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins.

In vitro synergy of polymyxins with other antibiotics for Acinetobacter baumannii: a systematic review and meta-analysis.

Science.gov (United States)

Ni, Wentao; Shao, Xiaodi; Di, Xiuzhen; Cui, Junchang; Wang, Rui; Liu, Youning

2015-01-01

In order to provide preliminary guidance for rational antibiotic combination therapy in the clinic, a systematic review and meta-analysis was performed to evaluate the in vitro synergistic activity of polymyxins combined with other antibiotics against Acinetobacter baumannii. An extensive literature search was undertaken without restriction according to region, publication type or language. All available in vitro synergy tests on antibiotic combinations consisting of polymyxins were included. The primary outcome assessed was the in vitro activity of combination therapy on bacterial kill or inhibition. In total, 70 published studies and 31 conference proceedings reporting testing of polymyxins in combination with 11 classes consisting of 28 antibiotic types against 1484 A. baumannii strains were included in the analysis. In time-kill studies, high in vitro synergy and bactericidal activity were found for polymyxins combined with several antibiotic classes such as carbapenems and glycopeptides. Carbapenems or rifampicin combination could efficiently suppress the development of colistin resistance and displayed a >50% synergy rate against colistin-resistant strains. Synergy rates of chequerboard microdilution and Etest methods in most antibiotic combinations were generally lower than those of time-kill assays. The benefits of these antibiotic combinations should be further demonstrated by well-designed clinical studies. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

The Hyr1 protein from the fungus Candida albicans is a cross kingdom immunotherapeutic target for Acinetobacter bacterial infection.

Directory of Open Access Journals (Sweden)

Priya Uppuluri

2018-05-01

Full Text Available Different pathogens share similar medical settings and rely on similar virulence strategies to cause infections. We have previously applied 3-D computational modeling and bioinformatics to discover novel antigens that target more than one human pathogen. Active and passive immunization with the recombinant N-terminus of Candida albicans Hyr1 (rHyr1p-N protect mice against lethal candidemia. Here we determine that Hyr1p shares homology with cell surface proteins of the multidrug resistant Gram negative bacterium, Acinetobacter baumannii including hemagglutinin (FhaB and outer membrane protein A (OmpA. The A. baumannii OmpA binds to C. albicans Hyr1p, leading to a mixed species biofilm. Deletion of HYR1, or blocking of Hyr1p using polyclonal antibodies, significantly reduce A. baumannii binding to C. albicans hyphae. Furthermore, active vaccination with rHyr1p-N or passive immunization with polyclonal antibodies raised against specific peptide motifs of rHyr1p-N markedly improve survival of diabetic or neutropenic mice infected with A. baumannii bacteremia or pneumonia. Antibody raised against one particular peptide of the rHyr1p-N sequence (peptide 5 confers majority of the protection through blocking A. baumannii invasion of host cells and inducing death of the bacterium by a putative iron starvation mechanism. Anti-Hyr1 peptide 5 antibodies also mitigate A. baumannii /C. albicans mixed biofilm formation in vitro. Consistent with our bioinformatic analysis and structural modeling of Hyr1p, anti-Hyr1p peptide 5 antibodies bound to A. baumannii FhaB, OmpA, and an outer membrane siderophore binding protein. Our studies highlight the concept of cross-kingdom vaccine protection against high priority human pathogens such as A. baumannii and C. albicans that share similar ecological niches in immunocompromised patients.

Ocorrência e perfil de sensibilidade a antimicrobianos em Pseudomonas aeruginosa e Acinetobacter sp. em um hospital terciário, no sul do Brasil

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Gabriele Mariani Machado

2011-04-01

Full Text Available INTRODUÇÃO: O principal mecanismo de resistência entre isolados de Pseudomonas aeruginosa e Acinetobacter sp. é a produção de metalo-β-lactamases (MβLs. As MβLs são enzimas capazes de hidrolisar cefalosporinas, penicilinas e carbapenêmicos, mas não monobactâmicos (aztreonam antibióticos que se encontram entre as principais opções terapêuticas para o tratamento de infecções causadas por bactérias não fermentadoras de glicose. MÉTODOS: Um estudo observacional, transversal, descritivo e retrospectivo foi desenvolvido para avaliar a frequência e o perfil de susceptibilidade cepas de P. aeruginosa e Acinetobacter sp. produtoras de MβLs isoladas no Hospital São Vicente de Paulo, Passo Fundo, Brasil. RESULTADOS: A produção de MβLs foi observada em 77,6% (n = 173/223 dos isolados de P. aeruginosa e em 22,4% (n = 50/223 dos isolados de Acinetobacter sp. Dentre as cepas produtoras de MβL, a maioria apresentou mais de 90% de resistência a seis antimicrobianos dos 12 testados, enfatizando a resistência a ceftazidima, gentamicina, aztreonam, piperaciclina/tazobactam, cefepime, ciprofloxacina, meropenem e tobramicina. CONCLUSÕES: Os índices de MβL encontrados confirmam a preocupação mundial com a disseminação desse mecanismo de resistência.

Infecção cutânea rara por Acinetobacter baumannii em imunocompetente: relato de um caso

OpenAIRE

Cirino,Pablo Vitoriano; Guimarães,Newton Sales; Follador,Ivonise

2008-01-01

O Acinetobacter baumanni é patógeno oportunista antigamente considerado de baixa virulência. Atualmente está envolvido em processos infecciosos que acometem pacientes imunocomprometidos,grandes queimados e pacientes em unidades de terapia intensiva que fazem uso de ventilação mecânica. Esse relato de caso chama atenção para infecção cutânea rara por essa bactéria em paciente imunocompetente.

Biodegradation of Medium Chain Hydrocarbons by Acinetobacter venetianus 2AW Immobilized to Hair-Based Adsorbent Mats (Postprint)

Science.gov (United States)

2010-09-01

open- water oil spills or treatment of large contaminated volumes such as ballast water or holding ponds. The practi- cal application of the mat is...SS, Al-Hasan RH, Salamah S, Al-Dabbous A. Biore- mediation of oily sea water by bacteria immobilized in biofilms coating macroalgae . Int Biodeter...adsorbent, for in situ degradation of hydrocarbons, has practical application in the bioremediation of oil in water emulsions. acinetobacter

Insights into the extremotolerance of Acinetobacter radioresistens 50v1, a gram-negative bacterium isolated from the Mars Odyssey spacecraft.

Science.gov (United States)

McCoy, K B; Derecho, I; Wong, T; Tran, H M; Huynh, T D; La Duc, M T; Venkateswaran, K; Mogul, R

2012-09-01

The microbiology of the spacecraft assembly process is of paramount importance to planetary exploration, as the biological contamination that can result from remote-enabled spacecraft carries the potential to impact both life-detection experiments and extraterrestrial evolution. Accordingly, insights into the mechanisms and range of extremotolerance of Acinetobacter radioresistens 50v1, a Gram-negative bacterium isolated from the surface of the preflight Mars Odyssey orbiter, were gained by using a combination of microbiological, enzymatic, and proteomic methods. In summary, A. radioresistens 50v1 displayed a remarkable range of survival against hydrogen peroxide and the sequential exposures of desiccation, vapor and plasma phase hydrogen peroxide, and ultraviolet irradiation. The survival is among the highest reported for non-spore-forming and Gram-negative bacteria and is based upon contributions from the enzyme-based degradation of H(2)O(2) (catalase and alkyl hydroperoxide reductase), energy management (ATP synthase and alcohol dehydrogenase), and modulation of the membrane composition. Together, the biochemical and survival features of A. radioresistens 50v1 support a potential persistence on Mars (given an unintended or planned surface landing of the Mars Odyssey orbiter), which in turn may compromise the scientific integrity of future life-detection missions.

Screening and characterization of a novel alkaline lipase from Acinetobacter calcoaceticus 1-7 isolated from Bohai Bay in China for detergent formulation

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Haikuan Wang

2012-03-01

Full Text Available A novel alkaline lipase-producing strain 1-7 identified as Acinetobacter calcoaceticus was isolated from soil samples collected from Bohai Bay, China, using an olive oil alkaline plate, which contained olive oil as the sole carbon source. The lipase from strain 1-7 showed the maximum activity at pH 9.0 under 40ºC. One interesting feature of this enzyme is that it exhibits lipase activity over a broad range of temperatures and good stability. It is also stable at a broad range of pHs from 4.0 to 10.0 for 24 h. Its catalytic activity was highly enhanced in the presence of Ca2+, Mg2+ and K+, but partially inhibited by Cu2+, Al3+, Fe3+ , Ba2+and Zn2+. The fact that it displays marked stability and activity in the presence of TritonX-100, Tween-20, Tween-80, SDS, Hydrogen peroxide, Sodium perborate, Sodium hypochlorite, Sodium citrate, Sodium taurocholate, Glycerine and NaCl suggests that this lipase is suitable as an additive in detergent formulations.

Post-surgical meningitis due to multiresistant Acinetobacter baumannii. Effective treatment with intravenous and/or intraventricular colistin and therapeutic dilemmas.

Science.gov (United States)

Paramythiotou, E; Karakitsos, D; Aggelopoulou, H; Sioutos, P; Samonis, G; Karabinis, A

2007-02-01

Post-surgical meningitis and/or ventriculitis caused by Gram-negative bacteria may be difficult to treat due to the emergence of multiresistant strains. Two patients with multiresistant Acinetobacter baumannii central nervous system infection, successfully treated with either intravenous and/or intraventricular colistin are presented. Unresolved issues such as dose and duration of intraventricular colistin are discussed.

Draft Genome Sequences of Six Multidrug-Resistant Clinical Strains of Acinetobacter baumannii, Isolated at Two Major Hospitals in Kuwait.

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Nasser, Kother; Mustafa, Abu Salim; Khan, Mohd Wasif; Purohit, Prashant; Al-Obaid, Inaam; Dhar, Rita; Al-Fouzan, Wadha

2018-04-19

Acinetobacter baumannii is an important opportunistic pathogen in global health care settings. Its dissemination and multidrug resistance pose an issue with treatment and outbreak control. Here, we present draft genome assemblies of six multidrug-resistant clinical strains of A. baumannii isolated from patients admitted to one of two major hospitals in Kuwait. Copyright © 2018 Nasser et al.

Radioactivity levels in surface water of lakes around Izmir / Turkey

International Nuclear Information System (INIS)

Doyurum, S.; Turkozu, D. A.; Aslani, M. A. A.; Aytas, S.; Eral, M.; Kaygun, A. K.

2006-01-01

Radioactivity presents in surface continental waters is mainly due to the presence of radioactive elements in the earth's crust, other artificial radionuclides have appeared due to such human activities as nuclear power plants, nuclear weapons testing and manufacture and use of radioactive sources It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements among dissolved and particulate phases in aquatic systems. The detection of high radionuclide concentrations was proposed as a public health problem in several areas and consequently studies into the risks of radionuclides were started in the 2000s. Especially, these radioactive substances in groundwater are an unwanted and involuntary risk factor from natural sources, not artificial sources. These radioactive substances include uranium, radon found in uranium series, and other radioactive substances such as radium and gross alpha. Uranium present in rock, soil, and natural materials, and is found in small quantities in air, water, and food that people always contact. In this project, lake water samples were collected from three lakes around Izmir-Turkey. In surface lake water samples, pH, mV and conductivity values were measured and alkaline content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. The radioactivity concentrations related to gross radium isotopes, gross-? and gross-? activities in the surface lake water were determined. The correlation among some parameters for water samples and concentrations of uranium, activity concentration of gross radium isotopes, gross alpha and gross beta radioactivity are also discussed

Imipenem-avibactam: a novel combination for the rapid detection of carbapenemase activity in Enterobacteriaceae and Acinetobacter baumannii by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Science.gov (United States)

Oviaño, Marina; Bou, Germán

2017-02-01

In the present study, we propose a novel matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for detecting carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii. For this, we analyzed a series of 131 isolates. Among them, a total of 115 Enterobacteriaceae: 79 of them carrying a carbapenemase enzyme (15bla KPC , 7bla NDM , 11bla IMP , 12bla VIM , and 34bla OXA-48 ) and 16 A. baumannii isolates: 15 of them carrying carbapenemases (10bla OXA-23, 2bla OXA-58, 2bla OXA-24 , and 1bla OXA-237 ). The rest of the isolates were noncarbapenemase producers and used as negative controls. The isolates were submitted to susceptibility testing using a combination of imipenem-avibactam and analysis by the MALDI-TOF Biotyper Compass software (Bruker Daltonik, Germany). The assay showed an overall sensitivity and specificity for carbapenemase detection of 98% and 100%, respectively. The combination of imipenem and avibactam displayed activity against KPC and OXA-48-producing Enterobacteriaceae and thus represents a new strategy for identifying and confirming these carbapenemases. However, the combination did not provide any benefit over A. baumannii. Copyright © 2016 Elsevier Inc. All rights reserved.

Emergence and Spread of Plasmid-Borne tet(B)::ISCR2 in Minocycline-Resistant Acinetobacter baumannii Isolates

OpenAIRE

Vilacoba, Elisabet; Almuzara, Marisa; Gulone, Lucía; Traglia, German Matias; Figueroa, Silvia A.; Sly, Gabriela Edith; Fernandez, Analia; Centron, Daniela; Ramirez, Maria Soledad

2015-01-01

Resistance to minocycline has emerged in multidrug-resistant Acinetobacter baumannii isolates from Buenos Aires Hospitals. Few reports about the description and dispersion of tet genes were published in this species. We observed the presence of tet(B) in all minocycline resistant isolates. This gene was found associated to the ISCR2 mobile element, which could in part explain its dispersion. Fil: Vilacoba, Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Co...

Genotypic and Phenotypic Correlations of Multidrug-Resistant Acinetobacter baumannii-A. calcoaceticus Complex Strains Isolated from Patients at the National Naval Medical Center

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Acinetobacter baumannii-calcoaceticus complex (ABC) infections have complicated the care of U.S. combat casualties. In this study, 102 ABC isolates from wounded soldiers treated at National Naval Medical Center (NNMC) were characterized by phenotype and genotype to identify clones in this population...

Simultaneous identification of multiple β-lactamases in Acinetobacter baumannii in relation to carbapenem and ceftazidime resistance, using liquid chromatography-tandem mass spectrometry

NARCIS (Netherlands)

Trip, H.; Mende, K.; Majchrzykiewicz-Koehorst, J.A.; Sedee, N.J.A.; Hulst, A.G.; Jansen, H.J.; Murray, C.K.; Paauw, A.

2015-01-01

Shotgun proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to detect β-lactamases in clinical Acinetobacter baumannii isolates. The correlation of the detection of β-lactamase proteins (rather than PCR detection of the corresponding genes) with the resistance

Rapid molecular characterization of Acinetobacter baumannii clones with rep-PCR and evaluation of carbapenemase genes by new multiplex PCR in Hospital District of Helsinki and Uusimaa.

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Tanja Pasanen

Full Text Available Multidrug-resistant Acinetobacter baumannii (MDRAB is an increasing problem worldwide. Prevalence of carbapenem resistance in Acinetobacter spp. due to acquired carbapenemase genes is not known in Finland. The purpose of this study was to examine prevalence and clonal spread of multiresistant A. baumannii group species, and their carbapenemase genes. A total of 55 Acinetobacter isolates were evaluated with repetitive PCR (DiversiLab to analyse clonality of isolates, in conjunction with antimicrobial susceptibility profile for ampicillin/sulbactam, colistin, imipenem, meropenem, rifampicin and tigecycline. In addition, a new real-time PCR assay, detecting most clinically important carbapenemase genes just in two multiplex reactions, was developed. The assay detects genes for KPC, VIM, IMP, GES-1/-10, OXA-48, NDM, GIM-1, SPM-1, IMI/NMC-A, SME, CMY-10, SFC-1, SIM-1, OXA-23-like, OXA-24/40-like, OXA-58 and ISAbaI-OXA-51-like junction, and allows confident detection of isolates harbouring acquired carbapenemase genes. There was a time-dependent, clonal spread of multiresistant A. baumannii strongly correlating with carbapenamase gene profile, at least in this geographically restricted study material. The new carbapenemase screening assay was able to detect all the genes correctly suggesting it might be suitable for epidemiologic screening purposes in clinical laboratories.

Identification of Acinetobacter baumannii of Human and Animal Origins by a Gene-Specific PCR.

Science.gov (United States)

Hamouda, Ahmed

2017-09-01

Acinetobacter baumannii is a notorious nosocomial pathogen known for its ability to cause severe infections, especially in intensive care units. The identification of a conserved gene encoding a hypothetical protein in A. baumannii isolates but not in other Acinetobacter species during a comparative genomic analysis was reported. For the purpose of this study, we call this gene, A.b_hyp gene. The aim of this study was to report the results of screening for the presence of the A.b_hyp gene in a worldwide collection of well-characterized A. baumannii collected from clinical and animal specimens. A total of 83 clinical, animal, and type strains were used. These comprised 73 A. baumannii isolates of clinical (n = 60) and animal origin (n = 13), and ten type strains, including a positive control strain, A. baumannii ATCC 19606. All isolates were examined by PCR amplification of the A.b_hyp gene. The A.b_hyp gene was detected in 72 isolates (99%) of A. baumannii but one clinical isolate failed to produce an amplicon. The control strain, A. baumannii ATCC 19606, was also positive for this gene. No bands were detected in non-A. baumannii species and therefore the isolates are thought to be negative for the gene. No bands were detected in non-A. baumannii isolates and therefore they are thought to be negative for the gene. The PCR A.b_ hyp method provides evidence that detection of this gene can be used as a reliable, easy, and low-cost biomarker for A. baumannii identification.

Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii.

Science.gov (United States)

Mayer, Letícia Eichstaedt; Hörner, Rosmari; Tizotti, Maisa Kräulich; Martini, Rosiéli; Roehrs, Magda Cristina Souza Marques; Kempfer, Cláudia Barbisan

2012-01-01

Metallo-β-lactamase (MBL) has been reported all over the world. The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. MPA significantly inhibited growth of the strains. The use of MPA can affect the results in phenotypic methods of MBL detection.

A study of the components of an active substance of high alkaline alkylsalicylate oil additives

Energy Technology Data Exchange (ETDEWEB)

Kravchuk, G G; Glavati, O L; Glavati, Ye V; Zhurba, A S

1981-01-01

The active substance of aklylsalicylate additives (Pr) MACK, dispersal-1 and AS-6OC (from Shell Oil) is isolated and studied. It is shown that the Pr is provided by the presence of both a neutral salicylate, as well as that of a high alkaline component (colloid CaCtheta/sub 3/, stabilized by salicylate). The free alkylphenols present in the Pr do not deteriorate its quality.

National substance use patterns on Twitter.

Directory of Open Access Journals (Sweden)

Hsien-Wen Meng

Full Text Available We examined openly shared substance-related tweets to estimate prevalent sentiment around substance use and identify popular substance use activities. Additionally, we investigated associations between substance-related tweets and business characteristics and demographics at the zip code level.A total of 79,848,992 tweets were collected from 48 states in the continental United States from April 2015-March 2016 through the Twitter API, of which 688,757 were identified as being related to substance use. We implemented a machine learning algorithm (maximum entropy text classifier to estimate sentiment score for each tweet. Zip code level summaries of substance use tweets were created and merged with the 2013 Zip Code Business Patterns and 2010 US Census Data.Quality control analyses with a random subset of tweets yielded excellent agreement rates between computer generated and manually generated labels: 97%, 88%, 86%, 75% for underage engagement in substance use, alcohol, drug, and smoking tweets, respectively. Overall, 34.1% of all substance-related tweets were classified as happy. Alcohol was the most frequently tweeted substance, followed by marijuana. Regression results suggested more convenience stores in a zip code were associated with higher percentages of tweets about alcohol. Larger zip code population size and higher percentages of African Americans and Hispanics were associated with fewer tweets about substance use and underage engagement. Zip code economic disadvantage was associated with fewer alcohol tweets but more drug tweets.The patterns in substance use mentions on Twitter differ by zip code economic and demographic characteristics. Online discussions have great potential to glorify and normalize risky behaviors. Health promotion and underage substance prevention efforts may include interactive social media campaigns to counter the social modeling of risky behaviors.

COST-EFFECTIVE PRODUCTION OF THE BIO-PLASTIC POLY-β-HYDROXYBUTYRATE USING ACINETOBACTER BAUMANNII ISOLATE P39

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Noha Salah Elsayed

2016-06-01

Full Text Available Being biodegradable and biocompatible natural polymer, poly-β-hydroxybutyrate (PHB drew the attention of scientists to substitute synthetic plastics in our daily lives. However, its industrial production is hampered by its high cost. In this study, an extensive screening program was done to isolate bacteria with high PHB productivity from agricultural fields and develop a cost-effective PHB production. A promising bacterial isolate Acinetobacter baumannii P39 was recovered and identified using 16S ribosomal gene sequencing. It produced 24% PHB per dry weight after 48 h. Several experiments were conducted to optimize the composition of the culture medium and environmental factors for the selected isolate. Results revealed that 60% aeration, 28°C incubation temperature and initial pH 7.5 showed the highest productivity. Besides, 0.7% corn oil and 0.1 g/L peptone were the best carbon and nitrogen sources, respectively. Substituting glucose with corn oil led to a 23% reduction in total input cost and an estimate price for 1kg PHB is 20.5 L.E. Strain improvement by UV mutation succeeded in improving PHB production by two fold in the selected mutant P39M2. Finally, this study valorizes usage of Acinetobacter isolate in PHB production in addition to solving the critical problem of high cost of production.

Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. II Influence in electro crystallization phenomena

International Nuclear Information System (INIS)

Llopis, J.; Gamboa, J. M.; Arizmendi, L.

1963-01-01

The action of foreign substances present on the surface of the electrodes, in electro crystallization phenomena, has been studied. The number of Ag crystals per square centimeter of Pt electrode varies with the polishing, the current density and the presence of multilayers of stearic acid. The statistical distribution of Ag crystals without and with multilayers and their influence on the concentration index and the deformation of Ag crystals has been studied. the size of these crystals increases as the current density decreases. (Author) 16 refs

Prevalence of Substance Use in a Rural Teenage Population.

Science.gov (United States)

Silverman, Wade H.

1991-01-01

Surveyed all secondary school students (n=1,175) in rural county school system to assess prevalence rates of substance use for teenagers and their parents. Age, sex, and race were related to frequency and type of substance abuse. Lifestyle variables such as music preferences, sexual activity, and choice of friends also related to substance use.…

Drama-based education to motivate participation in substance abuse prevention

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Cameron Amura

2007-04-01

Full Text Available Abstract Background The substance abuse prevention goal of the theatre production "TUNNELS" was to provide community education on substance abuse to an audience in Durham, NC and surrounding communities. The education effort intended to increase awareness and understanding of the risk and protective factors associated with alcohol and other drug use, and to promote pro-active behaviors in substance abuse prevention within the adult community. It was hypothesized that community-based education via drama would change attitudes toward alcohol and substance abuse, and increase participation in family and community activities aimed at substance abuse prevention. Methods A focus group comprised of educators, substance abuse researchers and local substance abuse counselors developed "life stories" of users of alcohol and other drugs and a local playwright incorporated these and other experiences into a series of six vignettes. The production was publicized throughout the Durham area, and 700 adults attending the play signed a consent form and completed the pre-play survey. The participant pool was restricted to those adults who completed both the time-1 and time-2 surveys and resided within Durham and surrounding communities. Paired comparisons of mean responses were analyzed using a paired sample two-tailed t-test. A telephone survey three months after the play assessed attitudes toward substance abuse as a disease, and whether the respondents had increased their participation in prevention activities including discussions of the play with others. Results Viewing the play increased the knowledge base of participants regarding substance abuse as a disease, even though the audience demonstrated an appreciation of risk and protective factors prior to attending the performance. In the pre-play survey, participants indicated a strong opinion that parental involvement in teen life was important, and therefore this was not increased as a result of viewing

Characterization and Testing the Efficiency of Acinetobacter baumannii Phage vB-GEC_Ab-M-G7 as an Antibacterial Agent

Directory of Open Access Journals (Sweden)

Ia Kusradze

2016-10-01

Full Text Available Acinetobacter baumannii is a gram-negative, non-motile bacterium that, due to its multidrug resistance, has become a major nosocomial pathogen .The increasing number of multidrug resistant (MDR strains has renewed interest in phage therapy. The aim of our study was to assess the effectiveness of phage administration in Acinetobacter baumannii wound infections in an animal model to demonstrate phage therapy as non-toxic, safe and alternative antibacterial remedy. Using classical methods for the study of bacteriophage properties, we characterized phage vB-GEC_Ab-M-G7 as a dsDNA myovirus with a 90kb genome size. Important characteristics of vB-GEC_Ab-M-G7include a short latent period and large burst size, wide host range, resistance to chloroform and thermal and pH stability. In a rat wound model, phage application effectively decreased the number of bacteria isolated from the wounds of successfully treated animals. This study highlights the effectiveness of the phage therapy and provides further insight into treating infections caused by MDR strains using phage administration.

Acid-base characteristics of powdered-activated-carbon surfaces

Energy Technology Data Exchange (ETDEWEB)

Reed, B.E. (West Virginia Univ., Morgantown (United States)); Jensen, J.N.; Matsumoto, M.R. (State Univ. of New York, Buffalo (United States))

Adsorption of heavy metals onto activated carbon has been described using the surface-complex-formation (SCF) model, a chemical equilibrium model. The SCF model requires a knowledge of the amphoteric nature of activated carbon prior to metal adsorption modeling. In the past, a single-diprotic-acid-site model had been employed to describe the amphoteric nature of activated-carbon surfaces. During this study, the amphoteric nature of two powdered activated carbons were investigated, and a three-monoprotic site surface model was found to be a plausible alternative. The single-diprotic-acid-site and two-monoprotic-site models did not describe the acid-base behavior of the two carbons studied adequately. The two-diprotic site was acceptable for only one of the study carbons. The acid-base behavior of activated carbon surfaces seem to be best modeled as a series of weak monoprotic acids.

Quantification of potential exposure of gray partridge (Perdix perdix) to pesticide active substances in farmlands

Energy Technology Data Exchange (ETDEWEB)

Bro, Elisabeth, E-mail: elisabeth.bro@oncfs.gouv.fr [National Game and Wildlife Institute (ONCFS), Research Department, Saint Benoist, BP 20, F 78 612 Le Perray en Yvelines Cedex (France); Millot, Florian, E-mail: florian.millot@oncfs.gouv.fr [National Game and Wildlife Institute (ONCFS), Research Department, Saint Benoist, BP 20, F 78 612 Le Perray en Yvelines Cedex (France); Decors, Anouk, E-mail: anouk.decors@oncfs.gouv.fr [National Game and Wildlife Institute (ONCFS), Research Department, Saint Benoist, BP 20, F 78 612 Le Perray en Yvelines Cedex (France); Devillers, James, E-mail: j.devillers@ctis.fr [Centre de Traitement de l' Information Scientifique (CTIS), 3 chemin de la Gravière, 69140 Rillieux La Pape (France)

2015-07-15

Estimating exposure of wild birds to plant protection products is of key importance in the risk assessment process evaluating their harmful potential. In this paper, we propose an ecologically-relevant methodology to estimate potential exposure to active substances (ASs) of a farmland focal bird, the gray partridge Perdix perdix. It is based on bird habitat use of fields at the time of pesticide applications. It accounts for spatio-temporal heterogeneity at population and landscape scales. We identify and quantify the potential exposure to 179 ASs of 140 clutches during pre-laying, laying, and incubation phases, and of 75 coveys. The data come from a large scale field study combining radiotelemetry and a farmer survey. They were collected in 12 different representative sites. The proportion of clutches potentially exposed to a given chemical was ≥ 5% for 32 ASs; prothioconazole and epoxiconazole ranking first. 71% of clutches were potentially exposed to ≥ 1 AS and 67% to ≥ 2 ASs. Mixtures involved 2 to 22 ASs. They emerged from commercial formulations, tank mixtures, bird habitat use, and combinations. ASs were fungicides (53%), herbicides (25%), and insecticides (16%) used on a variety of crops in April–June, when ground-nesting birds are breeding. The European Food Safety Authority conclusions report a long-term first-tier toxicity-to-exposure ratio (TER{sub lt}) < 5 for 11 out of 19 documented ASs, and higher-tier TER{sub lt} < 5 for 5 out of 10 ASs. This suggests a potential risk for bird reproduction in farmlands. Globally 13% of coveys were potentially exposed to 18 ASs during the first month (1–4 coveys per AS). The use of our field data in future research and risk assessment is discussed. - Highlights: • 71% of clutches and 13% of coveys are exposed to active substances. • Partridge clutches/coveys are mostly exposed to 32/3 substances. • Fungicides (53%), herbicides (25%), and insecticides (16%) dominate. • Some substances have the

Acinetobacter baumannii FolD ligand complexes --potent inhibitors of folate metabolism and a re-evaluation of the structure of LY374571.

Science.gov (United States)

Eadsforth, Thomas C; Maluf, Fernando V; Hunter, William N

2012-12-01